• Wind and Structures
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• v.28 no.5
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• pp.271-284
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• 2019

This paper describes the application of a novel virtual prototyping methodology to wind turbine blade design. Numeric modelling data and experimental data about turbine blade geometry and structural/dynamical behaviour are combined to obtain an affordable digital twin model useful in reducing the undesirable uncertainties during the entire turbine lifecycle. Moreover, this model can be used to track and predict blade structural changes, due for example to structural damage, and to assess its remaining life. A new interactive and recursive process is proposed. It includes CAD geometry generation and finite element analyses, combined with experimental data gathered from the structural testing of a new generation wind turbine blade. The goal of the research is to show how the unique features of a complex wind turbine blade are considered in the virtual model updating process, fully exploiting the computational capabilities available to the designer in modern engineering. A composite Sandia National Laboratories Blade System Design Study (BSDS) turbine blade is used to exemplify the proposed process. Static, modal and fatigue experimental testing are conducted at Clarkson University Blade Test Facility. A digital model was created and updated to conform to all the information available from experimental testing. When an updated virtual digital model is available the performance of the blade during operation can be assessed with higher confidence.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.269-278
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• 2010

Today's Virtual Reality(VR) technology has become considerably more affordable and sophisticated with rapidly advancing computer technology. Photo-realistic visual representations along with real-time interactivity are now achievable without special programing knowledge and expensive equipment. The purpose of this paper is to establish how simple, credible user testing methods based on VR simulations can be utilized to improve design decision making towards more sensible design solutions for end-users. Results of a case study demonstrate the value of potential user-testing feedback in a simulated 3D virtual service space, i.e., restaurant interior. User feedback from the VR simulation includes preferences in table location, privacy, and values of seating preferred tables. A new design framework incorporating an empirical testing method for service spaces is presented. The overall design process, the development of the VE, and the user testing method and findings are discussed. This study provides useful guidances for future efforts in the areas where such technology may benefit to understand end-user feedbacks in design process.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.3
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• pp.399-409
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• 2022

The purpose of this study is to examine the role of virtual community participation and engagement in the brand decision by building community and brand trust. In this study, two theories (Social Capital Theory and Theory of Collective Action) were tested. Both theories were linked based on existing literature, and empirical evidence was obtained through testing hypotheses. Students from five prestigious Pakistani business schools provided a total of 849 replies. The measurement model and structural model were both analyzed using the partial least square (PLS) method. The findings show that virtual community engagement and participation have a positive and significant impact on virtual community trust. Although virtual community engagement has a positive effect on brand trust, we found no evidence of a link between virtual community participation and brand trust. Later, these trusts positively influence brand choice. This study has several managerial implications. The suggested model of this study helps managers to get customers' insight, choose the right target market, and set integrated marketing communication strategies besides social media marketing strategies. The study represents a new perspective of consumer behavior that helps to understand how a customer behaves in virtual communities to trust and take the final decision to purchase.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.247-252
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• 2008

Systems architecture of information models for construction industry is introduced. The architecture ful fills international standards, such as ISO 10303(STEP) and IAI IFC, etc. It is defined in web service description language(WSDL) and ISO 10303-11(EXPRESS) language. A standard platform for this standard architecture is also developed. This platform has several tools which can transform EXPRESS description file into C++ or Java languages and which also can generate an IDL file or OWL file from an EXPRESS file. System architects, software engineers, information system consultants can use these standards to define their information model for construction industry in standardized way. Construction engineers can test this information model with ease using standard testing tools and testing method, which is also a part of standard architecture of information systems for virtual construction.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.616-618
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• 2004

The Simple Virtual Environment (SVE) library is the application programming interface fur creating the virtual environment easily. Even though it has a lot of efficient features, applying transformation to absolutely positioned objects is difficult. In this paper, we designed a simple method with which it is possible to rotate the absolutely positioned object freely. To test the method, we designed a simple virtual environment. The environment is designed with people, street and building objects. To reduce time consumption of displaying high-detailed people models, we only used texture-based objects. The person objects are modeled as quadric-shape and textured with front-view images of people. To make more realistic environment, objects always change its orientation themselves following to the user location. The result and the testing environment will be demonstrated.

• Journal of the Ergonomics Society of Korea
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• v.36 no.1
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• pp.37-52
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• 2017

Objective: The present study developed a user-centered 3D virtual liver surgery planning (VLSP) system called Dr. Liver to provide preoperative information for safe and rational surgery. Background: Preoperative 3D VLSP is needed for patients' safety in liver surgery. Existing systems either do not provide functions specialized for liver surgery planning or do not provide functions for cross-check of the accuracy of analysis results. Method: Use scenarios of Dr. Liver were developed through literature review, benchmarking, and interviews with surgeons. User interfaces of Dr. Liver with various user-friendly features (e.g., context-sensitive hotkey menu and 3D view navigation box) was designed. Novel image processing algorithms (e.g., hybrid semi-automatic algorithm for liver extraction and customized region growing algorithm for vessel extraction) were developed for accurate and efficient liver surgery planning. Usability problems of a preliminary version of Dr. Liver were identified by surgeons and system developers and then design changes were made to resolve the identified usability problems. Results: A usability testing showed that the revised version of Dr. Liver achieved a high level of satisfaction ($6.1{\pm}0.8$ out of 7) and an acceptable time efficiency ($26.7{\pm}0.9 min$) in liver surgery planning. Conclusion: Involvement of usability testing in system development process from the beginning is useful to identify potential usability problems to improve for shortening system development period and cost. Application: The development and evaluation process of Dr. Liver in this study can be referred in designing a user-centered system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.409-414
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• 2007

Nowadays, with the advancement of computational mechanics, and vehicle dynamics simulation linked up with virtual testing laboratory(VTL) and virtual proving ground(VPG) technologies has become a useful method for analyzing numerous driving performances and diverse noise/vibration characteristics. In this paper, the analytical vehicle model based on multi-body dynamics theory was developed to investigate the vibration characteristics according to various road conditions. For the purpose, the whole vehicle parameters, each vehicle's part parameter, and part connecting elements such as spring, damper, and bush were measured by an experiment. Also, the vehicle dynamics model, which includes the front suspension, rear suspension, steering, front wheel, rear wheel, and body subsystems has been constructed for computer simulation. With the developed vehicle dynamics model, three forces and three moments measured at each wheel center were applied to evaluate and analyze dynamics and vibration characteristics for miscellaneous road conditions.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.474-477
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• 2006

Recently, the needs for the virtual reality service of multimedia contents on the web are increasing. The services are provided by the parameter value of attribute informations of the contents. The Conventional method for managing the parameters is storing the informations separately for the contents, in this method managing and implementing the system are to be costing job. In this paper, a virtual reality service based on meta data is proposed. For the storing and managing the parameter information, we use the free space of the JPEG images. And for testing the effectiveness of the proposed system, we implemented the prototype virtual reality service model.

• Structural Engineering and Mechanics
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• v.72 no.5
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• pp.557-568
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• 2019

Accurate modeling of contact interface in bolted joints is crucial in predicting the dynamic behavior for bolted assemblies under external load. This paper presents a contact pressure distribution based non-uniform virtual material method to describe the joint interface of assembly structure, which is connected by sparsely distributed multi-bolts. Firstly, the contact pressure distribution of bolted joints is obtained by the nonlinear static analysis in the finite element software ANSYS. The contact surface around bolt hole is divided into several sub-layers, and contact pressure in each sub-layer is thought to be evenly. Then, considering multi-asperity contact at the micro perspective, the relationship between contact pressure and interfacial virtual material parameters for each sub-layer is established by using the fractal contact theory. Finally, an experimental platform for the dynamic characteristics testing of a beam lap structure with double-bolted joint is constructed to validate the efficiency of proposed method. It is found that the theoretical results are in good agreement with experimental results by impact response in both time- and frequency-domain, and the relative errors of the first four natural frequencies are less than 1%. Furthermore, the presented model is used to examine the effect of rough contact surface on dynamic characteristics of bolted joint.

• Journal of Information Technology Services
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• v.21 no.2
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• pp.127-143
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• 2022

In this study, a usability evaluation tool was developed for "ICANDUINO", a VR-based mobile application for maker education, and usability evaluation was conducted with a heuristic survey method for experts. The usability evaluation tool was derived through literature review and validated by two experts. It consisted of seven domains (effectiveness, efficiency, satisfaction, learnability, memorability, error, and cognitive load) and twenty-five sub-items. As a result of the usability evaluation conducted for six experts, it received the highest score in the domain of efficiency and the lowest score in the domain of error. The improvements of ICANDUINO were derived by analyzing the qualitative opinions of experts in each of the four stages (training, coding, tinkering, and testing) of making. the results of this study can be used as a guideline when evaluating the usability of a mobile app for education.