• Title/Summary/Keyword: Time Difference

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A Displacement Vector Estimation and Moving Object Extraction Using Difference Picture (Difference Picture를 이용한 이동벡터의 추정과 이동물체의 추출)

  • 장순화;김종대;김성대;김재균
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.7
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    • pp.807-818
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    • 1988
  • This paper proposes new algorithms for the estimation of displacement vector and moving object extraction using difference picture. First, the relations between the boundary of moving objects in two consecutive image and the boundary of difference picture regions are analyzed, then displacement vector estimation algorithm is proposed. Using the estimated displacement vector, moving objects are directly extracted from difference picture. Since the proposed algorithms do not process gray-valued image, they have a short processing time and are suitable to real time processing. From the experimental results, we observed that, if difference picture is wel extracted, the proposecd algorithms work well even in the circumstances of complex background, fast or slow motion, rotation etc., including occlusion where is not moving area.

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Model Checking for Time-Series Count Data

  • Lee, Sung-Im
    • Communications for Statistical Applications and Methods
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    • v.12 no.2
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    • pp.359-364
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    • 2005
  • This paper considers a specification test of conditional Poisson regression model for time series count data. Although conditional models for count data have received attention and proposed in several ways, few studies focused on checking its adequacy. Motivated by the test of martingale difference assumption, a specification test via Ljung-Box statistic is proposed in the conditional model of the time series count data. In order to illustrate the performance of Ljung- Box test, simulation results will be provided.

Three-dimensional Finite Difference Modeling of Time-domain Electromagnetic Method Using Staggered Grid (엇갈린 격자를 이용한 3차원 유한차분 시간영역 전자탐사 모델링)

  • Jang, Hangilro;Nam, Myung Jin;Cho, Sung Oh;Kim, Hee Joon
    • Geophysics and Geophysical Exploration
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    • v.20 no.3
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    • pp.121-128
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    • 2017
  • Interpretation of time-domain electromagnetic (TEM) data has been made mostly based on one-dimensional (1-D) inversion scheme in Korea. A proper interpretation of TEM data should employ 3-D TEM forward and inverse modeling algorithms. This study developed a 3-D TEM modeling algorithm using a finite difference time-domain (FDTD) method with staggered grid. In numerically solving Maxwell equations, fictitious displacement current is included based on an explicit FDTD method using a central difference approximation scheme. The developed modeling algorithm simulated a small-coil source configuration to be verified against analytic solutions for homogeneous half-space models. Further, TEM responses for a 3-D anomaly are modeled and analyzed. We expect that it will contribute greatly to the precise interpretation of TEM data.

The Relationship between the Personality of Elementary School Students and the Safety Accidents in the School (초등학생의 성격특성과 학교안전사고)

  • Kim, Chang-Hee;Park, Young-Soo
    • The Journal of Korean Society for School & Community Health Education
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    • v.4
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    • pp.1-20
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    • 2003
  • This study was not intended to analyze out the realities of the safety accidents in school. The purpose of this study was to find out the personality of elementary school students in 6th grade and analyze the relationship between the personality of elementary school students and the safety accidents in the school. We made a visit 12 elementary school personally in the B city of Gyeonggi Province and gave out 552 questionaries in order to accomplish the purpose of this study. And we analyzed the 501 answer data except the unfittable data 51 sheets-in case of no answer or untruthfulness. The inspection of the personality used the Eysenck Personality Questionnaire(EPQ) and the questionnaires of the safety accidents in the school were reorganized of the questionnaires which were used in Chun-Ok, Joen(1997) and One-Yong, Kim(1999)'s study to correspond with our purpose of study. Answer sheets were gone through the t and x2 test by using the program of SPPS. First, elementary school students are in the formative period in the life of a man. So many students's personality was in the middle group rather than in high and low group. In regard of the distintion between the boy students and the girl students, the boy students had higher score in Psychoticism(P) but the girl students had higher score in Neutroticism(N). And Lie(L) was showing a little more score in the girl students. Second, there was significant difference in the investigation of safety accidents in school according to sex distinction. 1) Comparing the boy students and the girl students, the rate of accidents was higher in boy rather than girl. And there was significant difference. 2) Comparing the grade of the school, the rate of accidents was higher in upper grade than lower grade both girls and boys. 3) In the kind of accidents, the traumatic Injuries were very popular and the next were contusions. There was significant difference in the traumatic injury and nosebleed. 4) The results of injured parts showed that the injuries of foot, leg, hand, arm hold a large majority. And there was a significant difference in head, face, foot, leg and etc. 5) Most accidents broke out during the break time and then accidents happened after school were the next. The flowings were lunch time and class time. There was a significant difference in accidents happened during the class, break time and lunch time. 6) Comparing the subjects, the most accidents broke out in the class of physics. 7) Among the cause of accidents, one's own carelessness was showing the highest rate. There was a significant distintion in the fight and game. 8) The safety accidents took place most in playground, and there was a significant difference. 9) Being slight wound was showing almost in the degrees of damage. And there was a significant difference. Third, the boy students were not showing the significant difference in relation to the personality, the frequency of accidents and the degrees of damage. But the girl students were showing the significant difference in relation to the Extraversion-Introversion(E) and the frequency of accidents. And there were a significant difference between E and N. Also they were showing the intense damages.

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The Three-Dimensional Partial Differential Equation with Constant Coefficients of Time-Delay of Alternating Direction Implicit Format

  • Chu, QianQian;Jin, Yuanfeng
    • Journal of Information Processing Systems
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    • v.14 no.5
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    • pp.1068-1074
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    • 2018
  • In this paper, we consider the delay partial differential equation of three dimensions with constant coefficients. We established the alternating direction difference scheme by the standard finite difference method, gave the order of convergence of the format and the expression of the difference scheme truncation errors.

Basic Research for the Tactual User Interface Design (촉각적 사용자 인터페이스 디자인에 관한 기초 연구 -소형 원형 버튼의 크기 판별을 중심으로-)

  • Yang, Seung-Mu;Jeong, Byung-Yong
    • IE interfaces
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    • v.13 no.2
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    • pp.253-257
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    • 2000
  • This study was conducted to test the significance of differences in the tactual difference thresholds and perception time for tactual direction type and finger type and radius size based on small circular button. The results show that difference threshold of vertical tactual perception is significantly greater than horizontal perception, but there are no significant differences in difference thresholds among finger types and radius sizes. Also, there are no significant differences in tactual perception time among tactual direction types, finger types, and radius types. These findings are applicable for tactual user interface design.

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Kinematic Variables Comparison of Setter Toss Motion on Volleyball According to Toss Types (배구경기 세터 토스 동작의 운동학적 비교분석)

  • Chung, Nam-Ju;Kim, Jae-Pil
    • Korean Journal of Applied Biomechanics
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    • v.25 no.1
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    • pp.57-64
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    • 2015
  • Purpose : The purpose of this study was to analyze setter toss motion kinematically according to toss types. Method : Dependent variables were elapsed time, vertical displacement of the body center, the projected speed of the ball, and differences of the joint angle to the target for four setters positioning. Result : There was no significant difference in the time but the ball contact time was shorter when the toss distance of P3 was longer. There was significant difference in the vertical displacement of COM (p<.05). The vertical displacement of COM showed that the vertical movement gradually decreased when the quick distance was longer. The vertical displacement of COM was difference (p<.05), also there was difference of the ball speed (p<.001) at the Release point(E4). There was significant difference in the knee joint angle at a certain moment among the Release(E4) and Landing point(E5)(p<.05). The hip joint was significant difference among the Apex(E2), Ball Touch(E3), Release(E4), and the Landing point(E5) on the surface(E2, E3, E4 p<.05; E5 p<.005). The shoulder angle was significant difference among the Ball Touch(E3), Release(E4) and the Landing point(E5) on the surface(E3, E4 p<.05; E5 p<.001). The elbow was significant difference in the Apex(E2) (p<.05). The wrist was significant difference in the Release(E4) (p<.05). Conclusion : If we find the clue to expect the direction of the setter's ball, we have to fine the clues in the Apex(E2) that hip join and elbow, Ball Touch(E3) that hip joint and shoulder joint, Release(E4) that wrist, elbow, hip joint, and knee joint.

A Method on the Control of Hydration Heat of Mass Concrete Considering the Difference of Setting Time (응결시간차를 활용한 매스콘크리트의 수화열 조정공법)

  • 심보길;윤치환;한민철;김기철;오선교;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.379-384
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    • 2001
  • This Paper Presents field application test results of mass concrete using super retarding agent. The field test was carried out at mat foundation(thickness 1m) of newly constructed information center of Chongju university. Placing lift composed of 2 layers, and each layer is 50cm. Fly ash and flowing method is also applied. Difference of setting time of concrete between with super retarding agent and without super retarding agent is considered. Concrete without super retarding agent is placed at upper layer and with super retarding agent at lower layer According to test results, the reducing method of hydration heat considering difference of setting time with super retarding agent can reduce the highest temperature about 3~4$^{\circ}C$, and delay the peak time about 3~4days. Compressive strength using super retarding agent is somewhat higher than that of normal concrete. Accordingly, super retarding agent does not affect the strength development.

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Multiple Model Prediction System Based on Optimal TS Fuzzy Model and Its Applications to Time Series Forecasting (최적 TS 퍼지 모델 기반 다중 모델 예측 시스템의 구현과 시계열 예측 응용)

  • Bang, Young-Keun;Lee, Chul-Heui
    • Journal of Industrial Technology
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    • v.28 no.B
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    • pp.101-109
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    • 2008
  • In general, non-stationary or chaos time series forecasting is very difficult since there exists a drift and/or nonlinearities in them. To overcome this situation, we suggest a new prediction method based on multiple model TS fuzzy predictors combined with preprocessing of time series data, where, instead of time series data, the differences of them are applied to predictors as input. In preprocessing procedure, the candidates of optimal difference interval are determined by using con-elation analysis and corresponding difference data are generated. And then, for each of them, TS fuzzy predictor is constructed by using k-means clustering algorithm and least squares method. Finally, the best predictor which minimizes the performance index is selected and it works on hereafter for prediction. Computer simulation is performed to show the effectiveness and usefulness of our method.

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A Simple Method to Reduce the Splitting Error in the LOD-FDTD Method

  • Kong, Ki-Bok;Jeong, Myung-Hun;Lee, Hyung-Soo;Park, Seong-Ook
    • Journal of electromagnetic engineering and science
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    • v.9 no.1
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    • pp.12-16
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    • 2009
  • This paper presents a new iterative locally one-dimensional [mite-difference time-domain(LOD-FDTD) method that has a simpler formula than the original iterative LOD-FDTD formula[l]. There are fewer arithmetic operations than in the original LOD-FDTD scheme. This leads to a reduction of CPU time compared to the original LOD-FDTD method while the new method exhibits the same numerical accuracy as the iterative ADI-FDTD scheme. The number of arithmetic operations shows that the efficiency of this method has been improved approximately 20 % over the original iterative LOD-FDTD method.