• Title/Summary/Keyword: 경사각

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Parametric study of optimum design variables of PPWS socket and stability analysis (PPWS용 정착소켓의 최적설계를 위한 매개변수해석 및 안정성 검토)

  • Yoo, Hoon;Seo, Ju-Won;Jung, Woon;Lee, Sung-Hyung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2010.04a
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    • pp.6-9
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    • 2010
  • 본 논문에서는 최소 중량을 갖는 PPWS용 소켓의 기하형상을 결정하기 위하여 소켓의 경사각, 스트랜드의 강도 및 스트랜드의 직경을 주요 설계변수로 결정하고 각 설계 경우에 대한 매개변수해석을 수행하였다. 소켓의 경사각은 5도에서 13도까지를 범위로 하였고 스트랜드의 강도는 1860MPa급, 1960MPa급 및 2100MPa급의 고강도 강선을 적용한 경우를 고려하였으며, 스트랜드의 직경은 91, 127, 169 및 217개의 강선을 적용한 경우를 대상으로 하였다. 또한, 매개변수해석에서 도출된 기하형상을 갖는 소켓의 안정성을 검토하기 위하여 유한요소해석을 이용하여 소켓을 해석하고 스트랜드의 허용인장력 작용시 소켓의 안정성을 검토하였다. 해석 결과, 소켓의 중량을 최소화하는 내부 경사각은 스트랜드의 직경에 큰 영향을 받음을 알 수 있었으며, 매개변수해석으로부터 설계된 소켓은 스트랜드의 허용인장력 작용시 충분한 안정성을 확보하고 있음을 알 수 있었다.

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Effect of Aspect Ratio and Inclination on Natural Convection in Circular Trapezoidal Cavities (부채형 공간내의 자연대류에 대한 간격비와 경사각의 영향)

  • 배태열;배대석;권순석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.11
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    • pp.2181-2188
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    • 1992
  • Two-dimensional natural convection within a circular trapezoidal cavity with parallel cylindrical top and bottom walls at different temperatures and two adiabatic side walls has been solved by finite-difference methods. This study has been conducted to evaluate the effects of aspect ratio and inclination in the natural convection for various Rayleigh numbers. The minimum average Nusselt number occurs at the point of transition from a conductive heat transfer to a convective heat transfer. Numerical results are compared to experimental results with qualitatively good agreement.

A Basic Study of Development of Miniature Size Electrostatic Induction Motor (초소형 정전유도형 전동기의 개발을 위한 기초연구)

  • 이동훈
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.10 no.5
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    • pp.57-65
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    • 1996
  • 초고속 정전유도형 정전전동기의 개발의 위한 기초연구로서 회전자 물질의 표면저항률, 비유전율 및 전하완하시정수의 변화에 따른 회전자의 회전속도특성을 조사하였다. 회전자표층물질의 비유전율 및 표면저항률은 클수록 회전자의 회전속도는 증가하였으며, 또한 이 두 요소를 곱한 회전지표면에 유도된 전하의 완화시정수가 클수록 회전속도는 증가하였다. 한편 회전자표층물질로서 도전성물질(Ti)을 폴리프로필렌 위에 불연속적으로, 즉 띠의 모양으로 증착한 시료를 사용하여 띠의 폭 및 경사각의 변화에 따른 회전자의 회전속도특성 및 토크 특성을 조사하였다. 이 경우 띠의 폭이 적어질수록 회전자의 회전수는 지수함수적으로 증가하였으며, 등간격으로 세분화한 것을 회전자의 축에 대해서 회전방향으로 경사각$\theta$만큼 기울였을 때 $\theta$=60。 및 150。일 때 회전자의 회전속도가 가장 큰 것으로 나타났으며, 특히 경사각 $\theta$=0。일때에 비해서 약 125[%]정도 높은 회전속도를 보였다. 최대토크 및 최대출력은 각각 {{{{25$\times$ { 10}^{ -6} [Nm]}}}}및 11.5[mW]이었다.

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Three-dimensional finite element analysis of stress distribution for different implant thread slope and implant angulation (임플란트 나사선 경사각과 식립 각도에 따른 3차원 유한요소 응력분석)

  • Seo, Young-Hun;Lim, Hyun-Pil;Yun, Kwi-Dug;Yoon, Suk-Ja;Vang, Mong-Sook
    • The Journal of Korean Academy of Prosthodontics
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    • v.51 no.1
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    • pp.1-10
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    • 2013
  • Purpose: The purpose of this study was to find an inclination slope of the screw thread that is favorable in distributing the stresses to alveolar bone by using three dimensional finite element analysis. Materials and methods: Three types modelling changed implant thread with fixed pitch of 0.8 mm is the single thread implant with $3.8^{\circ}$ inclination, double thread implant with $7.7^{\circ}$ inclination and the triple thread implant with $11.5^{\circ}$ inclination. And three types implant angulation is the $0^{\circ}$, $10^{\circ}$ and $15^{\circ}$ on alveolar bone. The 9 modelling fabricated for three dimensional finite element analysis that restored prosthesis crown. The crown center applied on 200 N vertical load and $15^{\circ}$ tilting load. Results: 1. The more tilting of implant angulation, the more Von-Mises stress and Max principal stress is increasing. 2. Von-Mises stress and Max principal stress is increasing when applied $15^{\circ}$ tilting load than vertical load on the bone. 3. When the number of thread increased, the amount of Von-Mises stress, Max principal stress was reduced since the generated stress was effectively distributed. 4. Since the maximum principal stress affects on the alveolar bone can influence deeply on the longevity of the implants. When comparing the magnitude of the maximum principal stress, the triple thread implant had a least amount of stress. This shows that the triple thread implant gave a best result. Conclusion: A triple thread implant to increase in the thread slope inclination and number of thread is more effective on the distribution of stress than the single and double thread implants especially, implant angulation is more tilting than $10^{\circ}$ on alveolar bone. Thus, effective combination of thread number and thread slope inclination can help prolonging the longevity of implant.

A Study on the Development of Multifuntional Real-Time Inclination and Azimuth Measurement System (다용도 실시간 경사각과 방위각 연속 측정 시스템 개발연구)

  • Kim, Gyuhyun;Cho, Sung-Ho;Jung, Hyun-Key;Lee, Hyosun;Son, Jeong-Sul
    • Journal of the Korean earth science society
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    • v.34 no.6
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    • pp.588-601
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    • 2013
  • In geophysics and geophysical exploration fields, we can use information about inclination and azimuth in various ways. These include borehole deviation logging for inversion process, real-time data acquisition system, geophysical monitoring system, and so on. This type of information is also necessarily used in the directional drilling of shale gas fields. We thus need to develop a subminiature, low-powered, multi-functional inclination and azimuth measurement system for geophysical exploration fields. In this paper, to develop real-time measurement system, we adopt the high performance low power Micro Control Unit (made with state-of-the-art Complementary Metal Oxide Semiconductor technology) and newly released Micro Electro Mechanical Systems Attitude Heading Reference System sensors. We present test results on the development of a multifunctional real-time inclination and azimuth measurement system. The developed system has an ultra-slim body so as to be installed in 42mm sonde. Also, this system allows us to acquire data in real-time and to easily expand its application by synchronizing with a depth encoder or Differential Global Positioning System.

A Study on the Sea Areas Dynamic Stability of LL-26(M) Light Buoy (LL-26(M) 등부표의 해역별 동적안정성에 관한 연구)

  • Moon, Beom-Sik;Gug, Seung-Gi;Kim, Tae-Goun
    • Journal of Navigation and Port Research
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    • v.44 no.3
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    • pp.166-173
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    • 2020
  • AtoN Accident causes navigation dangerous to ships and reduces the credibility of aids to navigation. The most light buoys on the sea have the highest accident rate from the influence of sea weather such as wind, current, and waves. However, in Korea, despite the different sea weather conditions in each sea area, in calculating the dynamic stability of the light buoy, there is a problem that only limit value conditions are applied to all sea areas. Thus, the purpose of this study was to analyze the dynamic stability of the LL-26(M) light buoy, the most installed buoy of its kind on the sea and suggest a stable operation plan for the LL-26(M) light buoy. To achieve this, after analyzing the weather for each sea area of the previous study related to the light buoy, the dynamic stability (inclination angle) was estimated by applying to the representative light buoys of each sea area wherein the number of accidents caused by sea weather was high. As a result of this study, the inclination angle of LL-26(M) light buoy for each sea area was different. That is, the inclination angle caused by winds was 10.329°-36.868°, the inclination angle caused by currents was 0.123°-18.834° and the inclination angle caused by waves was 4.777°-20.695°. The results of study can be used as basic data useful for installation standards for each sea area for stable operation of the LL-26(M) light buoy.

경사낙하 충돌조건하의 사용후핵연료 수송용기의 충돌거동

  • 구정회;서기석;정성환;도재범;김영진
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.05a
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    • pp.885-890
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    • 1995
  • 사용후핵연료 수송용기는 충돌사고에 대한 구조적 건전성을 입증하기 위하여 9 m 자유낙하조건에 대하여 수송용기의 충돌거동을 평가해야 한다. 본 연구의 목적은 수송용기가 9 m 높이에서 충돌면과 경사각을 갖고 충돌할 때의 동적거동을 파악하기 위한 것이다. 수송용기가 충돌과 함께 회전하며 연속충돌을 일으키는 45$^{\circ}$ 이하의 작은 경사각을 갖고 충돌할 매 수송용기에 발생하는 응력, 가속도, 충돌력 등을 분석하여 동적거동을 파악하였다. 또한, 수송용기의 경사각도를 변화시키며, 경사각도의 변화가 수송용기의 동적 거동에 미치는 영향을 파악하였다.

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Natural Convective Heat Transfer Adjacent to Slightly Inclined Isothermal Surface Immersed in Cold Pure Water (수평으로부터 약간 경사진 등온면이 저온의 순수물 속에 잠겨있을때 일어나는 자연대류 열전달)

  • 유갑종;엄용균
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.3
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    • pp.1001-1010
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    • 1991
  • 본 연구에서는 천이유동의 존재를 밝히고 천이영역과 경사각의 관계, 유동 및 열전달특성을 구명하고자 한다.이를 위해 유한차분방법(FDM)으로 수치해석하고 실 험결과와 비교, 검토하였다.

Construction and operation of Photovoltaic Generation System (태양광발전시스템 설치 및 운전 현황)

  • Park, K.H.
    • Proceedings of the KIEE Conference
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    • 2003.07e
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    • pp.28-30
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    • 2003
  • 본 논문은 10kW태양광 발전시스템의 설치 및 운전 상황에 대한 내용으로서 발전 뿐만아니라 학습용으로 이용할 수 있도록 10kW 단독운전 또는 7kW와 3kW 병렬운전이 가능하도록 구성되었다. 태양전지판은 20직렬 10병렬로 구성되며, 10병렬 태양전지판은 방위각 $0^{\circ}$, 경사각 $46^{\circ}\sim8^{\circ}$로 이루어져 있으므로 필요에 따라서 다양한 경사각으로 3kW까지 선택 운전할 수 있도록 구성되어 있다.

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An Optimum Slanting Angle in Reticulated Root Piles Installation under Compressive and Uplift Loads (압축 및 인발하중을 받는 그물식 뿌리말뚝의 최적 타설경사각)

  • 이승현;김명보
    • Geotechnical Engineering
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    • v.12 no.2
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    • pp.71-84
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    • 1996
  • In order to investigate the influence of slanting angle of reticulated root piles(RRP) on their bearing capacities, model tests of compressive and uplift loads on RRP with different slanting angles, which were installed in sandy soils with a relative density of 47%, were carried out. Each pile which is made of a steel bar of 5mm in diameter and 300mm in length, is coated with sand to be 6.5mm in diameter. One set of RRP consists of 8 piles which are installed in circular patterns forming two concentric circles, each of which has 4 piles. Slanting angles of RRP for load tests are 0$^{\circ}$, 5$^{\circ}$, 10$^{\circ}$, 15$^{\circ}$, 20$^{\circ}$, and 25$^{\circ}$. In addition, compressive load tests on circular footing whose diameter is the same as the outer circle of RRP were carried out. Test results show that maximum load bearing capacities of RRP by regression analysis are obtained at about 12$^{\circ}$ and 13$^{\circ}$ of slanting angles for compressive and uplift load tests, respectively. Maximum compressive bearing capacity is estimated to be 13oA bigger than that of the vertical RRP and 95% bigger than that of surface footing. Maximum uplift capacity is estimated to be 21% bigger than that of the vertical RRP. And it can be appreciated that increasing the slanting angle makes the load -Settlement behavior more ductile.

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