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Bad smells are signs of potential problems in code. Detecting bad smells, however, remains time consuming for software engineers despite proposals on bad smell detection and refactoring tools. Large Class is a kind of bad smells caused by large scale, and the detection is hard to achieve automatically. In this paper, a Large Class bad smell detection approach based on class length distribution model and cohesion metrics is proposed. In programs, the lengths of classes are confirmed according to the certain distributions. The class length distribution model is generalized to detect programs after grouping. Meanwhile, cohesion metrics are analyzed for bad smell detection. The bad smell detection experiments of open source programs show that Large Class bad smell can be detected effectively and accurately with this approach, and refactoring scheme can be proposed for design quality improvements of programs.

A surface profiler for optical elements used in synchrotron radiation beamlines has been developed. By measuring the precise positions of an incident and reflected laser beam, the surface profile of mirrors and gratings can be obtained. The profile of large mirrors up to 700 mm long and that of any other shape device such as plane and non-spherical mirrors can be also measured. The design concept and preliminary examples of profile measurements are reported.

Detecting bad smells in program design and implementation is a challenging task. Manual detection is proved to be time-consuming and inaccurate under complex situation. Weight based distance metrics and relevant conceptions are introduced in this paper, and the automatic approach for bad smells detection is proposed based on Jaccard distance. The conception of distance between entities and classes is defined and relevant computing formulas are applied in detecting. New weight based distance metrics theory is proposed to detect feature envy bad smell. This improved approach can express more detailed design quality and invoking relationship than the original distance metrics theory. With these improvements the automation of bad smells detection can be achieved with high accuracy. And then the approach is applied to detect bad smells in JFreeChart open source code. The experimental results show that the weight based distance metrics theory can detect the bad smell more accurately with low time complexity.

With the increasing of software requirements, software is becoming larger and larger. It becomes an important problem to maintain the software. Thus understanding the program exactly, rapidly and comprehensively plays an important role. This paper has presented the related research of program comprehension, summarized six typical program comprehension strategies and compared these strategies.

Software errors can potentially lead to disastrous consequences. Unfortunately, debugging software errors can be difficult and time-consuming. A comprehension oriented software fault location approach (COFL) is proposed in this paper to provide automated assistance in bug location. It not only locates program predicates predicting bugs, but also provides high efficiency demand-driven data flow and control flow analysis to help developers understand the causes and contexts of bugs.

According to the background of network processor XDNP, this article describes a design of Fast Bus Interface(FBI) verification platform based on VMM architecture. All of the components and codes in the verification platform are achieved by SystemVerilog and assertions are also used in the process of verification. Through resonable usage of SVA it bacomes much easier to check out errors occuring in the executive process of FBI quickly and exactly. And then, the valuable functional verification results are obtained.

Code variations are widely believed to impede program analysis. This paper introduces a program normalization approach to remove code variations. Semantic-preserving transformations are performed on the system dependence graphs of programs. As a result, various syntactically different but semantically equivalent constructs are transformed to the same system dependence graph representation, so that code variations are removed. This approach establishes a good framework for testing the semantic equivalence of source codes and it can facilitate program analysis.