• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.848-851
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• 2004

This paper studied a method for minimizing the noise level emitted from range hoods. Range hoods were used for discharging various hazardous materials generated during household cooking to the outdoors, thus preventing them from being diffused through rooms in the house since they are the main cause of air pollution within dwellings. This study assumed that static pressure was not applied at the discharge outlet of the range hood. As such, the range hood was installed on the wall without the use of a connecting duct or other connectors attached to its discharge outlet. The vibration having the greatest influence on the noise level was determined by measuring the vibration at the front side of the hood where the acoustic omission was at its maximum. A method was then proposed to reduce the noise by simply suppressing the vibration at the vibrating part.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.1
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• pp.63-68
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• 2016

This research investigates the deployment time of an active hood lift system(AHLS) activated a gunpowder actuator for the passenger vehicle. The deployment time of the system is investigated by changing the principal design parameters of the system. In order to achieve this goal, after introducing the geometric structure and operating principle of the AHLS, the dynamic equations of the system are formulated for deploying motion. Subsequently, using the dynamic equations, the deployment time of the system is determined by changing several geometric design parameters such as location of actuator. It is then identified which design parameters are main factors to affect the deployment time of AHLS.

• The Research Journal of the Costume Culture
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• v.11 no.2
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• pp.243-252
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• 2003

The study was designed to review the changes in designs and the manufacturing methods of french hood, one of the headdresses which play an important role in showing the appearance of costume, to understand design expression techniques through manufacturing of the head dress of the western costumes, and to provide materials to exert creativity for new designs. Based on literature review and portrait study, 1 manufactured a frenchhood. I set the study cope as from the late 15 century when frenchhood was used for the first time, to the mid 16 century. For the frenchhood selected, 1 examined the hair style, the characteristics of the french hood, and the pattern first, and proceeded to manufacturing. 1 used velvet and silk for the textile as explained in the literature. And, 1 purchased such similar ornaments as shown in the pictures, making the color so similar to the original to the most. Dimensions in manufacturing were those In the literature, since the study is focusing on the reproduction of the features of the portraits. Dimensions of detailed decoration were measured using the ratio of the headdress in the portraits.

• The KSFM Journal of Fluid Machinery
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• v.8 no.2 s.29
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• pp.9-15
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• 2005

This paper presents an experimental and numerical study on the overall performance and local flow characteristics of sirocco fan in a range hood. Measurement of overall performance for sirocco fans were conducted based on AMCA standard 210. The effects of flow blockages due to the motor inside the fan on the fan performance were investigated by experimentally and numerically and the results were compared with each other. The numerical and experimental results show the inlet flow blockage reduces the performance (ie. fan static pressure, design flow rate, maximum efficiency and free delivery flow rate) of fan. It is found that the blockage makes the flow field highly non-uniform through the blade and cause the efficiency decrement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1205-1208
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• 2006

This paper introduces a study for the noise reduction of a range hood for household. Generally, range hoods have a built-in sirocco fan from which rumbling noise is generated. Though the rumbling noise has low noise level. this noise makes most of the users nervous due to the its low frequency characteristics. For the purpose of noise reduction, in this study, a micro-perforated panel system is installed in the fan housing of range hood. From the experimental results, it is confirmed that the noise level emitted from the range hood is decreased over 2dB(A) in all frequency regions due to the effect of noise reduction by micro-perforated panel system.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.63-68
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• 2005

In the present paper, the study on the optimal horizontal air jet velocity of a range hood system has been studied by three dimensional numerical simulation. It has been shown that the air jet of a range flood system generates coanda effect confining the contaminated (high temperature) air in a certain region while the jet pushes out more contaminated air into a room as the jet velocity increases. Therefore, the optimal jet velocity has been determined by the combination of the two mechanism.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.76-79
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• 2016

자동차 산업의 발달과 전세계적으로 차량의 증가로 인해 보행자의 사고 발생율이 증가하고 있고 보행자의 안전에 대해 연구와 안전장비들이 계속적으로 개발되고 있다. 보행자와 차량의 충돌시 보행자의 상해를 감소시키는 시스템 중 화약식 액티브 후드 시스템(active hood system, AHS)은 부하가 화약성분이므로 부하의 성분을 검출하는데 한계가 있고, 위험성이 높으므로 정밀한 고장진단이 필요하다. 이러한 문제점을 해결하기 위해 화약의 부하저항을 측정하는 방법과 저항성 누설전류를 측정하는 방법을 제시하고, 이 방법을 점화회로의 이상 유무를 확인하는 고장진단 기법으로 제안한다. 그리고 고장진단시 squib가 점화되는 오동작을 방지하고저 고장진단 모드와 점화모드를 구별하여 진단전류와 점화전류를 구분하는 기법을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.9 no.1
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• pp.39-44
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• 1984

Three types of parabolic antenna to reduce the sidelobes and backlobe are compared to determine the best suppressive effect under same conditions which are side rim loading parabilic antenna, flanged prabolic antenna. The hooded parabolic antenna adhered polyurethan form impregnated carbon powder in shows the best shape of suppressed the side back lobes that is 5 to 10 dB suppression of sidelobe and 15dB suppression of back lobe for E-plane.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.513-519
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• 2005

The Korean Tilting Train eXpress may produced a strong micro-pressure wave in tunnel exit because of large train/tunnel area ration of conventional railways. This micro-pressure wave causes an impulsive noise which is a serious environmental noise pollution near tunnel exit. Tunnel hood can be the method of reducing the micro-pressure wave in tunnel exit. Therefore, parametric studies for tunnel hood are performed with respect to the hood length and size to investigate the effects of the tunnel hood. Also, axi-symmetric unsteady compressible flow solver was used to analyze train-tunnel relative motion. According to the result of numerical analysis, the maximum micro-pressure wave in tunnel exit is reduced by 56% throughout the hood establishment on conventional railways.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.12
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• pp.489-494
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• 2016

There have been many cases when an air curtain installed in the apartment could not remove the gases well, such as carbon dioxide and particles like as smoke, oils, and vapors generated during cooking to disperse pollutants into the room. This study used a numerical analysis to show how the pollutant-removing performance of the range hood is changed when the air curtain is installed front of the kitchen table. The result of this study was that when the air amount supplied by an air curtain through the slot was about 50% of the exhaust amount, the capturing efficiency of the range hood for pollutants increased 90% more than without an air curtain. Even when the amount of supplied air was small, the capturing efficiency improved markedly with the use of an upward air curtain. In case that the air flow rate of the slot was greater than 60%, the capturing efficiency decreased.