Showing papers on "Systems architecture published in 2004"

Rainbow: architecture-based self-adaptation with reusable infrastructure

Abstract: While attractive in principle, architecture-based self-adaptation raises a number of research and engineering challenges. First, the ability to handle a wide variety of systems must be addressed. Second, the need to reduce costs in adding external control to a system must be addressed. Our rainbow framework attempts to address both problems. By adopting an architecture-based approach, it provides reusable infrastructure together with mechanisms for specializing that infrastructure to the needs of specific systems. The specialization mechanisms let the developer of self-adaptation capabilities choose what aspects of the system to model and monitor, what conditions should trigger adaptation, and how to adapt the system.

Sensor network-based countersniper system

Abstract: An ad-hoc wireless sensor network-based system is presented that detects and accurately locates shooters even in urban environments. The system consists of a large number of cheap sensors communicating through an ad-hoc wireless network, thus it is capable of tolerating multiple sensor failures, provides good coverage and high accuracy, and is capable of overcoming multipath effects. The performance of the proposed system is superior to that of centralized countersniper systems in such challenging environment as dense urban terrain. In this paper, in addition to the overall system architecture, the acoustic signal detection, the most important middleware services and the unique sensor fusion algorithm are also presented. The system performance is analyzed using real measurement data obtained at a US Army MOUT (Military Operations in Urban Terrain) facility.

System, architecture, and method for logical server and other network devices in a dynamically configurable multi-server network environment

Abstract: Network architecture, computer system and/or server, circuit, device, apparatus, method, and computer program and control mechanism for managing power consumption and workload in computer system and data and information servers. Further provides power and energy consumption and workload management and control systems and architectures for high-density and modular multi-server computer systems that maintain performance while conserving energy and method for power management and workload management. Dynamic server power management and optional dynamic workload management for multi-server environments is provided by aspects of the invention. Modular network devices and integrated server system, including modular servers, management units, switches and switching fabrics, modular power supplies and modular fans and a special backplane architecture are provided as well as dynamically reconfigurable multi-purpose modules and servers. Backplane architecture, structure, and method that has no active components and separate power supply lines and protection to provide high reliability in server environment.

Autonomic computing: an overview

Abstract: The increasing scale complexity, heterogeneity and dynamism of networks, systems and applications have made our computational and information infrastructure brittle, unmanageable and insecure. This has necessitated the investigation of an alternate paradigm for system and application design, which is based on strategies used by biological systems to deal with similar challenges – a vision that has been referred to as autonomic computing. The overarching goal of autonomic computing is to realize computer and software systems and applications that can manage themselves in accordance with high-level guidance from humans. Meeting the grand challenges of autonomic computing requires scientific and technological advances in a wide variety of fields, as well as new software and system architectures that support the effective integration of the constituent technologies. This paper presents an introduction to autonomic computing, its challenges, and opportunities.

Software Architecture: The Next Step

Abstract: This position paper makes the following claims that, in our opinion, are worthwhile to discuss at the workshop. 1) The first phase of software architecture research, where the key concepts are components and connectors, has matured the technology to a level where industry adoption is wide-spread and few fundamental issues remain. 2) The traditional view on software architecture suffers from a number of key problems that cannot be solved without changing our perspective on the notion of software architecture. These problems include the lack of first-class representation of design decisions, the fact that these design decisions are cross-cutting and intertwined, that these problems lead to high maintenance cost, because of which design rules and constraints are easily violated and obsolete design decisions are not removed. 3) As a community, we need to take the next step and adopt the perspective that a software architecture is, fundamentally, a composition of architectural design decisions. These design decisions should be represented as first-class entities in the software architecture and it should, at least before system deployment, be possible to add, remove and change architectural design decisions against limited effort.

π-ADL: an Architecture Description Language based on the higher-order typed π-calculus for specifying dynamic and mobile software architectures

Abstract: A key aspect of the design of any software system is its architecture. An architecture description, from a runtime perspective, should provide a formal specification of the architecture in terms of components and connectors and how they are composed together. Further, a dynamic or mobile architecture description must provide a specification of how the architecture of the software system can change at runtime. Enabling specification of dynamic and mobile architectures is a large challenge for an Architecture Description Language (ADL). This article describes π-ADL, a novel ADL that has been designed in the ArchWare European Project to address specification of dynamic and mobile architectures. It is a formal, well-founded theoretically language based on the higher-order typed π-calculus. While most ADLs focus on describing software architectures from a structural viewpoint, π-ADL focuses on formally describing architectures encompassing both the structural and behavioural viewpoints. The π-ADL design principles, concepts and notation are presented. How π-ADL can be used for specifying static, dynamic and mobile architectures is illustrated through case studies. The π-ADL toolset is outlined.

System support for pervasive applications

Abstract: Pervasive computing provides an attractive vision for the future of computing. Computational power will be available everywhere. Mobile and stationary devices will dynamically connect and coordinate to seamlessly help people in accomplishing their tasks. For this vision to become a reality, developers must build applications that constantly adapt to a highly dynamic computing environment. To make the developers' task feasible, we present a system architecture for pervasive computing, called one.world. Our architecture provides an integrated and comprehensive framework for building pervasive applications. It includes services, such as discovery and migration, that help to build applications and directly simplify the task of coping with constant change. We describe our architecture and its programming model and reflect on our own and others' experiences with using it.

The influence of architecture in engineering systems

Abstract: The field of Engineering Systems is distinguished from traditional engineering design in part by the issues it brings to the top Engineering Systems focuses on abstractions like architecture and complexity, and defines system boundaries very broadly It also seeks to apply these concepts to the process of creating systems This paper summarizes the role and influence of architecture in complex engineering systems Using the research literature and examples, this paper defines architecture, argues for its importance as a determinant of system behavior, and reviews its ability to help us understand and manage the design, operation, and behaviors of complex engineering systems A INTRODUCTION Typical engineering design education focuses on specific aspects of design, such as the technical behavior of a set of elements interconnected in a certain way By contrast, Engineering Systems focuses on a number of abstract concepts first because they provide a general framework for guiding the development of many diverse kinds of systems, so that these systems will provide the desired functions in the desired ways Among these abstract concepts is that of system architecture In this paper, we explore this concept and provide a number of ways of appreciating system architecture’s importance in both the practical aspects of system design and in the intellectual aspects of understanding complex systems from a variety of viewpoints The paper begins with a definition of architecture and its influence on functional behavior, extra desired properties like flexibility and reliability (collectively called “ilities”), complexity, and emergent behaviors Architectures are not static but instead evolve over long periods as technologies mature They also evolve during the normal course of designing an individual system These evolutionary patterns are useful in understanding architecture’s importance The paper next provides several examples of architectures and illustrates how architecture affects the way systems are designed, built, and operated The examples include aircraft, automobiles, infrastructures, and living organisms The importance of architecture is framed in three domains of importance: as a way to understand complex systems, to design them, to manage them, and to provide long-term rationality by means of standards The abstract concepts of modularity and integrality are shown to be useful for categorizing systems and illustrating how architectural form can influence important system characteristics Several contrasts are noted between relatively small, deliberately designed products and evolutionary, less-managed large infrastructures Architecture’s ability to influence the functions and allied properties of systems is shown to extend to robustness, adaptability, flexibility, safety, and scalability Examples from recent research are given to show how some of these properties might be measured using network models of particular architectures

Computer system architecture and method providing operating-system independent virus-, hacker-, and cyber-terror-immune processing environments

Abstract: Information appliance, computing device, or other processor or microprocessor based device or system provides security and anti-viral, anti-hacker, and anti-cyber terror features, and can automatically create multiple sequentially or concurrently and intermittently isolated and/or restricted computing environments to prevent viruses, malicious or other computer hacking, computer or device corruption and failure by using these computing environments in conjunction with restricted and controlled methods of moving and copying data, combined with a process that destroys malicious code located in computing environments and data stores.

PIN: a binary instrumentation tool for computer architecture research and education

Abstract: Computer architecture embraces a tremendous number of ever-changing inter-connected concepts and information, yet computer architecture education is very often static, seemingly motionless. Computer architecture is commonly taught using simple piecewise methods of explaining how the hardware performs a given task, rather than characterizing the interaction of software and hardware. Visualization tools allow students to interactively explore basic concepts in computer architecture but are limited in their ability to engage students in research and design concepts. Likewise as the development of simulation models such as caches, branch predictors, and pipelines aid student understanding of architecture components, such models have limitations in the workloads that can be examined because of issues with execution time and environment. Overall, to effectively understand modern architectures, it is simply essential to experiment the characteristics of real application workloads. Likewise, understanding program behavior is necessary to effective programming, comprehension of architecture bottlenecks, and hardware design. Computer architecture education must include experience in analyzing program behavior and workload characteristics using effective tools. To explore workload characteristic analysis in computer architecture design, we propose using PIN, a binary instrumentation tool for computer architecture research and education projects.

Flow control system architecture

Abstract: One or more flow control modules, implemented on various types of network topologies, provide a number of functionalities for controlling the flow of IP packets (such as TCP/IP packets) over a network connection. The flow control modules may be implemented within a sender and/or receiver or may be deployed into a network as a separate device without requiring significant additional resources.

An ultra low-power processor for sensor networks

Abstract: We present a novel processor architecture designed specifically for use in low-power wireless sensor-network nodes. Our sensor network asynchronous processor (SNAP/LE) is based on an asynchronous data-driven 16-bit RISC core with an extremely low-power idle state, and a wakeup response latency on the order of tens of nanoseconds. The processor instruction set is optimized for sensor-network applications, with support for event scheduling, pseudo-random number generation, bitfield operations, and radio/sensor interfaces. SNAP/LE has a hardware event queue and event coprocessors, which allow the processor to avoid the overhead of operating system software (such as task schedulers and external interrupt servicing), while still providing a straightforward programming interface to the designer. The processor can meet performance levels required for data monitoring applications while executing instructions with tens of picojoules of energy.We evaluate the energy consumption of SNAP/LE with several applications representative of the workload found in data-gathering wireless sensor networks. We compare our architecture and software against existing platforms for sensor networks, quantifying both the software and hardware benefits of our approach.

Symphony: view-driven software architecture reconstruction

Abstract: Authentic descriptions of a software architecture are required as a reliable foundation for any but trivial changes to a system. Far too often, architecture descriptions of existing systems are out of sync with the implementation. If they are, they must be reconstructed. There are many existing techniques for reconstructing individual architecture views, but no information about how to select views for reconstruction, or about process aspects of architecture reconstruction in general. In this paper we describe view-driven process for reconstructing software architecture that fills this gap. To describe Symphony, we present and compare different case studies, thus serving a secondary goal of sharing real-life reconstruction experience. The Symphony process incorporates the state of the practice, where reconstruction is problem-driven and uses a rich set of architecture views. Symphony provides a common framework for reporting reconstruction experiences and for comparing reconstruction approaches. Finally, it is a vehicle for exposing and demarcating research problems in software architecture reconstruction.

Symphony: View-driven software architecture reconstruction

Abstract: Authentic descriptions of a software architecture are required as a reliable foundation for any but trivial changes to a system. Far too often, architecture descriptions of existing systems are out of sync with the implementation. If they are, they must be reconstructed. There are many existing techniques for reconstructing individual architecture views, but no information about how to select views for reconstruction, or about process aspects of architecture reconstruction in general. In this paper we describe view-driven process for reconstructing software architecture that fills this gap. To describe Symphony, we present and compare different case studies, thus serving a secondary goal of sharing real-life reconstruction experience. The Symphony process incorporates the state of the practice, where reconstruction is problem-driven and uses a rich set of architecture views. Symphony provides a common framework for reporting reconstruction experiences and for comparing reconstruction approaches. Finally, it is a vehicle for exposing and demarcating research problems in software architecture reconstruction.

An Overview of the SAE Architecture Analysis & Design Language (AADL) Standard: A Basis for Model-Based Architecture-Driven Embedded Systems Engineering

Abstract: Architecture Description Languages provide significant opportunity for the incorporation of formal methods and engineering models into the analysis of software and system architectures. A standard is being developed for embedded real-time safety critical systems which will support the use of various formal approaches to analyze the impact of the composition of systems from hardware and software and which will allow the generation of system glue code with the performance qualities predicted. The SAE AADL standard (International Society for Automotive Engineers (SAE) Architecture Analysis & Design Language) is based on the MetaH language developed under DARPA and US Army funding and on the model driven architectural based approach demonstrated with this technology over the last 12 years. The SAE AADL standard is aimed at supporting avionics, space, automotive, robotics and other real-time concurrent processing domains including safety critical applications.

CAFCR : A multi-view method for embedded systems architecting : Balancing genericity and specificity : Proefschrift

Abstract: This document addresses the way an architect can do his work. It shows many tools that belong to the architect toolkit: The CAFCR model, tools per 5 views (Customer Objectives, Application, Functional, Conceptual and Realization), Qualities, Story telling and Reasoning in multiple dimensions

Unity: experiences with a prototype autonomic computing system

Abstract: The behavior of a system results from the behaviors of its components, and from the interactions and relationships among them. In order to create computing systems that manage themselves, we will need to design both the behaviors of the individual elements, and the relationships that are formed among them. This paper describes a research project called Unity, carried out at IBM's Thomas J. Watson Research Center, in which we explore some of the behaviors and relationships that will allow complex computing systems to manage themselves; to be self-configuring, self-optimizing, self-protecting, and self-healing. The four principle aspects of Unity that we examine are the overall architecture of the system, the role of utility functions in decision-making within the system, the way the system uses goal-driven self-assembly to configure itself, and the design patterns that enable self-healing within the system.

Experimental cooperative control of fixed-wing unmanned aerial vehicles

Abstract: Recent years have seen rapidly growing interest in the development of networks of multiple unmanned aerial vehicles (UAVs), as aerial sensor networks for the purpose of coordinated monitoring, surveillance, and rapid emergency response. This has triggered a great deal of research in higher levels of planning and control, including collaborative sensing and exploration, synchronized motion planning, and formation or cooperative control. In this paper, we describe our recently developed experimental testbed at the University of Pennsylvania, which consists of multiple, fixed-wing UAVs. We describe the system architecture, software and hardware components, and overall system integration. We then derive high-fidelity models that are validated with hardware-in-the-loop simulations and actual experiments. Our models are hybrid, capturing not only the physical dynamics of the aircraft, but also the mode switching logic that supervises lower level controllers. We conclude with a description of cooperative control experiments involving two fixed-wing UAVs.

NGSCB: A Trusted Open System

Abstract: We describe Microsoft’s Next Generation Secure Computing Base (NGSCB). The system provides high assurance computing in a manner consistent with the commercial requirements of mass market systems. This poses a number of challenges and we describe the system architecture we have used to overcome them. We pay particular attention to reducing the trusted computing base to a small and manageable size. This includes operating the system without trusting the BIOS, most devices and device drivers and the bulk of the code of mass market operating systems. Furthermore, we seek to strengthen access control and network authentication in mass market systems by authenticating executable code at all system layers. We have implemented a prototype of the system and expect the full system to be mass deployed.

Remote discovery and system architecture

Abstract: Sending a discovery agent to a computing device determines the services provided by that first computing device. As a result, a first set of information is received from the agent that provides information indicative of the services provided by the computing device. That information can then be compared to other information, either from the same computing device at a different point in time, or from a second computing device. The other information is indicative of services performed by that computing device at a different point in time or the second computing device. From that, services provided by the computing device that were previously different on the first computing device or that are not available on the second computing device can be determined.

Internet-enabled real-time collaborative assembly modeling via an e-Assembly system: status and promise

Abstract: Collaborative CAD systems enabling collaboration in computer-aided design processes among distributed designers are gaining more and more attention. Yet, such systems, especially in support of collaborative assembly modeling, are hardly achievable. Targeting this gap, this paper addresses an Internet-enabled real-time collaborative assembly modeling system, named e-Assembly. This emerging system allows a group of geographically dispersed designers to jointly build an assembly model in real time over the Internet. In particular, this paper proposes a new assembly representation, called Collaborative Assembly Representation, for Internet-based collaborative assembly modeling. Also, collaborative assembly constraint satisfaction is addressed based on three coordination rules embedded in e-Assembly. Furthermore, the system architecture and realization of e-Assembly are provided. Finally, a prototypic implementation of e-Assembly is presented for demonstration and discussion.

A Port Ontology for Conceptual Design of Systems

Abstract: During conceptual design of systems, the emphasis is on generating the system architecture: the configuration of sub-systems and the interactions between them. Ports, as locations of intended interaction, play an important role at this stage of design. They are convenient abstractions for representing the intended exchange of signals, energy or material; they can be applied at different levels of detail, across different energy domains, and to all aspects of design: form, function, and behavior. But to play this versatile role, ports need to be represented in an unambiguous yet flexible fashion, accommodating the differences in vocabulary and approach across different disciplines and perspectives. In this article, we introduce the semantic structure for such an unambiguous representation: a port ontology. The ontology formalizes the conceptualization of ports such that engineers and computer aided design applications can reason about component connections and interactions in system configuration. It defines ports in terms of form, function and behavior attributes and further includes axioms that can be used to support a variety of engineering design tasks, such as port refinement, port compatibility checking, and the instantiation of interaction models. A LEGO example is used to illustrate the ontology and its applications in conceptual design. @DOI: 10.1115/1.1778191#

Engineering the complex SOC : fast, flexible design with configurable processors

Abstract: List of Figures. Foreword by Clayton Christensen. Foreword by John Hennessy. Author's Preface. Acknowledgments. 1. The Case for a New SOC Design Methodology. The Age of Megagate SOCs. The Fundamental Trends of SOC Design. What's Wrong with Today's Approach to SOC Design? Preview: An Improved Design Methodology for SOC Design. Further Reading. 2. SOC Design Today. Hardware System Structure. Software Structure. Current SOC Design Flow. The Impact of Semiconductor Economics. Six Major Issues in SOC Design. Further Reading. 3. A New Look at SOC Design. Accelerating Processors for Traditional Software Tasks. Example: Tensilica Xtensa Processors for EEMBC Benchmarks. System Design with Multiple Processors. New Essentials of SOC Design Methodology. Addressing the Six Problems. Further Reading. 4. System-Level Design of Complex SOCs Complex SOC System Architecture Opportunities. Major Decisions in Processor-Centric SOC Organization. Communication Design = Software Mode + Hardware Interconnect. Hardware Interconnect Mechanisms. Performance-Driven Communication Design. The SOC Design Flow. Non-Processor Building Blocks in Complex SOC. Implications of Processor-Centric SOC Architecture. Further Reading. 5. Configurable Processors: A Software View. Processor Hardware/Software Cogeneration. The Process of Instruction Definition and Application Tuning. The Basics of Instruction Extension. The Programmer's Model. Processor Performance Factors. Example: Tuning a Large Task. Memory-System Tuning. Long Instruction Words. Fully Automatic Instruction-Set Extension. Further Reading. 6. Configurable Processors: A Hardware View. Application Acceleration: A Common Problem. Introduction to Pipelines and Processors. Hardware Blocks to Processors. Moving from Hardwired Engines to Processors. Designing the Processor Interface. A Short Example: ATM Packet Segmentation and Reassembly. Novel Roles for Processors in Hardware Replacement. Processors, Hardware Implementation, and Verification Flow. Progress in Hardware Abstraction. Further Reading. 7. Advanced Topics in SOC Design. Pipelining for Processor Performance. Inside Processor Pipeline Stalls. Optimizing Processors to Match Hardware. Multiple Processor Debug and Trace. Issues in Memory Systems. Optimizing Power Dissipation in Extensible Processors. Essentials of TIE. Further Reading. 8. The Future of SOC Design: The Seaof Processors. Why Is Software Programmability So Central? Looking into the Future of SOC. Processor Scaling Model. Future Applications of Complex SOCs. The Future of the Complex SOC Design Process. The Future of the Industry. The Disruptive-Technology View. The Long View. Further Reading. Index.

ArchWare: Architecting Evolvable Software

Abstract: This paper gives an overview of the ArchWare European Project. The broad scope of ArchWare is to respond to the ever-present demand for software systems that are capable of accommodating change over their lifetime, and therefore are evolvable. In order to achieve this goal, ArchWare develops an integrated set of architecture-centric languages and tools for the model-driven engineering of evolvable software systems based on a persistent run-time framework. The ArchWare Integrated Development Environment comprises: (a) innovative formal architecture description, analysis, and refinement languages for describing the architecture of evolvable software systems, verifying their properties and expressing their refinements; (b) tools to support architecture description, analysis, and refinement as well as code generation; (c) enactable processes for supporting model-driven software engineering; (d) a persistent run-time framework including a virtual machine for process enactment. It has been developed using ArchWare itself and is available as Open Source Software.

Distributed content-based visual information retrieval system on peer-to-peer networks

Abstract: With the recent advances of distributed computing, the limitation of information retrieval from a centralized image collection can be removed by allowing distributed image data sources to interact with each other for data storage sharing and information retrieval. In this article, we present our design and implementation of DISCOVIR: DIStributed COntent-based Visual Information Retrieval system using the Peer-to-Peer (P2P) Network. We describe the system architecture and detail the interactions among various system modules. Specifically, we propose a Firework Query Model for distributed information retrieval, which aims to reduce the network traffic of query passing in the network. We carry out experiments to show the distributed image retrieval system and the Firework information retrieval algorithm. The results show that the algorithm reduces network traffic while increases searching performance.

A combined studio production system for 3-D capturing of live action and immersive actor feedback

Abstract: A new studio system for the production of three-dimensional (3-D) content is introduced. The system combines the ability to capture dynamic scenes, based on a multicamera system in a chroma-key environment, with a view-dependent projection for actor feedback. The system allows the generation and rendering of 3-D models in preview quality for on-set visualization in real time and in high quality for postproduction applications in an offline phase. The shape reconstruction is based on the computation of the visual hull. The view-dependent projection component allows actors to be immersed into a virtual scene and to interact with virtual components. The functional modules of the system were implemented in a highly distributed system using standard, inexpensive IT components. Therefore, the system is quite scalable and can be fitted into most studio environments. For the integration of the system components, a middleware architecture was developed.

Application of a Web-enabled real-time structural health monitoring system for civil infrastructure systems

Abstract: The system architecture of a novel structural health monitoring system that is optimized for the continuous real-time monitoring of dispersed civil infrastructures is presented. The monitoring system is based on a highly efficient multithreaded software design that allows the system to acquire data from a large number of channels, monitor and condition this data, and distribute it, in real time, over the Internet to multiple remote locations. Bandwidth and latency issues that impact the operation of monitoring systems are discussed. The application of the monitoring system under discussion to a long span, flexible bridge in the metropolitan Los Angeles region is described. The bridge had previously been instrumented with 26 strong motion accelerometers. Sample 'quick analysis' results continuously provided by the monitoring system are presented and interpreted. System identification results, obtained through off-line batch processing, are presented for a data set from a recent earthquake that automatically triggered the recording capability of the system. It is shown that, using a time domain system identification approach, the bridge stiffness and damping matrices can be identified from the earthquake data set and subsequently used to determine the bridge modal properties, such as frequencies and damping ratios. In this approach the bridge is modeled as a multi-input/multi-output system with order compatible with the number of available sensors. Implementation issues requiring further investigation are presented and discussed.