• 한국통신학회논문지
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• 제22권11호
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• pp.2459-2469
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• 1997

본 논문에서는 다단계 반경-지향 알고리듬을 이용한 Fractionally Spaced(FS) 둥화기에 구성한다. Fractionally Spaced 등화기는 수신 신호를 심볼율보다 빠르게 표본화하여 처리하므로 표본화 순간에 민감하지 않는 특성을 갖는다. 다단계 반경-지향 얄고리듬을 적용한 Fractionally Spaced 등화기는 일반적인 블라인드 알고리듬을 적용 한 경우보다 Fractionally Spaced 등화기의 특성을 그대로 유지하연서 빠른 수렴 속도에서나 수렴 후 적은 자승 평균을 갖는다. 또한 여러개의 심볼율 동화기를 독립적으로 동작시키도록 구성된 다중 모델 Fractionally Spaced 블라인드 등화기에 다단계 반경-지향 알고리듬을 적용하면 빠른 수렴 속도를 얻는다.

• 한국IT서비스학회지
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• 제16권4호
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• pp.223-234
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• 2017

The audible pedestrian signal (APS) is an add-on device which connects to the pedestrian signaling device and informs the contents and changes of the signaling by sound. It provides walking direction information of the pedestrian crossing so that the blind people can safely cross the pedestrian crossing. In an intersection where a plurality of audible pedestrian signal (APS) are installed at an intersection crosswalk, existing audible pedestrian signal (APS) operate simultaneously in the communication radius of a wireless remote controller, which may cause confusion for the blind people and the public may complain about the noise. In this paper, we developed a BLE (Bluetooth Low Energy)-based audible pedestrian signal (APS) system capable of supporting two-way communications with a smart-phone that can cross the intersection safely and improve the walking comfort and traffic safety for the blind people. The proposed method is a method in which the BLE beacon communication based audible pedestrian signal (APS) presents active service to the blind people, and the existing audible pedestrian signal (APS) is a way of requesting the passive service by the blind people with the wireless remote control by the unidirectional communication based on 358Mhz. The developed system is installed in the crossroad of Doma-dong, Seo-gu, Daejeon, and it is tested and operated by the blind people. The satisfaction evaluation and analysis of the audible pedestrian signal (APS) for the blind people have good results and are planned to be expanded in the future.

• 수산해양기술연구
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• 제53권2호
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• pp.187-195
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• 2017

We have studied the efficient operation of the radar and the appropriateness of the installation location, when constructing the VTS system. As the Civil-Military Complex Harbour (Kangjeong Port) is completed in 2016, we set the control area within 10 nautical miles centering on Kangjeong Port, and found out and removed the operational radar blind area of VTS system to provide safe navigation information for vessels that navigating this area. Assuming that two international cruise ships entering at the same time, we performed the radar simulation and compared the images by considering the three sites of Kangjeong Port, Miaksan and Seoguipo Port. Simulation results for a single radar installed at Kangjung Port indicate that the blind area was largely affected by two large cruise ships and the surrounding islands. The blind area due to Kogunsan was considerably large when installed in Miaksan, but the blind area due to the influences of Beomseom, Moonseom and Seopseom was negligibly large. It seems that additional radar installation is necessary as a complementary solution to solve this blind area. When two radars were installed at Miaksan and Kangjeong Port, the residual blind area due to the Seopseom was $0.25km^2$ at 0.1~0.33 nautical miles in the southeast direction from Seopseom. In addition, the remaining blind area with two cruise ships mutually influenced was $0.18km^2$, which did not occur with a single cruise ship.

• Journal of Information Science Theory and Practice
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• 제1권2호
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• pp.69-83
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• 2013

This paper aims to determine the preference and use of electronic information and resources by blind/visually impaired users in the leading National Capital Region (NCR) libraries of India. Survey methodology has been used as the basic research tool for data collection with the help of questionnaires. The 125 in total users surveyed in all the five libraries were selected randomly on the basis of willingness of the users with experience of working in digital environments to participate in the survey. The survey results were tabulated and analyzed with descriptive statistics methods using Excel software and 'Stata version 11'. The findings reveal that ICT have a positive impact in the lives of people with disabilities as it helps them to work independently and increases the level of confidence among them. The Internet is the most preferred medium of access to information among the majority of blind/visually impaired users. The 'Complexity of content available on the net' is found as the major challenge faced during Internet use by blind users of NCR libraries. 'Audio books on CDs/DVDs and DAISY books' are the most preferred electronic resources among the majority of blind/visually impaired users. This study will help the library professionals and organizations/institutions serving people with disabilities to develop effective library services for blind/visually impaired users in the digital environment on the basis of findings on information usage behavior in the study.

• ETRI Journal
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• 제26권2호
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• pp.101-111
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• 2004

This paper presents a near-optimum blind decision feedback equalizer (DFE) for the receivers of Advanced Television Systems Committee (ATSC) digital television. By adopting a modified trellis decoder (MTD) with a trace- back depth of 1 for the decision device in the DFE, we obtain a hardware-efficient, blind DFE approaching the performance of an optimum DFE which has no error propagation. In the MTD, the absolute distance is used rather than the squared Euclidean distance for the computation of the branch metrics. This results in a reduction of the computational complexity over the original trellis decoding scheme. Compared to the conventional slicer, the MTD shows an outstanding performance improvement in decision error probability and is comparable to the original trellis decoder using the Euclidean distance. Reducing error propagation by use of the MTD in the DFE leads to the improvement of convergence performance in terms of convergence speed and residual error. Simulation results show that the proposed blind DFE performs much better than the blind DFE with the slicer, and the difference is prominent at the trellis decoder following the blind DFE.

• 인지과학
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• 제18권4호
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• pp.351-370
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• 2007

본 연구는 두 정신물리학 실험을 통하여 상향적(bottom-up) 정보와 하향적(top-down) 정보가 맹점 채우기에 미치는 영향을 검증하였다. 두 실험 모두에서 맹점에 채워질 가능성이 동일한 두 자극을 맹점에 제시하였다. 이 두 자극이 맹점을 채우기 위해 경쟁할 때, 그 중 한 자극의 깊이 맥락을 조작하여 상향적 요인과 하향적 요인의 상호작용을 살펴보았다. 깊이 맥락은 맹점에 채워지는 자극들과 맹점 주변부 자극들 간의 상대적인 깊이로 정의되었으며, 실험 참가자들은 맹점에서 채워진 표적의 지각적 깊이를 보고하였다. 실험 결과, 맹점이 상향적 정보만 가진 자극보다 하향적 정보인 깊이 맥락이 첨가된 자극으로 대부분 채워졌다는 사실을 발견하였다. 통제 실험을 통하여 이러한 깊이 지각은 맹점이 위치한 주변시의 해상력 때문은 아닌 것으로 밝혀졌다. 위와 같은 실험 결과는 깊이 맥락정보와 같은 하향 처리 과정도 맹점 채워 넣기 과정에 영향을 미친다는 것을 시사한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5537-5555
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• 2017

Having the characteristics of unlinkability, anonymity, and unforgeability, blind signatures are widely used for privacy-related applications such as electronic cash, electronic voting and electronic auction systems where to maintain the anonymity of the participants. Among these applications, the blinded message is needed for a certain purpose by which users delegate signing operation and communicate with each other in a trusted manner. This application leads to the need of proxy blind signature schemes. Proxy blind signature is an important type of cryptographic primitive to realize the properties of both blind signature and proxy signature. Over the past years, many proxy blind signature algorithms have been adopted to fulfill such task based on the discrete logarithm problem (DLP) and the elliptic curve discrete log problem (ECDLP), and most of the existing studies mainly aim to provide effective models to satisfy the security requirements concerning a single blinded message. Unlike many previous works, the proposed scheme applies the signcryption paradigm to the proxy blind signature technology for handling multiple blinded messages at a time based on elliptic curve cryptography (ECC). This innovative method thus has a higher level of security to achieve the security goals of both blind signature and proxy signature. Moreover, the evaluation results show that this proposed protocol is more efficient, consuming low communication overhead while increasing the volume of digital messages compared to the performance from other solutions. Due to these features, this design is able to be implemented in small low-power intelligent devices and very suitable and easily adoptable for e-system applications in pervasive mobile computing environment.

• KIEAE Journal
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• 제11권2호
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• pp.105-111
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• 2011

Aims of this study is to investigate the daylighting control strategy of venetian blind system was performed as a function of ratio of shading height to window and slat angles in the preliminary stage of the parametric study. Floor-to-ceiling window walls of living spaces are used widely in apartment buildings since the Korean government has legally allowed elimination of the balcony area. Enlarging living area by balcony elimination, the larger glass area of window is exposed to the direct sunlight. As a common sunlight controlling device, blind system can be used in all orientations and all latitudes and it may obstruct, absorb, reflect and transmit solar radiation to building by proper adjusting. However, blind system can produce discomfort in occupant and less energy efficiency, if it has not been controlled optimally. The simulation model was based on the unit module of typical living space with balcony elimination. The room dimension was $6.0m(w){\times}6.9m(d){\times}2.7m(h)$ with floor to ceiling height of 2.5m. The blind system was simulated at five slat angles (horizontal, $30^{\circ}$, $45^{\circ}$ upward and downward tilted) and the four ratio of shading height to window (fully closed, partly opened, no-blind) using the Desktop RADIANCE 2.0 program. The series of simulation results indicates that the advantages of available daylight and outside of view can be improved by proper adjusting blind system.

• 한국정보과학회논문지:시스템및이론
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• 제29권5호
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• pp.299-306
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• 2002

'부분은닉서명(Partially Blind Signature)'기법은 전자화폐나 전자투표와 같이 사용자의 프라이버시가 중요시되는 응용에서 사용된다. 본 논문에서는 서명 요청자의 계산량을 줄이는 RSA 알고리즘에 기반한 부분은닉서명 기법을 제안한다. 서명 요청자는 메시지를 은닉하여 서명자에게 전송하고 서명자가 생성한 중간 서명으로부터 최종 서명을 생성하는 과정에서 계산을 필요로 한다. 논문에서 제안하고 있는 기법은 서명 요청자가 적은 계산량을 필요로 하는 모듈러 합과 곱 연산만으로 최종 서명을 계산할 수 있게 하므로 서명 요청자의 계산량을 많이 감소시킨다. 따라서, 이동통신 기기나 스마트카드, 전자지갑 같이 계산능력이 떨어지는 장치들에서 사용하기에 적합하다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.385-388
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• 2010

시각장애인은 움직임에 대한 제한으로 상대적으로 교육의 공평한 기회가 제공되고 있지 못한다. 본 논문에서는 시각장애인들이 정보격차 해소는 물론 웹 접근에 관한 연구와 시각장애인들의 정보습득 방법에 대한 선호도를 분석 조사하고 분석한다. 이 자료를 통해 시각장애인을 대상으로 한 초고속통신망에서 인터넷 웹서비스를 이용한 교육지원서비스 시스템을 설계하고, 분석하고, 실시간으로 교육 정보를 주고받을 수 있는 커뮤니티 프로그램을 개발하여, 원격에서 재택 교육지원시스템 활성화 방안을 제시하여 시각장애인의 교육지원 정보 접근서비스에 기여하고자 한다.