• 제목/요약/키워드: 1st-order system

검색결과 419건 처리시간 0.029초

HLA/RTI 기반의 시뮬레이션 조합 기술 (HLA/RTI based on the Simulation Composition Technology)

  • 김진규
    • 한국군사과학기술학회지
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    • 제19권2호
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    • pp.244-251
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    • 2016
  • In defense domain, mission level and engagement level simulation tools exist. In order to experiment a simulation scenario for obtaining results of both mission level and engagement level simulations, we should write a same simulation scenario in a mission level simulation tool as well as an engagement level simulation tool, and we have to operate these tools for analysis of each purpose. Moreover, we could not guarantee that these scenarios are completely same since each scenario is composed of different fidelities of simulation models, although the scenarios are written by a same experimenter and with same simulation purpose. To deal with the difficulties, I propose an approach to analysis of both mission level and engagement level simulations from one simulation result. For this, I have built Composite Combat Mission Planning Simulation Environment (CCMPSE). In this paper, the HLA/RTI based simulation composition technology and my experiences for the designed Composite Combat Mission Planning Simulation Control System (CCMPSCS) are explained. Moreover, This paper also conducts a case study with EADSIM, SADM, and the CCMPSCS. Finally, this paper provides lesson learned from the case study.

소나 시스템 설계를 위한 FFR 트랜스듀서 어레이의 등가회로 모델링 (Equivalent Circuit Modelling of FFR Transducer Array for Sonar System Design)

  • 김인동;최승수;이학수;이승우;문원규
    • 전기학회논문지
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    • 제66권4호
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    • pp.629-635
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    • 2017
  • Free-Flooded Ring (FFR) transducer array for use in Sonar system can be driven with large amplitude in a wide frequency band due to its structural characteristics, in which two resonances of a ring mode (1st radial mode) and an inner cavity vibration mode occur in a low frequency band. Since its sound wave generation characteristics are not influenced by the water pressure, the FFR transducer array is widely used in the deep sea. So FFR has been recognized as a low-frequency active sound source and has received much attention ever since. In order to utilize the FFR transducer array for SONAR systems in military and industrial applications, its equivalent electric circuit model is necessary especially to design the matching circuit between the driving power amplifier and the FFR transducer array. Thus this paper proposes the equivalent electric circuit model of FFR transducer array by using measured values of parameter, and suggest the improved method of parameter identification. Finally it verifies the effectiveness of the proposed circuit model of FFR transducer array by experimental measurements.

저온의 고-액상변화 모듈 용기의 배열에 따른 축냉시스템의 수치해석 (Numerical Analysis of Cold Storage System with Array of Solid-Liquid Phase Change Module)

  • 문수범
    • 해양환경안전학회지
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    • 제21권5호
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    • pp.577-582
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    • 2015
  • 본 논문은 육해상의 운송장치에 축냉시스템을 적용시키기 위한 기초 연구이다. 또한, 축냉재의 고액상변화에 대한 수치해석을 수행한 연구이다. 수치해석법으로는 유한차분법(Finite-Difference Method)을 이용하였으며, 1차원 비정상의 상태를 가정하여 계산하였다. 또한 용기는 직사각형의 구형용기로 가정하여 대칭의 조건을 이용하였다. 축냉을 목적으로 사용하는 열매체는 염화칼슘 수용액($CaCl_2$) 30wt%의 물성치를 사용하여 계산을 수행하였다. 계산에 영향을 미치는 요소로는 냉동고의 냉기 온도 및 냉기 유속이 있으며, 축냉재를 싸고 있는 용기는 플라스틱으로 가정하였다. 본 수치해석에서 경계층의 두께는 냉기의 속도 증가와 함께 얇게 되고 축열시간도 짧아지는 것을 확인할 수 있었다. 그리고 냉기의 유속이 빨라질수록 열전달이 촉진되어 축냉용기 전면부에서의 온도가 낮아짐을 알았다. 축냉용기의 후면부에서는 경계층이 두꺼워져 열전달이 전면부에 비해 작아짐을 알았다.

삼단중유연소 버너에서 다단비가 연소현상에 미치는 영향에 대한 수치 연구 (Numerical study on the effects of air staging on combustion in the three air stage heavy oil fired combustion system)

  • 이승수;김혁주;박병식;김종진;최규성
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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    • pp.235-241
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    • 2004
  • Computations were performed to investigate the effects of air staging on combustion in three stage heavy-oil fired combustion burner. The burner was designed for 3 MW. Different amounts of air are introduced into each 3 three stages by means of each dampers. The goal of the study is to understand combustion phenomena according to each air stage mass ratios through CFD. Air flow rates at three inlets are adjusted by dampers inside a burner. Here, injection conditions of liquid fuel are kept constant throughout all simulations. This assumption is made in order to limit the complexity of oil combustion though it may cause some disagreement. In case of cold flows, only longitudinal velocities arc considered, On the other hand, flow, temperature and NOx generations are taken into account for reactive flows. Simple parametric study was conducted by setting 1'st air stage mass ratio as a parameter. And an optimal operation condition was found. The computational study is based on k-e model, P-1 radiation model(WSGGM) and PDF, and is implemented on a commercial code, FLUENT.

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무기할당을 위한 계층적 레이지 그리디 알고리즘 (Hierarchical Lazy Greedy Algorithm for Weapon Target Assignment)

  • 정혜선
    • 한국군사과학기술학회지
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    • 제23권4호
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    • pp.381-388
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    • 2020
  • Weapon target assignment problem is an essential technology for automating the operator's rapid decision-making support in a battlefield situation. Weapon target assignment problem is a kind of the optimization problem that can build up an objective function by maximizing the number of threat target destructed or maximizing the survival rate of the protected assets. Weapon target assignment problem is known as the NP-Complete, and various studies have been conducted on it. Among them, a greedy heuristic algorithm which guarantees (1-1/e) approximation has been considered a very practical method in order to enhance the applicability of the real weapon system. In this paper, we formulated the weapon target assignment problem for supporting decision-making at the level of artillery. The lazy strategy based on hierarchical structure is proposed to accelerate the greedy algorithm. By experimental results, we show that our algorithm is more efficient in processing time and support the same level of the objective function value with the basic greedy algorithm.

협의 사례 분석을 통한 에너지사용계획 검토기준 재설정 연구 (A Study on the Reset of Examination Criteria for Energy Use Plan through Consultation Case Analysis)

  • 서광수
    • 한국태양에너지학회 논문집
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    • 제33권4호
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    • pp.59-69
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    • 2013
  • The Consultation about Energy Use Plan is prescribed by the Energy Use Rationalization Act. In order to reset Examination Criteria for Energy Use Plan, consultation case analysis from 2001 to 2010 were carried out and National Energy Master Plan was reviewed. This study proposes that Examination Criteria for Energy Use Plan be should divided into Urban & Tourism complex development project and Industrial complex development project for the prevention of civil complain. Also predicts that effect of energy savings calculated by Reset Examination Criteria on $1^{ST}$ energy demand BAU at 2030 is 2.2%, effect of new & renewable energy utilization at 2030 is 3% and the rate of $CO_2$ reduction to greenhouse gas emission BAU at 2020 is 1.1%.

Planning Directions of Community Facilities Integrating Generations based on Local Communities

  • Jae Hee CHUNG;Ji Min KIM;Su Jin LEE;Sung Ze YI
    • 융합경영연구
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    • 제12권1호
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    • pp.39-51
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    • 2024
  • Purpose: This study aims to derive planning directions of community facilities integrating generations based on local communities to promote sustainable intergenerational exchange by analyzing the spatial configuration and programs of domestic and foreign generation-integrated community facilities based on local communities. Research design, data and methodology: Through theoretical consideration, the concept of intergenerational integration, types of intergenerational exchange, and spatial arrangement types were identified. Then, case study analysis of domestic and foreign community facilities with well-planned intergenerational exchange spaces and programs were conducted to identify intergenerational integration, and to derive community facility planning direction. Results: The results of this research are as follows. First, in terms of humanware, in order to revitalize continuous exchange between the 1st, 2nd, and 3rd generations, a systematic support system is needed to build mutual trust through voluntary participation by each generation. Second, it is important to provide a variety of shared spaces while maintaining the uniqueness of each facility from a hardware perspective, and must be planned in such a way that selective interaction takes place with privacy and interaction in mind. Third, in terms of software, programs that meet the characteristics of each user must be provided. Conclusions: It is expected that the results of this research can be used as basic data for planning community facilities that integrate generations based on local communities, contributing to the search for sustainable ways to revitalize intergenerational exchange in the future.

볼테라 시스템을 이용한 파랑 중 파라메트릭 횡동요에 대한 연구 (Study on Volterra System for Variation of Metacentric Height in Waves and its Application to Analysis of Parametric Roll)

  • 이재훈;김용환
    • 대한조선학회논문집
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    • 제54권3호
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    • pp.227-241
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    • 2017
  • In this study, a Volterra system for the variations of metacentric height (GM) in waves is employed to simulate the parametric roll phenomena of ships in head sea condition. Using the present Volterra system, the transfer function of each harmonic component in the GM variation is computed for different ship models, including mathematical models and a real containership, and the results are validated through the comparison with the values obtained using the direct calculations based on a weakly nonlinear time-domain method. Then, a semi-analytic approach employing a 1-degree of freedom equation for roll motion is developed to simulate the parametric roll motions in irregular waves. In the derived approach, the nonlinear and time-varying restoring forces in the waves are approximated using the Volterra system. Through simulations of the parametric roll for different sea states, the effects of the 1st and 2nd-order harmonic components of the variations in the occurrence and amplitude of the parametric roll motions are investigated. Because of the strong nonlinearities in the phenomena, a stochastic analysis is conducted to examine the statistical properties of the roll motions in consideration of the sensitivities and uncertainties in the computations.

중국 중재법에 관한 연구 (A Study on the Chinese Arbitration Act)

  • 윤진기
    • 한국중재학회지:중재연구
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    • 제9권1호
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    • pp.183-232
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    • 1999
  • The legislative body of The People's Republic of China, the National People's Congress, enacted the first arbitration act in China's history on August 31st, 1994, which took effect on September 1, 1995. The problems revealed through a comparison of China's Arbitration Act with the UNCITRAL model arbitration law were studied as well as the enacting process, background, status and system, important contents, problems of Chaina's Arbitration Act, and the differences between the old arbitration regulations and the new arbitration act. These are all discussed in this paper. The Arbitration Act is the basic act ruling over china's arbitration system: it unified the previously confusing laws and regulations relevant to the arbitration system, and the act brings out fundamental changes in China's domestic arbitration to the level of international arbitration standards. It is possible to view this act as a cornerstone in China's arbitration system. But, as discussed in this paper, there are still a lot of problems with the new act and only a few of the merits which the UNCITRAL model arbitration law has. First, under China's Arbitration Act, parties enjoy autonomy to some degree, but the range of party autonomy, compared to that of the UNCITRAL model arbitration law, is too narrow. Second, because China's Arbitration Act didn't explicitly provide issues which can give rise to debate, a degree of confusion in its interpretation still remains. Third, China's Arbitration Act's treatment of some important principles was careless. Fourth, in some sections, China's Arbitration Act is less reasonable than the UNCITRAL model arbitration law. These problems must be resolved in order to develop China's arbitration system. The best way of resolving these problems for China is to adopt the UNCITRAL model arbitration law. But it is difficult to expect that China will accept this approach, because of the present arbitration circumstances in China. Although it is difficult to accept all the contents of the UNCITRAL model arbitration law, China's legislators and practitioners must consider the problems mentioned in this paper.

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어류군집에 따른 마장천(춘천)의 특이성 (Specificity of Majangcheon (Chuncheon) Based on Fish Community)

  • 이한규;이광열;장창원;이재용;천재룡;최재석
    • 환경영향평가
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    • 제28권2호
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    • pp.129-140
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    • 2019
  • 춘천시 소재 농경지 소하천인 마장천이 가진 생물서식처로서의 특이성을 알아보고자, 2016년 6월부터 2016년 9월까지 물리적 환경과 어류를 조사하였다. 마장천은 고도차가 3m인 완만한 하천으로, 유속은 $0.09-0.48m{\cdot}s^{-1}$의 범위를 보였고, 하상구조는 St. 3를 제외한 전 지점이 50% 이상 clay로 이루어져 있었다. 마장천에서 채집된 어류는 총 9과 22종 2,532개체였고, 이 중 납자루아과(Acheilognathinae)나 붕어(Carassius auratus) 등의 정수성 어종과, 피라미(Zacco platypus)나 대륙송사리(Oryzias sinensis) 등 부유성 어종이 주로 출현하였다. 마장천에 대한 어류서식처 특성을 조사한 결과 고도차가 3m인 완만한 하천이었고, 축척 1:25,000에서 1차 하천이었다. 마장천의 어류상 결과와 기 보고된 문헌들의 자료를 참고하여 대응분석을 수행한 결과, 마장천은 강원도 지역 하천보다 경기도 서해안 인근 하천에 가까운 경향을 나타내면서, 두 지역들과는 독립된 그룹으로 나타났다. 결과적으로 마장천은 어류군집이 독특하면서도 특이성이 있는 하천이었으며, 앞으로도 지속적인 연구가 필요하다고 판단된다.