• The Korean Journal of Nuclear Medicine
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• v.26 no.1
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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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• v.4 no.2
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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.

• Communications of the Korean Mathematical Society
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• v.35 no.2
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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.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.3
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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.

• Water for future
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• v.16 no.4
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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

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.1
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• pp.53-61
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• 2011

Edge notched A16061-T6 aluminum was repaired with a GFRP composite patch as a function of the number of stacking, Damage progress of specimen for tension load has been monitored by acoustic emission(AE), AE energy rate, hit rate, amplitude, waveform and 1st peak frequency distribution were analyzed. Fracture processes were classified into Al cracking, Fiber breakage, Resin cracking and Delamination. Displacement of a specimen can be divided into Region I, II and ill according to acoustic emission characteristics. Region II where the patch itself was actually fractured was focused on to clarify the AE characteristics difference for the number of stacking.

• YAKHAK HOEJI
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• v.41 no.2
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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.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.10 no.1
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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.

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.143-152
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• 2008

At an initial battle stage, counter-fire capability have critical impact on defeating the enemy in the future warfare. In this paper, we proposed an efficient method of counter-fire execution. To do that, hit-probability for each artillery type was evaluated using CEP and applied to calculate new target reference table of a counter-fire operation. In order to compare new result to the one obtained by using previous reference table from BTCS, we did simulation using MANA model. Simulation outputs show that new method is superior to previous method of counter-fire operation in various scenarios depending upon each method and usage of UAV.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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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.