• Nano
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• v.13 no.11
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• pp.1850126.1-1850126.10
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• 2018

Flexible strain sensors, as the core member of the family of smart electronic devices, along with reasonable sensing range and sensitivity plus low cost, have rose a huge consumer market and also immense interests in fundamental studies and technological applications, especially in the field of biomimetic robots movement detection and human health condition monitoring. In this paper, we propose a new flexible strain sensor based on thick CVD graphene film and its low-cost fabrication strategy by using the commercial adhesive tape as flexible substrate. The tensile tests in a strain range of ~30% were implemented, and a gage factor of 30 was achieved under high strain condition. The optical microscopic observation with different strains showed the evolution of cracks in graphene film. Together with commonly used platelet overlap theory and percolation network theory for sensor resistance modeling, we established an overlap destructive resistance model to analyze the sensing mechanism of our devices, which fitted the experimental data very well. The finding of difference of fitting parameters in small and large strain ranges revealed the multiple stage feature of graphene crack evolution. The resistance fallback phenomenon due to the viscoelasticity of flexible substrate was analyzed. Our flexible strain sensor with low cost and simple fabrication process exhibits great potential for commercial applications.

• Journal of Information Technology Applications and Management
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• v.16 no.4
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• pp.223-244
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• 2009

Defense R&D is an essential investment for the national security. Recently our nation has also begun to initiate a number of defense R&D projects. As a lot of fund and resources are allocated to these projects, we need to identify which projects to initiate and then how to manage these projects well. Though there have been a number of studies on R&D projects in commercial sector, there are only a few studies in defense R&D sector. Moreover, these existing defense R&D studies mainly deal with the former issues, which are occurring at the stage of project planing. We are more concerned with project management issues, such as how to manage projects that had already been evaluated to undertake at the planning stage. Specifically our study aims to identify project management factors leading to the success of defense R&D projects. Results of the empirical analysis indicate that management support, user-driven requirements management, and project planning capability are key elements for project performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.101-107
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• 2018

Recently, Korea's defense industry has advanced highly, and defense R&D budget is gradually increasing in defense budget. However, without objective analysis of defense industry technology, effective defense R&D activities are limited and defense budgets can be used inefficiently. Therefore, in addition to analyzing the defense industry technology quantitatively reflecting the opinions of the experts, this paper aims to analyze the defense industry technology objectively by quantitative methods, and to make efficient use of the defense budget. In addition, we propose a patent analysis method to grasp the characteristics of the defense industry technology and the vacant technology objectively and systematically by applying the big data analysis method, which is one of the keywords of the 4th industrial revolution, to the defense industry technology. The proposed method is applied to the technology of the firepower industry among several defense industrial technologies and the case analysis is conducted. In the process, the patents of 10 domestic companies related to firepower were collected through the Kipris in the defense industry companies' classification of the Korea Defense Industry Association(KDIA), and the data matrix was preprocessed to utilize IPC codes among them. And then, we Implemented association rule mining which can grasp the relation between each item in data mining technique using R program. The results of this study are suggested through interpretation of support, confidence lift index which were resulted from suggested approach. Therefore, this paper suggests that it can help the efficient use of massive national defense budget and enhance the competitiveness of defense industry technology.

• Journal of the Korea Society of Computer and Information
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• v.24 no.5
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• pp.27-33
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• 2019

One of serious security threats is a botnet-based attack. A botnet in general consists of numerous bots, which are computing devices with networking function, such as personal computers, smartphones, or tiny IoT sensor devices compromised by malicious codes or attackers. Such botnets can launch various serious cyber-attacks like DDoS attacks, propagating mal-wares, and spreading spam e-mails over the network. To establish a botnet, attackers usually inject malicious URLs into web source codes stealthily by using data hiding methods like Javascript obfuscation techniques to avoid being discovered by traditional security systems such as Firewall, IPS(Intrusion Prevention System) or IDS(Intrusion Detection System). Meanwhile, it is non-trivial work in practice for software developers to manually find such malicious URLs which are hidden in numerous web source codes stored in web servers. In this paper, we propose a security defense system to discover such suspicious, malicious URLs hidden in web source codes, and present experiment results that show its discovery performance. In particular, based on our experiment results, our proposed system discovered 100% of URLs hidden by Javascript encoding obfuscation within sample web source files.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.183-192
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• 2024

The purpose of this study is to empirically analyze the determining factors (economy, security, domestic politics, administration, and international politics) that affect the ROK-US defense cost sharing decision. Through this, we will gain a deeper understanding of the defense cost sharing decision process and improve the efficiency of defense cost sharing calculation and execution. The scope of the study is ROK-US defense cost sharing from 1991 to 2021. The data used in the empirical analysis were various secondary data such as Ministry of National Defense, government statistical data, SIPRI, and media reports. As an empirical analysis method, multiple regression analysis using time series was used and the data was analyzed using an autoregressive model. As a result of empirical research through multiple regression analysis, we derived the following results. It was analyzed that the size of Korea's economy, that is, GDP, the previous year's defense cost share, and the number of U.S. troops stationed in Korea had a positive influence on the decision on defense cost sharing. This indicates that Korea's economic growth is a major factor influencing the increase in defense cost sharing, and that the gradual increase in the budget and the negotiation method of the Special Agreement (SMA) for cost sharing of stationing US troops in Korea play an important role. On the other hand, the political tendencies of the ruling party, North Korea's military threats, and China's defense budget were found to have no statistically significant influence on the decision to share defense costs.

• Journal of Korean Society for Quality Management
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• v.47 no.2
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• pp.217-236
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• 2019

Purpose: This article aims 1) to identify key elements for building quality culture, 2) to design and analyze survey data from defense industry companies, and 3) to suggest directions for enhancing quality culture levels. Methods: Key elements and items for a quality culture are derived by investigating related references and using affinity diagram. Questionnaire items to investigate the quality culture level of the organizations are prepared and the survey data on the level of quality culture of military defense companies are analyzed. Results: 1) Descriptive statistical analyses are presented to compare the levels of the six key elements. 2) In each element items with low scores are identified, which should be improved. 3) Among six key elements, 'support 'element shows lowest level. 4) The quality culture level of the small-sized companies are relatively low. Conclusion: 1) To improve the quality culture level of the defense industry companies, it is necessary to provide quality education, to enhance recognition and rewards, and to invest resources for employees' self-development. 2) Small-sized companies can easily be adapted to quality-oriented cultural change if the CEO leadership focuses on quality culture.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.2
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• pp.117-125
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• 2023

Systematic performance evaluation of the Defense Acquisition Program is very important, since they are directly related to national security. In this paper, we reviewed various performance evaluation models from a methodological perspective for pragmatic performance evaluation, and the limitations of each model. In order to evaluate the performance of the Defense acquisition program efficiently, especially for the Naval ship Projects and considering their unique characteristics, both various stakeholders' participation, standard indicators for performance measurement, and tailoring them considering the projects' circumstances are necessary. We also propose indicators, contents, and detailed criteria example for the Requirements management. This approach enables a pragmatic and consistent evaluation of defense projects, and through this, meaningful insights could be acquired with accumulate data.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.552-560
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• 2023

Aircraft midair collisions are dangerous events that can cause massive casualties. To prevent this, civil aviation has mandated the installation of TCAS (ACAS), which is becoming more sophisticated with the help of new technologies. However, there are institutional problems in collecting data for TCAS research in Korea, limiting the ability to obtain data for personal research. ADS-B and Mode-S automatic broadcast various information about the flight status of the aircraft. This data also contains information about TCAS RA, which can be used by anyone to find examples of TCAS RA operation. We used the databases of ADS-B Exchange and Opensky-Network to acquire data and visually represent three TCAS RA cases through Python coding. We also identified domestic TCAS cases in the first half of 2023 and analyzed their characteristics to confirm the usefulness of the data.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.27-28
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• 2022

최근 우리나라에서도 인공지능 모델을 이용한 수온 예측 관련 연구가 활발히 진행되고 있으나 한반도 주변 해역의 수온 예측 연구에서는 주로 해수면 온도만을 예측하는데 중점을 두고 있다. 본 논문에서는 XBT(eXpendable Bathy-Thermograph) 데이터와 LightGBM(Light Gradient Boosting Model)을 이용하여 잠수함 작전 및 대잠전(Anti Submarine Warfare)에 있어서 군사적으로 중요한 동해의 수직 수온분포를 예측하였다. 동해 특정해역의 해수면부터 수심 200m까지 측정된 XBT 데이터를 이용하여 모델을 학습시키고 성능 평가지표(MAE, MSE, RMSE)와 수직 수온분포 그래프를 통해 예측 정확도를 평가하였다.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.56-61
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• 2023

Recently, advancement of AI-enabled autonomous MUM-T combat system and industrial revitalization are rapidly emerging as global issues. However, the Defense Business Act of the Ministry of National Defense in Korea is judged to be somewhat insufficient compared to NATO leading countries in advancement of operation part of a weapon system as MUM-T is centered on a weapon system's own device. We established the concept of AI-enabled autonomous MUM-T to strengthen international competitiveness of complex combat systems such as future global UGV, UAV, and UMS. In addition, NATO and US-centered autonomy, interoperability, and data standardization-based defense AI MUM-T top-level platform construction and operation plan, establishment of a national defense innovation committee such as the National Science and Technology Advisory Council, review and advisory function reinforcement, and additional governance measures are proposed.