• Title/Summary/Keyword: digital communication

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On the AGC Design of Wireless Communication Systems (무선통신 시스템에서 AGC 알고리즘 연구)

  • 예충일;김환우
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.6
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    • pp.567-572
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    • 2004
  • This paper shudies an automatic gain control(AGC) algorithm used in wireless communication cellular systems. The AGC design includes the selection of the appropriate analog-to-digital converter(ADC) and keeping the input power to the ADC constant to minimize the quantization noise generated from the analog-to-digital conversion process. In this paper the process to determine the required precision or the An is illustrated and the method to set the design parameters of the AGC is proposed. And the validity of the proposed algorithm is verified by computer simulation.

A Study on the Optimization of Inkjet Proofing for High Quality Offset Color Printing (고품질 오프셋 컬러인쇄를 위한 잉크젯 방식 교정인쇄에 최적화에 관한 연구)

  • Kim, Sung-Su;Kang, Sang-Hoon
    • Journal of the Korean Graphic Arts Communication Society
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    • v.24 no.2
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    • pp.69-78
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    • 2006
  • Proofing is one of the inspection operations of printing and can be considered a process control step. The three main kinds of proofs are press proofs, photomechanical proofs, and digital proofs. Photomechanical and digital proofs are also generally refered to as "off-press" proofs. Off-press color proofs are more economical than press proofs. Digital proofs offer fast production time along with a much lower cost per page. Hard-copy digital proofs can be output using thermal transfer printers, ink jet printers, and color laser copiers, as well as dye sublimation and electrophotographic technology. Ink jet method is commonly using because of the reasonal price. But ink jet system is difficult to reproduce an exact color proof. This research was carried out for the purpose of optimization of ink jet color proofing, using two kinds of ink jet printers with 6 colors (C, M, Y, K, mC, mM) and 4 colors (C, M, Y, K) system.

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A syudy of Algorithm using the method of HLMF and NCD on the 'Lak-seo nine palace' (HLMF 및 NCD 기법을 적용한 낙서구궁의 Algorithm에 관한 연구)

  • Han, Doung-Soo;Cho, Sung-Je
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.4 no.2
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    • pp.141-151
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    • 2011
  • This paper aim at producing a Digital Modeling of the science of divination using a study of a new method with a mathematical function on "Lak-seo nine palace". For that goal, we must study a new law of moving forward and a new common difference on 'Lak-seo nine place'. We call this "the method of HLMF and NCD". Therefore, When drawing up 'a plan of Lak-seo nine palace', we will provide convenience in the field, so we don't make it by handwrite, but will produce it by a digital mode.

Equalizationof nonlinear digital satellite communicatio channels using a complex radial basis function network (Complex radial basis function network을 이용한 비선형 디지털 위성 통신 채널의 등화)

  • 신요안;윤병문;임영선
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.9
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    • pp.2456-2469
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    • 1996
  • A digital satellite communication channel has a nonlinearity with memory due to saturation characeristis of the high poer amplifier in the satellite and transmitter/receiver linear filter used in the overall system. In this paper, we propose a complex radial basis function network(CRBFN) based adaptive equalizer for compensation of nonlinearities in digital satellite communication channels. The proposed CRBFN untilizes a complex-valued hybrid learning algorithm of k-means clustering and LMS(least mean sequare) algorithm that is an extension of Moody Darken's algorithm for real-valued data. We evaluate performance of CRBFN in terms of symbol error rates and mean squared errors nder various noise conditions for 4-PSK(phase shift keying) digital modulation schemes and compare with those of comples pth order inverse adaptive Volterra filter. The computer simulation results show that the proposed CRBFN ehibits good equalization, low computational complexity and fast learning capabilities.

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Spectral Analysis of Rectangular, Hanning, Hamming and Kaiser Window for Digital Fir Filter

  • Gautam, Ganesh;Shrestha, Surendra;Cho, Seongsoo
    • International journal of advanced smart convergence
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    • v.4 no.2
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    • pp.138-144
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    • 2015
  • Digital filters are extensively used in the world of communication. In order to design a digital finite impulse response (FIR) filter that satisfies all the required conditions is challenging. In this paper, design techniques of digital low pass FIR filters using Rectangular window method, Hamming window, Hanning window, and Optimal Parks McClellan method are presented. The stability, number of components required and filter coefficients are demonstrated for different design techniques. It is demonstrated that filter design using hamming window is comparatively better than rectangular and hanning window though the components required for all of the windowing technique are same, hamming shows higher stability. The stability is shown with the help of magnitude and phase spectrum of each window. Simulation is carried out using MATLAB and comparisons are made entirely based on the output of the simulation.

File Signature's Automatic Calculation Algorithm Proposal for Digital Forensic

  • Jang, Eun-Jin;Shin, Seung-Jung
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.3
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    • pp.118-123
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    • 2021
  • Recently, digital crime is becoming more intelligent, and efficient digital forensic techniques are required to collect evidence for this. In the case of important files related to crime, a specific person may intentionally delete the file. In such a situation, data recovery is a very important procedure that can prove criminal charges. Although there are various methods to recover deleted files, we focuses on the recovery technique using HxD editor. When recovering a deleted file using the HxD editor, check the file structure and access the file data area through calculation. However, there is a possibility that errors such as arithmetic errors may occur when a file approach through calculation is used. Therefore, in this paper, we propose an algorithm that automatically calculates the header and footer of a file after checking the file signature in the root directory for efficient file recovery. If the algorithm proposed in this paper is used, it is expected that the error rate of arithmetic errors in the file recovery process can be reduced.

Digital Outdoor Advertising Tecoration for the Metaverse Smart City

  • Yoo, Seung-Chul;Piscarac, Diana;Kang, Seungmi
    • International Journal of Advanced Culture Technology
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    • v.10 no.1
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    • pp.196-203
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    • 2022
  • Developing smart cities increasingly relies on metaverse technology. This has become much more apparent in the post-COVID-19 pandemic urban environment. The demand for fast processing of huge amounts of data and the convergence of various media types is essential for keeping city residents well-informed and safe. This paper builds on recent research on metaverse, smart cities, and digital outdoor advertising media. It proposes that "space culture media", which collectively functions by using physical or virtual spatial information, will play a key role in the smart city, functioning as an augmented city. Specifically, this paper deals with significant issues related to the smart city changes created by tecoration, a metaverse urban media space facilitated and enhanced through digital outdoor advertising.

Design and Implementation of APFS Object Identification Tool for Digital Forensics

  • Cho, Gyu-Sang
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.1
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    • pp.10-18
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    • 2022
  • Since High Sierra, APFS has been used as the main file system. It is a well-established file system that has been used stably thus far. From the perspective of digital forensics, there are still many areas to be investigated. Apple File System Reference is provided to the apple developer site, but it is not satisfactory to fully analyze APFS. Researchers know more about the structure of APFS than before, but they have not yet fully analyzed its structure to a perfect level about it. In this paper, we develop APFS object identification tool for digital forensics. The most basic and essential object identification and analysis of the APFS filesystem will be conducted with the tool. The analysis in this study serves as the background for an analysis of the checkpoint operation principle and structure, including the more complex B-tree structure of APFS. There are several options for the developed tool, but the results of two use cases will be shown here. Based on the implemented tool, it is hoped that more functions will be added to make APFS a useful tool for faster and more accurate analyses.

The Development Model of a non-rechargeable wrist-type smart-band for the vulnerable group

  • YU, Kyoungsung;SHIN, Seung-Jung
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.1
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    • pp.170-181
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    • 2022
  • We live in a digital age. Smartphones are used by everyone from children to the elderly. And many smart devices are pouring out and changing our daily life a lot. However, even in the development of this digital age, there are some marginalized groups. There are also those who are reluctant to expose their information in the digital age. They have difficulty making reservations on their smartphones, using payment systems, logging into the site using various authentication and verification procedures, and entering and leaving buildings. We still carry most IDs, seals, certificates, etc. in physical form. Those who use smartphones are enjoying the convenience of the times. However, among the underprivileged, the desire to pass everything with only one device is growing. In this study, the most suitable smart band model was proposed by collecting the Delphi survey and the opinions of the general public. Future research is required to improve practical usability and utility by developing cheaper and more convenient models.

Traveling to the Hangang River via Metaverse: Interaction Effects between Avatar Self-Congruence and Digital Age Type

  • Zong-Yi Zhu;Sumi Kim
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.21-30
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    • 2023
  • The aim of this study is to investigate how travelers' destination visit intentions are influenced by avatar self-congruence in the metaverse platform. We extended the impression management theory by considering both perceived enjoyment and social engagement, and illustrated the interaction effect based on users' digital age. To achieve this, we conducted an online survey with 302 users. The survey results revealed that avatar self-congruence significantly influenced users in terms of perceived enjoyment and social engagement, thereby affecting their destination visit intentions. This study also revealed a significant interaction effect between digital age type and avatar self-congruence on users' perceived enjoyment. The results of this study are expected to provide not only a theoretical reference for metaverse research and travel research but also managerial implications for destination management and metaverse applications.