• Title, Summary, Keyword: P-I

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P-I-OPEN MAPPINGS, P-I-CONTINUOUS MAPPINGS AND P-I-IRRESOLUTE MAPPINGS

  • Kim, Ji-Yoon;Kim, Chang-Su
    • The Pure and Applied Mathematics
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    • v.16 no.4
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    • pp.383-404
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    • 2009
  • The notions of P-I-open (closed) mappings, P-I-continuous mappings, P-I-neighborhoods, P-I-irresolute mappings and I-irresolute mappings are introduced. Relations between P-I-open (closed) mappings and I-open (closed) mappings are given. Characterizations of P-I-open (closed) mappings are provided. Relations between a P-I-continuous mapping and an I-continuous mapping are discussed, and characterizations of a P-I-continuous mapping are considered. Conditions for a mapping to be an I-irresolute mapping (resp. P-I-irresolute mapping) are provided.

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Balance-Swap Optimization of Economic Load Dispatch Problem using Quadratic Fuel Cost Function (이차 발전비용함수를 사용한 경제급전문제의 균형-교환 최적화)

  • Lee, Sang-Un
    • The Journal of The Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.243-250
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    • 2014
  • In this paper, I devise a balance-swap optimization (BSO) algorithm to solve economic load dispatch with a quadratic fuel cost function. This algorithm firstly sets initial values to $P_i{\leftarrow}P_i^{max}$, (${\Sigma}P_i^{max}$ > $P_d$) and subsequently entails two major processes: a balance process whereby a generator's power i of $_{max}\{F(P_i)-F(P_i-{\alpha})\}$, ${\alpha}=_{min}(P_i-P_i^{min})$ is balanced by $P_i{\leftarrow}P_i-{\alpha}$ until ${\Sigma}P_i=P_d$; and a swap process whereby $_{max}\{F(P_i)-F(P_i-{\beta})\}$ > $_{min}\{F(P_i+{{\beta})-F(P_j)\}$, $i{\neq}j$, ${\beta}$ = 1.0, 0.1, 0.1, 0.01, 0.001 is set at $P_i{\leftarrow}P_i-{\beta}$, $P_j{\leftarrow}P_j+{\beta}$. When applied to 15, 20, and 38-generators benchmark data, this simple algorithm has proven to consistently yield the best possible results. Moreover, this algorithm has dramatically reduced the costs for a centralized operation of 73-generators - a sum of the three benchmark cases - which could otherwise have been impossible for independent operations.

Dynamic Economic Load Dispatch Problem Applying Valve-Point Balance and Swap Optimization Method (밸브지점 균형과 교환 최적화 방법을 적용한 동적경제급전문제)

  • Lee, Sang-Un
    • The Journal of The Institute of Internet, Broadcasting and Communication
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    • v.16 no.1
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    • pp.253-262
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    • 2016
  • This paper proposes a balance-swap method for the dynamic economic load dispatch problem. Based on the premise that all generators shall be operated at valve-points, the proposed algorithm initially sets the maximum generation power at $P_i{\leftarrow}P_i^{max}$. As for generator i with $_{max}c_i$, which is the maximum operating cost $c_i=\frac{F(P_i)-F(P_{iv_k})}{(P_i-P_{iv_k})}$ produced when the generation power of each generator is reduced to the valve-point $v_k$, the algorithm reduces i's generation power down to $P_{iv_k}$, the valve-point operating cost. When ${\Sigma}P_i-P_d$ > 0, it reduces the generation power of a generator with $_{max}c_i$ of $c_i=F(P_i)-F(P_i-1)$ to $P_i{\leftarrow}P_i-1$ so as to restore the equilibrium ${\Sigma}P_i=P_d$. The algorithm subsequently optimizes by employing an adult-step method in which power in the range of $_{min}\{_{max}(P_i-P_i^{min}),\;_{max}(P_i^{max}-P_i)\}$>${\alpha}{\geq}10$ is reduced by 10; a baby step method in which power in the range of 10>${\alpha}{\geq}1$ is reduced by 1; and a swap method for $_{max}[F(P_i)-F(P_i-{\alpha})]$>$_{min}[F(P_j+{\alpha})-F(P_j)]$, $i{\neq}j$ of $P_i=P_i{\pm}{\alpha}$, in which power is swapped to $P_i=P_i-{\alpha}$, $P_j=P_j+{\alpha}$. It finally executes minute swap process for ${\alpha}=\text{0.1, 0.01, 0.001, 0.0001}$. When applied to various experimental cases of the dynamic economic load dispatch problems, the proposed algorithm has proved to maximize economic benefits by significantly reducing the optimal operating cost of the extant Heuristic algorithm.

A Swap Optimization for Dynamic Economic Dispatch Problem with Non-smooth Function (비평활 발전비용함수를 가진 동적 경제급전문제의 교환 최적화)

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.11
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    • pp.189-196
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    • 2012
  • This paper proposes Swap algorithm for solving Dynamic Economic Dispatch (DED) problem. The proposed algorithm initially balances total load demand $P_d$ with total generation ${\Sigma}P_i$ by deactivating a generator with the highest unit generation cost $C_i^{max}/P_i^{max}$. It then swaps generation level $P_i=P_i{\pm}{\Delta}$, (${\Delta}$=1.0, 0.1, 0.01, 0.001) for $P_i=P_i-{\Delta}$, $P_j=P_j+{\Delta}$ provided that $_{max}[F(P_i)-F(P_i-{\Delta})]$ > $_{min}[F(P_j+{\Delta})-F(P_j)]$, $i{\neq}j$. This new algorithm is applied and tested to the experimental data of Dynamic Economic Dispatch problem, demonstrating a considerable reduction in the prevalent heuristic algorithm's optimal generation cost and in the maximization of economic profit.

An Empirical Study on the Effects of the Determinants of Service Quality to Customer Satisfaction in P&I Insurance (P&I 보험의 서비스품질 결정요인이 고객만족에 미치는 영향에 관한 실증연구)

  • Park, Beom-Shik;Shin, Young-Ran;Shin, Han-Won
    • Journal of Navigation and Port Research
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    • v.35 no.10
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    • pp.855-861
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    • 2011
  • With the rapid growth and development of the Korean Shipping Industry both in external quantum and internal complexity, the marine insurance industry has accordingly expanded with it. This empirical study analyzes the quality factors of the Insurance and P&I Services using 5 factors of quality measures with 22 questions regarding the effect on customer satisfaction by the services offered by the P&I Clubs. The Study is expected to provide P&I Clubs with management tactics for customer satisfaction and the subsequent continued patronage supported by their members through the enhancement of the service quality. This study also provides direction for ship-owners and the members of the P&I Clubs in finding the most efficient service provider as well as in proposing competitive prices of the P&I insurance premium as their management tactic.

Partial Purification and Some Properties of Carboxymethyl Cellulases from Alkalophilic Cephalosporium sp. RYM-202 (호알칼리성 Cephalosporium sp. RYM-202가 생산하는 carboxymethyl cellulase의 부분정제 및 특성)

  • Kang, Myoung-Kyu;Park, Hee-Moon;Rhee, Young-Ha;Kim, Yun-Seog;Kim, Yeo-Kyung
    • The Korean Journal of Mycology
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    • v.21 no.4
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    • pp.301-309
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    • 1993
  • An alkalophilic Cephalosporium sp. RYM-202 capable of producing cellulase components was isolated from soil. This organism grew best at an initial pH 9.0 and produced cellulase maximal at an initial pH 9.5-10.0. Three carboxymethyl cellulases(CMCases), P-I-I, P-I-II and P-II-I, were partially purified by DEAE-Sephadex A-50 ion exchange column followed by Sephadex G-150 gel filtration. The optimum pH values for activity were 7.5 for P-I-I, 8.0-9.5 for P-I-II and 7.5-10.0 for P-II-I. All CMCases were stable between pH 4.5 and 12.0. Temperature optima for activity ranged between 40 and $60^{\circ}C$ and more than 50% of the maximum activity was observed at $20^{\circ}C$ for both of P-I-I and P-II-I. The activity of CMCases was significantly stable in the presence of various laundry components, such as, surfactants, chelating agents and alkaline proteinases.

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Optimization of Economic Load Dispatch Problem for Quadratic Fuel Cost Function with Prohibited Operating Zones (운전금지영역을 가진 이차 발전비용함수의 경제급전문제 최적화)

  • Lee, Sang-Un
    • The Journal of The Institute of Internet, Broadcasting and Communication
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    • v.15 no.5
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    • pp.155-162
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    • 2015
  • This paper proposes a deterministic optimization algorithm to solve economic load dispatch problem with quadratic convex fuel cost function. The proposed algorithm primarily partitions a generator with prohibited zones into multiple generators so as to place them afield the prohibited zone. It then sets initial values to $P_i{\leftarrow}P_i^{max}$ and reduces power generation costs of those incurring the maximum unit power cost. It finally employs a swap optimization process of $P_i{\leftarrow}P_i-{\beta}$, $P_j{\leftarrow}P_j+{\beta}$ where $_{max}\{F(P_i)-F(P_i-{\beta})\}$ > $_{min}\{F(P_j+{\beta})-F(P_j)\}$, $i{\neq}j$, ${\beta}=1.0,0.1,0.01,0.001$. When applied to 3 different 15-generator cases, the proposed algorithm has consistently yielded optimized results compared to those of heuristic algorithms.

Edgeworth and Cornish-Fisher Expansion for the Non-normal t

  • Hwang, Hark
    • Journal of the Korean Statistical Society
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    • v.7 no.1
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    • pp.3-10
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    • 1978
  • Let $X_i,...,X_n$ be a random sample from a distribution with cumulants $K_1, K_2,...$. The statistic $t = \frac{\sqrt{x}(\bar{X}-K_1)}{S}$ has the well-known 'student' distribution with $\nu = n-1$ degrees of freedom if the $X_i$ are normally distributed (i.e., $K_i = 0$ for $i \geq 3$). An Edgeworth series expansion for the distribution of t when the $X_i$ are not normally distributed is obtained. The form of this expansion is Prob $(t

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