• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2285-2289
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• 2005

Robot is composed of various devices but, those are incompatible with each other and hardly developing reusable control software. This study suggests standard abstract interface for robot software component to make portable device and reusable control software of robot, based on familiar techniques to abstract device in operating systems. This assures uniform abstracted interface to the device driver software like sensor and actuator and, control program can be transparent operation over device. This study can separately and independently develop devices and control software with this idea. This makes it possible to replace existing devices with new devices which have an improved performance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1231-1234
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• 2003

A sensor working in outdoor may generate some faulty signal owing to dust and high temperature. This paper describes an intelligent sensor system and controller which has a reconstruction mechanism for faulty signal. The faulty signals are dievided into two types as linear distortion and non linear distortion, respectively. The linear distorted signal is due to dust, and non linear distorted signal is due to physical breakdown of sensor or high temperature. These distorted signal have been reconstructed by the proposed method based on polynomial regression method and principal component analysis approach.. The proposed method has been applied to sun tracking system working in outdoor. For a robust and precision control of sun tracker, a fuzzy controller was also proposed. The fuzzy controller controls the tracker by using the collected sensor signal. The tolerance of the position control is within 1.5 degree. To show the validity of the developed system, some experiments in the field were illustrated.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3268-3283
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• 2018

With the advent of the Information Age, the source identification of digital images, as a part of digital image forensics, has attracted increasing attention. Therefore, an effective technique to identify the source of digital images is urgently needed at this stage. In this paper, first, we study and implement some previous work on image source identification based on sensor pattern noise, such as the Lukas method, principal component analysis method and the random subspace method. Second, to extract a purer sensor pattern noise, we propose a sample selection method to improve the random subspace method. By analyzing the image texture feature, we select a patch with less complexity to extract more reliable sensor pattern noise, which improves the accuracy of identification. Finally, experiment results reveal that the proposed sample selection method can extract a purer sensor pattern noise, which further improves the accuracy of image source identification. At the same time, this approach is less complicated than the deep learning models and is close to the most advanced performance.

• 한국산업정보학회논문지
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• 제17권1호
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• pp.63-71
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• 2012

대부분의 센서네트워크는 물리적인 세계에 대규모로 설치되기 때문에 일단 현장에 설치되면 디버깅이나 검증이 어렵다. 따라서 센서네트워크가 현장에 설치되기 전에 테스트베드 형태로 충분한 테스트와 검증이 이루어져야 한다. 테스트베드에서 센서네트워크를 테스트하고 검증할 때, 센서네트워크의 특성상 물리적인 세계와 상호작용을 해야 하기 때문에 물리적인 세계를 제어하여 자원제약적인 센서노드 수준에서 센서네트워크를 검증하는 것은 굉장한 비용과 시간을 필요로 한다. 본 논문에서는 센서네트워크의 네트워크 측면의 동직뿐만 아니라 응용 측면의 동작(즉, 센싱 알고리즘)을 보다 효율적으로 검증하고 평가하기 위한 소프트웨어 프레임워크를 제안한다. 본 논문은 제안된 소프트웨어 프레임워크를 적용해 센서네트워크 기반의 지능형 주차장 응용을 위한 시뮬레이터를 구현하여 평가함으로써 제안된 소프트웨어 프레임워크의 가능성을 검증한다.

• 한국융합학회논문지
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• 제8권8호
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• pp.51-57
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• 2017

무선 센서 네트워크는 자원 제약적인 센서 노드들로 구성되는 네트워크로, 분산 서비스 거부 공격, 라우팅 공격 등 다양한 악의적인 공격이 발생될 수 있다. 본 논문에서는 소프트웨어 정의 네트워킹 기술과 보안 기술을 융합하여 무선 센서 네트워크에 발생하는 다양한 공격을 탐지하고 방어하는 기법을 제안한다. 제안 기법에서는 서버에 있는 침입 탐지 및 방지 시스템이 SDN 컨트롤러를 통해 전달되는 오픈플로우 스위치의 로그 정보들을 축적하여 침입을 탐지하며, 침입을 탐지했을 때 오픈플로우 프로토콜을 이용하여 오픈플로우 스위치에 해당 침입에 대한 대응방안을 설정함으로써 침입을 방지할 수 있다. 본 논문에서는 분산 서비스 거부 공격 및 라우팅 공격 발생 시 침입 탐지 및 방지를 보임으로써 제안기법의 타당성을 보였다. 제안기법은 다른 기법과 달리 중앙 집중 서버에서 그래프 모델과 침입 탐지 모델을 융합하여 효과적이고 메시지 효율적으로 다양한 침입을 탐지하고 방지할 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권3호
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• pp.1321-1332
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• 2016

Wireless sensor networks (WSN) are self-organized networks that typically consist of thousands of low-cost, low-powered sensor nodes. The reliability and availability of WSNs can be affected by faults, including those from radio interference, battery exhaustion, hardware and software failures, communication link errors, malicious attacks, and so on. Thus, we propose a novel multi-agent fault tolerant system for wireless sensor networks. Since a major requirement of WSNs is to reduce energy consumption, we use multi-agent and mobile agent configurations to manage WSNs that provide energy-efficient services. Mobile agent architecture have inherent advantages in that they provide energy awareness, scalability, reliability, and extensibility. Our multi-agent system consists of a resource manager, a fault tolerance manager and a load balancing manager, and we also propose fault-tolerant protocols that use multi-agent and mobile agent setups.

• Smart Structures and Systems
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• 제5권4호
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• pp.469-482
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• 2009

The emerging sensor-based structural health monitoring (SHM) technology has a potential for cost-effective maintenance of aging civil infrastructure systems. The author proposes to integrate continuous and global monitoring using on-structure sensors with targeted local non-destructive evaluation (NDE). Significant technical challenges arise, however, from the lack of cost-effective sensors for monitoring spatially large structures, as well as reliable methods for interpreting sensor data into structural health conditions. This paper reviews recent efforts and advances made in addressing these challenges, with example sensor hardware and health monitoring software developed in the author's research center. The hardware includes a novel fiber optic accelerometer, a vision-based displacement sensor, a distributed strain sensor, and a microwave imaging NDE device. The health monitoring software includes a number of system identification methods such as the neural networks, extended Kalman filter, and nonlinear damping identificaiton based on structural dynamic response measurement. These methods have been experimentally validated through seismic shaking table tests of a realistic bridge model and tested in a number of instrumented bridges and buildings.

• 한국컴퓨터정보학회논문지
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• 제24권8호
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• pp.131-136
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• 2019

A wireless sensor network (WSN) consists of several sensor nodes and usually one base station. In this paper, we propose a method to monitor topics using a wireless sensor network. Fire threatens people, animals, and plants, and it takes a lot of recovery time when a fire occurs. For this reason, it is necessary to use a fire monitoring system that is easy to configure and fast to avoid fire. In this paper, we propose a fast and easily reliable fire detection system using WSN. The wireless node of the WSN measures the temperature and brightness around the node. The measured information is transferred to the workstation and to the base station. The workstation analyzes current and historical data records to monitor the fire and notify the manager.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.82-87
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• 2002

RFM is the sensor model of IKONOS imagery for end-users. IKONOS imagery vendors provide RPC (Rational Polynomial Coefficients), Ration Function Model coefficients for IKONOS, for end-users with imagery. So it is possible that end-users obtain geospatial information in their IKONOS imagery without additional any effort. But there are requirements still fur rigorous 3D positions on RPC user. Provided RPC can not satisfy user and company to generate precision 3D terrain model. In IKONOS imagery, physical sensor modeling is difficult because IKONOS vendors do not provide satellite ephemeris data and abstract sensor modeling requires many GCP well distributed in the whole image as well as other satellite imagery. Therefore RPC modification is better choice. If a few GCP are available, RPC can be modified by method which is introduced in this paper. Study on evaluation modified RPC in IKONOS reports reasonable result. Pseudo GCP generated with vendor's RPC and additional GCP make it possible through sequential solution.

• 대한임베디드공학회논문지
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• 제2권4호
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• pp.260-273
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• 2007

The wireless sensor network (WSN) nodes are required to operate for several months with the limited system resource such as memory and power. The hardware platform of WSN has 128Kbyte program memory and 8Kbytes data memory. Also, WSN node is required to operate for several months with the two AA size batteries. The MAC, Network protocol, and small application must be operated in this WSN platform. We look around the problem of memory and power for WSN requirements. Then, we propose a new computing model of system software for WSN node. It is the Atomic Object Model (AOM) with Dual Priority Scheduling. For the verification of model, we design and implement IEEE 802.15.4 MAC protocol with the proposed model.