• 한국인터넷방송통신학회논문지
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• 제17권4호
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• pp.181-185
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• 2017

본 논문에서는 광대역 무선랜용을 위한 2.32GHz와 5.79GHz의 대역에 만족하는 이중 대역 안테나를 설계하였다. 제안된 마이크로스트립 안테나의 기판은 FR-4(er=.43)이고, 크기는 $34mm{\times}50mm{\times}1.5mm$, 두께는 t=0.035mm이며 시뮬레이션은 CST Microwave Studio 2014를 사용하였다. 입력 대비 반사손실은 -10dB이하에서 동작하고, 이득은 2.32GHz일 때 -19.321dB, 5.79GHz일 때는 -13.033dB의 결과를 나타내었다. 임피던스 정합을 높이고 인접주파수 간의 간섭을 최소화 하였으며, 간단한 제작방식으로 소형화이고 무지향성의 특성을 보였다. 따라서 제안된 안테나는 광대역 무선랜용 대역을 동시에 만족하였다.

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.122-127
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• 1991

A bacterial strain NO. 32 which produced thermostable ${\alpha}$-amylase was isolated from soil and identified to genus of Bacillus. To enhance ${\alpha}$-amylase productivity, a successive mutation of Bacillus sp. No. 32 was attempted with treatment of N-methyl-N'-nitro-N-nitrosoguanidine (NTG). The resulting mutant, Bacillus sp. No. 32H417, which is risistant to refampicin and deficient in spore formation, produced about 90-fold high level of ${\alpha}$-amylase when compared with parental strain. The properties of the enzyme for thermostability were investigated. The optimal temperature and pH for enzyme reaction were 95$^{\circ}C$ and pH6.5, respectively, in the presence of 0.3mM $Ca^{2+}$ as an effective stabilizer.

• 기계저널
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• 제55권8호
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• pp.32-35
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• 2015

디자인-기술 융합 R&D는 디자이너 주도의 R&D를 의미하는 것이 아니라 사용자 중심의 사고에 의한 R&D를 의미하며 엔지니어를 포함한 R&D 프로젝트 조직 구성원 모두의 적극적인 디자인적 사고에 의한 아이디어 전개와 기술정보 공유에 의해 이뤄져야 한다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권1호
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• pp.129-140
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• 2017

In this paper, a $4{\times}32$-channel neural recording system capable of acquiring neural signals is introduced. Four 32-channel neural recording ICs, complex programmable logic devices (CPLDs), a micro controller unit (MCU) with USB interface, and a PC are used. Each neural recording IC, implemented in $0.18{\mu}m$ CMOS technology, includes 32 channels of analog front-ends (AFEs), a 32-to-1 analog multiplexer, and an analog-to-digital converter (ADC). The mid-band gain of the AFE is adjustable in four steps, and have a tunable bandwidth. The AFE has a mid-band gain of 54.5 dB to 65.7 dB and a bandwidth of 35.3 Hz to 5.8 kHz. The high-pass cutoff frequency of the AFE varies from 18.6 Hz to 154.7 Hz. The input-referred noise (IRN) of the AFE is $10.2{\mu}V_{rms}$. A high-resolution, low-power ADC with a high conversion speed achieves a signal-to-noise and distortion ratio (SNDR) of 50.63 dB and a spurious-free dynamic range (SFDR) of 63.88 dB, at a sampling-rate of 2.5 MS/s. The effectiveness of our neural recording system is validated in in-vivo recording of the primary somatosensory cortex of a rat.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1996년도 한국우주과학회보 제5권2호
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• pp.32-32
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• 1996

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.307-310
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• 2011

• Bulletin of the Korean Chemical Society
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• 제32권4호
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• pp.1411-1414
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• 2011

• 한국항해항만학회지
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• 제32권4호
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• pp.271-277
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• 2008

When performing steering by an autopilot (automatic steering gear), a sensitivity adjustment is mainly determined by P value and D value. These values differ in the optimal combination by model of ship and external forces. This research was carried out simulation case studies and examined movement of Pure Car Carrier, which easily received ship by wind pressure influence in low speed We investigated the relation of horizontal migration(transfer) of ship's body and P-D value. Based on it, four parameters of P-D at approaching berth could be suggested Hence there were suggestions of parameters; Distance to maximum lee point, Time to maximum lee point, Time to return to original course and Time to 300th second. The correlation of these parameters and P-D value were also considered. As a result, we think that this index, like formulated P-D, leads to an easy and safe navigation by utilizing these indices.

• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.4881-4883
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• 2015

A population-based relationship between low vitamin D status and increased cancer risk is now generally accepted. However there were only few studies reported on prognostic impact. To determine the effect of low vitamin D on progression of breast cancer, we conducted a cross-sectional analysis of vitamin D levels and clinico-pathological characteristics in 200 cases of breast cancer diagnosed during 2011-2012 at the National Cancer Institute of Thailand. Vitamin D levels were measured by high-performance liquid chromatography (HPLC). Clinical and pathological data were accessed to examine prognostic effects of vitamin D. We found that the mean vitamin D level was $23.0{\pm}6.61ng/ml$. High vitamin D levels (${\geq}32ng/ml$) were detected in 7% of patients, low levels (<32 ng/ml) in 93% Mean vitamin D levels for stages 1-4 were $26.1{\pm}6.35$, $22.3{\pm}6.34$, $22.2{\pm}6.46$ and $21.3{\pm}5.42ng/ml$ respectively (P=0.016) and 24.1 and 21.3 ng/ml for lymph node negative and positive cases (P=0.006). Low vitamin D level (<32 ng/ml) was significantly found in majority of cases with advanced stage of the disease (P=0.036), positive node involvement (P=0.030) and large tumors (P=0.038). Our findings suggest that low and decreased level of vitamin D might correlate with progression and metastasis of breast cancer.

• 한국수산과학회지
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• 제31권2호
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• pp.288-295
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• 1998

한국 동해 남부 연안 일광만에서 요각류 Arasrtia steueri의 알 생산력을 조사하였다. 실험실에서 온도 및 엽록소 $\alpha$ 농도와 알 생산력간의 관계식을 유도한 후, 현장의 수온과 엽록소 $\alpha$ 농도를 적용하여 현장 개체군의 알생산력을 추정하였다. 알의 평균 크기는 $80.52{\mu}m$이었고, 성체 암컷의 두흉부 길이와 알의 크기간에는 유의한 상관이 없었다. 현장 개체군의 알 생산력은 $0.32\~63.32{\mu}gC\;m^{-3}d^{-1}$ (평균 $13.33{\mu}gC\;m^{-3}d^{-1}$)이었으며, 알의 수로 나타내 면 $7.1\~1407.1\;eggs\;m^{-3}d^{-1}$(평균 $296.1\;eggs\;m^{-3}d^{-1}$)이었다. 암컷 한 마리당 알 생산력은 $5.4\~12.5\;eggs\;female^{-1}d{-1}$(평균 $8\;eggs\;female^{-1}d{-1}$)이었으며, 비알 생산율은 $0.028\~0.117\;d^{-1}$(평균 $0.064\;d^{-1}$)로 나타났다. 본 연구에서 추정된 알 생산력 (성체 암컷의 탄소 무게의 백분율)은 과소 평가된 것으로 나타났는데, 성체의 알에 대한 잠재적인 포식 가능성이 이러한 낮은 알 생산력과 관련이 있는 것으로 판단된다.