• Economic and Environmental Geology
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• v.26 no.4
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• pp.507-518
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• 1993

Paleomagnetic investigations have been carried out on the Tertiary sedimentary formations (Yeonil Group) in Pohang basin, southeastern Korea. A total of 215 samples were collected from 26 sites. Progressive thermal demagnetization indicates that many samples have unstable magnetization and do not reveal a characteristic direction. However, some samples from the lower and upper Duho Formation show a characteristic direction $D/I=7.8^{\circ}/48.3^{\circ}$ (${\alpha}_{95}=3.7^{\circ}$, k=174.1). Stepwise thermal demagnetization data show that some samples from the Hagjeon and middle Duho Formations reveal great-circle distributions moving from the present to a reversed direction of geomagnetic field. The mean of intersection points of the great-circles is nearly antipodal to the characteristic normal direction of the lower and upper Duho Formation. We infer that the Hagjeon Formation was formed during the reversed polarity chron C5B (16.2~14.7 Ma) and the Duho Formation 14.7~11.6 Ma based on our results and previous paleontologic and age dating data. Paleomagnetic direction for the Middle Miocene of Korea, analysed from the combined results of stable endpoints and great circles, is $D/I=8.7^{\circ}/53.9^{\circ}$ (${\alpha}_{95}=4.2^{\circ}$, k=74.8), and the corresponding paleopole is Lat./Long.=$82.7^{\circ}/230.2^{\circ}$ (${\delta}p=2.8^{\circ}$, ${\delta}m=5.9^{\circ}$). On the basis of this, we interpret that the opening of the East sea (Japan sea) or the synchronous clockwise rotation of the Southwest Japan exerted no structural influence on the Yeonil Group in the Middle Miocene.

• Economic and Environmental Geology
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• v.25 no.3
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• pp.351-358
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• 1992

The gravity measurement has been conducted at 327 station with an interval of 25 m along the survey lines of 1.6 km and 1.7 km traversing Hyungsan river and of 2.35 km and 2.42 km running N-S direction near Heunghae-eup in Pohang basin. Bouguer gravity anomalies were obtained, and geologic structure along four survey lines were interpreted by applying Fourier series and Talwani methods for two demensional body. A fault is in existence along the Hyungsan river, and northern block of it is displaced down by 150 m to 200 m relative to southern one. The thicknesses of Yeonil Group vary from 250 m to 550 m and from 150 m to 300 m in the northern and southern blocks of the fault, respectively. Another fault is in existence running E-W direction near Heunghae-eup, and its southern block is displaced down by about 250 m relative to its northern block. The thicknesses of Yeonil Group vary from 200 m to 400 m and from 500 m to 700 m in the southern and northern blocks of the fault, respectively. Above two faults are normal faults and make a graben structure, which results the age of rocks in the central region between the faults is younger than those of outside regions. This result coincides with that of paleontological study.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.234-243
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• 2012

The purpose of this study was to estimate the prevalence of musculoskeletal symptoms and work-related factors of these symptoms in dental hygienists. The self-administered questionnaire was surveyed and collected from August 1-12 of 2011 targeting 210 dental hygienists Seoul, Gyeonggi, Daegu, Pohang. Except 5 people whose responses are not clear and who suffered accident, the analysis was made on 205 people. Data analysis was performed using the chi square test and multiple logistic regression analysis using the SPSS WIN(ver 18.0) program, RULA and, REBA. The overall Experience rate of musculoskeletal symptoms was 95.6% (196/205). The specific Experience rate of musculoskeletal symptoms for different regions of the body were as follows:The highest was shown 82.4% in Neck-shoulders(R), 78% in Neck, 69.8% in shoulders(R), 66.3%in Wrist(R). Therefore, Improvements of working environments in dental clinics are needed to prevent musculoskeletal disease development in dental hygienists.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.345-346
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• 2012

본 연구는 치과진료실의 실내 공기질에 영향을 미치는 요인과 종사자의 실내자각증상과 관련성을 조사하여 치과위생사 개인의 발전과 건강 증진에 필요한 기초자료를 마련하고자 본 연구를 시행하였다. 전국(서울, 경기, 대구, 포항)의 종합병원, 치과병원, 치과의원의 치과위생사 210명을 대상으로 2011년 10월 1일부터 20일까지 자기기입식 설문지 조사를 시행한 후 회수하여 응답이 불분명한 5명을 제외한 205명에 대해서 분석 하였다. 수집된 자료는 SPSS WIN 15.0 프로그램을 이용하여 분석하였다. 그 결과 근무 중 휴식시간 유무별로는 근무 중 휴식시간이 없는 치과위생사가 67.3%로 높은 분포를 보였고, 건물 밖 외출 여부별로는 때때로가 54.6%로 절반 이상을 차지하였으며, 건물 밖 외출횟수별로는 1회 86.1%로 대부분을 차지하였으며, 근무기관의 계절별 자연환기 정도별로는 봄, 여름, 가을, 겨울 모두 1일 2회 이내가 절반 이상을 차지하였으며, 다음으로 1일 4회 이내 19.0%, 기타 9.8%, 1일 10회 이내와 하루 종일 2.4% 순이었다. 실내자각증상 호소율에 대해 살펴본 결과는 4점 만점 중 전체 평균이 2.45로 나타났다. 먼저 영역별로는 평균이 '목증상'과 '눈증상'이 각각 2.54로 가장 높았으며, 문항 중에는 평균이 '눈이 잘 피로해진다'가 3.00으로 가장 높게 나타났다. 근무환경 특성에 따른 실내자각증상은 야간진료 여부별로는 야간진료를 하는 치과위생사가 그렇지 않은 치과위생사보다 실내자각증상이 낮았으며, 야간진료 여부에 따라 유의한 차이를 보였다(t=2.07, p<.05). 실내자각증상과 직무스트레스의 관계는 물리환경(r=.259, p<.001)과 직무요구(r=.311, p<.001), 관계갈등(r=.172, p<.05), 조직체계(r=.158, p<.05), 보상 부적절(r=.197, p<.01), 그리고 직무스트레스(r=.275, p<.001)와 통계적으로 유의한 상관관계를 보였다.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.839-844
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• 2009

This research investigates the importance of the microbial metabolic pathways such as denitrification, iron reduction, and methanogenesis, in the degradation of organic matters of the sediments. There are statistically significant differences( P < 0.05) in the rates of denitrification, iron reduction, and methanogenesis according to the location: Site A has no plant, Site B is dominated by Scirpus, and Site C is dominated by Phragmites. Among them, Site C showed different methanogenesis rate depending on the sediments depth. The organic matter content increased from Site A to Site C. Site A had the smallest organic matter content whereas it showed the largest denitrification rate and iron reduction rate. Site C had the largest methanogenesis rate. Denitrification is the dominant pathways based on the assumption that anaerobic degradation of organic matter is mainly carried out through denitrification, iron reduction, and methanogenesis.

• Journal of the Korea Society for Simulation
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• v.20 no.1
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• pp.107-116
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• 2011

Recently, femtocell has been concerned as one of effective solutions to relieve shadow region and provide high quality services to users in indoor environments. Even though femtocell offers various benefits to cellular operators and users, many technical issues, such as interference coordination, network synchronization, self-configuration, self-optimization, and so on, should be solved to deploy the femtocell in current network. In this paper, we develop a simulator for evaluating performance of long term evolution (LTE) femtocell systems under various interference scenarios. The simulator consists of a main-module and five sub-modules. The main-module connects and manages five sub-modules which have the functionality managing user mobility, packet scheduling, call admission control, traffic generation, and modulation and coding scheme (MCS). To provide user convenience, the simulator adopts graphical user interface (GUI) which can observes simulation results in real time. We expect that this simulator can contribute to developing effective femtocell systems by supporting a tool for analyzing the effect of interference between macrocell and femtocell.

• The Journal of Sustainable Design and Educational Environment Research
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• v.14 no.2
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• pp.1-11
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• 2015

The existing school facility recommendations enacted in 1997 has not been suitable for current school curriculum. The objective of the paper is to present the school building area reflecting the current education policies and curriculum. This paper firstly reviewed previous school facility recommendations through literature review. Secondly, the statistical approach was carried out for analyzing the present situation of school building area by using statistical database of Korean Educational Development Institute. The paper did the field investigation and questionnaire. And, the final step proposed the school building area standards(minimum, optimum, maximum) by space program using Nelson model. The contents of analyzing space organization are 'entry and placement, outdoor space', 'space program' and 'phase structure and organization of unit space'.

• Journal of Agricultural Extension & Community Development
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• v.17 no.2
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• pp.261-277
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• 2010

This study is undertaken to present the facilitation plan of English library that specialized the resource-based learning to provide learning that is suited for student's own learning style and self-leading learning as the method to learn contents required for individuals as a method for improving the English education environment in the rural areas. For this purpose, a study was conducted to find out the possibility of facilitating English library in the rural areas on the basis of consulting for structuring and operating English library in public libraries located in isolated areas clustered with low income class in the urban areas where the conditions are similar to the rural areas and results are shown as the followings. First, it displayed the possibility to have the rural area located with many closed schools or small-sized schools to facilitate the available facilities to build up the environment to specialize in English education that would be as comparable as any facilities in any urban setting. Second, it would enable the conditions to moderate the conflict on education environment for local residents who felt inequality in education by providing the benefit for fine education linked to public education through English library without going through private education. And third, English library that has the limitations in locality or economic means would actively participate by local educational institutions and volunteers to enhance the sense of master for the local residents and bring residents together to make positive impact on local economy facilitation.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.27-37
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• 2018

The purpose of this study is figure out secondary education undergraduates' communication patterns and perceptions of use in KAKAOTALK, one of the most frequently used Social Network Service(SNS). The mixed method research was conducted of survey about 86 students and in-depth interview 10 of them. The chief implication of research showed that it has been firstly functioning them to sustain public and private network and to be an universal tool of expression their opinion, idea, themselves, however, they still regard face-to-face communication important. Secondly, they think that KAKAOTALK is a part of their everyday lives and regarded a communication space to freely express themselves and to adjust and manage their image. Thirdly, they psychologically solved their loneliness and were encouraged, moreover, the contents of communication were different according to usd of public or private team chat room. It needs a follow-up study comparatively to analyze other generation's cognitive psychological values in SNS and to suggest digital culture literacy guideline.

• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.191-206
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• 2004

The present study investigated the hypothesis that a extremely low frequency magnetic field partially suppresses the synthesis of melatonin in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 ${\mu}$T, whereas the value for the primary schoolchildren living away from overhead transmission power line 0.05 mT. From simple analyses, the mean melatonin levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, but not statistically significant differences in the levels of the melatonin (p=0.2421), whereas the statistically significant differences in the levels of the melatonin related to the distance from residence to power line less and more than 100 m by cut-off point (p=0.0139). In multiple linear regression analyses, distance from residence to power line (p=0.0146) and dietary habit about burned meat (p=0.0170) proved to be significant risk factors in the mean nocturnal melatonin levels in the primary schoolchildren. In conclusion, these results demonstrate that urinary levels of nocturnal melatonin are not altered in primary schoolchildren exposed to extremely low frequency magnetic field(ELF-MF) at overhead transmission power line.