• 청정기술
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• 제5권2호
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• pp.1-12
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• 1999

세정공정은 여러 산업체의 생산공정에 활용되고 있는 공정으로서 세정과정중 다양한 환경 오염물질을 배출하고 있다. 따라서, 환경 및 안전규제가 국내외적으로 엄격하여짐에 따라 기존의 세정공정에서 사용되었던 세정제를 환경문제나 유해성 문제를 야기시키지 않는 환경친화적인 세정제로 대체하는 것이 절실한 실정이다. 대체세정제를 선정하기 위해서 기존의 세정제에 필적할 만한 세정성을 갖춰야 하지만 세정성 평가방법이 정립되어 있지 않은 실정이다. 따라서 본 연구에서는 실험실이나 산업체에서 활용 가능한 여러 가지 세정평가법을 정리하여 보았고 국내외 현장 적용사례를 조사 분석하였다.

• Interaction and multiscale mechanics
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• 제1권3호
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• pp.369-379
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• 2008

A combined stochastic diffusion and mean-field model is developed for a systematic study of the grain growth in a pure single-phase polycrystalline material. A corresponding Fokker-Planck continuity equation is formulated, and the interplay/competition of stochastic and curvature-driven mechanisms is investigated. Finite difference results show that the stochastic diffusion coefficient has a strong effect on the growth of small grains in the early stage in both two-dimensional columnar and three-dimensional grain systems, and the corresponding growth exponents are ~0.33 and ~0.25, respectively. With the increase in grain size, the deterministic curvature-driven mechanism becomes dominant and the growth exponent is close to 0.5. The transition ranges between these two mechanisms are about 2-26 and 2-15 nm with boundary energy of 0.01-1 J $m^{-2}$ in two- and three-dimensional systems, respectively. The grain size distribution of a three-dimensional system changes dramatically with increasing time, while it changes a little in a two-dimensional system. The grain size distribution from the combined model is consistent with experimental data available.

• 대한기계학회논문집A
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• 제20권8호
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• pp.2468-2479
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• 1996

An upper bound solution is obtained to perform the process analysis of hot strip rolling process. The material flows within the roll bite at various geometries and frictional conditions are obtained from finite element analysis and the typical flow pattern which is necessary to determine the kinematically admissible velocity field is assumed. From the kinematically admissible velocity field, the upper bound energy is calculated and the rolling load, angle of neutral point and forward slip ratio at various operational conditions are obtained from upper bound energy. The process analysis of above mentioned parameters at various operational conditions have provided valuable information which is hard to obtain during rolling operation and the predicted ranges of quantitive values from these analyses lie whthin the bound of actual operational data.

• 한국태양에너지학회 논문집
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• 제34권3호
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• pp.49-56
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• 2014

A fiat-plate or vacuum tube solar collector have been mainly used for hot water supply of house because of some being difficult to get uniform energy density, so little applied into industrial field. This study is to apply the PTC(parabolic trough collector) solar collector into industrial field such as sludge dewatering system for energy reduction. The real scale system which composed of PTC Solar Collector and Thermal Dewatering (TDW) is established. PTC solar collector is designed to produce a hot water with $80^{\circ}C$ of temperature. And size of TDW is $630{\times}630mm$. Hot water produced from PTC solar collector is supplied into heating plate of TDW, and sludge like waterworks or wastewater is dewatered. PTC solar collector with $10m^2$ of area produce energy of average 5,618 kcal. As according to results from real scale performance, solar collector takes charge 94 % of the amount that TDW consume energy which is so large part if compare with boiler. It means that PTC solar collector is useful to apply industrial field under the condition of sufficient solar radiation. And it is analyzed that TDW by PTC solar collector has an economical validity.

• Asian Journal of Innovation and Policy
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• 제10권1호
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• pp.39-67
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• 2021

This study investigated the policy instruments pertinent to the establishment of a regional innovation system in the Mekong Delta that facilitates the development of a countermeasure towards various issues of industrial and technological nature. First, we conducted the research with regard to the status and environment of the region. Second, a field visiting survey was implemented to analyze the results of international efforts and regional capacity to solve the problems attendant upon introducing technologies related to the Fourth Industrial Revolution. Third, we derived the key policy issues and challenges from the results of the field visiting survey and experts' conference with a deep focus on technological transfer and international cooperation to enhance the capability in the science and technology field. Fourth, we conducted the opinion survey of the experts from Korea and Vietnam to converge local opinions from both countries and analyzed the results. The range of research subjects is responding to climate change, managing water resources, coordinating energy and industrial structure, making a resilient Mekong regional ecosystem, smartification of local cities, and improving the life quality of citizens, and so on. The results of this study are expected to be the beginning of fundamental research in the mid to long-term view of the Mekong Delta region innovation system of Korea and Vietnam and to evaluate the master plan.

• 산업경영시스템학회지
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• 제46권4호
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• pp.173-180
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• 2023

Smart factory companies are installing various sensors in production facilities and collecting field data. However, there are relatively few companies that actively utilize collected data, academic research using field data is actively underway. This study seeks to develop a model that detects anomalies in the process by analyzing spindle power data from a company that processes shafts used in automobile throttle valves. Since the data collected during machining processing is time series data, the model was developed through unsupervised learning by applying the Holt Winters technique and various deep learning algorithms such as RNN, LSTM, GRU, BiRNN, BiLSTM, and BiGRU. To evaluate each model, the difference between predicted and actual values was compared using MSE and RMSE. The BiLSTM model showed the optimal results based on RMSE. In order to diagnose abnormalities in the developed model, the critical point was set using statistical techniques in consultation with experts in the field and verified. By collecting and preprocessing real-world data and developing a model, this study serves as a case study of utilizing time-series data in small and medium-sized enterprises.

• 한국환경교육학회지:환경교육
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• 제14권1호
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• pp.43-55
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• 2001

The purpose of this study was to review the current status and problems of the national qualification system in the Environmental field focusing on deficiencies of the regulatory system and qualities of environmental professional including the Environmental control Professional Engineer, Environmental Engineer, Environmental Industrial Engineer and Environmental field. An overview of the environmental field, its current status, domestic qualification items and training conditions in environment-related areas, laws of environmental field, and data of the job analysis were reviewed. The concrete and extensive development plans for the qualification system of the Environmental field are as follows: First of all, a job analysis should be made of on the introduction of new systems or policy modification to reflect technical changes and national policies about the environmental field in the qualification exam. Second, it is essential to prepare policies that are suitable for the qualification system in the Environmental field and that improve its effectiveness. Third, the appropriate policy measures should be taken in order to elevate the social standing of Environmental field qualification holders.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2005년도 High Temperature Superconductivity Vol.XV
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• pp.79-79
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• 2005

• 한국산학기술학회논문지
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• 제16권10호
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• pp.6453-6457
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• 2015

본 논문에서는 솔레노이드의 자기 이론과 시뮬레이션을 통해 해석의 정확성을 검증하였다. 솔레노이드는 간단한 구조와 빠른 응답성을 바탕으로 기계 산업, 의료 등의 분야에 활발히 사용되어지고 있다. 솔레노이드 엑츄에이터는 전자기력을 활용하며 전류를 인가시키면 자기장이 형성되어 자기력을 발생시키고 플런저를 직선운동 또는 회전운동으로 구동을 시키는 장치이다. 이론 해석은 Biot-Savart's law를 통해 축방향 및 반경방향 자기장 (Magnetic flux density, B)의 값을 구했으며, 임의의 점 P에서의 자기장 값도 계산하였다. Ansys의 Magnetostatic Analysis를 이용하여 해석 시뮬레이션을 진행하였고, 그 결과를 비교하여 이론과 해석의 유사성을 살펴보았다. 비교 결과를 통해 오차 범위 안에서 error값이 존재함을 알 수 있었고, 따라서 정확성을 검증할 수 있었다.

• 산업경영시스템학회지
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• 제40권4호
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• pp.183-190
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• 2017

This paper proposes a dynamic magnetic field emulator (DMFE), which can electrically emulate information for the magnetic stripes of most widely used credit cards. Payment transactions with most common credit cards are performed by reading the card's information, encoded in magnetic stripes, using the reader head of a point-of-sale (POS) system. A stripe-type permanent magnet is attached to the back side of the credit card, and information for payments or value-added service is reorganized by exposing it to strong magnetic field. The process of data recording and retrieving as stated above has been pointed out as a major cause of illegal credit card use, because the information on the magnetic stripe is always exposed, and is thus vulnerable to forgery or alteration. A dynamic magnetic field emulator displays card information only when necessary by using the principle of solenoidal magnets. The DMFE proposed in this paper can prevent fraudulent use if it is operated with a device, like a smart phone, or a separate user-authentication procedure. In addition, because it is possible to display various information as needed, it can be utilized for a smart multi-card application, in which information for multiple cards is stored in one card, and can be selected and used as needed. This paper introduces the necessity of the DMFE and its manufacturing principles. As a result, this study will be helpful for making various application cases in payment, which is a core area of the Fintech (a newly-coined word of finance and technology) industry.