• 한국환경과학회지
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• 제28권1호
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• pp.107-123
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• 2019

The aerosol chemical components in $PM_{2.5}$ in several regions (Seoul, Busan, Daejeon, and Jeju Island) were investigated with regard to their concentration characteristics and optical properties. The optical properties of the various aerosol components (e.g., water-soluble, insoluble, Black Carbon (BC), and sea-salt) were estimated using hourly and daily aerosol sampling data from the study area via a modeling approach. Overall, the water-soluble component was predominant over all other components in terms of concentration and impact on optical properties (except for the absorption coefficient of BC). The annual mean concentration and Aerosol Optical Ddepth (AOD) of the water-soluble component were highest in Seoul (at the Gwangjin site) ($26{\mu}g/m^3$ and 0.29 in 2013, respectively). Further, despite relatively moderate BC concentrations, the annual mean absorption coefficient of BC ($21.7Mm^{-1}$) was highest in Busan (at the Yeonsan site) in 2013, due to the strong light absorbing ability of BC. In addition, high AODs for the water-soluble component were observed most frequently in spring and/or winter at most of the study sites, while low values were noted in summer and/or early fall. The diurnal variation in the AOD of each component in Seoul (at the Gwangjin site) was slightly high in the morning and low in the afternoon during the study period; however, such distinctions were not apparent in Jeju Island (at the Aweol site), except for a slightly high AOD of the water-soluble component in the morning (08:00 LST). The monthly and diurnal differences in the AOD values for each component could be attributed to the differences in their mass concentrations and Relative Humidities (RH). In a sensitivity test, the AODs estimated under RH conditions of 80 and 90% were factors of 1.2 and 1.7 higher, respectively, than the values estimated using the observed RH.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.175-180
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• 2005

In this study, we investigated the optimal medium composition for bacterial cellulose (BC) production by Gluconacetobacter sp. RKY5. Among the various kinds of carbon sources, glycerol was the most efficient as a sole carbon source and its optimal concentration for BC production was 15 g/L. The optimal concentration of yeast extract as a nitrogen source for BC production was found to be 8 g/L. $K_{2}HPO_{4}$ and acetic acid were selected respectively as a phosphate source and a secondary substrate, and both optimal concentrations were 3 g/L. The amount of produced BC was 4.59 g/L in a static culture and 6.5 g/L in a shaking culture condition with 150 rpm. These values were 2.1 and 2.7 times higher than those in a static (2.16 g/L) and a shaking (2.41 g/L) cultures using HS medium generally used for BC production.

• 한국응용곤충학회지
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• 제20권1호
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• pp.15-20
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• 1981

벼 품종에 대한 가해능력을 달리하는 벼멸구 생태형의 저항성품종에서의 우화율 유전양상을 분석하고자 실내에서 저항성 품종(Mudgo, ASD 7)을 식이로 이대사육해 인위적으로 유발시킨 유발생태형 2 및 3과 기존생태형 1 사이의 상호 정역교배를 실시하여 $P_1,\;P_2,\;F_l\; F_2,\;BC_1$ 및 $BC_2$의 각세대 $1\~2$령 약충을 공시품종인 Mudgo, ASD 7 $1\~2$엽기 유묘에 접종하여 그 우화율을 조사하였다. 우화율에 대한 유전분석 결과, Mudgo에서의 생태형 2와 생태형 1사이의 조합에서는 생태형 2가 불완전 우성의 단일유전자 ASD 7에서의 생태형 3과 생태형 1 사이의 조합에서는 생태형 3이 불완전열성의 단일 유전자에 의해 우화율이 지배되며, 생태형 2와 생태형 3의 대립관계는 불명확하였다.

• 방송공학회논문지
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• 제12권1호
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• pp.2-10
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• 2007

이 연구는 DVB-S2 전송시스템의 수신성능을 BC(Backward Compatibility) 모드에서 분석하였다. 송신기는 DVB-S(HP)와 DVB-S2(LP) 스트림을 계층적 비균등 8PSK로 변조시킨 신호를 전송하며, 수신기는 계층적 변조 신호를 복조하기 위하여 LSB에서 MSB 순으로 복조하는 방식과 사분면 추정지수와 LLR 계산기를 이용한 계층적 복조방식을 적용할 수 있다. 두 복조방식에 대한 성능분석을 AWGN 및 비선형 채널에서 통계적 분석과 모의실험을 통하여 수행하였으며 이 결과를 바탕으로 국내위성방송 환경에 적합한 LP/HP 스트림 비율을 제시하였다.

• 한국육종학회지
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• 제40권3호
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• pp.243-249
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• 2008

In the previous study, 141 $BC_3F_2$ lines from a cross between the Oryza sativa cv. Milyang 23 and O. glaberrima were used to identify favorable wild QTL alleles for yield component traits. In this study, we carried out QTL analysis of four grain morphology as well as four yield component traits using 141 $BC_3F_5$ lines from the same cross and compared QTLs detected in two different generations. The mean number of O. glaberrima segments in the 141 $BC_3F_5$ lines ranged from 1 to 13 with 2.69 and 5.71 of the average means of homozygous and heterozygous segments, respectively. There was a three-fold difference in the number of QTLs detected for four traits commonly evaluated in two generations (seven QTLs in the $BC_3F_5$ vs 21 in the $BC_3F_2$ population). The percentages of the phenotypic variance explained by QTLs in the BC3F5 population were similar to or less than those in the $BC_3F_2$ population. This is probably due to the difference in the genetic composition of two populations and the environmental effects. The locations of the QTLs commonly detected in both generations were in good agreement except for one QTL for spikelets per panicle. The yield QTL, yd3 was colocalized with the spikelets per panicle, spp3. Yield increase at this locus is due to the increase in spikelets per panicle, because both traits were associated with increase in spikelets per panicle and yield due to the presence of an O. glaberrima allele. Clusters of QTLs for grain morphology traits were observed in two chromosome regions. One cluster harboring five QTLs near SSR markers RM106 and RM263 was detected on chromosome 2. This population would serve as a foundation for development of the introgression line population from a cross between Milyang 23 and O. glaberrima.

• Journal of Microbiology and Biotechnology
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• 제21권7호
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• pp.739-745
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• 2011

During the production of grape wine, the formation of thick leathery pellicle/bacterial cellulose (BC) at the airliquid interface was due to the bacterium, which was isolated and identified as Gluconacetobacter hansenii UAC09. Cultural conditions for bacterial cellulose production from G. hansenii UAC09 were optimized by central composite rotatable experimental design. To economize the BC production, coffee cherry husk (CCH) extract and corn steep liquor (CSL) were used as less expensive sources of carbon and nitrogen, respectively. CCH and CSL are byproducts from the coffee processing and starch processing industry, respectively. The interactions between pH (4.5-8.5), CSL (2-10%), alcohol (0.5-2%), acetic acid (0.5-2%), and water dilution rate to CCH ratio (1:1 to 1:5) were studied using response surface methodology. The optimum conditions for maximum BC production were pH (6.64), CSL (10%), alcohol (0.5%), acetic acid (1.13%), and water to CCH ratio (1:1). After 2 weeks of fermentation, the amount of BC produced was 6.24 g/l. This yield was comparable to the predicted value of 6.09 g/l. This is the first report on the optimization of the fermentation medium by RSM using CCH extract as the carbon source for BC production by G. hansenii UAC09.

• 대한전자공학회논문지TC
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• 제44권1호
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• pp.79-84
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• 2007

본 논문에서는 자동 크기 조절 회로 (Automatic Level Controller_ALC)와 switched LC tank를 이용한 집적화된 저위상 잡음 다중 대역 CMOS 전압 제어 발진기를 제안하였다. 제안된 전압 제어 발진기는 0.13-um CMOS 공정으로 설계되었다. Switched LC tank는 MOS 스위치를 이용하여 스위칭되는 한 쌍의 캐패시터와 두 쌍의 인덕터로 설계되었다. 이 구조를 이용하여 4개의 대역 (2.986 ${\sim}$ 3.161, 3.488 ${\sim}$ 3.763, 4.736 ${\sim}$ 5.093, 그리고 5.35 ${\sim}$ 5.887 GHz) 동작이 하나의 전압 제어 발진기를 통하여 이루어졌다. 1.2 V의 공급 전압을 갖는 전압 제어 발진기는 각각 2.986 GHz에서 -118.105 dBc/Hz @ 1 MHz, 5.887 GHz에서 -113.777 dBc/Hz @ 1 MHz의 위상 잡음을 갖는다. 줄어든 위상 잡음은 가장 넓은 주파수 조절 범위인 2.986 ${\sim}$ 5.887 GHz에서 대략 -1 ${\sim}$ -3 dBc/Hz @ 1 MHz이다. 전압 제어 발진기는 전체 주파수 대역에서 4.2 mW ${\sim}$ 5.4 mW의 전력을 소모한다.

• BMB Reports
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• 제53권2호
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• pp.82-87
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• 2020

Circular RNAs (circRNAs), one kind of non-coding RNA, have been reported as critical regulators for modulating gene expression in cancer. In this study, microarray analysis was used to screen circRNA expression profiles of bladder cancer (BC) 5637 cells, T24 cells and normal control SV-HUC-1 cells. The data from the microarray showed that hsa_circ_0075828 (named circCASC15) was most highly expressed in 5637 and T24 cells. circCASC15 was highly expressed in BC tissues and cells. Overexpression of circCASC15 was closely associated with BC tumor stage and promoted cell proliferation significantly in vitro and in vivo. Mechanistically, circCASC15 could act as miR-1224-5p sponge to activate the expression of CREB1 to promote cell proliferation in BC. In short, circCASC15 promotes cell proliferation in BC, which might be a new molecular target for BC diagnosis and therapy.

• 한국산학기술학회논문지
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• 제9권5호
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• pp.1193-1200
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• 2008

본 논문은 질화갈륨 전력 소자를 이용한 이동통신 시스템용 전력증폭기 모듈에 대하여 기술하고 있다. 전치증폭단, 구동증폭단, 그리고 전력증폭단을 각각 설계, 제작하여 그 성능을 측정하고, 이를 바탕으로 통합 모듈을 설계하여 5Watt급 GaN 전력증폭기 모듈을 완성하였다. 하모닉 차단과 ACP를 개선하기 위하여 출력측에 결함접지구조를 삽입하였다. 개발된 질화갈륨 전력증폭기의 성능을 측정한 결과, 2.1GHz대역에서 58dB 이상의 이득, 37bBm 이상의 출력, 50dBc 이상의 하모닉 차단, 2-tone 입력시 35dBc 이상의 IMD3 특성, 그리고 35dBc 이상의 ACP 특성을 얻었다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.43-45
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• 2013

Background: The aim of this epidemiological study was to establish the laterality of breast cancer (BC) and its association with size, receptor status of the primary tumor and bone metastasis (BM) in a local population. Materials and Methods: This retrospective study included cases of BC from Jan-2009 to Dec-2011 who were referred for metastatic work up or follow up survey with Technetium-99m MDP bone scan (BS) to the Nuclear Medicine Department of Karachi Institute of Radiotherapy and Nuclear Medicine (KIRAN). A total of 384 patients out of 521 were included and all reviewed for age, primary tumor size (PTS), laterality, receptor status like estrogen receptor (ER) progesterone receptor (PR) and Her-2-Neu receptor, presence or absence of BM with sites of involvement and time interval between diagnosis of BC and appearance of BM. Results: The left to right sided BC proportion was significantly higher than unity (59%:41%; p<0.001). The right sided BC was observed in younger age group (46:52 years; p<0.0001) and with a smaller PTS than the left sided (3.43:4.15 cm; p<0.0001). The patients with BM had relatively higher negative receptor status with a significant predominance of right sided BC. The overall incidence of BM on BS was 28% and relatively higher in right than left breast (33%:24% p=0.068). The average number of BM sites was also significantly greater for the right side (6:4, P<0.0001). The % cumulative risk of BM in right breast was noted at significantly smaller PTS than left side with log rank value of 5.579; p<0.05. The Kaplan Meier survival plot for event free survival of BM in left sided BC was significantly higher than for the right side (log rank value=4.155, p<0.05), with an earlier appearance of BM in right BC. Conclusions: 1) A left sided predominance of BC was seen in local population; 2) right sided BC had a more aggressive behavior with extensive and earlier appearance of BM at relatively younger age, smaller PTS and receptor (s) negativity.