• Title/Summary/Keyword: Change-Point Detection

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Real-Time Face-Detection Based on Multiple Color-Spaces and Multiple Thresholds for Distance Measurement Between Speaker and Smart-Phone (화자(話者)와 스마트폰의 거리 측정을 위한 다중 색 좌표계와 다중 임계치 기반 실시간 얼굴검출)

  • Lee, Jae-Won;Kwon, Goo-Rak;Hong, Sung-Hoon
    • Journal of Korea Multimedia Society
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    • v.14 no.4
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    • pp.481-493
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    • 2011
  • As the development of mobile devices, mobile phones are equipped with many features. Video-call feature is one of them. In this paper, we present distance measurement between speaker and smart-phone using multiple color spaces and multiple thresholds. first, detect face based on skin color information. and second, measure distance between speaker and smart-phone using the detected face region. Especially, the first considering point in the development of face area detection is real-time processing and the second point is robustness to solve the problems of face detection errors due to rapid change of object movement, lighting and background between adjacent frames.

Object-based Building Change Detection from LiDAR Data and Digital Map Using Adaptive Overlay Threshold (적응적 중첩 임계치를 이용한 LiDAR 자료와 수치지도의 객체기반 건물변화탐지)

  • Lee, Sang-Yeop;Lee, Jeong-Ho;Han, Su-Hee;Choi, Jae-Wan;Kim, Yong-Il
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.3
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    • pp.49-56
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    • 2011
  • Because urban areas change rapidly, it is necessary to reflect urban changes in a digital map database in a timely manner. To address these issues, LiDAR data was used to detect changes in urban area buildings. The purpose of this study is to detect object-based building change using LiDAR data and existing digital maps, and classify change types. In the study, we classified change type using overlay and shape comparison with building layer of the digital maps and point-based extracted building outline from the LiDAR data. When applying the overlay method, we were able to increase the accuracy and objectivity of the change detection process throughout an adaptive threshold applied to each object. In the experiments, it was demonstrated that classifying and detecting changes in urban areas using the proposed method can provide superior classification accuracy compared with the existing methodology.

Error Correction Technique of Distance Measurement for ToF LIDAR Sensor

  • Moon, Yeon-Kug;Shim, Young Bo;Song, Hyoung-Kyu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.2
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    • pp.960-973
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    • 2018
  • This paper presents design for error correcting algorithm of the time of flight (ToF) detection value in the light detection and ranging (LIDAR) system sensor. The walk error of ToF value is generated by change of the received signal power depending on distance between the LIDAR sensor and object. The proposed method efficiently compensates the ToF value error by the independent ToF value calculation from the received signal using both rising point and falling point. A constant error of ~0.05 m is obtained after the walk error correction while an increasing error up to ~1 m is obtained with conventional method.

P-wave Detection Algorithm by Significant Point Extraction Method (특성점 추출에 의한 P파 검출 알고리즘에 관한 연구)

  • Hwang, Sun-Chul;Jeong, Hee-Kyo;Lee, Myoung-Ho
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.162-165
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    • 1989
  • This paper describes an algorithm of P-wave detection by significant point extraction method with digital differentiation. P-waves are detected by pattern matching algorithm with significant points. By means of defecting onset and offset points of P-waves, this algorithm can measure the PR intervals exactly which is important to diagnosis the atrial arrhythmia. Because P-wave duration is changed according to heart-rates, we calculate the R-R interval prior to the determination of P-wave duration threshold values in order to actively adapt to the change of P duration The results obtained from the proposed algorithm have defected successfully P-wave almost more than 90%.

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Structural Change Analysis in a Real Interest Rate Model (실질금리 결정모형에서의 구조변화분석)

  • 전덕빈;박대근
    • Korean Management Science Review
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    • v.18 no.1
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    • pp.119-133
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    • 2001
  • It is important to find the equilibrium level of real interest rate for it affects real and financial sector of economy. However, it is difficult to find the equilibrium level because like the most macroeconomic model the real interest model has parameter instability problem caused by structural change and it is supported by various theories and definitions. Hence, in order to cover these problems structural change detection model of real interest rate is developed to combine the real interest rate equilibrium model and the procedure to detect structural change points. 3 equations are established to find various effects of other interest-related macroeconomic variables and from each equation, structural changes are found. Those structural change points are consistent with common expectation. Oil Crisis (December, 1987), the starting point of Economic Stabilization Policy (January, 1982), the starting point of capital liberalization (January, 1988), the starting and finishing points of Interest deregulation (January, 1992 and December, 1994), Foreign Exchange Crisis (December, 1977) are detected as important points. From the equation of fisher and real effects, real interest rate level is estimated as 4.09% (October, 1988) and dependent on the underlying model, it is estimated as 0%∼13.56% (October, 1988), so it varies so much. It is expected that this result is connected to the large scale simultaneous equations to detect the parameter instability in real time, so induces the flexible economic policies.

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A Fast Bayesian Detection of Change Points Long-Memory Processes (장기억 과정에서 빠른 베이지안 변화점검출)

  • Kim, Joo-Won;Cho, Sin-Sup;Yeo, In-Kwon
    • The Korean Journal of Applied Statistics
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    • v.22 no.4
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    • pp.735-744
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    • 2009
  • In this paper, we introduce a fast approach for Bayesian detection of change points in long-memory processes. Since a heavy computation is needed to evaluate the likelihood function of long-memory processes, a method for simplifying the computational process is required to efficiently implement a Bayesian inference. Instead of estimating the parameter, we consider selecting a element from the set of possible parameters obtained by categorizing the parameter space. This approach simplifies the detection algorithm and reduces the computational time to detect change points. Since the parameter space is (0, 0.5), there is no big difference between the result of parameter estimation and selection under a proper fractionation of the parameter space. The analysis of Nile river data showed the validation of the proposed method.

MPEG Video Segmentation Using Frame Feature Comparison (프레임 특징 비교를 이용한 압축비디오 분할)

  • 김영호;강대성
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.2
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    • pp.25-30
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    • 2003
  • Recently, development of digital technology is occupying a large part of multimedia information like character, voice, image, video, etc. Research about video indexing and retrieval progresses especially in research relative to video. In this paper, we propose new algorithm(Frame Feature Comparison) for MPEG video segmentation. Shot, Scene Change detection is basic and important works that segment it in MPEG video sequence. Generally, the segmentation algorithm that uses much has defect that occurs an error detection according to a flash of camera, movement of camera and fast movement of an object, because of comparing former frames with present frames. Therefore, we distinguish a scene change one more time using a scene change point detected in the conventional algorithm through comparing its mean value with abutted frames. In the result, we could detect more corrective scene change than the conventional algorithm.

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An Empirical Approach to determine Road-Surface Conditions for Anti-Lock Brake System (Anti-Look Brake Systern을 위한 경험적 노면판단 방법)

  • 박병량;양순용
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.125-125
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    • 2000
  • An Empirical approach to determine a road-surface condition is presented The road-surface condition thus provided includes the detection of not only friction coefficient, but also abrupt surface-profile changes such as pitfalls and bumpers The former plays a key role in establishing the appropriate control strategy, while the latter allows to minimize unnecessary brake intervention induced by the aforementioned jut. In this paper, we use an empirically chosen variable, namely. the time-rate of change of vehicle speed estimated from the point where ABS engaged to the point where measurement taken Experimental results shoe that the proposed method is effective to infer various control variables critical for the control of ABS.

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An Imperfect Debugging Software Reliability Growth Model with Change-Point (변화점을 갖는 불완전수정 소프트웨어 신뢰도 성장모형 연구)

  • Nam, Kyung-H.;Kim, Do-Hoon
    • Journal of Korean Society for Quality Management
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    • v.34 no.4
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    • pp.133-138
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    • 2006
  • In this paper, we propose a software reliability growth model (SRGM) based on the testing domain, which is isolated by the executed test cases. This model assumes an imperfect debugging environment in which new faults are introduced in the fault-correction process. We consider that the fault detection rate of NHPP model is changed in the proposed SRGM. We obtain the maximum likelihood estimate, and compare goodness-of-fit with another existing software reliability growth model.

Modified information criterion for testing changes in generalized lambda distribution model based on confidence distribution

  • Ratnasingam, Suthakaran;Buzaianu, Elena;Ning, Wei
    • Communications for Statistical Applications and Methods
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    • v.29 no.3
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    • pp.301-317
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    • 2022
  • In this paper, we propose a change point detection procedure based on the modified information criterion in a generalized lambda distribution (GLD) model. Simulations are conducted to obtain empirical critical values of the proposed test statistic. We have also conducted simulations to evaluate the performance of the proposed methods comparing to the log-likelihood method in terms of power, coverage probability, and confidence sets. Our results indicate that, under various conditions, the proposed method modified information criterion (MIC) approach shows good finite sample properties. Furthermore, we propose a new goodness-of-fit testing procedure based on the energy distance to evaluate the asymptotic null distribution of our test statistic. Two real data applications are provided to illustrate the use of the proposed method.