• 대한기계학회논문집A
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• 제37권10호
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• pp.1297-1303
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• 2013

자동차 조향장치의 볼 조인트의 더스트 커버의 밀봉성과 응력 평가를 위하여 비선형 요한요소해석을 수행하였다. 주름형상과 항아리형상의 두 종류의 더스트 커버에 대하여 조립상태와 작동상태에 대하여 해석을 수행하여, 최대응력과 리브에서의 접촉응력 결과를 평가하고 비교하였다. 또한 작동상태에서의 몸통부 응력과 리브의 접촉응력이 조립상태 대비 증가하는 정도를 평가하였다. 해석 결과로부터 두 종류 모두 밀봉성이 우수한 것으로 확인되었으나, 상대적으로 최대응력이 작은 주름형상이 항아리형상보다 더 우수한 것으로 나타났다.

• 감성과학
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• 제12권1호
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• pp.77-86
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• 2009

자동차는 첨단공업 기술이 고도로 집적되어 있는 인간-기계 시스템(man machine system)이다. 자동차에 대한 새로운 감성요구를 실현하기 위해서는 인체와 오랜 시간 접촉해 있는 시트 표피재의 분석이 반드시 필요하다. 본 연구에서는 자동차 시트 표피재의 역학적 특성과 감성을 고려한 고급감을 예측하여 고감성 내장 표피재 개발에 기여하고자 한다. 감성용어는 Softness(유연한), Elasticity(탱글탱글한), Volume(풍성한), Stickiness (끈끈한)를 설정하였으며, 이와 대응하는 표피재의 역학적 특성 치를 측정하였다. 피혁의 특성평가에 의한 결과로 resilience, bending moment, thickness와 friction 값을 얻을 수 있었으며, 이러한 역학적 특성 치를 softness, elasticity, volume, stickiness 값으로 변화하기 위해 fuzzy logic을 사용하였다. 또한 Fuzzy logic의 결과인 Softness, Elasticity, Volume, Stickiness 값으로 피혁의 고급감을 예측하기 위한 신경망 모델(Neural network)을 구성하였다. 즉, 자동차 표피재 중 피혁의 4가지 물리량으로 인간의 감성인 표피재의 고급감을 예측하여 고감성 자동차 시트 표피재의 개발을 위한 예측 모델의 가능성을 평가하였다.

• 천문학회보
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• 제40권1호
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• pp.71.2-71.2
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• 2015

We present the high-resolution near-infrared spectra of standard stars observed with Immersion Grating Infrared Spectrograph (IGRINS). IGRINS covers the full spectral range of H and K bands simultaneously with a high spectral resolution (R=40,000), revealing many previously undetected and/or unknown lines. In this work, we present preliminary results of spectroscopic diagnostics for stellar physical parameters. Our ultimate goal is to provide a library of near-infrared spectra of standard stars, which covers all spectral types and luminosity classes, with a high-resolution and high signal to noise ratio ($SNR{\geq}200$).

• 자원리싸이클링
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• 제22권1호
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• pp.3-10
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• 2013

본 발표는 국내 흑색 점판암으로부터 우라늄 및 바나듐 회수의 일반적인 현황 및 연구개발에 관한 내용이다. 우라늄 화합물(yellow cake)의 세계적인 수급 및 향후 전망뿐만 아니라, 국내 우라늄광의 매장량, 품위 및 특성에 대해 설명하였다. 그리고 국내 우라늄광의 기술개발에 관한 기 연구 실적 및 수행중인 연구과제의 개략적인 내용에 대해 기술하였다. 또한, 우라늄 및 바나듐 성분이 함유된 국내 흑색 점판암을 대상으로 하여 침출, 분리정제 및 회수에 관한 기술을 하였다.

• 대한수학회논문집
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• 제20권3호
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• pp.437-442
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• 2005

In studying injective covers, the modules C such that Hom(E, C) = 0 and $Ext^1$(E, C) = 0 for all injective module E play an important role because of Wakamatsu's lemma. If C is a module over the ring k[[x, y]] with k a field, the class of these modules C contains the class $\={D}$ of all direct summands of products of modules of finite length ([3, Theorem 2.9]). In this paper we show that every module over any commutative ring has a $\={D}$-preenvelope.

• 한국광학회지
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• 제6권2호
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• pp.165-171
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• 1995

Infrared-Radio frequency double resonance (IRRFDR) and Infrared-Microwave double resonance (IRMWDR) spectroscopy have been used to probe a level of A symmetry for $CD_{3}$OH. Double resonance spectra of $CD_{3}$OH have been investigated over the range of 940 to 1020 $cm ^{-1}$ . Twenty K-type doublet transitions have been observed in both the radio frequency region, which covers 50 MHz to 1 GHz, and the microwave region, which covers 8 GHz to 12 GHz. The results propose new assignments of infrared (IR) absorption transitions and far-infrared (FIR) laser emission lines. These involve torsional excited levels and CO stretch states. Measurements of the A state splitting have permitted the determination of the asymmetry splitting parameters $S^{o}$(n, K) and $^{co}$ (n, K) for (n, K)=(0.3) and (1.3)

• KSBB Journal
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• 제23권1호
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• pp.8-17
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• 2008

There are many different approaches to healing of acute and chronic ulcer and large skin defect, such as burn. Currently available wound covers fall into two categories. Permanent covering, such as autografts, and temporary ones, such as allograft including de-epidermized cadaver skin, bioartificial skin, xenografts, and synthetic dressings. Autologous skin grafting in the form of split- or full-thickness skin is still the good standard. Following on from developments in the 1980s involving the use of cultured keratinocyte grafts in wound healing, the last decade has been great progress in the fabrication of composite bioartificial skin grafts. However, two bottleneck on producing cultured bioartificial skin, whether of the simple epithelial cell sheet type, or the more complex composite type, continue to be the generation of sufficient keratinocytes cheaply and quickly and develop biocompatible dermal scaffolds. This article covers the development, clinical application, and current research directions associated with bioartificial skin.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1125-1128
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• 2009

Conversion of light energy to electrical energy by using a solar cell has long been considered as one of the option for an electrical energy supply in the future. In the past, commercial use was restricted largely to remote area applications where conventional electricity is expensive. Recently, the major application of the solar cells changed to become generation of residential electricity in urban areas where the electricity is already supplied by the conventional grid. This paper covers the current market and technology status of the solar cells and future prospect of their terrestrial applications. Reviewing market trend, this paper discusses high efficiency approach in silicon solar cells, low cost approach in silicon solar cells and finally covers future prospects of silicon solar cells.

• Advances in concrete construction
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• 제10권4호
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• pp.279-287
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• 2020

The practice of splicing reinforcing bars in reinforced concrete structures to manage insufficient bar length is a common approach, which is mainly due to transportation limitations on bar length. The splicing of reinforcing bars side by side offers a simple and economical solution to the problem of continuity. This paper examines the influence of different structural parameters such as concrete cover, lap splice length, shear links confinement and concrete strength on the lap splices based on an extensive experimental database of laps and anchorage. The current study shows that increasing the lap splices beyond 50Ø has no additional benefit for increasing its strength. The results also show that relative to the measured stress, specimens with larger concrete side covers shows higher splice stress compared to the samples with smaller concrete covers.

• Journal of information and communication convergence engineering
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• 제10권3호
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• pp.225-230
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• 2012

The Korean nationwide differential global positioning system (NDGPS) reference station transmits a global positioning system (GPS) enhancement signal using minimum shift keying modulation with a 200 bps data rate. The ocean-based DGPS covers the service area of 100 NM with 300 W output power; on the other hand, the land-based DGPS transmits the output power of 500 W, which covers the service area of 100 km. The DGPS reference stations with high output power can radiate spurious signals, which may act as interference sources affecting the other DGPS reference stations or the wireless ground stations that utilize the medium frequency band. In this paper, the radiation spectrums of the DGPS reference stations are measured and analyzed in the spurious domain. The DGPS radiation spectrums are evaluated from the perspective of the interference effect.