• Title/Summary/Keyword: position probability

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Prediction of Rear-end Crash Potential using Vehicle Trajectory Data (차량 주행궤적을 이용한 후미추돌 가능성 예측 모형)

  • Kim, Tae-Jin;O, Cheol;Gang, Gyeong-Pyo
    • Journal of Korean Society of Transportation
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    • v.29 no.3
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    • pp.73-82
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    • 2011
  • Recent advancement in traffic surveillance systems has allowed the researchers to obtain more detailed vehicular movement such as individual vehicle trajectory data. Understanding the characteristics of interactions between leading and following vehicles in the traffic flow stream is a backbone for designing and evaluating more sophisticated traffic and vehicle control strategies. This study proposes a methodology for estimating rear-end crash potential, as a probabilistic measure, in real-time based on the analysis of vehicular movements. The methodology presented in this study consists of three components. The first predicts vehicle position and speed every second using a Kalman filtering technique. The second estimates the probability for the vehicle's trajectory to belong to either 'changing lane' or 'going straight'. A binary logistic regression (BLR) is used to model the lane-changing decision of the subject vehicle. The other component calculates crash probability by employing an exponential decay function that uses time-to-collision (TTC) between the subject vehicle and the front vehicle. The result of this study is expected to be adapted in developing traffic control and information systems, in particular, for crash prevention.

Experimental result of Real-time Sonar-based SLAM for underwater robot (소나 기반 수중 로봇의 실시간 위치 추정 및 지도 작성에 대한 실험적 검증)

  • Lee, Yeongjun;Choi, Jinwoo;Ko, Nak Yong;Kim, Taejin;Choi, Hyun-Taek
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.3
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    • pp.108-118
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    • 2017
  • This paper presents experimental results of realtime sonar-based SLAM (simultaneous localization and mapping) using probability-based landmark-recognition. The sonar-based SLAM is used for navigation of underwater robot. Inertial sensor as IMU (Inertial Measurement Unit) and DVL (Doppler Velocity Log) and external information from sonar image processing are fused by Extended Kalman Filter (EKF) technique to get the navigation information. The vehicle location is estimated by inertial sensor data, and it is corrected by sonar data which provides relative position between the vehicle and the landmark on the bottom of the basin. For the verification of the proposed method, the experiments were performed in a basin environment using an underwater robot, yShark.

A Study on the Communication Channel Model Using the Space Diversity Technique in Railroad Tunnel Section (철도터널구간에서 공간다이버 시티 기법을 이용한 통신채널 모델에 관한 연구)

  • Lee, Sang-Hyeok;Kim, Min-Seok;Jeon, Tae-Hyun;Lee, Jong-Woo
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.1044-1053
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    • 2010
  • Transmitting correct train control information is important in a train control system which demands safety. The train control information includes the maximum speed of trains, position of preceding trains, incline of tracks and curve sections etc. A radio frequency-communication based train control system is influenced by the noise and interference because the train control information is transmitted by wireless between a on-board system and wayside system. The radio frequency-communication based train control system is a mobile communication system due to moving trains. The inter symbol interference(ISI) occurs by the multipath fading in the mobile ommunication system. As signal-to-noise ratio(SNR) is decreased by the ISI, the train control information is not received correctly. In case of tunnel section, numerous reflected waves exist. Therefore, the power density of receiver is decreased by difference among the received times, magnitudes, phases through the multipath. So, the train suddenly is stopped by the fail-safe operation in the train control system on account of decreasing the power density of receiver. In this paper, a line of sight model-(Additive White Gaussian noise(AWGN) channel), rayleigh and rician fading model are presented. Probability density functions which are related to the SNR are derived from the models. The fading phenomenon severely occurs as a result of analyzing the probability density functions. So, the space diversity method is used in order to reduce the fading effect and it is demonstrated by using Matlab program.

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Performance of pilot-based signal detection for digital IoT doorlock system (디지털 도어락 시스템을 위한 파일럿 기반 신호검출 성능)

  • Lee, Sun Yui;Hwang, Yu Min;Sun, Young Ghyu;Yoon, Sung Hoon;Kim, Jin Young
    • Journal of IKEEE
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    • v.22 no.3
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    • pp.723-728
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    • 2018
  • This paper proposes a signal detection method for IoT door lock system which is a new application field of VLC (Visible Light Communication). This paper describes the signal detection technique for user recognition that needs to be overcome in order to apply VLC to door lock system which has a demand for new technology due to security issue. This system has security and high signal detection characteristics because it uses existing infrastructure to communicate with visible light. In order to detect the signal using FFT, the signal of the user who accesses the authentication channel based on the pilot signal is detected, and the performance of the false alarm probability and detection probability is shown in the channel model.

The System Position from High Firing Rate of Anti-Aircraft Gun system (고발사율 대공포 발사에 따른 체계자세 연구)

  • Hwang, Boo Il;Lee, Boo Hwan;Kim, Chi Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.6
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    • pp.611-615
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    • 2015
  • Anti-aircraft gun system is used for low-level air defense system and has more than twin guns with high firing rate in order to maximize the capability of defense. Gun's vibration and bullet's variance has a critical effect on accuracy and hit probability of weapon system such as anti-aircraft gun system with high firing rate. Typical mechanism to reduce the amount of vibration and shock during gun-fire process is very important design factor. In this paper, the suspension characteristics of the vehicle are studied for the improvement of isolating performance of gun firing system with high firing rate. Gun fire test for the vehicle is conducted and computational models using Recurdyn and Adams are created based on test results. Through this study, results of computational analysis are compared with the real test results, which includes type, location and quantity of suspension and gun mechanism are selected for anti-aircraft gun. From the result of this study, we could make basic design and consider the proper component of the system such as suspension and gun spring.

Jamming Effect of Stand-Off Jammer to Main Lobe of LPI Radar (LPI 레이더에 대한 원격지원 재머의 주엽 재밍 효과)

  • Lim, Joong-Soo;Chae, Gyoo-Soo
    • Journal of Convergence for Information Technology
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    • v.10 no.3
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    • pp.16-21
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    • 2020
  • This paper describes the jamming characteristics of a stand-off jammer jamming the LPI radar. The LPI radar reduces the side lobes of the receiving antenna to reduce the effect of jamming. It is easy a radar to predict the effect of jamming on a self-protection jammer where the jammer is in the same position as the target. However, for stand-off jammer jamming at different locations from the target, the prediction of jamming effect is complex. In this paper, the jamming effect of LPI radar is analyzed using signal to jamming ratio and burn-through range. Also, when the antenna's side lobe decreases below -30 dB, the stand-off jamming effect in the side lobe direction is weak. So we proposed a new jamming method for the main lobe and analyzed the jamming effect. This study is expected to be useful for the design and operation of aircraft jammers.

Investigating on the Building of 'Mathematical Process' in Mathematics Curriculum (수학과 교육과정에서 '수학적 과정'의 신설에 대한 소고)

  • Park, Hye-Suk;Na, Gwi-Soo
    • Communications of Mathematical Education
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    • v.24 no.3
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    • pp.503-523
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    • 2010
  • The current mathematics curriculum are consist of the following domains: 'Characteristics', 'Objectives', 'Contents', 'Teaching and learning method', and 'Assessment'. The mathematics standards which students have to learn in the school are presented in the domain of 'Contents'. 'Contents' are consist of the following sub-domains: 'Number and Operation', 'Geometric Figures', 'Measures', 'Probability and Statistics', and 'Pattern and Problem-Solving' (Elementary School); 'Number and Operation', 'Geometry', 'Letter and Formula', 'Function', and 'Probability and Statistics' (Junior and Senior High School). These sub-domains of 'Contents' are dealing with mathematical subjects, except 'Problem-Solving' at the elementary school level. In this study, the sub-domain of 'mathematical process' was suggested in an equal position to the typical sub-domains of 'Contents'.

Physical Modelling for Consistent Reasonable Thought and Stock-Price Flow Patterns (합리적 생각의 물리적 모델링과 주가 흐름 패턴 분석)

  • Park, Sangup
    • New Physics: Sae Mulli
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    • v.68 no.12
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    • pp.1364-1373
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    • 2018
  • A recognizable form having meaning is called a sign in semiotics. The sign is transformed into a physical counter form in this work. Its internal structure is restricted on the linguistic concept structure. We borrow the concept of a mathematical function from the utility function of a rational personal in the economy. Universalizing the utility function by introducing the consistency of independency on the manner of construction, we construct the probability. We introduce a random variable for the probability and join it to a position variable. Thus, we propose a physical sign and its serial changes in the forms of stochastic equations. The equations estimate three patterns (jumping, drifting, diffusing) of possible solutions, and we find them in the one-day stock-price flow. The periods of jumping, drifting and diffusing were about 2, 3.5, and 6 minutes for the Kia stock on 11/05/2014. Also, the semiotic sign (icon, index, symbol) can be expected from the equations.

Efficiency calculation of the nMCP with 10B doping based on mathematical models

  • Yang, Jianqing;Zhou, Jianrong;Zhang, Lianjun;Tan, Jinhao;Jiang, Xingfen;Zhou, Jianjin;Zhou, Xiaojuan;Hou, Linjun;Song, Yushou;Sun, XinLi;Zhang, Quanhu;Sun, Zhijia;Chen, Yuanbo
    • Nuclear Engineering and Technology
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    • v.53 no.7
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    • pp.2364-2370
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    • 2021
  • The nMCP (Neutron sensitive microchannel plate) combined with advanced readout electronics is widely used in energy selective neutron imaging because of its good spatial and timing resolution. Neutron detection efficiency is a crucial parameter for the nMCP. In this paper, a mathematical model based on the oblique cylindrical channel and elliptical pore was established to calculate the neutron absorption probability, the escape probability of charged particles and overall detection efficiency of nMCP and analyze the effects of neutron incident position, pore diameter, wall thickness and bias angle. It was shown that when the doping concentration of the nMCP was 10 mol%, the thickness of nMCP was 0.6 mm, the detection efficiency could reach maximum value, about 24% for thermal neutrons if the pore diameter was 6 ㎛, the wall thickness was 2 ㎛ and the bias angle was 3 or 6°. The calculated results are of great significance for evaluating the detection efficiency of the nMCP. In a subsequent companion paper, the mathematical model would be extended to the case of the spatial resolution and detection efficiency optimization of the coating nMCP.

Automatic Generation of Aimpoints Using 3D Target Shapes and CEP (3차원 모델 형상과 원형공산오차를 고려한 목표점 자동 생성 기법)

  • Kang, Yuna
    • Journal of the Korea Society for Simulation
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    • v.28 no.2
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    • pp.71-79
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    • 2019
  • This research proposes an automatic generation system of aimpoints with considering 3D target shapes and CEP(circular error probability) values after determining a target and an azimuth value. In the past, users decided aimpoints manually based on experience or just chose a middle point of the 3D model. Futhermore, it was not possible to select a proper position with consideration of azimuth because users should decide aimpoints before the azimuth value was determined. To solve this problem, this research provides a automatic system to compute proper aimpoints with 3D target shapes, azimuth values and CEP. This article contains the explanation of 3 steps for generating aimpoints automatically: first, generating a reference plane and candidate entry points, then computing scores of each entry points and finally determining an aimpoint from the entry point with the highest score. Users can easily determine a final aimpoint with high probability of success using this system.