The ASC-Alliance Projects: A Case Study of Large-Scale Parallel Scientific Code Development

Computational scientists face many challenges when developing software that runs on large-scale parallel machines. However, software-engineering researchers haven't studied their software development processes in much detail. To better understand the nature of software development in this context, the authors examined five large-scale computational science software projects operated at the five ASC-Alliance centers.     

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。     

Albero: A Visual Analytics Approach for Probabilistic Weather Forecasting

Probabilistic weather forecasts are amongst the most popular ways to quantify numerical forecast uncertainties. The analog regression method can quantify uncertainties and express them as probabilities. The method comprises the analysis of errors from a large database of past forecasts generated with a specific numerical model and observational data. Current visualization tools based on this method are essentially automated and provide limited analysis capabilities. In this paper, we propose a novel approach that breaks down the automatic process using the experience and knowledge of the users and creates a new interactive visual workflow. Our approach allows forecasters to study probabilistic forecasts, their inner analogs and observations, their associated spatial errors, and additional statistical information by means of coordinated and linked views. We designed the presented solution following a participatory methodology together with domain experts. Several meteorologists with different backgrounds validated the approach. Two case studies illustrate the capabilities of our solution. It successfully facilitates the analysis of uncertainty and systematic model biases for improved decision‐making and process‐quality measurements.     

相似代码检测工具及其案例分析

软件系统中的相似代码给软件维护带来很大困难,也是最易见的重构对象。如何有效地检测相似代码是软件工程领域的一个重要研究课题。本文介绍了常见的基于文本匹配的相似代码检测算法,尤其是检测源文件之间相似代码的动态文本匹配算法和源文件内部相似代码的后缀树算法,并将这两种算法结合起来,实现一个相似代码检测工具。该工具提供了时空代价平衡的相似代码检测能力,提供了精确有效的相似代码检测手段,帮助开发人员锁定相似代码,提高了重构活动的效率。本文介绍了该工具的架构和内部处理流程,并应用该工具搜索了若干实际应用系统的重复代码,检验了工具的可用性。还简单讨论了该工具和其他一些相似代码检测工具的优劣。     

一种相位编码算法在气象雷达中的应用

描述一种被称为SZ相位编码的解距离模糊方法在脉冲多普勒气象雷达中的应用．首先给出了该方法应用到某气象雷达上所采用的系统框图；然后介绍了SZ相位编码的原理和编码序列以及基于这种编码给出了气象雷达解距离模糊算法的详细流程，并着重介绍了频谱重构的频域处理方法；最后给出了用该方法同时解出一次和二次气象回波的Matlab仿真，结果表明该方法对平均速度的估算较为准确．     

Evaluation of Environments for Portals Development: A Case Study

With the growing application of the Internet, business portal software is becoming increasingly complex given the wide variety of technologies it must integrate. It is therefore most important to have development environments that enable this type of software to be built efficiently. This justifies the need to evaluate the quality of business portal development environments.

The objective of this article is to propose the definition of a quality model for business portal development environments, based on ISO/IEC 9126, with the appropriate metrics for estimating quality. the estimation model was evaluated through a case study using a commercial business portal development environment. the rational unified process (RUP) methodology was chosen to build a business portal prototype.     

Agile Project Management: A Case Study of a Virtual Research Environment Development Project

In this paper we use a case study of a project to create a Web 2.0-based, Virtual Research Environment (VRE) for researchers to share digital resources in order to reflect on the principles and practices for embedding eResearch applications within user communities. In particular, we focus on the software development methodologies and project management techniques adopted by the project team in order to ensure that the project remained responsive to changing user requirements without compromising their capacity to keep the project ‘on track’, i.e. meeting the goals declared in the project proposal within budget and on time. Drawing on ethnographic fieldwork, we describe how the project team, whose members are distributed across multiple sites (and often mobile), exploit a repertoire of coordination mechanisms, communication modes and tools, artefacts and structuring devices as they seek to establish the orderly running of the project while following an agile, user-centred development approach.     

Linking Model-Driven Development and Software Architecture: A Case Study

A basic premise of Model Driven Development (MDD) is to capture all important design information in a set of formal or semi-formal models which are then automatically kept consistent by tools. The concept however is still relatively immature and there is little by way of empirically validated guidelines. In this paper we report on the use of MDD on a significant real-world project over several years. Our research found the MDD approach to be deficient in terms of modelling architectural design rules. Furthermore, the current body of literature does not offer a satisfactory solution as to how architectural design rules should be modelled. As a result developers have to rely on time-consuming and error-prone manual practices to keep a system consistent with its architecture. To realise the full benefits of MDD it is important to find ways of formalizing architectural design rules which then allow automatic enforcement of the architecture on the system model. Without this, architectural enforcement will remain a bottleneck in large MDD projects.     

A Support Vector Machine Based Approach for Forecasting of Network Weather Services

We present forecasting related results using a recently introduced technique called Support Vector Machines (SVM) for measurements of processing, memory, disk space, communication latency and bandwidth derived from Network Weather Services (NWS). We then compare the performance of support vector machines with the forecasting techniques existing in network weather services using a set of metrics like mean absolute error, mean square error among others. The models are used to make predictions for several future time steps as against the present network weather services method of just the immediate future time step. The number of future time steps for which the prediction is done is referred to as the depth of prediction set. The support vector machines forecasts are found to be more accurate and outperform the existing methods. The performance improvement using support vector machines becomes more pronounced as the depth of the prediction set increases. The data gathered is from a production environment (i.e., non-experimental).     

Visualization of Neural Network Predictions for Weather Forecasting

Recurrent neural networks are prime candidates for learning evolutions in multi‐dimensional time series data. The performance of such a network is judged by the loss function, which is aggregated into a scalar value that decreases during training. Observing only this number hides the variation that occurs within the typically large training and testing data sets. Understanding these variations is of highest importance to adjust network hyper‐parameters, such as the number of neurons, number of layers or to adjust the training set to include more representative examples. In this paper, we design a comprehensive and interactive system that allows users to study the output of recurrent neural networks on both the complete training data and testing data. We follow a coarse‐to‐fine strategy, providing overviews of annual, monthly and daily patterns in the time series and directly support a comparison of different hyper‐parameter settings. We applied our method to a recurrent convolutional neural network that was trained and tested on 25 years of climate data to forecast meteorological attributes, such as temperature, pressure and wind velocity. We further visualize the quality of the forecasting models, when applied to various locations on the Earth and we examine the combination of several forecasting models.     

Toward a Service-Oriented Development Through a Case Study

The rapidly emerging technology of Web services paves a new cost-effective way of engineering software to quickly develop and deploy Web applications by dynamically integrating other independently developed Web-service components to conduct new business transactions. This paper reports our efforts on designing and developing a Web service of pass-through authentication (PTA) for 12 online electronic-payment Web applications. In accordance with how a PTA service is developed and integrated with a corresponding back-end e-payment system, our strategies can be categorized in three stages: end-to-end integration stage, Web-services-enabled stage, and Web-services-oriented stage. Derived from real-world industrial experience, this three-stage pathway can be applied to a broad range of Web-application development projects to guide smooth transformation from a specific application-oriented design and development model toward a reusable Web-services-oriented model. Furthermore, this paper contributes to an engineering process that leads to practical Web-services-oriented software development. New research issues revealed by this project are also reported.     

CASA and LEAD: Adaptive Cyberinfrastructure for Real-Time Multiscale Weather Forecasting

Two closely linked projects aim to dramatically improve storm forecasting speed and accuracy. CASA is creating a distributed, collaborative, adaptive sensor network of low-power, high-resolution radars that respond to user needs. LEAD offers dynamic workflow orchestration and data management in a Web services framework designed to support on-demand, real-time, dynamically adaptive systems     

Developing a Culture of Privacy: A Case Study

In building a culture of privacy, an organization must clearly articulate privacy as an organizational priority; communicate key privacy and security messages; educate across the organization; raise awareness of the importance of registering privacy incidents and breaches; build privacy into the fabric of the organization's activities; and make privacy information and guidance readily accessible. Accomplishing these objectives provides a framework to create or reinforce a privacy culture. In 2003, the province of Ontario, Canada, created the smart systems for health agency (SSHA) to connect healthcare professionals across the province.     

Quantitative Analysis of Development Defects to Guide Testing: A Case Study

Many quality improvement activities can be guided by defect analysis. Development defect analysis of software components can be used to guide testing with the goal of focusing on parts of the software that were fault-prone during development. We perform a case study using defect data from a large software product (medical record system). In this study, development defect data help to identify which parts of the software might profit from being tested more and earlier because they were fault-prone during development. Several testing guidelines are proposed to make system test more effective and more efficient.     

代码审查在软件开发中的应用研究

介绍了代码审查的定义、内涵、分类。讨论了代码审查的条件、步骤和注意事项。最后,结合软件项目开发,总结了代码审查后代码要达到的标准。对软件项目开发过程中进行代码审查具有较强的指导意义。     

Android智能手机天气预报系统设计及实现

在分析讨论Android应用系统设计原理的基础上,提出了Android智能手机天气实况预报系统用户界面以及获取并解析城市列表数据的设计方法,给出了在用户界面上呈现列表数据的设计过程,实现了一个简单的Android智能手机城市天气实况预报系统.系统在模拟器上通过调试并正常运行.     

一种用于机场气象预测的模糊神经网络模型

针对民用机场多因素气象预测问题的复杂性,该文构建出一种基于粗糙集的模糊神经网络模型。采用粗糙集理论约简属性,挖掘潜在规则,在此基础上建立模糊神经网络模型,并根据规则的统计性质和离散化结果初始化网络参数,采用BP算法训练网络。实例验证,该模型在收敛速度与预测精度上优于传统的神经网络模型。     

Visual Analysis of Spatio‐Temporal Data: Applications in Weather Forecasting

Weather conditions affect multiple aspects of human life such as economy, safety, security, and social activities. For this reason, weather forecast plays a major role in society. Currently weather forecasts are based on Numerical Weather Prediction (NWP) models that generate a representation of the atmospheric flow. Interactive visualization of geo‐spatial data has been widely used in order to facilitate the analysis of NWP models. This paper presents a visualization system for the analysis of spatio‐temporal patterns in short‐term weather forecasts. For this purpose, we provide an interactive visualization interface that guides users from simple visual overviews to more advanced visualization techniques. Our solution presents multiple views that include a timeline with geo‐referenced maps, an integrated webmap view, a forecast operation tool, a curve‐pattern selector, spatial filters, and a linked meteogram. Two key contributions of this work are the timeline with geo‐referenced maps and the curve‐pattern selector. The latter provides novel functionality that allows users to specify and search for meaningful patterns in the data. The visual interface of our solution allows users to detect both possible weather trends and errors in the weather forecast model. We illustrate the usage of our solution with a series of case studies that were designed and validated in collaboration with domain experts.     

Modularization of a Large-Scale Business Application: A Case Study

Large software systems, developed over several years, are the backbone of industries such as banking, retail, transportation, and telecommunications. With multiple bug fixes and feature enhancements, these systems gradually deviate from the intended architecture and deteriorate into unmanageable monoliths. This article presents a case study of a banking application besot with such problems and the modularization approach that the company adopted as a solution. It also highlights benefits unearthed as a result of this reengineering exercise.     

An Indigenous Process of Pedagogic Innovation: A Case Study on Curriculum Development

We describe our attempts at curriculum development at the undergraduate level working within the constraints of a large traditional university system. Curriculum reform is described as a three-step process of product innovation, accommodation and assimilation. In a dual-pronged strategy, students are constructively engaged, first, in investigative projects and assigned specific tasks, giving them a flavour of creative research, and, second, in development of curricular products. The process of transfer of pedagogic innovations into the formal classroom is enhanced by a teacher training programme that aims to provide experiential learning of research-based innovative teaching practices, catalyse a process of reflection through classroom research and establish a collaborative network of teachers.