• The Korean Journal of Physiology and Pharmacology
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• v.27 no.5
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• pp.449-456
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• 2023

N-methyl-D-aspartate (NMDA) receptors are ionic glutamine receptors involved in brain development and functions such as learning and memory formation. NMDA receptor inhibition is associated with autophagy activation. In this study, we investigated whether the NMDA receptor antagonists, memantine and ifenprodil, induce autophagy in human retinal pigment epithelial cells (ARPE-19) to remove N-retinylidene-N-retinylethanolamine (A2E), an intracellular lipofuscin component. Fluorometric analysis using labeled A2E (A2E-BDP) and confocal microscopic examination revealed that low concentrations of NMDA receptor antagonists, which did not induce cytotoxicity, significantly reduced A2E accumulation in ARPE-19 cells. In addition, memantine and ifenprodil activated autophagy in ARPE-19 cells as measured by microtubule-associated protein 1A/1B-light chain3-II formation and phosphorylated p62 protein levels. Further, to understand the correlation between memantine- and ifenprodil-mediated A2E degradation and autophagy, autophagy-related 5 (ATG5) was depleted using RNA interference. Memantine and ifenprodil failed to degrade A2E in ARPE-19 cells lacking ATG5. Taken together, our study indicates that the NMDA receptor antagonists, memantine and ifenprodil, can remove A2E accumulated in cells via autophagy activation in ARPE-19 cells.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.413-415
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• 2009

최근 지능형 로봇의 필요성과 활용성이 증가하면서 로봇의 형태와 사용 방법이 다양하게 발전하고 있다. 하드웨어적인 로봇의 발전은 과거부터 현재까지 많은 발전을 거듭해 왔으나, 로봇의 지능과 기능을 모듈화 하여 서비스 할 수 있는 방법은 많이 연구되지 못하였다. 지능로봇 서비스는 로봇의 형태와 사용 방법에 따라 서비스를 다르게 적용할 수 있을 뿐만 아니라, 다양한 응용 개발이 가능하여 쉽고 빠르게 로봇에 적용이 가능하다. 또한 컴포넌트 기반의 시뮬레이션 서비스를 개발함으로서 사용자(End User)의 설계 및 개발 시간 단축과 테스트 및 시뮬레이션 시간을 획기적으로 단축할 수 있다. 따라서 본 논문에서는 VPL 활용을 위한 지능로봇 시뮬레이션 서비스 컴포넌트 개발 연구 방법을 소개하고 제안한다. VPL은 인간친화적인 GUI환경으로 로봇 시뮬레이션 프로그램을 개발 할 수 있는 RDS 프로그램 방법이며, 다양한 서비스 개발을 통해 다양한 환경 그리고 다양한 시뮬레이션 로봇의 실험이 가능하다. 본 연구에서는 C# 언어를 사용하여 지능로봇 서비스 컴포넌트 개발 사례를 소개하고 실제 로봇 시뮬레이션 프로그램에 적용하여 실험하였다. 따라서 향후 많은 로봇 서비스 컴포넌트의 응용 개발과 로봇 산업, 교육 분야에 큰 도움이 될 것으로 기대한다.

• Composites Research
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• v.36 no.4
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• pp.264-269
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• 2023

Spent coffee grounds (SCG) are a ubiquitous byproduct of coffee consumption, representing a significant waste management challenge, as well as an untapped resource for economic development and sustainability. Improper disposal of SCG can result in environmental problems such as methane emissions and leachate production. This study aims to investigate the physicochemical properties of SCG and their potential as a reinforcement material in polypropylene (PP) to fabricate an eco-friendly composite via extrusion and injection molding, with SCG filler ratios ranging from 5-20%. To evaluate the effect of SCG on the morphological and mechanical properties of the bio- composite, thermogravimetric analysis, SEM, tensile, flexural, and impact tests were conducted. The results demonstrated that the addition of SCG lead to a slight increase in brittleness of the composite but did not significantly affect its mechanical properties. Impressively, the presence of a significant organic component in SCG contributed to the enhanced thermal performance of PP/SCG composites. This improvement was evident in terms of increased thermal stability, delayed onset of degradation, and higher maximum degradation temperature as compared to pure PP. These findings suggest that SCG has potential as a filler material for PP composites, with the ability to enhance the material's properties without compromising overall performance.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.475-475
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• 2022

The aim of this study is to identify the significant pollutant sources from the tributaries that are affecting the water quality of the study site, the Geum River and provide a solution to enhance the water quality. Multivariate statistical analysis modles such as cluster analysis, Principal component analysis (PCA) and positive matrix factorization (PMF) were applied to identify and prioritize the major pollutant sources of the two major tributaries, Gab-cheon and Miho-cheon, of the Geum River. PCA identifies three major pollutant sources for Gab-cheon and Miho-cheon, respectively. For Gab-cheon, wastewater treatment plant (WWTP), urban, and agricultural pollutions are identified as major pollutant sources. For Miho-cheon, agricultural, urban, and forest land are identified as major pollutant sources. On the contrary, PMF identifies three pollutant sources in Gab-cheon, same as PCA result and two pollutant sources in Miho-cheon. Water quality control scenarios are formulated and improvement of water quality in the river locations are simulated and analyzed with the Environmental Fluid Dynamic Code (EFDC) model. Scenario results were evaluated using a water quality index developed by Canadian Council of Ministers of the Environment. PCA and PMF appears to be effective to identify water pollution sources for the Geum river and also its tributaries in detail and thus can be used for the development of water quality improvement alternative of the above water bodies.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.3-20
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• 2005

The purpose of this study is to explore the possibility of commercialization of Korean traditional foods for the tourists. In order to develop suitable foods for the tourists, it is needed to identify the various traditional foods, its cooking process, and component parts. The author surveyed various traditional foods in Gyeonggi provinces through field visits and considered the followings: Significance of the foods in local areas and background of taking the foods, production of the foods for the tourists and foreigners, standard cooking process and mass production systems, best quality of foods and management for good qualities, period of circulation of foods, balanced nutritional elements, foods for the well-being concepts, scientific and reasonable inheritance mechanism for the foods, and concept of originality of the foods. For further development of traditional foods for the tourists, the followings should be considered: High quality of foodstuffs, advanced processing technology, marketing network, enforcement of publicity, supporting research institute on traditional foods, and automatic operation of processing facilities. As the result of this study, the following traditional foods in Gyeonggi provinces are recommended for the tourists: kongrungchang-gookbap, Moorutsook-goum, Gamja-boongsaengei, Sookboojaengei-sirudduk, Maemil-chongdduk, Gamja-ongshimi, Oksusu-ongshimi, Maemil-makguksoo, and Kotdung-chigi.

• Journal of Auto-vehicle Safety Association
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• v.15 no.3
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• pp.53-58
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• 2023

Defects in the vehicle itself were considered the biggest risk factor for traffic accidents as the electrical and electronic components of vehicles, which were not there before, increase. Therefore, the vehicles have been developed based on ISO 26262 (an international functional safety standard) which is focusing on functional defect safety evaluation of electrical and electronic component systems. However, in the future, as autonomous driving technology is applied, even vehicles without functional defects must be prepared for the dangerous traffic situation that may arise from exceptional or external factors. SOTIF (Safety Of The Intended Functionality) is a concept to prevent exceptional or external factors. The main objective of SOTIF is to decrease Unknown & Unsafe factors as much as possible by finding Known factors and Unsafe factors. In this study, Prescan provided SIEMENS, one of the autonomous driving simulators, is used to make scenarios of IGLAD traffic accident cases. From the simulation results, Unsafe & Safe cases were classified and analyzed to derive unsafe factors.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.58-68
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• 1997

In order to provide economic high-quality products to customers in a timely manner, companies have tried much effort to decrease the time period of engineering design and information management. As a part of this effort, we have developed the Drawing Information Management System(DIMS) based ofn GT(Group Technology) that could decrease design processing time by speedy and rational management of design processes. The characteristics of DIMS are as follows: First, the concept of Concurrent Engineering was applied to DIMS. Through LAN, reviewers are able to attach comments to dlectronic documents by anno- tation functions called Mark-up. The reviewer annotations are collected and combind with the original document to revise the documents. Second, we have developed a Classification and Coding(C&C) system suitable for electronic component parts bassed on GT(Group Technology). The C&C system makes both parts and drawing with similar characteriscs into families and helps users search existing documents or create new drawings promptly. Finally, DIMS provides the Engineering BOM(Bill of Material) using the concept of Family BOM based on model options.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1371-1374
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• 2011

MDA(Model Driven Architecture)는 추상적인 모델 계층을 사용하기 때문에 다양한 플랫폼에 적용가능하고, 각 모델 계층과 코드 생성의 자동화를 통해 개발의 효율성을 극대화한다. 본 연구에서는 XML 형태로 저장된 설계정보를 분석하여 MDA 기반 컴포넌트 설계 정보를 관리하는 도구를 개발하였다. 이 도구는 UML로 작성된 설계모델를 XMI(XML Metadata Interchage) 형태로 저장하여 각종 설계도구에서 Java, C++과 같은 언어에 대한 실제 프로그램 골격코드가 자동으로 생성되도록 하였다. 역으로 골격코드를 기반으로 구현된 콤포넌트의 원시코드를 수집하여 다시 컴포넌트 설계모델 정보를 추출하는 기능을 구현하였고, 이를 다시 시각적 정보로 재구성 하였다. 이러한 기능들은 기존의 단방향적 개발 구조 방식에서 벗어나 이미 개발되거나 개발 중인 프로그램에 대한 분석 및 평가 등을 통해서 재사용성을 높여주는 순환적인 개발 구조 방식을 제공한다.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.493-505
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• 2023

Comprehensive condition monitoring of large industry systems such as nuclear power plants (NPPs) is essential for safety and maintenance. In this study, we developed novel system-scale diagnostic technology based on deep-learning and IR thermography that can efficiently and cost-effectively classify system conditions using compact Raspberry Pi and IR sensors. This diagnostic technology can identify the presence of an abnormality or accident in whole system, and when an accident occurs, the type of accident and the location of the abnormality can be identified in real-time. For technology development, the experiment for the thermal image measurement and performance validation of major components at each accident condition of NPPs was conducted using a thermal-hydraulic integral effect test facility with compact infrared sensor modules. These thermal images were used for training of deep-learning model, convolutional neural networks (CNN), which is effective for image processing. As a result, a proposed novel diagnostic was developed that can perform diagnosis of components, whole system and accident classification using thermal images. The optimal model was derived based on the modern CNN model and performed prompt and accurate condition monitoring of component and whole system diagnosis, and accident classification. This diagnostic technology is expected to be applied to comprehensive condition monitoring of nuclear power plants for safety.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.1
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• pp.41-52
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• 2022

Development of a long-range artillery intercept system to counter the threat of enemy long-range artillery is in progress. This intercept system is a complex combination of several components. In addition, the ability to engage simultaneously is emphasized due to the characteristic of having to respond to numerous enemy bullets. In this study, the performance according to the arrangement of the detection asset and missile launchers, which are key components of the system, is analyzed. A simulation experiment was performed assuming the enemy attack at various azimuth and launch angles. As a result of the analysis, the radar seems to provide sufficient detection capability in any situation, but in the case of the launcher, the effect of the enemy's launch angle can be critical. It is recommended to place both radar and launchers behind the protection target.