Inclusive design for air travel

(Inclusive design in air travel by baird L and Dong H) This paper addresses the issue of inclusive design in air travel. Firstly the scale of the problem is defined with reference to passenger demographics, and the different stages of a typical commercial air travel. The relevant government legislation is described, with particular emphasis on the new EU Regulation that requires special assistance to be provided to any passenger who requests it. An assessment of current practices in the air travel industry indicates that existing guidelines are having little impact on design practice. Similarly, an analysis of the major stakeholders in the air travel industry illustrates that a number of different parties are involved in the design and management of a typical journey. The study identifies the needs to reduce the number of passengers who require special assistance through inclusive design. The future directions, which include empirical work, case studies and the possible development of an information tool aimed at the industry are described

Experimental studies on the shear resistance of original coal-shale joint

Purpose. Experimental study and theoretical modeling of the shear resistance of original coal-shale joint. Methods. A two-segment model was developed to describe the shear resistance-shear displacement curves obtained from the direct shear tests of eight coal-shale joints by letting the two segments of the fitting curve pass through the peak point of each curve. Findings. The two-segment model well describes the shear resistance variation of the coal-shale joints during the shear process, and there exist good relationships between the fitting parameters and the shear testing parameters. The initial slope of the softening part of the shear resistance – shear displacement curve can help to predict whether the coal pillar will burst drastically when it fails. Moreover, the normal displacement was very small in the pre-peak range which indicates that the complete detachment of original coal-shale joint surfaces has not occurred before the peak. Originality. Direct shear tests were conducted on original coal-shale specimens for the first time, and a two-segment model is developed to describe their shear resistance-shear displacement curves. The initial slope of the softening part of the shear resistance – shear displacement curve is proposed to predict the burst tendency of coal pillar. Different from unbonded rock joints, the detachment of the original coal-shale joint occurs just after the peak. Practical implications. The conclusions may have some help to understand the shear resistance mechanism of original coal-shale joint and to provide some new ideas of maintaining coal pillar stability.Мета. Експериментальне дослідження та теоретичне моделювання опору зсуву початкового шару вуглистого сланцю. Методика. Розроблено модель для опису кривих опору зсуву й зсувного зміщення, отриманих у результаті випробувань на прямий зсув восьми шарів вуглистого сланцю. Модель включає два сегменти апроксимуючої кривої, що проходять через вищі точки описуваних кривих. Результати. Запропонована модель достовірно описує зміну опору на зсув шарів вуглистого сланцю в про-процесі зсуву, при цьому визначено наявність тісного зв’язку між параметрами апроксимації та параметрами випробування на зсув. За початковим нахилом кривої в частині ослаблення опору зсуву й зсувного зміщення можна передбачити, чи відбудеться значне руйнування цілика вугілля при його обваленні. Нормальне зміщення є незначним у передпіковому діапазоні, що свідчить про те, що в цей час не відбувається повного відриву поверхонь шару вуглистого сланцю. Наукова новизна. Випробування на прямий зсув проводилися вперше на зразках початкового вуглистого сланцю. Двохсегментна модель була розроблена спеціально для опису кривих опору зсуву та зсувного зміщення досліджуваних шарів. За початковим нахилом кривої в частині ослаблення опору зсуву й зсувного зміщення можна передбачити характер руйнування цілика. На відміну від незв’язаних шарів породи, відділення початкового шару вуглистого сланцю відбувається після пікових значень досліджуваних кривих. Практична значимість. Висновки можуть допомогти зрозуміти механізм опору зсуву в первісному шарі вуглистого сланцю й окреслити нові підходи до збереження стабільності вугільного цілика.Цель. Экспериментальное исследование и теоретическое моделирование сопротивления сдвигу первоначального слоя углистого сланца. Методика. Разработана модель для описания кривых сопротивления сдвигу и сдвигового смещения, полученных в результате испытаний на прямой сдвиг восьми слоев углистого сланца. Модель включает два сегмента аппроксимирующей кривой которые проходят через высшие точки описываемых кривых. Результаты. Предлагаемая модель достоверно описывает изменение сопротивления на сдвиг слоев углистого сланца в процессе сдвига, при этом определено наличие тесной связи между параметрами аппроксимации и параметрами испытания на сдвиг. По начальному наклону кривой в части ослабления сопротивления сдвигу и сдвигового смещения можно предсказать, произойдет ли значительное разрушение целика угля при его обрушении. Нормальное смещение незначительно в предпиковом диапазоне, что свидетельствует о том, что в это время не происходит полного отрыва поверхностей слоя углистого сланца. Научная новизна. Испытания на прямой сдвиг проводились впервые на образцах первоначального углистого сланца. Двухсегментная модель была разработана специально для описания кривых сопротивления сдвигу и сдвигового смещения исследуемых слоев. По начальному наклону кривой в части ослабления сопротивления сдвигу и сдвигового смещения можно предсказать характер разрушения целика. В отличие от несвязанных слоев породы, отделение первоначального слоя углистого сланца происходит после пиковых значений исследуемых кривых. Практическая значимость. Выводы могут помочь понять механизм сопротивления сдвигу в первоначальном слое углистого сланца и обозначить новые подходы к сохранению стабильности угольного целика.The authors gratefully acknowledge funding by China National Natural Science Foundation (51109076) and the key scientific and technological project of Henan Province (152102210316)

Pumped spin-current and shot noise spectra in a single quantum dot

We exploit the pumped spin-current and current noise spectra under equilibrium condition in a single quantum dot connected to two normal leads, as an electrical scheme for detection of the electron spin resonance (ESR) and decoherence. We propose spin-resolved quantum rate equations with correlation functions in Laplace-space for the analytical derivation of the zero-frequency atuo- and cross-shot noise spectra of charge- and spin-current. Our results show that in the strong Coulomb blockade regime, ESR-induced spin flip generates a finite spin-current and the quantum partition noises in the absence of net charge transport. Moreover, spin shot noise is closely related to the magnetic Rabi frequency and decoherence and would be a sensitive tool to measure them.Comment: 4 pages, 3 figures, to be published in Phys. Rev. Lette

Algebraic approach to the Hulthen potential

In this paper the energy eigenvalues and the corresponding eigenfunctions are calculated for Hulthen potential. Then we obtain the ladder operators and show that these operators satisfy SU(2) commutation relation.Comment: 8 Pages, 1 Tabl

Shot noise in resonant tunneling through an interacting quantum dot with intradot spin-flip scattering

In this paper, we present theoretical investigation of the zero-frequency shot noise spectra in electron tunneling through an interacting quantum dot connected to two ferromagnetic leads with possibility of spin-flip scattering between the two spin states by means of the recently developed bias-voltage and temperature dependent quantum rate equations. For this purpose, a generalization of the traditional generation-recombination approach is made for properly taking into account the coherent superposition of electronic states, i.e., the nondiagonal density matrix elements. Our numerical calculations find that the Fano factor increases with increasing the polarization of the two leads, but decreases with increasing the intradot spin-flip scattering.Comment: Some typos correction. 6 pages, 3 figures, based on work presented at the 2004 IEEE NTC Quantum Device Technology Workshop, accepted for publication by IEEE transactions on Nanotechnolog

Super-Poissonian shot noise in the resonant tunneling due to coupling with a localized level

We report our studies of the shot noise spectrum in tunneling through an interacting quantum dot when an additional single-level quantum dot without tunnel coupling to leads is coherently side-connected to it. We show that the zero-frequency shot noise could reach a super-Poissonian value for appropriate ratios between dot-dot hoppings and dot-lead couplings, but the current is independent on the hopping. Moreover, the frequency spectrum of shot noise shows an obvious peak at the Rabi frequency, which is controllable by tuning the dot-lead couplings.Comment: 3 pages, 3 figures, Appl. Phys. Lett.(in press

Time-and event-driven communication process for networked control systems: A survey

Copyright © 2014 Lei Zou et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.In recent years, theoretical and practical research topics on networked control systems (NCSs) have gained an increasing interest from many researchers in a variety of disciplines owing to the extensive applications of NCSs in practice. In particular, an urgent need has arisen to understand the effects of communication processes on system performances. Sampling and protocol are two fundamental aspects of a communication process which have attracted a great deal of research attention. Most research focus has been on the analysis and control of dynamical behaviors under certain sampling procedures and communication protocols. In this paper, we aim to survey some recent advances on the analysis and synthesis issues of NCSs with different sampling procedures (time-and event-driven sampling) and protocols (static and dynamic protocols). First, these sampling procedures and protocols are introduced in detail according to their engineering backgrounds as well as dynamic natures. Then, the developments of the stabilization, control, and filtering problems are systematically reviewed and discussed in great detail. Finally, we conclude the paper by outlining future research challenges for analysis and synthesis problems of NCSs with different communication processes.This work was supported in part by the National Natural Science Foundation of China under Grants 61329301, 61374127, and 61374010, the Royal Society of the UK, and the Alexander von Humboldt Foundation of Germany