• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.489-499
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• 2018

A series of geological events such as the formation of the Antarctic continental ice sheets, the changes in ocean circulation and a mass extinction after the onset of Oligocene has been studied as major concerns by various researches. However, paleoclimatic and paleoceanographic changes during the most period of Oligocene since the Eocene-Oligocene transition (EOT) still remains unclear. Especially, although the late Oligocene warming (LOW) has been assessed as the largest period in the paleoceanographic changes, the detailed understanding on the changed components is very low. The purpose of this study is the reconstruction of the paleoceanographic history during the late Oligocene using core sediments from IODP Expedition 342 Site U1406 performed in J-Anomaly Ridge in North Atlantic. Because North Atlantic deep water (NADW) has flowed southward through the study area since the early Oligocene, this area has been considered to an important location for studies on the changes of NADW. The core sediment analyzed in this study were deposited from about 26.0 to 26.5 Ma as evidenced by both of onboard and shore-based paleomagnetic data, and this is corresponded to the earliest period of LOW. The sediment profile can be divided into three Units (Unit 1, 2 & 3) based on the changes in both of total number and test size of Oridorsalis umbonatus as well as grain size data of clastic sediments. Unit 2 represents largest values in these three data. Because the total number, test size of O. umbonatus and grain size can be proxy records on the oxygen concentration and circulation intensity of deep water, we interpreted that Unit 2 had been deposited during the period of relatively strengthened NADW. Previous Cibicidoides spp. stable isotope results from the low latitude region of the North Atlantic also support our interpretation that is the intensified formation of NADW during the identical period. In conclusion, our results present a new evidence for the previous ideas that the causes on LOW are directly related to the changes in NADW.

• Journal of agricultural medicine and community health
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• v.43 no.4
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• pp.258-269
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• 2018

Objectives: There was an outbreak of foodborne and waterborne disease among high school students at Okcheon in June, 2018. First attack occurred June $5^{th}$ but seven days later it was notified. The purpose of this investigation was to evaluate the pathogen of outbreak and cause of delayed notification. Methods: First, we did a questionnaire survey for 61 cases and 122 controls to find what symptoms they had and whether they ate foods or drank water from June $2^{nd}$ to June $12^{th}$. Second, we investigated the environment of cafeteria and drinking water. Third, we examined specimen of cases and environment to identify bacteria or virus. Results: Attack rate of this outbreak was 7.8%. Drinking water was strongly suspected as a source of infection in questionnaire survey but we could not find the exact time of exposure. Norovirus was identified in specimen of cases (2 students), drinking water (at main building and dormitory) and cafeteria (knife, dishtowel, hand of chef) Conclusions: We decided norovirus as the pathogen of this outbreak based on the clinical features of cases with diarrhea vomiting, abdominal pain and recovery within 2 or 3 days after onset, outbreak due to drinking water and microbiologic examination, And the cause of delayed notification might be the non-existence of the nurse teacher at that time and the lack of understanding of teachers on immediate notification under the outbreak. To prevent the delayed notification, notification system about outbreak of foodborne and waterborne disease in school is needed to be improved.

• Journal of Environmental Impact Assessment
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• v.27 no.6
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• pp.658-673
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• 2018

Social conflicts with extremely low frequency magnetic field(ELF-MF) exposures are expected to exacerbate due to continued increase in electric power demand and construction of high voltage transmission lines(HVTL). However, in current environmental impact assessment(EIA) act, specific guidelines have not been included concretely about EIA of ELF-MF. Therefore, this study conducted a standardization study on EIA method through case analysis, field measurement, and expert consultation of the EIA for the ELF-MF near HVTL which is the main cause of exposures. The status of the EIA of the ELF-MF and the problem to be improved are derived and the EIA method which can solve it is suggested. The main contents of the study is that the physical characteristics of the ELF-MF affected by distance and powerload should be considered at all stages of EIA(survey of the current situation - Prediction of the impacts - preparation of mitigation plan ? post EIA planning). Based on this study, we also suggested the 'Measurement method for extremely low frequency magnetic field on transmission line' and 'Table for extremely low frequency magnetic field measurement record on transmission line'. The results of this study can be applied to the EIA that minimizes the damage and conflict to the construction of transmission line and derives rational measures at the present time when the human hazard to long term exposure of the ELF-MF is unclear.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.1
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• pp.42-49
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• 2019

Objectives : Living donor liver transplantation (LDLT) is a life-saving therapy for patients with terminal liver disease. Many studies have focused on recipients rather than donors. The aim of this study was to assess the emotional status and personality characteristics of LDLT donors. Methods : We evaluated 218 subjects (126 male, 92 female) who visited Daegu Catholic University Medical Center from August 2012 to July 2018. A retrospective review of their preoperative psychological evaluation was done. We investigated epidemiological data and the Minnesota Multiphasic Personality Inventory-2 questionnaire. Subanalysis was done depending on whether subjects actually underwent surgery, relationship with the recipient, and their gender. Results : Mean age of subjects was $32.19{\pm}10.91years$. 187 subjects received LDLT surgery (actual donors) while 31 subjects didn't (potential donors). Donor-recipient relationship included husband-wife, parent-children, brother-sister etc. Subjects had statistical significance on validity scale L, F, K and all clinical scales compared to the control group. Potential donors had significant difference in F(b), F(p), K, S, Pa, AGGR, PSYC, DISC and NEGE scales compared to actual donors. F, D and NEGE scales were found to be predictive for actual donation. Subanalysis on donor-recipient relationship and gender also showed significant difference in certain scales. Conclusions : Under-reporting of psychological problems should be considered when evaluating living-liver donors. Information about the donor's overall psychosocial background, mental status and donation process should also be acquired.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.591-600
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• 2018

The objective of this study was to determine the changes in phytoplankton and long-term water quality of Juksan-Weir in Yeongsan River that took place between April 2010 and December 2015. The number of species used in this study was 288, which consisted of 6% of Cyanophyta, 26% of Bacillariophyta, 53% of Chlorophyta and the others (15%). The standing crops of phytoplankton ranged from $500cells{\cdot}mL^{-1}-29,950cells{\cdot}mL^{-1}$ with an average of $7,885cells{\cdot}mL^{-1}$. At the two site, 20 dominant genera of found. The dominant genera were 6 of Bacillariophyta, 6 of Cyanophyta, 7 of Chlorophyta and 1 of Cryptophyta. The most dominant genus among the phytoplankton was Stephanodiscus sp. (Total 59%, each 54% and 63%). The most dominant genus among the Cyanophyta was Microcystis sp., which had a cell abundance ratio of 17%. The results of two sites were 21% and 13%, and the upstream was higher than the downstream.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.18-41
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• 2011

The Safeguarding of Intangible Cultural Heritage in Korea has begun since1962 when the Cultural Properties Protection Act was established. Korean ICH Safeguarding system is initially derived from Cultural Properties Protection Act in Japan. Japan has started Important ICH Designation System in 1954 to concede the skills and artistic talents holders, thus it could implement the multilateral system management for adopting different ICH protection systems such as Important Intangible Folklore Properties, Selection and Preservation Techniques, and Documenting Records. However, Korea has solely adopted Important ICH Designation System since Cultural Properties Protection Act was introduced. Korean ICH Safeguarding System represented by the Certification System of ICH Skill Holders is to ensure skills and artistic holders who perform the elements of Intangible Cultural Heritage, and manage the safeguarding of intangible cultural heritage in order to let the skills and artistic holders instruct inheritors. As a result, it could build up the internal foundation for the diffusion of inheritors and established the related organizations. However, the inheritor-centered protection system has caused many problems as it is being lasted for more than fifty years. Fragmented designation measures, the cultural power of skill holders, and the research and evaluation methods have pointed out the difficulties of safeguarding and preservation measures of ICH. Moreover,the legitimacy of safeguarding system related in the authenticity of transmission in ICH has emerged to review the safeguarding system of ICH with diverse viewpoints. Therefore, this paper will review the implementation process and achievement of ICH safeguarding system to examine the problem and causes of the safeguarding system. The conference records of Cultural Property Association and articles of cultural properties policies directors, Cultural Property Association members, and professional experts are being used for the initial materials of this paper, and it is examined for the contents of designation system of Important Cultural Heritage, rather than overall cases. Thus such problems the limitation of expansion in ICH lists as inheritor-centered designation system, hierarchical and exclusive transmission system, inappropriate concept of archetype as the principle of ICH transmission are derived from the root of Important ICH designation system. Thus this paper demonstrates that this system must be revised for the expansion of ICH safeguarding system in Korea and points out multilateral protection system should be established as well as Certification System of Important ICH skill holders.

• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.252-269
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• 2019

Since the inauguration of the Kim Jong-un regime in 2012, the safeguarding and management system of cultural heritage in the Democratic People's Republic of Korea (DPRK) has been changing to a form similar to that of a democratic country's legal system. In addition, the National Authority for the Protection of Cultural Heritage (NAPCH) has continuously recorded and cataloged intangible cultural heritage elements in the DPRK, listing Arirang, kimchi-making, and ssireum on the UNESCO Intangible Cultural Heritage Representative List. In particular, the multinational nomination of ssireum in October 2018 is symbolic in terms of inter-Korean exchanges and cooperation for peace and reconciliation, raising expectations for the further multinational nomination of the two Koreas' intangible cultural heritage. Currently, South Korea lists 20 items on its Representative List of the Intangible Cultural Heritage of Humanity, three of which are shared by various countries with multinational nominations such as falconry, tug-of-war, and ssireum. However, when comparing the process of applying for multinational nomination in the three elements that follow, it is necessary to discuss whether these cases reflect the nature of multinational nomination. In particular, in the case of ssireum, without a working-level consultation between the two Koreas to prepare an application for a multinational nomination, each applied for a single registration; these applications were approved exceptionally as a multinational nomination by the Intergovernmental Committee under the leadership of the Secretary-General of UNESCO, and no bilateral exchanges have taken place until now. This is symbolic, formal, and substantially similar to the individual listings in terms of the spirit of co-listing on the premise of mutual exchange and cooperation. Therefore, the only way to strengthen the effectiveness of the multinational nomination between the two Koreas and to guarantee the spirit of multinational nomination is to request multilateral co-registration, including the two Koreas. For this, the Korean government needs a strategic approach, such as finding elements for multilateral co-listing; accumulating expertise, capabilities, and experience as a leading country in multilateral co-listing; and building cooperative governance with stakeholders. Besides, to reduce the volatility of inter-Korean cultural exchanges and cooperation depending on political situations and the special nature of inter-Korean relations, measures should be taken toward achieving inter-Korean cultural heritage exchanges and cooperation under a multilateral cooperation system using UNESCO, an international organization.

• The Journal of the Petrological Society of Korea
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• v.28 no.3
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• pp.171-193
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• 2019

This study aims to identify the geometry and internal structures of the Yeongdeok Fault, a branch fault of the Yangsan Fault, by detailed mapping and to characterize its kinematics by analyzing the attitudes of sedimentary rocks adjacent to the fault, slip data on the fault surfaces, and anisotropy of magnetic susceptibility (AMS) of the fault gouges. The Yeongdeok Fault, which shows a total extension of 40 km on the digital elevation map, cuts the Triassic Yeongdeok Granite and the Cretaceous sedimentary and volcanic rocks with about 8.1 km of dextral strike-slip offset. The NNW- or N-S-striking Yeongdeok Fault runs as a single fault north of Hwacheon-ri, Yeongdeok-eup, but south of Hwacheon-ri it branches into two faults. The western one of these two faults shows a zigzag-shaped extension consisting of a series of NNE- to NE- and NNW-striking segments, while the eastern one is extended south-southeastward and then merged with the Yangsan Fault in Gangu-myeon, Yeongdeok-gun. The Yeongdeok Fault dips eastward with an angle of > $65^{\circ}$ at most outcrops and shows its fault cores and damage zones of 2~15 m and of up to 180 m wide, respectively. The fault cores derived from several different wall rocks, such as granites and sedimentary and volcanic rocks, show different deformation patterns. The fault cores derived from granites consist mainly of fault breccias with gouge zones less than 10 cm thick, in which shear deformation is concentrated. While the fault cores derived from sedimentary rocks consist of gouges and breccia zones, which anastomose and link up each other with greater widths than those derived from granites. The attitudes of sedimentary rocks adjacent to the fault become tilted at a high angle similar to that of the fault. The fault slip data and AMS of the fault gouges indicate two main events of the Yeongdeok Fault, (1) sinistral strike-slip under NW-SE compression and then (2) dextral strike-slip under NE-SW compression, and shows the overwhelming deformation feature recorded by the later dextral strike-slip. Comparing the deformation history and features of the Yeongdeok Fault in the study area with those of the Yangsan Fault of previous studies, it is interpreted that the two faults experienced the same sinistral and dextral strike-slip movements under the late Cretaceous NW-SE compression and the Paleogene NE-SW compression, respectively, despite the slight difference in strike of the two faults.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.287-298
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• 2018

The zooplankton community and environmental factor were investigated on a weekly basis from March to November 2015 in Lake Paldang, Korea. The seasonal succession of zooplankton community structure was influenced by hydraulic and hydrological factors such as inflow, outflow and rainfall. However, the hydraulic retention time in 2015 (16.3 day) was affected by the periods of water shortage that had continued since 2014 and increased substantially compared to 2013 (7.3 day). Therefore, the inflow and outflow discharge were decreased, and the water quality (COD, BOD, TOC, TP, Chl-a) of Lake Paldang (St.1) was the same characteristics as the river type Bukhan river (St.3), compared with the lake type Namhan river (St.2) and Gyeongan stream (St.4). Zooplankton community dominated by rotifers (Keratella cochlearis, Synchaeta oblonga) in spring (March to May). However, Copepod (Nauplius) and Cladoceran (Bosmina longirostris) dominated in St.4. In summer (June to August), there was a few strong rainfall event and the highest number of individuals dominated by Keratella cochlearis (Rotifera) and Difflugia corona (Protozoa) were shown during the study period. In autumn (October to November), the water temperature was decreased with decrease in the total number of individuals showing Nauplius (Copepoda) as the dominant species. As a result of the statistical analysis about zooplankton variation in environmental factors, the continuous periods of water shortage increased the hydraulic retention time and showed different characteristic for each site. St.1, St.3 and St.2, St.4 are shown in the same group (p<0.05), showing the each characteristics of river type and lake type. Therefore, the water quality of catchment area and distribution of zooplankton community would be attributed to hydraulic and hydrological factors.

• Journal of Intelligence and Information Systems
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• v.25 no.1
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• pp.139-161
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• 2019

The utilization of the e-commerce market has become a common life style in today. It has become important part to know where and how to make reasonable purchases of good quality products for customers. This change in purchase psychology tends to make it difficult for customers to make purchasing decisions in vast amounts of information. In this case, the recommendation system has the effect of reducing the cost of information retrieval and improving the satisfaction by analyzing the purchasing behavior of the customer. Amazon and Netflix are considered to be the well-known examples of sales marketing using the recommendation system. In the case of Amazon, 60% of the recommendation is made by purchasing goods, and 35% of the sales increase was achieved. Netflix, on the other hand, found that 75% of movie recommendations were made using services. This personalization technique is considered to be one of the key strategies for one-to-one marketing that can be useful in online markets where salespeople do not exist. Recommendation techniques that are mainly used in recommendation systems today include collaborative filtering and content-based filtering. Furthermore, hybrid techniques and association rules that use these techniques in combination are also being used in various fields. Of these, collaborative filtering recommendation techniques are the most popular today. Collaborative filtering is a method of recommending products preferred by neighbors who have similar preferences or purchasing behavior, based on the assumption that users who have exhibited similar tendencies in purchasing or evaluating products in the past will have a similar tendency to other products. However, most of the existed systems are recommended only within the same category of products such as books and movies. This is because the recommendation system estimates the purchase satisfaction about new item which have never been bought yet using customer's purchase rating points of a similar commodity based on the transaction data. In addition, there is a problem about the reliability of purchase ratings used in the recommendation system. Reliability of customer purchase ratings is causing serious problems. In particular, 'Compensatory Review' refers to the intentional manipulation of a customer purchase rating by a company intervention. In fact, Amazon has been hard-pressed for these "compassionate reviews" since 2016 and has worked hard to reduce false information and increase credibility. The survey showed that the average rating for products with 'Compensated Review' was higher than those without 'Compensation Review'. And it turns out that 'Compensatory Review' is about 12 times less likely to give the lowest rating, and about 4 times less likely to leave a critical opinion. As such, customer purchase ratings are full of various noises. This problem is directly related to the performance of recommendation systems aimed at maximizing profits by attracting highly satisfied customers in most e-commerce transactions. In this study, we propose the possibility of using new indicators that can objectively substitute existing customer 's purchase ratings by using RFM multi-dimensional analysis technique to solve a series of problems. RFM multi-dimensional analysis technique is the most widely used analytical method in customer relationship management marketing(CRM), and is a data analysis method for selecting customers who are likely to purchase goods. As a result of verifying the actual purchase history data using the relevant index, the accuracy was as high as about 55%. This is a result of recommending a total of 4,386 different types of products that have never been bought before, thus the verification result means relatively high accuracy and utilization value. And this study suggests the possibility of general recommendation system that can be applied to various offline product data. If additional data is acquired in the future, the accuracy of the proposed recommendation system can be improved.