Optimal release time for software systems considering cost, testing-effort, and test efficiency

In this paper, we study the impact of software testing effort & efficiency on the modeling of software reliability, including the cost for optimal release time. This paper presents two important issues in software reliability modeling & software reliability economics: testing effort, and efficiency. First, we propose a generalized logistic testing-effort function that enjoys the advantage of relating work profile more directly to the natural flow of software development, and can be used to describe the possible testing-effort patterns. Furthermore, we incorporate the generalized logistic testing-effort function into software reliability modeling, and evaluate its fault-prediction capability through several numerical experiments based on real data. Secondly, we address the effects of new testing techniques or tools for increasing the efficiency of software testing. Based on the proposed software reliability model, we present a software cost model to reflect the effectiveness of introducing new technologies. Numerical examples & related data analyzes are presented in detail. From the experimental results, we obtain a software economic policy which provides a comprehensive analysis of software based on cost & test efficiency. Moreover, the policy can also help project managers determine when to stop testing for market release at the right time.     

微反应器中甲苯液相SO3磺化工艺研究

以具有快速强放热特性的甲苯液相SO3磺化为目标反应,利用微反应器热、质传递能力强的优点,以提高反应性能和过程可控性。针对微反应器内的甲苯液相SO3磺化工艺进行了研究,考察了反应温度、SO3质量分数、SO3与甲苯物质的量之比、空速(LHSV)、产物放置时间、溶剂极性和母液循环次数对产物选择性的影响。结果表明,在温度为28℃、LHSV为13 000 h-1、1,2-二氯乙烷为溶剂的条件下,通过母液多次循环,磺酸异构体产物中对甲苯磺酸的选择性高达96.54%,间甲苯磺酸选择性则降低至0.33%。     

Gauge capability studies for attribute data

A gauge repeatability and reproducibility (R&R) method is developed to assess the capability of a measurement system. Although gauge capability studies have received substantial attention, few studies have investigated attribute data despite their wide application in industry. The primary aim of this research is to develop a procedure, based on the generalized linear model, to evaluate the R&R of a measurement system for attribute data. To calculate repeatability of a system, the procedure integrates the iterative weighted least squares (IWLS) method and deviance analysis. The proposed procedure is applied to an inclusion measurement system to verify its adequacy to model the process capability. Copyright © 2007 John Wiley & Sons, Ltd.     

Residence time distributions and basic studies of flow and melting in a modular buss kneader

Experimental studies of residence time distribution, fill factor, temperature, and melting profiles of thermoplastic resins are presented. Residence time distributions were determined as a function of throughput and screw speed. The melting of polypropylene and low density polyethylene in the entrance region was investigated. Fill factor and temperature profiles are reported.     

The real-time functional test facility for advanced instrumentationand control in nuclear power plants

Testing and validation of the functions and performance of the digital instrumentation and control (I&C) system should be done prior to installation in nuclear power plants. The objective of the I&C Functional Test Facility (FTF) is to test and validate the functions of developed digital control and various monitoring systems. The FTF provides the simulated testing environment as an experimental test bed. The FTF software consists of a mathematical modeling program which simulates a three-loop 993 MWe pressurized water reactor and a supervisory program that comprises all the instructions necessary to run the FTF. The hardware equipment provides an interface between a host computer and a simple test panel or the developed target systems to be tested. The graphical user interface supports an easy and friendly interface between the FTF and users. It is implemented through a Picasso-3 graphic tool developed by the Halden Reactor Project. The FTF is applied to an advanced I&C system prototype, such as an automatic start-up intelligent control system, dynamic alarm system, accident identification system, and intelligent logic tracking system, to test its algorithm or performance. The results of the test show good operational performance of the FTF in normal and transient conditions     

A cruciform-dumbbell model for inverted dimer formation mediated by inverted repeats

Small inverted repeats (small palindromes) on plasmids have been shown to mediate a recombinational rearrangement event in Escherichia coli leading to the formation of inverted dimers (giant palindromes). This recombinational rearrangement event is efficient and independent of RecA and RecBCD. In this report, we propose a cruciform-dumbbell model to explain the inverted dimer formation mediated by inverted repeats. In this model, the inverted repeats promote the formation of a DNA cruciform which is processed by an endonuclease into a linear DNA with two hairpin loops at its ends. Upon DNA replication, this linear dumbbell-like DNA is then converted to the inverted dimer. In support of this model, linear dumbbell DNA molecules with unidirectional origin of DNA replication (ColE1 ori ) have been constructed and shown to transform E.coli efficiently resulting in the formation of the inverted dimer. The ability of linear dumbbell DNA to transform E.coli suggests that the terminal loops may be important in bypassing the requirement of DNA supercoiling for initiation of replication of the ColE1 ori.     

Global Optimization CAD in MM Wave Waveguide Cavity

This paper describes a global optimization design for power combiner of solid-state millimeter wave source in rectangular wave- guide cavity. The algorithm can determine a neighborhood of the global optimum of an objective function. In this paper, the performance parameter are presents by combining efficiency, tuning range, frequency drift, and FM noise were done the objective functions respectively. And it is to calculate the global optima respectively.     

盾构隧道下穿高速铁路站场安全风险评估管理方法

为提高风险评估对工程设计的指导性,本文结合某地铁区间盾构隧道下穿高速铁路站场工程实例,尝试将风险评估、数值模拟和工程设计结合起来形成反馈机制。首先采用安全风险层次-模糊综合评价法(AHP-FE)对工程进行了初步评估,得到了初步的设计阶段风险等级“高度”和主要风险源及排序;然后采用数值模拟方法对盾构下穿铁路站场进行了施工模拟,得到了主要风险源相关指标的预测值,并提出了系列控制措施;在此基础上,再一次采用安全风险模糊评估理论对工程进行风险分析,最后得到设计阶段允许的“中度”风险等级和相应的风险源排序。本文所遵循的风险评估方法和流程可以提高风险评估的准确性和合理性。     

电子束横焊3mm纯铌板的熔池形态研究

高能加速器纯铌超导腔内导体,要求加工后的外表面光滑平整,以保证其特殊性能的要求。在电子束平焊全熔透情况下,超导腔焊缝正面在反冲压力作用下易发生未焊满及塌陷等缺陷。本文采用合适的电子束横焊工艺参数,得到了符合工艺要求的正面余高焊缝。并且建立了3mm厚的高纯铌板横焊过程的二维模型,针对不同的焊接参数分别设计了不同尺寸和形状的熔池,结合VOF算法,模拟焊接熔池里液态金属自由表面存在状态,得到了不同焊接参数下熔池的演变过程。实验结果显示,焊接熔宽随焊接线能量的升高而增大,数值模拟与实验结果较吻合。