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Screening of Drought Stress Indicators and Analysis of Drought Resistance in Cultivated Rice Germplasm Resources in Guangxi 被引量:2
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作者 夏秀忠 曾宇 +4 位作者 李丹婷 农保选 刘开强 陈仁天 邓国富 《Agricultural Science & Technology》 CAS 2014年第7期1140-1144,共5页
This study aimed to screen drought stress indicators and analyze the drought resistance in 105 cultivated rice germplasm resources in Guangxi Zhuang Autonomous Region under drought stress in the whole growth period ba... This study aimed to screen drought stress indicators and analyze the drought resistance in 105 cultivated rice germplasm resources in Guangxi Zhuang Autonomous Region under drought stress in the whole growth period based on D value of seven morphological traits including panicle neck thickness,effective panicle number per plant,1 000-grain weight,filled grain number per panicle,total grain number,seed setting rate and yield per plant.According to the results,under drought stress,yield per plant exhibited significant positive correlation with panicle neck thickness and exhibited extremely significant positive correlation with other five morphological traits.Based on the identification and evaluation of comprehensive drought-resistance index D value,seven highly drought-resistant cultivated rice varieties were screened,accounting for 6.67%.Upland rice germplasm resources in Guangxi Zhuang Autonomous Region possess strong drought-resistance capacity,which could be used to screen highly drought-resistant rice germplasm materials.This study provided material basis and theoretical reference for breeding drought resistant rice cultivars in Guangxi Zhuang Autonomous Region. 展开更多
关键词 GUANGXI Rice germplasm resources Drought resistance Identification and evaluation
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Identification of Faba Bean(Vicia faba L.)Germplasm Resources in Hubei Province and Evaluation on Their Main Agronomic Traits 被引量:2
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作者 李莉 刘昌燕 +4 位作者 陈宏伟 万正煌 刘良军 伍广洪 黎大革 《Agricultural Science & Technology》 CAS 2017年第12期2219-2222,2228,共5页
Through field observation and lab analysis, 13 agronomic traits, including plant height and effective branching number per plant, etc., of 207 faba bean (Vicia faba L.) germplasms saved in Crop Middle-term Genebank ... Through field observation and lab analysis, 13 agronomic traits, including plant height and effective branching number per plant, etc., of 207 faba bean (Vicia faba L.) germplasms saved in Crop Middle-term Genebank of Hubei Province were evaluated, moreover, the identification on the disease resistance and the quality was carried out on parts of germplasm resources. The results showed that the faba beangermplasm resources in Hubei Province were abundant, the variation range of agronomic traits like the growth period, plant height and 100-bean weight, etc., was great, and the range of choice was wide. In the aspect of quality, there were 9 germplasms withthe content of crude protein higher than 30%, and the variation range of amylose content in total starch was large, which provided excellent sources of parents for breedinq hi.qh-quality faba bean varieties in Hubei Province. 展开更多
关键词 HUBEI Faba bean (Vicia faba L.) Variety resources Agronomic traits IDENTIFICATION
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统计学问答
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作者 刘勖 《食管外科电子杂志》 2014年第1期49-49,共1页
科研数据为什么要进行统计学处理?难道治愈率91%的某方法不是比治愈率90%的另一方法治疗效果更好吗?答:统计学是研究事物数量特征的科学,通过对数据资料的搜集、整理和分析,来认识事物的数量客观规律。由于在实际科研工作中往往不能对... 科研数据为什么要进行统计学处理?难道治愈率91%的某方法不是比治愈率90%的另一方法治疗效果更好吗?答:统计学是研究事物数量特征的科学,通过对数据资料的搜集、整理和分析,来认识事物的数量客观规律。由于在实际科研工作中往往不能对事物的总体进行普查性研究,即对总体中每个个体全部逐一进行研究,例如不可能对全国所有男性的身高逐一进行调查,只能随机抽取部分男性进行测量。所以,我们所得到的科研数据往往是从总体中随机抽取的部分观察对象的实测值组成的的数据,也就是样本。 展开更多
关键词 统计学分析 科研数据 数量特征 观察对象 数据 度量衡单位 定性观察 抽样误差 互不相容 定性资
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Research of relationship between uncertainty and investment
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作者 孟力 汪定伟 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第4期334-338,共5页
This study focuses on revealing the relationship between uncertainty and investment probability through real option model involving investment critical trigger and project earning. Use of Matlab software on the experi... This study focuses on revealing the relationship between uncertainty and investment probability through real option model involving investment critical trigger and project earning. Use of Matlab software on the experimental results showing that project earning volatility influences investment probability, led the authors to conclude that this notion is not always correct, as increasing uncertainty should have an inhibiting effect on investment, and that in certain situation, increasing uncertainty actually increases the investment probability and so, should have positive impact on investment. 展开更多
关键词 INVESTMENT UNCERTAINTY Real option Stochastic process
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QUALITATIVE REASONING BY COMPUTING WITH WORDS IN HERRERA-MARTíNEZ’S LINGUISTIC MODEL
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作者 Li Xinde Dai Xianzhong 《Journal of Electronics(China)》 2009年第4期564-570,共7页
Most of modern systems for information retrieval, fusion and management have to deal with more and more qualitative information (by linguistic labels) besides information expressed quantitatively (by numbers), sin... Most of modern systems for information retrieval, fusion and management have to deal with more and more qualitative information (by linguistic labels) besides information expressed quantitatively (by numbers), since human reports are better and easier expressed in natural language than with numbers. In this paper, Herrera-Martfnez's 2-Tuple linguistic representation model is extended for reasoning with uncertain and qualitative information in Dezert-Smarandache Theory (DSmT) framework, in order to overcome the limitations of current approaches, i.e., the lack of precision in the final results of linguistic information fusion according to 1-Tuple representation ( q1 )- The linguistic information which expresses the expert's qualitative beliefs is expressed by means of mixed 2 Tuples (equidistant linguistic labels with a numeric biased value). Together with the 2-Tuple representation model, some basic operators are presented to carry out the fusion operation among qualitative information sources. At last, through simple example how 2-Tuple qualitative DSmT-based (q2 DSmT) fusion rules can be used for qualitative reasoning and fusion under uncertainty, which advantage is also showed by comparing with other methods. 展开更多
关键词 Information fusion Qualitative reasoning under uncertainty Dezert-smarandache Theory (DSmT) 2-Tuple linguistic label
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The Optimal Nash Equilibrium Strategies Under Competition 被引量:1
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作者 孟力 王崇喜 +1 位作者 汪定伟 张爱玲 《Journal of Shanghai Jiaotong university(Science)》 EI 2004年第4期91-96,共6页
This paper presented a game theoretic model to study the competition for a single investment oppertunity under uncertainty. It models the hazard rate of investment as a function of competitors' trigger level. Unde... This paper presented a game theoretic model to study the competition for a single investment oppertunity under uncertainty. It models the hazard rate of investment as a function of competitors' trigger level. Under uncertainty and different information structure, the option and game theory was applied to researching the optimal Nash equilibrium strategies of one or more firm. By means of Matlab software, the paper simulates a real estate developing project example and illustrates how parameter affects investment strategies. The paper's work will contribute to the present investment practice in China. 展开更多
关键词 real options irreversible investment game theory UNCERTAINTY
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Research Progress in Agricultural Vulnerability to Climate Change
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作者 Shengcai Tao Yinlong Xu +2 位作者 Ke Liu Jie Pan Shiwei Gou 《Advances in Climate Change Research》 SCIE 2011年第4期203-210,共8页
With the deepening of climate change research, more attention has been paid to vulnerability to climate change. Compared with water resources, forests and other natural ecosystems, agriculture is more vulnerable to cl... With the deepening of climate change research, more attention has been paid to vulnerability to climate change. Compared with water resources, forests and other natural ecosystems, agriculture is more vulnerable to climate change, thereby scientifically assessing agricultural vulnerability to climate change is of great significance to the formulation of rational and effective adaptation strategies. In this paper, the authors give a comprehensive review of the research from the perspective of the definition of climate change vulnerability and agricultural vulnerability to climate change, research topics, and evaluation methodologies. Existing problems in current research, including scenario application, methods, and uncertainties, are analyzed, and meanwhile, a vision of the direction for future research in assessment of agricultural vulnerability is also presented. 展开更多
关键词 climate change VULNERABILITY AGRICULTURE
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Dynamic Portfolio Choice under Uncertainty about Asset Return Model
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作者 何朝林 孟卫东 《Journal of Donghua University(English Edition)》 EI CAS 2009年第6期645-650,共6页
The effect of uncertainty about stochastic diffusion model on dynamic portfolio choice of an investor who maximizes utility of terminal portfolio wealth was studied.It applied stochastic control method to obtain the c... The effect of uncertainty about stochastic diffusion model on dynamic portfolio choice of an investor who maximizes utility of terminal portfolio wealth was studied.It applied stochastic control method to obtain the closed-form solution of optimal dynamic portfolio,and used the Bayesian rule to estimate the model parameters to do an empirical study on two different samples of Shanghai Exchange Composite Index.Results show,model uncertainty results in positive or negative hedging demand of portfolio,which depends on investor's attitude toward risk;the effect of model uncertainty is more significant with the increasing of investment horizon,the decreasing of investor's risk-aversion degree,and the decreasing of information;predictability of risky asset return increases its allocation in portfolio,at the same time,the effect of model uncertainty also strengthens. 展开更多
关键词 dynamic portfolio model uncertainty estimation risk Bayesian analysis
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Urbanization-related warming in local temperature records:a review 被引量:7
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作者 WANG Jun YAN Zhong-Wei 《Atmospheric and Oceanic Science Letters》 CSCD 2016年第2期129-138,共10页
There have long been arguments about the impact of urbanization on local meteorological observations. This letter reviews up-to-date studies of the urbanization-related warming in the observed land surface air tempera... There have long been arguments about the impact of urbanization on local meteorological observations. This letter reviews up-to-date studies of the urbanization-related warming in the observed land surface air temperature series in China. Many previous studies have suggested that, over the past few decades, the local warming due to urbanization could have been about 0.1 °C/10 yr, or even larger. However, based on recently developed homogenized temperature records, the estimated urban bias is smaller. Major uncertainties arise from either the data quality or the techniques used to estimate the urbanization effect. A key example is the ‘observationminus-reanalysis' method, which tends to overestimate the urban signal in this region, partly due to systematic bias in the multi-decadal variability of surface air temperature in the reanalysis data. It is expected that improved numerical modeling with high-resolution information regarding the changing land surface in the region will help to further understand and quantify the effect of urbanization in local temperature records. 展开更多
关键词 URBANIZATION China land surface air temperature HOMOGENIZATION observation-minus-reanalysis method uncertainty
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Research on Application of Monte Carlo Simulation in the Income Approach of Asset Valuation A listed Company in China as an Example
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作者 Chen Lei Gu Mengdi 《Journal of Modern Accounting and Auditing》 2012年第9期1301-1310,共10页
The income approach of asset valuation estimates the asset value according to the asset-discounted future earnings or the capitalizing process. As a result, a reasonable prediction of asset-expected future returns has... The income approach of asset valuation estimates the asset value according to the asset-discounted future earnings or the capitalizing process. As a result, a reasonable prediction of asset-expected future returns has become one of the core contents of the income approach. The forecast on expected future earnings is generally based on many uncertain factors, such as strict conditions of assumption and the complexity of environment. However, the current valuation practice in this aspect varies greatly and sometimes depends on personally experienced judgment of appraisers. Therefore, the obtained valuation results tend to be simplified and absolutized. This paper takes a listed company in China as an example to explore the way of inserting an uncertainty analysis into the prediction of the income approach, and then to obtain a series of valuation results within a certain probability fluctuation range. Finally, it puts forward some suggestions about the Monte Carlo simulation (MCS). 展开更多
关键词 asset valuation income approach UNCERTAINTY PREDICTION Monte Carlo simulation (MCS)
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Molecular Discrimination of Wild Philippine Paddy Straw Mushroom ( Volvariella volvacea) 被引量:3
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作者 Evaristo A. Abella Geoff D. Robson Richard F. Preziosi 《Journal of Life Sciences》 2014年第1期27-34,共8页
Genetic diversity study of wild Philippine paddy straw mushroom (Volvariella volvacea) was conducted to establish a germplasm collection accessible to volvariella producers in the Philippines. Forty one wild strains... Genetic diversity study of wild Philippine paddy straw mushroom (Volvariella volvacea) was conducted to establish a germplasm collection accessible to volvariella producers in the Philippines. Forty one wild strains were collected from different geographical areas in Northern and Central Luzon region. Strains were differentiated using random amplified polymorphic DNA (RAPD). A single 10-based primer was used to generate randomly amplified polymorphic DNA (RAPD) in V. volvacea and differences were noted in band size (bp) ranging from 1,800 bp to 550 bp. Principal component analysis (PCA) of the RAPD data revealed 4 groups from wild strains. One strain showed RAPD pattern with band appearance at 1,750, 950 and 750 bp; 3 strains at 1,800 and 750 bp; 8 strains at 1,500 and 550; and the most abundant group with 29 strains at 750 bp. With observed lack of heterogeneity among strains, it is recommended that more collections from the wild should be undertaken for more diverse germplasm collection. Moreover, it is suggested that RAPD can be used to delineate strains of V. volvacea with potential importance on genetic diversity conservation and breeding. 展开更多
关键词 Volvariella volvacea genetic diversity random amplified polymorphic DNA (RAPD).
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Directional drilling in unstable environments 被引量:2
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作者 Hungerford Frank Ren Ting 《International Journal of Mining Science and Technology》 SCIE EI 2014年第3期397-402,共6页
Directional drilling has been established in the coal industry as a viable means of gas drainage, exploration and water management. But the environment in and around coal seams is not always conducive to stable condit... Directional drilling has been established in the coal industry as a viable means of gas drainage, exploration and water management. But the environment in and around coal seams is not always conducive to stable conditions while drilling and borehole stability after the drilling has been completed. This paper identifies the conditions which cause unstable drilling conditions and the various means which are used to attempt to manage or bypass those conditions. Ultimately, equipment does become bogged in these adverse environments and requires recovery by over-coring. 展开更多
关键词 Directional dril ing Borehole Stability Unstable dril ing conditions Over-coring
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A Service Selection Approach Based on Availability-Aware in Mobile Ad Hoc Networks 被引量:1
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作者 孙其博 王文彬 +1 位作者 邹华 杨放春 《China Communications》 SCIE CSCD 2011年第1期87-94,共8页
Service composition is considered to be an effective way for resource sharing and node collaboration in Mobile Ad hoc NETworks (MANETs) environment.In order to improve the reliability and shorten the response time of ... Service composition is considered to be an effective way for resource sharing and node collaboration in Mobile Ad hoc NETworks (MANETs) environment.In order to improve the reliability and shorten the response time of composite services,this paper first analyzes the node environments and network environments that affect the component services' availability,and then proposes an Environment-aware Quantitative Evaluation Model for Service Availability (EQEM-SA).In addition,based on EQEM-SA,a service field concept is proposed as well as the availability attenuation equation,where the availability value is considered as the field strength.Then the service selection approach based on service field model is presented.The effectiveness of the proposed approach is illustrated and compared with related references,and the results of experimental evaluations indicate that our approach significantly reduces the failure rate and shortens the service delay. 展开更多
关键词 MANETS AVAILABILITY service field service selection
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Reserch about the Causes and Countermeasures for the Contract Employees Loss of the University
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作者 Shubing Huang 《International English Education Research》 2014年第10期62-64,共3页
Human resource is already in society today one of the most important resources, the human resources stability has important implications, university should how to its important role and how to keep its stability, in t... Human resource is already in society today one of the most important resources, the human resources stability has important implications, university should how to its important role and how to keep its stability, in this thesis are introduced. In addition, concerning human resources loss and its have also means have relevant instruction, how to understand university human resources of stability,handled the problem, the university can better, faster development. 展开更多
关键词 Causes and Countermeasures University Loss The contract employees
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An Empirical Analysis of Employment Stability and the Wage Gap of Rural Migrants in China Based on Quantile Regression 被引量:1
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作者 Liu Baihui Kou Enhui 《China Economist》 2013年第6期98-111,共14页
Under the background of accelerated integrated urban-rural development, this paper offers an analysis on the short-term employment of rural migrants in China and resulting wage gap between long-term and short-term rur... Under the background of accelerated integrated urban-rural development, this paper offers an analysis on the short-term employment of rural migrants in China and resulting wage gap between long-term and short-term rural migrants. On the basis of correcting for sample selection problems arising from labor market participation and short-term employment, rural migrants' wage function is estimated using quantile regression method, and wage gap between long-term and short-term rural migrants is decomposed using MM method. Our empirical results suggest that those with a higher level of education, training experience and local employment recommended by family relations or in formal labor market are more likely to secure long-term labor contract," region and education have significant contributions to the wage of rural migrants," rural migrants of both long- and short-term contract types have great gaps at the bottom of salary distribution; and there exists a sticky floor effect in wage difference of rural migrants. These results have important policy implications in enhancing employment stability of rural migrants, improving income distribution equity, speeding up the process of urbanization, and balancing regional development. 展开更多
关键词 rural migrant workers wage gap quantile regression sticky floor effect
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Multi-objective planning model for simultaneous reconfiguration of power distribution network and allocation of renewable energy resources and capacitors with considering uncertainties 被引量:8
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作者 Sajad Najafi Ravadanegh Mohammad Reza Jannati Oskuee Masoumeh Karimi 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第8期1837-1849,共13页
This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously a... This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously and to improve power system's accountability and system performance parameters. Due to finding solution which is closer to realistic characteristics, load forecasting, market price errors and the uncertainties related to the variable output power of wind based DG units are put in consideration. This work employs NSGA-II accompanied by the fuzzy set theory to solve the aforementioned multi-objective problem. The proposed scheme finally leads to a solution with a minimum voltage deviation, a maximum voltage stability, lower amount of pollutant and lower cost. The cost includes the installation costs of new equipment, reconfiguration costs, power loss cost, reliability cost, cost of energy purchased from power market, upgrade costs of lines and operation and maintenance costs of DGs. Therefore, the proposed methodology improves power quality, reliability and security in lower costs besides its preserve, with the operational indices of power distribution networks in acceptable level. To validate the proposed methodology's usefulness, it was applied on the IEEE 33-bus distribution system then the outcomes were compared with initial configuration. 展开更多
关键词 optimal reconfiguration renewable energy resources sitting and sizing capacitor allocation electric distribution system uncertainty modeling scenario based-stochastic programming multi-objective genetic algorithm
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The uncertain analysis of micro agricultural project investment
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作者 DingPing Cheng 《International English Education Research》 2014年第6期6-8,共3页
We conduct uncertain analysis of micro agricultural project, including the break-even analysis of single product micro agricultural project, the boundary break-even points analysis of the double product micro agricult... We conduct uncertain analysis of micro agricultural project, including the break-even analysis of single product micro agricultural project, the boundary break-even points analysis of the double product micro agricultural project. We find out the critical point and the critical line of the break-everL We analyze the ability to resist risk. This analyses help the micro agricultural project's investors to price reasonably, forecast the earnings and make the correct decision. 展开更多
关键词 uncertainly analysis break-even analysis risk analysis
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A Prey- Predator Model for Venture Capital Investment
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作者 Letetia Mary Addison Balswaroop Bhatt David Owen 《Journal of Mathematics and System Science》 2017年第11期297-307,共11页
The Rosenzweig-Macarthur Model is used to partially explain Venture Capital investment cycles. Investment opportunities and the experience of the investors, represent the prey and predator respectively. Stability anal... The Rosenzweig-Macarthur Model is used to partially explain Venture Capital investment cycles. Investment opportunities and the experience of the investors, represent the prey and predator respectively. Stability analysis with respect to the interior equilibrium point is performed and dynamics of the system are investigated using numerical simulations and results are presented. The model shows that parameter variation affects the stability of the system and it experiences bifurcations. The results show that stability analysis is useful to provide a Venture Capitalist with the stability ranges of parameters in the system, to improve the quality of the investment process. 展开更多
关键词 prey- predator STABILITY Hopf bifurcations Venture Capital
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Specific Financial Constraints of Innovative Companies: Theoretical Approach
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作者 Younes Ettahri Abderrahim Laachach 《Journal of Modern Accounting and Auditing》 2016年第11期556-566,共11页
When a small and medium-sized enterprise (SME) decides to invest in an innovative project, it becomes attached to a high level of uncertainty (Hall & Lerner, 2009) and it could meet some financial constraints (K... When a small and medium-sized enterprise (SME) decides to invest in an innovative project, it becomes attached to a high level of uncertainty (Hall & Lerner, 2009) and it could meet some financial constraints (Kerr & Nanda, 2014). This work is trying to apprehend the specific financial problems which SMEs, working on innovative projects, might face in a context characterized by a lack of liquidity, and it aims to improve the understanding of previous theoretical and empirical studies that dealt with the subject of financing these innovative companies. Moreover, it appears that it is important to ask the following question: Are there specific financial constraints to innovative SMEs? In order to answer the preceding question, this paper presents firstly the concept of innovation within companies. Secondly, it describes the specificities bound to the diverse financing approaches: in terms of risk, uncertainty, asymmetric information and profitability of an innovative project, while developing a theoretical approach concerning the possible constraints of financing the innovative companies. 展开更多
关键词 FINANCING innovative company uncertainty CONSTRAINTS LITERATURE
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Evaluation Method for Offshore Wind Energy Resources Using Scatterometer and Weibull Parameters 被引量:2
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作者 Katsutoshi Kozai Teruo Ohsawa +1 位作者 Rinya Takahashi Yuko Takeyama 《Journal of Energy and Power Engineering》 2012年第11期1772-1778,共7页
The study discusses accuracy evaluation methods for offshore wind energy resources by using scatterometer SeaWinds-derived wind speed and Weibull parameters. The purpose of this study is to evaluate accuracies of SeaW... The study discusses accuracy evaluation methods for offshore wind energy resources by using scatterometer SeaWinds-derived wind speed and Weibull parameters. The purpose of this study is to evaluate accuracies of SeaWinds-derived Weibull mean wind speed and energy density by considering uncertainties inherent in SeaWinds wind speed estimates. In this study, 1159 SeaWinds-derived wind speeds covering the KEO buoy are used for estimating two Weibull parameters, scale and shape. On the other hand, observed wind speeds from 2004 to 2008 at the KEO buoy are used for simulating three kinds of wind speeds in order to quantify some uncertainties inherent in SeaWinds-derived wind speeds. It is found that uncertainties associated with wind speed estimates (operational wind speed range, sampling time) show small differences in scale, shape and Weibull mean wind speed except energy density among the simulated datasets. Furthermore, the upper and lower bounds of 90% confidence interval corresponding to SeaWinds number of observations indicate 4-2.5% error of Weibull mean wind speed and 4-6.8% error of energy density, respectively. 展开更多
关键词 Offshore wind energy resource SCATTEROMETER Weibull parameter.
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