排序方式： 共有42条查询结果，搜索用时 15 毫秒
31.
Montazery-Kordy H Miran-Baygi MH Moradi MH 《Journal of Zhejiang University. Science. B》2008,9(11):863-870
Objective: To develop a new bioinformatic tool based on a data-mining approach for extraction of the most infor-mative proteins that could be used to fred the potential biomarkers for the detection of cancer. Methods: Two independent datasets from serum samples of 253 ovarian cancer and 167 breast cancer patients were used. The samples were examined by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The datasets were used to extract the informative proteins using a data-mining method in the discrete stationary wavelet transform domain. As a dimensionality re-duction procedure, the hard threshoiding method was applied to reduce the number of wavelet coefficients. Also, a distance measure was used to select the most discriminative coefficients. To find the potential biomarkers using the selected wavelet coefficients, we applied the inverse discrete stationary wavelet transform combined with a two-sided t-test. Results: From the ovarian cancer dataset, a set of five proteins were detected as potential biomarkers that could be used to identify the cancer patients from the healthy cases with accuracy, sensitivity, and specificity of 100%. Also, from the breast cancer dataset, a set of eight proteins were found as the potential biomarkers that could separate the healthy cases from the cancer patients with accuracy of 98.26%, sensitivity of 100%, and specificity of 95.6%. Conclusion: The results have shown that the new bioinformatic tool can be used in combination with the high-throughput proteomic data such as SELDI-TOF MS to find the potential biomarkers with high discriminative power. 相似文献
32.
Thin-walled spread foundations are used in coastal projects where the soil strength is relatively low. Developing a predictive model of bearing capacity for this kind of foundation is of interest due to the fact that the famous bearing capacity equations are proposed for conventional footings. Many studies underlined the applicability of artificial neural networks (ANNs) in predicting the bearing capacity of foundations. However, the majority of these models are built using conventional ANNs, which suffer from slow rate of learning as well as getting trapped in local minima. Moreover, they are mainly developed for conventional footings. The prime objective of this study is to propose an improved ANN-based predictive model of bearing capacity for thin-walled shallow foundations. In this regard, a relatively large dataset comprising 145 recorded cases of related footing load tests was compiled from the literature. The dataset includes bearing capacity (Qu), friction angle, unit weight of sand, footing width, and thin-wall length to footing width ratio (Lw/B). Apart from Qu, other parameters were set as model inputs. To enhance the diversity of the data, four more related laboratory footing load tests were conducted on the Johor Bahru sand, and results were added to the dataset. Experimental findings suggest an almost 0.5 times increase in the bearing capacity in loose and dense sands when Lw/B is increased from 0.5 to 1.12. Overall, findings show the feasibility of the ANN-based predictive model improved with particle swarm optimization (PSO). The correlation coefficient was 0.98 for testing data, suggesting that the model serves as a reliable tool in predicting the bearing capacity. 相似文献
33.
The hypothesis that proportionately more boys than girls experience reading failure was tested on a sample of 708 children using both test-identified and teacher-identified criteria. Test-identified reading failure was defined by low scores on standardized reading achievement tests given at the end of first and third grade. For Severely Reading Disabled (total reading score at the 10th percentile or lower), the ratio of boys to girls was 1.4:1 at first grade and 1.3:1 at third. At both grades equal proportions of boys and girls were represented in the Reading Disabled category (total reading score between the 11th and 30th percentile). Teacher-identified reading failure criteria consisted of enrollment in LD and Chapter One (remedial reading) programs at first and third grades. Teacher-identified ratios of boys to girls in LD were 2:1 at both first and third grade, exceeding the test-identified ratios, while identification for Chapter One services did not show a gender difference. 相似文献
34.
Multipotentiality is widely cited as a characteristic of the most gifted individuals. It refers to their ability and interest to pursue various activities and goals especially as related to leisure and career choice. Multipotentiality appears beneficial, but can also lead to problems in career decision-making. Evidence for such problems, however, is contradictory and often anecdotal. This research, a follow-up study to Rysiew, Shore and Carson (1984), through the examination of longitudinal empirical data, sought to ascertain the outcomes of multipotentiality and to examine its effects on career decision-making. The sample comprised 180 participants (110 males and 70 females), which is 73% of 1984 sample. The average verbal IQ (Otis & Lennon, 1969) was 124.5. Results show that multipotentiality seemed not problematic, and evidence for career indecision was lacking. As for moderating variables, participants' considered experiences to be beneficial. 相似文献
35.
DEHGHANI Mohammad Hadi MAHVI Amir Hossein NAJAFPOOR Ali Asghar AZAM Kamal 《浙江大学学报(A卷英文版)》2007,8(9):1462-1468
The effectiveness of using acoustical (sonochemical) reactor for degradation of linear alkylbenzen sulfonate (LAS) from aqueous solution was investigated. LASs are anionic surfactants,found in relatively high amounts in domestic and industrial wastewaters. In this study,experiments on LAS solution were performed using methylene blue active substances (MBAS) method. The effectiveness of acoustical processor reactor for LAS degradation is evaluated with emphasis on the effect of treatment time and initial LAS concentration. Experiments were performed at initial concentrations of 0.2,0.5,0.8 and 1.0 mg/L,acoustic fre-quency of 130 kHz,applied power of 500 W and temperature of 18 °C～20 °C. At the conditions involved,LAS degradation was found to increase with increasing sonochemical time. In addition,as the concentration increased,the LAS degradation rate de-creased in the acoustical processor reactor. 相似文献
36.
37.
Hossein Shokouhi-Nejad Amir Rikhtehgar Ghiasi Mohammad Ali Badamchizadeh 《Journal of The Franklin Institute》2017,354(12):4801-4825
This paper concerns the simultaneous fault detection and control (SFDC) problem for a class of nonlinear stochastic switched systems with time-varying state delay and parameter uncertainties. The switching signal of detector/controller unit (DCU) is assumed to be with switching delay, which results in the asynchronous switching between the subsystems and DCU. By constructing a switching strategy depending on the state and switching delays, new sufficient conditions expressed by a set of linear matrix inequalities (LMIs) is derived to design DCU gains. This problem is formulated as an H∞ optimization problem and both mean square exponential stability and fault detection of augmented system are considered. A numerical example is finally exploited to verify the effectiveness and potential of the achieved scheme. 相似文献
38.
This paper precedes chaos control of fractional-order chaotic systems in presence of uncertainty and external disturbances. Based on some basic properties on fractional calculus and the stability theorems, we present a hybrid adaptive intelligent backstepping-sliding mode controller (FAIBSMC) for the finite-time control of such systems. The FAIBSMC is proposed based on the concept of active control technique. The asymptotic stability of the controller is shown based on Lyapunov theorem and the finite time reaching to the sliding surfaces is also proved. Illustrative and comparative examples and simulation results are given to confirm the effectiveness of the proposed procedure, which consent well with the analytical results. 相似文献
39.
Hossein Karami 《Asia Pacific Education Review》2013,14(3):435-444
There has been a growing consensus among the educational measurement experts and psychometricians that test taker characteristics may unduly affect the performance on tests. This may lead to construct-irrelevant variance in the scores and thus render the test biased. Hence, it is incumbent on test developers and users alike to provide evidence that their tests are free of such bias. The present study exploited generalizability theory to examine the presence of gender differential performance on a high-stakes language proficiency test, the University of Tehran English Proficiency Test. An analysis of the performance of 2,343 examinees who had taken the test in 2009 indicated that the relative contributions of different facets to score variance were almost uniform across the gender groups. Further, there is no significant interaction between items and persons, indicating that the relative standings of the persons were uniform across all items. The lambda reliability coefficients were also uniformly high. All in all, the study provides evidence that the test is free of gender bias and enjoys a high level of dependability. 相似文献
40.
Education and Information Technologies - Many studies have explored educational and pedagogical affordances of social media, but few studies have investigated their impact on emotional and... 相似文献