• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.383-386
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• 2008

기존 개발되어 왔던 센서 네트워크 시뮬레이터는 외부 환경적인 영향요소를 고려하지 않고 네트워크 중심적으로 설계 및 구현되어 왔다. 하지만 센서 네트워크의 사용 목적이 다양해지면서 센서 네트워크를 실내뿐만 아니라 실외 환경에도 적용하려 하고 있다. 실내보다 실외 환경에 센서 네트워크를 구축할 경우 가장 먼저 고려해야 할 사항은 초소형, 저전력의 특징을 가지고 있는 센서들을 배치하는 것이기 때문에 센서가 배치되는 지리적 요소를 고려해야 한다. 따라서 기존 센서 네트워크 시뮬레이터는 지리적 요소가 배제되어 있기 때문에 외부 환경에 적용하여 센서 네트워크를 시뮬레이션하게 되면 상당히 많은 차이점을 보일 수 밖에 없다. 따라서 본 연구에서는 외부 환경에 센서 네트워크를 구축 시 고려되는 핵심 영향요소 중 지리적 요소를 고려하여, 시뮬레이터에 접목시킬 수 있도록 세분화 및 분석하였다. 이를 통해 외부 환경에 센서 네트워크 구축 시 효율적으로 센서를 배치할 수 있도록 앞에서 분석한 지형 정보를 고려하여 센서 탐지 영역 감소율 분석을 위한 시뮬레이터 모듈을 설계한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.2
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• pp.163-168
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• 2008

Navigation system based on indoor location estimation is one of the core technologies in mobile robot systems. Wireless sensor network has great potential in the indoor location estimation due to its characteristics such as low power consumption, low cost, and simplicity. In this paper we present an algorithm to estimate the indoor location of mobile robot based on wireless sensor network and fuzzy modeling. ZigBee-based sensor network usually uses RSSI(Received Signal Strength Indication) values to measure the distance between two sensor nodes, which are affected by signal distortion, reflection, channel fading, and path loss. Therefore we need a proper correction method to obtain accurate distance information with RSSI. We develop the fuzzy distance models based on RSSI values and an efficient algorithm to estimate the robot location which applies to the navigation algorithm incorporating the time-varying data of environmental conditions which are received from the wireless sensor network.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.6
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• pp.51-60
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• 2011

Researches on indoor localization using the wireless sensor network have been actively carried out to be used for indoor area where GPS signal is not received. Computationally efficient WCL(Weighted Centroid Localization) algorithm is shown to perform relatively well. However, to get the best performance for WCL all the anchor nodes must send signal with power to cover 96% of the network. The fact that outside the transmission range of the fixed nodes drastic localization error occurs results in large mean error and deviation. Due to these problems the WCL algorithm is not easily applied for use in the real indoor environment. In this paper we propose SRS(Succesive Region Setting) algorithm which sequentially reduces the estimated location area using the signal strength from the anchor nodes. The proposed algorithm does not show significant performance degradation corresponding to transmission range of the anchor nodes. Simulation results show that the proposed SRS algorithm has mean localization error 5 times lower than that of the WCL under free space propagation environment.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.397-399
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• 2005

무선 센서노드를 활용한 다양한 네트워크 설계 기술은 실생활의 각종 정보 수집에서부터 환경 모니터링까지 폭넓은 활용범위를 바탕으로 저전력 노드 설계 기술, 노드간 라우팅 프로토콜, 초소형 운영체제 및 미들웨어기술 등 관련 연구가 활발히 수행되고 있으며, 실내 센서네트워크에 분포된 노드의 절대위치를 측정하는 위치인식 시스템은 노드의 이동성, 다수성 그리고 환경의 제약성으로 인해 이를 보완할 시스템이 요구되고 있다. 이에 본 논문에서는 고정 센서노드의 배치밀도에 따라 위치정보를 선별적으로 처리하는 위치데이터 처리기와 다중 위치데이터의 발생을 원천적으로 차단하는 노드간 라우팅 기법을 통해, 센서노드의 이동성과 다중성을 효과적으로 보완하는 실내 이동객체 위치인식 시스템을 설계하고 서비스 구현을 위한 센서네트워크 플랫폼을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.9
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• pp.2120-2126
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• 2010

This paper aims to realize the location tracking system using the Zigbee in the wireless sensor network. The wireless sensor network offers the user-oriented location tracking service in the ubiquitous environment. The location tracking service can track the location of an object or a person and provides it. The location tracking system realized in this paper can be used inside or outside without any black-out areas to measure the location of the moving nodes. In tracking inside the RSSI signals use and in tracking outside will connect with the GPS signals to track the location. Also, by using Zigbee, the wireless sensor network environment was established and by obtaining the location of the moving nodes, the real-time tracking is possible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.389-392
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• 2010

The problem for the air pollution in the office or the indoor except a specific working area is the continuously issue since the human beings have lived in the dwelling facilities. Measures for that problem are urgently needed. It's possible to solve for the freshair of outside with enough ventilation but that is the awkward situation to be managed by person. It's feasible to supervison and control easily if you use to sensor network under the network. It works out to sense, storage, process, deliver every kind of appliances and environmental information from the stucktags and sensors. And it is possible to utilize to measure and monitor about the place of environmental pollution which is difficult for human to install. It's studied constantly since it be able to compose easily more subminiature, low-power, low-cost than previous one. And also it spotlights an important field of study, graft the green IT and IT of which the environment and IT unite stragically onto the Network. This study compose a IAQM(Indoor Air Quality Management) under the network, suggest the application of supervision and control.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.315-324
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• 2018

Purpose: This paper propose a temporary indoor positioning scheme with devices of internet of things (IoT) for disastrous situations in places without the infrastructure of networks. Method: The proposed scheme is based on the weighted centroid localization scheme that can estimate the position of a target with simple computation. Results: It also is implemented with the IoT devices at the underground parking lot, where the network is not installed, of general office building. According to the experiment results, the positioning error was around 10m without a priori calibration process at $82.5m{\times}56.4m$ underground space. Conclusion: The proposed scheme can be deployed many places without the infrastructure of networks, such as parking lots, warehouses, factory, etc.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.147-154
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• 2009

Lately, superhigh speed network infra is developing with the fast speed, is evolved by step that existent appliances are digitalised and appliances are become remote control by being gear to network. Also, gearing in Home network and superhigh speed network infra, control appliances in Internet and research that do monitering is proceed. Therefore, describe about indoor environment automatic control system that use Wireless sensor and Microcontroler in this paper. Because using that electric power, Zigbee sensor and Wireless module, embodied system that measured in the room temperature and use ATmega128 Microcontroler and use each device (temperature, illumination, humidity) back in house and control humidifier, electric fan etc. Can use variously in Home network field by this Wireless sensor and Microcontroler base, and also can apply variously to several industry fields as well as Home network field.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.1
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• pp.56-65
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• 2006

Recently the study on service robots has been proliferated in many fields, and there are active developments for indoor services such as supporting for elderly people. It is important for robot to recognize objects and situations appropriately for effective and accurate service. Conventional object recognition methods have been based on the pre-defined geometric models, but they have limitations in indoor environments with uncertain situation such as the target objects are occluded by other ones. In this paper we propose a Bayesian network model to reason the probability of target objects for effective detection. We model the relationships between objects by activities, which are applied to non-static environments more flexibly. Overall structure is constructed by combining common-cause structures which are the units making relationship between objects, and it makes design process more efficient. We test the performance of two Bayesian networks for verifying the proposed Bayesian network model through experiments, resulting in accuracy of $86.5\%$ and $89.6\%$ respectively.

• 한국공간정보시스템학회:학술대회논문집
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• 2007.06a
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• pp.51-56
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• 2007

본 연구는 유비쿼터스 컴퓨팅 환경을 기반으로 실내 공간 위치정보를 표현하는 위치모델을 제안한다. 실내 공간은 실외공간과 마찬가지로 유클리디언 공간, 네트워크 공간, 기호 공간의 성격을 동시에 가지고 있다. 그러나 현재 실외공간을 대상으로 하는 위치서비스의 경우, 도로 혹은 평면 공간처럼 어느 한 공간을 가정하고 위치 서비스를 제공하는 반면, 실내공간에서의 위치서비스는 이 세 가지 공간을 동시에 고려해야하는 차이점이 있다. 이 논문은 세 가지 공간의 특성을 소개한 후, 각각의 공간을 위해 현재 사용되는 공간 위치모델을 간략히 소개한다. 이를 바탕으로, 실내 위치모델을 위한 요구사항을 정리하고, 세 가지 공간모델을 통합하는 실내 위치 모델을 제안한다. 특히 본 연구에서 제안하는 모델은 실내 공간들 간의 접근성 표현할 수 있으며, 현재 사용되고 있는 공간모델에 실내 위치모델을 위한 모델요소를 추가하는 형태로 설계되었으므로, 현재 개발된 지리정보 시스템들과의 호환성을 지원한다는 점에서 의의가 있다.