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1.
The analysis of the asynchronous behavior of the hysteresis machine is undertaken based on a model describing its cylindrical structure. Assuming that the hysteresis shell of the rotor is manufactured out of materials with finite conductivities, the influence of the induced eddy- currents on the machine performance is pointed out via Maxwell's equations and Poynting's theorem. The characteristics of the machine are computed as functions of slip and three interesting limiting cases are revealed. 相似文献
2.
The properties of the hysteresis machine are analyzed on the basis of a cylindrical model. The electromagnetic field in the various regions of the motor is derived by field-theoretical methods (such as Maxwell's equations and Poynting's theorem), and the resulting parameters are applied in turn in determining torques and other relevant quantities. Three limiting particular cases of special interest are examined. 相似文献
3.
D. Schieber 《Journal of The Franklin Institute》1975,299(6):433-447
A simplified model of the hysteresis motor is introduced and analyzed; field analysis is undertaken at hand of Maxwell's stress tensor and Poynting's theorem. The suggested approach provides deeper insight into the power interchange process between stator and rotor. 相似文献
4.
David Toliver 《Information processing & management》1981,17(2):61-68
A technique of online instruction and assistance to bibliographic data base searchers called Individualized Instruction for Data Access (IIDA) is being developed by Drexel University. IIDA assists searchers by providing feedback based on real-time analysis while searches are being performed. Extensive help facilities which draw on this analysis are available to users. Much of the project's experimental work, as described elsewhere [1–3], is concerned with the process of searching and the behavior of searchers. This paper will largely address itself to the project's computer system, which is being developed by subcontract with the Franklin Institute's Science Information Services. 相似文献
5.
D. Schieber 《Journal of The Franklin Institute》1980,310(3):189-206
In this paper a simplified model of the solid-rotor induction machine is discussed. Analysis is provided on the basis of Maxwell's equations yielding a dimensionless thrust-slip characteristic which permits rapid evaluation of various machine parameters in its performance. The salient feature of this kind of induction device—flat thrust-slip response—is borne out by the obtained curves. 相似文献
6.
The literature concerning information flow and organizational design for technological innovation is summarized and a conceptual framework of the process of organized technological innovation within the firm is developed. The framework incorporates Rosenbloom's premise that corporate strategy can serve to cut across both internal and external boundaries of the firm and is shown to be consistent with the relevant organizational and planning literatures. The potential for using mathematical models to represent a firm's corporate strategy, budgeting and resource allocation activities is discussed. We argue that such models are needed to provide for policy analysis and could lead to a simulation capability that serves as a surrogate for real-life experimentation. 相似文献
7.
Ravi Kathuria Narinder Nath Kathuria Abhishek Kathuria 《The Journal of High Technology Management Research》2018,29(2):227-236
To refine the theories of operations strategy, we need research from all different situational contexts, including different countries—both developing and developed. There have been many studies, including some replications, done in various parts of the world to further the debate on whether competitive priorities are mutually supportive or if they present potential trade-offs, but hardly any from a rapidly growing economy, such as India. This study is a significant attempt in that direction. After a thorough review of the literature, a set of hypotheses is introduced to test whether Indian manufacturers view competitive priorities as mutually supportive or trade-offs. The data from over 150 high-ranking individuals from over 75 manufacturers in India is used to test the hypotheses by way of cluster analysis and ANOVA. The resultant taxonomy reveals patterns that uniquely represent Indian manufacturers' view of the competitive priorities, namely quality, flexibility, delivery and price. The study findings have significant managerial implications, both for India and other developing as well as developed economies. The taxonomy will serve to gauge India's manufacturers' role in the world. From a researcher's perspective, this study makes a significant contribution to theory development, furthers our understanding of the strategic role of operations, moves forward the ongoing debate on the topic of trade-offs or complementarity, and paves the way for future studies in this topical area. 相似文献
8.
In this paper, we derive discrete versions of Green's identities (which appear in the study of potential field theory) as direct consequences of applying Tellegen's Theorem to the Graph—Theoretic Field Model (GTFM) of a field. The procedure herein is in marked contrast to the existing procedures where Green's Identities are derived from the Divergence Theorem by using some strictly mathematical operations. In particular, Green's third identity, which is the starting point formulation for the Boundary Integral Method, is singled out for special attention in terms of its discrete counterpart in the Graph—Theoretic Field Model. The first discrete identity is used to establish certain properties of solutions for the GTFM and a limiting process is applied to the three discrete identities to derive the traditional vector-calculus forms of Green's identities. 相似文献
9.
Leonard B. Loeb 《Journal of The Franklin Institute》1928,205(3):305-321
After a brief summary and discussion of Townsend's theory of the electrical breakdown of gases in the light of certain recent criticisms, it is shown that these are compatible with his theory except for one serious discrepancy. This discrepancy lies in the fact that at the assumed fields at which breakdown occurs in air, at atmospheric pressure, and in inert gases at low pressures, the of Townsend's theory cannot have the significance given it by Townsend, as the positive ions are incapable at these fields of acquiring the ionizing energy. Various solutions proposed are discussed and found inadequate. It seems necessary, in order to keep this otherwise successful theory, to doubt the validity of the assumption generally made for plane parallel electrodes, that the potential drop between the plates is uniform before the spark passes. If fields about ten times as great as those calculated from the uniform drop existed, the theory could be applied. It is shown that such fields are possible under the conditions of the spark potential experiments, due to space charges resulting from the difference of ionic and electronic velocities. The existence of such fields requires a finite spark lag interval of about 10?4 seconds, as yet not definitely observed. Experiments should be undertaken in laboratories equipped for the purpose to look for both the spark lag and the non-uniform field. 相似文献
10.
A simple theory is presented for decoupling a pair of lossless coupled nonuniform transmission lines (CNUTL), with a common return and supporting TEM waves, into two lossless nonuniform transmission lines (NUTL). This theory is independent of the port terminations, symmetry conditions, etc. The method directly relates the line parameters of the lossless CNUTL's to those of the decoupled lines and vice versa; further, the matrix parameters of the CNUTL's as a four-port are explicitly expressed in terms of those of the decoupled lines as two-ports. This theory is then utilized to study the applications of CNUTL's as directional couplers.It is shown that for CNUTL's to behave as a codirectional coupler, each of the decoupled lines should be a proportional line, while for contradirectional coupler action, the two decoupled lines have to be duals of each other. The coupling response of the codirectional coupler is found to be periodic, while the phase shift between coupled and transmitted signals varies linearly with frequency. The coupling response of various contradirectional couplers with smooth transition at one of the ends, for which the decoupled lines are “basic NUTL's with hyperbolic solutions”, are studied in detail. It is shown that all these couplers have a high-pass response and that the CNUTL's with “hyperbolic cosine squared lines” as decoupled lines have the best response of all the CNUTL's considered. 相似文献
11.
Dale B. Cherchas 《Journal of The Franklin Institute》1981,312(1):31-40
The probability of wheel climb commencing is calculated using Nadal's formula as a basis. In particular, the functional form of Nadal's formula is maintained with normal probability density functions used to describe the two arguments in Nadal's formula, namely contact plane angle and coefficient of friction at the contact point. The theoretical value of the probability of wheel climb commencing for a given lateral/vertical force ratio value at the wheel flange–railhead interface is then compared with experimental results for positive angles of attack. Theoretical results for negative angles of attack are generated for several cases. 相似文献
12.
E.E. Gdoutos 《Journal of The Franklin Institute》1981,312(5):361-371
An analysis of the plastic enclaves developed around the end points of rigid fiber inclusions embedded in an elastic plate is undertaken. The plate is subjected to a uniform uniaxial stress at any angle of inclination with the axis of the fiber. It is assumed that the material of the plate is elastic-perfectly plastic and that the deformations are small. A singular solution of the stress field in the vicinity of the end points of the fiber is used in conjunction with the Mises yield criterion to obtain the radius of the plastic zone under conditions of plane strain and generalized plane stress. The dependence of the size and shape of the plastic deformation on the orientation of the fiber, the Poisson's ratio of the plate and the state of stress (plane strain or generalized plane stress) is established. 相似文献
13.
Vivien Walsh 《Research Policy》1984,13(4):211-234
This paper describes a study of the determinants of the rate, direction and scale of inventive and innovative activity in the chemical industry over the period 1830–1980. Statistical data are interpreted in the light of case study material in three major sectors: dyestuffs, plastics and pharmaceuticals. Theories of technical change and economic growth, particularly those of Schmookler and Schmpeter, are examined in relation to this material on the chemical industry. The findings suggest that the importance of “demand pull” and “discovery push” factors, and the validity of Schmookler's and Schumpeter's theories, vary over an industry's life cycle. 相似文献
14.
Mauro Guazzo 《Information processing & management》1977,13(3):155-165
This paper challenges the meaningfulness of precision and recall values as a measure of performance of a retrieval system. Instead, it advocates the use of a normalised form of Shannon's functions (entropy and mutual information). Shannon's four axioms are replaced by an equivalent set of five axioms which are more readily shown to be pertinent to document retrieval.The applicability of these axioms and the conceptual and operational advantages of Shannon's functions are the central points of the work.The applicability of the results to any automatic classification is also outlined. 相似文献
15.
Zeynab Soltani Batool Zareie Farnaz Sharifi Milani Nima Jafari Navimipour 《The Journal of High Technology Management Research》2018,29(2):237-246
Customer Relationship Management (CRM) is a very important growing business practice in today's environment. It is used for managing the interaction between a company and its future and current customers. CRM approach's task is analyzing data about the history of customers with a company. It focuses on a way to retain customers, therefore it helps the growth of sales. This leads to improvement of company's business relationship with customers. Current study's goal is to determine how technology, organizational capability, customer orientation, and customer knowledge management influence CRM success. We try to see that how the performance of an organization is affected by the achievement of CRM. For testing the hypotheses, Partial Least Squares Structural Equation Modeling (PLS-SEM) was adopted. Results have indicated that the success of CRM is highly influenced through “information technology use”, also “customer orientation”, “organizational capability”, and “customer knowledge management” are related to CRM success. Finally, along with the future research avenues and limitations, study implications and findings are discussed. 相似文献
16.
Peter L. Daniels 《Research Policy》1997,25(8):1189-1207
This paper examines the hypothesis that economic internationalisation is acting to reduce the importance of national technology ‘gaps’ as determinants of trade patterns and performance. The cross-country analysis uses two approaches to assess the dynamic nature of the relationship between national investment in technological capability (proxied by both R&D activity and human capital) and technology-intensive (TI) trade performance. Natural resource endowment and the changing impact of physical capital formation are also investigated. The study includes approximately 48 nations and is based on data from the mid-1970s to 1990. The empirical evidence from one approach undertaken does not support the globalisation hypothesis as national investment in technology and human capital is shown to have maintained its link to international trade success in TI manufactures over the study period. However, the findings of the alternative approach are ambiguous. A positive association between technology investment catch-up and ongoing TI manufacturing trade performance is evident for the newly industrialised economies (NICs), but the results suggest that an inverse relationship may apply for many of the ‘mature’ Western economies. 相似文献
17.
Tefko Saracevic 《Information processing & management》1979,15(1):1-15
The rapid and rather chaotic evolution of information science has left the field's academic sector in a largely disorganized state. This essay examines the basic issues confronting information science education, issues that must be resolved if information science education and thus information science itself are to evolve in an orderly fashion. For the quality of a field's professional services and research activities depends upon the quality of its formal academic programs. The essay is organized in three parts. In this first part are considered definitions and in a historic context the emergence, evolution and current state of information science and its education. The second part considers the “externalities” of education—problems and unresolved questions in information science education that deal with: (i) academic affiliations, (ii) degree levels, (iii) admission requirements, (iv) jurisdiction and (v) financing. The third part considers the problems and unresolved questions in respect to internal aspects (“internalities”) of information science education: (i) objectives, (ii) content, (iii) teachers and (iv) teaching. It is suggested that information science cannot prosper; possibly even survive in the next decade if serious, concentrated action is not undertaken in the “externalities” and “internalities” of its education. Recommendations about the areas that need action are made. 相似文献
18.
Keith Dickson 《Research Policy》1983,12(2):113-120
This paper argues that the United Kingdom Ministry of Defence's (MoD) sponsorship of industrial semiconductor research and development (R&D) has, by its very nature, influenced the type of R&D performed, and the directions it has taken, to the extent of limiting its potential for subsequent commercial utilization. While much of the fault appears to lie with the semiconductor industry's response to MoD funding of its R&D, especially its over-reliance on such external support, the paper also suggests that the structure, modus operandi, and funding mechanisms of the MoD department concerned have significantly affected the industry's R&D activities. With these criticisms in mind, while at the same time noting the advantageous features of this department's activities, such as its relative autonomy, brief suggestions for ensuring more coherent and continuous state support for semiconductor R&D, including, for example, the use of innovation-oriented procurement policies, are offered. 相似文献
19.
Roberto De A. Martins 《Journal of The Franklin Institute》1981,311(5):331-337
A paper by Macagno (3) in this Journal is discussed. The origin of the concept of physical dimensions is traced back to ideas previously used in analytic geometry. Descartes' use of the word “dimension” in the study of physical magnitudes is shown to have properties completely different from Fourier's dimensions, being therefore unimportant to the evolution of dimensional analysis. It is also shown that the principle of homogeneity was used in the derivation of physical equations sixty years prior to the publication of Fourier's work, and that the latter was aware of this paper, that may be considered the earliest publication on dimensional analysis. 相似文献
20.
The physical interpretation of LDLt factorization and Bennett's method for matrix factor modification applied to structural analysis are studied. The sparsity of the matrix factors and their effect on matrix modification are examined. 相似文献