• 대한기계학회논문집B
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• 제28권10호
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• pp.1172-1177
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• 2004

The emission control of automobile has been intensified as a part of the countermeasure to decrease air pollution in the world. As the cars with an alternative fuel starts to get into the spotlight, the cars with low emission has been introduced and exhaust gas regulation forced in this country. These days, LPG vehicles, which infrastructure of fuel was already built up, and CNG vehicles are recognized for alternative fuel cars in this country. In this study, the constant volume combustion chamber was manufactured and used for experiments to obtain the combustion characteristics of propane mixture. The combustion characteristics was analyzed, with the change of supply conditions of propane fuel. Inside the combustion chamber, the maximum temperature increase with the initial pressure is going up. The burning velocity also seems to have the same characteristic as the temperature. However, the heat flux do not change much according to the theoretical correct mixture but it changes with the various initial temperature of the combustion chamber.

• 한국자동차공학회논문집
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• 제12권3호
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• pp.75-82
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• 2004

The allowable exhaust standard has been intensified as a part of the countermeasure to decrease air pollution in the world. As the cars with an alternative fuel starts to get into the spotlight, the cars with low emission has been introduced and exhaust gas regulation forced in this country. These days, LPG vehicles, which infrastructure of fuel was already built up, and CNG vehicles are recognized for alternative fuel cars in this country. In this study, the constant volume combustion chamber was manufactured and used for experiments to obtain the ignition characteristics of LPG fuel and the optimal ignition energy. The experiment measured the combustion characteristics, in regard to the change of combustion variable, and the change of ignition energy. During the combustion of fuel, the maximum temperature inside the combustion chamber is higher when the initial pressure is higher. The burning velocity also seems to have the same characteristic as the temperature. However, the heat flux did not change much with the theoretical correct mixture but the various initial temperature of the combustion chamber. The heat flux got faster and ignition energy bigger as the dwell time of the ignition system expanded. When the dwell time get longer, the ignition energy also increased then fixed. The ignition energy increased as the initial pressure inside the combustion chamber higher. The heat flux got faster as the dwell time expanded.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.77-81
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• 2009

The elderly population ratio of domestic is the actual condition where the countermeasure which is various for there is a possibility of saying that is already experiencing the aging society, is considered. The expansion of the elderly welfare facility of the area where is located among the rest in the situation as a matter of metropolitan area of domestic ephemerality and the price of land which the earth has, duplication operation etc. is having a problem point and the ephemerality which are various. About of composition different facility and leads with alternative and expansion and function of function and facility leads and the synergy effect which is various shows. So this study is consequently does the school facility which is located in life circle of the city center in middle of composition of the elderly welfare facility and other facility and in the object and under proposing boil the complex at the time of spatial composition blueprint with the elderly welfare facility and the school.

• Journal of the Korean Wood Science and Technology
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• 제20권3호
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• pp.39-54
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• 1992

Hollow core wood flush doors for wardrobes, and other general openings and bathroom were designed and fabricated to investigate the factors causing the bowing of them and to find out the countermeasure for the phenomena. Balance in grain orientation, thickness, specific gravity and M.C.(%) of face panel and symmetrical construction were the essential factors to prevent the deflection of flush doors just after manufacturing. Under one-sided severe service condition, the unbalance of M.C. between opposite face panels is inevitable. So the material as thick plywood with high stiffness is considered as an alternative for the stile. UF resin mixing into PVAc emulsion is preferred for bathroom.

• Korean Chemical Engineering Research
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• 제54권6호
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• pp.781-785
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• 2016

위험물인 염산을 취급하는 사업장에서 발생할 수 있는 사고를 알아내고 사고시 인근에 미치는 영향을 평가하여 어느 정도 위험이 있는지 알아보며 이에 대한 대비책을 적용하고자 하였다. 취급 화학물질 정보와 공정정보로부터 사고 시나리오를 선정하고 염산 누출시 사업장외로 영향을 미치는 사고 시나리오를 선정하여 환경부의 지침에 따라서 ALOHA를 활용하여서 평가하였다. 최악의 사고 시나리오를 비롯한 사고 시나리오를 평가하였으며 이들의 사고시 피해완화대책도 살펴보았다. 평가결과 염산생산시설은 현재의 안전조치가 충분하여서 추가의 개선대책이 필요하지 않은 것으로 판명되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1297-1301
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• 2007

The indoor air quality guideline of public transportation means was prepared recently. therefore we consider a countermeasure for the indoor air quality improvement of public transportation means. In this work, air-cleaner with roll filter system which developed alternative of indoor air quality guideline. The develpoed roll filter system is two function. the first function harmoniously circulated to heating and cooling air through HVAC system and secondary function removed PM(particluatie matters) which re-scatting to passenger's movement and suppled from outdoor air. Filter media of roll filter system select optimum electret mesh filter out of many filter media. Selected filter media was performanced tests of pressure drop, collection efficiency and dust holding capacity. Finally developed roll filter system was performanced bench test.

• 대한전기학회논문지:전력기술부문A
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• 제49권11호
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• pp.558-565
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• 2000

In this paper, we propose a method for mitigating for mitigating the effect of voltage of voltage sag in radial power distribution systems using load transfer switching (LTS). The term of LTS is defined that the weakness load points for voltage sag transfer to the alternative source during the fault clearing practices. The sequenced of proposed LTS method is divided into the search of weakness points for voltage sag using the risk assessment model and transfer behavior of weakness points. The search of weakness point is carried out using the risk assessment model of voltage sag and Monte Carlo simulation method and the historical reliability data in Korea Electric Power Corporation (KEPCO) are also used. Through the case studies, we verify the effectiveness of proposed LTS method and present the searching method of effective application points of LTS method using the risk assessment model.

• 디지털산업정보학회논문지
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• 제4권3호
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• pp.45-53
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• 2008

As internet is wide spread, the number of internet service provider is increased. Internet service providers gather the personnel information with inhabitants registration identification number for the user management and the adult authentication. The personnel information is spreaded thorough the Internet by the system hacking, mismanagement and malicious resale. And the personnel information is used for spam email, phishing scams, etc. by malicious others. So the Ministry of Information and Communication Republic of Korea developments I-PIN system of the personnel identification. But, I-PIN has some problem the guideline for it and the method of 5 I-PIN services. In this paper, we analyze the problem about the guideline for I-PIN and the method of 5 I-PIN services. And we propose the countermeasure about the problem.

• 한국해안·해양공학회논문집
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• 제31권5호
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• pp.305-313
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• 2019

최근 해수면상승이나 해상조건의 악화 등으로 인해 연안보존을 위한 해안구조물 수가 급격히 증가하고 있다. 해안구조물은 소실되거나 제거되어서는 안 된다는 조건에서 관련된 해안 생태계를 충족하면서 해안공학적 특성을 만족하도록 계획이 이루어져야 한다. 본 연구에서는 이를 위해 사다리꼴 형태의 개비온블록을 개발하였으며 이동상 2차원 단면실험을 통해 타당성을 검토하였다. 실험은 8가지의 침식형 및 퇴적형 파랑에 대해 수행하였으며, 실험결과 개비온 블록이 해빈단면의 침식을 억제하는 특성이 있음을 확인하였다. 새롭게 고안된 개비온 블록에 대한 실험결과 해빈침식 대책공법의 대안으로 가능성이 있을 것으로 판단되었다.

• International Journal of Internet, Broadcasting and Communication
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• 제16권1호
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• pp.17-28
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• 2024

As listed as one of the most important requirements for Post-Quantum Cryptography standardization process by National Institute of Standards and Technology, the resistance to various side-channel attacks is considered very critical in deploying cryptosystems in practice. In fact, cryptosystems can easily be broken by side-channel attacks, even though they are considered to be secure in the mathematical point of view. The timing attack(TA) and the simple power analysis attack(SPA) are such side-channel attack methods which can reveal sensitive information by analyzing the timing behavior or the power consumption pattern of cryptographic operations. Thus, appropriate measures against such attacks must carefully be considered in the early stage of cryptosystem's implementation process. The Montgomery multiplier is a commonly used and classical gadget in implementing big-number-based cryptosystems including RSA and ECC. And, as recently proposed as an alternative of building blocks for implementing post quantum cryptography such as lattice-based cryptography, the big-number multiplier including the Montgomery multiplier still plays a role in modern cryptography. However, in spite of its effectiveness and wide-adoption, the multiplier is known to be vulnerable to TA and SPA. And this paper proposes a new countermeasure for the Montgomery multiplier against TA and SPA. Briefly speaking, the new measure first represents a multiplication operand without 0 digits, so the resulting multiplication operation behaves in a very regular manner. Also, the new algorithm removes the extra final reduction (which is intrinsic to the modular multiplication) to make the resulting multiplier more timing-independent. Consequently, the resulting multiplier operates in constant time so that it totally removes any TA and SPA vulnerabilities. Since the proposed method can process multi bits at a time, implementers can also trade-off the performance with the resource usage to get desirable implementation characteristics.