• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.6
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• pp.695-700
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• 2005

In the sensor network, a lot of sensor nodes are scattered sparsely and organizes a united communication network between each node. After that, environmental information around each sensor node are gathered and analyzed. Because each node operates under resource constraint, the efficiency and hardware specification of a node should be maximized. There exist technical constraints until now but recent technical progress in IC fabrication and wireless network enables to construct a tiny embedded system, which has the properties of low cost, low power consumption, multi functions. Wireless sensor network becomes a modern research field with technical improvements, is studied in numerous laboratories, and is called as diverse different project names - Wireless Integrated Network Sensors (WINS), Mobile Ad hoc NETwork (MANET), Ubiquitous Sensor Network (USN). TinyOS is one of leading project and is widely used. In this paper, we suggest a sensor network, which uses TinyOS platforms and aims for context awareness in a home environment.

• Information and Communications Magazine
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• v.22 no.8
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• pp.35-50
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• 2005

무선 네트워킹과 소형화 기술의 발전은 고정된 기반시설이 없는 열악한 환경에서도 초소형의 센서 노드들을 무작위 배치하여 애드혹 네트워킹을 통해 순간적으로 네트워크 인프라를 구축하고 긴밀한 협동 작업을 통해 복잡한 환경감지를 가능하게 하는 센서 네트워크의 개발을 이루어냈다. 각 센서 노드들은 매우 제한적인 능력을 가지고 있지만 이들의 협동작업은 마치 미세한 신경세포 조직이 상호작용하여 동물의 신체활동을 가능하게 하듯이 기존의 네트워킹이나 컴퓨팅에서는 불가능했던 많은 응용들을 가능하게 하여 우리의 생활환경을 스마트한, 지능적인 환경으로 만들어 줄 수 있다. 본 고에서는 이러한 센서 네트워크의 기존 네트워크와의 차별화되는 특징 및 응용에 따른 다양한 보안이슈와 최신 보안기술 연구동향들을 살펴보기로 한다.

• Information and Communications Magazine
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• v.21 no.6
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• pp.89-101
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• 2004

최근 저전력의 무선통신과 적응형 자가조직(Self-organization)능력을 가진 초소형 마이크로센서의 하드웨어 기술 발전으로 다양한 기능의 센서를 이용한 무선 센서 네트워크의 구축이 가능하게 되었다. 무선 센서 네트워크는 현실세계의 여러 이벤트를 감지하는 센싱 작업을 기반으로 주로 과학용이나 군사용으로 많이 사용되고있다. 즉, 직접 접근이 용이하지 않은 전장에서의 적군감시, 열악한 환경을 모니터링 하는 지진감지, 교통의 감시와 제어를 위한 지능형 교통통제, 장기간의 관찰이 요구되는 생태감시 등 그 응용범위가 다양하게 확장되고 있다. (중략)

• Journal of Sensor Science and Technology
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• v.5 no.6
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• pp.15-24
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• 1996

In this study, as a part of the basic study for the application of optical fiber sensors to smart composite structures, the integrity of optical fiber sensors embedded within the composite structures was examined and then the laser signal transmitted through optical fiber sensors during the deformation of host structures was investigated. Firstly, it was found that bending test could be substituted for tensile test by comparing cumulative failure distribution based on weakest link theory and introducing the correction factor. Weibull parameters were obtained through the experiments and the correction factor was found to be applied to cumulative failure distribution derived from bending test. The integrity of embedded optical fiber sensors due to the thermal effect was evaluated by the comparison of the mean tensile strengths of cured and uncured optical fibers. Secondly, relationships between stress-strain curve obtained in tensile test of composite laminate and the intensity of laser signal transmitted through embedded optical fibers were examined and the possibility of the effective damage detection using optical fiber sensors was studied.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.4
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• pp.91-100
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• 2009

In this paper, we propose autonomous intelligent wheelchair system which recognize the commands using the gaze recognition and avoid the detected obstacles by sensing the distance through range sensors on the way to driving. The user's commands are recognized by the gaze recognizer which use a centroid of eye pupil and two reflection points extracted using a camera with infrared filter and two infrared LEDs. These are used to control the wheelchair through the user interface. Then wheelchair system detects the obstacles using 10 ultrasonic sensors and assists that it avoid collision with obstacles. The proposed intelligent wheelchair system consists of gaze recognizor, autonomous driving module, sensor control board and motor control board. The gaze recognizer cognize user's commands through user interface, then the wheelchair is controled by the motor control board using recognized commands. Thereafter obstacle information detected by ultrasonic sensors is transferred to the sensor control board, and this transferred to the autonomous driving module. In the autonomous driving module, the obstacles are detected. For generating commands to avoid these obstacles, there are transferred to the motor control board. The experimental results confirmed that the proposed system can improve the efficiency of obstacle avoidance and provide the convenient user interface to user.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.2
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• pp.124-129
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• 2013

Hexapod walking robots are superior to biped or quadruped ones in terms of walking stability. Therefore hexapod robots have the advantage in performing intelligent tasks based on walking stability. In this paper, we propose a hexapod robot that has one fore leg, one hind leg, two left legs, and two right legs and can perform various intelligent tasks. We build the robot by using 26 motors and implement a controller which consists of a host PC, a DSP main controller, an AVR auxiliary controller, and smart phone/pad. We show by several experiments that the implemented robot can perform various intelligent tasks such as uneven surface walking, tracking and kicking a ball, remote control and 3D monitoring by using data obtained from stereo camera, infrared sensors, ultra sound sensors, and contact sensors.

• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.86-93
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• 2010

With the introduction of smart phones, the augmented reality became popular and is increasingly drawing attention. The augmented reality in the mobile devices is becoming an individual area to study. Many applications of the augmented reality have been studied, but there are just a few studies on its combination with artificial intelligence in games. In this study, an artificial intelligence algorithm was proposed, which dynamically converts the state of the 3D agent in the augmented reality environment using the 3-Axis acceleration sensor in the smart phone. To control the state of the agent to which the artificial intelligence is applied, users used to directly enter the data or use markers to detect them. The critical values, which were determined via test, were given to the acceleration sensor to ensure accurate state conversion. In this paper, makerless tracking technology was used to implement the augmented reality, and the state of the agent was dynamically converted using the 3-Axis acceleration seonsor.

• Journal of KIISE
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• v.42 no.2
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• pp.190-202
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• 2015

Much research has been conducted on location-based intelligent personal assistants that can understand a user's intention by learning the user's route model and then inferring the user's destinations and routes using data of GPS and other sensors in a smartphone. The intelligence of the location-based personal assistant is contingent on the accuracy and efficiency of the real-time predictions of the user's intended destinations and routes by processing movement information based on uncertain sensor data. We propose a robust particle filter based on Dynamic Bayesian Network model to infer the user's routes. The proposed robust particle filter includes a particle generator to supplement the incorrect and incomplete sensor information, an efficient switching function and an weight function to reduce the computation complexity as well as a resampler to enhance the accuracy of the particles. The proposed method improves the accuracy and efficiency of determining a user's routes and destinations.

• Journal of KIISE:Information Networking
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• v.37 no.5
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• pp.396-402
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• 2010

The tracking of current location of residents is an essential requirement for context-aware service of smart houses. This paper presents a wireless sensor network system which could detect location transition such as entrance and exit to a room and also identify the user who passed the room, without duty of wearing any sort of tag. We designed new sensor node to solve the problem of short operation lifetime of previous work[1] which has two pyroelectric infrared (PIR) sensors and an ultrasonic sensor, as well as a 2.4 GHz radio frequency wireless transceiver. The proposed user identification method is to discriminate a person based on his/her height by using an ultrasonic sensor. The detection idea of entering/exiting behavior is based on order of triggering of two PIR sensors. The topology of the developed wireless sensor network system is simple star structure in which each sensor node is connected to one sink node directly. We evaluated the proposed sensing system with a set of experiments for three subjects in a model house. The experimental result shows that the averaged recognition rate of user identification is 81.3% for three persons. and perfect entering/exiting behavior detection performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.877-880
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• 2017

가정이나 사무실 등과 같은 다양한 현실 세계에서 서비스 로봇이 자율적으로 동작하기 위해서는 복잡한 작업을 수행할 수 있어야만 한다. 다양한 센서 데이터가 있는 서비스 환경에서 고수준의 의미 정보를 이해하는 것은 지식 기반 로봇에게 필수적인 능력 중 하나이다. 본 논문에서는 서비스 로봇에게 다양한 환경에서 주어진 작업을 효과적으로 해결할 수 있도록 저레벨의 센서 데이터와 고레벨의 의미 정보를 통합하는 인간-로봇 상호작용 온톨로지를 소개한다. 지능형 로봇 지식에는 다양한 서비스의 확장성을 위해 사용자, 로봇, 인지, 환경, 행위 5가지 온톨로지로 분류한다. 지능형 로봇 지식은 일반 지식 뿐만 아니라 로봇의 수행 능력, 구성요소 등의 전문 지식까지 정의하고 서비스 에이전트 간 상호작용을 위한 인터페이스를 표준화함으로써 지능형 로봇에 적합한 지능을 제공한다. Turtlebot2을 이용한 실험을 통해 온톨로지 기반의 통합 로봇 지식의 높은 효율성을 확인 할 수 있었다.