Amore Address Mapping with Overlapped Rotating Entries

A memory management unit that supports demand paging is implemented with standard logic and fast-access RAM chips, resulting in much faster address translation that that provided by the standard Motorola MC68451 MMU.     

LD泵浦的声光调Q腔内倍频激光器

研制成用ＬＤ泵浦的声光调Ｑ的Ｎｄ：ＹＶＯ４－ＫＴＰ腔内倍频激光器，得到了ＴＥＭ００模、频率高达１００ｋＨｚ的稳定的５３２ｕｍ绿激光脉冲系列输出，阈值泵浦功率为２７ｍＷ；在连续５７０ｍＷ的泵浦功率下，绿激光脉冲的峰值功率达１１００Ｗ，脉宽为４．６ｕｓ；输出功率稳定，在±５℃的工作温度变化下，输出功率变化小于±２％。此种器件可望得到广泛的应用。     

Assessing the usefulness of bibliometric indicators for the humanities and the social and beha vioural sciences: A comparative study

An evaluation was made of the use of bibliometric indicators for five disciplines in the humanities (social history, general linguistics, general literature, Dutch literature, and Dutch language) and three disciplines in the social and behavioural sciences (experimental psychology, anthropology, and public administration) in the Netherlands. Articles in journals were the predominant outlet in all disciplines. Monographs and popularizing articles were more important outlets in softer fields than in harder ones. The enlightenment function of scholarship was especially evident in Dutch literature and language, and public administration. Only some of the humanities disciplines are locally oriented. Although many publications were written in English, only experimental psychology, general linguistics, anthropology, and genrral literature were internationally oriented regarding output media. The impact of departments differed greatly both within and between disciplines. For all disciplines, bibliometric indicators are potentially useful for monitoring international impact, as expert interviews confirmed. Especially in Dutch language, Dutch literature and public administration, ISI-citation data are not very useful for monitoring national impact.     

Molecular analysis of intact preen waxes of Calidris canutus (Aves: Scolopacidae) by gas chromatography/mass spectrometry

The intact preen wax esters of the red knot Calidris canutus were studied with gas chromatography/mass spectrometry (GC/MS) and GC/MS/MS. In this latter technique, transitions from the molecular ion to fragment ions representing the fatty acid moiety of the wax esters were measured, providing additional resolution to the analysis of wax esters. The C₂₁−C₃₂ wax esters are composed of complex mixtures of hundreds of individual isomers. The odd carbon-numbered wax esters are predominantly composed of even carbon-numbered n-alcohols (C₁₄, C₁₆, and C₁₈) esterified predominantly with odd carbon-numbered 2-methyl fatty acids (C₇, C₉, C₁₁, and C₁₃), resulting in relatively simple distributions. The even carbon-numbered wax esters show a far more complex distribution due to a number of factors: (i) Their n-alcohol moieties are not dominated by even carbon-numbered n-alcohol moieties are not dominated by even carbon-numbered n-alcohols esterified with odd carbon-numbered 2-methyl fatty acids, but odd and even carbon-numbered n-alcohols participate in approximately equal amounts; (ii) odd carbon-numbered methyl-branched alcohols participate abundantly in these wax ester clusters; and (iii) with increasing molecular weight, various isomers of the 2,6-, 2,8-, and 2,10-dimethyl branched fatty acids also participate in the even carbon-numbered wax esters. The data demonstrate that there is a clear biosynthetic control on the wax ester composition although the reasons for the complex chemistry of the waxes are not yet understood.     

Experimental methodologies to evaluate allelopathic plant interactions

It is difficult to clearly and unambiguously demonstrate an allelopathic mechanism of plant interference. Several types of experimental methodologies such as the additive design, substitutive designs, and several types of plant yield-plant population functions are discussed in terms of their relative merits in terms of providing quantitative and qualitative information in the development of an empirical basis to describe a plant interaction. Additionally, several types of mathematical and graphical representations are presented using data from the velvetleaf (Abutilon theophrasti) and soybean (Glycine max) interaction. The design provides agronomically relevant information about crop yield losses but confounds the separate effects of population density and species proportion in mixtures. The replacement series design separates these two variables by maintaining a constant population of plants while varying the relative proportion of each species in mixtures. The replacement series diagram, relative yield, relative replacement rate, ratio diagram, a scaling test, and the regression of individual yield on the associate yield are discussed in terms of their utility in providing insights into a plant interaction. Individual plant yield-plant population functions such as the “Y-D” and “C-D” effects, the “3/2 power law of self-thinning,” and the “Sakai” test provide a basis to compare plant yield per plant versus plant population responses. Several types of interactions are characterized with this methodology. None of these experimental designs will clearly demonstrate an allelopathic plant interaction alone, but they do provide high-inference experimental methodologies to develop an empirical foundation to describe accurately a plant interaction upon which more specific hypotheses can be developed.     

From imagining to image: An examination of visual realisation of 3D forms

Abstract

Representation of ideas so that others may understand them is vital, and particularly so in the early stages of the design process; designers use many different techniques to make these representations.

Recent work at the Visualisation and Information Design Centre (VIDe) at the Coventry School of Art and Design has concentrated on supporting styling design. The previously‐developed technique of mapping 2D images over 3D computer models of vehicles has been extended: now, 2D facial photographs are mapped onto generic 3D head‐models to enhance a new technique for spectacle design. A summary of work in progress for computer assisted spectacle design, and for rapid car styling, is described here, along with details for improvements in sketch modelling, including texture mapping.

Photographs and reference CAD models are used in an attempt to verify the basic process; also ‘depth mapping’, ‘lines in space’ and other rapid modelling methods are discussed. Three different strategies for rapid computer modelling of cars are described and evaluated to ascertain if they may replace or enhance standard methods.     

A new,flexible and widely applicable software package for the simulation of one-dimensional moisture flow: SoWaM

Most one-dimensional soil moisture flow simulation models have restricted applicability due to (amongst other things): i) insufficient user flexibility; ii) a lack of user friendliness; iii) dependency on scale, temporal and/or spatial, and iv) fixed boundary conditions. Therefore, we developed a simple and highly flexible software package to simulate, visualize and analyze 1-D moisture flow in soils: SoWaM (Soil Water Model). The package has a modular setup and consists of a range of tools to visualize, analyze and compare input data and results. Soil hydraulic properties for each specified soil layer can be defined by either Van Genuchten parameters or cubical splines. Since the model does not impose limits on element size or time interval, it is possible to perform simulations in very high detail, both spatially and temporally. Furthermore, four different criteria for irrigation scheduling have been implemented. The SoWaM package provides an accurate, simple and highly flexible tool to simulate soil moisture flow and to evaluate the effects of various factors on soil water movement, such as timing and amount of irrigation, soil hydraulic properties and soil layering. Results of a case study are presented to illustrate model performance.     

How a cockpit calculates its speeds and why errors while doing this are so hard to detect

Recent incidents have shown that the production of take-off speeds is an activity vulnerable to miscalculations with a potential for disastrous outcomes. The aim of this paper is to analyze the calculation of the take-off speeds in a modern airline cockpit as a distributed cognitive activity in order to identify possible vulnerabilities in this process. We took the cockpit as the joint cognitive system under analysis and conducted an ethnographic study based on documental analysis, flight observations, interviews, and the analysis of 22 events involving failures related to the calculation of take-off speeds. The main argument is that the cognitive systems engineering perspective, with less focus on the human contribution than it is common in investigations, levels people and artifacts in the system as equal contributors to its eventual performance. Our analysis identified four assertions regarding vulnerabilities in the process of take-off speeds calculation: (1) representations at the level of the cockpit are always partial and incomplete; (2) some interactions require interpretation rather than institution; (3) interactions of agents do not follow a canonical process of coordination; (4) the control of the prevention of failures is accurate but inadequate. These vulnerabilities are a matter of interactions among cognitive systems in the cockpit, rather than vulnerabilities of individual agents, such as humans or artifacts.     

Improvement of luminance and luminous efficacy in PDPs

Abstract— The dependence of PDP luminance and efficacy on the input power was investigated for several Xe‐Ne gas mixtures. The input power was varied in two ways: namely, by changing the dielectric‐layer capacitance (thickness) and by changing the sustain voltage. A distinctly different behavior was found; for increasing capacitance the efficacy decreases markedly, whereas for increasing sustain voltage the efficacy increases. A design window comprising the combination of a high Xe concentration and a high sustain voltage was suggested. In this window, a high luminance and a high efficacy are concurrent. A 4‐in. test panel with 10% Xe in Ne has been realized showing a white luminance of 2040 cd/m² and an efficacy of 2.3 lm/W for continuous sustaining at 50 kHz with a sustain voltage of 225 V.     

Deep levels in GaInAs grown by molecular beam epitaxy and their concentration reduction with annealing treatment

X-ray diffraction (XRD), current–voltage (IV), capacitance–voltage (CV), deep-level transient Fourier spectroscopy (DLTFS) and isothermal transient spectroscopy (ITS) techniques are used to investigate the thermal annealing behaviour of three deep levels in Ga_0.986In_0.014As heavily doped with Si (6.8 × 10¹⁷ cm⁻³) grown by molecular beam epitaxy (MBE). The thermal annealing was performed at 625 °C, 650 °C, 675 °C, 700 °C and 750 °C for 5 min. XRD study shows good structural quality of the samples and yields an In composition of 1.4%. Two main electron traps are detected by DLTFS and ITS around 280 K, with activation energies of 0.58 eV and 0.57 eV, capture cross sections of 9 × 10⁻¹⁵ cm² and 8.6 × 10⁻¹⁴ cm² and densities of 2.8 × 10¹⁶ cm⁻³ and 9.6 × 10¹⁵ cm⁻³, respectively. They appear overlapped and as a single peak, which divides into two smaller peaks after annealing at 625 °C for 5 min.

Annealing at higher temperatures further reduces the trap concentrations. A secondary electron trap is found at 150 K with an activation energy of 0.274 eV, a capture cross section of 8.64 × 10⁻¹⁵ cm² and a density of 1.38 × 10¹⁵ cm⁻³. The concentration of this trap level is also decreased by thermal annealing.