• 한국신뢰성학회지:신뢰성응용연구
• /
• 제18권1호
• /
• pp.56-65
• /
• 2018

Purpose: The purpose of this study is to estimate shelf life of fuze MTSQ (Mechanical Time & Super Quick) KM577A1 from Ammunition Stockpile Reliability Program (ASRP) data. Methods: For many years, ammunition test data had been gathered from ASRP. In this study, lot selection criteria and reliability score of functioning time for fuze are proposed. Reliability score of functioning time and failure data are used to estimate shelf life. Results: The results of this study are as follows; The failure modes of fuze MTSQ KM577A1 are dud, inverse function and mechanical time functioning failure (not operating in intended time). Dud and inverse function are major failure modes. Fuze MTSQ KM577A1's shelf life ($B_5$) is estimated 18.2 years conservatively. Conclusion: Degradation of chemical components in fuze MTSQ KM577A1 is major factor for its reliability. And shelf life ($B_5$) of fuze MTSQ KM577A1 is estimated 18.2 years conservatively.

• 한국군사과학기술학회지
• /
• 제14권1호
• /
• pp.69-73
• /
• 2011

In the defence wireless communications, conventional Anti-Jamming techniques(Frequency Hopping/Spread Spectrum or Direct Sequence/Spread Spectrum) are used to overcome a intentional interfering signals which are single/multitone or partial band jammer etc. DS/SS techniques is very strong on tone jamming signal but not to be on a partial band jammer. So FH/SS AJ performances are expected method of an substitution of DS/SS, however FH/SS could not have good performance on some BMTJ(Band Multi-tone Jammer). So this paper proposes FH-CSS (Frequency Hopped - Chirp Spread Spectrum) to get more robustness against jammers(BMTJ, PBNJ) and analyze the AJ performances.

• 대한방사선기술학회지:방사선기술과학
• /
• 제22권2호
• /
• pp.47-51
• /
• 1999

We calculated the energy distribution and the percentage depth-dose at 10 cm in a $10{\times}10\;cm^2$ with a photon beam at SSD of 100 cm by using a Monte Carlo Simulation. PDD is used as a beam-quality specifier for radiotherapy beams. It is better than the commonly used values of TPR or nominal accelerating potential. The presence of electron contamination affects the measurement of PDD, but can be removed by the use of a 0.1 cm lead filter. It reduces surface dose from contaminant electrons from the accelerator by more than 90% for radiotherapy beams. The filter performs best when it is placed immediately below the head. An electron-contamination correction factor is introduced to correct for electron contamination from the filter and air. It converts PDD which includes the electron contamination with the filter in place into PDD for the photons in the filtered beam. The correction factor can be used to determine stopping-power ratio. Calculations show that the values of water-to-air slopping power ratio in the unfiltered beam are related to PDD.

• 한국균학회지
• /
• 제20권2호
• /
• pp.149-153
• /
• 1992

균사생장(菌絲生長)이 부진(不進)한 사철느타리버섯 (P. florida), 느타리버섯 (P. ostreatus) 및 이들 두 종(種)의 교배균주(交配菌株)로부터 30nm 및 23nm 의 구형(求刑) virus입자(粒子)를 단일(單一) 혹은 혼합형태(混合形態)로 분리(分離)하였다. 사철 느타리버섯으로부터 분리(分離)한 virus의 최적(最適) spectrum은 259.5nm 였다.

• 한국군사과학기술학회지
• /
• 제13권2호
• /
• pp.336-341
• /
• 2010

The burning interruption between the initiator and the delay column in a Zr-Ni K1 delay system used for a K510 fuze occurs with long-time storage. About 10 % failure probability of 15-years stored delay systems shows the failure mode in open literature. This paper shows storage lifetime improvement results for the delay system through changing the single-base delay column into double-base ones and controlling the manufacturing processes especially the initial inclusion of humidity. The double-base delay columns was implemented by inserting one delay column of fast burning rates between the initiator and the previous delay column of slow burning rates. Accelerated aging tests of the delay systems with double-base columns, and then the firing tests were performed to evaluate the improved lifetime. The double-base delay columns shows improved storage lifetime of the delay system through preventing the failure mode.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 춘계 학술발표회 논문집
• /
• pp.1455-1460
• /
• 2005

This paper presents the results of an experimental study on the ground deformation by trench excavation for Diaphragm Wall construction. The model tests are performed to investigate the back ground deformation by lowering of slurry level in trench after excavating. Through these, the deformation characteristic of the back ground due to stress release of excavated space was investigated. This study considered relative density of soil mass and the distance between trench and surcharge. An experiment was performed in order to observe the failure pattern of a slurry-supported trench excavated in sandy ground. From model tests, in order to predict reasonably the deformation behavior of the adjacent ground due to the underground excavation, it is significantly recommended that the ground settlement by trench excavation should be considered.

• 한국통신학회논문지
• /
• 제24권6A호
• /
• pp.864-870
• /
• 1999

상용위성통신의 경우 일반 광역 통신지원은 가능하지만 전시/유사시의 생존성과 보안성을 요하는 환경에서는 사용이 크게 제한되는 단점이 있다. 따라서, 본 논문은 군 위성시스템에 적용 가능한 세 가지 형태의 중계시스템을 제안하고 분석했으며, 상향링크 방해시의 지원 가능한 데이터율을 기준으로 성능을 분석/비교하여 군 운용환경에 따른 위성자원의 이용효율을 높이는 방안을 모색하였다. 이를 이해 중계기와 함정용 단말의 설계변수를 설정하여 적용하였으며, 또한, 각 대역별(UHF/SHF/EHF) 항방해 성능비교를 통하여 운용환경에 따른 생존성의 정도를 파악하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
• /
• pp.65-67
• /
• 2001

PLC (Power Line Communication) is the communication method using the existing power line installed in houses and offices to convert and transmit high frequency communication signal from tens of KHz to tens of MHz, and receive the filtered signal using high frequency filter. The advantage of PLC is that PLC uses the existing power line installed in houses and offices so it does not require separate power line. Easy and convenient access using electric outlets is another advantage of PLC. However, PLC has some disadvantages such as limited transmission power, high load interference and noise, variable signal attenuation, characteristic of impedance selective possibility of frequency property. This study designed the boiler temperature control system by unit using the modem designed on the basis of technology used for PLC modem, and designed remote control system using internet. After conducting experiments with those two systems, it was possible to control stably. By commercializing this product, we can avoid unnecessary heating of separate temperature control unit, and save the cost according1y, and it is possible to control on a remote site using internet in a more convenient way.

• 한국화재소방학회:학술대회논문집
• /
• 한국화재소방학회 2005년도 공동추계학술논문발표회 논문집
• /
• pp.81-85
• /
• 2005

Recently, fire resistance of high performance concrete for explosive spalling was issued as high performance concrete was vulnerable to the explosive spalling in initial fire. Therefore, in this study, an experiment about reduction effect to explosive spalling of high performance concrete is performed by adding several polymer fiber with various volume fraction, an then final fiber and volume fraction of that which reduce the explosive spalling of high performance concrete is presented. As the result of this study, the most fitted fiber volume fraction of reducing effect for explosive spalling at high performance concrete is under the 0.1%, as consider the flowability and efficiency.

• 농업과학연구
• /
• 제17권2호
• /
• pp.77-81
• /
• 1990

Chitin 합성 저해제인 buprofezin이 P. ostreatus 및 P. sajor-caju 균사의 생장과 원형질체 나출 및 재생에 미치는 영향을 조사한 바를 요약하면 buprofezin은 P. ostreatus 및 P. sajor-caju.의 균사생장을 심히 저해하였고 buprofezin의 첨가농도가 높을수록 균사생장 억제가 심하였다. Buprofezin 처리에 의하여 기균사가 증가하였으나 균사의 형태에는 변화가 없었다. 원형질체의 나출량은 buprofezin 200-500 ppm 첨가구의 균사에서 무처리보다 현저히 높은 결과를 보였고, 원형질체의 재생율은 buprofezin의 처리에 의하여 증가하였다.