An internetware application is composed by existing individual services, while transaction processing is a key mechanism to make the composition reliable. The existing research of transactional composite service （TCS...
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An internetware application is composed by existing individual services, while transaction processing is a key mechanism to make the composition reliable. The existing research of transactional composite service （TCS） depends on the analysis to composition structure and exception handling mechanism in order to guarantee the relaxed atomicity. However, this approach cannot handle some application-specific requirements and causes lots of unnecessary failure recoveries or even aborts. In this paper, we propose a relaxed transaction model, including system mode, relaxed atomicity criterion, static checking algorithm and dynamic enforcement algorithm. Users are able to define different relaxed atomicity constraint for different TCS according to application-specific requirements, including acceptable configurations and the preference order. The checking algorithm determines whether the constraint can be guaranteed to be satisfied. The enforcement algorithm monitors the execution and performs transaction management work according to the constraint. Compared to the existing work, our approach can handle complex application requirements, avoid unnecessary failure recoveries and perform the transaction management work automatically.
Sensor webs consisting of nodes with limited battery power and wireless communication are deployed to collect useful information from a variety of environments. One fundamental issue in sensor networks is the coverage...
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Sensor webs consisting of nodes with limited battery power and wireless communication are deployed to collect useful information from a variety of environments. One fundamental issue in sensor networks is the coverage problem, which reflects how well a sensor network is monitored or tracked by sensors. In this paper, a new 3-dimensional model is proposed to adapt to the practicality, which distinguishes it from other general existing models. Not only the issue of sensor characteristic, terrain and preferential coverage of grid points are modeled but also the perceive limit is taken into account in this 3-dimensional model and the feasibility is tested by simulations. Specially, we assume there are three types of obstacles in the 3-dimensional sensor field, Non-grid obstacles (NGO), Grid obstacles with sufficient height (GOS), and Grid obstacles with insufficient height (GOI). And here, we propose an algorithm for the efficient coverage in a 3-dimensional sensor field. After finding the grid point which is covered least effectively, we find out not one but a number of nodes, which are eager to be improved. So these weaker nodes will be meliorated via algorithm INTEGER_LOCAL_COV, which has been compared with the primary algorithms via simulations and been shown to exhibit excellent performance.
Wireless sensor networks (WSN) are deployed to monitor the physical world and to provide relevant data to the users. The coverage problem of WSN is one of the hot topics of research. Deploying insufficient nodes might...
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Wireless sensor networks (WSN) are deployed to monitor the physical world and to provide relevant data to the users. The coverage problem of WSN is one of the hot topics of research. Deploying insufficient nodes might leave blind spots or sensing holes, which can allow the object such as enemy to pass through. In this paper, a new algorithm MIN_STD_COV is proposed for the efficient coverage in the sensor field, which is designed to optimize the number of sensors and find out their placement to support distributed sensor networks. The MIN_STD_COV chases down the grid point which makes the wireless sensor network have the minimum Standard deviation (STD) during iteration. What should be emphasized is that the redundant coverage is taken into account in the new algorithm MIN_STD_COV. It's important for the algorithm to perform well in some conditions, i.e. preferential coverage. At the same time, we demonstrate that the placement problem can be translated into Integer Programming problem (IP) in order to obtain the global optimum value. In other words, two different solutions are presented in this paper. MIN_STD_COV would be compared to MAX_AVG_COV as well as to MAX_MIN_COV. Whether the preferential coverage is considered or not, it would be shown to exhibit excellent performance via simulations.
In a competitive market, quality is essential to the software. software test plays an important role during the software-developing period. Any saving on software test, will greatly reduce the total cost of software. ...
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ISBN:
(纸本)1424400384
In a competitive market, quality is essential to the software. software test plays an important role during the software-developing period. Any saving on software test, will greatly reduce the total cost of software. The key point of this paper is to build a software test process with the cost control management and to make tradeoff between the quality and the cost. Typical software testing model are analyzed and compared. A novel QC 3-D test model is introduced. The model combined with software test process, software quality cost and testing type. The computational formula is defined to calculate software quality cost. A software quality balance law is introduced to balance control cost and failure cost. By adjusting software test method and strategy, organization can reach the objective of the best balance between software quality and cost. An enterprise case is studied and the result is analyzed to prove the basic law. The result shows an optimistic point that will prove the accurate of the model and the law.
In this paper, we describe the integration of an Ada 2005 compiler into Microsoft's 2005 Visual Studio and its implications for the Ada community and beyond. Copyright 2006 ACM.
ISBN:
(纸本)1595935630
In this paper, we describe the integration of an Ada 2005 compiler into Microsoft's 2005 Visual Studio and its implications for the Ada community and beyond. Copyright 2006 ACM.
Cooperative caching is a very important technique for efficient data dissemination and sharing in mobile ad hoc networks (MANETs). Many applications have requirements on the consistency of the content cached on differ...
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Reusing software components is a textbook softwareengineering best practice. Developers reuse components written by others, combining them in unique ways to create new software products. Reusing software components c...
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Java's original security architecture was designed to facilitate the execution of software from remote systems while simultaneously preventing downloaded code from performing unauthorized operations on host machin...
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Java's original security architecture was designed to facilitate the execution of software from remote systems while simultaneously preventing downloaded code from performing unauthorized operations on host machines. The sandbox model of the Java Development Kit (JDK) 1.0's security architecture was found to be too restrictive;therefore the model was modified so that remote code could be allowed as trusted code. In the Java 2 platform, also known as JDK 1.2, the notion of trusted code was removed and security control mechanisms were implemented that could be applied to both application and applet code so the code could be run with configurable trust. Creating applications in Java does not guarantee that they are secure. Java developers need to understand and incorporate the new Java security architecture into their development process to make certain their applications are secure. This article looks at the implementation of the new architecture and the new mechanisms provided for ensuring security for Java code. It details the motivation for the security changes in a security architecture, gives a general overview of the architecture added, and then looks at some of the details of the mechanisms either changed or provided by the new architecture.
This paper presents interfacing techniques to integrate a virtual environment (VE), computer graphics, image-based modeling, and other technologies in a networked system for robot control. Technologies such as network...
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Previous years have seen rapid growth of online services that rely on large-scale server clusters to handle high volume of requests. Such clusters must adaptively control the CPU utilizations of many processors in ord...
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Previous years have seen rapid growth of online services that rely on large-scale server clusters to handle high volume of requests. Such clusters must adaptively control the CPU utilizations of many processors in order to maintain desired soft real-time performance and prevent system overload in face of unpredictable workloads. This paper presents DUC-LB, a novel distributed utilization control algorithm for cluster-based soft real-time applications. Compared to earlier works on utilization control, a distinguishing feature of DUC-LB is its capability to handle system dynamics caused by load balancing, which is a common and essential component of most clusters today. Simulation results and control-theoretic analysis demonstrate that DUC-LB can provide robust utilization control and effective load balancing in large-scale clusters
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