• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.2
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• pp.55-64
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• 1988

Stow nets have widely been used in the western sea of Korea from the olden age. The original structure of a stow net is a large square-sectional bag net made of 4 netting panels, and the front fringes of top and bottom panels are connected to the top and bottom beams respectively. Wire ropes, which is originated from the holding anchor are gradually forked and biforked, and finally 4 pieces of wire rope (biforked pendants) are jointed to each beam. Much convenience caused by long and heavy beams were problemed, then some studies have been carried out to improve the net since 1930's. The most effective improvement were achieved in 1980 by Mr. Han and his colleagues. The key point of improvement was that the beams were removed and the belt shaped shearing device made by canvas was attached to the side panels, the head rope and ground rope to the front fringe of top and bottom panel, and biforked pendants are joined to the shearing device. Even though this is the epoch-making improvement of a stow net, the further study should be required to find out more effective method. The authors carried out a model experiment on the stow net to determine the vertical and horizontal opening of a net mouth, and also examine the front, top and side-view configuration of the net. The model net was constructed depending on the Similarity Law of Fishing Gear in 1/10 and 1/20 scale and set against to the current at shallow and speedy flowing channel. The vertical and horizontal openings were determined by using scaled bamboo poles, and the configuration was observed by using specially prepared observation platform and underwater observation glass, and also photographed by using specially prepared underwater photographic equipment. The results obtained can be summarized as follows: 1. The opening height and width of the shearing device varied in accordance with the relative length of the biforked pendants. Considering the height and width of shearing device in 6 cases of the arrangement system of biforked pendants, the best result was obtained in the case that the 2nd, 3rd and 4th pendents from the bottom-most was 5%, 9% and 4% longer than that. 2. On the top-view configuration the excessive deformation of head rope and ground rope were observed. In the actual net, 54m long head rope and ground rope were attached to the front fringe of top and bottom panels so that the head rope may be lifted to make the net mouth open highly. But actually the head rope and the ground rope are streamed backward without any lift, and also the netting followed the ropes were deformed until the 2/5 in the whole length of the net. This deformation may be guessed to disturb the entrance of fish school into the net and also caused the net to get caught by obstacles in the sea bed and to be broken largely. 3. Hydrodynamic resistance R of the actual net may be deduced as R(kg)=29.2$\times$103 v1.65. It is also expressed as R(kg)=5.9$\times$d/l$\times$ab v1.65. depending on the formula deduced by Koyama to estimate the resistance of trawl nets, where d/l denote the ratio between diameter of netting twine and length of mesh leg in every part of side panel, a and b, the stretched circumference of the mouth and the stretched length of the net, respectively.

• Journal of Preventive Medicine and Public Health
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• v.22 no.2 s.26
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• pp.290-301
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• 1989

This is preliminary report on anthrax epidemic occurred in an island with about 100 residents. Since 1982 there had been sudden deaths among all kinds of domestic animals including cattle, dogs, ducks, chicken and goat but only a few among cats in an isolated island about three hours distance away by ferry boat from Mokpo city. From 1986 through 1988 nine human deaths and four patients occurred, which made the government intervene for investigation on June 25 1988. The epidemiological investigation consisted of interview survey and medical examination, medical record analysis, laboratory work to isolate the pathogens under the direction of hypothesis derived from the study and further confirmation of the pathogens by international institute. The summarized results are as followings: 1. According to the interview survey there were many deaths among domestic animals usually in cold and dry season such as January through March and September through November; 36 heads of cattle leaving one head, more than 40 hogs(all), hundreds of chicken leaving few alive, goats that had taken home from mountain and two or three cats out of around 40 had sudden deaths from 1982 till 1985, when the residents stopped to purchase and take them into the island anymore. Also there were eleven persons who had experienced the similar syndrome complex to those of admitted and expired patients and four of them revealed typical chest X-ray findings; from one of these four patients(Rho) B. anthracis is isolated. 2. Medical record on patients who had been admitted, showed common characteristics of the disease course. On admission they had either gastrointestinal or upper respiratory infection symptoms which invariably progressed to septicemic nature with pulmonary interstitial infiltration and mediastinal widening/bulging, and then to deadly acute respiratory distress syndrome. At the end stage chest X-ray revealed multiple bullous emphysema. One of another characteristics was oral ulceration with bleeding occurred in about 50% of the patients. Laboratory test results in common were leukocytosis with left shift and abnormal liver and kidney functions, particularly at the later stage of the illness. 3. Epidemiological characteristics was striking in that both mortality and incidence rates were high: the mortality rate was 8.7% average, male being three times higher than females but there was no distictive clustering by age group. The incidence rate for both sexes was 28.2% and there was no sex difference although a tendency of higher incidence among older ages was noticed. The highest mortality and incidence were observed in Won village where the first death of animal occurred and with the highest frequency among three villages of the island. 4. Among twelve bacilli species isolated from various specimens, two strains, one from patient and the other from soil where the recently died cow is hurried, were confirmed as B. anthracis by Pasteur Institute and CDC of USA(strain from soil). CDC reported that the strain did not produce capsule in bicarbonate media but reacted with the bacteriophage and one of five sera taken from the patients. Mode of transmission as well as incubation period of the agent has not been established yet, which needs further investigation in relation to the antigenic structure of the variant when it is confirmed.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.911-920
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• 2003

In this study, we analyzed the long-term surgical outcome of partial atrioventricular septal defects during the past 17 years at Seoul National University Hospital. Material and Method: A retrospective analysis on mortality, survival, and reoperation and their risk factors was done in 93 patients who underwent surgical correction of partial atrioventricular septal defects between April 1986 and December 2002. 32 patients were male and 61 were female with a median age of 68 months (3∼818 months) and a mean follow-up period of 108 months (1∼200 months). Result: There were 4 operative deaths (4.3%) and one mortality during the follow-up period. 3, 5, 10, and 15 year actuarial survival rates were 95.7%, 94.3%, 94,3%, and 94.3%, respectively. After the surgical correction, left atrioventricular valve Incompetence was improved in 61patients (67.7%), remained same as the preoperative status in 14 patients (15.1%), and was aggravated in 12 patients (12.9%). Reoperation was performed in 8 patients (9.0%) after a mean interval of 38.6 months (3∼136 months). Freedom from reoperation rates at 3, 5, 10, and 15 years after surgical correction were 94.0%, 91.4%, 91.4%, and 88,2%, respectively Reasons for reoperation were 7 left atrioventricular valve incompetence, 2 left ventricular outflow tract obstruction, a residual atrial septal defect, a left atrioventricular valve stenosis, and a right ventricular failure. Left ventricular outflow tract obstruction was the only statistically significant factor. In ten patients, significant arrhythmia was developed and three of them were supraventricular arrhythmia. Complete atrioventricular block occurred in 7 patients and permanent pacemakers were implanted in six of them. Conclusion: Surgical corrections of partial atrioventricular septal defects were performed with low operative mortality. Since left atrioventricular valve incompetence was the most common cause of reoperation and left ventricular outflow tract obstruction was the only risk factor for reoperation, a precise estimation of the left atrioventricular valve morphology and the structure of left ventricular outflow tract are needed. Although left ventricular outflow tract obstruction rarely developed, reoperation was frequently required and resection of subaortic tissue could be peformed but the possibility of recurrence was high, so modified Konno operation could be performed with satisfactory results. Complete atrioventricular block developed frequently in early periods, but was overcome with a precise anatomical understanding of conduction system and experience.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.279-288
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• 2007

In the present study, we focused on stem cells in the dental papilla of the tooth germ. The tooth germ, sometimes called the tooth bud, is the primordial structure from which a tooth is formed. The tooth germ consists of the enamel organ, the dental papilla, and the dental follicle. The dental papilla lies below a cellular aggregation of the enamel organ. Mesenchymal cells within the dental papilla are responsible for formation of dentin and pulp of a tooth. Tooth germ disappears as a tooth is formed, but that of a third molar stays in the jawbone of a human until the age of 10 to 16, because third molars grow slowly. Impacted third molar tooth germs from young adults are sometimes extracted for orthodontic treatment. In the present study, we evaluated the osteogenic activity and mineralization of cultured human dental papilla-derived cells. Dental papillas were harvested from mandible during surgical extraction of lower impacted third molar from 3 patients aged 13-15 years. After passage 3, the dental papilla-derived cells were trypsinized and subsequently suspended in the osteogenic induction DMEM medium supplemented with 10% fetal bovine serum, 50 g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate at a density of $1\;{\times}10^6\;cells/dish$ in a 100-mm culture dish. The dental papilla-derived cells were then cultured for 6 weeks and the medium was changes every 3 days during the incubation period. Dental papilla-derived cells showed positive alkaline phosphatase (ALP) staining during 42 days of culture period. The formation of ALP stain showed its maximal manifestation at day 7 of culture period, then decreased in intensity during the culture period. ALP mRNA level was largely elevated at 1 weeks and gradually decreased with culture time. Osteocalcin mRNA expression appeared at day 14 in culture, after that its expression continuously increased in a time-dependent manner up to day 28. The expression remained constant thereafter. Runx2 expression appeared at day 7 with no detection thereafter. Von Kossa-positive mineralization nodules were first present at day 14 in culture followed by an increased number of positive nodules during the entire duration of the culture period. Osteocalcin secretion was detectable in the culture medium from 1 week. The secretion of osteocalcin from dental papilla-derived cells into the medium greatly increased after 3 weeks although it showed a shallow increase by then. In conclusion, our study showed that cultured human dental papilla-derived cells differentiated into active osteoblastic cells that were involved in synthesis of bone matrix and the subsequent mineralization of the matrix.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.181-188
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• 2006

Changes in the fine structure of testicular Leydig cell from hatching to adulthood were studied in Korean native chickens of 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 21, 24, 28, 32, 44, 52 and 64 weeks (n=13 chickens per group) of age. The objective of this study were to elucidate Leydig cell ultrastructure during testicular development. Testes of chickens were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using $1{\mu}m$ sections stained with methylene blue-azure II, qualitative and quantitative(stereological) morphological studies were performed. The ultrastructural changes of the Leydig cell were investigated by ultrathin section with the transmission electron microscope. The stages of the Leydig cell development described focus on mitochondria, endoplasmic reticulum, and lipid droplets which are involved in androgens as fullows. 1) Approaching puberty. The closely packed Leydig cells and sparse intercellular space. The nucleus occupied a large portion of the Leydig cell volume. The population of Leydig cells contained two types of cells that differed in the appearance of their nuclei which were either highly electron-opaque or relatively electron-lucid. The cytoplasm was characterized by large amounts of lipid droplets, relatively few spherical mitochondria, and sparse smooth endoplasmic reticulum. 2) Puberty to adult. The Leydig cells which display features compatible with significant androgen synthesis: large volume of cytoplasm containing extended smooth endoplasmic reticulum, abundant mitochondria, and reduction of lipid droplets.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.3 no.2
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• pp.65-88
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• 2008

To achieve the age of 30,000 dollars GNP, The business with speed will hold a more crucial point than the business with scale, and the mass consumption market will be transformed and changed into the niche market. Moreover, it will not be easy for the company without the peculiar and creative technology to survive in the severe competition. Under these circumstances, The innovative company which knows how to use this new paradigm will select the better position in the changing market. Innovation type SMEs are contributing in maintaining the international competitiveness of domestic economy by serving high-tech and the promotion of employment. Also, Innovation type SMEs have the most important economic leverage in our domestic economy. It's a source of the growth in domestic economy. Therefore, A lot of countries have been trying to support innovation type SMEs (with a small capital and high-tech). And many countries also try to protect and promote the innovation type SMEs. Especially the Korean government is also promoting innovation type SMEs in many ways, because the future of innovation type SMEs are not bright. This study explored the three innovative SEMs and studied 1) entrepreneur characteristics, 2) the industry environment, 3) competitive strategies, and 4) resources and capabilities of organization, which have been considered as the success factors for entrepreneurial firms. This study also holds that the characteristics of entrepreneurs is one of the most important factor to impact the success of innovative SMEs. Most of entrepreneurs have started their business with high education career and field experiences and have high intentions in developing new/high techonologies, challenging spirits, and clear vision and goals. The innovative SMEs with small kinds of products and services, narrow market, and small resources are more sensitively impacted by the environment especially. But the SMEs which entered into market early could have the comparative excellencies in their market to survive and grow in the future. They also have competitive advantages in the market using differentiation strategies by technology innovation. Technology innovation and differention strategies are one of the success factors in SMEs, They entered into the niche market using this weapons. The capabilities of changing organization to their changing environment, the open orgarnization culture, the continuous employment education, and the building the organic organization are also success factors of innovative SMEs. The SMEs with the simple organization structure can make fast decisions and operate with the autonomous and flexible ways. These only three cases will not shown successful factors of over 12,000 Innovation type SMEs in Korea and this study of Innovation type SMEs is insufficient from all aspects. But this study have many implications for the future research and the entrepreneurs ready for their business.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.7-17
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• 1985

In order to determine the susceptible age of Enterobius vermicular is to anthelmintics and to observe the chronologie growth of female E. vermicularis in man, experimental infections were done. About 500 eggs were challenged to 19 volunteers. After 4, 8, 16, 20, 24, 28, 32 and 35 days of infection, each case was treated by either mebendazole or pyrantel pamoate. On the 40th day of infection all cases including control were treated again to terminate the experimental infection and to evaluate the effect of previous treatment. Each case collected 3-day stools to harvest the expelled worms. The results could be summarized as follows: 1. The infection rates of females were in range of 0.6~13.1 % in control cases. Because the collected worms showed comparable growth and development by day, the worms were concluded to be derived from experimental infection. 2. Cases that were treated with mebendazole on 4, 8 and 16 days after infection expelled 37.5%, 2.5% and 67.5% of the number expelled by a control case on the 40th day. Cases treated thereafter expelled no worms on the 40th day. 3. Cases that were treated with pyrantcl pamoates on 4, 8, 16, 24, 28, 32 and 35 days, expelled 90.7%, 25%, 45.3%, 8%, 2.7%, 5% and 29.3% of the number collected from control cases in respect. 4. All the worms collected were females. The total body length increased consistently and comparably from the 20th day of infection. Those collected on the 20th day were 2.5~3.0 mm long with vagina, sac-like structure and strands of ovaries; 24 day-old worms may have short uterus, 28 day-old worms had long uterus without eggs, 32 day-old worms began to produce eggs, 35 day-old worms showed wide variations in egg deposit in uterus, and 40 day-old worms had uterus filled with eggs from vulva to anal levels. From the above results, it was inferred that the life span of female Enterobius vermicularis was longer than 40 days, and the developmental stages of worms younger than 16 days resisted considerably to both mebendazole and pyrantel pamoate.

• Archives of design research
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• v.18 no.1 s.59
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• pp.91-104
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• 2005

In the past, the design education focused on the technique and skill to satisfy the production and consumption activities of a corporation based on beauty and practicality in the industrial age. Now, it's time to switchover to a life-quality enhancing education by harmonizing and meeting the public's physical and mental needs because design education is a character education which enhances the quality of life by uplifting people's aesthetic sense. This paper has emphasized on the importance of public education of design through the theoretical investigation on social environmental changes caused by the emergence of information society,,education problems, public education, and the necessity of design education. The reason why this study should be done has been suggested by investigating the necessity of this research and bringing up the issue. Furthermore, the current status and problems of public education on design have been analyzed. Then, based on the result, the development direction of design education has been suggested. This study can be concluded as follows: First, the design education should change from its vertical structure to a horizontal one. It should be widely spread to the public, getting off from its privatization for a certain group. Second, designers and the public should correct their way of thinking about design. The ordinary people as well as the designers should cultivate their capability to find and take care of design related issues in their everyday lives. Third, all people should be the subject of design education for the public. As a part of cultural education on the public's aesthetic sense, design education should be reborn as a field of study in which a sound public culture can be developed by the integration of human life and culture, exceeding the limit of school curriculum.

• Journal of Environmental Impact Assessment
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• v.25 no.6
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• pp.514-524
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• 2016

The Bio-Climatic impact Assessment System, BioCAS was utilized to produce analysis maps of daily maximum perceived temperature ($PT_{max}$) and excess mortality ($r_{EM}$) over the entire Seoul area on a heat wave event. The spatial resolution was 25 m and the Aug. 5, 2012 was the selected heat event date. The analyzed results were evaluated by comparing with observed health impact data - mortality and morbidity - during heat waves in 2004-2013 and 2006-2011,respectively. They were aggregated for 25 districts in Seoul. Spatial resolution of the comparison was equalized to district to match the lower data resolution of mortality and morbidity. Spatial maximum, minimum, average, and total of $PT_{max}$ and $r_{EM}$ were generated and correlated to the health impact data of mortality and morbidity. Correlation results show that the spatial averages of $PT_{max}$ and $r_{EM}$ were not able to explain the observed health impact. Instead, spatial minimum and maximum of $PT_{max}$ were correlated with mortality (r=0.53) and morbidity (r=0.42),respectively. Spatial maximum of $PT_{max}$, determined by building density, affected increasing morbidity at daytime by heat-related diseases such as sunstroke, whereas spatial minimum, determined by vegetation, affected decreasing mortality at nighttime by reducing heat stress. On the other hand, spatial maximum of $r_{EM}$ was correlated with morbidity (r=0.52) but not with mortality. It may have been affected by the limit of district-level irregularity such as difference in base-line heat vulnerability due to the age structure of the population. Areal distribution of the heat impact by local building and vegetation, such as spatial maximum and minimum, was more important than spatial mean. Such high resolution analyses are able to produce quantitative results in health impact and can also be used for economic analyses of localized urban development.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.2
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• pp.89-98
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• 2010

Sex and its tropic hormones influence the lacrimal system, corneal anatomy and disease, aqueous humor dynamics and glaucoma, crystalline lens and cataract, and retinal disease. Dry eye occurs especially frequently during pregnancy, oral contraceptive use, and after menopause, during which androgen levels decrease. Androgen control development, differentiation, and lipid production of sebaceous glands throughout the body, and androgen deficiency also leads to meibomian gland dysfunction and evaporative dry eye. On the other hand, estrogen causes a reduction in size, activity, and lipid production of sebaceous glands. Sex and its tropic hormones also influence the corneal anatomy and disease, and corneal thickening occurred on the second day of the menstrual cycle and around the time of ovulation and appeared to be related to estrogen levels. Fuchs' dystrophy is more commonly seen in postmenopausal women than men and may be linked to hormonal changes that occur with aging. In addition, overexpression of estrogen and progesterone receptors in the conjunctiva of vernal keratoconjunctivitis patients. Serum progesterone levels also may be associated with intraocular pressure especially in pregnant women, and for the women. For women with cataracts, hormone levels were typical of menopause, and there was a significant negative correlation between estradiol and follicular stimulating hormone levels. In addition, serum testosterone levels are associated with the development of diabetic retinopathy. Although the role of sex hormones on the eye is largely unknown, and the results should be interpreted with caution until replicated, the functions of sex hormones in ocular disease remains to be investigated, because they may be involved in structure and function of the ocular components, which are important in the pathogenesis of ocular disease.