• 제목/요약/키워드: Combat 21

검색결과 124건 처리시간 0.024초

고압 밀폐 가스 스프링에서의 열전달 효과 수치해석 및 실험적 검증 (The Numerical Analysis and Experimental Verification of the Heat Transfer Effect on the Highly Pressurized Gas Spring)

  • 한인식;최교준;김재용;이윤복
    • 한국자동차공학회논문집
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    • 제21권2호
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    • pp.87-97
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    • 2013
  • Recently the use of gas spring in the combat and commercial vehicle's suspension is increasing. Because of its nonlinear characteristics, the gas spring can support wide range of dynamic loads and gives good ride quality. In design of gas spring, isothermal and adiabatic processes are applied generally, but those processes could not produce heat transfer effect in the simulation. So in this study, heat transfer differential equation and BWR/Ideal state equation are used to calculate the pressure of gas spring which is changing with time. The numerical analysis showed that the pressure of gas spring forms a hysteresis loop in the both of the state equations. But the peak pressure value of BWR equation over 0.1Hz frequency are higher than that of adiabatic process. And the test results showed that the differences between test results and ideal gas equation are smaller than those of BWR equation, so the ideal equation is more accurate than BWR equation in this case.

Information Security and Its Aapplications on the Portal of the Deanship of Library Affairs at Northern Border University

  • Al Eawy, Yaser Mohammad Mohammad
    • International Journal of Computer Science & Network Security
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    • 제21권12호
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    • pp.183-188
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    • 2021
  • The study aimed to assess the state of electronic security for the website of the Deanship of Library Affairs at Northern Border University, as one of the university's electronic portals, which provides distinguished knowledge services to faculty members, through the Saudi Digital Library, and the integrated automated system for libraries (Symphony) with the definition of cyber security of the university, and the most important threats The study sought to analyze the opinions of a wide sample of faculty members, towards evaluating the state of electronic security for the Deanship of Library Affairs portal, through the use of both the analytical method, as well as the survey, using the questionnaire tool, and the study sample consisted of 95 A faculty member of all academic categories and degrees, and university faculties, and the study concluded that it is necessary to work to overcome the relative slowness of the university's Internet, with the faculty members notifying the information security services through e-mail and SMS service, with the continuous updating of operating systems, Apply and use the latest anti-spyware, hacking, and antivirus software at the university, while conducting extensive research studies towards information security services, and contracting It aims to introduce information security risks, and ways to combat and overcome them, and spread the culture of information security among faculty members.

무장데이터링크의 효과적인 운용을 위한 고려사항 고찰 (Research of Considerations for Effective Operation of Weapons Data Link)

  • 우상효;백인혜;권기정;김기범
    • 한국군사과학기술학회지
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    • 제21권6호
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    • pp.886-893
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    • 2018
  • U.S. and the allies attacked chemical weapons sites in Syria in 2018, and verbal battles are carried out about the effectiveness of the air strike. Syria claimed 13 missiles were shot down, and Russia claimed 71 missiles were shot down while the U.S. released pictures of completely destroyed targets, only. It led controversy about the effectiveness of missile defense system. If there is a method to observe mission success rate of the air strike, it can not only improve combat awareness but also can be a good sales strategy in military industry. This paper describes effects and considerations of a Weapon Data Link(WDL) technology which can be used as a smoking gun of effectiveness. The paper describes WDL abilities such as In-Flight Track Update, Loiter, and Bomb Hit Indication etc., and presents examples of expected effectiveness of the WDL. In addition, this paper briefly summarizes operational consideration for better performance.

The extent of the role of internal control of Northern Borders University in maintaining the non-waste of public money

  • Oweis, Khaled Adnan
    • International Journal of Computer Science & Network Security
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    • 제21권6호
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    • pp.187-199
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    • 2021
  • The research aims to measure the control procedures' effectiveness, followed by the University of Northern Borders employees. A questionnaire was developed and distributed to the target sample of financial and auditing affairs employees at the university, where the researcher followed the existing descriptive-analytical approach. The researcher relied on the field survey, and statistical analysis (spss) was used. The researcher has found that the control procedures used are highly efficient in reducing public money waste. The researcher has presented recommendations that may contribute to developing the work of oversight in combating waste of public money. These recommendations include: Increase the interaction between the General Oversight Office and the internal oversight departments at the University of Northern Borders, the incentives provided to the oversight and accounting staff for their efforts to combat public money waste. It encourages them to maintain public money and work to obliging employees to undertake training courses periodically to develop their skills and rehabilitate them in line with modern control procedures. Also, more studies and scientific research on the waste of public money and types of administrative and financial Corruption and the law in all state sectors and reach conclusions and recommendations will help decision-makers amend laws and regulations to serve the public benefit of the university and the state.

Periplanetasin-2 Enhances the Antibacterial Properties of Vancomycin or Chloramphenicol in Escherichia coli

  • Lee, Heejeong;Hwang, Jae Sam;Lee, Dong Gun
    • Journal of Microbiology and Biotechnology
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    • 제31권2호
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    • pp.189-196
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    • 2021
  • Periplanetasin-2 from cockroach exhibits broad-spectrum antimicrobial activity. The underlying antibacterial mechanisms rely on the stimulation of reactive oxygen species overproduction to induce apoptotic cell death. A promising strategy to increase the bioavailability of periplanetasin-2 involves reducing the dose through combination therapy with other antibacterials that show synergistic effects. Thus, the synergistic antibacterial activity of periplanetasin-2 with conventional antibacterial agents and its mechanisms was examined against Escherichia coli in this study. Among the agents tested, the combinations of periplanetasin-2 with vancomycin and chloramphenicol exhibited synergistic effects. Periplanetasin-2 in combination with vancomycin and chloramphenicol demonstrated antibacterial activity through the intracellular oxidative stress response. The combination with vancomycin resulted in the enhancement of bacterial apoptosis-like death, whereas the combination with chloramphenicol enhanced oxidative stress damage. These synergistic interactions of periplanetasin-2 can help broaden the spectrum of conventional antibiotics. The combination of antimicrobial peptides and conventional antibiotics is proposed as a novel perspective on treatments to combat severe bacterial infection.

게임 플레이어 모델을 위한 속성 추출과 모델 활용 사례 (Case study of property extraction and utilization model for the game player models)

  • 윤태복;양성일
    • 한국게임학회 논문지
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    • 제21권6호
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    • pp.87-96
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    • 2021
  • 산업의 발전에 따라 게임에 활용되는 기술도 고도화 되고 있다. 특히, 인공지능 기술은 게임로그를 수집하고 분석하여 패턴을 추출하고 게임의 자동화와 지능화를 위하여 활용되고 있다. 이러한 게임 플레이어의 패턴은 온라인 게임에서 플레이어 매칭, 적대적 NPC의 생성, 게임 월드의 밸런싱 등 적용 범위가 넓다. 본 연구에서는 게임 플레이어의 모델 생성 방법을 제안한다. 모델 생성을 위하여 사냥, 수집, 이동, 전투, 위기관리, 제작, 상호작용 등의 속성을 정의하였으며 의사결정나무 방법을 이용하여 패턴을 추출하고 모델링 하였다. 제안하는 방법의 검증을 위하여 상용 게임의 게임 로그를 이용하여 모델링하고 에러율을 확인하였으며 유효한 결과를 확인하였다.

Comparative Analysis of Grip Strength between Military Personnel and Civilian Adults

  • Hyo-Taek Lee
    • 대한물리의학회지
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    • 제19권3호
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    • pp.21-27
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    • 2024
  • PURPOSE: This study compared the grip strength of young adult male soldiers who had undergone military training with civilian adult males by indirectly examining the impact of military training on the grip strength and overall muscle mass. Grip strength, an essential biomarker for overall health and crucial combat abilities, was explored within the demanding conditions of military service. METHODS: The research measured the grip strength of soldiers actively serving in the military and compared it with data from healthy civilian males in their twenties to determine if a structured training regime significantly enhances grip strength more than a typical civilian lifestyle. The data were analyzed using descriptive statistics with the means and group differences assessed using a t-test (p < .05). An online survey was conducted among the military group to self-assess the changes in grip strength before and after enlistment to gauge the awareness of such changes. RESULTS: Significant differences were observed between the groups, with an observable increase in grip strength with age within the military group, suggesting that military training can positively impact muscle maintenance and enhance daily life. CONCLUSION: Further research will be needed to elucidate the effects of military physical training programs and their broader implications for military readiness and overall health.

전투기 J85-GE-21 터보제트 엔진 후기 연소기 연료펌프의 내부 피스톤 패킹 연료 누출 원인 (Cause of Fuel Leakage from the Inner Piston Packing of Afterburner Fuel Pump in an Aircraft J85-GE-21 Turbojet Engine)

  • 김익식;황영하;손경숙;이중훈;김성욱
    • Elastomers and Composites
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    • 제49권4호
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    • pp.305-312
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    • 2014
  • 대부분 군사용 초음속 전투기는 후기 연소기를 사용한다. 후기 연소기는 초음속 비행, 이륙, 전투 상황에 대해 비상 임무 수행을 가능하게 하는 중요한 역할을 한다. 최근 전투기 J85-GE-21 터보제트 엔진 후기 연소기 연료펌프의 내부 피스톤 패킹고무에서 반복적인 연료 누출 결함이 발생하였다. 이러한 결함은 두 제조사 중 한 제조사의 부품에서만 발생하였다. 따라서, 결함발생 원인을 제조사가 상이한 정상품 및 결함품에 대하여 다양한 비교 분석방법을 통하여 조사하였다. 결함분석에는 팽윤 또는 팽윤도, 총 황함량, 폴리머 확인, 카본블랙 함량 및 표면적, 경도와 같은 분석방법이 적용되었다. 결론적으로, 반복적인 연료 누출 결함의 주요 원인은 보강제 카본블랙의 함량 미달로 확인되었으며, 더불어 표면적이 작은 카본블랙과 함량이 낮은 황 적용이 결함원인에 부가적인 영향을 준 것으로 확인되었다.

미래병사체계를 위한 휴대형 연료전지 기술개발 동향 및 발전방안 (R&D Trends and Technology Development Plan on Portable Fuel Cell for Future Soldier System)

  • 이유화
    • 한국산학기술학회논문지
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    • 제21권6호
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    • pp.618-624
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    • 2020
  • 병사용 휴대형 전원은 전투원의 작전 수행 능력을 해치지 않는 범위의 휴대 하중을 지님과 동시에 전투장비의 소비전력에 대응하는 전기에너지를 공급할 수 있어야 한다. 특히 미래병사체계의 경우 전투장비의 고성능화에 따라 장비의 총 요구전력이 증가하고 있으므로 경량 고효율 특성을 가지는 휴대형 전원 개발이 필수적이다. 연료전지는 군용 전원으로 주로 적용되던 종래의 리튬 전지에 비해 중량 대비 에너지밀도가 높아 경량 소형화가 가능하여 휴대형 전원 시스템으로 활발한 연구개발이 진행되고 있다. 본 논문에서는 휴대형 전원으로 적용되는 연료전지의 특성을 살펴보고, 국내·외 군용 휴대형 연료전지 개발 현황을 조사한 후, 국외 선진 기술국의 개발 수준 대비 국내 기술 현황에 대해 분석한다. 또한, 미래병사체계용 전원으로의 적용을 위한 휴대형 연료전지 개발 시 고려해야할 주요 요소를 전력 공급 안정성, 휴대 용이성, 비용 절감 세 가지로 분류하고, 이와 관련된 기술을 중심으로 발전방안을 제시하여 향후 연료전지 기반 개인병사 체계용 휴대형 전원 기술 발전방안 수립 시 활용할 수 있도록 한다.

전투차량용 전기식 연료펌프의 고장분석 및 내열성능 평가 (Failure Analysis and Heat-resistant Evaluation of Electric Fuel Pump for Combat Vehicle)

  • 곽대환
    • 한국산학기술학회논문지
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    • 제21권11호
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    • pp.634-640
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    • 2020
  • 전투차량의 연료탱크에 설치되어 엔진으로 연료를 이송하는 장치인 전기식 연료펌프에 대하여 고장분석과 내열성능 평가가 수행되었다. 고장의 원인을 파악하기 위하여 직류 전동기가 적용된 연료펌프를 분해하여 검사를 수행하였다. 하우징 내부를 관찰한 결과를 바탕으로 고장 현상을 권선 소손, 브러시 조기 마모, 연료 혼입의 세 가지로 분류하였다. 연료펌프 내부 검사를 실시한 결과를 바탕으로, 과열에 의한 권선 소손을 고장을 발생시킨 주된 원인으로 추정하였다. 이에 따라서 전기식 연료펌프의 권선이 과열로 소손될 가능성을 확인하기 위하여 온도 센서를 고정자 표면과 브러시 홀더에 설치한 후 무부하 조건으로 24시간동안 가동을 실시하였다. 연료펌프의 주변 온도를 68 ℃로 설정하였을 때 고정자 온도는 최대 135.9 ℃까지 상승하였으며, 전동기의 고정자 및 회전자 권선이 소손되었다. 이 결과를 통해서 전기식 연료펌프를 위한 전동기 권선의 내열성능이 부족함을 확인할 수 있었으며, 이를 해결하기 위하여 현재 155 ℃ 이하에서 사용할 수 있는 절연등급 F종의 권선 및 함침액을 180 ℃ 이상에서도 사용할 수 있는 C종 이상의 절연등급으로 대체하도록 제안하였다.