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An Edge-based Method to Classify Open and Closed Eyes for Monitoring Driver’s Drowsiness
Jaeik Jo,Sung Joo Lee,Youn Joo Lee,Ho Gi Jung,Kang Ryoung Park,Jaihie Kim 대한전자공학회 2010 ICEIC:International Conference on Electronics, Inf Vol.1 No.1
Monitoring the drowsiness and inattention of a driver plays an important role in preventing car accidents. Previous researches show that many vehicular accidents in highway are caused by the fatigue due to long-time driving, inattention or dozing of a driver. To resolve these problems, we propose a method to classify open and closed eyes by analyzing horizontal edge of eye images. After initial locations of face and eyes are found by using object detection methods such as Adaboost, an edge-based method is used to extract feature from detected eye image. Then, open and closed eyes are classified by the threshold based on Bayesian rule and analysis of extracted feature. Experimental results show that open and closed eyes are reliably classified in actual vehicular environments.
Necessary and Sufficrent Geometric Conditions
Jaeik Lee,Jongnyun Lee 한국산업응용수학회 2005 한국산업응용수학회 학술대회 논문집 Vol.- No.-
This Paper deals with a geometric criterion for checking the incompressibility of ∂Hk-Γ, where Hk, and Γdenotes an orientable handle body of genus k and a finite system of pairwise disjoint simple closed curves in ∂Hk. Our theorem will turn out to be very applicable for various surfaces in Hk, and give us a visual approach in detecting the incompressibility of ∂Hk-Γ. So it provides us with useful information about compressing disks for ∂Hk-Γ when ∂Hk-Γ is compressible in Hk.
이재익(Jaeik Lee),이태훈(Taehun Lee),장경영(Kyung-Young Jhang) 한국비파괴검사학회 2009 한국비파괴검사학회지 Vol.29 No.5
이 논문은 표면파의 비선형특성을 이용하여 재료 표면의 열화손상을 평가한 사례 연구의 결과를 보고한다. 이 연구에서는 3점 굽힘 피로시험에 의해 표면에 피로열화를 가한 알루미늄 T6 시편을 대상으로 표면파의 음향 비선형 파라미터를 측정하기 위한 실험장치를 구성하였으며, 피로시험 전후에서 측정된 비선형 파라미터의 크기를 비교하였다. 특히 3점 굽힘 피로시험에 의한 표면피로손상은 시편의 중앙부 표면에 집중될 것이 예상되므로 이 주변에서의 비선형 파라미터의 변화를 세밀히 관찰하였다. 실험결과 피로손상이 거의 없는 시편의 가장자리에서는 비선형 파라미터가 피로시험 전후에서 큰 변화가 없었지만, 표면 피로열화가 집중된 중앙부에서는 뚜렷하게 증가하는 것으로 나타났다. This paper reports the results of a case study for the evaluation of surface damage by using acoustic nonlinearity of surface wave. In this study, the experimental system was constructed to measure the acoustic nonlinear parameter of surface wave in an Aluminum 6061 T6 specimen of which surface was damaged by the three point bending fatigue test, and magnitudes of nonlinear parameter measured before and after the fatigue test were compared. Especially, since the surface fatigue damage by the three point bending is concentrated at the central position of loading, the change in the nonlinear parameter around this position was monitored. Experimental results showed that the measured nonlinear parameter at the outside of this position after the fatigue test was almost same as the initial value before the fatigue test, since the fatigue damage at this position was little. However, clear increase in the nonlinear parameter was noticed after the fatigue test at the central position of specimen where the surface fatigue damage is expected to be concentrated.
이재익(Jaeik Lee),권구도(Goodo Kwon),이태훈(Taehun Lee),장경영(Kyung-Young Jhang) 한국비파괴검사학회 2009 한국비파괴검사학회지 Vol.29 No.4
본 연구의 목적은 탄성 표면파에서의 비선형 거동의 이론적 배경을 소개하고 실험적으로 검증하는 것으로서, 이론상의 표면파의 비선형 파라미터는 벌크파에서와 같이 전파된 표면파의 2차 고조파 성분과 기본파 성분 크기의 비에 의존한다. 이를 검증하기 위해 접촉식 탐촉자를 이용한 측정 시스템을 구축하였고, 표면파 전파거리와 인가전압 크기를 변화시키며 알루미늄 6061 합금의 비선형 파라미터를 측정하였다. 또한, 비선형 파라미터를 측정함에 있어서 주파수 의존적 감쇠의 영향을 고려하였다. 이러한 과정을 통한 결과는 탄성 표면파의 비선형 파라미터가 인가전압의 크기에 독립적이며, 2차 고조파 성분의 크기는 전파거리에 선형적으로 의존할 것이라는 이론적 예측과 일치한다. The goal of this study is to introduce the theoretical background of acoustic nonlinearity in surface wave and to verify its characteristics by experiments. It has been known by theory that the nonlinear parameter of surface wave is proportional to the ratio of 2<SUP>nd</SUP> harmonic amplitude and the power of primary component in the propagated surface wave, as like as in bulk waves. In this paper, in order to verify this characteristics we constructed a measurement system using contact angle beam transducers and measured the nonlinear parameter of surface wave in an Aluminum 6061 alloy block specimen while changing the distance of wave propagation and the input amplitude. We also considered the effect of frequency-dependent attenuation to the measurement of nonlinear parameter. Results showed good agreement with the theoretical expectation that the nonlinear parameter should be independent on the input amplitude and linearly dependent on the input amplitude and the 2<SUP>nd</SUP> harmonic amplitude is linearly dependant on the propagation distance.