• Title, Summary, Keyword: 측벽

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측벽부근을 항행하는 선박에 미치는 측벽영향에 관한 연구

  • Lee, Chun-Gi;Kim, Hui-Seong;Mun, Seong-Bae;Jeong, Tae-Gwon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.15-16
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    • 2014
  • 제한수역에서 측벽부근을 항행하는 대형선박에 미치는 측벽영향은 대단히 크고, 선박조종운동의 관점에서 보았을 때 상당히 중요한 문제이다. 이 연구에서는 측벽의 길이를 변화시키면서 측벽과 선박과의 종방향 및 횡방향 거리, 측벽의 길이 및 수심에 따른 측벽영향에 대하여 수치 계산하였다.

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The Interaction Effect Acting on a Vessel in the Proximity of Bank Wall (측벽근방을 항해하는 대형선박에 미치는 측벽의 영향)

  • 이춘기
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.197-202
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    • 2004
  • It is well known that the hydrodynamic interaction forces between ship and bank wall affect ship manoeuvring motion. This paper deals with the interaction effect acting on a ship navigating closely in the proximity of bank wail. In this paper, the calculation method based on the slender body theory for estimation of the hydrodynamic interaction forces between ship and bank wail is applied. The hydrodynamic interaction forces acting on a ship during passing through the proximity of the bank wail are predicted to evaluate an influence of these interaction forces on ship manoeuvrability. The calculation method used in this paper will be useful for prediction of ship manoeuvrability at the initial stage of design, for automatic control system of ship in confined waterways, for discussion of marine traffic control system and for construction of harbour.

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The Interaction Effect Acting on a Ship Hull in the Proximity of Bank Wall (측벽근방을 항해하는 대형선박에 미치는 측벽의 영향)

  • Lee, Chun-Ki;Park, Hain-Il
    • Journal of Navigation and Port Research
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    • v.28 no.5
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    • pp.333-337
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    • 2004
  • It is well known that the hydrodynamic interaction forces between ship and bank wall affect ship manoeuvring motion This paper deals with the interaction effect acting on a ship navigating closely in the proximity of bank wall. In this paper, the calculation method based on the slender body theory for estimation of the hydrodynamic interaction forces between ship and bank wall is applied. The hydrodynamic interaction forces acting on a ship during passing through the proximity of the bank wall are predicted to evaluate an influence of these interaction forces on ship manoeuvrability. The calculation method used in this paper will be useful for prediction of ship manoeuvrability at the initial stage of design, for automatic control system of ship in confined waterways, for discussion of marine traffic control system and for construction of harbour.

Environmental Survey to a Ventilation System on the Enclosed Farrowing-nursery Pig House in Winter (무창 분만ㆍ자돈사내에서 환기시스템별 혹한기 환경 조사)

  • 유용희;송준익;정종원;김태일;최희철;양창범;이영윤
    • Journal of Animal Environmental Science
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    • v.10 no.1
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    • pp.23-28
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    • 2004
  • This study was conducted to improve a ventilation system on the enclosed farrowing-nursery pig house in Korean swine facilities. This survey ventilation system types four major structures. The first structure has planer slot inlet, where air comes in, and these are placed outside the wall under the eave. Then the air from the pig house flows out through the chimney outlet operated by an exhaust fan(V1). The second structure has an air input through the perforated ceiling inlet, then the air from the pig house flows out through the chimney outlet operated by an exhaust fan(V2). Through the circular duct inlet placed inside the juncture of the entry wall, air also comes in(third structure). Then, air from the pig house flows out through the chimney outlet operated by an exhaust fan(V3), Similarly, air comes in through the circular duct inlet placed inside the juncture of the entry wall, but air from the pig house flows out through the side wall by an exhaust fan(V4). Temperature, relative humidity, air velocity and ammonia concentration(NH$_3$) were measured in the interior farrowing-nursery pig house during winter. The results were as follows; Interior temperature at the pig house was not remarkably different in all ventilation systems. The V4 system had low area air velocity, and this was better than other systems. It also had a lower ammonia concentration than other systems. V3 and V4 systems had stable airflow patterns, better than other systems. Therefore, it is suggested that the V3 and V4 ventilation system be applied in the enclosed farrowing-nursery pig house in winter.

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Experimental study on the behavior of the adjacent ground due to the sidewall failure in a shallow tunnel (얕은터널에서 측벽파괴시 주변지반 거동에 대한 실험적 연구)

  • Park, Chan Hyuk;Lee, Sang Duk
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.6
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    • pp.871-885
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    • 2017
  • Nowadays, the construction of tunnels with a shallow depth drastically in urban areas increases. But the effect of sidewall displacement in shallow tunnel on its behavior is not well known yet. Most studies on the shallow tunnel have been limited to the stability and the failure of the tunnel and the adjacent ground in plane strain state. Therefore, the model tests were conducted in a model ground which was built with carbon rods, in order to investigate the impact of the tunnel sidewall displacement on the lateral load transfer to the adjacent ground. The lateral displacement of the tunnel sidewall and the load transfered to the adjacent ground were measured in model tests for various overburdens (0.50D, 0.75D, 1.00D, 1.25D). As results, if the cover depth of tunnel was over a constant depth (0.75D) in a shallow tunnel, the tunnel sidewall was failed with a constant shape not depending on the tunnel cover depth and also not affected by the opposite side of the wall. But, if the cover depth of tunnel was under a constant depth (0.75D), the failure of the tunnel sidewall could affect the opposite sidewall. In addition, if the displacement of tunnel sidewall with 50% of the critical displacement occurred, the tunnel failure was found to be at least 75%. However, additional studies are deemed necessary, since they may differ depending on the ground conditions.

방파제 형상 연직구조물 부근을 항행하는 대형선박에 미치는 간섭력에 관한 연구

  • Lee, Chun-Gi;Mun, Seong-Bae;Gang, Il-Gwon;Lee, Dong-Seop;Park, Jin-Su
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.25-26
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    • 2013
  • 제한수역에서 측벽부근을 대형선박이 항행할 경우, 측벽으로 인하여 발생하는 유체력이 대형선박의 조종운동에 상당히 크게 영향을 미친다는 것은 잘 알려져 있다. 이 논문에서는 방파제형상을 하고 있는 측벽 부근을 대형선박이 항행하는 경우, 선박과 방파제 형상간의 간섭력 추정을 위해 세장체 이론을 토대로 한 계산 방법을 적용하였으며, 선박에 미치는 측벽의 영향을 파악하기 위하여 방파제길이, 방파제와 선박간의 거리 및 수심을 변수로 하여 선박과 측벽과의 간섭력을 수치 계산하였다.

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The Interaction Effects Between Two Vessels in the Proximity of Bank Wall in Restricted Waterways (제한수역에서 측벽부근을 항해하는 두 선박간의 상호영향)

  • Lee Chun- Ki
    • Journal of Navigation and Port Research
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    • v.29 no.1
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    • pp.17-22
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    • 2005
  • The manoeuvring of vessels and hydrodynamic interaction between them and bank wall in restricted waterways have been treated as important factors in channel design and safe piloting in the waterway areas. This paper examines the interaction forces and moments acting on two vessels running closely in the proximity of bank wall. The object of this paper is to propose a guideline of safe velocity of vessels and distance between them for navigating safely in confined sea areas.

Morphological Analysis of the Sinus Lateral Wall using Computed Tomography (전산화단층촬영법을 이용한 상악동 측벽의 형태학적 분석)

  • Kim, Yong-Gun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.27 no.3
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    • pp.285-292
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    • 2011
  • The purpose of thise study was to measure the thickness of the sinus lateral wall using computed tomography (CT), and to find the most suitable vertical position for lateral window opening prior to sinus elevation. Thirty patients requiring sinus elevation had CT images taken with Philips Brilliance iCT. The thickness of the sinus lateral wall was measured according to its vertical position against the sinus inferior border, and its mean was calculated through three repeated measurements. When measured 2 mm above the sinus inferior border (SIB+2), the thickness of the sinus lateral wall was observed to be more than 2 mm. When measured 3 mm above the sinus inferior border (SIB +3), the sinus lateral wall was less than 2 mm in thickness. It is recommended that the lateral wall window be made 3 mm above the sinus inferior border when performing sinus elevation using the lateral approach.

The Interaction Effects Between Two Vessels in the Proximity of Bank Wall in Restricted Waterways (제한수역에서 측벽부근을 항해하는 두 선박간의 상호영향)

  • Lee Chun-Ki;Yoon Jeom一Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.49-55
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    • 2004
  • The manoeuvring of vessels and hydrodynamic interaction between them and bank wall in restricted waterways have been treated as important factors in channel design and safe piloting in the water areas. This paper examines the interaction forces and moments acting on two vessels running closely in the proximity if bank wall. The object if this paper is to propose a guideline of safe velocity if vessels and distance between them for navigating safely in confined sea areas.

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A study of NMOSFET trench gate oxide uniformity according to voltage-current characteristic (NMOSFET의 트렌치게이트 산화막 균일도에 따른 전류-전압 특성연구)

  • Kim, Sang-Gi;Park, Kun-Sik;Kim, Young-Goo;Koo, Jin-Gun;Park, Hoon-Soo;Woo, Jong-Chang;Yoo, Sung-Wook;Kim, Bo-Woo;Kang, Jin-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.154-155
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    • 2008
  • 대전류용 전력소자를 제조하기 위해 고밀도 트렌치를 형성하여 이들을 병렬로 연결시켜 트렌치 게이트 NMOSFET를 제작하였다. 고밀도 트렌치 소자를 제작한 후 케이트 산화막 두께에 따른 전류-전압 특성을 분석하였다. 트렌치 측벽의 게이트 산화막 두께는 트렌치 측벽의 결정방황에 따라 산화막 두께가 다르게 성장된다. 특히 게이트 산화막 두께의 균일도가 나쁘거나 두꺼울수록 케이트 전류-전압 특성은 다르게 나타난다. 트렌치 형상에 따라 측벽의 산화막 두께가 불균일하거나 혹은 코너 부분의 산화막이 두께가 앓게 증착됨을 알 수 있었다. 이는 트렌치 측벽의 결정방향에 따라 산화막 성장 두께가 다르기 때문이다. 이러한 산화막 두께의 균일도를 향상시키기 위해 트렌치 코너 형상을 개선하여 트렌치 측벽의 게이트 산화막의 두께 균일도를 높였으며, 그 결과 소자의 전기적 특성이 개선되었다.

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