• Journal of the Korean Society of Marine Environment & Safety
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• v.6 no.1
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• pp.1-9
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• 2000

The paper describes system design of next-generation Ship Simulator using Virtual Reality (VRSS), well known as human-computer interaction. VRSS system is required to have special condition that comprises multiple user participants such as captain, officer, pilot, and quartermaster. To cope with that condition, core technologies were explored and proposed multi-networking system with broker server. The evaluation of the proposed system was done with PC-based immersion-type VR device, constituted with HMD (Head Mounted Display), Head Tracking Sensor, Puck, Headphone, and Microphone. Using the VR device, assessment test was carried out in a virtual bridge with 3D objects, which are created by VRML (Virtual Reality Model Language) program. As results of tests, it is shown that the cybernetic 3D objects were act as if real things in a real ship's bridge. Therefore, interesting interaction with participants can be obtained in the system, Thus, we found that the proposed system architecture can be applicable to VRSS system construction.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.53-56
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• 2005

In this study, the material characterization and the dynamic behavior of 3D orthogonal woven composite materials has been studied under transverse central low-velocity impact condition by means of the micromechanical model using finite elements. To build up the micromechanical model considering tow spacing and waviness, an accurate unit structure is stacked in x-y-z direction repeatedly. First, the mechanical properties of 3D orthogonal woven composites arc obtained by means of virtual experiment using full scale Finite Element Analysis based on the DNS concepts, and the computed elastic properties arc validated by comparison to available experimental results. Second, using the implementation of this validated micromechanical model, 3D transient finite-clement analysis is performed considering contact and impact, and the impact behavior of 3D orthogonal woven composite is investigated. A comparison study with the homogenized model will be carried out in terms of global and local behaviors.

• Journal of Fashion Business
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• v.24 no.4
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• pp.63-84
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• 2020

It is essential to consider the heavy industrial working environment factors which are regarded as harmful to workers' health and safety and suitable work motion factors for the workers' motion while developing the work clothes for painting workers in the machinery and shipbuilding industries. This study suggests the use of 3D virtual clothing simulations as a solution to protect the human body from hazardous working conditions accompanying the development of painting work clothes and assessing the work motion performance associated with the comfort while workers wear them during the work clothes. The initial aim of the study is to examine a male avatar to run work motions simultaneously within a 3D virtual clothing simulator, secondly, to present the simulation images of coverall type men's painting work clothes with the application of two experimental painting work motions and one control motion to the avatar, and finally, to present the distance analysis images of the painting work clothes and the avatar body and air gap rates through the analysis of cross-sections of the avatar body while wearing the coverall work clothes according to the work motions. The results showed that the distance degree of painting work clothes to the avatar body for each part of the human body when performing painting work motions. Moreover, 3D virtual clothing simulations enabled the creation of a male model avatar to run painting work motions together and the painting work clothes developed were found to be suitable for the painting work motions.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.1
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• pp.63-70
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• 2019

We aimed to propose a novel computational approach to predict the electromechanical performance of pre- and post-mitral valve cerclage annuloplasty (MVCA). Furthermore, we tested a virtual estimation method to optimize the left ventricular basement tightening scheme using a pre-MVCA computer model. The present model combines the three-dimensional (3D) electromechanics of the ventricles with the vascular hemodynamics implemented in a lumped parameter model. 3D models of pre- and post-MVCA were reconstructed from the computed tomography (CT) images of two patients and simulated by solving the electromechanical-governing equations with the finite element method. Computed results indicate that reduction of the dilated heart chambers volume (reverse remodeling) appears to be dependent on ventricular stress distribution. Reduced ventricular stresses in the basement after MVCA treatment were observed in the patients who showed reverse remodeling of heart during follow up over 6 months. In the case who failed to show reverse remodeling after MVCA, more virtual tightening of the ventricular basement diameter than the actual model can induce stress unloading, aiding in heart recovery. The simulation result that virtual tightening of the ventricular basement resulted in a marked increase of myocardial stress unloading provides in silico evidence for a functional impact of MVCA treatment on cardiac mechanics and post-operative heart recovery. This technique contributes to establishing a pre-operative virtual rehearsal procedure before MVCA treatment by using patient-specific cardiac electromechanical modeling of pre-MVCA.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.759-766
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• 2002

In the paper the authors describe the development of ITIS(Intelligent Tunneling Information System) for the Purpose of applying the 3D visualization technique, GIS, AI(Artificial Intelligence) to tunnel design and construction. VR(Virtual Reality) and 3D visualization techniques are applied in order to develope the 3D model of characteristics and structures of ground and rock mass. Database for all the materials related to site investigation and tunnel construction is developed using GIS technique. AI technique such as fuzzy theory and neural network is applied to predict ground settlement, decide tunnel support method and estimate ground and rock mass properties according to tunnel excavation steps. ITIS can help to inform various necessary tunnel information to engineers quickly and manage tunnel using acquired information based on D/B.

• International Journal of CAD/CAM
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• v.4 no.1
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• pp.1-10
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• 2004

Through reviewing and comparing the current virtual shopping malls web sites integrated VR into E-commerce, this paper analyzed both the advantages and disadvantages of two kinds of methods for product presentation: 2D image based and 3D model based presentation method. Using the virtual shopping mall (EasyMall) as a showcase, we presented the architecture of the system and the development technologies, especially those in the mixed presentation method. The presentation and customization methods in the two related modules, including the PhoneShow for mobile phone and EasyShow for textile products, were discussed. It indicated that the integration of E-commerce with VR could provide consumers with virtual experience and intelligent service for business activities. Furthermore, the product presentation methods can be made available for use in different cases.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1627-1635
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• 2001

Virtual manufacturing is a technology facilitating effective development and agile manufacturing of products via sophisticated computer models representing physical and logical schema and behavior of real manufacturing systems including manufacturing resources, environments, and products. For the successful application of this technology, a virtual plant as a well-designed and integrated environment is essential fur sharing information and engineering collaboration among diverse engineering activities. The systematic approaches and effective methods for construction and application of a virtual plant are proposed in this paper, such as a 3-D CAD modeling, cell and line simulations, databases and some information technologies. Measuring and 3-D CAD modeling technologies of many equipments, facilities and structures of the building are developed, and effective information management system managing CAD models, related files and data is implemented in WWW environments. Finally, precise simulations of unit cell lines and the whole plant are performed. For the beginning of implementing a Virtual Automotive Plant, the Virtual Plant fur the Body Shop of a Korean automotive company is constructed and implemented. We could obtain the benefit of savings in time and cost in many manufacturing preparation activities in the new car development processes.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.145-156
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• 2022

Nowadays, the complexity of object tracking models among hardware applications has become a more in-demand duty to complete in various indeterminable environment tracking situations with multifunctional algorithm skills. In this paper, we propose a virtual city environment using AirSim (Aerial Informatics and Robotics Simulation - AirSim, CityEnvironment) and use the DQN (Deep Q-Learning) model of deep reinforcement learning model in the virtual environment. The proposed object tracking DQN network observes the environment using a deep reinforcement learning model that receives continuous images taken by a virtual environment simulation system as input to control the operation of a virtual drone. The deep reinforcement learning model is pre-trained using various existing continuous image sets. Since the existing various continuous image sets are image data of real environments and objects, it is implemented in 3D to track virtual environments and moving objects in them.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.3
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• pp.112-121
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• 2002

This paper describes a new bike system for the postural balance rehabilitation training. Virtual environment and three dimensional graphic model is designed with CAD tools such as 3D Studio Max and World Up. For the real time bike simulation, the optimized WorldToolKit graphic library is embedded with the dynamic geometry generation method, multi-thread method, and portal generation method. In this experiment, 20 normal adults were tested to investigate the influencing factors of balancing posture. We evaluated the system by measuring the parameters such as path deviation, driving velocity, COP(center for pressure), and average weight shift. Also, we investigated the usefulness of visual feedback information by weight shift. The results showed that continuous visual feedback by weight shift was more effective than no visual feedback in the postural balance control It is concluded this system might be applied to clinical use as a new postural balance training system.

• Journal of International Society for Simulation Surgery
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• v.1 no.1
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• pp.23-26
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• 2014

The aim of this report is to evaluate accuracy using3D surgical simulationand digitally printedwafer in orthognathic surgery. 22-year-old female was diagnosed with mandibular prognathism and apertognathia based on 3D diagnosis using CT. Digital dentition images were taken by laser scanning from dental cast, and each STL images were integrated into one virtual skull using simulation software. Digitalized intermediate wafer was manufactured using CAD/CAM software and 3D printer, and used to move maxillary segment in real patient. Constructed virtual skull from 1 month postoperative CT scan was superimposedinto simulated virtual model to reveal accuracy. Almost maxillo-mandibular landmarks were placed in simulated position within 1 mm differences except right coronoid process. Thus 3D diagnosis, surgical simulation, and digitalized wafer could be useful method to orthognathic surgery in terms of accuracy.