• Journal of the Society of Naval Architects of Korea
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• v.45 no.1
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• pp.81-86
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• 2008

Recently, a mesh-size insensitive structural stress definition that provides a stress state at weld toe with relatively larger mesh size compared to conventional approaches has been proposed. The structural stress definition is based on the elementary structural mechanics theory and provides an effective measure of a stress state in front of weld toe. In this study, as an experimental validation of structural stress method in obtaining the fatigue strength of weldments, a series of fatigue test has carried out for longi-web connections, which are representative of ship-like structures. Based on the result from this study, it is expected to develop a more precise fatigue strength evaluation technique and to reduce time and cost associated with the fatigue design of ship and offshore structures.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.1
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• pp.71-82
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• 2001

In this study, Internet users were separated into 3 groups(clothing shoppers, clothing non-shoppers, non-shoppers). Shopping behavior of clothing shoppers(those who used the internet channel for clothing shopping) and the attitude to internet clothing shopping were examined. And characteristics of clothing shoppers were compared with characteristics of clothing non-shoppers(those who purchased goods except clothing on internet) and non-shoppers(those who purchased nothing on internet). The reason why clothing non-shoppers and non-shoppers didnt purchase clothing on internet was also investigated. Questionaire was used as method of gathering data. Mean, ANOVA, Duncan-test, t-test and $\chi$$^2$-test were used for data analysis. 1. Clothing shoppers considered carefully design, exchange & refund, quality and price and purchased generally T-shirt, underwear, jeans and sports wear. 2. Clothing shoppers thought clothing in internet shopping malls was not various in item, design, color, size and price. But they were satisfied with shopping convenience. 3. Clothing shoppers were more conscious of the shopping cost compared with clothing non-shoppers and non-shoppers Recreational shopping orientations and fashion leader orientations were low in both groups. Self-confidence in connection with clothing purchase were high in each groups, but that of clothing shoppers were relatively higher than clothing non-shoppers and non-shoppers. 4. The reason why clothing non-shoppers and non-shoppers didnt purchase clothing in internet shopping malls was that they wanted to buy after trying on clothing in a store, didnt believe the quality of clothing, didnt need to purchase clothing in internet shopping malls, and worried about exchange & refund.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.4 s.33
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• pp.1-5
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• 2004

A multi-layer flexible substrate is composed of copper(Cu)/polyimide that are known as good electrical conductivity, and low dielectric constant, respectively. In this study. conductor line of $5{\mu}m$-pitch was successfully fabricated without non-uniform pattern shape by electroplating copper and coating polyimide on patterned stainless steel. For multi-layer flexible substrate, via holes were drilled by UV laser and filled with electroplating copper and tin. And then, the PI layer with vias and conductor lines was stripped from stainless steel substrate. The PI layers were laminated at once with careful alignment between layers. Solid state reaction between tin and copper during lamination formed the intermetallic compounds of $Cu_6Sn_5$($\eta$-phase) and $Cu_3Sn$($\epsilon$-Phase) and achieved a complete inter-connection by vertically positioning the plugged via holes on via pad. The via formation process has several advantages; such as better electrical property and lower cost than V type via and paste via.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.7
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• pp.728-736
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• 2014

Due to the recent development of mobile wireless telecommunication, RRHs(Remote Radio Heads) are widely being utilized to expand the cell coverage. Wire-link, an existing connection between DU(Digital Unit) and RRH through fiber cables, is considered to have limitations in relation to cost for a wide range of applications. This paper focuses on replacing the wire-link by wireless transmission using millimeter-wave, and implementing cellular network system through RRH from a remote location. After an influence element analysis on millimeter-wave wireless link transmissions, a comparative analysis between wireless link and an existing fiber link method will be made by utilizing currently commercialized LTE(Long Term Evolution), to prove the compatibility of millimeter-wave wireless link RRH method in replacing fiber link method without a significant decline in data transmission performance.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.781-789
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• 2016

Busbar has been used as electric conductor within extra high voltage (EHV) gas insulated switchgear (GIS), which makes EHV GIS higher security, smaller size and lower cost. However, the main fault of GIS is overheating of busbar connection parts, circuit breaker and isolating switch contact parts, which has been already restricting development of GIS to a large extent. In this study, a coupled magneto-flow-thermal analysis is used to investigate the thermal properties of GIS busbar in steady-state. A three-dimensional (3-D) finite element model (FEM) is built to calculate multiphysics fields including electromagnetic field, flow field and thermal field in steady-state. The influences of current on the magnetic flux density, flow velocity and heat distribution has been investigated. Temperature differences of inner wall and outer wall are investigated for busbar tank and conducting rod. Considering the end effect in the busbar, temperature rise difference is compared between end sections and the middle section. In order to obtain better heat dissipation effect, diameters of conductor and tank are optimized based on temperature rise simulation results. Temperature rise tests have been done to validate the 3-D simulation model, which is observed a good correlation with the simulation results. This study provides technical support for optimized structure of the EHV GIS busbar.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.1-5
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• 2016

A bicycle is one of the most popular sporting goods in view of a sport activity and a human health. Metallic materials such as steel, aluminum, etc. were mainly used to the bicycle fork in the past. Nowadays, the carbon fiber reinforced composite materials are widely used to the manufacturing of a bicycle fork to reduce the weight and to increase the efficiency. Safety is a most important design parameter of a bicycle fork even if the weight and cost reduction are important. Bicycle failure may happen at the critical spot of a bicycle fork and cause the accident. In this paper, the composite bicycle fork will be analyzed to secure the safety and detect a critical spot by using the finite element method with Tsai-Wu failure criterion. The stress data were obtained for the laminated composites with various number of plies and fiber orientation under the bending load. Thus, design concept of a bicycle fork was proposed to secure the safety of a bicycle. The finite element analysis results show that the connection area between a steer tube and a fork blade is critical spot, and 75 or more layers of 0 degree are needed to secure the safety of a bicycle fork.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.202-208
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• 2016

In this study, the defect in connection with a C-tray was inspected using a low-cost camera. The four test items were the device overlapping in the tray, the bending of the tray, the loaded quantity of the tray, and the device pocket leaving, an algorithm was developed for defining and detecting the above defect types. Therefore, the developed handling system could extend the application of the stack of the c-tray and provide a quantity verification inspection on the packing processing. The machine operation control program, which can ensure the optimal inspection image to match the scan speed, was developed and the control program that can process the user gui and the vision image utilizing the control was developed. Overall, a mechanical system that is practicable for obtaining an image and processing the vision data was designed.

• Smart Media Journal
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• v.5 no.4
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• pp.124-130
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• 2016

Big data technologies are increasing the need for big data in many areas of the world. Recently, the health care industry has become increasingly aware of the importance of disease and health care services, as it has become increasingly immune to prevention and health care. To do this, we need a Big data system to collect and analyze the personal biometric data. In this paper, we design the biometric big data system using low cost wearable device. We collect basic biometric data, such as heart rate, step count and physical activity from Mi Band, and store the collected biometric data into MongoDB. Based on the results of this study, it is possible to build a big data system that can be used in actual medical environment by using Hadoop etc. and to use it in real medical service in connection with various wearable devices for medical information.

• The Korean Society of Law and Medicine
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• v.15 no.1
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• pp.239-262
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• 2014

The conventional medical appraisal which was done in the process of medical lawsuit was requested from the court to the designated hospital and was delivered as a pattern of one question and one answer in each. However, the comprehensiveness of medical appraisal which was pursued, for example, in Korea Medical Dispute Mediation and Arbitration Agency, could be guaranteed in terms of in-depth medical analysis as well as the broader capacity of the causality estimation besides. The comprehensiveness of appraisal would also include how well organized hospital system of medical care is and how well correlated job system among medical staffs, when medical dispute was happened at the hospital. This comprehensiveness will exert a big contribution on making a demonstrative medical care to prevent from the medical dispute and it could achieve the national plan of building the patient safety net which is effective in restoring the worsened quality of contemporary medical service. Therefore, the comprehensiveness of medical appraisal has to be designed to go forward interdisciplinary fused speciality rather than one division of medicine, which is also aiming at the reliable and consistent appraisal with the supreme dignity from one window. In addition to that, the objective and concrete frame of comprehensive appraisal under the computed connection has to be deliberated to make itself possible in collaboration with positive participation of medical community. The comprehensiveness of medical appraisal would serve to expand not only the capacity of speciality but also the ability of influence on a restorative justice, so that it give effect to an increased number of mediation and arbitration rather than medical lawsuit as well as a decreased number of the social cost and social conflict.

• Journal of Internet Computing and Services
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• v.9 no.6
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• pp.89-97
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• 2008

Recently, many organizations such as companies or institutions have demanded induction of very large-scale workflow management system in order to process a large number of business-instances. Workflow-related vendors have focused on physical extension of workflow engines based on device-level clustering, so as to provide very large-scale workflow services. Performance improvement of workflow engine by simple physical-connection among computer systems which don't consider logical-level software architecture lead to wastes of time and cost for construction of very large-scale workflow service environment. In this paper, we propose methodology for performance improvement based on logical software architectures of workflow engine. We also evaluate scalable performance between workflow engines using the activity instance based architecture and workcase based architecture, our proposed architecture. Through analysis of this test's result, we can observe that software architectures to be applied on a workflow engine have an effect on scalable performance.