• Journal of the Korean Society for Precision Engineering
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• v.18 no.11
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• pp.155-160
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• 2001

To achieve high precision cutting as well as production capability in the machine tool, it is needed to develop excellent rigidity statically, dynamically and thermally as well. In order to predict the qualitative behavior of a machine tool, simultaneous analysis of mechanics and heat transfer is required. Generally, machine tool designers have solved designing problems based on partial estimation of the specified rigidity. This study clears the inter-relationship between therm, and propose multi-phase optimization of machine tool structure using a genetic algorithm. The multi-phase solution method is consists of a series of mechanical design problem. At this first phase of static design problem, multi-objective optimization for the purpose of minimization of the total weight and static compliance minimization is solved using the Pareto Genetic Algorithm.

• International Journal of Vascular Biomedical Engineering
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• v.3 no.2
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• pp.17-24
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• 2005

The main purpose of our study is to propose a new methodology to develop the multi-parametric measure including linear and nonlinear measures of heart rate variability diagnosing cardiovascular disease. We recorded electrocardiogram for three recumbent postures; the supine, left lateral, and right lateral postures. Twenty control subjects (age: $56.70{\pm}9.23$ years), 51 patients with angina pectoris (age: $59.98{\pm}8.41$ years) and 13 patients with acute coronary syndrome (age: $59.08{\pm}9.86$ years) participated in this study. To develop the multi-parametric measure of HRV, we used the multiple discriminant analysis method among statistical techniques. As a result, the multiple discriminant analysis gave 75.0% of goodness of fit. When the linear and nonlinear measures of HRV are individually used as a clinical tool to diagnose cardiac autonomic function, there is quite a possibility that the wrong results will be obtained due to each measure has different characteristics. Although our study is a preliminary one, we suggest that the multi-parametric measure, which takes into consideration the whole possible linear and nonlinear measures of HRV, may be helpful to diagnose the cardiovascular disease as a diagnostic supplementary tool.

• Journal of Mechanical Science and Technology
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• v.15 no.5
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• pp.555-561
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• 2001

A new approach to analyze the multi-domain acoustic system divided and enclosed by flexible structures is presented in this paper. The boundary element formulation of the Helmholtz integral equation is used for the internal fields and the finite element formulation for the structures surrounding the fields. We developed a numerical analysis program for the structural-acoustic coupling problems of the multi-domain system, in which boundary conditions such as the continuity of normal particle velocity and sound pressure in the structural interfaces between Field 1 and Field 2 are not needed. The validity of the numerical analysis program is verified by comparing the numerical results with the experimental ones. Example problems are included to investigate the characteristics of the coupled multi-domain system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2035-2051
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• 2011

Theoretical Bit Error Rate (BER) and channel capacity analysis are always of great interest to the designers of wireless communication systems. At the center of such analyses people are often encountered with a high-dimensional multiple integrals with quite complex integrands. Conventional Gaussian quadrature is inefficient in handling problems like this, as it tends to entail tremendous computational overhead, and the principal order of its error term increase rapidly with the dimension of the integral. In this paper, we propose a new approach to calculate complex multi-fold integrals based on the number theory. In contrast to Gaussian quadrature, the proposed approach requires less computational effort, and the principal order of its error term is independent of the dimension. The effectiveness of the number theory based approach is examined in BER and capacity analyses for practical systems. In particular, the results generated by numerical computation turn out in good match with that of Monte-Carlo simulations.

• Transactions of Materials Processing
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• v.24 no.6
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• pp.418-425
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• 2015

Based on eco-friendly advantages and the enhanced development in the chemical and physical characteristics, liquid silicone rubber (LSR) is widely used in producing precision parts in the automotive, medical, electronics, aeronautical and many other industries. In the current work, a thermoplastic-thermoset multi component injection molding (MCM) was developed for a waterproof automotive connector housing using PBT and LSR resins. Measurements of the rheological characteristics of PBT and LSR were made to improve the reliability of the numerical analysis for the multi component injection process. With the measured viscosity, pvT and curing data, numerical analysis of the multi cycle injection molding was conducted using simulation software (Sigma V5.0).

• Korean Journal of Computational Design and Engineering
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• v.18 no.6
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• pp.428-438
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• 2013

The requirement for high performance visualization of engineering analysis of digital products is increasing since the size of the current analysis problems is more and more complex, which needs high-performance codes as well as high performance computing systems. On the other hand, different companies or customers do not have all the facilities or have difficulties in accessing those computing resources. In this paper, we present a multi-view supporting VR/AR system for providing supercomputing-based engineering analysis services. The proposed system is designed to provide different views supporting VR/AR visualization services depending on the requirement of the customers. It provides a sophisticated VR rendering directly dependent on a supercomputing resource as well as a remotely accessible AR visualization. By providing multi-view centric analysis services, the proposed system can be more easily applied to various customers requiring different levels of high performance computing resources. We will show the scalability and vision of the proposed approach by demonstrating illustrative examples with different levels of complexity.

• Journal of Fashion Business
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• v.19 no.2
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• pp.136-148
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• 2015

The purpose of this thesis is to study multi-view fashion design with an analysis of multi-view art's formation and philosophical perspective. The production of unique artwork is dependent on how we see, think and represent what is around us. Multi-view art has great potential as a concept related to the continuity of time and space, it is not limited to space and time but it extends to infinitely, according to the artist's will and imagination. The study of time and space has been used as principles for deriving the formative of multi-view art, and the principles applied for analyzing multi-view fashion design. And the formation of multi-view art is reflected in fashion design. Simultaneity, deconstructivity, continuity and virtuality in terms of multi-view art are support the formation of multi-view fashion design, such as fabrication, expandability, concealment and transparency. As such, it is important to study multi-view fashion design as a creative design method with immense potential for further development.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.3
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• pp.258-268
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• 2017

In this study, we aim to converge a technology for analyzing the hydraulic circuit of a loading arm with an- other one for analyzing multi-body dynamics by utilizing analysis software SimulationX. Further, this study intends to overcome the limitations of the existing technology for analyzing a hydraulic circuit with a variation at the rotation center of the moving mass and the difficulty of incorporating the behavior in a gravity field. First, the specifications of the hydraulic circuit components were reflected in an analysis model to secure reliability. Hydraulic circuit modeling was then performed using a single analysis model with a verified reliability. Subsequently, the multi-body system (MBS) model of the loading arm was formed. Finally, the analysis model of the hydraulic circuit and the MBS model were converged to check if the circuit analysis result was exactly reflected in the MBS model. The convergence analysis model has development cost-saving effect because it is capable of predicting the dynamic behavior of an object without the prototype.

• Structural Engineering and Mechanics
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• v.21 no.3
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• pp.255-273
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• 2005

Based on the random vibration theory, a response spectrum method is developed for seismic response analysis of linear, multi-degree-of-freedom structures under multi-support excitations is developed. Various response quantities, including the mean and variance of the peak response, the response mean frequency, are obtained from proposed combination rules in terms of the mean response spectrum. This method makes it possible to apply the response spectrum to the seismic reliability analysis of structures subjected to multi-support excitations. Considering that the tedious numerical integration is required to compute the spectral parameters and correlation coefficients in above combination rules, this paper further offers simplified procedures for their computation, which enhance dramatically the computational efficiency of the suggested method. The proposed procedure is demonstrated for tow numerical examples: (1) two-span continuous beam; (2) two-tower cabled-stayed bridge by using Monte Carlo simulation (MC). For this purpose, this paper also presents an approach to simulation of ground motions, which can take into account both mean and variation properties of response spectrum. Computed results based on the response spectrum method are in good agreement with Monte Carlo simulation results. And compared with the MSRS method, a well-developed multi-support response spectrum method, the proposed method has an incomparable computational efficiency.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.269-279
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• 2019

This study would present a risk analysis method to evaluate stable tap water supply in a multi-regional water supply system and propose a measure for the evaluation of the effect of the conjunctive operation of the multi-regional water supply system using this. Judging from the vulnerability for the crisis response of the entire N. multi-regional water supply system, as compared to the result of Scenario 1 in which no conjunctive pipes were operated, it was found that in Scenario 2, in which conjunctive pipes were partially operated, the vulnerability of crisis response decreased by about 30.6%, and as compared to Scenario 3, the vulnerability of crisis response decreased by 86.2%. In setting a plan for stable tap water supply in N multi-regional water supply system, using the estimated value and the method for the evaluation of the vulnerability of crisis response by pipe, by interval and by line, it is judged that this can be utilized as a basis for the judgment of the evaluation of the operation or the additional installation of conjunctive pipes.