• Title/Summary/Keyword: Military Power

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Improved Input Voltage Sensorless Control of Three-Phase AC/DC PWM PFC Converter using Virtual Flux Observer (가상자속관측기를 이용한 3상 AC/DC PWM PFC 컨버터의 입력전압 센서리스 제어 개선)

  • Kim, Young-Sam;So, Sang-Ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.4
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    • pp.566-574
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    • 2013
  • In this paper, direct power control system for three-phase PFC AC/DC converter without the source voltage sensors is proposed. The sinusoidal input current and unity effective power factor are realised based on the estimated flux in the observer. Both active and reactive power calculated using estimated flux. The estimation of flux is performed based on the reduced-order virtual flux observer using the actual currents and the command control voltage. Moreover, source voltage sensors are replaced by a estimated flux. DC output voltage has been compensated by DC output ripple voltage estimation algorithm. The active and reactive powers estimation are performed based on the estimated flux and Phase angle. The proposed algorithm is verified through simulation and experiment.

Research on direction of future Korean military force establishment -focus on North Korea's nuclear threat and neighboring countries' counter military threat operation- (미래 한국군 군사력 건설방향에 대한 연구 - 북한 핵위협과 주변국 위협대비를 중심으로 -)

  • Kim, Yeon Jun
    • Convergence Security Journal
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    • v.14 no.1
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    • pp.11-21
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    • 2014
  • South Korea should not be in subordinate position in international relationships like the past. As the status of middle power. South Korea achieves peaceful unification through overcoming North Korea's nuclear and conventional threats, and builds military power in Northeast Asia as a 'balancer'. This can firstly be achieved by constructing "attack systems triad". 'attack systems triad' can be established through integrating the C41SR as a common strategy for the purposes of preemptive deterrence and retaliatory deterrence against the dangers of the present and the future. Second, denial deterrence can be achieved by establishing "defense system triad" by combining common military power and defensive weapon system. Finally, development of independent advanced technological strategies can be achieved by building defense industry and combination of research and development through constructing "Infra triad". As for constructing and reinforcing the future of the ROK military, a unilateral principle and policy efforts to achieve the aforementioned force construction models are needed. This can only be achieved through the government's national vision to take on the role of mediator and a basis founded upon the consensus of the public.

Between Regime Change and Political Development: Myanmar's Defective Democracy and the Task for the Political Development (체제 전환과 정치발전의 사이에서: 미얀마의 결손민주주의와 정치발전의 과제)

  • JANG, Junyoung
    • The Southeast Asian review
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    • v.28 no.4
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    • pp.161-196
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    • 2018
  • The major object of this study is to analyze the political development of Myanmar's civilian government on the concept of defective democracy, and to investigate the main actors who delayed or stymied political development and their interrelation. In doing so, this study suggests the tasks required for political development overcoming the current political structure and behavior. The civilian government, which was launched in 2016, failed to achieve positive political development by following the behavior of military authoritarianism in terms of exercise of power and decision making structure. On the perspective of the government, delegative democracy and domain democracy have been strengthening since one person has taken over all political power and hesitate to take horizontal accountability for each power organizations. The military, which is responsible for national defence and security seeks illiberal democracy and exclusive democracy, keeping on an undemocratic constitution by the military and Burman ethnocentrism. The reasons why defective democracy has been occurred are that the lack of a group to run a democratic institutions and the limitation of power structure that fails to adhere to the principle of civilian control to the military due to long-term military rule. Therefore, there is a need for military's come back to barracks and transform the power structure to democratic of the civilian government which is tamed an authoritarian order for the political development in Myanmar. In order to achieve this, this study concludes that setting up a empowered democratic government is required.

Design and Development of 30W Military Grade DC-DC Converter for Guided Weapon and Aircraft (유도무기 및 항공기 탑재장비용 30W급 군사용 DC-DC 변환장치 개발)

  • Park, Sang-Min;Joo, Dong-Myoung;Chae, Soo-Yong;Kim, Hyung-Jung;Lee, Byoung-Kuk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.9
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    • pp.1341-1350
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    • 2017
  • In this paper, a high reliability 30W DC-DC converter is designed considering military standard (MIL-STD) for military applications such as guided weapon and aircraft. The performances and specifications of conventional military grade DC-DC converter are practically analyzed. The requirements for military grade DC-DC converter are established in consideration of MIL-STD and analysis results of conventional product. Two isolated DC-DC converter, forward and fly-back converter, are designed and compared to determine topology. From experimental results under various operating conditions, the forward topology satisfied performances and specifications of MIL-STD for military DC-DC converter.

Study on Increase the Production of Materiel(Military Vehicles) based 'Basic Plan for Defense Industry Promotion' (방산육성 기본계획 기반 군수품(군용차량) 생산량 증진 방안 연구)

  • Lee, Bumkoo;Lee, Sukhee;Kye, Joongeup;Lee, Chunbeom;Jung, Dohyun;Lee, Cheonsoo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.3
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    • pp.25-32
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    • 2014
  • There are many type vehicles in army. They are jeep and truck by basic type. Recently many countries are developing new conceptual military vehicles. And they try for export of those military vehicles to another countries. Also Korea Army is developing military tactical and combat vehicles, and considering various necessary factors for export. But as easing the cold war system tension and reducing of defense budget, decrease in quantity of military vehicles. We think this trend is accelerative. Therefore Government(Military) and defense industry make every effort to increasing sales and productions. In this study, I'll inquire '2013~2017 basic plan for defense industry promotion' for strengthen the power of international competitiveness, and then suggest the increasing method for productions of military vehicles.

A Study of Optimization Approach for GPS Anti-Jamming System's Integration on Military Aircraft Based on the Requirement of Capability (요구성능 기반의 군용 항공기 항재밍 GPS 체계 구축 최적화 방안 연구)

  • Lee, Moongul;Shin, Kisu;Choi, Jaesik
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.1
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    • pp.66-83
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    • 2015
  • Global Positioning System(hereafter; GPS) is recently an essential element in the various navigation and weapon delivery systems of military aircraft. However, GPS is vulnerable to the jamming threats since its signal power is very weak. Therefore, ROK defense has been concerning how to resolve this issue and how to integrate these systems needed, and is trying to acquire the proper anti-jamming GPS system. This study is to provide several schemes against the jamming threats effectively. We propose the several processes to analyze the required capability and demonstrate the result's of modeling and simulations(hereafter; M&S) for this integration of military aircraft, and the mathematical programming model for system optimization of military aircraft anti-jamming GPS system on the basis analysis of M&S results which could be considered available budget and the project characteristic. These schemes will be helpful on proper acquisition of these systems and. We are looking forward to contributing to the integration of anti-jamming GPS system of ROK military aircraft.

Operational Risk Assessment for Airworthiness Certification of Military Unmanned Aircraft Systems using the SORA Method

  • Namgung, Pyeong;Eom, Jeongho;Kwon, Taehwa;Jeon, Seungmok
    • Journal of Aerospace System Engineering
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    • v.15 no.4
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    • pp.64-74
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    • 2021
  • Unmanned Aircraft Systems (UAS) are rapidly emerging not only as a key military power, such as surveillance and reconnaissance for military purposes but also as a new air transportation means in the form of Urban Air Mobility (UAM). Currently, airworthiness certification is carried out focused on the verification of technical standards for flight safety suitability of aircraft design in accordance with the Military Aircraft Flight Safety Certification Act and does not employ the model for operational risk assessment for mission areas and airspace. In this study, in order to evaluate the risk of the mission area from the perspective of the UAS operator, a risk assessment simulation has been conducted by applying the Specific Operations Risk Assessment (SORA) model to the operating environment of the Korean military UAS. Also, the validity of the SORA model has been verified through the analysis of simulation results, and a new application plan for airworthiness certification of the military unmanned aerial system has been presented.

The Welfare Effects of the Military Purveyance Program of Livestock Products (축산물 군납사업의 사회적 후생효과 분석)

  • Chang, Jae Bong;Kim, Yoon Hyung
    • Journal of Korean Society of Rural Planning
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    • v.28 no.4
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    • pp.31-39
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    • 2022
  • This study empirically analyzed the welfare effect of the military purveyance program, which plays an important role in maintaining the sales channel and demand base in Korea's agricultural and livestock industry, as well as the stable supply of safe ingredients for military meals essential for the morale and combat power of soldiers. The military purveyance program causes additional demand for domestic livestock products, affecting the trading volumes and price levels in the market. This will change the welfare of producers and consumers, and affect the welfare of soldiers who are subject to military meals. The analysis results obtained through a simulation method based on the equilibrium displacement model are as follows. In the case of pork delivered for military service, producer surplus increased by KRW 55.3-62.2 billion and consumer surplus decreased by KRW 55.1~62.0 billion based on pork production in 2021. It wad analyzed that the consumer surplus in the military supply market, rather than the conventional market, increased by KRW 96.9 billion won, resulting in a total welfare gain of KRW 97.1 billion.

Design of the Electro-magnetic Compatibility(EMC) for Hybrid Electric Propulsion System (고전력 하이브리드 추진시스템의 전자파 적합성 설계 대책)

  • Lim, Jong-Kwang;Chang, Kyo-Gun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.4
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    • pp.366-373
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    • 2012
  • In this paper, serious changes in the electromagnetic environment with increasing power and energy capabilities for electric driving and military mission are discussed. Design and control strategies on the Electro-Magnetic Compatibility(EMC) for the series hybrid electric vehicle are proposed to minimize the effects of electromagnetic interferences.

A Study of Political Use of Naval Power in Solving International Conflicts (설득이론을 통한 해군력의 정치적 사용에 관한 고찰)

  • Yang, Jung-Seung
    • Strategy21
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    • s.30
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    • pp.236-262
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    • 2012
  • Morgenthau claims that in international relations, there are the economic, political, and military powers that enable a nation to achieve its political and diplomatic goals. This paper explores the possibility of resolving international conflicts with naval power. First, the theoretical and historical perspective, naval power was used as a final resort to force a nation's political or diplomatic objective on an enemy nation when negotiations failed, and this was done through the physical and psychological destruction of the enemy by naval power. But as the use of military power has decreased because of the invention of the nuclear weapon, the existence of a large and capable navy deterrent has become one of the most useful military options among a nation's diplomatic measures. In other words, he focused on the political usefulness of naval power as a deterrent and coercive diplomatic tool for persuading other nations to acquiesce, rather than using naval power and actual military action as a final resort. The reason for this is that compared to army and air force, navy's flexibility, continuity, and the ability to deter are greater. The navy provides excellent accessibility through its wide mobility on the sea, and it has been shown through research that the navy possesses a political usefulness that facilitates the solution of conflicts through presence, naval intervention, and naval blockade. On the other hand, among the factors that could improve the influence of the navy are alliance relations, a reliable and powerful navy, carrots and sticks that it would have to deal with in the case of successful or unsuccessful negotiations, and support from international opinion. On this paper I introduce E.N.Luttwak's naval suasion theory. By the his theory, there are two mode of naval suasion. One is latent naval suasion the other is active suasion. Latent suasion there are deterrent mode and supportive mode. Active naval suasion there are coercive mode and supportive mode. Coercive mode has positive and negative. The limitations of naval suasion have been identified as follows. First, because the objective of the use of naval power is persuading enemy nations, the results are unpredictable. Second, the leaders of all countries possess limited understanding on the complexities of naval power and therefore lack understanding of the usefulness of naval power when choosing options. Third, in case of failure through naval suasion, prestige and reputation of a nation can be damaged. Finally, the following are additional possible research topic. First, a research on the decision making process of choosing naval power as a measure to resolve conflicts is needed. Lastly, research on the size of the navy and types of ships required for efficient naval suasion is needed. Today's world requires cooperative security regime so that middle class navy also requires political use of naval power in solving international conflicts. Therefore, additional research on this topic is needed.

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