• Journal of the Korean association of regional geographers
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• v.3 no.2
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• pp.121-150
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• 1997

This Study puts the purpose to explicate the regionalities of land-lease farming by a comparative analisis of the five case study areas in Kungpook Province as the agricultural space system of Teagu metropolitan city. For the regional comparative analysis the province was divided into the three zones with the distance from the central city(Teagu): urban fringes, intermediate and remote zone, and then subdivided into the five regions by farming systems : horticulture, rice-farming, and dry-field farming. The data were collected from 77 land-leasing farmers by questionnaire and interview with farm managers in 5 sample villages representing the regionalities of the above five regions respectively. In spite of relatively restricted scope of the research areas, the analytical results appear remarkable regional differences in the characteristics of land-lease farming within a single agricultural space system. In the final analysis the regionalities of the five land-lease farming regions could be described respectively as follows. (1) Koryong-Gun in the inner urban fringe zone : The developing land-lease farming region of commercialized suburban horticulture with medium scale. (2) Songju-Gun in the outer urban fringe zone : The developing land-lease farming region of highly commercialized horticulture with large scale. (3) Uisong-Gun in the intermediate zone : The stagnated land-lease farming region of commercialized rice-farming with large scale. (4) Yongil-Gun in the intermediate zone : The stagnated land-lease farming region of commercializing dry-field farming with medium scale. (5) Ponghwa-Gun in the remote zone : The stagnated and delayed region in commercializing of intermountain dry-field land-lease farming with small scale. These varied regionalities resulted from the diverse spatiality as a complex of spatial orders and localities. The spatial orders in this study are frequently recognizable as a form of distance-decay, and the locality of a region is determined mostly by the its peculiarity of physical and population conditions. In the comparative analysis of the regionalities the degree of commercialization of a region is a most comprehensive and useful frame of reference because it reflects the degree of development of capitalist land-lease farming. Finally these apparent regional differentiations of land-lease farming within a agricultural space system raise the problem of impracticality of the existing uniform logic on the land-lease farming such as "large scale farms share larger part of leased farmland." This problem suggests the urgent need of reappraisal of many aspatial logics and theories on the land-lease farming.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.110-120
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• 2005

For utilizing vitrification to treat low and intermediate level waste, industrial pilot plant was designed and constructed in October 1999 at Daejon, Korea through the joint research program among NETEC, MOBIS and SGN. More than 70 tests were performed on simulated IER, DAW etc. including key nuclide surrogate(Cs, Co); this plant has been shown to vitrify the target waste effectively and safely, however, some dust are generated from the HTF(High Temperature Filter) as a secondary waste. In case of long term operation, it is also concerned that pipe plugging can be occurred due to deposited dust in cooling pipe namely, connecting pipe between CCM(Cold Crucible Melter) and HTF. In this regard, we have developed the special complementary system of the off-gas treatment system to recycle the dust from HTF to CCM and to remove the interior dust of cooling pipe. Main concept of the dust recycling is to feed the dust to the CCM as a slurry state; this system is regarded as of an important position in the viewpoint of volume reduction, waste disposal cost and glass melt control in CCM. The role of DRS(Dust Recycling System) is to recycle the major glass components and key nuclides; this system is served to lower glass viscosity and increase waste solubility by recycling B, Na, Li components into glass melt and also to re-entrain and incorporate into glass melt like Cs, Co. Therefore dust recycling is helpful to control the molten glass; it is unnecessary to consider a separate dust treatment system like a cementation equipment. The effects of Dust Cleaner are to prevent the pipe plugging due to dust and to treat the deposited dust by raking the dust into CCM. During the pilot vitrification test, overall performance assessment was successfully performed; DRS and Dust Cleaner are found to be useful and effective for recycling the dust from HTF and also removing the dust in cooling pipe. The obtained operational data and operational experiences will be used as a basis of the commercial facility.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.5
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• pp.217-227
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• 2017

The object of this study is to estimate the net volume transport and the residual flow that changed by space and time at southern part of Yeomha channel, Gyeonggi Bay. The cross-section observation was conducted at the mid-part (Line2) and the southern end (Line1) of Yeomha channel for 13 hours during neap and spring-tides, respectively. The Lagrange flux is calculated as the sum of Eulerian flux and Stokes drift, and the residual flow is calculated by using least square method. It is necessary to unify the spatial area of the observed cross-section and average time during the tidal cycle. In order to unify the cross-sectional area containing such a large vertical tidal variation, it was necessary to convert into sigma coordinate system by horizontally and vertically for every hour. The converted sigma coordinate system is estimated to be 3~5% error when compared with the z-level coordinate system which shows that there is no problem for analyzing the data. As a result, the cross-sectional residual flow shows a southward flow pattern in both spring and neap tides at Line2, and also have characteristic of the spatial residual flow fluctuation: it northwards in the main line direction and southwards at the end of both side of the waterway. It was confirmed that the residual flow characteristics at Line2 were changed by the net pressure due to the sea level difference. The analysis of the net volume transport showed that it tends to southwards at $576m^3s^{-1}$, $67m^3s^{-1}$ in each spring tide and neap tide at Line2. On the other hand, in the control Line1, it has tendency to northwards at $359m^3s^{-1}$ and $248m^3s^{-1}$. Based on the difference between the two observation lines, it is estimated that net volume transport will be out flow about $935m^3s^{-1}$ at spring tide stage and about $315m^3s^{-1}$ at neap tide stage as the intertidal zone between Yeongjong Island and Ganghwa Island. In other words, the difference of pressure gradient and Stokes drift during spring and neap tide is main causes of variation for residual current and net volume transport.

• Economic and Environmental Geology
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• v.43 no.1
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• pp.53-66
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• 2010

We report petrologic characteristics including $^{40}Ar-^{39}Ar$ absolute ages of the subsurface lavas recovered from borehole cores in two islets, Marado and Gapado, off the southwestern coast of Jeju in southernmost Korea and discuss on the volcanism in the region. The lavas in Gapado are apparently divided into one unit with bright colored, aphanitic texture and sheet jointed, and another unit with dark colored and massive. The outcrops often show differentially weathered pattern due to textural difference. While, the lavas in Marado have vesicular and glomerporphyric texture, even though each lava flow unit in Marado has slight unique texture with variation of vesicularity and phenocrysts. The chemical composition of rock core samples from Gapa borehole and Mara borehole shows that the lavas from Gapado and Marado are classified into basaltic trachyandesite($SiO_2$ 52.6-53.6 wt%, $Na_2O+K_2O$ 7.3-7.5 wt%) and tholeiitic andesite($SiO_2$ 51.7-52.8 wt%, $Na_2O+K_2O$ 3.6-4.1 wt%), respectively. The measured $^{40}Ar-^{39}Ar$ plateau ages range from $824{\pm}32\;Ka$(MSL -69 m) to $758{\pm}\;Ka$(MSL 19 m) for core samples of Gapa borehole and $259{\pm}168\;Ka$(MSL -26 m) for a core sample of Mara borehole, respectively. The absolute age of Gapado basaltic trachyandesite is well correlated with that of Sanbangsan trachyte(Won et al., 1986). Meanwhile, the age of a sample in Marado has $259{\pm}168\;Ka$(MSL -26 m) with poor plateau age formation and high error range. We report the data in caution but the rock composition and absolute age of Marado tholeiitic andesite are relatively correlated with those of lava units from Duksu and Sangmo-2 boreholes, indicating the volcanism during 260-150 Ka. On the basis of interpretation of occurrences of exposed and subsurface volcanic rocks of the study area, stratigraphic relationship with adjacent borehole cores and the bathymetry chart of surrounding area, it indicates that the lavas in Gapado were formed around 800 Ka during relatively early stage of volcanic activity in Jeju Island. Meanwhile, Marado may have originated around 260-150 Ka during relatively young stage of volcanism in Jeju Island. It is inferred that the volcanisms have originated in land and these islets were individual ancient volcanoes. The apparent topography has been re-shaped by tidal erosion due to transgression.

• Archives of design research
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• v.16 no.1
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• pp.181-198
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• 2003

The purpose of this study is to develop a on-line design tool for effectively coping with e-Business environment, or product design process into a Cyber model for traditional manufacturers which attempts new product development under such environment. It was finally developed as a model named $\ulcorner$Design Vortal Site; e-BVDS) that was based on the structure and style of internet web site. Results of the study can be described as follows ; \circled1 e-Business is based on the Internet. All processes in the context of e-Business require models whose structure and method of use are on-line styles. \circled2 In case that a traditional manufacturing business is converted into e-Business, it is better to first consider Hybrid Model that combines resources and advantages of both such traditional and digital businesses. \circled3 The product design process appropriate for e-Business environment has to have a structure and style that ensure utilization of the process as an Internet web site, active participation by product developers and interactive communication between participants in designing and designers. \circled4 $\ulcorner$e-BDVS) makes possible the use of designers around the wend like in-house designers, overcoming lack in creativity, ideas and human resources traditional business organizations face. However, the operation of $\ulcorner$e-BDVS$\lrcorner$ requires time and budget investments in securing related elements and conditions. \circled5 Cyber designers under $\ulcorner$e-BDVS$\lrcorner$ can easily perform all design projects in cyber space. But they have some limits in playing a role as designers and they have difficulty in getting rewards if such projects completed by them are not finally accepted. \circled6 $\ulcorner$e-BDVS) ensures the rapid use of a wide range of design information and data, reception of a variety of solutions and ideas and effective design development, all of which are not possible through traditional processes. However, this process may not be suitable to be used routine process or tool. \circled7 $\ulcorner$e-BDVS$\lrcorner$ makes it possible for out-sourcing or partners businesses to overcome restrictions in time and space and improve productivity and effectiveness. But such they may have to continue off-line works that can not be treated on-line.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.4
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• pp.29-41
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• 2015

Abandoned paddy field provides an excellent opportunity to improve the species diversity and habitat quality. Ecological characteristic on the changing of plant communities at different seral stages is a major basis data for ecological restoration. In this study, we investigated changes of the species composition and community indices on the plant community associated with abandonment of cultivated rice paddies. The ecological stability of the habitat was evaluated by using eco-floristic characters(Di; Disturbance index, AUI; Actual urbanization index). Survey sites were grouped into six stages(stageI (${\leq}3years$), stageII(3-5years), stageIII(5-7years), stageIV(7-10years), stageV(10-15years), stageVI(${\geq}20years$). Vegetation investigation was done from May 2009 to October 2012 and carried out phytosociological approach. The total flora were summarized as 176 taxa including 58 families, 127 genera, 157 species, 3 subspecies, 15 varieties and 1 forms. At each of successional stages, 64 taxa in stage I, 34 taxa in stage II, 84 taxa in stage III, 83 taxa in stage IV, 92 taxa in stage V, 23 taxa in stage VI were identified. Of the occurrence plants, the species with the highest r-NCD value were Alopecurus aequalis, Juncus effuusus var. decipiens, Persicaria thunbergii, Artemisia princeps, Salix koreensis and Alnus japonica at each stages. Herbaceous annual plants were dominated in the early stage, but its r-NCD value declined in the middle stage and the late stage. On the other hand, herbaceous perennial plants and Persicaria thunbergii, annual hydrophytes, increases in the middle stage. Woody plant and herbaceous plant which appeared in the forest edge increases in the late stage. Community indices correlate with successional stages. Richness and diversity index increase along the successional gradient. But dominance index decrease along the successional gradient. Evenness index was correlated with lower. In the ecological stability analysis of the habitat that evaluated by eco-floristic characters, stage I was the most unstable habitat. And the stability of the habitat has improved according to the successional stage.

• Science of Emotion and Sensibility
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• v.9 no.2
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• pp.111-118
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• 2006

The purpose of the study is to examine the effects of the positive menial stress, eustress, on autonomic nervous system(ANS) and human health. For this, we analyzed heart rate variability(HRV) parameters, the most promising markers of ANS function to assess the changes of emotional and physiological states of human body. We measured HRV Signal of World Cup group(281 male subjects: $29.8{\pm}5.6yr$., 187 female subjects: $29.0{\pm}5.4yr$.) in two stadiums at least an hour before the game during '2002 FIFA World Cup Korea/Japan' event. We also measured control group's(331 male subjects: $30.9{\pm}4.7 yr$., 344 female subjects: $30.2{\pm}5.2 yr$.) in the health promotion centers in two university hospitals at least a month before and after the world cup event period. Considering physiological differences between males and females, the data analysis was applied to 'male group' and 'female group' separately. As a result, some tendency was observed that is different from what we have known as the stress reaction. In general, all parameter values except that of mean heart rate tend to decrease under stressed condition. However, under eustressed condition, both heart rate and standard deviation of the Normal to Normal intervals(SDNN) were higher then those of normal condition(p<0.05). Especially, in case of female group, contrary to distressed condition, every frequency-domain powers showed tile higher value(p<0.05, p<0.001). Considering that decrease of HRV indicates the loss of one's health, the increase of SDNN and frequency parameters means that homeostasis control mechanism of ANS is functioning positively. Accordingly, induction of eustress from international sports event may affect positively to the people's health.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.54-62
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• 2005

The present study was to determine how seasonal rainfall intensity influences nutrient dynamics, ionic contents, oxygen demands, and suspended solids in a lotic ecosystem. Largest seasonal variabilities in most parameters occurred during the two months of July to August and these were closely associated with large spate of rainfall. Dissolved oxygen (DO) had an inverse function of water temperature (r = = = - 0.986, p<0.001). Minimum pH values of<6.5 were observed in the late August when rainfall peaked in the study site, indicating an ionic dilution of stream water by precipitation. Electrical conductivity (EC) was greater during summer than any other seasons, so the overall conductivity values had direct correlation (r = 0.527, p<0.01) with precipitation. Ionic dilution, however, was evident 4 ${\sim}$ 5 days later in short or 1 ${\sim}$ 2 weeks in long after the intense rain, indicating a time-lag phenomenon of conductivity. Daily COD values varied from 0.8 mg $L^{-1}$ to 7.9 mg $L^{-1}$ and their seasonal pattern was similar (r = 0.548, p<0.001) to that of BOD. Total nitrogen (TN) varied little compared to total phosphorus (TP) and was minimum in the base flow of March. In contrast, major input of TP occurred during the period of summer monsoon and this pattern was similar to suspended solids, implying that TP is closely associated (r = 0.890, p<0.01) with suspended inorganic solids. Mass ratios of TN : TP were determined by TP (r= -0.509, p<0.01) rather than TN (r= -0.209, p<0.01). The N : P ratios indicated that phosphorus was a potential primary limiting nutrient for the stream productivity. Overall data suggest that rainfall intensity was considered as a primary key component regulating water chemistry in the stream and maximum variation in water quality was attributed to the largest runoff spate during the summer monsoon.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.188-197
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• 2008

This research was a preliminary case study to determine the levels of total mercury in the tissues of sentinel species (Zacco platypus) and ecological health in relation to habitat characteristics and chemical conditions. We collected fishes in Gap Stream during June$\sim$October 2007 and analyzed the total mercury from five types of tissues such as liver, kidney, gill, vertebrae and muscle of Zaceo platypus using Direct Mercury Analyzer (DMA-80, US EPA Method 7473). Mean concentrations of total [Hg], based on all tissues, was 67.2 and $20.7\;{\mu}g\;kg^{-1}$, in the upstream and downstream site, respectively, indicating 3 times greater level in the upstream. In other words, the levels were higher in the pristine upstream than the downstream influenced by the wastewater disposal plant. Chemical water quality, based on BOD, COD and nutrients (TN, TP) showed that severe degradation occurred in the downstreams than the upstreams. Index of Biological Integrity (IBI) using fish multi-metric model averaged 32, indicating a "good$\sim$fair" condition and varied from 42 (excellent$\sim$good) at S2 to 22 (fair$\sim$poor) at S5 depending on the sites sampled. Qualitative Habitat Evaluation Index (QHEI) in the all sites averaged 142, which was judged as "good" habitat health, but showed a high variation (181 in Site 2 vs. 67 in Site 5). Overall data suggest that health conditions, based on IBI and QHEI, was better in the upstream sites but the mercury bioaccumulation levels in the fish tissues were opposite. We believe that measurements of various parameters are required for a diagnosis of integrative ecosystem health.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.4
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• pp.307-312
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• 2009

This experiment was conducted to compare the agronomic characteristics and productivity of induced annual legumes at paddy field of Cheonan and Naju from 2004 to 2006. Chinese milk vetch (wild type), crimson clover (C.V. Linkarus), forage pea (C.V. Austrian pea), hairy vetch (C.V. Oregon commen) were used in this study. At the Naju region, the earliest flowering on 2nd may was found in Chinese milk vetch, while the latest on 18th May in forage pea. Fresh, dry matter (DM) and crude protein (CP) yields of crimson clover were highest as 28,870, 6,986 and 943 kg/ha, respectively. but the yield of chinese milk vetch was low by 9,885, 1,749 and 338 kg/ha. At the Cheonan region, the most fast flowering date variety was Chinese milk vetch, hairy vetch was very late as 19th May. Fresh, DM and CP yields of hairy vetch were highest as 7,916, 1,141 and 113 kg/ha, respectively. but the yield of chinese milk vetch showed the lowest by 270, 42 and 8 kg/ha. The CP content of annual legumes was 14.3%. chinese milk vetch showed the highest CP content by 19.3% and hairy vetch showed the lowest content by 9.9%. The present data showed that the productivity was closely dependent on winter hardness, in conclusion, crimson clover at Naju and hairy vetch at Cheonan region was suggested to be the most proper species as winter crop after rice harvest on paddy field when considered the winter hardiness.