• Journal of the Economic Geographical Society of Korea
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• v.22 no.4
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• pp.438-457
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• 2019

The main purpose of this paper is to identify the entry types and locational determinants of North Korean workers in cross-border regions between North Korea and China. More specifically, the paper has attempted to divide the entry type of them in the regions into two; 1) entry via transactions between Chinese traders with North Korea and North Korea trade companies, and 2) entry via transactions between Korean-Chinese middlemen and North Korean trade companies. Also, it has analyzed main factors of their locational determinants in the spatial contexts of the regions. There have been changes in two perspectives in terms of the entry paths and types of them in accordance with the transformation of characteristics of United Nations sanction against North Korea from 'call-upon' to 'decide' after UN Security Council Resolution 2094 in 2013. Firstly, main agents who have dealing with North Korean trade companies which have right to dispatch North Korean workers have been changed from Chinese traders into Korean-Chinese brokers who are specialized in the introduction of North Korean workers with one-stop service from visa administrative to labor managements. Secondly, there has been a transfer of North Korean workers in the regions from formal to informal workers who has been admitted into China with a short stay or a tourist visa, and then remained illegally to be employed in China. Therefore, as demands on service which is able to guarantee the security of North Korean informal workers and their managements have increased, Korean-Chinese brokers have been stimulated in the regions after the operation of real international sanctions against overseas North Korean workers. In addition, the main factors of their locational determinants in cross-border regions between North Korea and China are could be analyzed in three perspectives; 1) an increase in real wages in accordance with the reform of the Chinese social insurance system after 2011, 2) the structural vulnerability of labor markets in the regions, 3) the utilization of stable and manageable workers.

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.524-540
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• 2005

This study has focused on the amount of evaporites and geochemical characteritics of evaporites from the acid mine drainage and on the variation of constituents in acid mine drainage during evaporation. The various colors of evaporites are frequently observed at the rock surfaces contacting acid mine drainage. In order to produce evaporites in the laboratory, acid mine drainages were sampled from the abandoned mine areas (GTa, GTb, GH and GB) and air-dried at room temperature. During the evaporation of acid mine drainages, TDS, EC values and the concentrations of major and minor ions increased, whereas ER and DO values decreased with time. The concentration of Fe increased gradually with evaporation time in the GTb and GB, whereas GH founded in one day but rapidly not detected in the other day after due to removal of Fe by formation-precipitation of amorphous Fe hydroxide. The amounts of the evaporites were produced in amounts of 4 g (GTa), 5 g (GB), 15 g (GH), and 24 g (GTb) from 4 liter of acid mine drainage after 80 days of the evaporation, respectively. In linear analysis from the products with the parameters which are the EC, TDS, salinity, ER, DO and pH contents in field, the determination coefficients were 0.98, 0.99, 0.98, 0.88, 0.89, and 0.25 respectively. If we measure the parameters in field, it would be easy to estimate the amount of evaporites in acid mine drainage. Gypsum and epsomite were identified in all of the evaporites by x-ray powder diffraction studies. Evaporite (GTb) was heated at 52, 65, 70, 95, 150, 250, and 350oC for one hour in electrical furnaces. Gypsum, $CaSO_4\cdot1/2H_2O$ and kieserite were identified in the heated evaporite by XRD. With increased heating temperature, the intensity of the peak at $7.66/AA$ (diagnostic peak of gypsum), the peak at 5.59A ($CaSO_4{\cdot}1/2H_2O)$ and the peak at $4.83{\AA}$ (kieserite) decreased in x-ray diffraction due to dehydration. In the SEM and EDS analysis for the evaporite, gypsum of well-crystallized, radiating cluster of fibrous, acicular, and columnar shapes were observed in all samples. Ca was not detected in the EDS analysis of the flower structures of GTb. Because of that, the evaporite with flower structures is thought to be eposmite.

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.130-149
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• 2017

The subalpine zone which is vulnerable to climate change could be functioning as a habitat for northern plant species especially in the Korean peninsula. In this study, classification of phytosociological community type and investigation on flora of vascular plants of Daecheongbong area in Mt. Seorak were carried out in order to provide a basic information for an ecological restoration and management of the vegetation through community ecological approach. Vegetation data were collected from 31 of quadrates from May to October, 2016. We analyzed vegetation types with phytosociological method, importance value with Curtis & McIntosh method, CCA using PC-ORD program tool, and flora of vascular plants. As a result, the forest vegetation was classified into Abies nephrolepis community. The community was divided 3 groups such as Pinus pumila group, Rhododendron brachycarpum group and Angelica decursiva group. Therefore, the vegetation had 3 kinds of units. The differential species group, it was classified into total of 7 species group units including Thuja koraiensis and Smilacina bicolor differential species group. The mean importance percentage (MIP) in VU 1 was shown Pinus koraiensis (24.1), A. nephrolepis (23.6) and Betula ermanii (10.5), and in VU 2, it was P. koraiensis (26.2), A. nephrolepis (20.8) and B. ermanii (10.5), and in VU 3, it was P. koraiensis (22.2), A. nephrolepis (16.4), B. ermanii (13.5) in the order, respectively. As for importance values of P. koraiensis and A. nephrolepis representative competition species, were different at each layers. The former (46.7) was higher than the latter (26.1) in tree layer, but the latter was higher than the former in subtree and, shrub and herb layers of VU 1. VU 2 and VU 3 also indicated the same tendency. P. pumila group and A. decursiva group were shown to have positive correlation with altitude and present species, respectively. The designated as the endemic plant was 11 taxa and, as the rare plant 24 taxa and 62.5% of vascular plant was northern plant species. It is necessary to continue further long-term monitoring of 3 vegetation units, IV of main competition species (P. koraiensis and A. nephrolepis) with stratum and main specific species (rare plants and endemic plants) considering vegetation science and, population and community ecology approaches.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.72-81
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• 2013

The objective of this study was to verify whether SCB(Slurry Composting & Bio-filtration) system can be applied for the treatment of anaerobic digestion(AD) wastewater and also, to identify the most effective set among three filtration compost beds tested. Results can be summarized as these; (a) When AD wastewater was sprayed on the top of beds which were mainly composed of sawdust and/or other media and, subsequently, filtrates collected and analyzed, there were large drop in the values of Electric Conductivity(EC), Total Suspended Solid(TSS), Biochemical Oxygen Demand(BOD), and Chemical Oxygen Demand(COD). In contrast, Total Nitrgen(T-N) and Total Phosphorus(T-P) were progressively elevated. We consider these changes as positive if the filtrate are to be utilized as liquid fertilizer. (b) When three sets of filtration beds (T1, T2, T3) were compared for their effectiveness, no significant difference was found among them. These indicate that expensive sawdust can be replaced in part with cheaper media such as woodchip, rice husks, or others. (c) At early stage of operation (within 20 days), BOD in filtrates were maintained at high level probably due to the lack of microbial activity. During the same stage, T-N, T-P was at low level but, were elevated to higher levels thereafter. These data, when combined, indicate that the filtration system needs at least a couple of weeks for the optimized microbial functioning. (d) The temperatures of the experimental beds were progressively dropped as the experiment continued through the fall season, although filtration effectiveness was not noticeably influenced.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.391-403
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• 1998

The study was carried out to devise a proper measure to increase the income of mountain villagers by producing sap water of Acer mono, and to make the most of sap water as local specialty to contribute to the local economy of mountain villages. All the processes from collecting to marketing of sap water of Acer mono was investigated. The survey was done from mid-January to mid-February in the 3 major sap water collecting regions, Toji-myon Kurey-gun(Piagol area of Mt. Chiri), Okryong-myon Kwangyang city(Mt. Baekun), and Jookhack-ri Sunchon(Mt. Chokey). A total of 90 householders who collect sap water, to say again, 30 householders in each region, were interviewed personally to make up questionnaires. The habitual or general practices about collecting sap water, the selling price, the sales process, labor power to collect and carry down, carrying distance and facilities, sales income and side income, and family income were investigated and examined. Spots of collecting sap water were not concentrated but scattered all over the collecting area. Collecting method, collecting amount, sales process, and selling price varied with the village and region. Sap water was collected by tapping or boring method, the latter of which was widely used in lots of regions except in Sunchon. Although the amount of sap production per family varied with region, the average amount was about 1,350 liters. Of all the sap water collected, 44% was consumed by drinking of on-the-spot visitors and 36% was sold by order, etc. Sap water was sold at the price varying from 10,000 won to 60,000 won per 18 liters. The average selling price was 41,000 won, but selling prices of 43,000 won and 45,000 wan amounted to 38% and 25%, respectively.

• Knowledge Management Research
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• v.21 no.3
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• pp.249-269
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• 2020

Recently, as the online market has matured, it is facing many problems to prevent the growth. The most common problem is the homogenization of online products, which fails to increase the number of customers any more. Moreover, although the portion of the online market has increased significantly, it now becomes essential to expand offline for further development. In response, many online firms have recently sought to expand their businesses and marketing channels by securing offline spaces that can complement the limitations of online platforms, on top of their existing advantages of online channels. Based on their competitive advantage in terms of analyzing large volumes of customer data utilizing information technologies (e.g., big data and artificial intelligence), they are reinforcing their offline influence as well through this online for offline (O4O) business model. On the other hand, most of the existing research has primarily focused on online to offline (O2O) business model, and there is still a lack of research on O4O business models, which have been actively attempted in various industrial fields in recent years. Since a few of O4O-related studies have been conducted only in an experience marketing setting following a case study method, it is critical to conduct an empirical study on O4O selection attributes and their impact on customer satisfaction and loyalty. Therefore, focusing on China's representative O4O business model, 'Fresh Hema,' this study attempts to identify some key selection attributes specialized for O4O services from the customers' viewpoint and examine the impact of these attributes on customer satisfaction and loyalty. The results of the structural equation modeling (SEM) with 300 O4O (Fresh Hema) experienced customers, reveal that, out of seven O4O selection attributes, four (mobile app quality, mobile payment, product quality, and store facilities) have an impact on customer satisfaction, which also leads to customer loyalty (reuse intention, recommendation intention, and brand attachment). This study would help managers in an O4O area well adapt to rapidly changing customer needs and provide them with some guidelines for enhancing both customer satisfaction and loyalty by allocating more resources to more significant selection attributes, rather than less significant ones.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.14-28
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• 2017

Mt. Seunghak's Miscanthus sinensis community is not only a landscape resource in terms of cultural services within the Ecosystem Services but also a site that is visited by many mountaineers in autumn. As the current Miscanthus sinensis community has been experiencing a rapid decline due to Korean forest succession characteristics, ongoing artificial management is thought to be needed for landscape resource use. The purpose of this study was to determine growth environment characteristics and the cause of the rapid decline of the Miscanthus sinensis community in Mt. Seunghak, which is located inside a large city with a large scale and outstanding accessibility. As the Miscanthus sinensis community is the representative early vegetation that appears temporarily in dry, barren soil, the Miscanthus sinensis community in Korean forest succession tends to be unsustainable. As the current soil on Mt. Seunghak is inappropriately fertile for the Miscanthus sinensis community, other wetland woody plant communities are anticipated to succeed it. If Miscanthus sinensis community maintenance is needed for Miscanthus sinensis landscape scenery, various alternatives apart from overall Miscanthus sinensis community maintenance should be determined for cost-effective management. For example, while many byways toward the inside of the Miscanthus sinensis community have affected the Miscanthus sinensis community growth environment, the installation of wooden fences and ropes has been a control in approach. As a result of this positive effect, many byways toward the inside of Miscanthus sinensis community have been restored naturally. Through viewable range analysis, as good scenery sites on the observatory have a good viewable range on the main trail as well, if these scenery sites are intensively managed, effective Miscanthus sinensis ccommunity management will be done despite maintenance budget cutbacks. This study is expected to be used as a basic material regarding the alternatives for a sustained Miscanthus sinensis community and the possibility of cultivating other growth in poor soils of fallow fields and unused land.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.87-99
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• 2017

Recently the increase in an abnormal climate events and meteorological disasters which causes a great damage to greenhouse facilities. To minimize and evaluate the expected damages it is necessary to prepare countermeasures and a management system in advance. For this purpose, a quantitative analysis of weather and abnormal climate are needed to investigate protected cultivation areas which are vulnerable to natural disasters. This study focused on protected cultivation areas in Jeolla province, South Korea. Surrogate variables were calculated to analyze the vulnerable areas to meteorological disasters, and spatial distribution analysis was also performed by using GIS to present vulnerable areas on map. The map thus created and was compared with actual data of damages by meteorological disasters which occurred in target areas. The result of the comparison is as follows: About 50% of the target areas showed an agreement between the map created in this study and the actual data, these areas includes Gwangju metropolitan city, Naju city, Yeongam County, Jangseong County, Hampyeong County, and Haenam County. On the other hand, other areas, including Gunsan city, Mokpo city, and Muan County, suffered low damage in spite of high levels of vulnerability to meteorological disasters. This result was considered to be affected by such variables as different structural designs and management systems of greenhouses by region. This study carried out an analysis of meteorological data to find out more detailed vulnerability to protected cultivation area and to create a map of vulnerable protected cultivation areas. In addition, the map was compared with the record of natural disasters to identify actual vulnerable areas. In conclusion, this study can be utilized as basic data for preventing and reducing damages by meteorological disasters in terms of design and management of greenhouses.

• Journal of Conservation Science
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• v.27 no.3
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• pp.333-344
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• 2011

Cleaning of foreign matter and corrosion products on surface among conservation treatment of iron artifacts is an important part for looking up a original form. The sand blaster is the most popular equipment when it removes the foreign matter and corrosion products on iron artifacts surface. Current foreign matter and corrosion products equipment, which mostly uses, is sand blaster. Glass dust which sprayed from sand blaster is harmful and causing environmental pollution. In order to solve these problems, we investigated the $CO_2$ snow cleaning that use a eco-friendly equipment to apply for cleaning foreign matter and corrosion products on surface of iron artifacts. It examined by using sand blaster and $CO_2$ snow cleaning to aged steel coupon and iron artifacts. In case of aged steel coupon, the result showed that the sand blaster and $CO_2$ snow cleaning methods were similar to the degrees of cleaning foreign matter and corrosion products, through surface roughness, color measurement and SEM. $CO_2$ snow cleaning applied to aged steel coupons weren't worn out the surface in comparison with sand blaster by SEM. When applied to the iron artifacts, power nozzle of the $CO_2$ snow cleaning was an excellent cleaning effect that surface wern't worn out in comparison with sand blaster. And, it showed that internal structure change of metal was no found before and after cleaning by X-ray radiography. Consequently, we confirmed that cleaning of the sand blaster and power nozzle of $CO_2$ snow cleaning were similar to the effect. But, it's very careful to use this method because of high outlet pressure of power nozzle for applying to the iron artifacts. As a result of experiments, it could be found that the cleaning methods should be selected depending on internal state of the artifacts.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.73-84
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• 2010

Gold and silver deposits within the Eunjeok and Sangeun mines are located in Yeongam district, Cheollanamdo-province. They are composed of vein ore bodies infilling the fractures of Cretaceous rhyolitic tuff. The Eunjeok mine have three gold and silver bearing hydrothermal veins which is infilling the fracture of rhyolitic tuff. Major ore minerals within the Eunjeok and Sangeun mines are arsenopyrite, pyrite, chalcopyrite, sphalerite and galena and minor ores are electrum, native silver and argentite. Sericitization is dominant in alteration zone and chloritization and dickitization is minor. Quartz veins in the Eunjeok and Sangeun mine have the similar paragenesis and vein textures such like breccia, crustiform, comb and vuggy morphology indicating the formation of typical epithermal environment. In order to carry out the preliminary feasibility study of mine according to the commodity and elucidate the occurrence features of mineral resources from Eunjeok and Sangeun mine, common commodity (Pb, Zn, Cu, Fe, Mo, W, Au and U), and industrial commodity (In, Re, Ga, Ge, Se, Te, Y, Eu and Sm) for 17 ore specimen were analyzed. It is tentatively thought that there is no exploitable mine for iron, lead, zinc, copper, tungsten and uranium based on the preliminary result. If the reserves are secured through the detailed prospecting in case of molybdenum and silver, it is tentatively thought that there will be exploitable deposits depending on international metal price. If we assume the vein width from 0.25 m to 2 m including alteration zone with the gold grade of 80g/t, it is inferred that the resources amount of the Eunjeok-Sangeun mines range from 6.5 to 65ton. However, as the vein structure of the Eunjeok and Sangeun mines is developed together with alteration zone, it should be estimated to include potential alteration zone in order to yield the average grade. It is needed to carry out more exploration in the near future because the reserves can be flexibly estimated according to the change of average grade considering the alteration zone.