Returns to growth in a nonparametric DEA approach

In this contribution, first the concept of returns to growth (RTG) of a high‐tech firm facing hyper‐competition in the new economy is introduced by describing a proportional relationship between growth in inputs and growth in outputs using the growth efficiency (GE) model of Sengupta. Second, both technology‐ and value‐based methods are suggested for estimating the RTG behavior of high‐tech firms. Third, although the GE concept seems closely related to the notion of total factor productivity change, this link remains unexplored: we suggest a link between both concepts. Finally, our empirical application to the Indian computer industry reveals that first, companies operating under increasing returns to scale (RTS) may exhibit constant or decreasing RTG; second, companies showing constant RTS may exhibit increasing or decreasing RTG; and third, companies showing decreasing RTS may exhibit constant or increasing RTG. These findings imply that RTS estimates need not provide proper information regarding the growth strategy behavior of high‐tech companies.     

Three-dimensional analysis of magnetic field distortion of ferromagnetic beam-plates by the boundary element method

Magnetoelastic buckling of a ferromagnetic beam-plate has been experimentally and theoretically studied by many investigators. A great discrepancy between the experimental results and the theoretical predictions has stimulated related studies. It has been supposed that the discrepancy could be attributed to the finite size of the test piece; this case has not yet been solved exactly, or even numerically. In this study the boundary element method is applied to solve for the magnetic field distribution around the finite specimen.     

Influence of different cold storage temperatures during the Rigor mortis phase on fillet contraction and longer-term quality changes of Atlantic cod fillets

Pre rigor produced fillets of Atlantic cod become shorter and more firm than post rigor produced fillets. In pre rigor excised muscle from warm-blooded animals and warm-water adapted fish, cold shortening, extensive contraction during cold storage, is known to occur. The aim of the present work was to study if the extent of fillet shortening in Atlantic cod could be reduced by a slight temperature increase during rigor contraction. The results demonstrate that fillets from this cold-water species showed no cold shortening. On the contrary, the fillets contracted the least when stored at 0 °C during rigor contraction.     

桥面铺装层脱层检测技术研究

针对桥面铺装层受破坏情况越来越严重的问题,简单分析桥面铺装层受破坏的各种现象和原因,着重说明桥面铺装层脱层现象以及其产生的原因.介绍目前计算铺装层层间应力的理论模型,提出一种实用的检测技术思想将应用成熟的光纤传感检测技术用于铺装层脱层检测.     

On the Long-Time <Emphasis Type="Italic">H</Emphasis><Superscript>2</Superscript>-Stability of the Implicit Euler Scheme for the 2D Magnetohydrodynamics Equations

Pursuing our work in Tone (Asymptot. Analysis 51:231–245, 2007) and Tone and Wirosoetisno (SIAM J. Number. Analysis 44:29–40, 2006), we consider in this article the two-dimensional magnetohydrodynamics equations, we discretize these equations in time using the implicit Euler scheme and with the aid of the classical and uniform discrete Gronwall lemma, we prove that the scheme is H ²-uniformly stable in time.     

Increasing quality of learning experience using augmented reality educational games

Multimedia Tools and Applications - Adequate pedagogical approaches for integration of technology in the learning process create new opportunities for improving the quality of teaching and learning...     

An interleaved high step‐up DC‐DC converter with double boost paths

This paper proposed a novel high step‐up converter with double boost paths. The circuit uses two switches and one double‐path voltage multiplier cell to own the double boost and interleaved effects simultaneously. The voltage gain ratio of the proposed DC‐DC converter can be three times the ratio of the conventional boost converter such that the voltage stress of the switch can be lower. The high step‐up performance is in accordance with only one double‐path voltage multiplier cell. Therefore, the number of diodes and capacitors in the proposed converter can be reduced. Furthermore, the interleaved property of the proposed circuit can reduce the losses in the rectifier diode and capacitor. The prototype circuit with 24‐V input voltage, 250‐V output voltage, and 150‐W output power is experimentally realized to verify the validity and effectiveness of the proposed converter. Copyright © 2014 John Wiley & Sons, Ltd.     

A VHF interferometry system for detecting anomalous propagation of FM radio broadcasting waves related to earthquakes and some preliminary results

Earthquake‐related anomalous electromagnetic phenomena have been reported in various frequency ranges over the past few decades. Investigation of the anomalous propagation of VHF transmitter waves is a promising approach to short‐term prediction and crustal activity monitoring. Anomalous propagation is believed to be generated by disturbances of the atmosphere above the epicenter or along the propagation path prior to large earthquakes. Consequently, over‐the‐horizon propagation has been received. A recent study shows that the appearance of anomalies was signi?cantly enhanced within 5 days of earthquakes with M ≥4.8. However, there is no information on the scattering location, that is, on the direction of wave arrival. Therefore, a simple interferometer system for VHF radio waves to identify the space‐time position of earthquake‐related atmospheric disturbances has been developed and installed at Chiba University. This paper describes the newly developed interferometer system and presents the results of fundamental tests to evaluate the performance of the new interferometer at Chiba. Data on over‐the‐horizon propagation of VHF radio waves obtained from 1‐year continuous measurement at Chiba are described. These are possible radio duct propagations and possible earthquake‐related anomalous propagations. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(1): 16–24, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22303     

High‐speed low‐voltage driving of high‐Xe‐content PDPs with priming particles

Abstract— Power savings, image‐quality improvement, and cost reduction are the major issues facing PDP development. High‐Xe‐content PDPs have attained improved luminous efficiency, but with sacrifices in higher switching and sustain voltages and slower discharge build‐up. By examining PDPs having 3.5%–30% Xe content, it was found that utilization of the space‐charge priming effect as well as wall‐charge accumulation are effective in obtaining a low operating voltage and a high switching speed. The improvements are enhanced for higher Xe pressures. By using space‐charge priming, the statistical time lag of the discharge triggering for the 30% Xe content is reduced significantly and becomes approximately equal to that of 3.5% Xe content. Once triggered, the formative time lag of the discharge becomes shorter and the space charge experiences diffusion/drift; hence, accumulation of the wall charge is faster for discharges with higher Xe contents. These indicate that the use of an erase addressing scheme, rather than a write addressing scheme, is preferable when driving high Xe‐content PDPs, because the erase addressing scheme provides the addressing operation with an abundant amount of priming particles. Also, the drive voltages are lower for the erase addressing scheme. In order to reduce the address voltage, it is effective to accumulate wall charges prior to addressing. It was found that there are limiting values for the charge accumulation, above which self‐erase discharges ignite and the wall charge is dissipated. The self‐erase discharge occurs at relatively low wall voltages when the Xe percentages becomes higher. The sustain pulse voltage can be reduced while keeping the luminous efficiency high by increasing the sustain pulse frequency. As the frequency is increased, a residual amount of space charge created by the preceding sustain pulse increases. Due to the priming effect of these space charge, the build‐up of the discharge current becomes faster, resulting in a lower voltage.