• Title/Summary/Keyword: focal point

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거리 영상 측정 오차의 기하학적 분석 (A geometric analysis of range measurement error)

  • 윤강식;이병욱;박래홍
    • 한국통신학회논문지
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    • 제22권6호
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    • pp.1259-1265
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    • 1997
  • 삼각측량의 원리를 이용하 거리 탐색기를 사용하여 거리 영상을 취득하는 경우에 발생하는 측정오차를 직관적으로 이해할 수 있도록 기하학적 방법으로 분석하였다. 그 결과로 추정 오차는 카메라에서 물체까지의 거리에 비례하는 것을 보였다. 또한 카메라 초점과 물체를 지나는 직선이 광원과 물체를 연결하는 직선과 직각인 경우 측정값이 가장 정밀한 것을 보였다. 또한 이 결과가 해석학의 기법을 사용하여 분석한 결과와 일치함을 보였고 실험을 통하여 이를 확인하였다. 본 연구 결과는 동일한 카메라가 광원을 사용한 경우에도 카메라의 방향과 물체까지의 거리를 변화시켜서 측정 정밀도를 향상시킬 수 있다는 것을 보인다.

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금형 생산관리를 위한 응용 소프트웨어의 개발 (Development of an Application Software for the Die-Production Information Management)

  • 공명달;김정자
    • 산업공학
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    • 제9권2호
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    • pp.143-158
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    • 1996
  • This paper deals with the development of a software module for production planning and scheduling activities of an actual die-production management system. Scheduling problems, such as master schedule and detailed schedule, are the focal point of the whole article and they are considered in terms of operation procedures. Schedule-explosion module and load levelling module are the essential components of schedule management. The scheduling module allocates the resources, determines the process priority and the planned start and completion dates of processes. Rescheduling can be done to manipulate unforeseen situations that schedule is delayed owing to inducing defectives, machine breakdowns and lumpy demands. This study indicates a practical model for the die-producation management and helps to apply it for jobs in the real situation.

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소형 태양 반사경 클러스터를 이용한 태양열 발전에 대한 타당성 연구 (A Feasibility Study of Using a Mini-dish Cluster for Solar Power Generation)

  • 오승진;이정성;현준호;김남진;천원기
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 추계학술대회
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    • pp.161-164
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    • 2006
  • This paper introduces a preliminary work for the design of a mini-dish cluster system for power general ion. Each mini-dish (typically has a 20 to 30cm in diameter) is designed with a simple parabolic profile, concentrating sun light (after the glass glazing cover to avoid dust deposition on the reflector and facilitate cleaning) onto a centrally located small plane(or concave) mirror which is placed on the bottom side of the transparent glass cover. The mirror with a mini-dish concentrator is designed to focus beam radiation onto a focal point before it enters a bundle of optical fibers connected to a remote receiver for power generation different options are considered In designing a mini-dish concentrator to maximize its effectiveness for the collection and use of solar energy.

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Long-term Synaptic Plasticity: Circuit Perturbation and Stabilization

  • Park, Joo Min;Jung, Sung-Cherl;Eun, Su-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제18권6호
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    • pp.457-460
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    • 2014
  • At central synapses, activity-dependent synaptic plasticity has a crucial role in information processing, storage, learning, and memory under both physiological and pathological conditions. One widely accepted model of learning mechanism and information processing in the brain is Hebbian Plasticity: long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD are respectively activity-dependent enhancement and reduction in the efficacy of the synapses, which are rapid and synapse-specific processes. A number of recent studies have a strong focal point on the critical importance of another distinct form of synaptic plasticity, non-Hebbian plasticity. Non-Hebbian plasticity dynamically adjusts synaptic strength to maintain stability. This process may be very slow and occur cell-widely. By putting them all together, this mini review defines an important conceptual difference between Hebbian and non-Hebbian plasticity.

Description of Range Control System in Space Center

  • Yun, Sek-Young;Choi,Yong-Tae;Lee, Hyo-Keun
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.53.2-53
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    • 2002
  • NARO Space Center is being developed as a national project for the Korea Space Development Program. Among the major missions of the Space Center, the Range Control System is the focal point for all command and control operation of the Space Center. The acquired data from the Tracking Stations and the on-site facilities is processed and distributed in the Control Center. Data processing or data fusion is needed for the exact tracking of the Launch Vehicle from several tracking systems. The first phase, which is the best telemetry source is selected among data streams that are received from each telemetry stations using some pre-defined criterion. Trajectory data and major telemetry parameters...

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CMG를 이용한 쿼드-로터의 자세제어 (Attitude Control of a Quad-rotor using CMG)

  • 오경현;최호림
    • 제어로봇시스템학회논문지
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    • 제20권7호
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    • pp.695-700
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    • 2014
  • In this paper, we utilize the CMG's momentum bias to control the roll/pitch attitude of the Quad-rotor. While the previous control approaches have used the thrust control approach, we design and add a new momentum controller (using CMG) in order to improve the transient response over the existing methods. The focal point of this paper is the design of a controller for a Quad-rotor's attitude using CMG. This leads to other tasks such as an identification of the model's parameters and mathematical nonlinear modeling. Then, the previous thrust controller is designed based on the linearized model. Finally, the overall system with our designed controller is implemented and tested in real time to show that the Quad-rotor is kept in a good balanced position faster than the traditional thrust-only control approach.

Time domain and frequency domain interpretation of safety diagnosis for concrete structure

  • Suh Baeksoo;An Jehun;Kim Hyoungjun;Kim Yongin
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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    • pp.464-469
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    • 2003
  • The traditional and still most widely used, test methods for concrete structures are destructive method, such as coring, drilling or otherwise removing part of the structure to permit visual inspection of the interior. While these methods are highly reliable, they are also time consuming and expensive, and the defects they leave behind often become focal point for deterioration. In this study, tomography by theoretical inversion method in case of elastic wave using impact-echo method among concrete non-destruction test method was made. Taken model experiments are theoretical inversion method and time domain and frequency domain test on pier test model at laboratory level. Also experiment concerning frequency domain on 3 kinds of tunnel model with I-dimension form was carried out.

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초음파 C-Scan을 이용한 구조용 세라믹스의 기계적 특성평가 (Evaluation of Mechanical Properties of Structural Ceramics ($Al_{2}O_{3}$) Using the High Frequency Ultrasonic C - Scan)

  • 장영권
    • 비파괴검사학회지
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    • 제9권2호
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    • pp.18-24
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    • 1989
  • Computer-aided high frequency ultrasonic is applied to aluminum oxide(85w%, 94w%, 96w%, and 99w%) MOR(modulus of rupture) samples to evaluate mechanical properties such as density variation, pore content, elastic modulus, shear modulus, and poisson's ratio. Ultrasonic wave velocity and attenuation measurement techniques were used as an evaluator of such properties. Pulse-echo C-Scan images with different fate setting method using 50MHz center frequency 1 inch focal length transducer allows evaluation of density variation and pore content. Elastic modulus calculated with the relation of density and ultrasonic velocity. It shows good reliability as compared with resonance method. Sintered density variation of $0.025g/cm^{3}$, that is 0.6% of theoretical density in $Al_{2}O_{3}$ samples can be observed by ultrasonic velocity measurement. Attenuation measurement method qualitatively agree with 4-point fracture testing result concerning of porosity content.

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전산기를 이용한 공정 제어구조 합성에 관한 연구 (A study on computer-aided synthesis of process control system structure)

  • 노균;윤인섭
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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    • pp.670-673
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    • 1987
  • The structure of chemical process has become increasingly complex, due to better management of energy and raw materials. As a consequence, the design of control systems for complete plants now constitutes the focal point of engineering interest, rather than controller designs for single processing units. Instead of traditional methods based on complex mathematical model, chemical processes are represented by structural array and cause-and-effect graph to apply non-numerical problem-solving techniques. A systematic logical procedure to synthesize alternatives of control system structure and some heuristic rules to select a feasible solution from the vast number of alternatives that are possible are considered in this study.

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