• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.350-355
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• 2009

Bond strength depends on characteristics of bonding surface and restorative technique. The majority of studies dealing with dentin bond strength were carried out on flat bonding surface, therefore, difference of bond strength between axial wall and pulpal wall is not clear yet. This study evaluated bonding difference between cavity walls in class I composite resin restoration with different filling techniques. Twenty extracted caries-free human third molars were used. Cavities were prepared in 6 ${\times}$4 ${\times}$3 mm box-type and divided into four groups according to filling technique and bonding surface: Group I; bulk filling - pulpal wall, Group II; bulk filling - axial wall, Group III; incremental filling - pulpal wall, Group IV; incremental filling - axial wall. Cavities were filled with Filtek $Z250^{(R)}$(3M/ESPE., USA) and Clearfill SE $bond^{(R)}$(Kuraray, Japan). After 24 hour-storage in $37^{\circ}C$water, the resin bonded teeth were sectioned bucco-lingualy at the center of cavity. Specimens were vertically sectioned into 1.0 ${\times}$1.0 mm thick serial sticks perpendicular to the bond surface using a low-speed diamond saw (Accutom 50, Struers, Copenhagen, Denmark) under water cooling. The trimmed specimens were then attached to the testing device and in turn, was placed in a universal testing machine (EZ test, Shimadzu Co., Kyoto, Japan) for micro-tensile testing at a cross-head speed of 1 mm/min. The results obtained were statistically analyzed using 2-way ANOVA and t-test at a significance level of 95%. The results were as follows: 1. There was no significant difference between bulk filling and incremental filling. 2. There was no significant difference between pulpal wall and axial wall, either. Within the limit of this study, it was concluded that microtensile bond strength was not affected by the filling technique and the site of cavity walls.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.6
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• pp.245-254
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• 2022

Proteins are the basic unit of all life activities, and understanding them is essential for studying life phenomena. Since the emergence of the machine learning methodology using artificial neural networks, many researchers have tried to predict the function of proteins using only protein sequences. Many combinations of deep learning models have been reported to academia, but the methods are different and there is no formal methodology, and they are tailored to different data, so there has never been a direct comparative analysis of which algorithms are more suitable for handling protein data. In this paper, the single model performance of each algorithm was compared and evaluated based on accuracy and speed by applying the same data to CNN, LSTM, and GRU models, which are the most frequently used representative algorithms in the convergence research field of predicting protein functions, and the final evaluation scale is presented as Micro Precision, Recall, and F1-score. The combined models CNN-LSTM and CNN-GRU models also were evaluated in the same way. Through this study, it was confirmed that the performance of LSTM as a single model is good in simple classification problems, overlapping CNN was suitable as a single model in complex classification problems, and the CNN-LSTM was relatively better as a combination model.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.192-193
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• 2002

지금까지 측면이 코어 가까이 연마된 잔일모드 광섬유와 평면 도파로 사이의 광결합을 이용한 소자들이 많이 연구되고 있다. 이를 이용한 소자들로는 광필터, 광변조기, 광스위치, 굴절계, 편광기 등이 있으며 최근에는 파장분할다중화(WDM)에서 인접채널간의 채널분리를 위한 소자로서 빗살필터의 연구 또한 활발히 이루어지고 있다. 이에 본 논문에서는 측면이 코어 가까이 연마된 단일모드 광섬유와 평면도파로 사이의 광결합을 이용한 빗살필터를 제작하였으며 열광학 효과를 이용하여 파장 가변 빗살 필터를 구현해 보았다. (중략)

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.268-270
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• 2002

본 논문에서는 온라인 뉴스 기사를 여과하여 사용자에게 관련있는 뉴스기사만을 선별적으로 여과하여 보여주는 정보여과 에이전트를 설계 및 구현하였다. 정보여과의 핵심이라고 할 수 있는 정확한 사용자 프로파일 구축과 정보에 대한 사용자의 적합성 반응인 명시적 피드백과 암시적 피드백을 모두 결합한 피드백을 사용하여 사용자 프로파일을 좀 더 정교하게 구축하는 방법을 기술하였다. 실험을 통하여 사용자의 결합된 적합성 피드백 행동에 기반한 정보여과 에이전트의 성능이 단일의 피드백만을 사용했을 때보다 더 좋은 정확성과 적응성을 지니고 있음을 보여 주었다.

• Korean Journal of Optics and Photonics
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• v.10 no.3
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• pp.248-253
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• 1999

In this paper, we have investigated a fiber type active coupler which utilizes the mode coupling between the side polished single mode optical fiber and the active multimode planar waveguide. The proposed device can be used for not only tunable wavelength filter or optical intensity modulator but also a tool for measuring optical properties of guiding material such as refractive index, birefringence, electro-optic coefficient, and thermo-optic coefficient. We gave designed and optimized a coupler structure using the BPM and fabricated the device using thermo-optic polymer as active planar waveguide overlay. The device showed that insertion loss was less then 0.5 dB, extinction ratio was -13 dB at the resonance wavelength, and the wavelength tunablity due to thermo-optic effect was -1.5 nm/$^{\circ}C$. The active coupler using thermo-optic effect can be used as a wavelength tunable filer, an optical intensity modulator and an optical sensor. pulses that are subsequently compressed by a dispersive optical fiber. Experimental results show that $sech^2$ shape pulses with a pulse width of ~14 ps and a time bandwidth product of ~0.34 are successfully generated at 10 GHz repetition rate. In contrast to other methods, such as higher order soliton compression, this approach does not depend on the optical power and thus shows promise for application to low-power lasers.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.7 s.337
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• pp.41-48
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• 2005

We design and fabricate 3-dB tandem directional coupler using the coplanar waveguide structure which is applicable to balanced amplifiers and mixers for 60 GHz wireless local area network system. The coupler comprises the multiple-sectional parallel-coupled lines to facilitate the fabrication process, and enable smaller device size and higher directivity than those of the conventional 3-dB coupler employing the edge-coupled line. In this study, we adopt the structure of two-sectional parallel-coupled lines of which each single-coupled line has a coupling coefficient of -8.34 dB and airbridge structure to monolithically materialize the uniplanar coupler structure instead of using the conventional multilayer or bonded structure. The airbridge structure also supports to minimize the parasitic components and maintain desirable device performance in V-band (50$\~$75 GHz). The measured results from the fabricated couplers show couplings of 3.S$\~$4 dB and phase differences of 87.5$^{\circ}{\pm}1^{\circ}$ in V-band range and show directivities higher than 30 dB at a frequency of 60 GHz.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.135-136
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• 2013

본 논문에서는 결합 인덕터를 이용한 풍력/태양광용 컨버터를 제안한다. 입력의 전류리플을 최대로 감소할 수 있도록 최적화된 결합계수를 선정하였고 인덕터의 결합계수를 조절하기 위한 코어의 구조뿐만 아니라 공극의 길이, 턴 수를 조절하여 결합 인덕터의 설계와 제작을 수행하였다. 본 논문의 풍력과 태양광용 컨버터에 있어서 각각의 인덕터 2개를 적용하는 것과 단일의 결합 인덕터를 적용 하는 것에 대해 비교검증의 실험을 수행하였다. 또한 결합계수의 변화에 따라 입력 전류의 리플이 최소화되는 값을 실험을 통해 확인하고 타당성을 입증하였다.

• Annual Conference on Human and Language Technology
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• 1995.10a
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• pp.13-17
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• 1995

본 논문은 한국어 특성을 적용하여 키워드를 자동으로 추출하는 기법을 제시한다. 기존에 제안된 명사 추출 시스템인 문법형태소 네트워크를 확장하여 단일 명사 뿐만 아니라 복합 명사를 색인어로 추출한다. 복합 명사는 단일 명사에 비해 보다 한정적 개념을 가지므로, 색인어로 추출될 때 문헌의 식별력을 높일 수 있다. 복합 명사를 구성하는 각각의 단일 명사를 인식함으로써 복합 명사를 분해하고, 간단한 구단위 구문분석을 수행하는 명사 결합 규칙에 따라 단일 명사들을 복합 명사로 합성하는 방법을 제시한다. 마지막으로 이와 같이 추출된 복합 명사에, 복합 명사를 구성하는 단일 명사간의 연관성을 고려하여 보다 정확한 가중치를 부여할 수 있는 새로운 가중치 부여 방안을 제시한다.

• Restorative Dentistry and Endodontics
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• v.30 no.3
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• pp.204-214
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• 2005

This study compared the microtensile bond strength (${\mu}$TBS) and microscopic change of two 2-step and two 1-step self-etching adhesives to dentin according to storage times in distilled water. Occlusal dentin was exposed in 48 human molars. They were divided to four groups by different adhesives: SE Bond group (Clearfil SE Bond), AdheSE group (AdheSE). Adper group (Adper Prompt L-Pop), and Xeno group (Xeno III) . Each group was stored in 37$^{\circ}C$ distilled water for 1, 15, and 30 days. Resin-bonded specimens were sectioned into beams and subjected to ${\mu}$TBS testing with a crosshead speed of 1 mm/minute. For SEM observation, one specimen was selected and sectioned in each group after each stroage time. Resin-dentin interface was observed under FE-SEM. In all storage times, mean ${\mu}$TBS of SE group was significantly higher than those of other groups (p < 0.05). There was no significant difference between mean ${\mu}$TBS of SE group and AdheSE group among all storage times, but significant difference between 1- and 30-day storage in mean y${\mu}$TBS of Adper group and Xeno group (p > 0.05). For 1-and 15-day storage, all groups showed the close adaptation between resin-dentin interfaces. For 30-day storage, resin-dentin interfaces showed wide gap in Adper group and separate pattern in Xeno III group.

• Journal of Information Management
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• v.38 no.1
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• pp.1-19
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• 2007

This study investigates the effect of data fusion on the retrieval effectiveness by performing an experiment combining multiple representations of Web documents. The types of document representation combined in the study include content terms, links, anchor text, and URL. The experimental results showed that the data fusion technique combining document representation methods in Web environment did not bring any significant improvement in retrieval effectiveness.