• Journal of the Korea Society for Simulation
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• v.12 no.1
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• pp.21-34
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• 2003

This paper deals with a case study of workload analysis of an operator in an automatic line for machining the race of ball bearing. Eleven machines and three hoppers are installed in the line which is operated by an operator. The elements of operation are separated into machine controlled elements, operator controlled elements and machine/operator controlled elements. In order to analyze the system, time and motion studies are used for gathering input data for the simulation model. The first objective of this study is to evaluate whether the workload of operator is reasonable or not. The second objective is to increase throughput by reducing tact time and the last one is to increase frequencies of inspection by reducing interval. Thus we suggest some ideas for improvement, and as a result, the throughput is improved about 9%. In spite of the increasing of throughput, the allowance of operator is also increased about 4%.

• Journal of Families and Better Life
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• v.17 no.3
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• pp.159-170
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• 1999

This study analyzes the relationships between social networks and loneliness. Subjects of this study are male and female undergraduate students residing in Soul and Jeonju city Questionaires were and the obtained results were analyzed through SPSS PC+ The results are as follows 1) The size of general social networks doesnt's show difference between male and female students but at the of intimate social networks female students' one is bigger than male students' And female students' contact frequency via telephone is higher than male students' but the direct contact frequency did not show the difference: 2) The bigger the size of social networks is and the higher the contack frequency is the more the mount of social supports female students get. And the bigger the size of social networks is the more the amount of social support male students get. But among male students there are no relationships between the contact frequency and the amount of social supports 3) The size and co tact frequency of social networks is negatively related to loneliness among female and male students 4) The amount of social supports explaines the degree of loneliness at 23% among female students and 18% among male students.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.59-62
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• 1994

Tact Electrical conductivity. optical absorption spectra of poly(p-phenylene vinylene) and their dependence on stretching are discussed in detail. The conductivity in the parallel direction to the stretching is higher over one order in magnitude than that in the perpendicular direction to the stretching is higher over one order in magnitude than that in the perpendicular direction to the stretching. The photocurrent spectrum for the ligh polarized parallel to the chain direction is much enhanced in lower photon energy compared with that for the light polarized perpendicular to that direction. The result may be originated in the difference of energies which is needed to photogenerate carriers wi th the light polarized parallel and perpendicular to the chain stretched direction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.94-98
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• 2012

The behavior of ozone micro bubble cleaning system was investigated to evaluate the solution as a new method of solar cell wafer cleaning in comparison with former conventional RCA cleaning. We have developed the ozone dissolution system in the ozonated water for more efficient cleaning conditions. The optimized cleaning conditions for solar cell wafer process were 10 ppm of ozone concentration and 12 minutes in cleaning periods, respectively. We have confirmed the cleaning reliability and cell efficiencies after ozone micro bubble cleaning. Using this new cleaning technology, it was possible to obtain higher efficiency, higher productivity, and fast tact time for applying cleaning in the fields on bare ingot wafer, LED wafers as well as the solar cell wafer.

• Ocean Systems Engineering
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• v.9 no.2
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• pp.157-177
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• 2019

Studies on motion response of a vessel is of great interest to researchers, since a long time. But intensive researches on stability of vessel during motion under dynamic conditions are few. A numerical model of vessel is developed and responses are analyzed in head, beam and quartering sea conditions. Variation of response amplitude operator (RAO) of vessel based on Strip Theory for different wave heights is plotted. Validation of results was done experimentally and numerical results was considered to obtain effect of damping on vessel stability. A scale model ratio of 1:125 was used which is suitable for dimensions of wave flume at National Institute of Technology Calicut. Stability chart are developed based on Mathieu's equation of stability. Ince-Strutt chart developed can help to capture variations of stability with damping.

• The Journal of Korea Robotics Society
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• v.17 no.4
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• pp.431-437
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• 2022

This paper deals with a study on the automatic depalletizing robot for parcels loaded in rolltainer of domestic postal distribution centers. Specifically, we proposed a robot system that detect parcels loaded in a rolltainer with a 3D camera and perform de-palletizing using a cooperative robot. In addition, we developed the task flow chart for parcel de-palletizing and the method of retreat motion generation in the case of collision with rolltainer. Then, we implemented the proposed methods to the robot's controller by developing robot program. The proposed robot system was installed at the Anyang Post Distribution Center and field tests were completed. Field tests have shown that the robotic system has a success rate of over 90% for depalletizing task. And it was confirmed that the average tact time per parcel was 7.3 seconds.

• Journal of information and communication convergence engineering
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• v.21 no.3
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• pp.239-243
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• 2023

Owing to the environment in which it has become difficult to face people, on-tact communication has been activated, and online video conferencing platforms have become indispensable collaboration tools. Although costs have dropped and productivity has improved, communication remains poor. Recently, various companies, including existing online videoconferencing companies, have attempted to solve communication problems by establishing a videoconferencing platform within the virtual reality (Virtual Reality) space. Although the VR videoconference platform has only improved upon the benefits of existing video conferences, the problem of manually summarizing minutes because there is no function to summarize minute documents still remains. Therefore, this study proposes a method for establishing a meeting minute summary system without applying cases to a VR videoconference platform. This study aims to solve the problem of communication difficulties by combining VR, a metaverse technology, with an existing online video conferencing platform.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.36-39
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• 1999

Steel tire cords were coated via RF Plasma Polymerization of acetylene in order to enhance adhesion to rubber compounds. Adhesion of tire cords was measured by TACT as a function of plasma polymerization and argon etching conditions such as power, treatment time and chamber pressure. Tested tire cords were analysed by SEM to elucidate the adhesion mechanism. The highest adhesion values were obtained with argon etching condition at 90W, 10min, 30mtorr followed by acetylene plasma polymerization condition at 10W, 30sec., 30mtorr. In SEM analysis, the plasma polymerized tire cord at the optimized condition showed 100% rubber coverage as observed from brass-plated steel tire cords.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.120-127
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• 2023

Recently, metaverse has attracted great attention worldwide with the development of related technologies and the demand for on-tact systems. The ideal metaverse should constitute a virtual world more similar to the realistic society with physical interactions. However, there are many constraints when we construct a virtual world using the existing commercialized metaverse platform. In this paper, we design and implement a university campus-based metaverse which minimizes the constraints, and create a virtual environment maps very similar to the real-world using Unity engine, Photon cloud and Playfab SDK for multi-user accessible to virtual world as a personal avatar. Also, this work includes attractive interaction based on exchange between users. Lastly, we illustrate our implemented metaverse works on Android phone, and it works without difficulty in terms of performance.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.359-361
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• 2023

관광산업은 뉴 노멀(New Normal) 시대에 언택트에서 온택트(On-tact)형식의 메타버스(Metaverse)로의 새로운 관광 패러다임 전환을 맞이하고 있다. 이에 이 연구는 뉴 노멀 시대에 직면하여 관광산업의 변화방향에 대한 문제의식을 가지고서 지역의 관광활성화 방안 중에서도 체류형 지역 관광 활성화를 위한 방안으로 메타버스를 활용한 관광 홍보마케팅에 대한 효율적인 방안들에 대해 제안한다.