• Computational Structural Engineering
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• v.7 no.3
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• pp.95-103
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• 1994

The safety related components in the nuclear power plant should be designed to withstand the seismic load. Among these components the integrity of reactor internals under earthquake load is important in stand points of safety and economics, because these are classified to Seismic Class I components. So far the modelling methods of reactor internals have been investigated by many authors. In this paper, the dynamic behaviour of reactor internals of Yong Gwang 1&2 nuclear power plants under SSE(Safe Shutdown Earthquake) load is analyzed by using of the simpled Global Beam Model. For this, as a first step, the characteristic analysis of reactor internal components are performed by using of the finite element code ANSYS. And the Global Beam Model for reactor internals which includes beam elements, nonlinear impact springs which have gaps in upper and lower positions, and hydrodynamical couplings which simulate the fluid-filled cylinders of reactor vessel and core barrel structures is established. And for the exciting external force the response spectrum which is applied to reactor support is converted to the time history input. With this excitation and the model the dynamic behaviour of reactor internals is obtained. As the results, the structural integrity of reactor internal components under seismic excitation is verified and the input for the detailed duel assembly series model could be obtained. And the simplicity and effectiveness of Global Beam Model and the economics of the explicit Runge-Kutta-Gills algorithm in impact problem of high frequency interface components are confirmed.

• Investigative Magnetic Resonance Imaging
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• v.14 no.2
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• pp.103-114
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• 2010

Purpose : To generate a Korean specific brain template, especially in patients with Alzheimer's disease (AD) by optimizing the voxel-based analysis. Materials and Methods : Three-dimensional T1-weighted images were obtained from 123 subjects who were 43 cognitively normal subjects and patients with 44 mild cognitive impairment (MCI) and 36 AD. The template and the corresponding aprior maps were created by using the matched pairs approach with considering differences of age, gender and differential diagnosis (DDX). We measured several characteristics in both our and the MNI templates, including in the ventricle size. Also, the fractions of gray matter and white matter voxels normalized by the total intracranial were evaluated. Results : The high resolution template and the corresponding aprior maps of gray matter, white matter (WM) and CSF were created with the voxel-size of $1{\times}1{\times}1\;mm$. Mean distance measures and the ventricle sizes differed between two templates. Our brain template had less gray matter and white matter areas than the MNI template. There were volume differences more in gray matter than in white matter. Conclusion : Gray matter and/or white matter integrity studies in populations of Korean elderly and patients with AD are needed to investigate with this template.

• Sijohaknonchong
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• v.44
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• pp.29-56
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• 2016

The purpose of this article is to shed light on the position and the importance of sijo (Korean traditional poetic form of Three-Line Stanzas) of the Korean poet Park Jae-sam among Korean sijo writers. Even though Park Jae-sam started his career as a poet writing two sijos and a poem, he began to write more poems than sijos later on. Anyway his interest in sijo writing has continued and he has served as a judge of sijo writing contests ever since. Especially in 1985, he published a collection of sijo. And each sijo writing in this collection are composed of three-line stanzas and each stanza of three lines. And each line has a rhythmic sound with a formal word formation. This article reveals that Park Jae-sam has pursued a happy unity of form and content in his sijo writings from the collection and that he has tried his hardest to realize this goal. This article notes that for this goal he puts stress on some methods of creating poetic images and the process of creating new ideas, the unity of Koreans's unique emotion of han(恨) and a sense of eternity, transcendence through ambivalent emotions, and the structure of statement mainly made of juxtaposed metaphors. And this articles also notes that as a most sincere lyric poet in the history of sijo he is much distinguished from other Korean poets in that he depicts mainly Koreans's unique emotions and their characteristics.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.721-728
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• 2004

Velopharyngeal closure is a sphincter mechanism between the activities of the soft palate, lateral pharyngeal wall and the posterior pharyngeal wall, which divides the oral and nasal cavity. It participates in physiological activities such as swallowing, breathing and speech. It is called a velopharyngeal dysfunction when this mechanism malfunctions. The causes of this dysfunction are defects in (1) length, function, posture of the soft palate, (2) depth and width of the nasopharynx and (3) activity of the posterior and lateral pharyngeal wall. The purposes of this study are to analyze the nasopharynx of cleft palate patients using cephalometry and to evaluate the degree of hypernasality using nasometry to find its relationship with velopharyngeal dysfunction. The following results were obtained : 1. In cephalometry, there were significant differences in soft palate length, soft palate thickness, nasopharyngeal depth, nasopharyngeal area, and adequate ratio between two groups. 2. In nasometry, there were significant differences between two groups in vowel /o/ and sentences including oral consonants. 3. In cleft palate patients, though no general correlation was found between Anatomic VPI and nasalance scores, vowel /i/ and sentences including oral consonants were slightly correlated. In conclusion, cephalometry and nasometer results were significantly different between the two groups. Though in the cleft palate group, Anatomic VPI and nasalance scores, which are indices for velopharyngeal closure, excluding the vowel /i/ and sentences including oral consonants show generally no significance.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.117-123
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• 2010

Tooth eruption is the movement of the tooth from the developing place in the alveolar bone to the functional position in the oral cavity. The permanent incisors originate from the dental lamina on the lingual side of preceding deciduous tooth and erupt to the level of the occlusion through the well developed gubernacular cord. Ectopic eruption is a developmental disturbance in the eruption pattern of the permanent dentition. Most of the ectopically erupted lower incisor has been found in lingual side. The ectopically erupted tooth could be repositioned by orthodontic force in the early mixed dentition, which could help preventing the problems of loss of space and the lingual tilting of the lower anterior teeth. An eight-year-old girl visited the department of pediatric dentistry, Yonsei Dental University Hospital, for the evaluation and the treatment of the lower right lateral incisor, which was horizontally erupted in the lingual side, parallel to the mouth floor. Her tongue was placed on the labial side of that tooth. There was no previous dental history of dental caries or trauma on the pre-occupied primary incisor. Clinical and radiographic examinations including the computed tomography(CT), showed no evidence of dilacerations on root. Therefore, we decided to start active orthodontic traction of the lower right lateral incisor. We designed the fixed type of buccal arch wire and the lip bumper with hook for the traction. Button was attached to the lingual side of the ectopically positioned tooth. Elastic was used between the appliance and the button on that tooth. After the tooth become upright over the tongue level, appliance was change to the removable type and periodic check-up with occlusal guidance was followed to monitor the position of the tooth. In this case using the fixed appliance with modified form of lip bumper and hook embedded in acrylic part instead of extraction was very efficient up-righting the ectopically erupted tooth toward the occlusal plane.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.409-414
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• 2009

The aim of this study was to investigate the ameliorating effects of deer antler extract on the learning and memory impairments induced by the administration of scopolamine (2 mg/kg, i.p.) in rats. Tacrine was used as a positive control agent for evaluating the cognition enhancing activity of deer antler extract in scopolamine-induced amnesia models. The results showed that the deer antler extract-treated group (200 mg/kg, p.o.) and the tacrine-treated group (10 mg/kg, p.o.) significantly ameliorated scopolamine-induced amnesia based on the Morris water maze test. Although there was no statistical significance of brain ACh contents among the experimental groups, the brain ACh contents of the deer antler extract-treated group was slightly higher than that of the scopolamine-treated group. The inhibitory effect of deer antler extract on the acetylcholinesterase activity in the brain was significantly lower than that of scopolamine-treated group. The tacrine- and the deer antler-treated groups reduced the MAO-B activity compared to the scopolamine-treated group, but not significantly. These results suggest that the deer antler extract could be an effective agent for the prevention of the cognitive impairment induced by cholinergic dysfunction.

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.1
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• pp.153-194
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• 2009

The resources of outer space are for the common exploitation of mankind, and it is a common responsibility of mankind to protect the outer space environment. With the rapid development of space science and technology, and especially with the busy space activities of some major space powers, environmental contamination or space debris is steadily increasing in quantity and has brought grave potential threats and actual damage to the outer space environment and human activities in space. Especially We must mitigate and seek out a solution to remove space debris which poses a threat directly to man's exploitation and use of outer space activities in the Low Earth Orbit (LEO) and in the Geostationary Orbit (GEO), through international cooperation and agreement in the fields of space science, economics, politics and law, in order to safeguard the life and property of mankind and protect the earth's environment. While the issue of space debris has been the subject of scientific study and discussion for some time now, it has yet to be fully addressed within the context of an international legal framework. During the earlier stages of the space age, which began in the late 1950s, the focus of international lawmakers and diplomats was the establishment of basic rules which sought to define the legal nature of outer space and set out the parameters for space activities and the nature and scope of activities carried out in outer space were quite limited. Consequently, environmental issues and the risks that might arise from the generation of space debris did not receive priority attention within the context of the development international space law. In recent years, however, the world has seen dramatic advances in technology and increases in the type and number of space-related activities which are being carried out. In addition, the number of actors in this field has exploded from two highly developed States to a vast array of different States, intergovernmental and nongovernmental organizations, including private industry. Therefore, the number of artificial objects in the near-Earth space is continually increasing. As has been previously mentioned, COPUOS was the entity that created the existing five treaties, and five sets of legal Principles, which form the core of space law, and COPUOS is clearly the most appropriate entity to oversee the creation of this regulatory body for the outer space environmental problem. This idea has been proposed by various States and also at the ILA Conference in Buenos Aires. The ILA Conference in Buenos Aires produced an extensive proposal for such a regulatory regime, dealing with space debris issues in legal terms This article seeks to discuss the status of international law as it relates to outer space environmental problem and space debris and indicate a course of action which might be taken by the international community to develop a legal framework which can adequately cope with the complexity of issues that have recently been recognized. In Section Ⅱ,Ⅲ and IV of this article discuss the current status of international space law, and the extent to which some of the issues raised by earth and space environment are accounted for within the existing United Nations multilateral treaties. Section V and VI discuss the scope and nature of space debris issues as they emerged from the recent multi-year study carried out by the ILA, Scientific and Technical Subcommittee, Legal Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space ("COPUOS") as a prelude to the matters that will require the attention of international lawmakers in the future. Finally, analyzes the difficulties inherent in the future regulation and control of space debris and the activities to protect the earth's environment. and indicates a possible course of action which could well provide, at the least, a partial solution to this complex challenge.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.4
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• pp.19-28
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• 2020

The Urban Heat Island (UHI) Effect has intensified due to urbanization and heat management at the urban level is treated as an important issue. Green space improvement projects and environmental policies are being implemented as a way to alleviate Urban Heat Islands. Several studies have been conducted to analyze the correlation between urban green areas and heat with linear regression models. However, linear regression models have limitations explaining the correlation between heat and the multitude of variables as heat is a result of a combination of non-linear factors. This study evaluated the Heat Island alleviating effects in Seoul during the summer by using a deep neural network model methodology, which has strengths in areas where it is difficult to analyze data with existing statistical analysis methods due to variable factors and a large amount of data. Wide-area data was acquired using Landsat 8. Seoul was divided into a grid (30m × 30m) and the heat island reduction variables were enter in each grid space to create a data structure that is needed for the construction of a deep neural network using ArcGIS 10.7 and Python3.7 with Keras. This deep neural network was used to analyze the correlation between land surface temperature and the variables. We confirmed that the deep neural network model has high explanatory accuracy. It was found that the cooling effect by NDVI was the greatest, and cooling effects due to the park size and green space proximity were also shown. Previous studies showed that the cooling effects related to park size was 2℃-3℃, and the proximity effect was found to lower the temperature 0.3℃-2.3℃. There is a possibility of overestimation of the results of previous studies. The results of this study can provide objective information for the justification and more effective formation of new urban green areas to alleviate the Urban Heat Island phenomenon in the future.

• Journal of the Korean association of regional geographers
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• v.22 no.4
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• pp.826-842
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• 2016

Depuis l'exposition mondiale 2012, la ville de Yeosu transforme remarquablement comme la ville touristique maraine $o{\grave{u}}$ on visit beaucoup, par la haute $d^{\prime}am{\acute{e}}nagement$ l'infrastructure pour son $d{\acute{e}}veloppement$. Pour cela, Yeosu, elle a besoin de programmes touristiques divers et de la $caract{\acute{e}}ristique$ $diff{\acute{e}}renci{\acute{e}}e$ de la $r{\acute{e}}gion$. On peut visiter des vestiages de la $r{\acute{e}}volte$ $arm{\acute{e}}e$ des villes de Yeosu et de Suncheon comme tourisme histoirique qui contient l'invasion japonaise en 1592, la $r{\acute{e}}volution$ paysan en 1894, $l^{\prime}activit{\acute{e}}$ de $r{\acute{e}}sistance$ contre Empire du Japon et la $r{\acute{e}}volte$ $arm{\acute{e}}e$ des villes de Yeosu et de Suncheon. Cette ${\acute{e}}tude$ a pour but de $d{\acute{e}}velopper$ le dark tourisme de Yeosu $apr{\grave{e}}s$ examiner son $applicabilit{\acute{e}}$ sur les vestiges. Pour cela, nous avons ${\acute{e}}valu{\acute{e}}s$ la $caract{\acute{e}}ristique$ de lieu des vestiges $fond{\acute{e}}s$ sur les conditions de vestiges et de tourisme de Yeosu. Nous avons aussi $essay{\acute{e}}s$ d'appliquer le dark tourisme, qui a les fonctions $d^{\prime}{\acute{e}}ducation$ et de symbole pour la $r{\acute{e}}gion$ $li{\acute{e}}e$ $\grave{a}$ l'histoire contemporaine, $\grave{a}$ des vestiges de la $r{\acute{e}}volte$ $arm{\acute{e}}e$ par la nouvel route touristique. Par ailleurs, nous avons besoin $d^{\prime}{\acute{e}}riger$ le Parc du $M{\acute{e}}morial$ de la Paix et le musee histoirique et de faire une loi $sp{\acute{e}}ciale$ pour la $r{\acute{e}}volte$ $arm{\acute{e}}e$ des villes de Yeosu et de Suncheon et de former le $comit{\acute{e}}$ consultatif touristique pour $d{\acute{e}}velopper$ le dark tourisme de Yeosu.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.739-746
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• 2010

The purposes of this study are 1) to develop an advanced chamber system within ${\pm}10%$ of air velocity at the particulate matter (PM) collection area, 2) to research theoretical characteristics of PM10 and PM2.5 samplers, 3) to assess the performance characteristics of PM10 and PM2.5 samplers through chamber experiments. The total six one-hour experiments were conducted using the cornstarch with an mass median aerodynamic diameter (MMAD) of $20\;{\mu}m$ and an geometric standard deviation of 2.0 at the two different air velocity conditions of 0.67 m/s and 2.15 m/s in the chamber. The aerosol samplers used in the present study are one APM PM10 and one PM2.5 samplers accordance with the US federal reference methods and specially designed three mini-volume aerosol samplers (two for PM10 and one for PM2.5). The overall results indicate that PM10 and PM2.5 mini-volume samplers need correction factors of 0.25 and 0.39 respectively when APM PM samplers considered as reference samplers and there is significant difference between two mini-volume aerosol samplers when a two-way analysis of variance is tested using the measured PM10 mass concentrations. The PM10 and PM2.5 samplers with the cutpoints and slopes (PM10: $10{\pm}0.5\;{\mu}m$ and $1.5{\pm}0.1$, PM2.5: $2.5{\pm}0.2\;{\mu}m$ and $1.3{\pm}0.03$) theoretically collect the ranges of 86~114% and 64~152% considering the cornstarch characteristics used in this research. Furthermore, the calculated mass concentrations of PM samplers are higher than the ideal mass concentrations when the airborne MMADs for the cornstarch used are smaller than the cutpoints of PM samplers and the PM samplers collected less PM in another case. The chamber experiment also showed that PM10 and PM2.5 samplers had the bigger collection ranges of 37~158% and 55~149% than the theocratical calculated mass concentration ranges and the relatively similar mass concentration ranges were measured at the air velocity of 2.15 m/s comparing with the 0.67 m/s.