• Title/Summary/Keyword: Characteristic time

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A Study for Parking Characteristic of A Large Scale Event (대규모행사시 주차장 이용특성 분석)

  • Lee, Young-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.9 no.3
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    • pp.191-197
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    • 2006
  • Prepare need in each branch for a large scale event. especially prepare for transportation problem is very important. most research for until at now parking prepare according city management however, parking prepare for large event is a necessity which it will parking characteristic. accordingly this research is conducted study for parking prepare subject of large event. this study result, vehicle demand for parking by stadium have many but vehicle demand for parking off stadium have few. accordingly large parking supply is ineffective. shuttle bus service in principal position of city is effective. study result showed that it included 85% parking at 6~7hour before large event start time. accordingly disposition time of parking manager is desirable 6~7hour before large event start time.

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Image Segmentation Using an Extended Fuzzy Clustering Algorithm (확장된 퍼지 클러스터링 알고리즘을 이용한 영상 분할)

  • 김수환;강경진;이태원
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.3
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    • pp.35-46
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    • 1992
  • Recently, the fuzzy theory has been adopted broadly to the applications of image processing. Especially the fuzzy clustering algorithm is adopted to image segmentation to reduce the ambiguity and the influence of noise in an image.But this needs lots of memory and execution time because of the great deal of image data. Therefore a new image segmentation algorithm is needed which reduces the memory and execution time, doesn't change the characteristices of the image, and simultaneously has the same result of image segmentation as the conventional fuzzy clustering algorithm. In this paper, for image segmentation, an extended fuzzy clustering algorithm is proposed which uses the occurence of data of the same characteristic value as the weight of the characteristic value instead of using the characteristic value directly in an image and it is proved the memory reduction and execution time reducted in comparision with the conventional fuzzy clustering algorithm in image segmentation.

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An Effects of the Strength Development of High Strength Mortar under Temperature History by Steam Curing (촉진양생에 의한 온도이력이 고강도 모르타르의 강도발현에 미치는 영향)

  • Kwon, Hee-Sung;Choi, Eung-Kyu;Lim, Nam-Ki;Lee, Young-Do;Jung, Sang-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.4
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    • pp.115-121
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    • 2008
  • The present study performed low-pressure steam curing with mortar specimens in order to examine the temperature profile and strength development of steam curing in high-strength specimens of 100MPa. In addition, as a basic research to utilize PC products, we examined the effects of curing temperature and time in steam curing cycle on strength development resulting from the hydration of cement within the range of high strength by changing four factors affecting the quality of PC displacement time, peak curing temperature, peak temperature duration, and ascending and descending gradient of temperature - in various patterns, and analyzed the optimal strength development characteristic based on the relation between temperature profile and strength development. With regard to the high-temperature curing characteristic of PC, we performed an experiment on the strength characteristic according to the temperature profile of high-strength mortar, and from the results of the experiment according to curing characteristic, displacement time, peak curing temperature, peak temperature duration, and ascending and descending gradient of temperature, we drew conclusions as follows.

Unconstrained e-Book Control Program by Detecting Facial Characteristic Point and Tracking in Real-time (얼굴의 특이점 검출 및 실시간 추적을 이용한 e-Book 제어)

  • Kim, Hyun-Woo;Park, Joo-Yong;Lee, Jeong-Jick;Yoon, Young-Ro
    • Journal of Biomedical Engineering Research
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    • v.35 no.2
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    • pp.14-18
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    • 2014
  • This study is about e-Book program based on human-computer interaction(HCI) system for physically handicapped person. By acquiring background knowledge of HCI, we know that if we use vision-based interface we can replace current computer input devices by extracting any characteristic point and tracing it. We decided betweeneyes as a characteristic point by analyzing facial input image using webcam. But because of three-dimensional structure of glasses, the person who is wearing glasses wasn't suitable for tracing between-eyes. So we changed characteristic point to the bridge of the nose after detecting between-eyes. By using this technique, we could trace rotation of head in real-time regardless of glasses. To test this program's usefulness, we conducted an experiment to analyze the test result on actual application. Consequently, we got 96.5% rate of success for controlling e-Book under proper condition by analyzing the test result of 20 subjects.

Design and Implementation of Optical Receiving Bipolar ICs for Optical Links

  • Nam Sang Yep;Ohm Woo Young;Lee Won Seok;Yi Sang Yeou1
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.717-722
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    • 2004
  • A design was done, and all characteristic of photodetectr of the web pattern type which a standard process of the Bipolar which Si PIN structure was used in this paper, and was used for the current amplifier design was used, and high-speed, was used as receiving optcal area of high altitude, and the module which had a low dark current characteristic was implemented with one chip with a base. Important area decreases an area of Ie at the time of this in order to consider an electrical characteristic and economy than the existing receiving IC, and performance of a product and confidence are got done in incense. First of all, the receiving IC which a spec, pattern of a wafer to he satisfied with the following electrical optical characteristic that produced receiving IC of 5V and structure are determined, and did one-chip is made. On the other hand, the time when AR layer of double is $Si_{3}N_{4}/SiO_{2}=1500/1800$ has an optical reflectivity of less than $10{\%}$ on an incidence optical wavelength of 660 ,and, in case of photo detector which reverse voltage made with 1.8V runs in 1.65V, an error about a change of thickness is very the thickness that can be improved surely. And, as for the optical current characteristic, about 5 times increases had the optical current with 274nA in 55nA when Pc was -27dBm. A BJT process is used, and receiving IC running electricity suitable for low voltage and an optical characteristic in minimum 1.8V with a base with two phases is made with one chip. IC of low voltage operates in 1.8V and 3.0V at the same time, and optical link receiving IC is going to be implemented

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A SPLIT LEAST-SQUARES CHARACTERISTIC MIXED FINITE ELEMENT METHOD FOR THE CONVECTION DOMINATED SOBOLEV EQUATIONS

  • OHM, MI RAY;SHIN, JUN YONG
    • Journal of applied mathematics & informatics
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    • v.34 no.1_2
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    • pp.19-34
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    • 2016
  • In this paper, we present a split least-squares characteristic mixed finite element method(MFEM) to get the approximate solutions of the convection dominated Sobolev equations. First, to manage both convection term and time derivative term efficiently, we apply a least-squares characteristic MFEM to get the system of equations in the primal unknown and the flux unknown. Then, we obtain a split least-squares characteristic MFEM to convert the coupled system in two unknowns derived from the least-squares characteristic MFEM into two uncoupled systems in the unknowns. We theoretically prove that the approximations constructed by the split least-squares characteristic MFEM converge with the optimal order in L2 and H1 normed spaces for the primal unknown and with the optimal order in L2 normed space for the flux unknown. And we provide some numerical results to confirm the validity of our theoretical results.

A Study of Korean (Industrial) Standards for Pneumatic Servo Valve (공압서보밸브 KS규격 정립에 관한 연구)

  • 김동수;이원희;최병오
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1231-1234
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    • 2003
  • Pneumatic servo valve which is widely applied in industrial world is advanced technology compounded with electric, electronic and machine. And It is consist of Linear Force Motor. Spool Commutation Mechanism and Microprocessor. In this study, we accomplished test method of Linear Force motor test, Static characteristic test, Dynamic characteristic test for KS(Koran industrial standard) of Pneumatic servo valve. we accomplished study about the main item of Static characteristic test which is related to unload flow characteristic test. And Dynamic characteristic test was step input test and frequency response test. Specially about frequency response test, There was a difficulty resulting from the time delay problem caused by the basic compressibility of air. In order to solve the problem in this study. we proposed two methods. First, displacement of the servo valve spool was directly measured by using a laser sensor. Second, method of calculating control flow by measuring pressure and temperature of chamber.

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Mechanisms of Oblique Shock-Induced Combustion Instability

  • Choi, Jeong-Yeol;Jeung, In-Seuck
    • Journal of the Korean Society of Combustion
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    • v.7 no.1
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    • pp.23-30
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    • 2002
  • Instability of oblique detonation waves (ODW) at off-attaching condition was investigated through a series of numerical simulations. Two-dimensional wedge of finite length was considered in $H_2/O_2/N_2$ mixtures at superdetonative condition. Numerical simulation was carried out with a compressible fluid dynamics code and a detailed hydrogen-oxygen combustion mechanism. Present result reveals that there is a chemical kinetic limit of the ODW detachment, in addition to the theoretical limit predicted by Rankine-Hugoniot theory with equilibrium chemistry. Result also presents that ODW still attaches at a wedge as an oblique shock-induced flame showing periodically unstable motion, if the Rankine-Hugoniot limit of detachment is satisfied but the chemical kinetic limit is not. Mechanism of the periodic instability is considered as interactions of shock and reaction waves coupled with chemical kinetic effects. From the investigation of characteristic chemical time, condition of the periodic instability is identified as follows; at the detaching condition of the Rankine-Hugoniot theory, (1) flow residence time is smaller than the chemical characteristic time, behind the detached shock wave with heat addition, (2) flow residence time should be greater than the chemical characteristic time, behind an oblique shock wave without heat addition.

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A Design Method Reducing the Effect of Zeros of a Cascaded Three-Parameters Controller: The Characteristic Ratio Assignment Approach (종속형제어기의 영점의 영향을 고려한 저차제어기의 설계: 특성비지정 접근법)

  • Hua, Jin Li;Lee, Kwan-Ho;Kim, Young-Chol
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.158-160
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    • 2005
  • This paper presents a new approach to the problem of designing a cascaded three-parameters controller for a given linear time invariant (LTD plant in unity feedback system. We consider a proportional-integral-derivative (PID) and a first-order controller with specified overshoot and settling time. This problem is difficult to solve because there may be no analytical solution due to the use of low-order controller and furthermore. the zeros of controller just appear in the zeros of feedback system. The key idea of our method is to impose a constraint on the controller parameters so that the zeros of resulting controller are distant from the dominant pole of closed-loop system to the left as far as the given interval. Two methods realizing the idea are suggested. We have employed the characteristic ratio assignment (CRA) in order to deal with the time response specifications. It is noted that the proposed methods are accomplished only in parameter space. Several illustrative examples are given.

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Characteristic of Evaporation Cooling in Water Droplet Impinging on Steel with Various Surface Roughness and Droplet Diameter (강에서 표면조도의 변화와 액적 직경에 따른 충돌 액적 증발 냉각 특성)

  • Jang, C.S.;Sohn, C.H.;Chung, S.W.;Choi, W.S.
    • Journal of the Korean Society for Heat Treatment
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    • v.19 no.3
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    • pp.141-148
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    • 2006
  • An experimental study is presented for water droplet impingement on a steel surface in the process of heat treatment. The objective of the present work is to examine characteristic of evaporation cooling due to surface roughness and droplet diameter under conductive heat input condition. The surface temperatures varied from $80{\sim}155^{\circ}C$, surface roughness was from $R_a=0.12{\mu}m$ to $R_a=1.14{\mu}m$ and droplet diameter was from 2.4 mm to 3.0 mm. The results show that the total evaporation time is shorter for the larger surface roughness and the smaller droplet size, the time average heat flux has maximum value for the larger surface roughness and the smaller droplet size. The total evaporation time has not influence on the nuclear boiling region.