• Sleep Medicine and Psychophysiology
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• v.26 no.1
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• pp.44-48
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• 2019

Objectives: Insomnia is one of the most prevalent sleep disorders. Recent studies suggest that cognitive and physical arousal play an important role in the generation of primary insomnia. Studies have also shown that information processing disorders due to cortical hyperactivity might interfere with normal sleep onset and sleep continuity. Therefore, focusing on central nervous system arousal and normalizing the information process have become current topics of interest. It has been well known that neurofeedback can reduce the brain hyperarousal by modulating patients' brain waves during a sequence of behavior therapy. The purpose of this study was to investigate effects of neurofeedback therapy on electroencephalography (EEG) characteristics in patients with primary insomnia. Methods: Thirteen subjects who met the criteria for an insomnia diagnosis and 14 control subjects who were matched on sex and age were included. Neurofeedback and sham treatments were performed in a random order for 30 minutes, respectively. EEG spectral power analyses were performed to quantify effects of the neurofeedback therapy on brain wave forms. Results: In patients with primary insomnia, relative spectral theta and sigma power during a therapeutic neurofeedback session were significantly lower than during a sham session ($13.9{\pm}2.6$ vs. $12.2{\pm}3.8$ and $3.6{\pm}0.9$ vs. $3.2{\pm}1.0$ in %, respectively; p < 0.05). There were no statistically significant changes in other EEG spectral bands. Conclusion: For the first time in Korea, EEG spectral power in the theta band was found to increase when a neurofeedback session was applied to patients with insomnia. This outcome might provide some insight into new interventions for improving sleep onset. However, the treatment response of insomniacs was not precisely evaluated due to limitations of the current pilot study, which requires follow-up studies with larger samples in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.3
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• pp.101-114
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• 2019

In this study, we carry out the numerical simulation to trace the yearly shoreline change of Mang-Bang beach, which is suffering from erosion problem. We obtain the basic equation (One Line Model for shoreline) for the numerical simulation by assuming that the amount of shoreline retreat or advance is balanced by the net influx of longshore and cross-shore sediment into the unit discretized shoreline segment. In doing so, the energy flux model for the longshore sediment transport rate is also evoked. For the case of cross sediment transport, the modified Bailard's model (1981) by Cho and Kim (2019) is utilized. At each time step of the numerical simulation, we adjust a closure depth according to pertinent wave conditions based on the Hallermeier's analytical model (1978) having its roots on the Shield's parameter. Numerical results show that from 2017.4.26 to 2017.10.15 during which swells are prevailing, a shoreline advances due to the sustained supply of cross-shore sediment. It is also shown that a shoreline temporarily retreats due to the erosion by the yearly highest waves sequentially occurring from mid-October to the end of October, and is followed by gradual recovery of shoreline as high waves subdue and swells prevail. It is worth mentioning that great yearly circulation of shoreline completes when a shoreline retreats due to the erosion by the higher waves occurring from mid-March to the end of March. The great yearly circulation of shoreline mentioned above can also be found in the measured locations of shoreline on 2017.4.5, 2017.9.7, 2017.11.7, 2018.3.14. However, numerically simulated amount of shoreline retreat or advance is more significant than the physically measured one, and it should be noted that these discrepancies become more substantial for the case of RUN II where a closure depth is sustained to be as in the most morphology models like the Genesis (Hanson and Kraus, 1989).

• Journal of Hospice and Palliative Care
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• v.22 no.3
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• pp.105-116
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• 2019

Purpose: Pediatric palliative care (PPC) is emphasized as standard care for children with life-limiting conditions to improve the quality of life. In Korea, a government-funded pilot program was launched only in July 2018. Given that, this study examined various PPC delivery models in other countries to refine the PPC model in Korea. Methods: Target countries were selected based on the level of PPC provided there: the United Kingdom, the United States, Japan, and Singapore. Relevant literature, websites, and consultations from specialists were analyzed by the integrative review method. Literature search was conducted in PubMed, Google, and Google Scholar, focusing publications since 1990, and on-site visits were conducted to ensure reliability. Analysis was performed on each country's process to develop its PPC scheme, policy, funding model, target population, delivery system, and quality assurance. Results: In the United Kingdom, community-based free-standing facilities work closely with primary care and exchange advice and referrals with specialized PPC consult teams of children's hospitals. In the United States, hospital-based specialized PPC consult teams set up networks with hospice agencies and home healthcare agencies and provide PPC by designating care coordinators. In Japan, palliative care is provided through several services such as palliative care for cancer patients, home care for technology-dependent patients, other support services for children with disabilities and/or chronic conditions. In Singapore, a home-based PPC association plays a pivotal role in providing PPC by taking advantage of geographic accessibility and cooperating with tertiary hospitals. Conclusion: It is warranted to identify unmet needs and establish an appropriate PPD model to provide need-based individualized care and optimize PPC in South Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.4
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• pp.24-32
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• 2019

According to the Ministry of Land, Infrastructure, and Transport, the total area of unexecuted urban planning facilities in Korea is about $1,257km^2$, of which 47% is the unexecuted urban green space and forests. In the case of Seoul, the total area of unexecuted urban planning facilities is about $66km^2$, which is 5.24% of the total unexecuted area in the entire country. In Seoul, approximately 88% of the total unexecuted area is urban green space and forests, which is higher than the national rate. About 92% of the unexecuted urban planning facilities are long-term unexecuted urban planning facilities that are more than 10 years old. This study assessed the economic value of potential ecosystem services, focusing on the regulation service, supporting service, and cultural service, for urban green space and forests of unexecuted urban planning facilities in Seoul by using meta-regression analysis. As a result, the value of the regulation service provided by the urban green space and forests in Seoul was about 16.39 billion KRW, the value of the supporting service was about 5.8 billion KRW, and the cultural service value was about 7.78 billion KRW. The total value of ecosystem services is about 33.93 billion KRW. The values of regulation service and cultural service were the highest, and that was attributed to the characteristics of the downtown area. The significance of this study is to evaluate the value of ecosystem services for unexecuted urban planning facilities in Seoul. The results of this study can be used not only in the process of urban planning or policymaking but also land compensation methods applying the concept of an ecosystem service payment system.

• 대한공업교육학회지
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• v.44 no.1
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• pp.23-51
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• 2019

The purpose of this study was to analysis school dropout of specialized vocational high school students using phenomenological research method. The interview for the research was carried out with 10 adolescents who dropped out specialized vocational high school from December 8 to 23, 2018. According to the result of the research, 31 themes were extracted from interviews with 10 research participants. And 10 theme clusters were categorized from these. And these clusters were divided into 3 domains : 'before school dropout', 'causes & process of school dropout, feeling about school dropout', 'after school dropout' Based on the finding of the study, major conclusions of this study were as follow: First, adolescents who dropped out specialized vocational high school suffered from hard school life, disappointing lead from teachers, stereotypical lesson. And they committed misdeeds, and had psychological difficulties. Some of them kept up the good relationship with their friends, teachers, parents, some of them did not. Some of them kept up the good relationship with their friends, teachers and parents, while some of them did not. Second, they chose dropout due to various different causes. The procedures of school dropout proceeded with comparative ease. The effect of dropout prevention program is very limited. The feeling they felt at the time of school dropout varied individually. Some adolescents who dropped out specialized vocational high school were satisfied while others were stressed out, regretting their decision. Third, they lived diligently working part-time jobs or preparing General Equivalency Diploma (GED) test after dropout. They experienced positive changes in their daily lives after dropout. But sometimes they experienced various difficulties and negative changes. Most of them had their goals, and they were preparing for them. Their expectation was low that their life will succeed if they returned to school. They wanted people to understand their decision about dropout. And multiple institutions are supporting adolescents who dropped out specialized vocational high school. They need practical support : Various information, activity for career experience, counseling etc.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.710-715
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• 2018

In this study, $ZnFe_2O_4@SnO_2@TiO_2$ core-shell nanoparticles (NPs), a photocatalytic material with magnetic properties, were synthesized through a three-step process. Structural properties were investigated using X-ray diffraction (XRD) analysis. It was confirmed that $ZnFe_2O_4$ of the spinel, $SnO_2$ of the tetragonal and $TiO_2$ of the anatase structure were synthesized. The magnetic properties of synthesized materials were studied by a vibrating sample magnetometer (VSM). The saturation magnetization value of $ZnFe_2O_4$, a core material, was confirmed at 33.084 emu/g. As a result of the formation of $SnO_2$ and $TiO_2$ layers, the magnetism due to the increase in thickness was reduced by 33% and 40%, respectively, but sufficient magnetic properties were reserved. The photocatalytic efficiency of synthesized materials was measured using methylene blue (MB). The efficiency of the core material was about 4.2%, and as a result of the formation of $SnO_2$ and $TiO_2$ shell, it increased to 73% and 96%, respectively while maintaining a high photocatalytic efficiency. In addition, the antibacterial activity was validated via the inhibition zone by using E. Coli and S. Aureus. The formation of shells resulted in a wider inhibition zone, which is in good agreement with photocatalytic efficiency measurements.

• Journal of The Korean Association For Science Education
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• v.38 no.6
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• pp.885-899
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• 2018

As 'Science Inquiry Experiment' is newly introduced in the high school curriculum, where inquiry and experiment oriented education is insufficient, this study aims to analyze teacher's practice of 'Science Inquiry Experiment' in depth and identify contradictions during its process in the perspective of Cultural Historical Activity Theory. The research participant is teacher SHIN who is exclusively responsible for Science Inquiry Experiment. Starting with reflection on the practice of Science Inquiry Experiment class conducted in the first semester, interviews with participants, participatory observation and local materials were used during the 2nd semester's Science Inquiry Experiment class. A descriptive analysis of the teacher SHIN's practice of Science Inquiry Experiment was carried out and the contradictions in the activity system of the teacher SHIN were identified. The result reveals that in the overall practice of teaching Integrated Science and Science Inquiry Experiment, there were contradictions between teacher SHIN's recognition about cooperation(subject) and shared responsibility with other teachers(division of labor), and between teacher SHIN's recognition about the subjects(subject) and contrasting contents in teacher training courses(community). In the practice of teaching Science Inquiry Experiment, there were specific contradictions between teacher SHIN's recognition about the subject(subject) and time of job assignment(rule), between experimental activities(object) and experimental tools(tool), and between purpose of the subject(object) and directions about assessment(rule). These contradictions directly or indirectly influence the practice of teaching Science Inquiry Experiment. There needs to be support for constructing an activity system capable of supporting and promoting teachers' practice of Science Inquiry Experiment, and we made several suggestions to resolve the problems.

• Korean Journal of Heritage: History & Science
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• v.42 no.3
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• pp.106-130
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• 2009

The aim of this paper is analysis of structure and development pattern about wooden coffin and chamber tombs in Gyeongju from the 2nd century B.C. to the 3rd century A.D. for researching to socio-political tendency and growth process of Sarokuk. Tombs buried with iron objects were built in Youngnam(嶺南) from the 2nd century B.C. with spread wooden coffin with stone mound(積石木棺墓). Also medium or small sized wooden coffin tombs buried with bronze mirror of western Han(前漢) and soft stoneware(瓦質土器) were appeared the 2nd century B.C. in Gyeongju, because of establishment of Han's commanderies(漢郡縣) in the Korean Peninsula and refuge from Daedong river(大同江) to Jinhan(辰韓). Separate tombs(獨立墓) with lots of bronze object ware assumed high ranked tombs of parsonage(司祭王) or local chief(地域首長). From the 2nd century A.D. the size of wooden coffin tombs became enlarged and funerary objects ware abundant, for example Sarari 130th tomb(舍羅里 130號). The burying pattern of this tomb is similar to wooden chamber tombs in Lelang(樂浪), which had prestige goods like lacquer ware and bronze mirror in wood box(木匣) beside coffin. Appearance of these wooden chamber tombs that were different from original wooden coffin tombs imply interaction between Lelang and these area with iron. Sarari community that held right of trade and distribution to outside through the geographical advantage grew up centered position in Gyeongju politically, socially, and culturally. Chamber in tomb as a new structural notion that can secure funerary objects became firmly was established from the 2nd century A.D. in Gyeongju and large sized wooden chamber tombs were generally built early of the 3rd century A.D. This tendency was reflected in stratification of community and growth as center of local state. After late of the 3rd century A.D. Gyeongju type wooden chamber tomb(慶州式木槨墓) which had subordinate outer coffin(副槨) was appeared and then subordinate outer coffin was as bigger as main chamber(主槨) the 4th century A.D., because of centralization and stratification in society and unification of various communities among the Gyeongju area.

• Economic and Environmental Geology
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• v.52 no.3
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• pp.223-230
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• 2019

The calcination of oyster shells have been studied as the possible substitute for the limestone used as an absorbent of $SO_2$ gas. However, since pure shells can not be used in calcination process, some impurities are contained and the changes in the characteristics of the calcination products are expected. In this study, the surface characteristics of the calcination products are investigated by mineralogical analysis according to the contents of NaCl, which can be derived from sea water, and sediments on the surface of the shell as impurities. The marine sediments on the shells were mainly composed of quartz, albite, calcite, small amounts of amphibole and clay minerals such as ilite, chlorite and smectite. After calcination of oyster shells mixed with 0.2-4.0 wt% sediments at $900^{\circ}C$ for 2 hours, regardless of the dehydration, dehydroxylation, and phase change of these minerals at the lower temperature than this experiment, no noticeable changes were observed on the specific surface area of the calcined product. However, when mixed with 0.1 to 2.0 wt% NaCl, the specific surface area generally increases as compared with the shell sample before calcination. The specific surface area increases with increasing amount of salt, and then decreases again. This is closely related to the changes of surface morphology. As the amount of NaCl increases, the morphology of the surface is similar to that of gel. It changes into a slightly angular, smaller particle and again looks like gel with increasing amount of NaCl. Our results show that NaCl affects morphological changes probably caused by melting of some oyster shells, but may have different effects on the specific surface area of calcination product depending on the NaCl contents.

• Journal of the Korean earth science society
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• v.40 no.3
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• pp.227-239
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• 2019

Heavy snowfall events frequently occur in the Gangwon province, and the snowfall amount significantly varies in space due to the complex terrain and topographical modulation of precipitation. Understanding the spatial characteristics of heavy snowfall and its prediction is particularly challenging during snowfall events in the easterly winds. The easterly wind produces a significantly different atmospheric condition. Hence, it brings different precipitation characteristics. In this study, we have investigated the microphysical characteristics of snowfall in the windward and leeward sides of the Taebaek mountain range in the easterly condition. The two snowfall events are selected in the easterly, and the snow particles size distributions (SSD) are observed in the four sites (two windward and two leeward sites) by the PARSIVEL distrometers. We compared the characteristic parameters of SSDs that come from leeward sites to that of windward sites. The results show that SSDs of windward sites have a relatively wide distribution with many small snow particles compared to those of leeward sites. This characteristic is clearly shown by the larger characteristic number concentration and characteristic diameter in the windward sites. Snowfall rate and ice water content of windward also are larger than those of leeward sites. The results indicate that a new generation of snowfall particles is dominant in the windward sites which is likely due to the orographic lifting. In addition, the windward sites show heavy aggregation particles by nearby zero ground temperature that is likely driven by the wet and warm condition near the ocean.