• Journal of the Korean Society for Precision Engineering
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• v.11 no.1
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• pp.97-107
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• 1994

The method is presented for determining the free vibration characteristics of a rotating blade having nonuniform spanwise properties and cantilever boundary condition. The equations which govern the coupled flapwise, chordwise and torsional motion of such a blade are solved using an integrating matrix method. By expressing the equation of motion in matrix notation, utilizing the integrating matrix as an operator, and applying the boundary condition, the equations are formulated into an eigenvalue problem whose solution may be determined by conventional method. Computed results are compared with experimental data.

• Annual Conference on Human and Language Technology
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• 2021.10a
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• pp.558-563
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• 2021

알츠하이머병 치매와 조현병 진단을 위한 2단계 분류 모델을 제안한다. 정상군과 환자군의 발화에 나타난 페어 언어 모델 간의 Perplexity 차이에 기반한 분류와 기존 단일 BERT 모델의 미세조정(fine-tuning)을 이용한 분류의 통합을 시도하였다. Perplexity 기반의 분류 성능이 알츠하이머병, 조현병 모두 우수한 결과를 보임을 확인 하였고, 조현병 분류 모델의 성능이 소폭 증가하였다. 향후 설명 가능한 인공지능 기법을 적용에 따른 성능 향상을 기대할 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.440-442
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• 2021

농업에 ICT 기술을 접목한 스마트팜은 단순한 생육 환경 모니터링에서 벗어나 작물 생육을 위한 최적의 환경을 발견하고 인공지능에 기반한 자율제어가 가능한 농업으로 나아가고 있다. 자율제어가 가능한 농업의 시작은 최적의 작물 생육 환경을 아는 것이다. 이를 위해서는 관련 데이터를 수집하는 것도 중요하지만, 수집된 데이터들의 품질을 검증하고 데이터를 분석하여 작물 생육 환경을 제어하기 위한 유용한 정보를 도출해야 할 필요가 있다. 본 연구에서는 사용자들이 수집한 데이터를 활용하여 작물 생장에 필요한 정보를 얻을 수 있도록 지원하는 애플리케이션의 프로토타이핑 결과를 기술한다. 이 시스템에서 사용자는 웹브라우저를 통해 수집된 데이터들을 입력하고 원하는 분석을 요청하게 되고, 서버는 사용자의 요청과 관련된 R 스크립트를 실행하고 분석 결과를 사용자에게 전달한다.

• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.427-439
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• 2023

The silverleaf whitefly, Bemisia tabaci, is a major pest distributing worldwide damaging over 900 host plant species, and is highly resistant to chemical pesti- cides. Due to the high pesticide resistance of whitefly, there is a need for alternatives to chemical control. Entomopathogenic fungi are candidates for biological pesticide that can overcome the resistance problem of chemical pesticide. Therefore, in this study, we tested pathogenicity of the entomopathogenic fungi to select high insec- ticidal activity against whitefly. As a result, IPBL-C (Cordyceps fumosorosea) and IPBL-F (Metarhizium pinghaense) isolates showed high insecticidal activity against whitefly. Additionally, as a result of culturing the selected isolates on spent coffee grounds medium, the conidia of IPBL-F produced on coffee grounds medium showed five times higher heat stability after heat treatment at 45℃ for one hour than conidia produced on PDA medium.

• Resources Recycling
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• v.33 no.2
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• pp.73-73
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• 2024

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.178-183
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• 2021

This paper describes a dynamic spectroscopic ellipsometry based on dual-wavelength calibration. DSE provides ellipsometric parameters at rates above 20 Hz, but the interferometer's sensitivity to temperature makes it difficult for that proposed system to maintain stable 𝜟k over long periods of time. To solve this problem, we set up an additional path in the DSE to perform simulations of the polarization phase calibration method using dual wavelengths. Through simulation, we were able to eliminate most of the polarization phase error and maintain a stable 𝜟k in the long-term stability experiment for 10 hours. This is the result that the 𝜟k stability of the proposed system is improved tens of times compared to the existing system.

• Korean Journal of Metals and Materials
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• v.47 no.11
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• pp.740-747
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• 2009

The purpose of this study is to identify the effect of electrolyte compositions on electrodeposited copper foil. First of all, the polyimide substrate was pretreated with plasma. Finally, copper foil was deposited on a Cu/Ni/Polyimide substrate using the electroplating technique. As the quantity of Cu increased, preferred orientations changed into (111). Increasing sulfuric acid, on the other hand, brought down the preferred orientation of (111). The lowest sheet resistance, surface roughness, and fine adhesion were detected when the ratio of $Cu^{2+}$ and $H_2SO_4$ is 50:50(g/l).

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.91-94
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• 2010

아이폰을 선두로 하여 세계적으로 스마트폰이 각광을 받기 시작했다. 더불어 스마트폰의 성능이 향상됨에 따라 사용자가 점점 증가하고 있다. 이에 따라, 스마트폰을 이용한 다양한 연구가 진행되고 있고 응용 프로그램(Application)도 다양하게 개발되고 있다. 본 논문에서는 스마트폰과 디지털 아카이브즈 시스템을 접목하여 자료 수집 전문 연구원(아키비스트)에게 보다 쉬운 자료 수집 환경을 제공한다. 또한, 일반 사용자들에게는 아카이브 자료를 쉽게 이용 할 수 있도록 편이성을 제공하고자 한다. 이를 위해 개발자에게 편리한 개발환경과 부대비용이 들지 않는 Google의 안드로이드(Android) 플랫폼을 선택하여 스마트폰 상의 디지털 아카이브즈 시스템을 구현 하였다.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.90-95
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• 2023

We describe an optimal alignment method for improving accuracy of dynamic spectroscopic polarimeter based on monolithic polarizing interferometer. The dynamic spectroscopic polarimeter enables real-time measurements of spectral ellipsometric parameters by using a spectral carrier frequency concept. However, the non-polarizing beam splitter used in the monolithic polarizing interferometer cannot maintain the polarization state perfectly due to phase retardation caused by optical anisotropic characteristics of the non-polarizing beam splitter, resulting in degraded measurement accuracy. The effect of the beam splitter can be minimized through optimal alignment of the polarizers used in the polarizing interferometer and the analyzer. We demonstrate how much the proposed alignment method can enhance the measurement accuracy by comparing with previous alignment approach.

• Korean Journal of Metals and Materials
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• v.48 no.10
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• pp.951-956
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• 2010

This study examined the effect of copper and sulfuric acid concentrations on the surface morphology and physical properties of copper plated on a polyimide (PI) film. Electrochemical experiments with SEM and a four-point probe were performed to characterize the morphology and mechanical characteristics of copper electrodeposited in the composition of an electrolyte. The resistivity and peel strength were controlled using a range of electrolyte compositions. A lower resistivity and high flexibility were obtained when an electrolyte with 20 g/l of copper was used. However, a uniform surface was obtained when a high current density that exceeded $20mA/cm^2$ was applied, which was maintained at copper concentrations exceeding 40 g/l. Increasing sulfuric acid to >150 g/l decreased the peel strength and flexibility. The lowest resistivity and fine adhesion were detected at a $Cu^{2+}:H_2SO_4$ ratio of 50:100 g/l.