• Journal of Information Processing Systems
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• 제19권4호
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• pp.540-553
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• 2023

The hollow letter CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is an optimized version of solid CAPTCHA, specifically designed to weaken characteristic information and increase the difficulty of machine recognition. Although convolutional neural networks can solve CAPTCHA in a single step, a good attack result heavily relies on sufficient training data. To address this challenge, we propose a seed filling algorithm that converts hollow characters to solid ones after contour line restoration and applies three rounds of detection to remove noise background by eliminating noise blocks. Subsequently, we utilize a support vector machine to construct a feature vector for recognition. Security analysis and experiments show the effectiveness of this algorithm during the pre-processing stage, providing favorable conditions for subsequent recognition tasks and enhancing the accuracy of recognition for hollow CAPTCHA.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2007년도 추계학술발표대회
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• pp.360-363
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• 2007

모바일 어플리케이션 소프트웨어의 GUI는 눈으로 보고 교감하는 것에 끝나지 않고 나날이 발전하여 소프트웨어의 성공여부를 결정하는 경우로 많이 부각되고 있다. 소프트웨어의 성공에 중요한 요소로 자리 잡히고 있으므로 소프트웨어의 성공을 위한 GUI 테스트가 요구되나 GUI 테스트는 많은 노력과 시간이 투자되는 테스트 분야이다. 이러한 자원의 소비의 줄이기 위해서 GUI 테스트의 자동화가 필요하리라 본다.

• 정보교육학회논문지
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• 제24권2호
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• pp.139-146
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• 2020

불확실한 미래를 살아가야 하는 미래 세대들이 배양해야 할 핵심역량은 무엇인가에 대한 논의가 뜨겁다. 미래 사회는 소프트웨어에 의해 작동되는 소프트웨어 중심사회가 될 것으로 예측하고 있다. 이러한 상황에서 전 세계적으로 소프트웨어 교육에 대한 관심이 폭발적으로 증가하고 있는 상황이며, 소프트웨어 교육을 통한 컴퓨팅 사고력 계발에 대한 관심도 증가하고 있는 상황이다. 이와 더불어 컴퓨팅 사고력은 무엇이며, 어떤 역량들로 구성되는 가에 대한 논의도 활발하게 진행되고 있으나, 컴퓨팅 사고력을 구성하는 역량 요소들 간의 관계에 대한 연구는 상대적으로 미흡한 상황이다. 이런 문제점을 해결하고자 본 연구는 다음과 같은 단계로 진행하였다. 첫째, 컴퓨팅 사고력의 5가지 역량 요소를 선정하였다. 둘째, 컴퓨팅 사고력의 역량 요소 간 관계성을 분석할 수 있는 경로 도형을 설정하였다. 셋째, 컴퓨팅 사고력을 검사할 수 있는 검사도구를 선정하였다. 넷째, 초등학교 3학년부터 6학년까지의 학생 801명을 대상으로 컴퓨팅 사고력 검사를 실시하였다. 다섯째, 컴퓨팅 사고력 검사 결과를 바탕으로 다양한 관점의 분석을 실시하여 시사점을 도출하였다.

• Structural Engineering and Mechanics
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• 제68권3호
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• pp.335-344
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• 2018

The execution of an experiment is a complex affair. It includes the preparation of test specimens, the measurement process itself and also the evaluation of the experiment as such. Financial requirements can differ significantly. In contrast, the cost of numerical simulations can be negligible, but what is the credibility of a simulated experiment? Discussions frequently arise concerning the methodology used in simulations, and particularly over the geometric model used. Simplification, rounding or the complete omission of details are frequent reasons for differences that occur between simulation results and the results of executed experiments. However, the creation of a very complex geometry, perhaps all the way down to the resolution of the very structure of the material, can be complicated. The subject of the article is therefore a means of creating the material structure of concrete contained in a test specimen. Because a complex approach is taken right from the very start of the numerical simulation, maximum agreement with experimental results can be achieved. With regard to the automation of the process described, countless material structures can be generated and randomly produced samples simulated in this way. Subsequently, a certain degree of randomness can be observed in the results obtained, e.g., the shape of the failure - just as is the case with experiments. The first part of the article presents a description of a complex approach to the creation of a geometry representing real concrete test specimens. The second part presents a practical application in which the numerical simulation of the compressive testing of concrete is executed using the generated geometry.

• 펄프종이기술
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• 제44권2호
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• pp.18-28
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• 2012

This study was to develop a novel automatic system for measuring St$\ddot{o}$ckigt sizing degree and contact angle at a time. The conventional methods to measure sizing degree had serious problems in obtaining significant differences according to different dosages of a sizing agent, and moreover they disclosed unique limitation due to liquid types used and tester's subjectivity. However, the newly developed system could get reproducible results through total automation of all procedures including liquid dropping, image acquisition and measurement of both St$\ddot{o}$ckigt sizing degree and contact angle. For the St$\ddot{o}$ckigt sizing test, the automatic system could measure sizing degree with more definite differences according to different dosage of AKD, compared to the conventional method. For the contact angle test, the automatic system showed a similar trend to the conventional method but had smaller contact angles due to distortion of an image focus by a sheet curl than the conventional testing machine. The problem from the image out of focus due to specimen curl will be overcome with adopting a new specimen holder for the future system.

• Toxicological Research
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• 제18권4호
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• pp.369-374
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• 2002

The present study was performed to validate an automated image analysis system (Loats Automated Micronucleus Scoring System) for the mouse bone marrow micronucleus assay, comparing with conventional microscopic scoring. Two studies were conducted to provide slides for a comparison of micro-nucleated polychromatic erythrocytes (MNPCEs) values collected manually to those collected by the auto-mated system. Test article A was used as an example of a compound negative for the induction of micronuclei and test article B was wed as a micronucleus-inducing agent to elicit a positive response. Cyclophosphamide was included to provide an positive control in two studies. Bone marrow samples were collected 24 h after administration of test article A and B in male ICR mice. The cells were fixed with absolute methanol and stained with May-Grunwald and Giemsa. The number of MNPCEs was determined by the analysis of 1000 total PCEs per bone marrow sample. In addition to micronucleus scoring, an index of bone marrow toxicity based on PCE ratio (% of PCEs to total erythrocytes) was determined for each sample. The automated and manual scoring was similar when the MNPCEs incidence induced by each test article was less than 10. However manual scoring was able to effectively enumerate micronucleated PCEs in mouse bone marrow when MNPCEs incidence was more than 10, such as cyclophosphamide treatment. Conversely, PCE ratio was superior in computer-assisted image analysis. Taken together, it is suggested that improvement of the automated image analysis may be necessary to render the automatic scoring as sensitive as manual scoring for routine counting of micronuclei, especially because it is superior in objectivity and high throughput scoring.

• 스마트미디어저널
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• 제9권3호
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• pp.107-115
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• 2020

최근 건설분야에 3차원 설계기술인 BIM이 의무화 되면서 다양한 활용사례에 대한 연구가 증가하고 있다. 특히 4차산업혁명의 핵심기술 중의 하나인 가상현실 기술과 BIM이 융합되면 사전 설계검토, 시공시뮬레이션 등 다양한 분야에 활용될 수 있다. 하지만 현재까지 가상현실 접목기술이 단순 프로토타입 수준이거나 모델하우스 정도에만 활용되고 있다. 또한 품질이 높은 가상현실 콘텐츠 제작시 비용이 많이 들기 때문에 관련 분야의 활성화가 어려운 상황이다. 이에 본 논문에서는 가상건설분야 활용도 및 품질을 높이기 위해 BIM을 활용해서 가상현실 콘텐츠를 제작할 때 시간 소요가 많이 발생하는 재질 매핑 시간을 단축시키는 연구를 진행하였다. 이를 위해 BIM 모델시 재질 매핑 가능하도록 객체 속성을 부여하였고, 건설분야에 가장 많이 활용되는 재질을 구성하였으며, 속성과 재질을 자동으로 매핑해 주는 자동화 머터리얼 기능 개발과 최종 테스트를 진행하였다. 테스트를 위해서 10개의 모델을 활용해서 3회 반복 테스트를 하여 최종적으로 약 50.16%의 생산성 향상을 달성하였다. 향후에는 재질 매핑 자동화 기능 고도화를 포함하여 대용량 BIM 모델을 기반으로 물리적인 데이터 경량화를 포함하여 BIM 데이터를 기반으로 가상현실 콘텐츠 제작과 관련된 생산성 향상 연구를 진행할 예정이다.

• 한국산학기술학회논문지
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• 제16권12호
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• pp.8753-8759
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• 2015

터빈 발전 사이클에서의 안정적인 발전 출력 유지관리를 위해서는 검증된 성능 측정 데이터 그룹과 이를 바탕으로 한 발전 출력 성능 계산 절차의 수립이 필요하다. ASME PTC(Performance Test Code)의 성능 계산 절차를 기반으로 본 연구에서는 터빈 출력에 의한 발전기 출력 성능 산정을 위해서 터빈 팽창선 모델과 발전기 출력 측정 데이터의 입력 검증 모델을 구성하였다. 또한 불확실한 측정 데이터에 대한 검증 모델도 구성하였다. 지난 연구에서는 신경회로망과 커널 회귀의 학습 방법을 사용하였으나 본 연구에서는 미측정 데이터에 대한 보완을 하기 위하여 서포트 벡터 머신 모델을 사용하여 발전기 출력 계산 데이터의 학습 모델을 구성하였으며, 학습 모델 구성을 위해서 관련 변수의 선정을 위한 절차와 학습 데이터 구간을 설정하는 알고리듬을 개발하였다. 학습의 결과 오차는 약 1% 범위 안에 있게 되어 추정 및 학습 모델로서 유용함을 입증하였다. 이 학습 모델을 사용하여 측정 데이터 중 상실된 부분에 대한 추정 모델을 구성함으로써, 터빈 사이클 보정 성능 계산의 신뢰성을 향상시킬 수 있음을 검증하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.1168-1176
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• 2010

Currently drilling investigation and the SPT in parallel not only organization and peculation sincerity quality historian of test to be old the data was abundant with the site ground investigation test which is representative and the research of empirical formula in compliance with many scholar was accomplished and was come. The data which is like this wide is used with geotechnical engineering data of plan and space-time of the field which is various. SPT with tentative voluntary skillful degree record method of variety and technical expert of equipment, according to site conditional is consistent the quality of ground condition but cannot be made to show there is a tendency and specially the point whose is difficult actually accurately to follow the interval which decides in quality as a matter of tentative standard of drill and the test in parallel and a tentative method exists. From the research which sees consequently also the skill of variety and technical expert of equipment of SPT, strong point of the SPT automation logger will be able to complement the problem point of quality etc. of site condition under comparison analyzing should have been boiled about SPT of existing and tentative methods and N-value.

• 상하수도학회지
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• 제22권4호
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• pp.429-436
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• 2008

Membrane system has been increasingly considered as a safe and cost-effective water treatment process especially in case of small scale water works. This research is a basis of membrane application in water works through a long period test with obtaining operation skills and evaluation of water quality and cost competitiveness. For the research, the UF membrane system was installed in small water treatment plant that uses river-bed water as raw water. The system was consisted of 2 stage membrane and operated in constant flow mode (Flux: 1.5, 1.0, 0.9, 0.6). In each different flux condition, TMP trends were showed better results at lower flux condition. And through the high flux condition test, it is certified that membrane system could deal with breakdown of one stage. Water quality of permeate was satisfied the water quality standards especially turbidity. To know what mainly causes fouling on membrane, the test by membrane with several cleaning agents and EDX analysis have done in lab. Through the tests, ferrous concentration in raw water, backwashing water and membrane surface etc. was high and it causes fouling inside and outside of membrane. So acid cleaning using organic acid such as oxalic acid is necessary in Chemical in Place (CIP). At the economical aspect the electrical cost of membrane system is higher than that of slow sand filtration but labor cost can be reduced by automation. However, the use of labor should be determined considering effectiveness and stability of operation. Because during the operation, there are several breakdown such as electrical shock by lightning, water drop in summer, etc.