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31.
The cost of maintaining a software system over a long period of time far exceeds its initial development cost. Much of the maintenance cost is attributed to the time required by new developers to understand legacy systems. High-level structural information helps maintainers navigate through the numerous low-level components and relations present in the source code. Modularization tools can be used to produce subsystem decompositions from the source code but do not typically produce high-level architectural relations between the newly found subsystems. Controlling subsystem interactions is one important way in which the overall complexity of software maintenance can be reduced.We have developed a tool, called ARIS (Architecture Relation Inference System), that enables software engineers to define rules and relations for regulating subsystem interactions. These rules and relations are called Interconnection Styles and are definedusing a visual notation. The style definition is used by our tool to infer subsystem-level relations in designs being reverse engineered from source code.In this paper we describe our tool and its underlying techniques and algorithms. Using a case study, we describe how ARIS is used to reverse engineer high-level structural information from a real application. 相似文献
32.
建立了挠性胶管阻尼耗能的简化模型。以此为基础分析了挠性胶管的阻尼耗能的一般规律,并得出了一些新的结论。 相似文献
33.
A nuclear microprobe with high spatial resolution and high analytical sensitivity was applied to analyze trace elements,especially lead,in vehicle exhaust of Shanghai city.The result shows that the chemical composition and its corresponding x-ray relative intensity are different among different vehicle exhausts.There are many kinds of metal elements in particles of vehicle exhaust.most are harmful to people,such as Ti,Cr,Mn,Pb,etc.We found that the lead concentration was 6820μg/g and the bromine concentration was 5300μg/g in the exhaust from Santana using leaded gasoline(SULG).which is higher than any other kinds of vehicle exhausts.We have also detected the minimum lead in the particles of unleaded gasoline and its content varies from one to another.Its mean concentration was 450μg/g and the highest reached 6210μg/g.The unleaded gasoline‘s Pb existed in the whole particle while the leaded gasoline‘s enriched in the surface of the particle and was more harmful to the human beings. 相似文献
34.
On the basis of the experimental data, we show that the difference between the macroscopic and microscopic fatigue crack growth rates in the second section of the kinetic diagram of fatigue fracture is caused by the effect of crack closure within the limits of its existence. We establish the relationships between the macroscopic and microscopic fatigue crack growth rates and the structure of the material in the second section of the diagram for various values of the load ratio with regard for the effect of crack closure and propose a procedure of examination of the fracture processes in structural materials based on the analysis of microscopic and macroscopic fatigue crack growth rates. 相似文献
35.
标准物质在分析测试中的重要地位及发展前景 总被引:2,自引:0,他引:2
标准物质在分析测试领域中无论在定值,方法的研究,误差确定等方面都有着重要地位。标准物质的质量保证及正确使用也应引起我们重视。随着科学技术迅速发展标准物质有着广阔发展前景。 相似文献
36.
采用被动式工艺生产冷轧带肋钢筋须经过减径、成型两台轧机连续轧制.要求钢材的秒流量相等,否则将造成断线停产或线材在拉丝机卷筒上打滑,致使卷筒严重磨损.用双层卷筒拉丝机提供动力生产冷轧带肋钢筋时,线材直径与卷筒直径的匹配是在一个小的调整范围,通过轧机拉力控制在一定范围变化,可保证成品尺寸符合公差要求而不产生打滑,从而避免了卷筒严重磨损. 相似文献
37.
Timothy Thomasma Kurt Hilbrecht 《International Journal of Flexible Manufacturing Systems》1991,3(3-4):231-250
Good methods are needed to specify, test, and debug material-handling control logic. This article surveys a number of representative methods for defining and describing control algorithms for programmable material-handling equipment used in flexible manufacturing systems. The methods are evaluated with regard to their suitability for communication between people and as bases for interfaces to automatic program generators. It is concluded that no single method is entirely satisfactory. Three methods (position diagrams, function block diagrams, and operation networks) have potential to be combined into an effective hybrid approach that minimizes the need for the user to switch between various conceptual models. 相似文献
38.
罗立祝 《机械工业高教研究》2008,(2):106-110
从高校招生的演变历史看,中国在1978年以前对工农阶层子女实行高校入学优惠政策主要源于国家对这一阶层的特殊偏好而实行平均主义分配政策所致。国家通过报考资格政策、优先录取政策和免试推荐入学政策人为地大幅度提高了工农阶层子女在高校大学生中所占的比例。从公平视角看,这项政策不仅违背了公平原则,而且降低了人才选拔的质量。 相似文献
39.
40.
在薄板坯连铸连轧流程上,经过对Ti微合金化技术研究,有效解决了Ti微合金化强度性能波动大的问题,开发出屈服强度450~700MPa高强钢。对试制钢组织性能和工业应用分析研究,表明该产品通板性能良好,通板强度差30MPa左右;成形性能良好,d=0时冷弯测试全部合格;同时还具有良好焊接性能,焊接后,强度波动较小,均在母材部位断开;试制钢显微组织为珠光体和铁素体,晶粒均匀细小,平均尺寸为4~8/μm;实物质量满足集装箱和汽车制造行业要求,具有广阔市场前景。 相似文献