• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1670-1679
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• 2011

In the area of wireless sensor networks, sensor coverage and network connectivity problems are caused by a limited detection range and the communication distance of the nodes. To solve the coverage and connectivity problems, many studies are suggested, but most research is restricted to apply into the real environment because they didn't consider various environmental factors on wireless sensor network deployment. So in this paper, we propose a node deployment strategy considering environmental factors and the number of nodes in surveillance and reconnaissance sensor networks(SRSN). The proposed node deployment method divides the installation of the surveillance and reconnaissance sensor networks system into four steps such as identification of influences factors for node placement through IPB process, sensor node deployment based on sensing range, selection of monitoring site, and relay node deployment based on RF communication range. And it deploys the sensor nodes and relay nodes considered the features of the surveillance and reconnaissance sensor network system and environmental factors. The result of simulation indicates that the proposed node deployment method improves sensor coverage and network connectivity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10B
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• pp.894-903
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• 2008

The position of sensors generally affects coverage, communication costs, and resource management of surveillance sensor networks. Thus we are required to place a sensor in the best location. However, it is difficult to consider that terrain and climate factors influencing sensors when sensor nodes are deployed in the real world, such as a mountain area or a downtown area. We therefore require a sensor deployment method for detecting effectively targets of interest in terms of surveillance area coverage in such environment. Thus in this paper, we analyze various environmental factors related to sensor deployment, and quantify these factors to use when we deploy sensors. By considering these quantified factors, we propose a practical and effective method for deploying sensors in terms of sensing coverage. We also demonstrate the propriety of the proposed method through implementing a sensor deployment management system according to the method.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.4
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• pp.158-168
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• 2009

As nation and society progresses, urban ground facilities and their management system get more complicated and the cost and effort to control the system efficiently grows exponentially. This study suggests to the deployment method of a sensor node by Wireless Sensor Network for controling the Urban Ground Facilities of National Facilities. First, we achieve the management facilities and method using the first analysis and then make the coverage of sensing and then set up the Sensor Node in Urban Ground Facilities. Second, we propose the solution way of repetition by the second analysis. And, we embody the GIS program by Digital Map and this method, we improve the reality by overlapping an aerial photo. Also we make an experience on the sensor node allocation using making program. we can remove the repetition sensor node about 50%, and we can confirm that the sensor nodes are evenly distributed on the road.

• Journal of Korea Multimedia Society
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• v.16 no.3
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• pp.354-365
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• 2013

Node deployment is one of the important problems in achieving good quality of service in wireless sensor network. The purpose of this paper is to develop an interactive system that supports user's decision makings in designing sensor fields. The system provides grid-based initial deployment algorithm supporting three types of node deployment pattern, area-fill, path-cover, and barrier-cover deployment pattern. After initial deployment, an iterative refinement algorithm can be applied, which takes care of the irregularity of the deployment area and the heterogeneity of sensors. The proposed system helps users to effectively deploy nodes in the sensor field, analyse the detection performance of the deployment, and perform network simulations. The developed system can be utilized as a part of the development environment of the surveillance sensor network system.

• Spatial Information Research
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• v.19 no.6
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• pp.111-121
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• 2011

In this paper, we proposes a sensor node positioning algorithm that utilizes the geo-spatial elements and considers the factors to represent the propagation loss generated by the various obstacles in the urban wireless environments. First, we measures the propagation loss about the radio frequencies in major road of the urban, and defines the correlation between the measured loss and the environment information for the road and its surrounding get from Urban GIS. Secondly, through the utilization of the loss-environment correlation, we describes the detailed instruction for requiring the radio coverage decision and deploy system implementation for the wireless sensor node in urban. By the consideration of interference factor by the building and the linear structure of road, we can evaluate the path loss below 5dB RMS error. And, we proposes the way to revise the sensor node deployment based on the corelation and the measured path loss.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.320-323
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• 2006

무선 센서 네트워크의 센서 노드들은 한번 배치되면 다시 회수되지 않으며, 외부 전원의 공급 없이 배터리만을 사용하여 작동하게 된다. 따라서 각 센서 노드는 매우 제한된 자원을 사용하여 환경을 감지하거나 주변 노드들과 통신을 해야 한다. 결국 무선 센서 네트워크에서 가장 중요한 요소는 센서 노드가 소모하는 에너지를 최대한 절약하여 네트워크의 수명을 늘리는 것이라고 할 수 있다. 본 논문에서는 에너지 효율적인 그라디언트 기반의 라우팅 기법을 제안한다. 이 기법은 패킷 발생 및 전달 횟수를 새로운 메트릭으로 사용하여 주변 노드의 에너지 사용량을 추정한다. 이를 통하여 에너지 소모가 특정 노드에게 집중되지 않도록 기존의 그라디언트 라우팅을 개선하였으며, 패킷 듣기(Packet Overhearing) 방식을 통하여 별도로 메시지를 주고받는 일 없이 메트릭을 측정할 수 있도록 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.151-153
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• 2005

무선 센서 네트워크는 방대한 응용분야와 유비쿼터스 환경 하에서 중요한 한 부분을 차지하며 그 유용성을 입증하고 있다. 이런 무선 센서 네트워크의 센서 노드는 작은 크기를 바탕으로 목표 장소에 임의로 배치되어 다양한 데이터를 수집하는 능력이 탁월하다 하지만 이런 장점은 센서 노드의 한정된 하드웨어 능력과 전원공급 문제, 물리적 노출 문제로 인해 스스로를 위험에 노출시키는 여지를 만들게 되었다. 즉 일반적으로 사용되어지는 네트워크 보안 방법을 무선 센서 네트워크에 적응하기에는 센서 노드 능력에 한계가 있으며, 환경적 요소로 인해 불가능하다. 따라서 무선 센서 네트워크의 특성을 감안한 효과적인 보안 방법이 필요하며, 이런 맥락에 본 논문은 무선 센서 네트워크의 하드웨어적인 한계를 감안한 대칭키(Symmetric key) 기반의 키 분배 기법을 제안하고자 한다. 제안하는 기법에서는 모든 노드가 공통으로 소유한 전체 마스터 키(master key)와 의사 난수 생성기(pseudo random number generator:PRNG), 그리고 특정 대상으로부터 분배되는 난수(random number)의 조합을 통해 임의의 키를 생성, 갱신함으로써 다양한 종류의 무선 센서 네트워크 모델에 유연하게 대처할 수 있도록 하였다. 또한 이를 위한 통신 회수를 최소화함으로써 효율성을 제공해 준다.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.495-498
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• 2009

유비쿼터스 시대에서 요구하는 가장 핵심적인 요소기술 즉 인프라이며 이를 이용한다면 다양한 시설물에서의 침입자에 대한 감시, RFID를 이용한 효율적인 인력배치에 응용이 가능하고 또한 온도, 조도, 연기 센서 등을 활용하면 실시간으로 화재 및 테러에 대해 조기에 인지하여 빠르게 대처할 수 있다. 본 논문에서는 USN이 적용되는 대상은 침입탐지를 감시해야 하는 구역, 보안감시 대상이 되는 구역, 위험물 관리와 같은 구역으로 분류하여 구역의 특성마다 센서와 카메라, Tag와 센서(Hybrid Reader)기술 등을 하나의 센서노드로 융합하여 관리대상에 이상유무가 있을 경우 빠르게 대처하거나, Tag와 센서(Hybrid Reader)기술을 이용한 효율적인 인력배치 및 관리할 수 있도록 USN을 구성한다.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.379-384
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• 2022

In a wireless sensor network, a large number of sensor nodes are deployed in an environment where direct access is difficult. It is difficult to supply power, such as replacing the battery or recharging it. It is very important to use the energy with the sensor node. Therefore, an important consideration to increase the lifetime of the network is to minimize the energy consumption of each sensor node. If the energy of the wireless sensor node is exhausted and discharged, it cannot function as a sensor node. Therefore, it is a method proposed in various protocols to minimize the energy consumption of nodes and maintain the network for a long time. We consider the center point and residual energy of the cluster, and the plot point and K-means (WSN suggests optimal clustering). We want to evaluate the performance of the KOCED protocol. We compare protocols to which the K-means algorithm, one of the latest machine learning methods, is applied, and present performance evaluation factors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1505-1510
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• 2008

In large-scale wireless sensor networks, the deployed nodes cannot be replaced or recharged after first deployment. Also, dead nodes maγ lead to the partition of whole networks. While performing data dissemination under a battery power constraint, energy efficiency is a key design factor of routing protocol. As a solution for the efficient data dissemination, in this paper, we propose a protocol namely Hierarchical Data Dissemination (HDD) which provides scalable and efficient data delivery to multiple sources and mobile sinks. HDD uses the facts that sink nodes are central gathering Points and source-centric data forwarding paths are constructed and it is maintained with two-tier communications. The performance of HDD is compared with TTDD about the energy consumption, data delivery time and data success ration. The extensive simulation results show that HDD Routing Protocol outperforms TIDD by more than $1.5{\sim}3times$ on energy consumption.