• 전기학회논문지P
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• 제57권3호
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• pp.270-274
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• 2008

The microwave sensor in which the sensitivity was excellent and a structure is simple was developed and it manufactured. And the sensing range that uses the developed product was confirmed. When the developed microwave sensor was set up in the ceiling of a building, we confirmed that the amplitude of the sensitive area increased as the tilting angle was enlarged. The sensitive area became a greatest in case the tilting angle was 65 degree. According to the height of a ceiling, because the sensing range is determined, in case of using in the building in which the height of a ceiling is enough secured it is determined to secure the more wide sensitive area. Moreover, the configuration of the circuit having the simple structure makes the miniaturization of a product, and the light weight possible. It is considered to have the price competitive power which it reduces the manufacturing cost, is sufficient.

• Ocean Systems Engineering
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• 제3권1호
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• pp.71-77
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• 2013

The effective tracking area of ultra short baseline (USBL) systems strongly relates to the safety of autonomous underwater vehicles (AUVs). This problem has not been studied previously. A method for determining the effective tracking area using acoustic theory is proposed. Ray acoustic equations are used to draw rays which ascertain the effective space. The sonar equation is established in order to discover the available range of the USBL system and the background noise level using sonar characteristics. The available range defines a hemisphere like enclosure. The overlap of the effective space with the hemisphere is the effective area for USBL systems tracking AUVs. Lake and sea trials show the proposed method's validity.

• 환경영향평가
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• 제20권4호
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• pp.489-496
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• 2011

The water pollution such as oil spill from stream and river because of car accidents have been frequent cases in the watershed of Dam. However we don't have any simulation methods about flow modeling on the watershed and stream tree. In this study aims to analyze water pollution accidents area on impact range for ANDONG-Dam. The focused watershed and the risk range of path analysis model was designed by GIS database. The frequency of transportation accidents which may occur from road accidents in the level of quantitative and qualitative analysis to map flow analysis using ArcHydro Model and Open Geospatial Consortium(OGC) API. and the path way from the accident point to the reservoir stayed on the path was simulated. The area of risk accessment index was displayed with cell and grid of dam area.

• 한국수소및신에너지학회논문집
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• 제30권1호
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• pp.29-34
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• 2019

Safety of hydrogen handling facilities is needed as supply of hydrogen cars has been expanded recently. In this study, the adequacy of safety regulations of hydrogen handling facilities and the risk of damage with hydrogen leakage were studied. The range of explosion hazard location of the hydrogen filling plant was investigated using the computational fluid dynamics (CFD) method, Explosive hazardous area is influenced by leakage type, hole size and sectional area. When the conditions of KS standard are applied, range explosive hazardous area is expanded 7.05 m, maximum. It is about 7 times larger than exceptional standard of hydrogen station. Meanwhile, distance from leakage point to 25% LEL of hydrogen is investigated 1.6 m. Considering the shape of charging hose, regulation of hydrogen station is appropriate.

• International journal of advanced smart convergence
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• 제8권2호
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• pp.218-226
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• 2019

The use of Information and Communication Technologies (ICT) is the key to operate a change from the traditional manual reading of water meters and sensors to an automated system where high frequency data is remotely collected and analyzed in real time, one of the main components of a Smart Water Grid. The recent boom of ICT offers a wide range of both wired and wireless technologies to achieve this objective. We review and present in this article the most widely recognized technologies and protocols along with their respective advantages, drawbacks and applicability range which can be Home Area Network (HAN), Building Area Network (BAN) or Local/Neighborhood Area Network (LAN/NAN). We also present our findings and we give recommendations on the application of ICT in Smart Water Grids and future work needed.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1259-1265
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• 2021

In the present study, a large-area hybrid gamma imaging system was designed by adopting coded aperture imaging on the basis of a large-area Compton camera to achieve high imaging performance throughout a broad energy range (100-2000 keV). The system consisting of a tungsten coded aperture mask and monolithic NaI(Tl) scintillation detectors was designed through a series of Geant4 Monte Carlo radiation transport simulations, in consideration of both imaging sensitivity and imaging resolution. Then, the performance of the system was predicted by Geant4 Monte Carlo simulations for point sources under various conditions. Our simulation results show that the system provides very high imaging sensitivity (i.e., low values for minimum detectable activity, MDA), thus allowing for imaging of low-activity sources at distances impossible with coded aperture imaging or Compton imaging alone. In addition, the imaging resolution of the system was found to be high (i.e., around 6°) over the broad energy range of 59.5-1330 keV.

• 교육시설
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• 제9권1호
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• pp.15-26
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• 2002

According to seventh curriculum, new types of school design have been developed recently. However there are hardly any data of national status about plan and area organization, types and number of rooms of those. On this background, the purpose of this study is to provide fundamental resources for architectural designing and planning of high schools and to recognize national status of plan organizations of high schools through collecting 53 school's standard design drawings(arrangement, plan drawing) which city, province education office drafted for 4 years(from 1997 to 2000) and analyzing them into plan types, building area and type, number and area of rooms. The results of this study are as follows: 1. The range of class number of designed 53 high schools varies from 24 to 36 and 36-class-schools are 47.2% of all. Average number of class is 34.1. As a result we can find out large scale schools are mainly designed. 2. Among 53 schools, 21 schools have the department system but few of them equipped sufficient rooms and their features are very manifold. After recognizing utilization status of each schools, the standards of room type, number and plan organization should be proposed. In terms of plan type for fluent level based transferring class, most of schools are not apt. 3. In the status of type and number of rooms related to class number, range is very wide. So simplification is necessary. 4. The variations of building area, area per a class and area per a student are very large so that standard of adequate area should be established. 5. That every school which has different plan organization from conventional schools exceeds ministry of education's minimum area standards shows those standards cannot cover the diverse plan design of school. So more adequate standards should be proposed. 6. Area and number of Teacher's research room and Home Base are also very manifold from school to school. They are also considered to be simplified immediately.

• Journal of Ecology and Environment
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• 제29권3호
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• pp.259-263
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• 2006

본 연구의 목적은 농촌지역의 너구리 행동권과 핵심지역의 면적을 분석하는 것으로서, 이를 위해 22개체를 포획하여 원격 무선추적을 실시하였다. 이 중 3개월 이상 무선 추적이 실시된 9개체의 행동권을 분석한 결과 평균 $0.80km^2$ (100% MCP)를 나타내었다. 성별 행동권은 수컷이 평균 $0.98km^2$ (100% MCP)를 나타내었고, 암컷은 평균 $0.58km^2$ (100% MCP)를 나타내어 수컷의 행동권이 넓었다. 그러나 95% MCP (Minimum Convex Polygon)를 적용했을 경우 수컷이 평균 $0.63km^2$, 암컷이 $0.42km^2$로서 차이가 많이 줄었다. 또한 암수 쌍이 함께 무선 추적된 두 쌍의 행동권은 95% MCP를 적용했을 경우 암수가 각각 $0.26km^2$와 $0.28km^2$로서 차이가 매우 적거나, $0.36km^2$와 $0.36km^2$로 통일했으며, 4 계절 모두 짝을 지어 함께 지냈다. 따라서 짝이 없거나 영역이 정해지지 않은 등의 경우를 제외하고 정상적으로 암수가 한 쌍이 되어 지내는 일상의 경우에는 암수의 행동권이 같다고 판단되어진다. 원격 무선 추적된 너구리 중 4 개체는 암수 쌍을 이루고 있었으며, 이들 두 쌍 모두 일부 일처제를 이루고 함께 이동하며 생활하였다.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.88-95
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• 2007

In this paper, the authors discussed the overview of a method for estimating working area for development of a monitoring system for labor management using RFID technology. RSSI (Receive Signal Strength Indication) data of RFID tag was obtained from readers set around the indoor space. An estimating model of the working area was prepared. The model had a range of the percentage of correctly classified from 61% to 95%. According to the result, the possibility of the monitoring system and the factors necessary to develop for practical were proposed.

• Geomechanics and Engineering
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• 제38권1호
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• pp.1-13
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• 2024

The construction adit plays a pivotal role in enhancing the working face during the excavation of long-distance and deep hydraulic tunnels. However, the intersection zone between the main tunnel and the construction adit exhibits more intricate deformation patterns in surrounding rock, posing a significant threat to stability during excavation. Taking the Xianglushan tunnel in Yunnan Province, China, as a case study, the FLAC3D software is employed to simulate the excavation process at the intersection. The simulation results are verified combined with the field deformation monitoring results, and the spatial distribution of tunnel rock deformation in the intersection area are analyzed. Five excavation conditions with different intersection angles are simulated, and the surrounding rock deformation of the tunnel intersection area with different intersection angles is analyzed, and its influence range is discussed. The results show that: (1) The surrounding rock deformation in the intersection area increases rapidly during the tunnel excavation. With the increase of construction distance, the deformation of intersection area is gradually stable. (2) The deformation distribution of the tunnel rock is uneven, and the deformation of main tunnel near the intersection area is larger than that far away from the intersection area. (3) With the increase of the intersection angle, the surrounding rock deformation of the tunnel intersection and its influence range decreases gradually. The research results have certain guiding significance for the construction safety of the tunnel intersection area.