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61.
Exact solutions, based on couple-stresses plane strain theory of elasticity, are presented for the normal, shear and couple-stresses, displacements and rotations of an infinite-length (in z-axis) rectangular thin plate simply supported at two opposite edges (i.e.xL) and bent by a uniform load. Exact solutions reduce to classical values as l→0. Here l is defined as the new elastic material constant taking account of couple stresses.  相似文献   
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63.
Information Economy and Changing Occupational Structure in Singapore   总被引:1,自引:0,他引:1  
Using population census data since 1921, this article traces changes in employment and occupational structure in Singapore in the past 80 years. This is a follow-up to an earlier paper by Kuo and Chen (1987) that reported the nascent formation of the information society in Singapore till the 1980s. It also makes an assessment of the role of proactive government policies in directing industrial restructuring and occupational changes in this city-state. It is found that the long-term growing trend in information-related occupations has been in tandem and supportive of industrial changes in Singapore. One more wave of growth of information producers (and certainly, innovators) and information distributors is expected in the next couple of decades. The momentum has started, and competition from regional countries similarly aspiring to be information and knowledge economies will quicken the pace. The government has initiated fundamental changes in the educational system to meet the challenges of the knowledge-based economy. The small city-state has also long adopted an adaptive philosophy to be responsive to the ever-changing environment, either in technology or in regional politics. Based on the trend analysis, it is expected that the emergent information society will graduate into full status when Singapore attains a developed country status in the forthcoming decades.  相似文献   
64.
Firms vary greatly in their rates of creating and adopting technological and organizational innovations, in part because of their choice of reference group. We argue that the selection of a reference group is a crucial and neglected source of firm heterogeneity. Comparisons to the average of other firms in a population cause most firms to adopt innovations once they are widely accepted. A distinctive feature of the minority of innovating firms that create innovations or adopt them early is that they compare themselves with, compete with, and try to differ from other innovating firms, whereas the majority of firms compare themselves with, and conform to, a broader group of firms. We elaborate this argument based on the behavioral theory of the firm and institutional theory, and test it on a two-period survey on adoptions of innovative organizational forms in Europe and the US. The analysis shows the predicted differences in the adoption patterns of innovating and imitating firms.  相似文献   
65.
Synchronous data transmission systems that transmit information over dispersive channels often employ adaptive equalization techniques in the processing of the received signals. Most equalizers presently used in communication systems are of the tapped delay line (TDL) type. In this paper, we propose a class of adaptive equalizers of which the TDL equalizer is a member. Another interesting member of this class is the Laguerre adaptive equalizer which is to be introduced in this paper. The configuration of the Laguerre equalizer is developed. It is found, as shown by the examples, that the Laguerre equalizer is more accurate, and is less sensitive to timing error than the conventional TDL equalizer.  相似文献   
66.
In this paper, an algorithm is developed to apply Hann, Hamming, Blackman and related windows directly in the transform domain for the discrete cosine transform and discrete sine transform. These algorithms are useful in applications where windowing is required in order to minimize edge effects caused by implicit symmetries in the transform domain that are not replicated in the real-world data. Examples of such applications include data communication, adaptive system identification and filtering, real-time analysis of financial market data, etc. Software implementations in C language are also given.  相似文献   
67.
The purpose of this study was to develop a poststructural feminist pedagogical model and to investigate whether vocational-and-technical college students receiving poststructural feminist instruction would exhibit better learning achievement and critical thinking ability, and express greater satisfaction with their classes than those receiving traditional instruction. In applying a poststructural feminist model, the researchers intended to help both the teacher and students work together to overcome the estrangement and alienation that have long been the norm in the contemporary Chinese education system. The research results show that the poststructural feminist pedagogy had a positive effect upon the participants in the experimental group. Several conclusions are elicited from the study. First, in the English language achievement post-test, the participants receiving the poststructural feminist instruction significantly outperformed those receiving the traditional banking instruction in terms of listening, vocabulary, grammar, and reading. Second, in the critical thinking ability post-test, the participants significantly outperformed those receiving the traditional banking instruction in terms of length, focus, content, organization, and style. Third, in regard to the students’ satisfaction, it was clearly shown that the students who received the instruction informed by poststructural feminist pedagogy expressed significantly greater satisfaction than those who had received traditional banking instruction in terms of instructional objective, teaching method/materials, teacher quality, class environment, and assessment.  相似文献   
68.
This paper considers the simultaneous stabilization of a set of nonlinear systems, that involve uncertain nonlinearities besides multiple time-varying delays in the states. Under the assumption that the upper bounds of delays are known, a memoryless simultaneously stabilizing state feedback controller is presented by proposing a control Lyapunov-Krasovskii functional (CL-KF) method. As required to establish the CL-KF approach, a systematic procedure is given to construct CL-KFs for the systems under consideration. By the obtained CL-KFs, a common stabilizing state feedback control law is established to drive all the systems to the origin. Examples are finally given to verify the benefit of the proposed design method.  相似文献   
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70.
Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 μm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 μm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 μl/min, enabling to process finger prick blood samples within minutes.  相似文献   
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