C++代码审查案例分析

本文通过一个软件白盒测试中代码审查的具体案例,分析制约代码审查高效的关键因素。介绍了这个案例中代码审查的过程,描绘出审查发现的代码缺陷数分布图;并由此提出将缺陷规则按照缺陷出现的频率等各种因素提供一种动态优先级;最后,评估了应用这种动态优先级进行代码审查的效果。     

Upper-Bound Elemental Technique (UBET) with convex circular parallelepiped and convex spherical elements for three-dimensional forging analysis

In this study, two kinematically admissible velocity fields are derived for the proposed three-dimensional convex circular parallelepiped and convex spherical UBET elements. Those elements are applied to three-dimensional closed-die forging having convex curve surfaces; the capability of the proposed elements is then demonstrated. From the derived velocity fields, the upper-bound loads on the upper die and the velocity field are determined by minimizing the total energy consumption with respect to some chosen parameters. Also, experiments of two closed-die forgings are performed with commercial pure lead billets at the ambient temperature. The theoretical predictions of the forming load correlated well with the experimental results. The results in this study confirm that the elements proposed in this work can effectively be used to predict the forming load accurately in three-dimensional closed-die forging with convex curve surfaces.     

1200mm中板精轧机电动压下变频调速技术的开发应用

重庆特殊钢集团公司中板分厂１２００ｍｍ精轧机电动压下系统采用变频调速新技术，调速范围宽，调速准确、方便，提高了轧机压下精度和生产率，取得了较好的经济效益     

Perceptual conformity and responsiveness to social reinforcement in chronic schizophrenics.

In a study with 94 institutionalized schizophrenic residents of a token economy ward, S. D. Asch's perceptual conformity procedure identified 20 "independents" and 12 "yielders." Performance on a letter cancellation task under different reinforcement conditions indicated that yielders evidenced maximum performance during the social reinforcement condition and independents performed best during token and monetary reinforcement conditions. Results are interpreted in the context of role theory and the impression-management hypothesis and suggest that patients will engage in behaviors which are reinforced in ways that are congruent with their orientation to the interpersonal world. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depression and everyday social interaction.

Examined the relationships between depressive symptoms and everyday social interaction in a nonclinical population. Depressive symptoms were measured using the Center for Epidemiological Studies Depression Scale, and social interaction was measured using a variant of the Rochester Interaction Record. People who were classified as at risk for depression had less rewarding interactions than people who were not at risk. Depressive symptoms and interaction quantity and quality were negatively correlated for participants above the cutpoint, whereas they were uncorrelated for those below the at-risk cutpoint. Results also suggest that, compared with nondepressed people, depressed people derive more rewards from interactions with their closest opposite-sex friends, relative to the rewards they derive from interactions with other opposite-sex friends. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimum die surface design of general three-dimensional section extrusions by using a surface model with tension parameter

In this paper, an integrated CAD/CAM/CAE method for the optimum die surface design of three-dimensional section extrusions has been proposed. The die surface is represented by a surface model with tension parameter and, therefore, general shapes of products, such as clover, polygonal, T- and L-sections and gear splines which can be designed using only one surface model. Tension parameter is used to obtain the straight line segments when those are required to present the product section. By applying the upper-bound method and the variable metric optimization scheme, the material flow is optimized and a minimum extrusion pressure is obtained. The optimum die surface is subsequently manufactured by using CAD/CAM software and NC machining for making the EDM electrode. Extrusion tests for straight-sided gear splines were performed to obtain the extrusion load and the experimental grid deformation. The theoretical predictions of gear spline extrusion are in close agreement with the experimental results. The numerical results of clover, polygonal, T- and L-shapes are also compared with results available in the literature. The results confirm that better extrusion performance could be obtained with the die surfaces which employed the developed design method. The proposed surface model and the optimum design method can be applied to the die design for general three-dimensional section extrusions.     

A strain energy minimization method for generating continuous NURBS-based motion curves in free-form surface machining

In spline-based free-form surface machining, segmented toolpaths are inevitable, and the discontinuities between segments cause large feedrate errors in the generated motion commands. Methods of the geometric design to create smooth composite curves may introduce new error sources in the original curve, and thus they are not suitable for motion planning in high precision free-form surface machining. In this paper, a strain energy minimization model (SEMM) and a non-uniform rational B-spline (NURBS)-based motion planning algorithm is proposed for free-form surface machining. The proposed SEMM and motion planning algorithm are capable of creating composite NURBS-based motion curves with up to C2 integral continuity without oscillations. Results from simulation show that with the proposed energy minimization model and motion curve generation algorithm, the feedrate errors caused by discontinuities in toolpaths can be effectively removed.     

Development of universal environment for constructing 5-axis virtual machine tool based on modified D–H notation and OpenGL

For construction of a universal 5-axis virtual machine simulation system, a new methodology is proposed in this paper. The OpenGL library is used to render the virtual environment and to display all motions of the virtual machine tool. In order to achieve the universal construction procedures, the D–H notation is adopted. The user interfaces are developed to help users to select the configuration of machine tool. Once the configuration is decided, the motion directions between adjacent links are known and the kinematic parameters are described by D–H notation. Then the post-processor is derived by D–H notation. Finally, the motion control simulation of the virtual machine tool is executed by D–H transformation matrix. This new methodology can assist developers in constructing the simulation system for the universal 5-axis virtual machine tool efficiently and effectively.     

Fractionation of Palm Kernel Oil by Short Path Distillation

Fractionation of palm kernel oil （PKO） by short path distillation （SPD） at two feed flow rates （135 g/h and 195 g/h） and six distillation temperatures, TD,s （200, 210, 220, 230, 240 and 250 ℃） was investigated. Other distillation parameters, such as vacuum pressure （0.001 mbar）, blade rotation speed （400 rpm） and temperature of the feed material （60 ℃） were kept constant. The fractionated products, known as residue and distillate, were analysed for physico-chemical properties including fatty acid composition （FAC）, triacylglycerol （TAG） composition, slip melting point （SMP）, thermal analysis by differential scanning calorimetry （DSC） and solid fat content （SFC）. Product yield was measured as well. Crystallisation behaviour of PKO and the fractionated products were studied by measurement of isothermal crystallisation, Tc,. at 0, 5, 10, 15, 20 and 25 ℃. The distillates, collected at all fractionation temperatures, were enriched with caprylic, capric and lauric acids. These fractions were also concentrated with low molecular weight and C36 TAGs. Distillates obtained at higher TDis （230-250 ℃） exhibited higher in SMP and SFC. On the other hand, the residual oils collected at all fractionation temperatures contained higher amount of long-chain fatty acid and palmitic acid. These fractions were enriched with high molecular weight TAGs. Residues obtained at lower Tois （200-220 ℃） were low in SMP and comparable SFC with PKO. Changes in fatty acid and TAG composition resulted in different crystallisation behaviour of the fractions. Distillates collected at all fractionation temperatures crystallised in a sharper peak while residues obtained at higher T Dis （230-250 ℃） showed broader crystallisation peaks, as shown by the DSC thermograms.     

基于相似度的问答社区问答质量评价方法

研究问答社区中回答质量的评价方法,针对具有多个答案的问题,提出一种基于相似度的问答社区中问答质量的评价方法。该方法利用问题与各答案之间的语义关系,通过计算每个答案和问题中语言"单位"之间的相似度和对应的权值,并引入HITS算法模型对权值进行调整,选取出最佳答案。实验结果表明,与仅基于文本特征的方法相比,该方法能够有效地提高回答质量的评估效果。