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Article

Ming‐Cheng Cheng and E.E. Kunhardt

A non‐equilibrium multi‐valley transport model for carriers in compound semiconductor devices has been developed. This macroscopic transport model provides an efficient…

Abstract

A non‐equilibrium multi‐valley transport model for carriers in compound semiconductor devices has been developed. This macroscopic transport model provides an efficient scheme for device modeling, and can overcome the difficulty in evaluating the relaxation times in multi‐valley conservation equations without a priori assumption of the displaced‐Maxwellian distribution. This model has been successfully applied to electron transport in GaAs subjected to rapidly time‐varying fields. The results have suggested that the macroscopic effective mass of electrons might be strongly dependent on average velocity.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 10 no. 4
Type: Research Article
ISSN: 0332-1649

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Article

Ming‐C. Cheng

Influence of forward scattering, including ionized‐impurity and polar optical‐phonon scattering, on electron transport phenomena in a 3‐valley n‐type GaAs model subjected…

Abstract

Influence of forward scattering, including ionized‐impurity and polar optical‐phonon scattering, on electron transport phenomena in a 3‐valley n‐type GaAs model subjected to a rapid change in field is studied. It is shown that the macroscopic effective mass of electrons in a nonparabolic band structure is smaller than the energy‐dependent effective mass, which is usually assumed for modeling of GaAs devices, during the interval of velocity overshoot when strong forward scattering is involved. As a consequence, the hydrodynamic transport model, where the macroscopic effective mass is assumed energy dependent, leads to a smaller overshoot velocity.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 11 no. 4
Type: Research Article
ISSN: 0332-1649

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Article

Ming‐C. Cheng and Rambabu Chennupati

The concept of the evolution of the distribution function is used to derive an energy‐scale distribution that is able to describe transport phenomena, including…

Abstract

The concept of the evolution of the distribution function is used to derive an energy‐scale distribution that is able to describe transport phenomena, including inter‐valley transfer effect, in the scale as small as the energy relaxation time. The energy‐scale distribution is used to study the evolution of electrons in n‐type GaAs under the influence of rapid change in field. Results indicate that, near the peak of strong velocity overshoot or the bottom of pronounced undershoot in the Γ valley caused by the rapid change in field, the energy‐scale distribution can not respond as fast as the distribution function calculated from the Monte Carlo method. The average velocity resulting from the energy‐scale distribution therefore leads to less pronounced overshoot and undershoot than those obtained from the Monte Carlo method. However, since velocity overshoot and undershoot are not pronounced in the L‐valleys, the L‐valley energy‐scale distribution is in excellent agreement with that determined by the Monte carlo simulation.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 4
Type: Research Article
ISSN: 0332-1649

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Article

Ming‐C. Cheng and Ying Wen

Accuracy of hydrodynamic transport equations using the energy‐dependent relaxation times has been studied for electron transport in Si 〈100〉. The concept of the…

Abstract

Accuracy of hydrodynamic transport equations using the energy‐dependent relaxation times has been studied for electron transport in Si 〈100〉. The concept of the hydro‐kinetic transport model is used to describe non‐equilibrium electron transport phenomena and to examine the validity for the assumption of energy‐dependent relaxation times. It has been shown that under the influence of a drastic increase in field the relaxation times might also strongly depend on the average velocity near the peak of strong velocity overshoot. In addition, the velocity dependence is found to be more pronounced at lower temperatures in Si 〈100〉.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 13 no. 4
Type: Research Article
ISSN: 0332-1649

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Article

Dwijesh K. Dutta Majumder and Swapan K. Dutta

To develop a mathematical and algorithmic approach of avoiding the limitations of deterministically computing the values of energy, time, position and momentum imposed by…

Abstract

Purpose

To develop a mathematical and algorithmic approach of avoiding the limitations of deterministically computing the values of energy, time, position and momentum imposed by Heisenberg's uncertainity principle (HUP) which is of profound significance from the point of view of some emerging science and technology like quantum computing, nano scale technology and chaotic dynamical systems.

Design/methodology/approach

A parametric method of establishing deterministic solutions for energy and momentum on the basis of quantized energy limits (instead of HUP) if developed in the non‐infinite non‐zero quantized energy limits where hidden deterministic solutions can be obtained for micro/nano structures.

Findings

The philosophical foundations of quantum mechanics as developed by Max Planck, Neils Bohrz, Werner Heisenburg, Dirac and Edwein Schrodinger is based on a duality concept of complimentarity notions. In most general logical sense for any physical reality qualitative dualism have to have a quantitative dualism may be hidden or virtual. The upper and lower limits of the dynamical quantum mechanical observables are determined based on the dimensional considerations for the physical constants H, C, G and H0. The conceptual basis and mathematical framework of the paper in based Norbert Wiener's work on theory of cybernetics and D. Dutta Majumdars' unified cybernetic and general dynamical systems theory.

Research limitations/implications

The testability of the theory needs to be established.

Originality/value

Without challenging HUP this is a contribution of tremendous practical implications.

Details

Kybernetes, vol. 36 no. 5/6
Type: Research Article
ISSN: 0368-492X

Keywords

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Article

John H. Bickford

History-based trade books have an important and expanding role in various curricula. Contemporary education initiatives urge English and language arts educators to spend…

Abstract

Purpose

History-based trade books have an important and expanding role in various curricula. Contemporary education initiatives urge English and language arts educators to spend half their time on non-fiction and history and social studies teachers to include diverse sources starting in the early grades. Diverse professional organizations annually make financial commitments to promote new trade books. Research indicates misrepresentations abound in history-based trade books, yet few empirical studies have been completed. The purpose of this paper is to research examine the historical representation of Abraham Lincoln, arguably the most consequential nineteenth-century American.

Design/methodology/approach

Data samples included trade books intended for early grades and middle grades students. These grade ranges were selected because these students have the least prior knowledge and are perhaps most dependent on the text. Qualitative content analysis research methods were employed.

Findings

Misrepresentations emerged regarding Lincoln’s poverty, actions, motivations for actions, and implications of his actions as seemingly necessary historical content was minimized, vaguely included, or omitted. Findings are juxtaposed across and between selected grade ranges.

Practical implications

Discussion focused on the significance of findings for teachers and researchers. Teachers are guided to supplement trade books with primary sources to position students to distinguish historical misrepresentations.

Originality/value

This research builds on previous scholarship on Lincoln-based trade books by expanding grade range, data samples and research questions.

Details

Social Studies Research and Practice, vol. 13 no. 2
Type: Research Article
ISSN: 1933-5415

Keywords

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Article

Stephen Brown and Christopher Hackley

Simon Cowell, the impresario behind The X Factor, a popular television talent show, has often been compared to P.T. Barnum, the legendary nineteenth century showman. This…

Abstract

Purpose

Simon Cowell, the impresario behind The X Factor, a popular television talent show, has often been compared to P.T. Barnum, the legendary nineteenth century showman. This paper aims to examine the alleged parallels in detail and attempts to assess this “Barnum reborn” argument.

Design/methodology/approach

Putative parallels between the impresarios are considered under the aegis of two long‐standing, if contentious, historical “theories”: time's cycle and the great man thesis.

Findings

Seven broad similarities between the showmen are identified: vulgarity, hyperbole, rivalry, publicity, duplicity, liminality and history. In each case, the arguments pro and con are explored, as is humanity's propensity to personify.

Originality/value

In accordance with the iconic literary critic Harold Bloom, who “strikes texts together to seek if they spark”, this paper strikes two celebrated showmen together to generate historical sparks.

Details

Journal of Historical Research in Marketing, vol. 4 no. 2
Type: Research Article
ISSN: 1755-750X

Keywords

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Article

Juan Velez-Ocampo, Karthik Govindan and Maria Alejandra Gonzalez-Perez

This theory testing paper compares and analyzes the internationalization process of two Mexican family-owned firms: Xignux and Grupo Alfa. This paper is intended to offer…

Abstract

Purpose

This theory testing paper compares and analyzes the internationalization process of two Mexican family-owned firms: Xignux and Grupo Alfa. This paper is intended to offer a theoretical understanding using existing frameworks such as OLI (ownership, location and internationalization), LLL (linkage, leverage and learning) and the Uppsala model. Furthermore, it tests whether the theoretical framework of organizational capabilities and international ventures fits the internationalization of these companies.

Design/methodology/approach

This paper is based on case study methodology using the companies’ publically available data. Both within-case and cross-case analysis were carried out to identify specific traits in the internationalization pattern of both firms; cases were also compared with literature to identify conflicts and similarities that enable a better understanding of the phenomenon.

Findings

It was found that not a single theory fully and satisfactorily explains the internationalization of both Xignux and Alfa, instead, issues like internationalization into low psychic distance countries, establishment of strategic alliances and the exploitation of locational-specific advantages contributed in the international expansion of the studied companies.

Originality/value

There is an increasing amount of available literature regarding internationalization strategies and internationalization theories applied to developing and emerging country firms. However, most of the studies analyze companies from Asia, and there are limited studies on multilatinas (i.e. Latin American multinationals). Furthermore, scholars in the field of international business are still debating whether the existing theories, or an adaptation of them, explain the internationalization of multilatinas.

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Book part

Chris Borthwick

Charles Darwin's correspondence with Dr. John Down indicates that both men thought of people with mental retardation as being akin to humanity's evolutionary predecessors…

Abstract

Charles Darwin's correspondence with Dr. John Down indicates that both men thought of people with mental retardation as being akin to humanity's evolutionary predecessors. Recent attempts to teach people with mental retardation to use the computer languages taught to apes show that this conceptualization of mental retardation has remained an unspoken and perhaps unformulated element in public and professional attitudes to people with disabilities ever since. Refuting this conceptualization points the way to a more productive approach to the conditions now classified as ‘mental retardation’.

Details

Expanding the Scope of Social Science Research on Disability
Type: Book
ISBN: 978-0-76230-551-3

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