摘要：A description of the Systems Dynamics paradigm is given and the reduced Qualitative System Dynamics (QSD) form explained. A simple example is given to illustrate the diagram construction. The principles of states (levels), rates and feedback loops are outlined. The QSD method is used to address the problem of accessibility by using human control of automation as an example, and applying the QSD method to evaluate the effects of the researcher and user in the de- sign of an accessible artefact. This simple automation model illustrates what can be found out from such a picture, in this indicating how the feedback from users has an influence on the time to deliver such designs.

摘要：Pair Programming (PP) that has gained extensive focus within pedagogical and industrial environments is a programming practice in which two programmers use the same computer to work together on analysis, design, and programming of the same segment of code. Distributed Pair Programming (DPP) system is a programming system to aid two programmers, the driver and the navigator, to finish a common task such as analysis, design and programming on the same software from different locations. This paper first reviews the existing DPP tools and discusses the interaction and coordination mechanism in DPP process. By means of activity theory and language-action theory, some basic requirements of the DPP system are presented. Then, a design framework of such system and functions of each sub-system are deeply analyzed. Finally, a system prototype is implemented by plug-in style in Microsoft Visual Studio environment.

摘要：Requirements of a system keep on changing based on the need of stakeholders or the system developers, making requirement engineering an important aspect in software development. This develops a need for appropriate requirement change management. The importance of requirements traceability is defining relationships between the requirements and artefacts extracted by the stakeholder during the software development life-cycle and gives vital information to encourage software understanding. In this paper, we have concentrated on developing a tool for requirement traceability that can be used to extend the requirement elicitation and identification of system-wide qualities using the notion of quality attribute scenarios to capture the non-functional requirements. It allows us to link the functional and non-functional requirements of the system based on the quality attribute scenarios template proposed by the Carnegie Mellon software Engineering Institute (SEI). Apart from this, the paper focuses on tracing the functional and non-functional requirements of the system using the concept of requirement traceability matrix.

摘要：In Brazil, the use of software and applications in railway geometric designs is rare. Currently, after the division and privatization of the national rail network, the concessionaires who assumed the administration, are investing in modernization, recovery and extension of this transport model to make it more efficient. The PIL （Program of Investment in Logistics） has generated growth of the sector in response to the amount of investments, greatly enhancing the load capacity and optimizing the geometric design, which would allow speed of 80 km/h. Based on this information, the objective of this research is to verify the software applications of Power Rail Track Program of Bentley Systems, Inc. for geometric designs in future deployments of railways in Brazil. This software is based on numerical calculations, including roller adjustment by the least squares method to calculate and choose the best alignments, and regression tools, to a fast and effectively optimization of various parameters of the geometry for a future or existing railway. Different variables that allow you to optimize the geometric design are analyzed, considering several optional alignments and complex restrictions present in geometric design, taking into account variables such as circular curves, transition, tangents and rays. The software regression tools include curvature diagrams identifying points and curves, tangent and spirals. The analysis results are presented quickly and points can be added or deleted from the regression analysis, providing improved tracing. The software also allows to detail the elements of the executive project of the railway line such as rails, joints, turning points, waypoints and others. The result of this study has shown that the application of the Power Rail Track Program generates significant cost savings in time and increases in productivity, providing greater opportunity to optimize the geometry and reducing geometric design costs.

摘要：Taking a specific production process as an example, this paper introduces the design of multi slot and unequal temperature PID controller based on single chip microcomputer. The mathematical implementation method of PID algorithm and the design method of the hardware and software are discussed, The principle diagram of the hardware circuit implementing the control algorithm and the features of the software possessed are also presented.

摘要：The quality factor of class diagram is critical because it has a significant influence on overall quality of the product, delivered finally. Testability analysis, when done early in the software creation process, is a criterion of critical importance to software quality. Reusability is an important quality factor to testability. Its early measurement in object oriented software especially at design phase, allows a design to be reapplied to a new problem without much extra effort. This research paper proposes a research framework for quantification process and does an extensive review on reusability of object oriented software. A metrics based model “Reusability Quantification of Object Oriented Design” has been proposed by establishing the relationship among design properties and reusability and justifying the correlation with the help of statistical measures. Also, “Reusability Quantification Model” is empirically validated and contextual significance of the study shows the high correlation for model acceptance. This research paper facilitates to software developers and designer, the inclusion of reusability quantification model to access and quantify software reusability for quality product.

摘要：Detecting well-known design patterns in object-oriented program source code can help maintainers understand the design of a program. Through the detection, the understandability, maintainability, and reusability of object-oriented programs can be improved. There are automated detection techniques;however, many existing techniques are based on static analysis and use strict conditions composed on class structure data. Hence, it is difficult for them to detect and distinguish design patterns in which the class structures are similar. Moreover, it is difficult for them to deal with diversity in design pattern applications. To solve these problems in existing techniques, we propose a design pattern detection technique using source code metrics and machine learning. Our technique judges candidates for the roles that compose design patterns by using machine learning and measurements of several metrics, and it detects design patterns by analyzing the relations between candidates. It suppresses false negatives and distinguishes patterns in which the class structures are similar. As a result of experimental evaluations with a set of programs, we confirmed that our technique is more accurate than two conventional techniques.

摘要：In this paper, we investigate empirically the relationship between object-oriented design metrics and testability of classes. We address testability from the point of view of unit testing effort. We collected data from three open source Java software systems for which JUnit test cases exist. To capture the testing effort of classes, we used metrics to quantify the corresponding JUnit test cases. Classes were classified, according to the required unit testing effort, in two categories: high and low. In order to evaluate the relationship between object-oriented design metrics and unit testing effort of classes, we used logistic regression methods. We used the univariate logistic regression analysis to evaluate the individual effect of each metric on the unit testing effort of classes. The multivariate logistic regression analysis was used to explore the combined effect of the metrics. The performance of the prediction models was evaluated using Receiver Operating Characteristic analysis. The results indicate that: 1) complexity, size, cohesion and (to some extent) coupling were found significant predictors of the unit testing effort of classes and 2) multivariate regression models based on object-oriented design metrics are able to accurately predict the unit testing effort of classes.

摘要：In order to overcome the main drawbacks of coaxial, waveguide, and stripline couplers, the analysis and the design of a compact coaxial-to-microstrip directional coupler convenient for power and antenna control application, are presented using the method of moments (MoM) in two dimensions. This technique is adapted to study the complex configuration of the line’s system, which does not have a simple analytical solution. The modeling of this structure consists in analyzing the primary inductive and capacitive matrices ([L] and [C]). When these matrices are determined, it is possible to calculate the inductive and capacitive coupling coefficients (kL and kC) and estimate the resulting scattering parameters of the coupler using an adapted numerical model. The coupler can be integrated into a printed circuit board (PCB) and operates over 17 to 35 dB coupling coefficients and is always compensated. The compensation is achieved by the proper displacement of a tuning ground plane with respect to the edge of the PCB from 0.1 to 3.3 mm. As an application, we present the design of a compact coupler with 7.5 × 4.8 × 25.8 mm of size and having approximately 20 dB of coupling coefficient at 2 GHz and a minimum directivity of 23.3 dB in the frequency range [0.1 - 4] GHz. In order to check our numerical calculations by the MoM we made simulations in 3D by using CST MICROWAVE STUDIO software for the same geometrical and physical parameters of our designed coupler. The results obtained by the two numerical models (MoM and CST) show a good agreement of the frequency responses of the coaxial-to-microstrip directional coupler. The studied structure represents a great improvement for high power measurement systems, since it has broad-band, good directivity, and can be easily designed and fabricated.

摘要：Ground Source Heat Pump technique and its operating principle are described in this paper. Ground heat exchanger is the key technique of ground source heat pump and its patterns are discussed. software is helpful to design ground heat exchanger. A project of Chinese Ground Source Heat Pump is introduced and its market is more and more extensive.