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121.
MH Skiadopoulos S Surman JM Tatem M Paschalis SL Wu SA Udem AP Durbin PL Collins BR Murphy 《Canadian Metallurgical Quarterly》1999,73(2):1374-1381
122.
Eye tracking has been used successfully as a technique for measuring cognitive load in reading, psycholinguistics, writing,
language acquisition etc. for some time now. Its application as a technique for measuring the reading ease of MT output has
not yet, to our knowledge, been tested. We report here on a preliminary study testing the use and validity of an eye tracking
methodology as a means of semi-automatically evaluating machine translation output. 50 French machine translated sentences,
25 rated as excellent and 25 rated as poor in an earlier human evaluation, were selected. Ten native speakers of French were
instructed to read the MT sentences for comprehensibility. Their eye gaze data were recorded non-invasively using a Tobii
1750 eye tracker. The average gaze time and fixation count were found to be higher for the “bad” sentences, while average
fixation duration and pupil dilations were not found to be substantially different for output rated as good and output rated
as bad. Comparisons between HTER scores and eye gaze data were also found to correlate well with gaze time and fixation count,
but not with pupil dilation and fixation duration. We conclude that the eye tracking data, in particular gaze time and fixation
count, correlate reasonably well with human evaluation of MT output but fixation duration and pupil dilation may be less reliable
indicators of reading difficulty for MT output. We also conclude that eye tracking has promise as a semi-automatic MT evaluation
technique, which does not require bi-lingual knowledge, and which can potentially tap into the end users’ experience of machine
translation output. 相似文献
123.
124.
Jung-Jen Allen Cheng Diran Apelian Roger D. Doherty 《Metallurgical and Materials Transactions A》1986,17(11):2049-2062
The rheocasting solidification process has been applied in the production of IN-100 nickel base superalloy. A high vacuum
furnace for rheocasting superalloys was used to rheocast ingots under different processing conditions. Processing variables
which were evaluated include stirring speed, isothermal stirring time, and volume fraction solid during isothermal stirring.
Ingots, furnace cooled at the same rate but without stirring, were also examined for comparison with the rheocast ingots.
A detailed microstructural examination was made of the resultant microstructure both on furnace cooling after stirring and
on reheating to the isothermal stirring temperature followed by water quenching. Rheocasting yielded fine-grained structures,
where the extent of microsegregatiori, the variation in macrostructure, and the solidification-induced porosity were found
to be reduced in comparison to the unstirred ingot. The grain size and nonuniformity in the as-cast ingot were reduced by
increasing the stirring speed, isothermal stirring time, or the volume fraction solid during stirring. The degree of the microsegregation
decreased significantly with increasing volume fraction solid. Grain boundaries, both with and without solute enrichment,
were found in the rosette-like solid particles after rheocasting, lending support to the Vogel-Cantor-Doherty model of rheocasting
based on the formation of grain boundaries by strain-induced recrystallization and by sintering. It is clear from these results
that the microstructure of this superalloy was significantly improved by rheocasting. Improved mechanical properties were
also found and will be reported separately. 相似文献
125.
O Eickelberg CO Sommerfeld C Wyser M Tamm F Reichenberger PG Bardin M Solèr M Roth AP Perruchoud 《Canadian Metallurgical Quarterly》1997,156(6):1987-1992
The matrix metalloproteinases (MMP) are proteolytic enzymes that are essentially involved in the turnover of the extracellular matrix (ECM). Their activity is counterbalanced by specific antagonists, the tissue inhibitors of metalloproteinases (TIMP). In this study, we sought to analyze the expression of MMP and TIMP isoforms in pleural effusions from 88 patients. We compared MMP and TIMP isoform expression in transudates (n = 21) and exudates (n = 67), the latter divided into exudates of paraneoplastic (n = 46) or parainfectious (n = 21) origin. Zymographic and Western blot analyses revealed constant expression of interstitial collagenase (MMP-1), gelatinase-A (MMP-2), and TIMP-1 in all 88 samples. In contrast, analyses of gelatinase-B (MMP-9) demonstrated a specific expression pattern, with high expression in exudates and lack of expression in transudates. Neutrophil collagenase (MMP-8) was detected in trace amounts, and correlated with the number of neutrophils in the effusion. Low levels of TIMP-2 were detected only in exudates and not in transudates. Quantitative analysis of the expression ratio of gelatinase-B to gelatinase-A revealed statistically significant differences between effusions of different origin. The ratio was highest in exudates of paraneoplastic origin and lowest in transudates. Our data thus suggest that interstitial collagenase, gelatinase-A, and TIMP-1 play a role in homeostasis of the pleural space in vivo as constitutively expressed proteins, whereas gelatinase-B and TIMP-2 expression are induced in specific disease states. These observations contribute to the understanding of the pathophysiology of pleural effusions, and may help to characterize and possibly distinguish effusions of different origin. 相似文献
126.
We developed a novel approach for the high-level production of a microbial transglutaminase (TGase) from Streptoverticillium in E. coli. The direct expression of the TGase gene in E. coli cells did not cause overproduction, probably due to the harmful influence of TGase activity, which introduces covalent crosslinks between proteins. Therefore, we fused the chemically synthesized TGase gene coding for the entire 331 amino acid residues at the amino terminus to a bacteriophage T7 gene 10 leader peptide (260 amino acids) using an inducible expression vector. The TGase gene was expressed as inclusion bodies in the E. coli cytoplasm. Restoring 15 amino acid residues upstream of the amino terminus of the mature TGase by a two-step deletion of the fusion sequence facilitated solubilization and subsequent proteolytic cleavage, thus releasing mature TGase. Although the mature form had less TGase activity than native TGase, because of the poor refolding rate, these results suggest that this system is suitable for the efficient production of TGase. 相似文献
127.
128.
129.
A wavelet-based watermarking algorithm for ownership verificationof digital images 总被引:18,自引:0,他引:18
Access to multimedia data has become much easier due to the rapid growth of the Internet. While this is usually considered an improvement of everyday life, it also makes unauthorized copying and distributing of multimedia data much easier, therefore presenting a challenge in the field of copyright protection. Digital watermarking, which is inserting copyright information into the data, has been proposed to solve the problem. In this paper, we first discuss the features that a practical digital watermarking system for ownership verification requires. Besides perceptual invisibility and robustness, we claim that the private control of the watermark is also very important. Second, we present a novel wavelet-based watermarking algorithm. Experimental results and analysis are then given to demonstrate that the proposed algorithm is effective and can be used in a practical system. 相似文献
130.
Experience of vascular thrombosis prophylaxis and treatment after reconstructive operation conduction on abdominal aorta and peripheral arteries in 244 patients, including 112 of them immediately after the operation, 32-up to one year time, 100-in long-term follow-up period was summarized. Main aetiological cause for thrombosis occurrence immediately after the operation were technical and tactical failures committed during its conduction, in the early postoperative period-the neointima hyperplasia in the anastomosis area, in late terms-the blood outflow disorder from the reconstructed segment due to the atherosclerosis progression. Original methods of reoperation conduction for the transplant thrombosis and the outflow arteries reconstruction were proposed. Mortality lowering from 8.8 to 5.3% and the extremity revascularization occurrence, in 75% of patients immediately after the operation and in 84%-in long-term period was promoted owing to tactics of postoperative thrombosis treatment elaborated. 相似文献