• Title/Summary/Keyword: Realtime System

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A Self-adjusting CN(Car Navigation) Algorithm on Digital Map using Traffic and Directional Information (디지탈 맵에서의 동적환경 적응형 차량 항법 알고리즘)

  • 이종헌;김영민;이상준
    • Journal of Internet Computing and Services
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    • v.3 no.6
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    • pp.35-41
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    • 2002
  • The Car Navigation System(CNS) requires lots of memory and calculating time because it works on the large and complex digital map. And the traffic circumstances vary time by time, so the traffic informations should be processed if we want to get mere realistic result. This paper proposes an effective path searching algorithm which uses less memories and calculating time by applying directional information between the starting place and destination place and by using realtime traffic informations.

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Robust Servo Control of High Speed Optical Pickups (고속 광 픽업 장치의 강인 서보 제어)

  • 임승철;정태영
    • Journal of KSNVE
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    • v.8 no.3
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    • pp.533-541
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    • 1998
  • Recently, optical disk drives are increasingly demanded to have higher speed as well as high information density, especially for applications like CD ROM drives. To this end, improvement of their optical pickup structure and control is recognized the very challenging issue. In this paper, the pickup is first analytically modelled in a plane to describe its coupled auto-focusing and auto-tracking motions. Subsequently, the model is linearized and combined with actuator dynamics for the auto-focusing system. With its unmeasurable parameters being estimated based on experimental data, an approximate I-DOF linear model is obtained neglecting the coupling term. To design the high speed and robust positional servo controller realistic design specifications are addressed, and H control method is employed based on the approximate model. Finally, taking the pickup in a commerical high speed CD ROM drive as an example performance of the designed controller is verified through realtime experiments.

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Development of a oscillating frequency measurement and adjustment system of a balance wheel of Mechanical Timer (기계식 타이머 밸런스 휠의 진동 주파수 측정 및 조정 장비의 개발)

  • Lee, D.J.;Park, S.B.;Ahn, J.H.
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.879-883
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    • 2000
  • A system for measuring and adjusting the oscillating frequency of a balance wheel whick determins the accuracy of mechanical timers. The balance wheel oscillates rotatively suspended by a hair spring which is welded at the other end to the pivot tube. The natural oscillatory frequency of the balance wheel is determined by the length of hairspring from the balance wheel to the point if other parameters the length in the torsional oscillation model are not changed, so the frequency of the balance wheel can be adjusted to meet a requirement by the adjustment of the hairspring length using ultrasonic welding. And the movement of wheel teeth is measured in realtime by a high speed photo fiber sensor and Auto Correlation is used to find a more accurate oscillation period from the measured signal with some variations.

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Applying Formal Methods to Modeling and Analysis of Real-time Data Streams

  • Kapitanova, Krasimira;Wei, Yuan;Kang, Woo-Chul;Son, Sang-H.
    • Journal of Computing Science and Engineering
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    • v.5 no.1
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    • pp.85-110
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    • 2011
  • Achieving situation awareness is especially challenging for real-time data stream applications because they i) operate on continuous unbounded streams of data, and ii) have inherent realtime requirements. In this paper we showed how formal data stream modeling and analysis can be used to better understand stream behavior, evaluate query costs, and improve application performance. We used MEDAL, a formal specification language based on Petri nets, to model the data stream queries and the quality-of-service management mechanisms of RT-STREAM, a prototype system for data stream management. MEDAL's ability to combine query logic and data admission control in one model allows us to design a single comprehensive model of the system. This model can be used to perform a large set of analyses to help improve the application's performance and quality of service.

A Realtime Parking lot Information System Using XML in Mobile Environments (모바일 환경에서의 XML을 이용한 실시간 주차정보시스템)

  • 김영돈;전현식;박현주
    • The Journal of Society for e-Business Studies
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    • v.9 no.2
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    • pp.123-143
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    • 2004
  • Nowadays, insufficient parking lots give rise to a serious problem. Cars are increased in geometrical progression, but parking lots that takes in cars are relatively limited. Often we spend a lot of time to look for a parking lot because of limited parking lot. To solve this problem, we can use real time parking lot information system provided from mobile vehicles. In this paper, we will tell you how to deliver the parking lot information in real time by construction wireless network environment to be provided real time information and making XML data that is easy to share and to exchange data between applications.

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Development and Implementation of Real Time Multibody Vehicle Dynamics Model (실시간 다물체 차량 동역학 모델 개발 및 구현)

  • O, Yeong-Seok;Kim, Seong-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.5
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    • pp.834-840
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    • 2001
  • A real time multibody vehicle dynamics model has been developed and implemented using a subsystem synthesis method based on recursive formulation. To verify real time simulation capability the developed model has been applied to HMMWV(High Mobility Multipurpose Wheeled Vehicle) with steering system. For the kinematically driven steering system, the coupled front suspension-steering subsystem can be decoupled into two SLA suspension subsystems, which improves the efficiency of simulation. To investigate theoretical efficiency, operational counting method has been also employed to compare the proposed model with the conventional recursive dynamics model. Various simulations such as unsymmetric bump run, step steering(J-turn) and sine steering input test have been carried out to verify the real time feasibility of the proposed model.

A Development on Induction Motor Drive Simulator using MATLAB Simulink (MATLAB Simulink를 이용한 유도전동기 구동 시뮬레이터 개발)

  • O Won-hyun;Kang Ho-Jin;Kim Jong-Sun;Shin Eun-Chul;Yoo Ji-Yoon;Kim Sung-Hwan;Park Tae-Sik
    • Proceedings of the KIPE Conference
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    • 2002.07a
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    • pp.217-221
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    • 2002
  • In this research a Matlab/Simulink/RTW - based on the realtime control system was developed for an induction motor vector control. On the Simulink window, the control system is designed In the form of block diagrams, program codes are produced automatically with the RTW(Real Time Workshop), then a DSP c compiler complies the program codes.

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Establishing PC-based Object-Oriented Urban Infrastructure Information System using GPS and TotalStation (GPS 및 Total Station을 이용한 PC용 개체지향 도시 기반 시설물 관리 시스템 구축)

  • 유상근;이규석
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.18 no.1
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    • pp.41-49
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    • 2000
  • This study was performed to establish PC-based Urban Infrastructure Information System(UIIS) using GPS and TotalStation as an alternative to UNIX-based UIIS. After carryig out this study, the following conclusions were derived: PC-based UIIS costs less time and money than UNIX-based UIIS. The coordinates of the control point of the site were obtained using DGPS, then based on this point, locational data were obtained using RTK GPS and TotalStation in the site with realtime data capture to enhance the accuracy of locational data. And image data were also entered into database together with the text data. So, the multimedia database is possible in UIIS.

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CNC System Improvement Research of NC Lathe Abrasion-Based on User Defined Module (NC선반 절삭공구마모 문제점 보정을 위한 CNC 성능개선 시스템 연구)

  • Park, Eun-Sik;Kim, Han-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.11 no.3
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    • pp.135-140
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    • 2008
  • This paper researched about Development Cutting Tool User Defined Module Based(PMCUDMS) on Simulation that was able to adapt themselves to rapid development of software and hardware to adopt. It is basic research that develops a scheme whereby technic make property. This paper theorized about to realize Cutting Tool User Defined Module Based on Simulation which is developing CNC Software flows from building Windows XP operating system's image that is possible realtime acting and multitasking to correct. And Cutting Tool User Defined Module Based on Simulation component which was consisted of basis OS, NC Code parser, Servo Motor Control, Simulator, Man-Machine Interface.

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A study on the Development of the Web-based collaborative WMS using RFID (RFID를 활용한 웹기반 협업 지원 창고관리시스템 개발에 대한 연구)

  • Lee Gwang-Ho;Park Je-Won;Choe Yun-Jeong;Lee Hui-Nam;Lee Gong-Seop;Lee Chang-Ho
    • Proceedings of the Safety Management and Science Conference
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    • 2005.05a
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    • pp.81-89
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    • 2005
  • The purpose of this study is to develop S/W of the web-based collaborative warehouse management system using RFID(Radio Frequency Identification). This S/W System supports the realtime inventory management and collaborative operations of relational companies in SCM. We look for benefits-reduce inventory levels, maxmize use of warehouse space, decrease the logistic cost, and increase competitive power of company, using this S/W

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