• 한국대기환경학회지
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• 제32권4호
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• pp.422-434
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• 2016

This study was conducted to understand roles of $NO_x(=NO+NO_2)$ on high $O_3$ episodes at an urban monitoring station in Seoul. Concentrations of NO, $NO_2$, $NO_y$ and $O_3$ were measured intensively at KIST monitoring station which located at urban center in Seoul metropolitan area during May 18~June 13, 2015. Sampling period was planed because high $O_3$ and PM occurred frequently during from late spring to early summer months in Seoul. The experimental site locates in NW from center of Seoul and is surrounded by residential area. Belt highway of the city runs from north to west side nearby experimental site. Vehicle exhaust emissions due to heavy traffic influenced $NO_x$ concentration at the site during northwesterly wind. Specific $NO_2$ concentration was measured by Blue Light photolytic converter, and it was compared to $NO_2$ concentration measured by molybedenum converter. $[NO_2]_{phtolysis}$ was usually lower than $[NO_2]_{molybedenum}$ during the experiment period; however their diurnal variations were very similar. The linear relationship between these $NO_2$ concentrations was found to be $[NO_2]_{phtolysis}$=0.64 $[NO_2]_{molybedenum}$ - 2.6, $r^2$=0.83 during May 16~8, 2015. The difference between $NO_2$ by molybdenum converter and by photolytic converter (${\Delta}NO_2=[NO_2]_{molybedenum}-[NO_2]_{phtolysis}$) accounted for residual $NO_y$ which can represent $NO_z$ (=$NO_y-NO_x$). $O_3$ concentration showed typical daily trend which has maximum at late afternoon and minimum during the night. $O_3$ increased at a rate of 7 ppb/hr since 8 am. and reached the maximum concentration (~80 ppb) at 3 pm.. The diurnal pattern of $O_3$ was inversely related with that of $NO_2$, suggesting that the formation of $O_3$ was the result of photochemical activity of $NO_2$.

• 한국환경농학회지
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• 제17권3호
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• pp.279-285
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• 1998

논, 밭, 임야, 오염지 토양과 폐수 등 124 지점의 미생물 급원에서 fenitrothion 분해미생물을 탐색하였다. 그 결과 총 1,071 균주를 1차 분리하였다. 배지별로는 nutrient agar, potato dextrose agar, Actinomyces isolation agar 및 basal salt medium 고체배지에서 각각 601, 201, 168, 101종의 활성균주를 1차 분리하였다. 이 중에서 fenitrothion 분해력이 상대적으로 우수한 미생물을 선발하기 위하여 액체배양을 통한 GLC분석 결과 분해율이 80% 이상인 균주 28종을 2차 선발하였다. 이들을 선발배지별, 미생물 급원별로 살펴보면 NA 배지에서는 논토양에서 3종, 밭 토양에서 3종, 임야 토양에서 2종, 오염지 토양에서 4종이 각각 분리되어 총 12종이 분리되었다. PDA 배지에서는 논 토양에서 1종, 밭 토양에서 2종, 임야 토양에서 2종, 오염지 토양에서 3종이 각각 분리되어 총 8종이 분리되었다. BSM 배지에서는 논 토양에서 1종, 임야 토양에서 1종, 오염지 토양엣 6종이 각각 분리되어 총 8종이 분리되었다. 그러나 AIA 배지에서는 모든 균주가 fenitrothion 분해율이 50% 이하이었다. 한편 100mg/ l의 고농도 fenitrothion 첨가 배지에서 2차 선발 균주를 강화배양하면 세균 중에는 Npa1과 NFo1 균주가, 사상균 중에서는 PFo1과 BPo1 균주가 분해율이 가장 높은 것으로 나타났다.

• 원예과학기술지
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• 제32권2호
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• pp.241-251
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• 2014

본 연구는 남부 지방에서 널리 사용되고 있는 상록활엽수인 돈나무의 내한성 예측을 위한 편리하고 신뢰성 있는 평가 모델 개발을 목적으로 전해질 용출법을 통한 내한성 평가에서 나타나는 실험방법 상의 오차를 최소화하는 내한성 평가 모델을 도출하고자 수행되었다. 평가 모델링은 저온 처리된 식물체에 대한 재생검사와 전해질 용출 평가로 구성되었고, 전해질 용출법에서 표본조직 선택, 최대 전해질 용출 측정을 위한 온도 처리법, 치사 온도 예측을 위한 통계 분석법에 의한 방법적 조합들로부터 예측된 치사 온도들이 재생검사 결과와 비교되었다. 재생 검사 결과 돈나무의 저온 치사 온도는 50% 미만의 생존율을 보이는 최고온도인 $^-10{\circ}C{\sim}-5^{\circ}C$로 분석되었고, 이 결과를 바탕으로 전해질 용출법에 의해 예측된 저온 치사 온도를 분석한 결과, 잎을 표본 조직으로 하여 냉각치사법으로 최대 전해질 용출을 측정한 방법적 조합에서 재생 검사 결과와 가장 근접한 예측 저온 치사 온도가 나타났다. 저온 치사온도 예측을 위한 통계 모델 평가에서는 선형보간법이 비선형회귀에 비하여 내한성을 과대평가하는 경향이 상대적으로 높았다. 결론적으로 돈나무 내한성 예측을 위한 내한성 평가 모델은 잎을 표본 조직으로 사용하고, 최대 전해질 용출 측정을 위한 온도 처리 방법으로 냉각치사법을 적용하며, 치사온도 예측을 위한 통계 분석 기법으로 비선형회귀를 활용하는 방법적 구성이 가장 적합한 것으로 나타났다.

• 한국산학기술학회논문지
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• 제19권10호
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• pp.559-568
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• 2018

본 연구는 한국 노인의 건강 및 건강행태 관련요인을 중심으로 성별에 따른 복부비만에 영향을 주는 요인을 파악하기 위해 수행되었다. 본 연구는 질병관리본부에 의해 2015년 1월부터 12월까지 시행된 제 6기 국민건강영양조사의 원시자료를 사용하였다. 본 연구의 대상자는 만 65세 이상 노인 중 허리둘레를 측정 한 남자 599명 (Weighted n=3,037,943), 여자 793명(Weighted n=3,840,452)이었다. 자료는 IBM SPSS 23.0 프로그램으로 복합표본설계 방법을 통해 분석하였다. 연구결과, 본 연구에서 한국노인은 성별에 따라 인구사회학적 요인, 건강관련 요인 및 건강행태에 있어 유의한 차이를 보였다. 남성노인의 복부비만 비율은 38.3%, 여성노인의 복부비만 비율은 50.5%인 것으로 나타났다. 건강 및 건강행태 관련 요인 중 한국의 남성노인의 복부비만에 영향을 주는 요인은 폭음빈도, 여성노인은 주관적 건강상태가 유의한 영향요인인 것으로 나타났다. 그러므로 한국 노인의 복부 비만 관리를 위한 프로그램은 성별에 따른 건강관련 요인 및 건강행태의 차이를 고려할 필요가 있다. 이에 남성의 경우 다양한 영향요인을 고려한 폭음관리 전략이 요구되며, 여성의 경우 주관적 건강상태에 따른 복부비만의 원인 분석 및 관리방법이 적용되어야 할 것이다.

• 한국대기환경학회지
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• 제29권6호
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• pp.789-800
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• 2013

$N_2O$ and $CH_4$, Greenhouse gas emission, Forest soil, Closed chamber technique, Soil uptake $N_2O$ and $CH_4$ are important greenhouse gases (GHG) along with $CO_2$ influencing greatly on climate change. Their soil emission rates are highly affected by bio-geo-chemical processes in C and N through the land-atmosphere interface. The forest ecosystems are generally considered to be net emission for $N_2O$; however, net sinks for $CH_4$ by soil uptake. Soil $N_2O$ and $CH_4$ emissions were measured at Mt. Taewha in Gwangju, Kyeonggi, Korea. Closed chamber technique was used for surface gas emissions from forest soil during period from May to October 2012. Gas emission measurement was conducted mostly on daytime (from 09:00 to 18:00 LST) during field experiment period (total 25 days). The gas samples collected from chamber for $N_2O$ and $CH_4$ were analyzed by gas chromatography. Soil parameters were also measured at the sampling plot. GHG averages emissions during the experimental period were $3.11{\pm}16.26{\mu}g m^{-2}hr^{-1}$ for $N_2O$, $-1.36{\pm}11.3{\mu}gm^{-2}hr^{-1}$ for $CH_4$, respectively. The results indicated that forest soil acted as a source of $N_2O$, while it acted like a sink of $CH_4$ on average. On monthly base, means of $N_2O$ and $CH_4$ flux during May (spring) were $8.38{\pm}48.7{\mu}gm^{-2}hr^{-1}$, and $-3.21{\pm}31.39{\mu}gm^{-2}hr^{-1}$, respectively. During August (summer) both GHG emissions were found to be positive (averages of $2.45{\pm}20.11{\mu}gm^{-2}hr^{-1}$ for $N_2O$ and $1.36{\pm}9.09{\mu}gm^{-2}hr^{-1}$ for $CH_4$); which they were generally released from soil. During September (fall) $N_2O$ and $CH_4$ soil uptakes were observed and their means were $-1.35{\pm}12.78{\mu}gm^{-2}hr^{-1}$ and $-2.56{\pm}11.73{\mu}gm^{-2}hr^{-1}$, respectively. $N_2O$ emission was relatively higher in spring rather than other seasons. This could be due to dry soil condition during spring experimental period. It seems that soil moisture and temperature mostly influence gas production and consumption, and then emission rate in subsoil environment. Other soil parameters like soil pH and chemical composition were also discussed with respect to GHG emissions.

• 한국산학기술학회논문지
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• 제19권1호
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• pp.660-665
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• 2018

세계적으로 해양 자원 개발을 비롯하여 재난 방지 및 군사적 목적 등을 위하여 수중 환경 감시 및 제어를 가능하게 하는 수중 무선 통신망에 대한 연구가 활발히 진행되고 있다. 국내에서도 호서대학교를 중심으로 '분산형 수중 관측 제어망'에 대한 연구가 진행되고 있는데, 본 논문에서는 해당 제어망 중 수중기지제어국과 수중기지국 사이의 음파 통신을 위한 인터폴레이터(Interpolator)를 연구하였다. 수중 음파 통신망은 양방향 듀플렉스(duplex) 통신을 위하여 서로 다른 4개의 주파수 링크를 정의하고 있으며, 링크에 따라 100배 혹은 200배 샘플링 레이트를 변환해야 한다. 또, 수중은 전원 공급이 원활하지 않은 환경이므로 저전력 설계가 중요하다. 따라서 저전력 인터폴레이터인 CIC 인터폴레이터를 기본으로 하여 링크에 따라 샘플링 레이트를 선택할 수 있도록 설계하였다. 하지만 CIC 인터폴레이터는 통과 대역 감쇠(passband droop)가 크고, 전이영역(transition region)이 넓기 때문에 채널 간격이 비교적 좁은 음파 통신에서는 저주파 대역 필터로서의 조건을 만족하기 어렵다. 이러한 문제를 해결하기 위하여 본 논문에서는 통과 대역 감쇠를 보상하기 위한 보상 필터(compensator)와 전이 영역을 줄이기 위한 하프밴드 필터(halfband filter)를 추가하였다. Matlab을 이용하여 알고리즘을 검증한 후 Verilog-HDL로 하드웨어를 설계하고 Modelsim에서 시뮬레이션하여 동작을 검증하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제22권8호
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• pp.1180-1185
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• 2009

Two experiments were carried out to study the effects of dietary energy level on nutrient digestion, nitrogen (N) utilization, growth performance, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding protein-3 (IGFBP-3) in plasma, liver and longissimus dorsi muscle in growing-finishing pigs. In experiment 1 (Exp 1), 15 castrated male pigs (Duroc${\times}$Landrace${\times}$Large White) (Body weight, BW, 55.6${\pm}$1.8 kg) were divided into three groups and fed rations containing 13.33, 14.87 and 17.35 MJ digestible energy (DE)/kg as treatments I, II and III, respectively, using soybean oil as an energy source. The experiment lasted 8 days and faecal and urinary samples were collected during the last 3 days. The results showed that the digestibility of dry matter (DM), energy and N was increased from treatments I to III (p<0.01). N-retention and N-retention rate were not influenced by dietary DE level (p>0.05). In experiment 2 (Exp 2), 36 female pigs (Duroc${\times}$Landrace${\times}$Large White) (BW 41.5${\pm}$3.8 kg) were divided into three groups. The pigs were fed with the same three rations used in Exp 1 for 60 days. At the end of Exp 2, eight pigs were selected from each group for blood sampling and 4 pigs for slaughter trial. The results indicated that average daily feed intake (ADFI) and N-intake were significantly decreased (p<0.01), and DE intake (p<0.01) and average daily gain (ADG) (p<0.05) were increased. IGF-I and IGFBP-3 in plasma were increased (p<0.05). No significant differences in IGF-I and IGFBP-3 in liver and longissimus dorsi muscle were found between different treatments. It was concluded that higher dietary DE level improved nutrient digestibility, ADG and feed/gain ratio when soybean oil was used as an energy source in the ration of growing-finishing pigs. No significant differences were found in Nretention and IGF-I and IGFBP-3 in liver and longissimus dorsi muscle between different treatments.

• 유통과학연구
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• 제10권8호
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• pp.25-34
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• 2012

Understanding customer' lifestyles important for banks because it will guide in determining marketing policies, such as services, pricing, service delivery and promotion decisions. From the customer' lifestyle, banks will know what kind of customers' attitudes, interests and opinions, so they also will understand what the costumer' needs and what services needed by them. For Islamic banks, customers understanding are important because, nowadays, the competition of the banks is not only with other Islamic banks but also with the well-established conventional banks offering Islamic products or services The aims of this research paper are to describe what factors underline the customer's lifestyle of both Islamic and conventional bank, to segment the bank customers based on their lifestyles and investigate the profile of each segments, to compare the characteristics of the segments, and to identify marketing policies based on the characteristics. The population of the study is banking customers in Indonesia, in which the researchers have used judgment sampling as sample selection. There were 186 customers of Islamic banks and 244 customers of conventional bank as respondents in this study. Statistical methods employed were exploratory factor analysis and cluster analysis. The finding of the study shows that there are twelve factor underlining the customers' lifestyle, namely: factor of fashion conscious, internet usage, sports spectator, financial and technology optimism, price sensitivity, independent, compulsive housekeeper, new brand tryer community activities, opinion leader, credit usage, and homebody. In addition, for Islamic banking, there are two market segments, namely fashionable-independent and innovative-social segment. Based on the lifestyle characteristics, the first segment has higher level in factor of fashion conscious, homebody, independent, optimism and price conscious, which is therefore called fashionable-independent segment. On the other hand, the second cluster has higher level in factor of new brand tryer, community minded, sport spectator, credit user, internet usage, opinion leader, and compulsive housekeeper, which is therefore called the innovative-social segment. Furthermore, for conventional banking, there are also two segments, namely persuasive-optimistic and sensitive-independent segment. The first segment has higher level on some factors, namely: opinion leader, optimism, internet usage rate, credit usage level, sport spectator, and new brand tryer. On the other hand, the second cluster is characterized by higher level in factor of price conscious, confidence, community minded, homebody, fashion conscious, and compulsive housekeeper. Managerial implications for the management of Islamic banks could be identified in this study as follows. Firstly, the twelve lifestyle factors of this study could be an alternative view in observe Islamic banking customers. The domination of both the fashionable conscious and the internet usage factor show that the aspects are quite instrumental in perceiving the customer' lifestyles, in which reflects the importance of these two aspects to customers. Secondly, in serving their customers, Islamic banks need to understand the customer lifestyle, in which the lifestyle segments found in this study provide a guide of how their needs were reflected. Finally, by understanding the segments and the characteristics each segment of the conventional banks, Islamic banks could adjust their marketing strategies differently from the conventional banks.

• 한국대기환경학회지
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• 제29권1호
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• pp.74-85
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• 2013

Since the underground transportation system is a closed environment, indoor air quality problems may seriously affect many passengers' health. The purpose of this study was to understand $PM_{10}$ characteristics in the underground air environment and further to quantitatively estimate $PM_{10}$ source contributions in a Seoul Metropolitan subway station. The $PM_{10}$ was intensively collected on various filters with $PM_{10}$ aerosol samplers to obtain sufficient samples for its chemical analysis. Sampling was carried out in the M station on the Line-4 from April 21 to 28, July 13 to 21, and October 11 to 19 in the year of 2010 and January 11 to 17 in the year of 2011. The aerosol filter samples were then analyzed for metals, water soluble ions, and carbon components. The 29 chemical species (OC1, OC2, OC3, OC4, CC, PC, EC, Ag, Al, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Si, Ti, V, Zn, $Cl^-$, $NO_3{^-}$, $SO_4{^{2-}}$, $Na^+$, $NH_4{^+}$, $K^+$, $Mg^{2+}$, $Ca^{2+}$) were analyzed by using ICP-AES, IC, and TOR after proper pretreatments of each sample filter. Based on the chemical information, positive matrix factorization (PMF) model was applied to identify the $PM_{10}$ sources and then six sources such as biomass burning, outdoor, vehicle, soil and road dust, secondary aerosol, ferrous, and brakewear related source were classified. The contributions rate of their sources in tunnel are 4.0%, 5.8%, 1.6%, 17.9%, 13.8% and 56.9% in order.

• 한국정보통신학회논문지
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• 제20권12호
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• pp.2317-2325
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• 2016

본 논문은 reference driver를 이용한 10비트 10MS/s 축차근사형(SAR: Successive Approximation Register) 아날로그-디지털 변환기(ADC: Analog-to-Digital Converter)를 제안한다. 제안하는 SAR ADC는 커패시터형 디지털-아날로그 변환기(CDAC: Capacitive Digital-to-Analog Converter), 비교기, SAR 로직, 그리고 공급 전압 노이즈에 대한 내성을 향상시키는 reference driver로 구성된다. ${\pm}0.9V$의 아날로그 입력전압을 가지는 SAR ADC를 위해 reference driver는 0.45V, 1.35V의 기준 전압을 생성한다. 설계된 SAR ADC는 $0.18{\mu}m$ CMOS 공정을 이용하여 제작되었으며 1.8V의 공급전압을 사용하였다. 제안된 SAR ADC는 reference driver를 이용하여 +/- 200mV의 공급 전압 변화에서도 ${\pm}0.9V$의 입력 범위를 유지한다. 10MS/s의 샘플링 주파수에서 5.32mW의 전력을 소모한다. 측정된 ENOB는 9.11 비트 이며, DNL과 INL은 각각 +0.60/-0.74 LSB와 +0.69/-0.65 LSB이다.