• Title/Summary/Keyword: constant power

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Sound Analysis on <Masculine Feminine> (영화 <남성 여성>의 사운드 분석)

  • Lee, Sang In
    • The Journal of the Korea Contents Association
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    • v.14 no.5
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    • pp.18-29
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    • 2014
  • was somewhat of a turning point for Godard, allowing the Novelle Vague auteur to address for the first time the current political climate of the world in one of his film, and this film is a film of constant questioning and is, in the truest sense, a 'talking film'. In this paper, I attempt to analyse the sound of this film to interpret the complicated sound structure in . Godard was aware of the power of sound and experimented diverse methods such as 'direct sound', interviewing using the effect of on-sound and off-sound, multiple narration, reading a text aloud, sound effect and music which are controled and selected by himself in this film. , with its largely improvised dialogue, was a work of journalism which was recorded a generation of Marx Coca-Cola.

Quick and Accurate Computation of Voltage Stability Margin

  • Karbalaei, Farid;Abasi, Shahriar
    • Journal of Electrical Engineering and Technology
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    • v.11 no.1
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    • pp.1-8
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    • 2016
  • It is well known that the behavior of PV curves is similar to a quadratic function. This is used in some papers to approximate PV curves and calculate the maximum-loading point by minimum number of power flow runs. This paper also based on quadratic approximation of the PV curves is aimed at completing previous works so that the computational efforts are reduced and the accuracy is maintained. To do this, an iterative method based on a quadratic function with two constant coefficients, instead of the three ones, is used. This simplifies the calculation of the quadratic function. In each iteration, to prevent the calculations from diverging, the equations are solved on the assumption that voltage magnitude at a selected load bus is known and the loading factor is unknown instead. The voltage magnitude except in the first iteration is selected equal to the one at the nose point of the latest approximated PV curve. A method is presented to put the mentioned voltage in the first iteration as close as possible to the collapse point voltage. This reduces the number of iterations needed to determine the maximum-loading point. This method is tested on four IEEE test systems.

Optimal Location and Sizing of Shunt Capacitors in Distribution Systems by Considering Different Load Scenarios

  • Dideban, Mohammadhosein;Ghadimi, Noradin;Ahmadi, Mohammad Bagher;Karimi, Mohammmad
    • Journal of Electrical Engineering and Technology
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    • v.8 no.5
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    • pp.1012-1020
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    • 2013
  • In this work, Self-adaptive Differential Evolutionary (SaDE) algorithm is proposed to solve Optimal Location and Size of Capacitor (OLSC) problem in radial distribution networks. To obtain the SaDE algorithm, two improvements have been applied on control parameters of mutation and crossover operators. To expand the study, three load conditions have been considered, i.e., constant, varying and effective loads. Objective function is introduced for the load conditions. The annual cost is fitness of problem, in addition to this cost, CPU time, voltage profile, active power loss and total installed capacitor banks and their related costs have been used for comparisons. To confirm the ability of each improvements of SaDE, the improvements are studied both in separate and simultaneous conditions. To verify the effectiveness of the proposed algorithm, it is tested on IEEE 10-bus and 34-bus radial distribution networks and compared with other approaches.

A Design and Voltage Control of a High Efficiency Generator with PM Exciter (고효율 영구자석 여자기 구조의 발전기 설계와 전압제어)

  • Jo, YeongJun;Lee, Dong-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.11
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    • pp.1827-1834
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    • 2016
  • This paper presents a high efficient generator with PM(Permanent Magnet) exciter. The proposed PM exciter for the generator can produce a linear output voltage according to the engine speed. This output voltage is directly used to control the field current of the generator to adjust the generator output voltage. In the proposed generator system, since the field winding current can be supplied by the PM exciter, the generator can self-start without any battery or an external power supply due to the low residential flux. Furthermore, the operating efficiency of the generator is higher than a conventional winding exciter. The main problem of the proposed generator system, the field winding current controller has to be embedded inside the generator, and it rotates according to the generator shaft. In this paper, the proper embedded current controller is designed for the proposed generator system. Due to the embedded controller cannot be connected to the outside the generator controller, the measured instantaneous output voltage of the generator is transferred by the photo isolated communication using shaft aligned infrared transmitter and receiver to keep the constant generator output voltage. In this paper, 10kW, 380V engine generator with PM exciter and the embedded DAVR(Digital Automatic Voltage Regulator) are described. The proposed high efficiency generator is simulated and tested to verify the effectiveness.

An Experimental Study on the Thermal Performance Measurement of Vertical Borehole Heat Exchanger(BHE) (수직형 지열 열교환기(BHE)의 열성능 측정에 관한 실험적 연구)

  • Lim Kyoung-Bin;Lee Sang-Hoon;Soung Nak-Won;Lee Chang-Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.8 s.251
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    • pp.764-771
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    • 2006
  • Knowledge of ground thermal properties is most important for the proper design of large BHE(borehole heat exchanger) systems. Thermal response tests with mobile measurement devices were first introduced in Sweden and USA in 1995. Thermal response tests have so far been used primarily for in insitu determination of design data for BHE systems, but also for evaluation of grout material, heat exchanger types and ground water effects. The main purpose has been to determine insitu values of effective ground thermal conductivity, including the effect of ground-water flow and natural convection in the boreholes. Test rig is set up on a small trailer, and contains a circulation pump, a heater, temperature sensors and a data logger for recording the temperature data. A constant heat power is injected into the borehole through the pipe system of test rig and the resulting temperature change in the borehole is recorded. The recorded temperature data are analysed with a line-source model, which gives the effective insitu values of rock thermal conductivity and borehole thermal resistance.

The Estimation of the Closed Form in NKPC Inflation Model: Focusing on the Korean Manufacturing Industries (1975-2010)

  • Bae, Joo Han;Kang, Joo Hoon;Hong, Seonghyi;Yoon, Ayoung
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.3
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    • pp.75-85
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    • 2014
  • This paper is to develop and estimate a closed form inflation model using the estimates for real marginal costs in manufacturing industries during the sample period 1975-2010. The production function in manufacturing industry incorporates labor, capital, domestic material, and foreign material, assuming constant returns to scale technology and AR(1) process of technological coefficient. We derive real marginal costs from firm's cost minimization with quarterly data and provide new evidences on the new Keynesian Phillips curve for Korea. The main empirical result is that the closed form coefficients ${\delta}_1$ and ${\delta}^{-1}_2$ in manufacturing for PPI inflation proved to be 0.5086 and 0.8779 respectively, similar to the estimates in the U.S. case. These results also are consistent with the functional relationship between the coefficients in hybrid model and its closed form. Thus the paper suggests that the empirical studies on inflation dynamics need to focus on the manufacturing industry with market power, treating PPI inflation as the dependent variable.

An Experimental Study on the Dynamic Characteristics of a Planetary Gear Train in the Low Speed Region (유성치차열의 저속영역에서의 동특성에 관한 실험적 연구)

  • Lee, J. H.;Cheon, G. J.;Kim, J. H.;Kim, C.;Han, D. C.;Myung, J. H.;Jeong, T. H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.4
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    • pp.121-129
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    • 1997
  • Gear train system test rig of power circulating type was fabricated, and systematic experiment for measuring dynamic characteristics of the planetary gear trains in the low speed region has been carried out using the test rig. The measured parameters are fillet strains of the sun gear and ring gear, carrier displacements, torques of the input and output shafts. The results are as follows : i) Even though the loading torque is constant, torque variation has been observed on the input and output hafts, ii) The variation of the torque has two frequency components, i.e. lower one of the input shaft rotation and higher one of the two teeth meshing, iii) The variation of the fillet strains shows the same tendency as that of the torque, iv) The loci of the carrier depend on the torque and rotational speed.

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Feed Rate Control for the Head-Feed Thresher (자동탈곡기(自動脱穀機)의 공급율(供給率) 제어(制御)(I) -공급율(供給率)에 따른 부하(負荷) 특성(特性)-)

  • Chung, C.J.;Ryu, K.H.;Choi, Y.S.
    • Journal of Biosystems Engineering
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    • v.13 no.3
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    • pp.20-31
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    • 1988
  • This study was undertaken to investigate the load characteristics of the head-feed thresher, which may be affected by various factors such as physical properties of grain, thresher design parameters and its operational condition. The study was conducted at an initial step toward developing an automatic feed-rate control system of the head-feed thresher. A microcomputer-based data acquisition system for the load-speed characteristic of the thresher-shaft and the rail-deflection of the feeding device in accordance with a varied feeding thickness was developed. The sensors being developed and used for sensing the torque and speed of the cylinder and the power-input-shaft and the feeding thickness showed a high accuracy. A microcomputer-based data acquisition system developed in this study was assessed as adequate for a rapid acquisition and analysis of data. The effect of the feed-rate on the torque and speed of the thresher shaft, when fed intermittently by bundles, affected not by the rice varieties but by the dryness of threshing material tested. When fed by the continuous constant thickness, the torque and speed of the cylinder due to the increase of the feed-rate or feeding thickness were given by the relation by the second order parabola.

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A Numerical Analysis for Fuel Consumption by Improvement of Intake/Exhaust Valve Timing in a Common Rail Diesel Engine for a Generator (커먼레일 디젤엔진의 흡배기밸브 타이밍 개선을 통한 연비절감에 대한 수치해석적 연구)

  • Kim, Seung Chul;Kim, Chung Kyun
    • Journal of Energy Engineering
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    • v.26 no.2
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    • pp.32-38
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    • 2017
  • The common rail diesel engine used in this study uses mechanically driven camshaft for the operation of intake and exhaust valves, and the timing of valve opening and closing is fixed according to the operating conditions of the vehicle. However, the electric generator engine operates at a constant speed and partial load. Therefore, in order to optimize the design of common rail diesel engine for power generation, the characteristics of diesel combustion and emissions according to the change of valve timing were examined and calculated in terms of fuel economy. The valve timing of the diesel engine influenced the combustion characteristics by changing the intake and exhaust flow and it was considered that the fuel efficiency of the generator could be improved.

Design of an Active Current Regulator for LED Driver IC (LED 구동 IC를 위한 능동 전류 조절기의 설계)

  • Yun, Seong-Jin;Oh, Tak-Jun;Jo, A-Ra;Ki, Seok-Lip;Hwang, In-Chul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.4
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    • pp.612-616
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    • 2012
  • This paper presents an active current regulator for LED driver IC. The proposed driver circuit is consists of DC-DC converter for supplying constant DC voltage to LED, active current regulator for compensating channel-to-channel current error from LED strings and feedback circuit for controlling duty ratio of the converter. The proposed active current regulator senses current of LED channels by equalizing both $V_{DS}$ and $V_{GS}$ at LED current control transistor. Because the proposed circuit directly measures the LED channel current without a sensing resistor and regulates all channel with same regulation loop, the power consumption and the current error are much small compared with previous works. The measured maximum efficiency of overall LED driver IC is approximately 94% and current error of LED channel-to-channel is under ${\pm}1.3%$. The proposed LED driver IC is fabricated Dongbu 0.35um BCD process.