• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.2
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• pp.117-127
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• 2010

Gound excavation is frequently executed in unsaturated soil conditions. In this paper, the effect of apparent cohesion in unsaturated soils on the ground behavior during underground excavation is studied. The VPPE (Volumetric Pressure Plate Extractor) test, the unsaturated triaxial test and the trap-door test were carried out to figure out how the behavior of soils varies depending on the variation of apparent cohesion. The test results show that the ground behavior is almost identical if the soil is either fully dry or fully saturated. However, if the soil is partially-saturated with the increase of water content, the ground behaves quite differently. In summary, the apparent cohesion in unsaturated soils plays key roles when excavating underground structures.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.69-79
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• 2019

The coastal area forms various sedimentary layers according to the environmental conditions such as the topography and geological features of the upper region of the river, ocean currents, and river mouth. Therefore, identifying the characteristics of the marine clay deposited in the coastal area plays a key role in the investigation of the formation of soft ground. In general, alluvial grounds are formed by a variety of factors such as changes in topography and natural environment, they have very diverse qualities depending on the deposited region or sedimentation conditions. The most important thing for the construction of social infrastructures in soft ground areas is economical and efficient treatment of soft ground. In this study, the author collected data from diverse laboratory and field tests on five areas in western and southern offshore with relatively high reliability, and then statistically analyzed them, thereby presenting standard constants for construction design. Correlation between design parameters such as over consolidation ratio, preconsolidation pressure was analyzed using linear and non-linear regression analyses. Also, proposed distribution characteristics of design parameters in consideration of each region's uncertainty through statistical analyses such as normality verification, outlier removal.

• Journal of the Society of Disaster Information
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• v.13 no.1
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• pp.59-72
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• 2017

Recently, urban environments are changing due to climate change and urbanization. Because of these, Urban disasters occur frequently. To solve this situation, the architects and urban planners have been presenting urban disaster prevention design, and the concepts of resilience are utilized in urban disaster prevention design. In this study, we analyzed the cases of urban disaster prevention design presented by architects and urban planners, and grasped the types and resilience characteristics of urban disaster prevention design. Further, the direction of urban disaster prevention design was proposed in the point of sustainability.

• The Journal of the Korea Contents Association
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• v.11 no.6
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• pp.42-50
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• 2011

This paper is to propose design and implementation methods of a pet dog management system that can effectively manage the pet dog in home through client such as a mobile terminal or a PC from remote location, in the absence of the owner in the house. Through this system, we can manage the dog efficiently via a series of monitoring and control functionalities of the dog such as observing of the dog's status, or feeding the dog, or taking the necessary measures on maintaining a healthy environment such as temperature/humidity sensing and turn on/off fans and lights, or sending SMS text to the owner from detection of the barking of the dog.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.688-695
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• 2014

In a small wireless environment, such as your home or office, a various network using WiMedia PHY can be mixed. Because these networks operate independently for each application, data conflict can occur between adjacent networks. To avoid data conflict, the resource in a different time zone can be utilized. However, if devices in a network increase, available resources in the network decrease, and then the lack of resources necessary to provide service can occur. To solve this problem, we propose collision avoidacne scheme for coexistence of various UWB systems. In this paper, we evaluate the performance of the proposed scheme through simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.791-794
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• 2008

최근 홈오토메이션 시스템(Home Automation System) 즉, 가정 자동화 시스템에 대한 관심과 수요가 커지면서 이를 위한 네트워크 구축에 관한 여러 연구 및 개발이 활발히 이루어지고 있다. 홈오토메이션 시스템이란 가정에서 사용되는 여러 가전기기 및 센서장비를 이용하여 집 안의 기기를 제어함으로써 가정을 안전하게 관리하고, 사용자의 편의를 극대화하여 인간의 생활수준을 향상시키는 기술을 말한다. 본 논문에서는 Cypress사의 PSoC 기반으로 가정 내에서 사용할 수 있는 온도, 습도, 가스검출, 불꽃감지와 같은 여러 환경 센서 및 인체감지센서를 이용한 방범 센서 장치 구현방법을 제안하고, PSoC 기반의 WirelessUSB를 이용하여 센서 및 호스트 PC와의 네트워크 시스템을 구축한다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.61-68
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• 2017

Bridge decks are members that rapidly deteriorated due to various environmental factors such as heavy vehicle and deicing salt, etc. As the lifespan of bridges built in Korea increases, it is expected that the demand for replacing the deteriorated bridge decks will increase. In other countries, Accelerated Bridge Construction technology using precast decks is already actively being used as a countermeasure for replacement demand of deteriorated bridge decks. In this study, bridge decks deterioration models are proposed by collecting and analysing the condition index data of domestic bridge decks. Also, the future replacement demands of deteriorated bridge decks in terms of replacement time and replacement scale are predicted.

• Journal of Global Scholars of Marketing Science
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• v.4
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• pp.213-239
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• 1999

소비자의 욕구와 개성화, 그리고 시장경쟁력에서 생산체제가 변화되면서 기업들의 물류환경여건도 변화를 가져와 물류가 기업들에게 당면한 주요 과제가 되었다. 사회 간접자본의 부족으로 인한 도로, 항만 등의 정체현상이 심화되고 3D업종에 속하는 물류부문은 더욱 인력난을 겪게 되면서 물류비상승이라는 부담을 안게 되었다. 그리고, 컴퓨터, 정보통신기술 등과 같은 첨단의 기술혁신이 이루어 집에 따라 컴퓨터 및 각종 기기들의 연결이 가능해지면서 물류정보시스템 구축이 활발하게 이루어져 가고 있다. 그러나, 이러한 현실에도 불구하고 기업들은 이에 대한 효율적인 대처 방안을 마련하지 못하고 물류에 대한 인식조차 못하고 있거나 잘못 이해하고 있는 실정이다. 본 논문은 이러한 문제점을 인식하여 물류정보시스템의 활용수준과 물류활동 연계 그리고 물류전략에 대한 이론을 정립하고 이를 근거하여 나라 기업률이 물류를 어떻게 인식하고 있는가를 물류정보시스템의 활용수준, 물류활동연계, 물류전략 등의 변수를 도입, 측정하여 봄으로써 우리나라 기업의 물류에 대한 문제점들을 규명하고 앞으로 물류의 능률적인 실시를 위한 올바른 방향을 제시하는데 그 목적을 두고 있다. 실종분석 결과 물류성과에 대한 물류정보시스템 활용수준과 물류연계수준은 물류성과에 영향을 미치는 것으로 나타났다. 그리고, 물류 기능별 정보시스템 활용수준과 물류차별화 전략이 물류성과에 상호작용 효과를 보이는 지를 알아본 결과 상호작용효과가 있는 것으로 나타났다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.175-182
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• 2008

In performing a risk analysis of structure for earthquake, it is imperative to identify the vulnerability of structures associated with various stages of damage. And the earthquake resisting capability is needed for structures like bridge. So the damage analysis of bridges with or without isolator for earthquake effects is necessary. In this paper, the risk analysis of seismic isolated LRB bridges considering earthquake effects such as PGA, PGV, SA, SV, and SI is performed using fragility curves to assure the earthquake resisting capability of the structures. And, the stability of fragility curve is investigated with respect to elastic modulus.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.2 s.54
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• pp.145-152
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• 2009

In performing a risk analysis on structure for earthquake, it is imperative to identify the vulnerability of structures associated with various stages of damage. And the earthquake resisting capability is needed for structures like bridge. So the damage analysis of bridges with or without isolator for earthquake effects is necessary. In this paper, the risk analysis of seismic isolated LRB bridges considering earthquake effects such as PGA, PGV, SA, SV, and SI is performed using fragility curves to assure the earthquake resisting capability of the structures. And, the stability of fragility curve is investigated with respect to input earthquake.