• Title/Summary/Keyword: Thomson

검색결과 213건 처리시간 0.021초

Protoplast Isolation and Regeneration of Fertile Plants from Arabidopsis Trp Mutant, trp1-100

  • Lim, Seon-hee;Kim, Young-soon;Lee, Eui-seung;Rose, Alan;Last, Robert;Cheong, Hyeon-sook
    • Animal cells and systems
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    • 제2권2호
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    • pp.239-242
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    • 1998
  • Arabidopsis trp1 mutant plants, deficient in phosphoribosyI anthranilate transferase (PAT) activity, accumulate anthranilate compounds, which render them blue fluorescence. The visible phenotype of trp1 makes the PAT gene an excellent reporter gene in the mutant. In order to develop a system for the homologous recombination using the phenotypic characteristic of trp1-100, we established optimum conditions for the isolation and regenera tion of protoplast from auxin-conditioned, trp1-100 root cultures. Trvptophan had to be supplemented in the germination medium for the efficient cell division and subsequent plant regeneration. When 10 uM tryptophan was added to the germination medium, we obtained the highest yield of protoplasts ($3{\times}10^6 cells/g$) and the best viability (92%). Thirty percent of root protoplast derived from meristematic cells underwent cell division within 5 days in callus-induction medium. Regenerated rosette leaves (2-3 mm) were transferred to rooting medium and finally acclimated to the soil for flowering.

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모델링 및 시뮬레이션을 통한 수소충전 프로토콜 영향인자 평가 (Evaluation of Influential Factors of Hydrogen Fueling Protocol by Modeling and Simulation)

  • 채충근;강수연;김한나;채승빈;김용규
    • 한국수소및신에너지학회논문집
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    • 제30권6호
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    • pp.513-522
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    • 2019
  • It is not easy to refuel quickly and safely with 70 MPa hydrogen. This is because the temperature in the vehicle tank rises sharply due to Joule-Thomson effect, etc. Thus protocols such as SAE J2601 in the United States and JPEC-S 0003 in Japan were established. However, they have the problem of over-complexity and lack of versatility by setting the preconditions for hot and cold cases and introducing a number of look-up tables. This study was conducted with the ultimate goal of developing new protocols based on complete real-time communication. Thermodynamic models were made and programs were developed for hydrogen refueling simulations. Simulation results confirmed that there are five parameters in the influencing factors of the hydrogen refueling protocol.

Atmospheric Stability Evaluation at Different Time Intervals for Determination of Aerial Spray Application Timing

  • Huang, Yanbo;Thomson, Steven J.
    • Journal of Biosystems Engineering
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    • 제41권4호
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    • pp.337-341
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    • 2016
  • Purpose: Evaluation of atmospheric conditions for proper timing of spray application is important to prevent off-target movement of crop protection materials. Susceptible crops can be damaged downwind if proper application procedure is not followed. In our previous study, hourly data indicated unfavorable conditions, primarily between evening 18:00 hrs in the evening and 6:00 hrs next morning, during clear conditions in the hot summer months in the Mississippi delta. With the requirement of timely farm operations, sub-hourly data are required to provide better guidelines for pilots, as conditions of atmospheric stability can change rapidly. Although hourly data can be interpolated to some degree, finer resolution for data acquisition of the order of 15 min would provide pilots with more accurate recommendations to match the data recording frequency of local weather stations. Methods: In the present study, temperature and wind speed data obtained at a meteorological tower were re-sampled to calculate the atmospheric stability ratio for sub-hour and hourly recommendations. High-precision evaluation of temperature inversion periods influencing atmospheric stability was made considering strength, time of occurrence, and duration of temperature inversion. Results and Discussion: The results indicated that atmospheric stability could be determined at different time intervals providing consistent recommendations to aerial applicators, thereby avoiding temperature inversion with minimal off-target drift of the sprayed liquid.

국내 연구자들의 SCI 학술지 발표 현황 분석 (A Research on Analyses of the Written SCI Journal Articles by Korean Researchers)

  • 김완종;유수현;이혜진;노경란
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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    • pp.861-865
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    • 2008
  • 최근 몇 년간 국가적으로 R&D 분야에 대한 예산 지원이 활발해지면서 국내 연구자들이 과학기술분야의 주요 학술지에 발표하는 논문의 양도 급격히 증가하고 있다. 하지만 이 연구자들이 발표한 논문을 수록하고 있는 학술지가 국내에서 얼마나 활용되고 있는지에 대한 연구는 이루어지지 않고 있다. 따라서 본 연구에서는 국내에서 연구를 수행하는 연구자들이 발표한 논문이 수록된 주요 학술지에 대한 분석을 통해 한국 연구자들이 주로 발표하는 학술지가 무엇인지를 알아보는데 그 목적이 있다. 이를 위하여 Thomson Reuters 사의 SCI(Science Citation Index) 데이터베이스에 수록된 학술지를 그 분석 대상으로 하였으며, 분석 기간은 2004년부터 2006년도까지 3년간의 데이터를 추출하여 분석하였다.

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The Effect of Foreign Ownership and Product Market Competition on Firm Performance: Empirical Evidence from Vietnam

  • HA, Thach Xuan;TRAN, Thu Thi
    • The Journal of Asian Finance, Economics and Business
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    • 제8권11호
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    • pp.79-86
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    • 2021
  • In recent years, firm performance has been a topic that attracts many researchers. It is extremely important to identify the factors that change firm performance. In the current trend of competition and integration, foreign ownership, product market competition is found to reduce agency costs and impact firm performance. The purpose of this research is to investigate the relationship between foreign ownership, product market competition, and firm performance. Our research using a quantile regression model, through panel data of 290 companies listed on the Vietnam stock exchange (include Ho Chi Minh and Hanoi stock exchanges) from 2017 to 2019 that was collected by Thomson - Reuters DataStream has shown that foreign ownership and product market competition have a positive impact on Tobin's Q but are not statistically significant with ROA. Critically, our quantile regression results suppose foreign ownership, product market competition have a significantly larger positive impact in high-performing firms relative to low-performing firms. The results help propose solutions to planners and managers to change foreign ownership and product market competition to increase business performance. Besides, through quantile regression analysis, managers need to pay attention to the impact on foreign ownership, product market competition; there will be a difference between high-performing firms relative to low-performing firms.

The Effect of Information Asymmetry on the Method of Payment and Post-M&A Involuntary Delisting

  • Thompson, Ephraim Kwashie;Kim, Chang-Ki
    • 아태비즈니스연구
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    • 제11권3호
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    • pp.1-20
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    • 2020
  • Purpose - This paper shows an unexplored area related to involuntary delisting. Specifically, this research investigates the effect of target firm information asymmetry on the likelihood that the acquirer or newly merged firm will be forcibly delisted post-merger. Design/methodology/approach - The research uses a sample gathered on local US mergers and acquisitions from the Thomson Reuters Securities Data Company (SDC) Platinum Mergers and Acquisitions database. It applies the logistic regression with industry and year effects and corrects the error term using clustering at the industry level. The research also matches the forced delisted firms to control firms based on industry, acquisition completion year, and firm size and then employs a matched sample analysis. Findings - Findings show that M&As between firms where the target firm is opaque and burdened with high information asymmetry issues are likely to be paid for using majority stock and that M&As involving such opaque targets also have a higher likelihood of getting delisted post-merger. Research implications or Originality - Our results are relevant given the very nature of M&As which involve two players: the acquirer and target who both may have different incentives. Acquirers especially have the tendency to suffer losses and even get delisted if they over-pay for or get merged to a poor target which conceals its poor performance evidenced by higher accruals quality.

Bank Capital, Efficiency and Risk: Evidence from Islamic Banks

  • ISNURHADI, Isnurhadi;ADAM, Mohamad;SULASTRI, Sulastri;ANDRIANA, Isni;MUIZZUDDIN, Muizzuddin
    • The Journal of Asian Finance, Economics and Business
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    • 제8권1호
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    • pp.841-850
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    • 2021
  • This study aims to evaluate the relationship between bank capital, efficiency, and risk in Islamic banks. We use data from 129 Islamic banks in the world, retrieved from various data sources. We retrieved specific banking data from Moody's Analytics BankFocus and Thomson Reuters Eikon, while data at the country level was obtained from the World Bank website. This study uses various estimates both Pooled OLS (Ordinary Least Square) and Random Effect (RE). However, to overcome the issue of serial correlation which could cause bias in the results of the study, we used fixed-effect (FE) cluster estimates. The research results confirm the previous findings that bank capital positively affects bank stability (natural logarithm of Z-Score) and negatively affects credit risk (loan loss provision to total liabilities). The findings also show that efficiency has the same effect. The interaction test of bank capital and efficiency shows that efficiency encourages banks to reduce risk, including when bank capital is relatively lower. This finding is expected to have implications for the authorities to boost bank efficiency in addition to establishing several regulations related to capital. The efficiency implemented by the bank will encourage banks to act prudently so that the bank can maintain its performance through risk mitigation.

Effects of the Fair Value of Biological Assets on the Cost of Debt: An International Study

  • ERFAN, Neven;ALI, Ijaz;KHAN, Soha;KHAN, Imran Ahmad
    • The Journal of Asian Finance, Economics and Business
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    • 제9권8호
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    • pp.71-80
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    • 2022
  • This study aims to investigate the effects of fair value valuation of biological assets and bearer plants measured at historical cost on the cost of third-party capital. The study contributes to the agricultural sector and the International Accounting Standard - IAS 41, which has been modified to remove the requirement to apply fair value for bearer plants, one of the primary biological assets with no active market. For this, 182 companies from 39 countries were studied in the years 2020 and 2021, with information taken from the Thomson Reuters Eikon platform. The methodology involves regression by the ordinary least squares method based on the model of Daly and Skaife (2016). The results show that the biological asset at fair value does not influence the cost of debt and that the measurement of bearer plants at historical cost has no effect on the cost of debt. Fair value did not change the perceived cost of debt of the analyzed companies in the studied period, contrary to Daly and Skaife (2016). Finally, the cost of third-party capital can be influenced by other aspects related to profit quality, which were not examined in this paper, such as profit management.

The COVID-19 Pandemic and Instability of Stock Markets: An Empirical Analysis Using Panel Vector Error Correction Model

  • ABDULRAZZAQ, Yousef M.;ALI, Mohammad A.;ALMANSOURI, Hesham A.
    • The Journal of Asian Finance, Economics and Business
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    • 제9권4호
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    • pp.173-183
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    • 2022
  • The objective of this research is to examine the influence of the COVID-19 pandemic on stock markets in a few developing and developed countries. This study uses daily data from January 2020 to May 2021 and obtained from World Health Organization and Thomson Reuters. The secondary data was evaluated through panel econometric methodology that includes different unit root tests, and to analyze the long-run relationship between variables, panel cointegration techniques were applied. The long-run causality among variables was examined through Panel Vector Error Correction Model. The overall findings of this study suggest a long-run association exists between several cases and death with the stock returns of the GCC and other stock markets. Furthermore, the VECM model also identified a long-run causality running from COVID cases and death towards the stock rerun of both sets of stock markets. However, a subsequent Wald test yielded mixed results, indicating no short-run causality between cases and deaths and stock returns in both groups; however, in the case of GCC, several COVID-19 cases are having a causal impact on stock markets, which is notable in light of the fact that the death rate in GCC is significantly lower than in many developed and developing countries.

고자기장용 자석을 위한 밀폐순환형 냉각장치 (Closed-Loop Cooling System for High Field Mangets)

  • 최연석;김동락;이병섭;양형석
    • 한국초전도ㆍ저온공학회논문지
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    • 제8권1호
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    • pp.59-64
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    • 2006
  • A closed-loop cryogenic cooling system for high field magnets is presented. This design is motivated by our recent development of cooling system for 21 tesla Fourier Transform ion Cyclotron Resonance (FT-ICR) superconducting magnets without any replenishment of cryogen. The low temperature superconducting magnets are immersed in a subcooled 1.8 K bath, which is connected hydraulically to the 4.2 K reservoir through a narrow channel. Saturated liquid helium is cooled by Joule-Thomson heat exchanger and flows through the JT valve, isenthalpically dropping its pressure to approximately 1 6 kPa, corresponding saturation temperature of 1.8 K. Helium gas exhausted from pump is now recondensed by two-stage cryocooler located after vapor purify system. The amount of cryogenic Heat loads and required mass flow rate through closed-loop are estimated by a relevant heat transfer analysis, from which dimensions of JT heat exchanger and He II heat exchanger are determined. The detailed design of cryocooler heat exchanger for helium recondensing is performed. The effect of cryogenic loads, especially superfluid heat leak through the gap of weight load relief valve, on the dimensions of cryogenic system is also investigated.