• Title/Summary/Keyword: Dynamic Strategy

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Assessing the Feasibility of an Accident Management Strategy Using Dynamic Reliability Methods

  • Moosung Jae;Kim, Jae-Hwan
    • Nuclear Engineering and Technology
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    • v.29 no.1
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    • pp.1-6
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    • 1997
  • This paper presents a new dynamic approach for assessing feasibility associated with the implementation of accident management strategies by the operators. This approach includes the combined use of both the concept of reliability physics and a dynamic event tree generation scheme. The reliability physics is based on the concept of a comparison between two competing variables, i.e., the requirement and the achievement parameter, while the dynamic event tree generation scheme on the continuous generation of the possible event sequences at every branch point up to the desired solution. This approach is applied to a cavity flooding strategy in a reference plant, which is to supply water into the reactor cavity using emergency fire systems in the station blackout sequence. The MAAP code and Latin Hypercube sampling technique are used to determine the uncertainty of the requirement parameter. It has been demonstrated that this combined methodology may contribute to assessing the success likelihood of the operator actions required during accidents and therefore to developing the accident management procedures.

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Dynamic Analysis of CRM Strategy for Online Shopping-mall (온라인쇼핑몰의 CRM 전략에 관한 동태적 분석: System Dynamics 기법을 활용한 고객만족도 분석을 중심으로)

  • Kang, Jae-Won;Lim, Jay-Ick;Lee, Sang-Gun
    • Information Systems Review
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    • v.9 no.3
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    • pp.99-132
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    • 2007
  • As customer management rises by important issue in electronic commerce, virtue study about CRM have proceeded much. However, because existent researches were positive researches of most statistical base, There are some limitation that does not show dynamic change with CRM flow by flowing of time, and can not forecast propriety and future result about CRM strategy. Therefore, in order to overcome existent limitation on these CRM study, this study designed dynamic model which draws factors that compose CRM strategy of on-line shopping mall, and do based on technique in system dynamics so that can analyze dynamic change between these factors. Concretely, atomized customer focuses in the on-line shopping mall and does based on Permission marketing theory, and applied CRM of different level to atomized customers and know change of customer satisfaction measurement and discomfort degree accordingly. According to the result of Simulation practice, situation that achieve CRM strategy of different level by atomize customer more increase the customer satisfaction than situation that is not so. Dynamic pattern that presented in this study is expected that can verify validity about CRM achievement strategy of different level at each CRM point of contact & how Internet enterprise including on-line shopping mall is establishing CRM strategy reasonably.

Algorithm for Search Space Reduction based on Dynamic Heuristic Value Change

  • Kim, Hyung-Soo;Moon, kyung-Seob
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.6
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    • pp.943-950
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    • 2002
  • Real time strategy game is a computer game genre of Playing with human or computer opponents in real time It differs from turn-type computer games in the game process method. Turn type games, such as chess, allow only one Player to move at a time. Real time strategy games allow two or more Players to move simultaneously. Therefore, in real time strategy computer games, the game components' movement plans must be calculated very quickly in order to not disturb other processes such as gathering resources, building structures, and combat activities. There are many approaches, which can reduce the amount of memory required for calculating path, search space, and reactive time of components. (or units). However, existing path finding algorithms tend to concentrate on achieving optimal Paths that are not as important or crucial in real time strategy game. This Paper introduces Dynamic Heuristic Af(DHA*) algorithm which is capable of reducing search space and reactive time of game units and compares with A* algorithm using static heuristic weighting.

Investigating Arithmetic Mean, Harmonic Mean, and Average Speed through Dynamic Visual Representations

  • Vui, Tran
    • Research in Mathematical Education
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    • v.18 no.1
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    • pp.31-40
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    • 2014
  • Working with dynamic visual representations can help students-with-computer discover new mathematical ideas. Students translate among multiple representations as a strategy to investigate non-routine problems to explore possible solutions in mathematics classrooms. In this paper, we use the area models as new representations for our secondary students to investigate three problems related to the average speed of a particle. Students show their ideas in the process of investigating arithmetic mean, harmonic mean, and average speed through their created dynamic figures. These figures really utilize dynamic geometry software.

Synchronous PI control scheme for DVR against a voltage sag in the power system (전력 계통내에서 순간 전압 강하에 빠른 응답 특성을 가진 DVR의 제어)

  • Kim M.B.;Lee S.H.;Moon G.W.;Youn M.J.
    • Proceedings of the KIPE Conference
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    • 2003.07b
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    • pp.554-559
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    • 2003
  • A new control strategy for dynamic voltage restorer (DVR) is proposed. It is based on synchronous PI control strategy which features fast response. Therefore, the proposed control strategy takes faster action against a voltage sag. Experimental results, executed by DSP, are shown to validate the proposed control strategy.

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Automatic Command Mode Transition Strategy of Direct Power Control for PMSG MV Offshore Wind Turbines (자동 지령모드절환 기능을 갖춘 PMSG MV 해상 풍력 발전기의 직접전력제어 방법)

  • Kwon, Gookmin;Suh, Yongsug
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.3
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    • pp.238-248
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    • 2016
  • In this study, an automatic command mode transition strategy of direct power control (DPC) is proposed for permanent magnet synchronous generators (PMSGs) medium-voltage (MV) offshore wind turbines (WTs). Benchmarking against the control methods are performed based on a three-level neutral-point-clamped (NPC) back-to-back type voltage source converter (VSC). The ramping rate criterion of complex power is utilized to select the switching vector in DPC for a three-level NPC converter. With a grid command and an MPPT mode transition strategy, the proposed control method automatically controls the generated output power to satisfy a grid requirement from the hierarchical wind farm controller. The automatic command mode transition strategy of DPC is confirmed through PLECS simulations based on Matlab. The simulation result of the automatic mode transition strategy shows that the proposed control method of VOC and DPC achieves a much shorter transient time of generated output power than the conventional control methods of MPPT and VOC under a step response. The proposed control method helps provide a good dynamic performance for PMSGs MV offshore WTs, thereby generating high quality output power.

Profit-oriented Impact Analysis of Demand Management Strategy on Design-Build Firms Using System Dynamics

  • Yoo, Wi-Sung
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.2
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    • pp.169-182
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    • 2012
  • In the past, a strategic management of work demands has been increasingly challenged to design-build (DB) firms. Such a management is capable of providing sufficient profitable impact of a project on them. Total project profit is mainly related to actual resources, work completion time, amount of rework, and costs. The degree of recycling work packages in the DB project delivery system is used as a measure of the quality of the performed work. However, there are few models available to evaluate the impact of a demand management strategy on the DB firms and to predict its behavior. We propose a decision-making support model as an aid for assessing the amount of rework and for predicting project profit resulting in a convincible demand management strategy. This model is constructed by using a dynamic feedback approach that can analyze the problems arising in complex managerial systems. For the purpose of illustration, widely acceptable strategies were applied into the model to explore their impacts on the DB firms. The results indicate that the model is helpful for the managers in selecting the most appropriate demand management strategy for successfully achieving their objectives.

Hybrid Control Strategy of Phase-Shifted Full-Bridge LLC Converter Based on Digital Direct Phase-Shift Control

  • Guo, Bing;Zhang, Yiming;Zhang, Jialin;Gao, Junxia
    • Journal of Power Electronics
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    • v.18 no.3
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    • pp.802-816
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    • 2018
  • A digital direct phase-shift control (DDPSC) method based on the phase-shifted full-bridge LLC (PSFB-LLC) converter is presented. This work combines DDPSC with the conventional linear control to obtain a hybrid control strategy that has the advantages of linear control and DDPSC control. The strategy is easy to realize and has good dynamic responses. The PSFB-LLC circuit structure is simple and works in the fixed frequency mode, which is beneficial to magnetic component design; it can realize the ZVS of the switch and the ZCS of the rectifier diode in a wide load range. In this work, the PSFB-LLC converter resonator is analyzed in detail, and the concrete realization scheme of the hybrid control strategy is provided by analyzing the state-plane trajectory and the time-domain model. Finally, a 3 kW prototype is developed, and the feasibility and effectiveness of the DDPSC controller and the hybrid strategy are verified by experimental results.

A Dynamic Processor Allocation Strategy for Mesh-Connected Multicomputers

  • Kim, Geunmo;Hyunsoo Yoon
    • Journal of Electrical Engineering and information Science
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    • v.1 no.1
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    • pp.129-139
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    • 1996
  • The processor allocation problem in mesh multicamputers is to recognize and locate a free submesh that can accommodate a request for a submesh of a specified size. An efficient submesh allocation strategy is required for achieving high performance on mesh multicomputers. In this paper, we propose a new best-fit submesh allocation strategy for mesh multicomputers. The proposed strategy maintains and uses a free submesh list to get global information for free submeshes. For an allocation request the proposed strategy tries to allocate a best-fit submesh which causes the least amount of potential processor fragmentation so as to preserve the large free submeshes as many as possible for later requests. For this purpose, we introduce a novel function for quantifying the degree of potential fragmentation of submeshes. The proposed strategy has the complete submesh recognition capability. Extensive simulation is carried out t compare the proposed strategy with the previous strategies and experimental results indicate that the proposed strategy exhibits the best performance along with about 10% to 30% average improvement over the best previous strategy.

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Modeling and Control Design of Dynamic Voltage Restorer in Microgrids Based on a Novel Composite Controller

  • Huang, Yonghong;Xu, Junjun;Sun, Yukun;Huang, Yuxiang
    • Journal of Electrical Engineering and Technology
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    • v.11 no.6
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    • pp.1645-1655
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    • 2016
  • A Dynamic Voltage Restorer (DVR) model is proposed to eliminate the short-term voltage disturbances that occur in the grid-connected mode, the switching between grid-connected mode and the stand-alone mode of a Microgrid. The proposed DVR structure is based on a conventional cascaded H-bridge multilevel inverter (MLI) topology; a novel composite control strategy is presented, which could ensure the compensation ability of voltage sag by the DVR. Moreover, the compensation to specified order of harmonic is added to implement effects that zero-steady error compensation to harmonic voltage in specified order of the presented control strategy; utilizing wind turbines-batteries units as DC energy storage components in the Microgrid, the operation cost of the DVR is reduced. When the Microgrid operates under stand-alone mode, the DVR can operate on microsource mode, which could ease the power supply from the main grid (distribution network) and consequently be favorable for energy saving and emission reduction. Simulation results validate the robustness and effective of the proposed DVR system.