• 제목/요약/키워드: S&P500

검색결과 1,263건 처리시간 0.025초

압력변화에 따른 퀴놀린 유도체와 p-치환 염화벤조일류의 속도론적 연구 (Kinetics on the Reaction of Substituted Quinolines and p-Substituted Benzoylchlorides under Various Pressures)

  • 임종완;김세경
    • 대한화학회지
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    • 제47권3호
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    • pp.206-212
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    • 2003
  • 온도(10, 15, 20, $25^{\circ}C$)와 압력(1, 200, 500, 1000 bar) 변화에 따라 p-치환염화벤조일류$(p-CH_3,\;p-H,\;p-NO_2)$와 퀴놀린 유도체(quinoline, 6-chloroquinoline)의 반응을 아세토니트릴 용매내에서 전기전도도법에 의하여 속도상수$(k_2)$를 구하였다. 이로부터 여러 활성화파라미터-활성화에너지$(Ea,\;{\Delta}V^{\neq},\;{\Delta}H^{\neq},\;{\Delta}S^{\neq}, \;{\Delta}G^{\neq})$를 구하였으며, 또한 Hammett반응상수 ${\rho}_X$와 기질의 치환기 효과에따른 ${\rho}_Y$를 구하였다. 속도상수는 온도와 압력 증가에 따라 증가하였으며, 친핵체인 quinoline과 기질에 전자 받게 치환기$(p-NO_2)$가 치환된 경우 더욱 증가 하였다. 이때 활성화부($({\Delta}V^{\neq})$, 활성화엔트로피$({\Delta}S^{\neq})$는 모두 음의 값으로 나타났으며, 모든 압력 조건에 따라서 친핵체의 치환기 효과 ${\rho}_X$는 음의 값을 ${\rho}_Y$는 양의 값을 나타내었다. 이러한 속도론적인 연구 결과 전반적인 반응은 $S_N2$ 반응메카니즘을 따르며, 압력이 증가함에 따라 결합형성이 진전되어지는 반응 메카니즘으로 진행됨을 알 수 있었다.

식물성 혈구 응집소(Phytohaemagglutinin)로 유도한 림파구 변형에 관한 인삼의 in vitro 및 in vivo효과 (IN VITRO EFFECT OF PANAX GINSENG ON PHYTOHAEMAGGLUTININ-INDUCED LYMPHOCYTE TRANSFORMATION AND ITS IN VIVO EFFECT)

  • Chong S.K.F.;Brown H.A.;Rimmer E.;Oberholzer V.;Hindocha P.;Walker-Smith J .A.;Carruthers L.
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1984년도 학술대회지
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    • pp.89-95
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    • 1984
  • Hydrocortisone과 ginseng 그리고 hydrocortisone과 ginseng의 혼합물이 phytohaemagglutinin (PHA-P)으로 유도한 모세혈관 림파구 변형에 미치는 영향을 검토하기 위하여 정상인 4명을 대상으로 연구하였다. 인삼의 농도를 0.16${\mu}g$/ml에서 1.60${\mu}g$/ml까지 증가시킴에 따라 PHA-P의 림파구 변형에 상관성이 있는 억제현상을 보였으며, hydrocortisone 500${\mu}g$/ml과 ginseng 0.8${\mu}/g$/ml을 동시 투여하였을 경우 각각 단일 물질 투여시 보다 상당한 PHA-P 변형의 억제효과를 나타냈다. 이는 인삼이 in vitro상에서 steroid와 유사한 효과를 갖고 있음을 시사해 주며, 면역에 hydrocortisone과 더불어 상당한 효과를 가지고 있다는 것을 보여주고 있다. in vivo상에서 6명의 정상인을 대상으로 PHA-P 변형에 대하여 인삼의 효과를 연구한 결과 4주에 이르러 상당한 억제효과가 관찰되었다.

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체리 왜성대목 '기셀라 5' 반경지 삽목 발근 특성 (Adventitious Rooting of Cherry Dwarfing Rootstock 'Gisela 5' in Semi-hardwood Cuttings)

  • 김승희;김홍림;강성구;곽용범
    • 현장농수산연구지
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    • 제21권1호
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    • pp.5-13
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    • 2019
  • 우리나라의 체리 재배는 1920년대 초반으로 추정되며, 그 재배면적은 2017년 기준 약500ha이다. 체리는 재배면적으로는 소면적 과수이지만 아이들과 여성, 특히 임산부에게 인기가 높은 고급 과실이다. 때문에 최근 그 수입량이 급증하였다. 우리나라에서 감과 또는 단 체리의 대목으로 사용된 것은 푸른잎벚나무(청엽앵, Prunus lannesiana) 실생과 영양번식 된 콜트(P. avium × P. pseudocerasus)이다. 최근 몇십년동안 기셀라시리즈와 같은 새로운 왜성대목이 독일에서 개발되었다. 그 중에서 몇몇 기셀라시리즈가 국제 묘목시장에서 유통되고 있다. 본 연구는 체리 왜성대목 '기셀라 5'의 여름시즌 삽목증식을 위한 최적의 발근조건을 구명코자 실시되었다. 시험에 이용된 8개 상토조건 중에서는 마사토+원예범용상토(1:1)와 마사토+질석(1:1)이 각각 93.6%, 88.9%의 높은 발근율을 나타냈다. 발근촉진을 위한 생장조정제 IBA 순간침지 실험에서는 500~2000 mg·L-1모두 95%이상의 높은 발근율을 나타냈다.

Effect of Dietary Vitamin E Supplementation on Serum α-Tocopherol and Immune Status of Crossbred Calves

  • Samanta, A.K.;Dass, R.S.;Rawat, Mayank;Mishra, S.C.;Mehra, U.R.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권4호
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    • pp.500-506
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    • 2006
  • An experiment was conducted with twenty crossbred male calves (7-15 days old) divided into 4 different experimental groups on the basis of body weights to study the effect of vitamin E supplementation on the serum ${\alpha}$-tocopherol concentration and immune response of the calves. All the calves were fed on milk and calf starter up to 13 weeks and afterwards, they were fed on concentrate mixture and oat hay up to 32 weeks of age. In addition, the calves in groups I, II, III and IV were supplemented with 0, 125, 250 and 500 IU feed grade DL-${\alpha}$-tocopheryl acetate, respectively. Blood samples were collected at 0 day and subsequently at 1, 2, 3, 4, 6 and 8 months of age to monitor the serum ${\alpha}$-tocopherol concentration in crossbred calves. After 24 weeks of experimental feeding, 4 animals from each group were intramuscularly inoculated with single dose (3 ml) of Haemorrhagic septiceaemia (Pasteurella multocida P52 strain) oil adjuvant vaccine. The cumulative group mean serum ${\alpha}$-tocopherol concentration (${\mu}g/100ml$) was 88.12, 210.11, 235.21 and 294.02 in-groups I, II, III and IV, respectively and differed significantly (p<0.001) among the four groups. Lymphocyte stimulation indices (LSI) did not differ among the groups significantly. The pooled mean ELISA antibody titer against Pasteurella multocida (P52 strain) was 788.02, 926.85, 1,214.00 and 1,109.51 for group I, II, III and IV, respectively, which indicated higher antibody titer in groups supplemented with vitamin E as compared to the control group. It may be concluded that vitamin E supplementation increased the ${\alpha}$-tocopherol concentration in serum and dietary supplementation of vitamin E at higher level has a humoral immune enhancing effect against killed bacterial antigen.

생약복합제제(삼황사심탕(三黃瀉心湯), 황련해독탕(黃連解毒湯))가 흰쥐의 실험적 고지혈증에 미치는 영향 (Effect of Composite Preparation of Crude Drugs on Experimentally Induced Hyperlipemia in Rats -Sam Whang Sasim Tang and Whang Ryun Haedok Tang)

  • 한성준;정명현
    • 생약학회지
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    • 제27권4호
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    • pp.397-407
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    • 1996
  • This study was attempted to investigate the effect of Composite Preparation (Sam Whang Sasim-Tang: SWST, Whang Ryun Haedok-Tang: WRHT) on the activities of GOT and GPT, the content of total lipids, triglyceride, total cholesterol. Phospholipid and ${\beta}-lipoprotein$ in the serum, and the change ratio of body and liver weight in the experimentally induced hyperlipemic rats, making use of the extract 150, 200, 300 and 500 mg/kg p.o. Significant test was performed by comparision with the values of corresponding experimentally hyperlipemic rats. The activities of S-GPT was significantly decreased in all dose of SWST and WRHT respectively. The activities of S-GPT was significantly decreased in dose of SWST 500 mg/kg and in all dose of WRHT respectively. The content of total lipids, triglyceride, total cholesterol and phospholipids were significantly decreased in all dose of two the extract. The rate of decrease on total lipids and triglyceride were remarkable in dose of SWST 300, 500 mg/kg and WRHT 200, 500 mg/kg, and then the content of total cholesterol was more remarkable in dose SWST 300, 500 mg/kg, and WRHT 150, 300 mg/kg, and the content of phospholipids was more remarkable in dose of the extract 150, 200 and 300 mg/kg. The content of ${\beta}-lipoprotein$ was significantly decreased in dose of WRHT 150, 200 and in all dose of SWST. Increase ratio of the body and liver weight were significantly decreased in dose of two the extract 300, 500 mg/kg respectively.

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Causality change between Korea and other major equity markets

  • Kwon, Tae Yeon
    • Communications for Statistical Applications and Methods
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    • 제25권4호
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    • pp.397-409
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    • 2018
  • The world financial markets are inter-linked in ways that varies according to market and time. We examine the causality of change focusing on the Korean market as related to the U.S. (S&P 500), Japan (Nikkei 225), Hong-Kong (HSI), and European (DAX) markets. In order to capture time-varying causality running from and to the Korea stock market, we apply the Granger causality test under a VAR model with a wild bootstrap rolling-window approach. We also propose a new concept of a significant causality ratio to measure the intensity of the Granger causality in each time unit. There are many asymmetric strengths in mutual Granger causal relationships. Moreover, there are cases with significant Granger causal relations only in one direction. The period with the most severe Granger causality both running from and to the KOSPI market is the GFC. The market that formed the two-way Granger causal relationship with the KOSPI market for the longest period is the S&P 500. The HSI and DAX markets have the strongest two-way Granger causal relationship with the KOSPI shortly after 2000, and the Nikkei market had the strongest two-way Granger causal relationship with the KOSPI market before the Asian financial crisis.

금융 실현변동성을 위한 내재변동성과 인터넷 검색량을 활용한 딥러닝 (Deep learning forecasting for financial realized volatilities with aid of implied volatilities and internet search volumes)

  • 신지원;신동완
    • 응용통계연구
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    • 제35권1호
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    • pp.93-104
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    • 2022
  • S&P 500과 RUSSELL 2000, DJIA, Nasdaq 100 4가지 미국 주가지수의 실현변동성(realized volatility, RV)을 예측하는데 있어서 사람들의 관심 지표로 삼을 수 있는 인터넷 검색량(search volume, SV) 지수와 내재변동성(implied volatility, IV)를 이용하여 LSTM 딥러닝(deep learning) 방법으로 RV의 예측력을 높이고자하였다. SV을 이용한 LSTM 방법의 실현변동성 예측력이 기존의 기본적인 vector autoregressive (VAR) 모형, vector error correction (VEC)보다 우수하였다. 또한, 최근 제안된 RV와 IV의 공적분 관계를 이용한 vector error correction heterogeneous autoregressive (VECHAR) 모형보다도 전반적으로 예측력이 더 높음을 확인하였다.

Nutrient Amendments Influence Endophytic Colonization of Rice by Serratia marcescens IRBG500 and Herbaspirillum seropedicae Z67

  • Gyaneshwar, P.;Reddy, Pallavolu M.;Ladha, Jagdish K.
    • Journal of Microbiology and Biotechnology
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    • 제10권5호
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    • pp.694-699
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    • 2000
  • Serratia marcescens IRBG500 and Herbaspirillum seropedicae Z67 grow endophytically in rice. The ability of these bacteria to colonize rice grown under increased nutrient availability was assessed in variety IR72 using strains marked with transposon-based gusA. The endophytic colonization was monitored via bacterial enumeration and histochemical visualization of GUS expression of bacteria in plant tissues. Rhizoplane and endophytic colonization by both bacteria was significantly inhibited in the rice plants grown in the presence of 10 mM $NH_4Cl$. In contrast, the addition of 10 mM $KNO_3$ showed no adverse effect on colonization. Increasing the concentration of $Ca^{2+}$ to 5 mM significantly reduced endophytic colonization by both bacterial strains, whereas the addition of 0.5 mM $Fe^{2+}$ substantially lowered the colonization of roots by S. marcescens IRBG500 but showed no effect on colonization by H. seropedicae Z67. Taken together, these finding suggest that, like in legume-rhizobial symbiosis as well as plant-pathogen interactions, nutrient status, particularly $NH_4^+$ and $Ca^{2+}$ concentrations in the surrounding medium, plays an important role in the regulation of endophytic infection and colonization processes in rice.

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음절 간 쉼 간격이 인공와우 아동의 어음이해도에 미치는 영향 (Influences of Inter-syllable Pause Duration on Speech Discrimination Score in Children with Cochlear Implantation)

  • 박정인;허승덕
    • 재활복지공학회논문지
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    • 제8권4호
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    • pp.245-250
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    • 2014
  • 이 연구의 목적은 음절 간 쉼 간격이 인공와우 이식(cochlear implantation; CI) 아동의 어음이해도(speech discrimination score; SDS)에 미치는 영향을 알아보고자 하는데 있다. 이 연구에는 CI 아동 12명이 참여하였다. 어음이해도 평가는 자체 제작한 무의미 3음절을 사용하였고, 음절 간 쉼 간격은 250, 500, 1,000ms로 조절하였다. 어음 강도는 대상자들이 가장 편하기 느끼는 강도(most comfortable loudness; MCL)로 하였다. 평가는 4지 선다형 보기에서 대상자들이 선택할 수 있는 방법(closed-set)으로 실시하였다. 어음이해도는 250, 500, 1,000 ms 순서로 62.08, 63.75, 69.58 %로 통계적으로 유의하지 않지만, 개선되는 경향이 나타났다(p = .4635). 이를 통해 음절 간 쉼 간격은 인공와우 이식 아동의 어음이해도에 영향을 미친다는 것을 알 수 있다.

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A 10-b 500 MS/s CMOS Folding A/D Converter with a Hybrid Calibration and a Novel Digital Error Correction Logic

  • Jun, Joong-Won;Kim, Dae-Yun;Song, Min-Kyu
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제12권1호
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    • pp.1-9
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    • 2012
  • A 10-b 500 MS/s A/D converter (ADC) with a hybrid calibration and error correction logic is described. The ADC employs a single-channel cascaded folding-interpolating architecture whose folding rate (FR) is 25 and interpolation rate (IR) is 8. To overcome the disadvantage of an offset error, we propose a hybrid self-calibration circuit at the open-loop amplifier. Further, a novel prevision digital error correction logic (DCL) for the folding ADC is also proposed. The ADC prototype using a 130 nm 1P6M CMOS has a DNL of ${\pm}0.8$ LSB and an INL of ${\pm}1.0$ LSB. The measured SNDR is 52.34-dB and SFDR is 62.04-dBc when the input frequency is 78.15 MHz at 500 MS/s conversion rate. The SNDR of the ADC is 7-dB higher than the same circuit without the proposed calibration. The effective chip area is $1.55mm^2$, and the power dissipates 300 mW including peripheral circuits, at a 1.2/1.5 V power supply.