• Smart Structures and Systems
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• 제23권2호
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• pp.123-139
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• 2019

Impact forces induced by external object collisions can cause serious damages to civil engineering structures. While accurate and prompt identification of such impact forces is a critical task in structural health monitoring, it is not readily feasible for civil structures because the force measurement is extremely challenging and the force location is unpredictable for full-scale field structures. This study proposes a novel approach for identification of impact force including its location and time history using a small number of multi-metric observations. The method combines an augmented Kalman filter (AKF) and Genetic algorithm for accurate identification of impact force. The location of impact force is statistically determined in the way to minimize the AKF response estimate error at measured locations and then time history of the impact force is accurately constructed by optimizing the error co-variances of AKF using Genetic algorithm. The efficacy of proposed approach is numerically demonstrated using a truss and a plate model considering the presence of modelling error and measurement noises.

• International Journal of Computer Science & Network Security
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• 제21권9호
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• pp.91-98
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• 2021

Peer to Peer Networks play an increasing role in today's networks, also it's expected that this type of communication networks evolves more in the future. Since the number of users that is involved in Peer to Peer Networks is huge and will be increased more in the future, security issues will appear and increase as well. Thus, providing a sustainable solution is needed to ensure the security of Peer to Peer Networks. This paper is presenting a new protocol called Malicious Trust Managers Identification (MTMI). This protocol is used to ensure anonymity of trust manager, that computes and stores the trust value for another peer. The proposed protocol builds a secure connection between trust managers by using public key infrastructure. As well as experimental testing has been conducted to validate the proposed protocol.

• 국제초고층학회논문집
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• 제9권4호
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• pp.369-376
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• 2020

Given the importance of quickly recovering livelihoods and economic activity after an earthquake, the seismic performance of the pile foundation is becoming more critical than before. In order to promote seismic retrofit of the pile foundations, it is necessary to develop a method for evaluating the seismic performance of the pile foundation based on the experimental data. In this paper, we focus on the building that was suffered severe damage to the pile foundation, conduct simulation analyses of the building, and report the results of evaluating the dynamic characteristics when piles are damaged using a system identification method. As a result, an analysis model that can accurately simulate the behavior of the damaged building during an earthquake was constructed, and it was shown that the system identification method could extract dynamic characteristics that may damage piles.

• 한국전자파학회논문지
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• 제27권1호
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• pp.33-41
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• 2016

의류 및 신발 등 패션잡화 매장관리 분야에서 RFID 기술을 적용하여 입출고, 재고관리 및 진품확인, 소비자접점형 서비스를 제공하기 위해서는 기술적인 요구사항 분석이 반드시 필요하다. 특히, 인식거리와 복수인식률은 RFID를 도입하는 데 있어 가장 중요한 성능 지표이지만, 부착매질에 따라 태그의 고유 성능 변화가 발생하여 실제 도입현장에서 많은 애로사항으로 작용하고 있다. 이런 문제점을 해결하기 위해 본 논문에서는 다양한 조건별 인식거리 및 복수인식률 시험분석을 통해 신발에 삽입되는 RFID 태그의 현실적인 최소 성능 요구사항을 제시하였다.

• Smart Structures and Systems
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• 제24권6호
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• pp.723-732
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• 2019

Globally road transport networks are subjected to continuous levels of stress from increasing loading and environmental effects. As the most popular mean of transport in the UK the condition of this civil infrastructure is a key indicator of economic growth and productivity. Structural Health Monitoring (SHM) systems can provide a valuable insight to the true condition of our aging infrastructure. In particular, monitoring of the displacement of a bridge structure under live loading can provide an accurate descriptor of bridge condition. In the past B-WIM systems have been used to collect traffic data and hence provide an indicator of bridge condition, however the use of such systems can be restricted by bridge type, assess issues and cost limitations. This research provides a non-contact low cost AI based solution for vehicle classification and associated bridge displacement using computer vision methods. Convolutional neural networks (CNNs) have been adapted to develop the QUBYOLO vehicle classification method from recorded traffic images. This vehicle classification was then accurately related to the corresponding bridge response obtained under live loading using non-contact methods. The successful identification of multiple vehicle types during field testing has shown that QUBYOLO is suitable for the fine-grained vehicle classification required to identify applied load to a bridge structure. The process of displacement analysis and vehicle classification for the purposes of load identification which was used in this research adds to the body of knowledge on the monitoring of existing bridge structures, particularly long span bridges, and establishes the significant potential of computer vision and Deep Learning to provide dependable results on the real response of our infrastructure to existing and potential increased loading.

• 인터넷정보학회논문지
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• 제8권3호
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• pp.45-56
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• 2007

최근 새로운 형태의 네트워크 환경인 유비쿼터스 컴퓨팅에 대한 연구가 활발하게 진행되고 있다. 본 논문에서는 유비쿼터스를 구현하기 위한 스마트 태그와 관련한 RFID 기술을 지하매설물 GIS에 적용하고자 한다. 유비쿼터스 환경을 위한 어플리케이션 개발은 새로운 네트워크 환경을 구체화시킬 수 있는 가장 중요한 연구이다. 이러한 연구는 현재 국내에서 IT839로 대표되는 다양한 어플리케이션 개발을 촉진시키고 있으며, 지리정보 시스템 구축은 IT839의 일환으로 사회 기반시설의 유비쿼터스화를 현실화하기 위해 다양한 연구가 이루어지고 있다. 따라서 기존의 지리정보 시스템들을 분석하고 능동형 RFID에 기반한 지하 매설물 관리 시스템을 위한 연구를 수행하고자 한다. 제안된 방식은 기존의 연구들에서 고려되지 않았던 지하 매설물에 대한 관리 방식으로써 소형화 디바이스인 능동형 RFID를 이용해 인증 과정을 수행함으로서 안전한 관리자 기능을 제공하며, 실시간적인 처리와 관리자의 자율성을 보장한다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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• pp.55-59
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• 2007

국가 R&D정보에 필요한 모든 정보를 정보의 소유에 관계없이 범 부처적으로 공동 활용하고자 하는 필요성이 대두되고 있다. 그러나, 국가 R&D정보는 부처별 각 연구관리전문기관별로 별도로 관리하고 있으며 상호 연계를 위한 식별체계의 부재로 인해 유사 중복과제 검증, 정보의 추적관리 등 통합적인 정보관리가 어려운 실정이다. 전 부처의 국가 R&D정보를 통합 관리하고 공동활용하기 위해서는 모든 정보에 항구적으로 유일한 URN기반 식별체계의 부여가 필요하다. 본 논문에서는 식별체계를 부여하기 위해 필수적인 식별메타데이터의 개념과 각 연구관리전문기관별 국가 R&D 과제관리번호의 현황을 살펴보고, 범부처 과제고유번호 및 정보식별자 부여를 위한 국가 R&D정보의 식별메타데이터 요소를 제안하고자 한다.

• 한국정보통신학회논문지
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• 제15권5호
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• pp.1045-1052
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• 2011

최근 복합 문화 시설이 증가하면서 지하 공간 활용이 확대됨에 따라, 사용자의 실내 위치에 따른 주변 정보만을 무선으로 제공해주는 맞춤형 서비스에 대한 요구도 확산되고 있다. LED 조명을 이용한 가시광 통신 방식의 경우, GPS를 사용할 수 없는 실내 공간에서 위치 기반 서비스를 구현하기에 적합하다. 이에 본 논문에서는 가시광 통신을 이용한 실내 위치 기반 서비스를 구현하기 위해 기준 위치를 구분하는 실험에 대해 다룬다. LED 조명의 특성을 고려하여 LED와 PD 간의 각도 및 거리에 따라 LED 조명별로 서로 다른 식별 패턴을 ASCII 코드로 전송한 결과 최대 1.75m의 거리까지 LED 조명의 식별자를 수신할 수 있음을 확인한다. 이러한 실험 결과를 통하여 LED 조명을 이용한 실내 네비게이션의 가능성을 확인해볼 수 있다.

• Smart Structures and Systems
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• 제29권3호
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• pp.475-484
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• 2022

The loss of cable tension for civil infrastructure reduces structural bearing capacity and causes harmful deformation of structures. Currently, most of the structural health monitoring (SHM) approaches for cables rely on contact transducers. This paper proposes a cable tension identification technology using percussion sound, which provides a fast determination of steel cable tension without physical contact between cables and sensors. Notably, inspired by the concept of tensioning strings for piano tuning, this proposed technology predicts cable tension value by deep learning assisted classification of "percussion" sound from tapping a steel cable. To simulate the non-linear mapping of human ears to sound and to better quantify the minor changes in the high-frequency bands of the sound spectrum generated by percussions, Mel-frequency cepstral coefficients (MFCCs) were extracted as acoustic features to train the deep learning network. A convolutional neural network (CNN) with four convolutional layers and two global pooling layers was employed to identify the cable tension in a certain designed range. Moreover, theoretical and finite element methods (FEM) were conducted to prove the feasibility of the proposed technology. Finally, the identification performance of the proposed technology was experimentally investigated. Overall, results show that the proposed percussion-based technology has great potentials for estimating cable tension for in-situ structural safety assessment.

• 동의신경정신과학회지
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• 제24권1호
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• pp.13-26
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• 2013

Objectives : The purpose of this study is to investigate the correlation between pattern identification of traditional Chinese medicine (TCM) and western medicine, examined by a systematic research of Chinese medicine papers. Methods : We searched for the papers regarding pattern identification of TCM published from 1994 to 2012 in CNKI (China National Knowledge Infrastructure http://www.cnki.net) at April, 2012. Results : A total of 30 studies were finally included; 18 studies of them were related to stroke (cerebral infarction) and there were 12 studies regarding other diseases, such as hypertension, chronic colonitis, vascular dementia, mild cognitive impairment and etc. All 30 studies were analyzed and classified by diseases, differentiation of syndromes, numbers of subjects, the instrument of pattern identification, items of western medicine examination and statistical results. Conclusions : According to our study, there are some correlations between pattern identification of TCM and various items of western medicine examination. The result suggests a possibility of using the western medicine examination data for pattern identification of TCM.