Eddy Current Effects on the Asynchronous Performance of the Hysteresis Machine

An analysis of the asynchronous behavior of the hysteresis machine is undertaken based on a “rectified” model of its structure. The hysteresis shell and the yoke of the rotor are assumed as being manufactured out of materials with finite conductivities. The field analysis undertaken via Maxwell's equations and Poynting's theorem shows the influence of the induced eddy currents on the machine performance at nonvanishing slips. The characteristics of the machine are computed as functions of slip, revealing three particularly interesting cases.     

On the Salient Properties of the Hysteresis Machine—I. Non-conducting Rotor

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.     

The origin of dimensional analysis

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.     

Electrodynamics of solid-rotor induction machines

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.     

The impact of the customer relationship management on the organization performance

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.     

On the Salient Properties of the Hysteresis Machine—II. Eddy-current Effects

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.     

Asynchronous performance of hysteresis motor

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.     

A state space approach to elasticity

The two-dimensional, plane stress problem of linear elasticity is analyzed within a state space framework. The medium considered is homogeneous and isotropic. Vlasov's mixed formulation of elasticity is used throughout. The field equations are derived in closed form, thus avoiding Vlasov's intermediate infinite series solution. Finally, all the properties of the transfer matrix are shown to follow directly from embedding the problem into a state space setting.     

Invention and innovation in the chemical industry: Demand-pull or discovery-push?

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.     

An essay on the past and future (?) of information science education—I: Historical overview

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.     

Generalized dual transposition and its applications

A theorem, similar to Tellegen's theorem, but for networks having dual topologies, is developed. This theorem is used in the frequency domain to define a new network operation called “generalized dual transposition”, whose applications in network synthesis are discussed. Finally, it is used in the time domain to define a network called “dual adjoint” and its relation to dual and adjoint networks established.     

The graph-theoretic field model—I. Modelling and formulations

The Graph-Theoretical Field Model provides a unifying approach for developing numerical models of field and continuum problems. The methodology examines the field problem from the first stages of conceptualization without recourse to the governing differential equations of the field problem; this is accomplished by deriving discrete statements of the physical laws which govern the field behaviour. There are generally three laws, and these are modelled by the “cutset equations”, the “circuit equations”, and the “terminal equations”. In order to establish these three sets of equations it is expedient first to spatially discretize the field in a manner similar to the finite difference method and then to associate a linear graph (denoted as the field graph) with the spatial discretization. The concept of “through” and “across” variables, which underlies the cutset and circuit equations respectively, enables one to define the graph in an unambiguous manner such that each “edge” of the graph identifies a pair of complementary variables. From a knowledge of the constitutive properties and the boundary conditions of the field it is possible to associate terminal equations with sets of edges. Since the resulting sets of equations represent the field equations, these equations provide the basis for a complete (but approximate) solution to the field or continuum problem. In fact, this system approach uses a two part model: one for the components and another for the interconnection pattern of the components which renders the formulation procedures totally independent of the solution procedure.This paper presents the theoretical basis of the model and several graph-theoretic formulations for steady-state problems. Examples from heat conduction and small- deformation elasticity are included.     

A theory for decoupling lossless coupled tapered lines with applications to directional couplers

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.     

The conductance of aqueous solutions of electrolytes

Since the Debye-Hückel theory clearly indicates, from thermodynamic considerations, that strong electrolytes are substantially completely dissociated in aqueous solutions, it has been necessary to replace, in the explanation of the conductances of such electrolytes, the Arrhenius theory, which assumes partial dissociation and constant ion mobilities, with a theory which provides for changing mobilities with increasing ion concentrations. To this end Debye and Hückel, and Onsager, suggest two mechanisms: the “electrophoretic effect” and “the time of relaxation effect,” both dependent upon interionic electrostatic attractions and repulsions. Experimental tests of Onsager's relations show that his equations account accurately, at least for very dilute solutions, for the changes with concentration of the conductances of solutions of electrolytes containing ions of widely differing mobilities and valencies. For higher concentrations semi-empirical equations are available. In contrast to the Arrhenius theory, the newer ideas call for changes in the transference numbers with the concentration, which have been found experimentally. Precision transference measurements have also furnished an experimental test of Kohlrausch's law of independent mobilities of ions. The theory of interionic attractions and repulsions is, in addition, of utility in dealing with the ionic part of solutions of weak electrolytes. By computing degrees of dissociation in a manner which allows for changing ion mobilities a test is obtained of the Debye-Hückel limiting relation connecting activity coefficients with ion concentrations.     

Discrete analogues of Green's identities through the graph—theoretic field model

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.     

An isoperimetric problem for continuous systems: The aeolian vibration of a conductor span

The equations of motion for perfectly mechanical systems which are restricted to satisfy given constraints are derived through the Lagrangian formulation for continuous media. Hamilton's equations for this situation are derived, and the equations for the balance of energy and angular momentum are generated from fundamental principles. These equations are all specialized to the example of a conductor which is vibrating under Aeolian excitation. Various models for the Hamiltonian density and the constraint energy density due to the wind energy input are also discussed.     

Analysis of orbital stability in lure system,based on dynamic harmonic balance

A criterion of orbital stability of a limit cycle in a Lure system is formulated using the dynamic harmonic balance (DHB) principle and the describing function (DF) method. It is demonstrated that a more precise formulation of orbital stability than that provided by the Loeb's criterion can be produced. This enhancement is achieved through elimination of the assumption that is used in Loeb's criterion derivation. It is demonstrated in the paper that this assumption does not hold. An example of analysis is given.     

University licensing and the flow of scientific knowledge

As university involvement in technology transfer and entrepreneurship has increased, concerns over the patenting and licensing of scientific discoveries have grown. This paper examines the effect that the licensing of academic patents has on journal citations to academic publications covering the same scientific research. We analyze data on invention disclosures, patents, and licenses from the University of California, a leading U.S. academic patenter and licensor, between 1997 and 2007. We also develop a novel “inventor-based” maximum-likelihood matching technique to automate and generalize Murray's (2002) “patent-paper pairs” methodology. We use this methodology to identify the scientific publications associated with University of California patents and licenses.Based on a “difference-in-differences” analysis, we find that within our sample of patented academic discoveries, citations to licensed patent-linked publications are higher in the three years after the license, although this difference is not statistically significant. We then disaggregate our sample into (a) patented discoveries that are likely to be used as “research tools” by other researchers (based on the presence of material transfer agreements (MTAs) that cover them) and (b) patented discoveries not covered by MTAs. Citations to publications linked to licensed patents in the latter subset (not covered by MTAs) are higher for publications linked to licensed patents, and this difference is statistically significant. In contrast, licensing of patented discoveries that are also research tools is associated with a reduction in citations to papers linked to these research advances, raising the possibility that licensing may restrict the flow of inputs to “follow-on” scientific research.     

International comparisons of R&D effort: The case of the Canadian pharmaceutical industry

The Canadian federal government, anxious to stimulate innovation, announced recently a policy objective for the economy: the attainment of industrial research expenditures reaching 1.5 percent of the gross national product. The proposed substantial increase over the current level is rationalized by comparison with economy-wide research intensities (GERD/GNP) in other OECD countries.This paper questions the economic validity and policy relevance of international aggregate comparisons. It argues that inter-country comparisons should take place at individual industry levels where technologies are similar and proposes a methodology for formulating R&D spending targets of this kind. The procedure is to estimate a model of the determinants of R&D intensity with data from several “criterion countries” and employ the results to “predict” a specific industry's research intensity in another country.In this paper such a model is formulated for the pharmaceutical industry of seven OECD countries. Plausible parameter estimates are derived and used to “forecast” the research intensity of the Canadian pharmaceutical industry. It is found that given the predominance of foreign ownership, the nature of patent protection and the level of other relevant variables in Canada, the performance of this sector is much above the OECD-derived standard; this Canadian industry presumably does not require governmental attention to its R&D activities.