• 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.47-54
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• 2006

This work proposes a dual-channel 6b 1GS/s ADC for ultra wide-band communication system applications. The proposed ADC based on a 6b interpolated flash architecture employs wide-band open-loop track-and-hold amplifiers, comparators with a wide-range differential difference pre-amplifier, latches with reduced kickback noise, on-chip CMOS references, and digital bubble-code correction circuits to optimize power, chip area, and accuracy at 1GS/s. The ADC implemented in a 0.18um 1P6M CMOS technology shows a signal-to-noise-and-distortion ratio of 30dB and a spurious-free dynamic range of 39dB at 1GS/s. The measured differential and integral non-linearities of the prototype ADC are within 1.0LSB and 1.3LSB, respectively. The dual-channel ADC has an active area of $4.0mm^2$ and consumes 594mW at 1GS/s and 1.8V.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.13-20
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• 2008

This paper describes the design of low power 12bit Digital-to-Analog Converter(D/A Converter) using Pseudo-Segmentation method which shows the conversion rate of 80MHz and the power supply of 1.8V with 0.18um CMOS n-well 1-poly 6-metal process for advanced wireless communication system. Pseudo-segmentation method used in binary decoder consists of simple parallel buffer is employed for low power because of simpler configuration than that of thermometer decoder. Also, using deglitch circuit and swing reduced drivel reduces a switching noise. The measurement results of the proposed low power 12bit 80MHz CMOS D/A Converter shows SFDR is 66.01dBc at sampling frequency 80MHz, input frequency 1MHz and ENOB is 10.67bit. Integral nonlinearity(INL) / Differential nonlinearity(DNL) have been measured ${\pm}1.6LSB/{\pm}1.2LSB$. Glich energy is measured $49pV{\cdot}s$. Power dissipation is 46.8mW at 80MHz(Maximum sampling frequency) at a 1.8V power supply.

• Korean Institute of Interior Design Journal
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• v.19 no.5
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• pp.217-225
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• 2010

Today's public libraries in communities are on the processes of changes to integrate information and communication technology into traditional library system in order to support current users' demands for the new digital era. The purpose of this study is to examine the changing characters on space design and space uses of community based public libraries by conducting case studies of three branch libraries which were built after 2004 in Ann Arbor, Michigan in the United States. As the conclusion of this research, the findings of the case studies are utilized as basic data for planning and design guidelines for public libraries as community resources. The study summarizes the characteristics of space design and space uses in public libraries as follow; first, the floor plans of small-scale public libraries are open visually as well as spatially. The space organization of the libraries is arranged by potential noise levels, as placing noisy spaces near the entrance halls and quiet spaces at the back. Main book shelves are located in the middle of the library buildings, while seats are arranged along the window sides. By placing various kinds of furniture in open reading areas, library users can select different types of seats and tables for their comforts. Second. the survey of observation also finds that a large number of users often use library computers and personal computers to connect the internet at the libraries. These personal computer users who are new user group in community based libraries preferred to sit in casual study areas and individual tables with one or two seats only. Third, the libraries, in addition, develop and provide various programs and events for people in communities. Especially, the programs for children, the elderly and new comers from the abroad are well prepared, thus provide opportunities for them to visit the libraries in regular bases. The survey finds that family entertainment and leisure activities are the important parts of the program as well as renting music CD and movie DVD are also important reasons for people to come. Thus, the libraries prepare high quality children's space and CD shelves near the entrance hall.

• Korean journal of communication and information
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• v.74
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• pp.177-196
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• 2015

This paper aims to plan a new research program on the parallel relationship between Korean press and political power, by providing concepts on the mode of existence of professional journalists in Korea. In the midst of the economic crisis of Korean journalism, relative deteriorisation in the political democracy and the liberty of press, and changes in news ecosystem due to the revolution of digital news, the status of professional journalists is at stake. In these circumstances, this paper argues that many existing researches on journalistic professionalism need to be reconstructed in the perspective of professional project. It enables, first of all, an evaluation on actual issues of professional journalists from the actor perspective, i.e. economic interests, social closure, regulative bargain with the authority. Secondly, concerning decoupling phenomenon of journalism and democracy which became salient in the contemporary society, this study raises a necessity to create new logical relations around concepts of journalist professionalism. And we will find, in this situation, a beginning of new evaluation on the mode of existence of professional journalists, that has been possibly developped within the old, assymetric relationship between State-press. And finally, this study proposes to consider a category of professional journalists as a vehicle that helps to conceptualize the old, parallel relationship between Korean press and political power.

• Journal of the Institute of Convergence Signal Processing
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• v.12 no.4
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• pp.333-340
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• 2011

KJJVC(Korea-Japan Joint VLBI Correlator) was installed at the KJCC(Korea-Japan Correlation Center) and has been operated by KASI(Korea Astronomy and Space Science Institute) from 2009. KJNC is able to correlate the VLBI observed data through KVN(Korean VLBI Network), VERA(VLBI Exploration of Radio Astrometry), and JVN(Japanese VLBI Network) and its joint network array. And it is used exclusively as computer in order to process the observed data for the scientific purpose KJJVC used the VSI(VLBI Standard Interface) as the VLBI international standard at the data input-output specification between each component. Especially, for correlating the observed data, the data is transmitted with 1024Mbps speed between Mark5B high-speed playback and RVDB(Raw VLBI Data Buffer). The EMI(Electromagnetic lnterference), which is occurred by data transmission with high-speed, cause the data loss and the loss occurrence is frequently often for long transmission cable. Finally it will be caused the data recognition error by decreasing the voltage level of digital data signal. In this paper, in order to minimize the data loss by measuring the EMI noise level in transmission of the VSI specification, the 3 methods such as 1) RC filtering method, 2) lmpedance matching using Microstrip line, and 3) Signal buffering method using Differential line driver, were proposed. To verify the effectiveness of each proposed method, the performance evaluation was conducted by implementing and simulations for each method. Each proposed method was effectively confirmed as the high-speed data transmission of the VSI specification.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.307-314
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• 2011

A new predistortion technique for dynamic spectrum allocation systems such as cognitive radio (CR) is proposed. The system model considered in this paper occupies a small band at a time, but the center frequency can be changed in the wide range of frequency. In this scenario. the front-end filter may not eliminate the harmonics of the power amplifier (PA) output. The proposed PD reduces the spectral regrowth of the fundamental signal at the carrier frequency (${\omega}_0$) and removes the harmonics ($2{\omega}_0$, $3{\omega}_0$, ...) at the same time. The proposed PD structure is composed of multiple predistorters (PDs) centered at integer multiples of ${\omega}_0$. The PD at ${\omega}_0$ is for removing spectral regrowth of the fundamental signal, and the others are for harmonic reduction. In the proposed PD structure, parameters of PDs are found jointly. Simulation results show that the spectral regrowth can be reduced by 20dB, and the 2nd and 3rd harmonics can be reduced down to -70dB from the power of the fundamental signal.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.147-153
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• 2016

The lightning protection of information and communication facilities is very important factor to improve a reliability of the action of these equipment. Especially the transient potential rise of ground electrode being injected with the lightning current is to be a basic data of the dielectric strength for both power and communication facilities so that more accurate analysis should be required. The transient potential rise can be calculated from the ground impedance and the ground impedance is strongly dependent upon the shape of the ground electrode and the frequency-dependence of soil. The Debye's equation which is able to calculate the characteristics of dielectrics is used to analyze the frequency-dependent of soil. Also, the method to calculate the transient potential rise from the ground impedance is specified in this paper. In order to analyze the transient potential rise resulting from calculations with Debye's equation, TLM(transmission line method) and case of ${\rho}$(resistivity)-constant are simulated, respectively. The length of a horizontal ground electrode is 30 m and simulations were performed at 10, 100, $1000{\Omega}{\cdot}m$ with the standard lightning current waveform. In result, the transient potential rise of horizontal ground electrode calculating with Debye's equation is lower than it of other models.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.77-87
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• 2021

Smart Factory refers to a factory that can be controlled by itself with an intelligent factory that improves productivity, quality and customer satisfaction by combining the entire process of manufacturing and production with digital automation solutions. The manufacturing industry around the world is rapidly changing, with Germany, Europe, and the United States at the center. In order to cope with such changes, the Korean government is also implementing a policy to spread the supply of smart factories for small and medium-sized companies, and related ministries and agencies such as the Ministry of Commerce, Industry and Energy, the Ministry of SMEs and Venture Business, the Korea Institute of Technology and Information Promotion, and local technoparks, as well as large companies such as Samsung, SK and LG are actively investing in smart manufacturing projects to support smart factories[1]. Factory Automation (FA) construction has many issues regarding the connection of heterogeneous equipment. The most difficult aspect of configuring various communications from various equipment is the reason. Although it may not be known if there are standards or products made up of the same company, it is not easy to build equipment that is old, up-to-date, and different use environments through a series of communications. To solve this problem, we would like to propose a method of communication using Modbus, one of FieldBus, which is one of the many industrial devices of PLC, a representative facility control system, and is used as a communication standard.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.985-994
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• 2022

This study diagnoses the maturity level of local government's spatial information policy in the face of the digital transformation period. To this end, by using the stratification (AHP) analysis technique, for the spatial information expert group, the importance evaluation is performed along with the selection of measurement indicators of the level of spatial informatization. First, the current status and indicators in terms of spatial information policies of local governments are studied through theoretical considerations. In addition, by examining previous studies, differentiation from this study is presented. In this study, 3 indicators and 18 detailed items of spatial informatization level evaluation indicators could be selected. As a result of the evaluation, the overall importance ranking for the measurement index was 0.125 (12.5%) for the establishment and utilizations of GIS Systems provided by local governments, 0.109 (10.9%) for the quality management of basic spatial information, 0.107 (10.7%) for the establishment and utilization of its own spatial information. 0.073 (7.3%) for the collaboration and sharing within the institution, 0.071 (7.1%) for the operation of education and support system on spatial information, 0.065 (6.5%) for the securing a dedicated organization and professional human resources, and interest at the institutional level were derived in the order of 0.053 (5.3%). The results of this study are expected to be usefully utilized as basic data to evaluate the level of spatial information policies promoted by local governments. In addition, if the local government's spatial information policy is pursued centering on the major indicators derived from the study, it is expected that efficient policy operation will be possible.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.307-313
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• 2022

As the development of renewable energy expands internationally to cope with global warming and climate change, the share of wind power generation has been gradually increasing. Although wind farms can produce electric power for 24 h a day compared to solar power plants, Their interfere with the operation of nearby radars or communication equipment must be analyzed because large-scale wind power turbines are installed. This study analyzed whether a land radio station can receive sufficient signals when a ship sailing outside the offshore wind farm transmits distress signals on the VHF band. Based on the geographic information system digital map around the target area, wind turbine CAD model, and wind farm layout, the area of interest and wind farm were modeled to enable numerical analysis. Among the high frequency analysis techniques suitable for radio wave analysis in a wide area, a dedicated program applying physical optics (PO) and shooting and bouncing ray (SBR) techniques were used. Consequently, the land radio station could receive the electromagnetic field above the threshold of the VHF receiver when a ship outside the offshore wind farm transmitted a distress communication signal. When the line of sight between the ships and the land station are completely blocked, the strength of the received field decreases, but it is still above the threshold. Hence, although a wind farm is a huge complex, a land station can receive the electromagnetic field from the ship's VHF transmitter because the wave length of the VHF band is sufficiently long to have effects such as diffraction or reflection.