• Title/Summary/Keyword: Reversion

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Using rough set to develop a volatility reverting strategy in options market (러프집합을 활용한 KOSPI200 옵션시장의 변동성 회귀 전략)

  • Kang, Young Joong;Oh, Kyong Joo
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.1
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    • pp.135-150
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    • 2013
  • This study proposes a novel option strategy by using characteristic of volatility reversion and rough set algorithm in options market. Until now, various research has been conducted on stock and future markets, but minimal research has been done in options market. Particularly, research on the option trading strategy using high frequency data is limited. This study consists of two purposes. The first is to enjoy a profit using volatility reversion model when volatility gap is occurred. The second is to pursue a more stable profit by filtering inaccurate entry point through rough set algorithm. Since options market is affected by various elements like underlying assets, volatility and interest rate, the point of this study is to hedge elements except volatility and enjoy the profit following the volatility gap.

Effects of Physical Improvement Practices at Plastic Film House Soil (시설재배 토양의 물리성 개선을 위한 처리방법별 효과 비교)

  • Kim, Lee-Yul;Cho, Hyun-Jun;Hyun, Byung-Keun;Park, Woo-Pung
    • Korean Journal of Soil Science and Fertilizer
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    • v.34 no.2
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    • pp.92-97
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    • 2001
  • Soil characteristics and crop productivity was compared between 5 soil physical treatment plots: check, reversion, subsoiling, explosive subsoiling and drainage in salt accumulated Gangseo Fine sandy loam soil from 1999 to 2000. Physical treatments of subsoil improved soil physical properties in the following order, reversion > drainage > explosive subsoiling > subsoiling > check. The effectiveness of physical treatment was sustained to the 2nd year after treatment. Soil moisture content of subsoil was highest in the reversion treatments and decreased in the order of drainage, subsoiling, and check. However there was little difference between treatments. The physical treatments increased fluctuation of soil moisture content. However the crop yield in the physical treatment plots were increased. It was considered that the increase of crop yield was caused by improvement of soil physical properties rather than soil water holding in the soil. An average increase rate of crop yield by physical treatments was 10 to 20 percent.

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Yellowing Inhibition of Bagasse Chemimechanical Pulp

  • Andulkhani Ali;Mirshokraie Seyed Ahmad;Latibari Ahmad Jahan;Enayati Ali Akbar
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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    • pp.337-347
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    • 2006
  • Papers made from unbleached and bleached bagasse chemimechanical pulp were chemically modified by acetylation. The effects of irradiation on unbleached and bleached also reduced papers of bagasse chemimechanical pulp before and after acetylation were investigated in this study. Chemimechanical pulp was prepared from bagasse and then bleached with hydrogen peroxide. Unbleached and hydrogen bleached pulps were reduced by Sodium borohydride in different procedures. Paper sheets were prepared from pulps and then acetylated using a technical grade of acetic anhydride. Accelerated photo-aging was run on the samples using fluorescent lamps to verify photo-stability of paper sheets before and after pretreatments. Brightness reversion (as Post-color number) and other optical properties of the paper sheets were measured. Efficient inhibition of photo-yellowing of papers made from bagasse CMP was achieved by acetylation. The acetylated unbleached CMP was noticeably photo-bleached during irradiation. Sodium borohydride reduction followed by acetylation had the same effect as acetylation alone at the same degree of reaction time and reductive treatment did not affect the yellowing rate to any great extent. The pre-reduced, acetylated unbleached papers were, however, not brightened during irradiation. Calculation done by Kubelka-Munk equation showed that reductive treatment had little effect in reducing the photo-yellowing of paper made from CMP pulp; a small stabilization effect was observed in the case of bleached CMP, while unbleached CMP was slightly more prone to discolor in the later phase of photo-reversion. The improved stability towards light may was closely related to the decrease in the phenolic hydroxyl content as a result of blocking by acetyl groups during treatment with acetic anhydride. The results support the hypothesis that phenolic hydroxyl has an important role in the process of photo-reversion of high-yield pulps. The results obtained in this study demonstrate that the acetylation of paper manufactured from peroxide bleached Bagasse CMP significantly retards light-induced discoloration. The inhibition of yellowing is connected with a decrease in the phenolic hydroxyl content of both unbleached and peroxide bleached papers.

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Reason and Prevention of Color Reversion of Corn Oil in Summer (옥수수기름의 하절기 변색현상 원인규명 및 방지대책)

  • Koo Bon-Soon
    • Food Science and Preservation
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    • v.11 no.4
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    • pp.485-490
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    • 2004
  • Crude corn oil (CCO) was obtained through the expression-extraction process from corn germ. The CCOs of final process at $90^{\circ}C,\;70^{\circ}C\;and\;50^{\circ}C$ were stored in outdoor storage tanks. From the samples, refined CCO (RCCO) were prepared with $0\%,\;10\%\;and\;20\%$ excessive of phosphoric acid, caustic solution and acidic clay were used in degumming-alkali refining-bleaching process. RCCOs were stored at room temperature in dark places. The color change was not effected by the amount of phosphoric acid, caustic solution and acidic clay, but temperature of process affects the color change. Finally, the prevention for color reversion of RCCO could be obtained by lowering the temperature of final process and optimal temperature of RCCO in summer was found about less than $50^{\circ}C$.

In vitro Antimutagenic Activity of Chitosan and Its Bio-antimutagenic Characteristics (Chitosan의 in vitro 돌연변이 억제효과 및 세포내 작용 특성)

  • Chun, Hyang-Sook;Chang, Hyun-Joo;Lee, Jong-Mi
    • Korean Journal of Food Science and Technology
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    • v.28 no.6
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    • pp.1059-1064
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    • 1996
  • The inhibitory effects of chitosan on mutagenicity induced by 3-amino-1-methyl-5H-pyrido [4,3-b] indole (Trp-P-2), sodium azide (SA), 2-nitrofluorene (2-NF), and 4-nitroquinoline oxide (4-NQO) were investigated using Salmonella typhimurium reversion assay and SOS Chromotest. In Salmonella typhimurium reversion assay. Chitosan showed 24-65% of inhibitory effect against the mutagenicity of an indirect-acting mutagen, Trp-P-2. On the other hand, no inhibitory effect was observed against the mutagenicity of direct-acting mutagens (2-NF, SA). In SOS chromotest. chitosan showed 46-49% effects on SOS function induced by 4-NQO. Chitosan inhibited the mutagenicity induced by Trp-P-2 with 9-39% of inhibition rate. It was also evaluated whether inhibitory effect of chitosan is due to its bio-antimutagenic or desmutagenic action. Chitosan at high concentrations showed a bio-antimutagenicity with dose-dependent manner, but it showed a desmutagenicity at low concentrations against the mutation induced by Trp-P-2.

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Genotoxicological Safety on Water-Soluble Fraction of Gamma Irradiated Korean Soybean Fermentation Foods (감마선 조사된 장류 물추출 분획의 유전독성학적 안전성 평가)

  • 육홍선;이은미;김동호;이경행;변명우;이현자;이영남
    • Journal of Food Hygiene and Safety
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    • v.15 no.4
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    • pp.297-303
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    • 2000
  • Gamma irradiation at 20 kGy was applied to Kanjang (soy sauce), Doenjang (soybean paste), Kochujang (hot pepper pasts) and Chungkukjang for their possible genotoxicity. The genotoxicity of 20 kGy-irradiated samples was evaluated by Salmonella typhimurium reversion assay. The Salmonella tester strains included TA98, TA100, TA1535 and TA1537 in the absence and presence of an exogenous metabolizing system (59 mix). All samples were negative in the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537. The results indicated that 20 kGy of gamma irradiation on water-soluble fraction of Kanjang, Doenjang, Kochujang and Chungkukjang were not shown mutagenicity.

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Reappraisal of Mean-Reversion of Stock Prices in the State-Space Model (상태공간모형에서 주가의 평균회귀현상에 대한 재평가)

  • Jeon, Deok-Bin;Choe, Won-Hyeok
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.11a
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    • pp.173-179
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    • 2006
  • In order to explain a U-shape pattern of stock returns, Fama and French(1988) suggested the state-space model consisting of I(1) permanent component and AR(1) stationary component. They concluded the autoregression coefficient induced from the state-space model follow the U-shape pattern and the U-shape pattern of stock returns was due to both negative autocorrelation in returns beyond a year and substantial mean-reversion in stock market prices. However, we found negative autocorrelation is induced under the assumption that permanent and stationary noise component are independent in the state-space model. In this paper, we derive the autoregression coefficient based on ARIMA process equivalent to the state-space model without the assumption of independency. Based on the estimated parameters, we investigate the pattern of the time-varying autoregression coefficient and conclude the autoregression coefficient from the state-space model of ARIMA(1,1,1) process does not follow a U-shape pattern, but has always positive sign. We applied this result on the data of 1 month retums for all NYSE stocks for the 1926-85 period from the Center for Research in Security Prices.

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Study on Mutagenicity of DehydroevodiamineㆍHCl(DHED) (치료제 DehydroevodiamineㆍHCl(DHED)의 변이원성 연구)

  • 성이숙;정성윤;정주연;채규영;진미령;최봉웅;장병모;김대경
    • YAKHAK HOEJI
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    • v.46 no.3
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    • pp.208-212
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    • 2002
  • Dehydroevodiamine HCl (DHED), which is a component separated from Evodia rutaecarpa Bentham, has novel anticholinesterase and antiamnesic activities in the scopolamine-induced amnesia model. Several studies suggest that DHED might be an effective drug for the Alzheimer's disease and the vascular type of dementia. In order to evaluate the mutagenic potential of DHED, Salmonella typhimurium reversion assay, chromosomal aberration test on Chinese hamster lung cells, in vivo micronucleus assay using mouse bone marrow cells, and comet assay were performed. DHED did not increase the number of revertant in the reverse mutation test using Salmonella typhimurium TA1535, TA1537, TA98, TA100. DHED HCl, at concentration of 5 and 10 $\mu\textrm{g}$/mι, increased the number of chromosome aberrated Chinese hamster lung cells with 5 and 10%, respectively. In mouse micronucleus test, no significant increase in the occurrence of micronucleated polychromatic erythrocyte was observed in ICR mice orally administered with DHED. DHED was tested for ability to induce genotoxic effect in L5178Y cells (mouse lymphoma cells) using the single cell gel electrophoresis assay (comet assay). In comet assay, tail moment did not increase in L5178Y cells treated with 10, 100, 300 $\mu$M DHED.

Purification and Biological Activities of MT 1155 Inducing Morphological Change of Rous Sarcoma Virus-Transformed Normal Rat Kidney Cell (Rous Sarcoma Virus에 의해 형질전환된 NRK 세포의 형태변화를 유도하는 활성물질 MT 1154의 분리와 생물학적 활성)

  • 안종석;박문수;박찬선;윤병대;민태익;안순철;오원근;이현선;윤병대
    • Microbiology and Biotechnology Letters
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    • v.21 no.1
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    • pp.59-65
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    • 1993
  • We isolated Actinomycetes strain GMT 1155 and purified the active compound, MT 1155, on the morphological reversion of ts/NRK cell from the isolate. MT 1155 was identified as toyocamycin having antifungal and antitumor activities from physico-chemical properties and UV, IR, $^1H$-NMR, $^13C$-NMR and mass spectrum. MT 1155 showed the morphologically reversional activity on ts/NRK cell and the cytotoxicity on CTLL cell at the final concentrations of 1.7 JlM and 0.2 11M, respectively and its $IC_{50}$ value on protein kinase A enzyme was 2.3 $\mu$M. Also it had strong antifungal activity against several pathogenic fungi but not antibacterial activity. And it did not inhibit both protein kinase C activity and the bleb-formation of K562 cell induced by phorbol esters.

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