Al-4at.%Zr합금의 기계적합금화 공정과 열처리과정에서 발생하는 상변화거동

박재필,김일호,권숙인,Park, Jae-Pil,Kim, Il-Ho,Kwun, S.I. 한국분말야금학회 2005 한국분말재료학회지 (KPMI) Vol.12 No.1

Four different mechanical alloying(MA) processes were employed to fabricate very fine intermetallic compound $Al_3Zr$ particles dispersed Al composite materials(MMC) with Al-4at.%Zr composition. Phase transformations including phase stability during MA and heat treatment processes were investigated. Part of Zr atoms were dissolved into Al matrix and part of them reacted with hydrogen produced by decomposition of PCA(methanol) to form hydride $ZrH_2$ during first MA process. These $ZrH_2$ hydrides disappeared when alloy powders were heat treated at $500^{\circC}$. Stable $Al_3Zr$ dispersoids with $DO_23$ structure were formed by heat treating the mechanically alloyed powders at $400^{\circC}$. On the other hand, metastable $Al_3Zr$dispersoids with $L1_2$ structure were formed during first MA of powers with Al-25at.%Zr composition. These metastable $Al_3Zr$ dispersoids transformed to stable $Al_3Zr$ with $DO_23$ structure when heat treated above $450^{\circC}$.

서남해안 2.5GW 해상풍력단지 건설의 경제효과분석

박재필 ( Jae Pil Park ),김민영 ( Min Young Kim ),황성원 ( Sung Won Hwang ),김형성 ( Hyoung Sung Kim ) 한국도서학회 2014 韓國島嶼硏究 Vol.26 No.3

MOTIE(Ministry of Trade, Industry & Energy) aims to build a Southwest 2.5GW offshore wind farm. The job will require help from the government, electric operator and manufacturers. The domestic offshore wind farm market will boost global competitiveness up until 2019. This research analyzes the economic impact of the offshore wind farm project. The local acceptance in terms of production, employment and value added are expected to be maximized. According to the quantitative analysis using the extended 2010 input-output table, we calculated that the production inducement impact will reach up to 13.5 trillion won. 11.07 trillion won from the offshore wind farm industry and 2.4 trillion won from others. Furthermore the impact of increase in employment is expected to reach 22,662. 9,883 will be from the wind farm industry and 12,779 from other fields. The impact is expected to be greater especially during the middle of the jobless growth period, Lastly, the value added inducement impact is expected to be 4.24 trillion won. Regarding economic impacts, strategies required for increasing local acceptance are as follows. First, in order to diversify and sophisticate the primary industry into a secondary or tertiary one, we need to develop the nearby wind farm site into a wind farm thema park. Attracting the wind farm production, installing and maintaining/repairing firms and establishing an experience center for K-12 students by providing them an education center for offshore wind energy can be specific means of development. Also, during the operation and after the destruction of facilities, the government should lay out the sub-structure of the wind farm as a sea ranch. Thirdly, the level of local acceptance regarding the community ownership of the offshore wind farm should increase to those of Middelgrunden(Denmark) and Navarra(Spain). Considering the economic condition of Buan, Gochang and the Yeonggwang area, community ownership is one of best solutions for the increment of local tax revenue. At last, considering the supports system of areas adjacent to power plants and ``Partnership management with local community’, the offshore wind farm operator may need to provide assistant policies to nearby communities. The policies should be based on Corporate Social Responsibility(CSR) such as education scholarship projects, local economy cooperative projects, sports/culture projects.

서남해안 2.5GW 해상풍력에 대한 지역수용성 분석-가시성 중심으로

박재필(Jaepil Park),황성원(Sungwon Hwang) 한국신재생에너지학회 2016 신재생에너지 Vol.12 No.3

With the movement of the Paris agreement, MOTIE planned to build Southwest 2.5GW offshore wind farm near Gochang, Buan and Yeonggwang to be the 3rd largest wind power in the world. But Southwest 2.5GW offshore wind farm faces the objections from the community. This research examined visibility that beach residents might determine if the offshore wind farm has significant effect on the acceptance. The result is as follows. First, the visibility and beach residence have a negative attitude towards acceptance. Second, according to Logit analysis, beach residency is the most crucial factor for the attitude toward offshore wind farm. Third, the former national project has statistically significant impact on acceptance. For example, the respondents who had favorable impression on the former national projects, tend to have positive acceptance on offshore wind farms. At a same time, the people expecting the former national projects had strong impact on offshore wind project, are inclined to have negative acceptance. Finally, to improve the local acceptance, I suggest that government should construct tourist attractions, connecting offshore wind farm and Byeonsan National Park, marine ranching, based on an underwater theme park and offshore wind farm cluster.

재료결정구조를 고려한 확률론적 응력부식균열 예측모델 개발

박재필(Jae Phil Park),반치범(Chi Bum Bahn) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.4

니켈기 합금 용접재의 시계열 피로데이터와 LSTM Network 및 Multiple Regression을 사용한 잔여피로수명 추정

박재필(Jae Phil Park),함준혁(Junhyuk Ham),김지현(Ji Hyun Kim),반치범(Chi Bum Bahn) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.6

교회(敎會)에서 교회(交會)로

박재필(Jae Piel Park) 장로회신학대학교 세계선교연구원 2016 선교와 신학 Vol.39 No.-

포스트모던 시대에서는 더 이상 수직적이고 교권적인 가르침 중심의 교회(敎會)로서는 선교도, 전도도 어렵다. 이제 교회는 교제를 통한 수평적, 관계 중심적 ‘교회(交會)’로의 변화를 통해서 지역사회 안으로 시나브로 스며들 수 있는 준비를 해야 한다. 놀이는 가장 관계 중심적인 행위이며, 가장 자연스러운 전인적 교제 양식(樣式)이다. 가르침 중심의 수직 문화의 장으로 인식되어온 ‘교회(敎會)’를 사귐과 교제 중심의 ‘교회(交會)’로 전환하는 교회의 체질 개선이 요구되는 이때에, 놀이에 대한 신학적, 성서적 그리고 목회적 이해를 꾀함으로써 교회에 대한 새로운 인식과 함께, 지역사회와 소통하는 교제로서의 놀이 선교와 놀이 목회에 대한 방안을 모색하고자 한다. 최근 선교적 교회론은 선교와 전도가 지역사회 속에서 무례하지 않게, 조용히 그러나 강력하게 스며들 것을 강조한다. 이에 교제 중심의 놀이를 통해 교회 안에서, 그리고 교회 밖 지역사회를 향해서 다가가는 ‘조은교회’와 ‘숲속샘터교회’의 사례를 통하여 놀이가 갖는 신학적, 성서적, 목회적 의의를 살피고, 놀이에 담겨있는 교제의 실천적 가치를 통해 ‘교회(敎會)에서 교회(交會)’로의 새로운 자리매김을 모색하고자 한다. In post-modern days, hierarchical and teaching-centered church system has faced difficulties with its mission and gospel preaching work, domestically and internationally. So all the churches are to prepare for gradual change from hierarchical-centered ministries to relationship- centered ones, to get around with local communities. Playing activities are the most relationship-oriented and natural means for “Koinonia” of christian communities. I emphasize that we lives in the era for new church system and try to find a solution in getting understandings of playing activities in light of theological, biblical and pastoral viewpoints. Recently, many researches for mission-oriented church system show that mission and gospel preaching works need to pervade local communities gently, quietly and forcefully. In this study, I take examples from both “Jo-Eun Church” and “Forest and Fountain Church". Then I depict their efforts in getting around with local communities, insisting its meaning, theologically, biblically and pastorally. In conclusion, I insist that playing activities have a practical value for change from Teaching-Centered Church to Playing-Centered Church system.

전자제어식 리버스 연속가변댐퍼용 파일럿밸브의 동특성 해석

박재필(J. P. Park),이현섭(H. S. Lee),김학은(H. E. Kim),권수종(S. J. Kuen),최병근(B. K. Choi),정용길(Y. G. Jung) 한국동력기계공학회 2004 한국동력기계공학회 학술대회 논문집 Vol.- No.-

Since semi-active suspension systems of automobile, of which suspension damper are controlled actively, exhibit high performance with light system weight, low cost and low energy consumption. From this view point, semi-active suspension systems are greatly expected to be in the mainstream of future controlled suspension systems. In this paper, mathematical modeling and dynamic characteristics analysis of a reverse continuously variable damper and pilot valve used for semi-active suspension systems are investigated. The mathematical model of piston with valve are proposed by IMAGINE/AMESim in the paper. To verify the mathematical model developed, the dynamic characteristics are simulated by AMESim and are compared with experimental results. It was confirmed that the developed models represent well the actual system and can be used for control system design.

시계열 피로 데이터를 이용한 MCMC 기반 확률론적 피로수명 예측

박재필(Jae Phil Park),반치범(Chi Bum Bahn),Subhashish Mohanty 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

전북 중소기업 정책자금의 성과 결정요인분석

박재필(Park, Jaepil),박의성(Park, Euisung) 한국산업경제학회 2016 한국산업경제학회 정기학술발표대회 논문집 Vol.2016 No.11

중소기업은 경제성장의 견인차로서 경제위기에 따른 실업을 흡수하여 경제의 안전망역할을 수행한다. 이처럼 중소기업 정책자금은 시장실패보완, 사회유대강화 및 경기대응 등에 이론적 배경을 두고 있다. 특히 전북에서는 중소기업청, 전라북도, 한국은행 전북본부, 전북신용보증재단 등이 주요한 정책자금 집행기관이며 이들 정책자금의 성과결정요인을 파악하기 위해 107개 지역 중소기업을 대상으로 설문을 실시했다. 설문에 기초한 성과 결정요인분석에 따르면 첫째, 이자율에 대한 만족도는 혁신성을 제외한 전반적 경영성과, 성장성, 안정성, 수익성 및 생산성을 개선시켰다. 둘째, 사용범위 및 용도의 만족도는 전반적 경영성과, 성장성, 수익성, 혁신성을 제고시켰다. 셋째, 시설자금이 필요한 경우에 전반적 경영성과, 성장성, 안정성이 높았다. 끝으로 전북 중소기업의 발전을 위한 정책적 시사점은 간접금융의 위험회피적인 성향을 지양하고 정책자금의 경기대응성 강화, 정책금리 현실화 및 정책자금의 차별화가 요구된다. SMEs, engine for economic growth, play a key role as job creator and social security net during the economic crisis. Especially, SME policy fund is theoretically founded on the market failure, social cohesion and counter-cyclicality. In Jeonbuk, SMBA, Jeonbukdo, BOK-Jeonbuk and Joenbuk Gredit Guarantee Foundatoin are major SMEs’ policy funds providers. In order to figure out determinants of performance of SMEs’ policy funds, BOK-Jeonbuk surveyed 107 firms throughout the Jeonbuk. The results of analysis are as follows. First, the satisfaction measurement on interest rate, has positive impact on general performance, growth, security, profit and productivity. Second, the satisfaction measurement on purpose, has positive effect on general performance, growth, profit and innovation. Third, the demand for facility fund, positively influences on the general performance, growth and security. In order to foster SMEs in Jeonbuk, indirect financing institutes should sublate risk-aversive behaviors of lending and policy fund requires counter-cyclicality, realization of interest rate and differentiation strategy.

CANYVAL-X 임무를 위한 시스템 개발

박재필(Jae-Pil Park),박상영(Sang-Young Park),송영범(Young Bum Song),김극남(Guk Nam Kim),이광원(Kwangwon Lee),오형직(Hyungjik Oh),임진철(Jin-Chul Yim),이은지(EunJi Lee),황순홍(Soon-Hong Hwang),김성우(SungWoo Kim),강석주(Seok Ju Kang) 한국항공우주학회 2016 한국항공우주학회 학술발표회 논문집 Vol.2016 No.4

CANYVAL-X 임무는 분리형 우주망원경(Virtual Telescope)의 핵심기술을 두 기의 큐브위성을 이용하여 우주공간상에서 검증하는 임무이다. 분리형 우주망원경의 핵심기술은 관측 대상에 대하여 두 위성의 상대위치와 상대 자세를 동시에 일치시키는 관성 정렬(Inertial Alignment) 상태를 유지하는 것이다. CANYVAL-X 임무를 위해서는 비전 정렬 시스템을 이용한 관성 정렬 기술, 위성 간 통신을 이용한 상대궤도 결정 기술, 추력기를 이용한 상대 궤도 제어 기술, 위성 분리 기술을 임무 궤도상에서 구현 할 수 있어야 한다. 본 연구에서는 이를 위해 1 Unit (10㎝×10㎝×10㎝) 큐브위성 제리 (Jerry)와 2 Unit (10㎝×10㎝×20㎝) 큐브위성 톰 (Tom)을 개발하였고, 개발 된 두 위성의 시스템 및 성능이 임무요구조건을 만족 하는 것을 확인하였다. 또한 환경시험을 통하여 두 위성이 우주환경에서 임무를 정상적으로 수행할 수 있는 것을 확인하였다. CANYVAL-X mission is demonstrating core technology of Virtual Telescope with two CubeSats. The core technology of Virtual Telescope is consisting inertial alignment. Inertial alignment is to maintain relative position and relative attitude of two satellites with respect to target object. The mission needs to develope vision alignment system, relative orbit control with thruster, relative orbit determination with inter-satellite link system and satellite separation system. For this mission, 1 Unit (10㎝×10㎝×10㎝) CubeSat Jerry and 2 Unit (10㎝×10㎝×20㎝) Tom are developed. This study presents that the system and function of two CubeSats are satisfies mission requirements. Also, it shows that the CubeSats are able to perform the mission in space environment with the results of environment test.