• 전기전자학회논문지
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• 제19권3호
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• pp.349-356
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• 2015

방공지휘통제경보체계는 작전환경에서의 적의 기습적 공중공격으로부터 우군의 부대, 시설 및 요충지 등을 방호하기 위하여, 전장의 탐지/식별센서, 경보전파/사격통제 및 타격체계를 유기적으로 결합하여 방공작전시 동시성과 통합성을 달성할 수 있는 체계이다. 방공지휘통제경보체계는 육군의 표준화된 가변형 메시지 포맷(KVMF) 메시지를 활용하여 체계 내 외부와의 통신하는데, 비트 단위의 메시지 처리가 짧은 시간동안 많이 발생하므로 메시지 처리 속도의 향상이 중요하다. 본 논문에서는 방공지휘통제경보체계의 KVMF 처리기 메시지 처리 속도 향상방안을 제안한다.

• Nuclear Engineering and Technology
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• 제43권5호
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• pp.447-458
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• 2011

This paper proposes an approximated contact force model to identify the nonlinear behavior of a fuel rod with gap supports; also, the numerical prediction of interfacial forces in the mechanical contact of fuel rods with gap supports is studied. The Newmark integration method requires the current status of the contact force, but the contact force is not given a priori. Taylor's expansion can be used to predict the unknown contact force; therefore, it should be guaranteed that the first derivative of the contact force is continuous. This work proposes a continuous and differentiable contact force model with the ability to estimate the current state of the contact force. An approximated convex and differentiable potential function for the contact force is described, and a variational formulation is also provided. A numerical example that considers the particularly stiff supports has been studied, and a fuel rod with hardening supports was also examined for a realistic simulation. An approximated proper solution can be obtained using the results, and abrupt changes from the contacting state to non-contacting state, or vice versa, can be relieved. It can also be seen that not only the external force but also the developed contact force affects the response.

• 한국가스학회지
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• 제14권6호
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• pp.1-6
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• 2010

하천통과 배관은 부력과 외부 충격을 방지하기 위하여 1.2~4m의 매설 깊이로 설치되어 운영된다. 하천통과 배관은 수압과 토하중에 의한 외압으로부터 소성붕괴에 대한 저항성을 가져야한다. 하천통과 배관에 수압과 토하중으로 발생하는 원주응력을 유한요소해석으로 파악하여 배관의 건전성에 미치는 영향을 평가하였다. 콘크리트 보호공이 없는 경우 동일 수심에서는 매설 깊이 증가에 따라 원주응력은 증가하나, 동일 매설 깊이에서는 수심이 증가함에 따라 배관에서 발생하는 원주응력은 감소하고 있었다.

• 항공우주시스템공학회지
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• 제9권3호
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• pp.23-30
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• 2015

In this study, a transient structural load analysis system was constructed to calculate the applied load on the suspension equipment corresponding to the aircraft flight conditions based on military specifications. Aircraft flight data (altitude, velocity, acceleration, angle of attack and etc. at aircraft center of gravity) were used as input parameters and the calculated load of the suspension equipment at wings on the left and right side was printed out for the structural load analysis. As a calculation procedure, first of all, load analysis was carried out at the center of gravity of the external store, Secondly, a trial reaction force analysis was conducted on hook and swaybrace of suspension equipment. All procedure of calculations was programed to analyze the structural load automatically. To verify the numerical results, structural load analysis using the experimental flight data was performed.

• 방사성폐기물학회지
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• 제20권4호
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• pp.523-531
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• 2022

The International Atomic Energy Agency (IAEA) entails independent decision-making for the safety supervision of civil nuclear facilities. To evaluate and review the safety of nuclear facilities, the national regulatory body usually consults independent institutions or external committees. Technical Support Organizations (TSOs) include national laboratories, research institutions, and consulting organizations. Support from professional organizations in other countries may also be required occasionally. Most of the world's major nuclear power countries adopt an independent nuclear safety supervision model. Accordingly, China has continuously improved upon the construction of such a system by establishing the National Nuclear Safety Administration (NNSA) as the decision-making department for nuclear and radiation safety supervision, six regional safety supervision stations, the Nuclear and Radiation Safety Center (NSC), a nuclear safety expert committee, and the National Nuclear and Radiation Safety Supervision Technology R&D Base, which serves as the test, verification, and R&D platform for providing consultation and technical support. An R&D system, however, remains to be formed. Future endeavors must focus on improving the technical support capacity of these systems. As an enhancement from institutional independence to capability independence is necessary for ensuring the independence of China's nuclear safety regulatory institution, its regulatory capacity must be improved in the future.

• Current Optics and Photonics
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• 제8권2호
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• pp.138-150
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• 2024

This study is essential for advancing our knowledge about the interaction between long-range high-power lasers and energetic materials, with a particular emphasis on understanding the response of a 155-mm shell under various surface irradiations, taking into account external factors such as atmospheric disturbances. The analysis addresses known limitations in understanding the use of non-realistic targets and the negligence of ambient conditions. The model employs the three-dimensional level-set method, computer-aided design (CAD)-based target design, and a message-passing interface (MPI) parallelization scheme that enables rapid calculations of the complex chemical reactions of the irradiated high explosives. Important outcomes from interaction modeling include the accurate prediction of the initiation time of ignition, transient pressure, and temperature responses with the location of the initial hot spot within the shell, and the relative magnitude of noise with and without the presence of physical ambient disturbances. The initiation time of combustion was increased by approximately a factor of two with atmospheric disturbance considered, while slower heating of the target resulted in an average temperature rise of approximately 650 K and average pressure increase of approximately 1 GPa compared to the no ambient disturbance condition. The results provide an understanding of the interaction between the high-power laser and energetic target at a long distance in an atmospheric condition.

• 한국통신학회논문지
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• 제40권2호
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• pp.355-362
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• 2015

본 연구에서는 X-밴드 레이더에서 사용하는 9.385[GHz] 서큘레이터를 Y형 WR112 도파관속에 페라이트를 삽입하여 제작을 하였다. 페라이트 설계는 B/R(Below Resonance) 모드 방식을 사용하여, 페라이트 내부에서 전계 분포가 120도의 회전이 발생하는 조건과 페라이트의 내부의 직류 자계의 세기와 외부 자계의 세기를 계산하였다. 또한, 임피던스 정합을 포함하여 대역폭, 선택도, 삽입손실 등, 서큘레이터의 성능 향상을 위하여 두 개의 페라이트 사이에 같은 형태의 유전체를 삽입하였다. 최적의 페라이트 형태 및 유전체를 얻기 위하여 CST MWS를 이용하였다. 9.385[GHz]에서 시뮬레이션 결과는 정재파비 1.02, 분리도 -40dB, 삽입손실 0.2dB의 결과를 얻었고, 측정 결과는 정재파비 1.03, 분리도 -38dB, 삽입손실 1.2dB 이었다. 분리도, 정재파비는 시뮬레이션 결과와 잘 일치 하였지만, 삽입손실은 약 1dB 정도 크게 발생하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.110-112
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• 2008

A linear generator driven by a hydrogen combustion engine has been developed. Unlike rotary engine-generator systems, the linear counterpart is inherently unable to start by itself unless external force is provided for initial compression/ignition cycle. When the generator is connected to utility power lines through a bidirectional power conversion system, however, the self start-up can be done by driving the generator as a motor. This paper introduces a prototype 1kW linear hydrogen engine-generator system being developed and shows the self start-up is possible with proper motoring mode.

• Asian Journal of Innovation and Policy
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• 제3권2호
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• pp.245-261
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• 2014

Knowledge, technology and information have special characteristics different from the ones of normal consumer products and services. Especially the value of such information varies according to external elements such as the provided environment, their method of utilization, and the level and purpose, etc. of the user. In this study, the indicators of information customer value are developed and measured to enhance customer-based values with efforts for making new customers and maintaining existing customers. The result is as follows: 14 customer value indicators were developed. Among the indicators, value gained versus effort, reduced time for research idea investigation and savings in time searching for equipment, and tools and materials got the highest score, which means that time-saving effects were the most important. The field study of this paper was conducted from information users in the field of national R&D, and thus future studies could be conducted in various industries in many countries to attain generalized results.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2005년도 통합학술대회 논문집
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• pp.5-28
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• 2005

This paper estimates the effect of networks on innovative performance at the firm level , using Korean Innovation Survey (KIS) dataset Product innovation, product improvement , and process innovation are used as proxies for innovative activity. The explanatory variables such as firm size, market concentration ratio, lagged profitability, foreign ownership, export ratio, firm's age, formal R&D activity, and industrial R&D intensity are yet other considerations. With two year-long (2000 and 2001) data from 1,124 Korean manufacturing firms, we estimated the logistic regression model. The research finding indicates that the external networks have a strong positive effect on innovative output regardless of type of innovation. However, the network effects by partner (other firms or research institutions) vary across the type of innovation. Especially, we found that the user-supplier linkage plays an important role in product ion innovation, product improvement, and process innovation.