• Title, Summary, Keyword: total system method

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Multi objective self adaptive optimization method to maximize ampacity and minimize cost of underground cables

  • Zarchi, Davoud Abootorabi;Vahidi, Behrooz
    • Journal of Computational Design and Engineering
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    • v.5 no.4
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    • pp.401-408
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    • 2018
  • This study presents a novel algorithm for the optimal placement of underground cables in a concrete duct bank to simultaneously maximize ampacity and minimize cable system cost for the first time. The self-adaptive particle swarm optimization (SAPSO) method -which has been used to solve multi-objective optimization problems- is used to solve the multi-objective problem. The main novelty of this paper is finding optimal cable placement by finding maximum ampacity and minimum cable system cost, simultaneously. The proposed method is used in a test case to show how the cable placement is affected by the total ampacity and cable cost in the duct bank. The obtained results show the total fundamental ampacity decrease and the total cable cost increase, on the existence of power system harmonics. The output of the optimization problem is a Pareto optimal solution which gives the cable placement for the concurrent maximized ampacity and minimized total cost. As a case in point, at a specific ampacity of the worst cable configuration, the total cable system cost is more than the total cost of the cable configuration obtained from the optimal Pareto solution, based on simulation results.

Effects of the Component Structures on the Vibration of the Total system Using Design Sensitivity Analysis (설계 민감도를 이용한 부분 구조물의 기여도 분석)

  • Lee, Sun-Byung;Yim, Hong-Jae;Kim, Hyo-Sik
    • Proceedings of the KSME Conference
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    • pp.533-539
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    • 2001
  • In this research, design Sensitivity Analysis is presented for commercial vehicle such as large scale structural system. The proposed method is based on vibration analysis of the total structure and design sensitivity to identify the contribution factor of the component structure to the total system structure. In addition, approximated equations derived from response surface method are used for representative section properties of the thin walled beams.

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Effective Compensation of the Distorted 1.12 Tbps WDM Signals Using Optimization of Total Dispersion

  • Lee, Seong-Real
    • Journal of information and communication convergence engineering
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    • v.5 no.4
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    • pp.377-381
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    • 2007
  • Nonlinear effects and chromatic dispersion are the main causes of pulse degradation in high bit-rate WDM transmission systems and several architectures have been proposed to compensate them by means of optical phase conjugation. In this paper, a new method to exploit an optical phase conjugator (OPC) for nonlinearity and dispersion cancellation is disclosed. The proposed method is using optimal total dispersion of each fiber sections and it is simpler than those previously described in literature. Power penalty between WDM channels and the maximum launch power in $28{\times}40$ Gbps WDM transmission system designed by optimal total dispersion are more decreased and more increased than those in the conventional WDM transmission system with OPC, respectively. Furthermore, optimal total dispersion proposed in this research should provide the flexible design of WDM system, which less depends on OPC position.

Use of equivalent spring method for free vibration analyses of a rectangular plate carrying multiple three-degree-of-freedom spring-mass systems

  • Wu, Jia-Jang
    • Structural Engineering and Mechanics
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    • v.21 no.6
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    • pp.713-735
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    • 2005
  • Due to the complexity of mathematical expressions, the literature concerning the free vibration analysis of plates carrying multiple three-degree-of-freedom (dof) spring-mass systems is rare. In this paper, the three degrees of freedom (dof's) for a spring-mass system refer to the translational motion of its lumped mass in the vertical ($\bar{z}$) direction and the two pitching motions of its lumped mass about the two horizontal ($\bar{x}$ and $\bar{y}$) axes. The basic concept of this paper is to replace each three-dof spring-mass system by a set of equivalent springs, so that the free vibration characteristics of a rectangular plate carrying any number of three-dof spring-mass systems can be obtained from those of the same plate supported by the same number of sets of equivalent springs. Since the three dof's of the lumped mass for each three-dof spring-mass system are eliminated to yield a set of equivalent springs, the total dof of the entire vibrating system is not affected by the total number of the spring-mass systems attached to the rectangular plate. However, this is not true in the conventional finite element method (FEM), where the total dof of the entire vibrating system increases three if one more three-dof spring-mass system is attached to the rectangular plate. Hence, the computer storage memory required by using the presented equivalent spring method (ESM) is less than that required by the conventional FEM, and the more the total number of the three-dof spring-mass systems attached to the plate, the more the advantage of the ESM. In addition, since manufacturing a spring with the specified stiffness is much easier than making a three-dof spring-mass system with the specified spring constants and mass magnitude, the presented theory of replacing a three-dof spring-mass system by a set of equivalent springs will be also significant from this viewpoint.

Energy constraint control in numerical simulation of constrained dynamic system

  • 윤석준
    • 제어로봇시스템학회:학술대회논문집
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    • pp.376-382
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    • 1991
  • In the analysis of constrained holonomic systems, the Lagange multiplier method yields a system of second-order ordinary differential equations of motion and algebraic constraint equations. Conventional holonomic or nonholonomic constraints are defined as geometric constraints in this paper. Previous works concentrate on the geometric constraints. However, if the total energy of a dynamic system can be computed from the initial energy plus the time integral of the energy input rate due to external or internal forces, then the total energy can be artificially treated as a constraint. The violation of the total energy constraint due to numerical errors can be used as information to control these errors. It is a necessary condition for accurate simulation that both geometric and energy constraints be satisfied. When geometric constraint control is combined with energy constraint control, numerical simulation of a constrained dynamic system becomes more accurate. A new convenient and effective method to implement energy constraint control in numerical simulation is developed based on the geometric interpretation of the relation between constraints in the phase space. Several combinations of energy constraint control with either Baumgarte's Constraint Violation Stabilization Method (CVSM) are also addressed.

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Effect of Super Heated Steam Treatment on Physical Property and Smoke Component of Burley Cut Tobacco (과열증기처리에 의한 Burley종 각초의 물리성 및 연기성분 변화에 관한 연구)

  • 김천석;안기영
    • Journal of the Korean Society of Tobacco Science
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    • v.17 no.2
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    • pp.139-148
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    • 1995
  • This study was carried out to investigate the effects of super heated steam on the physical and chemical changes of burley cut tobacco. Total sugar, total alkaloid, ether extracts, crude ash, total nitrogen and pH for leaf chemical constituents were analyzed. Filling power and fineness index for physical properties, and carbonyl compounds, phenol compounds, amonia, pH, hydrogen cyanide nicotine, carbon monoxide, total volatile base and tar for smoke components were also analyzed. The cut tobacco treated with super heated steam showed significant decrease in total sugar and total alkaloid. The filling power of the sample treated with the super heated steam system was increased abruptly when heated at over 250℃. The fineness index showed similar tendency to that of common toast method. Super heated steam treatment slightly decreased carbonyl compounds, phenol compounds, hydrogen cyanide, nicotine, carbon monoxide and tar in the tobacco. Especially the decrease of ammonia was the most remarkable. The pH of smoke was a little different compared with that in the common toast. The sensory test results showed that, compared to the common conveyer moving system, the tobacco treated with super heated steam system brought out more roasted flavor, lowered impact, irritation, and sting, further improved aftertaste, and lowered bitterness. The super heated steam treatment method used in the studies is expected to give better filling power, mild taste and toasted odor of tobacco than that of the common method for toast treatment. Key words : burley tobacco, super heated steam, expansion, toast.

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Extension and Appication of Total Least Squares Method for the Identification of Bilinear Systems

  • Han, Seok-Won;Kim, Jin-Young;Sung, Koeng-Mo
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.1E
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    • pp.59-64
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    • 1996
  • When the input-output record is available, the identification of a bilinear system is considered. It is assumed that the input is noise free and the output is contaminated by an additive noise. It is further assumed that the covariance matrix of the noise is known up to a factor of proportionality. The extended generalized total least squares (e-GTLS) method is proposed as one of the consistent estimators of the bilinear system parameters. Considering that the input is noise-free and that bilinear system equation is linear with respect to the system parameters, we extend the GTLS problem. The extended GTLS problem is reduced to an unconstrained minimization problem, and is solved by the Newton-Raphson method. We compare the GTLS method and the e-GTLS method in the point of the accuracy of the estimated system parameters.

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Stability Evaluation of Green Wall System due to Facing Rigidity (전면벽체 강성에 따른 그린월 시스템의 안정성 평가)

  • Park, Si-Sam;Kim, Hong-Taek;Kim, Seung-Wook;Kim, Yong-Eon
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.3
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    • pp.9-15
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    • 2006
  • The Green Wall system is one of segmental concrete crib type earth retaining wall. Green wall is constructed as procedures that lay the front stretchers, rear stretchers and headers then making a rigid body through harden filled soil of interior cell. Recently, Green Wall method is applied in variable cutting ground construction because of advantage which minimize to cut base ground. In case of Green Wall method is constructed with soil nail method, expect that total system stability will increase more than flexible facing because of facing stiffness is big. However, in this case of design, facing stiffness is not considered so that is poor economy. Hence, in this study, stability increasing effect of total system analyze about that soil nail method is constructed with rigidity facing like a Green Wall method. In present study, laboratory model tests was performed for analysis on stability increasing effect of total system about changing stiffness of facing. LEM analysis conducted for evaluation on safety factor of total system sliding that facing condition changed.

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Efficiency Comparison according to Power Conversion Method and Performance Estimation for Battery Source BLDC Motor Propulsion System of Small Ships (축전지 전원을 사용한 소형선박 추진용 BLDC모터의 전력변환방식에 따른 효율 비교 및 성능 추정)

  • Jeong, T.Y.;Jeong, S.K.
    • Journal of the Korea Society For Power System Engineering
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    • v.14 no.1
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    • pp.27-33
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    • 2010
  • We investigate some operation characteristics and energy efficiency of the BLDC motor system driven by different two types power conversion method depends on same battery source for applying to electrical motor propulsion system of a small ship. Also, we suggest an estimation manner of operating performances such as total running distance and operating speed of ships from basic discharge voltage characteristics of batteries. Through some experiments, direct power conversion was better than indirect method on the view point of energy efficiency and the voltage discharge characteristics could be used as important design factor for estimating operating performances of small ships driven by electrical motors.

Lifetime Management Method of Lithium-ion battery for Energy Storage System

  • Won, Il-Kuen;Choo, Kyoung-Min;Lee, Soon-Ryung;Lee, Jung-Hyo;Won, Chung-Yuen
    • Journal of Electrical Engineering and Technology
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    • v.13 no.3
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    • pp.1173-1184
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    • 2018
  • The lifetime of a lithium-ion battery is one of the most important issues of the energy storage system (ESS) because of its stable and reliable operation. In this paper, the lifetime management method of the lithium-ion battery for energy storage system is proposed. The lifetime of the lithium-ion battery varies, depending on the power usage, operation condition, and, especially the selected depth of discharge (DOD). The proposed method estimates the total lifetime of the lithium-ion battery by calculating the total transferable energy corresponding to the selected DOD and achievable cycle (ACC) data. It is also demonstrated that the battery model can obtain state of charge (SOC) corresponding to the ESS operation simultaneously. The simulation results are presented performing the proposed lifetime management method. Also, the total revenue and entire lifetime prediction of a lithium-ion battery of ESS are presented considering the DOD, operation and various condition for the nations of USA and Korea using the proposed method.