• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.609-616
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• 2023

In a wireless network environment, since sensors are not always connected to power, the life of a battery, which is an energy source supplied to sensors, is limited. Therefore, various studies have been conducted to extend the network life, and a layer-based routing protocol, LEACH(: Low-energy Adaptive Clustering Hierarchy), has emerged for efficient energy use. However, the LEACH protocol, which transmits fused data directly to the sink node, has a limitation in that it consumes as much energy as the square of the transmission distance when transmitting data. To improve these limitations, this paper proposes an algorithm that can minimize the transmission distance with multi-hop transmission where cluster heads are chained between cluster heads through relative distance calculation from sink nodes in every round.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.281-292
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• 2008

A main application of sensor networks are to monitor and to send information about a possibly hostile environment to a powerful base station connected to a wired network. To conserve power from each sensor, intermediate network nodes should aggregate results from individual sensors. However, it can make it that a single compromised sensor can render the network useless, or worse, mislead the operator into trusting a false reading. In this paper, we propose a protocol to give us a key aggregation mechanism that intermediate network nodes could aggregate data more safely. The proposed protocol is more helpful at multi-tier network architecture in secure sessions established between sensor nodes and gateways. From simulation study, we compare the amount of the energy consumption overhead, the time of key transmission and the ratio of of key process between the proposed method and LHA-SP. The simulation result of proposed protocol is low 3.5% a lord of energy consumption than LHA-SP, the time of key transmission and the ration of key process is get improved result of each 0.3% and 0.6% than LHA-SP.

• Smart Structures and Systems
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• v.16 no.1
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• pp.223-242
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• 2015

Wireless sensor networks (WSNs) have emerged as a novel solution to many of the challenges of structural health monitoring (SHM) in civil engineering structures. While research projects using WSNs are ongoing worldwide, implementations of WSNs on full-scale structures are limited. In this study, a WSN is deployed on a full-scale 17.3m-long, 11-bay highway sign support structure to investigate the ability to use vibration response data to detect damage induced in the structure. A multi-level damage detection strategy is employed for this structure: the Angle-between-String-and-Horizon (ASH) flexibility-based algorithm as the Level I and the Axial Strain (AS) flexibility-based algorithm as the Level II. For the proposed multi-level damage detection strategy, a coarse resolution Level I damage detection will be conducted first to detect the damaged region(s). Subsequently, a fine resolution Level II damage detection will be conducted in the damaged region(s) to locate the damaged element(s). Several damage cases are created on the full-scale highway sign support structure to validate the multi-level detection strategy. The multi-level damage detection strategy is shown to be successful in detecting damage in the structure in these cases.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.249-252
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• 2008

A wearable ubiquitous health care monitoring system using integrated ECG and accelerometersensors based on WSN is designed and developed. Wireless sensor network technology is applied for non intrusive healthcare in some wide area coverage with small battery support for RF transmission. We developed wearable devices which are wearable USN node, sensor board and base-station. Low power operating ECG and accelerometer sensor board was integrated to wearable USN node for user's health monitoring. The wearable ubiquitous healthcare monitoring system allows physiological data to be transmitted in wireless sensor network from on body wearable sensor devices to a base-station connected to server PC using IEEE 802.15.4. Physiological data displays and stores on server PC continuously.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.378-381
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• 2011

The group management system with Wireless Sensor Network and android application is proposed in this paper. The proposed system was composed of personal devices with sensor nodes of WSN, manager device of android platform, and the web server. The sensor node used by each group member send a data packet to the manager device every 2 seconds. The leader device displays and transmits entire information to the web server. The web server represents these information through web page. Therefore, guardians can assure their group member's safety and security on the web page. The RSSI value of each sensor node converted by computed log-normal path loss model into distance value and displays on the manager device and the web page.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3675-3681
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• 2009

One of the most important factors in the lifetime of WSN(Wireless Sensor Network) is the limited resources and static control problem of the sensor nodes. In order to achieve energy efficiency and network utilities, sensor nodes can be well organized into one cluster and selected head node and normal node by dynamic conditions. Various clustering algorithms have been proposed as an efficient way to organize method based on LEACH algorithm. In this paper, we propose an efficient clustering algorithm using information entropy theory based on LEACH algorithm, which is able to recognize environmental differences according to changes from data of sensor nodes. To measure and analyze the changes of clusters, we simply compute the entropy of sensor data and applied it to probability based clustering algorithm. In experiments, we simulate the proposed method and LEACH algorithm. We have shown that our data balanced and energy efficient scheme, has high energy efficiency and network lifetime in two conditions.

• 한국IT서비스학회:학술대회논문집
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• 2008.11a
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• pp.262-265
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• 2008

수천 개의 센서 노드들 간의 공동 작업을 기반으로 한 무선 센서 네트워크는 대규모 서식지 모니터링, 침입 탐지, 자동화된 실시간 위치 평가, 홈 어플리케이션, 과학적인 탐사 등 수많은 응용에 대한 새로운 플랫폼을 제공하고 있다. 본 논문은 수천 개의 센서노드들이 센서 필드에 전개되어 있는 경우에 센서 노드의 상태를 효율적으로 관리하기 위해 센서 노드의 위치를 탐지하기 위한 방법에 관하여 기술하였다. 기본적으로 PEGASIS 라우팅 알고리즘을 이용하여 노드들 간의 상대 거리 정보를 수집하여 센서 노드의 위치 정보를 탐지하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1297-1299
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• 2010

무선 통신에서는 무선 통신의 브로드캐스트한 특성으로 데이터의 기밀성 유지를 위한 암호화가 매우 중요하다. 특히 무선 센서 네트워크(WSN - Wireless Sensor Network)의 경우 일반적인 PC와는 다르게 다양한 환경에 위치할 수 있어 공격자에게 더 쉽게 노출 될 수 있는 문제점을 가지고 있다. 이런 환경에서 미리 저장된 해쉬 함수나 비밀 값에 의존한 키 분배를 할 경우 저장된 값이 노출될 경우 심각한 문제를 초래하게 된다. 그리고 D-H 키 분배 알고리즘의 경우 키 값을 안전하게 도출을 할 수 있지만 키를 도출한 대상에 대한 인증의 부재와 멀티 홉 환경에서 중간자 공격에 취약한 문제점을 드러내고 있다. 본 논문에서는 이런 문제를 해결하기위해 기존 연구를 응용하여 멀티 홉 환경에서 무선 통신의 특성을 이용한 비밀값 공유와 제 3의 노드를 이용한 간단한 인증이 가능한 기법을 제안한다.

• Journal of KIISE
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• v.44 no.7
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• pp.726-732
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• 2017

In practical distributed sensing and prediction applications over wireless sensor networks (WSN), environmental sensing activities are highly dynamic because of noisy sensory information from moving source signals. The recent distributed online convex optimization frameworks have been developed as promising approaches for solving approximately stochastic learning problems over network of sensors in a distributed manner. Negligence of mobility consequence in the original distributed saddle point algorithm (DSPA) could strongly affect the convergence rate and stability of learning results. In this paper, we propose an integrated sliding windows mechanism in order to stabilize predictions and achieve better convergence rates in cooperative detection of a moving source signal scenario.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.373-377
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• 2022

Wireless sensor networks are being used in various fields. Wireless sensor networks are applied in many areas, such as security, military detection, environmental management, industrial control, and home automation. There is a problem about the limit of energy that the sensor network basically has. In this paper, we propose the LEACH-CCBD (Low Energy Adaptive Clustering hierarchy - Centrailized with Cluster and Basestation Distance) algorithm that uses energy efficiently by improving network transmission based on LEACH-C among the representative routing protocols. The LEACH-CCBD algorithm is a method of assigning a cluster head to a cluster head by comparing the sum of the distance from the member node to the cluster distance and the distance from the cluster node to the base station with respect to the membership of the member nodes in the cluster when configuring the cluster. The proposed LEACH-CCBD used Matlab simulation to confirm the performance results for each protocol. As a result of the experiment, as the lifetime of the network increased, it was shown to be superior to the LEACH and LEACH-C algorithms.