• Korean System Dynamics Review
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• v.13 no.1
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• pp.159-182
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• 2012

Strategic decision on the execution of national security improvement project is greatly important for the present and future national security. Though, the importance of strategic decision, decision making process has been executed under one-way thinking framework. This research provides a decision-making tool with make-or-buy approach for the national security improvement policy execution methods: foreign purchase and military R&D project, and, via simulation, confirms dynamic change of military capability index respect to change in ratio of foreign purchase and military R&D. A result shows that current ratio of foreign purchases and military R&D is insufficient for national security improvement policy goal. Applying the model from this research provides an appropriate ratio for short term and long term defense strategy and policy goal, and consequent result of increase in national security capability. Thus, this research model can be effectively utilized for national security improvement project.

• Journal of computational fluids engineering
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• v.20 no.2
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• pp.81-87
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• 2015

For Underwater vehicles, Unwanted roll excursions are inevitable as they are caused by induced propeller torque, disturbances, and banking motion during turns. To estimate the manoeuvring performance of underwater vehicle, it is necessary to obtain the roll coefficient of body. This paper was covered estimation of roll coefficient of underwater vehicle using STAR-CCM+, commercial CFD(Computational Fluid Dynamics) code. The RANS equations for incompressible fluid flows was solved numerically by using a finite volume method. An MRF(Moving Reference Frame) Method was Also adopted for rotations of body. For the validation, the flow around a DARPA SUBOFF bare hull model was simulated and good agreement with experiments was obtained. And Pure roll coefficients were calculated and campared with the experimental data which were presented by Seoul National University. Finally, an underwater vehicle model with propeller was simulated and analyzed for estimation of roll coefficient variation caused by induced propeller torque.

• Journal of Digital Contents Society
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• v.19 no.6
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• pp.1197-1205
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• 2018

In this paper, we perform Single Image Super Resolution(SISR) for acquired images of EOTS or IRST from naval combat system. In order to conduct super resolution, we use Generative Adversarial Networks(GANs), which consists of a generative model to create a super-resolution image from the given low-resolution image and a discriminative model to determine whether the generated super-resolution image is qualified as a high-resolution image by adjusting various learning parameters. The learning parameters consist of a crop size of input image, the depth of sub-pixel layer, and the types of training images. Regarding evaluation method, we apply not only general image quality metrics, but feature descriptor methods. As a result, a larger crop size, a deeper sub-pixel layer, and high-resolution training images yield good performance.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.2
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• pp.189-195
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• 2015

There are many research works on the SAR image generation using EM(Electro Magnetic) simulation. Particularly, there are several dedicated S/Ws for SAR image generation and analysis. But, most of them are not available to the public due to the reason for defense and security. In this paper, we describe the generation of ISAR images for a realistic target model using the general purpose EM simulator like FEKO. This method can benefit us many advantages like building the database of many targets for target recognition with cost-and-time effective way.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.608-613
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• 2007

Prediction of corporate bankruptcies has long been an important topic and has been studied extensively in the finance and management literature because it is an essential basis for the risk management of financial institutions. Recently, support vector machines (SVMs) are becoming popular as a tool for bankruptcy prediction because they use a risk function consisting of the empirical error and a regularized term which is derived from the structural risk minimization principle. In addition, they don't require huge training samples and have little possibility of overfitting. However. in order to Use SVM, a user should determine several factors such as the parameters ofa kernel function, appropriate feature subset, and proper instance subset by heuristics, which hinders accurate prediction results when using SVM In this study, we propose a novel hybrid SVM classifier with simultaneous optimization of feature subsets, instance subsets, and kernel parameters. This study introduces genetic algorithms (GAs) to optimize the feature selection, instance selection, and kernel parameters simultaneously. Our study applies the proposed model to the real-world case for bankruptcy prediction. Experimental results show that the prediction accuracy of conventional SVM may be improved significantly by using our model.

• IE interfaces
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• v.23 no.3
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• pp.221-228
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• 2010

With the development of science and technology, modern submarines are equipped with high technology devices and multi-functioned precise armaments, consequently, acquisition cost as well as maintenance cost of the submarines are getting higher and higher. However, tight defense budget forces navy to significantly reduce military operating and maintenance costs. In this study, the maintenance and operating costs of submarine Jangbogo-II are estimated through M&S (Modeling and simulation) methodologies in order to reasonably and consistently work out the requirement verification system of Jangbogo-II. The maintenance and operating costs of Jangbogo-II along the next 25 years are estimated as 312.65 billion won via engineering analysis methods while 312.69 billion won from PRICE Model, which shows only 0.04 billion won differences as a whole. This study is expected to be able to provide meaningful decision making data for not only short and/or mid term operating planning but military budgeting.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.2
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• pp.106-114
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• 2020

NCW which is shaping favorable conditions with obtaining initiative through superiority in C2 and information sharing is critical to the result of the war in a modern warfare. An important requirement to attain superiority through an effective networking in a war-environment is to apply QoS to ensure priority in supporting critical mission and services. In order to obtain an effective NCOE through JCS-led QoS support, standard doucments have been reviewed and analyzed to understand the current level of technology and development. In addition, QoS-related policy documents which is currently being applied by the ROK armed forces have been analyzed to substantiated the JCS-led QoS model and propose the directions of development and enhancement required in the realm of technology, policy and system.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.614-621
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• 2016

Micro-Doppler (MD) shift caused by the micro-motion of a ballistic missile (BM) can be very useful to identify it. In this paper, the MD signatures of three scale-model BMs are investigated using a portable measurement system. The measurement system consists of an X-band 2-by-2 phase comparison mono-pulse radar, and a mechanical device that can impart controlled spinning and coning motions simultaneously to a model to yield the MD signature that replicates the characteristic of each target and the corresponding micro-motion. The coning motion determined the overall period of MD, and the spinning motion increased its amplitude. MD was also dependent on aspect angle. The designed system is portable, and can implement many micro-motions; it will contribute to analysis of MD in various situations.

• Design & Manufacturing
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• v.7 no.1
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• pp.28-33
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• 2013

During the cold forming, due to high working pressure acting on the die surface, failure mechanics must be considered before die design. One of the main reasons of die failure in industrial application of metal forming technologies is wear. The mechanisms of wear are consisted of adhesion, abrasion, erosion and so on. Die wear affects the tolerances of formed parts, metal flow, and costs of process. The only way to control these failures is to develop a prediction method on die wear suitable in the design state in order to optimize the process. The wear system is used to analyse 'operating variables' and 'system structure'. In this study, with AISI D2, AISI 1020, AISI 304SS materials, a series of the wear experiments of pin-on-disk type to obtain the wear coefficients from Archard's wear model and the upsetting processes are carried out to observe the wear phenomenon during the cold forming process. The analysis of upsetting processes are performed by the rigid-plastic finite element method. The result of the analysis is used to investigate the die wear the processes, and the analysis simulated die wear profiles are compared with the experimental measured die wear profiles.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1192-1197
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• 2013

In this paper Ubiquitous Medical Electronic Device Export was defined, and it's job analysis. The authors have been defined the job and classified duties and tasks of Ubiquitous Medical Electronic Device Export. To fine what is the most efficient task for Ubiquitous Medical Electronic Device Export, we have been investigated the levels of importance, difficulty, frequency and entry in each task. A DACUM committee is composed of total 12 members, which are one facilitator, 10 panel members, one coordinator & recorder to analyze the job of Ubiquitous Medical Electronic Device Export. Following is the result of this study. First, The process began with the identification of a job title and definition of Ubiquitous Medical Electronic Device Export. Second, a job model of Ubiquitous Medical Electronic Device Export is constructed based on the results of DACUM job analysis. 5 duties and 33 tasks are analyzed. Third, occupational specification was drawn up in consultation with SME council. Fourth, duty specification was drawn up in consultation. 33 tasks that are essential in entry level of occupation are identified. Fifth, task specification was drawn up in consultation. Detail task component which include skill, materials, knowledge, equipment, achievement level and tool was specified in task specification.