• 한국산업보건학회지
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• 제5권2호
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• pp.172-183
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• 1995

The airborne concentrations of the welding fumes produced during $CO_2$ arcwelding process at shipbuilding, shiprepairing, container manufacturing and car accessary manufacturing industry were investigated. The effects how much reduced the welding fume were checked when the portable fan was used. The results were as follows; 1.The geometric mean of welding fume concentration in shipbuilding factory was $10.05mg/m^3$. This exposure concentration was higher than other 3 manufacturing industries at 95% confidence level. 2. The sampling filters for welding fume could be digested with acid within 1 hour by microwave oven. The recoveries for investigated metal elements were all over 95%. 3. The optimal wavelength could be selected for the simultaneous analysis of 8 metal elements by ICP(Inductively Coupled Plasma). 4. Noxious gases($O_1,NO_2$) produced during $CO_1$ gas arc welding process were detected that the concentration of ozone($O_1$) was less than 0.01 ppm and that of nitrogen dioxide($NO_2$) was 0.01-0.03 ppm. 5. The geometric mean of welding fume particle diameter was $1.26{\mu}m$ and geometric standard deviation was 1.51 for the counts when particle an analyzer(ELZONE) had been used. 6. When the portable fan had been used,the reduced percent of total welding fume for workers was about 47.8% when portable fan was applied to blow and 71.7% when to exhaust.

• 산업경영시스템학회지
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• 제25권5호
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• pp.15-21
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• 2002

We studied the relations between variables related to fan's preference in a area of pro-baseball which is the most popular one among pro-sports. The dependent variables are pro-baseball team fan's preference to both the team and the products of the company which has a pro-baseball team, while the independent variables are sex, age, and hometown of fans. Eight hypotheses are constructed with those variables. For testing them a questionnaire was used, whose reliability was checked using Kronbach Alpha. Subjects were 314 college students in a local city. For statistical analysis nonparametric tests like Mann Whitney test, Kruskal-Wallis test, etc were used. Useful and significant results among variables were obtained. Since these results have important implications about management of pro-sports teams and fans and fans Preference to products in a view of sports marketing management, more researches should be done continuously in the future in this area.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2002년도 춘계 학술대회논문집
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• pp.65-70
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• 2002

Cross-Flow Fan(CFF) are widely used lot industrial equipments and household electric appliances. A design method for CFFs, however, has not been well established because of the complexity of the internal flow. Numerical analysis was performed by using STAR-CD. In this study present the internal flow of CFF, which has varies pin number, and their flowrate were compared

• 한국산업보건학회지
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• 제17권3호
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• pp.212-223
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• 2007

18 Local exhaust ventilation systems in 10 melting companies located in an industrial complex were tested to know the status of maintenance. Test items were fan flowrates, fan static pressures, rotational speeds and differential pressures of bag filters. Only 22% of the tested fans has more than 80% flowrate efficiency. 44% of the fans has lower than 60% efficiency. The performance of the fans are not in a good status. For the fans with lower than 60% efficiency, the analysis shows that the lower flowrate might be caused by the degradation of fan performance. On the other hand, for the fan s with higher than 60% efficiency, the main cause of flowrate reduction might be too much pressure losses due to clogging of filter bags. The degradation of fans usually lead the reduction of hood capture efficiency, resulting in the increase of contaminant concentrations in workplace. To keep fans in good status, self inspections should be periodically conducted. This inspection should include the measurements of flowrate and pressures. The most important thing to be performed is the initial test of local exhaust ventilation system because the initial test data should be used to know the level of system degradation.

• 한국유체기계학회 논문집
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• 제17권1호
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• pp.35-40
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• 2014

A multi-objective optimization of a regenerative fan for enhancing the aerodynamic and aeroacoustic performance was carried out using an integrated fan design system, namely, Total FAN-Regen$^{(R)}$. The Total FAN-Regen$^{(R)}$ was developed for non-specialists to carry out a series of design process, viz., computational preliminary design, three-dimensional aerodynamic and aeroacoustic analyses, and design optimization, for a regenerative fan. An aerodynamic analysis of the regenerative fan was conducted by solving three-dimensional Reynolds-averaged Navier-Stokes equations using the shear stress transport turbulence model. And, an aeroacoustic analysis of the regenerative fan was implemented in a finite/infinite element method by solving the variational formulation of Lighthill's analogy based on the results of the unsteady flow analysis. An optimum shape obtained by Total FAN-Regen$^{(R)}$ shows the enhanced efficiency and decreased sound pressure level as much as 1.5 % and 20.0 dB, respectively, compared to those of the reference design. The performance test was carried out for an optimized regenerative fan to validate the performance of the numerically predicted optimal design.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.192-197
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• 2001

This study is concerned with the reduction of noise radiation by an industrial fan unit. Among the noise sources involved in the fan unit, this article is focused on the noise source due to vibration of panels of the unit housing. It is shown here that noise radiation associated with the panel vibration can be as significant in some frequency ranges as that associated with other noise sources such as aeroacoustic fan noise.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2006년도 춘계학술발표논문집
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• pp.240-243
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• 2006

• 산업경영시스템학회지
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• 제26권4호
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• pp.6-11
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• 2003

이 논문에서 우리는 어떤 종류의 사람이 프로야구팀을 가진 기업에 충성하며, 프로팀에 충성하는 지를 연구했다. 충성심은 몇 개의 변수로 측정이 되며, 몇 개의 변수들은 또 그 하위변수로 측정이 된다. 종속변수는 충성심, 독립변수는 고객의 연령, 성별, 고향이다. 우리는 기존 연구를 보다 심화하여, 독립변수의 2차원적 효과를 연구했다. 그 사용하는 방법은 분산분석 등이며, 여섯 가지 유의적인 결과를 발견했다. 그 결과 우리는 충성스런 고객과 그렇지 않은 고객을 확인했으며, 보다 더 세분화된 고객 분석으로부터 보다 효율적인 고객경영이 가능하게 될 수 있다는 점이 이 연구의 잇점이라고 할 수 있다.

• 한국산학기술학회논문지
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• 제1권1호
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• pp.1-14
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• 2000

본 연구는 차량용 Air-conditioner 에 사용되고 있는 직교류형 팬의 개발에 관한 것이다. 가정용으로 사용되는 직교류형 팬을 차량용으로 전환하기 위해서는 날개의 길이, 형상 등을 새로이 설계해야 하며, 또한 성능이 충분히 유지되어야 한다. 이를 해결하기 위해 날개형상 설계, 사출성형 해석 그리고 시제품에 대한 성능평가 실험이 수행되었다. 개발의 주요 방법론은 성능을 만족시키는 최적의 날개형상을 구하고 이를 제작하기 위한 사출조건을 찾는 것으로 2년여에 걸쳐 개발이 성공적으로 완료되었다.

• 한국산학기술학회논문지
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• 제14권1호
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• pp.51-56
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• 2013

본 논문은 철도 차량에 사용하는 라인 플로우 팬의 소음 저감을 위해 소음원을 규명하여 저감하는 실험적인 연구이다. 라인 플로우 팬의 소음은 공기 유동에 의한 난류성 유동 및 랜덤성 소음, 블레이드 통과 주파수(681Hz)의 소음, 모터 회전에 의한 로터의 불균형(28.4Hz)의 구조물 진동에 의한 소음 등 여러 요인에 의해 발생된다. 각각의 소음원에 대해 대책을 수립하여 하우징 가이드 각도 및 거리 조정, 유동 통로의 형상 변경, 로터 밸런싱을 통해 총 5.7dB(A)의 소음을 저감하였다.