• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.115-120
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• 1998

Aerodynamic noise generated by automobile cooling fan is investigated. Automobile cooling fans radiate both discrete frequency noise as well as broadband noise. In the present work, the former is considered through free-wake panel method coupled with acoustic analogy fully considering the retarded time variation on the blade surface, while the latter is taken into account by three well-established broadband noise components. Experiments were performed to supplement necessary inputs as well as to provide the final comparison with the predicted noise spectrum. The predicted noise levels at blade passing frequencies agree well with the experimental data for the first few harmonics. Although the predicted broadband noise levels at higher frequencies fall below the experimental data due to the fundamental shortcomings of the utilized formulations, the analysis offers a detailed physical understanding of the fan noise generation processes.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 추계학술발표논문집 2부
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• pp.984-987
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• 2010

본 연구는 병원 종사자들의 작업관련 자각증상 호소율의 요인들을 파악하고자 시도되었다. 자료수집은 2010년 5월 18일부터 6월 18일까지 서울 소재 2개 종합병원 종사자 157명을 대상으로 설문조사를 하였다. 연구결과 첫째, 작업관련 자각증상 호소여부는 허리의 증상호소자가 평균 19.53점으로 비증상호소자의 평균 13.06점보다 유의하게 높았다(t=9.684, p=0.007) 둘째, 운동을 안하는 군에 비해 운동을 불규칙적으로 하는 군의 자각증상 호소률은 2.18배(OR=2.183, 95%, Cl=1.362-7.420)로 유의하게 높아지는 것으로 나타났다. 따라서 작업관련 증상관리를 위한 건강증진 프로그램 개발시 이에 대한 총체적인 반영이 필요할 것으로 본다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 2부
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• pp.792-795
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• 2011

After the year of 2000, compositions of stock holders in domestic firms are rapidly changing. In domestic stock market, the proportion of market value held by foreign investors reaches over 40%. There are several blue chip companies among those where foreign investors hold more than 50% of the stocks. There are still hot debates going on about whether the increase in the number of foreign investors contributes to domestic companies. This research attempted to determine foreign ownership increases enhance firm value empirically. It has been shown that foreign ownership variable has significant positive impact on Tobin's Q of firm value variable. The result suggests that foreign ownership increases in domestic corporations positively contribute to firm value, as they monitor and keep the management transparent as an institutional investor, and they work to soothe agency problems by the managements or the large stock holders.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 2부
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• pp.740-743
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• 2011

본 연구는 근골격계질환의 예방을 위해 전북권 지역에 해당하는 근로자들을 대상으로 설문조사를 하여 업종별 근골격계질환의 실태를 파악하고 이를 분석하였다. 조사분석 결과, 업종에 따른 근로자들의 신체 부위별 통증 호소 부위와 정도, 신체 부위별 통증 부위수, 각 신체 부위별 부적절한 작업 자세 등의 실태를 파악 할 수 있었다. 이를 통하여 근골격계질환에 대한 근로자들의 인식 개선과 근골격계질환의 유해요인을 감소시킬 수 있는 환경변화의 제도적 장치가 필요하며, 이를 인간공학적 시스템으로 재설계되어 예방 관리의 기틀을 마련해나가야 한다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 2부
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• pp.1044-1047
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• 2011

본 연구는 소방대원의 현장 작업자세 평가와 분석을 통하여 소방대원의 근골격계 부담작업 유해요인을 분석하고자 한다. B시에 소재하고 있는 소방서의 남자 소방대원을 대상으로 소방 현장에서 많이하는 자세 중 요구조자 이송작업자세, 방수작업자세, 유압구조장비 작업자세, 만능도끼작업 자세를 인간공학적 평가 기법인 Rapid Entire Body Assessment(REBA), Rapid Upper Limb Assessment(RULA)와 NIOSH Lifting Equation(NLE)를 이용하여 평가하고 분석하였다. 자세 분석결과, RULA 분석에서 모든 작업이 최고 점수인 7점으로 평가되었고 REBA는 5점에서 10점까지로 RULA분석에 비하여 낮은 점수를 나타내었다. 따라서, 소방대원들의 작업환경과 자세에 문제가 많다는 것을 알 수 있었다.

• 설비공학논문집
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• 제13권4호
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• pp.295-303
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• 2001

Condensation of vapor on solid inherently accompanies generation of liquid drops on the solid surface. However, these drops prevent the solid surface from directly contacting the saturated vapor, thus causing thermal resistance. This work investigates a novel mechanism for enhancing the condensation process, in which the condensed drops are rapidly removed from a solid surface by imposing vibration on them. In the experiments, a water drop pendant from a solid surface is vibrated at a fixed frequency while increasing the vibration amplitude. Upon repeating the experiments using various frequencies, it is revealed that there exist resonant frequencies at which the minimum vibration amplitudes inducing a fall-off of the pendant drops are remarkably less than those at neighboring frequencies. These frequencies are supposed to correspond to the resonant frequencies for different modes of drop shape oscillations. They are compared with the resonant frequencies predicted by relatively simple analyses, and the factors causing discrepancy between then are discussed.

• 대한안전경영과학회지
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• 제16권3호
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• pp.89-100
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• 2014

Construction victims have increased year by year. Disaster proportion is also increasing continuously. Looking over the causes of disasters by each type of work, fall from working platform indicate the highest rate above all so that it is urgently required to set up safety measures. This study is to grasp the present status of construction accidents, to identify areal characteristics of the top 20% accidents on the basis of working platforms with the highest accident rate, to grasp the causes of accidents after their analyses, and to present methods to reduce casualties related to working platforms. As measures to reduce construction disasters, this study proposes to improve safety management and training on working platforms, to complement safety regulations, and to better performance including the development and expansion of certified products suitable for safety regulations.

• 대한안전경영과학회지
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• 제16권3호
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• pp.273-277
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• 2014

Subcontracting business than the contracting business in shipbuilding industry is a lot of hazardous job and highly accident because of highly work intensity. In order to prevent the accidents, there is a need to analyze characteristic. of shipbuilding, to apply measures of risk assessment. In this paper, I suggested an improvement of the risk assessment through the actual condition research in shipbuilding industry. In the research method, I analysed accidents occurred until 2011-2013. Carried out the actual site survey while two weeks in May 2014. As a result, 1) The main pattern were caught-in or between, fall on the high level according to analyzed accidents. 2) To apply the weight show clear of magnitude for risk assessment. 3) Risk estimation of risk assessment is desirable to be quantization by accidents analysis, and to be greater than or equal to 4 steps.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2006년도 춘계학술발표논문집
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• pp.294-297
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• 2006

Measurement of network traffic have shown that the self-similarity is a ubiquitous phenomenon spanning across diverse network environments. In previous work, we have explored the feasibility of exploiting the long-range correlation structure in a self-similar traffic for the congestion control. we show that a multiple time scale TCP endows the underlying feedback control with proactivity by bridging the uncertainty gap associated with reactive controls which is exacerbated by the high delay-bandwidth product in broadband wide area networks. Third, we investigate the influence of the three traffic control dimensions-tracking ability, connection duration, and fairness-on performance.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 1부
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• pp.173-175
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• 2011

현대의 고도화된 산업현장에서 로봇의 사용은 보편화되고 있는 실정이다. 사람이 하기 어려운 작업을 대신함으로 인해 작업의 효율성과 생산의 극대화를 이루고 있다. 이런 가운데 로봇의 쓰임이 다양화되고 있는 추세에 있다. 그 중 한 분야로 무인 탐사 로봇을 만들어 보려 한다. 무인 탐사로봇의 주요기능으로는 악조건에서도 움직일 수 있는 이동체와 원거리에서도 사람이 실시간으로 볼 수 있는 영상전송기능 등을 필요로 한다. 이런 기능을 담당하는 부품들을 제어하기 위해 프로세서가 사용된다.