• Title/Summary/Keyword: Local control

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Optimum Blind Control to Prevent Glare Considering Potential Time Error (잠재적 시간 오차에 따른 현휘의 발생 방지를 위한 최적 블라인드 제어)

  • Seong, Yoon-Bok
    • Journal of the Korean Solar Energy Society
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    • v.32 no.2
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    • pp.74-86
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    • 2012
  • For the improvement of environmental comfort in the buildings with the blind control, the objective of this study is to prevent the direct glare caused by the daylight inlet. During the process of solar profile prediction, time are significant factors that may cause error and glare during the blind control. This research proposes and evaluates the correction and control method to minimize prediction error. For the local areas with different longitude and local standard meridian, error occurred in the process of the time conversion from local standard time to apparent solar time. In order to correct error in time conversion, apparent solar time should be recalculated after adjusting the day of year and the equation of time. To solve the problems by the potential time errors, control method is suggested to divide the control sections using the calibrated fitting-curve and this method is verified through simulations. The proposed correction and control method, which considered potential time errors by loop lop leap years, could solve the problems about direct glare caused by daylight inlet on the work-plane according to the prediction errors of solar profile. And also these methods could maximize daylight inlet and solar heat gain, because the blocked area on windows could be minimized.

Local motion planner for nonholonomic mobile robots

  • Hong, Sun-Gi;Choi, Changkyu;Shin, Jin-Ho;Park, Kang-Bark;Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.530-533
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    • 1995
  • This paper deals with the problem of motion planning for a unicycle-like robot. We present a simple local planner for unicycle model, based on an approximation of the desired configuration generated by local holonomic planner that ignores motion constraints. To guarantee a collision avoidance, we propose an inequality constraint, based on the motion analysis with the constant control input and time interval. Consequently, we formulate our problem as the constrained optimization problem and a feedback scheme based on local sensor information is established by simply solving this problem. Through simulations, we confirm the validity and effectiveness of our algorithm.

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A Study on Data Clustering Method Using Local Probability (국부 확률을 이용한 데이터 분류에 관한 연구)

  • Son, Chang-Ho;Choi, Won-Ho;Lee, Jae-Kook
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.1
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    • pp.46-51
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    • 2007
  • In this paper, we propose a new data clustering method using local probability and hypothesis theory. To cluster the test data set we analyze the local area of the test data set using local probability distribution and decide the candidate class of the data set using mean standard deviation and variance etc. To decide each class of the test data, statistical hypothesis theory is applied to the decided candidate class of the test data set. For evaluating, the proposed classification method is compared to the conventional fuzzy c-mean method, k-means algorithm and Discriminator analysis algorithm. The simulation results show more accuracy than results of fuzzy c-mean method, k-means algorithm and Discriminator analysis algorithm.

Scence Change Adaptive Bit Rate Control Using Local Variance (국부 분산을 이용한 장면 전환 적응 비트율 제어)

  • 이호영;김기석;박영식;송근원;남재열;하영호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.4
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    • pp.675-684
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    • 1997
  • The bit rate control algorithm which is capable of handing scene change is proposed. In MPEG-2 TM5, block variance is used to measure block activity. But block variance is not consistent with human visual system and does not differenciate the distribution of pixel values within the block. In target bit allocation process of TM5, global complexity, obtained by results of previous coded pictures, is used. Since I pictures are spaced relatively far apart, their complexity estimate is not very accurate. In the proposed algorithm local variance is used to measure block activity and detect scene change. Local variance, using deviation from the mean of neighboring pixels, well represents the distribution of pixel values within the block. If scene change is detected, the local variance information is used for target bit allocation process. Allocating target bits for I picture, the average local variance difference between previous and current I picture is considered. The experimental results show that the proposed algorithm can detect scene change very precisely and gives better picture quality and higher PSNR values than MPEG-2 TM5.

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Fuzzy Adaptive Traffic Signal Control of Urban Traffic Network (퍼지 적응제어를 통한 도시교차로망의 교통신호제어)

  • 진현수;김성환
    • Journal of Korean Society of Transportation
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    • v.14 no.3
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    • pp.127-141
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    • 1996
  • This paper presents a unique approach to urban traffic network signal control. This paper begins with an introduction to traffic control in general, and then goes on to describe the approach of fuzzy control, where the signal timing parameters at a given intersection are adjusted as functions of the local traffic network condition and adjacent intersection. The signal timing parameters evolve dynamically using only local information to improve traffic signal flow. The signal timing at an intersection is defined by three parameters : cycle time, phase split, off set. Fuzzy decision rules are used to adjust three parameters based only on local information. The amount of change in the timing parameters during each cycle is limited to a small fraction of the current parameters to ensure smooth transition. In this paper the effectiveness of this method is showed through simulation of the traffic signal flow in a network of controlled intersection.

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A Study on the Safe Position from the Local Fire in the Ship's Engine Rooms

  • Kim, Mann-Eun;Lee, Kyoung-Woo;Lee, Young-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.3
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    • pp.446-454
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    • 2008
  • Control devices for fire safety systems located in a engine room are to be arranged at a safe position which is easily accessible during a fire. To develop an interpretation for the safe position in engine rooms, calculation and experiments are carried out to determine a correlation between radiant heat and distance from fire in this paper. On the basis of results of this research, the control devices for a main engine are to be installed in the behind side of an obstruction to reduce radiant heat from the fire of the main engine. In case of other control devices, they are also to be provided in the same manner of control devices for the main engine or are to be placed with 5 meters far from fire hazards.

Speed Control of Marine Diesel Engines Using Fuzzy Gain Scheduling (퍼지 게인 스케줄링을 이용한 선박 디젤기관의 속도 제어)

  • 박승수;이현식;김도응;진강규
    • Journal of Advanced Marine Engineering and Technology
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    • v.26 no.6
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    • pp.638-645
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    • 2002
  • This paper presents a scheme for integrating PID control, gain scheduling and emerging techniques in the field of artificial intelligence, such as fuzzy logic and genetic algorithms for the speed control of a marine diesel engine. At first, local PID controllers are designed based on a local model obtained at each speed mode, whose parameters are optimally tuned using a real-coded genetic algorithm. Then, fuzzy "if-then" rules combine the local controllers as a consequence part to implement fuzzy gain scheduling. To demonstrate the performance of the proposed fuzzy PID controller on overall operating conditions, a set of simulation works on B'||'&'||'W's 4L80MC diesel engine are carried out.t.

The impact of radiotherapy on clinical outcomes in parameningeal rhabdomyosarcoma

  • Choi, Yunseon;Lim, Do Hoon
    • Radiation Oncology Journal
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    • v.34 no.4
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    • pp.290-296
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    • 2016
  • Purpose: Radiotherapy (RT) is considered a mainstay of treatment in parameningeal rhabdomyosarcoma (PM-RMS). We aim to determine the treatment outcomes and prognostic factors for PM-RMS patients who treated with RT. In addition, we tried to evaluate the adequate dose and timing of RT. Materials and Methods: Twenty-two patients with PM-RMS from 1995 to 2013 were evaluated. Seven patients had intracranial extension (ICE) and 17 patients had skull base bony erosion (SBBE). Five patients showed distant metastases at the time of diagnosis. All patients underwent chemotherapy and RT. The median radiation dose was 50.4 Gy (range, 40.0 to 56.0 Gy). Results: The median follow-up was 28.7 months. Twelve patients (54.5%) experienced failure after treatment; 4 local, 2 regional, and 6 distant failures. The 5-year local control (LC) and overall survival (OS) were 77.7% and 38.5%, respectively. The 5-year OS rate was 50.8% for patients without distant metastases and 0% for patients with metastases (p < 0.001). Radiation dose (<50 Gy vs. ${\geq}50Gy$) did not compromise the LC (p = 0.645). However, LC was affected by ICE (p = 0.031). Delayed administration (>22 weeks) of RT was related to a higher rate of local failure (40.0%). Conclusion: RT resulted in a higher rate of local control in PM-RMS. However, it was not extended to survival outcome. A more effective treatment for PM-RMS is warranted.

Design of a Prototype Fibre Optic Based Monitoring and Control System for Future KEPCO's 765kV Substation (765kV 변전소 감시제어용 시범시스템)

  • Jiang, Moon-Myung;Chung, Sang-Jin;Choi, Jong-Hyoub;Park, Jong-Myung
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.883-886
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    • 1996
  • Instead of point-to-point hard wiring between substation yard equipments and SCADA RTU(Remote Terminal Unit), fibre optic cable will be used in the portion between Local Units and Central Unit in the future KEPCO 765kV substation. The connections between substation yard equipments and nearby Local Unit remain the same hard wiring. The new fibre optic system will provide security especially during ground faults and is immune to electrical noise. A prototype system will be manufactured and installed in the existing 154kV Yeosan Substation by the end of July this year and operated for one year. By incorporating the operation experiences acquired in the system, an improved system will be commercially applied to 765kV Shin-An-Seong Substation where 345kV GIS will be installed initially and act as the switching station in the year 1998. The system is composed of one Central Unit and several Local Units. The Central Unit is composed of two workstation level computers, one is in operation and the other backup, and a Communication Control Unit. The Local Unit uses the existing SCADA RTU technology and takes the form of a distributed one. Between the Communication Control Unit and Local Units, the fibre optic system with star-coupler is used.

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Results of Radiation Therapy in Early Glottic Cancer (초기성문암의 방사선 치료 성적)

  • Ahn Sung Ja;Chung Woong Ki;Nam Taek Keun;Nah Byung Sik
    • Radiation Oncology Journal
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    • v.10 no.2
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    • pp.181-186
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    • 1992
  • A retrospective analysis was undertaken for 22 patients with early glottic cancer ($T_1N_0M_0$; 17, $T_2N_0M_0$; 5) who completed curative radiotherapy at the Department of Therapeutic Radiology, Chonnam University Hospital between November 1985 and December 1990. Median follow-up period was 39 months. The 3 year actuarial survival rate of T1, T2 was $81\%$ and $80\%$. respectively. Three patients ($13\%$) showed second malignant tumors and the site of the new primary was esophagus in two patients and lung in the other one. They were excluded from the local control analysis. The local control rate of T1. T2 group was $66\%$ and $50\%$. respectively. The surgical salvage rate and the ultimate local control rate of T1 group was $80\%$ (4/5) and $93\%$. and that of T2 group was $100\%\;(2/2)\;and\;75\%$. respectively. The local control rates of T1 stage were evaluated according to the various parameters. The local control rate of the superficial and exophytic lesion was better than that of the ulcerative and infiltrative one, and the involvement of anterior commissure was not seemed to be adverse prognostic factor. But the protracted treatment time showed the adverse effect on the local control of the disease. All of the eleven patients controlled by primary radiation therapy have maintained their voice well without any significant complication.

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