• Title/Summary/Keyword: digital communication system

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Physical principles of digital radiographic imaging system (디지털 방사선영상 시스템의 기본적 원리)

  • Choi, Jin-Woo;Yi, Won-Jin
    • Imaging Science in Dentistry
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    • v.40 no.4
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    • pp.155-158
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    • 2010
  • Digital radiographic systems allow the implementation of a fully digital picture archiving and communication system (PACS), and provide the greater dynamic range of digital detectors with possible reduction of X-ray exposure to the patient. This article reviewed the basic physical principles of digital radiographic imaging system in dental clinics generally. Digital radiography can be divided into computed radiography (CR) and direct radiography (DR). CR systems acquire digital images using phosphor storage plates (PSP) with a separate image readout process. On the other hand, DR systems convert X-rays into electrical charges by means of a direct readout process. DR systems can be further divided into direct and indirect conversion systems depending on the type of X-ray conversion. While a direct conversion requires a photoconductor that converts X-ray photons into electrical charges directly, in an indirect conversion, lightsensitive sensors such as CCD or a flat-panel detector convert visible light, proportional to the incident X-ray energy by a scintillator, into electrical charges. Indirect conversion sensors using CCD or CMOS without lens-coupling are used in intraoral radiography. CR system using PSP is mainly used in extraoral radiographic system and a linear array CCD or CR sensors, in panoramic system. Currently, the digital radiographic system is an important subject in the dental field. Most studies reported that no significant difference in diagnostic performance was found between the digital and conventional systems. To accept advances in technology and utilize benefits provided by the systems, the continuous feedback between doctors and manufacturers is essential.

Design of RF Digital Spectrum Analyser for Mobile Communication (이동 통신용 RF 디지털 스펙트럼 분석기 설계)

  • Woo, Kwang-Joon
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.6
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    • pp.29-34
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    • 2007
  • It is important to analyse the frequency spectrum for the measurement of modulated signal, distortion, and noise. The frequency spectrum analysis is performed by the execution of Radix-2 DIT DFT i.e. FFT algorithm. The discrete input signal converted by A/D converter from the input signal in time domain is mathematically transformed to the frequency spectrum by FFT algorithm. In this study, we design the digital spectrum analyser by the hardware based on the TMS320F2812 DSP and AD9244 converter, and by the software based on the C28x S/W modules. We can timely analyse the frequency spectrum in mobile communication system by the digital frequency analyser based on the high performance DSP and S/W modules. This real-time analysing capability is the important performance in the internet-based mobile communication server system.

A case study of digital intermediate space designed - The focus on the consumer community - (디지털 매개공간 유형에 관한 사례 연구 - 수용자 커뮤니티를 중심으로 -)

  • 서동진;임종훈
    • Korean Institute of Interior Design Journal
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    • no.29
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    • pp.281-288
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    • 2001
  • It shows 21st century as a networking society that is moving up the concept of global town and being industrialized with regional and personal connections. Individual's original idea and variety of 21th century may be respected by such environmental change, and age (Literary, human axis, technology axis, nature axis, kaining farming axis are central keyword) of culture that cultural capacity of individual becomes important fetters that create added value is forecasted to become. The moaning for space that is unemployment enemy by change of conceptional environment about cultural life and agreeable quality of life by development of Information-Communication technology may be required newly. As it does interaction along with development of science technique and Information-Communication technology, the future environment of various that complex! Is predicted to form network environment (existence space, cyberspace) newly. Human central interest is risen in technology balance hereupon, and these characteristic escaped in physical system that do with functional special quality and require human central and sensitive interaction. First, if examine about phenomenon by Digitize and chance aspect that is risen in 21th century, Digitize is time that action occurs fusion Tuesday that is various and Blur phenomenon of city·space, and the period to collapse the border between several individual. Second, importance more than man-centered and sensitive aspect of functional physical system is risen by digital age with development of technology medium, and as the five digital senses showed up, it suggests a sensual of the times and therefore the interest and direction get set up for the sensual sides of consumers. Third, special quality is, medium enemy by that digital space connotes meaning disk floret, variability, transparency, space red of extensity etc.. to burn and is digitalised, can be risen by symbolic, original individualities and emotional communication's the importance is required sensitivity enemy who is sympathy horn by fusion anger of individual. Technology of new media may open direction of new communication through interface that did not enjoy so far is going to supply new means that can express own to human

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A Study on the Filter Modeling of Fading Channel for Digital Transmission (디지털 전송을 위한 페이딩 채널의 필터 모델링에 관한 연구)

  • 임승각;김노환
    • KSCI Review
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    • v.2 no.1
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    • pp.55-67
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    • 1995
  • Recently, it is possible to high speed transmission of the non-voiced data, including voice, data, moving image instead of voice only in the past by changing the communication method to digital form from analog owing to the development of semiconductor and computer technology which for information transmission of the remote point. By doing so, we can get the improvement of the noise effect and low cost but the loss of transmission bandwidth. It is necessary to take some method in oreder to reducing the fading which is propotional to transmission bandwidth during the transmission of radio communication channel, especially. When we design the digital communication system, we must considered to the fading effect in order to determination of the transmitting power, modulation /demodulation method, transmission speed, bit error rate. This paper mainly concerns to the method to the channel simulator which descrives the fading effect during the transmission by computer model and digital filter modeling of the radio fading channel by unsing the transmitting and received signal. By taking the inverse of the characteristic of the modeled filter, it is possible to improvement of the communication system by reducing the distortion and inter-symbol interference which occurs in the channel.

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Development of User Interface for High Frequency Digital Oscilloscope based on Python (파이썬기반 고주파 디지털 계측기 사용자 인터페이스 개발)

  • Jeong, Eui-Hoon;Kim, Yong-Sik
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.6
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    • pp.37-42
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    • 2022
  • Recently, with the development of mobile communication technologies such as 5G, interest in oscilloscope technology based on high bandwidth and user-friendly UI is increasing. In this paper, we proposed a Python-based UI(user interface) SW for a high-bandwidth digital oscilloscope in connection with the study of a 13GHz band digital oscilloscope system. The proposed UI SW is designed not only to be executed integrally with the oscilloscope, but also to be run on a separate PC or laptop cooperating with the instrument through WiFi communication. Functions of the UI SW consists of displaying and analyzing signal data, storing signal data in an external storage device, generating test signal data, and reconfiguring the toolbar. Finally, we have shown that the proposed digital oscilloscope system operates normally by interworking test with the signal generator.

Digital-Radio Conversion System using Vector Synthesis Method (벡터합성방법에 의한 디지털-무선 변환시스템)

  • Joo Chang Bok;Kim Sung Ho
    • Journal of the Institute of Convergence Signal Processing
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    • v.1 no.2
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    • pp.131-137
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    • 2000
  • In this paper, as a compatible software radio transmission system, Digital-Radio conversion system which can directly change the digital signal generated by the logic circuit into radio signal is proposed. By the vector synthesis method, the digital signals can change directly into radio signal. If such a circuit is realized, RF circuit and an antenna can be composed by the simple one device, and the radio is directly controlled and performed by the software processing which is the essence of software radio. This Digital-Radio conversion system of this paper give many number of communication channels being offered by PN code and offer a hardware design flexibility by digitization, therefore it decrease the percentage ratio of hardware of system and give a more flexible function of software basis. In this paper, the principle of digital to radio signal generation algorithm is explained and the performance characteristics of proposed algorithm is shown in time base by the computer simulation method.

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A Scheduling System for MPEG-2 Digital Broadcasting (MPEG-2 디지털 방송을 위한 송출 스케줄링 시스템)

  • Bang, Jin-Suk;Hwang, Kyung-Min;Jung, Hoe-Kyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.2
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    • pp.240-246
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    • 2008
  • It has able to be possible that expression and store visual image from analog to digital without picture quality damaged via improvement of video compression technology. And also, It is possible to broadcasting digital image via transmission of digital image on MPEG-2 standardization. For this reason, the broadcasting business owners have converted broadcasting service from analog to digital. But, local SO(System Operator) has a difficult point which secure HD(High Definition) broadcasting program. In this paper, we designed and implemented Scheduling System for MPEG-2 Digital Broadcasting which gather HD broadcasting program from major broadcasting business owners and broadcast them.

Posture control of buoyancy sculptures using drone technology (드론 기술을 이용한 부력 조형물의 자세 제어)

  • Kang, Jingu
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.14 no.4
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    • pp.1-7
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    • 2018
  • The floating sculptures in the form of ad-ballon commonly used ropes in order to hold on. Relatively air flow is much less indoor than outdoor. Users of buoyancy sculptures hope to be able to maintain their desired posture without being fixed. This study applied drone technology to buoyancy sculptures. The drones can be moved vertically and horizontally, and the posture can be maintained, so buoyancy sculptures are easy to apply. Therefore, we have studied the control system of buoyancy sculpture using drone technology. Also, a control system that can maintain the desired posture at a constant height was studied. The overall shape was a light fiber material and helium gas for zero buoyancy to support the sculpture. The system configuration was STM32F103CB from ARM. In addition, the gyro and acceleration, geomagnetic sensors and motors are composed of small and medium size BLDC motors. The scheduling of the control system in the configuration of the control device was carefully considered. Because the role of the whole component becomes very important. The communication between the components is divided into the sensor fusion and the interface communication with the whole controller. Each communication technology is designed to expand. This study was implemented to actively respond from the viewpoint of posture control using the drone technology.

A System Architecture for Facility Fault Diagnosis and Repair Action in Smart Factory (스마트 팩토리에서 설비 장애 진단 및 조치 시스템 구조)

  • Cho, Jaehyung;Lee, Jaeoh
    • KNOM Review
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    • v.23 no.1
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    • pp.18-25
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    • 2020
  • Recently, a research on a smart factory was developed from a concept of factory automation(FA) to the formation of collecting and analyzing data. This trend is accelerated as the development of communication technology(5G) and IoT devices are developed in various ways according to the field situation. In addition, digital transformation has been actively conducted in the strengthening corporate competitiveness, and various optimization studies are being conducted through process re-adjustment by combining data received from various IoT equipment and automated facilities. Therefore, in this paper, we propose a system architecture and its related components in diagnosing and repairing facility failure using a prediction system which is one of the related researches.