• 한국기록관리학회지
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• 제8권1호
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• pp.27-43
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• 2008

본 연구에서는 기록관이 이용자들을 위하여 제공하고 있는 교육서비스 프로그램에 초점을 맞추어서, 선행연구 및 선진국의 사례들을 파악하고 정리하였다. 기록관의 교육서비스 프로그램은 첫째, 주로 초 중등 학생과 교사들을 대상으로 수행되고 있었으며, 둘째, 현행 교과과정과 밀접한 연관이 있는 일차 사료 활용에 중점을 두고 있었다. 셋째, 교사 및 교육전문가, 보존기록전문가(archivists)들간의 구체적이고도 지속적인 협력관계가 병행되고 있었으며, 넷째, 직접적인 강의 형태 외의 책자자료 및 웹 기반 자료로도 다양하게 교육기능이 제공되고 있었다. 마지막으로 기록관의 교육프로그램 대상 주제 영역은 역사 영역 뿐만 아니라 사회과학 및 인문 예술영역도 대상으로 수행되고 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.609-610
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• 2017

무선 통신 서비스의 증가에 따라 부족한 스펙트럼을 효율적으로 사용하고자하는 인지무선통신기법이 주목받고 있다. 인지무선통시에서는 주 사용자에 대한 간섭을 최소화하려는 노력이 중요한 기술적 요소가 된다. 본 논문에서 고려하고 있는 멀티채널을 갖는 에드혹 인지무선네트워크에서 멀티홉전송을 하기 위해서는 주 사용자와의 충돌뿐아니라 채널간의 간섭을 고려하여 경로 및 채널 선택이 이루어 져야한다. 멀티채널 환경에서 무선인지통신은 채널 간에 간섭과 주 사용자와의 충돌에 따라 서로 다른 용량를 갖게 된다. 본 논문에서는 멀티채널 환경에서 채널 간 간섭을 최소화하며 주 사용자와의 충돌을 줄임으로써 전송용량을 높일 수 있는 멀티홉 전송방식을 제안하고 성능을 비교 분석하였다.

• Nuclear Engineering and Technology
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• 제47권7호
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• pp.895-906
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• 2015

Background: Mitigation of primary water stress corrosion cracking (PWSCC) is a significant issue in the nuclear industry. Advanced nickel-based alloys with lower susceptibility have been adopted, although they do not seem to be entirely immune from PWSCC during normal operation. With regard to structural integrity assessments of the relevant components, an accurate evaluation of crack growth rate (CGR) is important. Methods: For the present study, the extended finite element method was adopted from among diverse meshless methods because of its advantages in arbitrary crack analysis. A user-subroutine based on the strain rate damage model was developed and incorporated into the crack growth evaluation. Results: The proposed method was verified by using the well-known Alloy 600 material with a reference CGR curve. The analyzed CGR curve of the alternative Alloy 690 material was then newly estimated by applying the proven method over a practical range of stress intensity factors. Conclusion: Reliable CGR curves were obtained without complex environmental facilities or a high degree of experimental effort. The proposed method may be used to assess the PWSCC resistance of nuclear components subjected to high residual stresses such as those resulting from dissimilar metal welding parts.

• 천문학논총
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• 제38권3호
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• pp.99-110
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• 2023

In this study, complaints from visitors in the science museum satisfaction survey were categorized into four primary factors and ten sub-factors. This categorization aimed to provide recommendations for enhancing the Geochang Wolseong Space Creative Science Museum as an illustrative case study. Futhermore, the study examimed the relative importance of each factor by surveying 90 science museum visitors. The following results are obtained. Firstly, it was evident that the Geochang Wolseong Space Creative Science Museum requires urgent improvement. Certainly, in the primary factors, issues related to the utilization environment emerged as the most significant sources of dissatisfaction, while in the sub-factors, the adequacy of fees was identified as the most prominent concern. Secondly, through the result of the IPA (Importance-Performance Analysis) of the complaint factors, four primary issues were identified as top priorities for consideration: fare adequacy, lack of convenient facilities, in sufficient publicity, and a lack of distinctiveness compared to similar facilities. Lastly, when analyzing the relationship between complaints and overall satisfaction, factors related to human service, environment, and educational content had negative effects. In contrast, factors associated with science museum operation exhibited a different trend, suggestinga structural impact relationship with the overall impact of complaints.

• 대한임베디드공학회논문지
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• 제9권6호
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• pp.353-360
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• 2014

In cognitive radio networks (CRNs), SU (secondary user)'s transmissions are frequently disrupted by PU (primary user)'s transmission. Therefore SU expereiences consecutive retransmission timeout and its exponential backoff, and subsequently, the TCP of SU does not proceed with the transmission even after the disruption is over or the SU succeeds to hold an idle channel. In order to solve this problem, we propose a cross-layer approach called TCP-Freeze-CR. Moreover we consider a practical scenario where either secondary transmitter (ST) or secondary receiver (SR) detects PU's transmission, which results in the need of spectrum synchronization mechanism. All of our proposals are implemented and verified with a real CRN testbed consisting of 6 software radios called USRP. The experimental results illustrate that standard TCP suffers from significant performance degradation and show that TCP-Freeze-CR greatly mitigates the degradation.

• Journal of information and communication convergence engineering
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• 제14권1호
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• pp.1-8
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• 2016

Spectrum sensing in cognitive radio networks allows secondary users to sense the unused spectrum without causing interference to primary users. Cognitive radio requires more accurate sensing results from unused portions of the spectrum. Accurate spectrum sensing techniques can reduce the probability of false alarms and misdetection. In this paper, a two-stage spectrum sensing scheme is proposed for cooperative spectrum sensing in cognitive radio networks. In the first stage, spectrum sensing is executed for each secondary user using energy detection based on double adaptive thresholds to determine the spectrum condition. If the energy value lies between two thresholds, a fuzzy logic scheme is applied to determine the channel conditions more accurately. In the second stage, a fusion center combines the results of each secondary user and uses a fuzzy logic scheme for combining all decisions. The simulation results show that the proposed scheme provides increased sensing accuracy by about 20% in some cases.

• Journal of Information Technology Applications and Management
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• 제12권4호
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• pp.123-131
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• 2005

Since most of the conventional web servers have been designed to Provide the general purpose and user's convenience as the primary goal, there is an overhead to apply them to the embedded system for remote monitoring and controlling the operation status of the Internet appliance. To cope with this overhead, an embedded Linux web server Is suggested in this paper The basic concept is to provide miniaturization and extendability by simplifying the requirements of web server as the services to the requests of web document for the user's menu and the execution of CGI Program for monitoring and controling the Internet appliance, and satisfying only the indispensable requirements of HTTP which are necessary for the interface with the conventional web browsers. For the evaluation of its feasibility, each module has been implemented on Linux environment, and tested with the MS Explorer 6.0.

• Journal of electromagnetic engineering and science
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• 제12권1호
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• pp.32-36
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• 2012

In this paper, we present a novel algorithm for detecting a bonded channel in a cognitive radio network where channel bonding is allowed for a higher data rate. The envelope detection algorithm is proposed to distinguish the center frequency of the received signal in order to determine whether the signal is transmitted by a primary user occupying a single channel or a secondary user occupying more than two channels when the channel is in use.

• 한국정밀공학회지
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• 제20권5호
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• pp.108-115
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• 2003

This paper is concerned with the development of Internet-based robot system controlled on the remote site via the Internet. In order to draw the public attention into this exciting system, we built the simple system by which a robot is moved in response to answer for the given OX quizzes. As the primary research fer Internet-based robot control, this study focuses on the development of user-friendly interface by which a beginner achieves information for a robot on the remote site from the 3D virtual simulator and the real camera image. for the compensation of Internet time delay, position prediction simulator is implemented in the user interface.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2010년도 하계학술대회
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• pp.119-122
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• 2010

Cognitive Radioo(CR)기술은 주파수 자원을 효율적으로 이용하기 위해 Joseph Mitora가 개념을 적립한 것으로 유비쿼터스 시대의 부족한 주파수 자원을 극복 할 수 있는 기술로 각광받고 있다. 이와 같은 무선인지 기술(CR)을 도입하기 위한 핵심적인 요소는 부사용자(Secondary User)가 주사용자(Primary User)의 통신을 방해하지 않도록 주파수 점유 여부를 정확하게 판단하는 Spectrum Sensing기술이다. 이 스펙트럼 센싱 기술에 두 가지 종류의 에러가 발생하는데 하나는 미검출 오류(miss error)이고 또 하나는 오경보 오류(false alarm error)이다. 따라서 본 논문은 이 두 가지를 합친 검출 오류(detection error)를 최소화 하기위해 협력 스펙트럼 센싱(Cooperative spectrum sensing)에서 몇 명 이상의 부사용자가 주사용자가 사용중이라 검출하였을 때 최종 결정이 주사용자가 사용한다고 결론 짓는 것이 최적인지를 수학적으로 분석하고 그 최적의 K값을 사용하여 전체 시스템의 성능을 향상 시키는 방법을 제시 한다.