• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.401-404
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• 2008

Bridges are exposed to very severe environment and experience, as service life increased, elevated traffic load and traffic flow, in addition to natural disasters. In comparing to other road structures, bridges may cause more significant damage, such as human-involved accidents, to the society in the event of collapse. A certain level of service shall be necessarily secured to assure the minimum safety of users. The cost for manage and preserve bridges will increase gradually and more restrictions will be loaded to efficiently distribute the limited resources, such as monetary budget and human resource etc. In order to enhance performance and serviceability of bridges with the limited resource, asset management technique has been applied into the bridge management system, which capitalizes the road infrastructures including bridges and assess them in accordance with the government finance report. In the application of asset management, there must be a tool for assess the performance of bridges and this study introduces the basic information on the definition and role of performance measures for asset management for bridges.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.544-547
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• 2008

In 1990, Korea building contractors were indifferent maintenance management cause focus on completion of construction before construction collapsed. Currently, structures monitoring systems are restrictive on large structures. Structures monitoring systems are limited many old and small structures in the whole nation. Recently, we make efforts application Ubiquitous technology as like sensor, sensor network system, and wireless communication system in construction. This paper applies bridge management system using Ubiquitous skill which is real-time monitoring report offering system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.79-90
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• 2015

Multipath routing technique is recognized as one of the effective approaches to improve the reliability of data forwarding. However, the traditional multipath routing focuses only on how many paths are needed to ensure a desired reliability. For this purpose, the protocols construct additional paths and thus cause significant energy consumption. These problems have motivated the study for the energy-efficient and reliable data forwarding. Thus, this paper proposes an energy-efficient concurrent multipath routing protocol with a small number of paths based on interaction between paths. The interaction between paths helps to reinforce the multipath reliability by making efficient use of resources. The protocol selects several nodes located in the radio overlapped area between a pair of paths as bridge nodes for the path-interaction. In order to operate the bridge node efficiently, when the transmission failure has detected by overhearing at each path, it performs recovery transmission to recover the path failure. Simulation results show that proposed protocol is superior to the existing multipath protocols in terms of energy consumption and delivery reliability.

• Journal of Environmental Science International
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• v.14 no.10
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• pp.905-910
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• 2005

The purpose of this study is the comparative analysis of Susan citizens' images of Eulsook-do as a coastal tourism destination before and after the construction of a road bridge across the Nakdong estuary in order to analyze local people's changes in leisure patterns. Analysis of the images of a pre-construction Eulsook-do that people aged both 40 and less and 50 and more had on five dimensions showed values higher than zero(0) that suggests neutral image, while their images of a post-construction Eulsook-do showed the shrinking size of pentagon on all five dimensions: ET(Entertainment), CA(Culture & Art), EE(Environment & Ecology), RC(Recreation) and LP(Leports) dimensions. Its pre- and post- construction image analysis conducted 20 years after it came to be built finds that the road bridge construction has led to the ecological, environmental disruption of the coast and the lower Nakdong river, having negative influence on the images of Eulsook-so.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.441-459
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• 2009

교량공사는 지상작업과 고소작업이 혼재하고 작업공종이 복잡하여 위험성이 높은 공사로 추락, 협착, 붕괴, 낙하 비래 재해의 발생빈도가 높다. 또한, 중량 부재의 운반, 조립, 양중 등의 작업과정에서 유해 위험 기계기구와 건설장비 사용에 따른 유해 위험 요인이 산재하여, 유해 위험의 정도와 재해 발생빈도 및 재해의 강도에 차이가 있어 위험성평가를 통한 정량화된 위험지수의 제시가 필요하다. 위험성 평가는 교량공사의 특성을 고려하여 교량 건설현장의 공종별 유해 위험요인을 세부공종별 요소작업에 따라 분류하고, 재해 발생정도와 피해정도에 따른 위험도가 평가되어야 한다. 이러한 교량 건설공사의 재해를 줄이는데 기여할 수 있도록 정량화된 교량공사 위험지수를 제시함으로써 체계적이고 효율적인 재해예방 활동에 필요한 기초자료를 제공할 것이다. 특히 교량공사 시공 상의 제반 위험요인을 사전에 점검하여 변경 보완 제거할 수 있는 재해 예방대책을 수립하여 재해를 최소화하는 연구가 필요하게 되었다. 건설현장에서 위험지수의 고저에 따라 자원을 적정하게 배분한다면 안전관리의 효율성이 제고되고, 궁극적으로 건설재해 감소에 기여하게 될 것으로 기대된다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.345-348
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• 2004

Every bridge node participating in multiple piconets and forming a scatternet should schedule the inter-piconet traffics in an efficient manner. Frequent piconet switching due to short polling intervals for the links of a bridge node leads to considerable time slots loss caused by the guard time and power consumption for transceiving and processing. On the other hand, restrained piconet switching may result in failures of fulfilling QoS (Quality of Service) requirements for some links. Tn this paper, we present a QoS aware inter-piconet scheduling scheme minimizing the piconet switching events within guaranteed QoS requirements. According to simulation results, the proposed scheme is confirmed to have great improvement in throughput and number of switching events over the credit scheme as current inter-piconet scheduling scheme for the scatter mode.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.224-229
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• 2009

Digital image recognition has been used for steel bridge surface assessment since late 1990s. However, the non-uniform illumination problems such as shades, shadows, and highlights are still challenges in image processing to date. Therefore, this paper develops a new approach to tackle the non-uniform illumination problem for rust image adjustment. The inhomogeneous illumination problem is divided into shades/shadows and highlights in this paper. The proposed BEMD-morphology approach (BMA) utilizes the bidimensional empirical mode decomposition to mitigate the shade/shadow effect, and the morphological processing to detect and replace the highlight area. Finally, the rust image processed with the BMA will be segmented by the K-Means algorithm, one of the most popular and effective methods, to show the effectiveness of illumination adjustment.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.157-161
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• 2011

BIM having started from architecture is being used in civil structure, but there are very few examples despite its effectiveness. In this paper, based on BIM technology, it is presented the method and result of developing web-based 5D system connecting cost, schedule and 3D model from the cable-stayed bridge. Through the system, the user can understand easily schedule on specific time and during some period and extract cost directly. This system also can manage various data types such as drawings, 3D models, documents and photos, for enhanced communication between stakeholders.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.23-24
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• 2011

In this paper, the 170W LLC half bridge DC-DC converter is designed for the lighting management system. The power conversion circuit consists of PFC and isolated LLC resonant converter. The topology of LLC half bridge resonant converter provides ZVS characteristic. And the stresses of voltage and current is smaller than that of the general resonant converters. So we can expect the higher efficiency. The optimal conditions for high efficiency were investigated through by experiment.

• Journal of KIBIM
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• v.8 no.1
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• pp.15-23
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• 2018

Geometry control of precast members is the most important technology for modular construction. In this paper, image-based modeling and rendering (IBMR) technology was adopted for 3D modeling of precast elements. It is necessary to use match-casting method for precast post-tensioned column assembly. Preassembly using 3D models created by image processing can minimize construction error. Augmented reality devices are used to check the geometry of the segment. Laboratory-scale tests were performed. The proposed process has been applied to the real precast bridge pier segments.