• 대한기계학회논문집
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• 제11권5호
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• pp.725-730
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• 1987

본 연구에서는 2사이클 기관의 흡입 포오트 부근의 가스 유동을 레이저 도플 러 유속계를 이용하여 측정하고 가스의 평균 속도, 속도 변동, 유속 벡터 등을 기관의 회전 속도, 실린더 헤드의 모양 및 실린더로의 흡입 속도 측정점의 위치 변화에 대하 여 비교 검토하고, 유동 특성을 고찰하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권2호
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• pp.87-98
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• 2022

This study aims to prepare a technical protocol for identifying the source of nitrate in water using nitrogen (δ¹⁵N) and oxygen (δ¹⁸O) stable isotope ratios. The technical processes for nitrate sources identification are composed of site investigation, sample collection and analysis, isotope analysis, source identification using isotope characteristics, and source apportionment for multiple potential sources with the Bayesian isotope mixing model. Characteristics of various nitrate potential sources are reviewed, and their typical ranges of δ¹⁵N and δ¹⁸O are comparatively analyzed and summarized. This study also summarizes the current knowledge on the dual-isotope approach and how to correlate the field-relevant information such as land use and hydrochemical data to the nitrate source identification.

• 대한가정학회지
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• 제47권6호
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• pp.91-108
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• 2009

The aim of this study was to assist the development of parenting-aid policies by analyzing information from life perspectives, family system theory, and integrated family policy perspectives. For this purpose, we conducted a literature using a variety of sources including internet sites, laws, published material related to current parenting-aid policies. Based on analyses we formulated four agendas: empowering parent competency, supporting diverse family parenting, guaranteeing parent's rights, and supporting parenting of dual-income families parenting. The results were as follow: Firstly, for empowering parent competency, we proposed the development of family relationship empowerment programs including family life cycle and children-raising support services. Secondly, for diverse family parenting, we proposed access to integrated parenting-aid programs dependent on family types. Thirdly, for guaranteeing parent’s rights, we proposed the supporting of child raising costs and tax returns to families with children, and provide child allowances. Finally, for dual-income family parenting, we proposed that schools and communities must recognize that dual-income families are a universal family type, establish family friendly business culture, and to develop a more democratic domestic family-relationship. This policy proposed a new paradigm where parents must be recognized as partners and stakeholder in development of family related policies. Ultimately, such policies will contribute to increased birth rate and development of a more respectful society.

• Human Ecology Research
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• 제58권2호
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• pp.255-266
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• 2020

This study observed and investigated the commute time of dual-earner couples from a family developmental perspective. It tested whether the household responsibility hypothesis was effective in explaining the gender gap in the commute time for these couples. I extracted 2,103 time diaries written by 1,266 matched couples from the 2014 Korean Time Use Survey data for this study. The sample was categorized by the age of the eldest child into four age groups of 0-6, 7-12, 13-18, and 19-29. Analytic results from ANOVA, Scheffé test, and OLS regression are as follows. First, husbands traveled longer hours to work than wives in all age groups, while the commute time of couples tended to increase along with the child' age. However, couples in the child group aged 7 to 12 had the shortest commute time. Second, domestic labor time of wives were negatively associated with the commute time, which appeared to support the household responsibility hypothesis. Third, in the child group aged 7 to 12, wives spent more time for work commute as their income increased; however, wives with traditional gender role attitudes had a shorter commute time in the child group aged 0 to 6. Forth, neither the wives' nor husbands' work characteristics were related to the wives' commute time; however, both wives' and husbands' work characteristics were related to the husbands' commute time. The findings suggest the possibility of spatial entrapment by working wives throughout the family life cycle due to household responsibilities, which provides implications for policy intervention in consideration of the gender gap in commute time for dual-earner couples.

• 대한기계학회논문집B
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• 제40권4호
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• pp.213-220
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• 2016

본 연구의 목적은 열대 지방에서 사용되는 특수목적 자동차용 에어컨 시스템의 냉방성능 특성을 고찰하는 것이다. 이를 위하여 R-134a를 사용하는 듀얼 냉동사이클을 구성하였고 냉매량 및 실내온도를 변화시켜가면서 냉방성능을 비교하였다. 외기온도 $40.0^{\circ}C$에서 듀얼 냉동사이클의 실내 냉각속도 및 압축비(토출압력) 등을 고려하여 최적 냉매량을 1.5kg으로 선정하였다. 실내온도가 증가할수록 냉방부하가 증가하여 $25.0^{\circ}C$에서 $32.5^{\circ}C$로 실내온도를 높일 경우 $15.0^{\circ}C$에 도달하는데 걸리는 시간은 86.5% 증가하였고, $32.5^{\circ}C$에서 $40.0^{\circ}C$로 증가할 경우 38.1% 증가하였다. 또한, 실내온도가 $25.0^{\circ}C$에서 $40.0^{\circ}C$로 증가할수록 냉방용량은 19.1 kW에서 20.5 kW로 7.3% 증가했으나 냉방성능(COP)는 4.67에서 5.1로 7.0%감소하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 추계학술대회
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• pp.297-302
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• 2004

본 연구에서는 수직배치형 블록을 가지는 컨테이너 터미널을 대상으로 안벽에서 컨테이너의 양${\cdot}$적하 작업을 담당하는 안벽크레인(Q/C)에 대한 하역생산성을 비교분석하였다. 분석 대상이 되는 안벽크레인의 유형은 기존의 싱글트롤리 타입외에 차세대 안벽크레인으로 인식되고 있는 듀얼트롤리, 더블트롤리, 수직순환식의 하역방식을 가지는 장비에 대한 하역생산성을 순작업시간당 생산성 측면에서 이들 하역장비의 성능을 측정해 보았다. 이들 차세대 컨테이너 크레인은 기존의 싱글트롤리 타입의 장비에 비해 기계적 싸이클 타임이 짧으며, 선회방식이 상이하여 현재의 싱글 트롤리타입보다 하역생산성이 매우 높을 것으로 보고 있다. 본 연구의 결과로 제시된 4가지 유형의 안벽크레인에 대해 작업싸이클타임과 시뮬레이션 기법을 이용하여 기계적생산성과 순작업생산성을 산출하였다.

• 항공우주산업기술동향
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• 제7권1호
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• pp.43-55
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• 2009

20세기 전반 극초음속 공기흡입식 추진시스템에 대한 개념이 정립된 이래 항공우주기술선진국은 이러한 개념을 구현하기 위하여 꾸준히 연구를 진행하였으며 2004년 NASA의 X-43A Hyper-X가 마하 10의 극초 음속 공기흡입식 비행을 성공적으로 수행하였다. 현재 각 국에서는 이러한 극초음속 공기흡입식 추진시스템을 SSTO(Single Stage to Orbit) 또는 TSTO(Two Stage to Orbit) 개념의 재사용 위성 발사체 및 극초음속 미사일에 적용하기 위한 프로젝트가 본격적으로 진행되고 있다. 본 논문에는 미국, 유럽, 호주 아시아에서 개발하고 있는 극초음속 공기흡입식 추진시스템의 역사 및 현황과 이러한 추진시스템을 적용한 비행체, 미사일 개발 연구를 정리하였다.

• Molecules and Cells
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• 제42권6호
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• pp.448-459
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• 2019

The phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway is a promising target for gastric cancer (GC) treatment; however the efficacy of PI3K/mTOR dual inhibitors in GC has not yet been maximized. Additionally, the effect of autophagy regulation by PI3K/mTOR dual inhibitors has not been clearly elucidated in GC treatment. We aimed to show that our newly developed PI3K/mTOR dual inhibitor, CMG002, when combined with an autophagy inhibitor, chloroquine (CQ), potently induces effective cancer cell death in Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) cells, where both the PI3K/AKT/mTOR and autophagy pathways play important roles in disease pathogenesis. EBV- and mock-infected AGS and NUGC3 GC cell lines were treated with CMG002 +/- CQ. PI3K/AKT/mTOR signaling pathway mediators, cellular apoptosis and autophagy markers were confirmed by Western blot assay. Cell viability was assessed using the Cell Counting Kit-8 (CCK-8) assay. CMG002 effectively blocked the PI3K/AKT/mTOR pathway by markedly decreasing phosphorylation of AKT and its downstream mediator S6. CMG002 induced G0/G1 cell cycle arrest and enhanced apoptotic cell death in AGS and NUGC3 cells, particularly EBV-infected cells compared with mock-infected cells, as confirmed by flow cytometric analyses and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assays. The combination of CMG002 plus CQ synergistically increased apoptotic cell death in EBV-infected GC cell lines when compared with CMG002 alone (P < 0.05). Our results suggest that the new PI3K/mTOR dual inhibitor, CMG002, when used in combination with the autophagy inhibitor, CQ, provides enhanced therapeutic efficacy against EBVaGC.

• 기술혁신학회지
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• 제17권1호
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• pp.124-145
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• 2014

국가연구개발사업은 시장실패를 교정하기 위한 정부정책 구현에 있어서 매우 중요한 활동이며 최근 재정규모의 확대로 인해 성과평가에 대한 중요성과 더불어 효율적인 관리체계 구축에 대한 논의가 진행되는 분야이다. 본 연구는 이러한 국가연구개발사업에 대해 전주기 관리방안을 모색하기 위한 탐색 연구이다. 체계적인 논의에 있어서 관리체계에 대한 사항을 사전평가의 관점을 중심으로 살펴보았다. 국외 사례와 국내 제도의 비교를 통해 현행 국가연구개발사업의 수명주기 관리와 관련하여 제도차원의 고려사항을 도출했고 국가연구개발사업의 사전분석에 대한 사례 자료를 수집하고 분석을 수행하였다. 이를 통해 현재 제도상의 문제점을 구체화하였으며 향후 국가연구개발사업의 전주기적 관리를 효과적으로 적용하기 위해서 연구개발 정부지출의 범주화와 지출성격에 따른 관리체계 이원화가 필요함을 제시하였다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.544-549
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• 2009

The purpose of this study is to investigate the field Operation Characteristics of a sea water heat source cascade heat pump system and system applicable to Building. Cascade heat pump system is composed R410A compressor, R134a compressor, EEV, cascade heat exchanger, Plate heat exchanger etc. Building area is $890m^2$ and has five floors above ground. R410A is used for a low-stage working fluid while R134a is for a high-stage. The system could runs at dual mode. One is mode of general R410A refrigeration cycle in summer and the other is cascade cycle. In order to gain a high temperature supply water in winter season, the system is designed to perform a cascade cycle. The filed test results show that the sea water heat source heat pump system exhibits a COP of about 5.5 in cooling mode along with a heating COP of about 4.0 in 1-stage heating mode. Cascade 2-stage heat pump system is enough to supply $60^{\circ}C$ water and heating COP is about 3.0