998 resultados para structured prediction


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This thesis has investigated the risk preferences of the Chinese company managers in kinds of simulated decision situations and their perceptions of risk concerning types of business decisions. Four studies are conducted: Study I is utility analysis. 214 company managers and 46 middle - school headmasters have responded to Utility Measurement Survey. The results indicate: (1) The risk preferences of the managers vary in the different decision situations. In most of the situations, most of the managers are risk aversion; In few situations, they are risk-seeking. (2) In some of the decision situations, there are significant differences on risk preference between business managers and school headmasters, male managers and female managers, senior managers and junior managers, managers with high qualifications and managers with low qualifications, non-state-owned firms' managers and state-owned firms' managers, medium-small sized firms' managers and large-sized firms' managers. In the other situations there aren't significant differences between them. (3) In all of the decision situations, so significant differences on risk preference are found among managers with different marriage, experience, age and education. Study II is risky decision simulation. The Risky Decision Situations Simulation Survey is administered to 82 company managers. The result indicates that firm culture, business condition, survival limit and risk preference of the superior influence the managers' risk decision-making behavior. Study III is perceptions of business decision risks. 68 company managers have filled in Decision Cases Risk Perception Inventory. The results indicate: (1) Inaccurate market analysis and prediction, instable politics and the changes of economic policy are the more risky elements to strategy decision. (2) Erroneous market analysis and prediction, appearance of new technology and the changes of market demands are the more risky elements to investment decision. (3) Poor quality control, backward technology and too large stocks are the more risky elements to production decision. (4) Shortage of development fund, wrong choice in development project and limitation of the development ability are the more risky elements to new production development decision. (5) No payment of the foreign partner's capital, the changes of national relevant policy, difficulty in marketing, too high selling prices of foreign partner's equipments are the more risky elements to joint-venture decision. (6) Unfamilarity with oneself and misjudgement in qualification of oneself are the more risky elements to personnel decision. (7) Bad market of the product, defects in product quality and the changes of consumers demands are the more risky elements to marketing decision. (8) Wrong strategy and ambiguous goals are the more risky elements to public relation decision. (9) Violation of the law, ambiguous goals and poor creation are the more risky elements to advertisement decision. (10) Deterioration of diplomatic relations, unsuitable products for foreign consumers and unfamilarity with foreign market are the more risky elements to international business decision. Study IV is structured interview. 5 company managers have answered all questions of the Interview Questionnaire. The results indicate: (1) The managers think that risks are the possible unfavourable consequences of decisions; (2) The self-ratings of the managers coordinate with the results of utility measurement; (3) The managers admit that risks always accompany bussiness decision; (4) Individual difference is found among managers on risk perception. This thesis has also pointed out the important implications of the research and discussed several further questions.

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A numerical approach has been developed for the correlation of retention limes (total retention lime) with temperature in gas chromatography, which allows the calculation of retention parameters including retention index from data acquired under two or more different temperature program conditions. By using this procedure the optimization of temperature condition can be further achieved, especially when a temperature-programmed run is the most suitable mode in the preliminary development of an analytical method for the analysis of an unknown sample.

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The soil organic partition coefficient (K-oc) is one of the most important parameters to depict the transfer and fate of a chemical in the soil-water system. Predicting K-oc by using a chromatographic technique has been developing into a convenient and low-cost method. In this paper, a soil leaching column chromatograpy (SLCC) method employing the soil column packed with reference soil GSE 17201 (obtained from Bayer Landwirtschaftszentrum, Monheim, Germany) and methanol-water eluents was developed to predict the K-oc of hydrophobic organic chemicals (HOCs), over a log K-oc range of 4.8 orders of magnitude, from their capacity factors. The capacity factor with water as an eluent (k(w)') could be obtained by linearly extrapolating capacity factors in methanol-water eluents (k') with various volume fractions of methanol (phi). The important effects of solute activity coefficients in water on k(w)' and K-oc were illustrated. Hence, the correlation between log K-oc and log k(w)' (and log k') exists in the soil. The correlation coefficient (r) of the log K-oc vs. log k(w)' correlation for 58 apolar and polar compounds could reach 0.987, while the correlation coefficients of the log K-oc-log k' correlations were no less than 0.968, with phi ranging from 0 to 0.50. The smaller the phi, the higher the r. Therefore, it is recommended that the eluent of smaller phi, such as water, be used for accurately estimating K-oc. Correspondingly, the r value of the log K-oc-log k(w)' correlation on a reversed-phase Hypersil ODS (Thermo Hypersil, Kleinostheim, Germany) column was less than 0.940 for the same solutes. The SLCC method could provide a more reliable route to predict K-oc indirectly from a correlation with k(w)' than the reversed-phase liquid chromatographic (RPLC) one.

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TEMPEST is a full-screen text editor that incorporates a structural paradigm in addition to the more traditional textual paradigm provided by most editors. While the textual paradigm treats the text as a sequence of characters, the structural paradigm treats it as a collection of named blocks which the user can define, group, and manipulate. Blocks can be defined to correspond to the structural features of he text, thereby providing more meaningful objects to operate on than characters of lines. The structural representation of the text is kept in the background, giving TEMPEST the appearance of a typical text editor. The structural and textual interfaces coexist equally, however, so one can always operate on the text from wither point of view. TEMPEST's representation scheme provides no semantic understanding of structure. This approach sacrifices depth, but affords a broad range of applicability and requires very little computational overhead. A prototype has been implemented to illustrate the feasibility and potential areas of application of the central ideas. It was developed and runs on an IBM Personal Computer.

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A model is developed for predicting the resolution of interested component pair and calculating the optimum temperature programming condition in the comprehensive two-dimensional gas chromatography (GC x GC). Based on at least three isothermal runs, retention times and the peak widths at half-height on both dimensions are predicted for any kind of linear temperature-programmed run on the first dimension and isothermal runs on the second dimension. The calculation of the optimum temperature programming condition is based on the prediction of the resolution of "difficult-to-separate components" in a given mixture. The resolution of all the neighboring peaks on the first dimension is obtained by the predicted retention time and peak width on the first dimension, the resolution on the second dimension is calculated only for the adjacent components with un-enough resolution on the first dimension and eluted within a same modulation period on the second dimension. The optimum temperature programming condition is acquired when the resolutions of all components of interest by GC x GC separation meet the analytical requirement and the analysis time is the shortest. The validity of the model has been proven by using it to predict and optimize GC x GC temperature programming condition of an alkylpyridine mixture. (c) 2005 Elsevier B.V. All rights reserved.

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This study sought predictors of mortality in patients aged >or=75 years with a first ST-segment elevation myocardial infarction (STEMI) and evaluated the validity of the GUSTO-I and TIMI risk models. Clinical variables, treatment and mortality data from 433 consecutive patients were collected. Univariable and multivariable logistic regression analyses were applied to identify baseline factors associated with 30-day mortality. Subsequently a model predicting 30-day mortality was created and compared with the performance of the GUSTO-I and TIMI models. After adjustment, a higher Killip class was the most important predictor (OR 16.1; 95% CI 5.7-45.6). Elevated heart rate, longer time delay to admission, hyperglycemia and older age were also associated with increased risk. Patients with hypercholesterolemia had a significantly lower risk (OR 0.46; 95% CI 0.24-0.86). Discrimination (c-statistic 0.79, 95% CI 0.75-0.84) and calibration (Hosmer-Lemeshow 6, p = 0.5) of our model were good. The GUSTO-I and TIMI risk scores produced adequate discrimination within our dataset (c-statistic 0.76, 95% CI 0.71-0.81, and c-statistic 0.77, 95% CI 0.72-0.82, respectively), but calibration was not satisfactory (HL 21.8, p = 0.005 for GUSTO-I, and HL 20.6, p = 0.008 for TIMI). In conclusion, short-term mortality in elderly patients with a first STEMI depends most importantly on initial clinical and hemodynamic status. The GUSTO-I and TIMI models are insufficiently adequate for providing an exact estimate of 30-day mortality risk.

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Struyf, J., Dzeroski, S. Blockeel, H. and Clare, A. (2005) Hierarchical Multi-classification with Predictive Clustering Trees in Functional Genomics. In proceedings of the EPIA 2005 CMB Workshop

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X. Wang, J. Yang, R. Jensen and X. Liu, 'Rough Set Feature Selection and Rule Induction for Prediction of Malignancy Degree in Brain Glioma,' Computer Methods and Programs in Biomedicine, vol. 83, no. 2, pp. 147-156, 2006.

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D.J. Currie, M.H. Lee and R.W. Todd, 'Prediction of Physical Properties of Yeast Cell Suspensions using Dielectric Spectroscopy', Conference on Electrical Insulation and Dielectric Phenomena, (CEIDP 2006), Annual Report, pp 672 ? 675, October 15th -18th 2006, Kansas City, Missouri, USA. Organised by IEEE Dielectrics and Electrical Insulation Society.

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John Warren and Chris Topping (2004). A trait specific model of competition in a spatially structured plant community. Ecological Modelling, 180 pp.477-485 RAE2008