Data mining for decision making in engineering optimal design

Often in modeling the engineering optimization design problems, the value of objective function(s) is not clearly defined in terms of design variables. Instead it is obtained by some numerical analysis such as FE structural analysis, fluid mechanic analysis, and thermodynamic analysis, etc. Yet, the numerical analyses are considerably time consuming to obtain the final value of objective function(s). For the reason of reducing the number of analyses as few as possible our methodology works as a supporting tool to the meta-models. The research in meta-modeling for multiobjective optimization are relatively young and there is still much to do. Here is shown that visualizing the problem on the basis of the randomly sampled geometrical big-data of computer aided design (CAD) and computer aided engineering (CAE) simulation results, combined with utilizing classification tool of data mining could be effective as a supporting system to the available meta-modeling approaches. To evaluate the effectiveness of the proposed method a study case in 3D wing optimal design is given. Along with the study case, it is discussed that how effective the proposed methodology could be in further practical engineering design problems

Constructive tool design for formal languages : from semantics to executing models

Embedded, distributed, real-time, electronic systems are becoming more and more dominant in our lives. Hidden in cars, televisions, mp3-players, mobile phones and other appliances, these hardware/software systems influence our daily activities. Their design can be a huge effort and has to be carried out by engineers in a limited amount of time. Computer-aided modelling and design automation shorten the design cycle of these systems enabling companies to deliver their products sooner than their competitors. The design process is divided into different levels of abstraction, starting with a vague product idea (abstract) and ending up with a concrete description ready for implementation. Recently, research has started to focus on the system level, being a promising new area at which the product design could start. This dissertation develops a constructive approach to building tools for system-level design/description/modelling/specification languages, and shows the applicability of this method to the system-level language POOSL (Parallel Object-Oriented Specification Language). The formal semantics of this language is redefined and partly redeveloped, adding probabilistic features, real-time, inheritance, concurrency within processes, dynamic ports and atomic (indivisible) expressions, making the language suitable for performance analysis/modelling. The semantics is two-layered, using a probabilistic denotational semantics for stating the meaning of POOSL’s data layer, and using a probabilistic structural operational semantics for the process layer and architecture layer. The constructive approach has yielded the system-level simulation tool rotalumis, capable of executing large industrial designs, which has been demonstrated by two successful case studies—an ATM-packet switch (in conjunction with IBM Research at Z¨urich) and a packet routing switch for the Internet (in association with Alcatel/Bell at Antwerp). The more generally applicable optimisations of the execution engine (rotalumis) and the decisions taken in its design are discussed in full detail. Prototyping, where the system-level model functions as a part of the prototype implementation of the designed product, is supported by rotalumis-rt, a real-time variant of the execution engine. The viability of prototyping is shown by a case study of a learning infrared remote control, partially realised in hardware and completed with a system-level model. Keywords formal languages / formal specification / modelling languages / systemlevel design / embedded systems / real-time systems / performance analysis / discrete event simulation / probabilistic process algebra / design automation / prototyping / simulation tool

Dynamic integrated modelling of information systems and business process simulation

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Business processes and information technology are two areas that are very closely related to the sustained competitive advantage in organisations. However, investment in information technology often leads to disappointment, which may in part be due to the non-alignment of the information system domain with the business process domain. Simulation modelling is an established technique often used in business process change projects, as it allows a comparison of different possible scenarios without the expense of physically implementing the system. However business process simulation fails to effectively capture the information systems perspective in the model. This thesis contends that by combining information systems modelling techniques with business process simulation the model will be able to capture all the four perspectives (functional, behavioural, organisational and informational) of an organisation, and the design of the business processes and the information system will be better aligned. Initially, attempts were made to integrate business process simulation with computer network simulation in a simple two- or three-layered simulation model, but this gave rise to significant problems the most significant being the underlying assumptions of the original hypothesis. This led to a refined hypothesis in which the layered models were discarded along with the network domain. The revised hypothesis aimed to capture the informational changes that occur in the information system and therefore combines prototyping with business process simulation. This overcomes the unsafe assumptions of the initial hypothesis about whether the system is 'correct' and provides a method of validating the design of the information system within the context of the business processes. The integrated model allows concurrent design of the information system domain and the business process domain and therefore ensures that the domains are better aligned. The framework is tested on a case study and the results indicate that it is an effective tool in the combined design of business processes and information systems

Drop Weight Testing Rig Analysis and Design

Crashworthiness studies are becoming increasingly important in mechanical design, particularly with the new advancement of the computer simulation codes. These studies generally require material and prototype testing for both modelling and validation. Large percentages of these studies lie on the limits of medium strain rate, which could be achieved by a drop weight test rig. Therefore, the drop weight test rig becomes an essential tool for such research activities besides the universal quasi-static testing machines. This paper is devoted to the analysis and design of the drop weight impact-testing rig. First, the different aspects of the mechanical design such as the propulsion, guidance, and frame layout, foundation and energy aspects are presented and discussed. Then, the basic types of data retrieval and analysis systems applicable for drop weight impact testing machines are presented and discussed. Data retrieval components considered in this study include the sensors for load, acceleration, and velocity measurements, image acquisition including high-speed cameras and PC-based image acquisition system, and data acquisition including oscilloscope or PC-based data acquisition system which utilizes an AID card and application software for visualizing and analyzing of the results. At the end of this article the designed and constructed test machine is presented as a case study

Evaluating the performance of passive chilled beams with respect to energy efficiency and thermal comfort

Existing modeling approaches for passive chilled beams determined from tests on individual chilled beams in a laboratory are not adequate for assessing overall energy usage and occupant comfort within building simulation programs. In addition, design guidelines for passive chilled beam systems are needed for identifying appropriate applications and optimal configurations. This thesis includes (i) extensive experimental studies for characterizing the performance of passive chilled beams, in both laboratory settings and in field studies, (ii) development of passive chilled beam performance prediction models, (iii) integration of these models into building simulation models/tools and (iv) use of building simulation for overall assessment of different passive chilled beam system configurations in different climates in order to provide guidelines for appropriate applications. Experiments were conducted with a single passive chilled beam in a laboratory setting and with multiple passive chilled beams installed in a real occupied office space. Based on the experimental results, models that can predict total cooling capacity and chilled surface temperature of passive chilled beams were developed. These models use essential operating conditions of the system and thermal conditions in the environment as inputs and are able to predict the energy and thermal comfort performances of the passive chilled beam system when integrated into a system simulation. The validity of using a model developed from laboratory tests on a single passive chilled beam in a system simulation for spaces with multiple chilled beams was evaluated. Comparison of laboratory and field measurements indicates that the conventional method of predicting total cooling capacity of a passive chilled beam from laboratory measurements underestimates its performance when installed in a system. These differences could have an important impact on system sizing and commissioning. Side-by-side field measurements were conducted to compare energy and comfort performance of a passive chilled beam system against constant and variable air volume systems for nearly identical office spaces. While maintaining very similar thermal comfort levels in the two offices, the passive chilled beam system led to a 57% reduction in electric energy compared to the constant air volume system. However, the variable air volume (VAV) system consumed 21% less energy compared to the passive chilled beam system during the field measurements. This is mostly because of the current configuration of the passive chilled beam system which represents the worst case scenario in terms of system configuration. The parallel air system used in the field measurement is a typical air system including the outdoor air and return air damper system. As a starting point followed by various configurations assessment with computer simulations, the return air damper was closed during the entire field measurements of the passive chilled beam system. In order to consider more realistic energy savings compared to VAV systems, alternative passive chilled beam configurations were evaluated using a system simulation model that was validated with the available measurements. The integrated simulation tool was developed and validated for the case study office space and was then used to perform comprehensive comparisons of alternative passive chilled beam and conventional systems in order to evaluate savings potential in various climatic zones. While maintaining the same thermal environments in spaces, the best passive chilled beam configuration provided electrical energy savings up to 24% for hot and humid climates and up to 35% savings for hot and dry climates compared to a variable air volume system. The radiation cooling effects of passive chilled beams were also analyzed through experiments and simulations. Both experiments and computer simulations revealed that the effect of the radiation cooling of passive chilled beams is not significant in terms of energy savings and thermal comfort improvement. Based on simulation results covering various passive chilled beam system configurations and climatic zones, the percentage of radiation cooling energy relative to total passive chilled beam cooling energy varied between 7 to 15

Development, implementation and pilot evaluation of a Web-based Virtual Patient Case Simulation environment – Web-SP

BACKGROUND: The Web-based Simulation of Patients (Web-SP) project was initiated in order to facilitate the use of realistic and interactive virtual patients (VP) in medicine and healthcare education. Web-SP focuses on moving beyond the technology savvy teachers, when integrating simulation-based education into health sciences curricula, by making the creation and use of virtual patients easier. The project strives to provide a common generic platform for design/creation, management, evaluation and sharing of web-based virtual patients. The aim of this study was to evaluate if it was possible to develop a web-based virtual patient case simulation environment where the entire case authoring process might be handled by teachers and which would be flexible enough to be used in different healthcare disciplines. RESULTS: The Web-SP system was constructed to support easy authoring, management and presentation of virtual patient cases. The case authoring environment was found to facilitate for teachers to create full-fledged patient cases without the assistance of computer specialists. Web-SP was successfully implemented at several universities by taking into account key factors such as cost, access, security, scalability and flexibility. Pilot evaluations in medical, dentistry and pharmacy courses shows that students regarded Web-SP as easy to use, engaging and to be of educational value. Cases adapted for all three disciplines were judged to be of significant educational value by the course leaders. CONCLUSION: The Web-SP system seems to fulfil the aim of providing a common generic platform for creation, management and evaluation of web-based virtual patient cases. The responses regarding the authoring environment indicated that the system might be user-friendly enough to appeal to a majority of the academic staff. In terms of implementation strengths, Web-SP seems to fulfil most needs from course directors and teachers from various educational institutions and disciplines. The system is currently in use or under implementation in several healthcare disciplines at more than ten universities worldwide. Future aims include structuring the exchange of cases between teachers and academic institutions by building a VP library function. We intend to follow up the positive results presented in this paper with other studies looking at the learning outcomes, critical thinking and patient management. Studying the potential of Web-SP as an assessment tool will also be performed. More information about Web-SP

Dynamic integrated modelling of information systems and business process simulation

Business processes and information technology are two areas that are very closely related to the sustained competitive advantage in organisations. However, investment in information technology often leads to disappointment, which may in part be due to the non-alignment of the information system domain with the business process domain. Simulation modelling is an established technique often used in business process change projects, as it allows a comparison of different possible scenarios without the expense of physically implementing the system. However business process simulation fails to effectively capture the information systems perspective in the model. This thesis contends that by combining information systems modelling techniques with business process simulation the model will be able to capture all the four perspectives (functional, behavioural, organisational and informational) of an organisation, and the design of the business processes and the information system will be better aligned. Initially, attempts were made to integrate business process simulation with computer network simulation in a simple two- or three-layered simulation model, but this gave rise to significant problems the most significant being the underlying assumptions of the original hypothesis. This led to a refined hypothesis in which the layered models were discarded along with the network domain. The revised hypothesis aimed to capture the informational changes that occur in the information system and therefore combines prototyping with business process simulation. This overcomes the unsafe assumptions of the initial hypothesis about whether the system is 'correct' and provides a method of validating the design of the information system within the context of the business processes. The integrated model allows concurrent design of the information system domain and the business process domain and therefore ensures that the domains are better aligned. The framework is tested on a case study and the results indicate that it is an effective tool in the combined design of business processes and information systems.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A design-for-casting integrated approach based on rapid simulation and modulus criterion

This paper presents a new approach to the design of cast components and their associated tools. The current methodology is analysed through a case study and its main disadvantages underlined. Then, in order to overcome these identified drawbacks, a new approach is proposed. Knowing that this approach is mainly based on a rapid simulation of the process, basics of a simplified physical model of solidification are presented as well as an associated modulus criterion. Finally, technical matters for a software prototype regarding the implementation of this Rapid Simulation Approach (RSA) in a CAD environment are detailed

A Study of Basic 3D Visualization Architecture for Network Operation and Management Tools

Recently, network operation tools using 3D visualization technologies have become more and more important. Generally, 3D visualized network operation tools are useful for computer network management or operation. However, a development of 3D visualized network operation tools requires advanced technical skills and highly cost. On the other hand, 3D computer graphics technologies become more familiar in recent years because of that computer hardwares and softwares are rapidly growing and obtain high performance. In this research, we have developed basic architecture of 3D visualization system for network operation and management tools, by using an open source 3DCG software ``Blender'' and a programming language ``Python``. In this paper, we explain details, results of evaluation and efficiency of the proposed architecture

Towards a Tool-based Development Methodology for Pervasive Computing Applications

Despite much progress, developing a pervasive computing application remains a challenge because of a lack of conceptual frameworks and supporting tools. This challenge involves coping with heterogeneous devices, overcoming the intricacies of distributed systems technologies, working out an architecture for the application, encoding it in a program, writing specific code to test the application, and finally deploying it. This paper presents a design language and a tool suite covering the development life-cycle of a pervasive computing application. The design language allows to define a taxonomy of area-specific building-blocks, abstracting over their heterogeneity. This language also includes a layer to define the architecture of an application, following an architectural pattern commonly used in the pervasive computing domain. Our underlying methodology assigns roles to the stakeholders, providing separation of concerns. Our tool suite includes a compiler that takes design artifacts written in our language as input and generates a programming framework that supports the subsequent development stages, namely implementation, testing, and deployment. Our methodology has been applied on a wide spectrum of areas. Based on these experiments, we assess our approach through three criteria: expressiveness, usability, and productivity