• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.5 no.2
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• pp.37-42
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• 2024

This study used a GPS tracker to determine characteristics of wintering habitat use by black-tailed gulls on the west coast of Korea. Results of this study showed a southward movement in December and a northward movement in March. The wintering habitat was confirmed to include the southwest coastal island area (Group 1), the inland coastal area (Group 2), and China (Group 3). The wintering home range was the narrowest in October and the widest in December. Home range of Group 1 was increased from November, showing the maximum in December, decreased in February, and then tended to increase again in March. Group 2 showed the widest home range in November and a narrow range of home range from December. Home range of Group 3 showed a mixed pattern of group 1 and group 2. The flight rate was the lowest in January and the highest in March. Day and night flight rates showed significant differences by month. This study identified wintering characteristics of the West Coast population of black-tailed gulls on the West Coast, including their wintering areas, migration periods, and use patterns. These wintering characteristics of black-tailed gull in the west coast area are thought to be affected by environmental factors (such as food resources and fishing activities) and geographical characteristics of the West Coast where many islands are distributed.

• Economic and Environmental Geology
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• v.45 no.5
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• pp.513-523
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• 2012

The upper sedimentary layer of the Ulleung Basin in the East Sea shows stacked mass-flow deposits such as slide/slump deposits in the upper slope, debris-flow deposits in the middle and lower slope, and turbidites in the basin plain. Shallow gases or gas hydrates are also reported in many area of the Ulleung Basin, which are very important in terms of marine resources, environmental changes, and geohazard. This paper aims at studying acoustic characteristics and distribution pattern of gas-related structures such as acoustic column, enhanced reflector, dome structure, pockmark, and gas seepage in the upper sedimentary layer, by analysing high-resolution chirp profiles. Acoustic column shows a transparent pillar shape in the sedimentary layer and mainly occurs in the basin plain. Enhanced reflector is characterized by an increased amplitude and laterally extended to several tens up kilometers. Dome structure is characterized by an upward convex feature at the seabed, and mainly occurs in the lower slope. The pockmark shows a small crater-like feature and usually occurs in the middle and lower slope. Gas seepage is commonly found in the middle slope of the southern Ulleung Basin. These gas-related structures seem to be mainly caused by gas migration and escape in the sedimentary layer. The distribution pattern of the gas-related structures indicates that formation of these structures in the Ulleung Basin is controlled not only by sedimentary facies in upper sedimentary layer but also by gas-solubility changes depending on water depth. Especially, it is interpreted that the chaotic and discontinuous sedimentary structures of debris-flow deposits cause the facilitation of gas migration, whereas the continuous sedimentary layers of turbidites restrict the vertical migration of gases.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.105-115
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• 2021

The geological CO2 sequestration in underground geological formation such as deep saline aquifers and depleted hydrocarbon reservoirs is one of the most promising options for reducing the atmospheric CO2 emissions. The process in geological CO2 sequestration involves injection of supercritical CO2 (scCO2) into porous media saturated with pore water and initiates CO2 flooding with immiscible displacement. The CO2 migration and distribution, and, consequently, the displacement efficiency is governed by the interaction of fluids. Especially, the viscous force and capillary force are controlled by geological formation conditions and injection conditions. This study aimed to estimate the effects of surfactant on interfacial tension between the immiscible fluids, scCO2 and porewater, under high pressure and high temperature conditions by using a pair of proxy fluids under standard conditions through pendant drop method. It also aimed to observe migration and distribution patterns of the immiscible fluids and estimate the effects of surfactant concentrations on the displacement efficiency of scCO2. Micromodel experiments were conducted by applying n-hexane and deionized water as proxy fluids for scCO2 and porewater. In order to quantitatively analyze the immiscible displacement phenomena by n-hexane injection in pore network, the images of migration and distribution pattern of the two fluids are acquired through a imaging system. The experimental results revealed that the addition of surfactants sharply reduces the interfacial tension between hexane and deionized water at low concentrations and approaches a constant value as the concentration increases. Also it was found that, by directly affecting the flow path of the flooding fluid at the pore scale in the porous medium, the surfactant showed the identical effect on the displacement efficiency of n-hexane at equilibrium state. The experimental observation results could provide important fundamental information on immiscible displacement of fluids in porous media and suggest the potential to improve the displacement efficiency of scCO2 by using surfactants.

• Analytical Science and Technology
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• v.32 no.6
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• pp.262-270
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• 2019

The stable isotopic composition of bone collagen plays an important role in reconstructing palaeodiet, nutrition, palaeoenvironment and their lifestyle. This is the first case in extracting palaeodietary information and breastfeeding pattern of Goryeo people using stable isotope analysis due to the lack of human remains in this period. We analyzed human bone collagen excavated from Gyeongju Donggung palace and Wolji pond No.3. The average values of δ¹³C and δ¹⁵N are as follows: (δ¹³C(‰) = -19.5 ± 0.9‰, δ¹⁵N(‰) = 11.1 ± 1.1 ‰, (n = 4). Stable carbon isotope values shows a mainly C₃ based diet such as rice and barley. Stable nitrogen isotope results implies the protein sources attributed to terrestrial animals. There are various age groups in this study, which are adult, child and infant. Two individuals within early childhood age ranges (< 3 years) shows more elevated δ¹⁵N values than that of adult and this result implies the continuation of breastfeeding in this group until the age of 3. The results provide new insight into the breastfeeding pattern of Goryeo people, where breastfeeding and weaning practices have important implication for fertility, population dynamics, migration pattern and disease.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.101-116
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• 1989

Proplast and Porous Polyethylene which have porous structures as low-modulus polymers have been recently used in maxillofacial plastic and reconstructive surgery. The purpose of this study was to compare the response of adajacent tissue, new bone formation and stability after augmentation by differen methods of subperiosteal graft using proplast and purous polythylene in rabbit mandible. The augmentation procedure was carried out by dividing into two groups, A and B. A group consisted of subperiosteal graft on the cortex, and the other B group was made up only graft following artificial decortication in the mandibular body of rabbit. The experimental animals were sacrificed on the 1st, 2nd, 4th and 8th week after grafting for macroscopic and light microscopic examination. The samples extracted at the 6th postgrafting week were also used for biometric testing and scanning electron microscopic examination. The results obtained from this study were as follows : 1. Macroscopically, infection of graft site, deformation and migration of graft material were not observed in all experimental groups. 2. B group showed more rapid and increased bone formation and the greater stability than A group, and tissue response was similar to each other. 3. In the tissue response, macrophages and cellular infiltrations were observed in Proplast group, but few in PHDPE group. 4. In bone formation of A group, Proplast group showed no bone formation until the 8th week, but PHDPE group showed small quantity of osteoid tissue from the 2nd week and appositional bone growth with new bone formation at the 8th week. 5. In bone formation of B group, both Proplast and PHDPE group showed bone formation, but PHDPE group showed more rapid and larger bone formation. 6. In pattern of bone formation, Proplast group mainly showed appositional bone growth pattern connected with graft site. On the other hand, PHDPE group showed mixed pattern of new bone formation in the pore connective tissue with appositional bone growth from graff site. 7. The maximum mean values of shear stress were serially $111.3gf/mm^{2}$ in PHDPE of B group, $84.8gf/mm^{2}$ in PHDPE of A group, $32.9gf/mm^{2}$ in Proplast B group, and $15.7gf/mm^{2}$ in Proplast of A group. From above results, It was suggested that the capacity of bone formation and stability between bone and graft material were dependent on the pore size and structure of graft material itself, the state of graft site and tissue response.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.3
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• pp.296-302
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• 2011

Idiopathic gingival fibromatosisrarely occurs, but frequently recurred after surgical removal. It usually occurs in generalized symmetrical pattern but sometimes in localized unilateral pattern. The localized pattern usually affects the maxillary molar and tuberosity area. This disease usually causes tooth migration, malocclusion, and problems in eating, speech, and esthetics. A boy showed dense gingival fibromatosis localized at primary maxillary right lateral incisor area at the age of 5 years, and his maxillary right lateral incisor become severely displaced at the age of 9 years. He had no medical and hereditary factors relevant to the gingival fibromatosis. However, the dense fibrous tissue was dominant in his labial gingiva of maxillary right incisors. In order to realign the displaced incisors by orthodontic treatment, the dense fibrous tissue covered the defect space between the central incisor and the displaced lateral incisor was surgically removed. The removed specimen was examined by simple immunohistochemical(IHC) array method. IHC array showed increased expression of CTGF, HSP-70, MMP-1, PCNA, CMG2, and TNF-${\alpha}$ in keratinocytes, fibroblasts, endothelial cells, and macrophages of gingival fibromatosis tissue. Therefore, it was suggested that the gingival fibromatosis be caused by the concomitant overexpression of CTGF, HSP-70, MMP-1, PCNA, CMG2, and TNF-${\alpha}$, and resulted in the fibroepithelial proliferation and the inflammatory reaction of gingival tissue.

• Information Systems Review
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• v.21 no.1
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• pp.113-133
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• 2019

Gentrification, caused by residents who are being forced out due to the rise of rent with vitalization by an excessive increase of city tourists and Touristification, meaning of phenomenon of residents' migration caused by residential area turning into tourist attraction have recently pointed out as a global problem. In Korea, the phenomenon such as environmental pollution, the rise of land value and rent, and the weakening of community culture in Jeju island and Bukchon Hanok Village has appeared as well. This phenomenon has become a serious problem by hindering resident's quality of life. In this circumstance, Smart tourism city has been regarded as a solution of these problems. Hence, this study chose Busan city, which has been designated as a smart city since 2015, and examined the complex impacts of the economic benefits, social costs, environmental substantiality, cultural benefits, and technical effects derived from tourism development on the residents' deteriorated quality of life based on Fuzzy-set Qualitative Analysis (fsQCA). As a result, three patterns of the hindrance to residents' quality of life were derived. If social costs of tourism development are perceived to be large, the residents perceive deteriorated quality of life, even if they recognize essential benefits (technological and economic benefits) (Pattern #1) or secondary benefits (environmental and cultural benefits) (Pattern #2) of tourism development. In addition, some residents were found not to recognize any benefits of tourism development (Pattern #3).

• Journal of agricultural medicine and community health
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• v.15 no.1
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• pp.28-40
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• 1990

Rapid industrialization has induced the migration of rural people to urban areas. Such migration has created enlarged the existing low income group. Residents of low income area have increased health risk owing to their poor living environment, low income. overwork and inappropriate health care. The general objective of this study was to group the pattern of medical care utilization of low income group. The specific objectives were to identify disease prevalence and medical care utilization of low income group. To meet the objectives of this study, household interview method was applied. A total of 1845 households in 5 areas such as Bongchon 5th Dong, Bongchon 2nd Dong, Sanggae 5th Dong, Sanggae 4th Dong, and Shinrim 7th Dong were visited and interviewed by field team during the period from April 19 to May 3. 1989. The major findings obtained from the information collected were as follows : The Number of room per household used was one to two rooms. The employment state of the head of household disclosed that 88.6% had a job and the remaining 11.4% were unemployed. The average monthly income was 502,770won. however, 30% of the total income was less than 300,000 won in Bongchon 5th dong area. and 34.5% in Shinrim 7th Dong area. 41.3% of households had debts, which was consisted of household expense(33.4%), income formulation(22.7%) and medical care cost(15.9%) etc. Prevalence rate of diseases during the preceding 30days before the date of the household interview was 387.7 per 1000 persons. The prevalence rate of female was higher than that of male. 8.9% of the sick persons wasn't receiving any medical treatment, and the main reasons of which were lack of economic availability(43.3%) and feeling of non treatment needed(33.7%). According to the study results it was found that the prevalence rate of chroic diseases and the disabled in low income resident areas was higher than that in the other areas. Therefore, the health status of this group should be improved through PHC approaches. In addition. in order to prevent the diseases and promote the health of those people, the health center as well as health subcenter should be strengthened.

• Journal of the Korean Geographical Society
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• v.36 no.4
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• pp.356-381
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• 2001

This study has three objectives. One of them is to debate on the incompatible Neo-Malthusianism and Comucopianism, which give us a comparative gauge for analysis of the population elements in Korea and Japan. The other is to investigate how a variety of population elements are related to specific regions, Korea and Japan. And the last is to compare and analyze the residential preference pattems and the degree of care for the future life for the aged over 50 ages. Various elements in population show that Japan is of type superior to Korea, and that the gap between two countries is getting narrow every year. Wiber's migration expectancy is much higher in Kwangiu-si and Chollanam-do than in Hiroshima-ken. Burial customs in funeral ceremony has been vanished in Japan, but only 30 percents in Korea is crematory. This burial customs being much stiff existent in Korea, the effect of the population decrease caused by the death is reduced. A case study through questionnaire on the residential preference patterns for the aged over 50 years old shows that Japanese than Korean are more dependent on their sons and daughters, and ‘loneliness of solitary life’is the first reason in both countries. The degree of care for the future life is also remarkably higher in Japanese than in Korean. These are related in various ways to their ages, scholarships and local areas(si or gun). A general cognition in which the shortage of labour forces comes into existence in aged society is of misconception, because it comes from taking labour forces away from the aged, not from being old society. Even a minute population change is worth notice since the inertia law is also applied to the population phenomenon. Malthusinism hold fairly good even now, and the notion is very important in which population, resources and environmental problems are no longer personal or a regional matters, but the global family's issues.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.1 s.38
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• pp.7-15
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• 2006

In-situ observation of electromigration in thin film pattern of 63Sn-37Pb solder was performed using a scanning electron microscope system. The 63Sn-37Pb solder had the incubation stage of electromigration for edge movement when the current density of $6.0{\times}10^{4}A/cm^2$ was applied the temperature between $90^{\circ}C\;and\;110^{\circ}C$. The major diffusion elements due to electromigration were Pb and Sn at temperatures of $90-110^{\circ}C\;and\;25-50^{\circ}C$, respectively, while no major diffusion of any element due to electromigration was detected when the test temperature was $70^{\circ}C$. The reason was that both the elements of Sn and Pb were migrated simultaneously under such a stress condition. The existence of the incubation stage was observed due to Pb migration before Sn migration at $90-110^{\circ}C$. Electromigration behavior of 63Sn-37Pb solder had an incubation time in common for edge drift and void nucleation, which seemed to be related the lifetime of flip chip solder bump. Diffusivity with $Z^*$(effective charges number) of Pb and Sn were strongly affect the electromigration-induced major diffusion element in SnPb solder by temperature, respectively.