• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권3호
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• pp.1321-1332
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• 2016

Wireless sensor networks (WSN) are self-organized networks that typically consist of thousands of low-cost, low-powered sensor nodes. The reliability and availability of WSNs can be affected by faults, including those from radio interference, battery exhaustion, hardware and software failures, communication link errors, malicious attacks, and so on. Thus, we propose a novel multi-agent fault tolerant system for wireless sensor networks. Since a major requirement of WSNs is to reduce energy consumption, we use multi-agent and mobile agent configurations to manage WSNs that provide energy-efficient services. Mobile agent architecture have inherent advantages in that they provide energy awareness, scalability, reliability, and extensibility. Our multi-agent system consists of a resource manager, a fault tolerance manager and a load balancing manager, and we also propose fault-tolerant protocols that use multi-agent and mobile agent setups.

• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.147-161
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• 2012

In recent years, machine-to-machine (M2M) communications are under rapid development to meet the fast-increasing requirements of multi-type wireless services and applications. In order to satisfy M2M communications requirements, heterogeneous networks convergence appears in many areas, i.e., mobile cellular networks (MCNs) and wireless sensor networks (WSNs) are evolving from heterogeneous to converged. In this paper, we introduce the system architecture and application requirement for converged MCN and WSN, where mobile terminals in MCN are acting as both sensor nodes and gateways for WSN. And then, we discuss the joint optimization of converged networks for M2M communications. Finally, we discuss the technical challenges in the converged process of MCN and WSN.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.731-748
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• 2010

Impact detection and health monitoring are very important tasks for civil infrastructures, such as bridges. Piezoceramic based transducers are widely researched for these tasks due to the piezoceramic material's inherent advantages of dual sensing and actuation ability, which enables the active sensing method for structural health monitoring with a network of piezoceramic transducers. Wireless sensor networks, which are easy for deployment, have great potential in health monitoring systems for large civil infrastructures to identify early-age damages. However, most commercial wireless sensor networks are general purpose and may not be optimized for a network of piezoceramic based transducers. Wireless networks of piezoceramic transducers for active sensing have special requirements, such as relatively high sampling rate (at a few-thousand Hz), incorporation of an amplifier for the piezoceramic element for actuation, and low energy consumption for actuation. In this paper, a wireless network is specially designed for piezoceramic transducers to implement impact detection and active sensing for structural health monitoring. A power efficient embedded system is designed to form the wireless sensor network that is capable of high sampling rate. A 32 bit RISC wireless microcontroller is chosen as the main processor. Detailed design of the hardware system and software system of the wireless sensor network is presented in this paper. To verify the functionality of the wireless sensor network, it is deployed on a two-story concrete frame with embedded piezoceramic transducers, and the active sensing property of piezoceramic material is used to detect the damage in the structure. Experimental results show that the wireless sensor network can effectively implement active sensing and impact detection with high sampling rate while maintaining low power consumption by performing offline data processing and minimizing wireless communication.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.84-86
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• 2010

센서 네트워크에서 이동체 트래킹, 상태 정보 관리 및 이벤트 순서화와 같은 기본적인 응용 서비스를 제공하기 위해서 시각 정보 제공 및 시각 동기는 기본적으로 요구되는 요소 중 하나이다. 제한된 자원과 에너지를 갖는 센서 네트워크의 특성을 고려하여 다양한 시각 동기 기법이 제시되어 왔으나, 시각 표현 방법에 대한 고려를 한 사례는 거의 없는 실정이다. UTC TOD와 같은 전역 시각 표현 방식은 센서 네트워크의 응용을 위해 매우 유용한 방식으로 볼 수 있다. 본 논문에서는 센서 네트워크에서 전역 시각 정보를 제공할 수 있는 시각 정보 관리 및 동기 기법에 대해 제시한다.

• 한국멀티미디어학회논문지
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• 제18권8호
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• pp.909-914
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• 2015

In wireless sensor networks, sensor nodes have a short transmission range and data is transferred from source to destination node using the multi-hop transmission. Sensor nodes are powered by battery and the link qualities are different, and the routing protocol in the wireless sensor network is one of the important technical issues. Multipath routing was proposed to reduce the data congestion and increase data throughput. In the multipath routing, however, each path can be interfered by the other path, and it can aggravate network performance. In this paper, we propose the multipath routing scheme for multi-rate wireless sensor networks. The multipath routing selects transmission paths to minimize transmission delay and path interference.

• Journal of information and communication convergence engineering
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• 제8권2호
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• pp.129-135
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• 2010

Wireless sensor networks (WSNs) are an emerging technology and offers economically viable monitoring solution to many challenging applications. However, deploying new technology in hostile environment, without considering security in mind has often proved to be unreasonably unsecured. Apparently, security techniques face many critical challenges in WSNs like data security and secrecy due to its hostile deployment nature. In order to resolve security in WSNs, we propose a novel and efficient secure framework called TriSec: a secure data framework for wireless sensor networks to attain high level of security. TriSec provides data confidentiality, authentication and data integrity to sensor networks. TriSec supports node-to-node encryption using PingPong-128 stream cipher based-privacy. A new PingPong-MAC (PP-MAC) is incorporated with PingPong stream cipher to make TriSec framework more secure. PingPong-128 is fast keystream generation and it is very suitable for sensor network environment. We have implemented the proposed scheme on wireless sensor platform and our result shows their feasibility.

• 한국정보통신학회논문지
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• 제17권4호
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• pp.996-1004
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• 2013

본 논문에서는 무선 센서 네트워크에서 센서 노드들 간의 에너지 소비 불균형을 개선하여 무선 센서 네트워크의 전체적인 수명을 연장할 수 있는 클러스터링 기법들을 제안한다. 무선 센서 네트워크의 생성 단계에서 무선 센서 네트워크의 에너지 소모를 줄이기 위해서 센서 노드들의 밀도에 따라 클러스터 헤더를 선출하여 클러스터를 형성한다. 그 이후 센서 네트워크가 활성화되는 동안 센서 노드들 간의 에너지 불균형을 개선하기 위하여 에너지 소모량을 추정한 후 릴레이 기반으로 다음 라운드의 클러스터 헤더를 선출한다.

• Smart Structures and Systems
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• 제11권5호
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• pp.497-510
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• 2013

Quick, accurate damage monitoring is strongly required for damage assessment in the aftermath of a large natural disaster. Wireless sensor networks are promising technologies to acquire damage information in a citywide area. The wireless sensor networks, however, would be faced with difficulty to collect data in real-time and to expand the scalability of the networks. This paper discusses a scheme of network architecture to cove a whole city in multi-tier heterogeneous networks, which consist of wireless sensor networks, access networks and a backbone network. We first review previous studies for citywide damage monitoring, and then discuss the feature of multi-tier heterogeneous networks to cover a citywide area.

• 디지털산업정보학회논문지
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• 제15권4호
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• pp.71-84
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• 2019

Various researchers conducted the research on two-factor authentication suitable for wireless sensor networks (WSNs) after Das first proposed two-factor authentication combining the smart card and password. After then, To improve the security of user authentication, elliptic curve cryptography(ECC)-based authentication protocols have been proposed. Jiang et al. proposed a privacy-aware two-factor authentication protocol based on ECC for WSM for resolving various problems of ECC-based authentication protocols. However, Jiang et al.'s protocol has the vulnerabilities on a lack of mutual authentication, a risk of SID modification and a lack of sensor anonymity, and user's ID exposed on sensor node Therefore, this paper proposed security enhanced privacy-aware two-factor authentication protocol for wireless sensor networks to solve the problem of Jiang et al.'s protocol, and security analysis was conducted for the proposed protocol.