• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.02a
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• pp.95-98
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• 2008

센서네트워크는 넓은 지역에 무선 인프라로 묶여 설치된 센서들을 사용하여 상황 인지로 감지된 데이터를 응용서비스 서버와 연동하는 기술이다. 이는 환경 감시, 대상 추적, 환자 모니터링, 군사적 목적 등 매우 다양한 분야에 사용될 수 있다. 센서네트워크 역시 기존 네트워크에서 필요로 하는 보안 기능을 요구한다. 그러나 센서네트워크에 사용되는 노드들이 사용할 수 있는 자원에 제약이 있어, 기존의 암호기술을 그대로 적용하는데 어려움이 있다. 이러한 센서네트워크에서의 키 분배 문제를 해결하기 위하여 인증센터를 사용하는 기법, 랜덤 키 사전 분배 기법, q-합성수 랜덤 키 사전 분배 기법, Blom 스킴, 위치 기반 키 사전 분배 기법 등이 제안되어 있다. 한편, 공개키 연산의 많은 부하로 인하여 공개키 기법을 센서네트워크에 적용하기에 적합하지 않으리라 여겨져 왔으나, 최근의 연구결과들에 의하면 PKI처럼 복잡한 시스템을 구현하는 것은 부적합할지라도 공개키를 이용한 키 분배 기법을 센서네트워크에 적용하는 것이 실효성이 있다는 것을 보여준다. 본 논문에서는 TinyOS 플랫폼에서 공개키를 이용하여 센서 노드 간 상호 인증 및 세션키를 생성하여 암호 데이터 통신을 수행하는 센서네트워크 플랫폼을 구현한 결과를 제시한다.

• Smart Structures and Systems
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• v.10 no.3
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• pp.209-228
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• 2012

Structural health monitoring with wireless sensor networks has received much attention in recent years due to the ease of sensor installation and low deployment and maintenance costs. However, sensor network technology needs to solve numerous challenges in order to substitute conventional systems: large amounts of data, remote configuration of measurement parameters, on-site calibration of sensors and robust networking functionality for long-term deployments. We present a structural health monitoring network that addresses these challenges and is used in several deployments for monitoring of bridges and buildings. Our system supports a diverse set of sensors, a library of highly optimized processing algorithms and a lightweight solution to support a wide range of network runtime configurations. This allows flexible partitioning of the application between the sensor network and the backend software. We present an analysis of this partitioning and evaluate the performance of our system in three experimental network deployments on civil structures.

• Journal of IKEEE
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• v.13 no.3
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• pp.39-46
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• 2009

Wireless sensor networks consist of small, autonomous devices with wireless networking capabilities. In order to further increase the applicability in real world applications, minimizing energy consumption is one of the most critical issues. Therefore, accurate energy model is required for the evaluation of wireless sensor networks. In this paper we analyze the power consumption for wireless sensor networks. To develop the power consumption model, we have measured the power characteristics of commercial Kmote node based on TelosB platforms running TinyOS. Based on our model, the estimated lifetime of a battery powered sensor node can use about 6.9 months for application of human detection using PIR sensors. This result indicates that sensor nodes can be used in a monitoring system for elderly living alone.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.5189-5208
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• 2015

To address the contradiction between data aggregation and data security in wireless sensor networks, a Recoverable Privacy-preserving Integrity-assured Data Aggregation (RPIDA) scheme is proposed based on privacy homomorphism and aggregate message authentication code. The proposed scheme provides both end-to-end privacy and data integrity for data aggregation in WSNs. In our scheme, the base station can recover each sensing data collected by all sensors even if these data have been aggregated by aggregators, thus can verify the integrity of all sensing data. Besides, with these individual sensing data, base station is able to perform any further operations on them, which means RPIDA is not limited in types of aggregation functions. The security analysis indicates that our proposal is resilient against typical security attacks; besides, it can detect and locate the malicious nodes in a certain range. The performance analysis shows that the proposed scheme has remarkable advantage over other asymmetric schemes in terms of computation and communication overhead. In order to evaluate the performance and the feasibility of our proposal, the prototype implementation is presented based on the TinyOS platform. The experiment results demonstrate that RPIDA is feasible and efficient for resource-constrained sensor nodes.

• Journal of Computing Science and Engineering
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• v.4 no.2
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• pp.128-152
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• 2010

With the advance of computer and communication technologies, wireless sensor networks (WSNs) are increasingly used in many aspects of our daily life. However, since the battery lifetime of WSN nodes is restricted, the WSN lifetime is also limited. Therefore, it is crucial to determine this limited lifetime in advance for preventing service interruptions in critical applications. This paper proposes a feasible static analysis approach to estimating the worstcase lifetime of a WSN. Assuming known routes with a given sensor network topology and SMAC as the underlying MAC protocol, we statically estimate the lifetime of each sensor node with a fixed initial energy budget. These estimations are then compared with the results obtained through simulation which run with the same energy budget on each node. Experimental results of our research on TinyOS applications indicate that our approach can safely and accurately estimate worst-case lifetime of the WSN. To the best of our knowledge, our work is the first one to estimate the worst-case lifetime of WSNs through a static analysis method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.92-95
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• 2010

A sow has a characteristic changing in its temperature. It is a suitable time that is decreasing after sow's body temperature increased to the highest point. We observe the variation of temperature through USN(Ubiqutous Sensor Network) system using wireless sensor inserted in the womb. The wireless sensor send massage to user's server and its server send SMS massage to user's cell phone. We contribute to user's income increase as it notice to suitable fecundation.

• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.46-52
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• 2012

The rapid water pollution in stream, river, lake and sea in recent years raises an urgent need for continuous monitoring and policymaking to conserve the global clean environment. In particular, the increasing water pollution in coastal marine areas adds to the importance of the environmental monitoring systems. In this paper, the mobile server is designed to gathers information of the water quality at coastal areas. The obtained data by the server is transmitted from field servers to the base station via multi-hop communication in wireless sensor network. The information collected includes dissolved oxygen(DO), hydrogen ion exponent(pH), temperature, etc. By the information provided the real-time monitoring of water quality at the coastal marine area. In addition, wireless sensor network-based flooding routing protocol was designed and used to transfer the measured water quality information efficiently. Telosb sensor node is programmed using nesC language in TinyOS platform for small scale wireless sensor network monitoring from a remote server.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4643-4660
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• 2014

Integrity authentication of biometric data in Wireless Body Area Network (WBAN) is a critical issue because the sensitive data transmitted over broadcast wireless channels could be attacked easily. However, traditional cryptograph-based integrity authentication schemes are not suitable for WBAN as they consume much computational resource on the sensor nodes with limited memory, computational capability and power. To address this problem, a novel lightweight integrity authentication scheme based on reversible watermark is proposed for WBAN and implemented on a TinyOS-based WBAN test bed in this paper. In the proposed scheme, the data is divided into groups with a fixed size to improve grouping efficiency; the histogram shifting technique is adopted to avoid possible underflow or overflow; local maps are generated to restore the shifted data; and the watermarks are generated and embedded in a chaining way for integrity authentication. Our analytic and experimental results demonstrate that the integrity of biometric data can be reliably authenticated with low cost, and the data can be entirely recovered for healthcare applications by using our proposed scheme.

• Journal of Sensor Science and Technology
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• v.15 no.6
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• pp.417-424
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• 2006

An ubiquitous healthcare monitoring system for elderly person at home was designed for continuous healthy monitoring of elderly person or patients. Human vital signals, such as ECG and body temperature, were monitored by terminal PC or PDA via ECG and temperature sensor nodes on the patient's body. From the ECG data, the heart rate, tachycardia, bradycardia and arrhythmia were diagnosed on the terminal PC or PDA to assist doctor's or nurse's aid or patient itself to monitor the patient's condition and give medical examination. Artificial judgement support system was designed in server computer and the system support a doctor or nurser for management or treatment of the patient. This system can be applied to vital signal monitoring system for solitude elderly person at self house or home health care service part. And this ubiquitous healthcare system can reduce the medical expenses in coming aging or aged society.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.6
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• pp.33-38
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• 2011

In recent years, mobile devices and high-hearth because of the multi-functional, battery usage is increasing. But compared to the required computing power increases the battery's energy capacity of the research is going slowly. In this paper we use the battery discharge characteristics, can be used in battery research and to increase the effective capacity, wireless transmission of power from the system just by turning off the technology to extend battery life is explained. Experimental transmission of images through the standard battery drain intervals according to measuring battery life, and applications used in these experiments and heuristic to optimize battery run time was achieved.