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Dans cette thèse, nous nous intéressons à la recherche d’architectures fiables pour les circuits logiques. Par ”fiable”, nous entendons des architectures permettant le masquage des fautes et les rendant de ce fait ”tolérantes" à ces fautes. Les solutions pour la tolérance aux fautes sont basées sur la redondance, d’où le surcoût qui y est associé. La redondance peut être mise en oeuvre de différentes manières : statique ou dynamique, spatiale ou temporelle. Nous menons cette recherche en essayant de minimiser tant que possible le surcoût matériel engendré par le mécanisme de tolérance aux fautes. Le travail porte principalement sur les solutions de redondance modulaire, mais certaines études développées sont beaucoup plus générales. / In this thesis, we mainly take into account the representative technique Triple Module Redundancy (TMR) as the reliability improvement technique. A voter is an necessary element in this kind of fault-tolerant architectures. The importance of reliability in majority voter is due to its application in both conventional fault-tolerant design and novel nanoelectronic systems. The property of a voter is therefore a bottleneck since it directly determines the whole performance of a redundant fault-tolerant digital IP (such as a TMR configuration). Obviously, the efficacy of TMR is to increase the reliability of digital IP. However, TMR sometimes could result in worse reliability than a simplex function module could. A better understanding of functional and signal reliability characteristics of a 3-input majority voter (majority voting in TMR) is studied. We analyze them by utilizing signal probability and boolean difference. It is well known that the acquisition of output signal probabilities is much easier compared with the obtention of output reliability. The results derived in this thesis proclaim the signal probability requirements for inputs of majority voter, and thereby reveal the conditions that TMR technique requires. This study shows the critical importance of error characteristics of majority voter, as used in fault-tolerant designs. As the flawlessness of majority voter in TMR is not true, we also proposed a fault-tolerant and simple 2-level majority voter structure for TMR. This alternative architecture for majority voter is useful in TMR schemes. The proposed solution is robust to single fault and exceeds those previous ones in terms of reliability.

The entity component system architecture (ECSA) is a data-oriented composition pattern and a data-driven design pattern. Data-oriented software takes into consideration generalized knowledge of hardware. Data-driven design is a methodology used to replace inflexible code with reusable components that can be added, deleted, or modified in interactive systems and games. This thesis explores the ECSA and its alternatives and their strengths and weaknesses. The paper details the creation of an ECSA and benchmarks its performance against object-oriented architectures. The hypothesis of this thesis is that the ECSA has CPU cache performance advantages over object-oriented architectures as tested by multiple benchmarks. The results suggest that the ECSA provides superior CPU performance. These results could be valuable for interactive game developers to get higher frame rates out of their games, MMORPG server developers to process millions of entities per second, and mobile developers to create battery-efficient apps.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Satellites are becoming more capable and complex, as such their downlink requirements are increasing. In addition, future satellite systems will be operating at Ka-band that provides ample bandwidth to support the increase in downlink rates up to 800 Mbps. This paper describes a new generation commercial solution that can support 800 Mbps telemetry processing for data reception, frame synchronization, time tagging, Reed-Solomon forward error correction, data routing, data storage, data playback for testing, networking, and Bit Error Rate (BER) Testing.

In the past several years, the usage of network is getting more and more popular and various types of network applications also have vigorous advancement. Because the benefits which network applications produced obtain a lot of enterprise's attention, each enterprise is eager to introduce the network to unify each kind of information system, and expects to achieve the synthesis effect as well. At present, the network system has been an indispensable infrastructure in the enterprise, but how to make it effective becomes a tough issue in an enterprise¡¦s business plan. In 1997, the International Standard Organization proposed the OSI Network Management Model, is also named FCAPS Model, to apply on the data network. FCAPS Model is mainly to define the functional scope of the network management system. Though it is easy to understand, it does not have the deeper explanations how to achieve these functions. Also, FCAPS fails to tell who should do what in a network system. As a result of such deficiencies, the enterprise often doesn¡¦t know how to do to apply FCAPS into the planning of a network management system. This research develops a network management architecture description language (NMADL) by using the concept of system architecture to construct an architecture-oriented network management model (AONMM). AONMM is an integrated model which consists of the viewpoint of structure and behavior. By integrating the structure and behavior into one unity, it clearly and completely describes the network management system. Furthermore, this research analyzes the problems of FCAPS Model and compares it with AONMM to verify AONMM¡¦s superiority. AONMM is a valuable referenced model for planning, analyzing and designing network management systems.

Software-based system architecture has been recognized as a foundation laying out the underpinnings that are critically important for successful engineering of large-scale complex systems. In recent years, architecting has played a more crucial role in engineering network-centric system of systems. The software paradigm has been shifting from treating software as a product (SaaP) to treating software as a service (SaaS). SaaS is also referred to as the Cloud Computing, where the term "cloud" is used as a metaphor for "network". As the complexity of the architecture of network-centric software-based system of systems has increased, the description of such architecture has posed significant technical challenges. The U.S. Department of Defense (DoD) has developed the DoD Architecture Framework [DoDAF 2009a, DoDAF 2009b] for describing system architectures. IEEE proposes a Recommended Practice for Architectural Description of Software-Intensive Systems [IEEE 2000]. SEI provides high-level guidelines for Documenting Software Architectures [Clements et al 2003]. However, all of the diagrams proposed by DoD, IEEE, and SEI are two-dimensional static graphical and textual representations that do not reveal the dynamic characteristics of a system architecture. This thesis presents a conceptual framework (CF) for specifying the architecture of a network-centric software-based system of systems. The developed CF provides the beginning part of a larger research effort. The main goal of the overall research is to employ the automation-based software paradigm and to automatically generate a visual simulation model of a system architecture, with which experiments can be conducted to assess the dynamic characteristics of that architecture. The CF, developed in the research described herein, enables the automatic generation of a visual simulation model representing a system architecture. The proposed CF is evaluated in half a dozen case studies to demonstrate that it provides the necessary elements for automatic generation of a simulation model as the description of a complex system of systems architecture. / Master of Science

Database technology is already recognised and increasingly used in administering and organising large bodies of data and as an aid in developing software. This thesis considers the applicability of this technology in small but potentially expanding application environments with users of varying levels of competence. A database system architecture with the following main characteristics is proposed: Database technology is already recognised and increasingly used in administering and organising large bodies of data and as an aid in developing software. This thesis considers the applicability of this technology in small but potentially expanding application environments with users of varying levels of competence. A database system architecture with the following main characteristics is proposed:Database technology is already recognised and increasingly used in administering and organising large bodies of data and as an aid in developing software. This thesis considers the applicability of this technology in small but potentially expanding application environments with users of varying levels of competence. A database system architecture with the following main characteristics is proposed : 1. It is based on a set of software components that facilitates the implementation and evolution of a software development environment centered on a database. 2. It enables the implementation of different user interfaces to provide adequate perceptions of the information content of the database according to the user's competence, familiarity with the system or the complexity of the processing requirements. 3. it is oriented toward databases that require moderate resources from the computer system to start an application. Personal or small-group databases are likely to benefit most from this approach.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / We have long used standards to guide the development process of software systems. Standards such as POSIX, X-Windows, SQL have become part of the language of software developers and have guided the coding of systems that are intended to be portable and interoperable. Standards also have a role to play in the integration of commercial off-the-shelf (COTS) products. At NASA's Goddard Space Flight Center, we have been participating on the Renaissance Team, a reengineering effort that has seen the focus shift from custom-built systems to the use of COTS to satisfy prime mission functions. As part of this effort, we developed a process that identified standards that are applicable to the evaluation and integration of products and assessed how those standards should be applied. Since the goal is to develop a set of standards that can be used to instantiate systems of differing sizes and capabilities, the standards selected have been broken into four areas: global integration standards, global development standards, mission development standards, and mission integration standards. Each of the areas is less restrictive than the preceding area in the standards that are allowed. This paper describes the process that we used to select and categorize the standards to be applied to Renaissance systems.