Airpower plays a key role in neutralizing military threats and securing victory in wars. This study analyzes newly introduced fighter forces by considering factors like performance, power index, operational environment, airbase capacity, survivability, and sustainment capability to devise an optimal deployment strategy that enhances operational efficiency and effectiveness. Using optimization methods like mixed integer programming (MIP), the study incorporates constraints such as survivability and mission criticality. The focus is on major Air Force operations, including air interdiction, defensive counter-air, close air support, and maritime operations. Experimental results show the proposed model outperforms current deployment plans in both wartime and peacetime in terms of operations and sustainment.
전 세계적으로 배출되는 폐플라스틱을 석유화학제품으로 재활용하는 순환경제가 본격화되고 있다. 따라서, 화학적 재활용 중 하나인 폐플라스틱 열분해유 생산을 위한 파일럿 규모의 시설도 건설되 고 상업적 생산이 시작되고 있다. 본 연구에서는 파일럿 플랜트에서 조건별로 생산된 총 4종의 폐플라 스틱 열분해유를 활용하기 위해 분리된 각각의 유분의 물성 및 구성성분 분석을 통해 나프타, 선박유 및 보일러유 등 다양한 원료‧연료 등으로 사용이 가능한지 확인해보고자 한다. 폐플라스틱 열분해유의 넓은 비점으로 인하여 경질유분은 상압 및 감압증류를 통해 분리하였고, 중질유분은 감압증류를 통해 분 리하였다. 경질유분(fraction 1)은 나프타를 목적으로 물리적 특성, 탄소분포 및 구성성분을 분석하였는 데, 탄소분포, 비점 등은 적합하지만, 초기 폐플라스틱 열분해유에 비해 염소 함량, 올레핀 및 방향족이 높아 전처리공정이 필요하다, 또한 중질유분(fraction 2)은 보일러유 등을 목적으로 할 때, 적합한 밀도, 동점도, 발열량 및 윤활성 등 물리적 특성을 가졌지만, Si 및 전산가 등이 높았다. 분리하고 남은 잔류물 (residue)은 높은 발열량, 낮은 황 함량, 산소 함량 등은 C중유급 연료로서의 사용이 가능할 것으로 판단되었다. 결론적으로, 분리된 폐플라스틱 열분해유에서 분리되는 모든 유분은 전처리만 가능하다면 나프 타 원료뿐만 아니라 저급 연료로도 활용이 가능하리라 판단된다.
Recently, corrosion problems caused by quarantine disinfectant have occurred in the door panel of commercial trucks. As a way to solve this problem, a drain hole is being drilled in the door panel, and the door panel is being designed again for this purpose. Reinforcing parts such as frames or brackets for rigidity are attached to the inner and outer door panels, and spot welding is performed for assembly. X-rays and nugget diameter measurements of the welds were performed to confirm the results of performing according to various conditions for such spot welding. Through this study, it was confirmed that the pressing force had a greater effect on the welding quality than the amount of welding current.
본 연구는 8종의 생약 복합추출물인 Derma Genie™-DLP121의 피부 건강 개선 효능을 확인하 고자 하였다. 이를 위해, in vitro model에서 Derma Genie™의 생리 활성 정도를 평가했으며, 4종의 피부 세포 내 항산화, 항염, 보습 증진, 주름 개선 및 미백 효능을 분석하였다. 실험 결과, Derma Genie™에는 22.577 mg GAE/g의 폴리페놀이 함유되었고, DPPH assay에서는 최대 74.947%의 radical 소거능을 보였 다. Lipopolysaccharide를 처리하여 과염증 반응을 유도한 RAW 264.7 세포에서는 Derma Genie™가 산 화 질소(NO) 뿐만 아니라, 3종의 염증성 사이토카인(Il-6, Il-1β, Tnf-α)의 농도 의존적인 감소 효과를 매개하여 상당한 항염 효능이 있음을 입증하였다. 또한 Derma Genie™는 히알루론산을 생성하는 효소인 HAS1 및 HAS2의 유전자 발현은 증가시키고, 히알루론산 분해 효소 HYAL1의 발현은 저해시켜 세포 내 보습 증진 효능을 나타내었다. 뿐만 아니라, ultraviolet B (UVB)에 의한 세포 생존율 감소 및 주름 연관 유전자(COL1A1, COL3A1)의 발현 감소가 Derma Genie™ 처리 시 개선됨을 확인하였다. 특히 최대 농도 의 Derma Genie™ (1 mg/mL)와 UVB를 병용 처리한 군에서 주름 연관 인자인 COL1A1 및 COL3A1의 발현량이 각각 55.080 및 57.103% 개선됨을 보였다. 마지막으로, α-MSH로 멜라닌 합성을 유도시킨 B16F10에서 Derma Genie™의 병용 처리는 세포 내 멜라닌 함량을 최대 95.159% 감소시켰다. 이는 Derma Genie™가 세포 내 tyrosinase 활성을 억제함으로써 미백 효능을 가지는 것으로 판단되었다. 따라 서 이러한 결과는 Derma Genie™가 피부세포 내 항산화, 항염, 보습 증진, 주름 개선 및 미백 효능이 존재 함을 보여주며, 피부건강 증진을 위한 신규 기능성 화장품 원료로의 활용 가능성을 제고하였다.
In order to prevent disconnection of the hydraulic pump EDV cable, this study judged the vibration generated by the pump as the greatest effect on disconnection, and confirmed the vibration effect. And it had a structure that was vulnerable to vibration because of the wire flow space inside the EDV cable connector. After applying the improved adapter, vibration analysis, excitation test, and bending strength test were performed to confirm the effectiveness of design change and improvement. As a result of vibration analysis, the amount of vibration was reduced by about 10 times compared to the existing product, and the strength increased by about 4 times in the bending strength test was confirmed to increase the effect of preventing disconnection due to vibration.
In this article, to solve the problems about obsolescence of parts and unable to driving turret when internal components are failure, the DC-DC boost converter in the gun/turret drive system of mobile weapon was improved. The power converting circuit in converter is changed by applying the latest components, and the control circuit is changed from analog to digital. Also, the power converting circuits were modularized in three parallel so that it could be driven even when some components failed. The improved DC-DC boost converter secured stability such as converting to voltage in a linear manner in the entire section from the start of boosting to the end. Also, through the modular configuration, turret driving system can operates when some components failed.
KCEV(Korean Combat Engineer Vehicle) perform the mission of removing mines and various military obstacles buried in the battlefield and opening passageways. It is characterized by modifying the chassis of the K1 series tank and equipping it with an excavator, track-width mine plough, and magnetic signature duplicator. KCEV has a steering wheel, and steering force is transmitted to the transmission steering lever through the steering linkage and acceleration linkage. KCEV can be steered in up to 3 gears, and it was confirmed that there was a risk of interference with the acceleration linkage as a bending occurred in the steering linkage when steering to the right in 3 gears. In this study, we examined the bending of the acceleration linkage and proposed a method to increase the stiffness of the acceleration linkage tube to improve it. Structural analysis was conducted to confirm the effect of increasing rigidity, and the improvement was confirmed by applying it to an actual vehicle. As a result, it was confirmed that not only the bending displacement of the steering linkage was reduced, but also the stress in the bent area was reduced.
In this study, we addressed the prevention of fire extinguishing device malfunction caused by noise in the fire detector of automatic fire extinguishing devices applied to mobile equipment such as armored vehicles and tanks. The automatic fire extinguishing system consists of a fire detection unit, an automatic control unit, and a fire suppression unit. In the case of a fire detector, it is a major component of the fire detection unit. Even though no fire occurred during operation in the field, a number of fire extinguisher sprays occurred, and the malfunction of the fire detector, which is a fire detection unit, was reproduced. The cause was identified as noise in the fire detector connector due to vibration and shock that may occur during operation of the mobility equipment. In order to solve this problem, noise generated momentarily from a fire detector is treated as an exception, and when a fire signal is transmitted from the fire detector to the automatic control unit for more than a certain period of time, Software has been improved to enable fire extinguishers to operate. This study analyzed the causes of malfunctions in automatic fire extinguishing devices, which are components of mobile equipment, and derived improvement measures to improve the reliability of automatic fire extinguishing devices.
This study focuses on optimizing the uniform pressing process in precision manufacturing, addressing challenges posed by surface roughness and height differences between components. In real-world conditions, such irregularities can lead to non-uniform pressure distribution during pressing, negatively affecting product quality. To mitigate these issues, a buffer protection layer was introduced between the press and components. The optimization process was conducted through finite element analysis (FEA) to determine the ideal material properties, including elastic modulus, Poisson's ratio, and thickness of the buffer layer. Two surface roughness scenarios were examined to assess the impact of surface conditions on pressing uniformity. The results indicate that a higher elastic modulus, Poisson’s ratio, and thicker buffer layers are more effective in achieving uniform pressing, particularly under rougher surface conditions. This study provides a practical solution for improving the precision and reliability of pressing processes, ensuring better product consistency and enhancing overall manufacturing efficiency.
In this study used Computational Fluid Dynamic analysis to examine NOx reduction in hydrogen combustion, analyzing six conditions with varying air/fuel ratios, temperatures, and concentrations. Results were compared between two combustor shapes and previous experimental data. Findings showed increased air/fuel ratios decreased flame temperature and increased post-combustion O2. NOx emissions peaked at high temperatures and low O2. Numerical results aligned with previous experimental trends, validating the approach. Combustor shape differences, reflecting variations in fuel and air pipes, significantly affected flow rates and combustion positions. This reduced NOx emissions up to a certain air/fuel ratio, but excessive increases diminished this effect. The study highlights the complex relationship between combustor design, operating conditions, and NOx emissions. Further research is needed to optimize NOx reduction by considering pipe numbers and combustion locations. Future studies should explore various combustor geometries, fine-tune air/fuel ratios, and investigate additional parameters influencing NOx formation and reduction in hydrogen combustion systems.
This paper delves into the standard system for selecting aviation tools. Generally, standards are seen as foundational and fundamental. However, in actual practice, there are often instances where a thorough differentiation of the standard unit system isn't properly executed, resulting in product defects in certain companies. Therefore, through the insights gathered in this study, we aim to reaffirm the basic principles and move forward with the objective of manufacturing products of impeccable quality in accordance with future quality improvement policies. Ultimately, we aspire for K-Defense to emerge as a prominent leader in the global market.
1995년 이후 성평등 전략으로서 모든 분야에 젠더 관점을 고려해야 한다는 성 주류화 전략이 채택되면서 성평등은 국제사회와 각국이 함께 추구해야 할 목표가 되었다. 그리고 실무자들의 역량강화를 위한 성주류 화 가이드라인이 개발되어 왔으나 빠르게 변화하는 국내외적 상황을 고 려하고, 한국의 경험에 기반한 가이드라인 개발이 필요하다. 본 연구에서 는 국제개발협력 실무자를 위한 성주류화 가이드라인개발을 위해 지속가 능발전목표(SDGs)가 채택된 2015년 이후 국제사회와 각국에서 발간한 성주류화 가이드라인을 수집하고, 21개 가이드라인을 분석하였다. 이를 통해 성주류화 가이드라인에 포함되어야 할 요소와 내용, 그리고 방향을 도출하였다. 개발협력의 실무자를 위한 가이드라인에는 성주류화에 관한 개념과 방법에 대한 충분한 이해, 프로그램이나 사업의 단계별 적용에 대한 세부 가이드라인, 그리고 사례분석을 통해 현장의 구체적 상황 이 해가 필수 요소이며, 발간 이후에도 실무자, 전문가, 수여국의 젠더 관점 수용을 위한 지속적 노력이 필요함을 확인하였다.
Wireless sensor systems are primarily used for monitoring natural environments or industrial automation. The physical environment where these systems are installed is often unstable, making it difficult to replenish sensor energy immediately. Complex and harsh conditions can impact the network's structure, affecting monitoring performance. Wireless sensor systems consist of hundreds of sensors that collect data from hazardous environments and transmit information to a central system. However, due to the system's physical structure, information delays or losses may occur. This paper proposes a distance-based tree structure to address these issues in wireless sensor systems, and experimental results confirm its superior performance.
An electric initiator is a component that is located in the thermal battery or propulsion unit to transfer energy first. Initiator tests include X-ray test, non-destructive leak testing, circuit/insulation resistance test, and CBT (Closed Bomb Test). Among them, CBT is a key element in evaluating the performance of initiator, and the reliability of the test results is important for judgment of the required performance. This study conducted inter-laboratory comparative tests to secure the reliability and repeatability & reproducibility of the initiator CBT. A comparative test was conducted with a mass production acceptance test agency to verify whether the reliability was secured.