• The KIPS Transactions:PartB
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• v.11B no.4
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• pp.477-484
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• 2004

The technique of sequential pattern mining means generating a set of inter-transaction patterns residing in time-dependent data. This paper proposes a new method for generating sequential patterns with the use of Hellinger measure. While the current methods are generating single dimensional sequential patterns within a single attribute, the proposed method is able to detect multi-dimensional patterns among different attributes. A number of heuristics, based on the characteristics of Hellinger measure, are proposed to reduce the computational complexity of the sequential pattern systems. Some experimental results are presented.

• The Korean Journal of Applied Statistics
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• v.21 no.2
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• pp.247-264
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• 2008

This paper considers the integrated process control procedure for detecting special causes in an ARIMA(0,1,1) process that is being adjusted automatically after each observation using a minimum mean squared error adjustment policy. It is assumed that a special cause can change the process mean and the process variance. We derive expressions for the process deviation from target for a variety of different process parameter changes, and introduce a control chart, based on the generalized likelihood ratio, for detecting special causes. We also propose the integrated process control scheme bases on the future loss. The future loss denotes the cost that will be incurred in a process remaining interval from a true out-of-control signal.

• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.49-52
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• 2004

RADARSAT is one of many possible data sources that can play an important role in marine surveillance including ship detection because radar sensors have the two primary advantages: all-weather and day or night imaging. However, atmospheric effects on SAR imaging can not be bypassed and any remote sensing image has various geometric distortions. In this study, radiometric and geometric calibrations for RADARSAT/SAR data are tried using SGX products georeferenced as level 1. For radiometric calibration, information on the magnitude of the radar backscatter coefficient of the imaged terrain is extracted from the processed image data. Conversion method of the pixel DNs to beta nought and sigma nought is also investigated Finally, automatic geometric calibration based on the header file is compared to a marine chart.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2569-2574
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• 2012

HMS(Hull Mount Sonar) equipment mounted on PCC(Patrol Combat Corvette) is suitably designed for active mode, and the specific character of sensor or system is not appropriate for the frequency range to detect a torpedo. In this article, in order to implement the function of detecting torpedoes with HMS of existing PCC, I will analyze the feature of input signals each PCCs and design a circuit to compensate reversely for the input signal in certain frequency. And also, I will suggest the most adequate torpedo defense system suitable for the special operating environment and the characteristic of naval vessels, implementing functions such as AGC of input signal and fixing the frequency range of different input signals per different warships.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.151-154
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• 2013

We typically have a variety of equipment that can detect and track targets, and detect and track target quickly and accurately through the exchange of the information between each piece of equipment. These equipments have similar detection area(FOV), but some are different due to the limits of the resolution of the equipments. In this paper, we studied the method of reducing time to search and detect target, and also did the method of tracking automatically it.

• Proceedings of the Korean Society of Computer Information Conference
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• 2010.07a
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• pp.319-322
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• 2010

본 논문에서는 저가의 비용으로 구축이 가능한 USB 인터페이스용 PC 카메라를 이용한다. 사람의 침입이나 사람의 움직임을 감시할 필요가 있는 장소에 카메라를 설치하여 영상을 계속 감시한다. 감시가 필요한 장소에 설치된 각 카메라의 영상에 변화를 저장하여 기록하는데 있어서, 비교적 적은 비용이 필요하다. 또한 감시가 필요한 장소를 보다 안전하고 정확하게 감시할 수 있는 무인 침입탐지시스템에 영상처리와 영상인식 기술을 이용하여 실시간 감시시스템을 구현한다. 구현한 시스템은 웹을 기반으로 다양한 원격지의 화상 자료의 신속한 전송, 정확성의 구현, 특정 움직임의 캡처 및 선택, 검색, 자동 움직임 감지 등의 장점을 제공한다. 또한 독자적 시스템을 제공하여 다수의 시스템을 영상 입력 서버로 이용이 가능하도록 하였다. 뿐만 아니라, 서버에 C/S 형태의 시스템도 함께 제공하여, 영상인식 모듈을 탑재할 수도 있다. 덧붙여 인터넷을 통한 자료의 전송기술 및 QoS 만족을 위한 자료의 압축 및 품질 향상 기술을 적용하여 원격 출력과 원격 전송이 가능하여 저장 장치의 유지 관리 및 설치면에서 많은 경제적 이점이 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.353-356
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• 2017

앱 인벤터는 GUI 환경에서 블록 편집기를 사용하여 앱을 개발한다. 따라서 누구나 쉽게 앱 프로그래밍을 시작할 수 있다는 장점이 있다. 또한, 앱 인벤터의 공식 사이트의 gallery 공간에 공개된 수많은 공개 앱 소스(aia 파일)를 쉽게 구할 수 있기 때문에 다른 사람이 만든 앱의 소스를 그대로 가져다가 이미지만 바꿔서 자신이 만든 것처럼 앱을 공개할 수도 있다. 그러나 직접 블록 단위로 비교해보지 않고서는 표절이나 도용 여부를 판단하는 것은 쉽지 않다. 따라서 본 논문에서는 앱 인벤터로 개발한 앱들의 유사도를 자동으로 계산해주는 도구를 개발하였다. 원본 프로그램과 도용된 프로그램은 유사도가 높게 계산될 것임을 예상할 수 있기 때문에 유사도 계산 프로그램은 코드 도용을 확인하는 목적으로 활용될 수 있다. 본 논문에서 구현한 도구의 평가를 위해서 다양한 실험을 수행하였고, 실제로 유사도가 높았던 앱들이 서로 공통된 블록을 다수 포함하고 있음을 밝혀내었다. 이러한 실험결과를 바탕으로 우리가 개발한 도구가 앱 인벤터로 개발한 앱에 대해서 소스 표절이나 코드 도용을 탐지하는 목적으로 활용될 수 있을 것으로 기대한다.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.251-257
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• 2015

Intrusion protection system is a security system that stop abnormal traffics through automatic activity by finding out attack signatures in network. Unlike firewall or intrusion detection system that defends passively, it is a solution that stop the intrusion before intrusion warning. The security performance of intrusion protection system is influenced by security auditability, user data protection, security athentication, etc., and performance is influenced by detection time, throughput, attack prevention performance, etc. In this paper, we constructed a convergence performance evaluation model about software product evaluation to construct the model for security performance evaluation of intrusion protection system based on CC(Common Criteria : ISO/IEC 15408) and ISO international standard about software product evaluation.

• Journal of IKEEE
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• v.23 no.2
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• pp.448-453
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• 2019

Under the conflicting objectives of maximum user satisfaction and fast launching, there exist great needs for automated mobile app testing. In automated app testing, detection of usage-state changes is one of the most important issues for minimizing human intervention and testing of various usage scenarios. Because conventional approaches utilizing pre-collected training examples can not handle the rapid evolution of apps, we propose a novel method detecting changes in usage-state through graph-entropy. In the proposed method, widgets in a screen shot are recognized through DNNs and 'onverted graphs. We compared the performance of the proposed method with a SIFT (Scale-Invariant Feature Transform) based method on 20 real-world apps. In most cases, our method achieved superior results, but we found some situations where further improvements are required.

• Journal of Auto-vehicle Safety Association
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• v.12 no.4
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• pp.13-22
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• 2020

This paper presents an adaptive feedback based actuator fault detection and tolerant control algorithms for longitudinal functional safety of autonomous driving. In order to ensure the functional safety of autonomous vehicles, fault detection and tolerant control algorithms are needed for sensors and actuators used for autonomous driving. In this study, adaptive feedback control algorithm to compute the longitudinal acceleration for autonomous driving has been developed based on relationship function using states. The relationship function has been designed using feedback gains and error states for adaptation rule design. The coefficients in the relationship function have been estimated using recursive least square with multiple forgetting factors. The MIT rule has been adopted to design the adaptation rule for feedback gains online. The stability analysis has been conducted based on Lyapunov direct method. The longitudinal acceleration computed by adaptive control algorithm has been compared to the actual acceleration for fault detection of actuators used for longitudinal autonomous driving.