• Title/Summary/Keyword: time-synchronization

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Stitching Method of Videos Recorded by Multiple Handheld Cameras (다중 사용자 촬영 영상의 영상 스티칭)

  • Billah, Meer Sadeq;Ahn, Heejune
    • Journal of Korea Society of Industrial Information Systems
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    • v.22 no.3
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    • pp.27-38
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    • 2017
  • This Paper Presents a Method for Stitching a Large Number of Images Recorded by a Large Number of Individual Users Through a Cellular Phone Camera at a Venue. In Contrast to 360 Camera Solutions that Use Existing Fixed Rigs, these Conditions must Address New Challenges Such as Time Synchronization, Repeated Transformation Matrix Calculations, and Camera Sensor Mismatch Correction. In this Paper, we Solve this Problem by Updating the Transformation Matrix Using Time Synchronization Method Using Audio, Sensor Mismatch Removal by Color Transfer Method, and Global Operation Stabilization Algorithm. Experimental Results Show that the Proposed Algorithm Shows better Performance in Terms of Computation Speed and Subjective Image Quality than that of Screen Stitching.

A study on the Performance Improvement in Trapping Signal Processing Method of RLG (RLG Trapping 신호처리 기법의 성능개선에 관한 연구)

  • Yoo, Ki-Jeong;Kim, Cheon-Joong;Shim, Kyu-Min
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.10
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    • pp.1003-1010
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    • 2008
  • In this paper, we propose the new method to decrease the navigation error by measurement time synchronization error in RLG Trapping signal processing. There are two methods to eliminate the dither motion in RLG. One is the stripping signal processing method. Another is the trapping signal processing method. This two methods have various error sources in measurement output. We perform the error modelling and analysis for the measurement time synchronization error between angular rate from RLG and acceleration from accelerometer in the trapping signal processing method. And we verify the navigation performance through simulation and experiment. Results of simulation and experiment show that the proposed method is very effective in decreasing the navigation error.

Design of Digital Governor Controller for Frequency Stability Improvement (주파수 안정도 개선을 위한 디지털 조속기 제어기 개발)

  • Lee, Sang-Hun;Choi, Sang-Gyu;Lee, Hwa-Chun;Song, Seung-Gun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.9
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    • pp.64-72
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    • 2012
  • The interest in wind power generation area such as developing and operating wind-diesel pilot complex in remote and island regions that have difficulty in having power plant and connecting to power system is growing rapidly in the world. We have installed and researched the hybrid system in Sekgok Pilot Complex to meet the new generation system. From the monitored data of the system, the performance of each diesel power plant is outstanding. However, step out problem was detected with respect to load sharing and synchronization with decentralized power supply. An advanced controller design having better response time and stability is needed to solve such problem. In this paper, we proposed the algorithm, through digital controller of Governor, which is applied to hybrid system. As a result, we obtained the stable frequency value in variable loading conditions. Also, we proved the advanced response time and stability through the simulation and experiment by applying additional current signal to the control algorithm.

Fault Diagnosis in Semiconductor Etch Equipment Using Bayesian Networks

  • Nawaz, Javeria Muhammad;Arshad, Muhammad Zeeshan;Hong, Sang Jeen
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.2
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    • pp.252-261
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    • 2014
  • A Bayesian network (BN) based fault diagnosis framework for semiconductor etching equipment is presented. Suggested framework contains data preprocessing, data synchronization, time series modeling, and BN inference, and the established BNs show the cause and effect relationship in the equipment module level. Statistically significant state variable identification (SVID) data of etch equipment are preselected using principal component analysis (PCA) and derivative dynamic time warping (DDTW) is employed for data synchronization. Elman's recurrent neural networks (ERNNs) for individual SVID parameters are constructed, and the predicted errors of ERNNs are then used for assigning prior conditional probability in BN inference of the fault diagnosis. For the demonstration of the proposed methodology, 300 mm etch equipment model is reconstructed in subsystem levels, and several fault diagnosis scenarios are considered. BNs for the equipment fault diagnosis consists of three layers of nodes, such as root cause (RC), module (M), and data parameter (DP), and the constructed BN illustrates how the observed fault is related with possible root causes. Four out of five different types of fault scenarios are successfully diagnosed with the proposed inference methodology.

Fault Tolerant Clock Management Scheme in Sensor Networks (센서 네트워크에서 고장 허용 시각 관리 기법)

  • Hwang So-Young;Baek Yun-Ju
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.9A
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    • pp.868-877
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    • 2006
  • Sensor network applications need synchronized time to the highest degree such as object tracking, consistent state updates, duplicate detection, and temporal order delivery. In addition, reliability issues and fault tolerance in sophisticated sensor networks have become a critical area of research today. In this paper, we proposed a fault tolerant clock management scheme in sensor networks considering two cases of fault model such as network faults and clock faults. The proposed scheme restricts the propagation of synchronization error when there are clock faults of nodes such as rapid fluctuation, severe changes in drift rate, and so on. In addition, it handles topology changes. Simulation results show that the proposed method has about $1.5{\sim}2.0$ times better performance than TPSN in the presence of faults.

Lot Planning & Scheduling in the Integrated Steelmaking Process

  • Park Hyungwoo;Hong Yushin
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2002.05a
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    • pp.109-113
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    • 2002
  • Steel industry is the most capital intensive and the largest energy consuming industry, which operate huge and complex facilities to supply various steel products as the primary materials to almost every manufacturing industry Major steel products are hot-rolled and cold-rolled coils, plates, and wires that are produced through molten iron making, molten steel making, casting, and rolling. Each process runs in batch between setups and the specifications or bach are different with each other High energy consuming and heavy material handling require careful synchronization or processes, as well. Considering the synchronization or processes, the lot planning and scheduling problem in the integrated steelmaking process rovers the roll grouping with given casts. the sequencing or rolls over time, and the machine assignment and time scheduling or charges and casts. The problem is investigated by dividing it into two cases whether single or parallel machines at the molten steel making and the continuous casting processes. Problem descriptions and solution approaches or each instance are introduced. To test their performance and conformity, implementation or the algorithms and numerical experiments are carried out with real world and constructed data sets.

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The Synchronization of ASEAN +3 Business Cycles: Prerequisites for Common Currency Union

  • RIYANTO, Feri Dwi;ERLANDO, Angga;HARYANTO, Tri
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.3
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    • pp.781-791
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    • 2021
  • This study aims to analyze the relationship between the business cycles of the ASEAN +3 countries. In addition, the effects of the spillover value on the coincident indicators are determined. This study employs secondary data and uses multivariate time series of five ASEAN countries, namely, Indonesia, Malaysia, Singapore, Thailand, and the Philippines. The proxy was the real gross domestic product (GDP) collected annually from the CEIC, the IMF, and the World Bank for the period from 1964 to 2016. The data was plotted against two time periods, 1964-1998 as the pre-crisis period, and 1999-2016 as the post-crisis period. The index data was changed to the base year 2010. The data was subsequently separated from the trends and the cyclic components. The cyclic components were obtained by using Hondrick-Prescott filter, and them were further analyzed. The analytical method used was Contemporaneous and Cross-Correlation tools. The results showed that, before and after the crisis, the value of the business cycle correlation between ASEAN +3 countries was stronger and moved together at the same level of lag value. The implication of this research was an initial finding of the ASEAN +3 countries' prerequisites for the formation of a common currency.

Code Acquisition of W-CDMA Signals by Double-Dwell Serial Search (이중적분 직렬검색을 이용한 W-CDMA 신호의 코드획득에 관한연구)

  • 김강온;차화준;전준수;김철성
    • Proceedings of the IEEK Conference
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    • 2000.06a
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    • pp.189-192
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    • 2000
  • In this paper, we consider a code acquisition of W-CDMA signals over multipath Rayleigh fading channel when double-dwell serial search code acquisition is used for initial synchronization. We derive the detection and false alarm probability, and mean acquisition time mathematically by taking into account of multiple H$\_$l/ cells and double-dwell serial search. It is noteworthy that the more the number of the post-detection integration, the shorter the mean acquisition time in low SNR.

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Code Acquisition of W-CDMA Signals Over Multipath Rayleigh Fading (다경로 레일리 페이딩 채널에서 W-CDMA 신호의 코드획득에 관한 연구)

  • 차화준;김강온;김철성
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.233-236
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    • 2000
  • In this paper, we consider a code acquisition of W-CDMA signals over multipath Rayleigh fading channel when double-dwell serial search code acquisition is used for initial synchronization. We derive the detection and false alarm probability, and mean acquisition time mathematically by taking into account of multiple H$_1$ cells and double-dwell serial search. It is noteworthy that the more the number of the post-detection integration, the shorter the mean acquisition time in low SNR.

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Implementation of a Line-voltage Sensorless Active Power Filter (입력전원 센서리스 능동형 전력필터의 구현)

  • Jeong, Gang-Youl
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.189-191
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    • 2005
  • This paper proposes an implementation of a line- voltage sensorless three-phase active power filter. The line synchronization for an active power filter does not require any additional hardware. It can be properly operated under various line-voltage variation. Current compensation is done in the time domain allowing fast time response. All control functions are implemented in software using a single-chip microcontroller, thus simplifying the control circuit. It is shown via experimental results that the proposed controller gives good performance for the line-voltage sensorless active power filter.

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