• 한국전산유체공학회:학술대회논문집
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• 2006.05a
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• pp.94-99
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• 2006

As part of a Department of Defense Grand Challenge Project, advanced high performance computing (HPC) time-accurate computational fluid dynamics (CFD) techniques have been developed and applied to a new area of aerodynamic research on microjets for control of small and medium caliber projectiles. This paper describes a computational study undertaken to determine the aerodynamic effect of flow control in the afterbody regions of spin-stabilyzed projectiles at subsonic and low transonic speeds using an advanced scalable unstructured flow solver in various parallel computers such as the IBM SP4 and Linux Cluster. High efficiency is achieved for both steady and time-accurate unsteady flow field simulations using advanced scalable Navier-Stokes computational techniques. Results relating to the code's portability and its performance on the Linux clusters are also addressed. Numerical simulations with the unsteady microjets show the jets to substantially alter the flow field both near the jet and the base region of the projectile that in turn affects the forces and moments even at zero degree angle of attack. The results have shown the potential of HPC CFD simulations on parallel machines to provide to provide insight into the jet interaction flow fields leading to improve designs.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.3
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• pp.215-221
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• 2011

To improve the naval ship acquisition process, systems engineering, modeling and simulation, etc. have been introduced, and there has been ongoing research on acquisition systems for effective support of it. However, due to characteristics of the naval ship acquisition process, development process mainly carried out at a shipyard such as basic design, detailed design, construction and test is difficult to integrate with the acquisition systems of IPT(Integrated Project Team). In addition, research aimed to improve this is rather lacking. In this paper, the naval ship product structure concept proposed in previous research was applied to the basic design system at shipyard, and basic research for expanding the coverage of naval ship acquisition systems to the basic design phase is performed. A data structure of modeling system appropriate to the basic design phase was proposed through research findings and the prototype system based on it was implemented.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.218-226
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• 2016

In the original design of K2 tank the Vertical Sensor Unit(VSU) was mounted to measure the attitude of the main gun to enhance the hit probability. In this research, as a part of efforts to reduce the cost of K2, it was theoretically simulated and evaluated to use the data from Inertial Navigation System(INS) for the calculation of the gun attitude instead of the direct measurement using VSU. It was found that the negative effect of INS approach is negligible and the elimination of VSU is technically possible and beneficial to the system.

• Journal of Astronomy and Space Sciences
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• v.33 no.4
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• pp.305-311
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• 2016

The spatial size and variation of Arctic sea ice play an important role in Earth's climate system. These are affected by conditions in the polar atmosphere and Arctic sea temperatures. The Arctic sea ice concentration is calculated from brightness temperature data derived from the Defense Meteorological Satellite program (DMSP) F13 Special Sensor Microwave/Imagers (SSMI) and the DMSP F17 Special Sensor Microwave Imager/Sounder (SSMIS) sensors. Many previous studies point to significant reductions in sea ice and their causes. We investigated the variability of Arctic sea ice using the daily sea ice concentration data from passive microwave observations to identify the sea ice melting regions near the Arctic polar ice cap. We discovered the abnormal melting of the Arctic sea ice near the North Pole during the summer and the winter. This phenomenon is hard to explain only surface air temperature or solar heating as suggested by recent studies. We propose a hypothesis explaining this phenomenon. The heat from the deep sea in Arctic Ocean ridges and/or the hydrothermal vents might be contributing to the melting of Arctic sea ice. This hypothesis could be verified by the observation of warm water column structure below the melting or thinning arctic sea ice through the project such as Coriolis dataset for reanalysis (CORA).

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.197-208
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• 1999

Recently, risk management is a very important issue in many industrial applications. This paper describes a general structure for risk management and suggests a new risk assessment methodology. In risk management applications of financial or insurance industries, there are many methodologies developed for practical use. However, areas for improvement exist to facilitate the application of the methods. Two major risk assessment methodologies have been developed and widely applied in system engineering. One is in its original development application from aerospace and defense industry, and the other was developed in applied software engineering. In a large and complicated system development application, an effective risk management can reduce total development cost as well as uncertainty in achieving project goals of schedule and performance.

• Journal of Applied Reliability
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• v.18 no.2
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• pp.161-172
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• 2018

Purpose: Test & Evaluation items are main contents which verify performance of the development system and they are deduced going through project management system stages. However, there is no systematic or standardized framework for Test & Evaluation items, so a lot of differences occur between projects and people are questioning whether verification items are selected for the optimization of the development system. In this regard, this research proposes the process of deducing Test & Evaluation items in a systematic way during a development stage by applying QFD (Quality Function Deployment) technique which reflects customers' requirements. Methods: Test & Evaluation items are recognized as customers' requirements, and QFD technique which refines and gathers various requirements of customers effectively during general products' development stage is applied to complete HOQ (House of Quality) Conclusion: There is no specific methodology for Test & Evaluation items, so currently, they are selected by including items which are given by similar projects or higher authorities. However, by utilizing QFD technique, selection of evaluation items which goes through more systematic process is expected to be possible.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.163-168
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• 2021

The article discusses the use of the concept of digitalization in the science of education. The influence of information technologies on the ability to self-study is analyzed. Various technologies that are used in science and education are shown. The issues of the advantages of using IT as a tool for creating conditions for the implementation of the problem-activity approach and the organization of project activities are considered. The possibilities are shown, which gives the opportunities that the use of ICT of distance educational resources in the educational process gives. Shown is their auxiliary form of transmission, information retrieval; working out skills and consolidating what has been learned. Based on the analysis of the presented material of the article, you can see what problems can be solved using IT and remote resources.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.10
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• pp.53-62
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• 2019

The purpose of this study is to analyze the way historical heritage was dealt with during the massive urban development period of the 1960s through the case of Deoksugung Palace. The wall of Deoksugung Palace was rebuilt and relocated in 1961. Later, it was rebuilt and relocated again in 1968, and Daehanmun Gate was soon moved back too. I analyzed the opinions of the Seoul Metropolitan Government, the Cultural Heritage Committee, experts and citizens that occurred during this process and reached the following conclusion. First, in 1961, the existing stone walls of Deoksugung Palace were rebuilt rather than restored and conserved for the urbanscape at the time. Second, in the 1960s, the Cultural Heritage Committee focused on the conservation of the origin of Daehanmun Gate, while citizens valued the overall harmony and function of Deoksugung Palace. Third, unlike the 1970s project led by the president to renovate national security and national defense sites, there was a call from citizens to realize the preservation of Deoksugung Palace.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.78-78
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• 2020

The Se San and Srepok river basins (2S) are the two major tributaries of the Mekong River, both of which originate in the territory of Viet Nam and flow to Cambodia to meet at Stung treng with the Sekong river (originating in Lao PDR) to form the 3S river basin before joining the Mekong mainstream. In the territory of Viet Nam, the 2S river basins are located in the Central Highlands including 5 provinces, arranged by geographical location from north to south namely Kon Tum, Gia Lai, Dak Lak, Dak Nong and Lam Dong. This is a region with a very important strategic position in terms of economy, politics and defense for the whole country with many potential advantages for economic development. However, the limited and vulnerable basin water resources are under the pressure of socio-economic development in line with increasing water demands for various sectors. In order to overcome the water management challenges, a long-term water resources planning has conducted to support the 2S River Basin Committee (RBC) in effective planning and operation as part of the WB Mekong-Integrated Water Resources Management (IWRM) Project. This paper introduces the outline and progress of the river basin planning using analytical DSS toolkits to analyze, evaluate and formulate the planning options.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.9-15
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• 2023

The task of generating a reduced thermal model of a satellite must be performed at least once in a satellite project to shorten the time of orbital thermal analysis and perform thermal analysis coupled to a launch vehicle. Although there are various methods for generating a reduced thermal model, an intuitive and convenient iso-thermal mesh generation method is used the most widely in practice. However, there is still a lack of research on automation of the isothermal mesh generation method. In this paper, we proposed an automated generation method of satellite reduced thermo-mathematical model based on the isothermal mesh generation method considering temperature tolerance and fixed nodes. The proposed method was validated using three different temperature tolerance cases. The average temperature difference satisfied the guidelines of ECSS.