In this study, the structural performance of the specimen fabricated through 3D printing was evaluated through monotonic loading experiments analysis to apply to 3D printed structures. The compression and flexural experiments were carried out, and the experimental results were compared to the finite element model results. The loading directions of specimens were investigated to consider the capacity of specimens with different curing periods, such as 7 and 28 days. As a result, the strength tended to increase slightly depending on the stacking direction. Also, between the 3D-printed panel composite and the non-reinforced panel, the bending performance depended on the presence or absence of composite reinforcement.

When an earthquake occurs, the severity of damage is determined by natural factors such as the magnitude of the earthquake, the epicenter distance, soil properties, and type of the structures in the affected area, as well as the socio-economic factors such as the population, disaster prevention measures, and economic power of the community. This study evaluated the direct economic loss due to building damage and the community’s recovery ability. Building damage was estimated using fragility functions due to the design earthquake by the seismic design code. The usage of the building was determined from the information in the building registrar. Direct economic loss was evaluated using the standard unit price and estimated building damage. The standard unit price was obtained from the Korean Real Estate Board. The community’s recovery capacity was calculated using nine indicators selected from regional statistical data. After appropriate normalization and factor analysis, the recovery ability score was calculated through relative evaluation with neighboring cities.

본 연구는 미국의 동아시아 안보전략과 해외주둔군 전략, 확장억제전 략의 변화를 분석하고, 북한의 핵무기 고도화에 대비한 주한미군과 핵우 산 정책을 고찰한다. 한미동맹이 체결된 1953년 이후, 미국은 한반도 안 보의 중심 역할을 수행했으나 비대칭 동맹으로 인한 동맹 딜레마와 미군 의 역할 및 규모 변화가 발생했다. 핵우산 정책은 냉전기 소련의 핵전술 에 대항하여 확장되어 현재까지 적용되고 있으며, 2023년에는 워싱턴 선 언을 통해 한미 핵협의그룹(NCG)이 창설되었다. 이를 통해 상시적인 확 장억제가 논의되고 있으며, 굳건한 한미 동맹체제와 안보공약이 SCM을 통해 재확인되었다. 이제는 냉전 시기의 미군 주둔과 자동개입 문제는 중국의 G2국가 발전, 북한의 핵과 미사일 도발 등으로 시대적 변수가 달 라져 있다. 따라서 미국의 주한미군 정책, 개입 문제, 확장억제전략에 대 한 신중한 검토와 대비가 필요하다. 본 연구는 미국의 동아시아 전략, 주 한미군, 확장억제전략에 대해 고찰하고 한반도 안보에 대한 전망을 목적 으로 한다.

호장은 마디풀과에 속하는 다년초로 우리나라를 포함한 동아시아에서 잘 자생한다. 호장근은 호장의 뿌리로 항염증과 진경제로 사용되어 왔으며 유효성분으로 emodin을 포함하고 있다. 피부의 표피는 자극, 해로운 물질을 차단하고 수분 증발을 방지함으로써 체내를 보호하는 중요한 역할을 한다. 본 연구에 서는 호장근과 그 유효성분인 emodin이 피부 장벽과 보습능에 미치는 영향에 대해 평가하고자 하였다. 먼 저 호장근은 ABTS+ radicals을 우수하게 제거함으로써 항산화 효능이 뛰어남을 확인하였다. 다음으로, 실 시간 중합연쇄효소반응을 통해 각질형성세포의 분화에 중요한 역할을 하는 filaggrin의 유전자 발현을 비교 한 결과, 호장근과 emodin에 의해 농도-의존적으로 filaggrin mRNA 발현이 증가하였다. 또한, 호장근과 emodin은 히알루론산 합성에 중요한 역할을 하는 HAS-2 mRNA 발현을 유의하게 증가시키는 것으로 나 타났다. 종합적으로, emodin을 유효성분으로 포함하는 호장근은 피부 장벽 강화와 보습능 증강을 위한 기 능성 화장품 소재로서 활용될 수 있을 것으로 기대된다.

Despite the presence of the p-Channel MOSFET inrush current limiter circuit within the power supply unit of military radar, The internal MOSFET and DC-DC Converter has been damaged due to the high inrush current. In this paper, the cause of the high inrush current was identified by analyzing the p-Channel MOSFET inrush current limiter circuit. Based on the analysis, the high inrush current was reduced by about 60% by adjusting the time constant of the source-to-gate elements compared to before improvement.

This study explores strategies to address the variability of heat energy using renewable energy and heat grids to achieve carbon neutrality. Renewable energy source introduce fluctuations that can impact the stability of power systems, while heat grids provide a systematic infrastructure for efficient supply of heat energy and power generation. Jeju Island is chosen as a case study, focusing on balance control based on groundwater-based geothermal energy to optimize the distribution of heat energy. The results demonstrate that the 3rd control method is the most effective in maintaining the target temperature in greenhouses, and specific temperature settings and objectives are proposed for each control method based on crop requirements. These research findings contribute to achieving carbon neutrality and reducing power consumption.

This paper is a study on the malfunction that occurred during the power supply logic of the Gunner Display Device during Mortar Functional Firing under low temperature conditions. As a result of the phenomenon reproduction test and its analysis, the cause of the malfunction of the Gunner Display Device was Glitch, which occurred in the process of converting the image signal, and the improved software was applied to the Gunner's Display System by ignoring some of the image signal conversion process that causes Glitch. The improved Gunner Display Device passed the validity test and applied the improvement to the mortars. As a result of this study, several suggestions for power supply and control logic were proposed. It is expected that this study will be used as a reference in the future design of similar weapons systems.

본 논문의 목적은 급변하는 현대전 양상과 글로벌 우주안보 환경 변화에 대응하기 위한 한국군의 국방 우주력 발전을 위해서 필요한 과제에 대해 고찰해 봄에 있다. 탈냉전시기 미래전 양상은 정보통신 무기체계가 복합체계를 구성하여 ‘네트워크화’ 된 전장 환경 하에서 우주와 사이버, 전자기 위협까지 포함하는 전장공간으로 진화됐다. 이에 본고에서는 4차 산업혁명의 유무인 복합체계 활용과 우주영역인식(SDA)에 대한 패러다임 전환 하에서 합동성에 기반 한국군의 국방 우주력 구축에 필요한 과제에 대해 집중적으로 고찰했다. 4 차 산업혁명 기술과 융합된 국방 우주력의 이론적 고찰과 탈냉전시기 미 국, 러시아, 중국, 일본, 북한의 우주 군사화 양상을 아더 라이케(Arther Lykke)가 제안한 목표, 방법, 수단 이론 등을 중심으로 분석했다. 한국군은 우주안보 위협에 대비하고 우주영역인식(SDA) 변화에 대응하기 위해서 항공우주청 설립, 우주기술 및 군사력 증진, 한미 우주협력 및 우주동맹 확대, 민관군 협력 및 우주관련 예산 확충, 체계적인 인력양성 등의 필요성에 대해 제시했다.

In this paper, the EMP-related standards and test methods used by the civilian and military have been introduced. The incoming EMP signal for seven military RF antennas which are the first to face EMP threats among military weapon systems have been also measured and analyzed. Overall, as the applied signal strength increased, the strength of the EMP signal entering in the antenna also showed an upward trend. The highest level of entering was observed at the peak value of the applied EMP signal, 50 kV/m. And at the peak value, all antennas received threatening signals. In particular, antennas in low frequency bands such as AM and FM were getting high voltage signals as high as thousands of volts. This means that the weapon systems linked to the antennas could suffer severe damage. Therefore, based on this paper, systematic research for EMP threat should be conducted to identify EMP vulnerabilities of major weapons systems and to devise practical protective measures.

It is essential to select materials with excellent mechanical properties to prevent chemical and mechanical damage to the surfaces of materials used in machines and structures and to extend their lifespan. Co-based stellite alloy, which has wear resistance, heat resistance, and corrosion resistance, is essential for products used in harsh environments. However, due to the problem of enormous costs, research on hard facing, which uses a stellite coating layer only on the contact surface, is urgently required. Currently, high-facing research on Stellite coating layers is focused on powder, and GMAW research using wire is relatively lacking. In this study, welding experiments were performed to form stable weld beads using stellite 6 welding wire, and the correlation between parameters and weld beads was analyzed. A CMT welder was used to minimize the heat effect on the base material.