• ALGAE
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• 제32권4호
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• pp.349-357
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• 2017

Korean mariculture Undaria pinnatifida was collected during the months of January, February, March, and December of 2010, as well as from January of 2011 to investigate the changes in the carbon and nitrogen stable isotope ratios (${\delta}^{13}C$ and ${\delta}^{15}N$) and heavy metal with respect to it growth and to identify the factors that influence such changes. The blades of U. pinnatifida showed ${\delta}^{13}C$ and ${\delta}^{15}N$ in the range (mean) of -13.11 to -19.42‰ (-16.93‰) and 2.99 to 7.57‰ (4.71‰), respectively. Among samples with the same grow-out period, those that weighed more tended to have higher ${\delta}^{13}C$ suggesting a close association between the carbon isotope ratio and growth rate of U. pinnatifida. Indeed, we found a very high positive linear correlation between the monthly average ${\delta}^{13}C$ and the absolute growth rate in weight ($r^2=0.89$). Nitrogen isotope ratio tended to be relatively lower when nitrogen content in the blade was higher, probably due to the strengthening of isotope fractionation stemming from plenty of nitrogen in the surrounding environment. In fact, a negative linear correlation was observed with the nitrate concentration in the nearby seawaters ($r^2=0.83$). Concentrations of Cu, Cd, Pb, Cr, Hg, and Fe in the blades showed a rapid decrease in their concentration per unit weight in the more mature U. pinnatifida. Specifically, compared to adult samples, Cu, Hg, and Pb were concentrated by 30, 55, and 73 folds, respectively, in the young blades. Therefore, U. pinnatifida tissue ${\delta}^{13}C$ is as an indirect indicator of its growth rate, while ${\delta}^{15}N$ values and heavy metal concentrations serve as tracers that reflect the environmental characteristics.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권3호
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• pp.1-10
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• 2013

This study was performed to summarize application of ${\delta}^{13}C$, ${\delta}^{37}Cl$ and ${\delta}D$ of trichloroethylene (TCE) to studies on environmental forensic field regarding identification of TCE sources and evaluation of contribution of TCE to groundwater using data collected from literatures. ${\delta}^{13}C$, ${\delta}^{37}Cl$ and ${\delta}D$ of TCE give some information regarding sources of TCE because they show specific value according to manufacturing method. Also, TCE do not show a significant isotopic fractionation owing to adsorption and dilution. The isotopic fractionation mainly occurs by biodegradation. In addition, isotopic fractionation factor for TCE is different according to a kind of microorganism participated in biodegradation. However, the isotopic data of TCE have to be applied with chemical compositions of TCE and other hydrogeologic factors because isotopic fractionation of TCE is influenced by various factors.

• Journal of the korean society of oceanography
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• 제32권2호
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• pp.63-68
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• 1997

Stable isotope profiles with fine-scale resolution were constructed from the fossil mollusk shells, Mercernaria mercernaria, obtained from the late Pleistocene transgressive deposits of Gomez Pit, Virginia, USA. Incremental sampling were made along the axis of maximum growth to provide high-resolution ${\delta}^{18}$O and ${\delta}^{13}$C records. The ${\delta}^{18}$O shell profiles exhibit a series of pronounced cycles in the overall amplitude, corresponding to strong seasonal variations in temperature, which is apparently positive environmental variable. Contrasts between the patterns of ${\delta}^{18}$O and ${\delta}^{13}$C profiles reflect the relationship influencing the seasonal carbon cycling in the shallow marine environment. Positive anomalies of the ${\delta}^{13}$C values during the summer were observed to be out of phase with the ${\delta}^{18}$O profile. Such relatively heavier carbon source may be alternated due to seasonal methanogenesis during the summer. A hypothesized methane-based system may be operated in the shallow and marginal marine environment, resulting in a ${\delta}^{13}$C enriched bicarbonate pool, in which the heavier isotope seems to be incorporated to the shell carbonate.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권5호
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• pp.10-19
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• 2012

The aim of this study was to examine chemical and isotopic compositions of groundwater and lake water near an area contaminated by petroleum and to evaluate influence of petroleum on them during the period from March to August 2011. In dry season, $Ca^{2+}$ and $SO{_4}^{2-}$ were dominant in the groundwater and lake water and $Ca^{2+}$ and $HCO{_3}^-$ were significant in wet season. ${\delta}^{18}O$ and ${\delta}D$ of the groundwater and lake water were plotted near LMWL (${\delta}D=8.06{\delta}^{18}O+12.5$). ${\delta}^{18}O$ and ${\delta}D$ of the lake water did not show seasonal variation. However, ${\delta}^{18}O$ and ${\delta}D$ of the groundwater were enriched in wet season compared with those in dry season because of influence of small ponds around wells where evaporation losses were slightly experienced. Redox condition of most lake water was oxidation environment in contact with the atmosphere during the study period. However, redox condition of groundwater was transitional environment in dry season and oxidation environment in wet season because of influence of contaminant such as petroleum. In some groundwater, the concentrations of $NO{_3}^-$ in some groundwater were less than 1 mg/L because of denitrification. Also, $NO{_3}^-$ showed positive correlation with $SO{_4}^{2-}$ and weak negative correlation with $HCO{_3}^-$, because of influence of denitrification.

• 분석과학
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• 제32권2호
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• pp.65-76
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• 2019

Despite the expansion of sewage treatment facilities to reduce pollutants in the tributaries of the Han River, water pollution accidents such as fish deaths continue to frequently occur. The purpose of this study was to identify the pollutant sources using water quality and stable isotope ratio (${\delta}^{15}N$, ${\delta}^{13}C$, ${\delta}^{15}N-NH_4$, ${\delta}^{15}N-NO_3$) analysis results in the three inflow tributaries (Gulpocheon (GP), Anyangcheon (AY) and Sincheon (SC)) of the Han River. Water quality was analyzed in June and October from 2013 to 2017, and the results showed that the concentrations of nutrients, such as T-N, $NO_3-N$, and T-P, were increased at GP4, AY3, SC3, and SC4, which lie downstream of sewage treatment facilities. The results of ${\delta}^{15}N$ for June 2017 indicated that the source of nitrogen was sewage or livestock excreta at GP4 and SC4, and organic fertilizers at AY3 and SC3. ${\delta}^{15}N-NO_3$ results suggested that the source of nitrogen was related to organic sewage, livestock or manure at GP4, AY3 and SC4. Therefore, GP4 and SC4 were more influenced by effluent from sewage treatment facilities than by their tributaries, AY3 and SC3 were considered to be influenced more by their tributary than effluent from sewage treatment facilities. With the results of this study, the source of contamination (sewage treatment facility effluent) of river inflow downstream of Han River could be confirmed using water quality and stable isotope ratio.

• 한국환경과학회지
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• 제12권2호
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• pp.139-144
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• 2003

The Yellow River began ceasing affected by natural factors and the unreasonable human activities. The flow broke in the Yellow River and water and sediment flowing into the sea decreased, which lowered the speed of newly formed wetland extending to the sea. The water environment deteriorated; Its composing structure tended to be unsteady; The biologic diversity decreased and wetland function reduced. To ensure that the Yellow River delta and its ecosystem develops sustainablly, it is significant to reduce times and days of the ceasing, keep certain runoff and sediments in the river to the sea and make its watercourse stable.

• 한국물환경학회지
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• 제31권2호
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• pp.159-165
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• 2015

The organic matter sources of phytoplankton and related environmental factors influencing algal bloom in Paldang reservoir were studied using nitrogen and carbon isotope ratio(${\delta}^{15}N$, ${\delta}^{13}C$). Phytoplankton samples for stable isotope analysis were collected from four points in reservoir using a plankton net. Physicochemical water quality, algal taxa and hydrological data were collected from published monitoring material. Phytoplankton samples were analyzed by IRMS. CN ratio of each sample was very similar to that of phytoplankton from literature cited. ${\delta}^{15}N$ of each sample was decreased during July. Mixing and dilution of nitrogen sources due to increment of influx by concentrated rainfall were considered as the main reason for the decline of ${\delta}^{15}N$. Based on analyzed ${\delta}^{15}N$ value of each sample, nitrogen source of Bughan river sample was presumed to come from soil. The nitrogen sources of Namhan river and Kyeongan stream samples seemed to be sewage or animal waste. Low ${\delta}^{15}N$ value in August (2012) seemed to be influenced by isotope fractionation due to the blooming of nitrogen-fixation blue-green algae (Anabaena spp.). Variation in ${\delta}^{15}N$ values particularly by blue-green algal bloom was considered the important factor for estimating the organic matter sources of phytoplankton.

• 암석학회지
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• 제28권1호
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• pp.1-13
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• 2019

길이 및 간격-누적빈도 도표를 통하여 도출한 파라미터를 이용하여 쥬라기 거창화강암에서 발달하는 결의 특성을 분석하였다. 3개 면 및 3개 결의 평가는 (1~2) 경사각(${\alpha}^{\circ}$및 ${\beta}^{\circ}$), (3) 교차각(${\alpha}-{\beta}^{\circ}$), (4) 지수차(${\lambda}_S-{\lambda}_L$), (5~12) 선의 길이(oa, ob, ol, os, ss', ll', ls' 및 sl'), (13~15) 길이 비(ol/os, ss'/ll' 및 ll'/sl'), (16) 평균길이((ss'+ll')/2), (17~23) 면적(${\Delta}oaa^{\prime}$, ${\Delta}obb^{\prime}$, ${\Delta}oaa_a^{\prime}$, ${\Delta}obb_a^{\prime}$, ${\Delta}ll^{\prime}s^{\prime}$, ${\Delta}ss^{\prime}l^{\prime}$ 및 ⏢$ll^{\prime}ss^{\prime}$) 및 (24~25) 면적차(${\Delta}obb^{\prime}-{\Delta}oaa^{\prime}$ 및 ${\Delta}obb_a^{\prime}-{\Delta}oaa_a^{\prime}$)와 같은 25개 파라미터를 이용하여 수행하였다. 첫째로, 11개 파라미터(그룹 I: No. 1, 3~4, 7, 9~10, 13, 15~16, 20 및 25), 3개 파라미터(그룹 II: No. 5, 8 및 17) 그리고 2개 파라미터(그룹 III: No. 12 및 22)의 값은 각각 H(3번 결) < G(2번 결) < R(1번 결), R < G < H 및 G < H < R의 순서이다. 반면에, 상기한 3개 그룹에 속하는 파라미터의 값은 3개 면에 대하여 역순을 보여준다. 둘째로, 3개 면 및 3개 결에 대한 종합도를 작성하였다. 관계도로부터, 길이와 간격과 관련된 두 도표가 형성하는 분포형을 도출하였다. 간격과 관련된 도표는 일번 면(G1 & H1, R') 및 3번 결(H1 & H2, H)의 도면에서 상향만곡을 보여준다. 반면에, 길이와 관련된 도표는 하향 만곡을 보여준다. 이들 두 도표는 상부구간에서 볼록렌즈의 형태를 취한다. 더불어, 두 도표는 하부구간에서 서로 교차한다. 3개 면($H^{\prime}{\rightarrow}G^{\prime}{\rightarrow}R^{\prime}$) 그리고 3개 결($R{\rightarrow}G{\rightarrow}H$) 사이의 두 도표가 형성하는 전반적인 형태는 역순을 보여준다. 마지막으로, 이러한 유형의 상관성 분석은 3개 채석면의 판별에 유용하다.

• 한국해양공학회지
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• 제21권2호
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• pp.22-34
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• 2007

We present basic data for developing new research topics and closely examine the existing data on the development and organization of the Nakdong River Estuary Delta by analyzing various studies of the area, including ocean engineering, coastal engineering, ocean environmental engineering, geomorphological, and geological studies. We first defined the general concepts related to the estuary and delta and reviewed the historical development of the Nakdong River Estuary Delta over the past 100 years. We then examined the origin and core elements of the estuary deposits that constitute the delta. In addition, we scrutinized the main factors affecting the development of the delta and analyzed existing research on delta development mechanisms by core researchers. The construction of an estuary barrage is one of the main factors effecting estuarine circulation and has altered the physical oceanic environment, area of deposition, atmospheric environment, and vegetation community of the delta. These factors affect the estuary circulation in turn, altering the delta. Along the Nakdong River, an unsteady-state sandy barrier appears at approximately three times the distance of the wavelength of incident offshore waves, and this terrain forms approximately 10-15 years after reclamation in the interdistributary upper stream and transforms the shoreline. It is necessary to develop a technique to predict terrain change that reproduces the erosion and accumulation of estuarine deposits. To determine the parameters and variables necessary to reproduce this system, continuous on-site monitoring is necessary. The existing research did not fully examine the terrain changes in Nakdong River Estuary or the periodic developmental characteristics. To understand the future process of estuary delta development, it is necessary to establish an integrated management system.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.469-472
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• 2005

본 논문에서는 음석인식 시스템을 구현함에 있어서 잡음의 영향에 강인한 특성을 가지는 효과적인 음성특징 파라미터에 대해 제안한다. ASR(Automatic Speech Recognition)에 사용되는 가장 기본적인 파라미터인 MFCC와 DCT를 이용한 DCTCs를 기본적인 파라미터로 설정하였다. 또한, 음성의 변이구간에 대한 정보를 가지도록 Cepstrum을 재구성한 delta-Cepstrum, delta-delta-Cepstrum 파라미터를 제안하고, HMM을 이용하여 인식성능을 비교하였다. 그리고 각각의 파라미터의 차원을 축소하기 위해 LDA 알고리즘을 적용하고 이에 대한 인식성능을 비교하였다. 실험결과 다양한 조건의 잡은 환경에서 기존의 파라미터보다 LDA를 이용하여 차원 축소된 delta-delta-Cepstrum 파라미터가 향상된 인식성능을 나타내었다.