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181.
This research endeavors to address the question of how to enhance project performance through exploring the relationships among information technology (IT) governance, project governance and project performance. The research utilizes an empirical survey methodology. The survey of 533 working professionals in various industries renders 282 usable responses or a response rate of 53.91%. The results suggest that both IT governance and project governance have a positive impact on project performance. Moreover, we found that three dimensions of IT governance (i.e., strategy setting, value delivery, and performance management) are positively associated with project performance while all three dimensions of project governance (i.e., portfolio direction, project sponsorship as well as project effectiveness & efficiency, and disclosure & reporting) are positively associated with project performance. Additionally, the alignment between IT governance and project governance is also found to be positively associated with project performance. These findings provide evidence to project management professionals in regard to IT governance and project governance being part of the operational strategy in facilitating the success of projects. It also demonstrates the importance of the alignment strategy between IT governance and project governance in enhancing project performance.  相似文献   
182.
在当代建筑中,新乡土建筑可以看作是现代性与传统性的统一体。在《New Vernacular Architecture》老练精妙而又颇具可读性的介绍中,维基·理查森(Vicky Richardson)对建筑中的乡土性进行了图文并茂的分析和展示。这里节选的便是其导论部分,它为建筑的乡土性提供了一份详尽的历史性分析,展示了它是如何体现出笔者所描述的“充满质疑的建筑”(“architecture in denial”)观的——一种对于理念进展的质疑和一份对于“原生”建筑形式真实性的执信。  相似文献   
183.
The capacity to detect low levels of healthy and sub-lethally injured Salmonella enterica cells in chocolate by two alternative rapid detection methods iQ-Check(TM)Salmonella II real-time PCR (Bio-Rad) and VIDAS? Easy SLM (BioMérieux) was assessed and compared with ISO 6579:2005. Chocolate, a low moisture food known to support the survival of Salmonella, was challenged as food matrix. Buffered peptone water (BPW) did not support the recovery of low levels of sub-lethally injured S. enterica independent of the detection method, while BPW supplemented with milk powder enabled detection by the three examined methods. However, inhibition of real-time PCR was observed since for one out of three repetitions of chocolate inoculated with a low number of sub-lethally injured S. enterica cells, no PCR signal was obtained. Therefore, attention should be paid to the enrichment step to avoid false negative results due to the presence of especially sub-lethally injured Salmonella cells in chocolate. An appropriate sample preparation (such as enrichment media and conditions for incubation) remains the key factor for reliable detection including sub-lethally injured cells and should be evaluated, if necessary optimized, for each detection assay.  相似文献   
184.
A comparative study examining Bolton broth and Preston broth for enrichment and reliable detection of Campylobacter jejuni (both healthy and freeze stressed cells) was performed. Tested as pure cultures, Bolton broth enabled faster resuscitation and growth of C. jejuni compared to Preston broth. When C. jejuni was co-incubated with extended-spectrum-beta-lactamase (ESBL) producing Escherichia coli isolated from Belgian poultry meat preparations, the latter dominated in the Bolton enrichment broth and crowded the mCCDA plates. This resulted in the inability to recover C. jejuni by ISO 10272-1:2006 standard method. Preston broth did not support the growth of the ESBL E. coli isolates, but showed longer detection time of C. jejuni compared to Bolton broth. The use of the same antibiotic (sodium cefoperazone) in Bolton broth and in mCCDA plates may explain the problems encountered for detection of C. jejuni, as high numbers of ESBL E. coli present after enrichment in Bolton broth, also caused overgrowth and masked the few C. jejuni colonies present on the mCCDA plates. The use of Campylobacter spp. specific real-time PCR circumvented these problems and enabled rapid detection of the pathogen after 24 h enrichment in both Bolton and Preston broth, for both healthy and freeze stressed cells.  相似文献   
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A picture of the type and frequency of problems in arbitration which subsequently brings the dispute to Court for resolution. As arbitration is a private matter between the parties, information about cases is not normally available. So where cases incorporate Court action the resulting judgements provide useful sources of data.  相似文献   
188.
Modern satellite communication systems are required to serve heterogeneous and geographically dispersed user demands with limited resources. In this paper, we investigate methodologies for dynamic resource allocation in Geosynchronous Earth Orbit (GEO) High-throughput Satellite (HTS) systems. We designed three solution approaches FlexBeamOpt v1 , FlexBeamOpt v2 , and FlexBeamOpt v3 , each as a hybridization of custom heuristics, integer linear programming, and/or constraint programming. We test the performance of the three approaches on 12 test instances that vary in user distribution (realistic, random, and clustered), user numbers (500 vs. 5000 users), and demand distribution (uniform vs. random). We observed that FlexBeamOpt v1  consistently outperformed FlexBeamOpt v2  and FlexBeamOpt v3  in terms of demand coverage and number of users covered for realistic and random user distribution test instances but at the cost of computation time. FlexBeamOpt v3  is the fastest in these instances. For clustered user distribution instances, FlexBeamOpt v3  performed better in terms of demand coverage and number of users covered, at the cost of using more beams. For these test instances, FlexBeamOpt v2  is the fastest in terms of computation time while providing a comparable solution quality.  相似文献   
189.
Robust Synchronization of Absolute and Difference Clocks Over Networks   总被引:1,自引:0,他引:1  
We present a detailed re-examination of the problem of inexpensive yet accurate clock synchronization for networked devices. Based on an empirically validated, parsimonious abstraction of the CPU oscillator as a timing source, accessible via the TSC register in popular PC architectures, we build on the key observation that the measurement of time differences, and absolute time, requires separate clocks, both at a conceptual level and practically, with distinct algorithmic, robustness, and accuracy characteristics. Combined with round-trip time based filtering of network delays between the host and the remote time server, we define robust algorithms for the synchronization of the absolute and difference TSCclocks over a network. We demonstrate the effectiveness of the principles, and algorithms using months of real data collected using multiple servers. We give detailed performance results for a full implementation running live and unsupervised under numerous scenarios, which show very high reliability, and accuracy approaching fundamental limits due to host system noise. Our synchronization algorithms are inherently robust to many factors including packet loss, server outages, route changes, and network congestion.  相似文献   
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