• 한국자동차공학회논문집
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• 제1권1호
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• pp.101-109
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• 1993

Dynamic characteristics of an electro-magnetic clutch transmission system were investigated by using Bondgraph modeling method. Simulation results showed that when the rotor engaged with the armature, the response time of the current, the driver torque, the rotational speed and the relative sliding time between the driver and the driven side decreased, as the gap size between the rotor and the armature decreased and the number of coil turns increased. Also, when the rotor disengaged with the armature, the delay time increased with the decreased gap size and the increased number of coil turns. It was found that the experimental results of the current, the driver torque, the rotational speeds were in good accordance with the theoretical results. The results of this study can be used as basic design materials of the electro-magnetic clutch.

• 한국임상수의학회지
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• 제16권2호
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• pp.448-453
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• 1999

The three-dimensional structure of the Sertoli cell in the Korean native bull was investigated by scanning electron microscopy. Morphologically, four types of Sertoli cell processes were evident: 1) sheet-like processes, 2) sleeve-like processes, 3) bough-like processes and 4) finger-like processes. The sheet-like processes rested upon more than half of the surface of each spermatogonia, spermatocyte and spermatid. Sleeve-like processes, bough-like processes and finger-like processes are observed in the middle and apical portion of seminiferous tubule. All Sertoli cell processes are originated from Sertoli cell column. Just before spermiation, the apical sheet-like processes are shifted from their position at the spermatid head, and bough-like processes covered the disengaged residual body, after which the residual body was no longer evident in the tubule. Though the mechanism for this elimination is not known, the process suggests a reciprocity between the Sertoli and germ cells.

• 한국초전도ㆍ저온공학회논문지
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• 제10권3호
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• pp.43-46
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• 2008

Design of current lead for 21T superconducting magnets is presented. The current lead is composed of a normal metal element, conducting the current from room temperature to intermediate temperature, and an HTS element, conducting the current down to liquid helium temperature. The metal element is disengaged from the HTS element without breaking vacuum after excitation. The optimization of the lead is performed to minimize the thermal heat load when carrying operational current with some margin. In order to confirm the feasibility of our new design, the intermediate joint between a normal metal and HTS element is fabricated and the reliability is tested during engage and disengage performance. The effects of vacuum level and performance cycle on the electrical contact resistance are also investigated.

• 한국노년학
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• 제36권3호
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• pp.765-783
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• 2016

본 연구는 한국노인의 사회적 연계망 자체를 좀 더 심도있게 이해하기 위하여 2014년도 노인실태조사자료(65세 이상 10,279명)를 활용하여 관계망 크기, 연계와의 접촉 빈도, 연계에 대한 친밀도를 중심으로 잠재프로파일분석(LPA)을 실시하였다. 그 결과 노인의 사회적 연계망은 고립형(11.6%), 가족의례형(17.7%), 가족친밀형(23.6%), 제한적 다층친밀형(28.4%), 다층형(18.8%)의 다섯 개 유형으로 도출되었다. 또한 도출된 잠재집단 유형별 특징을 비교하였고, 사회적 관계망 유형에 영향을 미치는 요인을 분석하기 위한 다항로지스틱회귀분석을 실시하였다. 분석결과, 고립형 노인의 3/4은 여성이며 독거가구 비율이 약 절반을 차지하는 것으로 나타났다. 또한 상대적으로 평균연령이 높고, 도시지역에 거주하는 노인, 신체적 제한이 있는 노인, 사회적 지위가 낮은 직종에 종사한 노인이 고립형에 속할 가능성이 높은 것으로 나타났다. 반면 다층형의 경우 여성보다는 남성노인이, 연령이 낮을수록, 학력이 높을수록, 전문 관리 사무직에 종사한 노인일수록 다층형에 속할 가능성이 높았다. 한편 가족의례형과 가족친밀형은 배우자 혹은 자녀를 중심으로 연계망이 형성되어 있고, 노인부부가구의 비중이 높다는 공통점을 가지고 있으나, 가족의례형은 상대적으로 여성 비중이 높다는 특징이 있다. 그리고 제한적 다층친밀형은 배우자보다는 자녀와 친구 이웃과의 연계망의 크기, 빈도, 친밀도가 다층형 다음으로 높은 집단으로 여성노인 및 저학력이면서 농림어업에 종사한 비중이 높게 나타났다. 이러한 연구결과에 기초하여 노년기의 사회적 연계망 유형의 다양성이 갖는 학술적 및 정책적 함의와 향후 연구방향을 논의하였다.

• 한국심리학회지 : 문화 및 사회문제
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• 제23권2호
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• pp.239-270
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• 2017

본 연구는 조직 내 구성원들이 조직 및 업무 관련하여 의도적으로 침묵을 선택하는 동기를 밝히고, 이를 측정할 수 있는 척도의 개발을 그 목적으로 한다. 이를 위해 연속된 3개의 연구를 수행하였다. 먼저 연구 1에서는 직장인 104명을 대상을 조직 내 침묵 경험에 대한 개방형 설문을 실시하였고, 이에 대한 응답내용을 바탕으로 조직 구성원들의 침묵동기에 대한 총 60개의 예비문항을 개발하였다. 연구 2에서는 연구 1에서 개발된 예비문항에 대해 481명을 대상으로 설문조사를 실시하였다. 이에 대한 탐색적 요인분석 및 ESEM 분석을 통해 침묵동기에 대한 5요인(방어적 침묵, 체념적 침묵, 비관여적 침묵, 기회주의적 침묵, 관계적 침묵)을 도출하고 최종 20개 문항을 개발하였다. 또한 개발된 침묵동기 척도와 유사개념(일반적 침묵행동, 발언행동) 간 변별성 검증을 위해 척도 간 ESEM 분석을 실시하였고, 그 결과 본 연구에서 개발된 침묵동기 척도는 일반적 침묵행동 및 발언행동과 변별되는 개념으로 나타났다. 연구 3에서는 침묵동기 척도의 타당화를 위해 직장인 339명에게 설문을 실시하고 확인적 요인분석을 통해 척도의 구성타당도를 검증하였다. 분석결과 침묵동기의 5요인 구조모형의 부합도가 높게 나타나 침묵동기 척도의 구성타당도가 입증되었다, 마지막으로 이러한 연구결과를 토대로 연구의 시사점과 제한점, 그리고 추후 연구방향에 대해서 논의하였다.

• 한국자동차공학회논문집
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• 제24권2호
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• pp.183-190
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• 2016

Engine torque is transferred to the transmission where drag torque is minimized improving fuel efficiency. This is particularly true in a wet clutch pack. This study measures slip friction when the wet clutch pack in a DCT (Dual-Clutch Transmission) is disengaged, and the friction pads are slipping. Shudder engagement velocity, and applied forces can be measured under various working conditions through these torque transfer experiments. Test results demonstrate that the design parameters, and engagement conditions of wet clutch packs can be optimized to reduce shudder and frictional vibration during engagement in a dual clutch transmission.

• Advances in Energy Research
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• 제7권1호
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• pp.53-66
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• 2020

Before the industrial revolution architecture has been shaped by the natural and cultural inputs. Local constraints become more effective determinants of architecture in the rural contexts because by being disengaged from the webs of transportation and communication, rural settlements have achieved sustainability in difficult conditions. The examples of rural settlement and architecture have provided sustainability through integration with natural inputs within the geographical context because they have reached the goals of ecological design within the local constraints. Although this feature of the rural cultural landscapes has been emphasized frequently, tangible standards could not be developed in order to interpret their ecological design principles from the perspectives of the contemporary building sector and planning. However, the historical experience indicates that the sustenance of ecological performance can be possible as a result of integrated planning at the overall scale of the settlement. Therefore, the existing standards are not qualified for interpreting the rural contexts. This study develops a method for analysing, interpreting and evaluating traditional rural settlements and certifying new implementations in the rural environments in the light of the given literature review, discussion and methodological proposal.

• 가정과삶의질연구
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• 제24권4호
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• pp.75-92
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• 2006

This study examines the psychological independence in the family system of unmarried women to see how well they become psychologically independent within the relationships with family. A total of 452 subjects of the study were sampled from 20 to 30 unmarried women living in Seoul, Incheon and Gyeonggi-do. The results of the study are as follows: First, the scores of unmarried women's perception of family system were normal category. The scores of family system of unmarried women showed to be distributed to high scores among the overall ranges of scores which means they recognized their family system in general in a healthy way. Second, the level of the subjects' psychological independence from their fathers was shown to be higher than that from their mothers. The result means unmarried women were more dependent on their mothers than fathers. Third, the family system of unmarried women affected the level of psychological independence from their parents. The sub-factors of the family system significantly affected the level of psychological independence. Particularly, enmeshed and disengaged boundary and cooperative factors between spouses and generations affected the level of psychological independence. Fourth, the family system affected each sub-factor of psychological independence of unmarried women. Even though family system were different depending on each sub-factor of psychological independence, they affected the level of psychological independence.

• 한국정밀공학회지
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• 제26권1호
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• pp.112-119
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• 2009

An automatic transmission of construction equipment is controlled by hydraulic and electronic system for doing in various functions like as shifting and operation. The shifting is operated by the engaged and disengaged clutch motion from hydraulic power. On the shifting process, suitable pressure control to the clutch is required for smooth shifting. Hydraulic control system in the automatic transmission is divided by the pilot control type and the direct control type greatly. The direct control type has an advantage than the pilot control type. Because the structure is simple, the design and the manufacture are having less troubles and the system can be maximized precision pressure control. However, the excellent performance proportional control valve should be used to achieve proper control-ability. In this study, the dynamic analysis model composing the automatic transmission and hydraulic system for forklift truck is presented to simulate the characteristics of hydraulic system about the direct control type. That model is verified the validity compared the results of the testing examination. Parameters of input signal are analyzed to reduce the output torque according to input control signal is affected in shifting characteristic.

• International Journal of CAD/CAM
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• 제3권1_2호
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• pp.19-29
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• 2003

Disassembly is a fundamental process needed for component reuse and material recycling in all assembled products. Integral attachments, also known as 'snap' fits, are favored fastening means in design for assembly (DFA) methodologies, but not necessarily a favored choice for design for disassembly. In this paper, design methods of a new class of integral attachments are proposed, where the snapped joints can be disengaged by the application of localized heat sources. The design problem of reversible integral attachments is posed as the design of compliant mechanisms actuated with localized thermal expansion of materials. Topology optimization technique is utilized to obtain conceptual layout of snap-fit mechanisms that realizes a desired deformation of snapped features for joint release. Two design approaches are attempted and design results of each approach are presented, where the geometrical configuration extracted from optimal topologies are simplified to enhance the manufacturability for the conventional injection molding technologies. To maximize the magnitude of deformation, a design scheme has been proposed to include boundary conditions as design variables. Final designs are verified using commercial software for finite element analysis.