• 대한임베디드공학회논문지
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• 제11권3호
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• pp.135-141
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• 2016

Indoor zone-based services have continuously become popular by increased prevalence of smartphones. Bluetooth and ultrasound can be used for zone detection. However, bluetooth does not guarantee precise zone detection if the signal degrades due to the obstacles. Ultrasound can be easily forged by recording sound on the smartphone. For that reason, zone detection based on ultrasound has a security hole. To remedy each limitation, we propose an advanced zone detection method, that combines bluetooth and ultrasound. An authentication server issues a one-time password to the user over bluetooth. The user generates an ultrasound signal that encodes the password. In this manner, the proposed method ensures secure and accurate zone detection.

• 디지털산업정보학회논문지
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• 제9권4호
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• pp.95-101
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• 2013

MANET has an advantage that can build a network quickly and easily in difficult environment to build network. In particular, routing protocol that uses in existing mobile environment cannot be applied literally because it consists of only mobile node. Thus, routing protocol considering this characteristic is necessary. Malicious nodes do extensive damage to the whole network because each mobile node has to act as a router. In this paper, we propose technique that can detect accurately the suspected node which causes severely damage to the performance of the network. The proposed technique divides the whole network to zone of constant size and is performed simultaneously detection technique based zone and detection technique by collaboration between nodes. Detection based zone translates the information when member node finishes packet reception or transmission to master node managing zone and detects using this. The collaborative detection technique uses the information of zone table managing in master node which manages each zone. The proposed technique can reduce errors by performing detection which is a reflection of whole traffic of network.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2015년도 제52차 하계학술대회논문집 23권2호
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• pp.279-281
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• 2015

Location awareness is an important capability for mobile-based indoor services. Those indoor services have motivated the implementation of methods that need high computational load cost and complex mechanisms for positioning prediction. These mechanisms, such as opportunistic sensing and machine learning, require more energy consumption to achieve accuracy. In this paper, we propose the Bluetooth Low Energy indoor zone detection (BLEIZOD) technique. This method exploits the concept of proximity zone to reduce the load cost and complexity. Our proposed method implements the received signal strength indicator (RSSI) function more effectively to gain accuracy and reduce energy consumption.

• Journal of Power Electronics
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• 제16권2호
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• pp.760-768
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• 2016

Three-phase grid-connected inverters are widely applied in the fields of new energy power generation, electric vehicles and so on. Islanding detection is necessary to ensure the stability and safety of such systems. In this paper, feature recognition technology is applied and a novel islanding detection method is proposed. It can identify the features of inverter systems. The theoretical values of these features are defined as codebooks. The difference between the actual value of a feature and the codebook is defined as the quantizing distortion. When islanding happens, the sum of the quantizing distortions exceeds the threshold value. Thus, islanding can be detected. The non-detection zone can be avoided by choosing reasonable features. To accelerate the speed of detection and to avoid miscalculation, an active islanding detection method based on feature recognition technology is given. Compared to the active frequency or phase drift methods, the proposed active method can reduce the distortion of grid-current when the inverter works normally. The principles of the islanding detection method based on the feature recognition technology and the improved active method are both analyzed in detail. An 18 kVA DSP-based three-phase inverter with the SVPWM control strategy has been established and tested. Simulation and experimental results verify the theoretical analysis.

• 제어로봇시스템학회논문지
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• 제5권2호
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• pp.228-236
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• 1999

In this paper, we propose visual-based self-localization and obstacle detection algorithms for indoor mobile robots. The algorithms do not require calibration, and can be worked with only single image by using the projective invariant relationship between natural landmarks. We predefine a risk zone without obstacles for a robot, and update the image of the risk zone, which will be used to detect obstacles inside the zone by comparing the averaging image with the current image of a new risk zone. The positions of the robot and the obstacles are determined by relative positioning. The method does not require the prior information for positioning robot. The robustness and feasibility of our algorithms have been demonstrated through experiments in hallway environments.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5873-5877
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• 2011

본 논문은 안전관리 지역 내에서 아이와 같은 객체의 움직임에 대한 분석 연구이다. 안전관리 지역 내의 객체의 이상상황을 감지하여, 만일 비정상적인 상황이 감지되면 사전에 정해진 업무를 수행하도록 설계되어진다. 인적자원을 통하여 안전관리가 필요한 지역에 대해서 지속적으로 이상상황에 대한 감지업무를 수행한다는 것은 불가능한 사항이므로 이러한 감지 시스템의 도입을 통하여 안정적으로 지역의 신뢰도를 높일 수 있다. 따라서 본 논문에서는 객체의 검지를 통하여 현재의 상황을 인식하여 그에 대한 대응을 위한 것이다. 본 논문에서 제안한 방안을 통하여 센서 기반 분석시스템을 이용하여 객체의 이동상황 및 이상상황 감지를 수행한다.

• 대한교통학회지
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• 제26권4호
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• pp.265-273
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• 2008

영상기반 교통감지시스템은 교통정보 수집을 기본으로 상충, 사고감지, 기후감지 등 다양한 정보를 수집하는 데 이용되고 있다. 본 논문은 VDS에서 검지영역을 설정할 때 단위거리별 픽셀길이를 자동 계산하여, 이를 기반으로 교통정보 및 상충정보를 수집하는 시스템을 개발한다. 본 알고리즘은 교차로에 검지영역 내 검지라인을 세분화하여 설정함으로써 교통정보의 정확도를 높이고, 개별차량의 교차로 통과속도 및 점유율을 자동으로 계산해 주며, 나아가 모든 교차로에 일반화하여 적용할 수 있다. 본 알고리즘은 분당교차로에 설치된 CCTV영상을 대상으로 실험하였으며, 상용화 제품과의 교통정보 비교분석을 통하여 알고리즘을 검증하였다.

• 한국정보통신학회논문지
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• 제9권8호
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• pp.1787-1792
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• 2005

원격탐사와 GIS의 접목은 해안정보와 지리정보 뿐만 아니라 교통정보 등에 많이 이용되고 있다. 본 연구는 10m급 중해상도를 가지는 SPOT 위성영상으로 LPF(Low Pass Filtering) 기법으로 해안지역의 섬 경계 추출에 관한 연구이다. 연구대상지역은 남해지역으로 원격탐사기법으로 해안지역에 존재하는 섬을 검출하기 위해 LPT를 적용한 후 Sobel 연산자로 경계검출 한 후 GIS를 활용하여 백터자료를 구축하였다. 분석결과 5${\times}$5 convolution mask를 사용하여 섬 경계 추출하는 것이 가장 효과적인 것으로 나타났다. 본 연구를 바탕으로 배타적 경계수역에서 발생할 해양분쟁에서 과학적이고 합리적인 근거자료의 제시가 가능할 것으로 판단된다.

• 전자공학회논문지S
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• 제35S권1호
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• pp.68-79
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• 1998

In this paper, we propose a model-based FDI(fault detetion and isolation) algorithm to detect and isolate fault in a linear system. The proposed algorithm is gased on an HFC(hydrid fault classifier) which consists of an FCART2(fault classifier by ART2 neural network) and an FCFM(fault classifier by fault models) which operate in parallel to isolate faults. The proposed algorithm is functionally composed of three main parts-parameter estimation, fault detection, and isolation. When a change in the system occurs, the estimated parameters go through a transition zone in which errors between the system output and the stimated output and the estimated output cross a predetermined thrseshold, and in this zone the estimated parameters are tranferred to the FCART2 for fault isolation. On the other hand, once a fault in the system is detected, the FCFM statistically isolates the fault by using the error between ach fault model out put and the system output. From the computer simulation resutls, it is verified that the proposed model-based FDI algorithm can be performed successfully to detect and isolate faults in a position control system of a DC motor.

• 정보보호학회논문지
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• 제33권6호
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• pp.929-938
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• 2023

모바일 장치에서 사용되는 ARM 프로세서는 하드웨어 기반의 격리 실행 환경인 TrustZone 개념을 도입하여 신뢰 실행 환경인 Secure World와 비신뢰 실행 환경인 Normal World를 구현하였다. 악성 소프트웨어의 종류 중 루트킷은 관리자 권한을 획득하고 자신의 존재를 숨기면서 백도어를 만든다. Secure World에서 동작하는 프로세스는 메모리 접근에 제한이 없고, 격리되어 있어 Secure World에서 루트킷이 실행되었을 때 탐지하기 어렵다. 본 논문에서는 하드웨어 기반의 성능 측정 모니터인 Performance Monitoring Unit을 활용하여 Secure World 루트킷의 이벤트를 측정하고 딥러닝 기반으로 루트킷을 탐지하는 기법을 제시한다.