From stand-alone programs towards grid-aware services and components: a case study in agricultural modelling with interpolated climate data

We identify three key issues to be taken into account when designing the next generation of software environments for agricultural modelling. There is a burgeoning need to support collaborative research in a search for answers to big research questions, to integrate the work of data providers and model developers and to provide more generic systems. We describe the concepts of software design of a framework, designed with these points in mind, which facilitates the integration of point-based agricultural models with methods to interpolate climate data. Our approach allows the inter-working of model and interpolation through Fortran functions that are invoked from a central framework. We advocate that the framework code remains open to collaborators, such that it may be adapted to different classes of application, whilst recognising that some module developers need to retain their control on individual elements of the software. The rationale presented within the paper continues a major move away from the stand-alone programs that still dominate agricultural models and interpolation methods.Secondly, the paper considers how these approaches are extendable to exploit opportunities in the emerging Web Service and Grid context. The emerging technology of the Grid allows geographically distributed resources in hardware, software, data and network to be co-ordinated to meet the needs of “virtual organisations.” We explore how the modularity of our existing code can be exploited in the Grid environment, whilst noting the pre-requisite of a co-operative culture in which both software developers and data providers seek to deliver services to the widest possible community of users.     

第三代软件工程环境研究：一个可配置的开放式系统框架

关于软件工程环境有多种定义。E.Fedchak曾将其定义为“共同构成软件开发与支持框架的一组工具、结构、规则和方法(proeedures)的集合。”〔2〕。C.J.Tully在第九届国际软件工程年会(I CSEg)上又将软件工程环境定义为“为了获得更高的生产率和更高的产品质量,用于支持程序设计者、软件工程师、系统设计者和项目管理者等活动的一组计算机辅助设施。     

Modelling Off-the-Shelf Information Systems Requirements: An Ontological Approach

Requirements for choosing off-the-shelf information systems (OISR) differ from requirements for development of new information systems in that they do not necessarily provide complete specifications, thus allowing flexibility in matching an existing IS to the stated needs. We present a framework for OISR conceptual models that consists of four essential elements: business processes, business rules, information objects and required system services. We formalise the definitions of these concepts based on an ontological model. The ontology-based OISR model provides a framework to evaluate modelling languages on how appropriate they are for OISR requirements specifications. The evaluation framework is applied to the Object-Process Methodology, and its results are compared with a similar evaluation of ARIS. This comparison demonstrates the effectiveness of the ontological framework for evaluating modelling tools on how well they can guide selection, implementation and integration of purchased software packages.     

Architecture without numbers — CAAD based on a 3D modelling system

The paper describes an advanced demonstration system which brings together a number of recent developments in CAAD (computer-aided architectural design). This demonstration system illustrates how an important new form of input device, a 3D modelling systemm can be linked with building performance software and ‘indicative’ computer output graphics. The 3D modelling system uses electronically interrogable building elements. The user assembles these elements on a baseboard, providing a tangible model of the design. The model is then interrogated by the CAD system, which recovers the geometry data describing the topology of the model. The user changes the design by reassembling the model elements. A particular aspect of this demonstration is that the user has the option to generate building design data and assimilated building performance data without the need to handle this data in numeric form. It is likely that many of the features present in this demonstration system will be evident in future ‘production’ CAAD systems.     

Understanding and validating results in model-based decision support systems

This paper focuses on the issue of how to construct a software environment for modelling systems that enhances the usefulness of models as problem solving aids. The limitations of currently available modelling systems are explored and current approaches to overcoming these limitations are reviewed. A framework for the user-model interface of a model-based DSS is proposed that incorporates a range of powerful capabilities for aiding a user in interpreting, understanding, and validating model results.     

A framework for creating hybrid-open source software communities

Abstract The open source software (OSS) model is a fundamentally new and revolutionary way to develop software. The success of the OSS model is also setting the stage for a structural change in the software industry; it is beginning to transform software industry from manufacturing to a service industry. Despite the success of the OSS model, for‐profit organizations are having difficulty building a business model around the open source paradigm. Whereas there are some isolated empirical studies, little rigorous research has been done on how traditional organizations can implement and benefit from OSS practices. This research explores how organizations can foster an environment similar to OSS to manage their software development efforts to reap its numerous advantages. Drawing on organizational theory, we develop a framework that guides the creation and management of a hybrid‐OSS community within an organization. We discuss the implications of this framework and suggest areas for future research.     

Bond graph aided design of controlled systems

An active or controlled system is generally composed of two parts: a passive basis and a control architecture containing actuators and sensors. When dealing with such a system, the first point usually considered is the study of the system without control. To do this, we need a model in order to get simulation-based results on the frequency domain and dynamical behaviour for dimensioning purpose. The second step is then to design a control architecture, with its actuators and sensors, specified in a way allowing the objectives to be reached as accurately and cheaply as possible. Since many years, the bond graph methodology has shown its qualities for modelling and generation of physical insight, specially when applied to multidisciplinary systems. The aim of this paper is to show how a bond graph model may be used for analysis of structural properties, i.e., properties depending only on the model structure and on the type of elements composing it, but not on the numerical values of the parameters. The properties pointed out in this way are generic, and can be used for “integrated design”, i.e., the simultaneous design of the passive system model, its control architecture and control laws for specific aims. The proposed methodology depends on causal manipulations on the bond graph model (assignment of integral and derivative causality, causal path and loops); its application may necessitate a return to the model in order to check and sometimes modify the modelling hypotheses. The proposed procedure is implemented on an example, which will be the guideline of the presentation.     

Software defined cloud: Survey,system and evaluation

Next generation cloud systems will require a paradigm shift in how they are constructed and managed. Conventional control and management platforms are facing considerable challenges regarding flexibility, dependability and security that next generation systems must handle. The cloud computing technology has already contributed in alleviating a number of the problems associated with resource allocation, utilization and management. However, many of the elements of a well-designed cloud environment remain “stiff” and hard to modify and adapt in an integrated fashion. This includes the underlying networking topologies, many aspects of the user control over IaaS, PaaS or SaaS layers, construction of XaaS services, provenance and meta-data collection, to mention but few. In many situations the problem may be due to inadequacy of service abstraction. Software Defined Systems (SDSys) is a concept that help abstract the actual hardware at different layers with software components; one classical example of this abstractions are hypervisors. Such abstraction provides an opportunity for system administrators to construct and manage their systems, more easily, through flexible software layers. SDSys is an umbrella for different software defined subsystems including Software Defined Networking (SDN), Software Defined Storage (SDStorage), Software Defined Servers (Virtualization), Software Defined Data Centers (SDDC), Software Defined Security (SDSec) etc. and ultimately Software Defined Clouds (SDCloud). Individual solutions and seamless integration of these different abstractions remains in many respects a challenge. In this paper, the authors introduce Software Defined Cloud (SDCloud), a novel software defined cloud management framework that integrates different software defined cloud components to handle complexities associated with cloud computing systems. The first part of paper presents, for the first time, an extensive state of the art critical review of different components of software defined systems, constructing the proposed SDCloud. The second part of the paper proposes the novel concept of SDCloud, which is implemented and evaluated for its feasibility, flexibility and potential superiority.     

基于EFI的USB设备驱动的开发

可扩展固件接口(EFI)是英特尔提出的下一代BIOS的全新架构,将会逐步取代现有的BIOS.EFI提供了对USB设备的支持,用户无需进入操作系统,就可以使用USB设备.以USB设备驱动程序开发为例,描述了EFI下设备驱动程序开发的一般过程和方法.包括EFI下驱动模式的分析,USB协议架构和传送方式的解析,以及如何开发EFI下的USB设备驱动程序.     

Visualization of geometric algorithms

Investigates the visualization of geometric algorithms. We discuss how limiting the domain makes it possible to create a system that enables others to use it easily. Knowledge about the domain can be very helpful in building a system which automates large parts of the user's task. A system can be designed to isolate the user from any concern about how graphics is done. The application need only specify “what” happens and need not be concerned with “how” to make it happen on the screen. We develop a conceptual model and a framework for experimenting with it. We also present a system, GASP (Geometric Animation System, Princeton), which implements this model. GASP allows quick generation of 3D geometric algorithm visualizations, even for highly complex algorithms. It also provides a visual debugging facility for geometric computing. We show the utility of GASP by presenting a variety of examples     

Investigating ARIMA models of software system quality

In this paper, we investigate how to incorporate program complexity measures with a software quality model. We collect software complexity metrics and fault counts from each build during the testing phase of a large commercial software system. Though the data are limited in quantity, we are able to predict the number of faults in the next build. The technique we used is called times series analysis and forecasting. The methodology assumes that future predictions are based on the history of past observations. We will show that the combined complexity quality model is an improvement over the simpler quality only model. Finally, we explore how the testing process used in this development may be improved by using these predictions and suggest areas for future research.     

SUMLOW: early design‐stage sketching of UML diagrams on an E‐whiteboard

Most visual diagramming tools provide point‐and‐click construction of computer‐drawn diagram elements using a conventional desktop computer and mouse. SUMLOW is a unified modelling language (UML) diagramming tool that uses an electronic whiteboard (E‐whiteboard) and sketching‐based user interface to support collaborative software design. SUMLOW allows designers to sketch UML constructs, mixing different UML diagram elements, diagram annotations, and hand‐drawn text. A key novelty of the tool is the preservation of hand‐drawn diagrams and support for manipulation of these sketches using pen‐based actions. Sketched diagrams can be automatically ‘formalized’ into computer‐recognized and ‐drawn UML diagrams and then exported to a third party CASE tool for further extension and use. We describe the motivation for SUMLOW, illustrate the use of the tool to sketch various UML diagram types, describe its key architecture abstractions and implementation approaches, and report on two evaluations of the toolset. We hope that our experiences will be useful for others developing sketching‐based design tools or those looking to leverage pen‐based interfaces in software applications. Copyright © 2007 John Wiley & Sons, Ltd.     

Improving bi-manual 3D input in CAD modelling by part rotation optimisation

Part modelling in a CAD environment requires a bi-manual 3D input interface to fully exploit its potentialities. In this research we provide extensive user tests on bi-manual modelling using different devices to control 3D model’s rotation. Our results suggest that a simple trackball device is effective when the user task is mostly limited to rotation control (i.e. when modelling parts in a CAD environment). In our tests, performances are even better than those achieved with a specifically designed device. Since the task of rotating a CAD part often shows the need of flipping the controlled object, we introduce a non linear transfer function which combines the precision of a zero order control mode with the ability to recognise fast movements. This new modality shows a significant improvement in the user’s performances and candidates itself for integration in next generation CAD interfaces.     

跨平台自动测试系统标准信息框架研究

以未来一体化的新型综合装备保障性发展的需求为背景,分析了跨平台自动测试技术体系的研究内容和技术特点,重点论述了跨平台自动测试系统信息框架构建的意义及构建策略,以及如何将该信息框架应用于跨平台自动测试平台,最后阐述了跨平台自动测试系统软环境的初步构架方案.     

A quality‐of‐service‐based framework for creating distributed heterogeneous software components

Component‐based software development offers a promising solution for taming the complexity found in today's distributed applications. Today's and future distributed software systems will certainly require combining heterogeneous software components that are geographically dispersed. For the successful deployment of such a software system, it is necessary that its realization, based on assembling heterogeneous components, not only meets the functional requirements, but also satisfies the non‐functional criteria such as the desired quality of service (QoS). In this paper, a framework based on the notions of a meta‐component model, a generative domain model and QoS parameters is described. A formal specification based on two‐level grammar is used to represent these notions in a tightly integrated way so that QoS becomes a part of the generative domain model. A simple case study is described in the context of this framework. Copyright © 2002 John Wiley & Sons, Ltd.     

Consistent Modelling of Users, Devices and Sensors in a Ubiquitous Computing Environment

This paper describes the use of an accretion-resolution user modelling representation to model people, places and objects. We explain the motivation for the key properties of the representation, especially those of particular importance for ubiquitous computing: firstly, for flexibility in interpreting the typically noisy and potentially conflicting evidence about users’ locations; secondly, to support users in scrutinising their user model, the processes that determine its contents and the way that it is used in the ubiquitous computing environment. A novel and important aspect of this work is our extension of the representation beyond modelling just users, using it also to represent the other elements such as devices, sensors, rooms and buildings. We illustrate our approach in terms of models we have been building for a system which enables users to gain personalised information about the sensors and services in a ubiquitous computing environment. We report experiments on the scalability and the management of inconsistency in modelling of location, based on accretion-resolution