• 대한핵의학회지
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• 제26권1호
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• pp.8-13
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• 1992

Low doses of ionizing radiation from external or internal sources cause heterogeneous distribution of energy deposition events in the exposed biological system. With the cell being the individual element of the tissue system, the fraction of cells hit, the dose received by the hit, and the biological response of the cell to the dose received eventually determine the effect in tissue. The hit cell may experience detriment, such as change in its DNA leading to a malignant transformation, or it may derive benefit in terms of an adaptive response such as a temporary improvement of DNA repair or temporary prevention of effects from intracellular radicals through enhanced radical detoxification. These responses are protective also to toxic substances that are generated during normal metabolism. Within a multicellular system, the probability of detriment must be weighed against the probability of benefit through adaptive responses with protection against various toxic agents including those produced by normal metabolism. Because irradiation can principally induce both, detriment and adaptive responses, one type of affected cells may not be simply summed up at the expense of cells with other types of effects, in assessing risk to tissue. An inventory of various types of effects in the blood forming system of mammals, even with large ranges of uncertainty, uncovers the possibility of benefit to the system from exposure to low doses of low LET radiation. This experimental approach may complement epidemiological data on individuals exposed to low doses of ionizing radiation and may lead to a more rational appraisal of risk.

• Industrial Engineering and Management Systems
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• 제4권2호
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• pp.176-183
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• 2005

The theory of signal detection has been applied to a wide range of practical situation for a long time, including sonar detection, air traffic control and so on. In general, in this theory, sensitivity parametric index d' and bias parametric index $\beta$ are used to evaluated the performance of vigilance. These indices use observer's response "hit" and "false alarm" to explain and evaluate vigilance, but not considering reaction time. However, the reaction time of detecting should be considered in measuring vigilance in some supervisory tasks such as unlimited monitoring tasks (e.g., supervisors in nuclear plant). There are some researchers have used the segments of reaction time to generate a pair of probabilities of hit and false alarm probabilities and plot the receiver operating characteristic curve. The purpose of this study was to develop a quantitative vigilance-measuring model by fuzzy sets, which combined the concepts of hit, false alarm and reaction time. The model extends two-values logic to multi-values logic by membership functions of fuzzy sets. A simulated experiment of monitoring task in nuclear plant was carried out. Results indicated that the new vigilance-measuring model is more efficient than traditional indices; the characteristics of vigilance would be realized more clearly in unlimited monitoring task.

• 대한수학회논문집
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• 제35권2호
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• pp.371-399
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• 2020

Let P_s := 𝔽₂[x₁, x₂, …, x_s] = ⊕_n⩾0(P_s)_n be the polynomial algebra viewed as a graded left module over the mod 2 Steenrod algebra, ${\mathfrak{A}}$. The grading is by the degree of the homogeneous terms (P_s)_n of degree n in the variables x₁, x₂, …, x_s of grading 1. We are interested in the hit problem, set up by F. P. Peterson, of finding a minimal system of generators for ${\mathfrak{A}}$-module P_s. Equivalently, we want to find a basis for the 𝔽₂-graded vector space ${\mathbb{F}}_2{\otimes}_{\mathfrak{A}}$ P_s. In this paper, we study the hit problem in the case s = 5 and the degree n = 5(2^t - 1) + 6 · 2^t with t an arbitrary positive integer.

• 한국군사과학기술학회지
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• 제9권3호
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• pp.12-19
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• 2006

A gun barrel of infantry fighting vehicle is supported like a type of cantilever. Temperature of a gun barrel is increased by heat transfer due to the combustion of propellant charge during the firing. Thus, the muzzle of a gun barrel is deflected in accordance with its temperature and the accuracy rate is decreased by deflection of the muzzle. In this study, deflection of a gun barrel is estimated by measuring its restoration rate because measuring the deflection rate is difficult due to the vibration of the gun barrel during the firing. In order to obtain the relations between deflection rate and restoration rate of the 40mm gun barrel of Next Infantry Fighting Vehicle(NIFV) under varying temperature, measurement of deflection rate and restoration rate is carried out using 5.56mm Remington rifle barrel. Effect of the estimated deflection rate of a gun barrel of NIFV on the hit probability is also analyzed.

• 물과 미래
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• 제16권4호
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• pp.253-257
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• 1983

In an attempt to study the frequency and characteristics of typhoons which hit the Korean Peninsula a period of 40 years from 1946 through 1979 was covered to collect necessary data with respect to occurrence of typhoons and their influence Typhoons which occurred between 1959 and 1980 were grouped according to their treking routes and strengths for detailed analyses. The results are summarized as follow; 1. The average annual occurrence of typhoons in the western pacific ocean was found to be 28, only two of which attacked the Korean Peninsula. 2. The annual probabilities of typhoons attacking were 0.925 for one or more, 0.700 for twice or more and 0.323 for there times or moro. 3. The monthly probabilities were found to be 0.228 in July, 0.434 in August and 0.194 in September. 4. An half of the typhoons which hit the Korean Pennisula passed through the western coast and the rest through the southern and eastern coasts in similan proportions. 5. The western coast is hit most frequently in July and less afterwords, visa-vis the southern and the eastern coast. 6. The minimum SLP averaged 983 mb and ordered by the treking routes as S

• 비파괴검사학회지
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• 제31권1호
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• pp.53-61
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• 2011

본 연구는 편측 노치가 삽입된 A16061-T6 알루미늄 합금 평판 시편에 대해 유리섬유강화플라스틱(GFRP) 복합재 패치의 적층수를 변수로 하여 보수히고, 인장 하중에 따른 시편의 손상 과정을 음향방출법(acoustic emission, AE)으로 실시간 분석하였다. AE 에너지 발생률(AE energy rate), hit 발생률(hit rate), AE 진폭(AE amplitude) 거통과 파형 및 1차 중심주파수(1st peak frequency)의 대역을 조사하여, 시편 파괴시 알루미늄 크랙(Al cracking), 섬유 파단(fiber breakage), 수지 균열(resin cracking), 층간 분리(delamination)로 분류하였다. 시편의 변위를 음향방출 특성에 따라 구간(region) I, II, III으로 나눌 수 있었으며, 패치 자체가 실제 파괴되는 구간인 구간 II를 세부적으로 분석하여 패치의 적층수에 따른 AE 특성 차이를 구하였다.

• 약학회지
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• 제41권2호
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• pp.260-267
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• 1997

To establish prediabetes in vitro model concerning the etiology of IDDM(Insulin Dependent Diabetes Mellitus) in cellular level we have designed prediabetes in vitro models in pa ncreatic beta cells. HIT-T15, RINm5F and isolated rat islets were chosen as pancreatic beta cells, and streptozotocin (STZ) used as diabetogenic agent. Degree of beta cell destruction to establish prediabetic in vitro model was determined by cell proliferation and insulin release using thymidine uptake and radio immuno assay. When HIT-T15 and RINm5F cells were treated with STZ, the degree of cell deterioration was dependent upon the origin and passage number of beta cells, and in the case of isolated islets STZ showed the more sensitivity than above two beta cell lines. The concentration and exposure time of STZ treatment to establish prediabetes in vitro model in beta cell lines and isolated rat islets were 2 ~ 10mM, 30 min. and 1 ~ 5mM, 30 min., respectively.

• 척추신경추나의학회지
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• 제10권1호
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• pp.97-106
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• 2015

Objectives: The Purpose of this study is to report three cases on tension-type headache treated by Chuna manipulative therapy. Methods: Three patients diagnosed tension-type headache were treated with Chuna manipulative therapy only. To evaluate effect of treatment, visual analogue scale(VAS) and headache impact test(HIT) were used. We checked VAS and HIT score three times(pretreatment, post-treatment, follow-up). An interval among each evaluation time is 4 weeks. Results: At post-treatment evaluation, VAS and HIT score declined significantly compared with pre-treatment. At follow-up evaluation, the pain did not increased. Conclusions: These results suggests that Chuna manipulative therapy may be effective for tension-type headache.

• 한국시뮬레이션학회논문지
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• 제17권4호
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• pp.143-152
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• 2008

미래전에 있어서, 전투 초기단계의 대화력전 능력은 적을 무력화 시키는데 핵심역할을 수행한다. 본 논문에서는 효율적인 대화력전 수행방안을 제안하였다. 이를 위해, CEP를 사용한 명중확률을 산출한 후 대화력전 작전시 활용 가능한 새로운 사격제원 계산에 적용하였다. 새로운 표적제원의 타당성 검증을 위해 MANA 모델을 사용하여 시뮬레이션을 수행하였다. UAV 운용여부 등을 포함한 다양한 시나리오 상황 하에서 시뮬레이션 수행 결과, 새로운 사격제원산출 방법을 사용한 명중률이 기존의 BTCS 사격제원에 의한 명중률 보다 우수한 것으로 나타났다.

• 한국군사과학기술학회지
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• 제19권2호
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• pp.218-226
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• 2016

In the original design of K2 tank the Vertical Sensor Unit(VSU) was mounted to measure the attitude of the main gun to enhance the hit probability. In this research, as a part of efforts to reduce the cost of K2, it was theoretically simulated and evaluated to use the data from Inertial Navigation System(INS) for the calculation of the gun attitude instead of the direct measurement using VSU. It was found that the negative effect of INS approach is negligible and the elimination of VSU is technically possible and beneficial to the system.