• Title/Summary/Keyword: ripple reduction

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A Study on the Economic Analysis of the Defense Acquisition Projects -Focued on ○○ Guided Missile- (국방획득사업 경제성 분석에 관한 연구 -○○유도무기사업 사례를 중심으로-)

  • Lim, Yong-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.10
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    • pp.394-400
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    • 2018
  • Recently, it is expected to significantly increase the defense budget by acquiring large-scale weapons systems to enhance defensive capabilities. In order to secure funds needed to acquire such weapons systems, it is necessary to improve the efficiency of the defense budget. In addition, interest in economic factors affecting the domestic economy such as export opportunities and employment creation are increasing, as well as budget reduction of the defense acquisition business. In order to respond to these demands, this study conducted cost- benefit analysis and examined economic ripple effects in the implementation of defense procurement projects. However, research on economic analysis methodology considering characteristics of defense acquisition projects is still in its early stage. This study proposes a methodology to analyze the economic feasibility of defense acquisition projects and conducted a case study on the economic feasibility of the ${\bigcirc}{\bigcirc}$ guided missile project which is being prepared against local provocation. The proposed economic analysis method provides the cost-effectiveness analysis that has been performed in many weapon system acquisition projects in connection with the more general cost-benefit analysis method. This study contributes to the establishment of an improved theoretical methodology for weapon system acquisition projects.

Control and Analysis of an Integrated Bidirectional DC/AC and DC/DC Converters for Plug-In Hybrid Electric Vehicle Applications

  • Hegazy, Omar;Van Mierlo, Joeri;Lataire, Philippe
    • Journal of Power Electronics
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    • v.11 no.4
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    • pp.408-417
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    • 2011
  • The plug-in hybrid electric vehicles (PHEVs) are specialized hybrid electric vehicles that have the potential to obtain enough energy for average daily commuting from batteries. The PHEV battery would be recharged from the power grid at home or at work and would thus allow for a reduction in the overall fuel consumption. This paper proposes an integrated power electronics interface for PHEVs, which consists of a novel Eight-Switch Inverter (ESI) and an interleaved DC/DC converter, in order to reduce the cost, the mass and the size of the power electronics unit (PEU) with high performance at any operating mode. In the proposed configuration, a novel Eight-Switch Inverter (ESI) is able to function as a bidirectional single-phase AC/DC battery charger/ vehicle to grid (V2G) and to transfer electrical energy between the DC-link (connected to the battery) and the electric traction system as DC/AC inverter. In addition, a bidirectional-interleaved DC/DC converter with dual-loop controller is proposed for interfacing the ESI to a low-voltage battery pack in order to minimize the ripple of the battery current and to improve the efficiency of the DC system with lower inductor size. To validate the performance of the proposed configuration, the indirect field-oriented control (IFOC) based on particle swarm optimization (PSO) is proposed to optimize the efficiency of the AC drive system in PHEVs. The maximum efficiency of the motor is obtained by the evaluation of optimal rotor flux at any operating point, where the PSO is applied to evaluate the optimal flux. Moreover, an improved AC/DC controller based Proportional-Resonant Control (PRC) is proposed in order to reduce the THD of the input current in charger/V2G modes. The proposed configuration is analyzed and its performance is validated using simulated results obtained in MATLAB/ SIMULINK. Furthermore, it is experimentally validated with results obtained from the prototypes that have been developed and built in the laboratory based on TMS320F2808 DSP.

A basic study on development of Women's Fashion Design using Global Market Oriented-Supersensitive Jacquard (글로벌 마켓 지향 고감성 자카드를 활용한 여성복 디자인 개발에 대한 기초적 연구)

  • Kim, Young-Mi;Cho, So-Young;Ahn, Hee-Jung
    • Journal of Fashion Business
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    • v.14 no.4
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    • pp.91-101
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    • 2010
  • This paper has the purpose of suggesting a development-method on the fashion products that would secure the competitiveness in the global markets through creating supersensitive practical products on the basis of developing originative fashion-goods being made of jacquard that is fine quality of couture. This paper has collected data through the cases of the developed nations in fashion, precedent studies and all the related literature on the subject. The results of this researching are as following: The first, it is expected that the necessity of developing new fashion products would be appealed toward the prestige group of consumers who are seeking for the fine quality and super-sensitivity in female fashion in Korea, and it is the current situation that the products made of jacquard are gradually expanding not only in the area of apparel, fashion goods and interior but also another areas. The current situation of the global market suggests the necessary strategy of survival, that is, the development of supersensitive materials and creative products which would be able to keep the high quality and lower the selling price through cost reduction. The second, the suggestion of the direction in developing the products of the female fashion made of jacquard has two points - the development of the texture that would realize a unique form and the development of the material that would be able to realize planar pattern and three dimensional pattern which are woven with thin and light materials with various solidity and delicacy through various techniques of mixing and three dimensional expression. The third, the expected ripple effect and utilization generated from the development of fashion products are as followings: As material characteristics of jacquard, It needs the specialization of various techniques and specialized production system in using jacquard, and the specialized technique and system would make it possible to produce not only the higher value-added products through expressing affluent colors and delicate design but also competitive products through cutting the process and cost, eventually, it would lead to the expansion of the jacquard market of super-sensitive prestige. Therefore, it is remarkable that various development of products toward the global market and the prestige female fashion market can suggest the vision that make the national fashion industry develop into the higher value-added knowledge industry integrating technology and culture.

Development of 1.2[kW]Class Fuel Cell Power Conversion System (1.2[kW]급 연료전지용 전력변환장치의 개발)

  • Suh, Ki-Young;Kim, Chil-Ryong;Cho, Man-Chul;Kim, Jung-Do;Yoon, Young-Byun;Kim, Hong-Sin;Park, Do-Hyung;Ha, Sung-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.6
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    • pp.117-125
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    • 2007
  • Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system. It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system. Therefor, this paper, consists of an isolated DC-DC converter to boost the fuel cell voltage 380[VDC] and a PWM inverter with LC filter to convent the DC voltage to single-phase 220[VAC]. Expressly, The fuel cell system which it proposes DC-DC the efficient converter used PWM the phase transient control law and it depended to portion resonance ZVS switching, loss peek voltage and electric current of realization under make schedule, switching frequency anger and the switch reduction. And mind benevolence it sprouted 2 in stop circuit and it added and a direct current voltage and the electric current where the ingredient is reduced in load side ripple stable under make whom it will be able to supply. Besides the efficiency of 92[%]is obtained over the wide output voltage regulation ranges and load variations. Also, under make over together the result leads simulation and test, the propriety confirmation.

An Analysis of Changes in Air Pollutant Emissions Due to the Introduction of the Special Act on the Improvement of Air Quality in Port Areas -Focusing on Incheon Port (항만지역등 대기질 개선에 관한 특별법 도입에 따른 대기오염물질 배출량 변화 분석 -인천항을 중심으로 )

  • Lee, Min-Woo;Lee, Hyang-Sook;Lee, Jung-Wook
    • Journal of Korea Port Economic Association
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    • v.39 no.3
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    • pp.107-122
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    • 2023
  • This study aims to analyze the effect of reducing air pollutant emissions of the ship fuel oil sulfur content regulation policy, which has been gradually introduced for three years. In addition, the emission reduction effect of VSR and AMP was also analyzed. The analysis was conducted on NOx, CO, VOC, SOx, TSP, PM10, and PM2.5, which are provided by EEA, and the spatial scope of the analysis was conducted on Incheon Port, which is located in the metropolitan area of Korea and has a large ripple effect on air pollution. Three scenarios were constructed for analysis. Scenario 1: If there is no policy, Scenario 2: If only fuel oil sulfur content regulation was implemented, Scenario 3: The analysis was conducted by reflecting fuel oil sulfur content regulation, VSR, and AMP. As a result of the analysis, in the case of scenario 1, 4,801 tons, 4,932 tons, and 5,144 tons of air pollutants were emitted during the three-year period. In Scenario 2, 4,219 tons, 4,152 tons, and 3,989 tons were discharged, and in Scenario 3, 4,198 tons, 4,138 tons, and 3,973 tons were discharged. The findings of this study are anticipated to be applied as fundamental research in port air environment management and Incheon Metropolitan City air management.