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131.
This study investigated cues that permit prediction of turns during passive movement through a virtual environment. Effects on simulator sickness (SS), presence and enjoyment were examined. Subjects were exposed to complex visual motion through a cartoon-like simulated environment in a driving simulator. Forward velocity remained constant and the motion path was the same across all experimental conditions. Using a within-subject design, we examined visual paths that provided different levels of cue salience - detailed, simplified and no cues - for the upcoming simulated vehicle motion. Following each trial, participants completed questionnaires on SS, presence and enjoyment. After all of the trials were completed, a debriefing determined participants' perceptions of vehicle motion attributes and their awareness of the prediction cues. The results showed that SS in the no-cue condition was significantly greater than that in the conditions that provided vehicle motion cues. Presence and enjoyment responses were not different across the conditions. No participants reported differences between prediction cue conditions or recognized that the vehicle motion followed the same path across trials. However, participants tended to report that the motion was smoother for the detailed-cue than the no-cue condition. Participants ranked turn predictability as higher in conditions with prediction cues. The results support the hypothesis that unobtrusive and unreported motion cues may alleviate SS in a virtual environment. 相似文献
132.
Space-time super-resolution 总被引:3,自引:0,他引:3
Shechtman E Caspi Y Irani M 《IEEE transactions on pattern analysis and machine intelligence》2005,27(4):531-545
We propose a method for constructing a video sequence of high space-time resolution by combining information from multiple low-resolution video sequences of the same dynamic scene. Super-resolution is performed simultaneously in time and in space. By "temporal super-resolution," we mean recovering rapid dynamic events that occur faster than regular frame-rate. Such dynamic events are not visible (or else are observed incorrectly) in any of the input sequences, even if these are played in "slow-motion." The spatial and temporal dimensions are very different in nature, yet are interrelated. This leads to interesting visual trade-offs in time and space and to new video applications. These include: 1) treatment of spatial artifacts (e.g., motion-blur) by increasing the temporal resolution and 2) combination of input sequences of different space-time resolutions (e.g., NTSC, PAL, and even high quality still images) to generate a high quality video sequence. We further analyze and compare characteristics of temporal super-resolution to those of spatial super-resolution. These include: the video cameras needed to obtain increased resolution; the upper bound on resolution improvement via super-resolution; and, the temporal analogue to the spatial "ringing" effect. 相似文献
133.
Demonstrated a possible application of a threshold utility model for evaluating the student selection procedure based on 1,554 applications made to the Faculty of Humanities at the Hebrew University of Jerusalem. Results show that the predictor was useful, unless its costs were very large. This conclusion is generalizable across the different definitions of success, since the utility ratios and the prior probabilities of success tended to neutralize one another. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
134.
135.
MADE is the acronym for the ESPRIT project 6307, whose aim is to develop an object oriented multimedia application development environment. As part of this project the MADE help system is designed to be a distributed hypermedia system with additional support for run-time object monitoring and contextual help. 相似文献
136.
Michal Kleiber Tran Duong Hien Eligiusz Postek 《International journal for numerical methods in engineering》1994,37(19):3291-3308
Finite element formulations for structural sensitivity analysis of non-linear systems with fixed overall shape are discussed. Both the direct differentiation and adjoint variable methods are employed. The resulting sensitivity algorithms are consistent with time integration scheme adopted for solving equilibrium problem. Effectiveness and computational aspects of the procedures are discussed and compared. Numerical algorithms are shown to be readily implemented in existing finite element codes. Large-scale examples illustrate the paper. 相似文献
137.
Svatopluk Zeman Michal Roh
Zdenk Friedl Ale Ri
ka Antonín Ly
ka 《Propellants, Explosives, Pyrotechnics》2010,35(4):339-346
X‐ray crystallographic study of 2,2′,2″,2′′′,4,4′,4″,4′′′,6,6′,6″,6′′′‐dodecanitro‐1,1′ : 3′1″ : 3″,1′′′‐quaterphenyl (DODECA) has been carried out. Nonbonding interatomic distances of oxygen atoms inside of all the nitro groups are shorter than those corresponding to the intermolecular contact radii for oxygen. By means of the DFT B3LYP/6‐31(d, p) method a difference of 136 kJ mol−1 between the X‐ray and DFT structures of DODECA was found. The bearer of the highest initiation reactivity in its molecule in solid phase should be the nitro group at 4′′′‐position, in contrast to those at 2′‐ or 2″‐positions in its isolated molecule. The most reactive nitro group in the DODECA molecule can be well specified by the relationship between net charges on nitro groups and charges on their nitrogen atoms, both of them for the X‐ray structure. The 15N chemical shift, corresponding to this nitro group for the initiation by impact and shock, correlates very well with these shifts of the reaction centers of the other six “genuine” polynitro arenes. 相似文献
138.
Concentration of trace elements in arable soil after long-term application of organic and inorganic fertilizers 总被引:4,自引:0,他引:4
Dharam Uprety Michal Hejcman Jiřina Száková Eva Kunzová Pavel Tlustoš 《Nutrient Cycling in Agroecosystems》2009,85(3):241-252
The Ruzyně Fertilizer Experiment (RFE, the Czech Republic) was established on a permanent arable field (illimerized Luvisol)
in 1955. The effects of long-term application of several organic fertilizers (dung water, farmyard manure, poultry litter)
and mineral N, P and K fertilizers on plant-available (extracted by CaCl2), easily mobilizable (extracted by EDTA), potentially mobilizable (extracted by HNO3) and total concentrations of trace elements were investigated in 2008. Concentrations of all analyzed trace elements in the
applied fertilizers did not exceed the limits permitted by Czech national legislation. Concentrations of As, Cd and Cr were
highest in single superphosphate, those of Cu, Mn and Ni were highest in poultry litter and those of Pb and Zn were highest
in dung water. Poultry litter had the second highest concentration of As and Zn. Poultry litter supplied the soils with considerable
amounts of Cu, Mn and Zn and increased their concentrations in the soil. There was also a significant increase in plant availability
of Mn, Ni and Zn and a decrease in soil pH. Although all fertilizers were applied for five decades, total concentrations of
As, Cr, Cu, Ni, Pb and Zn in soil remained far below Czech legislation limits. For Cu and Zn this was probably due to the
relatively low mean annual application rates of poultry litter. Total Cd concentrations in soil exceeded the legislative limit
even in the control (without any fertilizer inputs) and the effect of treatment was not significant. This indicates that fertilizers
were not the main source of Cd in the experimental area. Therefore, common cropping practices do not induce soil contamination
by trace elements even if they have been applied for more than 50 years. 相似文献
139.
Jiří Pinkas Ivana Císařová Ana Conde Rosa Fandos Michal Horáček Jiří Kubišta Karel Mach 《Inorganic chemistry communications》2009,12(1):11-14
Thermolysis of [TiMe2(η5-C5Me4Ph)2] (4) at 145 °C for 5 h afforded the singly tucked-in paramagnetic titanocene [Ti(III)(η5-C5Me4Ph){η5:η1-C5Me3Ph(CH2)}] (9). In distinction to the singly tucked-in permethyltitanocene [Ti(III)(η5-C5Me5){η5:η1-C5Me4(CH2)}] (1) which was found crystallographically disordered [J.M. Fischer, W.E. Piers, V.G. Young, Jr., Organometallics 15 (1996) 2410] the single crystal X-ray diffraction analysis of 9 afforded molecular parameters with nearly by one order better precision as measured by esd-values. 相似文献
140.
Robert Reiberger Kateina Radilov Michal Kr Vclav Zima Pavel Majer Jií Brynda Martin Dra
ínský Jan Konvalinka Milan Koíek Ale Machara 《International journal of molecular sciences》2021,22(14)
The part of the influenza polymerase PA subunit featuring endonuclease activity is a target for anti-influenza therapies, including the FDA-approved drug Xofluza. A general feature of endonuclease inhibitors is their ability to chelate Mg2+ or Mn2+ ions located in the enzyme’s catalytic site. Previously, we screened a panel of flavonoids for PA inhibition and found luteolin and its C-glucoside orientin to be potent inhibitors. Through structural analysis, we identified the presence of a 3′,4′-dihydroxyphenyl moiety as a crucial feature for sub-micromolar inhibitory activity. Here, we report results from a subsequent investigation exploring structural changes at the C-7 and C-8 positions of luteolin. Experimental IC50 values were determined by AlphaScreen technology. The most potent inhibitors were C-8 derivatives with inhibitory potencies comparable to that of luteolin. Bio-isosteric replacement of the C-7 hydroxyl moiety of luteolin led to a series of compounds with one-order-of-magnitude-lower inhibitory potencies. Using X-ray crystallography, we solved structures of the wild-type PA-N-terminal domain and its I38T mutant in complex with orientin at 1.9 Å and 2.2 Å resolution, respectively. 相似文献