检索结果-内蒙古大学图书馆

Efficient exact Boolean schedulability tests for fixed priority preemption threshold scheduling

JOURNAL OF systemS AND SOFTWARE 2017年 134卷 153-169页

作者： Kim, Saehwa Hankuk Univ Foreign Studies Dept Informat Commun Engn Yongin 17035 Gyeonggi Do South Korea

Fixed priority preemption threshold scheduling (PTS) is effective in scalable real-time system design, which requires system tuning processes, where the performance of schedulability tests for PTS matters much. This paper proposes five methods for efficient exact Boolean schedulability tests for PTS, which returns the Boolean result that tells whether the given task is schedulable or not. We regard the sufficient test for fully preemptive fixed priority scheduling (FPS) and the early exit in the response time calculations as the conventional approach. We propose (1) a new sufficient test, (2) new initial values for the start/finish times, (3) pre calculation of the interference time within the start time, (4) incremental start/finish time calculation, and (5) early exits in start/finish time calculations. These are based on some previous work for FPS. The new initial start time, pre-calculation, and the incremental calculations also can be used for the exact response time analysis for PTS. Our empirical results show that the overall proposed methods reduce the iteration count/run time of the conventional test by about 60%/40%, regardless of the number of tasks and the total utilization. (C) 2017 Elsevier Inc. All rights reserved.

关键词： Real-time systems and embedded systems Fixed priority scheduling Preemption threshold scheduling system integration and implementation

来源：评论

学校读者我要写书评

暂无评论

An ontology-based intrusion alerts correlation system

引用

EXPERT systemS WITH APPLICATIONS 2010年第10期37卷 7138-7146页

作者： Li, Wan Tian, Shengfeng Beijing Jiaotong Univ Sch Comp & Informat Technol Beijing 100044 Peoples R China

Alert correlation techniques effectively improve the quality of alerts reported by intrusion detection systems, and are sufficient to support rapid identification of ongoing attacks or predict an intruder's next likely goal. In our previous work, an alert correlation approach based on our XSWRL ontology has been proposed. This paper focuses on how to develop the intrusion alerts correlation system according to our alert correlation approach. At first, the multi-agent system architecture consisting of agents and sensors is shown. The sensors collect security relevant information, and the agents process the information. Then we present each modules of the system in detail. The State Sensor collects information about security state and the Local State Agent and Center State Agent preprocess the security state information and convert it to ontology. The Attack Sensor collects information about attack and the Local Alert Agent and Center Alert Agent preprocess the alert information and convert it to ontology. The Attack Correlator correlates the attacks and outputs the attack sessions. (C) 2010 Elsevier Ltd. All rights reserved.

关键词： Alert correlation Intrusion detection Ontology system integration and implementation

来源：评论

学校读者我要写书评

暂无评论

Temporal partitioning of communication resources in an integrated architecture

引用

IEEE TRANSACTIONS ON DEPENDABLE AND SECURE COMPUTING 2008年第2期5卷 99-114页

作者： Obermaisser, Roman Vienna Univ Technol A-1040 Vienna Austria

Integrated architectures in the automotive and avionic domain promise improved resource utilization and enable a better coordination of application subsystems compared to federated systems. An integrated architecture shares the system's communication resources by using a single physical network for exchanging messages of multiple application subsystems. Similarly, the computational resources ( for example, memory and CPU time) of each node computer are available to multiple software components. In order to support a seamless system integration without unintended side effects in such an integrated architecture, it is important to ensure that the software components do not interfere through the use of these shared resources. For this reason, the DECOS integrated architecture encapsulates application subsystems and their constituting software components. At the level of the communication system, virtual networks on top of an underlying time-triggered physical network exhibit predefined temporal properties ( that is, bandwidth, latency, and latency jitter). Due to encapsulation, the temporal properties of messages sent by a software component are independent from the behavior of other software components, in particular from those within other application subsystems. This paper presents the mechanisms for the temporal partitioning of communication resources in the Dependable Embedded Components and systems ( DECOS) integrated architecture. Furthermore, experimental evidence is provided in order to demonstrate that the messages sent by one software component do not affect the temporal properties of messages exchanged by other software components. Rigid temporal partitioning is achievable while at the same time meeting the performance requirements imposed by present-day automotive applications and those envisioned for the future ( for example, X-by-wire). For this purpose, we use an experimental framework with an implementation of virtual networks on top of a Time Division

关键词： system architectures real-time and embedded systems system integration and implementation fault tolerance computer network performance distributed architectures infrastructure protection.

来源：评论

学校读者我要写书评

暂无评论

Quatrain: Accelerating Data Aggregation between Multiple Layers

引用

IEEE TRANSACTIONS ON COMPUTERS 2014年第5期63卷 1207-1219页

作者： Ren, Jinglei Wu, Yongwei Zhu, Meiqi Zheng, Weimin Tsinghua Univ Dept Comp Sci & Technol Tsinghua Natl Lab Informat Sci & Technol TNLIST Beijing 100084 Peoples R China Tsinghua Univ Shenzhen Res Inst Shenzhen 518057 Peoples R China

Composition of multiple layers (or components/services) has been a dominant practice in building distributed systems, meanwhile aggregation has become a typical pattern of data flows nowadays. However, the efficiency of data aggregation is usually impaired by multiple layers due to amplified delay. Current solutions based on data/execution flow optimization mostly counteract flexibility, reusability, and isolation of layers abstraction. Otherwise, programmers have to do much error-prone manual programming to optimize communication, and it is complicated in a multithreaded environment. To resolve the dilemma, we propose a new style of inter-process communication that not only optimizes data aggregation but also retains the advantages of layered (or component-based/service-oriented) architecture. Our approach relaxes the traditional definition of procedure and allows a procedure to return multiple times. Specifically, we implement an extended remote procedure calling framework Quatrain to support the new multireturn paradigm. In this paper, we establish the importance of multiple returns, introduce our very simple semantics, and present a new synchronization protocol that frees programmers from multireturn-related thread coordination. Several practical applications are constructed with Quatrain, and the evaluation shows an average of 56% reduction of response time, compared with the traditional calling paradigm, in realistic environments.

关键词： Distributed programming distributed systems data communications interfaces system integration and implementation asynchronous/synchronous operation client/server frameworks patterns procedures functions and subroutines

来源：评论

学校读者我要写书评

暂无评论

MobileTrust: a trust enhanced security architecture for mobile agent systems

引用

INTERNATIONAL JOURNAL OF INFORMATION SECURITY 2010年第3期9卷 153-178页

作者： Lin, Ching Varadharajan, Vijay Macquarie Univ Sydney NSW 2109 Australia

While offering many practical benefits for distributed applications, mobile agent systems pose some fundamental security challenges. In this paper, we present a new approach to mobile agent security which helps to address some of these challenges. We present a new technique, which we refer to as trust enhanced security, and apply it to mobile agent-based systems;this new technique advocates a shift in security solutions from security-centric to trust-centric. This extends the traditional security mechanisms by enabling trust decisions through explicit specification and management of security-related trust relationships. The integration of the trust decisions into security decision-making process leads to our trust enhanced security performance. A formal trust model is proposed and is incorporated into the development of a novel trust management architecture-MobileTrust for mobile agent-based applications. We have conducted detailed practical investigations to evaluate and validate the emergent properties of the trust enhanced security technique. We present and discuss the key results in this paper.

关键词： Mobile code security Trust model Trust management Trust architecture Trust enhanced security system integration and implementation Security performance verification

来源：评论

学校读者我要写书评

暂无评论

SYNAPSE plus plus: Code Dissemination in Wireless Sensor Networks Using Fountain Codes

引用

IEEE TRANSACTIONS ON MOBILE COMPUTING 2010年第12期9卷 1749-1765页

作者： Rossi, Michele Bui, Nicola Zanca, Giovanni Stabellini, Luca Crepaldi, Riccardo Zorzi, Michele Univ Padua Dept Informat Engn I-35131 Padua Italy Consorzio Ferrara Ric I-44124 Ferrara Italy Royal Inst Technol Wireless KTH SE-16440 Kista Sweden Univ Illinois Dept Comp Sci Urbana IL 61801 USA

This paper presents SYNAPSE++, a system for over the air reprogramming of wireless sensor networks (WSNs). In contrast to previous solutions, which implement plain negative acknowledgment-based ARQ strategies, SYNAPSE++ adopts a more sophisticated error recovery approach exploiting rateless fountain codes (FCs). This allows it to scale considerably better in dense networks and to better cope with noisy environments. In order to speed up the decoding process and decrease its computational complexity, we engineered the FC encoding distribution through an original genetic optimization approach. Furthermore, novel channel access and pipelining techniques have been jointly designed so as to fully exploit the benefits of fountain codes, mitigate the hidden terminal problem and reduce the number of collisions. All of this makes it possible for SYNAPSE++ to recover data over multiple hops through overhearing by limiting, as much as possible, the number of explicit retransmissions. We finally created new bootloader and memory management modules so that SYNAPSE++ could disseminate and load program images written using any language. At the end of this paper, the effectiveness of SYNAPSE++ is demonstrated through experimental results over actual multihop deployments, and its performance is compared with that of Deluge, the de facto standard protocol for code dissemination in WSNs. The TinyOS 2 code of SYNAPSE++ is available at http://***/download.

关键词： Wireless sensor networks distributed networks data communications protocol architecture protocol verification error control codes system integration and implementation

来源：评论

学校读者我要写书评

暂无评论

Efficient Optimal Priority Assignment for Fixed Priority Preemption Threshold Scheduling

引用

JOURNAL OF INFORMATION SCIENCE AND ENGINEERING 2018年第2期34卷 319-335页

作者： Kim, Saehwa Hankuk Univ Foreign Studies Dept Informat Commun Engn Gyeonggi Do 449791 South Korea

This paper proposes an efficient priority assignment algorithm for fixed priority preemption threshold scheduling (PTS), which we named FAST-TRAVERSE. It is optimal in the sense that it always finds a feasible priority assignment if one exists. While there are existing optimal algorithms, they are inefficient to be used in practice. The key ideas of FAST-TRAVERSE are to prune sibling traverses and preemption threshold assignments if possible based on the notion of the effective blocking task. The empirical evaluation results clearly show that FAST-TRAVERSE achieves the largest feasibility and can be employed as an on-line priority assignment algorithm for PTS.

关键词： real-time systems and embedded systems system integration and implementation real-time feasibility scalability fixed-priority scheduling

来源：评论

学校读者我要写书评

暂无评论

Integrating heterogeneous engineering knowledge and tools for efficient industrial simulation model support

引用

ADVANCED ENGINEERING INFORMATICS 2015年第3期29卷 575-590页

作者： Novak, Petr Serral, Estefania Mordinyi, Richard Sindelar, Radek Czech Tech Univ Prague 16636 6 Czech Republic Vienna Univ Technol Christian Doppler Lab Software Engn Integrat Flex A-1040 Vienna Austria Katholieke Univ Leuven Res Ctr Management Informat B-3000 Leuven Belgium

Design of simulation models and their integration into industrial automation systems require knowledge from several heterogeneous data sources and tools. Due to the heterogeneity of engineering data, the integration of the tools and data are time-consuming and error-prone tasks nowadays. The key goal of this article is to provide an effective and efficient integration of heterogeneous data sources and tools as a knowledge basis to support dynamic simulation for industrial plants. The integrated knowledge is utilized both (i) in the design phase of simulation models for defining structure and interfaces of the models and (ii) in the runtime phase of industrial systems for model-driven configuration of the integrated environment. Reaching such goals with a manual approach or point-to-point integration is not beneficial as it may be possible for a few tools and data sources, but quickly gets very complex. A growing number of elements increases the risk of errors and the effort needed for integration. The proposed solution is based on a specification of a common data model to represent engineering knowledge and a service-oriented tool integration with the Engineering Service Bus. Engineering knowledge is integrated in a knowledge base implemented with ontologies in Web Ontology Language-Description Logic (OWL-DL). The proposed approach is demonstrated and evaluated on an educational hydraulic system. Major results of the article are: (i) a data model to represent engineering knowledge for dynamic industrial systems, (ii) the integration platform that, based on this model, integrates the tools for system design and runtime, and (iii) basic design-time and runtime processes for the integrated industrial simulations. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Knowledge modeling Data transformation Ontology design Integrated environment system integration and implementation

来源：评论

学校读者我要写书评

暂无评论

Reducing Unauthorized Modification of Digital Objects

引用

IEEE TRANSACTIONS ON SOFTWARE ENGINEERING 2012年第1期38卷 191-204页

作者： van Oorschot, Paul C. Wurster, Glenn Carleton Univ Sch Comp Sci Carleton Comp Secur Lab Ottawa ON K1S 5B6 Canada

We consider the problem of malicious modification of digital objects. We present a protection mechanism designed to protect against unauthorized replacement or modification of digital objects while still allowing authorized updates transparently. We use digital signatures without requiring any centralized public key infrastructure. To explore the viability of our proposal, we apply the approach to file-system binaries, implementing a prototype in Linux which protects operating system and application binaries on disk. To test the prototype and related kernel modifications, we show that it protects against various rootkits currently available while incurring minimal overhead costs. The general approach can be used to restrict updates to general digital objects.

关键词： Protection mechanisms software release management and delivery system integration and implementation access controls file organization operating systems

来源：评论

学校读者我要写书评

暂无评论

Synthesizing Multithreaded Code from Real-Time Object-Oriented Models via Schedulability-Aware Thread Derivation

引用

IEEE TRANSACTIONS ON SOFTWARE ENGINEERING 2014年第4期40卷 413-426页

作者： Kim, Saehwa Hankuk Univ Foreign Studies Dept Informat Commun Engn Yongin 449791 Gyeonggi Do South Korea

One of the major difficulties in developing embedded systems with object-oriented modeling is to translate a designed model into code that satisfies required real-time performance. This paper proposes scenario-based implementation synthesis architecture with timing guarantee (SISAtime) that addresses these difficulties. The problems that SISAtime must solve are: how to synthesize multithreaded-code from a real-time object-oriented model;and how to design supporting development tools and runtime system architecture while ensuring that the scenarios in the system have minimal response times and the code satisfies the given timing constraints with a minimal number of threads. SISAtime provides a new scheduling algorithm which minimizes scenario response times. SISAtime also provides a new thread derivation method that derives tasks and maps tasks to threads while automatically assigning task scheduling attributes. We have fully implemented SISAtime by extending the RoseRT development tool that uses UML 2.0 as a modeling language, and we applied it to an existing industrial private branch exchange system. The performance evaluation results show that the response times, context switches, and the number of threads of the system with SISAtime were reduced by 21.6, 33.2, and 65.2 percent, respectively, compared to the system with the best known existing thread derivation method.

关键词： Multitasking object-oriented design methods real-time systems and embedded systems system integration and implementation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：