• Journal of the Korean Institute of Navigation
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• v.6 no.1
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• pp.41-59
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• 1982

In the Sailing Rules of International Regulation for Preventing Collisions at Sea, 1972, any definite distance between two vessels approaching each other is not referred for adequate maneuvering to avoid collision. At sea the officer in charge of bridge duty is required to guess safe distance before he takes maneuvering actions needed to avoid collision. Papers on safe distances calculated on the base of the motiional characteristics of ships for collision avoiding actions are very few. In this paper, the minimum safe approaching distances necessary for actions to be taken to avoid collision are calculated in numerical numbers definitely by mathematic formula based on the maneuvering indices got from experiments of actual ships. On the assumption that two vessels same in size and conditions are approaching each other, the author calculated the minimum safe approaching distance as 4.5 times, sufficient safe approaching one as 9.0 times the length of the ship involved in head-on situation and 5.0 times, 10 times respectively the length of the ship in each case mentioned above in crossing situation.

• Wind and Structures
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• v.19 no.1
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• pp.35-58
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• 2014

A numerical simultaneous solution involving a linear elastic model was applied to study the fluid-structure interaction (FSI) of membrane structures under wind actions, i.e., formulating the fluid-structure system with a single equation system and solving it simultaneously. The linear elastic model was applied to managing the data transfer at the fluid and structure interface. The monolithic equation of the FSI system was formulated by means of variational forms of equations for the fluid, structure and linear elastic model, and was solved by the Newton-Raphson method. Computation procedures of the proposed simultaneous solution are presented. It was applied to computation of flow around an elastic cylinder and a typical FSI problem to verify the validity and accuracy of the method. Then fluid-structure interaction analyses of a saddle membrane structure under wind actions for three typical cases were performed with the method. Wind pressure, wind-induced responses, displacement power spectra, aerodynamic damping and added mass of the membrane structure were computed and analyzed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.31
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• pp.177-186
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• 1994

Most causes of accidents are due to physical unsafety conditions and human unsafety actions. The design of safety work by ergonomics method is one of the methodes which effectively reduce these unsafety conditions and unsafety actions. This paper presents considerations in design of safety work. And when we try to analyze the accident event by means of probability, there exist some problems because of fuzziness in physical unsafety conditions' components and human unsafety actions' components which are the causes of basic event. For this reason, it is impossible for input probability of basic event to define a crisp value. In consideration of the uncertain probability of components, this paper deals with the Fuzzy set theory by membership value and suggests calculation procedure and analysis of disaster event.

• Journal of the Korean Society of Safety
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• v.13 no.1
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• pp.112-118
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• 1998

Human errors performed during the operations have a dominant portion of the accidents. But the systematic human error evaluation methodology universally accepted is not developed yet. One of the difficulties in performing human reliability analysis is to evaluate the performance shaping factors which represent the characteristics and the circumstances in the discriminate manner. For assessing a specific human action more exactly, it is necessary to consider all of the PSFs at the same time which make an effect on the human action. In this paper, dynamic influence diagrams are introduced to model simultaneously their effects on the specific human action. And the human actions and their subsequent PSFs are categorized and classified as the complementary works. A new human error evaluation methodology using influence diagrams is developed. This methodology involves the categorization of PSFs and the PSFs quantification. The applied analysis results for the example task are shown for representative purposes. It is shown that this approach is very flexible in that it can be applied to any kind of actions.

• Korean Journal of Microbiology
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• v.5 no.1
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• pp.7-14
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• 1967

The synergistic actions of certain antimetabolic agents for Saccharomyces cerevisiae and Lactobacillus plantarum on radiation sterilization have been studied. The used chemical agents are sorbic acid, vitamin-$K_3$, dehydroacetic acid, p-oxybutyl benzoate and nitrofurazone, those are the permitted as food preservatives. Experimental results are as following, 1) Survival fraction of yeast which was gamma-irradiated and influenced by sorbic acid or vitamin $K_3$ is much reduced than that of only irradiated respectively. 2) It seems like that the used chemicals acts synergistically on radiation sterilization. Sodium-dehydroacetate and p-oxybutyl benzoate are proved to be also synergistic but weakly. 3) Survival fraction of Lact. plantarum which was gamma-irradiated and influenced by sorbic acid, dehydroacetic acid or nitrofurazone respectively much reduced than that of only irradiated group, it can be estimated as synergistic action of chemical affected on radiation sterilization. 4) It was found that nutrient componets can affect radiation sterilization of microorganisms protectively.

• Korean Journal of Pharmacognosy
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• v.16 no.2
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• pp.65-72
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• 1985

These studies were conducted to investigate the effect of 'Inchungbaek' water extract on analgesic and sedative actions, the relaxing action of isolated ileums, vasodilating action and blood pressure. The results of these studies were summarized as follows: Analgesic and sedative actions of 'Inchungbaek' were recognized in mice and rats. The relaxing action of isolated ileums were seen in mice and rabbits, antagonist action was seen acetylcholine and $BaCl_2-induced$ contraction of isolated ileums, and then recognized direct action in the ileum smooth muscle. Hypotensive and vasodilating actions due to vascular smooth muscle relaxation were noted in rabbits and cats.

• Journal of Pharmaceutical Investigation
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• v.6 no.3
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• pp.70-76
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• 1976

Pharmacological studies on the water extracts of Sambbcus latipnna var. coreana have confirmed that there are: 1) Remarkable sedative actions in preteated mice with C.N.B (caffeine and sodium benzoate) by the administration of intraperitoneal injection. 2) Antihypertensive actions in rabbits intraperitoneally injected with the extract, and as antihypertensive components, rutin, and crystal A (m.p. $250{\sim}254^{\circ}$, Liberman-Buchard's reaction, positive) were isolated from Sambucus latipinna var. coreana. 3) Marked diuretic actions in mice intramuscular injection with the dose of 600mg/kg.

• Journal of Korean Elementary Science Education
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• v.24 no.5
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• pp.602-611
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• 2005

The 'Mobile Science Lab' is a public program designed to bring teenagers to be engaged in the activities of science and technology. In this study, we attended to elementary school students' participating actions in the program and intended to understand their enjoyment of science from sociocultural and practical perspectives. By drawing on case materials culled from our database, we articulated the features of the enjoyable science activities in the form of two major claims. First, students had rich opportunities to communicate emotionality, which therefore grounds emerging actions on the positive emotional valence. Second, ongoing actions opened up new action possibilities not only to the actors themselves, but also to other community members. The results of this study constitute theoretical frameworks for understanding enjoyment without dichotomizing emotion and cognition, and thereby contribute to designing enjoyable activities of learning science.

• The Korean Journal of Pharmacology
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• v.11 no.1 s.17
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• pp.61-79
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• 1975

The recent knowledge about the effects and the biological roles of prostaglandins(PGs) in the female reproductive system were reviewed on the following view points in detail and the authors also argued on the efficacy and reliability for the induction of labour and therapeutic abortions in midtrimester pregnancy. 1. The actions of PGs on the myometrium in vivo and in vitro and the effects of ovarian hormones on the actions of PGs. 2. The actions of PGs on the fallopian tube. 3. The role of PGs in the initiation of menstrual bleeding and dysmenorrhea. 4. The biological action of PGs on the mechanism of labour and parturition. 5. The efficacy and reliability of PGs for therapeutic abortion in the first and midtrimester pregnancy. 6. The biological role of PGs in the activity and life-span of corpus luteum.

• YAKHAK HOEJI
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• v.20 no.1
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• pp.97-106
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• 1976

The actions of Atractylodes rhizoma alba on renal function of dog were investigated with water and methanol extract of it, utilizing clearance technique. Water extract elicited diuresis while methanol extract induced antidiuresis in the dog when they were given intravenously. The diuresis induced by the intravenous water extract seemed to be closely related to the decrement of reabsorption of electrolytes in renal tubules. On the contrary, the antidiuresis by intravenous methanol extract appeared to be related to the increment of renal reabsorption of sodium. Water and methanol extract, when infused into a renal artery, exhibited identical resposes to the intravenous actions confined only to the infused kidney, inferring that renal actions of water and methanol extract are not mediated by any endognous humoral extract are not mediated by any endogenous humoral agents. From these observations it is concluded that diuretic action of water extract and antidiuretic action of methanol extract were brought about by direct action in the renal tubules.