• Smart Structures and Systems
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• 제17권3호
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• pp.445-470
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• 2016

In this study, the Bayesian probabilistic framework is investigated for modal identification and modal identifiability based on the field measurements provided in the structural health monitoring benchmark problem of an instrumented cable-stayed bridge named Ting Kau Bridge (TKB). The comprehensive structural health monitoring system on the cable-stayed TKB has been operated for more than ten years and it is recognized as one of the best test-beds with readily available field measurements. The benchmark problem of the cable-stayed bridge is established to stimulate investigations on modal identifiability and the present paper addresses this benchmark problem from the Bayesian prospective. In contrast to deterministic approaches, an appealing feature of the Bayesian approach is that not only the optimal values of the modal parameters can be obtained but also the associated estimation uncertainty can be quantified in the form of probability distribution. The uncertainty quantification provides necessary information to evaluate the reliability of parametric identification results as well as modal identifiability. Herein, the Bayesian spectral density approach is conducted for output-only modal identification and the Bayesian model class selection approach is used to evaluate the significance of different modes in modal identification. Detailed analysis on the modal identification and modal identifiability based on the measurements of the bridge will be presented. Moreover, the advantages and potentials of Bayesian probabilistic framework on structural health monitoring will be discussed.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.281-286
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• 2009

The proposed technique uses cyclic frame structure, where three periods such as beacon period (BP), mesh contention access period (MCAP) and slotted period (SP) are in a data frame. This paper studies on a mechanism to allow communication nodes (6lowpan) in a PAN with different logical channel for global healthcare applications monitoring technology. The proposed super framework structure system has installed 6lowpan sensor nodes to communicate with each other. The basic idea is to time share logical channels to perform 6lowpan sensor node. The concept of 6lowpan sensor node and various biomedical sensors fixed on the patient BAN (Body Area Network) for monitoring health condition. In PAN (hospital area), has fixed gateways that received biomedical data from 6lowpan (patient). Each 6lowpan sensor node (patient) has IP-addresses that would be directly connected to the internet. With the help of IP-address service provider can recognize or analyze patient data from all over the globe by the internet service provider, with specific equipments i.e. cell phone, PDA, note book. The NS-2.33 result shows the performance of data transmission delay and data delivery ratio in the case of hop count in a PAN (Personal Area Networks).

• 한국공간정보시스템학회 논문지
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• 제11권2호
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• pp.45-53
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• 2009

The fast progress on multimedia data acquisition technologies has enabled collecting vast amount of videos in real time. Although the amount of information gathered from these videos could be high in terms of quantity and quality, the use of the collected data is very limited typically by human-centric monitoring systems. In this paper, we propose a framework for analyzing long traffic video using series of content-based analyses tools. Our framework suggests a method to integrate theses analyses tools to extract highly informative features specific to a traffic video analysis. Our analytical framework provides (1) re-sampling tools for efficient and precise analysis, (2) foreground extraction methods for unbiased traffic flow analysis, (3) frame property analyses tools using variety of frame characteristics including brightness, entropy, Harris corners, and variance of traffic flow, and (4) a visualization tool that summarizes the entire video sequence and automatically highlight a collection of frames based on some metrics defined by semi-automated or fully automated techniques. Based on the proposed framework, we developed an automated traffic flow analysis system, and in our experiments, we show results from two example traffic videos taken from different monitoring angles.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.423-438
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• 2010

Wireless smart sensors enable new approaches to improve structural health monitoring (SHM) practices through the use of distributed data processing. Such an approach is scalable to the large number of sensor nodes required for high-fidelity modal analysis and damage detection. While much of the technology associated with smart sensors has been available for nearly a decade, there have been limited numbers of fulls-cale implementations due to the lack of critical hardware and software elements. This research develops a flexible wireless smart sensor framework for full-scale, autonomous SHM that integrates the necessary software and hardware while addressing key implementation requirements. The Imote2 smart sensor platform is employed, providing the computation and communication resources that support demanding sensor network applications such as SHM of civil infrastructure. A multi-metric Imote2 sensor board with onboard signal processing specifically designed for SHM applications has been designed and validated. The framework software is based on a service-oriented architecture that is modular, reusable and extensible, thus allowing engineers to more readily realize the potential of smart sensor technology. Flexible network management software combines a sleep/wake cycle for enhanced power efficiency with threshold detection for triggering network wide operations such as synchronized sensing or decentralized modal analysis. The framework developed in this research has been validated on a full-scale a cable-stayed bridge in South Korea.

• 국제지역연구
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• 제21권1호
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• pp.303-324
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• 2017

유엔임무단에 파병되는 한국군의 평화활동 성과를 측정하는 현행평가방식에 대해 적절성, 타당성, 신뢰성문제가 불가피하게 제기되고 있다. 이에 본고는 유엔현장임무단과 국제개발커뮤니티에서 널리 채택한 바 있는 성과기반평가(RBE)모델을 한국군 파병부대의 평화활동에 부합하도록 보완 및 적용하는 방안을 제시하고자 한다. 연구결과, 논리체계모형을 토대로 기획과 평가단계를 통합하는 RBE모델을 토대로 파병 전기획, 파병기간 중 모니터링과 단계적 평가, 파병 후 영향평가의 사이클로 귀결되는 틀을 제안하였다. 둘째, 현행 한국군 평화활동의 모니터링과 평가체계를 RBE모델 기준을 적용하여 검증한 결과, 평가조직 운용 및 논리체계모형에 해당되는 요소들이 기준을 충족하지 못하거나 부분적으로만 충족하였고 파병사후 영향평가는 거의 수행하지 않은 것으로 나타났다. 결론적으로 전술한 문제점들의 해결방안과 민-관-군 분야 전문가가 참여하는 합동조사단 운용을 정책제안으로 제시하였다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제12권1호
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• pp.43-55
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• 2006

본 논문에서는 여러 자동화 장비들의 제어 및 모니터링 소프트웨어에 대한 쉬운 개발, 유지보수, 확장성을 향상시킬 수 있는 프레임웍을 제안하고자 한다. 본 논문에서 제안하는 프레임웍은 세 가지(IID, MAP, CMIML)의 XML 문서와 두개(VI Wizard, Generator)의 툴로 구성된다. IID는 장비에 대한 인터페이스를 기술하고, MAP은 IID에서 기술된 인터페이스와 실제 장비 드라이버 API간의 연결정보를 기술하며, CMIML은 제어 및 모니터링 소프트웨어를 기술한다. 제안하는 프레임웍의 범용성과 플랫폼 독립성을 지원하기 위하여 IID, MAP, CMIML은 XML 문서 형식으로 기술되었다. VI Wizard는 IID와 기작성된 CMIML을 입력으로 소프트웨어를 기술하는 CMIML(플랫폼 독립적인 중간 문서)을 생성하고, Generator는 VI Wizard에서 생성된 CMIML과 MAP을 이용하여 제어 및 모니터링 소프트웨어(플랫폼 종속적인 코드)를 자동 생성한다. 제안하는 프레임웍은 GUI 기반으로 제어 및 모니터링 소프트웨어를 자동 생성함으로써 쉬운 개발과 유지보수성을 제공하고, XML 기반의 기술문서 사용으로 플랫폼 독립성을 제공하면서 범용적으로 사용할 수 있도록 한다. 또한 플랫폼 종속적인 코드 재사용이 아닌 플랫폼 독립적인 소프트웨어 기술 문서를 재사용함으로써 재사용성을 증가시킬 수 있다.

• 제어로봇시스템학회논문지
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• 제17권11호
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• pp.1074-1081
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• 2011

As robotics systems are becoming more complex there is the need to promote component based robot development, where systems can be constructed as the composition and integration of reusable building block. One of the most important challenges facing component based robot development is safeguarding against software component failures and malfunctions. The health monitoring of the robot software is most fundamental factors not only to manage system at runtime but also to analysis information of software component in design phase of the robot application. And also as a lot of monitoring events are occurred during the execution of the robot software components, a simple data treatment and efficient memory management method is required. In this paper, we propose an efficient events monitoring and data management method by modeling robot software component and monitoring factors based on robot software framework. The monitoring factors, such as component execution runtime exception, Input/Output data, execution time, checkpoint-rollback are deduced and the detail monitoring events are defined. Furthermore, we define event record and monitor record pool suitable for robot software components and propose a efficient data management method. To verify the effectiveness and usefulness of the proposed approach, a monitoring module and user interface has been implemented using OPRoS robot software framework. The proposed monitoring module can be used as monitoring tool to analysis the software components in robot design phase and plugged into self-healing system to monitor the system health status at runtime in robot systems.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.1203-1206
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• 2012

본 논문은 다양한 기기로 구성된 분산 IT 환경에서 보다 신속한 장애 탐지 및 원인 파악을 위한 Monitoring framework을 제안한다. 제안된 Framework은 전통적인 Event Correlation 기법과 전통적 기법의 문제점 해결을 위한 Probing 기법을 혼용한(Hybrid) 것인데, 이를 통해 각각의 기법이 지닌 한계를 극복하고, 장애탐지 능력을 향상시킨다. 즉, Event Correlation 기법은 임계영역에서 장애 판별이 어려운 문제점이 있는데, 이러한 경우 장애 여부를 확신하기 위해 Probe station을 이용하여 Probe를 실행함으로써 장애 판단 능력을 향상시켰다. 또한 Probing 기법은 복잡한 분산 IT 환경에서 Probe Set를 구성하는 어려움이 있는데, 이를 회피하는데 도움을 준다. 본 논문에서는 Web 기반 애플리케이션에서 User-Session을 기반으로 추출한 Http Packet를 Probe set으로 이용하여 구현하였다.

• Smart Structures and Systems
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• 제32권3호
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• pp.179-193
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• 2023

This study explores an alternative to the existing centralized process for data anomaly detection in modern Internet of Things (IoT)-based structural health monitoring (SHM) systems. An edge intelligence framework is proposed for the early detection and classification of various data anomalies facilitating quality enhancement of acquired data before transmitting to a central system. State-of-the-art deep neural network pruning techniques are investigated and compared aiming to significantly reduce the network size so that it can run efficiently on resource-constrained edge devices such as wireless smart sensors. Further, depthwise separable convolution (DSC) is invoked, the integration of which with advanced structural pruning methods exhibited superior compression capability. Last but not least, quantization-aware training (QAT) is adopted for faster processing and lower memory and power consumption. The proposed edge intelligence framework will eventually lead to reduced network overload and latency. This will enable intelligent self-adaptation strategies to be employed to timely deal with a faulty sensor, minimizing the wasteful use of power, memory, and other resources in wireless smart sensors, increasing efficiency, and reducing maintenance costs for modern smart SHM systems. This study presents a theoretical foundation for the proposed framework, the validation of which through actual field trials is a scope for future work.

• 전자공학회논문지CI
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• 제46권2호
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• pp.106-113
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• 2009

최근 건설 현장에서의 많은 안전사고 발생으로 인해, 건축물의 건전성 감시(Structural Health Monitoring, SHM)에 대한 많은 연구가 진행되고 있다. 이러한 SHM의 활용을 위한 대표적인 적용 기술이 무선 센서네트워크 기술(Wireless Sensor Networks, WSN)이다. 본 논문에서는 이러한 무선 센서네트워크 기술을 바탕으로 카메라가 장착된 휴대단말기에 3D 시각화와 증강현실(Augmented Reality, AR) 기술을 적용한 관찰 가능한 정보의 범위를 확장시켜주는 WIVA(WSN Monitoring Framework based on 3D Visualization and Augmented Reality in Mobile Devices) 시각화 시스템을 제안하였다. 제안된 시스템을 이용해 3층 건물 테스트베드에서의 화재 발생 실험을 수행하였다. 이를 통해, IEEE 802.15.4를 이용한 WSN 데이터를 활용한 3D와 AR 모드에서의 효용성을 검증하였다.