Automatic Implication Checking for CHR Constraints

Constraint Handling Rules (CHRs) are a high-level rule-based programming language commonly used to define constraint solvers. We present a method for automatic implication checking between constraints of CHR solvers. Supporting implication is important for implementing extensible solvers and reification, and for building hierarchical CHR constraint solvers. Our method does not copy the entire constraint store, but performs the check in place using a trailing mechanism. The necessary code enhancements can be done by automatic program transformation based on the rules of the solver. We extend our method to work for hierarchically organized modular CHR solvers. We show the soundness of our method and its completeness for a restricted class of canonical solver as well as for specific existing non-canonical CHR solvers. We evaluate our trailing method experimentally by comparing with the copy approach: runtime is almost halved.     

Design and analysis of a stable set-up protocol for transcoding multicast trees in active networks

Based on active networking, an advanced streaming service was designed to offer different formats of the same stream using a single multicast tree. To that end, the initial format of the stream that is sent into the tree is transcoded to the other requested formats in the nodes of the tree, based on application level functionality residing in these network nodes. To set up such a multicast tree (including the necessary forwarding state in the nodes) and to install the necessary functionality in the nodes, a number of tree set-up procedures were designed. In this paper, performance aspects of these procedures are investigated: the stability and consistency of the forwarding state during the set-up procedures and the influence of dynamic user behaviour on the multicast tree. This performance assessment is based on a thorough analysis of the different set-up procedures and on simulations of the procedures. Based on the analysis, it is seen that great care must be taken during the set-up procedures in order to avoid interference with the existing streams. Therefore, extensions for the procedures are proposed. Furthermore, the influence of dynamic user behaviour on session state and performance attributes is analysed.     

Aspect-oriented Programming for Dynamic Web Service Selection,Integration and Management

In service-oriented computing, applications are often created by integrating third-party Web Services. Current integration approaches, however, require client applications to hardcode references to specific Web Services, thereby affecting adaptability and robustness. Moreover, support for client-side management is rarely provided. To enable the development of more flexible and robust applications, we propose to insert a new layer between the client applications and the Web Services: the Web Services Management Layer (WSML). This layer decouples Web Services from client applications and enables hot-swapping between semantically equivalent Web Services based on availability. This mechanism allows for dynamic switching between Web Services based on selection policies that encapsulate changing business requirements. In addition, with WSML, client-side management concerns (e.g., caching, billing and logging) can be decoupled from the applications. In this paper, we identify a list of requirements for WSML to realize dynamic integration and client-side service management, and provide support for service criteria to govern the selection, integration and composition of Web Services. We also show that dynamic Aspect-Oriented Programming (AOP) is well suited to implement the core functionality of WSML.     

SCR-based ESD protection in nanometer SOI technologies

This paper introduces an SCR-based ESD protection design for silicon-on-insulator (SOI) technologies. SCR devices or thyristors, as they are sometimes better known, have long since been used in Bulk CMOS to provide very area efficient, high performance ESD protection for a wide variety of circuit applications. The special physical properties and design of an SOI technology however, renders straightforward implementation of an SCR in such technologies impossible. This paper discusses these difficulties and presents an approach to construct efficient SCR devices in SOI. These devices outperform MOS-based ESD protection devices by about four times, attaining roughly the same performance as diodes. Experimental data from two 65 nm and one 130 nm SOI technologies is presented to support this.     

Statistical Monitoring of a Sealing Process by Means of Multivariate Accelerometer Data

A multivariate control charting procedure is applied to on-line seal quality evaluation of a packaging process by means of an accelerometer. Based on physical insight it is elucidated in a first step which information in the raw accelerometer data are relevant with respect to the goal of detecting bad seals. Next, a principal component analysis (PCA) based processing of this multivariate information is performed and the related Hotelling's T² and Q test statistics are calculated for further data representation. In a last step proper control charts based on these statistics are used as a process monitoring tool for on-line distinction between good and bad seals. The obtained results show that a correct monitoring of accelerometer signals can be a useful tool for the on-line detection of 'bad seals' in a packaging process.     

汽车本地网络的机电一体化解决方案

汽车功能机电一体化模块和LIN总线基础设施相连接,在可靠性、整合速度和成本上显示出明显的优势.要实现一个可满足性能和热设计限制的最佳机电一体化解决方案,需要从几种候选技术中做出明智的选择.     

Parenting and adolescent problem behavior: An integrated model with adolescent self-disclosure and perceived parental knowledge as intervening variables.

Parental monitoring, assessed as (perceived) parental knowledge of the child's behavior, has been established as a consistent predictor of problem behavior. However, recent research indicates that parental knowledge has more to do with adolescents' self-disclosure than with parents' active monitoring. Although these findings may suggest that parents exert little influence on adolescents' problem behavior, the authors argue that this conclusion is premature, because self-disclosure may in itself be influenced by parents' rearing style. This study (a) examined relations between parenting dimensions and self-disclosure and (b) compared 3 models describing the relations among parenting, self-disclosure, perceived parental knowledge, and problem behavior. Results in a sample of 10th- to 12th-grade students, their parents, and their peers demonstrated that high responsiveness, high behavioral control, and low psychological control are independent predictors of self-disclosure. In addition, structural equation modeling analyses demonstrated that parenting is both indirectly (through self-disclosure) and directly associated with perceived parental knowledge but is not directly related to problem behavior or affiliation with peers engaging in problem behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A developmental contextual perspective on identity construction in emerging adulthood: Change dynamics in commitment formation and commitment evaluation.

A developmental contextual test of a dual-cycle model of identity formation is presented. In addition to a commitment-formation cycle-represented by Marcia's (1966) classical dimensions of exploration in breadth and commitment making--the model comprises a commitment-evaluation cycle--constituted by 2 additional dimensions of exploration in depth and identification with commitment. In a sample of 402 college students assessed 4 times over 2 years, both dimensions of the commitment-formation cycle and exploration in depth increased across time. Identification with commitment showed a slight decrease across time. Latent growth curve (LGC) modeling analyses indicated that the 2 identity cycles are interwoven in a dynamic interplay that defines identity formation. Contextual influences on identity development were identified through a natural experiment. Commitment evaluation constituted the core identity cycle in the normative-progression group (i.e., students who moved on to the sophomore year). Both commitment formation and commitment evaluation were at work in the reorientation group (i.e., students who repeated their freshman year or changed their major). Implications and suggestions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Flexible Grid service management through resource partitioning

In this paper, a distributed and scalable Grid service management architecture is presented. The proposed architecture is capable of monitoring task submission behaviour and deriving Grid service class characteristics, for use in performing automated computational, storage and network resource-to-service partitioning. This partitioning of Grid resources amongst service classes (each service class is assigned exclusive usage of a distinct subset of the available Grid resources), along with the dynamic deployment of Grid management components dedicated and tuned to the requirements of a particular service class introduces the concept of Virtual Private Grids. We present two distinct algorithmic approaches for the resource partitioning problem, the first based on Divisible Load Theory (DLT) and the second built on Genetic Algorithms (GA). The advantages and drawbacks of each approach are discussed and their performance is evaluated on a sample Grid topology using NSGrid, an ns-2 based Grid simulator. Results show that the use of this Service Management Architecture in combination with the proposed algorithms improves computational and network resource efficiency, simplifies schedule making decisions, reduces the overall complexity of managing the Grid system, and at the same time improves Grid QoS support (with regard to job response times) by automatically assigning Grid resources to the different service classes prior to scheduling.