• Journal of Sensor Science and Technology
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• v.32 no.2
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• pp.105-109
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• 2023

In this study, we present a power-efficient driving method for gas sensor systems based on the analysis of input signal characteristics. The analysis of the gas sensor output signal characteristics in the frequency domain shows that most of the signal portions are distributed in a relatively low frequency region when extracting the gas sensor signal, which can lead to further performance improvement of the gas sensor system. Therefore, the proposed gas signal extracting technique changes the operating frequency of the read-out circuit based on the frequency characteristics of the output signal of the gas sensor, resulting in a reduction of power consumption at the whole system level. The proposed sensing technique, which can be applied to a general-purpose commercial gas sensor system, was implemented in a printed circuit board (PCB) to verify its effectiveness at the commercial level.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9B
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• pp.821-828
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• 2006

In this paper, we introduce a concrete, practical Ubiquitous Organizational Information (UOI) service framework, providing novice users intelligent and useful services respecting the environment. The UOI framework consists of hierarchical network architecture and is based on distributed sensor networks. To provide a rich array of services, the modular software framework and foundation software is designed. The UOI framework and foundation software is implemented on our hardware prototype. We define three representative UOI services and illustrate each service flow operating in our UOI network. In addition, we describe some details in the implementation of a distributed UOI network on the UOI test-bed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.2
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• pp.323-329
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• 2001

In this paper, we present a collaborative method for material delivery using a distributed vehicle agents system. Generally used AGV(Autonomous Guided Vehicle) systems in FA require extraordinary facilities like guidepaths and landmarks and have numerous limitations for application in different environments. Moreover in the case of controlling multi vehicles, the necessity for developing corporation abilities like loading and unloading materials between vehicles including different types is increasing nowadays for automation of material flow. Thus to compensate and improve the functions of AGV, it is important to endow vehicles with the intelligence to recognize environments and goods and to determine the goal point to approach. In this study we propose an interaction method between hetero-type vehicles and adaptive fuzzy logic controllers for sensor-based path planning methods and material identifying methods which recognizes color. For the purpose of carrying materials to the goal, simple color sensor is used instead vision system to search for material and recognize its color in order to determine the goal point to transfer it to. The proposed method reaveals a great deal of improvement on its performance.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.289-290
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• 2009

In this paper we designed the sensor system that is based on the PT, CT and microprocessors for measuring power of distributed energy resource of ocean side.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1535-1538
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• 2004

In this paper, an Intelligent Bed Robot System (IBRS) is proposed, that is a special bed equipped with robot manipulator. To assist a patient using IBRS, pose and motion estimation process is fundamental. It is designed to help the elderly and the disabled for their independent life in bed without other assistants. For this purpose, we use the pressure sensor distributed mattress for detecting the change of motion on the bed. Using that data, we control the robot arm to move to the appropriate position and serve to the user. In addition, we can estimate the user's intention based on the change of pressure and use those data to control the robot arm guide.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.231-236
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• 2009

본 연구에서는 집이나 사무실과 같은 일상 공간에서 발생할 수 있는 연간의 일상생활행위 (ADL: Activities of Daily Living) 들을 인지하는 분산 모델을 제시한다. 사용자의 환경 정보, 위치 정보 및 행위 정보를 간단한 센서들이 부착된 가정용 기기들과 가구, 식기들을 통해 무선 센서 네트워크를 통해 수집하며 분석한다. 하지만 이와 같은 다양한 기기의 활용과 충분히 분석되어지지 않은 데이터들은 본 논문에서 제시하는 일상 환경에서 고차원의 ADL 모델을 구축하기 어렵게 한다. 그러나 ADL들이 생성하는 센서 데이터들과 센서 데이터들의 순서들은 어떤 행위가, 이루어지고 있는지 인지할 수 있도록 도와준다. 따라서 이 센서 데이터들의 순서를 특정 행위 패턴을 분석하는 데 활용하고, 이를 통해 분산 선형 시간 추론 알고리즘을 제안한다. 이 알고리즘은 센서 네트워크와 같은 소규모 시스템에서 행위를 인지하는 데 적절하다.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.275-276
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• 2006

선박 및 해양기자재의 안전 진단을 위한 기존의 기술은 접 센서(point sensor)를 이용한 변형률 측정 기술이 대부분이라 할 수 있다. 본 논문은 기존의 기술보다 효율적으로 응용될 수 있는 광섬유 센서를 이용한 분포 개념의 온도 및 변형률 측정(DTSS: Distributed Temperature & Strain Sensing) 기술에 대해 소개하고 있다. 이 기술은 선체 응력 모니터링, 해양 구조물 안전진단, subsea flowline 모니터링, platform의 riser 안정성, umbilical 모니터링 등에 활용될 수 있다.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.11-15
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• 2018

The application of Wireless Sensor Networks requires a wise utilization of limited energy resources. Therefore, a wide range of routing protocols with a motivation to prolong the lifetime of a network has been proposed in recent years. Hierarchical clustering based protocols have become an object of a large number of studies that aim to efficiently utilize the limited energy of network components. In this paper, the effect of mismatch in parameter estimation is discussed to evaluate the robustness of a distanced based algorithm called distributed clustering protocol in homogeneous and heterogeneous environment. For quantitative analysis, performance simulations for this protocol are carried out in terms of the network lifetime which is the main criteria of efficiency for the energy limited system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.86-90
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• 2006

We prosed a distributed fiber-optic sensor system with 10 fiber Bragg gratings, for over temperature protection relay in power systems. We applied Gaussian line-fitting algorithm to compensate the distortion effects in the wavelength-scanned Farby-Perot filter demodulation scheme. Compared with the highest-peak-detection method, the proposed algorithm was proved to minimize the random errors of distorted PD profiles. From experimental results, the overall measurement error was within 1 % compared with the reference thermocouple and the linearity error was less than 0.37 %.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1785-1786
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• 2007

저가형 센서 노드와 임베디드 기술의 발달로 인하여 센서 노드가 보다 넓은 범위에서 사용되고 있으며, 센서 네트워크에 대한 연구 또한 활발히 진행 되고 있다. 하지만 많은 센서 노드로부터 오는 데이터를 처리하게 되면서 계산량 증가 및 노이즈에 의한 데이터 왜곡현상 등의 각종 문제가 고려되고 있다. 본 논문에서는 분배형 확장 칼만 필터(Distributed Extended Kalman Filter)를 설계하고 분배형 센서 융합 알고리즘을 이용하여 이러한 문제를 해결하고, 이동 개체의 위치 및 경로를 추정 한다.