• 한국해양공학회지
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• 제24권3호
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• pp.1-10
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• 2010

In this study, hybrid smart sensor nodes were developed for the autonomous structural health monitoring of prestressed concrete (PSC) girders. In order to achieve the objective, the following approaches were implemented. First, we show how two types of smart sensor nodes for the hybrid health monitoring were developed. One was an acceleration-based smart sensor node using an MEMS accelerometer to monitor the overall damage in concrete girders. The other was an impedance-based smart sensor node for monitoring the local damage in prestressing tendons. Second, a hybrid monitoring algorithm using these smart sensor nodes is proposed for the autonomous structural health monitoring of PSC girders. Finally, we show how the performance of the developed system was evaluated using a lab-scaled PSC girder model for which dynamic tests were performed on a series of prestress-loss cases and girder damage cases.

• 융합보안논문지
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• 제12권3호
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• pp.67-73
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• 2012

본 논문에서는 지그비를 이용한 무선 기반 센서 네트워크 단점을 극복하기 위하여 유무선 네트워크 연동 기술을 이용한 하이브리드 센서 네트워크 구현 방안을 제시하였다. 제안된 유무선 연동 센서 네트워크는 CATV망에서의 저손실 전송 특성을 바탕으로 실내 무선 환경의 열악한 전송 특성을 보완할 수 있으며, 마찬가지로 동일 주파수 대역의 무선랜과 블루투스의 간섭에서도 자유로울 수 있다. 또한 이미 충분한 인프라가 구축되어 있는 CATV망을 변경없이 사용하고, 기존 무선망의 전송 부정확성에 대한 안정성과 예측 가능한 전송 링크를 제공함으로써 네트워크 설계가 보다 효율적이었으며, 센서 네트워크의 안정성과 높은 신뢰성을 보장하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.286-286
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• 2010

In this paper, we proposed that optimum installation methods and characteristics of the hybrid type flame-sensor. The hybrid type flame-sensor has the high responsive performance. This research introduced the characteristics of the hybrid type flame-sensor, it was consist of IR/UV flame detector and proposed the optimum installation methods of false alarm reduced to resemble fire.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3151-3168
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• 2021

Internet of Things (IoT) connects several objects with embedded sensors and they are capable of exchanging information between devices to create a smart environment. IoT smart devices have limited resources, such as batteries, computing power, and bandwidth, but comprehensive sensing causes severe energy restrictions, lowering data quality. The main objective of the proposal is to build a hybrid protocol which provides high data quality and reduced energy consumption in IoT sensor network. The hybrid protocol gives a flexible and complete solution for sensor selection problem. It selects a subset of active sensor nodes in the network which will increase the data quality and optimize the energy consumption. Since the unused sensor nodes switch off during the sensing phase, the energy consumption is greatly reduced. The hybrid protocol uses Dijkstra's algorithm for determining the shortest path for sensing data and Ant colony inspired variable path selection algorithm for selecting active nodes in the network. The missing data due to inactive sensor nodes is reconstructed using enhanced belief propagation algorithm. The proposed hybrid method is evaluated using real sensor data and the demonstrated results show significant improvement in energy consumption, data utility and data reconstruction rate compared to other existing methods.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.327-330
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• 2005

In this study, the nature of brittleness, one of the main problems of GFRP(Glass Fiber Reinforced Plastic) Re-bar, is improved. Therefore, Hybrid GFRP Rod is developed by attaching FBG sensor to the new GFRP Rod with toughness, essential for flexural reinforcement of the concrete. The test was performed with specimens of Hybrid GFRP Rod. According to the test, data measured by electric gauge sensor are compared with data measured by FBG sensor.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.527-533
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• 2004

Utilization of new lighter materials, more tough and durable than existing materials, is getting larger in recent constructions. FRP, stronger and lighter than present materials, can be formed in various shapes and has high durability, which makes it more profitable as a new material in construction fields. However, effort to use FRP in real construction is toddling and FRP is used primarily as reinforcing material in connote structure. We are about to develop Hybrid FRP Rod for the development of advanced construction material which is based on IT, by Hybridization of HIP, spotlighted as new construction material, and optical sensor in smart measurement. Beforehand, it is required to fully understand the properties of tension test operated in Hybrid FRP Rod. For this, a specimen was made by hybridization of FRP Rod and FBG sensor. Strain of Hybrid FRP Rod was measured comparing electric sensor and FBG sensor.

• ETRI Journal
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• 제36권6호
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• pp.1016-1022
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• 2014

This paper presents a hybrid model solution for user motion recognition. The use of a single classifier in motion recognition models does not guarantee a high recognition rate. To enhance the motion recognition rate, a hybrid model consisting of decision trees and artificial neural networks is proposed. We define six user motions commonly performed in an indoor environment. To demonstrate the performance of the proposed model, we conduct a real field test with ten subjects (five males and five females). Experimental results show that the proposed model provides a more accurate recognition rate compared to that of other single classifiers.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.330-333
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• 2009

WSNs is evolving different kinds of networks depending on different circumstances, among those we have HWSNs (Hybrid Wireless Sensor Networks) which invokes sensor nodes mobility. In hybrid wireless sensor networks (HWSNs), reducing energy consumption of resource constrained and adaptability to the sensors nodes motion are the crucial problems; to overcome this we need a scalable MAC protocol. Many MAC protocols have been proposed by different researchers, but in this paper we propose LMAC because it outperforms S-MAC, T-MAC and D-MAC protocols comparing to its improvement of energy efficiency and mobile adaptability.

• 인터넷정보학회논문지
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• 제9권6호
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• pp.15-25
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• 2008

이동 에드 혹 네트워크와 센서 네트워크의 차이 때문에 이동 에드 혹 네트워크를 위한 pre-existing autoconfiguration를 센서 네트워크에 간단히 적용할 수 없다. 그러나, 아직 지역적으로 효과적인 유일한 주소 할당이 필요한 메커니즘이 있다. 본 논문은 지역적인 센서 네트워크의 하이브리드 방식의 아이디 할당 계획안을 제안한다. 이러한 하이브리드 방식은 proactive IDs assignment와 reactive IDs assignment를 결합한 방식이다. 제안된 계획안은 reactive IDs assignment을 사용하여 효율적인 통신을 고려하고, zone-based self-organized clustering with Byzantine Agreement를 사용하여 공격에 대한 안전을 고려한다. 따라서 본 논문은 네트워크 트래픽을 최소화하고 센서 네트워크의 이탈한 노드로부터 네트워크를 회복하는 문제를 해결한다.

• Smart Structures and Systems
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• 제7권5호
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• pp.393-416
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• 2011

Hybrid acceleration-impedance sensor nodes on Imote2-platform are designed for damage monitoring in steel girder connections. Thus, the feasibility of the sensor nodes is examined about its performance for vibration-based global monitoring and impedance-based local monitoring in the structural systems. To achieve the objective, the following approaches are implemented. First, a damage monitoring scheme is described in parallel with global vibration-based methods and local impedance-based methods. Second, multi-scale sensor nodes that enable combined acceleration-impedance monitoring are described on the design of hardware components and embedded software to operate. Third, the performances of the multi-scale sensor nodes are experimentally evaluated from damage monitoring in a lab-scaled steel girder with bolted connection joints.