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.

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.

R170/R290 혼합냉매 적용 히트펌프 성능 평가

박기정(Ki-Jung Park),이철희(Cheol-Hee Lee),정동수(Dongsoo Jung) 대한설비공학회 2008 설비공학 논문집 Vol.20 No.9

In this study, performance of R170/R290 mixtures is measured on a heat pump bench tester in an attempt to substitute R22. The bench tester is equipped with a commercial hermetic rotary compressor providing a nominal capacity of 3.5 ㎾. All tests are conducted under the summer cooling and winter heating conditions of 7/45℃ and -7/41 ℃ in the evaporator and condenser respectively. During the tests, the composition of R170 is varied from 0 to 10% with an interval of 2%. Test results show that the coefficient of performance (COP) and capacity of R290 are up to 15.4% higher and 7.5% lower than those of R22 for both conditions respectively. For R170/R290 mixture, the COP decreases and the capacity increases with an increase in the amount of R170. The mixture of 4%R170/96%R290 shows the similar capacity and COP as those of R22. For the mixture, the compressor discharge temperature is 16~30℃ lower than that of R22. There is no problem with mineral oil since the mixture is mainly composed of hydrocarbons. The amount of charge is reduced up to 58% as compared to R22. Overall, R170/R290 mixture is a good long term 'drop-in'. candidate to replace R22 in residential air-conditioners and heat pumps.

임계 열유속 근방까지의 풀 비등 열전달계수

박기정(Ki-Jung Park),정동수(Dongsoo Jung) 대한설비공학회 2008 설비공학 논문집 Vol.20 No.9

In this work, pool boiling heat transfer coefficients(HTCs) of 5 refrigerants of differing vapor pressure are measured on horizontal smooth square surface of 9.52 ㎜ length. Tested refrigerants are R123, R152a, R134a, R22, and R32 and HTCs are taken from 10 ㎾/㎡ to critical heat flux of each refrigerant. Wall and fluid temperatures are measured directly by thermocouples located underneath the test surface and by thermocouples in the liquid pool. Test results show that pool boiling HTCs of refrigerants increase as the heat flux and vapor pressure increase. This typical trend is maintained even at high heat fluxes above 200 ㎾/㎡. Zuber's prediction equation for critical heat flux is quite accurate showing a maximum deviation of 21% for all refrigerants tested. For all refrigerant data up to the critical heat flux, Stephan and Abdelsalam's well known correlation underpredicted the data with an average deviation of 21.3% while Cooper's correlation overpredicted the data with an average deviation of 14.2%. On the other hand, Gorenflo's and lung et al's correlation showed only 5.8% and 6.4% deviations respectively in the entire nucleate boiling range.

웹기반 유전체 분석시스템 개발

박기정(Kiejung Park),서화정(Hwajung Seo),태홍석(Hongseok Tae),김기봉(Ki-Bong Kim),남혜원(Hyeweon Nam),이대상(Daesang Lee) 한국정보과학회 2003 정보과학회지 Vol.21 No.6

경제서비스화가 소득불균등에 미치는 효과에 대한 연구

박기정(Ki Jeong Park),이현창(Hyun Chang Yi) 한국경제연구학회 2008 한국경제연구 Vol.20 No.-

본 연구는 한ㆍ미 FTA 등 시장개방으로 인해 경제서비스화가 더욱 촉진될 것으로 전망되는 가운데 경제서비스화 진전 등 산업구조의 변화가 소득불균등에 미치는 효과를 산업별 요인분해를 통해 실증분석하였다. 소득의 구성항목별ㆍ소득분위별ㆍ산업별 소득불균등지표를 추정해 본 결과 우리 나라의 산업별 임금격차요인에 의한 불균등도는 지속적으로 축소되고 있으나 2000년 이후 경제서비스화의 진전으로 인해 서비스부문 내의 임금불균등 정도가 심화되었고, 이는 다시 전반적인 임금불균등도의 악화로 이어졌음을 알 수 있었다. 산업별 요인분해 결과 소득불평등 정도는 근로소득에 의해 결정됨을 확인할 수 있었으며, 그 중 서비스부문 내 임금불균등의 기여율이 가장 큰 비중(70%)을 차지하였고 소득불균등 심화에서도 가장 주요한 원인으로 나타났다. The trend toward service economy has become predominant not only in the aspects of production, expenditure, and industrial organization but also in employment composition. It is the widely diversified levels of productivity and wage that characterize service sectors, such as finance, insurance, whole sale, and retail trade, distinctively from manufacture. Thus, the bigger the portion of workers employed in service industries grows, the more likely adverse impacts on income distribution would incur. This paper showed the effects of the expansion of the service sector on the income inequality quantitatively using industry-level wage and employment data of Korea. Using a variance decomposition method, we found that the widening of the earning inequality was attributed in a large part to the expansion of the service economy. Given the enlargement of both the share of services and the wage gap within service sectors, some long-horizon policies are needed to mitigate the income inequality such as public investments in vocational training programs for enhancing overall productivity in service sectors and a kind of social safety net for unskilled people.

주의력결핍 과잉행동장애 아동의 약물치료가 운동협응력에 미치는 효과 : 개방연구

박기정(Kee Jeong Park),권국주(Kukju Kweon),이세정(Saejeong Lee),임연신(Yun Shin Lim),정유숙(Yoo Sook Joung),김효원(Hyo-Won Kim) 대한소아청소년정신의학회 2017 소아청소년정신의학 Vol.28 No.4

Objectives: The objective of this study was to investigate the effect of pharmacological treatments for attention-deficit hyperactivity disorder (ADHD) on motor coordination, using the Developmental Coordination Disorder Questionnaire (DCDQ). Methods: The participants were recruited from April 2015 to November 2016 from the Department of Psychiatry of Asan Medical Center and were treated for 3 months with methylphenidate or atomoxetine. The illness severity at baseline and 3 months were scored using the ADHD Rating Scale (ARS), Clinical Global Impression-Severity Scale (CGI-S) and/or Clinical Global Impression-Improvement Scale (CGI-I). A total of 39 children with ADHD (age 8.0±1.4 years, 36 boys) completed the Advanced Test of Attention (ATA) and their parents completed the DCDQ at baseline and 3 months. The paired t-test, mixed between-within analysis of variance and correlation analysis were used. Results: The CGI-S (p<0.001), ARS (p<0.001), and fine motor/hand writing (p=0.005) on the DCDQ were significantly changed between pre-treatment and post-treatment. When the participants were divided into those who were suspected of having developmental coordination disorder (DCD) (n=23) and those who probably did not (n=16), the control during movement, fine motor/hand writing and general coordination scores on the DCDQ showed the main effects for group (p<0.001, p<0.001 and p<0.001, respectively). The fine motor/hand writing on the DCDQ has a significant main effect for time [F(1,37)=7.31, p=0.010, η<SUP>2</SUP>=0.405] and the interaction effect between group and time was also significant [F(1,37)=4.63, p=0.038, η<SUP>2</SUP>=0.111]. The baseline visual commission error on the ATA is significantly correlated with the changes in the DCDQ total scores (r=0.330, p=0.040). Conclusion: Our results provide preliminary evidence that pharmacological treatment for ADHD improves not only the core symptoms of ADHD, but also the motor coordination. Further studies are needed to confirm the effect of the pharmacological treatment for ADHD on the motor coordination.

극저온 열처리 공정이 6061 알루미늄 합금의 잔류응력과 인장특성에 미치는 영향

박기정 ( Ki Jung Park ),고대훈 ( Dea Hoon Ko ),김병민 ( Byung Min Kim ),임학진 ( Hak Jin Lim ),이정민 ( Jung Min Lee ),조영래 ( Young Rae Cho ) 대한금속재료학회(구 대한금속학회) 2011 대한금속·재료학회지 Vol.49 No.1

To develop a 6061 aluminum alloy with low residual stress and high tensile strength, a cryogenic treatment process was investigated. Compared to the conventional heat treatment process for precipitation hardening with artificial aging, the cryogenic treatment process has two additional steps. The first step is cryogenic quenching of the sample into liquid nitrogen, the second step is up-hill quenching of the sample into boiling water. The residual stress for the sample was measured by the sin2 ψ method with X-ray diffraction. The 6061 aluminum alloy sample showed 67% relief in stress at the cryogenic treatment process with artificial aging at 175℃. From this study, it was found that the optimum cryogenic treatment process for a sample with low residual stress and high tensile strength is relatively low cooling speed in the cryogenic quenching step and a very high heating speed in the up-hill quenching step.

중성자 핵변환 도핑을 위한 수조 내 수력 회전장치 개념 설계

박기정(Ki-Jung Park),서경우(Kyoungwoo Seo),김성훈(Seong Hoon Kim) 대한기계학회 2018 大韓機械學會論文集B Vol.42 No.7

실리콘의 중성자핵변환도핑(Neutron transmutation doping, NTD)은 연구용 원자로(Research Reactor) 이용의 중요한 아이템 중 하나이다. 고품질의 NTD 조사 웨이퍼를 생산하기 위해서는 NTD 조사 과정에서 NTD 조사체를 일정한 속도로 장시간 회전시키는 것이 필요하다. 본 연구에서는 기존의 많은 연구용 원자로에 적용 중인 모터를 이용한 기계식 회전 방식의 단점을 보완할 수 있는 수력 회전장치(Hydraulic rotation device, HRD)에 대한 개념설계를 수행하였다. 수력회전장치는 유량 공급 펌프를 이용하여 어떠한 기계 구동부 없이 수력을 이용하여 실리콘 잉곳을 일정한 속도로 회전시킬 수 있는 새로운 개념의 회전장치이다. NTD 조사를 위한 수력회전장치는 스러스트 베어링 부분(Thrust bearing part)과 저널 베어링 부분(Journal bearing part) 그리고 임펄스 제트 부분(Impulse jet part)의 세 부분으로 구성된다. 각 부분으로 연결된 노즐에서 형성된 고압의 제트류에 의해 회전체의 안정적인 부상, 지지 및 일정속도의 회전을 구현하도록 설계하였다. 본 연구에서 제안된 수력회전장치 개념은 향후 실제 적용을 위해 제작 및 실험을 통해 추가 검증되어야 한다. Neutron transmutation doping (NTD) of silicon is one of the important items in the utilization of a research reactor. For the production of high-quality NTD silicon, it is necessary to rotate the silicon ingot at a uniform speed and in a certain position in the NTD irradiation sites for uniform irradiation of the NTD during the NTD irradiation process. In this study, a hydraulic-driven rotation system is proposed to make up for the weakness of the motor-driven rotation system as the conventional method, which is needed to enhance the reliability of NTD systems. The hydraulic rotation device (HRD) for the NTD to rotate the silicon ingot at a uniform speed is designed conceptually to apply the new concept of a hydraulic-driven rotation system. The HRD designed for the NTD consists of a thrust bearing part, journal bearing part, and an impulse jet part. High-pressure water jets are supplied through each nozzle. The thrust bearing part is designed for the stable levitation of the silicon ingot and HRD in the pool. The journal bearing part is designed to support the HRD during thrust and rotation. The impulse jet part is designed for uniform rotation of the HRD. Through the proposed design, the potential for application to a new NTD rotation system will be verified.

음의 푸아송 비를 이용한 압전 에너지 하베스팅 성능 증대 연구

박기정(Park Gi Jeong),김도건(Do Geon Kim),윤헌준(Heonjun Yoon) 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.5