• 한국소음진동공학회논문집
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• 제14권5호
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• pp.370-376
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• 2004

The overall aim of this paper is to determine coupling loss factor of welding point between shell and cylinder using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it ispossible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one way (uni-directional) power flow between multi-sub structures. Using these conditions, it is possible to find the equation of coupling loss factor expressed as above two loss factors. To check the effectiveness of above equation, this paper used two-stage application. The first approach was application between simple cylinder and shell. The next was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.969-972
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• 2003

The overall aim of this paper is to determine coupling loss factor of welding point between shell and cylinder using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it is possible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one way(nl- directional) power flow between multi-sub structures. Using these conditions, it is possible to find the equation of coupling loss factor expressed as above two loss factors. To check the effectiveness of above equation, this paper used two stage application. The first approach was application between simple cylinder and shell. The next was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding Point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure

• 대한기계학회논문집A
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• 제24권8호
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• pp.2007-2014
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• 2000

It has been reported that the dynamic stress intensity factor for a propagating crack is increasing or decreasing according to the increasement of the crack propagating velocity. It is confirmed in this study that the increasement or decreasement of stress intensity factor with crack growing velocity is accused by loading condition. When the crack propagates under a constant displacement along upper and lower boundary in finite plate, the dynamic stress intensity factor decreases according to the increasement of the propagating crack velocity. When the crack propagates under a constant stress along upper and lower boundary in finite plate, the dynamic stress intensity factor increases according to the increasement of the propagating crack velocity. The increasement or decreasement of stress intensity factor with crack growing velocity is greater in a fast crack propagation velocity than in a slow one.

• 상하수도학회지
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• 제28권1호
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• pp.125-134
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• 2014

6 sigma is a management innovation strategy which improves most of all managerial processes including transactional and project based operations such as marketing, purchasing, accounting, and construction. Even though 6 sigma is trying to solve problems from the customer's viewpoint in the scientific manner, project leader feels some difficulties in implementation because of several reasons. Especially the difficulties are prevalent in construction site. This paper investigates the cause of the difficulties through questionnaires, analyzes the investigation results, and verifies the critical success factors of 6 sigma implementation. Factor analysis has been usually employed in reducing quantity of data and summarizing information chaos. In this study, several variables from questionnaires are grouped into just only four factors by the process of factor analysis. The critical success factors are extracted as project management system, implementation mechanism, site condition, and project ownership. Some ideas for each individual success factor are suggested, which are expected to be useful in successful implementation of 6 Sigma in construction site.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 2부
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• pp.156-162
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• 2006

It was hypothesized that mobile 3D provide the sense of presence in different quantity and quality aspects in virtual reality. And it was supposed that the construction of presence involves various levels and dimensions. The factors of mobile 3D game are divided into 4 super-factors; condition factor, interface factor, attention factor, feedback factor that resulted into 20 sub-factors resulted from the factor analysis. Our primary goal is the development of valid Mobile 3D presence scale, and to find out the factor structure of the scale.

• 복식
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• 제58권9호
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• pp.29-37
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• 2008

The purpose of this study was to investigate insulation of thermal clothing under still and dynamic air conditions(with 2.1m/sec air velocity) and decrease of insulation in both conditions, to analyze correlations among them, and to estimate insulation and decrease of insulation using factors, such as fabric insulation, fabric weight, clothing weight, air permeability, and water vapor resistance. A total of 25 kinds of clothing were tested(9 types for suits, 6 types of jacket, 5 types for shirts, and 5 types for trousers). The results of this study were as follows; Thermal resistance of clothing under the dynamic air condition decreased comparing to that of clothing under still air condition in all types of clothing. Decrease in shirts was the biggest(47.5%), followed by suits(39.51%), trousers(37.48%), and jackets(34.49%) in sequence. Thermal resistance of clothing under dynamic air condition showed very high correlation(0.98, p<0.01) with that of clothing under still air condition, followed by thermal resistance of fabric(0.86, p<0.01). Decrease in thermal resistance of clothing showed the highest correlation with air permeability. It didn't show correlation with other factors. Regression analysis showed that fabric thickness would be useful factor for estimating thermal resistance of clothing and air permeability also would be useful factor for estimating decrease in thermal resistance of clothing.

• 대한토목학회논문집
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• 제29권6D호
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• pp.685-691
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• 2009

본 연구는 다양한 기상 요인의 영향 정도에 따른 속도 변화를 분석하여 고속도로의 교통상황 분류를 목적으로 하였다. 서해대교의 RWIS와 VDS 자료를 활용하여 요인분석한 결과 교통상황에 영향을 주는 기상요인은 날씨, 온도, 시정거리로 나타났다. 각 요인에 따른 교통상황을 분류하기 위해 요인별로 분산분석을 실시한 결과 날씨는 맑음과 강우, 온도는 $5^{\circ}C$ 이하와 이상, 시정거리는 강우 시에만 10km 이하와 이상으로 분류되어 총 5개 유형의 교통상황으로 분류되었다. 보다 원활한 교통관리를 위해 각 상황별로 교통량-속도 모형을 추정하였으나 분석자료의 부족으로 설명력은 다소 낮게 나타났다. 그러나 장기간의 자료를 본 연구에서 제시된 분석과정에 입각하여 분석할 경우 기상요인에 따른 유형별 교통관리가 가능할 것으로 기대된다.

• Reproductive and Developmental Biology
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• 제36권1호
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• pp.13-19
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• 2012

In order to provide the basis for developing practical mouse embryonic stem cells (mESCs) culture method, how the endogenous level of self-renewal-stimulating factor genes was altered in the mESCs by different extracellular signaling was investigated in this study. For different extracellular signaling, mESCs were cultured in 2 dimension (D), 3D and integrin-stimulating 3D culture system in the presence or absence of leukemia inhibitory factor (LIF) and transcriptional level of $Lif$, $Bmp4$ and $Wnt3a$ was evaluated in the mESCs cultured in each system. The expression of three genes was significantly increased in 3D system relative to 2D system under LIF-containing condition, while only $Wnt3a$ expression was increased by 3D culture under LIF-free condition. Stimulation of integrin signaling in mESCs within 3D system with exogenous LIF significantly up-regulated transcriptional level of $Bmp4$, but did not induce transcriptional regulation of $Lif$ and $Wnt3a$. In the absence of LIF inside 3D system, the expression of $Lif$ and $Bmp4$ was significantly increased by integrin signaling, while it significantly decreased $Wnt3a$ expression. Finally, the signal from exogenous LIF significantly caused increased expression of $Lif$ in 2D system, decreased expression of $Bmp4$ in both 2D and 3D system, and decreased expression of $Wnt3a$ in integrin-stimulating 3D system. From these results, we identified that endogenous expression level of self-renewal-stimulating factor genes in mESCs could be effectively regulated through artificial and proper manipulation of extracellular signaling. Moreover, synthetic 3D niche stimulating endogenous secretion of self-renewal-stimulating factors will be able to help develop growth factor-free maintenance system of mESCs.

• 한국심리학회지 : 문화 및 사회문제
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• 제19권3호
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• pp.367-388
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• 2013

본 연구에서는 운전 시뮬레이션을 통해 구현된 위험 운전상황에서 운전자의 문화성향(개인주의 문화성향과 집단주의 문화성향)에 따른 귀인양식(상대운전자의 운전태도를 포함한 성향 귀인 또는 도로여건 등을 포함한 상황귀인)에서의 차이를 비교하였다. 실험참가자들의 문화성향은 Singelis 등(1995)의 문화성향 척도를 사용하여 분류하였고, 위험 운전상황은 상대운전자에 의한 갑작스러운 끼어들기와 급정거 상황으로 나누어 제시하되, 각각의 위험 운전상황은 상대운전자의 의도가 분명히 드러나는 조건과 도로여건 등과 같은 상황변인이 강조되는 방식으로 시나리오 조건을 다시 구분하였다. 본 연구의 결과를 요약하면 다음과 같다. 첫째, 전반적으로 살펴보면 '급정거: 상황강조' 시나리오 조건을 제외한 모든 시나리오 조건에서 실험참가자들의 귀인점수는 상황귀인 점수보다는 성향귀인 점수가 더 높았다. 둘째, 실험참가자들의 문화성향을 동시에 고려할 경우 문화성향의 유형에 따라 매우 상이한 결과를 보였다. 즉, '끼어들기: 성향강조' 시나리오 조건을 제외한 모든 시나리오 조건들에서 개인주의 문화성향 집단의 경우에는 시나리오 유형과 상관없이 상대운전자의 성향요인으로 귀인하는 경향이 강했던 반면, 집단주의 문화성향의 집단의 경우 상황요인에 대한 귀인점수가 높아져 성향귀인 점수와 상황귀인 점수 사이에서의 차이가 감소하였다. 본 연구의 시사점과 추후의 연구주제 및 연구방법에 대해 논의하였다.

• 한국기계가공학회지
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• 제11권1호
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• pp.26-32
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• 2012

Polishing is one of the important methods in manufacturing of Si wafers and in thinning of completed device wafers. This study will report the characteristic of wafer according to processing time, machining speed and pressure which have major influence on the abrasion of Si wafer polishing. It is possible to evaluation of wafer abrasion by load cell and infrared temperature sensor. The characteristic of wafer surface according to processing condition is selected to use a result data that measure a pressure, machining speed, and the processing time. This result is appeared by the characteristic of wafer surface in machining condition. Through that, the study cans evaluation a wafer characteristic in variable machining condition. It is important to obtain optimal condition. Thus the optimum condition selection of ultra precision Si wafer polishing using load cell and infrared temperature sensor. To evaluate each machining factor, use a data through each sensor. That evaluation of abrasion according to variety condition is selected to use a result data that measure a pressure, machining speed, and the processing time. And optimum condition is selected by this result.