• Journal of the Korean Regional Science Association
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• v.39 no.2
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• pp.47-61
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• 2023

Satisfaction on the residential environment is a major factor influencing the choice of residence and migration, and is directly related to the quality of life in the city. As online services of real estate increases, people's evaluation on the residential environment can be easily checked and it is possible to analyze their satisfaction and its determining factors based on their evaluation. This means that a larger amount of evaluation can be used more efficiently than previously used methods such as surveys. This study analyzed the residential environment reviews of about 30,000 apartment residents collected from 'Zigbang', an online real estate service in Seoul. The apartment review of Zigbang consists of an evaluation grade on a 5-point scale and the evaluation content directly described by the dweller. At first, this study labeled apartment reviews as positive and negative based on the scores of recommended reviews that include comprehensive evaluation about apartment. Next, to classify them automatically, developed a model by using Bidirectional Encoder Representations from Transformers(BERT), a deep learning-based natural language processing model. After that, by using SHapley Additive exPlanation(SHAP), extract word tokens that play an important role in the classification of reviews, to derive determining factors of the evaluation of the residential environment. Furthermore, by analyzing related keywords using Word2Vec, priority considerations for improving satisfaction on the residential environment were suggested. This study is meaningful that suggested a model that automatically classifies satisfaction on the residential environment into positive and negative by using apartment review big data and deep learning, which are qualitative evaluation data of residents, so that it's determining factors were derived. The result of analysis can be used as elementary data for improving the satisfaction on the residential environment, and can be used in the future evaluation of the residential environment near the apartment complex, and the design and evaluation of new complexes and infrastructure.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.173-187
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• 2023

In an era of population decline, depopulated regions facing challenges in attracting inbound population migration must enhance urban vitality through the attraction of living populations. This study focuses on Busan, a city experiencing population decline, comparing the spatiotemporal distribution characteristics of registered residents and living populations in various administrative districts (Eup-Myeon-Dong) using mobile communication big data. Administrative districts are typified based on population change patterns, and regional characteristics are analyzed using indicators related to urban decline and vitality. Spatiotemporal distribution analysis reveals generally similar density patterns between registered residents and living populations; however, a distinctive feature is observed in the city center areas where the density of registered residents is low, while the density of living populations is high. Divergent trends in spatial patterns of change between registered residents and living populations show clusters of registered population decline in low-density areas and clusters of living population decline in high-density areas. Areas adjacent to declining living populations exhibit large clusters of population changes, indicating a spillover effect from high-density to neighboring areas. Typification results reveal that, even in areas with a decline in registered residents, there is active population influx due to commuting or visiting. These areas sustain an increase in the number of businesses, confirming the presence of industrial and economic growth. However, approximately 47% of administrative districts in Busan are experiencing a decline in both registered residents and living populations, indicating ongoing regional decline. Urgent measures are needed for enhancing urban vitality. The study emphasizes the necessity of utilizing living population data as an urban planning indicator, considering the increasing limit distance of urban activities and growing interregional interaction due to advancements in transportation and communication.

• Korean Journal of Materials Research
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• v.26 no.12
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• pp.688-695
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• 2016

Recrystallization behavior has been investigated for commercial purity AA1050 (99.5wt%Al) and high purity 3N Al (99.9wt% Al). Samples were cold rolled with 90% of thickness reduction and were annealed isothermally at 290, 315, and 350o C for various times until complete recrystallization was achieved. Hardness measurement and Electron Backscatter Diffraction(EBSD) analyses, combined with Grain Orientation Spread(GOS), were employed to investigate the recrystallization behavior. EBSD analysis combined with GOS were distinctly revealed to be a more useful method to determine the recrystallization fraction and to characterize the recrystallization kinetics. As the annealing temperature increased, recrystallization in AA1050 accelerated more than that process did in Al 3N. Both AA1050 and Al 3N showed the same temperature dependence of the n value of the Johnson-Mehl-Avrami-Kolmogorov equation(JMAK equation), i.e., n values increased as annealing temperature increased. Activation energy of recrystallization in AA1050 is about 176 kJ/mol, which is comparable with the activation energy of grain boundary migration in cold-rolled AA1050. This value is somewhat higher than the activation energy of recrystallization in Al 3N.

• Korea journal of population studies
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• v.18 no.2
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• pp.98-114
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• 1995

Since 1962 the Korean society has undergone a rapid transformation under government policies to achieve maximum economic growth. Urbanization via massive rural to urban migration has been observed to be connected with a rapid economic development. Based on the data from the government publications such as Population and Housing Census Reports and Korean Urban Yearbooks, this study measures inequalities in terms of the distribution of urban population. In a historical context, the pace of urbanization during the period 1966-1970 was characterized as the most rapid and the urban-rural growth difference(URGD), which is a valuable measure of the pace of urbanization, was the highest. In terms of regional pattern, Seoul dominated the urbanization picture of Korea during the period 1966-1970. Its annual growth rate was the fastest among those shown during the period 1960 to 1990 and also highest. However, Seoul's primacy was pulled down since 1970. The Gini coefficient, which is the most common general measure of inequalities in distribution, was the highest in 1980. Since 1980 it has continued to fall. As a result, it was lower in 1990 than in 1970. Despite lowering Gini coefficient, inequalities are still large. A concentration index also showed the same trends as those of Gini coefficent.

• Archives of Plastic Surgery
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• v.32 no.6
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• pp.727-732
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• 2005

The treatment of wounds of the lower extremity caused by diabetes or vascular dysfunction remains a difficult problem for the plastic surgeon. The use of negative pressure in wound healing is a relatively new method to facilitate chronic wound healing by secondary healing. The use of vacuum-assisted closure(VAC) system is purposed to reduce local edema, increase regional blood flow, enhance epithelial migration, preserve a moist wound environment, reduce bacterial colonization, promote granulation tissue formation, and mechanically enhance wound closure. The VAC also can be used as a dressing for anchoring an applied split thickness skin graft. We reviewed the data from 20 consecutive patients with non-healing wound in lower extremity at Dong-A University from March 2002 to December 2004. We used the VAC in 20 patients and compared the results with the control group. In the VAC using group, mean application duration was about 3 weeks and dressing change was done every other day. The follow-up period of patients ranged from 3 months to 30 months with a mean of 17 months. The points of comparison with control group are wound size, granulation tissue proliferation rate, operation method, preoperative time, postoperative healing time, complication, and cost. With those points, we propose to approve the efficiency of the VAC in non-healing wound. As a result, the VAC used in non-healing wound decrease wound size, accelerate granulation tissue formation, do a wound closure with less invasive operation method, make less postoperative complication, can make operation time shorter. Therefore it is cost effect. Our results demonstrate the usefulness of VAC as an adjunct in management of chronic wounds with other extrinsic factors.

• Journal of Korean Society of Rural Planning
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• v.19 no.1
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• pp.109-122
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• 2013

The rapid rural urban migration and aging has generated an over-depopulation problems in rural areas since the 1980s. The purpose of this study constructs the marginal size of rural over-depopulated village through the analysis of the residential disparities such as farmer's ratio, basic life service accessibility, and levels of social and economic factors for each village community. This marginal scale could support evaluating diverse rural policies, which have been planned to apply to the rural development programs at the village level. The major challenges for over-depopulated villages are the lack of basic facilities, production infrastructures and inactive communities in the village. Therefore, the quantitative analysis of rural residential disparities according to rural village scale can provide the criteria for rural over-depopulated villages. We utilized Korea Agricultural Survey Data(2010) including specific residential condition of village level. The present study adopt multinomial-logit model for quantitative analysis of different village scales and decomposition techniques to separate the direct effect by the village scale factor from the endowment effects by regional or area characteristics, and residual effect by unknown factors. The present study found that the minimum scale of a rural over-depopulated village was 40 and 60 houses for the respective conditions of farmer's ratios less than 50% and greater than 75%. It was concluded based on the study findings that threshold scale could support evaluating the diverse rural policies, which have been planned to apply to the rural development programs at the village level.

• The Journal of Fisheries Business Administration
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• v.24 no.2
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• pp.1-16
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• 1993

Because of the radical changes in the domestic and foreign economic circumstances Koreaa fisheries is confronted with difficulties. Along the end of the UR marine products of other nations are rushing into Korea. Also migration of labor to other industries and rise of wage level in Korean fisheries deteriorate managerial conditions. But in Korea which has little natural resourses fisheries is still more important. That is \circled1 creating job opportunites \circled2 increase of income \circled3 supply of foodstuffs and animal protein \circled4 acquisition of foreign currency \circled5 enlargement of domestic market for industrial products \circled6 development of other interrelated industries \circled7 rational use of domestic resourses \circled8 diversification of population and production activites \circled9 contribution to balanced growth of national economy by the developing regional economy. These roles of fisheries in national economy mentioned above are to be excuted forward. In spite of the radical change in the economic circumstances at the end of the UR fisheries if crucial in Korea as a industry. For this our fisheries is to be made to compete with foreign fisheries. Through the cheap price and high quality our fisheries must be came to compete with foreign fisheries and meet the people's needs for marine products. For this it is necessary to maintain high productivity and competitive power. Now with the exception of a portion of the deep - sea fishing, our fisheries is generally paltry, Especially inshore fishery which is the main stock in our fisheries is very paltry and so productivity and competetive power are very low. So to develop our fisheries which has s comparative disadvantage active polices that follows below are to be promoted on a large scale. \circled1 improvement of structure \circled2 augmentation of productivity in fishing ground by making fisheries resourses \circled3 enlargement of finantial and monetary assistance \circled4 effective administration of fisheries cooperative union \circled5 activation of R&D etc These polices which need to be scientific and comprehensive are very valuable. Especially without making fishieries resources we cannot expect economy of scale, promotion of productivity and development of fisheries. And we do also endeavour to gather the results of the study and investigation about fisheries domestic and foreign and do ceaselessly put these to practical use systimatically.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.303-314
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• 2011

This paper proposes a differential pricing model for industrial land based on locational characteristics, using Support Vector Regression (SVR) as a land pricing methodology. The initial selling price of industrial land is set based on the total cost of site development that comprises the land acquisition cost and tax, land development expense, infrastructure installation cost, labor cost, migration expense, selling and administrative expense, capital cost, and so on. However, the current industrial land pricing method unreasonably applies the same price per square meter to all parcels within an industrial complex without considering differences in price depending on the location of each parcel. Therefore, this paper proposes an empirical land pricing model to solve this irrationality and verifies its validity and applicability.

• Economic and Environmental Geology
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• v.29 no.6
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• pp.689-698
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• 1996

The coal-bearing metapelites from the Hoenam area are interbedded within the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with trace amount of biotite, chlorite, pyrite, rutile and barite. Although the formation was mined for coal, and the contents of V, U and Mo are a higher grade in coal formations than the host metapelites. The ratios of Al/Na and K/Na in coal formation are very heterogeneous and wide range from 10.28 to 90.91 and from 3.73 to 36.60, respectively. The V content increase with increasing Al and Ba contents, but the U and Mo are not related with other elements. Those are suggested that controlled of mineral compositions in coaly metapelites due to substitution, migration and reequilibrium of elements by regional metamorphism. These coal formation were deposited in basin of marine environments and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of Al content versus La, La against Ce, the ratios of La/Ce (0.23 to 0.73) and Th/U (0.03 to 16.6). These rocks also show much variation in $La_N/Yb_N$ (0.53 to 14.19), Th/Yb (0.51 to 6.00) and La/Th (0.15 to 18.92), and their origin is explained by derivation from a mixture of sedimentary and metasedimentary rocks. The wide range in trace and REE element characteristics as Co/Th (0.07 to 3.00), La/Sc (0.04 to 23.48), Sc/Th (0.06 to 7.57), V/Ni (2 to 3319), Cr/V (0.03 to 1.06) and Ni/Co (1.00 to 79.85) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation.

• Journal of the korean society of oceanography
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• v.32 no.4
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• pp.181-190
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• 1997

A large subtidal sand ridge (Jungang Satoe) in Asan Bay, on the west coast of Korea, was studied in order to understand the morphology and sediment transport trend in a macrotidal setting, by means of analyzing sediment samples, current data, side-scan sonographs and seismic profiles. The ridge is about 15 km long and 2-5 km wide, with a relief of about 15 m. It is elongated in the flow direction of flood (SE) and ebb (NW) tidal currents, but asymmetrical in cross section. The western and southwestern side of the ridge is characterized by relatively gentle slopes averaging 0.4$^{\circ}$, whereas on the northeastern side, relatively steep slopes were mapped with 1.6$^{\circ}$ slope angles. Tidal currents associated with the ridge are very strong; maximum surface velo-cities range from neap values of 50 cm/s to spring values of 130 cm/s. The shear velocities during flood and ebb are strong enough to erode and transport sands on the ridge. Sand waves and megaripples (dunes) are the most common bedforms produced by the tidal currents, which show regional differences in shape and size on the ridge. The distribution pattern of these bedforms in-dicates that the flood tidal currents are dominant on the offshore (northwest) side of the ridge, whereas the onsho.e (southeast) side of the ridge is ebb-dominated. The sand transport path as inferred from bedform orientations is directed toward the ridge crest on the flanks, whereas on the crest, it is near-longitudinal to the ridge axis. The convergent, upslope movement of sands on the ridge flanks appears to be important in sand ridge building and maintenance. A significant ridge migration toward the northeast can be suspected on the basis of the ridge morphology, which may cause offshore hazards for navigation.