• Title/Summary/Keyword: positions

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Localization for Cooperative Behavior of Swarm Robots Based on Wireless Sensor Network (무선 센서 네트워크 기반 군집 로봇의 협조 행동을 위한 위치 측정)

  • Tak, Myung-Hwan;Joo, Young-Hoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.8
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    • pp.725-730
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    • 2012
  • In this paper, we propose the localization algorithm for the cooperative behavior of the swarm robots based on WSN (Wireless Sensor Network). The proposed method is as follows: First, we measure positions of the L-bot (Leader robot) and F-bots (Follower robots) by using the APIT (Approximate Point In Triangle) and the RSSI (Received Signal Strength Indication). Second, we measure relative positions of the F-bots against the pre-measured position of the L-bot by using trilateration. Then, to revise a position error caused by noise of the wireless signal, we use the particle filter. Finally, we show the effectiveness and feasibility of the proposed method though some simulations.

An Acoustic Analysis of the Aspiration Merger in Korean

  • Mi, Jang
    • Phonetics and Speech Sciences
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    • v.3 no.1
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    • pp.67-75
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    • 2011
  • In Korean, 'Aspiration Merger' is the result of the heteromorphemic sequence of lenis stop and /h/ becoming a single aspirated stop word-medially. However, the contrast between lenis stop-plus-/h/ and an underlying aspirated stop is maintained when they span Phonological Phrase boundaries. By varying the position in the prosodic domain such as APP (Across Phonological Phrase) and PPM (Phonological Phrase Medial) positions, the phonetic properties of the two categories are compared. In the results from noise duration and change of intensity, lenis stop-plus-/h/ show a large difference between the APP and PPM positions. The results from a noise duration comparison show that the two categories are completely neutralized into aspirated stop in the PPM position and the complete neutralization is sensitive to prosodic phrasing.

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The Moon's Spectral Irradiance Computation using Relative Positions between the Sun, Moon, and the Satellite (태양, 달, 위성의 위치를 이용한 달의 방사조도 계산)

  • Seo, Seok-Bae;Song, Young-Joo
    • Aerospace Engineering and Technology
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    • v.12 no.1
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    • pp.152-162
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    • 2013
  • The spectral irradiance of the Moon is used to monitor the performance of on-board satellite's visible channel detectors. This paper established a method to compute the spectral irradiance of the Moon using the relative positions between the Sun, Moon, and the COMS (Communication, Ocean, Meteorological Satellite), which is generated through the COMS FDS (Flight Dynamics Subsystem). The established computation method is applied to the algorithm which is developed to detect and compensate the degradations of COMS MI (Meteorological Imager) visible channel detectors.

On the Coastline Date Compression in Digital Chart Selecting Conspicuous Coast Positiona as Node Points (현저한 해안 위치를 절점으로 선정하는 디지털 해도에서의 해안선 데이터 압축)

  • 임정빈;고광섭;최낙현
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.4 no.1
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    • pp.13-20
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    • 1998
  • Since the digital chart consists of a large number of points, the effective method for the coastline data compression(CDC), storing the data compactly and reproducting the coastline feature accurately, is important. In the CDC, the key technique is to determine the optimal positions as node points in given coastlines. In this paper, a new CDC method, selecting node points with conspicuous coast positions in the view point on navigation and adopting spline interpolation to the nodes partly, is proposed. Using the northern part of KEOJE-DO coastline in Korean chart No.204, CDC experiments are carrie out with various compression ratio. The results fro the influence of coastline shape according to various CDC methods are discussed and presented.

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VISUAL MEASUREMENT METHOD USING A CIRCULAR GROOVE IMAGE FOR MEASURING INTERNAL DEFECTS OF PIPES IN NUCLEAR POWER PLANT

  • Choi, Young-Soo;Jeong, Kyung-Min;Lee, Sung-Uk;Jung, Seung-Ho
    • Nuclear Engineering and Technology
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    • v.40 no.5
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    • pp.419-428
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    • 2008
  • During the overhaul period of nuclear power plants in Korea, an ROV(Remotely Operated Vehicle) enters the cold-leg pipes connected with the reactor to examine the state of the thermal sleeves and their positions in the safety injection nozzles. To measure the positions of the thermal sleeves or scratches with video images recorded during the examination, time-varying camera parameters should be known, such as the focal length and principal points used for the capturing each video image. In this paper, we propose a camera calibration and measurement scheme by using a single image containing two circular grooves of a cylindrical nozzle whose radius and distance are known.

A Study of KHST Passenger Safety During Accidents by Computer Simulation Techniques (컴퓨터 시뮬레이션기법을 이용한 고속전철 승객안전도 해석 및 평가)

  • 윤영한;구정서;이재완
    • Proceedings of the KSR Conference
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    • 2002.10a
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    • pp.60-65
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    • 2002
  • The computer simulation techniques were adopted to evaluate effects of seating positions of passenger under the various accident scenarios. The baseline of computer simulation model was tunned by the sled impact tests which conducted under the upright and standard seating positions. This study shows the effect of relative velocity between occupant and struck vehicle while occupant is impacted to a front seat's seatback. Although, base on the current accident scenarios, KHST is performed well enough to protect average adult male occupants. However, Results from the tests indicate small size occupant or higher impact speed may cause sever neck and femur injuries.

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Worst case analysis of circulating type ropeway using optimal design technique (최적설계 기법을 이용한 순환식 삭도 선로의 최악조건 해석)

  • 최수진;신재균
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.3
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    • pp.554-560
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    • 1989
  • An optimal design technique is used as a systematic approach to analyze the worst case of a circulating type ropeway for a given geometry and operating conditions. Worst case is meant here the case when the positions and weights of the cars are so conditioned that the minimum of all the reaction forces between the main rope and the towers is minimum. In the course of this study, a general theory for the deflections and tensions of the main rope were also derived taking into account of the variation of the weights and positions of the individual cars. And through an analysis of example ropeways, some general conditions for the worst case are deduced.

A Study on the Interaction between Distributed Cracks (분포 크랙들 사이에서의 상호 간섭에 관한 연구)

  • Han, Moon-Sik;Cho, Ja-Eung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.6
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    • pp.63-69
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    • 2005
  • For the case that center crack is surrounded by four small cracks which are symmetrically distributed around center crack, the same values of normalized stress intensity factor of center crack according to the position of the tip of small cracks are located on the smooth curve. And the stress intensity factor according to any position of small cracks can be sufficiently obtained from this curve. The plastic zones between distributed cracks are also investigated by changing the positions of nearly small cracks. The occurrence of plastic zone due to the interaction between center crack and small cracks are analyzed by finite element method. The mechanical behavior at the vicinity of crack tips is investigated by plastic areas. The changes of plastic zones according to positions of distributed cracks are drawn schematically. The safety of materials is also analyzed.

Target Positioning in Remote Area Using Strip Sensor Modeling of SPOT Imagery (SPOT 위성영상의 스트립 센서모델링을 이용한 비접근지역 위치결정 연구)

  • Kim, Man-Jo;Hwang, Chi-Jung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.2
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    • pp.155-160
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    • 2012
  • In this paper, a strip modeling method is developed for the acquisition of target positions in remote area and validated using the imagery of SPOT satellite. This method utilizes the parameters given in header files and constructs a camera model without ground control points. In most cases, the root mean squared error of check points is less than pixel size with one ground control point. The model error of reference image is evaluated using ground control points and used to remove the model error of target images acquired along the same satellite orbit, which enables one to calculate target positions in remote area where no ground control points are available.

Characteristic analysis of contact-less energy transmission system using 3D finite element method (3차원 유한요소법을 이용한 비접촉 전력 전달 장치 특성 해석)

  • Woo Kyung il;Park Han Seok;Cho Yun Hyun
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.803-805
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    • 2004
  • This paper proposes the calculation method of magnetic coupling coefficient of the contact-less energy transmission system by 3D finite element method with a variation of the secondary core positions. The primary, secondary self and leakage inductances and the capacitances of a resonant circuit are calculated by the finite element analysis results. From these values, the magnetic coupling coefficients are obtained. The secondary voltages and currents at the secondary core positions are calculated by using the resonant circuit and compared.

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