• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.517-532
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• 2017

The transverse ventilation system, commonly applied to urban tunnel, is necessary to be distributed with airflow uniformly. In this study, we developed a program that can optimize the opening ratio of ports to ensure ventilation performance of design criteria through a uniform airflow distribution even though ventilation interval becomes longer. And program's prediction performance was verified by comparison with TUNVEN DUCT program. For comparison, Semi-transverse ventilation system was applied. Both programs predicted a similar port size and air flow distribution, and the variation range of the calculated values was 11.71% and 1.36%, respectively. This program is very useful for port optimization design of transverse and semi-transverse ventilation system, because it is possible to analyze various tunnel lengths and supply/exhaust port installation conditions.

• Journal of Families and Better Life
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• v.25 no.3 s.87
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• pp.107-118
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• 2007

The purpose of this study was to investigate the characteristics of leisure behavior and preference for leisure environment of the five-day workweek company employees according to gender for developing leisure facilities in residential community planning. The questionnaire survey was used. The subjects of questionnaire survey were 338 staffs of 7 companies, who were living in apartment complex. The questionnaire consisted of way of life about leisure, leisure necessity, actual condition and need of leisure spaces, and leisure satisfaction. Frequency, percentage, and mean, ${\chi}2-test$, t-test, and factor analysis were used for data analysis. The major results were as follows. 1) In terms of leisure time in weekend, the available leisure time distribution, and leisure cost, there were not difference between men and women. 2) After five-day workweek, the men and women showed to increase their leisure activities and to engage in diverse forms of leisure. Also, they showed an increased desired ratios in participating in each leisure activities. 3) Leisure was necessary to strengthen the unity of family and cultivate the sentiment. 4) Even though current main area for leisure were in their house, men were likely to change them from in the house to around and near their house. And they needed leisure facilities which was closer to their house. 5) The degree of satisfaction of leisure facilities in residential environment was low and there were not difference between men and women. This result implicated to improve and develope leisure space and facilities near the residental environment for promoting leisure behavior of both women and men. In particular it is necessity to create the good atmosphere of leisure facilities for women.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.406-411
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• 2004

Inverted Impaction of the permanent maxillary central incisor is rare. The causes of impaction are trauma and periapical inflammation of primary maxillary incisor teeth. Treatment options for a inverted incisor is extraction, surgery and orthodontic traction, transplantation, and spontaneous eruption guidance. Treatment depends on the incisor's root development and the space available for eruption. If root development is immature, prognosis would be good. We reported successful treatment for inverted maxially central incisor of proper eruption and normal root development by correction of a eruption route. But further observation will be required to evaluate the final root development state and amount of at tachment gingiva.

• Journal of Korea Spatial Information System Society
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• v.9 no.1
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• pp.79-90
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• 2007

In this paper we proposed and implemented an incident detection model which combines fuzzy algorithm and traffic pattern in order to enhance the efficiency of incident detection for the highways with lamps. Most of the existing algorithms dealt with highways without lamps and can not be used for detecting incidents in the highways with lamps. The data used for model building are traffic volume, occupancy, and speed data. They have been collected by a loop sensor at 5 minutes interval at a point in the Internal Circular Highway of Seoul for the period of 3 months. In this model, the three parameters collected by sensor were fuzzified and combined with the daily traffic pattern of the link. The test of efficiency of the propsed model was performed by comparing the result of proposed model with traditional APID algorithm and fuzzy algorithm without the pattern data respectively. The result showed significant amount of improvement in reducing the false incident detection rate by 18%.

• Fire Science and Engineering
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• v.13 no.3
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• pp.3-17
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• 1999

Smoldering is a non-flaming combustion mode, characterized by thermal degradation and c charring of the virgin material, evolution of smoke and emission of visible glow. A big fire may @ occur even in a confined environment having a limited amount of oxygen, due to smoldering c combustion through a porous solid material. This paper presents a theoretical analysis on the effect of smoldering combustion on fire occurrence based on a report about fire investigation of a real f fire accident. It is assumed that the propagation of the smolder wave is one-dimensional, d downward, opposing an upward forced flow and steady in a frame of reference moving with the s smolder wave. Smoldering combustion is modeled by a one-step reaction mechanism, without c considering pyrolysis. It is found that dominant parameters controlling smoldering combustion i include mass flux of oxidizer entering the reaction zone and void fraction of solid fuel. It is also found that the mechanism of transition to flaming is critically influenced by these two parameters.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.3
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• pp.89-95
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• 2009

One of the criteria provided by the law to designate the Impact Fee Zone requires that the increase rate of the development permit should exceed that of the entire locality by more than twenty percent. Since the permits are issued to scattered parcels on the individual basis, however, it renders significant difficulties in accurately figuring out the finite local areas that exceed such legal criteria. This study, in this context, tries to join the development permit time-series data with the Korea Land Information System (KLIS) so that, with the aid of the landform layer and existing infrastructure layer, it could pinpoint the local area where the development activities are concentrating. Taking a sector in Yangpyong County as the case, the study practically demonstrates as to how the designation process is geospatially processed.

• Clean Technology
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• v.17 no.3
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• pp.225-230
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• 2011

Characteristics of hydrocarbon selective catalytic reduction of NOx using various noble metal catalysts were investigated. The best active metal is Pt, supports are $CeO_2$ and $TiO_2$ by strong interactions between active metals, and 55% of conversion rate of NOx is shown. Pd, Rh and Ag catalysts presented a conversion of less than 20% as active metals, and supports also showed the poor activity compared to $SiO_2$ and $ZrO_2$. Experiments were performed with different types of reducing agents, amount, concentration of oxygen and space velocity in order to investigate the performance of catalysts according to operating conditions. The results confirm that the methane is better than propane as a reducing agent, and as the ratio of methane/nitrogen oxide increases, the catalytic activity increased, as the concentration of oxygen increases and space velocity decreases, the performance of catalysts increased.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.409-415
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• 2005

Impaction of permanent incisor occurs rare than the canine & third molar. But it's often observed in school age child. The causes of impaction are trauma, space deficiency, mesiodens, infections of root apex, etc. In spite of elimination of cause, normal eruption of impacted tooth is rare. Though eruption is normal, the position of tooth will be incorrect. Because the impacted tooth results in malocclusion, root resorption of adjacent tooth, pathologic cystic change, it should be confirmed the precise position by clinical and radiographic exam and found the correct location by appropriate treatment plan. In case of pathologic change of impacted tooth and injury to adjacent tooth, it will be extracted. But through orthodontic retraction, the function and esthetics of tooth can be restored. It is important that impacted tooth should be detected early and diagnosed correctly, and appropriate treatment plan should be made. Before impacted tooth is retracted, the considerations of space for alignment and anchorage should be preceded and through appropriate force and mechanics, the side effects, for example, a root resorption should be minimized. In this study, we guided impacted tooth to normal position by using a forced eruption.

• Broadcasting and Media Magazine
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• v.27 no.1
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• pp.59-70
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• 2022

메타버스 서비스란 '가상', '초월' 등을 뜻하는 영어 단어 '메타(Meta)'와 우주를 뜻하는 '유니버스(Universe)'의 합성어다. 현실세계와 같은 사회.경제.문화 활동이 이루어지는 3차원의 가상세계를 의미한다. 코로나 상황 속에서 비대면 소통의 수단 중 하나로 주목받으며 업무, 친목, 각종 행사 등 다양한 분야에서 활용되고 있다. 2022년 신년 사업 계획에서 메타버스 단어가 들어가지 않은 곳이 없다고 한다. 그만큼 핵심 키워드로 떠오르고 있다. 즉, 메타버스는 현실을 초월한 가상의 세계로 스마트폰, 컴퓨터 등 디지털 미디어에 담긴 세계를 뜻한다. 세상은 점차 바뀌어 가고 있다. 글로벌 통계 전문 업체 스태티스타는 2021년 307억 달러(약 35조 3265억 원) 규모이던 메타버스 시장 규모가 2025년에는 약 2969억 달러(약 341조 6428억 원)까지 커질 것으로 예측하였다. 현재 시장에서 통용되고 있는 메타버스에 대한 정의는, '현실세계의 사회·경제·문화적 활동이 유사하게 실현되거나, 현실에서 제공하지 못하는 경험을 제공하는 3차원 디지털 가상공간'으로 요약된다. 2021년의 메타버스는 더 이상 상상의 영역이 아니며, 현실세계 영역으로 침투하고 있는 것이다. 현실세계와 연결되는 가상세계, 실재감을 느낄 수 있는 가상공간이 점점 현실이 되어가고 있다. 1990년대 처음으로 등장한 메타버스 개념이 2020년대에 재부상 하였는데, 과거의 메타버스보다 몰입감과 실재감 있는 경험을 제공할 수 있는 XR 기술의 결합에 대한 기대감 때문이다. 지나온 30여 년간 메타버스가 뜨거운 주목을 받게 된 이유는 기술의 발전에 있다. 초고속인터넷 5G 상용화와 더불어 6G 출현, 가상현실, 증강현실이 일상에 스며들었기 때문이다. 이러한 기술 발달은 현실세계의 물리적 객체와 가상의 객체가 상호 작용할 수 있는 혼합현실까지 발전시키는 촉매제가 되었다. 여기에 지난 2년 동안 전 세계를 강타한 코로나19로 인해 비대면, 온라인 서비스가 확산되면서 메타버스는 개념이 아닌, 우리 일상의 한 부분으로 인정받게 되었다. 현재 우리 사회는 과거에는 불가능하다고 생각했던 사회적 거리두기, 재택근무, 온라인 수업 등을 진행하면서 이렇게도 사회가 돌아갈 수 있다는 것을 점차 느껴가고 있다. 더불어 현재 코로나로 인해 멀게만 느껴졌던 메타버스 세계를 반강제적으로 경험하고 있기도 하다. 이처럼 본 고에서는 최근에 나타난 메타버스를 이해하고 방송미디어(계)와 접목된 유형과 기술적, 서비스 사례를 파악하고, 주요 기업들의 추진 방향, 주요 시사점 및 결론으로 도출해보았다.

• Journal of the Korean Geosynthetics Society
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• v.22 no.3
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• pp.105-117
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• 2023

The recent global energy supply crisis has led to increased uncertainty in international energy markets. These market changes lead to a rise in global energy prices and development is expanding to the extreme cold regions (Arctic Circle) where undeveloped energy resources are abundantly stored. Arctic Circle has a special business environment such as natural environment, laws, institutions and culture, research on location evaluation of development areas is necessary in advance. In this study, the spatial information of Alberta, Canada, where non-traditional energy resource development activities have recently been active, was collected and analyzed. In addition, an optimal location evaluation model for resource development was developed using construction environment spatial information data and the reliability is verified by comparing and analyzing the existing resource development areas.