• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.464-470
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• 1997

Severe accident analysis has been performed for the Wolsung nuclear power plants in Korea to investigate severe accident phenomena of CANDU-600 reactors as a part of Level II PSA study. The accident sequence analyzed in this paper is loss of active heat sinks(LOAH) which is caused by loss of off-site power, diesel generators, and DC power. ISAAC (Integrated Severe Accident Analysis Code)computer code developed by KAERI (Korea Atomic Energy Research Institute) was used in this analysis. This paper describes the important thermal-hydraulics and source term behaviors in the primary system and inside containment, and the failure mechanism of calandria vessel and containment. In addition, some insights for accident management program(AMP) are also given.

• Korean Journal of Psychosomatic Medicine
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• v.3 no.1
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• pp.91-97
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• 1995

Pain is a complex symptom consisting of a sensation underlying potenial disease and associated emotional state. Acute pain is a reflex biological response to injury, in contrast, chronic pain consists of pain of a mininum of 6 months duration and associates with physical, emotional past experience, economic resources of the patient, family and society. Moreover, chronic pain is characterized by physiological affective and behavioral responses that are quite different than those of acute pain. The different type of stimuli exciting pain receptor are mechanical, thermal and chemical stimli and chronic pain are concerned with three of all stimli. The major three components of pain central(Analgesia) system in the brain and spinal cord are 'periaqueductal gray area of the mesencephalon', 'the raphe magnus nucleus' and 'pain inhibitory complex located in the dorsal horns of the spinal cord'. But unfortunately, the central biochemical mechanisms of chronic pain are not clearly defined. To proper management of chronic pain, comprehensive urderstanding as a psychosomatic aspect and multidisciplinary therapeuti-team approach must be emphasized.

• Clean Technology
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• v.22 no.1
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• pp.45-52
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• 2016

This study reports on the modeling and simulation of heat transfer in packaging boxes used for vaccine shipping. Both water and n-tetradecane are used as primary insulation materials inside a multi-slab system. The one-dimensional model, which is a spherical model using a radius equivalent to the rectangular geometry of container, is applied in this study. N-tetradecane with low thermal diffusivity and proper phase transition temperature exhibits higher heat transfer resistance during both heating and cooling processes compared to water. Thus, n-tetradecane is a better candidate as an insulating material for packaging containers for vaccine shipping. Furthermore, the developed method can also become a rapid and economic tool for screening appropriate phase change materials used as insulation materials with suitable properties in logistics applications.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.559-567
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• 2018

In this paper, we propose a new load forecasting method for smart air conditioning (A/C) based on the modified thermodynamics of indoor temperature and the unbiased finite memory estimator (UFME). Based on modified first-order thermodynamics, the dynamic behavior of indoor temperature can be described by the time-domain state-space model, and an accurate estimate of indoor temperature can be achieved by the proposed UFME. In addition, a reliable A/C load forecast can be obtained using the proposed method. Our study involves the experimental validation of the proposed A/C load forecasting method and communication construction between DR server and HEMS in a test bed. Through experimental data sets, the effectiveness of the proposed estimation method is validated.

• Journal of information and communication convergence engineering
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• v.3 no.2
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• pp.101-104
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• 2005

Recently advanced countries are making every effort to promote the efficiency of electric power production and supply, to deal with the environmental problems, and to develop the new energy. In particular, they are driving forward to develop various technologies for electric power in mid-long term, that are technology for building infrastructure of power transportation, establishing service network for account management using electronic technologies, elevating economic productivity by innovative electronic technologies, control-ling the discharge of global warming gas, using clean efficient energy, and so forth. However, power technology of Korea lagged behind than technology of advanced countries. Also, resources for developing power technology are limited in our country. Therefore, it is necessary to improve the efficiency of R&D investment. For it, our country must compare and analyze with technologies of advanced countries which are taking competitive advantage in the main future energy. Through comparative analysis, limited R&D resources of our country must be concentrated on technologies that can secure competitive advantage from now on.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.235-240
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• 2008

Since urban railway transit is one of the most essential transportation systems, its power facilities must ensure high reliability and safety. Currently, urban railway operating organizations perform TBM (Time Based Maintenance) on power facilities. However, in order to improve management efficiency and system safety, CBM (Condition Based Maintenance) is preferred. Among various power facilities, mold transformers has been chosen as the object of study since it is widely used for the purpose of minimizing volume and weight, and due to safety against fire. In this paper, various transformer failure cases due to electric, thermal, mechanical and environmental factors have been collected and analyzed. In addition, investigation on national and international condition based maintenance cases and the characteristics of sensors widely used for transformer monitoring has been performed to suggest the optimal condition based maintenance technique for urban railway systems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.7
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• pp.623-629
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• 2004

Rapid development of electronic technology requires small size, high density packaging and high power of electronic devices, which result in more heat generation by the electronic system. Present cooling technology may not be adequate for the thermal management in the current state-of-the-art electronic equipment. Forced convective heat transfer in a channel filled with pin-fin array is studied experimentally in this paper as an alternative cool-ing scheme for a high heat-dissipating equipment. Various configurations of the pin-fin array are selected in order to find out the effect of spacing and diameter of the pin-fin on the heat transfer and pressure drop characteristics. In the low porosity region, interfacial heat transfer and pressure drop seem to show different trend compared to the conventional heat transfer process.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.290-291
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• 2023

모빌리티 기술의 발전으로 자율주행 및 센서 데이터 처리를 위한 신뢰할 수 있는 고성능 저장 시스템의 수요가 증가하고 있다. SSD(Solid State Drive)는 빠른 데이터 처리 속도의 장점뿐만 아니라 외부 충격에 강한 내구성과 저전력의 특징 때문에 모빌리티 환경의 저장 시스템으로 사용되고 있다. 그러나 고온에 장시간 노출되면 NAND 플래시 메모리 소자에 손상이 발생할 수 있는 특성 때문에 모빌리티 내부 SSD의 온도를 관리해야 한다. 본 논문에서는 SSD의 외부 및 내부의 온도를 측정하여 저장장치가 고온에 장시간 노출되지 않도록 쿨링 시스템을 설계하고 실험을 통하여 적정 온도를 유지할 수 있는 최적화 방법을 제안한다. 또한 실험을 통해 쿨링 시스템이 SSD의 내부와 외부에 미치는 온도 변화를 측정하여 제안하는 시스템의 효과를 증명한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.735-737
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• 2017

An Off grid or remote solar electric systems are an energy supply to our home or to our companies without the utility of Grid at all. Off grid solar systems are very important for those who live in remote locations especially for developing countries where getting the electric grid is extremely expensive, inconvenient or for those who doesn't need to pay a monthly bill with the electric bill in general. The main critical components of any solar power system or renewable energy harvesting systems are the energy storage systems and its charge controller system. Energy storage systems are the essential integral part of a solar energy harvesting system and in general for all renewable energy harvesting systems. To provide an optimal solution of both high power density and high energy density at the same time we have to use hybrid energy storage systems (HESS), that combine two or more energy storage technologies with complementary characteristics. In this present work, design and simulation we use two storage systems supercapacitor for high power density and lithium based battery for high energy density. Here the system incorporates fast-response supercapacitors to provide power to manage solar smoothing and uses a battery for load shifting. On this paper discuss that the total energy throughout of the battery is much reduced and the typical thermal stresses caused by high discharge rate responses are mitigated by integrating supercapacitors with the battery storage system. In addition of the above discussion the off grid solar electric energy harvesting presented in this research paper includes battery and supercapacitor management system, MPPT (maximum power point tracking) system and back/boost convertors. On this present work the entire model of off grid electric energy harvesting system and all other functional blocks of that system is implemented in MATLAB Simulink.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.361-364
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• 2009

KEPRI has studied planar type SOFC stacks using anode-supported single cells and kW class co-generation systems for residential power generation. A 1kW class SOFC system consisted of a hot box part, a cold BOP part and a water reservoir. A hot box part contains a SOFC stack made up of 48 cells with $10{\times}10cm^2$ area and ferritic stainless steel interconnectors, a fuel reformer, a catalytic combustor and heat exchangers. Thermal management and insulation system were especially designed for self-sustainable operation. A cold BOP part was composed of blowers, pumps, a water trap and system control units. When a 1kW class SOFC system was operated at $750^{\circ}C$ with hydrogen, the stack power was 1.2kW at 30 A and 1.6kW at 50A. Turning off an electric furnace, the SOFC system was operated using hydrogen and city gas without any external heat source. Under self-sustainable operation conditions, the stack power was about 1.3kW with hydrogen and 1.2kW with city gas respectively. The system also recuperated heat of about 1.1kW by making hot water. Recently KEPRI developed stacks using $15{\times}15cm^2$ cells and tested them. KEPRI will develop a 5 kW class CHP system using $15{\times}15cm^2$ stacks by 2010.