• Title/Summary/Keyword: AR(1)

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Synthetic Streamflow Generation Using Autoregressive Modeling in the Upper Nakdong River Basin

  • Rubio, Christabel Jane P.;Oh, Kuk-Ryul;Ryu, Jae-H.;Jeong, Sang-Man
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.1
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    • pp.81-88
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    • 2010
  • The analysis and synthesis of various types of hydrologic variables such as precipitation, surface runoff, and discharge are usually required in planning and management of water resources. These hydrologic variables are mostly represented using stochastic models. One of which is the autoregressive model, that gives promising results in time series modeling. This study is an application of this model, which aimed to determine the AR model that best represents the historical monthly streamflow of the two gauging stations, namely Andong Dam and Imha Dam, both located in the upper Nakdong River Basin. AR(3) model was found to be the best model for both gauging stations. Parameters of the determined order of AR model ($\phi_1$, $\phi_2$ and $\phi_3$) were also estimated. Using several diagnostic tests, the efficiency of the determined AR(3) model was tested. These tests indicated the accuracy of the determined AR(3) model.

SiO2 식각 시 CF4+Ar 혼합비에 따른 플라즈마 내의 화학종 분석

  • Hong, Gwang-Gi;Yang, Won-Gyun;Ju, Jeong-Hun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.238-239
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    • 2011
  • 최근 반도체 산업은 더 높은 성능의 회로 제작을 통해 초고집적화를 추구하고 있다. 이를 위해서 회로 설계의 최소 선폭과 소자 크기는 지속적으로 감소하고 있고 이를 위한 배선 기술들은 플라즈마 공정을 이용한 식각공정에 크게 의존하고 있다. 식각공정에 있어서 반응가스의 조성은 식각 속도와 선택도를 결정하는 중요한 요소이다. 본 연구에서는 CIS QMS (closed ion source quadrupole mass spectrometer)를 이용하여 CF4+Ar를 이용한 실리콘 산화막의 플라즈마 식각 공정 시 생성되는 라디칼과 이온 종들을 측정하였다. Ar 이온이 기판표면과 충돌하여 기판물질간의 결합을 깨놓으면, 반응성 기체 및 라디칼과의 반응성이 커져서 식각 속도를 향상 시키게 된다. 본 실험에서는 2 MHz의 RPS (remote plasma source)를 이용하여 플라즈마를 발생시키고 13.56 MHz의 rf 전력을 기판에 인가하여 식각할 웨이퍼에 바이어스 전압을 유도하였다. CF4/(CF4+Ar)의 가스 혼합비가 커질수록 식각 부산물인 SiF3의 양은 증가 하였으며, CF4 혼합비가 0일 때(Ar 100%) 비하여 1일 때(CF4 100%) SiF3의 QMS 이온 전류는 106배 증가하였다. 이때의 Si와 결합하여 SiF3를 형성하는 F라디칼의 소모는 0.5배로 감소하였다. 또한 RPS power가 800 W일 때 플라즈마에 의해서 CF4는 CF3, CF2, CF로 해리 되며 SiO2 식각 시 라디칼의 직접적인 식각과 Si_F2의 흡착에 관여되는 F라디칼의 양은 CF3 대비 7%로 검출되었고, 식각 부산물인 SiF3는 13%로 측정되었다. Ar의 혼합비를 0 %에서 100%까지 증가시켜 가면서 측정한 결과 F/CF3는 $1.0{\times}105$에서 $2.8{\times}102$로 변화하였다. SiF3/CF3는 1.8에서 6.3으로 증가하여 Ar을 25% 이상 혼합하는 것은 이온 충돌 효과에 의한 식각 속도의 증진 기대와는 반대로 작용하는 것으로 판단된다.

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Steroidogenic acute regulatory protein (StAR) and peripheral-type benzodiazepine receptor (PBR) are decreased in human apoptotic embryos

  • Lee, Hyo-Jin;Kim, Jin-Hee;Yang, Hyun-Won
    • Animal cells and systems
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    • v.15 no.3
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    • pp.211-218
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    • 2011
  • Fragmentation in human pre-implantation embryos has been suggested as the process of apoptosis. We have previously demonstrated a direct relationship between the increased reactive oxygen species (ROS) and apoptosis in human pre-implantation embryos. ROS is known to suppress the function of mitochondria in which steroidogenic acute regulatory protein (StAR) and peripheral-type benzodiazepine receptor (PBR) are presented. Therefore, the purpose of this study was to examine the expression of StAR and PBR in human pre-implantation embryos and to evaluate whether reduction of these proteins is associated with apoptosis. Apoptosis was detected by annexin V-fluorescein isothiocyanate (FITC) and mitochondrial membrane potential was measured by 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-benzimidazolyl-carbocyanine iodide (JC-1). Immunofluorescence staining and Western blotting were applied to examine the expression of StAR and PBR in the embryos. Lipid droplets in the embryos were stained with Oil Red O. The fragmented pre-implantation embryos were stained with annexin V-FITC, but not the normal ones. The mitochondria with active membrane potential were present less in the fragmented embryos compared with the non-fragmented embryos. We also confirmed that both StAR and PBR were expressed in the embryos and their expression levels were lower in the fragmented ones. In addition, the number and size of lipid droplets were increased in the fragmented embryos. The present study provides evidence that reduction of StAR and PBR in human pre-implantation embryos is associated with an increase in the lipid droplets leading to apoptosis.

Implementation of Real-time Object Tracking Algorithm based on Non-parametric Difference Picture and Kalman Filter (비모수적 차영상과 칼만 필터를 이용한 실시간 객체 추적 알고리즘의 구현)

  • 김영주;김광백
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.10C
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    • pp.1013-1022
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    • 2003
  • This paper implemented the real-time object tracking algorithm that extracts and tracks the moving object adaptively to input frame sequence by using non-parametric image processing method and Kalman filter-based dynamic AR(2) process method. By applying non-parametric image processing to input frames, the moving object was extracted from the background adaptively to diverse environmental conditions. And the movement of object was able to be adaptively estimated and tracked by modeling the various movement of object as dynamic AR(2) process and estimating based on the Kalman filter the parameters of AR(2) process dynamically changing along time. The experiments of the implemented object tracking system showed that the proposed method tracked the moving object as more approximately as the estimation error became about l/2.5∼1/50 of one of the traditional tracking method based on linear Kalman filter.

Comparison Studies of Hybrid and Non-hybrid Forecasting Models for Seasonal and Trend Time Series Data (트렌드와 계절성을 가진 시계열에 대한 순수 모형과 하이브리드 모형의 비교 연구)

  • Jeong, Chulwoo;Kim, Myung Suk
    • Journal of Intelligence and Information Systems
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    • v.19 no.1
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    • pp.1-17
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    • 2013
  • In this article, several types of hybrid forecasting models are suggested. In particular, hybrid models using the generalized additive model (GAM) are newly suggested as an alternative to those using neural networks (NN). The prediction performances of various hybrid and non-hybrid models are evaluated using simulated time series data. Five different types of seasonal time series data related to an additive or multiplicative trend are generated over different levels of noise, and applied to the forecasting evaluation. For the simulated data with only seasonality, the autoregressive (AR) model and the hybrid AR-AR model performed equivalently very well. On the other hand, if the time series data employed a trend, the SARIMA model and some hybrid SARIMA models equivalently outperformed the others. In the comparison of GAMs and NNs, regarding the seasonal additive trend data, the SARIMA-GAM evenly performed well across the full range of noise variation, whereas the SARIMA-NN showed good performance only when the noise level was trivial.

Effect of Water Extract of Aconiti Lateralis Preparata Radix on Lung Injury in LPS-induced Septic C57BL6 Mice (부자 추출물이 LPS로 유도된 C57BL6 마우스의 패혈증 연관 급성 폐 손상에 미치는 영향)

  • In-Seung Lee;Mina Boo;Jae Ouk Sim;Seung-Ho Baek;Jinbong Park
    • Journal of Convergence Korean Medicine
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    • v.4 no.1
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    • pp.19-27
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    • 2022
  • Objectives: TSepsis and subsequent acute lung injury (ALI) is a critical state of health caused by infection or endotoxins. This study was conducted to evaluate the effect of Water Extract of Aconiti Lateralis Preparata Radix (AR) on lipopolysaccharide (LPS)-induced sepsis in C57BL/6 mice. Methods: Male C57BL/6 mice were intraperitoneally injected with LPS to induce sepsis and ALI. AR was orally fed twice at 30 min and 180 min after LPS injection. At 24 h post injection, mice were sacrificed, bronchoalveolar lavage fluid (BALF) and blood was collected, and lung tissue was harvested. Hematoxylin and eosin staining was performed in lung tissues, wet/dry ratio of the lung tissue was measured, and the serum cytokine and chemokine levels were analyzed. Results: AR revoked the LPS-induced pathological changes in lung tissues, such as abnormal histological structures, immune cell infiltration and lung edema. Also, AR suppressed the neutrophil infiltration into the lung which was greatly increased by LPS injection based on the cell content of collected BALF. Serum cytokines and chemokines were measured, and AR reversed the LPS-induced increase of cytokines such as interleukin 1 beta, interleukin 6, tumor necrosis factor alpha and chemokines including C-X-C motif chemokine ligand 1 and 2. Conclusion: TAR showed a protective effect in the pathological progress of LPS-induced ALI. Especially, AR suppressed lung edema and infiltration of neutrophils by inhibiting cytokine and chemokine expressions. Such results demonstrate the potential of AR as a therapeutic agent for sepsis and sepsis-induced ALI.

Network pharmacology-based prediction of efficacy and mechanism of Myrrha acting on Allergic Rhinitis (네트워크 약리학을 활용한 알레르기 비염에서의 몰약의 치료 효능 및 기전 예측)

  • Yebin Lim;Bitna Kweon;Dong-Uk Kim;Gi-Sang Bae
    • The Journal of Korean Medicine
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    • v.45 no.1
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    • pp.114-125
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    • 2024
  • Objectives: Network pharmacology is an analysis method that explores drug-centered efficacy and mechanism by constructing a compound-target-disease network based on system biology, and is attracting attention as a methodology for studying herbal medicine that has the characteristics for multi-compound therapeutics. Thus, we investigated the potential functions and pathways of Myrrha on Allergic Rhinitis (AR) via network pharmacology analysis and molecular docking. Methods: Using public databases and PubChem database, compounds of Myrrha and their target genes were collected. The putative target genes of Myrrha and known target genes of AR were compared and found the correlation. Then, the network was constructed using STRING database, and functional enrichment analysis was conducted based on the Gene Ontology (GO) Biological process and Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathways. Binding-Docking stimulation was performed using CB-Dock. Results: The result showed that total 3 compounds and 55 related genes were gathered from Myrrha. 33 genes were interacted with AR gene set, suggesting that the effects of Myrrha are closely related to AR. Target genes of Myrrha are considerably associated with various pathways including 'Fc epsilon RI signaling pathway' and 'JAK-STAT signaling pathway'. As a result of blinding docking, AKT1, which is involved in both mechanisms, had high binding energies for abietic acid and dehydroabietic acid, which are components of Myrrha. Conclusion: Through a network pharmacological method, Myrrha was predicted to have high relevance with AR by regulating AKT1. This study could be used as a basis for studying therapeutic effects of Myrrha on AR.

Identification, sequence characterization and expression analysis of the arginine kinase gene in response to laminarin challenge from the Oriental land snail, Nesiohelix samarangae (동양달팽이(Nesiohelix samarangae)의 arginine kinase 유전자 분석 및 발현 패턴에 관한 연구)

  • Jeong, Ji Eun;Lee, Yong Seok
    • The Korean Journal of Malacology
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    • v.29 no.3
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    • pp.171-179
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    • 2013
  • Arginine kinase (ArK) is known to play an important role in most invertebrates the level of ATP by phosphorylation of phosphagens in cell and immuninty in living organisms. ArK has been identified in many kinds of organisms ranging from invertebrate to vertebrate. However, no ArK gene has been cloned and investigated from N. samarangae. This leads us to identify ArK cDNA (NsArK) from the expressed sequence tag (EST) sequencing of N. samarangae. Sequence analysis indicated that the coding region of 1,065 bp contains 355 amino acid residues. Molecular phylogenetic analysis shows that NsArK had very high similarities with mollusca and arthropoda. In an attempt to investigate a potential role of NsArK in the digestive gland of N. samarangae, expression patterns were analyzed. RT-PCR analsysis shows that NsArK mRNA is induced in the rane of 1.2 fold at 6 hr by laminarin when compared with the control. The immunnologial and physiological role of NsArK remains to be further investigated in N. samarangae.

Comparative Analysis of Obesity by $\beta$-II, III, Adrenergic Receptor Gene Polymorphism in Korean Young Females ($\beta$-II, III Adrenergic Receptor 유전자 다형성에 따른 20대 한국여성의 식이 섭취량, 비만도 및 체성분의 비교연구)

  • 홍정미;김중학;박윤신;최선미;윤유식;안홍석
    • Journal of Nutrition and Health
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    • v.35 no.8
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    • pp.870-879
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    • 2002
  • The purpose of this study was to investigate the obesity and state of dietary intake of 216 young Korean females, and the influence of $\beta$-II, III Adrenergic receptor (AR) gene polymorphism upon obesity and dietary intake. The average weight, height and BMI of the subjects were 160 cm, 54 kg, and 20.9 kg/$m^2$, respectively. The average triceps skinfold thickness, waist circumference, hip circumference and WHR were 21.7mm, 73.1cm, 93.3cm and 0.78, respectively. The results of body composition measurement using bioimpedance method, average body fluid, body protein, mineral mass and body fat were 29.271, 7.22 kg, 6.79 kg and 19.16 kg, respectively. A dietary survey was conducted using 24-hour recall method. Average calorie intake was 1621 ㎉, which is 81% of Korean RDA. We detected 182 (84.3%) Gln27 (QQ) homozygotes and 34 (15.7%) Gln27Glu (QE) heterozygotes for $\beta$-II AR polymorphism. For $\beta$-III AR polymorphism, we detected 163 (75.5%) Trp64 (WW) and 53 (24.5%) Trp 64Arg (WR). The results of comparing of obesity by $\beta$-II AR gene polymorphism, obesity index and BMI of QE type were slightly higher than those of the QQ type. For $\beta$-III AR gene polymorphism, the mean BMI, obesity index, fat mass and percent body fat (%) of the WR type were significantly higher than those of the WW type (p < 0.05). These findings suggest that genetic variability in the human $\beta$-III AR is associated with obesity among young Korean females. We also evaluated the effect of the simultaneous presence of the $\beta$-II AR and $\beta$-III AR polymorphism on obesity. We found that the BMI and obesity index of the mutant type in both $\beta$-II AR and $\beta$-III AR were significantly higher than those of the type that has only one gene mutation or has no mutation (p < 0.05), indicating a synergistic effect of $\beta$-II AR and $\beta$-III AR polymorphism on obesity. No association was found between $\beta$-II Ad or $\beta$-III AR polymorphism and dietary intake.

Ionization and Attachment Coefficients in CF4, CH4, Ar Mixtures Gas (CF4, CH4, Ar 혼합기체의 전리와 부착계수)

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.61 no.1
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    • pp.13-17
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    • 2012
  • Ionization and Attachment Coefficients in pure $CH_4$, $CF_4$ and mixtures of $CF_4$ and Ar, have been analyzed over a range of the reduced electric field strength between 0.1 and 350[Td] by the two-term approximation of the Boltzmann equation (BEq.) method and the Monte Carlo simulation (MCS). The calculations of electron swarm parameters require the knowledge of several collision cross-sections of electron beam. Thus, published momentum transfer, ionization, vibration, attachment, electronic excitation, and dissociation cross-sections of electrons for $CH_4$, $CF_4$ and Ar, were used. The results of the Boltzmann equation and the Monte Carlo simulation have been compared with the data presented by several workers. The deduced transport coefficients for electrons agree reasonably well with the experimental and simulation data obtained by Nakamura and Hayashi. The energy distribution function of electrons in $CF_4$-Ar mixtures shows the Maxwellian distribution for energy. That is, f(${\varepsilon}$) has the symmetrical shape whose axis of symmetry is a most probably energy. The proposed theoretical simulation techniques in this work will be useful to predict the fundamental process of charged particles and the breakdown properties of gas mixtures.