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101.
检测和分析了Q-52-51型摩托车车轮轮毂从材料成分,力学性能和金相组织。结果表明,轮毂在径向冲击检测时开裂的主要原因是镁含量偏高,以及热处理加热温度高造成组织过热所致。  相似文献   
102.
Many substrates do not sustain the conventional glazing process (i.e., vitreous glazing) due to the relatively high temperature required by this treatment (i.e., up to 1400 °C in some cases) to fuse glazes after their application on the surface to be covered. Flame spraying could appear as a solution to circumvent this limitation and to avoid thermal decomposition of substrates. This contribution describes some structural attributes of glaze coatings manufactured by flame spraying. It also discusses the influence of the feedstock powder morphology and some of its physical properties on coating characteristics. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.  相似文献   
103.
Programmers build large‐scale systems with multiple languages to leverage legacy code and languages best suited to their problems. For instance, the same program may use Java for ease of programming and C to interface with the operating system. These programs pose significant debugging challenges, because programmers need to understand and control code across languages, which often execute in different environments. Unfortunately, traditional multilingual debuggers require a single execution environment. This paper presents a novel composition approach to building portable mixed‐environment debuggers, in which an intermediate agent interposes on language transitions, controlling and reusing single‐environment debuggers. We implement debugger composition in Blink, a debugger for Java, C, and the Jeannie programming language. We show that Blink is (i) simple: it requires modest amounts of new code; (ii) portable: it supports multiple Java virtual machines, C compilers, operating systems, and component debuggers; and (iii) powerful: composition eases debugging, while supporting new mixed‐language expression evaluation and Java native interface bug diagnostics. To demonstrate the generality of interposition, we build prototypes and demonstrate debugger language transitions with C for five of six other languages (Caml, Common Lisp, C#, Perl 5, Python, and Ruby) without modifications to their debuggers. Using real‐world case studies, we show that diagnosing language interface errors require prior single‐environment debuggers to restart execution multiple times, whereas Blink directly diagnoses them with one execution. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
104.
105.
In Spring 2012, instruction librarians collaborated with first year composition (FYC) faculty to study students’ research habits as they related to writing. We collected process narratives from students in the introductory FYC course at the beginning and end of the fall semester, and a group of librarians and FYC faculty coded them together. Although we did not achieve one of our initial research goals, we still gained valuable insight into how our students perceive sources and the research process. We applied what we learned to create new instructional materials and developed a valuable relationship with FYC faculty.  相似文献   
106.
Delay composition in preemptive and non-preemptive real-time pipelines   总被引:1,自引:1,他引:0  
Uniprocessor schedulability theory made great strides, in part, due to the simplicity of composing the delay of a job from the execution times of higher-priority jobs that preempt it. In this paper, we bound the end-to-end delay of a job in a multistage pipeline as a function of job execution times on different stages under preemptive as well as non-preemptive scheduling. We show that the end-to-end delay is bounded by that of a single virtual “bottleneck” stage plus a small additive component. This contribution effectively transforms the pipeline into a single stage system. The wealth of schedulability analysis techniques derived for uniprocessors can then be applied to decide the schedulability of the pipeline. The transformation does not require imposing artificial per-stage deadlines, but rather models the pipeline as a whole and uses the end-to-end deadlines directly in the single-stage analysis. It also does not make assumptions on job arrival patterns or periodicity and thus can be applied to periodic and aperiodic tasks alike. We show through simulations that this approach outperforms previous pipeline schedulability tests except for very short pipelines or when deadlines are sufficiently large. The reason lies in the way we account for execution overlap among stages. We discuss how previous approaches account for overlap and point out interesting differences that lead to different performance advantages in different cases. Further, we also show that in certain cases non-preemptive scheduling can result in higher system utilization than preemptive scheduling in pipelined systems. We hope that the pipeline delay composition rule, derived in this paper, may be a step towards a general schedulability analysis foundation for large distributed systems.
Tarek AbdelzaherEmail:
  相似文献   
107.
Automatic composition of broadcast sports video   总被引:1,自引:0,他引:1  
This study examines an automatic broadcast soccer video composition system. The research is important as the ability to automatically compose broadcast sports video will not only improve broadcast video generation efficiency, but also provides the possibility to customize sports video broadcasting. We present a novel approach to the two major issues required in the system’s implementation, specifically the camera view selection/switching module and the automatic replay generation module. In our implementation, we use multi-modal framework to perform video content analysis, event and event boundary detection from the raw unedited main/sub-camera captures. This framework explores the possible cues using mid-level representations to bridge the gap between low-level features and high-level semantics. The video content analysis results are utilized for camera view selection/switching in the generated video composition, and the event detection results and mid-level representations are used to generate replays which are automatically inserted into the broadcast soccer video. Our experimental results are promising and found to be comparable to those generated by broadcast professionals.  相似文献   
108.
在面向服务计算领域,服务合成正成为分布异构资源整合、业务集成的一个新型计算模式。在开放互联的因特网环境下,由于存在多个功能相似但服务质量不同的服务提供商,从而导致一个抽象的服务合成方案存在多条可执行路径。然而,在满足用户综合QoS约束需求的情况下,如何有效协同单个服务的QoS从多条候选路径选出一条优化的执行路径,便成为服务合成QoS研究中的一个关键问题。遗憾的是,该问题还没有得到很好的解决。为此,我们提出一个采取渐进约束违背删除策略建立优化执行路径的方法。我们的方法能够避免探测多条执行路径,而是在靠本地最优化策略建立的执行路径上,通过全局QoS计算和QoS约束检查模型找出QoS约束违背,并进而采取渐进约束违背删除策略逐渐删除这些约束违规,并建立起一条近优的执行路径。实验表明,我们的方法很好地降低了建立优化执行路径的时间复杂性。  相似文献   
109.
非编译成份包括注释、程序书写风格和命名规则等几个部分,其中程序书写风格可分为空白行、行缩进和换行等。合理地使用非编译成份,可以提高程序的可读性、可理解性、可修改性、可维护性等质量特性。然而,只有高质量的非编译成份才能起到期望的效果。本文旨在提出一种非编译成份的评价方法,促进这些成份质量的提高。在介绍每一种非编译成份后,分别提出了针对这些成份的度量方法。最后,采用加权合成的方式,得到非编译成份的整体度量。  相似文献   
110.
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