• Journal of Life Science
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• v.11 no.4
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• pp.346-353
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• 2001

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) a prototype of the highly toxid halogenated arylhydrocarbons, bioaccumulates in the food chain and induces a complex spectrum of pathological responses. However, its effect on the nerve system is relatively not well studied. In this study we evaluated TCDDs cytotoxicity on the cortical cell and investigated its effect on the expression 2,3-cyclic nucleotide 3-phosphodiesterase(CNPase), a marker for oilgodendrocytes, The survival rates of 4 DIV cortical cells, that are dissociated from E18 rat cortex and maintained in the presence of TCDD, were 88.8, 83.6, 78.5, and 78.6%(5,10, 20 and 50 nM, respectively) where the reduction in 20 and 50mM TCDD were statistically very significant(p<0.01). Imunocytochemistry of cultured cells revealed that the intensities of immunostaining with an anti-CNP1&2 antibody depended on the concentrations of the toxin. Immunoblot analysis also showed differential expression of CNP1 and CNP2 in the presence of TCDD; the CNP1 expression was dose-dependently decreased. Interestingly, the expression of CNP2 in the presence if TDCC; the CNP1 expression was dose-dependently decreased. Interestingly, the expression of CNP2 fluctuated with the TCDD concentration. These results indicated that CNP1 and 2 are differentially regulated by TCDD, implying the functions of oligodendrocytes are modulated by the toxin.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.209-223
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• 1998

The aim of this study was to evaluate welders' exposure to hexavalent chromium (Cr(VI)) and nickel (Ni) during welding operations in a Korean shipyard. The airborne Cr(VI) and Ni concentrations were measured during metal inert gas (MIG) welding on mild and stainless steel, and manual metal arc (MMA) welding on mild steel. The geometric mean (GM) of Cr(VI) concentrations inside the welding helmet during MIG welding on mild steel were $0.0018mg/m^3$ inside a ship section, and $0.0015-0.0026mg/m^3$ at the welding shops. All of the personal breathing zone air samples were below the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value ($TLV^{(R)}$) of $0.01mg/m^3$. Conversely, eighty-eight percent(21 of 24) of the personal breathing zone air samples exceeded the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit of $0.001mg/m^3$. Ni was not detected on 20 of 23 air samples collected during MIG welding on mild steel. The three Ni samples above the limit of detection ranged from 0.015 to $0.044mg/m^3$. The GM of Cr(VI) concentrations during MMA welding on mild steel were $0.0013mg/m^3$, but Ni was not detected in the air samples during this operation. It is assumed that the airborne Cr(VI) and Ni during mild steel welding were derived from the base metals which contained about 0.03% Cr and 0.03% Ni. The GM of airborne total Cr, Cr(VI) and Ni concentrations during MIG welding on stainless steel were 4.02, 0.13 and $0.86mg/m^3$, respectively, and the levels of Cr(VI) and Ni were above the ACGIH-$TLV^{(R)}$. Cr(VI) comprised about 35.5% of the total chromium(Cr) from MIG welding on mild steel, and about 8.4% of total Cr from MIG welding on stainless steel. The ratios of Cr(VI) to total Cr were significantly different among welding shops. It was concluded that welders were exposed to high levels of Cr(VI) and Ni during welding on stainless steel, and were exposed to low levels of Cr(VI) even during welding on mild steel.

• Journal of Navigation and Port Research
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• v.29 no.3 s.99
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• pp.203-213
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• 2005

The International Maritime Organization(IMO) which is responsible for measures to improve the safety and security of international shipping and to prevent marine pollution from ships is a specialized agency of the United Nations. It is involved in legal matters, including liability and compensation issues and the facilitation of international maritime traffic as well. But the ROK has not been actively coping with the environment of the shipping industry because of the absence of the organization or researching bodies that specialized in the field related to IMO. Therefore this paper investigates the maritime administration system of the major countries such as the USA, japan and the UK. And particularly by conducting IMO research and responding system, this study gathers relevant materials from those countries for the comparison and analysis with the purpose of providing the ROK with the assistance in forming the responding measures in the shipping and shipbuilding industries.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.51-55
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• 2007

This thesis deals with the legal principles, case law decisions and suggestions for the Sale & Purchase of ships concerning enactment proposal of maritime law. Recently, the shipbuilding market has shown a major shift towards East Asia, particularly Korea, Japan and China. The major Korean shipyards in particular have engaged in substantial investment programmes both to expand their overall shipbuilding capacity and to enter new markets, such as for liquefied natural gas(LNG) carriers. The Korean Government has recently taken interest in the sale & purchase of used ships, utilizing the Internet and has made plans for building the Shipping Exchange in korea. So this thesis examines the situation of the world's shipping industry and the different kinds of the Sale & Purchase of ships. deals with the legal principles, and case law decisions. describes Forms of Shipbuilding Contracts and Memorandums of Agreement of second-hand ships. And makes suggestions for 1) the Shipbuilding Contracts of the shipowner's Association of Korea and 2) The Korean Shipbrokers' Association's Memorandum of Agreement for Ship Sale & Purchase in the korean shipping industry. Having reached the end of this thesis. the writer suggests to make terms of sale of ships in the korean civil code and commercial code, Additionally. the writer suggests to make a special law in relation to the Sale & Purchase of ships. Furthermore, the writer suggests expanding the Shipping Exchange in Korea.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.248-254
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• 2015

There has been no previous study on technology development of large capacity drainage pump for rescue sinking ship in the country. The agricultural drainage pump was widely used for rescue sinking ship but this pump has several problems such as efficiency, low displacement and malfunction in winter. Therefore, this paper proposes to solve the problems for swiftly rescue sinking ship and develops the drainage pump system that has $20m^3/min$ mass flow rate specification at suction head 8 m. The centrifugal pump type the most commonly used in the field of naval architecture and ocean engineering was selected and designed based on the requirement specification. The blade design of impeller was derived from the Stepanoff coefficient and requirement specification and used computational fluid dynamics to review the target mass flow rate according to the impeller RPM at design operating conditions. We also performed structure analysis of the impeller to find structurally vulnerable points for the pump in service and completed the theoretical design of drainage pump system.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.73-81
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• 2018

In this paper, East Asian thoughts in Choi In-ho's novels have been studied based on Emmanuel Levinas' philosophical theories. He is a philosopher who dealt with the matter of subject formed through the encounter the others. The author of this paper quoted his ethics of responsibility, viewing that East-Asian thoughts put stress on the relationship with the others. The conclusions are like these; first, in the novel, Sang Do, there is a true relationship between the subject and the others thinking in the side of the other. Human relationship is like Sangsunyaksoo, which means when subject goes low, there appears a place the other can stay in. Second, in the novel Yoorim the essence of Neo-Confucianism shows up through Kyung thought, in which subject serves on the other in respect. That's like what Levinas said, "responsibility to others". Third, in the novel The Road without Road there appears Jinsokppuli, the central value of Korean Buddhists' Zen thoughts, meaning that you are not differentiated from me. In the times when the nation had been lost, Kyung Ho, who answered the call of people was a man who found what Levinas said, "the other who stays in me". As a conclusion the thoughts such as Sangsunyaksoo, Kyung, and Muae which show up in Choi In-ho's novels are connected with Levinas' ethics of responsibility and well shown as good examples of East Asian ethics.

• Journal of Pharmaceutical Investigation
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• v.37 no.4
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• pp.237-242
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• 2007

The chemical formula of indapamide is 3-(aminosulfonyl)-4-chloro-N-(2,3-dihydro-2-methyl-1H-indol-l-yl)-benzamide, Indapamide is an oral antipertensive diuretic agent indicated for the treatment of hypertensive and edema. Indapamide inhibits carbonic anhydrase enzyme. Transdermal drug delivery systems, as compared to their corresponding classical oral or injectable dosage form counterparts, offer many advantages. The most important advantages are improved systemic bioavailability of the pharmaceutical active ingredients (PAI), because the first-pass metabolism by the liver and digestive system are avoided; and the controlled, constant drug delivery profile (that is, controlled zero-order absorption). Also of importance is the reduced dose frequency compared to the conventional oral dosage forms (that is, once-a-day, twice-a-week or once-a-week). Other benefits include longer duration of therapeutic action from a single application, and reversible action. For example, patches can be removed to reverse any adverse effects that may be caused by overdosing. In order to evaluate the effects of vehicles and penetration enhancers on skin permeation of Indapamide, the skin permeation rates of Indapamide from vehicles of different composition were determined using Franz cells fitted with excised hairless skins. Solubility of Indapamide in various solvents was investigated to select a vehicle suitable for the percutaneous absorption of Indapamide, The solvents used were Tween80, Tween20, Labrasol, Lauroglycol90 (LG90) and Peceol. Lauroglycol90 increase the permeability of indapamide approximately 3.75-fold compared with the control. Tween80, Tween20, Labrasol, Lauroglycol90 (LG90) and Peceol showed flux of $0.06ug/cm^2/hr,\;0.4ug/cm^2/hr,\;0.21ug/cm^2/hr,\;0.72ug/cm^2/hr,\;0.29ug/cm^2/hr$, respectively.

• Journal of Pharmaceutical Investigation
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• v.39 no.6
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• pp.401-409
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• 2009

Ketrorolac tromethamine (KT), a nonsteroidal anti-inflammatory drug (NSAID) is required repeated administration due to its short blood half-life. To avoid dose-dependent side effects of KT, sustained-release pellets containing KT were prepared by coating with Eudragit$^{(R)}$ RS 100 and Eudragit$^{(R)}$ NE 30D. The in vitro and in vivo drug release behavior of KT from Eudragit$^{(R)}$ RS 100 and NE 30D coated pellet (SR-A), Eudragit$^{(R)}$ RS 100 coated pellet (SR-B) and conventional commercial immediate-release tablet (IR) was investigated. KT from SR-A and SR-B was slowly released over several hours, whereas IR showed rapid initial release in vitro. The pharmacokinetic study in vivo was performed by oral administration in beagle dogs. 5 mg IR was administered 3 times at intervals 5 hr. Five milligrams of IR was administered 3 times at intervals of 5 hr and 15 mg of SR-A and SR-B did once. After administering IR, KT concentration in blood showed high peak- trough fluctuation and stomach ulcer were discovered. On the other hand, SR-A and SR-B sustainedly released KT and reduced the occurrence of stomach ulcer. There sustained-release pellets will be effective system to minimize dosedependent of side effect and improve patient compliance.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.305-310
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• 2012

Through our entire life, oral care products such as toothpaste are used. Thus the safety of oral care products used every day to our mouth is very important. As the previous study in animal tests or clinical trials, surfactant in toothpaste may cause the oral irritation. However, EU cosmetics legislation prohibits animal testing of cosmetics and its ingredient for animal welfare. Therefore the development of alternative in vitro test has been actively performed to replace or reduce using the animal in many areas. However, the way to evaluate oral mucosal toxicity has been done using animal models or clinical trials from now on. Even more, the experiment with human oral 3D tissue or human oral cell line is used recently. The aim of this study is the development of oral mucosal irritation method without using animal for the safety of the oral care product. We developed in vitro test method for oral irritation by using human oral cell line (YD-38 cell) acceptable to toothpaste which contains insoluble material. By the results of this assay, we could discriminate toothpaste with or without irritating substance as same manner in animal studies reported previously. In addition, we confirmed that toothpaste for babies and children toothpaste irritated oral musoca lower than the general adult toothpaste. The present study suggest that this new in vitro method by using human oral cell line (YD-38 cell) could be used for evaluation of oral irritation without using animal.

• Conservation Science in Museum
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• v.17
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• pp.69-84
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• 2016

Yuso is the term for decorative tassels of a braided string which hangs a scroll painting. This study, drawing on extant research concerning the yuso made for Joseon period portrait scrolls of kings and meritorious retainers, focuses on the yuso created to hang literati portraits. Concretely, It examines yuso of seven portraits in the collection of the National Museum of Korea in order to characterize their appearance and determine their material composition. The study found that most of the yuso are sixteen-strand strings braided into a rounded cross-section(dongdahoe). The seven yuso, of which six are red and one indigo-blue, reflect the popular style associated with Joseon period literati portraits. The yuso for the portrait of Yun Geup(duksu 3503) is made from gilded paper. Analysis showed Fe particles present in a red pigment underlying the gold layer, suggesting the presence of red ochre(seokganju), an iron oxide mineral. The yuso of the portrait of Shin Im(duksu 4846) is used a paper which contains gold as well as traces of Pb, Hg and Ag. The paper in the yuso for the portrait of Yi Seongwon(bongwan 10122) mainly consisted of Ag, indicating silver paper having been used in its fabrication. The inner paper in the yuso of the portrait of Yi Seogu(sinsu 1065) is a leather combined with Ag, Fe, and Br, according to chemical analysis. The FTIR of the leather sample reveals that the spectrum in the fingerprint region is nearly identical to that of sheepskin, indicating the yuso was made from gold-coated sheepskin.