<p>When designing an open system, there might be no implementation available for cer- tain components at verification time. For such systems, verification has to be based on assumptions on the underspecified components. In this thesis, we present a framework for the verification of open systems through explicit state space representation.</p><p>We propose Extended Modal Transition Systems (EMTS) as a suitable structure for representing the state space of open systems when assumptions on components are writ- ten in the modal<i> μ</i>-calculus. EMTSs are based on the Modal Transition Systems (MTS) of Larsen. This representation supports state space exploration based verification tech- niques, and provides an alternative formalism for graphical specification. In interactive verification, it enables proof reuse and facilitates visualization for the user guiding the verification process.</p><p>We present a two-phase construction from process algebraic open system descriptions to such state space representations. The first phase deals with component assumptions, and is essentially a maximal model construction for the modal<i> μ</i>-calculus that makes use of a powerset construction for the fixed point cases. In the second phase, the models obtained are combined according to the structure of the open system to form the complete state space. The construction is sound and complete for systems with a single unknown component and sound for those without dynamic process creation. We suggest a tableau-based proof system for establishing open system properties of the state space representation. The proof system is sound and it is complete for modal <i>μ</i>-calculus formulae with only prime subformulae.</p><p>A complete framework based on the state space representation is offered for the auto- matic verification of open systems. The process begins with specifying the open system by a process algebraic term with assumptions. Then, the state space representation is ex- tracted from this description using the construction described above. Finally, open system properties can be checked on this representation using the proof system.</p>

<p><i>Peer learning</i> means learning from and with each other. Collaboration and co-operation in a friendly environment is, however, something that is neither easy nor obvious for students attending the university. Though, different methods and technological solutions can be implemented to facilitate and improve peer learning as well as dialogue and reflection.</p><p>The aims of this thesis were to study the implementation and use of inno-vative methods and technologies, and its effects on the learning process in mediated peer learning in higher education, as well as methods for facilitating peer learning through students’ individual and group reflection. The aim was also to study end-user involvements in the development processes.</p><p>Dialogue sheets as a medium, i.e. a large sheet of paper with questions (about learning and reflection in this case) printed around its perimeter as support and guidance to the dialogue, have been investigated. Furthermore, the use of peer-to-peer (P2P) technology as mediator in learning has also been studied. The use of P2P technology in learning can be encapsulated in the expression <i>peer-to-peer learning</i>, hence the title “Mediated peer (to peer) learning”. In addition, the evolvement of content-based services in the 3G market has also been studied, introducing a proposed general interpretation of how technology evolution affects the players in a certain market. Dialogue sheets and P2P technology are but two examples of media enhancing peer learning. Many other forms of media can of course enhance peer learning as well, but as computers and the Internet are considered to be the media into which all previous media converge, the thesis starts with the “oldest” medium, the paper, and ends with the “newest” medium, the Internet.</p><p>The conclusions of this thesis can be summarised as:</p><p>The future of learning involves various media enhancing the learning experience. The development and evolution of these media should be the result of cooperation and interaction between learners, teachers, and the university. Failing to cooperate can cause serious problems for the universities.</p><p>By building and maintaining an infrastructure, both analogue and digital, the learning institutions can enable flexible learning, including peer learning, utilising multiple media forms, and also support learners’ indi-vidual learning styles, i.e. promote the learner-centric approach to learning, as well as increase the need for and appreciation of teachers as guides and mentors.</p><p>• By promoting various forms of mediated learning, including P2P technology solutions, teachers and universities can contribute to the defusing of P2P in the public debate, as also socially unquestionable activities then can be associated with the technology. They also foster students in respecting others’ intellectual rights, and can promote alternative copyright schemes, such as creative common</p>

<p>This research work has focused on studies of image control for better reproduction in offset and has been applied practically. This research work has resulted in a survey of color management knowledge, a communication list concerning ICC profiles, an educational kit, a proposal for a new terminology and a patent concerning image adaptation.</p><p>The work is divided into following three areas:</p><p><b>1) image classification</b></p><p>A better understanding of image processing can avoid misunderstandings in the print and leading to more satisfied customers. To achieve optimal print quality for different images, it is important to adapt the prepress settings to the image category. Images can be divided into different categories depending on their image content, key information and tone distribution.</p><p>Trials have been carried out in which the IT.8 test chart has been adapted to different image categories. The results of the image adaptation suggest that an adjustment only to low-key images (dark images) is sufficient, as even normal-key images then show a better similarity to the original image. The low-key image showed more details in dark areas.</p><p><b>2) color separation</b></p><p>Two studies has been carried out. The purpose has been to investigate the knowledge level in color separation, the use of ICC-profiles and the understanding of color management in various printing houses in Sweden. This was done to identify and suggest new applications and suggested actions. These studies indicate that there is a serious problem in the graphic arts industry. The problem is that there is both an insufficient knowledge of color management and a lack of communication. There is a lack of competence and a lack of literature and instructions which can help printers to better understand the technology, and communication suffers through a lack of a common language.</p><p><b>3) suggested actions and the development of tools</b></p><p>Terminology simplification is crucial for the users. A new term for separation “Compensation by Black”, CB, has been suggested. A single term should make it easier for the users to understand and use the different settings which impact the image reproduction. A new tool/kit for the evaluation of ICC-profiles has been created. The goal of this educational kit is to facilitate and exemplify the practical understanding of profiles and their use for the users.</p>

<p>In this thesis we investigate two separate cryptographic notions: mix-nets and hierarchical group signatures. The former notion was introduced by Chaum (1981). The latter notion is introduced in this thesis, but it generalizes the notion of group signatures which was introduced by Chaum and Heyst (1991).</p><p>Numerous proposals for mix-nets are given in the literature, but these are presented with informal security arguments or at best partial proofs. We illustrate the need for a rigorous treatment of the security mix-nets by giving several practical attacks against a construction of Golle et al. (2002). Then we provide the first definition of security of a mix-net in the universally composable security framework (UC-framework) introduced by Canetti (2001). We construct two distinct efficient mix-nets that are provably secure under standard assumptions in the UC-framework against an adversary that corrupts any minority of the mix-servers and any set of senders. The first construction is based on the El Gamal cryptosystem (1985) and is secure against a static adversary, i.e., an adversary that decides which parties to corrupt before the execution of the protocol. This is the first efficient UC-secure mix-net in the literature and the first sender verifiable mix-net that is robust. The second construction is based on the Paillier cryptosystem (1999) and secure against an adaptive adversary, i.e., an adversary that decides which parties to corrupt during the execution of the protocol. This is the first efficient adaptively secure mix-net in any model. An important subprotocol in the above constructions is a zero-knowledge proof of knowledge of a witness that a party behaves as expected. There are two known approaches for constructing such a protocol given by Neff (2002) and Furukawa and Sako (2002) respectively. We present a third independent approach.</p><p>We introduce the notion of hierarchical group signatures. This is a generalization of group signatures. There are several group managers, and the signers and group managers are organized in a tree in which the signers are the leaves and the group managers are internal nodes. Given a signature, a group manager learns if it is an ancestor of the signer, and if so to which of its immediate subtrees the signer belongs, but it learns nothing else. Thus, the identity of the signer is revealed in a hierarchical way. We provide a definition of security of hierarchical group signatures and give two provably secure constructions. The first construction is secure under general assumptions. It is impractical and of purely theoretical interest. The second construction is provably secure under standard complexity assumptions and almost practical.</p>

No description available.

<p>As the companies of today are good at protecting themselves against external threats, but are having problems with internal threats, we focused on how information can be protected from ending up in the wrong hands. First and foremost to protect information from employees who might steal it and sell it to another company. Since the security investments needed are connected to the financial costs of implementing them we have tried to create a balance between the investments needed and the cost of implementing them. The different kinds of protection needed are first and foremost protection to make data less accessable, passwords and traceability. While it is hard for us to estimate the amount of money a company lose by the hour when the production stands still, we have not been able to use any of the excising models to calculate the profit of installing countermeasures. We have, however, been able to find a model that works excellent for the average company who is beginning to install computer security.</p> / <p>Då dagens företag är duktiga på att skydda sig mot hot utifrån, men har svårare med interna hot har vi försökt att inrikta oss på hur informationen skall skyddas från att komma i felaktiga händer. Då i första hand från att anställda skall stjäla den och sälja den vidare. Då omfattningen av skydd som skall installeras är kopplade till hur kostnaden för de åtgärder som krävs har vi försökt skapa en balansgång mellan de skydd som är aktuella och kostnaden för dessa. De skydd som är aktuella är framförallt olika skydd mot åtkomst av data, lösenordshantering och spårbarhet i systemet. Då det är svårt för oss att uppskatta hur mycket ett företag förlorar per timme som produktionen står still har vi inte kunnat nyttja någon av de färdiga modeller som finns för att räkna på förtjänsten med att installera säkerhetsåtgärder kontra att inte göra det. Dock har vi hittat en modell som fungerar utmärkt för genomsnittsföretaget som skall börja med datasäkerhet.</p>

<p>This master’s thesis describes a deterministic dependency parser using a memorybased</p><p>learning approach to parse unrestricted English text. A converter transforms</p><p>the Wall Street Journal section of the Penn Treebank to an intermediate dependency</p><p>representation which is used to train the parser using the TiMBL (Daelemans, Zavrel,</p><p>Sloot, & Bosch, 2003) library. The output of the parser is labeled dependency graphs,</p><p>using as arc labels a combination of bracket labels and grammatical role labels constructed</p><p>from the Penn Treebank II annotation scheme (Marcus, Kim, et al., 1994). The</p><p>parser reaches a maximum unlabeled attachment score of 87.1% and produces labeled</p><p>dependency graphs with an accuracy of of 86.0% with the correct head and arc label</p><p>recognised. The results are close to the state of the art in dependency parsing, and the</p><p>parser also outputs arc labels that other parsers do not produce.</p>

<p>Hur hanterar datorvana personer små mängder elektronisk information? Vad händer när dessa människor vill åt information som finns sparad på något annat ställe än där den ursprungligen skrevs? Ett problemområde är bokmärkeshantering i webbläsare och ett annat är elektronisk anteckningsföring. I detta examensarbete intervjuades fem personer för att analysera vilka behov som finns kring webbaserad informationshantering. Därefter analyserades dessa behov och genom itereringar togs en behovslista fram tillsammans med tre olika konceptplaner som stöd för vidareutveckling. Delar av konceptplanerna implementerades som en wiki med det serverbaserade skriptspråket PHP som grund. Resultatet blev ett förslag på hjälpmedel för personer som ska samarbeta i ett studiesammanhang och då främst studenter på högskola och universitet. Tekniker som undersöktes var främst wiki-tekniken tillsammans med PHP, bloggning, bookmarklets och JavaScript.</p> / <p>How do people used to computers handle small pieces of information? What happens when these people want to access the information on another location? One problem area is bookmark handling in browsers and another is electronic note handling. To be able to analyse the need for web based information structuring, five people were interviewed. The needs were then analysed and through iterations a list of specific needs were derived along with three conceptual plans as a support for further development. Parts of the conceptual plans were implemented as a wiki using the server based scripting language PHP as a base. The result was a suggestion for auxiliary means for people in collaborative learning environments in university education. Technologies that were examined were mainly the wiki technique using PHP, blogging, bookmarklets and JavaScript.</p>

<p>This report is an examination paper in computer science at University of Växjö. The report will focus on the possibility to create adaptable systems and to cost calculate the work needed to modify a system to meet new demands. A project [demos] developed by Interactive Institute studio [12-21] in Växjö is the starting point in our work. They have during a period of two years developed a prototype of a system which intends to get youth and democratic selected representatives a communication platform where they may communicate with SMS. Today they are in a position when they want to develop the system for other user groups with slighter different purpose and to do that they need a more flexible system. In a problem analysis they found out three mayor drawbacks in the system that needed to be changed; member system, the interface to the mobile operator and the managing of messages. These scenarios were analysed with a method called ALMA and in this analyse we found out that the system as it is now is hard to modify. After redesigned and modified the system from [demos.v1] to [demos.v2] we analysed the system again with the ALMA-method and besides the three initial scenarios we also added three new forthcoming scenarios to see how the developed version will meet this demands. The result of this test showed that [demos.v2] was better developed to stand new changes at lower costs than the original system.</p> / <p>Denna rapport är en examensuppsats om 10 poäng i datalogi vid Växjö Universitet. Rapporten avser att belysa möjligheten att skapa anpassningsbara system och att kostnadsberäkna modifierbarheten i ett system. Utgångspunkten i arbetet är ett projekt [demos], drivet av Interactive Institute studio [12-21] i Växjö. De har under två års tid arbetat fram en prototyp till ett system där demokratiskt valda representanter under särskilda arbetsformer ska kommunicera med ungdomar via t.ex. SMS. De är idag i det läget att de vill modifiera systemet till nya användargrupper som systemet måste anpassas till och för att underlätta arbetet behöver de ett mer anpassningsbart system. Vid en problemanalys fann man framför allt tre saker som behövdes åtgärdas. Medlemshanteringen, gränssnittet mot mobiloperatören och hanteringen av skapade meddelanden. Genom att analysera dessa fall mer noggrant med ALMA-metoden fann man systemet i dess nuvarande form svåra att modifiera. Efter att gjort om designen testades demos.v2.0 med ALMA-metoden igen och förutom de tre nämnda</p><p>Förändringsscenarierna testades ytterliga några tänkta förändringsscenarion. Resultatet av det senare testet visade att [demos.v2.0] klarade av förväntade förändringar i högre grad än tidigare version och samtliga tre ursprungliga förändringsscenarion var fullt modifierbara till rimlig kostnad.</p>

<p>Syftet med detta arbete var att undersöka möjligheten att få ett väl fungerande interface mellan ©VizzAnalyzer [3] och Javadoc, och därmed kunna producera htmldokumentation av de analyserade klasserna. VizzAnalyzer analyserar javaprogram och producerar därvid ett abstrakt syntaxträd (AST) som representerar det analyserade programmet. Detta AST kan sedan kopplas till javadocs interna AST-modell för att representera de klasser som förekommer vid analysen. Resultatet av detta blir då en komplett dokumentation av de analyserade klasserna. Det finns även möjligheter att dynamiskt lägga in ytterligare information om dem som kommit fram vid analysen. Utöver interfacet till VizzAnalyzer gjordes också ett mer generellt interface som kan kopplas till vilket program som helst som kan producera en lämplig representation av ett analyserat program. Detta gäller då främst javakod, men i och med att klasser, metoder, fält mm. enbart är representerade som text innan de behandlas av javadocinterfacet, finns det också möjligheter att använda det för andra objektorienterade språk.</p> / <p>The purpose of this work was to examine the possibility to get a well functioning interface between ©VizzAnalyzer [3] and Javadoc, thereby be able to produce html documentation of the analysed classes. The VizzAnalyzer analyses java programs and so produces an abstract syntax tree (AST) that represents the analysed program. This AST can then be coupled to the internal AST model of javadoc to represent the classes that were part of the analysis. The result of this is a complete documentation of the analysed classes. There is also the possibility to add further information about them that may have been discovered during analysis. A more general interface was also made in addition to the interface for VizzAnalyzer. This interface can be coupled with any program that can produce a suitable representation of the analysed program. This is mostly pertinent to java code, but due to classes being represented only as text before they are processed by the interface, there is a possibility to use it for other object oriented languages.</p>