• Title/Summary/Keyword: digital communication system

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Design of an 1.8V 8-bit 500MSPS Low-Power CMOS D/A Converter for UWB System (UWB 시스템을 위한 1.8V 8-bit 500MSPS 저 전력 CMOS D/A 변환기의 설계)

  • Lee, Jun-Hong;Hwang, Sang-Hoon;Song, Min-Kyu
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.12 s.354
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    • pp.15-22
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    • 2006
  • In this paper, 1.8V 8-bit 500MSPS Low-power CMOS Digital-to-Analog Converter(DAC) for UWB(Ultra Wide Band) Communication Systeme is proposed. The architecture of the DAC is based on a current steering 6+2 full matrix type which has low glitch and high linearity. In order to achieve a high speed and good performance, a current cell with a high output impedance and wide swing output range is designed. Further a thermometer decoder with same delay time and low-power switching decoder for high efficiency performance are proposed. The proposed DAC was implemented with TSMC 0.18um 1-poly 6-metal N-well CMOS technology. The measured SFDR was 49dB when the output frequency was 50MHz at 500MS/s sampling frequency. The measured INL and DNL were 0.9LSB and 0.3LSB respectively. The DAC power dissipation was 20mW and the effective chip area was $0.63mm^2$.

The Government's Supporting Strategies to the Productive Prosumer Economy for the Successful Transition to the Fourth Industrial Revolution Era: Human Resource Development Perspectives for Solving Job problems (4차 산업혁명시대, 생산적인 프로슈머 이코노미로의 전환을 위한 정책제언: 일자리문제 해결을 위한 인적자원개발의 관점에서)

  • Lim, Ji-Sun
    • Informatization Policy
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    • v.24 no.2
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    • pp.87-104
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    • 2017
  • The Fourth Industrial Revolution, which is based on the development of information and communication technology (ICT), is expected to replace human knowledge work, which will cause problems of mass unemployment and wide income gap from job polarization. Furthermore, the change is expected to be rapid and wide, demanding proactive measures to respond to such abrupt social changes. However, previous literatures assume that the traditional form of employment will continue and provide limited solutions only. On the other hand, the Fourth Industrial Revolution will enable transition to the Prosumer Economy, which will ultimately lead consumers to become producers through increased job flexibility. If the prosumer economy arrives and the consumers become producers, it will no longer be the matter of finding workplace but rather, the matter of finding the work itself. In this regard, the new technologies of the Fourth Industrial Revolution can be the fundamental solution to such job issues. This paper suggests stable transition to the Prosumer Economy in order to solve the job issues in the age of the Fourth Industrial Revolution. In order to effectively support the process, this paper suggests first, ensuring the amount of education by shortening labor time; second, facilitating life-time education through free online education service; and third, closing the digital divide through mandatory use of the e-government system.

Development of Android Smartphone App for Corner Point Feature Extraction using Remote Sensing Image (위성영상정보 기반 코너 포인트 객체 추출 안드로이드 스마트폰 앱 개발)

  • Kang, Sang-Goo;Lee, Ki-Won
    • Korean Journal of Remote Sensing
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    • v.27 no.1
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    • pp.33-41
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    • 2011
  • In the information communication technology, it is world-widely apparent that trend movement from internet web to smartphone app by users demand and developers environment. So it needs kinds of appropriate technological responses from geo-spatial domain regarding this trend. However, most cases in the smartphone app are the map service and location recognition service, and uses of geo-spatial contents are somewhat on the limited level or on the prototype developing stage. In this study, app for extraction of corner point features using geo-spatial imagery and their linkage to database system are developed. Corner extraction is based on Harris algorithm, and all processing modules in database server, application server, and client interface composing app are designed and implemented based on open source. Extracted corner points are applied LOD(Level of Details) process to optimize on display panel. Additional useful function is provided that geo-spatial imagery can be superimposed with the digital map in the same area. It is expected that this app can be utilized to automatic establishment of POI (Point of Interests) or point-based land change detection purposes.

The Study on the Influence of Domestic Credit Card Design Elements on Credit Card Selection -Focusing on 30, 40 Housewives- (국내 신용카드디자인요소가 신용카드 선택에 미치는 영향에 관한 연구 -전업주부 30, 40대를 중심으로-)

  • Cho, Hye-Ryung;Kim, Seung-In
    • Journal of the Korea Convergence Society
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    • v.8 no.11
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    • pp.263-269
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    • 2017
  • Credit card holders are showing a higher level of psychology to show their identity beyond the means of payment. The purpose of this study is to investigate which design factors affect the 30th and 40th generation housewives when issuing credit cards. A total of 200 people in the 30s and 40s housewives who live in Seoul and the metropolitan area were selected from among the customers who use the credit card, and the effect of the design factors of the domestic credit card on the selection of the credit card, Based on previous studies, questionnaires were prepared and surveyed. As a result of the survey, it was found that the color design of the credit card design element was the achromatic system and the main image was the simple design which only used the color without emphasizing the image or the logo, and then the character type was preferred. I prefer not to have a card decoration, and I have found that a metal-like card material is the most preferred. Through this, I would like to suggest directions for the design development for 30 and 40 housewives in credit card companies.

Implementation of Stopping Criterion Algorithm using Variance Values of LLR in Turbo Code (터보부호에서 LLR 분산값을 이용한 반복중단 알고리즘 구현)

  • Jeong Dae-Ho;Kim Hwan-Yong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.9 s.351
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    • pp.149-157
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    • 2006
  • Turbo code, a kind of error correction coding technique, has been used in the field of digital mobile communication system. As the number of iterations increases, it can achieves remarkable BER performance over AWGN channel environment. However, if the number of iterations is increased in the several channel environments, any further iteration results in very little improvement, and requires much delay and computation in proportion to the number of iterations. To solve this problems, it is necessary to device an efficient criterion to stop the iteration process and prevent unnecessary delay and computation. In this paper, it proposes an efficient and simple criterion for stopping the iteration process in turbo decoding. By using variance values of LLR in turbo decoder, the proposed algerian can largely reduce the average number of iterations without BER performance degradation in all SNR regions. As a result of simulation, the average number of iterations in the upper SNR region is reduced by about $34.66%{\sim}41.33%$ compared to method using variance values of extrinsic information. the average number of iterations in the lower SNR region is reduced by about $13.93%{\sim}14.45%$ compared to CE algorithm and about $13.23%{\sim}14.26%$ compared to SDR algorithm.

An Effective Mitigation Method on the Signal-Integrity Effects by Splitting of a Return Current Plane (귀환 전류 평면의 분할에 기인하는 신호 무결성의 효과적인 대책 방법)

  • Jung, Ki-Bum;Jun, Chang-Han;Chung, Yeon-Choon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.3
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    • pp.366-375
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    • 2008
  • Generally a return current plane(RCP) of high speed digital and analog part is partitioned. This is achieved in order to decrease the noise interference between subsystem in PCBs(Printed Circuit Boards). However, when the connected signal line exists between each sub system, this partition will cause unwanted effects. In a circuital point of view, RCP partition has a bad influence upon signal integrity. In a EMI(Electromagnetic Interference) point of view, the partition of the return current plane becomes a primary factor to increase the radiated emission. Component bridge(CB) is usecl for the way of maintaining signal integrity, still specific user's guide doesn't give sufficient principle. In a view point of signal integrity, design principle of multi-CB using method will be analyzed by measurement and simulation. And design principle of noise mitigation will be provided. Generally interval of CB is ${\lambda}/20$ ferrite bead. In this study. When multi-CB connection is applied, design principle of ferrite bead and chip resistor is proved by measurement and simulation. Multi-connected chip resistance$(0{\Omega})$ is proved to be more effective design method in the point of signal integrity.

Analysis on designer's cognitive thinking process in 3D animation design (3D 애니메이션 제작을 위한 디자이너의 인지적 사고과정 분석)

  • Kim, Kie-Su
    • Cartoon and Animation Studies
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    • s.20
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    • pp.1-14
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    • 2010
  • The success of a three-dimensional blockbuster movie, AVARTA, brought an public attention on the expansion of three-dimensional computer applications, and it allows experts predict further hardware technology developments to support the such applications. Futhermore, an internet based infra structure and three-dimensional structure, third generation network community, advanced computer networks have influenced advancement in computer technology within the 3D game industry and the spread of 2D computer animation technologies. This advancement of computer technologies allow the industry to overcome a limitation of generating cultural design contexts existed within 2D network community. However, despite of the expansion of 2D and 3D computer technologies, a limitation of analysing designers' intentions on morphology of digital contents and user interface still exists. Therefore, the purpose of this study is to analyze (1) present conditions of the 3D industry and (2) protocols of designers' cognitive design processes based on their design communication, contents, and tools. Analysis was conducted based on literature reviews and case precedent analyses. For the analysis, a 2D Avarta sketch character was designed and then applied into a 3D game system. Observations how designers solve cultural problem within the structure via Avarta were conducted. Outcomes were then coded for further analysis.

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Cooperative Multi-Agent Reinforcement Learning-Based Behavior Control of Grid Sortation Systems in Smart Factory (스마트 팩토리에서 그리드 분류 시스템의 협력적 다중 에이전트 강화 학습 기반 행동 제어)

  • Choi, HoBin;Kim, JuBong;Hwang, GyuYoung;Kim, KwiHoon;Hong, YongGeun;Han, YounHee
    • KIPS Transactions on Computer and Communication Systems
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    • v.9 no.8
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    • pp.171-180
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    • 2020
  • Smart Factory consists of digital automation solutions throughout the production process, including design, development, manufacturing and distribution, and it is an intelligent factory that installs IoT in its internal facilities and machines to collect process data in real time and analyze them so that it can control itself. The smart factory's equipment works in a physical combination of numerous hardware, rather than a virtual character being driven by a single object, such as a game. In other words, for a specific common goal, multiple devices must perform individual actions simultaneously. By taking advantage of the smart factory, which can collect process data in real time, if reinforcement learning is used instead of general machine learning, behavior control can be performed without the required training data. However, in the real world, it is impossible to learn more than tens of millions of iterations due to physical wear and time. Thus, this paper uses simulators to develop grid sortation systems focusing on transport facilities, one of the complex environments in smart factory field, and design cooperative multi-agent-based reinforcement learning to demonstrate efficient behavior control.

Scattering Characteristic from Building Walls with Periodic and Random Surface (규칙적 또는 불규칙적 구조를 가지는 빌딩벽면에서의 전자파 산란 특성)

  • 윤광렬
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.4
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    • pp.428-435
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    • 2004
  • With the rapid and wide-spread use of cellular telephones much attention has been focussed on propagation in the urban area crowed with buildings and houses. It is often surrounded by hills, forests, and mountains. The importance of surface scattering intereference between transmitters and receivers on the rough surfaces has been interested and investigated. Therefore, a prediction method is necessary to estimate the influence of rough surfaces on microwave radio propagation. Moreover, most of the mobile communications are performed based on the digital communication system rather than the analog one. In this case, we must pay more careful attention to the signal delay caused by the phase delay due to the multi-path propagation. In this paper we have analyzed numerically scattering of electromagnetic waves from building walls by using FVTD(Finite Volume Time Domain) method. We consider three different types of rough surfaces such as periodic, random, and composite structures. We calculate the bistatic normalized radar cross section (NRCS) for horizontal and vertical polarization, and we take account of the conventional optical reflection which corresponds to the n-th Bragg reflection for periodic structures. In addition, we investigated what conditions are needed in order to be able to ignore the higher order Bragg reflection for the periodic structures.

Implementation of Stopping Criterion Algorithm using Sign Change Ratio for Extrinsic Information Values in Turbo Code (터보부호에서 외부정보에 대한 부호변화율을 이용한 반복중단 알고리즘 구현)

  • Jeong Dae-Ho;Shim Byong-Sup;Kim Hwan-Yong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.7 s.349
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    • pp.143-149
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    • 2006
  • Turbo code, a kind of error correction coding technique, has been used in the field of digital mobile communication system. As the number of iterations increases, it can achieves remarkable BER performance over AWGN channel environment. However, if the number of iterations is increased in the several channel environments, any further iteration results in very little improvement, and requires much delay and computation in proportion to the number of iterations. To solve this problems, it is necessary to device an efficient criterion to stop the iteration process and prevent unnecessary delay and computation. In this paper, it proposes an efficient and simple criterion for stopping the iteration process in turbo decoding. By using sign changed ratio of extrinsic information values in turbo decoder, the proposed algorithm can largely reduce the average number of iterations without BER performance degradation. As a result of simulations, the average number of iterations is reduced by about $12.48%{\sim}22.22%$ compared to CE algorithm and about $20.43%{\sim}54.02%$ compared to SDR algorithm.