• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.360-367
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• 1990

The several glycoside hydrolysing enzymes related to rutin degradation are found to be rhamnosidase, glucosidase and rutinosidase. Rutinosidase was purified to electrophoretic homogeneity from cell extracts of rutin-degrading strain, MT-57, which was identified as a Arthrobacter sp. Its molecular weight was estimated to be 42, 000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 40, 000 by gel filtration. The optimum pH for enzyme was found to be 7.5, and relatively stable in alkaline solution. The optimum temperature for enzyme was $45^{\circ}C$, being stable up to $50^{\circ}C$ for 20 min. The Bm value of enzyme for rutin was 0.5 $\mu \textrm m$. The enzyme activity was increased by the chelating agent such as EDTA, $NaN_3$, and 8-hydroxyquinoline, was strongly inhibited by $CO_{2+}, Ni^{2+}$, and $Cu^{2+}$. The enzyme had high substrate specificity in the rutinoside.

• Journal of KIISE:Software and Applications
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• v.26 no.2
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• pp.284-296
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• 1999

문자 인식 및 영상 인식 분야의 대부분의 연구들은 이진영상(binary image)을 바탕으로 이루어진다. 하지만, 입력영상에서 보다 많은 정보를 얻기 위해 명도영상(grayscale image) 으로 입력받아 필요한 정보를 추출한후 이진영상으로 변환하여 처리하는 방법도 많이 사용되고 있다. 이런 경우, 명도영상으로부터의 보다 깨끗한 이진영상의 획득 여부는 시스템의 성능과도 밀접한 관계가 있다. 본 논문에서는 기존의 대부분의 이진화 방법과는 달리, 실제 이진화를 수행하기 이전에 여러 가지 필터링 기법을 사용하여 영상의 질을 개선시키는 영상개선기법을 사용한후, 기존의 이진화방법을 사용하여 명도영상을 이진화하는 방법을 제안하고자 한다. 영상의 질을 개선시키기 위해서 BM 필터링, 경게선 개선 필터링, Erosion필터링 방법을 사용하였으며 , 기존의 이진화방법으로는 전역적 이진화 방법중 하나로써 클래스간 분산을 이용한 Ostu 방법[1]을 사용하였다. 다양한 종류의 문서를 대상으로 실험하였는데 평가실험에 사용된 영상은 문서 특성에 따라 균일하지 않은 배경을 가진 영상, 순수하게 텍스트로만 구성된 영상, 선성분이 많으며 명도값이 다양하게 나타나는 영상, 텍스트와 선성분이 함께있는 영상 등 크게 4가지 부류로 구분하였고, 평가대상 영상에 대해 매개변수의 개수, 끊어진/잃어버린 /뭉게진 물체가 적은 정도, 실행속도, 매개변수 결정의 용이성, 잡영이 적은 정도를 평가기준으로 선정한 후, 정량적인 평가가 어려운 항목에 대해서는 9개의 등급으로 나누어 이진화 된 영상의 특성을 분석, 평가하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.312-312
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• 2019

지구온난화로 인하여 기상학적 변동성 증가 및 수질, 수자원, 생태계 등의 다양한 영역에 영향을 야기하고 있으며, 이를 통한 피해가 전 세계적으로 증가하고 있는 추세이다. 이에 본 연구에서는 최근 다양한 분야에서 수문학적 빈도에 영향을 미친다고 알려진 AO(Arctic Oscillation), NAO(North Atlantic Oscillation), ENSO(El $Ni{\tilde{n}}o$-Southern Oscillation), PDO(Pacific Decadal Oscillation), MJO(Madden-Julian Oscillation)등의 외부인자중 SST, MJO를 활용하여 계절단위의 수문량 정도에서 기상학적 변량과 관측유역 강수량의 관계를 정립하고 발생 가능한 24시간 지속시간 극치강수량을 모의하였다. 이를 위하여 Bayesian 통계기법을 이용한 비정상성 빈도해석모형을 근간으로 외부 기상인자에 의한 계절강수량 예측모형인 계층적 베이지안 네트워크(Hierarchical Bayesian Network, HBN)를 구축한 후 산정된 결과를 입력 자료로 하여 직접적으로 일단위 이하의 극치강수량을 상세화 시킬 수 있는 베타 모델(four parameter beta, 4PB)을 연계한 계층적 베이지안 네트워크 베타모델(Hierarchical Bayesian Network-4beta Model, HBN4BM)을 개발하여 기상변동성을 고려한 상세화 모형을 개발하였다. 여름강수량 산정 결과 한강 유역의 경우 2016년은 관측값 573.85mm, 모의 값 567.15mm를 나타내어 약 1.2%의 오차를 나타냈으며, 2017년 및 2018년은 4.5%, 6.8%의 오차에서 모의가 이루어졌다. 금강의 경우 2016년은 다른 연도에 비하여 35.2%라는 큰 오차를 보였지만 불확실성 구간에서 모의가 이루어 졌으며, 2017년 및 2018년은 0.3%, 2.1%의 작은 오차가 발생하였다. 24시간 모의 결과는 최소 0.7%에서 최대 27.1%의 오차를 나타냈으며, 평균적으로 16.4%의 오차 결과가 모의되어 모형의 신뢰성을 확인하였다.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3399-3404
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• 2013

A new accepter unit, pyrrolo[3,2-b]pyrrole-2,5-dione, was prepared and utilized for the synthesis of the conjugated polymers containing electron donor-acceptor pair for OPVs. Pyrrolo[3,2-b]pyrrole-2,5-dione unit, regioisomer of the known pyrrolo[3,4-c]pyrrole-1,4-dione, is originated from the structure of stable synthetic pigment. The new conjugated polymers with 1,4-diphenylpyrrolo[3,2-b]pyrrole-2,5-dione, thiophene and carbazole were synthesized using Suzuki polymerization to generate P1 and P2. The solid films of P1 and P2 show absorption bands with maximum peaks at about 377, 554 and 374, 542 nm and the absorption onsets at 670 and 674 nm, corresponding to band gaps of 1.85 and 1.84 eV, respectively. To improve the hole mobility of the polymer with 1,4-bis(4-butylphenyl)-pyrrolo[3,2-b]-pyrrole-2,5-dione unit, which was previously reported by us, the butyl group at the 4-positions of the N-substituted phenyl group was substituted with hydrogen and methyl group. The field-effect hole mobility of P2 is $9.6{\times}10^{-5}cm^2/Vs$. The device with $P2:PC_{71}BM$ (1:2) showed $V_{OC}$ value of 0.84 V, $J_{SC}$ value of 5.10 $mA/cm^2$, and FF of 0.33, giving PCE of 1.42%.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.6-13
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• 2009

For X-band phased array systems, a power amplifier, a 6-bit phase shifter, a 6-bit digital attenuator, and a SPDT transmit/receive (T/R) switch are fabricated and measured. All circuits are demonstrated by using CMOS 0.18 um technology. The power amplifier has 2-stage differential and cascade structures. It provides 1-dB gain-compressed output power ($P_{1dB}$) of 20 dBm and power-added-efficiency (PAE) of 19 % at 8-11 GHz frequencies. The 6-bit phase shifter utilizes embedded switched filter structure which consists of nMOS transistors as a switch and meandered microstrip lines for desired inductances. It has $360^{\circ}$ phase-control range and $5.6^{\circ}$ phase resolution. At 8-11 GHz frequencies, it has RMS phase and amplitude errors are below $5^{\circ}$ and 0.8 dB, and insertion loss of $-15.7\;{\pm}\;1,1\;dB$. The 6-bit digital attenuator is comprised of embedded switched Pi-and T-type attenuators resistive networks and nMOS switches and employes compensation circuits for low insertion phase variation. It has max. attenuation of 31.5 dB and 0.5 dB amplitude resolution. Its RMS amplitude and phase errors are below 0.4 dB and $2^{\circ}$ at 8-11 GHz frequencies, and insertion loss is $-10.5\;{\pm}\;0.8\;dB$. The SPDT T/R switch has series and shunt transistor pairs on transmit and receive path, and only one inductance to reduce chip area. It shows insertion loss of -1.5 dB, return loss below -15 dB, and isolation about -30 dB. The fabricated chip areas are $1.28\;mm^2$, $1.9mm^2$, $0.34\;mm^2$, $0.02mm^2$, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.1-4
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• 2005

This experiment was conducted to investigate the soil nitrogen credit of biological nitrogen fixation (BNF) and the nitrogen balance of soybean in soybean-barley cropping systems. Soybean cultivar, Shinpaldalkong2 and barley cultivar, Olbori, were used in soybean mono-cropping (SM), barley monocropping (BM), and barley­soybean double cropping system. The barley-soybean double cropping system was treated with two different levels of nitrogen fertilizers, 0 nitrogen fertilizer (BS-F0), and standard nitrogen fertilizer (BS-F1). Nitrogen and organic matter concentrations in soil of BS-F1 plot on October, 2001 were increased $4.8\%\;and\;5.9\%$, respectively, compared with those on October, 2000. The ranges of BNF rate in soybean were $69.1\~ 88.2\%$ in two years, and the rate was the highest in BS-F0 plot and the lowest in SM plot. The ranges of nitrogen harvest index (NHI) in all treatments were $83.9\~86.7\%$. The yield was 270 kg/10a in BS­F1 plot and 215 kg/10a in BS-F0 plot. However, the nitrogen balances were +0.6 kg/10a of gain of soil nitrogen in BS-F0 plot and -0.4 kg/10a of loss of soil nitrogen in BS-F1 plot. In comparisons of SM and BS-F1 plots, although the seed yields were similar in two plots, the loss of soil nitrogen was higher in SM than BS-F1 plot. Overall, our results suggest that barley-soybean double cropping system was more effective in respect to seed productivity and soil nitrogen conservation than soybean monocropping system, and the N credit to following crops by soybean cultivation was identified in soybean double cropping system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.91-99
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• 2018

This paper has proposed a low-noise and high-linear RF receiver supporting TV white space from 470 MHz to 698 MHz), which is implemented in $0.13-{\mu}m$ CMOS technology. It consists of a low-noise amplifier, a RF band-pass filter, a RF amplifier, a passive down-conversion mixer, and a channel-selection low-pass filter. A low-noise amplifier and RF amplifier provide a high voltage gain to improve the sensitivity level. To suppress strong and nearby interferers, two RF filtering schemes have been performed by using a RF BPF and a down-conversion mixer. The proposed LPF has been based on the common-gate topology and adopted a bi-quad cell to achieve -24dB/oct characteristics. In addition, the RF receiver can support the overall TV band by controlling a LO frequency. The simulated results show a voltage gain of 56 dB, a noise figure of less than 2 dB, and an out-of-channel IIP3 of -2.3 dBm. It consumes 37 mA from a 1.5 V supply voltage.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.9
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• pp.58-67
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• 2009

This paper presents a fully digital gain control system with a new high bandwidth and wide dynamic range power detector for DVB-S2 application. Because the peak-to-average power ratio (PAPR) of DVB-S2 system is so high and the settling time requirement is so stringent, the conventional closed-loop analog gain control scheme cannot be used. The digital gain control is necessary for the robust gain control and the direct digital interface with the baseband modem. Also, it has several advantages over the analog gain control in terms of the settling time and insensitivity to the process, voltage and temperature variation. In order to have a wide gain range with fine step resolution, a new AGC system is proposed. The system is composed of high-bandwidth digital VGAs, wide dynamic range power detectors with RMS detector, low power SAR type ADC, and a digital gain controller. To reduce the power consumption and chip area, only one SAR type ADC is used, and its input is time-interleaved based on four power detectors. Simulation and measurement results show that the new AGC system converges with gain error less than 0.25 dB to the desired level within $10{\mu}s$. It is implemented in a $0.18{\mu}m$ CMOS process. The measurement results of the proposed IF AGC system exhibit 80-dB gain range with 0.25-dB resolution, 8 nV/$\sqrt{Hz}$ input referred noise, and 5-dBm $IIP_3$ at 60-mW power consumption. The power detector shows the 35dB dynamic range for 100 MHz input.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.1
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• pp.126-142
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• 2016

This paper presents a wide-frequency-range, low-power transceiver with an automatic impedance-matching calibration for TV-white-space (TVWS) application. The wide-range automatic impedance matching calibration (AIMC) is proposed for the Drive Amplifier (DA) and LNA. The optimal $S_{22}$ and $S_{11}$ matching capacitances are selected in the DA and LNA, respectively. Also, the Single Pole Double Throw (SPDT) switch is integrated to share the antenna and matching network between the transmitter and receiver, thereby minimizing the systemic cost. An N-path filter is proposed to reject the large interferers in the TVWS frequency band. The current-driven mixer with a 25% duty LO generator is designed to achieve the high-gain and low-noise figures; also, the frequency synthesizer is designed to generate the wide-range LO signals, and it is used to implement the FSK modulation with a programmable loop bandwidth for multi-rate communication. The TVWS transceiver is implemented in $0.13{\mu}m$, 1-poly, 6-metal CMOS technology. The die area of the transceiver is $4mm{\times}3mm$. The power consumption levels of the transmitter and receiver are 64.35 mW and 39.8 mW, respectively, when the output-power level of the transmitter is +10 dBm at a supply voltage of 3.3 V. The phase noise of the PLL output at Band 2 is -128.3 dBc/Hz with a 1 MHz offset.

• Journal of Life Science
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• v.34 no.4
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• pp.264-270
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• 2024

This study is conducted to analyze environmental factors that affect the ecology of boreal digging frog and use them as basic data for selecting (or creating) suitability of alternative habitats for survival and monitoring method from 2020 to 2022 after boreal digging frog were relocated to the alternative habitats in 2019. Analyzing the environment of the alternative habitats showed that the criteria suited the followings: distance from wetlands, grasslands and rivers was within 5 m, the low-rise grassland was 6,000 m², soft soil was at a depth of ≥20 cm, and the area of permanent wetlands was 5,000 m² wide. As a result of the correlation analysis between meteorological factors and population (n) and breeding, there was a significant correlation between rainfalls and breeding (p<0.01). During the monitoring, it was confirmed that the SVL (Snout-Vent Length) and BM (Body Mass) of the translocated population were maintained (p>0.05), and it was found that the proximity of the habitat and spawning pond, securing food space (grasslands), soil quality, and wetlands could function as an alternative habitat if conditions were met. As a result of analyzing the meteorological factors affecting the population of boreal digging frog, the SVL had a statistical impact on the minimum temperature, maximum temperature, relative humidity, and the rainfall (p<0.05). In the case of breeding, rainfall was found to be affected (p<0.01), and the population was statistically affected by the average temperature, minimum temperature, and relative humidity (p<0.05).