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91.
92.
Application of the Tauc-Lorentz formulation to the interband absorption of optical coating materials
Recent progress in ellipsometry instrumentation permits precise measurement and characterization of optical coating materials in the deep-UV wavelength range. Dielectric coating materials exhibit their first electronic interband transition in this spectral range. The Tauc-Lorentz model is a powerful tool with which to parameterize interband absorption above the band edge. The application of this model for the parameterization of the optical absorption of TiO2, Ta2O5, HfO2, Al2O3, and LaF3 thin-film materials is described. 相似文献
93.
94.
We present two methods for determining the sentiment expressed by a movie review. The semantic orientation of a review can be positive, negative, or neutral. We examine the effect of valence shifters on classifying the reviews. We examine three types of valence shifters: negations, intensifiers, and diminishers. Negations are used to reverse the semantic polarity of a particular term, while intensifiers and diminishers are used to increase and decrease, respectively, the degree to which a term is positive or negative. The first method classifies reviews based on the number of positive and negative terms they contain. We use the General Inquirer to identify positive and negative terms, as well as negation terms, intensifiers, and diminishers. We also use positive and negative terms from other sources, including a dictionary of synonym differences and a very large Web corpus. To compute corpus-based semantic orientation values of terms, we use their association scores with a small group of positive and negative terms. We show that extending the term-counting method with contextual valence shifters improves the accuracy of the classification. The second method uses a Machine Learning algorithm, Support Vector Machines. We start with unigram features and then add bigrams that consist of a valence shifter and another word. The accuracy of classification is very high, and the valence shifter bigrams slightly improve it. The features that contribute to the high accuracy are the words in the lists of positive and negative terms. Previous work focused on either the term-counting method or the Machine Learning method. We show that combining the two methods achieves better results than either method alone. 相似文献
95.
Six published methods of rotor slip estimation for sensorless speed control were evaluated using simulated data. Only two of these showed signs of being usable. Both are based on the steady-state machine model and produce a fair slip accuracy for a machine running under perfect field alignment conditions. It was not determined whether the other four techniques were unsuccessful because they require a closed-loop speed controller, were presented incorrectly in the literature, or contain fundamental deficiencies. On the basis of these evaluations, a new technique was developed, and both measured and predicted results are presented to show that it works well. Moreover, this new technique has many features that make it theoretically and practically more attractive than most existing techniques 相似文献
96.
97.
Diana M. R. Harvey 《Journal of microscopy》1982,127(2):209-221
Freeze-substitution is a technique suitable for the preparation of unicellular and multicellular plant and animal specimens for conventional light microscopy, TEM and SEM. It is also widely used as a means of preparing animal and plant tissues for the localization of water soluble substances by analytical electron microscopy, autoradiography or visual detection of precipitates. The technical requirements of preparation, together with an evaluation of the procedures, are presented for various applications. Careful selection and evaluation of freezing technique, substitution solvent and regime are required for meaningful results. 相似文献
98.
This work describes a framework that combines techniques from Adaptive Hypermedia and Natural Language processing in order to create, in a fully automated way, on-line information systems from linear texts in electronic format, such as textbooks. The process is divided into two steps: an off-line processing step, which analyses the source text, and an on-line step, which executes when a user connects to the system with a web browser, moment at which the contents and hyperlinks are generated. The framework has been implemented as the Welkin system, which has been used to build three adaptive on-line information sites in a quick and easy way. Some controlled experiments have been performed with real users aimed to provide positive feedback on the implementation of the system. 相似文献
99.
Diana H.P. Low Bharadwaj Veeravalli David A. Bader 《Journal of Parallel and Distributed Computing》2007
In this paper, we address the problem of multiple sequence alignment (MSA) for handling very large number of proteins sequences on mesh-based multiprocessor architectures. As the problem has been conclusively shown to be computationally complex, we employ divisible load paradigm (also, referred to as divisible load theory, DLT) to handle such large number of sequences. We design an efficient computational engine that is capable of conducting MSAs by exploiting the underlying parallelism embedded in the computational steps of multiple sequence algorithms. Specifically, we consider the standard Smith–Waterman (SW) algorithm in our implementation, however, our approach is by no means restrictive to SW class of algorithms alone. The treatment used in this paper is generic to a class of similar dynamic programming problems. Our approach is recursive in the sense that the quality of solutions can be refined continuously till an acceptable level of quality is achieved. After first phase of computation, we design a heuristic scheme that renders the final solution for MSA. We conduct rigorous simulation experiments using several hundreds of homologous protein sequences derived from the Rattus Norvegicus and Mus Musculus databases of olfactory receptors. We quantify the performance based on speed-up metric. We compare our algorithms to serial or single machine processing approaches. We testify our findings by comparing with conventional equal load partitioning (ELP) strategy that is commonly used in the parallel processing literature. Based on our extensive simulation study, we observe that DLT paradigm offers an excellent speed-up characteristics and provides avenues for its use in several other biological sequence processing related problem. This study is a first time attempt in using the DLT paradigm to devise efficient strategies to handle large scale multiple protein sequence alignment problem on mesh-based multiprocessor systems. 相似文献
100.
Mittal Vijay A.; Tessner Kevin D.; Trottman Hanan D.; Esterberg Michelle; Dhruv Shivali H.; Simeonova Diana I.; McMillan Amanda L.; Murphy Erin; Saczawa Mary E.; Walker Elaine F. 《Canadian Metallurgical Quarterly》2007,116(2):260
The link between movement abnormalities and psychotic disorders is presumed to reflect common neural mechanisms that influence both motor functions and vulnerability to psychosis. The prodromal period leading to psychotic disorders represents both a viable point for intervention and a developmental period that, if studied, could shed light on etiology; however, no published studies have examined the temporal progression of this link. A group with high levels of prodromal symptomatology (i.e., adolescents with schizotypal personality disorder [SPD]; n = 42) and both psychiatric controls (with other personality disorders or conduct disorder [OD]; n = 30) and nonpsychiatric controls ([NC]; n = 49) were recruited. Videotapes of structured psychiatric interviews were coded for movement abnormalities by raters blind to participants' diagnostic status, and follow-up assessments were conducted 1 year later. Controlling for psychotropic medications, the authors found that adolescents with SPD exhibited significantly more motor abnormalities in the face and upper body than did OD and NC controls. At baseline, movement abnormalities were positively correlated with the severity of positive, negative, and total prodromal symptoms. Within the SPD group, baseline movement abnormalities predicted symptom severity 1 year later. Movement abnormalities represent an early risk indicator that may be predictive of later symptom severity and potentially of psychosis onset. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献