• Annual Conference of KIPS
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• 2023.05a
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• pp.224-226
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• 2023

본 논문에서는 연합학습 모델을 타겟으로 하는 특성 추론 공격 및 방어 기법과 관련된 연구들을 소개한다. 연합학습 시스템에 특화된 2가지 특성 추론 공격 및 이에 대한 방어 기법들에 대해 정리하고, 향후 연구 방향을 조망하고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.335-338
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• 2023

국방 무기체계의 운용유지를 위해서는 숙련자에 의한 신뢰성있는 정비 지원이 필요하다. 특히, 고도의 기술력을 바탕으로 연구/제작된 해군 무기체계를 유지하기 위해서는 이와같은 정비 지원이 무엇보다 중요하다. 해군에서는 효과적인 정비지원을 위해 수개의 정비지원부대를 조직하여 운용하고 있다. 원활한 정비지원부대의 운용을 위해 다년간 기술력을 축적한 정비인원의 중도 이탈을 예방하는 것이 요구되므로, 본 논문에서는 머신러닝을 적용하여 해군 정비지원부대의 퇴직자 예측 모델을 제안하였다. 정비인력의 만족도와 관계가 있을 것으로 예상되는 봉급, 특근율 등을 변수로 사용하였고, F1 Score를 통해 모델의 성능을 평가한 결과 0.7이상의 높은 성능을 보였다. 이 모델을 통해 조기 퇴직이 예상되는 그룹의 공통 개선소요를 파악하여 사전 조치가 가능할 것으로 판단하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.339-342
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• 2023

해군에서 운용하는 각 함정은 여러 가지 무기체계를 동시에 탑재하고 있는, 고가의 복합무기체계이다. 주어진 기간동안 효과적인 정비를 수행함으로써, 가동률을 극대화하는 것이말로 복합무기체계인 함정을 효과적으로 운용하는 방법이며, 경제적인 국방운용이라 부를 수 있을 것이다. 정비인시는 여러 무기체계가 동시에 탑재된 복합무기체계 정비의 핵심이다. 정비인시를 정확하게 알고 있어야만, 제한된 정비기간을 각 무기체계에 정확히 할당할 수 있을 것이며, 최적의 요소에 대한 정비가 수행될 수 있을 것이다. 본 연구에서는 해군에서 운용중인 특정장비에 대한 약 10년간의 정비자료를 이용하여 정비인시를 예측하는 모델을 제안하였다. 모델의 성능은 R2 Score를 통해 0.69의 준수한 수치를 보였다. 이 모델을 통해 조금더 세밀하고, 정확한 정비인시 예측과 정비계획 수립이 가능하리라 판단하였다.

• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.1-10
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• 2024

In the era of big data, the growth of e-commerce transactions brings forth both opportunities and risks, including the threat of data theft and fraud. To address these challenges, an automated real-time fraud detection system leveraging machine learning was developed. Four algorithms (Decision Tree, Naïve Bayes, XGBoost, and Neural Network) underwent comparison using a dataset from a clothing website that encompassed both legitimate and fraudulent transactions. The dataset exhibited an imbalance, with 9.3% representing fraud and 90.07% legitimate transactions. Performance evaluation metrics, including Recall, Precision, F1 Score, and AUC ROC, were employed to assess the effectiveness of each algorithm. XGBoost emerged as the top-performing model, achieving an impressive accuracy score of 95.85%. The proposed system proves to be a robust defense mechanism against fraudulent activities in e-commerce, thereby enhancing security and instilling trust in online transactions.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.4
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• pp.466-473
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• 2024

An Emergency Destruction System is inevitable for ensuring safety both at sea and in populated areas, particularly during emergency detonations triggered by abnormal missile flight or upon mission completion. This paper introduces a novel method for developing an Emergency Destruction System capable of precisely calculating the Instantaneous Impact Point(IIP) during high-speed, maneuverable long-range surface-to-air missile flight tests. The Emergency Destruction System designed for long-range surface-to-air missile flight tests generates impact position tables that meticulously incorporate wind errors and navigation equations based on the Earth's ellipsoidal model. Factors such as the Coriolis effect and the direction of the gravitational acceleration vector are accounted for, significantly enhancing the accuracy of IIP determination amidst highly variable missile speed and attitude.

• Structural Engineering and Mechanics
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• v.90 no.6
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• pp.531-542
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• 2024

This study proposes a ground anchor using electromagnetic induction and utilizes an extended structure using hinges and links and mounting and sensing using electromagnets. The aim is to secure the anchor force, excluding grout, and to secure various sensing capabilities, including ground behavior. We propose a design based on the drilling diameter of 150 mm, and the materials used were STS304 and Aluminum 6061-T6. Computerized analysis was performed to confirm structural safety and functional implementation. The pull-out experiment was conducted by simulating the bedrock environment on a model earthwork as an experiment to check whether anchor force was generated by the insertion and tension of the anchor. The environmental pollution of grout, the difficulty of removing strands, and the inability to check whether the anchor is seated, which were pointed out as disadvantages of the existing ground anchor, were solved. Therefore, this study suggest that it can be effectively utilized as a secure and monitored anchoring solution in eco-friendly construction practices, including the installation of landslide prevention barriers.

• The Korean Journal of Food & Health Convergence
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• v.10 no.2
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• pp.7-11
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• 2024

Glutathione (GSH) is a vital compound composed of glutamic acid, cysteine, and glycine, crucial for cellular functions including oxidative stress defense and detoxification. It has widespread applications in pharmaceuticals, cosmetics, and food industries due to its antioxidant properties and immune system support. Two primary methods for GSH synthesis are enzymatic and microbial fermentation. Enzymatic synthesis is efficient but costly, while microbial fermentation, particularly using yeast strains like Candida albicans, offers a cost-effective alternative. This study focuses on genetically modifying C. albicans mutants, specifically targeting glutathione reductase (GLR1) and gamma-glutamylcysteine synthetase (GCS1) genes, integral to GSH synthesis. By optimizing these mutants, the research aims to develop a model for efficient GSH production, potentially expanding its applications in the food industry.

• Archives of Metallurgy and Materials
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• v.67 no.4
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• pp.1525-1529
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• 2022

Co-Cr-Mo based sheet I-WP lattice was fabricated via laser powder bed fusion. The effect of microstructure and the I-WP shape on compressive mechanical response was investigated. Results of compression test showed that yield strength of the sheet I-WP was 176.3 MPa and that of bulk Co-Cr-Mo (reference material) was 810.4 MPa. By applying Gibson-Ashby analytical model, the yield strength of the lattice was reversely estimated from that of the bulk specimen. The calculated strength of the lattice obtained was 150.7 MPa. The shape of deformed lattice showed collective failure mode, and its microstructure showed that strain-induced martensitic transformation occurred in the overall lattice. The deformation behavior of additively manufactured sheet I-WP lattice was also discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.1
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• pp.55-62
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• 2015

The electromagnetic force induced by an intense electric current pulse, which generates an electromagnetic field around the metal jet originating from a shaped charge, can disperse and scatter the high-speed metal jet. An electric device consisting of an RLC circuit applies an intense electric current pulse that flows in the circuit while the metal jet passes between two electrodes. In this study, the metal jet formation was simulated using the ALE technique in 2-D, and a 3-D finite element model was mapped using 2-D simulation results to induce the electric current directly. The deformed shapes of the metal jet and the electromagnetic force were calculated using a finite element analysis by inducing the electric current directly, and the major parameters of the intense electric current pulse for breaking up the metal jet were examined.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.525-538
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• 2014

Safety of reactive systems is one of the most important research areas in the field of weapon development. A NoGo response or at least a low-order explosion should be ensured to prevent unexpected accidents when the reactive system is impacted by high-velocity projectile. We investigated the shock-induced detonation of cased reactive systems subject to a normal projectile impact to the cylindrical surface based on two-dimensional hydrodynamic simulations using the I&G chemical rate law. Two types of energetic materials, namely LX-17 and AP-based solid propellant, were considered to compare the dynamic responses of the reactive system when subjected to the threshold impact velocity. It was found that shock-to-detonation transition phenomena occurred in the cased LX-17, whereas no full reaction occurred in the propellant.