• Title/Summary/Keyword: 1-D Analysis

Search Result 13,855, Processing Time 0.055 seconds

An Analysis of MODIS Aerosol Optical Properties and Ground-based Mass Concentrations in Central Korea in 2009 (2009년 한국 중부 지역에서 MODIS 에어로졸 광학 성질과 질량 농도의 분석)

  • Kim, Hak-Sung;Kim, Ji-Min;Sohn, Jung-Joo
    • Journal of the Korean earth science society
    • /
    • v.33 no.3
    • /
    • pp.269-279
    • /
    • 2012
  • Satellite-retrieved data on Aerosol Optical Depth (AOD) and ${\AA}$ngstr$\ddot{o}$m exponent (AE) using a Moderate Resolution Imaging Spectrometer (MODIS) were used to analyze large-scale distributions of atmospheric aerosols in East Asia. AOD was relatively high in March ($0.44{\pm}0.25$) and low in September ($0.24{\pm}0.21$) in the East Asian region in 2009. Sandstorms originating from the deserts and dry areas in Northern China and Mongolia were transported on a massive scale during the springtime, thus contributing to the high AOD in East Asia. Although $PM_{10}$ with diameters ${\leq}10{\mu}m$ was the highest in February at Anmyon, Cheongwon and Ulleung, which is located leeward about half-way through the Korean Peninsula, AOD rose to a high in May. The growth of hygroscopic aerosols moving with increases in relative humidity prior to the Asian monsoon season contributed to a high AOD level in May. AE typically reaches its highest value ($1.30{\pm}0.37$) in August due to anthropogenic aerosols originating from industrial areas in Eastern China, while AOD stays low in summer due to the removal process caused by rainfall. The linear correlation coefficients of the MODIS AOD and ground-based mass concentrations of $PM_{10}$ at Anmyon, Cheongwon and Ulleung were 0.4-0.6. Four cases (six days) of mineral dustfall from sandstorms and six cases (twelve days) of anthropogenically polluted particles were observed in the central area of the Korean Peninsula in 2009. $PM_{10}$ mass concentrations increased at both Anmyon and Cheongwon in the cases of mineral dustfall and anthropogenically polluted particles. Cases of dustfall from sandstorms and anthropogenic polluted particles, with increasing $PM_{10}$ mass concentrations, exhibited higher AOD values in the Yellow Sea region.

Neuronal Cell Protective Effect of Dendropanax morbifera Extract against High Glucose-Induced Oxidative Stress (High Glucose로 유도된 산화 스트레스에 대한 황칠나무 잎 추출물의 뇌신경세포 보호 효과)

  • Kim, Jong Min;Park, Seon Kyeong;Guo, Tian Jiao;Kang, Jin Yong;Ha, Jeong Su;Lee, Du Sang;Kwon, O-Jun;Lee, Uk;Heo, Ho Jin
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.7
    • /
    • pp.938-947
    • /
    • 2016
  • Antioxidant activities and neuroprotective effects of ethyl acetate fraction from Dendropanax morbifera (EFDM) against high glucose-induced oxidative stress and neurotoxicity were investigated to confirm their physiological activities. An 80% ethanolic extract of D. morbifera showed the highest contents of total phenolic compounds as well as 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. The extract was fractionated using several solvents, and the ethyl acetate fraction showed the highest activities in ferric reducing/antioxidant power and malondialdehyde inhibitory assays. To evaluate the neuroprotective effect based on antioxidant activities, cell viability was assessed using PC12 and MC-IXC cells in $H_2O_2$- and high glucose-induced cytotoxic assays, respectively. EFDM evidently showed neuroprotective effects in all cells (neuron-like PC12 cells and human brain-originated neuroblastoma MC-IXC cells). Inhibitory effect of the extract on acetylcholinesterase (AChE) as an acetylcholine-hydrolyzing enzyme was performed to examine the effect on cognitive function. EFDM presented an AChE inhibitory effect. Finally, high-performance liquid chromatography analysis showed that the major phenolic compound of EFDM is probably a rutin.

An Analysis of Nursing education Research in China : 1990-1998 (중국 간호교육관련 연구실태 분석)

  • Ko Il-Sun;Li Chun-Yu;Kim Jing-Ai
    • The Journal of Korean Academic Society of Nursing Education
    • /
    • v.5 no.2
    • /
    • pp.177-190
    • /
    • 1999
  • This study has been conducted on the basis of the literature review of Nursing Education Research in China from 1990 through August 1998. Its purpose was to support the basic data of nursing education which is risen as major revolutionary of nursing in China and those for exchange of information between Korea-China nursing education. It is retrospective and descriptive research analyzing one hundred eighty articles published in The Journal of China Nursing. The results of the study were as follows. 1. Only 33.3% of the professors of Technical Nursing School who have played of major role of nursing education in China have carried out the study related to nursing education. Baccalaureate program professors have marked 22.2% of all studies, and diploma program professors have done 12.2% of all. Therefore, the professors of above the diploma program have done total 44.4%. It explains that the professors of baccalaureate and diploma programs have done more studies related to nursing education than those of Technical Nursing School. 2. In terms of the study design, most of the studies(38.8%) were case studies introducing the curriculum contents that were done at education institutions. And then, 28.5% were reviewing the articles, and 15.6% were descriptive studies. 3. In terms of the content of the study, 38.3% were relevant to education of Technical Nursing School, 15.0% were about baccalaureate education, and 10.4% is about diploma. 4. To analyze the specific contents of the studies ; a. In baccalaureate program, human resources (professor or teaching), course extension, lab, classes, teaching method, education philosophy, goal of education, evaluation method, and human resource development were included. b. In diploma program, teaching contents evaluation method, teaching method, and educational system were included c. In the technical school, there were qualification of professors , teaching method, evaluation method, opening the courses, teaching contents, goal of education and so on. d. Beyond these, there were practice guidance and appraisement, teaching method, and opening new courses which were not specially indicated as educational curriculum and score management as continuing education. What is above tell us that the study regarding development of university system has been progressed actively and widely. It has been for the effort of revolution which based on the China government force to reform of nursing education process during last 10 years. On the base of the result, we suggest the following questions and the alternatives. 1) Since most articles are case studies related to teaching methods and the others doesn't propose the research method. the study which is applied more exact research method is needed. 2) No study is regarding social change and health policy. Because University program, founded in 1983 is on the beginning point, the research about curriculum have to be taken as a top priority as well as to reflect social needs which are based on social changes and national health policy 3) Only one review article study tells nursing Human resource. To appear in large numbers in nursing manpower, avoid the present hospital nurses training system. Then, the study for manpower development which is able to accomplish in many fields has to be advanced. 4) Most studies did not have literature review processes, so it was impossible for researcher to know the past study tendency and there is no relation among studies as to same subject, the education about research method is needed.

  • PDF

Influence of $NH_4^+$ and $NO_3^-$ Ratios in Fertigation Solution on Growth of Snapdragon Plug Seedlings and Changes in Medium Chemical Properties ($NH_4^+:NO_3^-$ 시비 비율이 금어초 플러그 묘 생장과 상토 화학성 변화에 미치는 영향)

  • Lee, Poong-Ok;Lee, Jong-Suk;Choi, Jong-Myung
    • Journal of Bio-Environment Control
    • /
    • v.19 no.4
    • /
    • pp.251-256
    • /
    • 2010
  • Objective of this research was to investigate the influence of $NH_4^+$ and $NO_3^-$ ratios in liquid feeding on the growth of snapdragon 'Potomac Red' and changes in medium chemical properties. The seeds were sown into 200 plug trays and fertigated once a week with nutrient solution containing various ratios of $NH_4^+$ and $NO_3^-$ such as 0 : 100, 27 : 73, 50 : 50, 73 : 27, and 100 : 0. The total N concentrations were adjusted to 50, 100 and $150\;mg{\cdot}L^{-1}$ in plug stages of 2, 3, and 4, respectively. Determination of seedling growth and analysis of plant tissue and root medum were conducted at 56 days after sowing. The treatment of 27 : 73 ($NH_4^+:NO_3^-$) had the greatest plant height, fresh weight, and dry weight. The N and P contents in 27 : 73 ($NH_4^+:NO_3^-$) treatment based on the above ground plant tissues were 2.39 and 0.39%, respectively, which were the greatest among treatments. The elevation of $NH_4^+$ ratio in fertigation solution decreased tissue Ca and Mg contents, but that did not influence tissue K content. The variations in $NH_4^+:NO_3^-$ ratios impacted the soil solution pH and the difference among treatments had been severe since three weeks after sowing. Elevation of $NH_4^+$ ratios in fertigation solution increased electrical conductivity and concentrations of K, Ca, and Mg in soil solution of root medum. The $NH_4^+$ and $NO_3^-$ concentrations in the soil solution were high in weeks 2, 3, and 4, then decreased gradually as the biomass of seedlings increased. Medium P concentration decreased gradually as seedlings grew, but statistical differences were not observed among treatments.

Analysis of Telomere Length and Telomerase Activity of Tissues in Korean Native Chicken (한국 재래닭의 주령별 각 조직의 텔로미어 함량과 텔로머레이스 활성도 분석)

  • Jung G.S.;Cho E.J.;Choi D.S.;Lee M.J.;Park C.;Jeon I.S.;Sohn S.H.
    • Korean Journal of Poultry Science
    • /
    • v.33 no.2
    • /
    • pp.97-103
    • /
    • 2006
  • Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomere length and telomerase activity have been studied extensively, very little is known to analyze the telomere dynamics in chicken cells. This study was carried out to analyze the telomere distribution and telomerase activity of Korean Native Chicken cells along with aging. The cells were collected from brain, heart, liver, kidney and germinal tissues during physiological stages. Telomere distribution was analyzed by Quantitative-Fluorescence in situ Hybridization (Q-FISH) techniques using the chicken telomeric DNA probe. Telomerase activity was performed by Telomeric Repeat Amplification Protocol (TRAP) assay. In results, the telomeres of chicken were found at the ends of all chromosomes with the interstitial telomeres on chromosomes 1, 2 and 3. The amount of telomeres on chicken cells was decreased along with aging in most tissues. Furthermore, the telomere quantity was significantly different among tissues. The relative amount of telomeres in proliferous cells such as testis cells had much more than those of liver, brain, heart, blood and kidney cells. The telomerase activity was down-regulated in cells of brain, heart and liver tissues. Whereas gonadal cells showed a constitutive activity of telomerase during all stage of life. In conclusions, the telomere quantity and telomerase activity in chicken are closely relate to cell proliferation and tissue specificity during developmental stages and aging. There is also closely correlated between the amounts of telomeric DNA and telomerase activity in chicken tissues.

Corporate Bond Rating Using Various Multiclass Support Vector Machines (다양한 다분류 SVM을 적용한 기업채권평가)

  • Ahn, Hyun-Chul;Kim, Kyoung-Jae
    • Asia pacific journal of information systems
    • /
    • v.19 no.2
    • /
    • pp.157-178
    • /
    • 2009
  • Corporate credit rating is a very important factor in the market for corporate debt. Information concerning corporate operations is often disseminated to market participants through the changes in credit ratings that are published by professional rating agencies, such as Standard and Poor's (S&P) and Moody's Investor Service. Since these agencies generally require a large fee for the service, and the periodically provided ratings sometimes do not reflect the default risk of the company at the time, it may be advantageous for bond-market participants to be able to classify credit ratings before the agencies actually publish them. As a result, it is very important for companies (especially, financial companies) to develop a proper model of credit rating. From a technical perspective, the credit rating constitutes a typical, multiclass, classification problem because rating agencies generally have ten or more categories of ratings. For example, S&P's ratings range from AAA for the highest-quality bonds to D for the lowest-quality bonds. The professional rating agencies emphasize the importance of analysts' subjective judgments in the determination of credit ratings. However, in practice, a mathematical model that uses the financial variables of companies plays an important role in determining credit ratings, since it is convenient to apply and cost efficient. These financial variables include the ratios that represent a company's leverage status, liquidity status, and profitability status. Several statistical and artificial intelligence (AI) techniques have been applied as tools for predicting credit ratings. Among them, artificial neural networks are most prevalent in the area of finance because of their broad applicability to many business problems and their preeminent ability to adapt. However, artificial neural networks also have many defects, including the difficulty in determining the values of the control parameters and the number of processing elements in the layer as well as the risk of over-fitting. Of late, because of their robustness and high accuracy, support vector machines (SVMs) have become popular as a solution for problems with generating accurate prediction. An SVM's solution may be globally optimal because SVMs seek to minimize structural risk. On the other hand, artificial neural network models may tend to find locally optimal solutions because they seek to minimize empirical risk. In addition, no parameters need to be tuned in SVMs, barring the upper bound for non-separable cases in linear SVMs. Since SVMs were originally devised for binary classification, however they are not intrinsically geared for multiclass classifications as in credit ratings. Thus, researchers have tried to extend the original SVM to multiclass classification. Hitherto, a variety of techniques to extend standard SVMs to multiclass SVMs (MSVMs) has been proposed in the literature Only a few types of MSVM are, however, tested using prior studies that apply MSVMs to credit ratings studies. In this study, we examined six different techniques of MSVMs: (1) One-Against-One, (2) One-Against-AIL (3) DAGSVM, (4) ECOC, (5) Method of Weston and Watkins, and (6) Method of Crammer and Singer. In addition, we examined the prediction accuracy of some modified version of conventional MSVM techniques. To find the most appropriate technique of MSVMs for corporate bond rating, we applied all the techniques of MSVMs to a real-world case of credit rating in Korea. The best application is in corporate bond rating, which is the most frequently studied area of credit rating for specific debt issues or other financial obligations. For our study the research data were collected from National Information and Credit Evaluation, Inc., a major bond-rating company in Korea. The data set is comprised of the bond-ratings for the year 2002 and various financial variables for 1,295 companies from the manufacturing industry in Korea. We compared the results of these techniques with one another, and with those of traditional methods for credit ratings, such as multiple discriminant analysis (MDA), multinomial logistic regression (MLOGIT), and artificial neural networks (ANNs). As a result, we found that DAGSVM with an ordered list was the best approach for the prediction of bond rating. In addition, we found that the modified version of ECOC approach can yield higher prediction accuracy for the cases showing clear patterns.

Transformation of Potato using the Phosphinothricin Acetyltransferase Gene as the Selectable Marker Gene (감자의 형질전환을 위한 표지유전자로서 Phosphinothricin Acetyltransferase 유전자의 이용)

  • Jeong, J.H.;Yang, D.C.;Bang, K.S.;Han, S.S.
    • Korean Journal of Weed Science
    • /
    • v.18 no.3
    • /
    • pp.205-213
    • /
    • 1998
  • This experiment was carried out to produce herbicide resistant potatoes hawing only chimeric phosphinothricin acetyltransferase (PAT) genes without using antibiotic selectable marker. The pDY502 vector having only PAT gene was reconstructed for transformation of potato. The reconstructed vector was introduced to Agrobacterium tumefaciens MP90 disarmed, and they were used for potato transformation. Hormonal requirement for plant regeneration from leaves and stem explants of potato was investigated. From this experiment, MS medium treated with IBA 0.1 mg/L + BA 0.5 mg/L was the best for potato regeneration, and the ratio of shoot regeneration was 54% for leaf and 46% for stem in that condition. For transformation, explants of potato leaves and stems were cocultured with A. tumefaciens MP90 containing reconstructed vector harvoring only PAT gene. When the potato explants were placed on various concentrations of bialaphos and all the potato explants were dead on medium with over 5.0mg/L bialaphos. By this selection methods, the explants cocultured with Agrobacterium produced the putative transgenic shoots on medium with 5mg/L bialaphos treatment after 3-4 weeks. Second selection was performed by transferring the shoot tips of putative transgenic to medium containing 20mg/L of bialaphos. The shoot tips grew well on the second selection medium, indicating the production of successful transgenic plants. But normal shoots were dead in same cytotoxic medium. Incorporation of the PAT gene into transgenic potatos were confirmed by PCR analysis of DNA and Southern hybridization. These results show that the PAT gene can serve as a selectable marker and herbicide resistant genes for transformation of potato.

  • PDF

Analysis of masseter muscle in facial asymmetry before and after orthognathic surgery using 3-dimensional computed tomography (3차원 전산화 단층 사진을 이용한 안면비대칭 환자의 악교정 수술 전, 후 교근 분석)

  • Seo, Seung-Ah;Baik, Hyoung-Seon;Hwang, Chung-Ju;Yu, Hyung-Seog
    • The korean journal of orthodontics
    • /
    • v.39 no.1
    • /
    • pp.18-27
    • /
    • 2009
  • Objective: The purpose of this study was to understand the differences in masseter muscle(MM) between the shifted and non-shifted sides in facial asymmetry patients, and the changes shown by MM after mandibular surgery. Methods: Pre- and post-operative CT scans were performed on 12 Class III patients with facial asymmetry who were treated by intraoral vertical ramus osteotomy and 10 subjects with normal occlusion. Using the V-works 4.0 program(Cybermed, Seoul, Korea), 3-dimensional images of the mandible, and MM were reconstructed, and evaluated. Results: In the asymmetry group, the MM angle between the shifted and non-shifted sides was only significantly different(p<0.05). Compared with normal occlusion, the asymmetry group showed a significantly smaller volume and maximum cross-sectional area in both sides of MM(p<0.05). After mandibular surgery, the angle of MM(p<0.01) and differences in angle between the shifted and non-shifted sides of MM(p<0.05) were significantly decreased. The thickness in the maximum cross-sectional area was significantly increased(p<0.01). After surgery, MM in facial asymmetry patients was similarly changed to those in the normal occlusion group except for widths. Conclusions: MM in facial asymmetry was definitely different from those in normal occlusion. However, this study suggests that MM changed symmetrically in conjunction with the mandible after proper mandibular surgery.

A Longitudinal Study of the Effects of Media Use on the Evaluation of the Leading Candidate in the Korean 2007 Presidential Election -An Analysis of the Panel Data with Latent Growth Modeling- (미디어 이용이 후보자 평가에 미치는 영향에 대한 종단연구 -잠재성장모형을 통한 17대선 패널 데이터 분석을 중심으로-)

  • Kim, Joo-Han;Kim, Min-Gyu;Jin, Young-Jae
    • Korean journal of communication and information
    • /
    • v.44
    • /
    • pp.76-107
    • /
    • 2008
  • The present study has explored the effects of media use on the evaluation of the presidential candidate's morality. We hypothesized that the perception of the candidates' morality during the 2007 Korean President Election would be influenced by the amount of the different types of media use. Using a set of panel data, a total of 1,199 citizens (584 females (48.7%), 615 males (51.3%), Mage=42.77, SDage=13.34) were assessed four times from August to December in 2007. The results indicated that (a) the level of TV use for political information, the level of newspaper use for political information, and the level of Internet use for political information increased during the five months; (b) the initial level of political involvement contributed differently to the initial levels of media use; (c) the initial level of political involvement negative influenced the initial level of TV use for political information; (d) the growth of political involvement positively influenced the growth of TV use for political information; (e) the intial level of TV use for political information increased both the initial levels of the perception of candidates' morality and the change of the perception of candidates' morality; (f) the change of TV use for political information negatively affected the perception of candidates' morality; and (g) the initial level of Internet use for political information negatively affected the initial level of the perception of candidates' morality, and the change of Internet use for political information negatively affected the perception of candidates' morality.

  • PDF

WHICH INFORMATION MOVES PRICES: EVIDENCE FROM DAYS WITH DIVIDEND AND EARNINGS ANNOUNCEMENTS AND INSIDER TRADING

  • Kim, Chan-Wung;Lee, Jae-Ha
    • The Korean Journal of Financial Studies
    • /
    • v.3 no.1
    • /
    • pp.233-265
    • /
    • 1996
  • We examine the impact of public and private information on price movements using the thirty DJIA stocks and twenty-one NASDAQ stocks. We find that the standard deviation of daily returns on information days (dividend announcement, earnings announcement, insider purchase, or insider sale) is much higher than on no-information days. Both public information matters at the NYSE, probably due to masked identification of insiders. Earnings announcement has the greatest impact for both DJIA and NASDAQ stocks, and there is some evidence of positive impact of insider asle on return volatility of NASDAQ stocks. There has been considerable debate, e.g., French and Roll (1986), over whether market volatility is due to public information or private information-the latter gathered through costly search and only revealed through trading. Public information is composed of (1) marketwide public information such as regularly scheduled federal economic announcements (e.g., employment, GNP, leading indicators) and (2) company-specific public information such as dividend and earnings announcements. Policy makers and corporate insiders have a better access to marketwide private information (e.g., a new monetary policy decision made in the Federal Reserve Board meeting) and company-specific private information, respectively, compated to the general public. Ederington and Lee (1993) show that marketwide public information accounts for most of the observed volatility patterns in interest rate and foreign exchange futures markets. Company-specific public information is explored by Patell and Wolfson (1984) and Jennings and Starks (1985). They show that dividend and earnings announcements induce higher than normal volatility in equity prices. Kyle (1985), Admati and Pfleiderer (1988), Barclay, Litzenberger and Warner (1990), Foster and Viswanathan (1990), Back (1992), and Barclay and Warner (1993) show that the private information help by informed traders and revealed through trading influences market volatility. Cornell and Sirri (1992)' and Meulbroek (1992) investigate the actual insider trading activities in a tender offer case and the prosecuted illegal trading cased, respectively. This paper examines the aggregate and individual impact of marketwide information, company-specific public information, and company-specific private information on equity prices. Specifically, we use the thirty common stocks in the Dow Jones Industrial Average (DJIA) and twenty one National Association of Securities Dealers Automated Quotations (NASDAQ) common stocks to examine how their prices react to information. Marketwide information (public and private) is estimated by the movement in the Standard and Poors (S & P) 500 Index price for the DJIA stocks and the movement in the NASDAQ Composite Index price for the NASDAQ stocks. Divedend and earnings announcements are used as a subset of company-specific public information. The trading activity of corporate insiders (major corporate officers, members of the board of directors, and owners of at least 10 percent of any equity class) with an access to private information can be cannot legally trade on private information. Therefore, most insider transactions are not necessarily based on private information. Nevertheless, we hypothesize that market participants observe how insiders trade in order to infer any information that they cannot possess because insiders tend to buy (sell) when they have good (bad) information about their company. For example, Damodaran and Liu (1993) show that insiders of real estate investment trusts buy (sell) after they receive favorable (unfavorable) appraisal news before the information in these appraisals is released to the public. Price discovery in a competitive multiple-dealership market (NASDAQ) would be different from that in a monopolistic specialist system (NYSE). Consequently, we hypothesize that NASDAQ stocks are affected more by private information (or more precisely, insider trading) than the DJIA stocks. In the next section, we describe our choices of the fifty-one stocks and the public and private information set. We also discuss institutional differences between the NYSE and the NASDAQ market. In Section II, we examine the implications of public and private information for the volatility of daily returns of each stock. In Section III, we turn to the question of the relative importance of individual elements of our information set. Further analysis of the five DJIA stocks and the four NASDAQ stocks that are most sensitive to earnings announcements is given in Section IV, and our results are summarized in Section V.

  • PDF