• Title/Summary/Keyword: dropping

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Evaluation of Floor Impact Sound Performance according to the Reduction Methods (바닥충격음 저감방안에 따른 성능평가)

  • 김경우;최경석;최현중;양관섭
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.131-136
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    • 2004
  • Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. The character and level of impact noise generated depends on the object striking the floor, on the basic structure of the floor, and on the floor covering. This study base on the evaluate of isolation performance of impact sound according to the impact noise reduction methods. Reduction methods consist of four ways. First way is increase thickness of bare floor and other ways are using the soft coverings on the floor and ceiling assembles. Last way is make floating floor with shock absorbing materials.

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Shock Response Analysis of Small Form Factor Optical Disk Drive using Finite Element Method (유한 요소법을 이용한 초소형 광디스크 드라이브의 충격해석)

  • 김시정;장영배;박노철;박영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.173-176
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    • 2004
  • Nowadays, mobile devices are very common equipments such as mobile phone, PDA, etc. These equipments need information storage devices. Optical storage devices have more advantages than other storage devices, but it is not free from shock situation like dropping by user's mistakes. A complete model of a Small Form Factor Optical(SFFO) disk drive subject to shock loads is developed to investigate the response of the pickup/disk interface. With this model, we can simulate the drop test and consider the matters of shock simulation using commercial software(Ansys/LS-Dyna).

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Dynamic Behavior of Heterogeneous Impinging Droplets onto High Temperature Plate (고온평판에 충돌하는 비균일혼합액적의 동적거동 특성)

  • Lee, Choong Hyun;Kim, Kyung Chun
    • Journal of the Korean Society of Visualization
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    • v.13 no.3
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    • pp.20-23
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    • 2015
  • In this experiment, a heterogeneous droplet consisted of de-ionized water and olive oil was made through two 31G injection needles. The injection flow rate was $50{\mu}{\ell}/min$ and the droplet size was 2 mm. The droplet was impinged onto a sapphire plate which was heated up to $300^{\circ}C$ by a heater. Two high speed cameras were used for visualization, and the frame rate was 20,000 fps. A 150W metal halite lamp was used for illumination. The dropping height was fixed to 20 mm and the corresponding Weber number was 10.6 based on water. Due to different boiling points of two liquids, partial boiling features of heterogeneous droplet was observed. At the Leidenfrost condition, micro explosion phenomenon has occurred.

Transient Responses of an Airplane Taking off from and Landing Very Large Floating Stricture in Waves (항공기 이 .착륙 시 초대형 부유식 해양구조물의 시간 영역 응답 해석)

  • 신현경;이호영;임춘규;강점문;윤명철
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.10a
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    • pp.63-67
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    • 2000
  • Up to this day, Most studies of hydroelasticity are inclined to frequency domain atnlysis. Thos amlysis Q the landing, take-4, and dropping of airaqft on a structure. So, the concern of this prrper is a tra a VLFS subjected to dymmic lazd induced by airplane larndirrg and take-off. To predict added mass, dampr exciting force, the source-dipole distribution method were used The responses are accomplished by Fdoimain analysis method is based on Newmark $\beta$ method to pursuit time step pnzcedure taking advantage function for hvdrodvnumic effects.

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A Study on the Improvement of Transmission Efficiency for Multimedia Service Quality (멀티미디어 서비스 품질의 전송 효율성 향상을 위한 연구)

  • 문호선;하동문;김용득
    • Proceedings of the IEEK Conference
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    • 2002.06e
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    • pp.83-86
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    • 2002
  • In this paper while a router is routing all packet to the next hop, it inspects whether there is congestion on this current hop router or not and if the router discovers that it has some congestion, it informs that the packet is experienced to congestion. The packet arrived to next hop including some information about the congestion is processed first and it has wider bandwidth than another packet The amount of congestion is recorded to the DS field of IP header by congestion experience level. In the next hop when the packet including the congestion information is routed, the standard packet dropping ratio of the current router is changed in proportion to congestion experience that is recorded in IP header on of that. When the packet that has experienced congestion before is arrived, the router extends the drop threshold value not to drop the packet. It mean that transferring the audio or video stream, if the packet is already experienced the congestion in another hop, the router can provide the better service quality about 15∼25% than another.

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Hydroxylamine Effect on the Determination of Dissolved Oxygen by the Azide-Modified Winkler Method and Polarography (修正된 아자이드 Winkler 법과 폴라로그래피에 의한 溶存酸素의 측정에 관한 하이드록실아민의 영향)

  • Chung, Keun Ho;Ree, Jony Iuir;Kim, Chun Seek
    • Journal of Environmental Health Sciences
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    • v.12 no.2
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    • pp.11-15
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    • 1986
  • Hydroxlamine effect on the determination of dissolved oxygen by the azide-modified Winkder method and polarography has been studied. It was found that hydroxylamine interference on the dissolved oxygen by the azide-modified Winklet method can be eliminated completely by using permanganate. An inexpensive and convenient polarograph device was constructed. Dissolved oxygen in an air-saturated 0.1 F KCl solution undergoes, independent of hydroxylamine concentrations a two-step irreversible reduction at the dropping electrode the $H_2O_2$ produced in the first step is reduced to $H_2$O in the second. Two waves of equal size result, the first with a half-wave potential (E1/2) at about -0.13 V and the second at about -0.91 V (vs. SCE).

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A Study on the computer aided design for flow control valve of vane pump (베인 펌프용 유량 제어부의 전산설계에 관한 연구)

  • 이윤태
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.04a
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    • pp.555-560
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    • 2000
  • The modeling and the numerical analysis are done so as to develop the Computer Aided Design program for the design of flow control valve attached to the vane pump. The factors affecting the flow rate characteristics, are analyzed by the experiments and the numerical methods. It is shown that the main factor affecting to the first control flow is the diameter of small rod of the spool, the main factor affecting to the second control flow is the diameter of big rod of the spool, the main factors affecting to the cut off are the main spring constant, the initial displacement of main spring and small diameter of the spool, and the dropping slope characteristics of flow rate are decided by the chamfer of spool and the dynamic characteristics of the spool.

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A Polarographic Study of Mo-thiocyanate (V) Complex (Mo-Thiocyanate (V) 錯物의 電極還元 反應에 關한 硏究)

  • Sang-O Oh;Yu-Chul Park
    • Journal of the Korean Chemical Society
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    • v.14 no.2
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    • pp.141-145
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    • 1970
  • The reduction of Mo-thiocyanate (V) complex on dropping mercury electrode has been studied at ionic strength 0.6 with pH less than 2.3. D-C polarogram obtained from acidic solutions are reversible, diffusion controlled current. The electrode reaction of Mo-thiocyanate(V) may be represented as follows. $MoO(SCN)_3\;+\;2H^+\;+\;2e\;{\to}\;Mo(SCN)_2{^+}\;+\;H_2O\;+\;SCN^-$From this reaction, the half wave potential assumed to be $E_{1/2}\;=\;E_0'\;-\;0.059\;pH\;-\;0.03\;log{\;frac{[Mo(SCN)_2{^+}][SCN^-]}{[MoO(SCN)_3]}}$Considering the dissociation of this complex, however, it was estimated that the electrode reaction may be written by. $MoO^{+3}\;+\;3SCN^-\;+\;2H^+\;+\;2e\;{\to}\;Mo(SCN)_2{^+}\;+\;SCN^-\;+\;H_2O$.

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Effect of Anti-dropping on Environmemt and Oriental Melon(Cucumis melo L) in Plastic Films House. (연질필름 피복시설내 방적처리가 시설환경 및 참외 생육에 미치는 영향)

  • Jeon, Hee;Kwon, Young-Sam;Kim, Hyun-Hwan;Lee, Si-Young
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1997.05a
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    • pp.53-58
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    • 1997
  • 시설내 방적처리별 광환경, 개선 효과는 수적율이 환기나 송풍 단독으로 처리한 경우보다 2.6-5.8% 가량 낮은 2.7%를 보여 투광율이 송풍, 환기 단독 처리구보다 2.7-4.9% 가량 높아 67.4%를 보인 송풍+환기개선처리에서 가장 우수하였고 하우스 공간에서의 정식후 6일간 적산최저기온은 무처리에 비하여 4.6$^{\circ}C$가 낮았으나 작물이 정식된 터널에서는 0.8$^{\circ}C$ 정도 낮았다. 참외의 생육은 환경이 방적효과로 광환경이 우수한 송풍+환기개선처리에서 두 처리보다 엽수가 3-5매 가량 많고 착과율도 4-8% 정도 높아 전체적인 수량이 3,630kg/10a로 무처리에 비하여 43%나 증수되었다.

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Efficient Video Streaming Policy using Gateway in the mobile Network Environment (이동 통신 환경에서 Gateway를 이용한 효율적인 비디오 전송 방법)

  • Tak, Kwang-Ok;Park, Si-Yong;Jung, Ki-Dong
    • Annual Conference of KIPS
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    • 2003.11b
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    • pp.1281-1284
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    • 2003
  • 본 논문에서는 무선 이동 통신 환경에서 동영상 전송시 발생하는 패킷 손실 및 지연을 줄이고 최대한 모바일 호스트에서 손상 없이 플레이 할 수 있도록 gateway를 이용하여 media 서버에서 mobile host까지의 적절한 전송 스케줄을 구한다. 모바일 호스트의 구조상 작은 버퍼량을 가지고 있으며, 그리고 무선 통신 환경은 유선에 비하여 작은 대역폭을 가지고 있다. 미디어 스트림을 전송하는데 있어서 dropping 없이 패킷이 전송될 수 있도록 gateway상에서 버퍼링을 실시한다. 이 논문에서는 gateway와 mobile host간의 transmission rate를 조절하여 gateway상의 버퍼량을 최소화시키는 전송 스케줄 방법을 제안한다.

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