• Title/Summary/Keyword: digital position acquisition

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Digital Position Acquisition Method of PET Detector Module using Maximum Likelihood Position Estimation (최대우도함수를 이용한 양전자방출단층촬영기기의 검출기 모듈의 디지털 위치 획득 방법)

  • Lee, Seung-Jae;Baek, Cheol-Ha
    • Journal of the Korean Society of Radiology
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    • v.15 no.1
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    • pp.1-7
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    • 2021
  • In order to acquire an image in a positron emission tomography, it is necessary to draw the position coordinates of the scintillation pixels of the detector module measured at the same time. To this end, in a detector module using a plurality of scintillation pixels and a small number of photosensors, it is necessary to obtain a flood image and divide a region of each scintillation pixel to obtain a position of a scintillation pixel interacting with a gamma ray. Alternatively, when the number of scintillation pixels and the number of photosensors to be used are the same, the position coordinates for the position of the scintillation pixels can be directly acquired as digital signal coordinates. A method of using a plurality of scintillation pixels and a small number of photosensors requires a process of obtaining digital signal coordinates requires a plurality of photosensors and a signal processing system. This complicates the signal processing process and raises the cost. To solve this problem, in this study, we developed a method of obtaining digital signal coordinates without performing the process of separating the planar image and region using a plurality of flash pixels and a small number of optical sensors. This is a method of obtaining the position coordinate values of the flash pixels interacting with the gamma ray as a digital signal through a look-up table created through the signals acquired from each flash pixel using the maximum likelihood function. Simulation was performed using DETECT2000, and verification was performed on the proposed method. As a result, accurate digital signal coordinates could be obtained from all the flash pixels, and if this is applied to the existing system, it is considered that faster image acquisition is possible by simplifying the signal processing process.

The renewal of digital map using LiDAR data. (LiDAR 자료를 이용한 수치지도 갱신)

  • 이원희;유기윤
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.04a
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    • pp.479-484
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    • 2003
  • The renewal of digital map takes much time and the manual process. LiDAR data allows reduction of time, automatic manner, and acquisition of the precise position. So it is used to renew the digital map of 1:5,000 scale. From the accuracy test results using aerial imagery and digitizing, renewal of digital map are feasible in automatic manner to some extent.

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A FPGA Design of Improved Acquisition System for DS-CDMA (DS-CDMA을 이용한 개선된 동기 획득 시스템의 FPGA 설계)

  • 박종우;조병록;송재철
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.67-70
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    • 1999
  • DS-CDMA is used to widely spread spectrum for a cellular mobile digital communication that maximizing users- capacity at the limited frequency bandwidth, solving technical matters with the channel. Especially, the capability of a spread spectrum receiver relied on fast code acquisition time at the demodulation. In this paper, we considered that fast code acquisition time when a spread spectrum system is designed, and existed code acquisition system set up one code epoch on a position at initial processing, but the proposed code acquisition system improved that two code epoch are set up at the same time, therefore code acquisition time is diminished in effect. The structure modeling to VHDL language. Its synthesized the synthesized and, is implemented FPGA chip

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A Study on the Adaptive Friction Compensator Design of a Hydraulic Proportional Position Control System (유압 비례 위치제어시스템의 적응 마찰력 보상기 설계에 관한 연구)

  • 이명호;박형배
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.6
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    • pp.77-83
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    • 2003
  • This paper deals with a position control problem of a hydraulic proportional position control system using a nonlinear friction compensation control. As nonlinear friction, stiction and coulomb friction forces are considered and modeled as deadzone and external disturbance respectively. In order to compensate this nonlinearities, we designed the controller which is the adaptive friction compensator using discrete time Model Reference Adaptive Control method in this paper. Digital Signal Processing board is employed for data acquisition and manipulation. The experimental results show that response is slow and steady-state error cannot be compensated properly without friction compensation but this compensator is effective to obtain fast response and good steady-state response.

Optimization Methodology of Quality Measurement of Digital Correlator (디지털 상관기 성능 측정의 최적화 기법)

  • Yeom, Jae-Hwan;Jeong, Goo-Young;Roh, Duk-Gyoo;Oh, Se-Jin;Kim, Kwang-Dong;Lee, Chang-Hoon
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.371-372
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    • 2006
  • In this paper, we propose a method that measures quality of digital correlator. Quality of digital correlator in field of image composition of radio astronomy have as important position for acquisition of radio wave image with high precision. Digital correlator should have wide bandwidth and high precision to study on deep space. Digital correlator, therefore, should be designed to have high speed processing and high precision. But, real time measurement of quality of digital correlator using acquisition data is difficult to compare accuracy of result because digital correlator should process a large quantity of data with high speed. Measurement method of quality, also, has intricate implementation of experiment equipment. this paper present methods that compose experiment equipment without external installation easily and verify quality of digital correlator perfectly.

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The prediction of floating position of human model after wearing life-jacket based on the three dimensional modeling (3차원 모델링을 통한 구명복 착용 후 부양자세 예측)

  • Bi, Chong-Song;Kim, Dong-Joon;Park, Jong-Heon;Min, Kyong-Cheol;Lee, Jae-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.3
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    • pp.257-266
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    • 2011
  • Recently, the manufacturers of life-jacket are very interested in the acquisition of USCG(US Coast Guard) approval because the acquisition of USCG approval has an important role in the purchasing decision of the buyer's. Be based on criterion of USCG, we studied how to predict the change of floating position of human model with life-jacket to verify the backside restore. For this, in this study, the human model and the lifejacket was modeled in three dimension, the application program for prediction of floating position was developed, and plugged-in commercial program.

A Study on 3D-Coordinate Extraction of Structure by Using The Digital Camera (디지털 카메라를 이용한 구조물의 3차원 좌표 추출에 관한 연구)

  • Kim, Kam-Lae;Kim, Hak-Joon;Park, Yong
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.10a
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    • pp.219-224
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    • 2003
  • Recently, the number of the use of Digital Photogrammetry is increasing, the Digital Photogrammetry is used for the acquisition of images, remote sensing and three dimension location. Especially, the three dimension location is more activated to use digital camera for the Digital Photogrammetry. The reason is that it is cheap and easy to use and also it has high confidence. Using non-metric digital camera not metric camera, in this research, to get images and apply the images to the Direct Liner Transformation which is one of the techniques in Digital Photogrammetry to get three dimensional location of a point. Ⅰ programmed the procedure with Visual C++ to get the position of points speedly and I tested possibility whether it can analyze the displacement and the existence of structure with measurement system which is structured by a inexpensive non-metric digital camera.

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On Study for the CIM By DAS(DATA Acquisition System) (CIM구축을 위한 생산현장의 정보화 사례연구)

  • Lee, Jong-Hyung;Lee, Youn-Heui
    • Journal of the Korean Society of Industry Convergence
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    • v.8 no.2
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    • pp.69-76
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    • 2005
  • This study for Customer Satisfaction(Customer Focus) by Profit security' in the field Process improvement activity and man-power upgrade by DAS(DATA Acquisition System) in the Plant that is fusion Off Line and On Line(IT), Especially the basic of the most foundation in the beginning Step of Toyota system is 3-jeong(a standard instrument; right volume, right box, right position), 5S(Seiri, Seiton, Seisoh, Seiketsu, Sitsuke ; KAISEN, KANBNA System(for Logistic), Further more KPC has established the digital environment such as CIM ; Computer Integrated Manufacturing), IMS ; Intelligent Manufacturing System ERP ; Enterprise Resource Planning, DAS; Data Acquisition System, Autonomous QC & SPC etc,.) in order to realize the intelligent informatization, which is core base for obtaining the competitive power and for responding to the various 21C management environment in flexibility. In this digital management environment, continuously and powerfully they would advance for becoming the best of the world. For strategic changes to take place in industry 3 key important factors need to be included ; Integration of tasks function and process, Decentralization of information, Responsibility, Finally simplification of products and product structures.

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Feasibility study of multiplexing method using digital signal encoding technique

  • Kim, Kyu Bom;Leem, Hyun Tae;Chung, Yong Hyun;Shin, Han-Back
    • Nuclear Engineering and Technology
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    • v.52 no.10
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    • pp.2339-2345
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    • 2020
  • Radiation imaging systems consisting of a large number of channels greatly benefit from multiplexing methods to reduce the number of channels with minimizing the system complexity and development cost. In conventional pixelated radiation detector modules, such as anger logic, is used to reduce a large number of channels that transmit signals to a data acquisition system. However, these methods have limitations of electrical noise and distortion at the detector edge. To solve these problems, a multiplexing concept using a digital signal encoding technique based on a time delay method for signals from detectors was developed in this study. The digital encoding multiplexing (DEM) method was developed based on the time-over-threshold (ToT) method to provide more information including the activation time, position, and energy in one-bit line. This is the major advantage of the DEM method as compared with the traditional ToT method providing only energy information. The energy was measured and calibrated by the ToT method. The energy resolution and coincidence time resolution were observed as 16% and 2.4 ns, respectively, with DEM. The position was successfully distributed on each channel. This study demonstrated the feasibility that DEM was useful to reduce the number of detector channels.

Friction Compensator Design of a Hydraulic Proportional Position Control System (유압 비례 위치제어 시스템의 마찰력 보상기 설계)

  • 이명호
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.4
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    • pp.130-135
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    • 1998
  • This paper deals with a position control problem of a hydraulic proportional position control system using a friction compensation control. There are many nonlinearities in hydraulic systems. With only proportional controller, response is slow and steady-state error cannot be compensated properly. Controller designed in this paper achieves fast transient response through the velocity and acceleration feedback and good steady-state response through the friction compensator. A/D and D/A board is employed for data acquisition and manipulation. The experimental results are compared with computer simulation results using Matlab.

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