• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.99-113
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• 1999

The role of a GIS as a tool for a national information infrastructure can best be fulfilled once GIS standards are implemented. In this paper, we have identified what the contents of GIS standards in other countries are, and what should be the future direction for implementing a nation's GIS standards. Based on a detailed review on GIS standards in the USA, Australia, Japan and the United Kingdom, we derived the following: (1) A nations's GIS standards should include both geographic information content standards and geographic information service standards: (2) A nation's GIS standards should be a profile of ISO GIS standards: (3) Each GIS standards should be developed on the bassis of the Entity-Relationship Model using Unified Modeling Language: and (4) Experts in GIS should pay much more attention on studies on GIS service standardization. As for building the national GIS Standards for Korea, we recommend both GIS Content Standards and GIS Service Standards be simultaneously developed. GIS Content Standards include geographic feature content standard, feature classification standard, portrayal standard, rules for application standards, spatial reference model and terminology. GIS Service Standards include standards for data sharing such as metadata standard and transfer standard, quality standard, quality principle and portrayal standards.

• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.81-98
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• 1999

The purpose of this study is to provide a common model and implementation strategies for reusing GIS components in local governments. The common model includes several solutions to remove stumbling blocks step by step in reusing or exchanging GIS application systems between local governments. Elements of the model are component architecture, common business process model, common function model, and data model. The elements are the minimum standards for reusability. In order to realize the desirable common model at present, however, the following problems remain : usable components are insufficient in spatial domains and existing GIS application systems require reinvestment to accommodate the new component technology. Three questions are raised to maximize reusability from a monolithic structure toward layered and the componentized GIS application systems : (1) How can the application systems be reused within a local government?, (2) Can the systems be exchanged when they are in the same computing platform?, and (3) When the systems are componentized by standardized interfaces, are the components replaceable between the systems in local governments? Some strategies are presented to accomplish the objectives implicated in the questions. For the actual implementation, several issues such as evaluation procedures for component products, ownership and commercialization issues, will be brought up in the future. Central and local governments, and commercial party need to co-operate each other to maximize the reusability. Reducing overlapping investments in local governments and obtaining competitive component technology in the commercial party should be recognized as critical tasks for the more efficient and economical GIS implementation.

• Journal of Soil and Groundwater Environment
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• v.10 no.5
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• pp.11-17
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• 2005

Characteristics of phenanthrene removal in the Electrokinetic (EK)-Fenton process were investigated in a 2-dimensional test cell in a viewpoint of the effect of gravity and electrosmotic flow (EOF). When the constant voltage of 100 V was applied to this system, the current decreased from 1,000 to 290 mA after 28 days, because soil resistance increased due to the exhaustion of ions in soil by electroosmosis and electromigration. Accumulated EOF in two cathode reservoirs was 10.3 L and the EOF rate was kept constant for 28 days. At the end of operation, the concentration of phenanthrene was observed to be very low near the anode and increased in the cathode region because hydrogen peroxide was supplied from anode to cathode region following the direction of EOP. Additionally, the concentration of phenanthrene decreased at the bottom of the test cell because the electrolyte solution containing hydrogen peroxide was largely transported toward the bottom due to a low capillary action in the soil with high porosity. Average removal efficiency of phenanthrene by EK-Fenton process was 81.4% for 28 days. In-situ EK-Fenton process would overcome the limitations of conventional remediation technologies and effectively remediate the contaminated sites.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.749-758
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• 1997

Myocardial ischemia-reperfusion injury is known to be mediated by reactive oxygen species. The myocardial cell is equipped with endogenous antioxidant defensive system which can be adaptively stimulated by various oxidative stress. It is postulated that an increased oxygen partial pressure induced by hyperbaric oxygenation impose an oxidative stress on the cells, resulting alterations in the endogenous antioxidant system. In this study we investigated the effect of hyperbaric oxygenation on the activities of myocardial antioxidant enzymes and observed whether the hyperbaric oxygenation could protect the ischemia-reperfusion injury of heart. Rats or rabbits were pretreated with hyperbaric $oxygenation(2{\sim}3\;atm\;O_2/1{\sim}3\;hrs/1{\sim}10\;days)$. The changes in activities of major antioxidant enzymes(superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phasphate dehydrogenase), functional recovery and infarct size were observed in the experimentally induced ischemia-reperfused hearts. In the hearts isolated from rats pretreated with $2\;atm\;O_2/1{\sim}2\;hrs$ for 5 days, the functional recovery after reperfusion(20 min) following global ischemia(25 min) was significantly increased without any observable oxygen toxicity. Lactate dehydrogenase release was also significantly reduced in this hyperbaric oxygenated rat hearts. In in vivo regional ischemia(30 min) model of rabbit hearts, pretreatrment with $2\;atm\;O_2/1\;hr$ for 5 days significantly limited the infarct size. Among the myocardial antioxidant enzymes of rat hearts pretreated with the hyperbaric oxygenation, the activities of catalase, superoxide dismutase and glucose-6-phosphatase dehydrogenase were increased, while those of glutathione peroxidase and reductase were not changed. There were lethal cases in the groups of rats exposed to 3 atm $3\;atm\;O_2/2{\sim}3\;hrs$ for 5 days. A lipid-peroxidation product, rnnlondialdehyde was increased in brains and livers of the rats exposed to$2\;atm\;O_2/2{\sim}3\;hrs/5\;days\;and\;3\;atm\;O_2/1\;hr/5days$. The present results suggest that the pretreatment of hyperbaric oxygenation can protect the post-ischemic rererfused hearts in association with a stimulation of the activities of myocardial antioxidant defensive enzymes, and that the hyperbaric oxygenation of $2\;atm\;O_2/1\;hr$for 5 days would be a safe condition which does not produce any oxygen toxicity.

• Journal of Preventive Medicine and Public Health
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• v.2 no.1
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• pp.61-76
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• 1969

A review has been made of mortality trends in Korea from 1958 to 1967 analyzing the data by sex, age and cause of death. The crude death rates and age specific death rates were estimated by the model of N. Keyfitz life table which had been developed by the data of the 1960's national census. The cause specific death rates shown in this article are based on the following: all deaths occurring in the death-registration are expressed as a numberator, while the denominator was estimated from the regular national census data by interpolation method. It is estimated that only an average of about 40% of deaths which occurred during a year were registered during 1958 to 1967. The validity and the reliability of the diagnosis of causes of death seem to be extremely poor in this country. Therefore the cause specific death rates in this article are aimed to reveal trends of causes of registered death ana not for the actual level of death rates. For 10 years very interesing mortality trends were observed : 1. The trend in the crude death rates was downward slowly. 2. The estimated death rate for the infant in 1960 was still high up to 100 per 1,000. 3. The rates for mortality attributed to such infectious diseases as pneumonia, bronchitis, gastroenteritis and measles decreased an average 40-60%. 4. The death rates for over-all tuberculosis decreased only 9.8%. 90% of the decrease was contributed by those in the less-than-15 year age group. 5. The death rates for chronic diseases, such as vascular diseases affecting the central nervous system, malignant neoplasm, major heart diseases and all accidents rose about 40-60%. 6. The rank order of the 10 leading causes of death showed large changes over the years, except for pneumonia and tuberculosis which occupyed 1st and 2nd places respectively. Vascular diseases affecting the central nervous system moved from 5th to 3rd place and malignant neoplasm from 6th to 4th place, The major heart diseases moved from 10th to 6th place and all accidents from 10th to 7th place. On tile other hand, gastroenteritis moved from 3rd to 5th place and influenja from 4th to 8th place.

• Korean Business Review
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• v.12
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• pp.209-237
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• 1999

With the increasing speed of internationalization of corporations under WTO system foreign direct investment is considered as the important means of international cooperation as well as avoiding trade barrier. From this point of view the study on foreign direct investment of Korean corporations is of great importance. Many studies till now, however, are concerned with the macroscopic analysis of foreign direct investment of Korean corporations, not with the establishment of strategy appropriate to the environment of host country and the investment performance. In order to meet the problems mentioned above this thesis aims at accomplishing the following three tasks. (1) synthetic assessment of existing theories of foreign direct investment. (2) systematic adjustment of factors of environment in the foreign direct investment activities. (3) analysis of above factors in the foreign direct investment of Korean textile industry and proper proposal of strategic model for the individual corporation. The results of analysis according to the aim of the study are as follows: (1) To lead foreign direct investment successfully, variable and effective information-presentation should be offered with priority. (2) The investment strategy through regional diversification is required. (3) The localization of decision making has to be attempted assertively. (4) The global network system is needed for more recommendable foreign direct investment. (5) More aggressive and outgoing attitude like developing into the local market and obtaining the high-technology is desperately needed.

• Journal of Korean Academy of Nursing
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• v.4 no.3
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• pp.105-116
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• 1974

This study was made on patients who were Hospitalized due to sickness caused by the abuse of marihuana at the Psychiatric Section of a hospital during the period from Feb. to Oct., 1974. The following conclusion was obtained by reviewing the literature with respect to the nursing, and problem solving of those patients. 1. It appears that marihuana is a comparatively mild intoxicant in ordinary preparation without causing physical dependence or tolerance. 2. According to the status of men who are marihuana smokers, approximately 20% of them were college students, those preparing to retake college entrance examinations, non-employed and pharmacists. The men belong mostly to the middle foreigner′s mistress of higher, income bracket, and in the case of women, most of the smokers were US. servicemen entertainers. 3. Dynamic developmental factors: Case 1. : The patient had a characteristic, hysterical and emotionally unitable character, and was of low intelligence, In addition, to this already existing problem, the added uses of marihuana caused a mental illness to develope. Case 2 : The character, was reserved and introspective, her creative power and sentiment was fading and his ability of self-control was weakened. She used the smoking of marihuana to get rid of her own feeling of inferiority complex and tensions coming from interpersonal relationships. Case 3 : The patient was unconditionally resistive to the authoritativeness of superiors and irresponsible in his relationship with women, in his attitude concerning sex in general. He smoked marihuana because he felt become peace-loving and get enchanted experience through smoking it. 4. The points of issue appearing from the above case; (1) Movement of anti-social feelings against the "established system" by the youngsters. (2) Family problem. (3) Shamelessness, loss of motivation, disorderly attitude toward the sex, (4) Worries concerning the future. (5) Lack of knowledge concerning smoking of cigarette and marihuana. Chronic use of marihuana made, those youngman who had originally been ambitions to achieve something in life, lazy, inefficient, unable to make long-term plans, are such weak mined persons that they did not try to overcome problems when encountered. This will pose a great and important question in the mental health of the society, 5. Treatment and Problem sieving According to the literature, we will have to place importance upon hospitalized treatment The phases of treatment were divided into five parts. (1) Prehospital phase (2) Withdrawal Phase (3) Rehabilitation phase (4) Transitional phase (5) After-care phase The experiments have proved that there was much progress in the recovery of patients through environment therapy, supportive therapy and group psychotherapy. This was the above mentioned 5 phases of treating process in accordance with the weekly schedule of the hospital. It was thought that the patients would require prolonged after care management even after they were released from the hospital and that they will also require periodic visit, to the hospital and doctor′s interview with their family. In conclusion, the question of the young generation and marihuana smoking is becoming a great social problem in which their resistances to the "established system" and society is growing in the from of antiestablishment movements. In our country, the smoking of marihuana is gradually developing, therefore, I think, that it would be a very fortunate thing for us, if this report could be helpful for the motivation of further study on the questions of the young generation and its problems.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.129-134
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• 2001

Since NNK is one of the most abundant tobacco-specific alkaloids and a strong carcinogenic nitrosamine, it has been used for evaluating a potential of carcinogenicity in the animal models. The present study has attempted to examine the potential of carcinogenicity of NNK in human epithelial cells, from which the cell type the most of cancers including oral cancer and nasal cavity cancer are originated. The cellular model used for the study is a human keratinocyte cell system immortalized by Ad12-SV40 hybrid virus. The cellular system has successfully been used for the carcinogenicity studies because of its limitless life span, epithelial morphology and nontumorigenicity. When cells were treated with a variety of NNK concentrations, levels of saturation density and soft agar colony formation were increased in a dose-dependent fashion. Colonies of large cell aggregates were above 5 at the higher doses. The results indicate that exposure of human cells with NNK induced loss of contact inhibition and increases of anchorage independence and cellular adhesion, which are typical characteristics of the neoplatically transformed cells. When cells were exposed with 100uM NNK for 2hr, mRNA levels of IL-1 and PAI-2 were increased in a dose-dependent manner, but expression of TGF- 1 was not affected. While expression of growth regulatory factors were altered with a short-term exposure, there was no alteration of these factors in the NNK-transformed cells. However, mRNA levels of fibronectin were increased both in the short-term treatment and in the transformation. The results suggest that altered expression of extracellular matrix such as fibronectin following short-term exposure might be fixed in the genome and these altered properties be continuously transfered throughout the cell division. Western blot analysis showed a translocation of PKC- from cytosolic fraction to the particulate fraction, indicating a possible role of NNK in the signal transduction pathway. The present study provided an evidence that NNK in the smoking may be associated with epithelial origin cancer such as oral and nasal cavity cancers. In addition, this study suggested that altered expression of extracellular matrix and PKC may play an important role in the carcinogenic mechanism of NNK.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.182-190
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• 2007

Statement of problem: Titanium has many advantages of high biocompatibility, physical properties, low-weight, low price and radiolucency, but it is incompatible with conventional dental porcelain due to titanium's oxidative nature. Many previous studies have shown that they used the method of sandblast for surface treatment prior to porcelain application, the researches are processing about the method of acid etching or surface coating. Purpose: The purpose of this research is to study the effect on bond strength of surface roughness between titanium and porcelain with the same surface topography. Material and method: In this study, we evaluated the bond strength by using 3-point bending test based on ISO 9693 after classified 8 groups - group P : polished with #1200 grit SiC paper, group S10 : $1.0{\mu}m$ surface roughness with sandblasting, group S15 : $1.5{\mu}m$ surface roughness with sandblasting, group S20 : $2.0{\mu}m$ surface roughness with sandblasting, group S25 : $2.5{\mu}m$ surface roughness with sandblasting, group S30 : $3.0{\mu}m$ surface roughness with sandblasting, group S35 : $3.5{\mu}m$ surface roughness with sandblasting, group E : $1.0{\mu}m$ surface roughness with HCl etching. Results: Within the confines of our research, the following results can be deduced. 1. In the results of 3-point bending test, the bond strength of sandblasting group showed significant differences from one of polishing group, acid etching group(P<.05). 2. The bond strength of sandblasting groups did not show significant differences. 3. After surface treatments, the group treated with sandblasting showed irregular aspect formed many undercuts, in the SEM photographs. The bond strength of sandblasting group was higher than 25 MPa, the requirement of ISO 9693. Conclusion: In above results, bond strength of titanium and low-fusing porcelain is influenced more to surface aspect than surface roughness. And titanium has clinically acceptable bond strength below surface roughness of $3.5{\mu}m$.

• Journal of Technologic Dentistry
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• v.31 no.1
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• pp.23-36
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• 2009

The goal of esthetic restoration is to achieve morphologic, optical, and biologic acceptance. Creation of a natural looking ceramic restoration, which blends harmoniously with surrounding dentition, is not always achieved. A successful color match is an important aspect of any esthetic dental restoration. Since natural enamel has inherent translucency, it is important that ceramic restorations reproduce the translucency and color of the natural teeth. However, the final color match of porcelain crowns to adjacent natural dentition remains some problem. Difficulties related to color matching arise from the structural differences that exist between metal ceramic crowns and natural teeth, the limited range of available ceramic shades, inadequate shade guides, different types of metal alloys, repeated firing, the condensation technique, and varying compositions of ceramic materials. Many factors contribute to the esthetic success of dental restoration: optical properties such as color and its elements of hue, value, and chroma; translucency and opacity; light transmission and scattering; and metamerism and fluorescence. The purpose of this study was to determine the color changes of metal-ceramic system with different veneering porcelain powder after repeated firing. The objectives of this in vitro study were to measure the lightness($L^*$), chromaticity($a^*$), chromaticity($b^*$), chroma($C^*$), hue(h), reflectance(%), color difference(${\Delta}E$). The following conclusions were obtained: 1. An increase in the number of firings resulted in decrease in lightness($L^*$) but increase in chromacticity($a^*$) with all porcelain. After the second sintering resulted in decrease in chromacticity($b^*$) with opaque-dentin porcelain and dentin porcelain but in increase with enamel porcelain and translucency porcelain. And after the second sintering resulted in decrease in chroma($C^*$) with opaque-dentin porcelain and dentin porcelain, but on the whole side in decrease with enamel porcelain and translucency porcelain. 2. After the second firing, a increase in the number of firings resulted in decrease reflectance(%) in all wavelength. 3. There were noticeable color differences(${\Delta}E$) between first sintering and multiple firings(dentin porcelain: 5.29~8.15, opaque-dentin porcelain: 4.83~8.2, enamel porcelain: 8.93~13.15, translucency porcelain: 9.37~12.91), but the color difference(${\Delta}E$) after second sintering were down to 4.87 in all porcelain. 4. Given the NBS Criteria, a 'trace' was not found this study but a 'slight' was found 2-3, 3-5 in dentin porcelain, 2-3 in opaque-dentin porcelain, 3-5, 5-10 in enamel porcelain and translucency porcelain, a 'noticeable' was 2-5, 3-10, 5-10 in dentin porcelain and opaque-dentin porcelain, 2-3, 2-5, 3-10 in enamel porcelain 2-3, 3-10 in translucency porcelain, an 'appreciable' was 1-2, 1-3, 2-10 in dentin porcelain 1-2, 1-3, 2-10, 3-10 in opaque-dentin porcelain, 2-10 in enamel porcelain, 2-5, 2-10 in translucency porcelain, a 'much' was 1-5, 1-10 in dentin porcelain and opaque-dentin porcelain, 1-2, 1-3, 1-5 in enamel porcelain 1-2, 1-3, 1-5, 1-10 in translucency porcelain, a 'very much' was 1-10 in enamel porcelain.