No description available.

Thesis (Ph. D.)--Oregon State University, 1996. / Typescript (photocopy). Includes bibliographical references (leaves 144-152). Also available on the World Wide Web.

No description available.

This thesis is missing page 95, copies of this thesis do not have the page. -Digitization Centre / A new high-level, high-order computer programming language designed to complement multi-processor, parallel computing systems is presented, These systems permit a high-order of operation by performing many instructions simultaneously, thus producing significant increases in computing The proposed language is so constructed as to give the user a free and natural format, to express problems which exhibit natural or inherent parallelism® In order to demonstrate some of the main features, a small subset of the language has been written, and implemented as a sequential simulation. In order to relate the language to hardware schemes, a parallel processing array computer is briefly examined. A core language to communicate with parallel computing systems may be constructed from the concepts developed. / Thesis / Master of Engineering (ME)

Master of Science / Department of Computing and Information Sciences / John M. Hatcliff / There are a number of network situations where different networks have different security policies and still need to share information. While it is important to allow some data to flow between the two networks, it is just as important that they don't share any data that violates the respective security policies of the networks. Constraints on data sharing are often phrased in terms of classification levels of data (e.g. top secret, secret, public). They might also be stated in terms of the contents of the data (e.g. are there military base names, is the location correct). The software and hardware that works to solve these problems is called Cross Domain Solutions (CDS). There are a variety of hardware platforms capable of implementing CDS. These platforms are all configured in different ways and they are often proprietary. Not only are there a number of platforms on the market, many are difficult to understand, verify, or even specify. The Guardol project provides an open, non-proprietary, and domain-specific language for specifying CDS security policies and implementing CDS. Guardol is designed to be easy to understand and verify. This thesis describes the design and implementation of primary Guardol components. It includes a description of the Eclipse GUI plug-ins that have been developed for the project as well as a description of new formal analyses and translations that have been developed for the language. The translation is used to plug into external tools for model checking and the analyses help to make the translation clean and efficient. The analyses are also useful tools to help make the use of Guardol easier for developers.

The past trend of increasing processor throughput by increasing the clock frequency and the instruction level parallelism is no longer feasible due to extensive power consumption and heat dissipation. Therefore, the current trend in computer hardware design is to expose explicit parallelism to the software level. This is most often done using multiple, relatively slow and simple, processing cores situated on a single processor chip. The cores usually share some resources on the chip, such as some level of cache memory (which means that they also share the interconnect, e.g., a bus, to that memory and also all higher levels of memory). To fully exploit this type of parallel processor chip, programs running on it will have to be concurrent. Since multi-core processors are the new standard, even embedded real-time systems will (and some already do) incorporate this kind of processor and concurrent code. A real-time system is any system whose correctness is dependent both on its functional and temporal behavior. For some real-time systems, a failure to meet the temporal requirements can have catastrophic consequences. Therefore, it is crucial that methods to derive safe estimations on the timing properties of parallel computer systems are developed, if at all possible. This thesis presents a method to derive safe (lower and upper) bounds on the execution time of a given parallel system, thus showing that such methods must exist. The interface to the method is a small concurrent programming language, based on communicating and synchronizing threads, that is formally (syntactically and semantically) defined in the thesis. The method is based on abstract execution, which is itself based on abstract interpretation techniques that have been commonly used within the field of timing analysis of single-core computer systems, to derive safe timing bounds in an efficient (although, over-approximative) way. The thesis also proves the soundness of the presented method (i.e., that the estimated timing bounds are indeed safe) and evaluates a prototype implementation of it. / Den strategi som historiskt sett använts för att öka processorers prestanda (genom ökad klockfrekvens och ökad instruktionsnivåparallellism) är inte längre hållbar på grund av den ökade energikonsumtion som krävs. Därför är den nuvarande trenden inom processordesign att låta mjukvaran påverka det parallella exekveringsbeteendet. Detta görs vanligtvis genom att placera multipla processorkärnor på ett och samma processorchip. Kärnorna delar vanligtvis på några av processorchipets resurser, såsom cache-minne (och därmed också det nätverk, till exempel en buss, som ansluter kärnorna till detta minne, samt alla minnen på högre nivåer). För att utnyttja all den prestanda som denna typ av processorer erbjuder så måste mjukvaran som körs på dem kunna delas upp över de tillgängliga kärnorna. Eftersom flerkärniga processorer är standard idag så måste även realtidssystem baseras på dessa och den nämnda typen av kod.  Ett realtidssystem är ett datorsystem som måste vara både funktionellt och tidsmässigt korrekt. För vissa typer av realtidssystem kan ett inkorrekt tidsmässigt beteende ha katastrofala följder. Därför är det ytterst viktigt att metoder för att analysera och beräkna säkra gränser för det tidsmässiga beteendet hos parallella datorsystem tas fram. Denna avhandling presenterar en metod för att beräkna säkra gränser för exekveringstiden hos ett givet parallellt system, och visar därmed att sådana metoder existerar. Gränssnittet till metoden är ett litet formellt definierat trådat programmeringsspråk där trådarna tillåts kommunicera och synkronisera med varandra. Metoden baseras på abstrakt exekvering för att effektivt beräkna de säkra (men ofta överskattade) gränserna för exekveringstiden. Abstrakt exekvering baseras i sin tur på abstrakta interpreteringstekniker som vida används inom tidsanalys av sekventiella datorsystem. Avhandlingen bevisar även korrektheten hos den presenterade metoden (det vill säga att de beräknade gränserna för det analyserade systemets exekveringstid är säkra) och utvärderar en prototypimplementation av den. / Worst-Case Execution Time Analysis of Parallel Systems / RALF3 - Software for Embedded High Performance Architectures

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The advantages of using visual programming to create, modify, test and display a telemetry stream are presented. The failure to fully deploy the high-gain antenna of the Galileo spacecraft has resulted in a software redesign of the computer systems onboard the spacecraft to support the low-gain antenna mission. Visual programming software is being used to test new algorithms as part of the ground support for the spacecraft Test Bed. It is very important that any new software algorithms be thoroughly tested on the ground before any modifications are made to the spacecraft. The advantage of using a visual programming language (LabVIEW, National Instruments) is that it provides easy visibility into the decommutation process that is being modified by the Galileo programming support team. In addition, utilities were written using visual programming to allow real-time data display and error detection. A data acquisition board is used to clock in the actual synchronous telemetry signal from the Test Bed at rates below 10 kHz. The time to write and modify the code using visual programming is significantly less (by a factor of 4 to 10) than using text-based code. The gains in productivity are attributed to the communication among the customer, developer, and computer that are facilitated by the visual syntax of the language.

It is well known that parallelization of software is a difficult problem to solve. This project aimed to research a possible solution by creating a programming language for parallelization and subsequently analyzing its syntax and semantics. This analysis consisted of readability and writability tests followed by a subjective discussion from the point of view of the author. The project resulted in the Majo programming language. Majo uses a graph based concurrency model with implicit shared data synchronization. The model is integrated into the languages design, making it easier to use. The analysis of the language showed that the integration of the threading model simplifies the writing of parallel software. However, there are several syntactic elements that could be improved upon, especially regarding the communication between concurrently executing threads. In conclusion, the author believes that the way forward in regards to parallel programming is to make programming languages more human centric and design syntax in a way that intuitively expresses the underlying semantics.

Esse trabalho relata o estudo sobre a aplicação da tecnologia adaptativa na área de linguagens de programação e códigos, tendo como objetivo a proposição de mecanismos que permitam a escrita de códigos que possam se auto-modificar segundo os conceitos da tecnologia adaptativa. Essa proposta é feita por meio da descrição de uma linguagem de montagem para programação adaptativa e de seu mecanismo de execução. Em adição à linguagem, foi desenvolvido um ambiente de execução baseado em um novo dispositivo adaptativo (autômato de execução adaptativo), com o intuito de evitar certas dificuldades existentes à modificação de código impostas pelos mecanismos de execução. Para poder representar e executar códigos adaptativos, esse dispositivo agrega características de execução de ambientes tradicionais e dos autômatos adaptativos. Essa dissertação apresenta o resultado dessa pesquisa, consolidando os conceitos desenvolvidos por meio de exemplos de funcionamento de códigos adaptativos e considerações sobre a linguagem. / This research studies the application of the Adaptive Technology in the field of programming Language and codes, which objective is the proposition of a mechanism designed to build codes capable of self-modifying in compliance which the concepts of Adaptive Technology. This proposal is formulated by means of the description of an assembly language for adaptive programming and its run-time mechanism. In addition to the language proposal, a run-time mechanism based on a new adaptive device (adaptive execution automata) is conceived. That avoids some difficulties to perform code modification existent in traditional run-time mechanisms. In order to represent and execute the adaptive codes, this device aggregates characteristic of the traditional run-time mechanism and the adaptive automata. The present dissertation describes the results of this study, consolidating the concepts developed by means of examples about the code execution operation and considerations about the language.

Esse trabalho relata o estudo sobre a aplicação da tecnologia adaptativa na área de linguagens de programação e códigos, tendo como objetivo a proposição de mecanismos que permitam a escrita de códigos que possam se auto-modificar segundo os conceitos da tecnologia adaptativa. Essa proposta é feita por meio da descrição de uma linguagem de montagem para programação adaptativa e de seu mecanismo de execução. Em adição à linguagem, foi desenvolvido um ambiente de execução baseado em um novo dispositivo adaptativo (autômato de execução adaptativo), com o intuito de evitar certas dificuldades existentes à modificação de código impostas pelos mecanismos de execução. Para poder representar e executar códigos adaptativos, esse dispositivo agrega características de execução de ambientes tradicionais e dos autômatos adaptativos. Essa dissertação apresenta o resultado dessa pesquisa, consolidando os conceitos desenvolvidos por meio de exemplos de funcionamento de códigos adaptativos e considerações sobre a linguagem. / This research studies the application of the Adaptive Technology in the field of programming Language and codes, which objective is the proposition of a mechanism designed to build codes capable of self-modifying in compliance which the concepts of Adaptive Technology. This proposal is formulated by means of the description of an assembly language for adaptive programming and its run-time mechanism. In addition to the language proposal, a run-time mechanism based on a new adaptive device (adaptive execution automata) is conceived. That avoids some difficulties to perform code modification existent in traditional run-time mechanisms. In order to represent and execute the adaptive codes, this device aggregates characteristic of the traditional run-time mechanism and the adaptive automata. The present dissertation describes the results of this study, consolidating the concepts developed by means of examples about the code execution operation and considerations about the language.