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Testing Results (testing + result)
Selected AbstractsMahalanobis distance-based traffic matrix estimationEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 3 2010Dingde Jiang This letter studies large-scale IP traffic matrix (TM) estimation problem and proposes a novel method called the Mahalanobis distance-based regressive inference (MDRI). By using Mahalanobis distance as an optimal metric, we can get rid of the highly ill-posed nature of this problem. We describe the TM estimation into an optimal process, and then by optimising the regularised equation about this problem, TM's estimation can accurately obtained. Testing results are shown to be promising. Copyright © 2010 John Wiley & Sons, Ltd. [source] A new technique for non-destructive field measurement of rock-surface strength: an application of the Equotip hardness tester to weathering studiesEARTH SURFACE PROCESSES AND LANDFORMS, Issue 12 2007Hisashi Aoki Abstract Tafone-like depressions have developed on the Aoshima sandstone blocks used for a masonry bridge pier in the coastal spray zone. A thin layer of partial granular disintegration was found on the surface in depressions. To evaluate quantitatively the strength of the thin weathered layer, the hardness was measured at the surface of the sandstone blocks using both an Equotip hardness tester and an L-type Schmidt hammer. Comparison of the two testing results indicates that the Equotip hardness value is more sensitive in evaluating the strength of a thin layer of weathered surface rock than the Schmidt hardness value. By applying two methods, i.e. both the repeated impact method and the single impact method, the Equotip tester can evaluate the strengths of fresh internal and weathered surficial portions of rocks having a thin weathering layer. Comparison of the two strengths enables evaluation of strength reduction due to weathering. Copyright © 2007 John Wiley & Sons, Ltd. [source] Improved bonding of adhesive resin to sintered porcelain with the combination of acid etching and a two-liquid silane conditionerJOURNAL OF ORAL REHABILITATION, Issue 1 2001H. Kato This study determined the bond strengths of adhesive resins joined to a feldspathic porcelain (VMK 68) for the purpose of developing the most durable surface preparation for the porcelain. Three porcelain surfaces,ground, air-abraded with alumina, and etched with hydrofluoric acid,were prepared. A two-liquid porcelain conditioner that contained both 4-methacryloyloxyethyl trimellitate anhydride (4-META) and a silane coupler (Porcelain Liner M) was used as the priming agent. Each of the two liquid components of the conditioner was also used individually in order to examine the effects of the respective chemical ingredients on adhesive bonding. Two methyl methacrylate (MMA)-based resins initiated with tri- n -butylborane (TBB) either with or without 4-META (MMA-TBB and 4-META/MMA-TBB resins) were used as the luting agents. Shear bond strengths were determined both before and after thermocycling. Shear testing results indicated that thermocycling was effective for disclosing poor bonding systems, and that both mechanical and chemical retention were indispensable for bonding the porcelain. Of the combinations assessed, etching with hydrofluoric acid followed by two-liquid priming with the Porcelain Liner M material generated the most durable bond strength (33·3 MPa) for the porcelain bonded with the 4-META/MMA-TBB resin (Super-Bond C&B). [source] Collagen gene expression and mechanical properties of intervertebral disc cell,alginate culturesJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2001Anthony E. Baer Cells of the intervertebral disc have a limited capacity for matrix repair that may contribute to the onset and progression of degenerative disc changes. In this study, the biosynthetic capacity of cells isolated from specific regions of the porcine intervertebral disc was evaluated in vitro. Using a competitive reverse transcription-polymerase chain reaction technique, gene expression levels for types I and II collagen were quantified in cells cultured for up to 21 d in a three-dimensional alginate culture system and compared to levels obtained for cells in vivo. The mechanical properties of cell-alginate constructs were measured in compression and shear after periods of culture up to 16 weeks. Cells from the anulus fibrosus expressed the most type I collagen mRNA in vivo and in vitro, while cells from the transition zone expressed the most type II collagen mRNA in vivo and in vitro. Mechanical testing results indicate that a mechanically functional matrix did not form at any time during the culture period; rather, decreases of up to 50% were observed in the compressive and shear moduli of the cell,alginate constructs compared to alginate with no cells. Together with results of prior studies, these results suggest that intervertebral disc cells maintain characteristics of their phenotype when cultured in alginate, but the molecules they synthesize are not able to form a mechanically functional matrix in vitro. © 2001 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Concurrent validity of the Slosson full-range intelligence test: Comparison with the Wechsler intelligence scale for children,third edition and the Woodcock Johnson tests of achievement,revisedPSYCHOLOGY IN THE SCHOOLS, Issue 1 2002Nancy L. Bell This study examined the concurrent validity of the Slosson Full-Range Intelligence Test (S-FRIT) by comparing S-FRIT scores to the scores of the Wechsler Intelligence Scale for Children,Third Edition (WISC-III) and the Woodcock-Johnson Tests of Achievement,Revised (WJ-R). Data from 123 elementary students' screening and psychological testing results were examined. Results revealed that the S-FRIT scores were more related to overall intelligence, verbal, and math abilities than nonverbal intelligence, reading, or written language abilities. Further, it was found that 89% of the participants' S-FRIT Full-Range IQ scores fell within one standard deviation of their WISC-III FSIQ scores, with an average discrepancy of 7.6 points. Discrepancies between S-FRIT and WISC-III scores were also examined by educational diagnostic categories and ability levels. Limitations and suggestions for future research are provided. © 2002 John Wiley & Sons, Inc. [source] Control Charts for Monitoring Field Failure DataQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 7 2006Robert G. Batson Abstract One responsibility of the reliability engineer is to monitor failure trends for fielded units to confirm that pre-production life testing results remain valid. This research suggests an approach that is computationally simple and can be used with a small number of failures per observation period. The approach is based on converting failure time data from fielded units to normal distribution data, using simple logarithmic or power transformations. Appropriate normalizing transformations for the classic life distributions (exponential, lognormal, and Weibull) are identified from the literature. Samples of size 500 field failure times are generated for seven different lifetime distributions (normal, lognormal, exponential, and four Weibulls of various shapes). Various control charts are then tested under three sampling schemes (individual, fixed, and random) and three system reliability degradations (large step, small step, and linear decrease in mean time between failures (MTBF)). The results of these tests are converted to performance measures of time to first out-of-control signal and persistence of signal after out-of-control status begins. Three of the well-known Western Electric sensitizing rules are used to recognize the assignable cause signals. Based on this testing, the ,X -chart with fixed sample size is the best overall for field failure monitoring, although the individual chart was better for the transformed exponential and another highly-skewed Weibull. As expected, the linear decrease in MTBF is the most difficult change for any of the charts to detect. Copyright © 2005 John Wiley & Sons, Ltd. [source] Specific critical concentrations of low dosage hydrate inhibitors in a THF,NaCl hydrate formation solutionASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2010Ailin Ding Abstract Hydrate formation and its attendant problems are well known in the oil and gas industry. The desire to reduce the costs and environmental impact of traditional hydrate inhibitors has led to a focus on the design, development and evaluation of novel and environmentally friendly low dosage hydrate inhibitors (LDHIs). In this study, two LDHIs, namely Luvicap® EG and Gaffix® VC-713, were tested using tetrahydrofuran (THF) as a hydrate promoter and a ball-stop rig. The ball stop-time was used to determine the inhibition efficiency. The concentration effect of inhibitors, salts and solvents on the ball-stop time was investigated. Results indicated that the inhibition efficiency of an inhibitor is sensitive to the micro-environment of the THF-hydrates activities which includes the concentration and types of these additives. The reproducibility and consistency of the test results were also largely dependent on the concentration of inhibitors. Reliable information was provided only if the concentration of the inhibitor was above a critical concentration, below which the testing results scattered drastically and were inconsistent. As the critical concentration was inhibitor-dependent, a specific critical concentration (SCC) was proposed which is the first reported in such investigations. We concluded that the inhibition efficiency of an LDHI should be determined by both the ball-stop time and its SCC. Comparison of ball-stop times between two inhibitors should be made above their SCCs. Salt and solvent concentrations and other additives present in the operating systems should also be considered when a suitable LDHI concentration is determined for a particular field application. Copyright © 2010 Curtin University of Technology and John Wiley & Sons, Ltd. [source] | ||||||||||