• Title/Summary/Keyword: digital communication systems

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A Study on Re-design of Quality Requirements for Disaster Communication Systems (재난통신 체계에 따른 품질요건 재설계에 관한 연구)

  • Yang, Jung-Mo;Kim, Jeong-Ho
    • Journal of Digital Convergence
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    • v.13 no.10
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    • pp.327-335
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    • 2015
  • Wireless mesh networks for public safety and disaster have been developing in a direction from TETRA(TErrestrial Trunked RAdio) to take advantage of the Public Safety-LTE(Long Term Evolution) technology. In Korea, the Disaster Safety Network Building Project has been promoted in order to unify disaster communication systems among disaster response agencies. In this study, the trends of the network construction for national disaster communication and corresponding representative cases of overseas have been analyzed. Through this process, the disaster communication area in line with the purpose of communications. As a result, the disaster communication can be divided into five distinctive areas: the control, the response, the on-site, the victim and the alarm communications. Based on the re-designed communication areas, quality requirements have also been re-organized in this study. Ultimately the construction method for the Disaster Communication systems without exclusion zone will be presented.

Chaotic Phenomena in Addiction Model for Digital Leisure

  • Bae, Youngchul
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.4
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    • pp.291-297
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    • 2013
  • Chaotic dynamics have been studied by many researchers in the fields of biology, physics, and engineering. Interest in chaos is also expanding to the social sciences such as politics, economics, and others, including the prediction of societal events. The concept of leisure has developed from a passive concept correlated with relaxation, entertainment, and ideology formation into a positive concept that assumes a more active role. As information and communications technology develops, digital leisure activity is expected to continue spreading. This expansion of digital leisure function correctly, as well as. Traditional leisure activity functions correctly more, whereas digital leisure activity is predicted to function incorrectly more often. In this paper, we propose a mathematical addiction model of digital leisure that deals with its dysfunctions such as addiction to digital leisure, including computer games, internet search, internet chatting, and social media. Herein, to solve addiction to digital leisure, we propose a model derived from a nicotine addiction.

Implementation of GPU System for SDR in WiBro Environment (WiBro 환경에서 SDR을 위한 GPU 시스템 구현)

  • Ahn, Sung-Soo;Lee, Jung-Suk
    • 전자공학회논문지 IE
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    • v.48 no.3
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    • pp.20-25
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    • 2011
  • We developed a method of accelerating the operation speed of communication systems for SDR(Software Defined Radio) systems in WiBro environment. In this paper, we propose a new scheme of using GPU(Graphics Processing Unit) for implementing the communication system which perform with the functionality of SDR. In general, communication systems is made by DSP(Digital Signalling Processor) or FPGA(Field Programmable Gate Array). However, in this case, there are exist the problem of implementation and debugging caused by each CPU characteristic. The GPU is optimized for vector processing because it usually consists of multiple processors and each processor in GPU is composed of a set of threads. We also developed Framework to use GPU and CPU resources effectively for reducing the operation time. From the various simulation, it is confirmed that GPU system have good performance in WiBro system.

The implementation of the Remote Control and Measurement Systems using CDMA Modem (CDMA 모뎀을 이용한 원격 제어 및 계측 시스템 구현)

  • Lee, Myung-Eui
    • Journal of Advanced Navigation Technology
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    • v.16 no.2
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    • pp.351-359
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    • 2012
  • This paper deals with the design and development of the remote control and measurement systems using CDMA(Code Division Multiple Access) data modem. We propose a bi-directional data communication link without the public IP address in CDMA modem device by the TCP/IP packet and SMS(Short Message Service) communication. The remote control and measurement systems are implemented by a Telit WM-800 modem as DCE(Data Communication Equipment), and Atmel AT89C51 microcontroller as DTE(Data Terminal Equipment). The user application software for the control and measurement system user, and the firmware software of device drivers for peripherals such as a digital input/output device, AD/DAC(Analog to Digital/Digital to Analog Converter), LCD, and temperature/humidity sensor are written in Microsoft C and Keil C language respectively for further various applications. The experimental result of the proposed control and measurement systems implemented in this paper is evaluated via real-time experiments, which works well as designed.

A Study on Sequential Digital Logic Systems and Computer Architecture based on Extension Logic (확장논리에 기초한 순차디지털논리시스템 및 컴퓨터구조에 관한 연구)

  • Park, Chun-Myoung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.2
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    • pp.15-21
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    • 2008
  • This paper discuss the sequential digital logic systems and arithmetic operation algorithms which is the important material in computer architecture using analysis and synthesis which is based on extension logic for binary logic over galois fields. In sequential digital logic systems, we construct the moore model without feedback sequential logic systems after we obtain the next state function and output function using building block T-gate. Also, we obtain each algorithms of the addition, subtraction, multiplication, division based on the finite fields mathematical properties. Especially, in case of P=2 over GF($P^m$), the proposed algorithm have a advantage which will be able to apply traditional binary logic directly.The proposed method can construct more efficiency digital logic systems because it can be extended traditional binary logic to extension logic.

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Protection Ratio between ATSC Digital Broadcasting and WiBro Systems (ATSC 디지털 방송시스템과 WiBro 시스템 간 보호비 도출 연구)

  • Lee, Hui-Soo;Kang, Dong-Hoon;Park, Hyo-Bae;Oh, Wang-Rok
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.11
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    • pp.61-65
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    • 2009
  • It is crucial to derive a protection ratio between two communication systems before deploying a new communication systems in the vicinity of frequencies occupied by the existing communication systems. In this paper, computer simulation based protection ratio estimating scheme between ASTC (Advanced Television Systems Committee) digital broadcasting systems and WiBro (Wireless Broadband Internet) systems is proposed. The proposed scheme can be effectively exploited when a new communication services are deployed in the surplus frequency band after the expiration of the analog television broadcasting scheduled in 2012 in Korea.

Design of Gateway for In-vehicle Sensor Network

  • Kim, Tae-Hwan;Lee, Seung-Il;Hong, Won-Kee
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2005.11a
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    • pp.73-76
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    • 2005
  • The advanced information and communication technology gives vehicles another role of the third digital space, merging a physical space with a virtual space in a ubiquitous society. In the ubiquitous environment, the vehicle becomes a sensor node, which has a computing and communication capability in the digital space of wired and wireless network. An intelligent vehicle information system with a remote control and diagnosis is one of the future vehicle systems that we can expect in the ubiquitous environment. However, for the intelligent vehicle system, many issues such as vehicle mobility, in-vehicle communication, service platform and network convergence should be resolved. In this paper, an in-vehicle gateway is presented for an intelligent vehicle information system to make an access to heterogeneous networks. It gives an access to the server systems on the internet via CDMA-based hierarchical module architecture. Some experiments was made to find out how long it takes to communicate between a vehicle's intelligent information system and an external server in the various environment. The results show that the average response time amounts to 776ms at fixec place, 707ms at rural area and 910ms at urban area.

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Development and Validation of a Digital Literacy Scale in the Artificial Intelligence Era for College Students

  • Ha Sung Hwang;Liu Cun Zhu;Qin Cui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.8
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    • pp.2241-2258
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    • 2023
  • This study developed digital literacy instruments and tested their effectiveness on college students' perceptions of AI technologies. In creating a new digital literacy test tool, we reviewed the concept and scale of digital literacy based on previous studies that identified the characteristics and measurement of AI literacy. We developed 23 preliminary questions for our research instrument and used a quantitative approach to survey 318 undergraduates. After conducting exploratory and confirmatory factor analysis, we found that digital literacy in the age of AI had four ability sub-factors: critical understanding, artificial intelligence social impact recognition, artificial intelligence technology utilization, and ethical behavior. Then we tested the sub-factors' predictive powers on the perception of AI's usefulness and ease of use. The regression result shows that the most common powerful predictor of the usefulness and ease of use of AI technology was the ability to use AI technology. This finding implies that for college students, the ability to use various tools based on AI technology is an essential competency in the AI era.

Interference Analysis of Digital HD Radio System considering Angular Effect (각도 효과를 고려한 디지털 HD Radio 시스템에서의 간섭 분석)

  • Kim, Joo-Seok;Jung, Won-Ho;Lee, Yong-Tae;Baek, Myung-Sun;Kim, Kyung-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.1
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    • pp.45-50
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    • 2012
  • In the current wireless communication technology, the digital radio system replaces the analog radio broadcasting. Since the in-band digital radio systems are used in the existing analog radio frequency band, interference problems of digital radio are caused. It is important to effectively analyze the interference. In this paper, to analyze SINR and BEP (bit error probability) of digital radio system, we propose the analysis method considering angular effect. The angular effect means a method to analyze the interference when the receiver is located in different directions around the transmitter. These results are able to give basic information for the allocation of digital radio networks.

A Design of Low Power Digital Matched Filter using Rounding for IMT-2000 Communication Systems (IMT-2000 통신시스템에서의 라운딩을 이용한 저전력 디지털 정합필터의 설계)

  • Park, Ki-Hyun;Ha, Jin-Suk;Nam, Ki-Hun;Cha, Jae-Sang;Lee, Kwang-Youb
    • Journal of IKEEE
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    • v.8 no.1 s.14
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    • pp.145-151
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    • 2004
  • For wide-band spread spectrum communication systems such as IMT-2000, a digital matched filter is a key device for rapid spreading code synchronization. Although a digital matched filter can be implemented easily, large power consumption at the higher chip rate and large summation delay of longer chip length are the bottleneck of practical use. In this paper, we propose a optimized partial correlation digital matched filter structure which can be constructed of the so-called generalized hierarchical Golay sequence. a partial correlation structure can reduce the number of correlators, but enlarge the size of flip-flops. In this paper, The proposed approach focuses on efficient circuit size, power dissipation, maintaining the operating throughput. A proposed digital matched filter reduce the size of flip-flops by rounding method. and it reduces about 45 percentages of power dissipation and chip area as compared with digital matched filter which is not rounded. rounding. The proposed architecture was verified by using Xilinx FPGA.

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