Distributed simulation of building systems for legacy software reuse

The use of integrated building performance simulation can substantially help in improving a building design with regards to comfort levels and fuel consumption, while reducing emission of greenhouse gasses. However, the traditional tools that are closed for inter-communication, limit the modeler to use of components only available within that particular package. This paper gives an overview of distributed simulation approach that can alleviate above limitation. Each program can represent only a part of a building system that is able to model, exchanging the necessary information during the execution and bridging the gaps between the tools. Several important issues closely connected with its implementation, such as synchronization, are pointed out, and the sensitivity of a model on different coupling strategies is studied. The paper concludes with highlighting the gained flexibility in modeling and simulation of building performance that arises from the distributed approach

Development of an online collaborative working environment for design and manufacturing

This research is to develop a novel collaborative working environment (CWE) for manufacturing and design using advanced Web/Internet technologies such as Web Service, Grid Service and other related software tools/packages. To achieve the above, the following research modules are developed by the author: A service oriented framework for computer aid design, which acts as an online collaboration system, has been developed with the utilisation of the latest technology, Web Service. The concept of Service-Oriented Architecture has been implemented in the framework. Users from anywhere in the world can join the design process from their PCs, no matter what operation system they are using. The service-oriented system has the capability of going through firewalls and can afford multi-users due to the characteristics of Web service. Also the loose-coupling structure makes the system very easy to be updated. Another module for the CWE is to solve the software sharing problem when the platform is used among several geographically dispersed users or organisations. A software package bank system has been developed, which utilised the ideology of service oriented approach and successfully solved traditional problems in this field. Based on the outcomes mentioned above, the research finally developed a more powerful infrastructure using Grid service, which is a further development of Grid computing and Web service. The Grid service is considered to be the most important future solvent for Internet

Visual programming environments for multi-disciplinary distributed applications

A Problem Solving Environment is a complete, integrated computing environment for composing, compiling and running applications in a specific problem area or domain. A Visual Programming Environment is one possible front end to a problem solving environment. It applies the visual programming paradigms of "point and click" and "drag and drop", via a Graphical User Interface, to the various constituent components that are used to assemble an application. The aim of the problem solving environment presented here is to provide the ability to build up scientific applications by connecting, or plugging, software components together and to provide an intuitive way to construct scientific applications. Problem solving environments promise a totally new user environment for computational scientists and engineers. In this new paradigm, individual programs combined to solve a problem in their given area of expertise, are wrapped as components within an integrated system that is both powerful and easy to use. This thesis aims to address: problems in code reuse the combination of different codes in new ways and problems with underlying system familiarity and distribution. This is achieved by abstracting application composition using visual programming techniques. The work here focuses on a prototype environment using a number of demonstration problems from multi-disciplinary problem domains to illustrate some of the main difficulties in building problem solving environments and some possible solutions. A novel approach to code wrapping, component definition and application specification is shown, together with timing and usage comparisons that illustrate that this approach can be used successfully to help scientists and engineers in their daily work.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

An agent-based service-oriented approach to evolving legacy software systems into a pervasive computing environment.

This thesis focuses on an Agent-Based Service-Oriented approach to evolving legacy system into a Pervasive Computing environment. The methodology consists of multiple phases: using reverse engineering techniques to comprehend and decompose legacy systems, employing XML and Web Services to transform and represent a legacy system as pervasive services, and integrating these pervasive services into pervasive computing environments with agent based integration technology. A legacy intelligent building system is used as a case study for experiments with the approach, which demonstrates that the proposed approach has the ability to evolve legacy systems into pervasive service environments seamlessly. Conclusion is drawn based on analysis and further research directions are also discussed

A mechanism for creating web service interface to scientific applications.

Science is becoming increasingly multi-disciplinary and complicated. To solve complex scientific problems, we often need to integrate software and customize workflows to suit a particular problem. To make progress on key scientific issues, extended scientific collaborations are growingly dependent on complex workflows for data analysis and simulation. Service Oriented Architecture has gained popularity in recent years within scientific research community. It has been broadly accepted as a means of structuring interactions among distributed software services. Service Oriented Architecture is a new paradigm for accessing, integrating and coordinating loosely coupled software systems in a standardized way. It aims to reduce the cost of building and maintaining complex software systems while increasing their re-usability. However, most of the large industrial and scientific applications available today were written well before the introduction of Grid computing and Service Oriented Architectures. Hence, they are neither service oriented nor Grid-aware. There is a growing need to integrate them into Grid-aware applications based on Service Oriented Architecture. How to integrate these legacy applications into the Grid with the least possible effort and the best performance has become a crucial point. The majority of the applications developed and used by scientific communities are command-line applications. They are written in FORTRAN, C, and a host of scripting languages. In addition to being fast and efficient, these applications represent state-of- the-art science; however, they are bound by many limitations which make it difficult to compose complex workflows from them and run them on a distributed set of resources. By converting these command-line legacy applications into Application Services, it becomes easy to compose complex workflows from them and run them on the distributed resources. There are some research programs aiming at integrating the legacy codes into Grid infrastructure. Some frameworks have been developed to compose and run scientific workflows on a Grid. A number of systems are available to allow scientists to Grid- enabling their existing applications without having to write extra code or modify their applications. But most of them do not provide a toolkit for wrapping an application as a Grid-aware Web service. Few of the systems have addressed the issue of security. This thesis presents an approach to reducing the required effort needed in developing Application Services for end users. Also during the execution of complex scientific workflows, Application Services often become unavailable primarily due to the unreliable nature of the resources that host them. When an Application Service becomes unavailable, all workflows that are accessing it have to stop, and this means wasting a great deal of time and resources. This thesis offers a new solution to this problem, via providing a mechanism by which Application Service can be created on-demand from workflows in case it is unavailable

HVAC system simulation: overview, issues and some solutions

Integrated performance simulation of buildings’ heating, ventilation and air-conditioning (HVAC) systems can help in reducing energy consumption and increasing occupant comfort. Recognizing this fact, in the last forty years many tools have been developed to help achieving this goal. In this paper we introduce a categorization of these tools with respect to which problems they are meant to deal with and summarize current approaches used for modelling (i) HVAC components, (ii) HVAC control and (iii) HVAC systems in general. Further in this paper, we list issues associated with applications of HVAC modelling and simulation. Finally, we present and discuss co-simulation as one of solutions that can alleviate some of the recognized issues