지하주차장 보행안전 평가 프레임워크 개발 및 적용

한재성(Jaesung Han),박기정(Kijung Park) 대한인간공학회 2019 大韓人間工學會誌 Vol.38 No.3

Objective: This study aims to develop a pedestrian safety assessment model for underground parking facilities that comprehensively measure the pedestrian safety level of an underground parking facility. Background: Although underground parking spaces have many potential risks that can cause pedestrian accidents, assessment frameworks that enable to comprehensively measure and monitor the risk levels of underground parking facilities have not been widely discussed in the literature. In this regard, it is necessary to develop a safety assessment framework that can objectively and quantitatively capture the safety level in an underground parking facility. Method: 381 indicators that are associated with general pedestrian safety were extracted from the extant literature first. Then, these indicators were streamlined and standardized based on the importance of each indicator. Finally, a total of ten identified major indicators with sub-indicators and three safety factors categorizing these indicators were derived as a basis of a safety assessment framework. A weighted average scoring system using Analytic Hierarchy Process (AHP) was employed for the indicators measured in a Likert scale and their associated factors to quantify the overall safety level. The proposed framework was applied to a case study of a Korean university. Results: The results showed the overall safety level of the undergraduate parking facility at the university is in a range of "requiring minor treatment". However, the visibility factor had a low safety score, which requires immediate treatment. Based on the assessment results, a sensor system was proposed to improve the safety score of visibility. Conclusion: This study proposed an assessment framework that can objectively measure the safety level of an undergraduate parking space based on multi-criteria for pedestrian safety. The proposed framework can be a useful basis to continuously monitor the progress of underground-parking safety. Application: The proposed framework can be applied to any type of undergroundparking spaces.

원자력 발전용 고온고압 시험장치 내 배수라인 오리피스 개념 설계

박기정(Ki-Jung Park),이선일(Sunil Lee),박주현(Joo Hyun Park),최용석(Yong-Seok Choi) 한국유체기계학회 2021 한국유체기계학회 학술대회 논문집 Vol.2021 No.12

GGEx18의 ethyl acetate 분획물에 의한 고지방식이 비만 마우스의 식이효율과 혈중 leptin 농도에 미치는 영향

박기정,이희영,이혜림,윤미정,박선동,이용태,심지빈,최홍화,신순식,Park, Ki-Jeong,Lee, Hee-Young,Lee, Hye-Rim,Yoon, Mi-Chung,Park, Sun-Dong,Lee, Yong-Tae,Shen, Zhi-Bin,Cui, Hong-Hua,Shin, Soon-Shik 대한한의학방제학회 2011 大韓韓醫學方劑學會誌 Vol.19 No.1

Objectives : This study was designed to determine the effects of the GGEx18 ethyl acetate fraction(EF) on body weight gain, feeding efficiency ratio, and obesity-related factors in plasma as well as histology of liver and adipose tissues using high fat diet-fed male C57BL/6N obese mice. Methods : 8 weeks old, high fat diet-fed obese male mice were divided into 5 groups: C57BL/6N normal, control, EF(1), EF(2) and EF(3). After mice were treated with EF for 9 weeks, we measured body weight gain, food intake, feeding efficiency ratio, fat weight, plasma leptin and lipid levels. We also analysed histology of liver and adipose tissues on high fat diet-fed male C57BL/6N obese mice. Results : Compared with control, EF-treated mice had significantly lower body weight gain and feeding efficiency ratio. Consistent with the effects on body weight gain, EF significantly decreased the adipose tissue weight compared with control. Consistent with the effects on feeding efficiency ratio, EF significantly decreased plasma leptin concentrations compared with control. EF reduced the size of adipocytes as well as hepatic lipid accumulation compared with control. EF seems to be safe since not only the plasma levels of ALT and AST are within the normal range, but also EF did not show any toxic effects on organs. EF(3) was most effective among EF(1), EF(2), and EF(3) at doses of 25, 50, and 100 mg/kg, respectively. Conclusions : These results demonstrate that EF effectively reduces body weight gain, feeding efficiency ratio in high fat diet-fed obese mice, leading to the modulation of obesity. In addition, EF decreases the size of adipocytes and improves plasma lipids and controls hepatic lipid accumulation, suggesting that EF may act as a therapeutic agent for obesity.

평활관과 낮은 핀관에서 R245fa의 풀 비등 열전달계수

박기정(Ki-Jung Park),이요한(Yohan Lee),임병덕(Byeongdeok Lim),정동수(Dongsoo Jung) 대한설비공학회 2011 설비공학 논문집 Vol.23 No.3

In this work, pool boiling heat transfer coefficients(HTCs) of R22, R123, R134a, and R245fa are measured on both horizontal plain and 26 fpi low fin tubes. The pool boiling temperature is maintained at 7℃ and heat flux is varied from 80 ㎾/㎡ to 10 ㎾/㎡ with an interval of 10 ㎾/㎡. Wall temperatures are measured directly by thermocouples inserted through holes of 0.5 ㎜ diameter. Test results show that HTCs of high vapor pressure refrigerants are usually higher than those of low pressure fluids in both plain and low fin tubes. On a plain tube, HTCs of R245fa are 23.3% higher than those of R123 while on a 26 fpi low fin tube, HTCs of R245fa are 46.3% higher than those of R123. The fin effect is more prominent with low vapor pressure refrigerants than with high vapor pressure ones due to a sweeping effect.

개방 수조형 연구용 원자로의 조사체 냉각 계통 개념 설계

박기정(Ki-Jung Park),정민규(Minkyu Jung),서경우(Kyoungwoo Seo),김성훈(Seong-Hoon Kim) 대한기계학회 2019 대한기계학회 논문집. Transactions of the KSME. C, 산업기술과 혁신 Vol.7 No.2

연구용 원자로는 핵분열 연쇄 반응으로 발생한 중성자를 기초 연구에서 산업 및 공학적 응용 연구까지의 광범위한 분야에 걸쳐 이용하는 원자로이다. 이 중성자를 이용하는 가장 중요한 분야 중 하나는 매우 다양하게 사용되는 동위 원소 생산 분야이다. 여러 동위 원소 중 Mo-99는 전 세계적으로 의학 진단 등의 의료 분야에서 많이 사용되고 있으며, 이에 대한 수요가 해마다 증가하고 있다. Mo-99 조사시 발생하는 열량은 핵연료에서 발생하는 열량과 비슷한 수준으로 안정적인 Mo-99 생산을 위해서는 충분한 냉각 시스템 설계가 동반되어야 한다. 특히 외부 반사체에서 Mo-99 타깃을 조사할 경우 Mo-99 냉각을 위한 별도의 냉각 계통이 설계되어야 한다. 외부 반사체 내에서의 냉각수 흐름 방향에 따라 냉각계통 설계가 크게 달라지게 되며, 각 유동 방향에 따른 장단점을 분석하여 계통 설계에 적용해야 한다. 본 연구에서는 Mo-99를 포함한 조사체 냉각 계통 설계에 적용 가능한 냉각 계통 개념을 제안하였으며, 이를 바탕으로 개방 수조형 연구용 원자로의 조사체 냉각 계통 개념 설계를 수행하였다. Research reactors are nuclear reactors that utilize fission chain reactions for a wide range of applications, from basic research to industrial and engineering applications. One of the most important application areas is the radioisotope production area. Mo-99 is widely used in medical fields such as medical diagnosis and the demand for Mo-99 is increasing every year. The heat generated by Mo-99 irradiation is similar to that from nuclear fuel, so sufficient cooling system design must be accompanied by stable Mo-99 production. In particular, when Mo-99 target is irradiated on an out-core reflector, an independent cooling system for Mo-99 should be designed. The design of the cooling system depends on the flow direction of the cooling water in the out-core reflector. The characteristic of each flow direction should be analyzed and applied to the conceptual design. In this study, the applicable conceptual design of irradiation targets cooling system of open pool research reactor was proposed.

수조형 연구용 원자로의 운전모드에 따른 수조 냉각을 위한 열교환기 성능 예측

박기정(Ki-Jung Park),박홍범(Hong Beom Park) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

부품영상인식을 통한 SPOT용접 자동화시스템의 설계 및 구현

박기정(Ki-Jung Park),송하주(Ha-Joo Song) 한국멀티미디어학회 2010 한국멀티미디어학회 학술발표논문집 Vol.2010 No.2

기존의 SPOT용접시스템은 작업자의 부주의로 인한 불량이 자주 발생한다. 이를 위해 비전카메라를 설치해서 용접되는 부품을 인식하고, 용접된 제품과 수량 등의 관리항목을 집중 관리하는 SPOT용접 자동화시스템을 제안한다. 제안하는 시스템은 공급기에서 공급한 너트나 볼트를 사람의 육안만으로 확인하여 용접하는 기존의 방식과는 달리, 비전카메라를 이용하여 부품의 유무와 뒤집힘 등을 확인한 후 용접하고, 수량카운터와 드레싱 등의 관리항목을 자동 관리한다. 따라서 용접 불량률을 감소시키고 작업 관리자의 업무 효율성을 높일 수 있다.

팽창 메타물질 기반 압전 에너지 하베스팅의 수학적 해석

박기정(Gijeong Park),김도건(Dongeon Kim),윤헌준(Heonjun Yoon) 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.11

신냉매 R1234yf의 외부 응축 열전달계수

박기정(Ki-Jung Park),이철희(Cheol-Hee Lee),강동규(Dong Gyu Kang),정동수(Dongsoo Jung) 대한설비공학회 2010 설비공학 논문집 Vol.22 No.6

In this study, external condensation heat transfer coefficients(HTCs) of R134a and R1234yf are measured on a plain, low fin, and Turbo-C tubes at the saturated vapor temperature of 39℃ with the wall subcooling of 3~8℃. R1234yf is a new alternative refrigerant of low greenhouse warming potential for replacing R134a which is one of the greenhouse gases controlled by Kyoto protocol and is used extensively in mobile air-conditioners. Test results show that the external condensation HTCs of R1234yf are very similar to those of R134a for all three surfaces tested. For the application of condensation heat transfer correlations to the design of condensers charged with R1234yf, thorough property measurements are needed for R1234yf in the near future.

단백질 1차 배열 다중정렬을 위한 알고리즘

박기정,신준호,박찬규,Park, Kie-Jung,Sheen, Joon-Ho,Park, Chan-Kyu 생화학분자생물학회 1989 한국생화학회지 Vol.22 No.3

분자생물학에서 컴퓨터는 많은 수의 분자배열을 짧은 시간 내에 비교 정렬하는데 이용되어 왔다. 이를 위해, 다른 접근방법들과 몇 가지 점에서 차이를 보이는 새로운 알고리즘이 제안되었다. MAlign이라 명명된 이 알고리즘은 비교 배열들간의 동시 비교를 효과적으로 수행할 수 있는 방법을 도입, 전체적 상동성을 검색할 수 있게 고안되었다. 동시 비교성의 결여는 기존의 알고리즘들이 갖는 문제점 중의 하나이었는데 이것을 consensus 또는 compacted sequence를 비교 과정에 도입함으로써 해결하였으며, 상동성 벡터 (homology vector) 개념을 적용하여 각 중간 배열들의 상동성 값을 벡터전사의 과정으로 비교함으로써 전체적인 비교를 용이하게 하였다. 몇몇 실험결과로부터, 다중배열 비교에 있어서는 일대일 대응 배열에서 나타난 높은 상동성값이 유지되는 것과 상동성이 높아질수록 이러한 결과가 더욱 두드러짐을 알 수 있었다. 이러한 정근방법을 이용하여 Copper 결합 단백질들과 세균의 신호 발생 단백질들에 대한 다중정렬 결과가 제시되었다. One application of computer in molecular biology has been the use of its power for comparing a large number of molecular sequences in very short time. For this purpose, a new algorithm is proposed which differs in several aspects from other approaches. Our algorithm, called MAlign, is designed to seek global homology by introducing an effective way to make simultaneous comparisons among test sequences. One problem in previous algorithms which were limited in its ability to compare sequences simultaneously has been solved by introducing intermediate consensus or compacted sequences and including them for comparison. In addition, a homology vector concept was applied to provide uniform representation for each intermediate, which makes global comparison easier. Several test results indicate that high homology values obtained from pairwise alignment are maintained after multiple alignment of those sequences, which is more apparent in higher homology values. Sample alignment results using this approach for three different copper binding proteins as well as bacterial signaling proteins are presented.