The work presented here extends an existing algorithm for testing if an inclusion relation exists between two markup schemata, to only take into account the parts of the grammar that have been used in a given subset of its language. Statistics for this purpose are gathered in combination with validation when documents are entered and are stored along with them in the repository. This modified subtyping relation is used to determine compatibility with the current database when a schema is upgraded.

The topic of this thesis is style sheet languages for structured documents on the web. Due to characteristics of the web — including a screen-centric publishing model, a multitude of output devices, uncertain delivery, strong user preferences, and the possibility for later binding between content and style — the hypothesis is that the web calls for different style sheet languages than does traditional electronic publishing. Style sheet languages that were developed and used prior to the web are analyzed and compared with style sheet proposals for the web between 1993-1996. The dissertation describes the design of a web-centric style sheet language known as Cascading Style Sheets (CSS). CSS has several notable features including: cascading, pseudo-classes and pseudo-elements, forward-compatible parsing rules, support for different media types, and a strong emphasis on selectors. Problems in CSS are analyzed, and recommended future research is described.

The World Wide Web has succeeded in large part because its software architecture has been designed to meet the needs of an Internet-scale distributed hypermedia system. The Web has been iteratively developed over the past ten years through a series of modifications to the standards that define its architecture. In order to identify those aspects of the Web that needed improvement and avoid undesirable modifications, a model for the modern Web architecture was needed to guide its design, definition, and deployment. Software architecture research investigates methods for determining how best to partition a system, how components identify and communicate with each other, how information is communicated, how elements of a system can evolve independently, and how all of the above can be described using formal and informal notations. My work is motivated by the desire to understand and evaluate the architectural design of network-based application software through principled use of architectural constraints, thereby obtaining the functional, performance, and social properties desired of an architecture. An architectural style is a named, coordinated set of architectural constraints. This dissertation defines a framework for understanding software architecture via architectural styles and demonstrates how styles can be used to guide the architectural design of network-based application software. A survey of architectural styles for network-based applications is used to classify styles according to the architectural properties they induce on an architecture for distributed hypermedia. I then introduce the Representational State Transfer (REST) architectural style and describe how REST has been used to guide the design and development of the architecture for the modern Web. REST emphasizes scalability of component interactions, generality of interfaces, independent deployment of components, and intermediary components to reduce interaction latency, enforce security, and encapsulate legacy systems. I describe the software engineering principles guiding REST and the interaction constraints chosen to retain those principles, contrasting them to the constraints of other architectural styles. Finally, I describe the lessons learned from applying REST to the design of the Hypertext Transfer Protocol and Uniform Resource Identifier standards, and from their subsequent deployment in Web client and server software.

Audio conferencing is only efficient if the right tools are used and if the flow of task-inherent work processes is not disturbed by unsuited technology. Therefore, we suggest to structure the original task into two asynchronous preparation phases, one without and one with a link to the audio conference. This is followed by the actual conference and the assessment phase, which ends one itineration of processing the original task. The object-oriented audio conference software is written in C/C++ and runs on Sun workstations under SunOS 5.3 The audio mixing part is based on IBM compatible PCs running DOS. The PCs are equipped with ISDN interfaces, an analogue telephone interface, a digital signal processor board, and Ethernet interface cards allowing network access over TCP/IP. The audio conferencing service can be fully accessed and controlled over the Internet. The system is realizable with existing low-cost workstation technology, but still provides a good audio conference signal and a user-friendly interface.

To study acoustic effects in premixed laminar flames the compressible Navier-Stokes equations with stiff source terms for the chemistry are numerically solved by a cell centered finite volume method. Three basic numerical problems are discussed which deal with gas mixtures, convergence acceleration for subsonic simulations and the computation of the inviscid fluxes at the volume interfaces taking the viscous terms, the source terms and 2D effects into account. Conservative Euler solvers for gas mixtures produce numerical errors, if the temperature and the ratio of specific heats are not constant. For mixtures of calorically perfect gases, a simple correction of the total energy per unit volume is proposed to avoid these errors. This is done in a physical way and only the total energy looses some of its conservativity. Numerical simulations of contact discontinuity convection, a shock tube problem and shock-interface interactions in 1D and 2D yield much more accurate solutions, if the correction is applied. The straightforward extension to 3D is outlined. As the ratio of the acoustic and entropy wave speeds is large for low Mach number flames, a lot of time steps are necessary with an explicit scheme to simulate a contact discontinuity crossing the computational domain. An easy way is shown how one can use much larger time steps with an explicit code to obtain the steady state solution. The method is based on the idea that the ratio of the acoustic and entropy wave speeds gets closer to one by subtracting a constant value from the pressure in the whole field. Only the inviscid terms of the energy equation are influenced by that pressure decrease. As long as compressibility effects remain small, the error remains small. Moreover, the error can be corrected by solving a scalar equation after each time step such that the steady state solution of the modified scheme is equal to the steady state of the non-modified scheme. Applying a conventional Riemann solver for flame simulations and even for 2D Euler simulations without source terms can lead to dramatic inaccuracies. A new approach for a flux solver is introduced, which takes viscous terms, source terms and 2D effects into account. The basic idea is to distribute the source terms, which also contain the viscous terms and 2D effects, to the corresponding volume interfaces. The price is a nonlinear algebraic system for six unknowns instead of a linear system for three unknowns to evaluate the fluxes. Simulations of premixed laminar flames in 1D and 2D and a 2D Euler simulation without source terms yield much more accurate results, if the new solver is applied. Unsteady simulations of two colliding flames producing sound show results which correspond almost precisely to the analytic solution. Thus, opposed to conventional Riemann solvers, our new flux solver is able to compute acoustic effects in flames accurately. Finally numerical results of acoustic interaction with a 2D Bunsen flame show a flattened flame shape which is at least qualitatively comparable with experimental measurements. The present approach for a flux solver is more general and can be applied to solve other systems of partial differential equations which contain inviscid terms, e.g. for the shallow water equations.

This thesis deals with the design and implementation of a group and session management system for collaborative applications. The need for such a system has been identified during work on group communication systems and collaborative applications. Currently, the support for collaborative applications provided by group communication systems is not very powerful (from the point of view of designers of collaborative applications). The goal of this thesis is to develop a system which provides designers of collaborative applications with group and session management functionality that can be used to easily build group communications. The architecture of the group and session management system (GMS) consists of a component which is integrated on the user side (typically, the direct user of the group and session management system is a group communication system), and a specialized directory service which is accessed by the user-side component. The two main aspects of the group and session management system are the data model and the functional model. The data model describes the object types which can be used for group and session management and the operations which can be used with these object types. The functional model describes how the operations are carried out inside GMS, ie how GMS works internally. The GMS data model consists of six object types and a number of relations which can be established between objects of these types. The user object type represents a person or entity using GMS. Each user has an identity (a name) and one or more methods of self-authentication. The group object type is used to define groups which can consist of users and/or groups. The flow object type represents one connection for data transport. The session data type is the main metaphor for group communication. Each session is used to logically group a number of flows and to create an abstraction for management, authorization, and admission control for flows. Two additional object types are certificates and flow templates, which are used for security purposes and for storing information related to the creation of flows. GMS is a distributed system which defines two protocols: an access protocol for communicating with the distributed system, and a system protocol for communications between the distributed entities of the system. The access protocol is based on a reliable, connection-oriented transport service. The system protocol uses two different transport services: a reliable, connection-oriented service and a reliable, FIFO ordered multicast service. A prototype of GMS has been implemented on a Unix platform and a number of performance tests and evaluations have been performed. The results showed that the GMS approach to group and session management is feasible and that the system can easily be used by designers of group communication systems. However, the prototype implementation has some performance drawbacks, for which possible solutions are also suggested.

The developments in information technology of the last years have led to major advances in high-speed networking, multimedia capabilities for workstations and also distributed multimedia applications. In particular, multimedia applications for computer supported cooperative work have been developed that allow groups of people to exchange information and to collaborate and cooperate joint work. However, existing communication systems do not provide end-to-end guarantees for multipoint communication services which are needed by these applications. In this thesis, a communication architecture is described that offers end-to-end performance guarantees in conjunction with flexible multipoint communication services. The architecture is implemented in the Multipoint Communication Framework (MCF) that extends the basic communication services of existing operating systems. It orchestrates endsystem and network resources in order to provide end-to-end performance guarantees. Furthermore, it provides multipoint communication services where participants dynamically join and leave. The communication services are implemented by protocol stacks which form a three layer hierarchy. The topmost layer is called multimedia support layer. It accesses the endsystem's multimedia devices. The transport layer implements end-to-end protocol functions that are used to forward multimedia data. The lowest layer is labelled multicast adaptation layer. It interfaces to various networks and provides a multipoint-to-multipoint communication service that is used by the transport layer. Each layer contains a set of modules that implement a single protocol function. Protocol stacks are dynamically composed out of modules. Each protocol uses a single module on each layer. Applications specify their service requirements as Quality of Service (QoS) parameters. MCF maps these QoS parameters to the above mentioned layers, where they are used to calculate the needed resources. A resource manager reserves memory, CPU and multimedia devices in the endsystem. Access to the CPU is provided by a real-time scheduler for periodic tasks, which executes the protocols. The reservation of network resources is delegated to the network resource manager. MCF orchestrates endsystem and network resources in order to provide a guaranteed service covering the whole path from multimedia device to multimedia device. The evaluation of MCF shows that the proposed architecture results in an easy to use and efficient solution. The dynamic composition of protocol stacks offers high flexibility and allows applications to transport any multimedia data over any network. Resource reservations provide the performance guarantees needed for continuous media such as audio or video.

The rise and success of the modern science, first in physics, later in biology and medicine, was based on a mechanic-linear model of causality. Its only category of explanation of natural processes is the mechanical machine. Such a point of view is reductionistic and does not justice to living organisms. As human beings using and processing signs we cannot recognize ourselves in this model. As all living creatures we perceive, interpret and answer the stimuli of the environment. To explain the behavior of organisms we need a semiotic-circular causality. Semiotics, the study of signs, try to perceive and interpret processes of signs. Language serves as a paradigmatic model. Semiotics can be subdivided in semantics, the theory of meaning, in syntax, the theory of the forms and the arrangement of the signs, and in pragmatics, the theory of the contextual rules of communication. Pragmatics as a subject of inquiry in its own right attained its scientific status in the last few decades only. Semiotics are not concerned exclusively with language, but help as so-called "biosemiotics" also to explain the network of communication on and between the different levels of organisation of molecules, cells, organs or organism. Living organisms are networks connecting these levels with each other and with the environment. The Denkstil of established pharmacology is likewise restricted to mechanic causality. Phenomena unexplained by physics are classified as unscientific. As a consequence the placebo effect is defined as 'non-specific' or 'non-characteristic'. Such negative definitions exclude concrete questions of investigation. If we accept a biosemotic view in pharmacology, that is to say that we see drugs as signs consisting of a physical vehicle equipped with meaning, then the lock-and-key-concept becomes the syntactic level and the effect on the metabolism of the cell mediated by second messengers, on the organ and on the organism becomes the semantic level. The establishment of structure-effect-relations are the only goal of the classic pharmacology, just as syntax and semantics are the only domain of the classic semiotics. But the therapy with drugs must be seen in a broader treatment context. One has to include the level of the organism of the doctor-patient-relation or the placebo effect and of the internal organismic system levels as individual response to a drug, dependent on the genetic idiosyncrasy, the environment of the cell, the recent past, the thermodynamic activity etc. The assumption of steady state conditions are unrealistically restrictive. The semiotic expansion of the pharmacology will not invalidate the achievements of classic pharmacology, but elucidates in addition a view of the pragmatic components and makes the scientific integration of the placebo phenomenon into the drug therapy possible. The placebo effect looses its inconsistency. From a biosemiotic point of view the randomized placebo controlled double blind trial must be seen as a restriction to unrealistic conditions of investigation. The pragmatic regularities and thus a scientific approach to the processes happening within the therapeutic triangle of therapist, drug and patient are excluded. The comparison of a drug with a placebo is a category-mistake. By comparing semantics with pragmatics, the investigator confounds the levels of analysis. A semiotic pharmacology expanded by pragmatics increases the number of aspects of the therapeutical situation. Pharmacology ought to pay more attention to pragmatic aspects of drug therapy.

Biometric methods for verifying, i.e. authenticating, someone's identity are increasingly being used. Today's commercially available biometric systems show good reliability. However, they generally lack user acceptance. Users show an antipathy touching a fingerprint scanner and they dislike looking into an iris scanner that might eventually malfunction and impair their vision. In general, they favour systems with the least amount of interaction. Using gait as a biometric feature would lessen such problems since it requires no subject interaction other than walking by. Consequently, this would increase user acceptance. And since highly motivated users achieve higher recognition scores, it increases the overall recognition rate as well. This monograph describes a biometric system that uses individual characteristics of human gait for authentication. Two sensors measuring different physical properties of the walking person were used. First, a force sensor measures the Ground Reaction Force (GRF) perpendicular to the floor and second, a video sensor captures a side view of the passing person. Computationally efficient algorithms were developed to extract five different feature types, i.e. modalities, from the acquired gait data. A novel variant of the Generalised Principal Component Analysis (GPCA) was devised to reduce data dimensionality without losing, or even better, with improving person separability. Last but not least, a Bayes Risk Criterion approach is used to fuse the five modalities. In the final investigation the performance and discriminatory power of all modalities was analysed. In addition, the influence of changing clothes, shoes, backpacks, and bags on the recognition quality was investigated. It could be shown that fusing all five modalities drastically improves the overall system robustness compared to the best individual modality. Finally, an extensive discussion of the limitations and possible future improvements of the current system is included.

Due to technological changes in cartography, traditional paper atlases have increasingly been replaced by digital atlas information systems (AIS) during the last 20 years. AIS offer both user-friendly interfaces and high-quality multimedia visualisation techniques, yet they still lack the functionality to perform spatial analysis. This functionality, however, offers a great potential for the future development of AIS. Therefore, this dissertation investigates how GIS analysis functions can be integrated with AIS, and how these functions can be rendered accessible to a broad range of expert and non-expert users. The emphasis of this dissertation is placed on using environmental vector data sets within AIS. In the theoretical first part of the study, a new scientific approach called "GIS analysis in atlas information systems" was developed. This approach first points out that the following GIS functions are suited for AIS: measurements, queries, reclassification and aggregation, graphical and geometrical overlay, analysis of surfaces, network analysis and statistics. Since analysis of surfaces is usually not based on a vector model, it cannot be considered for AIS with environmental vector data sets. Secondly, the approach states that these GIS functions have to be easy to use, reliable (i. e., ensuring correct results), data independent and fast (i. e., performed within a short time) in order to be successful in AIS. These requirements, however, can only be met if the technical structure of the AIS is flexible enough to allow authors to individually design and develop the graphical user interface and the GIS functions. In the practical second part of the study, the scientific approach was realised by developing the application AGAIS (Analytical Geographic Atlas Information System). As examples of environmental vector data sets, the digital soil-suitability and precipitation maps of Switzerland were used. The graphical user interface was developed using the multimedia authoring system Macromedia Director, while the GIS functions were programmed with an external shared library written in C++. In accordance to the scientific approach, only those functions were implemented in AGAIS that are suited for AIS with environmental vector data and make sense for the soil-suitability and precipitation maps. The GIS functions were adapted in such a way as to meet the requirements of users not having any GIS technical knowledge. Thus, using AGAIS, it is possible to perform complex queries and reclassification without knowing the syntax of a query language. In addition, these functions ensure correct results. When two map layers are graphically overlaid, map elements can easily be compared with the two-dimensional, likewise overlaid legend. The geometrical overlay is rendered transparent to the users by progressively drawing the intersection points and the newly built polygons on the map. In so doing, users gain insight into the process of a complex GIS function. Moreover, they get the impression of a shorter waiting time. Finally, when users perform statistical analysis, they can at a glance identify the distribution and correlation pattern of attributes in coloured diagrams. This study shows that GIS functions can be successfully integrated with AIS. These functions, however, must be carefully chosen, considerably adapted, and simplified so that atlas users can understand them by intuition. Therefore, the functions and the user interface cannot be adopted from common GIS, but have to be redesigned according to the needs of atlas users. In future, integrating GIS functionality will positively influence the development of AIS and will extend their field of application. Complex spatial analysis, so far mainly performed by GIS specialists, is now available to a broader range of users. Although AIS will become more analytical in the future, they are not likely to grow together with GIS. On the contrary, they will remain independent and closed systems.

A detailed experimental and numerical study of three-dimensional laminar flow over a backward-facing step with an expansion ratio of 2 and a downstream aspect ratio of 20 is presented. Experimental results for transitional and turbulent flow are also reported. Experiments were based on both Digital and Stereoscopic Particle Image Velocimetry; a spectral element method was used for the simulations. The focus of the present work was two-fold: (i) A passive control scheme for inducing global unsteadiness, suggested in previous work, was implemented, and the controlled flow was studied in the laminar and turbulent regimes. (ii) In the uncontrolled flow, the effects of sidewalls on the flow structure were studied at laminar, transitional, and turbulent Reynolds number values. The control scheme consisted of external flow recirculation due to suction at the step wall and blowing at the lower wall. The problem geometry was fixed and, thus, for a given Reynolds number, the flow dynamics depended only on the recirculation volume flow rate. For laminar flow, periodic vortex shedding from the step edge was observed within a range of recirculation flow rates, both in experiments and two-dimensional simulations. Global stability analysis calculations support the present simulation results. The experimental laminar flow was found to be strongly three-dimensional, exhibiting streamwise vortices in the shear layer regions. For turbulent flow, the present control scheme significantly increased mixing in the region immediately after the sudden expansion. This led to a decrease in reattachment length of the order of 70% in comparison to the non-manipulated flow. The control scheme was found to be robust to variations in the suction/blowing velocity boundary conditions. In the present study of sidewall effects, both experimental and computational results illustrated that, for laminar flow, a wall-jet is present at the channel lower wall, directed towards the channel mid-plane, in agreement with previous observations. In the present work, the development of self-similar wall-jet profiles with increasing distance from the sidewalls is demonstrated. The intensity of this secondary flow increased with Reynolds number in the laminar regime, and decreased in the transitional and turbulent regimes. The effect of sidewalls on the primary and upper wall recirculation zones is demonstrated, which explains the discrepancies in the previous literature between experiments and two-dimensional simulations.

The coda of seismic waves consists of that part of the signal after the directly arriving phases. In a finite medium, or in one that is strongly heterogeneous, the coda is dominated by waves which have repeatedly sampled the medium. Small changes in a medium which may have no detectable influence on the first arrivals are amplified by this repeated sampling and may thus be detectable in the coda. We refer to this use of multiple-sampling coda waveforms as coda wave interferometry. We have exploited ultrasonic coda waves to monitor time- varying rock-properties in a laboratory environment. We have studied the dependence of velocity on uni-axial stress in Berea sandstone, the temperature dependence of velocity in granite and in aluminum, and the change in velocity due to an increase of water saturation in sandstone. Furthermore, We applied coda wave interferometry to seismic data excited by a hammer source, collected at an experimental hard rock mine, Idaho Springs, CO. We carried out a controlled stress-change experiment in a pillar and we were able to monitor the internal stress change. We used coda wave interferometry to monitor temporal changes in the subsurface of the Mt. Erebus Volcano, Antarctica. Mt. Erebus is one of the few volcanoes known to have a convecting lava lake. The convection provides a repeating seismic source producing seismic energy that propagates through the strongly scattering geology in the volcano. There are many other possible applications of coda wave interferometry in geophysics, including dam and nuclear waste deposit monitoring, time-lapse reservoir characterization, earthquake relocation, stress monitoring in surface mining and rock physics.

Communication networks lend themselves to the study of a variety of optimization problems. A fundamental problem among them that is intensively investigated is that of call admission control, or call control for short. The problem arises in the following setting. The communication network consists of nodes (e.g. terminals, routers, et cetera) which are connected to each other via links (e.g. optical cables). These links carry data between nodes. They have a certain bandwidth capacity associated with them. A call is a communication request between any two nodes of the network. It is associated with a bandwidth requirement, i.e. the rate at which data is communicated between the nodes. A call may be accepted into the network if (i) a route connecting the two nodes exists and (ii) the bandwidth requirement of the call can be reserved along all the links of one such route. Once a call is accepted a profit is accrued by the network. The optimization problem arises due to the fact that the sum of the bandwidth requirements of calls that are routed through any link of the network should not exceed its bandwidth capacity. The call control problem is to maximize the number (or profits) of calls that can be accepted into the network such that the capacity constraints on the links are not violated. A ring topology is one in which the nodes are connected to each other forming a cycle. In all-optical networks, the ring topology is a popular configuration. Bigger networks are formed from individual rings by interconnecting them. Some top reasons that make the ring topology a favoured one are its simplicity, scalability and survivability in the presence of link failures. This thesis mainly investigates several variants of call control on ring based topologies for two reasons. Firstly, all-optical networks are in the forefront of revolutionizing communications today and the ring topology is the building block of such networks. Secondly, rings are simple topologies on which several network optimization problems have been studied in the past and there are several others which have not been resolved. The goal of our research, the outcome of which is the thesis presented here, is to address a few such problems pertaining to call control. There are two basic variants of call control that we consider, namely on- line and off-line. In the off-line version of call control, it is assumed that all the calls that occur in the network are given in advance. An algorithm for this version can decide which calls to accept and which to reject taking this overall picture into consideration. In the online version, calls arrive into the network in a sequence, one after the other. An algorithm for the on-line version makes a decision to accept a call that is presented to it only based on what decisions it made in the past and the current state of the network. In particular, it has no knowledge of the calls that might be presented to it in the future. A tree of rings is a graph obtained by connecting several disjoint rings in a "tree"-like fashion, by identifying vertices in different rings. The tree of rings topology is a natural result of interconnecting rings in all-optical networks to form larger networks. We investigate on-line call control problems on trees of rings. Non-preemptive randomized algorithms with competitive ratios that are best possible up to constant factors are given. Fixed parameter tractability is an emerging area to tackle NP-hard problems. We view call control problems from this perspective. Fixed parameter tractability results are shown for variants of the off-line call control problems on arbitrary graphs, undirected and bidirected trees of rings. To the best of our knowledge, these are the first such results for the call control problem. For two variants of off-line call control problems in rings, we present polynomial time approximation algorithms. When the route of a call can be determined by the algorithm, we present an algorithm that accepts and routes at most 3 calls fewer than what an optimal algorithm can achieve. When the routes are pre-determined we present an algorithm that achieves a profit that is at least one-half of that achieved by an optimal algorithm. For various special cases, we present optimal polynomial time algorithms or approximation schemes. We also give an indication of the difficulty of finding an optimal polynomial algorithm for the general problem. For addressing the off-line call control problem for calls with arbitrary bandwidth requirements, a starting point would be to study it on the simple topology of a line. A line is simply a set of nodes connected to form a path. We identify several restrictions for which algorithms with "nice" ratios are achievable.

Cardiovascular diseases such as atherosclerosis, coronary heart disease, and dilated cardiomyopathy, are the principal cause of mortality in industrialized countries. Chronic inflammatory processes are of major importance in the pathogenesis of atherosclerotic disease and myocarditis. Initial injury is likely to be elicited by infectious agents that can sustain chronic immune responses and immunopathology by persisting in the cardiovascular system. Such chronic infections may eventually overcome tolerance and induce reactivity against self-antigens with exacerbation of the disease. Indeed, autoimmune reactions have been hypothesized to be involved in the pathogenesis of myocarditis and atherosclerosis. To shed light on the mechanisms behind chronic cardiovascular diseases, we used a transgenic mouse model in which autoimmunity can be specifically elicited in the heart and the aorta (SM-LacZ mice). The two first studies deal with the role and significance of B cells and their accompanying autoantibody signatures in systemic and heart-specific autoimmunity, respectively. The third and the fourth sections describe how virus elicited CD8+ T cells can either be exhausted and functionally impaired in conditions of high antigen expression in the periphery, or lead to the exacerbation of atherosclerosis and chronic immunopatholgy in a model of antigen persistence in the cardiovascular system. In the first part of this work we present a preliminary investigation on the autoimmune B cell response engendered following infection with cytopathic (vaccinia virus, VV and vesicular stomatitis virus, VSV) or non-cytopathic (lymphocytic choriomeningitis virus, LCMV) viruses. Applying the SEREX method (serological identification of recombinantly expressed antigens), we show that viruses induce antibodies against a broad panel of autoantigens. Furthermore, the different viruses triggered distinct autoantibody responses, thus suggesting that virus infections may leave specific "autoantibody fingerprints" in the infected host. The second chapter is dedicated to the characterization of the anti-self IgG response in organ-specific autoimmunity. Here the SEREX approach was used to molecularly dissect heart-specific autoimmune B cell responses that develop during the course of experimental autoimmune myocarditis (EAM). Upon immunization with a peptide derived from cardiac myosin heavy chain $\alpha$ (myhc$\alpha$) we found that the vast majority of the autoantibodies generated in BALB/c mice was specific for portions of the myosin protein that did not encompass the immunogenic peptide, hence revealing intramolecular epitope spreading. This strong focusing on myhc$\alpha$ was also a hallmark of the B cell response against heart antigens, that was induced upon myocardial damage following MCMV infection which generally precipitates a broad spectrum of anti-self antibodies. Furthermore, myocarditis severity correlated with both intra- and intermolecular epitope spreading. Therefore, evaluation of the focusing of an antibody response to disease-related self-determinants may help to assess both the susceptibility to and the progression rate of autoimmune cardiac damage. The third study investigates the fate of transgene-specific CD8+ T cells following abortive infection with a recombinant adenovirus. We found that specific CD8+ T cells expanded only in a very narrow dose range and that they were functionally impaired. Infection of SM-LacZ mice led to the deletion of these specific CD8+ T cells and, consequently, transgenic mice did not develop myocarditis. Our results suggest that the outcome of vaccination with recombinant adenoviruses is critically dependent on the antigen load in peripheral tissues. The last chapter is an immunologic analysis of the mechanisms underlying atherosclerosis in an infectious situation. Although hypercholesterolemic APOE(-/-) and APOE(-/-)$\times$SM-LacZ mice mounted comparable T cell responses to a recombinant MCMV-LacZ virus, persistent expression of the $\beta$galactosidase transgene in the vasculature, as it occurs in APOE(-/-)$\times$SM-LacZ mice, dramatically exacerbated atherosclerosis and elicited chronic cellular infiltrations in the aorta. Therefore, our data provide evidence for the role of persistent vascular infections with pathogens and the ensuing specific immunopathology in atherogenic processes.

Currently more than 1'000'000 total knee arthroplasties, TKAs, are implanted world wide each year, thereof 40'000 TKAs in Switzerland. Because of higher life expectancies it is expected that the number of total knee implantations will increase in the next few years. The goals of a TKA are longevity of the implant components and high satisfactory patient rates. Today the rate of a good patient outcome is around 85%, which still leaves a significant absolute number of patients needing early revision surgery. The most common causes for revision surgery are polyethylene (PE) wear, loosening, knee instability and infection. PE wear, loosening and instability are factors associated with altered joint biomechanics after total knee replacement. The femoral component rotational alignment profoundly affects the knee joint's mechanics in flexion as well as in extension, in all six degrees of freedom. A malrotated femoral component could lead to ligament unbalancing causing lateral flexion instability and pain while standing up from a chair or walking down stairs. In order to avoid these problems a comprehensive mechanical understanding of the knee joint as regards to the alignment of the implant component in TKA is important. A three dimensional computer based model visualising the joint's kinematics during different motion patterns contributes to this understanding and makes it possible to estimate the load at the knee joint. Such a model requires accurate in vivo kinematic and kinetic data to visualise and calculate the load at the joint of different motion patterns of daily activities. Previous investigations in gait analysis used kinematic and kinetic information from skin mounted markers and force plates during level walking. The problem of this measurement technique is the large error in kinematic data acquisition caused by the movement of the skin and muscles relative to the underlying bone. Video-fluoroscopy enables the measurement of kinematics of implant components more accurately by a three-dimensional numeric reconstruction of the single plane projection view in the fluoroscopic images, thus avoiding skin movement artefacts. However, this technique is limited to the field of view of the fluoroscopic screen. This problem was solved by using a motor driven trolley built in the laboratory to carry the fluoroscopic unit (x-ray source, image intensifier, c-arm). This movable system allows the tracking of the knee joint during level walking, and a sit down task. An intensity based registration algorithm reconstructs the six degrees of freedom of the implant components relative to the focus of the fluoroscope. The three dimensional reconstruction is within a translational accuracy of 3.1 mm and a rotational accuracy of 1.6$^\circ$. Video-fluoroscopy only acquires kinematic data. This means that the loads in the knee joint can not be estimated. In this study was force plate data coupled with the moving fluoroscopic system enabling inverse dynamic calculation. The unit mover was optically tracked by VICON in order to transform the fluoroscopic coordinate system into the global coordinate system with its origin on the centre of one force plate, thereby coupling the fluoroscopic system with the force plate. This transformation was performed within an accuracy of $\pm$ 1 mm. This measuring system results in seven times more accurate inverse dynamic calculation than classic instrumented gait analysis would achieve. The local mechanics of the total knee was visualised in a three dimensional computer model. The model included TKA geometry from CAD software, and bone geometry from CT scans of the individual. It visualised the kinematics of the implant components during the activities mentioned above. Furthermore, femoral component malrotation was simulated to estimate the alternated strain at the posterior cruciate ligament, the medial, and the lateral collateral ligaments. The simulation of five different degrees of femoral component malrotation shows the relationship between the strain and forces produced by the ligaments under these conditions. The simulation shows that an internally rotated femoral component has a more profound effect on the forces in the ligaments than an external rotational malalignment. This might lead to pain on the medial side and condylar lift-off on the lateral side during a sit down task, as observed by clinicians. This work sets a basis for further investigation of TKA discussing the patient's outcome and contributing to a better mechanical understanding of the knee joint. It may help clinicians and implant developers discuss the effects of their implant design or alignment of the implant components under dynamic loading.

The recent rise and widespread adoption of wireless networking technologies for mobile communication applications has sparked numerous visions of an ever more networked and interactive world. One such vision proposed in the late nineties are Wireless Sensor Networks (WSN), where wireless communication and computing elements are combined with integrated sensors to enable tightly coupled interaction with the physical world. As a new application domain for wireless technology, key challenges here are (i) the limited resources of the highly integrated nodes that are to be leveraged by the amount of devices deployed and the collaboration between them, (ii) the tight coupling of application, nodes and the environment and (iii) the broad usage profile by systems-experts and non-expert users alike. First medium-scale experiments and field-trials have reported that it is increasingly hard to design, develop, deploy, test and validate systems consisting of more than a hand-full of nodes, especially when situated in a real-world environment. Prototypical applications are scarce, seldom consisting of more than a few tens to a hundred nodes. Setting up large, heterogeneous, interactive and functional systems as forecast in the visions is no small task; currently more an art than a systematic engineering effort. Coordinated methods and tools for the design and deployment of wireless networked embedded systems are missing today. With this work, we contribute to the design and development of wireless networked embedded systems. The specific contributions are presented and discussed in the context of a vertical slice of the design space concerned and the relevant questions encountered: (i) Functional and qualitative requirements of a location management service for WSNs based on measurements and simulation have been developed. We present one of the earliest algorithms for the distributed computation of node location. (ii) A novel platform for fast-prototyping of WSNs has been developed. This platform has successfully served numerous researchers, among ourselves, as an underlying infrastructure for experimentation and education. (iii) The BTnode platform has been used to develop multihop networks and topology control mechanisms for Bluetooth scatternets. To our knowledge, the experiments presented are the largest connected Bluetooth scatternets reported of to date. (iv) The concept of a deployment-support network as a powerful tool for the development, deployment, test and validation of WSNs is presented in conjunction with experimental evidence on the feasibility of the approach.

Alzheimer's disease (AD) is the most common form of dementia in the elderly and affects almost 30% of the population over 85 years of age. The cause and mechanisms of the disease are still unknown, yet a large body of evidence supports the so called amyloid cascade hypothesis. According to this model, abnormal accumulation and deposition of A$\beta$ peptide lead through a series of processes to fibril formation and synaptic dysfunction, neuronal loss and finally dementia. No cure for this disease is available yet and definite diagnosis is only possible by histological analysis of post mortem brain tissue. The diagnosis of a patient is a very complicated, expensive and time-consuming process including a variety of analyses such as neuropsychological testing, neuro-imaging, and blood tests. In specialized centers the accuracy of this diagnostic workup reaches 80–90%. The aim of this study was to screen the proteome of the cerebrospinal fluid (CSF) of patients with AD, patients with other neurological disorders including other types of dementia, and healthy age-matched control subjects for differences. For the CSF proteome analysis surface enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF MS) was used. This method combines a chromatographic sample prefractionation step and mass spectrometric protein analysis in one technology. The data was analyzed using classification tree software, a bio-informatics tool based on a binary recursive partitioning algorithm. A proteomic pattern for the diagnosis of Alzheimer's disease was found consisting of 5 nodes representing peaks with molecular weights of 14 kDa, 11.7 kDa, 66 kDa, 4.2 kDa, and 80 kDa. This pattern reached a sensitivity of 80% and specificities of 75% (AD versus healthy control subjects), 95% (AD versus other neurological disorders), and 85% (AD versus both other groups). These values are comparable to the diagnostic accuracy obtained by standard diagnostic procedures. However, the combination of several diagnostic patterns into a "committee of experts" analysis led to correct classification of up to 100% of the test samples. By these patterns together with univariate statistical analysis of the proteomic data seven putative bio-marker candidates were found, three of which were identified. Two of these marker candidates were shown to be different forms of transthyretin, namely the glutathionylated form and an N-terminally truncated form, whereas the third bio-marker was shown to be Apolipoprotein AI. Transthyretin is a thyroid hormone carrier protein which also binds A$\beta$ peptide and has been reported to protect neurons against A$\beta$ toxicity. Apolipoprotein AI is the major component of plasma HDL and participates in the reverse transport of cholesterol from tissues to the liver. Apolipoprotein AI therefore plays a role in cholesterol metabolism and homeostasis which is believed to play a role in the mechanism of Alzheimer's disease pathology. The putative markers not yet identified have molecular weights of 4.6 kDa, 7.7 kDa, 40 kDa and 51 kDa and seem to separate more generally the healthy status from neurological disease. In conclusion, the principle of using protein patterns in CSF for the diagnosis of Alzheimer's disease was demonstrated and three bio-marker candidates which may be interesting from a pathophysiological point of view were identified.

Designing and editing XML Schemas can be simplified by the use of a conceptual model. Therefore a conceptual model, that can handle the fundamental parts of the W3C XML Schema standard has been created and implemented. In addition algorithms have been developed, that describe the derivation of an XML schema from the model (export) and the generation of a model out of an existing XML Schema (import). Furthermore a graphical editor has been developed, that supports users creating and editing the model. XML schema import and export functionalities have been integrated as well.

In the past few years, a number of constraint languages for XML documents has been proposed. They are cumulatively called schema languages or validation languages and they comprise, among others, DTD, XML Schema, RELAX NG, Schematron, DSD, xlinkit. One major point of discrimination among schema languages is the support of co-constraints, or co-occurrence constraints, e.g., requiring that attribute A is present if and only if attribute B is (or is not) present in the same element. Although there is no way in XML Schema to express these requirements, they are in fact frequently used in many XML document types, usually only expressed in plain human-readable text, and validated by means of special code modules by the relevant applications. In this paper we propose SchemaPath, a light extension of XML Schema to handle conditional constraints on XML documents. Two new constructs have been added to XML Schema: conditions — based on XPath patterns — on type assignments for elements and attributes; and a new simple type, xsd:error, for the direct expression of negative constraints (e.g., it is prohibited for attribute A to be present if attribute B is also present). A proof-of-concept implementation is provided. A Web interface is publicly accessible for experiments and assessments of the real expressiveness of the proposed extension.

XML is universally recognized as the standard document format for the purpose of interchange and device-independent presentation. Literature shows many efforts towards the development of formal and conceptual models for XML, although no commonly accepted model exists as yet. In this paper, we present a survey of some formal and conceptual modeling techniques, and discuss the merits and shortcomings of such techniques. We then present HNR (Heterogeneous Nested Relations) a formal modeling method for representing XML, and discuss how this formal model could be used to derive many useful results on XML query language, and how this could lead to a potential conceptual modeling technique as well.

This report examines the use of knowledge organization systems — schemes for organizing information and facilitating knowledge management — in a digital environment. Knowledge organization systems serve as bridges between a user's information needs and the material in a collection. Examples of such systems include term lists, such as dictionaries; classification schemes, such as Library of Congress Subject Headings; and relationship lists, such as thesauri. These and other types of knowledge organization systems, which vary in complexity, structure, and function, can improve the organization of digital libraries and facilitate access to their content.

Change detection is an important part of version management for databases and document archives. The success of XML has recently renewed interest in change detection on trees and semi-structured data, and various algorithms have been proposed. We study here different algorithms and representations of changes based on their formal definition and on experiments conducted over XML data from the Web. Our goal is to provide an evaluation of (i) the quality of the results (ii) the performance of the tools. We also consider in which context each of these algorithms can be best used.

In order to automate SLA management it is essential to specify SLAs in precise and unambiguous manner as well as keep the specification flexible. While precision will help automate the process of monitoring and metric collection, flexibility will enable extending it to unforeseen service level agreement specifications.

The SGML and XML standards use a variation of regular expressions called content models for modeling the markup structures of document elements. SGML content models may include so called and groups, which are excluded from XML. An and group, which is a sequence of subexpressions separated by an &-operator, denotes the sequential catenation of its subexpressions in any possible order. If one wants to shift from SGML to XML in document production, one has to translate SGML content models to corresponding XML content models. The allowed content models in both SGML and XML are restricted by a requirement of determinism, which means that a parser recognizing document element contents has to be able to decide without lookahead, which content model token to match with the current input token, while processing the document from left to right. It is known that not all SGML content models can be expressed as an equivalent XML content model. It is also known that transforming an SGML content model into an equivalent XML content model may cause an exponential growth in the length of the content model. We discuss methods of eliminating and groups and analyze the circumstances where they can be applied. We derive a tight bound of e n! on the number of symbols in the result of eliminating an and group of n symbols, where e = 2.71828... is the base of natural logarithms. We present the analysis in a pedagogical manner, emphasizing mathematical methods which are typical to the analysis of algorithms. We also show that minimal deterministic automata for recognizing an and group of n distinct element names contain 2^n states and n^{2n-1} transitions, excluding the failure state and transitions leading to it.

The Standard Generalized Markup Language (SGML) and the Extensible Markup Language (XML) allow users to define document-type definitions (DTDs), which are essentially extended context-free grammars expressed in a notation that is similar to extended Backus-Naur form. The right-hand side of a production, called a content model, is both an extended and a restricted regular expression. The semantics of content models for SGML DTDs can be modified by exceptions (XML does not allow exceptions). Inclusion exceptions allow named elements to appear anywhere within the content of a content model, and exclusion exceptions preclude named elements from appearing in the content of a content model. We give precise definitions of the semantics of exceptions, and prove that they do not increase the expressive power of SGML DTDs when we restrict DTDs according to accepted SGML practice. We prove the following results: 1. Exceptions do not increase the expressive power of extended context-free grammars. 2. For each DTD with exceptions, we can obtain a structurally equivalent extended context-free grammar. 3. For each DTD with exceptions, we can construct a structurally equivalent DTD when we restrict the DTD to adhere to accepted SGML practice. 4. Exceptions are a powerful shorthand notation — eliminating them may cause exponential growth in the size of an extended context-free grammar or of a DTD.

This report is a review of personal bibliographic management software and systems — it provides a fairly comprehensive review of available systems, functionality and issues in personal bibliographic data management. It was produced as part of background research for the SWAD-E Semantic Blogging Demonstrator Research and was funded by HP Labs as part of the SWARA project based in ILRT.

The Web is a linked literature: we wish to discover what the authors of Web pages are choosing to link and what they are choosing to link to. It is hoped that understanding interconnectedness as it is practised in the Web through links will enable us to see what kinds of hypertext are achievable using common technologies and what is impracticable. Understanding the arrangement of the links helps us to understand the construction of the page as a whole which in turn helps us to understand the purpose of the links. This paper discusses a search for examples of good subject-based hypertext linking, the linking statistics that we drew from those pages and the linking practises that the statistics represent. We also show how the analysis of how hypertext links are written can be applied to the problem of Web page reading in non-standard and reduced-bandwidth Web browsing applications.

Schema matching is a critical step in many applications, such as XML message mapping, data warehouse loading, and schema integration. In this paper, we investigate algorithms for generic schema matching, outside of any particular data model or application. We first present a taxonomy for past solutions, showing that a rich range of techniques is available. We then propose a new algorithm, Cupid, that discovers mappings between schema elements based on their names, data types, constraints, and schema structure, using a broader set of techniques than past approaches. Some of our innovations are the integrated use of linguistic and structural matching, context-dependent matching of shared types, and a bias toward leaf structure where much of the schema content resides. After describing our algorithm, we present experimental results that compare Cupid to two other schema matching systems.

Das vorliegende Dokument beschreibt Regeln, welche bei der Benutzung von XML und von XML Schemas in eCH Standards zu berücksichtigen sind. Dabei wird das Schwergewicht auf Basismechanismen und Grundsatzüberlegungen gestellt, welche sich die Benutzern von XML Schemas in der Regel stellen.

Das vorliegende Dokument beschreibt, in welcher Form XML Namespaces beschrieben werden sollten, so dass die Benutzer von XML-basierten Vokabularen im Rahmen von eCH eine einfache Quelle haben, über die sie Dokumentation zu einem XML Namespace finden können. Ausgehend von einem einfachen XML Schema können zu einer Definition eines XML Vokabulars auf diese Art auf eine einfache Art Beschreibungen zu einem XML Namespace erzeugt werden, aus denen sowohl menschen- als auch maschinenlesbare Information gewonnen werden kann.

Das vorliegende Dokuments behandelt die innere Struktur von XML Schemas, d.h. den Aufbau und den Zusammenhang der sogenannten "XML Schema Komponenten". Dies ist vor allem dann wichtig, wenn das Schema wiederverwendet werden soll, z.B. indem Teile in einem neuen Kontext wiederverwendet werden sollen, oder indem eine neue Version des Schemas definiert werden soll. In beiden Fällen wirkt sich die innere Struktur des Schemas stark darauf aus, wie einfach diese Aufgabe ausgeführt werden kann.

Im vorliegenden Dokument wird beschrieben, welche Dokumentation für XML Schemas zu erstellen ist, damit die nötigen Grundlagen für die Implementierung einer Schnittstelle für den XML-basierten Datenaustausch vorhanden sind. Ausgangspunkt ist ein Datenmodell des Ausschnitts der Realität, über welchen Informationen ausgetauscht werden sollen. Davon abgeleitet werden für die jeweils interessierenden Transaktionen Datenmodelle für den Datenaustausch (Austauschmodelle). Ein Austauschmodell wiederum dient als Grundlage für eines oder auch verschiedene Schemas (Austauschschemas). Nur wenn die Modelle wohldefiniert und dokumentiert sind, und wenn die Beziehungen zwischen den Modellen (Referenz- und Austauschmodelle) und den Schemas (Austauschmodell und -schemas) wohldefiniert und dokumentiert sind, können unabhängige Implementierer die Schnittstelle korrekt umsetzen.

Das vorliegende Dokument definiert Hilfskomponenten, die zur Definition von XML Schemas verwendet werden können. Diese Hilfskomponenten können eingesetzt werden, um wiederkehrende Aspekte von Datenmodellen auf existierende und gemeinsame XML Schema Definitionen abzubilden. Auf diese Weise müssen keine neuen XML Schema Komponenten für diese Aspekte eines Datenmodells definiert werden, und durch die Verwendung wiederverwendbarer Komponenten wird es einfacher, ein XML Schema zu verstehen, in dem diese Hilfskomponenten verwendet werden.

While the information contained in XML documents can be accessed using numerous standards and technologies, accessing the information in an XML Schema currently is only possible using proprietary technologies. XML is increasingly being used as a typed data format, and therefore it becomes more important to gain access to the type system of an XML document class, which in many cases is an XML Schema. The XML Schema Path Language (SPath) presented in this paper provides access to XML Schema components by extending the well-known XPath language to also include the domain of XML Schemas. Using SPath, XML developers gain better access to XML Schemas and thus can more easily develop software which is type- or schema-oriented.

This paper presents a general model of a Group Management Service (GMS) which is designed to support collaborative interactions among groups of distributed users using different applications. There are two main benefits of such a service. Firstly, it would be easier to implement new collaborative applications because of the possibility to use an existing service. Secondly, it would be possible for different applications to share collaboration relevant information because of a common database of information about users and groups maintained by the GMS. One important property of the GMS is its flexibility with respect to the information stored. It is possible to store application-independent as well as application-dependent information. Using an object-oriented approach, applications can share the application-independent information (such as a group's members and administrative information) and can also use the GMS to store application-dependent information which can only be interpreted by a closed set of applications (those who know the syntax and semantics of the application-dependent information). The model of the GMS is very simple and consists mainly of two classes of objects, namely user and group. A small set of operations is provided for querying and modifying GMS information. The possibility to store application-dependent information is realized by allowing using application to create derived classes (ie subclasses) of the classes user and group. Thus it is possible for applications using the GMS to implement their own user and group classes without losing the ability to manage these objects with the GMS. Two applications are presented which may use the GMS to manage their users and groups. Both applications use application-specific derived classes of user and group. However, it is still possible for these applications to share the application-independent information of their users and groups.

Today most CSCW systems are built on top of standard operating systems. Only a few frameworks for generic support of CSCW applications exist. These platforms mostly concentrate on the management of workflows and on the layer on top of them, the CSCW applications. Little work is done in exploring the impacts of new networks onto support for CSCW. The project described in this paper focuses on providing CSCW applications with an efficient shared information space. Efficiency in this context means the utilization of network technology which offers much better services than today's networks.

Asynchronous messaging between cooperating software components proves to be useful in many scenarios. One framework supporting this functionality is Sun's J2EE platform with its Message-Driven Beans (MDB) model. We present a novel way to use MDBs by providing a way to add routing information to the messages, which is then used to send a message through a given path of processing components. We call this model Routed Message-Driven Beans (RMDB), and the two main topics that are important for RMDBs are (1) the message format that is used for the routing information, and (2) the API which can be used by programmers to take advantage of the abstraction provided by RMDBs. Performance measurements show that the overhead caused by our RMDB framework is acceptable if messages are routed through several EJBs.

Web technologies today go far beyond simply enabling the creation of Web pages. XML and metadata formats based on it make it possible to manage metadata in a powerful and flexible way. In this paper, we describe the concept and the prototype of an application for the management of metadata for a specific domain, metadata associated with pictures. The goal of the paper is to highlight the benefits which result from employing Web technologies instead of proprietary data formats. While we think that both application developers as well as users could benefit from such an approach, we are aware that in many real-world cases other issues (such as the ability to bind users to a certain product) also play an important role. Nevertheless, in this paper we show that open and well-documented technologies not only can make software development easier, but also open up synergies between standards-compliant products. While the prototype we present in this paper is not sophisticated enough to be released to the general public, we hope that software vendors will consider incorporating some of the concepts introduced in this paper.

The World Wide Web is by far the most successful hypermedia system, its name often being used synonymously for the Internet. However, it is based on a rather restricted hypermedia model with limited linking functionality. Even though underlying systems may provide a richer data model, there is still the question of how to present this information in a Web-based interface in an easily understandable way. Assuming an underlying system similar to Topic Maps, which allows storing, managing, and categorizing meta data and links, we propose a presentation of extended links. We try to provide a usable way for users to handle the additional functionality. The mechanism is based on already available technologies like DHTML. It is one facet of our approach to make the Web more interconnected and to work towards a more richly and openly linked Web.

In this paper, we investigate the requirements for linkbase access on the Web. The recent advancements of Web technologies (XML, XLink, and XPointer) have brought us one step closer to the vision of using the Web as an Open Hypermedia System (OHS). However, some of the pieces to make this work are still missing, and this paper discusses which they are and the status of the current work in these areas. Concentrating on one of these pieces, the access to linkbases, the paper than continues by describing the prerequisites and requirements of such an access mechanism, and closes with a list of requirements and design principles that we will use in a next step to specify and implement a linkbase access protocol.

We propose the Open Web, which aims at transforming the Web into an Open Hypermedia System. Based on the Extensible Linking Language (XLink), we investigate the possibilities for implementing linkbase access methods. Linkbases are collections of so-called third-party links, which are links which live outside the resources that they are linking, and thus must be found and retrieved somehow when presenting the resources that they are linking. We focus on the protocol issues of accessing linkbases, concentrating on how such a new protocol could and should be designed. In addition to our design goal of specifying a protocol for accessing the linkbase Web service, be believe that our protocol considerations can serve as a blueprint for other areas where Web access to services is required.

This report describes a proposal for a data model for XLink. It defines the data model as contributions of XLink to the XML Infoset. The data model is meant as a clarification of the link model implicitly defined by XLink. It is also meant as the foundation for future work on XLink, for example a DOM module for XLink support, a CSS module for styling XLinks, or a protocol for accessing XLink linkbases.

XML and its data model, the XML Information Set, are used for a large number of applications. These applications have widely varying data models, ranging from very simple regular trees to irregularly structured graphs using many different types of nodes and vertices. While some applications are sufficiently supported by the data model provided by the XML Infoset itself, others could benefit from extensions of the data model and assistance for these extensions in supporting XML technologies (such as the DOM API or the XSLT programming language). In this paper, we describe the Extensible XML Information Set (EXIS), which is a reformulation of the XML Infoset targeted at making the Infoset easier to extend and to make these extensions usable in higher-level XML technologies. EXIS provides a framework for defining extensions to the core XML Infoset, and for identifying these extensions (using namespace names). Higher-level XML technologies (such as DOM or XPath) can then support EXIS extensions through additional interfaces, such as a dedicated DOM module, or XPath extension mechanisms (extension axes and/or functions). In order to make EXIS work, additional efforts are required in these areas of higher-level XML technologies, but EXIS itself could be used rather quickly to provide a foundation for well-defined Infoset extensions, such as XML Schema's PSVI contributions, or the reformulation of XLink as being based on a data model (rather than a syntax).

XML Schema is a very expressive grammar-based schema language that additionally supports advanced data modeling techniques, namely through its type concept, and allows for describing relationships between structural elements in an expressive and semantically meaningful way. Upcoming type-aware XML technologies like XSLT 2.0, XQuery, and XPath 2.0 increasingly strive to use this structural information, but its retrieval is difficult and only partially possible. Both a unified data model for XML Schema and a set of accessor functions are necessary for enabling new technologies to utilize XML Schema's full capabilities. We will present a function library relying on an XML-based representation of XML Schema's data model and demonstrate how this substantially enhances XPath 2.0 and XSLT 2.0 and how this proves highly beneficial to applications.

XML Schema is a complex language for defining schemas for classes of XML documents, and its inherent complexity as well as its XML transfer syntax make it hard to read XML Schemas for humans. This is a problem, because in many cases XML Schemas are not only used for validation purposes, but also as the data model for classes of XML documents, which must be understood by developers working with these documents. This report looks at various visualizations of XML Schemas in existing software tools and compares them in terms of how well they are suited to represent the data model behind the XML Schema syntax. of today, no available tool provides a level of abstraction that would be appropriate for a data model perspective; most of them are visualizations of the syntax rather than the model. The tools included in this report are the Eclipse XML editors, XML Spy, oXygen, Turbo XML, and Stylus Studio. This report is not a complete evaluation of these tools, it only looks at them in terms of their schema visualization and their support of a less syntax-centered view of XML Schema.

XML and Service-Oriented Architectures (SOA) make it easier to develop loosely coupled systems, but they do not eliminate the fundamental necessity of communications that there must be an underlying shared model. Because of the popularity of SOA, it becomes increasingly important to be able to quickly and efficiently integrate information systems, rather than using an expensive top-down process. The XML landscape evolved bottom-up, and so far it has not yet reached a stage where XML is explicitly targeted in conceptual models. Filling this gap with guidelines and best practices thus is the most pragmatic approach. The approach presented in this paper is a structured view accompanied by guidelines for how interoperability can be achieved on the model level today.

Information today is often distributed among many different system within a complex IT environment. Using this information for creating knowledge organization systems and services thus involves using this distributed information and re-purposing it within new applications. The current trend in Web technologies to build systems not in a monolithic fashion, but rather intended as building blocks within a constantly evolving and unplanned landscape of information processing agents. This approach can be used as a foundation for building Knowledge Organization Mashups. We investigate the possibilities and challenges of this type of application, and as a case study describe a service for managing bibliographic metadata.

Because of its success, XML is increasingly used in many different application areas, and is moving towards the center of applications, evolving from an exchange format to the native data format of application components. These developments suggest that similar to other core areas of application design, XML should be designed conceptually before the implementation tasks of designing markup and writing schemas are approached. In this paper, we describe why conceptual modeling will become an important part of the XML landscape, what issues need to be addressed, and what the requirements for a conceptual modeling language for XML are.

XML has become an important standard for exchanging structured data between applications, but XML increasingly penetrates applications and is thus also becoming an important part of application development. The current state of XML specifications and technologies provides support in many aspects of application development, while other aspects are still only poorly supported. We describe as an example the development of an XML-centric application and identify and describe the areas where today's support for application developers could and should be improved. This case study thus can help developers to focus on the problem areas of today's support for XML-centric application development, and may also serve as an agenda for areas where more research and tools are required to improve the development of XML-centric applications.

The creation, management and dissemination of bibliographic information is a common task for almost all people working in a research environment, and it also is a (often weak) way of knowledge management. Current tools and methods are either centered on the process of document preparation using bibliographic references, or on the aspect of creating annotations and/or relationships describing bibliographic resources. As a result, bibliography management in many cases is still carried out with fairly simple tools and methods, and with little or no support for sharing the information. In the ShaRef project, the areas of document preparation, knowledge management, and information sharing among workgroup members are treated as equally important. As a result, ShaRef enables users to create, manage, and disseminate bibliographic information in a wide variety of use cases.

In this paper, we describe a real-life application which has been designed around an XML data model and various XML technologies. We describe the rationale behind this design, and the benefits from the information system design point of view. We believe that XML-centric design has a lot of benefits, and that future developments in the area of XML technologies will better support this design style and help to make it even more advantageous. XML-centric design allows to leverage an ever-increasing number of XML-based technologies. We describe some of the XML technologies that helped us implementing some of the core parts of the software, and point out some others that we do not yet use, but are actively investigating for possible future developments.

In this paper we present an approach to organize e-government schemas in Switzerland. On the political side, Switzerland is a challenging environment for any federation-wide harmonization and cooperation, because many authorities are organized independently. On the technical side, we describe an approach which aims at increasing the federation-wide cooperation through providing interested parties with a low barrier-to-entry, and with clearly visible benefits through the continuous evolution of a directory of e-government schemas. This paper describes a light-weight Semantic Web approach, enabling schema authors to create namespace descriptions that provide a minimal semantic description of the namespace's subject. Using these namespace descriptions, RDF data is extracted and serves as source for a highly interlinked directory of e-government schemas in Switzerland.

Collections of references are an important part of scientific and scholarly work. For many people, collections of references are the most advanced form of formal knowledge representation they are using. However, today's standards and tools for collections of references are pretty poor, providing closed environments with no or little extension mechanisms. In this paper, we describe our goal to design and implement an advanced system for collections of references. The primary goal of this system is to provide users with a tool that matches their requirements of semantic richness vs. usability, which are competing goals. As a first step towards this goal, we designed and conducted a survey among the employees of a large university, trying to find out how people are managing their references today, and what their expectations are if a new tool became available. The results of the survey are presented, followed by conclusions that are the guiding principles for the upcoming ShaRef project. The goal of this project is to design and implement a system for reference management that runs Web-based as well as stand-alone, is easy to use, supports collaborative collections of references and collection sharing, has an open and extensible data model, covers the majority of user requirements according to the 80/20 principle, and thus provides scientists and scholars with a better way to manage their collections of references.

E-commerce technologies have reached a level of maturity where many businesses are no longer hampered by technological limitations. However, the adoption of e-commerce technologies is slower than anticipated. We argue one of the limitations is a psychological barrier, which is created by the perception that e-commerce technologies are a whole new set of technologies which are completely different from computer networking. By applying metaphors from basic networking technologies (such as bridges and routers), we try to (1) demonstrate that e-commerce technologies are — in many ways — comparable to computer networking, and (2) show that convincing businesses to adopt e-commerce technologies could be made easier by showing them that e-commerce is basically computer networking taken to another level. We also believe that using these metaphors will make it easier to talk about e-commerce technologies, to reuse existing knowledge about networking architectures on this new level, and to identify the areas where additional work needs to be done.

XML Schema is a schema language for XML, providing advanced features for creating types, deriving types, and a library of built-in simple datatypes. The model behind XML Schema are XML Schema components, and XML Schema uses XML syntax for representing XML Schema components. In this report, we present an alternative syntax for XML Schema, which is defined using EBNF productions. Since the new syntax has been designed with the design goals of readability and compactness, it is called XML Schema Compact Syntax (XSCS). XSCS has been created for making XML Schema easier to read and write by humans, while XML Schema's XML syntax is better suited for automated processing of XML Schemas. Consequently, XSCS is not meant as a replacement of the XML syntax, but as a complementary syntax.

Group communications require special support for name and address management, QoS support, and connection establishment. The group and session management system (GMS) is a distributed directory system which is specifically designed to support group communication infrastructures. This report briefly introduces the concepts of GMS, the data types available, and then gives a specification of GAP, the GMS access protocol. GAP is specified by state diagrams describing the behavior of two communication entities, the PDU syntax in ASN.1, and the PDU semantics in comments given for each PDU.

Group communications require special support for name and address management, QoS support, and connection establishment. The group and session management system (GMS) is a distributed directory system which is specifically designed to support group communication infrastructures. This report briefly introduces the concepts of GMS, the data types available, and then gives the specification of GSP, the GMS system protocol. This protocol is used for communication between GSAs, ie it is used for GMS's internal communication. GSP is specified by state diagrams, time sequence diagrams, textual descriptions, the PDU syntax in ASN.1, and the PDU semantics in comments given for each PDU.

Multi-user multimedia editing ought to be supported by different means. Besides technical means required for editing a given document by several users simultaneously, there is also a demand for communication mechanisms which are able to support the synchronization of the users. The system presented in this paper does not only offer multi-user multimedia editing capabilities but also provides a shared workspace and an environment for communication both via terminals and via telephone. The shared workspace is a concept which allows the members of a conference to share documents and other data. Telephone communications enable members of a collaborative editing session to have conference connections and to dynamically form subgroups.

In this second edition of the bestselling title, the author explains the important and relevant XML technologies and their capabilities clearly and succinctly with plenty of real-life projects and useful examples. He outlines the elements of markup — demystifying concepts such as attributes, entities, and namespaces — and provides enough depth and examples to get started. Learning XML is a reliable source for anyone who needs to know XML, but doesn't want to waste time wading through hundreds of web sites or 800 pages of bloated text.

Version Control with Subversion introduces the powerful new versioning tool designed to be the successor to CVS. An introduction to Subversion is followed by a guided tour of its capabilities. Later chapters cover more complex topics of branching, repository administration, and other advanced features. If you've never used version control, you'll find everything you need to get started. And if you're a seasoned CVS pro, it will help you make a painless leap into Subversion.

Essential CVS is a complete and easy-to-follow reference that helps programmers and system administrators apply order to the task of managing large quantities of documents. The book covers basic concepts and usage of CVS, and features a comprehensive reference for CVS commands — including a handy Command Reference Card for quick, on-the-job checks. The book also includes advanced information on all aspects of CVS that involved automation, logging, branching and merging, and "watches."

Poor design and a failure to consider the user often act against the effectiveness in online communication. Designing Usable Electronic Text, Second Edition explores the human issues that underlie information usage and stresses that usability is the main barrier to the electronic medium's campaign to gain mass acceptance. The book is a revision of the successful First Edition with a new emphasis on the Web and hypertext design and their impacts. With the emergence of new uses of information, such as e-commerce and telemedicine, text presentation will take on a new and greater importance. Its focus on the design framework and its empirical approach make it a unique book.

Paratexts are those liminal devices and conventions, both within and outside the book, that form part of the complex mediation between book, author, publisher and reader: titles, forewords, epigraphs and publishers' jacket copy are part of a book's private and public history. In this first English translation of Paratexts, Gerard Genette shows how the special pragmatic status of paratextual declaration requires a carefully calibrated analysis of their illocutionary force. With clarity, precision and an extraordinary range of reference, Paratexts constitutes an encyclopedic survey of the customs and institutions as revealed in the borderlands of the text. Genette presents a global view of these liminal mediations and the logic of their relation to the reading public by studying each element as a literary function. Richard Macksey's foreword describes how the poetics of paratexts interact with more general questions of literature as a cultural institution, and situates Gennet's work in contemporary literary theory.

Much of the business transacted on the Web today takes place through information exchanges made possible by using documents as interfaces. For example, what seems to be a simple purchase from an online bookstore actually involves at least three different business collaborations — between the customer and the online catalog to select a book; between the bookstore and a credit card authorization service to verify and charge the customer's account; and between the bookstore and the delivery service with instructions for picking up and delivering the book to the customer. Document engineering is needed to analyze, design, and implement these Internet information exchanges. This book is an introduction to the emerging field of document engineering.

A variety of "key recovery," "key escrow," and "trusted third-party" encryption requirements have been suggested in recent years by government agencies seeking to conduct covert surveillance within the changing environments brought about by new technologies. This report examines the fundamental properties of these requirements and attempts to outline the technical risks, costs, and implications of deploying systems that provide government access to encryption keys.

The OpenURL Framework Standard defines an architecture for creating OpenURL Framework Applications. An OpenURL Framework Application is a networked service environment, in which packages of information are transported over a network. These packages have a description of a referenced resource at their core, and they are transported with the intent of obtaining context-sensitive services pertaining to the referenced resource. To enable the recipients of these packages to deliver such context-sensitive services, each package describes the referenced resource itself, the network context in which the resource is referenced, and the context in which the service request takes place. This Standard specifies how to construct these packages as Representations of abstract information constructs called ContextObjects. To this end, the OpenURL Framework Standard defines the following core components: Character Encoding, Serialization, Constraint Language, ContextObject Format, Metadata Format, and Namespace. In addition, this Standard defines Transport, a core component that enables communities to specify how to transport ContextObject Representations. Finally, this Standard specifies how a community can deploy a new OpenURL Framework Application by defining a new Community Profile, the last core component. This Standard defines the OpenURL Framework Registry and the rules that govern the usage of this Registry. The OpenURL Framework Registry contains all instances of all core components created by communities that have deployed OpenURL Framework Applications. This Standard defines and registers the initial content of the OpenURL Framework Registry, thereby deploying two distinct OpenURL Framework Applications.

This part of ISO 639 provides a code consisting of language code elements comprising two-letter language identifiers for the representation of names of languages. The language identifiers according to this part of ISO 639 were devised originally for use in terminology, lexicography and linguistics, but may be adopted for any application requiring the expression of language in two-letter coded form, especially in computerized systems. The alpha-2 code was devised for practical use for most of the major languages of the world that are not only most frequently represented in the total body of the world's literature, but which also comprise a considerable volume of specialized languages and terminologies. Additional language identifiers are created when it becomes apparent that a significant body of documentation written in specialized languages and terminologies exists. Languages designed exclusively for machine use, such as computer-programming languages, are not included in this code.

Specifies a set of 128 control and graphic characters such as letters, digits and symbols with their coded representation. Applies to alphabets of the Latin script.

Specifies the elements to be included in bibliographic references to published monographs and serials, to chapters, articles, etc. in such publications and to patent documents. Sets out a prescribed order for the elements of the reference and establishes conventions for the transcription and presentation of information derived from the source publication.

The purpose is to coordinate and standardize the use of identifying numbers so that each international standard book number is unique to a title or edition of a book or other monographic publication (serial publications excluded) published or produced by a specific publisher or producer. The standard specifies the construction of an ISBN and the location of the printed number on the publication.

Specifies the requirements for a generalized exchange format suitable for bibliographic descriptions. Describes a framework for communications between data processing systems. Replaces the second edition.

ISO/IEC TR 9573-11:2004 defines the document structures and style specifications for standards document interchange (in particular, ISO standards). Element types and attributes for ISO standards are defined and two profiles (a database-oriented profile and a document-oriented profile) are provided. The document structures are described by an SGML (ISO 8879) DTD, an XML DTD, and a RELAX NG (ISO/IEC 19757-2) schema. The style specifications are described by DSSSL (ISO/IEC 10179), XSLT, and XSL. Rendering examples and a list of processing tools are provided for information.

Specifies the volume and file structure of compact read-only optical disks (CD-ROM) for the information interchange between information processing systems. Defines: the attributes of the volume and the descriptors recorded on it; the relationship among volumes of a volume set; the placement of files; the attributes of the files; recorded structures intended for input or output data streams of an application program when required to be organized as sets of records; three nested levels of medium interchange; two nested levels of implementation; requirements for the processes provided within information processing systems.

Specifies the processing of valid Standard Generalized Markup Language (SGML) documents. Document Style Semantics and Specification Language (DSSSL) defines the semantics, syntax, and processing model of languages for the specification of documentation processing. Provides means for externalization of style characteristics and other techniques for associating style information with an SGML document.

Presents four document type definitions and additional facilities conforming to ISO 8879. Intended to provide document architectures for the creation and interchange of books, articles and serial publications. Specifies the SGML declaration defining the syntax used by the document type definitions and document instances; the document type definitions for the document classes books, articles, serials; a document type definition for Mathematics which may be embedded in other SGML applications.

Defines a notation, Extended BNF, for specifying the syntax of a linear sequence of symbols. It defines both the logical structure of the notation and its graphical representation.