• 한국정보기술학회 영문논문지
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• 제10권2호
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• pp.15-31
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• 2020

Various websites have been created due to the increased use of the Internet, and the number of documents distributed through these websites has increased proportionally. However, it is not easy to collect newly updated documents rapidly. Web crawling methods have been used to continuously collect and manage new documents, whereas existing crawling systems applying a single node demonstrate limited performances. Furthermore, crawlers applying distribution methods exhibit a problem related to effective node management for crawling. This study proposes an efficient distributed crawler through stepwise crawling node allocation, which identifies websites' properties and establishes crawling policies based on the properties identified to collect a large number of documents from multiple websites. The proposed crawler can calculate the number of documents included in a website, compare data collection time and the amount of data collected based on the number of nodes allocated to a specific website by repeatedly visiting the website, and automatically allocate the optimal number of nodes to each website for crawling. An experiment is conducted where the proposed and single-node methods are applied to 12 different websites; the experimental result indicates that the proposed crawler's data collection time decreased significantly compared with that of a single node crawler. This result is obtained because the proposed crawler applied data collection policies according to websites. Besides, it is confirmed that the work rate of the proposed model increased.

• 한국융합학회논문지
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• 제11권6호
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• pp.359-365
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• 2020

이 연구의 목적은 2019년 세계여자핸드볼선수권대회에서 상위 6개 국가에 대한 전력분석으로 주요득점 경로와 슈팅 유형별 성공률, 어시스트 빈도, 스틸, 블록, 슈팅 유형별 골키퍼 방어율에 대한 정보를 수집하여 분석하였다. 연구 결과를 바탕으로 다음과 같은 결론을 얻었다. 첫째, 득점 경로 분석결과, 대회 1위 네덜란드와 2위 스페인은 6m슛과 7m슛이 가장 많았으며, 3, 4, 5, 6위에서도 6m슛이 가장 많이 나타났다. 둘째, 슈팅 유형별 성공률 분석결과에서는 상위 6팀 모두 7m슛, 돌파슛, 속공슛 등으로 나타났다. 셋째, 어시스트 빈도분석 결과 기록에 의하면 대회 4위의 노르웨이가 6팀 중 가장 많은 어시스트를 기록했다. 넷째, 스틸 빈도분석 결과 6개 팀 중 노르웨이는 평균 5.2회로 가장 많은 스틸을 기록하였다. 다섯째, 슈팅 유형별 골키퍼 방어율을 분석한 결과 6팀 골키퍼 모두가 9m 슈팅에 대한 방어율이 가장 높은 것으로 나타났다. 따라서, 심층적인 경기전략분석을 위해서는 선수 개인 경기력에 대한 특성파악 및 정보 수집을 통하여 향후 후속연구로 진행될 필요가 있다고 생각된다.

• 대한치과의사협회지
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• 제11권7호
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• pp.469-473
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• 1973

The authors, to collect some necessary data to promote correcting the toothbrushing method, the most basic home dental care, and to arrest the attention to the dentifrices in Korea, observed and evaluated the cervical abrasion experience rate in 8,000 Korean male and female adults from 19 to 52 years in the age, which had been extracted by the stratified random sampling method. The obtained results were as follows; 1. Cervical abrasion experience rate was 18.6% in Korean adults. 2. Cervical abrasion experience rate in male adults was higher than that in female adults. 3. Cervical abrasion experience rate was gradually increased by ageing. 4. It seemed the cervical abrasion experience rates in the adults in Honam and Youngnam district to be higher than those in the other districts. 5. In Korean adults, the further detail inveatigations into the cervical abrasion were required.

• 상하수도학회지
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• 제31권3호
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• pp.249-256
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• 2017

Recently, application areas based on M2M (Machine-to-Machine communications) and IoT (Internet of Things) technologies are expanding rapidly. Accordingly, water flow and water quality management improvements are being pursued by applying this technology to water and sewage facilities. Especially, water management will collect and store accurate data based on various ICT technologies, and then will expand its service range to remote meter-reading service using smart metering system. For this, the error in flow rate data transmitting should be minimized to obtain credibility on related additional service system such as real time water flow rate analysis and billing. In this study, we have identified the structural problems in transmitting process and protocol to minimize errors in flow rate data transmission and its handling process which is essential to water supply pipeline management. The result confirmed that data acquisition via communication system is better than via analogue current values and pulse, and for communication method case, applying the industrial standard protocol is better for minimizing errors during data acquisition versus applying user assigned method.

• 대한교통학회지
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• 제14권4호
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• pp.107-129
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• 1996

Recently, surveillance system designed to collect various trsffic information are becoming new areas of development . Among these, the image detector is a ayatem which can measure the travel time and speed in realtime and this is emerging as the most effcient tool to be available in future related areas. But in measuring wide-area information in realtime, the image detector are yet full of problem in its accuracy. The aim of this ahesis is to develop an algorithms which can collect wide-area information such as travel time and travel speed in urban networks and freeways in realtime. The information on wide-area such as travel time and travel speed is important in accomplishing strategic function in traffic control. The algorithm developed from this study is based on the image tracking model which tracks a moving vehicle form image datas collected continuously, and is constructed to perform realtime measurement. To evaluate the performance of the developed algorithms, 600 ind vidual vehicles in total were used as data for the study, and this evaluation was carried out with the differenciation of day and night condition at the access roads in front of AJou University, In the statistical analysis results, the error rate was recorded as 5.69% and it has proved to be applicable on the field in both day and noght conditions.

• 농업과학연구
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• 제47권2호
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• pp.239-253
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• 2020

This study identified consumer perceptions of biotechnology crops, provided the types and sources of information on agricultural biotech that consumers demand, and derived effective methods of providing agricultural biotech information by analyzing problems and improving the information available online regarding agricultural biotech. The analysis of sources of information on agricultural biotech showed that there were differences between preference and reliability. Respondents preferred the Internet (47.6%) and TV (36.3%), while they relied on TV (36.3%) the most, followed by the Internet (26.6%), and academic papers and technical books (23.1%). Only 27.1% of the respondents answered that they collect information on agricultural biotech proactively. The higher frequency of information collection indicated a higher satisfaction rate with the information that was being collected. Survey results for the websites that respondents preferred and relied on to collect information were that the most preferred websites were web portals (53.4%), while reliability rates across the various types of websites were relatively even: web portals (28.4%), academic institution websites (19.1%), and websites that provide professional information (18.2%). Surveys that examined factors that were important in choosing the websites for collecting information on biotech indicated that factors such as "Providing verified data and citation" and "Providing objectivity" were the most important. Examining the preferences and factors of preference by content type showed that the demand for visual aids, such as photos, tables, graphs, and videos, was high, and there were statistically significant differences between the factors of preference by content type.

• 한국건설순환자원학회논문집
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• 제5권4호
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• pp.458-465
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• 2017

본 연구에서는 굴 패각을 원료(골재)로 활용하기 위한 물리적인 가공방법에 관한 것을 실험을 통해 검토하고자 하였다. 실험결과 굴 패각의 형상에 의해 분쇄된 굴 패각의 적정 입도는 10mm 보다 작아야 될 것으로 판단된다. 또한 가동시간과 회수율, 각 입도별 잔류율과 다양한 입도분포를 고려할 때 굴 패각의 분쇄에는 커터 밀이 적합한 것으로 나타났다. 커터 밀의 경우, 8mm의 내부 스크린을 적용할 때, 회수율은 97.3% 12mm를 적용할 때, 98.2%, 20mm일 때, 98.9%로 나타나 스크린 사이즈가 커짐에 따라 회수율은 다소 증가되는 것으로 나타났다. 커터 밀의 내부 스크린과 인버터의 속도 차이에 의한 실험결과 스크린의 크기가 작을수록, 인버터의 속도가 빠를수록 조립률은 낮아지는 것으로 나타났으며, 동일한 스크린에서 인버터 속도의 상승은 더욱 낮은 입도범위의 재료 회수가 가능한 것으로 나타났다.

• 한국언론정보학보
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• 제60권
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• pp.150-171
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• 2012

SNS 이용자를 대상으로 한 온라인 서베이 결과, SNS 이용자의 이용동기는 '정보', '참여', '교류'로 추출됐다. SNS 이용동기에 따른 SNS 이용 여부에서 SNS 이용동기는 해당 SNS의 특성을 잘 설명하는 것으로 나타났다. 정보를 얻는 것이 목적인 SNS 이용자는 '트위터'와 '미투데이'와 같은 소통 중심 SNS를 더 많이 이용했다. SNS에 참여하는 것이 목적인 SNS 이용자는 가장 많은 가입자를 확보하고 있는 '싸이월드'를 더 많이 이용했다. 다른 사람과 교류하는 것이 목적인 SNS 이용자는 관계 중심 SNS인 '페이스북'과 '싸이월드'를 더 많이 이용한 것으로 나타났다. 이러한 경향은 SNS 이용동기에 따른 SNS 이용시간 및 접속횟수에서도 비슷하게 나타났다. 한편 정보를 얻고 다른 사람과의 교류를 하는 것이 목적인 SNS 이용자는 SNS 메시지를 긍정적으로 평가하는 반면에, SNS에 참여하는 것이 목적인 SNS 이용자는 부정적으로 인식하는 경향이 있었다. 이는 SNS의 이용동기에 따라 SNS 메시지에 대한 인식이 달라질 수 있다는 것을 확인시켜 준다.

• 자원리싸이클링
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• 제27권2호
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• pp.11-23
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• 2018

자원고갈, 원자재 가격상승 그리고 환경규제 강화 등의 원인으로 자동차 부품의 재제조 필요성이 요구되고 있다. 재제조를 위해서는 코어의 안정적인 수급이 수반되어야 한다. 현재 재제조 기업은 다양한 경로를 통하여 코어를 회수하고 있지만, 폐자동차에서 발생하는 코어의 회수율은 저조한 편이다. 매년 수십만대가 발생하는 폐자동차에서의 코어를 체계적으로 회수할 수 있다면 재제조를 위한 코어의 회수율을 더욱 향상시킬 수 있을 것이다. 따라서 본 논문에서는 폐자동차에서 발생하는 코어를 회수하기 위한 방안으로 폐자동차에 대한 등급분류체계를 확립하고자 하였다. 우선 등급 분류에 영향을 주는 요소들을 선정하고 평가를 위한 범위를 결정하였다. 다음 영향요소들 간의 가중치를 산정하여 최종 등급 분류 체계를 구축하였다. 마지막으로 사례연구를 통해 실제 입고된 폐자동차의 해체 등급을 평가하여 2등급의 판정을 도출하였다.

• 한국운동역학회지
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• 제22권4호
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• pp.379-386
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• 2012

The aim of this study was to investigate and identify the differences in lower extremity energy dissipation strategies between drop-landing and countermovement-jump maneuvers. Fourteen recreational athletes(Age : $23.3{\pm}2.1years$, Height : $172.3{\pm}4.0cm$, Weight : $69.2{\pm}4.7kg$) were recruited and instructed to perform drop-landing from 45 cm height and countermovement-jump from 45 cm to 20 cm height. The landing phase was taken as the time between initial contact and peak knee flexion. A motion-capture system consisting of eight infra-red cameras was employed to collect kinematics data at a sampling rate of 200 Hz and a force-plate was used to collect GRF data at a sampling rate of 2000 Hz. Paired t-test was performed to determine the difference in kinematics and kinetics variables between each task. During the countermovement-jump task, all of lower extremity joint ROM and the hip joint eccentric moment were decreased and the ankle joint plantarflexion moment was increased than drop-landing task. In the eccentric work during countermovement-jump task, the ankle joint displayed greater while knee and hip joint showed lesser than drop-landing. Therefore, the knee joint acted as the key energy dissipater during drop-landing while the ankle joint contributed the most energy dissipation during countermovement-jump. Our findings collectively indicated that different energy dissipation strategies were adopted for drop-landing and countermovement-jump.