• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.404-409
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• 2008

This paper consists largely of two parts: the first part introduces the revised railway human reliability analysis (R-HRA) method which is to be used under the railway risk assessment framework, and the second part presents the features of a computer software which was developed for aiding the R-HRA process. The revised R-HRA method supplements the original R-HRA method by providing a specific task analysis guideline and a classification of performance shaping factors (PSFs) to support a consistent analysis between analysts. The R-HRA software aids the analysts in gathering information for HRA, qualitative error prediction including identification of external error modes and internal error modes, quantification of human error probability, and reporting the overall analysis results. The revised R-HRA method and software are expected to support the analysts in an effective and efficient way in analysing human error potential in railway event or accident scenarios.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.6
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• pp.736-745
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• 2002

In network delivery of compressed video, packets may be lost if the channel is unreliable like Internet. Such losses tend to of cur in burst like continuous bit-stream error. In this paper, we propose an effective error-concealment approach to which an error resilient video encoding approach is applied against burst errors and which reduces a complexity of error concealment at the decoder using data hiding. To improve the performance of error concealment, a temporal and spatial error resilient video encoding approach at encoder is developed to be robust against burst errors. For spatial area of error concealment, block shuffling scheme is introduced to isolate erroneous blocks caused by packet losses. For temporal area of error concealment, we embed parity bits in content data for motion vectors between intra frames or continuous inter frames and recovery loss packet with it at decoder after transmission While error concealment is performed on error blocks of video data at decoder, it is computationally costly to interpolate error video block using neighboring information. So, in this paper, a set of feature are extracted at the encoder and embedded imperceptibly into the original media. If some part of the media data is damaged during transmission, the embedded features can be extracted and used for recovery of lost data with bi-direction interpolation. The use of data hiding leads to reduced complexity at the decoder. Experimental results suggest that our approach can achieve a reasonable quality for packet loss up to 30% over a wide range of video materials.

• Journal of Science Education
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• v.36 no.1
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• pp.153-165
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• 2012

This study investigated the frequent mistakes and the causes of the alternative conceptions in the animal classification by using the questionnaire and interview with the middle school students (N=300). As results, some students have difficulties classifying suggested animals into vertebrates or invertebrates : snakes (31.7%), shrimps (28.3%), turtles (25.6%), frogs (24.7%), and starfish (10.7%) in order of precedence. These errors seemed to be caused by intuitive thinking over characteristics of physical motions and appearance of suggested animals, wrong inference from comparing to features of familiar animals and the lack of observation experience of the vertebrate backbone. Furthermore, the results showed that relatively many students made a mistake classifying subgroup members of vertebrates such as classifying salamanders into the class Reptilia (45.3%) and turtles into Amphibia (40.3%). It is likely that those errors are affected by ambiguousness of classification terminology (e.g. the term of Amphibia) and weak ability in relating the physiological and ecological feature to standard of classification feature. In addition, sociocultural factors could influence animal classification as 'bat in birds', 'whale in fish, and 'penguin in mammals'. The present study implied that teaching and learning animal classification may require an appropriate guide focused on activities to explore major characteristics used for the animal classification standard through providing more chances of animal observation rather than the cramming method of learning induced by technical memorizing.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.263-264
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• 2016

본 연구에서는 국내 정보 교사가 가지고 있는 교사 전문성의 특성에 대해 고찰하였다. 교사가 가져야 하는 전문성의 여러 종류 중 인지적 영역의 전문성은 학생 성취에 중요한 역할을 담당하기 때문에 가장 중요한 부분으로 볼 수 있다. 교사가 가지고 있는 인지적 영역의 전문성을 교과에 대한 지식, 일반적 교육학 지식, 교수 내용 지식으로 나누어 생각할 때 정보 교사는 세 가지의 전문성을 가지고 있다. 먼저 교과의 내용이 빠르게 변하기 때문의 지식의 개정이 빠르고, 교수내용지식의 많은 부분이 컴퓨팅 도구의 활용과 이에서 발생하는 오류에 대한 내용으로 구성된다는 점이다. 또한 이러한 이유 때문에 정보 교사의 교수내용지식 또한 꾸준히 변화하게 된다.

• Proceedings of the Korean Association for Survey Research Conference
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• 2000.06a
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• pp.15-34
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• 2000

Since the results of the election forecasting survey that was executed jointly by T.V. stations and survey research companies in the 16th Korea General Election(April 13, 2000) had many errors, the reliability of the election forecasting survey was greatly damaged. Therefore, in order to recover the reliability and to increase the accuracy of the election forecasting survey I the future, we figure out the sources of the survey\\`s errors and suggest methods of reducing them through deeply analyzing the forecasting data from many angles. In addition, we discuss some problems and an improvable direction on exit poll executed for the first time.

• Survey Research
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• v.1 no.2
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• pp.15-34
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• 2000

Since the results of the election forcasting survey that was executed jointly by T.V. stations and survey research companies in the 16th Korea General Election(April 13, 2000) had many errors, the reliability of the election forecating survey was greatly damaged. Therefore, in order to recover the reliability and to increase the accuracy of the election forecasting survey in the future, we figure out the sources of the survey's errors and suggest methods of reducing them through deeply analyzing the forecasting data from many angles. In addition, we discuss some problems and an improvable direction on exit poll executed for the first time.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.885-905
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• 2010

This study questions that mathematical evaluations strive to memorize fragmentary knowledge and have an objective test. To solve these problems on mathematical education We did descriptive test. Through the descriptive test, students think and express their ideas freely using mathematical terms. We want to know if that procedure is correct or not, and, if they understand what was being presented. We studied this because We want to analyze where and what kinds of faults they committed, and be able to correct an error so as to establish a correct mathematical concept. The result from this study can be summarized as the following; First, the mistakes students make when solving the descriptive tests can be divided into six things: error of question understanding, error of concept principle, error of data using, error of solving procedure, error of recording procedure, and solving procedure omissions. Second, students had difficulty with the part of the descriptive test that used logical thinking defined by mathematical terms. Third, errors pattern varied as did students' ability level. For high level students, there were a lot of cases of the solving procedure being correct, but simple calculations were not correct. There were also some mistakes due to some students' lack of concept understanding. For middle level students, they couldn't understand questions well, and they analyzed questions arbitrarily. They also have a tendency to solve questions using a wrong strategy with data that only they can understand. Low level students generally had difficulty understanding questions. Even when they understood questions, they couldn't derive the answers because they have a shortage of related knowledge as well as low enthusiasm on the subject.

• Electronics and Telecommunications Trends
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• v.10 no.4 s.38
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• pp.113-127
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• 1995

본 고에서는 이동국과 기지국간 신호방식에 적용되는 PCS 무선 접속 프로토콜에 대하여 기술한다. 기본적인 내용구성은 Proposed W-CDMA PCS 표준화를 기본으로 하여 무선 인터페이스 프로토콜 기능 및 구조 그리고 기본호절차와 메시지 포맷 및 내용으로 이루어져 있다. 또한 오류 조건 처리에 대하여도 기술한다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.118-120
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• 2004

네트워크 노드의 고장진단 내용을 모바일 클라이언트에 실시간으로 서버하기 위하여는 정보를 최소화하여야 한다. 이를 위해 고장진단의 내용을 인덱스하고 인덱스 된 정보만을 모바일 클라이언트에 서버함으로 모바일 클라이언트가 소요하는 비용을 최대한으로 줄였다. 네트워크 관리자는 모바일 환경을 이용하여 실시간으로 메인 서버에 접속하며, 자신이 관리하는 시스템의 상태를 파악하여 오류나 고장의 시간을 줄임으로 효율적으로 시스템을 운영한다. 로그는 메인 서버에 순차적으로 저장되고 인덱스 됨으로 모바일 환경에서의 검색 속도를 향상시킨다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.481-483
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• 2001

본 논문에서는 Linux 상에서 SNMP (Simple Network Management Protocol) 에이전트(Agent)를 구현하고, 기존의 복잡한 명령어 체계를 향상하기 위해 shell을 통만 CLI (Command Line Interface)와 Jave를 통만 EMS(Element Management Station) 시스템을 설계하고 구현하였다. 연구 개발된 에이전트는 매너저의 요정에 응답을 하고, 시스템 상의 오류와 같은 상황이 발생했을 때, 매니저에게 TRAP을 발생시키는 기능을 갖는다. 본 논문에서는 개발된 SNMP 에이전트의 개발 환경, 개발 내용과 실험내용에 대해 언급하였다.