• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.45.1-45.1
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• 2017

Optical variability is one way to probe the nature of the central engine of AGN at smaller linear scales, and previous studies have shown that optical variability of AGN is more prevalent at longer timescales and at shorter wavelengths. To understand the properties and physical mechanism of variability, we are performing the KMTNet Active Nuclei Variability Survey (KANVaS). Especially, we investigated intra-night variability of AGN with KMTNet data which observed COSMOS field during 3 separate nights from 2015 to 2016 in B, V, R, and I bands. Each night was composed of 5, 9, and 11 epochs with 20-30 min cadence. To find AGN in the COSMOS field, we applied multi-wavelength selection methods. Using X-ray, mid-infrared, and radio selection methods, 50-60, 130-220, 20-40 number of AGN are detected, respectively. Achieving photometric uncertainty ~0.01mag by differential photometry, we employed a standard time-series analysis tool to identify variable AGN, chi-square test. Preliminary results indicate that there is no evidence of intra-night optical variability of AGN. It is possible that previous studies discovered intra-night variability used inappropriate photometric error. However, main reason seems that our targets have fainter magnitude (higher photometric error) than that of previous studies. To discover variability of AGN, we will investigate longer timescale variability of AGN.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.65.2-65.2
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• 2018

Through MIRIS $Pa{\alpha}$ Galactic plane survey, a lot of $Pa{\alpha}$ blobs were detected along the plane. To reveal their characteristics, we are planning to collect NIR high-resolution spectroscopic data for them by using Immersion GRating INfrared Spectrograph (IGRINS). Here, we present the preliminary results of the IGRINS observations for a Herbig Be star, MWC 1080, which is one of the $Pa{\alpha}$ blobs detected in Cepheus. This Herbig Be star is known to possess a lot of young stellar objects (YSOs) and bright MIR ($10-20{\mu}m$) nebulosity in its vicinity. From IPHAS $H{\alpha}$ data, we revealed large extended $H{\alpha}$ features that correlate well with MIR and 13CO morphologies around MWC 1080. A part of the $H{\alpha}$ features shows a bow shock shape to the northeast of the primary star MWC 1080A, which seems to be due to an outflow from MWC 1080A. Through IGRINS observations, we detected faint [Fe II] ${\lambda}1.644{\mu}m$ and H2 1-0 S(1) ${\lambda}2.122{\mu}m$ emission lines around the bow shock feature. Interestingly, to the east region of MWC 1080A, we also detected strong [Fe II] and H2 emission lines with a couple of velocity components, which suggests the detection of a new outflow from another YSO. Broad $Br{\gamma}$ ${\lambda}2.1662{\mu}m$ line and H2 lines with various velocity components were detected around the bright MIR and $H{\alpha}$ nebulosity as well.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.32.1-32.1
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• 2018

Searching for low surface brightness (LSB) dwarf galaxies in low density environments (isolated and group) can help us resolve the discrepancy between observation and theory known as the 'missing satellite' problem. They are also important to study the evolution of low mass galaxies in these environments. Although the number of dwarfs in such environments is rapidly increasing in many recent studies, it is still not easy to characterize their general properties. Motivated by this, we present preliminary results of our search for LSB dwarf galaxies around 60 nearby galaxies (D<50Mpc) using deep optical images. Imaging data from Maidanak Astronomical Observatory (MAO) in Uzbekistan as a part of Intensive Monitoring Survey of Nearby Galaxies (IMSNG; Im in prep.) and other archival data are used to find previously unknown LSB dwarf galaxies. Extended LSB sources (central surface brightness ${\mu}_0$ > $23mag/arcsec^2$) are first selected in the ${\mu}_0$ - magnitude plane (Rines & Geller 2008). The dwarf galaxy candidates are chosen by visual inspection. We discuss whether these candidates are actual satellite galaxies, by measuring the projected number densities in group environments and in the field. Also, their structural and photometric properties are compared with those of previously discovered dwarf galaxies in the literature.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.28 no.4
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• pp.235-243
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• 2017

Objectives: This study aimed to evaluate the mental health status of the children of psychiatric patients in order to plan for the resources that may be necessary to help these children achieve their full potential. Methods: Forty-eight children (age 9-18) whose parents were registered in 5 community mental health centers located in Seoul were recruited. Tests assessing 3 psychological domains were conducted: 1) cognition: Korean version of Learning Disability Evaluation Scale, Comprehensive Attention Test, 2) parent reported emotion and behavior: Korean Child Behavior Checklist, Korean attention-deficit hyperactivity disorder Rating Scale, and 3) self-reported emotion and behavior: Korean Beck's Depression Inventory-II/Children's Depression Inventory-II, Korean Youth Self Report). We defined the children as having a high risk of developing mental health problems if their test scores were over the cut-off levels in 2 or more of the 3 domains assessed. Results: Twelve (25%) children were classified as having a high risk of developing mental health issues. 20 (41.6%) children scored above the cut-off in only one of the domains. Conclusion: Our results suggest that the children of psychiatric patients might be vulnerable to mental illness and need early prevention or interven-tions for the sake of their mental health.

• The Journal of Korean Association of Computer Education
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• v.4 no.1
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• pp.127-134
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• 2001

Many teachers at vocational high schools have had difficulties overcoming the gap between what students know and what students have to achieve in many topics. Mathematics is toughest of all, since most of textbooks in electronics are assuming student's basic knowledge in math. Considering that many students with very low achievements are entering vocational high schools, reality is far from such assumption. Inevitably, we have to face two difficult questions; do we have enough time to teach these kids all the math that they need in two years? If not, what alternatives we should adopt? We just do not have enough time and therefore find out a way to cope with harsh reality. According to our preliminary study, we suggest that multimedia-based CAI may be the best way to attack this problem. From hardware point of view, fortunately, many of vocational high schools are reasonably equipped for multimedia-based education. However there have been hardly any effort to develop courseware for vocational education in Korea. In this paper, a CAI title for learning basic characteristics of alternating current has been designed and implemented. The developed multimedia-based CAI title has been applied with respect to first grade students at local vocational high schools. A survey after classes shows that CAI could help student feel much comfortable with Basic Electricity course and grasp physical understanding much easily. Accordingly we conclude that classes adopting CAI would be of great help to put education in vocational high schools on the right track.

• The Korean Journal of Emergency Medical Services
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• v.9 no.2
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• pp.5-20
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• 2005

Purpose: This study is to examine the relationship between safety awareness and safety accident occurrence with elementary school students. Materials and methods: It selected 10 elementary schools under the supervision of Jeonnam Board of Education and sampled 700 students randomly from 2-3 classes in the 5th and the 6th grade. One preliminary survey was conducted to revise and complement the contents and forms of questionnaire with 70 students of a school from Apr. 1 to 6, 2004 and this study was conducted from Apr. 10 to 30, 2004. Total 700 questionnaires were distributed and 681 were collected (97%) and 602 were used for final analysis except 79 lacking responses. Data collected were analyzed with SPSS statistical program. Results: The average score of safety awareness of subjects by area was high as 2.72 points out of a possible 3. Area showing the highest safety awareness was safety from fire. Girl students had higher safety awareness than boy students. The fifth graders had higher safety awareness than the sixth graders. In safety awareness by the number of siblings, single son or single daughter showed the highest safety awareness. 53.2% of the subjects experienced accident for one year, the frequency of accident was mostly once and most of accidents were occurred at school. Accidents for the last year were higher in boy students, the sixth graders. According to relationship between safety awareness and safety accident, group with lower safety awareness in school safety(P < .022), traffic safety(P < .016), fire safety(P < .019), home safety(P < .007) and accident treatment and first aid(P < .003) had higher safety accidents than that with higher safety awareness. Conclusion: Development of safety education program by grade, that of parents safety education program, field experience and practice with students, teachers and parents and various safety education programs should be substantially and repeatedly accomplished for prevention education of safety accidents. In addition, to prevent and cope with safety accidents, safety education should be reflected on normal education, safety education textbook be developed, special safety education teachers be employed for safety education.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.639-645
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• 2006

During abstinence from alcohol, craving is elicited by the cues and contexts previously associated with alcohol, and contributes to relapse. To prevent the craving and relapse experienced by alcoholics, cue-exposure therapy (CET) has been used to extinguish the association between alcohol and alcohol-related cues and contexts. This study applied CET, using a virtual reality (VR) system, to eight members of an Alcoholics Anonymous group, in eight sessions. Cues and contexts most likely to elicit an urge to drink were selected through a preliminary survey in order to compose VR-CET scenarios: a glass, bottle, food, and a bar were judged to be the most tempting for people in alcohol dependence and abstinence. By these cues and contexts, a Japanese style pub and a western bar were composed. Each session was administered for 30 minutes by a psychiatrist and included an introduction, immersion, VR navigation, interviews about feelings, and self-report questionnaires about cravings. The eight sessions consisted of initial and closing sessions, and six cue- and context-focused sessions. As a result, a reduction in cue-elicited craving after VR-CET was reported. A mean score of 15.75 (SD = 10.91) on the Alcohol Urge Questionnaire in the first session decreased to 11.57 (SD = 6.88) in the final session.

• Journal of the Korean Geotechnical Society
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• v.20 no.8
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• pp.15-27
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• 2004

Sliding aspects of rock slope, where large-scaled tension cracks are induced during preliminary excavation, have been analyzed. Structure of rock mass is investigated by performing the electrical resistivity survey and the orientations and positions of discontinuities are measured from DOM-drilled core log. Geological evidence far primary failure movement has been detected and clay minerals which possess swelling properties are identified through XRD analysis. Slope stability is examined by considering the orientations of discontinuities and their trace distributions on the cut-face and neighboring natural slope surface. Both orientations and positions of failure-invoking discontinuity planes, traces of which are exposed within the anticipated sliding region, are concerned fur analyzing the preferred sliding directions. Regional sliding vectors are assessed based on the relative positions of potential sliding planes in the boreholes and the general trend of anticipated failure movement of rock slope is also investigated.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.558-566
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• 2012

This study was conducted to offer preliminary data for a natural restoration by the actual condition survey of quarries after extracting rock materials. The mountain restoration area according to a farming and fishing village organize project was restored by green landscape after quarry. However, planting tree species were died due to poor maintenance and administration after restoration works and surface soil loss and erosion occurred during a summer rainfall season because of poor slope greening. It will be needed to review restoration constructions to establish a natural friendly and flawless construction through the selection of optimum restoration works and the examination of soil and geological characteristics. In addition, it is necessary to apply cost-reducing program of restoration constructions. Quarry areas could be restored by the selection of simple and optimum construction works because the most areas were dominant in earth-sand rocks, soft-rocks, and weather-rocks. In addition, the restoration construction project should be examined thoroughly by restoration specialists during green restoration planning and review processes.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5095-5099
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• 2016

The relative lack of information on breast cancer etiology in Burkina Faso led us to undertake the present work to highlight risk factors. This prospective study was conducted using a questionnaire between January 2015 and February 2016 on women admitted to Yalgado OUEDRAOGO hospital, for consultation or supervision. The characteristics of multiparous breast cancer patients (n = 44) were compared with their non-multiparous counterparts (n = 36). The study found that increased risk of breast cancer among non-multiparous cases was related to body mass index (BMI) (p <0.001), age at menopause (p <0.004) and use of oral contraception (p <0.021) while abortion (p <0.002) was a risk factor among multiparous cases. These results suggest that even if multiparity is associated with a decreased risk in some women, avoidance of abortion during reproductive life should be recommended. The results provide preliminary information, which now need to be supplemented by survey of a larger sample in the national territory.