• Korean Journal of Soil Science and Fertilizer
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• v.40 no.1
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• pp.98-107
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• 2007

Most of plastic film house plots in Korea have salinity problems caused by salt accumulations associated with continuous cropping including the heavy applications of chemical fertilizers, and high evapotranspiration. The objective of this study was to investigate soil properties and watermelon (Citrullus lanatus Thunb.) productivity in plastic film houses as influenced by the short-term crop rotation in the continuous watermelon-cultivated soils. The short-term rotational crops selected were corn, Chinese cabbage, radish, young radish, lettuce, spinach, and onion. Soil pH increased in most plots where a short-term crop was added to the crop rotation, except where radish was added. The content of soil organic matter significantly decreased in the lettuce-cultivated plot. The available phosphorus content in the soils increased with the cultivations of spinach and onion. Exchangeable Ca and Mg tended to increase in most of plots where a short-term rotational crop was grown, whereas the exchangeable K was clearly reduced by more than 50% in the same plots. Cultivation of rotational crops during the post-harvest season significantly decreased the electrical conductivity (EC) and the concentrations of soluble anions, such as chloride ($Cl^-$), nitrate ($NO_3{^-}$), and sulfate ($SO{_4}^{2-}$) in the soils. In particular, the EC decrease was related with the decrease in soil $K^+$ to $Ca^{2+}$ and $Mg^{2+}$ ratio. In all plots cultivated with the shot-term rotational crops, the ratios of bacteria to fungi (B/F) increased. However, the improvement in soil properties after adding a rotational crop did not result in a clear improvement in watermelon quantity or quality as measured by fruit weight and sugar content. Therefore, the addition of short-term rotational crops to a continuous watermelon cropping system would be beneficial to improve target soil properties in plastic film house plots studied.

• Ocean policy research
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• v.33 no.2
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• pp.83-119
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• 2018

Under the Korean Marine Environment Management Act (hereunder, the KMEMA), the duty to arrange spill clean-up equipments, including spill clean-up vessels, required by the article 67 of the KMEMA is in essence the provision of public goods since it is a precautionary or preventive measure for the efficient performance of oil spill cleaning up. Also the obligation to control marine pollution and the duty to arrange of anti-pollution measures imposed on polluters is the obligation imposed by the public law in accordance with "the Polluter-Pays Principle". Therefore, the execution of such obligations shall be accompanied by the minimum legal and institutional arrangements. On the other hand, judging whether to form the roles of the public and private sectors in providing public goods is basically a matter of policy decision. However, even if the private sector is allowed to participate in the provision of public goods, it is imperative that a minimum requirement be provided to secure the public interest. Although major countries allows polluters to conclude a preliminary contract with a civil anti-pollution management company, these civilian institutions are in principle constituted by the owners of oil storage facilities. Additionally it is worth noting that it operates as a non-profit organization. In particular, if the practitioner performs pollution control for commercial purposes, their profitability may depend on the size of the pollution, the period spent on pollution control, the size of the equipment and manpower mobilized in the pollution control, and so on. Considering the above problems, caution should be taken to allow marine environmental management companies to be un-limitedly entrusted with the responsibility of arranging measures such as pollution control. In order to allow the marine environmental management contractor to be entrusted for the assignment of duty to protect the marine environment, the marine environment management business should be expanded so that the marine pollutant management capacity satisfies the statutory control capacity. For this purpose, it is necessary to manage and supervise the maintenance and improvement of the control capability of the marine environment management business. It is also necessary to discuss the introduction of the grading system for the control ability of the civil control companies alike in major countries.

• Journal of vocational education research
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• v.37 no.1
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• pp.77-100
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• 2018

The purpose of this study was to explore how the college students of the beauty department changed their perspective about jobs, career development, and self-reflection in the process of job shadowing. We selected 8 students who were enrolled in the beauty department of a college located in the capital area and conducted individual in-depth interviews with them. According to the result of the study, First, participants have learned attitude, knowledge, competence, and an important matter necessary to achieve a excellent performance in the beauty job. In particular, they figured out that a core competency for a successful beauty job is to share a social relationship with the clients. Second, they recognized that doing a beauty job is very tough and then set a criteria to make a decision of their future job. Doing a Job shadowing made them being change in the area of job and their job perspective. Finally, they looked themselves back how they are satisfying with developing their career at the beauty department. This study is significantly meaningful in that it contextually showed how the college students are developing their job careers through an indirect job experience from a constructive point of view. Moreover, this study is different from the existing studies focusing on student's direct work experiences such as the existing internship programs, which focused on exploring the student's indirect work experience and the process of their vicarious learning. The result of the current study has a practical implication in terms of providing a basic perspective for career education for students of colleges.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.245-262
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• 2019

The objectives of this study were to construct a three-dimensional water quality model (EFDC) for the river reach between Chilgok Weir and Gangjeong-Goryong Weir (GGW) located in Nakdong River, and evaluate the effect of hydraulic changes, such as water level and flow velocity, on the control of water quality and algae biomass. After calibration, the model accurately simulated the temporal changes of the upper and lower water temperatures that collected every 10 minutes, and appropriately reproduced changes in organic matter, nitrogen, phosphorus, and cyanobacteria. However, the simulated values were overestimated for the diatoms and green algae cell density, possibly due to the uncertainties of the parameters associated with algae metabolism and the lack of zooplankton predation function in the simulations. As a result of scenario simulation of running the water level of GGW from EL. 19.44 m to EL. 14.90 m (4.54 m drop), Chl-a and algae cell density decreased significantly.In particular,the cyanobacteria on the surface layer, which causes algal bloom, declined by 56.1% in the low water level scenario compared to the existing management level. The results of this study are in agreement with the previous studies that maintenance of critical flow velocity is effective for controlling cyanobacteria, and imply that hydraulic control such as decrease of water level and residence time in GGW is an alternative to limit the overgrowth of algae.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.455-463
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• 2018

This study was carried out to assess the distribution and pollution level of organic matters and nutrients in surface sediments of the Yeongsan River Basin. The surface sediments were collected from the mainstream (12) and tributaries sites (4) for two years from 2015 to 2016, and the particle sizes, organic matters (Ignition Loss, COD, TOC) and nutrients (TN, TP, SRP) were analyzed. The distribution of particle sizes was dominated by sand in the upstream sites (MS1-MS7) and by silt loam in the downstream sites (MS8-MS12), but MS3 and MS6, located slightly upstream of the two weirs, were found to be mostly loamy sand and silt loam, respectively. As a results of the correlation assessment, the organic matters (IL, COD, TOC) were strongly correlated with particle sizes, while the nutrients (TP, SRP) were weak except for TN. The concentrations of organic matter and nutrient were higher at the downstream and the sites nearby the two weirs (MS3, MS6). In particular, the TP concentration at the MS3 site sampled in the second half period of the years was higher than that in the first half periods. Comparing of sediments criteria, the organic matters and nutrients were evaluated to have almost no toxic effects at all sites.

• Journal of Arbitration Studies
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• v.31 no.2
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• pp.3-22
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• 2021

Civil and commercial disputes can be resolved through alternative dispute settlement systems other than court proceedings. Among them, the arbitration procedure is a system that is clearly distinguished from the mediation procedure in which the dispute is terminated by agreement between the parties. The arbitration proceedings shall have the same effect as the result of the final judgment by the decision of a third-party arbitrator, and its essence is a judgment. The Korean Arbitration Association Studies was founded in December 1990 to recognize the importance of arbitration procedures and conduct specialized research on them, with professional research on 'arbitration procedures' continuing until today. Thus, the Korean Arbitration Association Studies is positioned as the only specialized research organization in the field of arbitration. In the case of the Korean Arbitration Association Studies, which is the only society in Korea related to arbitration and alternative dispute resolution, the members are mainly scholars majoring in trade and commerce and ones majoring in law. This situation reflects the distinctive character of the arbitration system because it is a matter of dispute procedures related to trade and commerce and many scholars who research trade and commerce need to prepare for possible disputes. In addition, the arbitration procedure is a dispute settlement procedure that substitutes for litigation because it has research value as a legal system. In particular, the 'Journal of Arbitration Studies' published by the Korean Arbitration Association plays a role in mediation, as well as mediation and presentation of research papers in the ADR field. This study analyzes the trends of mediation and ADR-related papers published in 'Journal of Arbitration Studies', an academic journal of the Korean Arbitration Association Studies, in four dimensions, celebrating the 30th anniversary of the Korean Arbitration Association Studies. First, this study examined which sub-themes are mainly studied among the various viewpoints of mediation through thematic analysis. Second, it looked at what methodology was used to study intervention at the methodological level. Third, it assessed what countries and regions had been mainly studied at the regional level. Fourth, in terms of content, what kind of research had been mainly conducted and what kind of research was relatively insufficient was investigated, analyzing the research results of the last 30 years and presenting a milestone for the research direction of 'Journal of Arbitration Studies' in the future.

• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.521-529
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• 2021

Background: The coronavirus disease (COVID-19) has caused changes in human activity, and these changes may possibly increase or decrease exposure to fine dust (PM_2.5). Therefore, it is necessary to evaluate the exposure to PM_2.5 in relation to the outbreak of COVID-19. Objectives: The purpose of this study was to compare and evaluate the exposure to PM_2.5 concentrations by the variation of dynamic populations before and after the outbreak of COVID-19. Methods: This study evaluated exposure to PM_2.5 concentrations by changes in the dynamic population distribution in Guro-gu, Seoul, before and after the outbreak of COVID-19 between Jan and Feb, 2020. Gurogu was divided into 2,204 scale standard grids of 100 m×100 m. Hourly PM_2.5 concentrations were modeled by the inverse distance weight method using 24 sensor-based air monitoring instruments. Hourly dynamic population distribution was evaluated according to gender and age using mobile phone network data and time-activity patterns. Results: Compared to before, the population exposure to PM_2.5 decreased after the outbreak of COVID-19. The concentration of PM_2.5 after the outbreak of COVID-19 decreased by about 41% on average. The variation of dynamic population before and after the outbreak of COVID-19 decreased by about 18% on average. Conclusions: Comparing before and after the outbreak of COVID-19, the population exposures to PM_2.5 decreased by about 40%. This can be explained to suggest that changes in people's activity patterns due to the outbreak of COVID-19 resulted in a decrease in exposure to PM_2.5.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.2
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• pp.91-108
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• 2022

In most cases, optical images have been used as training data of DL (Deep Learning) models for object detection, recognition, identification, classification, semantic segmentation, and instance segmentation. However, properties of 3D objects in the real-world could not be fully explored with 2D images. One of the major sources of the 3D geospatial information is DSM (Digital Surface Model). In this matter, characteristic information derived from DSM would be effective to analyze 3D terrain features. Especially, man-made objects such as buildings having geometrically unique shape could be described by geometric elements that are obtained from 3D geospatial data. The background and motivation of this paper were drawn from concept of the intrinsic image that is involved in high-level visual information processing. This paper aims to extract buildings after classifying terrain features by training DL model with DSM-derived information including slope, aspect, and SRI (Shaded Relief Image). The experiments were carried out using DSM and label dataset provided by ISPRS (International Society for Photogrammetry and Remote Sensing) for CNN-based SegNet model. In particular, experiments focus on combining multi-source information to improve training performance and synergistic effect of the DL model. The results demonstrate that buildings were effectively classified and extracted by the proposed approach.

• The Korean Journal of Archival Studies
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• no.72
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• pp.205-239
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• 2022

Park Yong-gil's personal letter 'To You' collection is a valuable historical document that contains aspects of modern and contemporary Korea, managed by the Late Spring Moon Ik-Hwan Memorial Foundation. These letters were written for about 10 years and 3 months, and there are currently about 2,304 letters left, and support is needed to secure social feasibility for long-term preservation of historical materials and to establish a stable record management system. The purpose of this article is to introduce Park Yong-gil's letter, which has not been introduced in earnest, to the archival community, and to comprehensively review the whole story and examine the tasks. To this end, the meaning of the letter in Park Yong-gil's personal life was examined, and the value of this letter was particularly highlighted in terms of being a letter written as a part of Okbaraji. And by investigating and analyzing the status of the archives, the internal and external characteristics of the letter were comprehensively analyzed. The characteristics of Park Yong-gil's letter identified as a result of the study are that it is a letter sent to one person, and it is accumulated with a considerable amount and aggregation. In particular, it is expected to have a diverse user base in that it is easy to empathize with because it contains the familiar subject matter of letters and the stories of contemporaries, and contains a variety of informational values about contemporary events and people. Based on these historical and cultural values and various useful values of the letter 'To you', various research and development of services should be made in the future.

• Korean Journal of Heritage: History & Science
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• v.55 no.3
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• pp.152-176
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• 2022

This paper, a basic study on the restoration of arrow quivers during the Three Kingdoms Period, aimed to contribute details to the existing plan to restore the arrow quivers. The arrow quivers of the Three Kingdoms Period consist of a pouch for holding arrows and a backpiece. However, the two parts do not remain, and only metal parts have been excavated. The excavated arrow quivers were classified into three types for restoration. Centered on the pouch, the quivers were classified into type 1 made up of a W-shaped part and ㄷ-shaped part, and type 2 with only the band-shaped piece identified. Type 3 is similar to type 2, but it is assumed to be a separate type where an iron band extending from the hanging piece(吊手金具) is connected to a band-shaped piece. Before proposing a restoration plan for the three types of arrow quivers, the location of the hanging piece (吊手金具) and the observation of organic matter were reflected. In addition, such details as the location of the hanging piece (吊手金具), which cannot be identified by the excavation status alone, were derived from the ways of wearing the arrow quivers observed in the Joseon Dynasty, Shosoin (正倉院), and Haniwa (埴輪) in Japan. Referring to the existing record on the transformation of arrow quivers based on the hanging piece (吊手金具), the arrow quivers change from type 1 to types 2 and 3 in this paper. However, some of types 2 and 3 maintain the ways of wearing of type 1, and there were cases where the old-fashioned parts were kept. In particular, in Haman (咸安), it was confirmed that the typical type 1 was buried up until late periods.