• Title, Summary, Keyword: 군집분석

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Eco-friendly remediation and reuse for coastal dredged materials using a bioaugmentation technology (생물증강법을 이용한 오염해양준설토의 환경친화적 정화 및 재활용)

  • Kim, In-Soo;Ha, Shin-Young;Koh, Sung-Cheol
    • Korean Journal of Microbiology
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    • v.51 no.4
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    • pp.374-381
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    • 2015
  • Occurrences of coastal dredged materials are ever increasing due to port construction, navigational course maintenance and dredging of polluted coastal sediments. Ocean dumping of the coastal dredged materials has become virtually prohibited as London Treaty will be enacted as of the year 2012. It will be necessary to treat and recycle the dredged materials that may carry organic pollutants and heavy metals in a reasonable and effective process: collection of the dredged materials, liquid and solid separation, and treatment of organic compounds and heavy metals. In this study we have developed a continuous bioreactor system that can treat a mixture of silt and particulate organic matter using a microbial consortium (BM-S-1). The steady-state operation conditions were: pH (7.4-7.5), temperature ($16^{\circ}C$), DO (7.5-7.9), and salt concentration (3.4-3.7%). The treatment efficiencies of SCOD, T-N and T-P of the mixture were 95-96%, 92-99%, and 79-97%. The system was also effective in removal of heavy metals such as Zn, Ni, and Cr. Levels of MLSS during three months operation period were 11,000-19,000 mg/L. Interestingly, there was little sludge generated during this period of operation. The augmented microbial consortium seemed to be quite active in the removal of the organic component (30%) present in the dredged material in association with indigenous bacteria. The dominant phyla in the treatment processes were Proteobacteria and Bacteroidetes while dominant genii were Marinobacterium, Flaviramulus, Formosa, Alteromonadaceae_uc, Flavobacteriaceae_uc. These results will contribute to a development of a successful bioremediation technology for various coastal and river sediments with a high content of organic matter, inorganic nutrients and heavy metals, leading to a successful reuse of the polluted dredged sediments.

Mapping and Race Specific Reaction of the Resistance Gene Pi45(t) in Rice (벼 도열병 저항성 유전자 Pi45(t)의 균계 특이적 반응과 고밀도지도 작성)

  • Kim, Dong-Min;Ju, Hong-Guang;Yang, Paul;Han, Seong-Sook;Roh, Jae-Hwan;Ahn, Sang-Nag
    • Korean Journal of Breeding Science
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    • v.43 no.1
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    • pp.42-49
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    • 2011
  • QTL analysis for blast resistance was carried out using 140 $BC_3F_3$ lines derived from a cross between Ilpum as a recurrent parent and Moroberekan as a donor parent. 140 $BC_3F_3$ lines with the parents were inoculated with nine blast isolates. To identify QTLs for resistance to nine blast isolates, 134 SSR markers showing polymorphisms between the parents were genotyped for the 140 $BC_3F_3$ lines. A total of 17 resistance QTLs to nine isolates were detected on chromosomes 2, 3, 4, 6, 7, 9 and 10. The phenotypic variance explained by each QTL ranged from 8.2% to 26.4%. The Moroberekan alleles contributed the positive effect at these 17 QTL loci. In a previous study, the QTL, Pi45(t) for durable resistance to blast was identified using a sequential planting method. To know the relationship between Pi45(t) and the isolate-specific resistance gene, an $F_2$ population was developed from a cross between Ilpum and an introgression line harboring Pi45(t). $F_3$ lines segregating for the Pi45(t) were inoculated to three isolates. $F_3$ lines from the $F_2$ plants with the Moroberekan segment at the target region showed resistance to two isolates. This result seems to indicate that the Pi45(t) and the isolate-specific resistance gene are tightly linked or the resistance is controlled by the same gene(s). The markers linked to genes controlling blast resistance would be useful in developing blast resistance lines in the breeding program.

A Modern Translation of Chinese Traditional Garden Space - Focusing on Qujiang Pool Heritage Park - (중국(中國) 전통원림(傳統園林) 공간(空間) 조영(造營) 원리의 현대적 탐구(探究) - 곡강지(曲江池) 유적공원(遺蹟公園)을 중심으로 -)

  • Wei, Tian-Tian;Kim, Jeong-Moon;Tian, Chao-Yang
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.3
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    • pp.93-107
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    • 2019
  • The purpose of this paper is to explore the application of Chinese traditional garden space construction principle studied by predecessors in modern park landscape, and to find more methods of traditional garden space construction inheritance and innovation through research. Tian Chaoyang's book "Fifteen Lectures on Chinese Classical Gardens and Modern Translation" mentions that Chinese traditional gardens are combining time and space, so he draws a brief pattern diagram containing the principle of the space construction. According to this principle of space construction, the researchers chose Qujiang Pool Heritage Park, which combines modern and traditional, then analyzed its spatial structure and and space elements. The results are as follows. The complex spatial structure of the park is composed of spatial boundary lines and spatial routes. The complex boundary space is composed of bridges, squares, plants, rows of buildings and other elements. The water space in the center of the park is designed in accordance with the traces of the historical water system, and its natural zigzag shoreline expands the water space. The central water space is divided into the big pool and the small pool, the Yanbo island and Bird island are created respectively. The building at the park boundary connects the park's interior and exterior. Most of the buildings in the park are located in the convex corner of the route or space. Through this research, it can be concluded that Qujiang park also applies the space construction principle combining time and space. And then, the garden elements of Qujiang park are recreating the history and culture of Qin, Han, Sui and Tang dynasties with modern methods, thus creating a park with Chinese regional characteristics. Since the Tang dynasty was the most prosperous period in Qujiang, the park was dominated by Tang culture. Through the research of this paper, we can see that the space construction principle of Qujiang Pool Heritage Park is the inheritance of the space construction principle of Chinese traditional garden. And the landscape element of Qujiang park is the landscape created by combining traditional history and culture, which is the innovative part of modern garden. Through this study, the creation of modern landscape with Chinese characteristics can provide some hints on the direction of inheritance and innovation.

The Nature of the Tomb Form and the Group Tomb Complex of the Wooden Chamber Tombs with Stone Mound in the Early Silla Phase (신라 전기 적석목곽분의 묘형과 집단복합묘군의 성격)

  • Choi, Byung-Hyun
    • MUNHWAJAE Korean Journal of Cultural Heritage Studies
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    • v.50 no.4
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    • pp.168-197
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    • 2017
  • This paper considers two aspects of the wooden chamber tombs with stone mound that were constructed in Wolseong North Burial Ground, in Gyeongju: tomb form and the group tomb complex. The basic unit of a wooden chamber tomb with stone mound consisted of a single round mound, covered with an additional earthen layer and surrounded by a circle of protective stones, within which a single wooden chamber was located. The form of a wooden chamber tomb with stone mound could therefore 1) be round, consisting of a single tomb unit, 2) consist of two or more attached tomb units, 3) or consist of multiple attached chambers in a single mound. The single tomb contained the burial of a single individual, and the attached tomb contained two or more individuals who were blood relations or connected by marriage. Multiple attached chambers tombs usually consisted of wooden chamber burials of the lowest rank, and have only been identified in the royal burial area of Wolseong North Burial Ground. At the Jjoksaem Area of Wolseong North Burial Ground, which is currently, under investigation, tombs have been found in small clusters along the slightly raised ground. This is likely the result of small groups of kin relations, upon selecting points along the slightly raised ground as their burial area, having constructed midsized and large single tombs and attached tombs along the axis of the slightly raised ground, which were then surrounded by smaller 'satellite' tombs. It is through this process that the tomb complex of the different groups came to be formed. The tombs of the royal burial area of Wolseong North Burial Ground, including the Daereungwon Tomb Complex, also formed group tomb complexes. Forming the centers of the group tomb complexes of the royal tomb area were huge individual round tombs where the Maripgan rulers were laid to rest or a gourd-shaped dual mound tomb, which was the final resting place of the king and his queen consort. These central tombs were surrounded by large and smaller tombs. Of the individuals that were buried in the group tomb complexes, there would have been individuals that were of equal status or social position, such as husbands and wives or blood relations, but it is unlikely that all of the buried individuals were related by blood, given the significant difference in the sizes of the tombs. It is likely that the individuals buried in the lower ranked tombs included in the group tomb complexes were 'dependents' of the deceased of the central tomb and his or her direct family who maintained a subservient relationship. Such tomb forms and group tomb complexes that can be observed amongst the wooden chamber tombs with stone mounds of Wolseong North Burial Ground provide insights into the nature of the social groups of the Silla center during the Maripgan Period. It is hoped that future studies undertaking a more detailed analysis of the data may make further contributions to unveiling the various aspects of Silla society.

Quantitative Assessment Technology of Small Animal Myocardial Infarction PET Image Using Gaussian Mixture Model (다중가우시안혼합모델을 이용한 소동물 심근경색 PET 영상의 정량적 평가 기술)

  • Woo, Sang-Keun;Lee, Yong-Jin;Lee, Won-Ho;Kim, Min-Hwan;Park, Ji-Ae;Kim, Jin-Su;Kim, Jong-Guk;Kang, Joo-Hyun;Ji, Young-Hoon;Choi, Chang-Woon;Lim, Sang-Moo;Kim, Kyeong-Min
    • Progress in Medical Physics
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    • v.22 no.1
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    • pp.42-51
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    • 2011
  • Nuclear medicine images (SPECT, PET) were widely used tool for assessment of myocardial viability and perfusion. However it had difficult to define accurate myocardial infarct region. The purpose of this study was to investigate methodological approach for automatic measurement of rat myocardial infarct size using polar map with adaptive threshold. Rat myocardial infarction model was induced by ligation of the left circumflex artery. PET images were obtained after intravenous injection of 37 MBq $^{18}F$-FDG. After 60 min uptake, each animal was scanned for 20 min with ECG gating. PET data were reconstructed using ordered subset expectation maximization (OSEM) 2D. To automatically make the myocardial contour and generate polar map, we used QGS software (Cedars-Sinai Medical Center). The reference infarct size was defined by infarction area percentage of the total left myocardium using TTC staining. We used three threshold methods (predefined threshold, Otsu and Multi Gaussian mixture model; MGMM). Predefined threshold method was commonly used in other studies. We applied threshold value form 10% to 90% in step of 10%. Otsu algorithm calculated threshold with the maximum between class variance. MGMM method estimated the distribution of image intensity using multiple Gaussian mixture models (MGMM2, ${\cdots}$ MGMM5) and calculated adaptive threshold. The infarct size in polar map was calculated as the percentage of lower threshold area in polar map from the total polar map area. The measured infarct size using different threshold methods was evaluated by comparison with reference infarct size. The mean difference between with polar map defect size by predefined thresholds (20%, 30%, and 40%) and reference infarct size were $7.04{\pm}3.44%$, $3.87{\pm}2.09%$ and $2.15{\pm}2.07%$, respectively. Otsu verse reference infarct size was $3.56{\pm}4.16%$. MGMM methods verse reference infarct size was $2.29{\pm}1.94%$. The predefined threshold (30%) showed the smallest mean difference with reference infarct size. However, MGMM was more accurate than predefined threshold in under 10% reference infarct size case (MGMM: 0.006%, predefined threshold: 0.59%). In this study, we was to evaluate myocardial infarct size in polar map using multiple Gaussian mixture model. MGMM method was provide adaptive threshold in each subject and will be a useful for automatic measurement of infarct size.

A Study on Developing a VKOSPI Forecasting Model via GARCH Class Models for Intelligent Volatility Trading Systems (지능형 변동성트레이딩시스템개발을 위한 GARCH 모형을 통한 VKOSPI 예측모형 개발에 관한 연구)

  • Kim, Sun-Woong
    • Journal of Intelligence and Information Systems
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    • v.16 no.2
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    • pp.19-32
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    • 2010
  • Volatility plays a central role in both academic and practical applications, especially in pricing financial derivative products and trading volatility strategies. This study presents a novel mechanism based on generalized autoregressive conditional heteroskedasticity (GARCH) models that is able to enhance the performance of intelligent volatility trading systems by predicting Korean stock market volatility more accurately. In particular, we embedded the concept of the volatility asymmetry documented widely in the literature into our model. The newly developed Korean stock market volatility index of KOSPI 200, VKOSPI, is used as a volatility proxy. It is the price of a linear portfolio of the KOSPI 200 index options and measures the effect of the expectations of dealers and option traders on stock market volatility for 30 calendar days. The KOSPI 200 index options market started in 1997 and has become the most actively traded market in the world. Its trading volume is more than 10 million contracts a day and records the highest of all the stock index option markets. Therefore, analyzing the VKOSPI has great importance in understanding volatility inherent in option prices and can afford some trading ideas for futures and option dealers. Use of the VKOSPI as volatility proxy avoids statistical estimation problems associated with other measures of volatility since the VKOSPI is model-free expected volatility of market participants calculated directly from the transacted option prices. This study estimates the symmetric and asymmetric GARCH models for the KOSPI 200 index from January 2003 to December 2006 by the maximum likelihood procedure. Asymmetric GARCH models include GJR-GARCH model of Glosten, Jagannathan and Runke, exponential GARCH model of Nelson and power autoregressive conditional heteroskedasticity (ARCH) of Ding, Granger and Engle. Symmetric GARCH model indicates basic GARCH (1, 1). Tomorrow's forecasted value and change direction of stock market volatility are obtained by recursive GARCH specifications from January 2007 to December 2009 and are compared with the VKOSPI. Empirical results indicate that negative unanticipated returns increase volatility more than positive return shocks of equal magnitude decrease volatility, indicating the existence of volatility asymmetry in the Korean stock market. The point value and change direction of tomorrow VKOSPI are estimated and forecasted by GARCH models. Volatility trading system is developed using the forecasted change direction of the VKOSPI, that is, if tomorrow VKOSPI is expected to rise, a long straddle or strangle position is established. A short straddle or strangle position is taken if VKOSPI is expected to fall tomorrow. Total profit is calculated as the cumulative sum of the VKOSPI percentage change. If forecasted direction is correct, the absolute value of the VKOSPI percentage changes is added to trading profit. It is subtracted from the trading profit if forecasted direction is not correct. For the in-sample period, the power ARCH model best fits in a statistical metric, Mean Squared Prediction Error (MSPE), and the exponential GARCH model shows the highest Mean Correct Prediction (MCP). The power ARCH model best fits also for the out-of-sample period and provides the highest probability for the VKOSPI change direction tomorrow. Generally, the power ARCH model shows the best fit for the VKOSPI. All the GARCH models provide trading profits for volatility trading system and the exponential GARCH model shows the best performance, annual profit of 197.56%, during the in-sample period. The GARCH models present trading profits during the out-of-sample period except for the exponential GARCH model. During the out-of-sample period, the power ARCH model shows the largest annual trading profit of 38%. The volatility clustering and asymmetry found in this research are the reflection of volatility non-linearity. This further suggests that combining the asymmetric GARCH models and artificial neural networks can significantly enhance the performance of the suggested volatility trading system, since artificial neural networks have been shown to effectively model nonlinear relationships.

Community Dynamics of Phytoplankton and Bacteria as Affected by Physicochemical Environmental factors in Hoeya Dam Reservoir (회야댐 저수지에서 물리 ${\cdot}$ 화학적 환경요인에 따른 식물플랑크톤과 세균 군집의 변화)

  • Kim, Dae-Kyun;Choi, Ae-Ran;Lee, Hye-Kyeong;Kwon, O-Seob;Kim, Jong-Seol
    • Korean Journal of Ecology and Environment
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    • v.37 no.1
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    • pp.26-35
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    • 2004
  • We investigated the effect of physicochemical environmental factors on the community dynamics of phytoplanktons and bacteria at the Hoeya Dam Reservoir, a drinking water reservoir for Ulsan city. Water samples were collected and analyzed every two to four weeks at three sites along the reservoir from April to October, 2001. During the study period, the Secchi depths were between 0.4 and 3.5 m. At the surface layer of water column, temperature ranged 10.2 ~ $32.0^{\circ}C$, pH 7.3${\sim}$9.6, dissolved oxygen 5.5 ${\sim}$ 12.4 mg $L^{-1}$, $BOD_5$ 0.8 ${\sim}$ 5.0 mg $L^{-1}$, $COD_{Mn}$ 3.7 ${\sim}$ 10.0 mg $L^{-1}$, and Chl-a 8.9 ${\sim}$ 60.9 mg $m^{-3}$. At the bottom layer, temperature varied 7.2 ${\sim}$ $28.9^{\circ}C$, pH 7.1 ${\sim}$ 9.3, dissolved oxygen 0.6 ${\sim}$ 9.7 mg $L^{-1}$, $BOD_5$ 0.8 ${\sim}$ 4.5 mg $L^{-1}$, $COD_{Mn}$ 3.9 ${\sim}$ 10.0 mg $L^{-1}$, and Chl-a 4.3 ${\sim}$ 81.9 mg $m^{-3}$. The numbers of phytoplanktons were 7.4${\pm}10^2{\sim}2.6{\pm}10^5$ cells $mL^{-1}$ at surface and 2.5${\pm}10^2{\sim}2.4{\pm}10^4$ cells $mL^{-1}$ at bottom, and were positively correlated with water temperature and Chl- a concentration. Genus Stephanodiscus and genus Oscillatoria dominated on April and on May, respectively. Cyanobacterial blooms of Aphanizomenon, Microcystis, Anabaena were observed from June to early September, and thereafter Stephanodiscus and Aulacoseiral dominated again. Total microbial counts ranged 1.73${\pm}10^4{\sim}1.68{\pm}10^5$ cells $mL^{-1}$, and were positively correlated with water temperature and phytoplankton counts at surface water. Heterotrophic plate counts (HPCs) ranged 30${\sim}4.1{\pm}10^3$ CFU $mL^{-1}$, and were positively correlated with $BOD_5$ and $NO^3\;^-$-N concentration at bottom water. Unlike the total microbial counts, the numbers of fecal coliforms and fecal streptococci as well as HPCs were higher at the bottom than the surface layer and were highest at the upper a site among the three sampling sites. Since the concentrations of fecal coliforms and streptococci were still high at the bottom of site c, where intake for water treatment plant is located, it appeared that special management of water treatment processes may be needed especially after strong rainfall.