• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.354-374
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• 2016

This study explored spatiotemporal variability of water quality in correspondence with hydrometeorological factors in the five stations of Paldang Reservoir located in the Han River during 4 years from May 2012 to December 2015. Variability of basic water quality factors were largely related with seasonal fluctuations of hydrology. Temperature stratification occurred in the deep dam station, and prolonged hypoxia was observed during the draught year. Nitrogen nutrients were increased with decreasing inflow in which changing pattern of $NH_4$ reversed to $NO_3$ by the effect of treated wastewater effluent. Phosphorus increase was manifest during the period of high inflow or severe drought. Chl-a variation was reversely related with both flow change and AGP(algal growth potential) variations. Our study demonstrated that water quality variability in Paldang Reservoir was largely attributed to both natural and operational changes of inflow and outflow (including water intake) based on major pollution source of the treated wastewater (total amount of $472{\times}10^3m^3d^{-1}$) entering to the water system from watershed. In the process of water quality variability, meteorological (e.g., flood, typhoon, abnormal rainfall, scorching heat of summer) and hydrological factors (inflow and discharge) were likely to work dynamically with nutrients pulse, dilution, absorption, concentration and sedimentation. We underline comprehensive limnological study related to hydro-meteorolology to understand short- and long-term water quality variability in river-type large reservoir and suggest the necessity of P-free wastewater treatment for the effective measure of reducing pollution level of Paldang drinking water resource.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.4
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• pp.347-370
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• 2011

Slurry type shield would be very effective for the tunnelling in a sandy ground, when the slurry pressure would be properly adjusted. Low slurry pressure could cause a tunnel face failure or a ground settlement in front of the tunnel face. Thus, the stability of tunnel face could be maintained by applying an excess slurry pressure that is larger than the active earth pressure. However, the slurry pressure should increase properly because an excessively high slurry pressure could cause the slurry flow out or the passive failure of the frontal ground. It is possible to apply the high slurry pressure without passive failure if a horizontal impermeable layer is located in the ground in front of the tunnel face, but its location, size, and effects are not clearly known yet. In this research, two-dimensional model tests were carried out in order to find out the effect of a horizontal impermeable layer for the slurry shield tunnelling in a saturated sandy ground. In tests slurry pressure was increased until the slurry flowed out of the ground surface or the ground fails. Location and dimension of the impermeable layer were varied. As results, the maximum and the excess slurry pressure in sandy ground were linearly proportional to the cover depth. Larger slurry pressure could be applied to increase the stability of the tunnel face when the impermeable layer was located in the ground above the crown in front of the tunnel face. The most effective length of the impermeable grouting layer was 1.0 ~ 1.5D, and the location was 1.0D above the crown level. The safety factor could be suggested as the ratio of the maximum slurry pressure to the active earth pressure at the tunnel face. It could also be suggested that the slurry pressure in the magnitude of 3.5 ~4.0 times larger than the active earth pressure at the initial tunnel face could be applied if the impermeable layer was constructed at the optimal location.

• Journal of Soil and Groundwater Environment
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• v.14 no.4
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• pp.33-44
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• 2009

Water curtain of an underground LPG storage cavern is a facility to prevent leakage of high pressure gases, for which groundwater should flow freely towards the cavern and groundwater level also must be stably maintained. In this study, in order to evaluate qualities of seepage water and surrounding groundwater of an underground LPG storage cavern in Yeosu, 4 rounds of samplings, field measurements and laboratory analyses (February, May, August, October of 2007) were conducted. According to field measurements, pH was weak acidic to neutral but it gradually increased with time. Electrical conductivity (EC) of groundwater near a salt stack showed very high values between 10.47 and 38.50 mS/cm. Dissolved oxygen (DO) showed a very wide range of 0.20~8.74 mg/L and a mean of oxidation-reduction potential (ORP) was 159 mV, which indicated an oxidized condition. Levels of $Fe^{2+}$ and $Mn^{2+}$ were mostly less than 3 mg/L. All of seepage waters showed a Na-Cl type while only groundwater near the salt stack showed a Na-Cl type with a high total dissolved solid. The other groundwaters exhibited typical $Ca-HCO_3$ types. Levels of aerobic bacteria were mostly very high (573-39,520 CFU/mL). Based on the analyses of these hydrochemistry and biological characteristics, it is concluded that there are no particular problems in groundwater and seepage water, which not causing a trouble in the cavern operation. However, both for control of bio-clogging and for sustainable operation of the water curtain system, a regular hydrochemical and microbiological monitoring is required for the seepage water and surrounding groundwater.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.297-303
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• 2018

With the changing trend of the building construction to high rising and large scaling, the underground structure has been increased, and its usage also increased and variety. Hence, to protect the underground structure against underground water, various water proofing methods has been developed. Among the many water proofing methods, the combined water proofing method using both asphalt seal and sheet has been widely used to secure the sufficient performance and decrease the construction failure. However, during the summer period of extremely high temperature conditions, the asphalt sealing materials were separated and leaked into the structure. Therefore, the aim of the research is to provide the quality standard of asphalt sealing material based on the various temperature changes depending on seasons. According to the experimental results, the temperature of the sealing materials applied on the slab was increased up to $54^{\circ}C$ which was $3^{\circ}C$ higher than the structure temperature of $51^{\circ}C$. Based on the melting test for asphalt sealing materials applied on the outside wall of the structure, in the case of water-dispersing typed materials showed significant melting down due to its slow evaporation and low viscosity. Furthermore, from the accelerated test conducted indoor conditions, a solvent-type and water-dispersing typed materials showed significant melting down due to their low viscosity and melting point in ambient conditions. Based on these results, viscosity and melting point are found as the important factors on asphalt sealing materials' quality, and it is necessary to designate the quantitative level of the viscosity and melting point for quality control.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.268-286
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• 2018

The eutrophication and algal blooms by harmful cyanobacteria (CyanoHAs) and freshwater redtide (FRT) that severely experiencing in typical regulated weir system of the Nakdong River are one of the most rapidly expanding water quality problems in Korea and worldwide. To compare with the factors of rainfall, hydrology, and dominant algae, this study explored spatiotemporal variability of the major water environmental factors by weekly intervals in eight weir pools of the Nakdong River from January 2013 to July 2017. There was a distinct difference in rainfall distribution between upstream and downstream regions. Outflow discharge using small-scale hydropower generation, overflow and fish-ways accounted for 37.4%, 60.1% and 2.5%, respectively. Excluding the flood season, the outflow was mainly due to the hydropower release through year-round. These have been associated with the drawdown of water level, water exchange rate, and the significant impact on change of dominant algae. The mean concentration (maximum value) of chlorophyll-a was $17.6mg\;m^{-3}$ ($98.2mg\;m^{-3}$) in the SAJ~GAJ and $29.6mg\;m^{-3}$ ($193.6mg\;m^{-3}$) in the DAS~HAA weir pools reaches, respectively. It has increased significantly in the downstream part where the influence of treated wastewater effluents (TWEs) is high. Indeed, very high values (>50 or $>100mg\;m^{-3}$) of chlorophyll-a concentration were observed at low flow rates and water levels. Algal assemblages that caused the blooms of CyanoHAs and FRT were the cyanobacteria Microcystis and the diatom Stephanodiscus populations, respectively. In conclusion, appropriate hydrological management practices in terms of each weir pool may need to be developed.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.336-346
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• 2021

The enforcement of the Nagoya Protocol, which regulates the acquisition and use of genetic sources, an essential material for biotechnology R&D, has imposed a burden for additional documentation works to researchers. In the past, countries regarded genetic resources as a common human heritage and thus allowed researchers to use them freely. However, they can no longer afford the luxury of such freedom now since many countries are introducing new laws and regulations on the acquisition and use of the resources as the Nagoya Protocol recognizes the exclusive ownership of genetic resources. Therefore, Korea, which is highly dependent on foreign genetic resources, needs a more systematic response. This paper aims to review the key contents of the Nagoya Protocol to raise awareness among domestic and foreign genetic resource users, including researchers of environment and ecology and present the overall structure, and flow of acquisition, access, and benefit sharing (ABS) for the use of foreign genetic resources to help them respond appropriately to the new landscape. The researchers' efforts and support at the national level are necessary at the same time to appropriately respond to the Nagoya Protocol. First, the researchers must understand the overall framework and the specific response in each stage under the Nagoya Protocol scheme. It is necessary to respond to the ABS procedure of the resource provider country from accessing genetic resources to sharing benefits resulting from it. In that regard, the Nagoya Protocol has imposed more restrictions on research activities and raised the burden outside of research. The current trend of recognizing the country's sovereign rights over genetic resources is likely to continue and widespread worldwide as resource-rich countries are expected to continue protecting their resources. Therefore, our study will help environmental ecology researchers understand ABS and conduct research under the Nagoya Protocol and legal obligations of resource provider countries step by step, from access to benefit sharing.

• (The)Study of the Eastern Classic
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• no.32
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• pp.425-441
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• 2008

Most of Korea's Kyungmaedorock(auction book: 競賣圖錄) and pictorial record of exhibitions in the modern times were usually published in the 1930s. Although 1930s were periods of the Great Depression when economic slump continued because of the aftereffect of the slump in the stocks issued by the US in 1929, during this period, Japan began regular continental invasion starting from invasion of the northeastern area of China. To curio dealers, the 1930s were 'boom period of curio transaction' and in urban cultural aspects, the period is evaluated as the one when the first step of modernism was formed. Collection, photo-printing and arrangement of the data related to modern exhibitions including the Auction Book being published at that time are very important because they enable us to know characteristics of fine arts in the transition period from paintings & writings to fine arts in addition to enabling us to revert the circulation history of our paintings & writings and curios. Furthermore, these data will become important data for reconstitution of the circulation history of the Eastern Asia's modern art works. Although the pictorial record of Joseon's Exhibitions of Chinaware and Wooden Works(朝鮮陶磁木工展) is a small and thin one, it records our country's high level chinaware and wooden works. Although we can't know the exact time for 'Joseon's exhibitions of chinaware and wooden works', they are assumed to have been held in Tokyo, Japan in the 1930s and there seems to have been sale of works, too. As such, studies of the books such as the auction book and exhibitions under Japanese imperialism have the first importance in the fact that through which we can examine the course of outflow of our art works to Japan. Furthermore, they can be studies of art-sociology that examine flow and phase of recognition and taste of art works of those days. And from now on, comparative studies of auctions and exhibitions being held in Japan such as Tokyo, Osaka and etc. as well as art markets in Seoul during modern times would also be necessary.

• (The)Study of the Eastern Classic
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• no.49
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• pp.393-430
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• 2012

In this paper, Bowen's family therapy from the perspective of the theory, narrative analysis of Korean novels, three Regis - tration Subsection.Bowen's description of the individual's behavior is causing problems within the family of anxiety and self-differentiation using two variables. The home if problems or conflicts expressed in these works, the figures showed that the undifferentiated ego at the center of the problem. Undifferentiated ego character felt extreme anxiety when their alienation from the relationship of the family-oriented jeokjangja Undifferentiated ego to relieve anxiety and to consolidate their position in the family relationship, so people were strongly united with each other. Sohyunseongnok, Chossisamdaerok series structures and patterns of a series of domestic problems occur, "mother and son, self-differentiation self undifferentiated undifferentiated ego and self-differentiation mother son, mother and self-ego undifferentiated undifferentiatedcan be subdivided into the son '.Established a symbiotic relationship between them and the U.S. established the presence of a pattern, healer, depending on the deployment method depends narrative. And is divided accordingly, self-determination and to the Son, a son, a son to be born again through repentance of the execution. Depending on the presence or absence healer than what was described on the deployment structure differs. Undifferentiated ego and self undifferentiated mother son family therapist within the family, the problem is solved. Son, a son to repent and be born again, and that caused the problem. Ego Undifferentiated mother and son self-differentiation, undifferentiated ego and self-differentiation mother son home my healer in the absence son committed suicide and executions each tragedy occurred. Personal level, but occurred at home conflicts or problems about this when analyzing the Three-generation stories of the Joseon Dynasty, by applying the theory of Bowen's Family Therapy view dimension in the relationship between family were. Toughness or desire of any one individual, but serious conflicts and problems within the family, the institution of the family itself is the root cause was. And was able to reveal aspects of narrative flow, depending on the presence or absence of family therapists vary significantly depending on his role in the rest of the family comfort and peace determines whether the Three-generation stories of the Joseon Dynasty, received an important narrative of men and axis formation. In a gauze-like situation of this problem in the Three-generation stories of the Joseon Dynasty, a personal desire or toughness in confined without the dimension of the entire family. And extrinsic psychological approach against the background of the wall in the main narrative of the sufferings of women of Korean novels, approached significance.

• Journal of Intelligence and Information Systems
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• v.27 no.4
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• pp.23-48
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• 2021

The Korean economy has achieved continuous economic growth for the past several decades thanks to the government's export strategy policy. This increase in exports is playing a leading role in driving Korea's economic growth by improving economic efficiency, creating jobs, and promoting technology development. Traditionally, the main factors affecting Korea's exports can be found from two perspectives: economic factors and industrial structural factors. First, economic factors are related to exchange rates and global economic fluctuations. The impact of the exchange rate on Korea's exports depends on the exchange rate level and exchange rate volatility. Global economic fluctuations affect global import demand, which is an absolute factor influencing Korea's exports. Second, industrial structural factors are unique characteristics that occur depending on industries or products, such as slow international division of labor, increased domestic substitution of certain imported goods by China, and changes in overseas production patterns of major export industries. Looking at the most recent studies related to global exchanges, several literatures show the importance of cultural aspects as well as economic and industrial structural factors. Therefore, this study attempted to develop a forecasting model by considering cultural factors along with economic and industrial structural factors in calculating the import volume of each country from Korea. In particular, this study approaches the influence of cultural factors on imports of Korean products from the perspective of PUSH-PULL framework. The PUSH dimension is a perspective that Korea develops and actively promotes its own brand and can be defined as the degree of interest in each country for Korean brands represented by K-POP, K-FOOD, and K-CULTURE. In addition, the PULL dimension is a perspective centered on the cultural and psychological characteristics of the people of each country. This can be defined as how much they are inclined to accept Korean Flow as each country's cultural code represented by the country's governance system, masculinity, risk avoidance, and short-term/long-term orientation. The unique feature of this study is that the proposed final prediction model can be selected based on Design Principles. The design principles we presented are as follows. 1) A model was developed to reflect interest in Korea and cultural characteristics through newly added data sources. 2) It was designed in a practical and convenient way so that the forecast value can be immediately recalled by inputting changes in economic factors, item code and country code. 3) In order to derive theoretically meaningful results, an algorithm was selected that can interpret the relationship between the input and the target variable. This study can suggest meaningful implications from the technical, economic and policy aspects, and is expected to make a meaningful contribution to the export support strategies of small and medium-sized enterprises by using the import forecasting model.

• Journal of Korea Port Economic Association
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• v.37 no.3
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• pp.117-128
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• 2021

In order for the users (shipping firms and shippers) and suppliers (stevedoring firms) in the container terminal industry to win-win, it is necessary to have some appropriate diverse market conditions for the industry. This study analyses the basic conditions and demand and supply characteristics of the industry and investigates the market performance of Busan container ports. First, this article analyses the basic characteristics of demand and supply. As the demand characteristics, there are five ones such as 1) exogeneity of demand, 2) function as export/import transportation and hub for transshipment, 3) increase of users' bargaining power, 4) high substituting elasticity, 5) reduction of volume growth. As the supply characteristics, there are seven ones such as 1) inelasticity of supply, 2) homogeneity of stevedoring services, 3) over-supply, 4) adoption of cutting-edge stevedoring technology, 5) scale economy and impossibility of storage, 6) labor market rigidity, 7) enhancing port's role in SCM. In addition, this study conducts the so-called structure-conduct-performance analysis. For the structure analysis, 1) lacks of scale economy in stevedoring companies, 2) high entry barrier, 3) strengthening of shipping firms' bargaining power, 4) transitory permission scheme for tariff are analyzed. For the conduct analysis, 1) price discrimination between export/import and transshipment, 2) mid-term length of terminal use contract, 3) continuous investment in equipment, 4) low level of cooperation among terminal operating firms are derived. For the performance analysis, 1) inequality in profitability, 2) reduction of export/import cost, 3) delay in adopting cutting-edge technology, 4) idle equipment are analyzed. Following this logical flow, the hypothesis that the market structure influences the market conduct is tested based on the actual dataset. As a future agenda in the conclusion, this article recommends the so-called port industrial policy.