• Structural Engineering and Mechanics
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• 제31권3호
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• pp.333-347
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• 2009

Due to structural complicacy, structural health monitoring for civil engineering needs more accurate and effectual methods of damage identification. This study aims to import multi-source information fusion (MSIF) into structural damage diagnosis to improve the validity of damage detection. Firstly, the essential theory and applied mathematic methods of MSIF are introduced. And then, the structural damage identification method based on multi-mode information fusion is put forward. Later, on the basis of a numerical simulation of a concrete continuous box beam bridge, it is obviously indicated that the improved modal strain energy method based on multi-mode information fusion has nicer sensitivity to structural initial damage and favorable robusticity to noise. Compared with the classical modal strain energy method, this damage identification method needs much less modal information to detect structural initial damage. When the noise intensity is less than or equal to 10%, this method can identify structural initial damage well and truly. In a word, this structural damage identification method based on multi-mode information fusion has better effects of structural damage identification and good practicability to actual structures.

• Smart Structures and Systems
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• 제31권6호
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• pp.573-583
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• 2023

Although unmanned aerial vehicles have been used to overcome the limited accessibility of human-based visual inspection, unresolved issues still remain. Onsite inspectors face difficulty finding previously detected damage locations and tracking their status onsite. For example, an inspector still marks the damage location on a target structure with chalk or drawings while comparing the current status of existing damages to their previous status, as documented onsite. In this study, an augmented-reality-based structural inspection system with onsite damage information marking was developed to enhance the convenience of inspectors. The developed system detects structural damage, creates a holographic marker with damage information on the actual physical damage, and displays the marker onsite via an augmented reality headset. Because inspectors can view a marker with damage information in real time on the display, they can easily identify where the previous damage has occurred and whether the size of the damage is increasing. The performance of the developed system was validated through a field test, demonstrating that the system can enhance convenience by accelerating the inspector's essential tasks such as detecting damages, measuring their size, manually recording their information, and locating previous damages.

• 한국안전학회지
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• 제31권2호
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• pp.127-132
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• 2016

In this study, the plan to construct a disaster information categorization system that can be objectively and efficiently performed was suggested in order to perform disaster management task systematically. Recently, the damage of natural disasters is gradually growing larger and faster, increasing the economic loss. Especially, as for the domestic storm damage, the damage from strong wind was found to be greater than the damage from torrential rain. Also, strong wind was found to be inflicting a great damage on human life, property and agricultural crops, so the necessity to study damage restoration from strong wind is increasing. Nevertheless, the damage items categorized in the domestic disaster year book are often comprehensive or unclear in criteria, and thus fail to reflect items or matters due to actual disaster damage. It is difficult to aggregate damage accurately such that it does not correspond to the national compensation scope or the damage amount is calculated according to subjective judgment of the investigator in charge. As such, if the disaster information management is inadequate by not applying accurate categorization criteria from damage amount calculation, there can be an issue with fairness when paying the damage support aid. Therefore, this study suggested a categorization plan for objective and efficient execution of disaster information management task in order to resolve such issues. It is expected that quick and efficient execution would be possible in disaster information management and task procedure domestically by constructing systematic categorization system related to disaster information.

• 한국지진공학회논문집
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• 제22권3호
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• pp.121-128
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• 2018

Severe earthquakes can cause damage to society both socially and economically. An appropriate initial response can alleviate damage from severe earthquakes. In order to formulate an appropriate initial response, it is necessary to identify damage situations in societies; however, it is difficult to grasp this information immediately after an earthquake event. In this study, an earthquake damage assessment methodology for buildings is proposed for estimating damage situations immediately after severe earthquakes. A response spectrum database is constructed to provide response spectra at arbitrary locations from earthquake measurements immediately after the event. The fragility curves are used to estimate the damage of the buildings. Earthquake damage assessment is performed from the response spectrum database at the building scale to provide enhanced damage condition information. Earthquake damage assessment for Gyeongju city and Pohang city were conducted using the proposed methodology, when an earthquake occurred on September 12, 2016, and November 15, 2017. Results confirm that the proposed earthquake damage assessment effectively represented the earthquake damage situation in the city to decide on an appropriate initial response by providing detailed information at the building scale.

• 지적과 국토정보
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• 제50권2호
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• pp.81-100
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• 2020

본 연구는 풍수해로부터 발생 가능한 피해를 추정하기 위한 공간정보 DB 활용 방안과 공간정보의 품질 점검 기준을 제안하고자 하였다. 국가재난관리정보시스템, 국가공간정보통합체계 공개자료 목록을 대상으로 공간정보 DB 중 풍수해 피해 추정을 위해 활용될 수 있는 데이터를 피해유형별로 매핑하였으며, 해당 데이터를 활용하여 피해 분석을 위한 품질 점검 기준 항목을 제안하였다. 본 연구를 통해 풍수해 피해 추정을 위한 공간정보 DB 활용이 가능할 것이며, 품질 점검 기준을 통해 분석 결과의 신뢰성을 담보할 수 있을 것이다.

• 전기전자학회논문지
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• 제18권1호
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• pp.45-56
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• 2014

최근 전 세계적으로 호우, 지진, 태풍 등의 재난으로 인한 피해가 증가하고 있다. 한반도 역시 거듭된 기후 변화에 따라 호우 일수가 매년 증가하고 있으며, 지난 30년간의 지진 통계에 따르면 지진 발생 가능성도 높아지고 있다. 또한 지구 온난화의 심화에 따라 인근 바닷가의 기온 상승으로 강도 높은 태풍이 한반도에 올 가능성이 증대되고 있다. 이처럼 호우, 지진, 태풍으로 인한 재해의 발생 가능성이 증가하고 있으며, 그로인한 수변구조물의 피해와 규모 역시 증가하고 있지만 수변구조물에 대한 피해 정보의 관리가 부족하다. 본 연구에서는 수변구조물 통합관리를 위하여 자연재해로 인한 피해정보를 분류하고, 피해 정보를 표현하기 위한 데이터베이스를 설계하였다. 또한 피해정보 관리 시스템을 구현하여 예제 질의를 수행하여 구현한 시스템의 동작과 가능성을 확인하였다.

• 국제학술발표논문집
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• The 8th International Conference on Construction Engineering and Project Management
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• pp.505-509
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• 2020

Twitter is a useful medium to grasp various damage situations that have occurred in society. However, it is a laborious task to spot damage-related topics according to time in the environment where information is constantly produced. This paper proposes a methodology of constructing a knowledge structure by combining the BERT-based classifier and the community detection techniques to discover the topics underlain in the damage information. The methodology consists of two steps. In the first step, the tweets are classified into the classes that are related to human damage, infrastructure damage, and industrial activity damage by a BERT-based transfer learning approach. In the second step, networks of the words that appear in the damage-related tweets are constructed based on the co-occurrence matrix. The derived networks are partitioned by maximizing the modularity to reveal the hidden topics. Five keywords with high values of degree centrality are selected to interpret the topics. The proposed methodology is validated with the Hurricane Harvey test data.

• Smart Structures and Systems
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• 제25권2호
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• pp.169-181
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• 2020

Sensor placement is a crucial aspect of bridge health monitoring (BHM) dedicated to accurately estimate and locate structural damages. In addressing this goal, a sensor placement framework based on the deflection influence line (DIL) analysis is here proposed, for the optimal design of damage detection-oriented BHM system. In order to improve damage detection accuracy, we explore the change of global stiffness matrix, damage coefficient matrix and DIL vector caused by structural damage, and thus develop a novel sensor placement framework based on the Fisher information matrix. Our approach seeks to determine the contribution of each sensing node to damage detection, and adopts a distance correction coefficient to eliminate the information redundancy among sensors. The proposed damage detection-oriented optimal sensor placement (OSP) method is verified by two examples: (1) a numerically simulated three-span continuous beam, and (2) the Pinghu bridge which has existing real damage conditions. These two examples verify the performance of the distance corrected damage sensitivity of influence line (DSIL) method in significantly higher contribution to damage detection and lower information redundancy, and demonstrate the proposed OSP framework can be potentially employed in BHM practices.

• Smart Structures and Systems
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• 제10권4_5호
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• pp.443-458
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• 2012

The structural health monitoring (SHM) benchmark study on optimal sensor placement problem for the instrumented Canton Tower has been launched. It follows the success of the modal identification and model updating for the Canton Tower in the previous benchmark study, and focuses on the optimal placement of vibration sensors (accelerometers) in the interest of bettering the SHM system. In this paper, the sensor placement problem for the Canton Tower and the benchmark model for this study are first detailed. Then an information entropy based sensor placement method with the purpose of damage detection is proposed and applied to the benchmark problem. The procedure that will be implemented for structural damage detection using the data obtained from the optimal sensor placement strategy is introduced and the information on structural damage is specified. The information entropy based method is applied to measure the uncertainties throughout the damage detection process with the use of the obtained data. Accordingly, a multi-objective optimal problem in terms of sensor placement is formulated. The optimal solution is determined as the one that provides equally most informative data for all objectives, and thus the data obtained is most informative for structural damage detection. To validate the effectiveness of the optimally determined sensor placement, damage detection is performed on different damage scenarios of the benchmark model using the noise-free and noise-corrupted measured information, respectively. The results show that in comparison with the existing in-service sensor deployment on the structure, the optimally determined one is capable of further enhancing the capability of damage detection.

• 한국환경과학회지
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• 제19권3호
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• pp.353-363
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• 2010

The most efficient measures to reduce damage from natural disasters include activities which prevent disasters in advance, decrease possibility of disasters and minimize the scale of damage. Therefore, developing of the risk assessment model is very important to reduce the natural disaster damage. This study estimated a typhoon damage which is the biggest damage scale among increased natural disasters in Korea along with climate change. The results of 3-second gust at the height of 10m level from the typhoon 'Maemi' which did considerable damage to Korean in 2003, using the wind data at the height of 700 hPa. September 12th 09 LST~13th 12 LST period by the time a typhoon Maemi approached to the Korean peninsula. This study estimate damage amount using 'Fragility curve' which is the damage probability curve about a certain wind speed of the each building component factors based on wind load estimation results by using 3-second gust. But the fragility curve is not to Korea. Therefore, we use the fragility curves to FPHLM(FDFS, 2005). The result of houses damage amount is about 11 trillion 5 million won. This values are limit the 1-story detached dwelling, $62.51\sim95.56\;m^2$ of total area. Therefore, this process is possible application to other type houses.