• Title/Summary/Keyword: K-factor approach

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An Empirical Study on the Performance Improvement Strategy for Korean Shipping Companies by the Balance Score-card (외항선사의 성과개선 구축전략에 관한 실증연구)

  • Ahn, Ki-Myung;Um, Man-Sung;Ha, Min-Ho
    • Journal of Navigation and Port Research
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    • v.32 no.3
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    • pp.185-192
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    • 2008
  • This paper firstly aims to classify the applicability of the Balanced Scorecard approach to Korean ocean-going shipping firms' management system. The applicability of this approach from Korean shipping firms using Balanced Scorecard will create more effective and efficient organizational performance with reflecting non-financial indexes and making a balance among missions in organization. Secondly, the paper suggests positive information and theoretical evidences to improve Korean shipping firms' management system with examining an availability of the Balanced Scorecard as one method of management tools. So these factors are analysed by structural equation model. This study provides CEO in Korean ocean-going shipping firm the guideline and availability of the Balanced Scorecard as to what kinds of factors should be considered and what is the most critical factor to adopt the BSC into their business.

An Improved Dynamic Programming Approach to Economic Power Dispatch with Generator Constraints and Transmission Losses

  • Balamurugan, R.;Subramanian, S.
    • Journal of Electrical Engineering and Technology
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    • v.3 no.3
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    • pp.320-330
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    • 2008
  • This paper presents an improved dynamic programming (IDP) approach to solve the economic power dispatch problem including transmission losses in power systems. A detailed mathematical derivation of recursive dynamic programming approach for the economic power dispatch problem with transmission losses is presented. The transmission losses are augmented with the objective function using price factor. The generalized expression for optimal scheduling of thermal generating units derived in this article can be implemented for the solution of the economic power dispatch problem of a large-scale system. Six-unit, fifteen-unit, and forty-unit sample systems with non-linear characteristics of the generator, such as ramp-rate limits and prohibited operating zones are considered to illustrate the effectiveness of the proposed method. The proposed method results have been compared with the results of genetic algorithm and particle swarm optimization methods reported in the literature. Test results show that the proposed IDP approach can obtain a higher quality solution with better performance.

The Situation Analysis of Fashion Retail Store According to Attributes of Visual Store Environment in Korean Traditional Market (재래시장의 시각적 점포환경 속성에 따른 재래시장 패션점포의 현황분석)

  • Park, Hyun-Hee;Jeon, Jung-Ok
    • Journal of the Korean Home Economics Association
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    • v.46 no.6
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    • pp.1-11
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    • 2008
  • The purpose of this study is to find the component factors and attributes of visual store environment and to suggest visual merchandising strategies which fit for fashion retail store in Korean traditional market. For the study, observation and in-depth interview were executed for consumers who had purchase experiences at Korean traditional market in city area. The results were as follows. First, the component factors of visual store environment for Korean traditional market were external factor, internal factor, and structural factor. Second, the attributes of visual store environment in Korean traditional market were approach convenience, cleanness, attractiveness, publicity, efficiency, and informativeness. On the basis of these six attributes, real states of fashion retail store in Korean traditional market were analyzed. This study has a meaning in confirming the possibility of differential approach method on the basis of the attributes of visual store environment in Korean traditional market.

Curvature ductility of high strength concrete beams according to Eurocode 2

  • Bouzid, Haytham;Kassoul, Amar
    • Structural Engineering and Mechanics
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    • v.58 no.1
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    • pp.1-19
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    • 2016
  • Recently, the high-strength concrete is increasingly used in the construction of reinforced concrete structures due to its benefits, but this use is influenced negatively on the local ductility of structural elements. The objective of this study is the prediction of a new approach to evaluate the curvature ductility factor of high strength concrete beams according to Eurocode 2. After the presentation of the Constitutive laws of materials and the evaluation method of curvature ductility according to the Eurocode 2, we conduct a parametric study on the factors influencing the curvature ductility of inflected sections. The calibrating of the obtained results allows predicting a very simple approach for estimating the curvature ductility factor. The proposed formula allows to calculate the curvature ductility factor of high strength concrete beams directly according to the concrete strength $f_{ck}$, the yield strength of steel $f_{yk}$ and the ratio of tension and compression reinforcements ${\rho}$ and ${\rho}^{\prime}$ respectively, this proposed formula is validated by theoretical and experimental results of different researchers.

Seismic Reliability Analysis of Offshore Wind Turbine Jacket Structure Using Stress Limit State (응력한계상태를 이용한 해상풍력발전기 재킷구조물의 지진신뢰성해석)

  • Lee, Gee-Nam;Kim, Dong-Hyawn
    • Journal of Ocean Engineering and Technology
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    • v.30 no.4
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    • pp.260-267
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    • 2016
  • Considering the effect of dynamic response amplification, a reliability analysis of an offshore wind turbine support structure under an earthquake is presented. A reliability analysis based on the dynamic response requires a large amount of time when using not only a level 3 approach but also level 2 such as a first order reliability method (FORM). Moreover, if a limit state is defined by using the maximum stress at a structural joint where stress concentration occurs, a three-dimensional element should be used in the finite element analysis. This makes the computational load much heavier. To deal with this kind of problem, two techniques are suggested in this paper. One is the application of a quasi-static structural analysis that takes the dynamic amplification effect into account. The other is the use of a stress concentration factor to estimate the maximum local stress. The proposed reliability analysis is performed using a level 2 FORM and verified using a level 3 simulation approach.

A General Description of Tool Surface Based on Finite Element Mesh and Its Application to 3-D Sheet Forming Processes (유한요소격자에 기초한 일반적인 금형면 묘사와 3차원 박판성형공정에의 응용)

  • Yun, Jeong-Hwan;Kim, Jong-Bong;Yang, Dong-Yeol;Kim, Seok-Gwan;Yu, Dong-Jin;Lee, Jae-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.3 s.174
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    • pp.550-559
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    • 2000
  • One of the most important factor to be considered for the analysis of sheet metal forming processes is the tool surface description for arbitrarily- shaped sheet metal parts. In the present study , finite element approach is used to describe the arbitrarily shaped tool surface. In finite element mesh approach, tool surfaces ar, described by finite elements. The finite elements mesh description of the tool surface, which is originally described by CAD data, needs much time and time-consuming graphic operation. The method, however, has been widely used to describe a complex tool surface. In the present study, the contact searching algorithm for the finite element mesh approach is developed based on cell strategy method and sheet surface normal scheme. For the verification purpose, a clover cup drawing, Baden-Baden oilpan problem and a trunk floor drawing were investigated. The computational results based on the finite element approach were compared with the results of available parametric patch approach and experiments.

Derivation of response spectrum compatible non-stationary stochastic processes relying on Monte Carlo-based peak factor estimation

  • Giaralis, Agathoklis;Spanos, Pol D.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.581-609
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    • 2012
  • In this paper a novel non-iterative approach is proposed to address the problem of deriving non-stationary stochastic processes which are compatible in the mean sense with a given (target) response (uniform hazard) spectrum (UHS) as commonly desired in the aseismic structural design regulated by contemporary codes of practice. This is accomplished by solving a standard over-determined minimization problem in conjunction with appropriate median peak factors. These factors are determined by a plethora of reported new Monte Carlo studies which on their own possess considerable stochastic dynamics merit. In the proposed approach, generation and treatment of samples of the processes individually on a deterministic basis is not required as is the case with the various approaches found in the literature addressing the herein considered task. The applicability and usefulness of the approach is demonstrated by furnishing extensive numerical data associated with the elastic design UHS of the current European (EC8) and the Chinese (GB 50011) aseismic code provisions. Purposely, simple and thus attractive from a practical viewpoint, uniformly modulated processes assuming either the Kanai-Tajimi (K-T) or the Clough-Penzien (C-P) spectral form are employed. The Monte Carlo studies yield damping and duration dependent median peak factor spectra, given in a polynomial form, associated with the first passage problem for UHS compatible K-T and C-P uniformly modulated stochastic processes. Hopefully, the herein derived stochastic processes and median peak factor spectra can be used to facilitate the aseismic design of structures regulated by contemporary code provisions in a Monte Carlo simulation-based or stochastic dynamics-based context of analysis.

A Possible Path per Link CBR Algorithm for Interference Avoidance in MPLS Networks

  • Sa-Ngiamsak, Wisitsak;Varakulsiripunth, Ruttikorn
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.772-776
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    • 2004
  • This paper proposes an interference avoidance approach for Constraint-Based Routing (CBR) algorithm in the Multi-Protocol Label Switching (MPLS) network. The MPLS network itself has a capability of integrating among any layer-3 protocols and any layer-2 protocols of the OSI model. It is based on the label switching technology, which is fast and flexible switching technique using pre-defined Label Switching Paths (LSPs). The MPLS network is a solution for the Traffic Engineering(TE), Quality of Service (QoS), Virtual Private Network (VPN), and Constraint-Based Routing (CBR) issues. According to the MPLS CBR, routing performance requirements are capability for on-line routing, high network throughput, high network utilization, high network scalability, fast rerouting performance, low percentage of call-setup request blocking, and low calculation complexity. There are many previously proposed algorithms such as minimum hop (MH) algorithm, widest shortest path (WSP) algorithm, and minimum interference routing algorithm (MIRA). The MIRA algorithm is currently seemed to be the best solution for the MPLS routing problem in case of selecting a path with minimum interference level. It achieves lower call-setup request blocking, lower interference level, higher network utilization and higher network throughput. However, it suffers from routing calculation complexity which makes it difficult to real task implementation. In this paper, there are three objectives for routing algorithm design, which are minimizing interference levels with other source-destination node pairs, minimizing resource usage by selecting a minimum hop path first, and reducing calculation complexity. The proposed CBR algorithm is based on power factor calculation of total amount of possible path per link and the residual bandwidth in the network. A path with high power factor should be considered as minimum interference path and should be selected for path setup. With the proposed algorithm, all of the three objectives are attained and the approach of selection of a high power factor path could minimize interference level among all source-destination node pairs. The approach of selection of a shortest path from many equal power factor paths approach could minimize the usage of network resource. Then the network has higher resource reservation for future call-setup request. Moreover, the calculation of possible path per link (or interference level indicator) is run only whenever the network topology has been changed. Hence, this approach could reduce routing calculation complexity. The simulation results show that the proposed algorithm has good performance over high network utilization, low call-setup blocking percentage and low routing computation complexity.

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Korean Housing Cycle: Implications for Risk Management (Factor-augmented VAR Approach)

  • KWON, HYUCK-SHIN;BANG, DOO WON;KIM, MYEONG HYEON
    • KDI Journal of Economic Policy
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    • v.39 no.3
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    • pp.43-62
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    • 2017
  • This paper proposes an integrated risk-management framework that includes 1) measuring the risk of credit portfolios, 2) implementing a (macro) stress test, and 3) setting risk limits using the estimated systematic latent factor specific to capture the housing market cycle. To this end, we extract information from a set of real-estate market variables based on the FAVAR methodology proposed by Bernanke, Boivin and Eliasz (2005). Then, we show the method by which the estimated systematic factor is applied to risk management in the housing market in an integrated manner within the Vasicek one-factor credit model. The proposed methodology is well fitted to analyze the risk of slow-moving and low-defaultable forms of capital, such as alternative investments.

Dependence of the Gain Factor of the Reflective Polarizer on the Configuration of Optical Sheets

  • Lee, Byung-Woo;Yu, Mi-Yeon;Ko, Jae-Hyeon
    • Journal of Information Display
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    • v.10 no.1
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    • pp.28-32
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    • 2009
  • The correlation between the optical performance of the reflective polarizer, which is a key optical component for the brightness enhancement of the liquid crystal display (LCD), and the configuration of optical sheets was investigated in a direct-lit CCFL (cold-cathode fluorescent lamp) backlight. The optical gain of the reflective polarizer, the polarization state of the light emitted from each film, and the loss factor for the polarization conversion process occurring in the lower part of the backlight were determined using a phenomenological approach for the polarization recycling process. The present study suggests that the correlation between the optical performance of the brightness enhancement films and the backlight configuration should be carefully considered in the optimization of the backlight structure.