• Title/Summary/Keyword: Optimum method

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A Study on Beam Error Method of Coherent Interference Signal Estimation using Optimum Covariance Weight Vector (최적 공분산 가중 벡터를 이용한 상관성 간섭 신호 추정의 빔 지향 오차)

  • Cho, Sung Kuk;Lee, Jun Dong;Jeon, Byung Kook
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.4
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    • pp.53-61
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    • 2014
  • In this paper, we proposed covariance weight matrix using SPT matrix in order to accurate target estimation. We have estimated a target using modified covariance matrix and beam steering error method. We have minimized beam steering error in order to estimation desired a target. This method obtain optimum covariance weight using modified SPT matrix. This paper of proposal method is showed good performance than general method. We updated a weight of covariance matrix using modified SPT matrix. We obtain optimum covariance matrix weight to application beam steering error method in order to beam steering toward desired target. Through simulation, we showed that compare proposal method with general method. It have improved resolution of estimation target to good performance more proposed method than general method.

Blank Design in Sheet Metal forming Process Using the Rollback Method (롤백방법을 이용한 박판금속성형공정에서의 블랭크 설계)

  • 김종엽;김낙수;허만성
    • Transactions of Materials Processing
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    • v.8 no.5
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    • pp.454-464
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    • 1999
  • A new blank design method is proposed to predict the optimum initial blank shape in the sheet metal forming process. The rollback method for blank shape design takes the difference between the deformed blank contour and the target contour shape into account. the minimization object function R is proposed. Based on the method, a computer program composed of blank design module, FE-analysis module and mesh generation module is developed. The rollback method is applied to square cup, reentrant cross section, L-shaped cup drawing process with the flange of uniform size around its periphery to confirm its validity. The optimum initial blank shape is obtained from an arbitrary blank shape after several modifications. Good agreements are recognized between the numerical results and the published experimental results for initial blank shape and thickness strain distribution. It is concluded that the rollback method is an effective and convenient method for an optimum blank shape design.

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Comparison of Flocculati on-Spectrophotometry and Streaming Current Detector Method to the Control of Flocculants for the Removal of Humic Acid

  • Sang-Kyu Kam;Lee
    • Journal of Environmental Science International
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    • v.1 no.2
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    • pp.137-144
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    • 1992
  • Flocculation-spectrophotometry and streaming current detector( SCD ) method were investigated and compared in order to determine the optimum dosages of synthetic cationic polymers of different charge density and molecular mass for the removal of humic acid. The optimum dosage for each of the polymers was determined with the dosage at which the lowest absorbance of humic acid was shown for the formal. and was determined with the dosage required during charge neutralization of humic acid for the latter It was in good agreement between both methods and there is a strong inverse correlation between the optimum dosage and charge density of the polymers, with highly charged polymer giving the lowest optimum dosage, pointing out the importance the charge neutralization. By flocculation-spectrophotometry, it was found that the absorbance of humid acid with the amount of each of the polymers dosed, changes sharply for polymers of high charge density, but changes rather broadly for polymers of low and middle charge density, Both methods showed that a stoichiometric correlation exists between the optimum dosage of each of the cationic polymers and the negatively charged humic acid.

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Comparison of Flocculation-Spectrophotometry and Streaming Current Detector Method to the Control of Flocculants for the Removal of Humic Acid

  • Kam Sang-Kyu;An Lee-Sun;Lee Min-Gyu
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.1 no.2
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    • pp.137-144
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    • 1997
  • Flocculation-spectrophotometry and streaming current detector(SCD) method were investigated and compared in order to determine the optimum dosages of synthetic cationic polymers of different charge density and molecular mass for the removal of humic acid. The optimum dosage for each of the polymers was determined with the dosage at which the lowest absorbance of humic acid was shown for the former and was determined with the dosage required during charge neutralization of humic acid for the latter. It was in good agreement between both methods and there is a strong inverse correlation between the optimum dosage and charge density of the polymers, with highly charged polymer giving the lowest optimum dosage, pointing out the importance the charge neutralization. By flocculation-spectrophotometry, it was found that the absorbance of humic acid with the amount of each of the polymers dosed, changes sharply for polymers of high charge density, but changes rather broadly for polymers of low and middle charge density. Both methods showed that a stoichiometric correlation exists between the optimum dosage of each of the cationic polymers and the negatively charged humic acid.

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A study for the system voltage and reactive power control (계통전압.무효전력 제어에 관한 연구)

  • 송길영
    • 전기의세계
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    • v.14 no.3
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    • pp.10-17
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    • 1965
  • This paper presents a method of the voltage-reactive power control in the long and short range operations and introduces a conception, "optimum control pattern." The optimum control pattern, aiming at the over-all system control, is defined as the optimum voltage distribution which minimizes the system operating cost under the conditions that the specified power be supplied and the system voltage be kept within the specified bounds. The following procedure was adopted to obtain this optimum pattern. In the first place, a power system was divided into three blocks, namely, load, substation and generator. Lagrange's, multiplier method is applied to each block in turn, paying attention only at the operating voltage distribution. Phase angles at each bus are then modified so that the continuity of active power is maintained. This procedure may be called "block relaxation method with Lagrange's multipliers." In a long range operation, this control pattern determines the optimum installation capacity of reactive power sources. In a short range operation, it also gives the reference state of real time control and the optimum switching capacity of reactive power souces. The real time control problem is also studied from the standpoint of cooperation of control devices such as generators, shunt capacitors, shunt reactors and ratio load controllers. A proposal for the real time control will contribute to the automation of power system operation in the near future. in the near future.

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An Analysis of Optimum Transmission Range in MANETs under various Propagation Models (다양한 전파 환경 하에서 MANET 최적 통달거리 분석)

  • Choi, Hyungseok;Lee, JaeYong;Kim, ByungChul
    • Journal of Internet Computing and Services
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    • v.15 no.2
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    • pp.1-7
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    • 2014
  • This paper presents an analytical method for finding the optimum transmission range in mobile ad hoc networks(MANETs). The results are particularly useful for the operation of military networks, as the transmission range affects the throughput, delay, and battery consumption. Plus, the proposed method allows the optimum transmission range to be determined in advance when deploying combatants with mobile terminals. And we analyze the battery life-time and the optimum transmission range under various propagation scenarios based on Hata propagation model. The proposed method obtains the optimum transmission range in a MANET based on the operational conditions.

Optimal Design of Structures with Standardized Structural Members (규격부재를 사용한 구조물 최적설계)

  • Yoo, Yung Myun;Lee, Hang Sup
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.6 no.4
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    • pp.1-9
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    • 1986
  • In this paper research results of developing a method of selecting design variables of an optimization problem from a finite set of pre-specified numbers, which can be utilized for the structural optimization with standardized structural members, is presented. The method first finds a continuous optimum under the assumption that design variables can be varied continuously. Then a pseudo-optimum is determined by selecting numbers from the set that are near to the continuous optimum and do not violate constraints. The pseudo-optimum is further improved to obtain the final discrete optimum from the set which minimizes cost function of the problem. In this research, the method is combined with the gradient projection optimization algorithm. The method is applied to several minimum weight truss optimization problems with constraints on the stresses, displacements, and design variables. As the results, it is found that the method can be efficiently applied to various optimization problems of which design variables must be chosen from a standard.

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Optimum Structural Design of Space truss with consideration in Snap-through buckling (뜀-좌굴을 고려한 공간 트러스의 최적구조설계에 관한 연구)

  • Shon, Su-Deok;Lee, Seung-Jae;Choi, Jae-Hyun
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.2
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    • pp.89-98
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    • 2012
  • This study investigates the optimum structural design of space truss considering global buckling, and is to obtain the minimal weight of the structure. The mathematical programming method is used for optimization of each member by member force. Besides, dynamic programming method is adapted for consideration in snap-through buckling. The mathematical modeling for optimum design of truss members consists of objective function of total weight and constrain equations of allowable tensile (or compressive) stress and slenderness. The tangential stiffness matrix is examined to find the critical point on equilibrium path, and a ratio of the buckling load to design load is reflected in iteration procedures of dynamic programming method to adjust the stiffness of space truss. The star dome is examined to verify the proposed optimum design processor. The numerical results of the model are conversed well and satisfied all constrains. This processor is a relatively simple method to carry out optimum design with consideration in global buckling, and is viable in practice with respect to structural design.

A Study on the Application Plan of Air-Conditioning and Renewable Complex Systems in the Small Schools. (소규모 학교의 냉난방 및 신재생에너지복합시스템 적용방안에 관한 연구)

  • Kim, Ji-Yeon;Park, Hyo-Soon;Hong, Sung-Hee;Kim, Seong-Sil;Hur, Inn-Ku;Suh, Seung-Jik
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.946-951
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    • 2009
  • The research aims to study a new, optimum and renewable energy application method that can cover the minimum energy and operation costs within a range of school budgets. By deriving the optimum application method, it is expected to maximize the cooling/heating and water heating energy saving efficiencies for educational facilities. Therefore, this research carried out a study on the new/renewable energy utilization technique diffusion expansion method and the optimum method. As a result, the first optimum plan was introduced with the multi-type geothermal heat pump 174kW + solar heat collector $94\;m^2$ + highly efficient electronic cooling/heating device (EHP) 249.4kW. On the other hand, the second optimum plan was induced as the multi-type geothermal heat pump 255.2kW + highly efficient electronic cooling/heating device (EHP) 168.2kW.

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A Study on the Application Plan of Air-Conditioning and New and Renewable Systems in the Large High Schools (대규모 고등학교의 냉난방 및 신재생에너지시스템 적용방안에 관한 연구)

  • Kim, Ji-Yeon;Park, Hyo-Soon;Kim, Seong-Sil;Suh, Seung-Jik
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.10
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    • pp.564-574
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    • 2009
  • The study is conducted to study a new, optimum and new and renewable energy application method that can cover the minimum energy and operation costs within a range of school budgets. By deriving the optimum application method, it is expected to maximize the cooling/heating and hot water supply energy saving efficiencies for educational facilities. Therefore, this research implemented a study on the new and renewable energy utilization technique diffusion expansion method and the optimum method. As a result, the first optimum plan was introduced with the multi-type geothermal heat pump 475.6 kW+highly efficient electronic cooling/heating device(EHP) 545.2 kW. On the other hand, the second optimum plan was induced as the multi-type geothermal heat pump 261kW+solar heat collector $240\;m^2$+highly efficient electronic cooling/heating device(EHP) 759.8 kW.