In closed conduit water systems, being able to accurately measure flow is absolutely essential. For many meter designs, including electromagnetic induction meters (also known as magnetic flow meters), the greatest accuracy is achieved when the device is calibrated correctly. Optimal meter accuracy often depends on the flow conditions associated with the upstream geometry in the pipe system. Manufacturers typically give standards for the length of straight pipe required upstream of the meter. These standards vary, however, and do not address every possible configuration that may be installed upstream of the straight pipe requirement. An investigation on the effects of the length of straight pipe between a single 90° elbow and the upstream side of magnetic flow meters was completed in this research. Eleven 10-inch meters were chosen for testing. The procedure included a baseline test with more than forty diameters of straight pipe between the elbow and the meter. The accuracy of the meter was determined over a range of flow velocities typical for operation of this type and size of meter. Further tests were performed with the meter installed only three diameters downstream of the elbow. These tests constitute Phase I. In Phase II, four meters were tested with the upstream pipe length varying from a close-coupled installation to ten diameters of straight pipe between the elbow and the meter to observe variances in accuracy with distance from the elbow. The intent of the research was to show whether manufacturer accuracy specifications are achievable in actual application. It was determined that very few meters meet the manufacturer’s specification for accuracy even when installation requirements were met. Post-factory calibrations and minimization of velocity profile disruption through consideration of upstream geometry is recommended.

Accurate flow measurement is essential for the management of any type of fluid system. In order for a meter to accurately measure the flow, some installation requirements must be met. These installation requirements are meant to produce a condition where there are limited flow disturbances as the fluid enters the meter. If flow disturbances do occur, the meter may produce inaccurate measurements. This research investigated the effect on accuracy that different types of 12-inch flow meters have as a result of being installed in pipelines of differing inside diameter. The types of meters chosen for this research were the portable ultrasonic meter, the magnetic meter, and four types of differential pressure meters: classical Venturi, Halmi Venturi Tube, V-cone, and the wedge meter. Each meter was tested for accuracy with ten different pipe schedules installed upstream forming a pipewall offset varying between +0.125 inches and 0.937 inches. Ten flow rates between 400gpm and 6,550gpm were considered for each test setup. The meters’ accuracy during each test series was compared to the specified accuracy as defined by the manufacturer of the meter. All results were displayed graphically for comparison. In general, most of the meters tested were affected by the disturbances caused by the pipewall offsets, and some meters were more affected than others. The measurement error was found to be as high as 8% for the ultrasonic meter type. This research demonstrated that for accurate flow measurement, most flow meters require that the inside diameter of the piping be the same as the inside diameter as the meter. Laboratory tests showed that the wedge meter was not dependent upon the upstream pipe installation. Normally, it is recommended that laboratory calibrations be performed to ensure the accurate use of any meter type.

In this study, water meter accuracy in response to short, intermittent flows was tested. Burst flows have short durations (a few seconds or less), and occur at a variety of flow rates. For some types of meters, it is difficult to accurately measure short, intermittent flow rates. Depending on the meter type, an intermittent flow can result in either under-registering or over-registering of the actual throughput. During the testing for this research, water was passed through meters for various time combinations, test setups, and flows. It should be understood that realistically, a household setting will not see burst flows occurring in a repeated manner. For the purposes of laboratory testing, however, time-on and condensed time-off combinations were used. The reduced time off allowed for a controlled test procedure and efficient data collection. Ultrasonic, electromagnetic, nutating disc, and oscillating piston meters were tested. The meter types were found to perform differently under the varying test setups, time combinations, and flow rates. The electromagnetic meters were generally unaffected by burst flows. Burst flows caused one of the ultrasonic meter models to have decreased accuracies, while the other model remained mostly unaffected. Nutating disc and oscillating piston meters were generally affected by burst flows only at the lowest flow.

This study investigated empathic accuracy in adolescent romantic relationships. The project examined the relationships between psychological characteristics and relationship outcomes (i.e., satisfaction and aggression) to determine if the relationships were mediated by empathic accuracy. Participants were 92 heterosexual couples aged 14-18 years old who lived in rural areas in Utah and Arizona. Couple members completed surveys assessing attitudes and behaviors in their relationships and a video-recall procedure in which partners rated their own and their partner's behaviors during problem-solving discussion. Empathic accuracy was generally not related to psychological characteristics or outcomes. It became apparent that there were limitations with the methodology used to measure empathic accuracy. Due to the very strong correlations between participants' ratings of themselves and their ratings of their partners, ratings of self and partner were collapsed for each interaction variable to capture interpretations/biases employed by the participants in evaluating aspects of their interactions. The global video-recall ratings were then analyzed to determine if they mediated the relationships between psychological characteristics and outcomes. Rejection sensitivity emerged as an important psychological characteristic, and interpretations of conflict and sarcasm mediated the relationship between rejection sensitivity and outcomes of aggression and satisfaction.

Web information retrieval is a relatively new research area that has attracted a significant amount of interest from researchers around the world since the emergence of the World Wide Web in the early 1990s. The problems facing successful web information retrieval are a combination of challenges that stem from traditional information retrieval and challenges characterised by the nature of the World Wide Web. The goal of any information retrieval system is to provide an information need fulfilment in response to an information need. In a web setting, this means retrieving as many relevant web documents as possible in response to an inputted query that is typically limited to only containing a few terms expressive of the user's information need. This thesis is primarily concerned with firstly reviewing pertinent literature related to various aspects of web information retrieval research and secondly proposing and investigating a novel concept and context-based approach. The approach consists of techniques that can be used together or independently and aim to provide an improvement in retrieval accuracy over other approaches. A novel concept-based term weighting technique is proposed as a new method of deriving query term significance from ontologies that can be used for the weighting of inputted queries. A technique that dynamically determines the significance of terms occurring in documents based on the matching of contexts is also proposed. Other contributions of this research include techniques for the combination of document and query term weights for the ranking of retrieved documents. All techniques were implemented and tested on benchmark data. This provides a basis for performing comparison with previous top performing web information retrieval systems. High retrieval accuracy is reported as a result of utilising the proposed approach. This is supported through comprehensive experimental evidence and favourable comparisons against previously published results.

<p>W. Ickes, L. Stinson, V, Bisonette och S. Garcia (1990) standard stimulus paradigm är en metod för att mäta avläsning av en individs tankar och känslor. För att undersöka tjejer och killars empatiska avläsningsförmåga testades gymnasieelever med Ickes metod. Nittioåtta elever fick se en film som stannades av undersökningsledarna vid tio tillfällen. Deltagarna skulle vid varje stopp försöka läsa av kvinnan i filmens tankar och känslor och skriva ner dessa. Resultaten visade att tjejer är bättre än killar på att läsa av andra. Betyg i svenska och samhällskunskap, men inte matematik hade positivt samband med empati. Studien visade också att individer som gråter ofta har bra avläsningsförmåga. Tjejer med bra betyg och nära till gråt verkar ha de bästa intellektuella och emotionella verktygen för empatisk avläsning.</p>

The accuracy issue of a rapid prototyping-direct laser sintering system is studied in this paper. The sources of errors are analyzed for their contribution to the final accuracy of built parts. The error sources are related to the hardware and software of the machine, the materials and the process. Special measures were exploited to improve the accuracy of the direct laser sintering system and process. For the errors caused by hardware like laser scanner, compensation by software was developed to correct the errors resulting from galvano-mirrors and F-θ lens. A compensation function mode was added to the slicing software to compensate the errors caused by material shrinkage and laser beam offset. Based on the analysis and improvement, a desired accuracy of 0.2mm has been achieved for the direct laser sintering system, which was verified by experiments. / Singapore-MIT Alliance (SMA)

High levels of accuracy in transcription, aminoacylation of tRNA, and mRNA translation are essential for all life forms. However, high accuracy also necessarily means large energy dissipation and slow kinetics. Therefore, in vivo there is a fine tuned balance between rate and accuracy of key chemical reactions. We have shown that in our optimized in vitro bacterial protein synthesis system we have in vivo compatible rate and accuracy of ribosomal protein elongation. Our measurements of the temperature and the pH dependence of peptide bond formation with native substrates also suggest that the chemical step of peptidyl transfer, rather than tRNA accommodation, limits the rate of peptide bond formation. This work has made it possible to study ribosomal peptidyl transfer with native substrates. Furthermore, we have developed a general theoretical model for the rate-accuracy trade-off in enzymatic reactions. When considering this trade-off for protein synthesis in the context of the living bacterial cell, where cognate aa-tRNAs compete for ribosome binding with an excess of non-cognate aa-tRNAs, the model predicts an accuracy optimum where the inhibitory effect of non-cognate substrate binding and the efficiency loss due to high discard rate of cognate aa-tRNAs are minimized. However, these results also show that commonly used biochemical systems for protein synthesis studies operate at exceptionally suboptimal conditions. This makes it difficult, if not impossible, to relate the biochemical data to protein synthesis in the living cell. To validate our theoretical model we developed a method, based on variation of the concentration of Mg2+ ions in the buffer, to study the rate-accuracy trade-off of bacterial protein synthesis in vitro. We found a linear trade-off between rate and accuracy of tRNA selection on the ribosome, from which we could estimate the maximal accuracy. Exploiting this method for a complete set of single-mismatch readings by one tRNA species, we found simple patterns of genetic code reading, where the accuracy was highest for the second and lowest for the third codon position. The results bridge the gap between in vivo and in vitro protein synthesis and allow calibration of our test tube conditions to those of the living cell.

Transtibial stump volume can change dramatically postoperatively and jeopardise prosthetic fitting. Differences between individuals make it hard to give general recommendations of when to fit with a definitive prosthesis. Measuring the stump volume on every patient could solve this, but most methods for volume assessments are too complicated for clinical use. The aim of this study was to evaluate accuracy and intra- and interrater precision of a method to estimate stump volume from circumferential measurements. The method approximates the stump as a number of cut cones and the tip as a sphere segment. Accuracy was evaluated theoretically on six scanned stump models in CAPOD software and manually on six stump models. Precision was evaluated by comparing measurements made by four CPOs on eight stumps. Measuring devices were a wooden rule and a metal circumference rule. The errors were estimated with intraclass correlation coefficient (ICC), where 0,85 was considered acceptable, and a clinical criterion that a volume error of ±5% was acceptable (5% corresponds to one stocking). The method was accurate on all models in theory but accurate on only four models in reality. The ICC was 0,95-1,00 for intrarater precision but only 0,76 for interrater precision. Intra- and interrater precision was unsatisfying when using clinical criteria. Variations between estimated tip heights and circumferences were causing the errors. The method needs to be developed and is not suitable for stumps with narrow ends. Using a longer rule (about 30 cm) with a set square end to assess tip heights is recommended to improve precision. Using a flexible measuring-tape (possible to disinfect) with a spring-loaded handle could improve precision of the circumferential measurements.

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