Dynamic Interaction of Waves with a Moored Structure

Changje Kim(金昌?),Hongsun Yu(兪洪善),Hideaki Noda(野田英明) 한국해양공학회 1992 韓國海洋工學會誌 Vol.6 No.2

This paper presents the method of numerical analysis concerned with the hydropdynamic forces and moments of the floating bodies exerted by waves. The analytic methods of hydrodynamic wave forces and moments for large volume structures are generally classified into four categories ; the strip method, the boundary element method, the finite element method, and the potential matching method. In the case of the comparatively large structures, diffraction theory can be applied. However, there are no application limits of diffraction theory which have been known concerning with the analytic method of the rectangular structures.<br/> In this paper, the two-dimensional B.E.M. is treated for a moored small rectangular structure in order to evaluate applicability of diffraction theory. Numerical calculation is carried out for the structure. The results are compared with some other ones for verification. The result shows that diffraction theory is applicable to structures smaller than 0.15 in the ratio of the representative structure length d to wave length L for rectangular ones.

In-vitro Vein Modeling for the Evaluation of an Artificial Venous Valve

Changje Lee(이창제),Kyung-Wuk Kim(김경욱),Hyoung-Ho Kim(김형호),Young Ho Choi(최영호) 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.5

Single Plane Illumination Microscopy – MicroPIV를 이용한 버블 유동에서 외부 자계 영향을 받는 자성입자 가시화

이창제(Changje Lee),조경래(Gyeong-rae Cho),이상엽(Sangyoup Lee) 한국가시화정보학회 2021 한국가시화정보학회지 Vol.19 No.1

This study measured the velocity of magnetic particles inside the power generation using external heat sources. Single Plane Illumination Microscopy (SPIM) was used to measure magnetic particles that are simultaneously affected by bubbly flow and magnetic field. It has the advantage of reducing errors due to particle superposition by illuminating the thin light sheet. The hydraulic diameter of the power generation is 3mm. Its surface is covered with a coil with a diameter of 0.3 mm. The average diameter of a magnetic particle is 200nm. The excitation and emission wavelengths are 530 and 650nm, respectively. In order to find out the flow characteristics, a total of four velocity fields were calculated in wide and narrow gap air bubbles, between the wall and the air bubble and just below the air bubble. Magnetic particles showed up to 8.59% velocity reduction in the wide gap between air bubbles due to external magnetic field.

한글 문서 인식 시스템 SILNOON의 개발 현황

조창제(Changje Cho),이승호(Seungho Lee),고병기(Pyongki Ko),김의경(Euikyoung Kim),이광호(Kwangho Lee),하진영(Jinyoung Ha),김진형(Jin H Kim) 한국정보과학회 1988 한국정보과학회 학술발표논문집 Vol.15 No.2

본 논문에서는 한국과학기술원 전산학과 인공지능연구실에서 개발하고 있는 한글 문서 인식 시스템 SILNOON을 소개한다. 본 연구는 한글로 작성된 인쇄체 문서를 인식하여 컴퓨터 화일로 구성하고, 인식된 문서를 편집 및 수정하여 레이저 프린터를 통하여 출력할 수 있는 실용적인 시스템의 개발을 그 목적으로 한다. 이 시스템은 크게 전처리, 문자 인식, 후처리 등으로 구성된다. 본 논문에서는 문자 인식, 후처리 과정에 중점을 두어 설명하고 개인용 컴퓨터(IBM PC/AT)에 구현하여 실험한 결과를 발표한다.

외부 자계 영향을 받는 자성 나노 입자 거동에 대한 2색 형광 PIV 적용

이창제(ChangJe Lee),이상엽(Sangyoup Lee) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

Particles which have different material conditions and mechanical properties behave their special motions under the external conditions. Fe3O4 particles which have magnetic properties also have their own characteristics such as align through the solenoid-nozzle in external magnetic field. When the external magnetic field appears. Fe3O4 particles have been changed because of their magnetism compare with other non-magnetic particles like polystyrene particles. To optimize the solenoid-nozzle, change the magnet wire span size and connection method. The result show that span layer 1 and parallel connection generated high amp then span layer 5 and serial connection. We used 200nm fluorescent magnetic nano particles and 500nm fluorescent polystyrene particles which have different emission wavelength range to separate each image of particles under the one and two phase flow in the solenoid-nozzle. Both particles excited from 532nm laser system and their emission signals were imaged with two color fluorescent Particle Image Velocimetry (PIV). One EM-CCD camera with dichroic filter were used to capture images for separate phases. Instantaneous images for both magnetic and nonmagnetic nano particle was captured simultaneously.

PIV를 이용한 외부자계 영향을 받는 채널 내 비자성입자와 자성입자의 정렬도 추정

이창제(ChangJe Lee),김가영(Ka-yeong Kim),이상엽(Sangyoup Lee) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

Particles which have different material conditions and mechanical properties behave their special motions under the external conditions. Fe3O4 particles which have magnetic properties also have their own characteristics such as align through the solenoid-nozzle in external magnetic field. When the external magnetic field appears, Fe3O4 particles have been changed because of their magnetism compare with other non-magnetic particles like polystyrene particles. For imaging these changes such as alignment of magnetic particles, it is necessary to systematize PIV set-up and solenoid-nozzle in external magnet. We used fluorescent magnetic particles and same size of fluorescent polystyrene particles which have different emission wavelength range to separate each image of particles under the one-phase flow in the nozzle. Also, we controlled the flow rate, nozzle size, and observation view of nozzle. Both particles excited from laser system and their emission signals were imaged with long working distance objective lens system and CCD camera. In addition, its possible for analyzing of two kinds of particles behaviors using average cross-correlation method. Based on these systems, we compared each velocity and vorticity of magnetic particles and non-magnetic particles in magnetic condition. This study will provide optically relevant micro PIV for estimation of magnetic and non-magnetic particles alignment.

PIV를 이용한 이상 유동에서 자성입자 거동 측정

이창제(ChangJe Lee),이상엽(Sangyoup Lee) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

Particles which have different material conditions and mechanical properties behave their special motions under the external conditions. Fe3O4 particles which have magnetic properties also have their own characteristics such as align through the solenoid-nozzle in external magnetic field. When the external magnetic field appears, Fe3O4 particles have been changed because of their magnetism compare with other non-magnetic particles like polystyrene particles. To optimize the solenoid-nozzle, change the magnet wire span size and connection method. The result show that span layer 1 and parallel connection generated high amp then span layer 5 and serial connection. We used 1um fluorescent magnetic nano particles and 1um fluorescent polystyrene particles which have different emission wavelength range to separate each image of particles under the one and two phase flow in the solenoid-nozzle. Both particles excited from 532nm laser system and their emission signals were imaged with two color fluorescent Particle Image Velocimetry(PIV). One EM-CCD camera with dichroic filter were used to capture images for separate phases. Instantaneous images for both magnetic and nonmagnetic nano particle was captured simultaneously.

고령자의 공적연금 수령여부와 수령금액에 영향을 미치는 요인 : 성별에 따른 비교를 중심으로

박창제 ( Changje Park ),김영현 ( Yeong Hyeon Kim ) 한국아동가족복지학회 2021 한국가족복지학 Vol.26 No.3

Objective: The purpose of this study is to compare determinants of public pension benefit eligibility and benefits by gender and discuss their policy implications. Methods: From Data from the Korean Retirement & Income Study(Ver.8.0) conducted in 2019, 4,961 elders over 62 years of age(Male 1,998, Female 2,963) were selected and analyzed. Results: The results are summarized as follows. First, age have positive effect on public pension benefit eligibility of male elders but negative effect on that of female elders. Second, having a spouse have negative effect on public pension benefit eligibility and benefits of female elders but positive effect on those of male elders. Third, education level have positive effect on public pension benefits for male elders and female elders. Fourth, earnings have negative effect on the public pension benefits of male elders. Fifth, earned income have negative effect on public pension benefit eligibility and benefits of male elders but negative effect on those of female elders. Sixth, retirement preparation have positive effect on public pension benefit eligibility and benefits for both male elders and female elders. Seventh, self responsibility for retirement have positive effect on with public pension benefit eligibility and benefits for both male elders and female elders. Conclusions: These findings indicate that it is are needed to strengthen multilateral policy for retirement income security, and in particular, strengthen multilateral policy for women's public retirement income security.

치매노인에 대한 가족의 보호형태별 비용분석

박창제(Park, Changje) 한국노년학회 2004 한국노년학 Vol.24 No.4

본 연구의 목적은 치매노인에 대한 가족의 보호형태별 비용을 추정한 다음, 추정결과를 바탕으로 치매노인 부양가족을 지원할 정책방안을 모색하는 데 있다. 본 연구를 위한 조사 대상은 65세 이상 치매노인을 수발하는 부양가족을 보호형태별로 분하여 설문조사하였다. 즉, 가정보호, 주간보호, 단기보호, 병원보호, 그룹홈으로 구분하여 비확률 표집방법을 통해 주부양파를 대상으로 면접조사를 행하였다. 회수된 설문지 중에서 가정보호 108부, 주간보호 136부, 병원 71부, 단기보호 17부, 그룹홈 7부가 본 연의 분석 표본으로 선정되었다. 분석 결과 다음과 같은 사실을 확인할 수 있었다. 첫째, 주부양자의 학력이 상당히 높다. 이렇게 주부양자의 교육수준이 높아지게 되면 부양여성들이 높은 인적자본을 요하는 전문적인 직업을 가질 가능성이 있고, 전통적인 가족지향의 가치보다는 개인적인 행복에 대한 선호가 증가하여 치매노인에 대한 부양의 기회비용이 크질 수밖에 없을 것이다. 둘째, 치매노인 부양가구가 소득에 비하여 직접지불부담비중이 아주 크며 경제적 상태가 나쁠수록 그 비중이 크게 증가한다는 것을 알 수 있다. 이러한 점은 사회적 평등을 실현하기 위해 치매부양가족을 위한 직접비용에 대한 대책마련의 필요성이 있음을 의미한다. 셋째, 총비용중에서 간접비용이 아주 높았다. 간접비용이 직접비용에 비하여 거의 2배로 추정되었다. 이러한 사실은 정책당국자가 지금까지 부양자의 직접비용에만 관심을 집중하여왔다는 점에서 정책의 우선순위에서 신중한 고려의 필요성이 있다. 넷째, 치매 정도별로 보면 직접비용에서는 최고도일 때 가장 높고, 그 다음이 중도, 고도, 경도의 순서를 보였다. The purpose of this study is to analyse the costs by caregiving types of family with the demented elderly empirically, and then to explore policy measures to support families with the dependent elderly using the results of analysis. For this research, primary caregivers that provide caregiving to demented elderly were drawn and survey ed(N=380). Among collected data, data for 339 primary caregivers were used for this study. The subjects used in this study consisted of family caregivers from various settings that give care to the demented elderly. The 108 subjects were caregivers from home care that family provide most care, the 136 subjects were caregivers utilizing day care programs for the demented elderly, the 71 subjects were caregivers utilizing hospital care, the 71 subjects were caregivers utilizing short term care, and the 7 subjects were caregivers utilizing group home. The results of this study can be summarized as follows. First, the primary caregiver's education level is high. With more educated, these higher-educated female caregivers may have professions that requires high human capital formation and prefer personal well-being to traditional value. Therefore, the opportunity costs associated with caregiving for the demented elderly must be increased. Second, caregiving households with the demented elderly accounted for significantly high direct costs relative to household income and households with lower economic status undertake higher direct cost relative to household income. This suggests that the policy to assist direct cost of families with the demented elderly be required to improve social equality. Third, the larger component of this cost was indirect costs. In this context, indirect costs must be evaluated significant item in social considerations for caregivers of the demented elderly. Fourth, the direct costs of family were significantly different by severity of dementia.

부양가족의 치매노인에 대한 보호형태와 보호비용의 결정요인

박창제 한국사회보장학회 2004 사회보장연구 Vol.20 No.3

본 연구의 목적은 치매노인에 대한 가족의 보호 형태와 비용에 미치는 요인을 실증적으로 분석하고, 분석결과에 대한 함의에 대하여 논의하는 것이다. 이를 위해 조사대상은 65세 이상 치매노인을 수발하는 부양가족으로 설정하고, 비확률 표집방법을 통해 선정하였다. 조사된 설문지 중에서 사용가능한 것으로 보호형태별 재가노인 108부, 주간보호 136부, 병원 71부, 단기보호 17부, 그룹홈 7부가 본 연구의 분석 표본으로 선정되었다. 치매노인가족에 대한 부양행동을 체계적이고, 합리적으로 설명할 수 있도록 가계생산경제모형을 바탕으로 가족의 비공식 보호모형, 가족의 보호비용모형, 공식 보호서비스 모형을 도출하였다. 종합하여 볼 때 본 연구의 결과는 부양가족들이 치매노인을 보호하는 형태와 비용에 대한 선택과 결정이 체계적으로 이루어진다는 것을 보여준다. 이러한 보호형태와 비용에 대한 결정은 피부양자의 특성, 부양가족의 소득, 부양생산기술, 가계생산기술, 부양자 선호의 요인들의 영향을 받는다는 사실을 확인할 수 있었다. 따라서 치매노인 부양가족을 지원하기 위한 복지정책은 이러한 영향요인을 적절히 고려하여 수립되어야 한다. The purpose of this study is to analyse determinants of the caregiving types and costs of family with the demented elderly empirically, and then to discuss the findings and implications for the results of analysis. Among collected data for this research, data for 339 primary caregivers were used for this study. The subjects used in this study consisted of family caregivers from various settings that give care to the demented elderly. The 108 subjects were caregivers from home care that family provide most care, the 136 subjects were caregivers utilizing day care programs for the demented elderly, the 71 subjects were caregivers utilizing hospital care, the 71 subjects were caregivers utilizing short term care, and the 7 subjects were caregivers utilizing group home. To explain family caregiving behaviors for demented elderly systematically and rationally, family caregiver's decision-making models regarding informal care, caregiving cost, formal-care service choice was drawn by an economic model of household production. Taken together, the results of this study suggest that family caregivers do systematically determine and choose the types and costs of caregiving for the demented elderly. They also show that these determinations is influenced by a set of care recipient sociodemographic factors, as well as the household income of caregiving family, the production technology of the care setting, the technology of household production, and the caregiver's preferences. The policy measures to support families with the dependent elderly need to be designed by considering these research results.