• 전자공학회논문지 IE
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• v.48 no.1
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• pp.30-35
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• 2011

In this paper, we propose a method to improve the performance of initial channel estimation (CE) for the multiband-OFDM (MB-OFDM) UWB. The performance of the initial CE can be generally improved as increasing the number of the used preamble symbols. The MB-OFDM specification presents two CE symbols per band in preamble format. The performance of CE estimation with two CE symbols may be satisfied in relatively high sensitivity -77.5 and -72.5 dBm for 200 Mbps and 480 Mbps data rate, respectively, but can not be enough in the degraded 55 Mbps and 110 Mbps sensitivities such as -83.5 and -80.5 dBm, respectively. A method proposed in this paper achieves the performance improvement by extending CE estimation region to packet synchronization (PS) symbols and frame synchronization (FS) symbols including two CE symbols. This can improve the CE performance in the degraded SNR and increase the link-margin by reducing the error rate in physical-layer header. The link-margin improvement obtained by the proposed CE preamble can induce the decrease of error-rate in physical-layer header and increase of communication throughput. Simulation results for the proposed initial method show that the performance is improved by about 0.7 dB at 10-4 bit-error-rate using '4' symbols than initial method using only two CE symbols.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.6
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• pp.17-26
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• 2008

In this paper, we propose a distributed multi-view video coding method employing illumination compensation for multi-view video coding. Distributed multi-view video coding (DMVC) methods can be classified either into a temporal or an inter-view interpolation-based ones according to ways to generate side information. DMVC with inter-view interpolation utilizes characteristics of multi-view videos to improve coding efficiency of the DMVC by using side information based on the inter-view interpolation. However, mismatch of camera parameters and illumination change between two views could bring about inaccurate side information generation. In this paper, a modified distributed multi-view coding method is presented by applying illumination compensation in generating the side information. In the proposed encoder system, in addition to parity bits for AC coefficients, DC coefficients are transmitted as well to the decoder side. By doing so, the decoder can generate more accurate side information by compensating illumination changes with the transmitted DC coefficients. We found that the proposed algorithm is $0.1{\sim}0.2\;dB$ better than the conventional algorithm that does not make use of illumination compensation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.7
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• pp.32-37
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• 2008

Satellite communication systems including the DVB-S2 (Digital Video Broadcasting - Satellite Version 2) system require operations under low signal-to-noise ratio (SNR) and large frequency offset values, and the initial frame synchronization process necessitates a robust correlation method. While a variety of conventional correlation structures exist for the initial synchronization, each method has different characteristics and performance in different channel environments. In this paper, we propose new correlation methods which exhibit enhanced performance in low SNR and large frequency offsets, and analyze their performance. The proposed methods use the magnitude sum and vector sum of extended differential correlation values, to maximize the correlation between the received signal and the synchronization sequence by using the spanned differential correlation result. The magnitude sum correlation method has better performance compared to conventional methods including the approximated ML (Maximum likelihood) method for SNR values below 4 dB with or without frequency offsets. The vector sum correlation method has improved performance over the magnitude sum method for channels with relatively small frequency offsets.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.135-148
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• 2020

The ongoing development of autonomous driving-related technology may cause different kinds of accidents while testing new changes. As a result, more information on ODD suitable for the domestic road environment will be necessary to prevent safety accidents. Besides, implementation of the Autonomous Vehicle Act will increase autonomous driving demonstrations on roads currently in use. This study describes an ODD for demonstrating an autonomous driving shuttle in downtown areas. It addresses a possible scenario of autonomous driving around a downtown road in Anyang. Geometric, operational, and environmental factors are considered while maintaining a domestic road environment and safety. Autonomous driving shuttles are demonstrated in 30 nodes, each identified by node type and signal-communication. Link criteria are an autonomous driving restriction in 42 morning peak (8-9am) hours, 39 non-peak (12-13pm) hours, and 40 afternoon peak (18-19pm) hours. In the future, conclusions may be considered for preliminary safety assessments of roads where autonomous driving tests are performed.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.1
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• pp.97-108
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• 2000

The purpose of this study was to assess the present status of the course content of Fundamental Nursing in accordance with the study objectives which were developed for the National Qualifying Examination by the first Faculty-Workshop in January, 1999 and the study objectives as related to other Nursing courses. The study sample included all schools of nursing and the members of the faculty for Fundamental Nursing of seventy schools(66.7%), out of the target population of 105, responded to a questionnaire which was developed by the research team. The collected data were analyzed by frequencies, percentages, means, and standard deviation using the SAS(Statistical Analysis System). The results are as follows : 1) According to this survey the course content of Fundamental Nursing as described in the study objectives for the National Examination, 223(86.77%) study objectives were included in the course of Fundamental Nursing by more than 70% of the schools of nursing, But twenty-three of the study objectives are not included by $30{\sim}50%$ of the schools of nursing. They consider this content to be taught in other courses. The study objectives, which less than 50% of the schools reported as being included in their course in Fundamental Nursing were, all study objectives for 'nursing assessment(communication)', 'nursing assessment (physical examination)', 'record and report', 'sex', and 'use of computer program for nursing diagnosis' and 'use of computerized nursing planning program' 2) Items that were not included in the study objectives for Fundamental Nursing but were included in course content for over 50% of the schools included, 'health of individual, family, community', 'change of nursing practice'. 'professionality of nursing' and all of the study objectives belonging to 'loss and grief' and 'nursing during all stages of surgical operations'. We hope that these results will be helpful in modifying the study objectives for the National Examination as developed by the first Faculty-Workshop and recommend the need for continuous survey research to produce content that is in accordance with study objectives and a National Examination that reflects the content of Fundamental Nursing.

• Journal of Digital Contents Society
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• v.16 no.5
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• pp.681-689
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• 2015

This study aims to survey the effectiveness of the international distance learning between Korean and Japanese university students. This research is based on NWCCDL (Namseoul-Waseda Cross-Cultural Distance Learning) project in the spring semester, 2015. This project is the cross-cultural distance learning project between N University in Korea and W University in Japan, and the most important thing of this project is that this project is manipulated through the utilization of ICT. This research consists with two parts: the first is to introduce the NWCCDL project; the participants' information, and the contents and procedure of the on-line chatting program, and BBS(Bulletin Board System) activities. The second is to review on the students' satisfaction for the project and the utilization of ICT in English language education context. The analytic results of the questionnaire includes the students' satisfaction on this project and their reflection on the effectiveness of using ICT in English language classroom of Korea. The results prove that the most of the students are satisfied with the NWCCDL Project in the spring semester, 2015 and the most of the students agree with the fact that the utilization of ICT is very effective in English language education of Korea.

• Journal of Digital Contents Society
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• v.16 no.5
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• pp.849-869
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• 2015

Since South Korean government pushed ahead with decentralization system in 1990s, each local government has developed 'local government's character' so that communication between local residents and between local government and residents could be going well for rural solidarity. Local governments have designed their sole symbolic characters, applied the characters to local specialities and tourist goods, and used the designed characters for the promotion of area. There is no difference between South Korea and Japan in the function of local government's character as above-mentioned details. However, 'Yuru-chara' characters which are designed by local governments in Japan are rising dramatically in the field of Japanese major characters. 'Yuru-chara' characters' name awareness is expanded to the entire area of Japan as well as the designed area. A remarkable difference in how to promote character rather than character design caused such a successful outcome. The local governments in Japan carried out a promotion for local residents in various, friendly, and active ways, utilized local government's character as a way to publicize the image of area, and turned the character into products to bring additional effects. In the above process, there was a remarkable difference between Japan and South Korea. The purpose of this study was to research detail data related to the characters of the local governments in Japan, to analyze the promotion of the characters, and to suggest a strategy for promoting the characters of the local governments in South Korea.

• Informatization Policy
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• v.18 no.3
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• pp.3-24
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• 2011

The purpose of this paper is to indicate possible future research directions for social network services(SNS) by reviewing past and recent trends in SNS studies. The framework used for the analysis is the New Media Evolutionary Model(NMEM) proposed by Wimmer and Dominick, a four-phase system for research on new media development. Although early forms of SNS emerged in the late 1990s, most research in this field has been published in the past five years. We searched for SNS-related articles published from 2006 to August 2011 from academic journal archives in information systems, communication, marketing, and other fields, and classified them according to the NMEM to analyze the current state of SNS research. Researchers in this field have so far focused on the first two phases of the model(the media itself and use of the media), but little research has been conducted on the third(effects of the media) and fourth phases(improvements in the media). Although SNS research is still in its early stages, we suggest the need for more studies on the effects of SNS and how it can be improved. Very few studies test existing theories or build new theories related to SNS. Thus, a more rigorous approach towards SNS research is warranted, and future research should focus on theory building and testing.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.4
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• pp.213-221
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• 2018

South Korea has been reluctant to open its geospatial information overseas to ensure security as a divided country. However, this cannot continue as the domestic and international environments related to geospatial information and the industrial ecosystem of information and communication technologies have been changing dramatically. Within this context, this study aims to analyze the causal relations among relevant variables and how they change and interact with time using a systems thinking process. First, causal maps were created for the domains of national security, map-based convergence service, and corporate competition. Then, the causal maps for each domain were integrated, based on which the points for policy intervention and dominant feedback loops were identified. The analysis results showed that securing the self-sufficiency of domestic geospatial businesses is a key element to determine the whole causal map, and the variable that changes the dominant feedback loop from a vicious circle to a virtuous one is the decision to open geospatial information overseas. In this study, I found the policy leverage that is a policy intervention point that can produce a great effect with little input by building a causal map of the interactions between major variables. This study is significant in that it identified and analyzed the dominant feedback loop as to which causal structure would dominate the system in the long term. The results of this study can be used to discuss not only the impacts of map data overseas opening on the national security and geospatial information industry, but also the interactions in the future when Google or other global companies request to release the geospatial information.

• International Journal of Railway
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• v.1 no.4
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• pp.143-148
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• 2008

This paper is the output of a collaborative European project concerning the barrier free accessibility for disabled persons to regional and long distance trains in Europe. Disabled people represent around 13% of the population in Europe. This is approximately 63 million people. The range of disabilities includes people with reduced mobility including wheel chair users, viewing and hearing impaired people and other forms of impairment. Improving accessibility aims at contributing to the provision of public transport services to all citizens in an equitable way. The purpose of the project was to analyse and to evaluate the existing solutions at selected European railways for all required modules at the entrance (doors, information and safety solutions), to derive a design concept, to develop a mock-up in meeting the needs of rail travellers with the above mentioned impairments and to test it with user groups. The project also aims at deriving components for the determination of standards. The EUPAX Design Mock-up test was performed to verify the advantages of the layout of the train segment including the different modules such as access area (including the access door, gaps between platform and train as well as boarding aid devices), entrance vestibule, information systems inside and outside the train, emergency facilities, toilet with all conveniences and the additional test arrangements regarding push buttons, steps and emergency equipment. For this purpose a questionnaire was developed for the assessment of the EUPAX segment and the additional test arrangements. With the help of this questionnaire it was possible to execute a quantitative and qualitative evaluation. During three test phases 67 experts and handicapped persons from 6 countries have evaluated the Industrial Design mock-up based on this questionnaire. The test group covered persons from North (Denmark) to the South (Italy) and from the West (Spain) to the Middle of Europe (Germany). This is especially important for the generalization (harmonisation) of the results for all European countries. According to COST 335 the information for people with reduced mobility should be clear, concise, accurate and timely. So that all information can be received from persons, they must be transferred on at least two of the three possible ways (acoustical, visual, tactile), a so called "2-sense-principle". Based on the results ergonomic specifications/ solutions for the ergonomic design of the access area, the acoustic, visual and tactile information and the emergency devices including the emergency communication system were developed, related to the benefiting passenger groups.