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Sample records for 85th percentile speed

  1. Relationship between speed and traffic accident and speed limit on freeway

    CHENG Guo-zhu; PEI Yu-long

    2008-01-01

    To develop an equation between discrete degree of speed and traffic accident on freeway in China and give reasonable suggestions of speed management, the relation model was established between speed standard deviation and accident rate per 100,000,000 vehicle kilometers by regression analysis. The model shows that the more discrete is the speed distribution, the higher is the accident rate, which provides theoretical gist for speed limit on freeway. It is suggested that speed limit should be set according to 85th percentile speed obtained by the relationship between 85th percentile speed and Rcc, (curvature change rate of single circular curve), anddifferent speed limits should be set for cars and trucks. Through analyzing spot speed data of eight freeways in China, regression models were established between 85th percentile speed and RCCs and 15th percentile speed and RCCs. Reasonable speed limit suggestion values are put forward through these models.

  2. Anatolij Svidzynskyj's 85th birthday

    Editorial Board

    2014-06-01

    Full Text Available This year a prominent Ukrainian theoretical physicist and public leader Anatolij Svidzynskyj marks his 85th birthday. Anatolij Svidzynskyj was born on 1 March 1929 in Mohyliv-Podilskyy (Ukraine to a family of a physics teacher and an economist. Since 1939 and to the end of WWII Svidzynskyj's family lived in Kiev. In 1945 they moved to Lviv, where A. Svidzynskyj graduated from the Faculty of Physics and Mathematics of the Lviv State University. Vasyl Milyanchuk was his first supervisor. Due to his advice A. Svidzynskyj moved to Moscow State University where Mykola Boholiubov worked at the time. Under Bogoliubov's supervision the PhD thesis ``On the method of functional averaging in the theory of Green's function'' was written, which was defended in 1956 at Lviv State University. One of the most important results obtained in the thesis is an exact solution of Bloch-Nordsieck model that describes an infrared asymptotic of the electron Green's function in a realistic theory - quantum electrodynamics. In this way, a non-analytical dependence of this function on a coupling constant was obtained, and the nature of infrared divergences in quantum electrodynamics was clarified.

  3. Effectiveness of Motorcycle speed controlled by speed hump

    Pornsiri Urapa

    2014-09-01

    Full Text Available Speed humps are one of the traffic calming measures widely accepted to control vehicle speed in the local road. Humps standards from the western countries are designed mainly for the passenger car. This study, therefore, aims to reveal the effectiveness of speed hump to control the motorcycle speed. This study observes the free-flow speed of the riders at the total of 20 speed bumps and humps. They are 0.3-14.8 meter in width and 5-18 centimeter in height. The results reveal that the 85th percentile speeds reduce 15-65 percent when crossing the speed bumps and speed humps. Besides, this study develops the speed model to predict the motorcycle mean speed and 85th percentile speed. It is found that speed humps follow the ITE standard can control motorcycle crossing speeds to be 25-30 Kph which are suitable to travel on the local road.

  4. Quantile regression provides a fuller analysis of speed data.

    Hewson, Paul

    2008-03-01

    Considerable interest already exists in terms of assessing percentiles of speed distributions, for example monitoring the 85th percentile speed is a common feature of the investigation of many road safety interventions. However, unlike the mean, where t-tests and ANOVA can be used to provide evidence of a statistically significant change, inference on these percentiles is much less common. This paper examines the potential role of quantile regression for modelling the 85th percentile, or any other quantile. Given that crash risk may increase disproportionately with increasing relative speed, it may be argued these quantiles are of more interest than the conditional mean. In common with the more usual linear regression, quantile regression admits a simple test as to whether the 85th percentile speed has changed following an intervention in an analogous way to using the t-test to determine if the mean speed has changed by considering the significance of parameters fitted to a design matrix. Having briefly outlined the technique and briefly examined an application with a widely published dataset concerning speed measurements taken around the introduction of signs in Cambridgeshire, this paper will demonstrate the potential for quantile regression modelling by examining recent data from Northamptonshire collected in conjunction with a "community speed watch" programme. Freely available software is used to fit these models and it is hoped that the potential benefits of using quantile regression methods when examining and analysing speed data are demonstrated. PMID:18329400

  5. Tutorial: Calculating Percentile Rank and Percentile Norms Using SPSS

    Baumgartner, Ted A.

    2009-01-01

    Practitioners can benefit from using norms, but they often have to develop their own percentile rank and percentile norms. This article is a tutorial on how to quickly and easily calculate percentile rank and percentile norms using SPSS, and this information is presented for a data set. Some issues in calculating percentile rank and percentile…

  6. Managing speed at school and playground zones.

    Kattan, Lina; Tay, Richard; Acharjee, Shanti

    2011-09-01

    Since speeding is one of the major causes of frequent and severe traffic accidents around school and playground areas, many jurisdictions have reduced the speed limits in these areas to protect children who may be at risk. This paper investigated the speed compliance, mean speed and 85th percentile speed at selected school and playground zones in the City of Calgary in Alberta. Our results showed that the mean speed was lower and the rate of compliance was higher in the school zone compared to the playground zone, 2 lane roads relative to 4 lane roads, roads with fencing, traffic control devices and the presence of speed display device or children, and zones that were longer (> 200 m). Accordingly, this study provided recommendations to improve the effectiveness of school and playground zone speed limits. PMID:21658518

  7. Iowa House of Representatives District Boundaries for 2013 - 2022_85th - 89th General Assemblies

    Iowa State University GIS Support and Research Facility — Iowa Legislative House district boundaries, enacted April 19, 2011, effective beginning with the elections in 2012 for the 85th General Assembly. The districts will...

  8. Percentile residual life orders

    Franco Pereira, Alba M.; Lillo, Rosa E.; Romo, Juan; Shaked, Moshe

    2011-01-01

    In this paper we study a family of stochastic orders of random variables defined via the comparison of their percentile residual life functions. Some interpretations of these stochastic orders are given, and various properties of them are derived. The relationships to other stochastic orders are also studied. Finally, some applications in reliability theory and finance are described.

  9. Using Appropriate Speed Tables Regarding to the Speed Limit of Streets

    Amir Falamarzi

    2014-04-01

    Full Text Available In the present decade along the increasing trend of using private vehicles, calming the local streets and residential areas has been important for local authorities. There are many unsuccessful experiences of traffic calming implementations because of lacking knowledge and engineered assessment before implementing them. Considering the design speed of traffic, calming measure is an essential factor to employ these measures. Design speed of different size of speed humps is investigated in previous studies because of its circular shape but for speed tables it is unknown. In this research the design speeds of two common speed tables in the city of Tehran have been examined, 6.5 and 8.5 m speed table. For calculating the design speed of the speed tables, we asked 220 drivers to participate in our experiment by installing a GPS tracker in their vehicles and encouraging them to drive normally. Crossing speeds over 6.5 and 8.5 m speed tables have been analyzed by collecting totally 220 samples. We pick out 100 correct samples for each speed table and the 85th percentile speed has been calculated for them, consequently the results of 85th percentile calculation of the crossing speeds have been proposed as the design speeds. For 6.5 m speed table, design speed is calculated 41.5 km/h and for 8.5 m speed table, design speed is calculated 47.5 km/h. the comparison of recent findings and past finding of 9.5 m speed table which is used in Denmark with a design speed of 80 km/h reveals that 1 m increasing with the length of a 6.5 speed table plateau will result 3 km/h increase in its design speed. The findings of this research can help traffic calming experts to take in consideration of the relation between speed table physical characteristics and its design speed. Furthermore by finding the design speed of speed tables, we can choose suitable speed tables for streets with different speed limits according to the design speed of speed tables.

  10. 50th Percentile Rent Estimates

    Department of Housing and Urban Development — Rent estimates at the 50th percentile (or median) are calculated for all Fair Market Rent areas. Fair Market Rents (FMRs) are primarily used to determine payment...

  11. "17% at or above the 95th percentile"——What is wrong with this statement?

    Weimo; Zhu

    2012-01-01

    <正>When reporting the prevalence of childhood obesity in the USA a few years ago,the magazine U.S.News & World Report stated: "...some 17 percent of kids are now obese,which means they’re at or above the 95th percentile for weight in relation to height for their age;an additional 17 percent are overweight, or at or over the 85th percentile." Anyone with some basic training in measurement or statistics will realize that this statement is incorrect.This is because the percentile is defined as the value below which a certain percent of observations fall in a population.For example,the 15th

  12. EJSCREEN States Percentiles Lookup Table--2015 Intranet

    U.S. Environmental Protection Agency — The States table provides percentile breaks of important EJSCREEN elements (demographic indicators and indexes, environmental indicators and indexes) at the state...

  13. EJSCREEN Regions Percentiles Lookup Table--2015 Intranet

    U.S. Environmental Protection Agency — The Regions table provides percentile breaks of important EJSCREEN elements (demographic indicators and indexes, environmental indicators and indexes) at the EPA...

  14. EJSCREEN National Percentiles Lookup Table--2015 Intranet

    U.S. Environmental Protection Agency — The USA table provides percentile breaks of important EJSCREEN elements (demographic indicators and indexes, environmental indicators and indexes) at the national...

  15. Waist Circumferences of Chilean Students: Comparison of the CDC-2012 Standard and Proposed Percentile Curves

    Rossana Gómez-Campos

    2015-07-01

    Full Text Available The measurement of waist circumference (WC is considered to be an important means to control overweight and obesity in children and adolescents. The objectives of the study were to (a compare the WC measurements of Chilean students with the international CDC-2012 standard and other international standards, and (b propose a specific measurement value for the WC of Chilean students based on age and sex. A total of 3892 students (6 to 18 years old were assessed. Weight, height, body mass index (BMI, and WC were measured. WC was compared with the CDC-2012 international standard. Percentiles were constructed based on the LMS method. Chilean males had a greater WC during infancy. Subsequently, in late adolescence, males showed values lower than those of the international standards. Chilean females demonstrated values similar to the standards until the age of 12. Subsequently, females showed lower values. The 85th and 95th percentiles were adopted as cutoff points for evaluating overweight and obesity based on age and sex. The WC of Chilean students differs from the CDC-2012 curves. The regional norms proposed are a means to identify children and adolescents with a high risk of suffering from overweight and obesity disorders.

  16. Evaluating the safety impact of increased speed limits on rural highways in British Columbia.

    Sayed, Tarek; Sacchi, Emanuele

    2016-10-01

    Maximum speed limits are usually set to inform drivers of the highest speed that it is safe and appropriate for ideal traffic, road and weather conditions. Many previous studies were conducted to investigate the relationship between changed speed limits and safety. The results of these studies generally show that relaxing speed limits can negatively affect safety, especially with regard to fatal and injury crashes. Despite these results, several road jurisdictions in North America continue to raise the maximum speed limits. In 2013, the British Columbia Ministry of Transportation and Infrastructure initiated a speed limits review. The review found that the 85th percentile speed on many highway segments was 10km/h higher than corresponding posted speed limits and 1300km of rural provincial highway segments were recommended for higher speed limits. Most of the highway segments had 10km/h speed limit increase with a small section having 20km/h speed limit increase. As speed limit changes can have a substantial impact on safety, the main objective of this study is to estimate the effect of the increased speed limits on crash occurrence. A before-after evaluation was undertaken with the full Bayesian technique. Overall, the evaluation showed that changed speed limits led to a statistically significant increase in fatal-plus-injury (severe) crashes of 11.1%. A crash modification function that includes changes in the treatment effect over time showed that the initial increase of the first post-implementation period may slightly decrease over time. PMID:27447060

  17. Blood Pressure Percentiles for School Children

    İsmail Özanli

    2016-06-01

    Full Text Available Objective: The prevalence of hypertension in childhood and adolescence is gradually increasing. We aimed to in­vestigate the blood pressure (BP values of children aged 7-18 years. Methods: This study was conducted in a total of 3375 (1777 females, 1598 males children from 27 schools. Blood pressures of children were measured using sphyg­momanometer appropriate to arm circumference. Results: A positive relationship was found between sys­tolic blood pressure (SBP and diastolic blood pressure (DBP and the body weight, height, age and body mass index (BMI in male and female children. SBP was high­er in males than females after the age of 13. DBP was higher in males than the females after the age of 14. The mean annual increase of SBP was 2.06 mmHg in males and 1.54 mmHg in females. The mean annual increase of DBP was 1.52 mmHg in males and 1.38 mmHg in fe­males. Conclusion: In this study, we identified the threshold val­ues for blood pressure in children between the age of 7 and 18 years in Erzurum province. It is necessary to com­bine and evaluate data obtained from various regions for the identification of BP percentiles according to the age, gender and height percentiles of Turkish children.

  18. EJSCREEN States Percentiles Lookup Table--2015 Public Release

    U.S. Environmental Protection Agency — The States table provides percentile breaks of important EJSCREEN elements (demographic indicators and indexes, environmental indicators and indexes) at the state...

  19. EJSCREEN National Percentiles Lookup Table--2015 Public Release

    U.S. Environmental Protection Agency — The USA table provides percentile breaks of important EJSCREEN elements (demographic indicators and indexes, environmental indicators and indexes) at the national...

  20. EJSCREEN Regions Percentiles Lookup Table--2015 Public Release

    U.S. Environmental Protection Agency — The Regions table provides percentile breaks of important EJSCREEN elements (demographic indicators and indexes, environmental indicators and indexes) at the EPA...

  1. The use of percentiles and percentile rank classes in the analysis of bibliometric data: Opportunities and limits

    Bornmann, Lutz; Leydesdorff, Loet; Mutz, Ruediger

    2012-01-01

    Percentiles have been established in bibliometrics as an important alternative to mean-based indicators for obtaining a normalized citation impact of publications. Percentiles have a number of advantages over standard bibliometric indicators used frequently: for example, their calculation is not based on the arithmetic mean which should not be used for skewed bibliometric data. This study describes the opportunities and limits and the advantages and disadvantages of using percentiles in bibli...

  2. Alternative Statistical Frameworks for Student Growth Percentile Estimation

    Lockwood, J. R.; Castellano, Katherine E.

    2015-01-01

    This article suggests two alternative statistical approaches for estimating student growth percentiles (SGP). The first is to estimate percentile ranks of current test scores conditional on past test scores directly, by modeling the conditional cumulative distribution functions, rather than indirectly through quantile regressions. This would…

  3. On the calculation of percentile-based bibliometric indicators

    Waltman, Ludo

    2012-01-01

    A percentile-based bibliometric indicator is an indicator that values publications based on their position within the citation distribution of their field. The most straightforward percentile-based indicator is the proportion of frequently cited publications, for instance the proportion of publications that belong to the top 10% most frequently cited of their field. Recently, more complex percentile-based indicators were proposed. A difficulty in the calculation of percentile-based indicators is caused by the discrete nature of citation distributions combined with the presence of many publications with the same number of citations. We introduce an approach to calculating percentile-based indicators that deals with this difficulty in a more satisfactory way than earlier approaches suggested in the literature. We show in a formal mathematical framework that our approach leads to indicators that do not suffer from biases in favor of or against particular fields of science.

  4. Classification of EMG Signal Based on Human Percentile using SOM

    M.H. Jali

    2014-07-01

    Full Text Available Electromyography (EMG is a bio signal that is formed by physiological variations in the state of muscle fibre membranes. Pattern recognition is one of the fields in the bio-signal processing which classified the signal into certain desired categories with subject to their area of application. This study described the classification of the EMG signal based on human body percentile using Self Organizing Mapping (SOM technique. Different human percentile definitively varies the arm circumference size. Variation of arm circumference is due to fatty tissue that lay between active muscle and skin. Generally the fatty tissue would decrease the overall amplitude of the EMG signal. Data collection is conducted randomly with fifteen subjects that have numerous percentiles using non-invasive technique at Biceps Brachii muscle. The signals are then going through filtering process to prepare them for the next stage. Then, five well known time domain feature extraction methods are applied to the signal before the classification process. Self Organizing Map (SOM technique is used as a classifier to discriminate between the human percentiles. Result shows that SOM is capable in clustering the EMG signal to the desired human percentile categories by optimizing the neurons of the technique.

  5. Percentile curves for skinfold thickness for Canadian children and youth.

    Kuhle, Stefan; Ashley-Martin, Jillian; Maguire, Bryan; Hamilton, David C

    2016-01-01

    Background. Skinfold thickness (SFT) measurements are a reliable and feasible method for assessing body fat in children but their use and interpretation is hindered by the scarcity of reference values in representative populations of children. The objective of the present study was to develop age- and sex-specific percentile curves for five SFT measures (biceps, triceps, subscapular, suprailiac, medial calf) in a representative population of Canadian children and youth. Methods. We analyzed data from 3,938 children and adolescents between 6 and 19 years of age who participated in the Canadian Health Measures Survey cycles 1 (2007/2009) and 2 (2009/2011). Standardized procedures were used to measure SFT. Age- and sex-specific centiles for SFT were calculated using the GAMLSS method. Results. Percentile curves were materially different in absolute value and shape for boys and girls. Percentile girls in girls steadily increased with age whereas percentile curves in boys were characterized by a pubertal centered peak. Conclusions. The current study has presented for the first time percentile curves for five SFT measures in a representative sample of Canadian children and youth. PMID:27547554

  6. How to analyse percentile impact data meaningfully in bibliometrics: The statistical analysis of distributions, percentile rank classes and top-cited papers

    Bornmann, Lutz

    2012-01-01

    According to current research in bibliometrics, percentiles (or percentile rank classes) are the most suitable method for normalising the citation counts of individual publications in terms of the subject area, the document type and the publication year. Up to now, bibliometric research has concerned itself primarily with the calculation of percentiles. This study suggests how percentiles can be analysed meaningfully for an evaluation study. Publication sets from four universities are compare...

  7. Establishing percentiles for junior tennis players based on physical fitness testing results.

    Roetert, E P; Piorkowski, P A; Woods, R B; Brown, S W

    1995-01-01

    An important aspect of this study was the establishment of a data base. A broad data base allows for data on certain parameters to be greatly expanded and will also enhance the use and interpretation of statistical methods. A longitudinal study of these variables may also assist in monitoring the players' progress over a period of time, and can provide a useful supplement to subjective coaching appraisals. The means and standard deviation for each test were calculated according to the USTA age and gender groups, that is, 12s, 14s, and 16s for each separate gender. Additionally, the mean and standard deviations for the ages, heights, and weights of each grouping were also calculated. Once the means and standard deviations were calculated, percentile tables were developed for each of the USTA groupings (by age and gender). The percentiles for each USTA test are presented in Appendix 1. A percentile is defined as the point on the distribution below which a given percentage of the scores is found. Percentiles can provide a norm-referenced interpretation of an individual score within a distribution that often consists of scores from a comparable group of individuals. Using the USTA protocol, players and coaches now have a set of normative data by which individual player's fitness scores may be compared with participants of the USTA Area Training Centers (See appendix 1). From the test results, coaches and players can determine which fitness areas need to be improved for athletes on an individual basis. Specific training programs can then be designed based on an athlete's fitness testing results. Proper interpretation of the USTA fitness testing data base results can lead to an easy way to determine the relative position of a given fitness score in the distribution, recognizing weaker areas for the purpose of injury prevention and performance enhancement. Each player can be given a profile detailing their percentile rank relative to other area training center

  8. Up-and-Down and the Percentile-Finding Problem

    Oron, Assaf P

    2008-01-01

    Up-and-Down (U&D) is a popular sequential design for estimating threshold percentiles in binary experiments. However, U&D application practices have stagnated, and significant gaps in understanding its properties persist. The first part of my work aims to fill gaps in U&D theory. New results concerning stationary distribution properties are proven. A second focus of this study is nonparametric U&D estimation. An improvement to isotonic regression called "centered isotonic regression" (CIR), and a new averaging estimator called "auto-detect" are introduced and their properties studied. Bayesian percentile-finding designs, most notably the continual reassessment method (CRM) developed for Phase I clinical trials, are also studied. In general, CRM convergence depends upon random run-time conditions -- meaning that convergence is not always assured. Small-sample behavior is studied as well. It is shown that CRM is quite sensitive to outlier sub-sequences of thresholds, resulting in highly variable...

  9. On generalized multinomial models and joint percentile estimation

    Das, I.; Mukhopadhyay, S.

    2012-01-01

    This article proposes a family of link functions for the multinomial response model. The link family includes the multicategorical logistic link as one of its members. Conditions for the local orthogonality of the link and the regression parameters are given. It is shown that local orthogonality of the parameters in a neighbourhood makes the link family location and scale invariant. Confidence regions for jointly estimating the percentiles based on the parametric family of link functions are ...

  10. Two stage group acceptance sampling plan for half normal percentiles

    Muhammad Azam; Muhammad Aslam; Saminathan Balamurali; Affifa Javaid

    2015-01-01

    In this paper, a time truncated life test based on two stage group acceptance sampling plan for the percentile lifetime following half-normal distribution is proposed. The optimal parameters for the proposed plan are determined such that both producer’s and consumer’s risks are satisfied simultaneously for the given experimentation time and sample size. The efficiency of the proposed sampling plan is discussed in terms of average sample number with the existing sampling plan. The proposed sam...

  11. Percentile growth charts for biomedical studies using a porcine model.

    Corson, A M; Laws, J; Laws, A; Litten, J C; Lean, I J; Clarke, L

    2008-12-01

    Increasing rates of obesity and heart disease are compromising quality of life for a growing number of people. There is much research linking adult disease with the growth and development both in utero and during the first year of life. The pig is an ideal model for studying the origins of developmental programming. The objective of this paper was to construct percentile growth curves for the pig for use in biomedical studies. The body weight (BW) of pigs was recorded from birth to 150 days of age and their crown-to-rump length was measured over the neonatal period to enable the ponderal index (PI; kg/m3) to be calculated. Data were normalised and percentile curves were constructed using Cole's lambda-mu-sigma (LMS) method for BW and PI. The construction of these percentile charts for use in biomedical research will allow a more detailed and precise tracking of growth and development of individual pigs under experimental conditions. PMID:22444086

  12. Percentile distribution of blood pressure readings in relation to body mass index: a populationbased cross-sectional study ADOPOLNOR

    Krzyżaniak Alicja

    2015-03-01

    than girls. Similar pattern was found for age-related changes in BMI. The quotation of 3rd, 5th, 10th, 15th, 25th, 50th, 75th, 85th, 90th, 95th, and 97th at any given BMI between 12 kg/m2 and 35 kg/m2 provided indication of the entire variation in blood pressure of adolescent males and females aged 10-18 years. The sex- and BMI-specific reference values and charts for systolic and diastolic blood pressure may be a useful tool in monitoring blood pressure for early detection of its abnormal level and treatment of children and adolescents with high blood pressure.

  13. Two stage group acceptance sampling plan for half normal percentiles

    Muhammad Azam

    2015-07-01

    Full Text Available In this paper, a time truncated life test based on two stage group acceptance sampling plan for the percentile lifetime following half-normal distribution is proposed. The optimal parameters for the proposed plan are determined such that both producer’s and consumer’s risks are satisfied simultaneously for the given experimentation time and sample size. The efficiency of the proposed sampling plan is discussed in terms of average sample number with the existing sampling plan. The proposed sampling plan is explained with the help of industrial examples.

  14. Nonparametric confidence intervals based on extreme bootstrap percentiles

    Lee, SMS

    2000-01-01

    Monte Carlo approximation of standard bootstrap confidence intervals relies on the drawing of a large number, B say, of bootstrap resamples. Conventional choice of B is often made on the order of 1,000. While this choice may prove to be more than sufficient for some cases, it may be far from adequate for others. A new approach is suggested to construct confidence intervals based on extreme bootstrap percentiles and an adaptive choice of B. It economizes on the computational effort in a proble...

  15. Physical Fitness Percentiles of German Children Aged 9-12 Years: Findings from a Longitudinal Study.

    Kathleen Golle

    Full Text Available Generating percentile values is helpful for the identification of children with specific fitness characteristics (i.e., low or high fitness level to set appropriate fitness goals (i.e., fitness/health promotion and/or long-term youth athlete development. Thus, the aim of this longitudinal study was to assess physical fitness development in healthy children aged 9-12 years and to compute sex- and age-specific percentile values.Two-hundred and forty children (88 girls, 152 boys participated in this study and were tested for their physical fitness. Physical fitness was assessed using the 50-m sprint test (i.e., speed, the 1-kg ball push test, the triple hop test (i.e., upper- and lower- extremity muscular power, the stand-and-reach test (i.e., flexibility, the star run test (i.e., agility, and the 9-min run test (i.e., endurance. Age- and sex-specific percentile values (i.e., P10 to P90 were generated using the Lambda, Mu, and Sigma method. Adjusted (for change in body weight, height, and baseline performance age- and sex-differences as well as the interactions thereof were expressed by calculating effect sizes (Cohen's d.Significant main effects of Age were detected for all physical fitness tests (d = 0.40-1.34, whereas significant main effects of Sex were found for upper-extremity muscular power (d = 0.55, flexibility (d = 0.81, agility (d = 0.44, and endurance (d = 0.32 only. Further, significant Sex by Age interactions were observed for upper-extremity muscular power (d = 0.36, flexibility (d = 0.61, and agility (d = 0.27 in favor of girls. Both, linear and curvilinear shaped curves were found for percentile values across the fitness tests. Accelerated (curvilinear improvements were observed for upper-extremity muscular power (boys: 10-11 yrs; girls: 9-11 yrs, agility (boys: 9-10 yrs; girls: 9-11 yrs, and endurance (boys: 9-10 yrs; girls: 9-10 yrs. Tabulated percentiles for the 9-min run test indicated that running distances between 1

  16. Binorm-a fortran subroutine to calculate the percentiles of a standardized binormal distribution

    McCammon, R.B.

    1977-01-01

    BINORM is a FORTRAN subroutine for calculating the percentiles of a standardized binormal distribution. By using a linear transformation, the percentiles of a binormal distribution can be obtained. The percentiles of a binormal distribution are useful for plotting purposes, for establishing confidence intervals, and for sampling from a mixed population that consists of two normal distributions. ?? 1977.

  17. Waist circumference, waist-hip ratio and waist-height ratio percentiles and central obesity among Pakistani children aged five to twelve years

    Mushtaq Muhammad Umair

    2011-11-01

    to 85th WHtR percentile irrespective of age and gender. Twelve percent children (95% CI 10.1-13.0 had a WC ≥90th percentile and 16.5% children (95% CI 14.7-18.1 had a WHtR ≥0.5 while 11% children (95% CI 8.9-11.6 had both WC ≥90th percentile and WHtR ≥0.5. Significant predictors of central obesity included higher grade, urban area with high socioeconomic status (SES, high-income neighborhood and higher parental education. Children studying in higher grade (aOR 5.11, 95% CI 1.76-14.85 and those living in urban area with high SES (aOR 82.34, 95% CI 15.76-430.31 showed a significant independent association. Urban area with high SES and higher parental education showed a significant independent association with higher WC and higher WHtR while higher grade showed a significant independent association with higher WC. Conclusions Comprehensive worldwide reference values are needed to define central obesity and the present study is the first one to report anthropometric indices predictive of central obesity for Pakistani school-aged children. Eleven percent children were centrally obese and strong predictors included higher grade, urban area with high SES and higher parental education. These findings support the need for developing a National strategy for childhood obesity and implementing targeted interventions, prioritizing the higher social class and involving communities.

  18. Development of a Three-Dimensional Finite Element Chest Model for the 5(th) Percentile Female.

    Kimpara, Hideyuki; Lee, Jong B; Yang, King H; King, Albert I; Iwamoto, Masami; Watanabe, Isao; Miki, Kazuo

    2005-11-01

    Several three-dimensional (3D) finite element (FE) models of the human body have been developed to elucidate injury mechanisms due to automotive crashes. However, these models are mainly focused on 50(th) percentile male. As a first step towards a better understanding of injury biomechanics in the small female, a 3D FE model of a 5(th) percentile female human chest (FEM-5F) has been developed and validated against experimental data obtained from two sets of frontal impact, one set of lateral impact, two sets of oblique impact and a series of ballistic impacts. Two previous FE models, a small female Total HUman Model for Safety (THUMS-AF05) occupant version 1.0Beta (Kimpara et al. 2002) and the Wayne State University Human Thoracic Model (WSUHTM, Wang 1995 and Shah et al. 2001) were integrated and modified for this model development. The model incorporated not only geometrical gender differences, such as location of the internal organs and structure of the bony skeleton, but also the biomechanical differences of the ribs due to gender. It includes a detailed description of the sternum, ribs, costal cartilage, thoracic spine, skin, superficial muscles, intercostal muscles, heart, lung, diaphragm, major blood vessels and simplified abdominal internal organs and has been validated against a series of six cadaveric experiments on the small female reported by Nahum et al. (1970), Kroell et al. (1974), Viano (1989), Talantikite et al. (1998) and Wilhelm (2003). Results predicted by the model were well-matched to these experimental data for a range of impact speeds and impactor masses. More research is needed in order to increase the accuracy of predicting rib fractures so that the mechanisms responsible for small female injury can be more clearly defined. PMID:17096277

  19. Percentiles of percentage body fat in German children and adolescents: An international comparison

    Peter Schwandt; Arnold von Eckardstein; Gerda-Maria Haas

    2012-01-01

    Background: Age- and gender-specific percentiles of body mass index in children and adolescents are a cornerstone categorizing overweight and obesity in youths worldwide. Since corresponding worldwide growth curves of percent body fat (% BF) are missing, the purpose was to contribute smoothed percentiles of percentage body fat from a large urban sample of German youths and to include them in actual national and international percentile curves. Methods: We estimated % BF in 22 113 German y...

  20. BMI percentiles for the identification of abdominal obesity and metabolic risk in children and adolescents: Evidence in support of the CDC 95th percentile

    Harrington, Deirdre M.; Amanda E. Staiano; Broyles, Stephanie T.; Gupta, Alok K; Katzmarzyk, Peter T.

    2012-01-01

    Objectives BMI percentiles have been routinely and historically used to identify elevated adiposity. This paper aimed to investigate the optimal Centers for Disease Control and Prevention (CDC) body mass index (BMI) percentile that predicts elevated visceral adipose tissue (VAT), fat mass and cardiometabolic risk in a biracial sample of children and adolescents. Participants and Methods This cross-sectional analysis included 369 white and African American children (5–18 y). BMI was calculated...

  1. Development of a percentile based three-dimensional model of the buttocks in computer system

    Wang, Lijing; He, Xueli; Li, Hongpeng

    2016-05-01

    There are diverse products related to human buttocks, which need to be designed, manufactured and evaluated with 3D buttock model. The 3D buttock model used in present research field is just simple approximate model similar to human buttocks. The 3D buttock percentile model is highly desired in the ergonomics design and evaluation for these products. So far, there is no research on the percentile sizing system of human 3D buttock model. So the purpose of this paper is to develop a new method for building three-dimensional buttock percentile model in computer system. After scanning the 3D shape of buttocks, the cloud data of 3D points is imported into the reverse engineering software (Geomagic) for the reconstructing of the buttock surface model. Five characteristic dimensions of the buttock are measured through mark-points after models being imported into engineering software CATIA. A series of space points are obtained by the intersecting of the cutting slices and 3D buttock surface model, and then are ordered based on the sequence number of the horizontal and vertical slices. The 1st, 5th, 50th, 95th, 99th percentile values of the five dimensions and the spatial coordinate values of the space points are obtained, and used to reconstruct percentile buttock models. This research proposes a establishing method of percentile sizing system of buttock 3D model based on the percentile values of the ischial tuberosities diameter, the distances from margin to ischial tuberosity and the space coordinates value of coordinate points, for establishing the Nth percentile 3D buttock model and every special buttock types model. The proposed method also serves as a useful guidance for the other 3D percentile models establishment for other part in human body with characteristic points.

  2. Development of a percentile based three-dimensional model of the buttocks in computer system

    Wang, Lijing; He, Xueli; Li, Hongpeng

    2016-04-01

    There are diverse products related to human buttocks, which need to be designed, manufactured and evaluated with 3D buttock model. The 3D buttock model used in present research field is just simple approximate model similar to human buttocks. The 3D buttock percentile model is highly desired in the ergonomics design and evaluation for these products. So far, there is no research on the percentile sizing system of human 3D buttock model. So the purpose of this paper is to develop a new method for building three-dimensional buttock percentile model in computer system. After scanning the 3D shape of buttocks, the cloud data of 3D points is imported into the reverse engineering software (Geomagic) for the reconstructing of the buttock surface model. Five characteristic dimensions of the buttock are measured through mark-points after models being imported into engineering software CATIA. A series of space points are obtained by the intersecting of the cutting slices and 3D buttock surface model, and then are ordered based on the sequence number of the horizontal and vertical slices. The 1st, 5th, 50th, 95th, 99th percentile values of the five dimensions and the spatial coordinate values of the space points are obtained, and used to reconstruct percentile buttock models. This research proposes a establishing method of percentile sizing system of buttock 3D model based on the percentile values of the ischial tuberosities diameter, the distances from margin to ischial tuberosity and the space coordinates value of coordinate points, for establishing the Nth percentile 3D buttock model and every special buttock types model. The proposed method also serves as a useful guidance for the other 3D percentile models establishment for other part in human body with characteristic points.

  3. Comparison of daily percentiles of streamflow and rainfall to investigate stream aquifer connectivity

    Brodie, Ross S.; Hostetler, Stephen; Slatter, Emily

    2008-01-01

    SummaryA frequency analysis approach was used to investigate the hydraulic connectivity between streams and aquifers, by comparing daily percentiles of streamflow and rainfall. Three Australian streams were examined - a dominantly gaining stream (Wilsons River, NSW), a dominantly gaining stream modified by significant water extraction (Ovens River, Victoria) and a dominantly losing stream (Mooki River, NSW). For the gaining stream examples, a lag is observed between the seasonal peak in the low-flow percentile curves and the seasonal peak in the daily rainfall percentile curve. Cross-correlation was used to calculate the time-shift that provides the best fit between the streamflow and rainfall percentile curves. There is a good correlation ( r2 > 0.8) between the reference rainfall percentile curve and the shifted streamflow percentile curves for gaining streams. The lags evident between the rainfall and streamflow percentile curves represent the processes of first replenishing catchment storages (such as soil moisture and groundwater) and subsequent release to the stream. This is largely a function of catchment hydrogeology as well as climate, notably the magnitude and regularity of rainfall events. Catchment size is not a controlling factor. Analysis of these lags provides insights into the dynamics of groundwater recharge, storage and release. Changes in the lag times over the flow percentiles can reflect changes in the dominant catchment storage contributing to streamflow. For the Wilsons River, the contribution from a groundwater system with longer flow paths increases at lower flow percentiles. This can be critical when protecting minimum streamflows, as near-stream groundwater flow may not be the only determining factor. The impact of water extraction can be recognised in this analysis. For the Ovens River, streamflow deficits relative to the rainfall percentile curve correspond to the summer period of high irrigation demand. Such a deficit was also observed

  4. Comparison of Per Cent Predicted and Percentile Values for Pulmonary Function Test Interpretation

    Smita Pakhale; Zoheir Bshouty; Marras, Theodore K

    2009-01-01

    BACKGROUND: Pulmonary function tests (PFTs) are commonly interpreted as a fraction of predicted normal values, with an abnormal test often defined as less than 80% or greater than 120% of the predicted value. However, recommendations of the American Thoracic Society/European Respiratory Society suggest using a percentile-based approach to define an abnormal test (less than the fifth or greater than the 95th percentiles).OBJECTIVE: To compare PFT values obtained by the per cent predicted metho...

  5. Analysis of extreme top event frequency percentiles based on fast probability integration

    In risk assessments, a primary objective is to determine the frequency with which a collection of initiating and basic events, Ee leads to some undesired top event, T. Uncertainties in the occurrence rates, xt, assigned to the initiating and basic events cause uncertainty in the top event frequency, zT. The quantification of the uncertainty in zT is an essential part of risk assessment called uncertainty analysis. In the past, it has been difficult to evaluate the extreme percentiles of output variables like zT. Analytic methods such as the method of moments do not provide estimates of output percentiles and the Monte Carlo (MC) method can be used to estimate extreme output percentiles only by resorting to large sample sizes. A promising altemative to these methods is the fast probability integration (FPI) methods. These methods approximate the integrals of multi-variate functions, representing percentiles of interest, without recourse to multi-dimensional numerical integration. FPI methods give precise results and have been demonstrated to be more efficient than MC methods for estimating extreme output percentiles. FPI allows the analyst to choose extreme percentiles of interest and perform sensitivity analyses in those regions. Such analyses can provide valuable insights as to the events driving the top event frequency response in extreme probability regions. In this paper, FPI methods are adapted a) to precisely estimate extreme top event frequency percentiles and b) to allow the quantification of sensitivity measures at these extreme percentiles. In addition, the relative precision and efficiency of alternative methods for treating lognormally distributed inputs is investigated. The methodology is applied to the top event frequency expression for the dominant accident sequence from a risk assessment of Grand Gulf nuclear power plant

  6. CONFERENCES AND SYMPOSIA Commemoration of the 85th birthday of S I Syrovatskii(Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 26 May 2010)

    2010-12-01

    A scientific session of the Physical Sciences Division, Russian Academy of Sciences (RAS), was held on 26 May 2010 at the conference hall of the Lebedev Physical Institute, RAS. The session was devoted to the 85th birthday of S I Syrovatskii. The program announced on the web page of the RAS Physical Sciences Division (www.gpad.ac.ru) contained the following reports: (1) Zelenyi L M (Space Research Institute, RAS, Moscow) "Current sheets and reconnection in the geomagnetic tail"; (2) Frank A G (Prokhorov General Physics Institute, RAS, Moscow) "Dynamics of current sheets as the cause of flare events in magnetized plasmas"; (3) Kuznetsov V D (Pushkov Institute of Terrestrial Magnetism, the Ionosphere, and Radio Wave Propagation, RAS, Troitsk, Moscow region) "Space research on the Sun"; (4) Somov B V (Shternberg Astronomical Institute, Lomonosov Moscow State University, Moscow) "Strong shock waves and extreme plasma states"; (5) Zybin K P (Lebedev Physical Institute, RAS, Moscow) "Structure functions for developed turbulence"; (6) Ptuskin V S (Pushkov Institute of Terrestrial Magnetism, the Ionosphere, and Radio Wave Propagation, RAS, Troitsk, Moscow region) "The origin of cosmic rays." Papers based on reports 1-4 and 6 are published in what follows. • Metastability of current sheets, L M Zelenyi, A V Artemyev, Kh V Malova, A A Petrukovich, R Nakamura Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 933-941 • Dynamics of current sheets underlying flare-type events in magnetized plasmas, A G Frank Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 941-947 • Space research of the Sun, V D Kuznetsov Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 947-954 • Magnetic reconnection in solar flares, B V Somov Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 954-958 • The origin of cosmic rays, V S Ptuskin Physics-Uspekhi, 2010, Volume 53, Number 9, Pages 958-961

  7. Anthropometry of height, weight, arm, wrist, abdominal circumference and body mass index, for Bolivian adolescents 12 to 18 years: Bolivian adolescent percentile values from the MESA study Referencias antropométricas de los adolescentes bolivianos de 12 a 18 años: estatura, peso, circunferencia del brazo, muñeca y abdominal, índice de masa corporal: Percentiles de adolescentes bolivianos (PAB del estudio MESA

    A. Baya Botti

    2009-06-01

    Full Text Available Anthropometry is important as clinical tool for individual follow-up as well as for planning and health policymaking at population level. Recent references of Bolivian Adolescents are not available. The aim of this cross sectional study was to provide age and sex specific centile values and charts of Body Mass Index, height, weight, arm, wrist and abdominal circumference from Bolivian Adolescents. Data from the MEtabolic Syndrome in Adolescents (MESA study was used. Thirty-two Bolivian clusters from urban and rural areas were selected randomly considering population proportions, 3445 school going adolescents, 12 to 18 y, 45% males; 55% females underwent anthropometric evaluation by trained personnel using standardized protocols for all interviews and examinations. Weight, height, wrist, arm and abdominal circumference data were collected. Body Mass Index was calculated. Smoothed age- and gender specific 3rd, 5th, 10th, 25th, 50th, 75th, 85th, 90th, 95th and 97th Bolivian adolescent percentiles(BAP and Charts(BAC where derived using LMS regression. Percentile-based reference data for the antropometrics of for Bolivian Adolescents are presented for the first time.La antropometría es una herramienta clínica importante para el seguimiento individual de los pacientes así como para la planificación de políticas públicas. En Bolivia no existen referencias antropométricas nacionales para adolescentes. El objetivo de este estudio transversal fue de desarrollar percentiles y diagramas de crecimiento para peso, talla, índice de masa corporal, presión arterial sistólica y diastólica, circunferencia de muñeca, brazo y abdominal de adolescentes bolivianos. Los datos antropométricos en el estudio MESA (Síndrome metabólico en adolescentes bolivianos fueron obtenidos a partir de 32 unidades muestrales, considerando proporcionalidad muestral con reposición. Fueron evaluados 3445 adolescentes de 12 a 18, 45% hombres; 55% mujeres, de colegios de

  8. Sensitivity analysis for high percentiles of ochratoxim-a exposure distribution

    Albert, I.; Gauchi, J. P.

    2001-07-01

    High percentile estimations of the exposure to the mycotoxin Ochratoxin-A (OTA) in food, for the French population, were calculated in a previous study by a Monte Carlo type simulation method from real consumption and contamination data. In this paper, from the same data (but only for the children class), we focus on sensitivity analysis (SA) of the high 95 th and 99 th percentiles (the simulation outputs), relatively to the variation of the parameters of the fitted probability density functions (the simulation inputs), necessary for having a relevant and stable estimation of these percentiles. After some preliminary trials, we postulated a quadratic polynomial model and we used an experimental design approach depending on a resolution-V fractional factorial design of 6561 experiments to lead to an optimal estimation of the polynomial model parameters. The factors ranges were established by bootstrap sampling taking into account the consumption dependencies by the Iman and Conover method and, eventually, taking into account the parameter correlation of the fitted probability densities. Finally, we have validated and useful parsimonious polynomial models for each desired percentile showing a major influence of the distribution parameters of the two foods Cereals and Pork, and eventually three with Fruit Juices in the sensitivity of the percentiles. (Author) 7 refs.

  9. Estimation of a monotone percentile residual life function under random censorship.

    Franco-Pereira, Alba M; de Uña-Álvarez, Jacobo

    2013-01-01

    In this paper, we introduce a new estimator of a percentile residual life function with censored data under a monotonicity constraint. Specifically, it is assumed that the percentile residual life is a decreasing function. This assumption is useful when estimating the percentile residual life of units, which degenerate with age. We establish a law of the iterated logarithm for the proposed estimator, and its n-equivalence to the unrestricted estimator. The asymptotic normal distribution of the estimator and its strong approximation to a Gaussian process are also established. We investigate the finite sample performance of the monotone estimator in an extensive simulation study. Finally, data from a clinical trial in primary biliary cirrhosis of the liver are analyzed with the proposed methods. One of the conclusions of our work is that the restricted estimator may be much more efficient than the unrestricted one. PMID:23225621

  10. How much do different ways of calculating percentiles influence the derived performance indicators? - A case study

    Schreiber, Michael

    2013-01-01

    Bibliometric indicators can be determined by comparing specific citation records with the percentiles of a reference set. However, there exists an ambiguity in the computation of percentiles because usually a significant number of papers with the same citation count are found at the border between percentile rank classes. The present case study of the citations to the journal Europhysics Letters (EPL) in comparison with all physics papers from the Web of Science shows the deviations which occur due to the different ways of treating the tied papers in the evaluation of the percentage of highly cited publications. A strong bias can occur, if the papers tied at the threshold number of citations are all considered as highly cited or all considered as not highly cited.

  11. Age-specific percentile-based reference curve of serum procalcitonin concentrations in Japanese preterm infants.

    Fukuzumi, Noriko; Osawa, Kayo; Sato, Itsuko; Iwatani, Sota; Ishino, Ruri; Hayashi, Nobuhide; Iijima, Kazumoto; Saegusa, Jun; Morioka, Ichiro

    2016-01-01

    Procalcitonin (PCT) levels are elevated early after birth in newborn infants; however, the physiological features and reference of serum PCT concentrations have not been fully studied in preterm infants. The aims of the current study were to establish an age-specific percentile-based reference curve of serum PCT concentrations in preterm infants and determine the features. The PCT concentration peaked in infants at 1 day old and decreased thereafter. At 1 day old, serum PCT concentrations in preterm infants <34 weeks' gestational age were higher than those in late preterm infants between 34 and 36 weeks' gestational age or term infants ≥37 weeks' gestational age. Although the 50-percentile value in late preterm and term infants reached the adult normal level (0.1 ng/mL) at 5 days old, it did not in preterm infants. It took 9 weeks for preterm infants to reach it. Serum PCT concentrations at onset in late-onset infected preterm infants were over the 95-percentile value. We showed that the physiological feature in preterm infants was significantly different from that in late preterm infants, even in those <37 weeks' gestational age. To detect late-onset bacterial infection and sepsis, an age-specific percentile-based reference curve may be useful in preterm infants. PMID:27033746

  12. AGE AND GENDER SPECIFIC BMI PERCENTILES ARE LIMITED FOR TRACKING THE CHILDHOOD OBESITY EPIDEMIC

    Purpose: To evaluate pediatric nutrition and physical activity interventions a reliable and feasible way of tracking change in body status is needed. Historically, body mass index (BMI) has been used in adults. BMI percentiles or Z scores, which are theoretically age and gender adjusted, have been...

  13. BMI percentile-for-age overestimates adiposity in early compared with late maturing pubertal children

    Sørensen, Kaspar; Juul, Anders

    2015-01-01

    -groups, P ≤ 0.041) was found with early compared with late maturation, despite similar BIA-estimated body fat percentage (BIA-BF%). Neither BMI nor BIA-BF% differed for a given stage of maturation. BMI percentile-for-age and prevalence of overweight/obesity were higher in the early compared with late...

  14. The substantive and practical significance of citation impact differences between institutions: Guidelines for the analysis of percentiles using effect sizes and confidence intervals

    Williams, Richard; Bornmann, Lutz

    2014-01-01

    In our chapter we address the statistical analysis of percentiles: How should the citation impact of institutions be compared? In educational and psychological testing, percentiles are already used widely as a standard to evaluate an individual's test scores - intelligence tests for example - by comparing them with the percentiles of a calibrated sample. Percentiles, or percentile rank classes, are also a very suitable method for bibliometrics to normalize citations of publications in terms o...

  15. Statewide Analysis of the Drainage-Area Ratio Method for 34 Streamflow Percentile Ranges in Texas

    Asquith, William H.; Roussel, Meghan C.; Vrabel, Joseph

    2006-01-01

    The drainage-area ratio method commonly is used to estimate streamflow for sites where no streamflow data are available using data from one or more nearby streamflow-gaging stations. The method is intuitive and straightforward to implement and is in widespread use by analysts and managers of surface-water resources. The method equates the ratio of streamflow at two stream locations to the ratio of the respective drainage areas. In practice, unity often is assumed as the exponent on the drainage-area ratio, and unity also is assumed as a multiplicative bias correction. These two assumptions are evaluated in this investigation through statewide analysis of daily mean streamflow in Texas. The investigation was made by the U.S. Geological Survey in cooperation with the Texas Commission on Environmental Quality. More than 7.8 million values of daily mean streamflow for 712 U.S. Geological Survey streamflow-gaging stations in Texas were analyzed. To account for the influence of streamflow probability on the drainage-area ratio method, 34 percentile ranges were considered. The 34 ranges are the 4 quartiles (0-25, 25-50, 50-75, and 75-100 percent), the 5 intervals of the lower tail of the streamflow distribution (0-1, 1-2, 2-3, 3-4, and 4-5 percent), the 20 quintiles of the 4 quartiles (0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45, 45-50, 50-55, 55-60, 60-65, 65-70, 70-75, 75-80, 80-85, 85-90, 90-95, and 95-100 percent), and the 5 intervals of the upper tail of the streamflow distribution (95-96, 96-97, 97-98, 98-99 and 99-100 percent). For each of the 253,116 (712X711/2) unique pairings of stations and for each of the 34 percentile ranges, the concurrent daily mean streamflow values available for the two stations provided for station-pair application of the drainage-area ratio method. For each station pair, specific statistical summarization (median, mean, and standard deviation) of both the exponent and bias-correction components of the drainage-area ratio

  16. Menstruation disorders in adolescents with eating disorders ? target body mass index percentiles for their resolution

    Vale, B; De Brito, S.; Paulo, L; Moleiro, P.

    2014-01-01

    Objective To analyse the progression of body mass index in eating disorders and to determine the percentile for establishment and resolution of the disease. Methods A retrospective descriptive cross-sectional study. Review of clinical files of adolescents with eating disorders. Results Of the 62 female adolescents studied with eating disorders, 51 presented with eating disorder not otherwise specified, 10 anorexia nervosa, and 1 bulimia nervosa. Twenty-one of these adolescents had menstrual d...

  17. Relationships between walking and percentiles of adiposity inolder and younger men

    Williams, Paul T.

    2005-06-01

    To assess the relationship of weekly walking distance to percentiles of adiposity in elders (age {ge} 75 years), seniors (55 {le} age <75 years), middle-age men (35 {le} age <55 years), and younger men (18 {le} age <35 years old). Cross-sectional analyses of baseline questionnaires from 7,082 male participants of the National Walkers Health Study. The walkers BMIs were inversely and significantly associated with walking distance (kg/m{sup 2} per km/wk) in elders (slope {+-} SE: -0.032 {+-} 0.008), seniors (-0.045 {+-} 0.005), and middle-aged men (-0.037 {+-} 0.007), as were their waist circumferences (-0.091 {+-} 0.025, -0.045 {+-} 0.005, and -0.091 {+-} 0.015 cm per km/wk, respectively), and these slopes remained significant when adjusted statistically for reported weekly servings of meat, fish, fruit, and alcohol. The declines in BMI associated with walking distance were greater at the higher than lower percentiles of the BMI distribution. Specifically, compared to the decline at the 10th BMI percentile, the decline in BMI at the 90th percentile was 5.1-fold greater in elders, 5.9-fold greater in seniors, and 6.7-fold greater in middle-age men. The declines in waist circumference associated with walking distance were also greater among men with broader waistlines. Exercise-induced weight loss (or self-selection) causes an inverse relationship between adiposity and walking distance in men 35 and older that is substantially greater among fatter men.

  18. Age-specific percentile-based reference curve of serum procalcitonin concentrations in Japanese preterm infants

    Noriko Fukuzumi; Kayo Osawa; Itsuko Sato; Sota Iwatani; Ruri Ishino; Nobuhide Hayashi; Kazumoto Iijima; Jun Saegusa; Ichiro Morioka

    2016-01-01

    Procalcitonin (PCT) levels are elevated early after birth in newborn infants; however, the physiological features and reference of serum PCT concentrations have not been fully studied in preterm infants. The aims of the current study were to establish an age-specific percentile-based reference curve of serum PCT concentrations in preterm infants and determine the features. The PCT concentration peaked in infants at 1 day old and decreased thereafter. At 1 day old, serum PCT concentrations in ...

  19. Estimated monthly percentile discharges at ungaged sites in the Upper Yellowstone River Basin in Montana

    Parrett, Charles; Hull, J.A.

    1986-01-01

    Once-monthly streamflow measurements were used to estimate selected percentile discharges on flow-duration curves of monthly mean discharge for 40 ungaged stream sites in the upper Yellowstone River basin in Montana. The estimation technique was a modification of the concurrent-discharge method previously described and used by H.C. Riggs to estimate annual mean discharge. The modified technique is based on the relationship of various mean seasonal discharges to the required discharges on the flow-duration curves. The mean seasonal discharges are estimated from the monthly streamflow measurements, and the percentile discharges are calculated from regression equations. The regression equations, developed from streamflow record at nine gaging stations, indicated a significant log-linear relationship between mean seasonal discharge and various percentile discharges. The technique was tested at two discontinued streamflow-gaging stations; the differences between estimated monthly discharges and those determined from the discharge record ranged from -31 to +27 percent at one site and from -14 to +85 percent at the other. The estimates at one site were unbiased, and the estimates at the other site were consistently larger than the recorded values. Based on the test results, the probable average error of the technique was + or - 30 percent for the 21 sites measured during the first year of the program and + or - 50 percent for the 19 sites measured during the second year. (USGS)

  20. Percentile Distributions of Birth Weight according to Gestational Ages in Korea (2010-2012).

    Lee, Jin Kyoung; Jang, Hye Lim; Kang, Byung Ho; Lee, Kyung-Suk; Choi, Yong-Sung; Shim, Kye Shik; Lim, Jae Woo; Bae, Chong-Woo; Chung, Sung-Hoon

    2016-06-01

    The Pediatric Growth Chart (2007) is used as a standard reference to evaluate weight and height percentiles of Korean children and adolescents. Although several previous studies provided a useful reference range of newborn birth weight (BW) by gestational age (GA), the BW reference analyzed by sex and plurality is not currently available. Therefore, we aimed to establish a national reference range of neonatal BW percentiles considering GA, sex, and plurality of newborns in Korea. The raw data of all newborns (470,171 in 2010, 471,265 in 2011, and 484,550 in 2012) were analyzed. Using the Korean Statistical Information Service data (2010-2012), smoothed percentile curves (3(rd)-97(th)) by GA were created using the lambda-mu-sigma method after exclusion and the data were distinguished by all live births, singleton births, and multiple births. In the entire cohort, male newborns were heavier than female newborns and singletons were heavier than twins. As GA increased, the difference in BW between singleton and multiples increased. Compared to the previous data published 10 years ago in Korea, the BW of newborns 22-23 gestational weeks old was increased, whereas that of others was smaller. Other countries' data were also compared and showed differences in BW of both singleton and multiple newborns. We expect this updated data to be utilized as a reference to improve clinical assessments of newborn growth. PMID:27247504

  1. Parental Activity as Influence on Childrenˋs BMI Percentiles and Physical Activity

    Erkelenz, Nanette; Kobel, Susanne; Kettner, Sarah; Drenowatz, Clemens; Steinacker, Jürgen M.

    2014-01-01

    Parents play a crucial role in the development of their children’s lifestyle and health behaviour. This study aims to examine associations between parental physical activity (PA) and children’s BMI percentiles (BMIPCT), moderate to vigorous PA (MVPA) as well as participation in organised sports. Height and body weight was measured in 1615 in German children (7.1 ± 0.6 years, 50.3% male) and converted to BMIPCT. Parental BMI was calculated based on self-reported height and body weight. Childre...

  2. Ensemble hydrological prediction of streamflow percentile at ungauged basins in Pakistan

    Waseem, Muhammad; Ajmal, Muhammad; Kim, Tae-Woong

    2015-06-01

    Streamflow records with sufficient spatial and temporal coverage at the site of interest are usually scarce in Pakistan. As an alternative, various regional methods have been frequently adopted to derive hydrological information, which in essence attempt to transfer hydrological information from gauged to ungauged catchments. In this study, a new concept of ensemble hydrological prediction (EHP) was introduced which is an improved regional method for hydrological prediction at ungauged sites. It was mainly based on the performance weights (triple-connection weights (TCW)) derived from Nash Sutcliffe efficiency (NSE) and hydrological variable (here percentiles) calculated from three traditional regional transfer methods (RTMs) with suitable modification (i.e., three-step drainage area ratio (DAR) method, inverse distance weighting (IDW) method, and three-step regional regression analysis (RRA)). The overall results indicated that the proposed EHP method was robust for estimating hydrological percentiles at ungauged sites as compared to traditional individual RTMs. The comparative study based on NSE, percent bias (PBIAS) and the relative error (RE) as performance criteria resulted that the EHP is a constructive alternative for hydrological prediction of ungauged basins.

  3. Speeding Up

    YU SHUJUN

    2010-01-01

    In the wake of the global financial crisis, China has amazed the world with the speed of its economic recovery. But what has been even more surprising is the speed of its railway evolution. The unveiling of the 1,069-km Wuhan-Guangzhou High-speed Railway on December 26, 2009 pushed China's high-speed rail sys-tem-the total mileage, the average speed and the technology-to rank first in the world almost overnight.

  4. Trends in surface wind speed and significant wave height as revealed by ERA-Interim wind wave hindcast in the Central Bay of Bengal

    Shanas, P.R.; SanilKumar, V.

    and waves during the southwest monsoon season. We observed statistically declining trends in the mean and extreme wind speed (90th percentile) with increasing trend in extreme significant wave height (SWH). Seasonal analysis also investigated and found...

  5. The effect of optic disc diameter on vertical cup to disc ratio percentiles in a population based cohort: the Blue Mountains Eye Study

    Crowston, J G; Hopley, C R; Healey, P R; Lee, A.; Mitchell, P

    2004-01-01

    Objective: The 97.5th percentile for vertical cup to disc ratio (VCDR) has been proposed as a useful tool to assist in the diagnosis of glaucoma in population studies. Previous reports of VCDR percentiles have either not been adjusted for disc size or have been calculated by regression analysis from small hospital based cohorts. The authors’ aim was to generate VCDR percentiles in a large, population based sample.

  6. Augmenting BMI and waist-height ratio for establishing more efficient obesity percentiles among school-going children

    Panjikkaran Seeja

    2009-01-01

    Full Text Available Research Questions: 1. Are all the existing methods for estimating the obesity and overweight in school going children in India equally efficient? 2. How to derive more efficient obesity percentiles to determine obesity and overweight status in school-going children aged 7-12 years old? Objectives: 1. To investigate and analyze the prevalence rate of obesity and overweight children in India, using the established standards. 2. To compare the efficiency among the tools with the expected levels in the Indian population. 3. To establish and demonstrate the higher efficiency of the proposed percentile chart. Study Design: A cross-sectional study using a completely randomized design. Settings: Government, private-aided, unaided, and central schools in the Thrissur district of Kerala. Participants: A total of 1500 boys and 1500 girls aged 7-12 years old. Results: BMI percentiles, waist circumference percentiles, and waist to height ratio are the ruling methodologies in establishing the obese and overweight relations in school-going children. Each one suffers from the disadvantage of not considering either one or more of the obesity contributing factors in human growth dynamics, the major being waist circumference and weight. A new methodology for mitigating this defect through considering BMI and waist circumference simultaneously for establishing still efficient percentiles to arrive at obesity and overweight status is detailed here. Age-wise centiles for obesity and overweight status separately for boys and girls aged 7-12 years old were established. Comparative efficiency of this methodology over BMI had shown that this could mitigate the inability of BMI to consider waist circumference. Also, this had the advantage of considering body weight in obesity analysis, which is the major handicap in waist to height ratio. An analysis using a population of 1500 boys and 1500 girls has yielded 3.6% obese and 6.2% overweight samples, which is well within

  7. Inproved grade length limitation of freeways

    XING En-hui; PEI Yu-long

    2006-01-01

    A method of ascertaining grade length limitation of freeways in mountain terrain is presented. The relationship models between 15th percentile speeds and grades were built through the surveys and analyses of operation speeds on 7 typical sections of 3 freeways in mountain terrain. Using 15th percentile and 85th percentile as speed limitations, the methods of determining admitted velocities were put forward according to the grades. Deceleration distances of longitudinal slopeways were analyzed utilizing the theories of vehicle. According to the results of analysis, grade length limitation was loosed. Finally the values of grade length limitation for freeways were put forward. The results could be used as references for freeway design.

  8. To Leonid Viktorovich Sharonov's 85th anniversary (1929-1991

    O. E. Kochneva

    2014-12-01

    Full Text Available Brief review of a course of life, scientific and educational activity of professor, doctor of geological and mineralogical sciences, outstanding scientist Leonid Viktorovich Sharonov is provided.

  9. Parental Activity as Influence on Childrenˋs BMI Percentiles and Physical Activity

    Nanette Erkelenz, Susanne Kobel, Sarah Kettner, Clemens Drenowatz, Jürgen M. Steinacker and the Research Group "Join the Healthy Boat - Primary School"

    2014-09-01

    Full Text Available Parents play a crucial role in the development of their children’s lifestyle and health behaviour. This study aims to examine associations between parental physical activity (PA and children’s BMI percentiles (BMIPCT, moderate to vigorous PA (MVPA as well as participation in organised sports. Height and body weight was measured in 1615 in German children (7.1 ± 0.6 years, 50.3% male and converted to BMIPCT. Parental BMI was calculated based on self-reported height and body weight. Children’s MVPA and sports participation as well as parental PA were assessed via parental questionnaire. Analysis of covariance (ANCOVA, controlling for age and family income was used to examine the association between parental and children’s PA levels as well as BMIPCT. 39.7% of the parents classified themselves as physically active and 8.3% of children were classified as overweight or obese. Lower BMIPCT were observed with both parents being physically active (44.5 ± 26.3 vs. 50.2 ± 26.9 and 52.0 ± 28.4, respectively. There was no association between parental and children’s PA levels but children with at least one active parent displayed a higher participation in organised sports (102.0 ± 96.6 and 117.7 ± 123.6 vs. 73.7 ± 100.0, respectively. Children of active parents were less likely to be overweight and obese. The lack of association between subjectively assessed parental PA and child MVPA suggests that parental support for PA in children is more important than parents being a role model. More active parents, however, may be more likely to facilitate participation in organised sports. These results underline the importance of the inclusion of parents in health promotion and obesity prevention programmes in children.

  10. Measured speed versus true speed

    Perez, Israel

    2010-01-01

    The theoretical predictions, derived from the Lorentz and the Tangherlini transformations, for the one-way speed of any physical entity are confronted with the corresponding expressions for the one-way measured speed obtained from a gedanken experiment. The experiment demonstrates that, for an inertial frame $K'$ in motion relative to an inertial frame $K$ where the one-way speed of light is isotropic, even the special theory of relativity renders the one-way speed of light as function of the...

  11. State Disparities in Time Trends of Adolescent Body Mass Index Percentile and Weight-Related Behaviors in the United States

    Taber, Daniel R.; Stevens, June; Poole, Charles; Maciejewski, Matthew L.; Evenson, Kelly R.; Ward, Dianne S

    2012-01-01

    Evidence is conflicting as to whether youth obesity prevalence has reached a plateau in the United States overall. Trends vary by state, and experts recommend exploring whether trends in weight-related behaviors are associated with changes in weight status trends. Thus, our objective was to estimate between-state variation in time trends of adolescent body mass index (BMI) percentile and weight-related behaviors from 2001 to 2007. A time series design combined cross-sectional Youth Risk Behav...

  12. Percentile Values for Running Sprint Field Tests in Children Ages 6-17 Years: Influence of Weight Status

    Castro-Pinero, Jose; Gonzalez-Montesinos, Jose Luis; Keating, Xiaofen D.; Mora, Jesus; Sjostrom, Michael; Ruiz, Jonatan R.

    2010-01-01

    The aim of this study was to provide percentile values for six different sprint tests in 2,708 Spanish children (1,234 girls) ages 6-17.9 years. We also examined the influence of weight status on sprint performance across age groups, with a focus on underweight and obese groups. We used the 20-m, 30-m, and 50-m running sprint standing start and…

  13. Application of Radial Basis Function Methods in the Development of a 95th Percentile Male Seated FEA Model.

    Vavalle, Nicholas A; Schoell, Samantha L; Weaver, Ashley A; Stitzel, Joel D; Gayzik, F Scott

    2014-11-01

    Human body finite element models (FEMs) are a valuable tool in the study of injury biomechanics. However, the traditional model development process can be time-consuming. Scaling and morphing an existing FEM is an attractive alternative for generating morphologically distinct models for further study. The objective of this work is to use a radial basis function to morph the Global Human Body Models Consortium (GHBMC) average male model (M50) to the body habitus of a 95th percentile male (M95) and to perform validation tests on the resulting model. The GHBMC M50 model (v. 4.3) was created using anthropometric and imaging data from a living subject representing a 50th percentile male. A similar dataset was collected from a 95th percentile male (22,067 total images) and was used in the morphing process. Homologous landmarks on the reference (M50) and target (M95) geometries, with the existing FE node locations (M50 model), were inputs to the morphing algorithm. The radial basis function was applied to morph the FE model. The model represented a mass of 103.3 kg and contained 2.2 million elements with 1.3 million nodes. Simulations of the M95 in seven loading scenarios were presented ranging from a chest pendulum impact to a lateral sled test. The morphed model matched anthropometric data to within a rootmean square difference of 4.4% while maintaining element quality commensurate to the M50 model and matching other anatomical ranges and targets. The simulation validation data matched experimental data well in most cases. PMID:26192960

  14. Height, weight and BMI percentiles and nutritional status relative to the international growth references among Pakistani school-aged children

    Mushtaq Muhammad Umair

    2012-03-01

    Full Text Available Abstract Background Child growth is internationally recognized as an important indicator of nutritional status and health in populations. This study was aimed to compare age- and gender-specific height, weight and BMI percentiles and nutritional status relative to the international growth references among Pakistani school-aged children. Methods A population-based study was conducted with a multistage cluster sample of 1860 children aged five to twelve years in Lahore, Pakistan. Smoothed height, weight and BMI percentile curves were obtained and comparison was made with the World Health Organization 2007 (WHO and United States' Centers for Disease Control and Prevention 2000 (USCDC references. Over- and under-nutrition were defined according to the WHO and USCDC references, and the International Obesity Task Force (IOTF cut-offs. Simple descriptive statistics were used and statistical significance was considered at P Results Height, weight and BMI percentiles increased with age among both boys and girls, and both had approximately the same height and a lower weight and BMI as compared to the WHO and USCDC references. Mean differences from zero for height-, weight- and BMI-for-age z score values relative to the WHO and USCDC references were significant (P Conclusion Pakistani school-aged children significantly differed from the WHO and USCDC references. However, z score means relative to the WHO reference were closer to zero and the present study as compared to the USCDC reference. Overweight and obesity were significantly higher while underweight and thinness/wasting were significantly lower relative to the WHO reference as compared to the USCDC reference and the IOTF cut-offs. New growth charts for Pakistani children based on a nationally representative sample should be developed. Nevertheless, shifting to use of the 2007 WHO child growth reference might have important implications for child health programs and primary care pediatric clinics.

  15. Speed mathematics

    Handley, Bill

    2012-01-01

    This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud

  16. Birth Weight Ratio as an Alternative to Birth Weight Percentile to Express Infant Weight in Research and Clinical Practice: A Nationwide Cohort Study

    Kazemier, Brenda M.; Schuit, Ewoud; Mol, Ben Willem J.; Pajkrt, Eva; Ganzevoort, Wessel

    2014-01-01

    Objective. To compare birth weight ratio and birth weight percentile to express infant weight when assessing pregnancy outcome. Study Design. We performed a national cohort study. Birth weight ratio was calculated as the observed birth weight divided by the median birth weight for gestational age. The discriminative ability of birth weight ratio and birth weight percentile to identify infants at risk of perinatal death (fetal death and neonatal death) or adverse pregnancy outcome (perinatal death + severe neonatal morbidity) was compared using the area under the curve. Outcomes were expressed stratified by gestational age at delivery separate for birth weight ratio and birth weight percentile. Results. We studied 1,299,244 pregnant women, with an overall perinatal death rate of 0.62%. Birth weight ratio and birth weight percentile have equivalent overall discriminative performance for perinatal death and adverse perinatal outcome. In late preterm infants (33+0–36+6 weeks), birth weight ratio has better discriminative ability than birth weight percentile for perinatal death (0.68 versus 0.63, P  0.01) or adverse pregnancy outcome (0.67 versus 0.60, P < 0.001). Conclusion. Birth weight ratio is a potentially valuable instrument to identify infants at risk of perinatal death and adverse pregnancy outcome and provides several advantages for use in research and clinical practice. Moreover, it allows comparison of groups with different average birth weights. PMID:25197283

  17. Glycemic index and glycemic load of thirteen year old children whose waist circumference (WC ≥ 90 percentile dependent on BMI

    Zuzanna Goluch-Koniuszy

    2011-06-01

    Full Text Available Background. One of the reasons for the accumulation of fat tissue (including visceral fat tissue in the body is an unbalanced diet in respect of the amount and the structure of carbohydrates and the value of the glycemic index (GI and the glycemic load (GL. The research describing the dependence between the BMI (Body Mass Index, WC (Waist Circumference, WHtR (Waist-to-Height Ratio, and GI and GL indexes in adults exists but only a limited number of works discuss children during the pubertal spurt. Therefore the objective of this research is the evaluation of the state of nutrition of 13-year-old children with waist circumference ≥ 90 percentile with various BMI, taking into consideration GL and GL of their meals. Material and methods.The state of nutrition (BMI, WC, WHtR of 871 thirteen-year-old children of both sexes was evaluated and 230 children with WC ≥ 90 percentile were selected (26.4% of the total number examined and divided into three groups regarding the BMI. In 71 children (30.9% of the selected group the method of nutrition, energy and nutritive value of menus, structure of consumption of food groups and GI and GL value were evaluated, on the basis of the analysis of their three day menus, which had been documented. Results.Significantly higher values of BMI and WC were ascertained in boys than in girls. No essential differences in values of WHtR index were ascertained between boys and girls. The analysis of children’s menus, in both sexes with a waist circumference ≥ 90 percentile showed, regardless of BMI value, a low realisation of recommended energetic value of the diet and low realisation of recommended supply of: dietary fibre, fat, mineral components (K, Ca, P, Mg, Fe, Zn, Cu, vitamins (E, B1, PP and liquids with simultaneous occurrence of protein in general and animal protein, sodium and vitamins (A, B2, B6 supply. A significantly higher supply of the most of aforementioned ingredients was ascertained in the

  18. Use of percentile rank sum method in identifying repetitive high occupational radiation dose jobs in a nuclear power plant

    The cost-effective reduction of occupational radiation dose (ORD) at a nuclear power plant could not be achieved without going through an extensive analysis of accumulated ORD data of existing plants. Through the data analysis, it is required to identify what are the jobs of repetitive high ORD at the nuclear power plant. In general the point value method commonly used, over-estimates the role of mean and median values to identify the high ORD jobs which can lead to misjudgment. In this study, Percentile Rank Sum Method (PRSM) is proposed to identify repetitive high ORD jobs, which is based on non-parametric statistical theory. As a case study, the method is applied to ORD data of maintenance and repair jobs at Kori units 3 and 4 that are pressurized water reactors with 950 MWe capacity and have been operated since 1986 and 1987, respectively in Korea. The results were verified and validated, and PRSM has been demonstrated to be an efficient method of analyzing the data. (authors)

  19. Percentile Distributions of Median Nitrite Plus Nitrate as Nitrogen, Total Nitrogen, and Total Phosphorus Concentrations in Oklahoma Streams, 1973-2001

    Haggard, Brian E.; Masoner, Jason R.; Becker, Carol J.

    2003-01-01

    Nutrients are one of the primary causes of water-quality impairments in streams, lakes, reservoirs, and estuaries in the United States. The U.S. Environmental Protection Agency has developed regional-based nutrient criteria using ecoregions to protect streams in the United States from impairment. However, nutrient criteria were based on nutrient concentrations measured in large aggregated nutrient ecoregions with little relevance to local environmental conditions in states. The Oklahoma Water Resources Board is using a dichotomous process known as Use Support Assessment Protocols to define nutrient criteria in Oklahoma streams. The Oklahoma Water Resources Board is modifying the Use Support Assessment Protocols to reflect nutrient informa-tion and environmental characteristics relevant to Oklahoma streams, while considering nutrient information grouped by geographic regions based on level III ecoregions and state boundaries. Percentile distributions of median nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorous concentrations were calculated from 563 sites in Oklahoma and 4 sites in Arkansas near the Oklahoma and Arkansas border to facilitate development of nutrient criteria for Oklahoma streams. Sites were grouped into four geographic regions and were categorized into eight stream categories by stream slope and stream order. The 50th percentiles of median nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorus concentrations were greater in the Ozark Highland ecoregion and were less in the Ouachita Mountains ecoregion when compared to other geographic areas used to group sites. The 50th percentiles of median concentrations of nitrite plus nitrate as nitrogen, total nitrogen, and total phosphorus were least in first, second, and third order streams. The 50th percentiles of median nitrite plus nitrate as nitrogen, total nitrogen and total phosphorus concentrations in the Ozark Highland and Ouachita Mountains ecoregions were least in

  20. Dynamic Contrast-Enhanced MRI of Cervical Cancers: Temporal Percentile Screening of Contrast Enhancement Identifies Parameters for Prediction of Chemoradioresistance

    Purpose: To systematically screen the tumor contrast enhancement of locally advanced cervical cancers to assess the prognostic value of two descriptive parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Methods and Materials: This study included a prospectively collected cohort of 81 patients who underwent DCE-MRI with gadopentetate dimeglumine before chemoradiotherapy. The following descriptive DCE-MRI parameters were extracted voxel by voxel and presented as histograms for each time point in the dynamic series: normalized relative signal increase (nRSI) and normalized area under the curve (nAUC). The first to 100th percentiles of the histograms were included in a log-rank survival test, resulting in p value and relative risk maps of all percentile–time intervals for each DCE-MRI parameter. The maps were used to evaluate the robustness of the individual percentile–time pairs and to construct prognostic parameters. Clinical endpoints were locoregional control and progression-free survival. The study was approved by the institutional ethics committee. Results: The p value maps of nRSI and nAUC showed a large continuous region of percentile–time pairs that were significantly associated with locoregional control (p < 0.05). These parameters had prognostic impact independent of tumor stage, volume, and lymph node status on multivariate analysis. Only a small percentile–time interval of nRSI was associated with progression-free survival. Conclusions: The percentile–time screening identified DCE-MRI parameters that predict long-term locoregional control after chemoradiotherapy of cervical cancer.

  1. Which percentile-based approach should be preferred for calculating normalized citation impact values? An empirical comparison of five approaches including a newly developed citation-rank approach (P100)

    L. Bornmann; L. Leydesdorff; J. Wang

    2013-01-01

    For comparisons of citation impacts across fields and over time, bibliometricians normalize the observed citation counts with reference to an expected citation value. Percentile-based approaches have been proposed as a non-parametric alternative to parametric central-tendency statistics. Percentiles

  2. Body Fat Percentile Curves for Korean Children and Adolescents: A Data from the Korea National Health and Nutrition Examination Survey 2009-2010

    Kim, Kirang; Yun, Sung Ha; Jang, Myoung Jin; Oh, Kyung Won

    2013-01-01

    A valid assessment of obesity in children and adolescents is important due to significant change in body composition during growth. This study aimed to develop percentile curves of body fat and fat free mass using the Lambda, Mu, and Sigma method, and to examine the relationship among body mass index (BMI), fat mass and fat free mass in Korean children and adolescents, using the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010. The study subjects were 834 for boys an...

  3. Speeding or not speeding? When subjective assessment of safe, pleasurable and risky speeds determines speeding behaviour

    Florent Lheureux

    2012-01-01

    Full Text Available It is hypothesized that in a given situation speeding behaviour is determined by three subjective speed assessments: the speed perceived as the riskiest, the speed perceived as the safest, and the speed perceived as the most pleasurable. Specifically, if these assessments are high, drivers are expected to circulate faster. Such speed perceptions are also viewed as influenced by attitudes towards speed and speed limits. 177 car drivers, included 102 men and 75 women between 18 and 72 years (M = 43, SD = 21 and with a mean driving experience of 22 years (SD = 19, answered to a questionnaire about their attitudes towards speed and speed limits, the speeds they considered as the riskiest, the safest, and the most pleasurable in three different contexts, as well as their usual speed. Data analyses (ANOVA and path analyses confirmed the influence of the three types of speed assessment on the usual speed and that the influence of attitudes on this behaviour is mediated by these three assessments. Results suggest that not only a change in attitudes and beliefs is desirable, but a concrete specification (e.g., 100 Km/h of speeds perceived as safe, pleasurable and risky is also needed in order to reduce speeding behaviour.

  4. Measures for speed management.

    2009-01-01

    Measures for speed management are essential for limiting the negative effects of driving too fast and at inappropriate speeds. To begin with, safe and credible speed limits need to be determined. Dynamic and variable speed limits that take into account the current circumstances, such as weather cond

  5. Speed and income

    Fosgerau, Mogens

    2005-01-01

    The relationship between speed and income is established in a microeconomic model focusing on the trade-off between travel time and the risk of receiving a penalty for exceeding the speed limit. This is used to determine when a rational driver will choose to exceed the speed limit. The relationship...... between speed and income is found again in the empirical analysis of a cross-sectional dataset comprising 60,000 observations of car trips. This is used to perform regressions of speed on income, distance travelled, and a number of controls. The results are clearly statistically significant and indicate...... an average income elasticity of speed of 0.02; it is smaller at short distances and about twice as large at the longest distance investigated of 200 km....

  6. 46 CFR 154.1864 - Vessel speed within speed reduction.

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vessel speed within speed reduction. 154.1864 Section... Vessel speed within speed reduction. The master shall ensure that the speed of the vessel is not greater than the posted speed reduction....

  7. Generation of a head phantom according to the 95. percentile Chinese population data for evaluating the specific absorption rate by wireless communication devices

    A Chinese head phantom (CHP) is constructed for evaluating the specific absorption rate (SAR) by the wireless transceivers. The dimensions of the head phantom are within 4 % difference compared with the 95. percentile data from the China's standard. The shell's thickness and the configuration of the pinna are the same as those of the specific anthropomorphic mannequin (SAM). Three computable models for the mobile phones are generated and used in the SAR simulations with the SAM and the CHP. The results show that the simulated SAR from the SAM head is similar. Its morphological reason has been analysed. The authors discuss the conservativeness of the two head phantoms as well. The CHP can be used in the inter-laboratory evaluation for the SAR uncertainty. It can also provide the information for the SAR variability due to physical difference, which will benefit the maintenance and the harmonisation of the standards. (authors)

  8. More Than Just Speed

    2011-01-01

    The 1,318-km Beijing-Shanghai High-Speed Railway will finally come into operation at the end of June.Since construction began three years ago,the speedy railway has grabbed worldwide attention because of its design as the world’s longest and fastesthigh-speed rail line utilizing the most advanced technology.

  9. Speed enforcement in Norway

    Elvik, Rune

    2015-01-01

    This paper probes the relationship between changes in the risk of apprehension for speeding in Norway and changes in the amount of speeding. The paper is based on a game-theoretic model of how the rate of violations and the amount of enforcement is determined by the interaction between drivers and...

  10. First and second order Markov chain models for synthetic generation of wind speed time series

    Hourly wind speed time series data of two meteorological stations in Malaysia have been used for stochastic generation of wind speed data using the transition matrix approach of the Markov chain process. The transition probability matrices have been formed using two different approaches: the first approach involves the use of the first order transition probability matrix of a Markov chain, and the second involves the use of a second order transition probability matrix that uses the current and preceding values to describe the next wind speed value. The algorithm to generate the wind speed time series from the transition probability matrices is described. Uniform random number generators have been used for transition between successive time states and within state wind speed values. The ability of each approach to retain the statistical properties of the generated speed is compared with the observed ones. The main statistical properties used for this purpose are mean, standard deviation, median, percentiles, Weibull distribution parameters, autocorrelations and spectral density of wind speed values. The comparison of the observed wind speed and the synthetically generated ones shows that the statistical characteristics are satisfactorily preserved

  11. Iowa Senate District Boundaries for 2013 - 2022_85th - 89th General Assemblies

    Iowa State University GIS Support and Research Facility — This coverage contains polygons representing the Iowa Senate district boundaries for the years 2012-2021. These boundaries were created by redistricting after the...

  12. Percentile values for aerobic performance running/walking field tests in children aged 6 to 17 years: influence of weight status Valores de percentiles de los tests de campo de capacidad aeróbica en niños de 6 a 17 años: influencia del peso corporal

    J. Castro-Piñero

    2011-06-01

    Full Text Available The aim of this study was to provide percentiles values for four different aerobic performance tests in 2752 (1,261 girls Spanish children aged 6 to 17.9 years. Aerobic performance was assessed by the shuttle run test (20mSRT, 1-mile, 1/2-mile and 1/4-mile run/walk tests. Height and weight were measured, and body mass index was calculated. Boys had significantly better score than girls in the studied tests in all age groups, except in 1/4-mile test in 6-7 year old children. Underweight children had similar performance than their normalweight counterparts, and underweight boys had better performance than their obese counterparts. Overweight and obese children had lower performance than their normalweight counterparts. Having percentile values of the most used field tests to measure aerobic performance in youth may help to identify children and adolescents at risk for the major chronic diseases, as well as to evaluate the effects of alternative interventions.El propósito de este estudio fue proporcionar los valores de percentiles para cuatro pruebas de rendimiento aeróbico en 2752 (1261 chicas niños españoles con edades de 6 a 17,9 años. El rendimiento aeróbico se evalúo mediante la carrera durante 20 minutos (20mSRT, y las pruebas de correr / caminar 1 milla, ½ milla y ¼ de milla. Se midieron el peso y la talla y se calculó el índice de masa corporal. Los chicos tuvieron puntuaciones significativamente mejores que las chicas en las pruebas evaluadas y para todos los grupos de edad, excepto en la prueba de ¼ de milla en el grupo de 6-7 años. Los niños con peso bajo mostraron un rendimiento similar a sus homólogos con peso normal y los primeros tuvieron un rendimiento mejor que sus homólogos obesos. Los niños obesos y con sobrepeso tuvieron un menor rendimiento que sus homólogos con peso normal. El disponer de valores de percentiles para las pruebas empleadas más habitualmente para evaluar el rendimiento aeróbico en los j

  13. High-Speed Photography

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) copyright 1998 Society of Photo-Optical Instrumentation Engineers

  14. High-Speed Photography

    Paisley, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Schelev, M.Y. [General Physics Institute, Moscow (Russia)

    1998-08-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) {copyright} {ital 1998 Society of Photo-Optical Instrumentation Engineers.}

  15. Wind_Speeds_Master

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set included wind speeds for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came from...

  16. Speeding up Transportation

    2007-01-01

    @@ 2007 was an excellent year for the transportation industry, marked by high speed railway transportation, development of the national expressway network and launch of the Chang'e lunar probe satellite.

  17. High speed data acquisition

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab

  18. High speed data acquisition

    Cooper, P.S.

    1997-07-01

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab.

  19. High Speed Economy

    Vadim Dumitrascu; Roxana Arabela Dumitrascu

    2013-01-01

    The use of knowledge in business opens vast possibilities for the spectacular intensification of the rhythms of the processes of economic value creation. High speeds are a fundamental feature of the knowledge economy. The sources of high speeds in business are certain economic, technological and commercial processes with the nature of some positive feedbacks. What generates it is the organization of knowledge in the form of networks. The organizations competitiveness is marked by the ability ...

  20. Police enforcement and driving speed.

    2008-01-01

    Speed limits are violated frequently in the Netherlands. As speed is an important factor in road crashes, the surveillance of driving speeds is one of the spearheads in the policy plans of the Dutch police. Different methods of speed enforcement have proved to be effective in reducing speed and cras

  1. Paranasal sinuses in children: size evaluation of maxillary, sphenoid, and frontal sinuses by magnetic resonance imaging and proposal of volume index percentile curves

    Our objective was to establish the age-related 3D size of maxillary, sphenoid, and frontal sinuses. A total of 179 magnetic resonance imaging (MRI) of children under 17 years (76 females, 103 males) were included and sinuses were measured in the three axes. Maxillary sinuses measured at birth (mean±standard deviation) 7.3±2.7 mm length (or antero-posterior)/4.0±0.9 mm height (or cranio-caudal)/2.7±0.8 mm width (or transverse). At 16 years old, maxillary sinus measured 38.8±3.5 mm/36.3±6.2 mm/27.5±4.2 mm. Sphenoid sinus pneumatization starts in the third year of life after conversion from red to fatty marrow with mean values of 5.8±1.4 mm/8.0±2.3 mm/5.8±1.0 mm. Pneumatization progresses gradually to reach at 16 years 23.0±4.5 mm/22.6±5.8 mm/12.8±3.1 mm. Frontal sinuses present a wide variation in size and most of the time are not valuable with routine head MRI techniques. They are not aerated before the age of 6 years. Frontal sinuses dimensions at 16 years were 12.8±5.0 mm/21.9±8.4 mm/24.5±13.3 mm. A sinus volume index (SVI) of maxillary and sphenoid sinus was computed using a simplified ellipsoid volume formula, and a table with SVI according to age with percentile variations is proposed for easy clinical application. Percentile curves of maxillary and sphenoid sinuses are presented to provide a basis for objective determination of sinus size and volume during development. These data are applicable to other techniques such as conventional X-ray and CT scan. (orig.)

  2. Standing adult human phantoms based on 10th, 50th and 90th mass and height percentiles of male and female Caucasian populations

    Cassola, V. F.; Milian, F. M.; Kramer, R.; de Oliveira Lira, C. A. B.; Khoury, H. J.

    2011-07-01

    Computational anthropomorphic human phantoms are useful tools developed for the calculation of absorbed or equivalent dose to radiosensitive organs and tissues of the human body. The problem is, however, that, strictly speaking, the results can be applied only to a person who has the same anatomy as the phantom, while for a person with different body mass and/or standing height the data could be wrong. In order to improve this situation for many areas in radiological protection, this study developed 18 anthropometric standing adult human phantoms, nine models per gender, as a function of the 10th, 50th and 90th mass and height percentiles of Caucasian populations. The anthropometric target parameters for body mass, standing height and other body measures were extracted from PeopleSize, a well-known software package used in the area of ergonomics. The phantoms were developed based on the assumption of a constant body-mass index for a given mass percentile and for different heights. For a given height, increase or decrease of body mass was considered to reflect mainly the change of subcutaneous adipose tissue mass, i.e. that organ masses were not changed. Organ mass scaling as a function of height was based on information extracted from autopsy data. The methods used here were compared with those used in other studies, anatomically as well as dosimetrically. For external exposure, the results show that equivalent dose decreases with increasing body mass for organs and tissues located below the subcutaneous adipose tissue layer, such as liver, colon, stomach, etc, while for organs located at the surface, such as breasts, testes and skin, the equivalent dose increases or remains constant with increasing body mass due to weak attenuation and more scatter radiation caused by the increasing adipose tissue mass. Changes of standing height have little influence on the equivalent dose to organs and tissues from external exposure. Specific absorbed fractions (SAFs) have also

  3. Standing adult human phantoms based on 10th, 50th and 90th mass and height percentiles of male and female Caucasian populations

    Computational anthropomorphic human phantoms are useful tools developed for the calculation of absorbed or equivalent dose to radiosensitive organs and tissues of the human body. The problem is, however, that, strictly speaking, the results can be applied only to a person who has the same anatomy as the phantom, while for a person with different body mass and/or standing height the data could be wrong. In order to improve this situation for many areas in radiological protection, this study developed 18 anthropometric standing adult human phantoms, nine models per gender, as a function of the 10th, 50th and 90th mass and height percentiles of Caucasian populations. The anthropometric target parameters for body mass, standing height and other body measures were extracted from PeopleSize, a well-known software package used in the area of ergonomics. The phantoms were developed based on the assumption of a constant body-mass index for a given mass percentile and for different heights. For a given height, increase or decrease of body mass was considered to reflect mainly the change of subcutaneous adipose tissue mass, i.e. that organ masses were not changed. Organ mass scaling as a function of height was based on information extracted from autopsy data. The methods used here were compared with those used in other studies, anatomically as well as dosimetrically. For external exposure, the results show that equivalent dose decreases with increasing body mass for organs and tissues located below the subcutaneous adipose tissue layer, such as liver, colon, stomach, etc, while for organs located at the surface, such as breasts, testes and skin, the equivalent dose increases or remains constant with increasing body mass due to weak attenuation and more scatter radiation caused by the increasing adipose tissue mass. Changes of standing height have little influence on the equivalent dose to organs and tissues from external exposure. Specific absorbed fractions (SAFs) have also

  4. Standing adult human phantoms based on 10th, 50th and 90th mass and height percentiles of male and female Caucasian populations

    Cassola, V F; Kramer, R; De Oliveira Lira, C A B; Khoury, H J [Department of Nuclear Energy, Federal University of Pernambuco, Avenida Professor Luiz Freire, 1000, CEP 50740-540, Recife, PE (Brazil); Milian, F M, E-mail: rkramer@uol.com.br [Department of Exact Science and Technology, State University of Santa Cruz, Campus Soane Nazare de Andrade, Km 16 Rodovia Ilheus-Itabuna, CEP 45662-000, Ilheus, BA (Brazil)

    2011-07-07

    Computational anthropomorphic human phantoms are useful tools developed for the calculation of absorbed or equivalent dose to radiosensitive organs and tissues of the human body. The problem is, however, that, strictly speaking, the results can be applied only to a person who has the same anatomy as the phantom, while for a person with different body mass and/or standing height the data could be wrong. In order to improve this situation for many areas in radiological protection, this study developed 18 anthropometric standing adult human phantoms, nine models per gender, as a function of the 10th, 50th and 90th mass and height percentiles of Caucasian populations. The anthropometric target parameters for body mass, standing height and other body measures were extracted from PeopleSize, a well-known software package used in the area of ergonomics. The phantoms were developed based on the assumption of a constant body-mass index for a given mass percentile and for different heights. For a given height, increase or decrease of body mass was considered to reflect mainly the change of subcutaneous adipose tissue mass, i.e. that organ masses were not changed. Organ mass scaling as a function of height was based on information extracted from autopsy data. The methods used here were compared with those used in other studies, anatomically as well as dosimetrically. For external exposure, the results show that equivalent dose decreases with increasing body mass for organs and tissues located below the subcutaneous adipose tissue layer, such as liver, colon, stomach, etc, while for organs located at the surface, such as breasts, testes and skin, the equivalent dose increases or remains constant with increasing body mass due to weak attenuation and more scatter radiation caused by the increasing adipose tissue mass. Changes of standing height have little influence on the equivalent dose to organs and tissues from external exposure. Specific absorbed fractions (SAFs) have also

  5. The Factor Structure, Predictors, and Percentile Norms of the Center for Epidemiologic Studies Depression (CES-D Scale in the Dutch-speaking Adult Population of Belgium

    Qian Wu

    2016-01-01

    Full Text Available The Center of Epidemiologic Studies Depression Scale (CES-D is a commonly used self-report scale to measure depressive symptoms in the general population. In the present study, the Dutch version of the CES-D was administered to a sample of 837 Dutch-speaking adults of Belgium to examine the factor structure of the scale. Using confirmatory factory analysis (CFA, four first-order models and two second-order models were tested, and the second-order factor model with three pairs of correlated error terms provided the best fit to the data. Second, five socio-demographic variables (age, gender, education level, relation status, and family history of depression were included as covariates to the second-order factor model to explore the associations between background characteristics and the latent factor depression using a multiple indicators and multiple causes (MIMIC approach. Age had a significantly negative effect on depression, but the effect was not substantial. Female gender, lower education level, being single or widowed, and having a family history of depression were found to be significant predictors of higher levels of depression symptomatology. Finally, percentile norms on the CES-D raw scores were provided for subgroups of gender by education level for the general Dutch-speaking adult population of Belgium.

  6. Effect of Anatomical Modeling on Space Radiation Dose Estimates: A Comparison of Doses for NASA Phantoms and 5th, 50th, and 95th Percentile UF Hybrid Phantoms

    Bahadori, A.; VanBaalen, M.; Shavers, M.; Semones, E.; Dodge, C.; Bolch, W.

    2010-01-01

    The estimate of absorbed dose to individual organs of a space crewmember is affected by the geometry of the anatomical model of the astronaut used in the radiation transport calculation. For astronaut dosimetry, NASA currently uses the computerized anatomical male (CAM) and computerized anatomical female (CAF) stylized phantoms to represent astronauts in its operational radiation dose analyses. These phantoms are available in one size and in two body positions. In contrast, the UF Hybrid Adult Male and Female (UFHADM and UFHADF) phantoms have organ shapes based on actual CT data. The surfaces of these phantoms are defined by non-uniform rational B-spline surfaces, and are thus flexible in terms of body morphometry and extremity positioning. In this study, UFHADM and UFHADF are scaled to dimensions corresponding to 5th, 50th, and 95th percentile (PCTL) male and female astronauts. A ray-tracing program is written in Visual Basic 2008, which is then used to create areal density maps for dose points corresponding to various organs within the phantoms. The areal density maps, along with appropriate space radiation spectra, are input into the NASA program couplet HZETRN/BRYNTRN, and organ doses are calculated. The areal density maps selected tissues and organs of the 5th, 50th, and 95th PCTL male and female phantoms are presented and compared. In addition, the organ doses for the 5th, 50th, and 95th PCTL male and female phantoms are presented and compared to organ doses for CAM and CAF.

  7. Variable Speed Rotor System Project

    National Aeronautics and Space Administration — Variable speed rotors will give helicopters several advantages: higher top speed, greater fuel efficiency, momentary emergency over-power, resonance detuning...

  8. High speed photography

    Slemc, Tadej

    2010-01-01

    The main purpose of photography is to capture a moment in time and transfer the captured information onto the photographic paper. High speed photography is a photography technique in which parts of a very fast phenomenon are being captured. A phenomenon, which usually happens too fast to be captured by the human eye. An example of such is contact of a water drop with another surface. A person is capable to register the contact, but it is only by means of the high speed photography that one is...

  9. Cloud speed sensor

    V. Fung

    2013-10-01

    Full Text Available Changing cloud cover is a major source of solar radiation variability and poses challenges for the integration of solar energy. A compact and economical system that measures cloud motion vectors to estimate power plant ramp rates and provide short term solar irradiance forecasts is presented. The Cloud Speed Sensor (CSS is constructed using an array of luminance sensors and high-speed data acquisition to resolve the progression of cloud passages across the sensor footprint. An embedded microcontroller acquires the sensor data and uses a cross-correlation algorithm to determine cloud motion vectors. The CSS was validated against an artificial shading test apparatus, an alternative method of cloud motion detection from ground measured irradiance (Linear Cloud Edge, LCE, and a UC San Diego Sky Imager (USI. The CSS detected artificial shadow directions and speeds to within 15 and 6% accuracy, respectively. The CSS detected (real cloud directions and speeds without average bias and with average weighted root mean square difference of 22° and 1.9 m s−1 when compared to USI and 33° and 1.5 m s−1 when compared to LCE results.

  10. Variable speed generators

    Boldea, Ion

    2005-01-01

    With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

  11. High Speed Network Sampling

    2005-01-01

    Abstract Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

  12. Speed mathematics simplified

    Stoddard, Edward

    1994-01-01

    Entertaining, easy-to-follow suggestions for developing greater speed and accuracy in doing mathematical calculations. Surefire methods for multiplying without carrying, dividing with half the pencil work of long division, plus advice on how to add and subtract rapidly, master fractions, work quickly with decimals, handle percentages, and much more.

  13. More Than Just Speed

    2008-01-01

    Following more than 10 years of deliberation and planning,construc- tion of the 1,320-km Beijing-Shanghai High-speed Railway began in mid- April.Following the world’s most elevated Qinghai-Tibet Railway,which

  14. Speeding Up Innovation

    Sørensen, Flemming; Mattsson, Jan

    2016-01-01

    Minimisation of time-to-market strategies can provide companies with a competitive advantage in dynamic and competitive environments. Using parallel innovation processes has been emphasised as one strategy to speed up innovation processes and consequently minimise the time-to-market of innovations...

  15. High speed network sampling

    2010-01-01

    Abstract Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

  16. Comparison of measured and simulated wind speed data in the North Atlantic

    Winterfeldt, J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Kuestenforschung

    2008-11-06

    they are assimilated into the reanalysis or not. For open ocean areas no value added to the reanalysis forcing is found by the use of the RCMs neither for instantaneous wind speed nor its frequency distribution. The RCMs add value in the wind speed frequency distribution in coastal areas, especially for higher wind speed percentiles. In case of rough coastal areas with a complex orography added value is indicated also in the instantaneous wind speeds. In comparison to the unnudged simulation the spectrally nudged simulations better represent both observed instantaneous wind speed and its frequency distribution. An influence of the observations' assimilation status on these findings can not be seen. (orig.)

  17. Speed-calming measures and their Effect on driving speed

    Agerholm, Niels; Knudsen, Daniel; Variyeswaran, Kajan

    2016-01-01

    Speeding increases the risk and severity of accidents, especially for vulnerable road users. Hence, minimisation of speeding in built-up areas is vital. Some countries widely use speed-calming measures (SCs). Documentation shows that SCs reduce speeding considerably although various types and...... designs of SCs affect this reduction. This paper includes studies of the effects from establishment of sinus speed humps of height 10 cm and length 950 cm and chicanes (with a free carriageway width of 5,30 cm and a length between the 0.5 m wide obstacles of 18 m) as a before/after study where the speed....... Despite the apparent absence of more distant effects of each SC, there is an overall reduced average speed on the full length of a road with SCs. Humps reduce the mean speed comparable to the reduction from chicanes, but the speed variation is less reduced near chicanes, and especially prior to the...

  18. Role of Age, Gender and Education in Information Processing Speed

    Martina Knežević

    2015-07-01

    Full Text Available Letter Digit Substitution Test (LDST is based on earlier developed substitution tests – the Wechsler's Digit Symbol Substitution Test (DSST and the Symbol Digit Modalities Test (SDMT. The performance on these tests depends on many different cognitive processes, including visual scanning, mental flexibility, sustained attention, psychomotor speed, and the speed of information processing. The LDST consists of "over-learned" signs – letters and digits – and participants only have to learn the letter-digit association, which makes performance relatively less dependent on memory and complex visual processes than it is in the DSST or SDMT. The aim of this study was to investigate to what extent age, sex, level of education of the participants and level of education of their parents influence LDST performance. A total of 334 participants (191 females aged 18-25 years were included in the study. Females and higher-level educated participants outperformed males and lower-level educated participants. Parents educational level only indirectly influenced the performance on the LDST, possibly through the participants level of education. Additionally, we derived normative data for the LDST for the ages between 18 and 25 years. Normative data in percentiles and z-values for the ages 18 to 25 years are presented, according to sex and level of education, which is compatible with and supplements the previously reported norms in other studies.

  19. Improving speed behaviour : the potential of in-car speed assistance and speed limit credibility.

    Nes, C.N. van Houtenbos, M. & Schagen, I.N.L.G. van

    2009-01-01

    Speeding is still a common practice on many roads and it contributes to a significant number of crashes. Two new approaches to solve speeding issues are focused on: intelligent speed assistance systems (ISA) and speed limit credibility. Research has indicated that ISA is promising with respect to im

  20. Constant Speed Ramps

    Perdomo, Oscar M

    2013-01-01

    In this paper we show all possible ramps where an object can move with constant speed under the effect of gravity and friction. The planar ramp are very easy to describe, just rotate a curve with velocity vector (tanh(as),sech(as)). Recall that tanh(as)^2+sech^2(as) = 1. Therefore, the solution of the planar constant speed problem is connected with easy to describe examples of curves with arc-length parameter. For ramps in the space, we show that there are as many ramps as tangent unit vector fields in the south hemisphere. A video explaining these results can be found at http://www.youtube.com/watch?v=iBrvbb0efVk

  1. High speed door assembly

    Shapiro, C.

    1991-12-31

    This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  2. The Relation of Speeded and Unspeeded Reasoning with Mental Speed.

    Wilhelm, Oliver; Schulze, Ralf

    2002-01-01

    Studied the contribution of mental speed to task performance on reasoning tasks under timed and untimed conditions for 227 participants and for 90 participants working under time conditions. Results suggest that the use of speeded reasoning tests is likely to lead to overestimates of the relation between mental speed and reasoning ability. (SLD)

  3. Fourth-grade children’s dietary recall accuracy for energy intake at school meals differs by social desirability and body mass index percentile in a study concerning retention interval

    Guinn, Caroline H.; Baxter, Suzanne D.; Royer, Julie A.; Hardin, James W.; Mackelprang, Alyssa J.; Smith, Albert F.

    2010-01-01

    Data from a study concerning retention interval and school-meal observation on children’s dietary recalls were used to investigate relationships of social desirability score (SDS) and body mass index percentile (BMI%) to recall accuracy for energy for observed (n=327) children, and to reported energy for observed and unobserved (n=152) children. Report rates (reported/observed) correlated negatively with SDS and BMI%. Correspondence rates (correctly reported/observed) correlated negatively wi...

  4. Using Microsoft Excel to compute the 5% overall site X/Q value and the 95th percentile of the distribution of doses to the nearest maximally exposed offsite individual (MEOI).

    Vickers, Linda D

    2010-05-01

    This paper describes the method using Microsoft Excel (Microsoft Corporation One Microsoft Way Redmond, WA 98052-6399) to compute the 5% overall site X/Q value and the 95th percentile of the distribution of doses to the nearest maximally exposed offsite individual (MEOI) in accordance with guidance from DOE-STD-3009-1994 and U.S. NRC Regulatory Guide 1.145-1982. The accurate determination of the 5% overall site X/Q value is the most important factor in the computation of the 95th percentile of the distribution of doses to the nearest MEOI. This method should be used to validate software codes that compute the X/Q. The 95th percentile of the distribution of doses to the nearest MEOI must be compared to the U.S. DOE Evaluation Guide of 25 rem to determine the relative severity of hazard to the public from a postulated, unmitigated design basis accident that involves an offsite release of radioactive material. PMID:20386192

  5. Safe Speeds and Credible Speed Limits (SaCredSpeed): New Vision for Decision Making on Speed Management.

    Aarts, L. Nes, N. van Wegman, F.C.M. Schagen, I.N.L.G. van & Louwerse, R.

    2009-01-01

    Speed is an inherent characteristic of mobility and a hazard to safety. Several approaches exist of how to manage speed. In the Netherlands, the emphasis has mainly been on harm minimisation during the last decades, due to the implementation of the Sustainable Safety vision. Speed management remains

  6. Pay as You Speed, ISA with incentive for not speeding

    Lahrmann, Harry; Agerholm, Niels; Tradisauskas, Nerius;

    2012-01-01

    To simulate a market introduction of Intelligent Speed Adaptation (ISA) and to study the effect of a Pay as You Speed (PAYS) concept, a field trial with 153 drivers was conducted during 2007–2009. The participants drove under PAYS conditions for a shorter or a longer period. The PAYS concept...... consisted of informative ISA linked with economic incentive for not speeding, measured through automatic count of penalty points whenever the speed limit was exceeded. The full incentive was set to 30% of a participant's insurance premium. The participants were exposed to different treatments, with and...... without incentive crossed with informative ISA present or absent. The results showed that ISA is an efficient tool for reducing speeding particularly on rural roads. The analysis of speed data demonstrated that the proportion of distance driven above the speed where the ISA equipment responded (PDA) was a...

  7. Speed Limits for Entanglement

    Hartman, Thomas

    2015-01-01

    We show that in any relativistic system, entanglement entropy obeys a speed limit set by the entanglement in thermal equilibrium. The bound is derived from inequalities on relative entropy with respect to a thermal reference state. Thus the thermal state constrains far-from-equilibrium entanglement dynamics whether or not the system actually equilibrates, in a manner reminiscent of fluctuation theorems in classical statistical mechanics. A similar shape-dependent bound constrains the full nonlinear time evolution, supporting a simple physical picture for entanglement propagation that has previously been motivated by holographic calculations in conformal field theory. We discuss general quantum field theories in any spacetime dimension, but also derive some results of independent interest for thermal relative entropy in 1+1d CFT.

  8. In situ local shock speed and transit shock speed

    S. Watari

    Full Text Available A useful index for estimating the transit speeds was derived by analyzing interplanetary shock observations. This index is the ratio of the in situ local shock speed and the transit speed; it is 0.6–0.9 for most observed shocks. The local shock speed and the transit speed calculated for the results of the magnetohydrodynamic simulation show good agreement with the observations. The relation expressed by the index is well explained by a simplified propagation model assuming a blast wave. For several shocks the ratio is approximately 1.2, implying that these shocks accelerated during propagation in slow-speed solar wind. This ratio is similar to that for the background solar wind acceleration.

    Keywords. Interplanetary physics (Flare and stream dynamics; Interplanetary shocks; Solar wind plasma

  9. Non-intrusive speed sensor

    Wyett, L.

    1986-01-01

    In Phase I of the Non-Intrusive Speed Sensor program, a computerized literature search was performed to identify candidate technologies for remote, non-intrusive speed sensing applications in Space Shuttle Main Engine (SSME) turbopumps. The three most promising technologies were subjected to experimental evaluation to quantify their performance characteristics under the harsh environmental requirements within the turbopumps. Although the infrared and microwave approaches demonstrated excellent cavitation immunity in laboratory tests, the variable-source magnetic speed sensor emerged as the most viable approach. Preliminary design of this speed sensor encountered no technical obstacles and resulted in viable and feasible speed nut, sensor housing, and sensor coil designs. Phase II of this program developed the variable-source magnetic speed sensor through the detailed design task and guided the design into breadboard fabrication. The speed sensor and its integral speed nut were evaluated at both unit and system level testing. The final room-temperature and cryogenic spin testing of the hardware demonstrated that the sensor was capable of generating sufficient output signal to enable remote speed sensing from 1500 to 40000 rpm over a speed nut/sensor separation of 3.5 inches.

  10. High-speed AC motors

    Jokinen, T.; Arkkio, A. [Helsinki University of Technology Laboratory of Electromechanics, Otaniemi (Finland)

    1997-12-31

    The paper deals with various types of highspeed electric motors, and their limiting powers. Standard machines with laminated rotors can be utilised if the speed is moderate. The solid rotor construction makes it possible to reach higher power and speed levels than those of laminated rotors. The development work on high-speed motors done at Helsinki University of Technology is presented, too. (orig.) 12 refs.

  11. High-Speed Schlieren Movies of Decelerators at Supersonic Speeds

    1960-01-01

    High-Speed Schlieren Movies of Decelerators at Supersonic Speeds. Tests were conducted on several types of porous parachutes, a paraglider, and a simulated retrorocket. Mach numbers ranged from 1.8-3.0, porosity from 20-80 percent, and camera speeds from 1680-3000 feet per second (fps) in trials with porous parachutes. Trials of reefed parachutes were conducted at Mach number 2.0 and reefing of 12-33 percent at camera speeds of 600 fps. A flexible parachute with an inflatable ring in the periphery of the canopy was tested at Reynolds number 750,000 per foot, Mach number 2.85, porosity of 28 percent, and camera speed of 36oo fps. A vortex-ring parachute was tested at Mach number 2.2 and camera speed of 3000 fps. The paraglider, with a sweepback of 45 degrees at an angle of attack of 45 degrees was tested at Mach number 2.65, drag coefficient of 0.200, and lift coefficient of 0.278 at a camera speed of 600 fps. A cold air jet exhausting upstream from the center of a bluff body was used to simulate a retrorocket. The free-stream Mach number was 2.0, free-stream dynamic pressure was 620 lb/sq ft, jet-exit static pressure ratio was 10.9, and camera speed was 600 fps. [Entire movie available on DVD from CASI as Doc ID 20070030973. Contact help@sti.nasa.gov

  12. Models of Speed Discrimination

    1997-01-01

    visual search for the detection of speed deviation. 2. Perception of moving objects. 3. Exploring the role of eye movements in various visual tasks.

  13. How to Improve Reading Speed

    王仲亮

    2008-01-01

    @@ It is well known that reading plays an important role not only in our daily life but also in learning a foreign language.And,of course,reading depends on reading speed to some degree.So it is natural that it is important to improve reading speed.

  14. When is speed a problem?.

    Wesemann, P.

    1986-01-01

    It is relatively useless to make pronouncements on what, in certain circumstances, is a safe driving speed for road users; it is interesting, however, to indicate what is an optimum speed from the social point of view, after weighing up the various pros and cons, including safety. Ultimately this is

  15. NTF – wind speed comparison

    Vesth, Allan; Gómez Arranz, Paula

    The report describes measurements carried out on a given turbine. A comparison between wind speed on the met mast and Nacelle Wind speed are made and the results are presented on graphs and in a table. The data used for the comparison are the data that are same as used for the power curve report...

  16. High Speed Viterbi Decoder Architecture

    Paaske, Erik; Andersen, Jakob Dahl

    1998-01-01

    The fastest commercially available Viterbi decoders for the (171,133) standard rate 1/2 code operate with a decoding speed of 40-50 Mbit/s (net data rate). In this paper we present a suitable architecture for decoders operating with decoding speeds of 150-300 Mbit/s....

  17. Optimal Speed Control for Cruising

    Blanke, M.

    1994-01-01

    With small profit margins in merchant shipping and more than eighty percent of sailing time being cross ocean voyages, speed control is crucial for vessel profitability......With small profit margins in merchant shipping and more than eighty percent of sailing time being cross ocean voyages, speed control is crucial for vessel profitability...

  18. The need for speed: global optic flow speed influences steering.

    Kountouriotis, Georgios K; Mole, Callum D; Merat, Natasha; Wilkie, Richard M

    2016-05-01

    How do animals follow demarcated paths? Different species are sensitive to optic flow and one control solution is to maintain the balance of flow symmetry across visual fields; however, it is unclear whether animals are sensitive to changes in asymmetries when steering along curved paths. Flow asymmetries can alter the global properties of flow (i.e. flow speed) which may also influence steering control. We tested humans steering curved paths in a virtual environment. The scene was manipulated so that the ground plane to either side of the demarcated path produced larger or smaller asymmetries in optic flow. Independent of asymmetries and the locomotor speed, the scene properties were altered to produce either faster or slower globally averaged flow speeds. Results showed that rather than being influenced by changes in flow asymmetry, steering responded to global flow speed. We conclude that the human brain performs global averaging of flow speed from across the scene and uses this signal as an input for steering control. This finding is surprising since the demarcated path provided sufficient information to steer, whereas global flow speed (by itself) did not. To explain these findings, existing models of steering must be modified to include a new perceptual variable: namely global optic flow speed. PMID:27293789

  19. Achievement of Student Behavior Percentile Evaluation System Based on the B Method%基于B方法的学生行为百分考核系统的设计

    梁昊

    2013-01-01

    Building student behavior percentile evaluation system becomes necessary in student management because of the increasing number of college students. Introduce the concept of the B method to join with the traditional UML language. Design student behavior percentile evaluation system using Java language combined with the SQL Server database. Explain some code's function in the system at the same time. The normal running of the system could improve the information technology level in student management and teachers’ work efficiency.%高校学生人数的不断增加使得构建学生行为百分考核系统成为学生管理的必要举措,系统构建中引入了B方法的概念,将传统UML语言与B方法相结合,利用Java语言结构结合SQL Server数据库,设计了学生行为百分考核系统,同时阐述了部分代码在系统中的作用。结果表明,系统的正常运行能够不断提高学生管理的信息化水平和教师的工作效率。

  20. Pay as You Speed, ISA with incentives for not speeding

    Lahrmann, Harry Spaabæk; Agerholm, Niels; Tradisauskas, Nerius;

    2012-01-01

    the reduction of a 30% discount on the driver's car insurance premium, which therefore produced the name, Pay as You Speed. The ISA equipment consists of a GPS-based On Board Unit with a mobile phone connection to a web server. The project was planned for a three-year test period with 300 young car drivers......, but it never succeeded in recruiting that number of drivers. After several design changes, the project eventually went forward with 153 test drivers of all ages. This number represents approximately one thousandth of all car owners in the proving ground of North Jutland in Denmark. Furthermore the project......The Intelligent Speed Adaptation (ISA) project we describe in this article is based on Pay as You Drive principles. These principles assume that the ISA equipment informs a driver of the speed limit, warns the driver when speeding and calculates penalty points. Each penalty point entails...

  1. Forecasting wind speed financial return

    D'Amico, Guglielmo; Prattico, Flavio

    2013-01-01

    The prediction of wind speed is very important when dealing with the production of energy through wind turbines. In this paper, we show a new nonparametric model, based on semi-Markov chains, to predict wind speed. Particularly we use an indexed semi-Markov model that has been shown to be able to reproduce accurately the statistical behavior of wind speed. The model is used to forecast, one step ahead, wind speed. In order to check the validity of the model we show, as indicator of goodness, the root mean square error and mean absolute error between real data and predicted ones. We also compare our forecasting results with those of a persistence model. At last, we show an application of the model to predict financial indicators like the Internal Rate of Return, Duration and Convexity.

  2. High-Speed Electrochemical Imaging.

    Momotenko, Dmitry; Byers, Joshua C; McKelvey, Kim; Kang, Minkyung; Unwin, Patrick R

    2015-09-22

    The design, development, and application of high-speed scanning electrochemical probe microscopy is reported. The approach allows the acquisition of a series of high-resolution images (typically 1000 pixels μm(-2)) at rates approaching 4 seconds per frame, while collecting up to 8000 image pixels per second, about 1000 times faster than typical imaging speeds used up to now. The focus is on scanning electrochemical cell microscopy (SECCM), but the principles and practicalities are applicable to many electrochemical imaging methods. The versatility of the high-speed scan concept is demonstrated at a variety of substrates, including imaging the electroactivity of a patterned self-assembled monolayer on gold, visualization of chemical reactions occurring at single wall carbon nanotubes, and probing nanoscale electrocatalysts for water splitting. These studies provide movies of spatial variations of electrochemical fluxes as a function of potential and a platform for the further development of high speed scanning with other electrochemical imaging techniques. PMID:26267455

  3. Predictors of Social Mobilization Speed

    Alstott, Jeff; Velu, Chander

    2013-01-01

    Mobilization across social networks is becoming increasingly influential, but little is known about what traits of individuals and their relationships affect their speed of mobilization between them. We ran a global social mobilization contest and recorded personal traits of the participants and those they mobilized. We examined how those traits influenced the speed of mobilization. Individuals mobilized faster when they heard about the contest directly from the contest organization, and decreased in speed when hearing from less personal source types (e.g. family vs. media). Mobilization was faster when the mobilizer and the mobilized heard about the contest through the same source type, and slower when both individuals were in different countries. Females mobilized other females faster than males mobilized other males. Mobilization was faster with young recruiters and old recruits, and slower with old recruiters and young recruits. These findings suggest ways to optimize the speed of social mobilization.

  4. Animal evolution: trilobites on speed.

    Budd, Graham E

    2013-10-01

    A new study quantifies rates of morphological and molecular evolution for arthropods during the critical Cambrian explosion. Both morphological and molecular evolution are accelerated--but not so much to break any speed limits. PMID:24112983

  5. Factors Influencing Drivers' Speeding Behaviour

    Wallén Warner, Henriette

    2006-01-01

    Every year many people all over the world are killed and severely injured in road traffic accidents. Even though driving too fast is a behaviour well known to contribute to both the number and the outcome of these accidents, drivers are still speeding. The general aim of this thesis, and its five empirical studies, is therefore to further the knowledge about drivers speeding behaviour by using the theory of planned behaviour and the model underpinning the driver behaviour questionnaire as fra...

  6. 36 CFR 4.21 - Speed limits.

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Speed limits. 4.21 Section 4... TRAFFIC SAFETY § 4.21 Speed limits. (a) Park area speed limits are as follows: (1) 15 miles per hour... superintendent may designate a different speed limit upon any park road when a speed limit set forth in...

  7. Methods of speed measurement. Geschwindigkeitsmessverfahren

    Baeumer, K.; Rath, K.; Rogge, H.; Wiegand, H.

    1990-09-27

    In a method, i.e. the operation of a device for contactless measurement of speeds, speed-time curves and decay frequencies in liquid jets and flames two light beams emitted by strong light source are focussed in such a way in the measured volume of a fluid layer or flame layer that the light transmission in the measured volume can be measured at a focal distance s by means of two light-sensitive detectors. Speeds and speed-time curves in injection jets and flames can be inferred from the shift in time s of the transmission curves by means of the equation v=s/t. Furthermore, the recorded transmission-time curve can be used for harmonic analysis studies by means of a digital Fourier analysis (FFT analysis). The speed v or, as the case may be, the speed-time curve in the layer of a fluid or flame and the frequencies f determined with the frequency spectrum permit a calculation of the wavelength according to the wave equation =vxf, and this in turn determines the ball size in jets of fluid and flames.

  8. Low speed phaselock speed control system. [for brushless dc motor

    Fulcher, R. W.; Sudey, J. (Inventor)

    1975-01-01

    A motor speed control system for an electronically commutated brushless dc motor is provided which includes a phaselock loop with bidirectional torque control for locking the frequency output of a high density encoder, responsive to actual speed conditions, to a reference frequency signal, corresponding to the desired speed. The system includes a phase comparator, which produces an output in accordance with the difference in phase between the reference and encoder frequency signals, and an integrator-digital-to-analog converter unit, which converts the comparator output into an analog error signal voltage. Compensation circuitry, including a biasing means, is provided to convert the analog error signal voltage to a bidirectional error signal voltage which is utilized by an absolute value amplifier, rotational decoder, power amplifier-commutators, and an arrangement of commutation circuitry.

  9. Performance evaluation of high speed compressors for high speed multipliers

    Nirlakalla Ravi

    2011-01-01

    Full Text Available This paper describes high speed compressors for high speed parallel multipliers like Booth Multiplier, Wallace Tree Multiplier in Digital Signal Processing (DSP. This paper presents 4-3, 5-3, 6-3 and 7-3 compressors for high speed multiplication. These compressors reduce vertical critical path more rapidly than conventional compressors. A 5-3 conventional compressor can take four steps to reduce bits from 5 to 3, but the proposed 5-3 takes only 2 steps. These compressors are simulated with H-Spice at a temperature of 25°C at a supply voltage 2.0V using 90nm MOSIS technology. The Power, Delay, Power Delay Product (PDP and Energy Delay Product (EDP of the compressors are calculated to analyze the total propagation delay and energy consumption. All the compressors are designed with half adder and full Adders only.

  10. Frank Robert Tangherlini — the Founder of an Alternative Relativistic Kinematics (On the Occasion of His 85th Birthday

    Malykin G. B.

    2009-01-01

    Full Text Available Already fifty years ago, Frank Robert Tangherlini, an American theoretical physicist, suggested an original procedure which, targeting the synchronization of clocks located in two different inertial reference frames of the space, was different from that Einstein had introduced. As a result of these, Tangherlini had deduced the so-called the Tangherlini transformations, which are a sort of the transformations of the spatial coordinates and time being moved from one inertial reference frame into another one. The Tangherlini transformations differ from the Lorentz transformations (which can be meant classic ones in the theory of relativity and, in particular, suggest the velocity of light to be anisotropic in a moving inertial reference frame. The Tangherlini transformations being applied provide adequate explanations to all well-known interference experiments checking of the Special Theory of Relativity.

  11. Frank Robert Tangherlini — the Founder of an Alternative Relativistic Kinematics (On the Occasion of His 85th Birthday

    Malykin G. B.

    2009-01-01

    Full Text Available Already fifty years ago, Frank Robert Tangherlini, an American theoretical physicist, suggested an original procedure which, targeting the synchronization of clocks located in two different inertial reference frames of the space, was di erent from that Einstein had introduced. As a result of these, Tangherlini had deduced the so-called the Tangher- lini transformations, which are a sort of the transformations of the spatial coordinates and time being moved from one inertial reference frame into another one. The Tangher- lini transformations differ from the Lorentz transformations (which can be meant clas- sic ones in the theory of relativity and, in particular, suggest the velocity of light to be anisotropic in a moving inertial reference frame. The Tangherlini transformations be- ing applied provide adequate explanations to all well-known interference experiments checking of the Special Theory of Relativity.

  12. Generalized Geometric Quantum Speed Limits

    Pires, Diego Paiva; Cianciaruso, Marco; Céleri, Lucas C.; Adesso, Gerardo; Soares-Pinto, Diogo O.

    2016-04-01

    The attempt to gain a theoretical understanding of the concept of time in quantum mechanics has triggered significant progress towards the search for faster and more efficient quantum technologies. One of such advances consists in the interpretation of the time-energy uncertainty relations as lower bounds for the minimal evolution time between two distinguishable states of a quantum system, also known as quantum speed limits. We investigate how the nonuniqueness of a bona fide measure of distinguishability defined on the quantum-state space affects the quantum speed limits and can be exploited in order to derive improved bounds. Specifically, we establish an infinite family of quantum speed limits valid for unitary and nonunitary evolutions, based on an elegant information geometric formalism. Our work unifies and generalizes existing results on quantum speed limits and provides instances of novel bounds that are tighter than any established one based on the conventional quantum Fisher information. We illustrate our findings with relevant examples, demonstrating the importance of choosing different information metrics for open system dynamics, as well as clarifying the roles of classical populations versus quantum coherences, in the determination and saturation of the speed limits. Our results can find applications in the optimization and control of quantum technologies such as quantum computation and metrology, and might provide new insights in fundamental investigations of quantum thermodynamics.

  13. Dazzle camouflage affects speed perception.

    Nicholas E Scott-Samuel

    Full Text Available Movement is the enemy of camouflage: most attempts at concealment are disrupted by motion of the target. Faced with this problem, navies in both World Wars in the twentieth century painted their warships with high contrast geometric patterns: so-called "dazzle camouflage". Rather than attempting to hide individual units, it was claimed that this patterning would disrupt the perception of their range, heading, size, shape and speed, and hence reduce losses from, in particular, torpedo attacks by submarines. Similar arguments had been advanced earlier for biological camouflage. Whilst there are good reasons to believe that most of these perceptual distortions may have occurred, there is no evidence for the last claim: changing perceived speed. Here we show that dazzle patterns can distort speed perception, and that this effect is greatest at high speeds. The effect should obtain in predators launching ballistic attacks against rapidly moving prey, or modern, low-tech battlefields where handheld weapons are fired from short ranges against moving vehicles. In the latter case, we demonstrate that in a typical situation involving an RPG7 attack on a Land Rover the reduction in perceived speed is sufficient to make the grenade miss where it was aimed by about a metre, which could be the difference between survival or not for the occupants of the vehicle.

  14. Brushless tachometer gives speed and direction

    Nola, F. J.

    1977-01-01

    Brushless electronic tachometer measures rotational speed and rotational direction, maintaining accuracy at high or low speeds. Unit is particularly useful in vacuum environments requiring low friction.

  15. High-speed photonics interconnects

    Chrostowski, Lukas

    2013-01-01

    Dramatic increases in processing power have rapidly scaled on-chip aggregate bandwidths into the Tb/s range. This necessitates a corresponding increase in the amount of data communicated between chips, so as not to limit overall system performance. To meet the increasing demand for interchip communication bandwidth, researchers are investigating the use of high-speed optical interconnect architectures. Unlike their electrical counterparts, optical interconnects offer high bandwidth and negligible frequency-dependent loss, making possible per-channel data rates of more than 10 Gb/s. High-Speed

  16. Speeding chemical reactions by focusing

    Lacasta, A. M.; Ramírez-Piscina, L.; Sancho, J. M.; Lindenberg, K.

    2013-04-01

    We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, and obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate ˜t-1/2 to very close to the perfect mixing rate, ˜t-1.

  17. Speeding chemical reactions by focusing

    Lacasta, A M; Sancho, J M; Lindenberg, K

    2012-01-01

    We present numerical results for a chemical reaction of colloidal particles which are transported by a laminar fluid and are focused by periodic obstacles in such a way that the two components are well mixed and consequently the chemical reaction is speeded up. The roles of the various system parameters (diffusion coefficients, reaction rate, obstacles sizes) are studied. We show that focusing speeds up the reaction from the diffusion limited rate (t to the power -1/2) to very close to the perfect mixing rate, (t to the power -1).

  18. Motor Integrated Variable Speed Drives

    Singh, Yash Veer

    A new trend in the variable speed drives (VSDs) is to develop fully integrated systems, which lead to low-cost products with shorter design cycles. Motor Integrated design of VSDs will reduce cable length to connect drive with machine windings and installation time for end user. The electric drives...... converter losses and its size so it can fit inside the motor housing. Weight and volume of a filter inductor has to come down drastically to make it a suitable power converter for motor integrated variable speed drives. Introduction of active power electronic switches can ensure very high performance and...

  19. Instant PageSpeed optimization

    Jaiswal, Sanjeev

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. Instant PageSpeed Optimization is a hands-on guide that provides a number of clear, step-by-step exercises for optimizing your websites for better performance and improving their efficiency.Instant PageSpeed Optimization is aimed at website developers and administrators who wish to make their websites load faster without any errors and consume less bandwidth. It's assumed that you will have some experience in basic web technologies like HTML, CSS3, JavaScript, and the basics of netw

  20. High-speed pulse techniques

    Coekin, J A

    1975-01-01

    High-Speed Pulse Techniques covers the many aspects of technique in digital electronics and encompass some of the more fundamental factors that apply to all digital systems. The book describes the nature of pulse signals and their deliberate or inadvertent processing in networks, transmission lines and transformers, and then examines the characteristics and transient performance of semiconductor devices and integrated circuits. Some of the problems associated with the assembly of these into viable systems operating at ultra high speed are also looked at. The book examines the transients and w

  1. The Speeding Car Design Challenge

    Roman, Harry T.

    2009-01-01

    All too often, one reads about high-speed police chases in pursuit of stolen cars that result in death and injury to people and innocent bystanders. Isn't there another way to accomplish the apprehension of the thieves that does not put people at such great risk? This article presents a classroom challenge to use technology to remotely shutdown…

  2. Speed Judgements of Transparent Stimuli

    Mulligan, Jeffrey B.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    When two moving patterns are combined additively, observers often perceive two transparent surfaces, even when there are no cues supporting this segmentation in a frozen snapshot. We examined the ability of observers to make quantitative judgments about the speed of one of the patterns under these conditions. The component patterns consisted of band-pass filtered random noise presented in a spatial Gaussian contrast envelope, presented for 250 ms. On each trial a standard pattern appeared on one side of the fixation point, while a test pattern appeared on the other. The test pattern moved in the same direction as the standard, but with a speed which varied from trial to trial using a staircase procedure. The subjects' task was to report the side of the fixation point on which faster motion was seen. In some conditions the test stimulus was made to appear transparent by adding a mask pattern. When the mask was stationary, or moved slowly with respect to the test, no significant biases were introduced and discrimination performance was comparable to the no-mask condition (typically 3%). If the mask moved over the test with similar speed, however, the task became much harder, regardless of whether the mask moved opposite or orthogonal to the test. (Some subjects commented on a perceived directional repulsion between tests and orthogonally moving masks.) These results suggest the use of non-directional temporal channels in the performance of the speed discrimination task.

  3. High-speed OTDM switching

    Jepsen, Kim Stokholm; Mikkelsen, Benny; Clausen, Anders;

    1998-01-01

    Optical TDM (OTDM) continues to be of interest both for point-point transmission and as a networking technology for both LANs and long-distance fibre transmission. Recent research has demonstrated enabling techniques for OTDM networks at high speeds. In conclusion, OTDM is emerging as an attractive...

  4. 14 CFR 29.1509 - Rotor speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor speed. 29.1509 Section 29.1509....1509 Rotor speed. (a) Maximum power-off (autorotation). The maximum power-off rotor speed must be... minimum power-off rotor speed must be established so that it is not less than 105 percent of the...

  5. 14 CFR 27.1509 - Rotor speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor speed. 27.1509 Section 27.1509... Rotor speed. (a) Maximum power-off (autorotation). The maximum power-off rotor speed must be established... minimum power-off rotor speed must be established so that it is not less than 105 percent of the...

  6. 14 CFR 91.117 - Aircraft speed.

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft speed. 91.117 Section 91.117... speed. (a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10... than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed....

  7. 14 CFR 25.1507 - Maneuvering speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maneuvering speed. 25.1507 Section 25.1507....1507 Maneuvering speed. The maneuvering speed must be established so that it does not exceed the design maneuvering speed V A determined under § 25.335(c)....

  8. 45 CFR 3.26 - Speed limit.

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit....

  9. Exploring of Chinese High-speed Railways

    liuYoumei

    2004-01-01

    Based ion experiences of high-speed railways in foreign countries,the speed-raise situation of the Chinese railways,the research & development and test of high-speed transportation carries,as well as the prospective of high-speed railway in China are introduced.

  10. Improving homogeneity by dynamic speed limit systems.

    Nes, N. van Brandenberg, S. & Twisk, D.A.M.

    2010-01-01

    Homogeneity of driving speeds is an important variable in determining road safety; more homogeneous driving speeds increase road safety. This study investigates the effect of introducing dynamic speed limit systems on homogeneity of driving speeds. A total of 46 subjects twice drove a route along 12

  11. Circuit Regulates Speed Of dc Motor

    Weaver, Charles; Padden, Robin; Brown, Floyd A., Jr.

    1990-01-01

    Driving circuit regulates speed of small dc permanent-magnet motor in tape recorder. Two nested feedback loops maintain speed within 1 percent of constant value. Inner loop provides coarse regulation, while outer loop removes most of variation in speed that remains in the presence of regulation by the inner loop. Compares speed of motor with commanded speed and adjusts current supplied to motor accordingly.

  12. Cutting tool materials for high speed machining

    LIU Zhanqiang; AI Xing

    2005-01-01

    High speed machining (HSM) is one of the emerging cutting processes, which is machining at a speed significantlyhigher than the speed commonly in use on the shop floor. In the last twenty years, high speed machining has received great attentions as a technological solution for high productivity in manufacturing. This article reviews the developments of tool materials in high speed machining operations, and the properties, applications and prospective developments of tool materials in HSM are also presented.

  13. Unconscious local motion alters global image speed.

    Sieu K Khuu

    Full Text Available Accurate motion perception of self and object speed is crucial for successful interaction in the world. The context in which we make such speed judgments has a profound effect on their accuracy. Misperceptions of motion speed caused by the context can have drastic consequences in real world situations, but they also reveal much about the underlying mechanisms of motion perception. Here we show that motion signals suppressed from awareness can warp simultaneous conscious speed perception. In Experiment 1, we measured global speed discrimination thresholds using an annulus of 8 local Gabor elements. We show that physically removing local elements from the array attenuated global speed discrimination. However, removing awareness of the local elements only had a small effect on speed discrimination. That is, unconscious local motion elements contributed to global conscious speed perception. In Experiment 2 we measured the global speed of the moving Gabor patterns, when half the elements moved at different speeds. We show that global speed averaging occurred regardless of whether local elements were removed from awareness, such that the speed of invisible elements continued to be averaged together with the visible elements to determine the global speed. These data suggest that contextual motion signals outside of awareness can both boost and affect our experience of motion speed, and suggest that such pooling of motion signals occurs before the conscious extraction of the surround motion speed.

  14. The Effects of Fructose-Containing Sugars on Weight, Body Composition and Cardiometabolic Risk Factors When Consumed at up to the 90th Percentile Population Consumption Level for Fructose

    Joshua Lowndes

    2014-08-01

    Full Text Available The American Heart Association (AHA and World Health Organization (WHO have recommended restricting calories from added sugars at lower levels than the Institute of Medicine (IOM recommendations, which are incorporated in the Dietary Guidelines for Americans 2010 (DGAs 2010. Sucrose (SUC and high fructose corn syrup (HFCS have been singled out for particular concern, because of their fructose content, which has been specifically implicated for its atherogenic potential and possible role in elevating blood pressure through uric acid-mediated endothelial dysfunction. This study explored the effects when these sugars are consumed at typical population levels up to the 90th percentile population consumption level for fructose. Three hundred fifty five overweight or obese individuals aged 20–60 years old were placed on a eucaloric diet for 10 weeks, which incorporated SUC- or HFCS-sweetened, low-fat milk at 8%, 18% or 30% of calories. There was a slight change in body weight in the entire cohort (169.1 ± 30.6 vs. 171.6 ± 31.8 lbs, p < 0.01, a decrease in HDL (52.9 ± 12.2 vs. 52.0 ± 13.9 mg/dL, p < 0.05 and an increase in triglycerides (104.1 ± 51.8 vs. 114.1 ± 64.7 mg/dL, p < 0.001. However, total cholesterol (183.5 ± 42.8 vs. 184.4 mg/dL, p > 0.05, LDL (110.3 ± 32.0 vs. 110.5 ± 38.9 mg/dL, p > 0.05, SBP (109.4 ± 10.9 vs. 108.3 ± 10.9 mmHg, p > 0.05 and DBP (72.1 ± 8.0 vs. 71.3 ± 8.0 mmHg, p > 0.05 were all unchanged. In no instance did the amount or type of sugar consumed affect the response to the intervention (interaction p > 0.05. These data suggest that: (1 when consumed as part of a normal diet, common fructose-containing sugars do not raise blood pressure, even when consumed at the 90th percentile population consumption level for fructose (five times the upper level recommended by the AHA and three times the upper level recommended by WHO; (2 changes in the lipid profile are mixed, but modest.

  15. Low Speed Avian Maneuvering Flight

    Ros, Ivo

    2013-01-01

    Low speed avian maneuvering flight is an ecologically crucial behavior that has contributed to the explosive diversification of several avian taxa by allowing access to complex spatial environments. Negotiating a sharp aerial turn requires finely tuned interactions between an animal's sensory-motor system and its environment. My thesis work focuses on how aerodynamic forces, wing and body dynamics, and sensory feedback interact during aerial turning in the pigeon (Columba livea).

  16. Dazzle camouflage affects speed perception

    Scott-Samuel, Nicholas E.; Roland Baddeley; Palmer, Chloe E.; Cuthill, Innes C.

    2011-01-01

    Movement is the enemy of camouflage: most attempts at concealment are disrupted by motion of the target. Faced with this problem, navies in both World Wars in the twentieth century painted their warships with high contrast geometric patterns: so-called “dazzle camouflage”. Rather than attempting to hide individual units, it was claimed that this patterning would disrupt the perception of their range, heading, size, shape and speed, and hence reduce losses from, in particular, torpedo attacks ...

  17. Blood Pressure Percentiles for School Children

    İsmail Özanli; Sebahat Tülpar; Yunus Yılmaz; Fatih Yıldız

    2016-01-01

    Objective: The prevalence of hypertension in childhood and adolescence is gradually increasing. We aimed to in­vestigate the blood pressure (BP) values of children aged 7-18 years. Methods: This study was conducted in a total of 3375 (1777 females, 1598 males) children from 27 schools. Blood pressures of children were measured using sphyg­momanometer appropriate to arm circumference. Results: A positive relationship was found between sys­tolic blood pressure (SBP) and diastolic blood pr...

  18. The Speed of Galileon Gravity

    Brax, Philippe; Davis, Anne-Christine

    2015-01-01

    We analyse the speed of gravitational waves in coupled Galileon models with an equation of state $\\omega_\\phi=-1$ now and a ghost-free Minkowski limit. We find that the gravitational waves propagate much faster than the speed of light unless these models are small perturbations of cubic Galileons and the Galileon energy density is sub-dominant to a dominant cosmological constant. In this case, the binary pulsar bounds on the speed of gravitational waves can be satisfied and the equation of state can be close to -1 when the coupling to matter and the coefficient of the cubic term of the Galileon Lagrangian are related. This severely restricts the allowed cosmological behaviour of Galileon models and we are forced to conclude that Galileons with a stable Minkowski limit cannot account for the observed acceleration of the expansion of the universe on their own. Moreover any sub-dominant Galileon component of our universe must be dominated by the cubic term. For such models with gravitons propagating faster than ...

  19. Healthy Eating in Out-of-School Time: The Promise and the Challenge

    Wiecha, Jean L.; Hall, Georgia; Gannett, Ellen; Roth, Barbara

    2012-01-01

    More than 30 percent of American children are either overweight or obese, with a body mass index (BMI) in the 85th percentile or above. Although prevalence varies by age, sex, and ethnicity, all groups are affected. Risk of serious health problems increases with increasing BMI. Childhood obesity, characterized by BMI in the 95th percentile or…

  20. Systems and methods for vehicle speed management

    Sujan, Vivek Anand; Vajapeyazula, Phani; Follen, Kenneth; Wu, An; Forst, Howard Robert

    2016-03-01

    Controlling a speed of a vehicle based on at least a portion of a route grade and a route distance divided into a plurality of route sections, each including at least one of a section grade and section length. Controlling the speed of the vehicle is further based on determining a cruise control speed mode for the vehicle for each of the plurality of route sections and determining a speed reference command of the vehicle based on at least one of the cruise control speed mode, the section length, the section grade, and a current speed.

  1. Early life cognitive abilities and body weight: cross-sectional study of the association of inhibitory control, cognitive flexibility, and sustained attention with BMI percentiles in primary school children.

    Wirt, Tamara; Schreiber, Anja; Kesztyüs, Dorothea; Steinacker, Jürgen M

    2015-01-01

    The objective of this study was to investigate the association of different cognitive abilities with children's body weight adjusted for further weight influencing sociodemographic, family, and lifestyle factors. Cross-sectional data of 498 primary school children (7.0 ± 0.6 years; 49.8% boys) participating in a health promotion programme in southwest Germany were used. Children performed a computer-based test battery (KiTAP) including an inhibitory control task (Go-Nogo paradigm), a cognitive flexibility task, and a sustained attention task. Height and weight were measured in a standardized manner and converted to BMI percentiles based on national standards. Sociodemographic features (migration background and parental education), family characteristics (parental body weight), and children's lifestyle (TV consumption, physical activity, consumption of sugar-sweetened beverages and breakfast habits) were assessed via parental questionnaire. A hierarchical regression analysis revealed inhibitory control and cognitive flexibility to be significant cognitive predictors for children's body weight. There was no association concerning sustained attention. The findings suggest that especially cognitive abilities known as executive functions (inhibitory control and cognitive flexibility) are associated with children's body weight. Future longitudinal and intervention studies are necessary to investigate the directionality of the association and the potential of integrating cognitive training in obesity prevention strategies. This trial is registered with ClinicalTrials.gov DRKS00000494. PMID:25874122

  2. Early Life Cognitive Abilities and Body Weight: Cross-Sectional Study of the Association of Inhibitory Control, Cognitive Flexibility, and Sustained Attention with BMI Percentiles in Primary School Children

    Tamara Wirt

    2015-01-01

    Full Text Available The objective of this study was to investigate the association of different cognitive abilities with children’s body weight adjusted for further weight influencing sociodemographic, family, and lifestyle factors. Cross-sectional data of 498 primary school children (7.0 ± 0.6 years; 49.8% boys participating in a health promotion programme in southwest Germany were used. Children performed a computer-based test battery (KiTAP including an inhibitory control task (Go-Nogo paradigm, a cognitive flexibility task, and a sustained attention task. Height and weight were measured in a standardized manner and converted to BMI percentiles based on national standards. Sociodemographic features (migration background and parental education, family characteristics (parental body weight, and children’s lifestyle (TV consumption, physical activity, consumption of sugar-sweetened beverages and breakfast habits were assessed via parental questionnaire. A hierarchical regression analysis revealed inhibitory control and cognitive flexibility to be significant cognitive predictors for children’s body weight. There was no association concerning sustained attention. The findings suggest that especially cognitive abilities known as executive functions (inhibitory control and cognitive flexibility are associated with children’s body weight. Future longitudinal and intervention studies are necessary to investigate the directionality of the association and the potential of integrating cognitive training in obesity prevention strategies. This trial is registered with ClinicalTrials.gov DRKS00000494.

  3. A study of speed limits and speed control measures for the urban arterial road

    Wichuda Satiennam; Phongphan Tankasem; Thaned Satiennam

    2015-01-01

    Speed limits in accordance with environment and road functions have been used as a fundamental tool for speed management and road safety. This paper presents literatures review of speed limits measure and results from the study on speed limits problem and driver attitude toward the speed limit and speed control measure. Area of study is on the arterial road where the Mittaprab Highway passed through Khon Kaen City. The study found that improper designation of road functions is the main cause ...

  4. Speed behaviour as a choice between observing and exceeding the speed limit

    LETIRAND, F; Delhomme, P.

    2005-01-01

    Despite speed behaviour being defined as a choice between several possible speeds, studies using theory of reasoned action or theory of planned behaviour to predict and understand speed behaviour have focused on exceeding and not on observing the speed limit. This study examines whether the evaluation of exceeding but also of observing the speed limit contributes to improving predictions of self-reported speed behaviour and determining intentions to produce each of these two behavioural optio...

  5. Deleuze and Epicurean Philosophy: Atomic Speed and Swerve Speed

    Michael James Bennett

    2013-12-01

    Full Text Available This paper reconstructs Gilles Deleuze’s interpretation of Epicurean atomism, and explicates his claim that it represents a problematic idea, similar to the idea exemplified in early, “barbaric” accounts of the differential calculus. Deleuzian problematic ideas are characterized by a mechanism through whose activity the components of the idea become determinate in relating reciprocally to one another, rather than in being determined exclusively in relation to an extrinsic paradigm or framework. In Epicurean atomism, as Deleuze reads it, such a mechanism of determination can be found in the famous atomic “swerve”. It is necessary to bear this interpretation of Epicurean atomism in mind when understanding Deleuze and Guattari’s promulgation of a new image of thought in What is Philosophy?, which has an explicitly Epicurean inspiration. The paper argues that this inspiration is particularly evident to the extent that Deleuze and Guattari identify the sub-representative feature that lies at the heart of their new image of thought with “chaos”, defined as “infinite speed”. I claim that infinite speed, this otherwise puzzling feature of What is Philosophy?, ought to be understood in the light of Deleuze’s interpretation of Epicurus. Moreover, the Epicurean distinctions between different speeds must be read together with Deleuze’s appropriation of the metaphysics of the ancient Stoics, who, although widely recognized as Deleuze’s Hellenistic counterparts, lack important theoretical resources that the Epicureans provide for Deleuze.

  6. Intelligent Speed Adaptation in Company Vehicles

    Agerholm, Niels; Tradisauskas, Nerius; Waagepetersen, Rasmus;

    2008-01-01

    This paper describes an intelligent speed adaptation project for company vehicles. The intelligent speed adaptation function in the project is both information and incentive, which means that the intelligent speed adaptation equipment gives a warning as well as penalty points if the driver is...... speeding. Each month the driver with that monthpsilas fewest points wins an award. The paper presents results concerning speed attitude on the first three of a planned 12 months test period. In all 26 vehicles and 51 drivers from six companies participate in the project. The key result is that speeding is...... reduced from 18.7% to 7.4% on urban roads with a speed limit of 50 km/h while it is reduced from 18.9% to 4.7% on rural roads with a speed limit of 80 km/h....

  7. Speed Optimization in Liner Shipping Network Design

    Brouer, Berit Dangaard; Karsten, Christian Vad; Pisinger, David

    In the Liner Shipping Network Design Problem (LSNDP) services sail at a given speed throughout a round trip. In reality most services operate with a speed differentiated head- and back-haul, or even individual speeds on every sailing between two ports. The speed of a service is decisive for the...... bunker consumption in the network as well as the transit time of cargo. Speed optimization has been considered for tramp shipping showing significant reductions in fuel consumption. However, variable speeds has not been considered for post optimization of the LSNDP, where speed optimization could result...... in changes to the cargo flow due to transit time restrictions as well as significant savings in fuel consumption and required vessel deployment due to a weekly frequency requirement. We present a heuristic method to calculate variable speed on a service and present computational results for improving...

  8. Estimation of Maximum Wind Speeds in Tornadoes

    Dergarabedian, Paul; Fendell, Francis

    2011-01-01

    A method is proposed for rapidly estimating the maximum value of the azimuthal velocity component (maximum swirling speed) in tornadoes and waterspouts. The method requires knowledge of the cloud-deck height and a photograph of the funnel cloud—data usually available. Calculations based on this data confirm that the lower maximum wind speeds suggested by recent workers (roughly one-quarter of the sonic speed for sea-level air) are more plausible for tornadoes than the sonic speed sometimes ci...

  9. Light Speed Invariance is a Remarkable Illusion

    Gift, Stephan J. G.

    2007-01-01

    Though many experiments appear to have confirmed the light speed invariance postulate of special relativity theory, this postulate is actually unverified. This paper resolves this issue by first showing the manner in which an illusion of light speed invariance occurs in two-way light speed measurement in the framework of a semi-classical absolute space theory. It then demonstrates a measurable variation of the one-way speed of light, which directly invalidates the invariance postulate and con...

  10. Displacement speeds in turbulent premixed flame simulations

    Day, Marcus S.; Shepherd, Ian G.; Bell, J.; Grcar, Joseph F.; Lijewski, Michael J.

    2007-07-01

    The theory of turbulent premixed flames is based on acharacterization of the flame as a discontinuous surface propagatingthrough the fluid. The displacement speed, defined as the local speed ofthe flame front normal to itself, relative to the unburned fluid,provides one characterization of the burning velocity. In this paper, weintroduce a geometric approach to computing displacement speed anddiscuss the efficacy of the displacement speed for characterizing aturbulent flame.

  11. 49 CFR 236.813 - Speed, slow.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour....

  12. 36 CFR 1004.21 - Speed limits.

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Speed limits. 1004.21 Section 1004.21 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.21 Speed limits. (a) Speed limits in the area administered by the Presidio Trust are as follows: (1) 15 miles...

  13. 14 CFR 25.103 - Stall speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Stall speed. 25.103 Section 25.103... STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Performance § 25.103 Stall speed. (a) The reference stall speed, VSR, is a calibrated airspeed defined by the applicant. VSR may not be less than a 1-g...

  14. 33 CFR 401.28 - Speed limits.

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Speed limits. 401.28 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum speed over the bottom for a vessel of more than 12 m in overall length shall be regulated so as not...

  15. 50 CFR 38.13 - Speed limits.

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Speed limits. 38.13 Section 38.13 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles,...

  16. 49 CFR 236.811 - Speed, medium.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour....

  17. Why Does Light Have a Finite Speed?

    Brusca, Stephen

    1985-01-01

    Examines the question "Why does light travel at speed c?", dispelling the widespread qualitative notion that the speed of light results from time delays in the interaction of electric and magnetic fields. Also presents information by which readers can work on their own qualitative insights concerning the speed of light. (JN)

  18. Towards high-speed scanning tunneling microscopy

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices

  19. Automatic speed management systems : great safety potential ?

    Oei, H.-l.

    1992-01-01

    An account is given of speed management experiments carried out in The Netherlands on four 2-lane rural roads with a speed limit of 80 km/h. The experiment involved an information campaign, warning signs and a radar camera system. Fixed signs advised a speed of between 60 and 80 km/h and an automati

  20. Measurement of the Speed of Gravity

    ZHU Yin

    2011-01-01

    From the Liénard-Wiechert potential in both the gravitational field and the electromagnetic field,it is shown that the propagation speed of gravitational field (waves) can be tested by comparing the measured speed of gravitational force with the measured speed of Coulomb force.

  1. Factors Affecting the Speed of Free Writing

    Ferrier, Jonathan; Horne, Joanna; Singleton, Chris

    2013-01-01

    Factors affecting the free writing speed of 11-year-old students were investigated using the Group and Individual Assessment of Handwriting Speed. Intelligence, gender, legibility and whether the student has special educational needs or speaks English as an additional language were all found to impact on writing speed to a significant extent. In…

  2. Wind Speed Simulation Using Wavelets

    A. H. Siddiqi

    2005-01-01

    Full Text Available Most of the renewable energy sources have direct or indirect link with the sun. Wind is also a form of solar energy. It is initiated by uneven heating of the atmospheric air by the sun, affected from the topography and surface roughness of the earth's surface and rotation of the earth. The earth's terrain, water surfaces and vegetation cover modifies wind flow patterns. Wind energy or wind power terms describe the process by which the wind is used to generate mechanical energy or electricity. In view of this, there has been several studies of wind speed characteristics in different parts of the world using Weibull distribution and Fourier method of time series analysis. Wavelet methods invented in mid-eighties have attracted attention of Engineers, Physicists, Computer Scientists and Mathematicians alike for applications purposes in diverse fields. So much so that two prominent workers of this field Coifman and Daubechies have been given prestigious awards of U.S.A. in the year 2000 for their contribution in this field. In the present study we apply wavelet methods and related software to study wind speed data of certain places in Saudi Arabia.

  3. The effect of anatomical modeling on space radiation dose estimates: a comparison of doses for NASA phantoms and the 5th, 50th, and 95th percentile male and female astronauts

    Bahadori, Amir A; Bolch, Wesley E [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Van Baalen, Mary; Semones, Edward J [NASA Johnson Space Center, Houston, TX 77058 (United States); Shavers, Mark R [Wyle Integrated Science and Engineering, Houston, TX 77058 (United States); Dodge, Charles, E-mail: wbolch@ufl.edu [University of Houston-Downtown, Houston, TX 77002 (United States)

    2011-03-21

    The National Aeronautics and Space Administration (NASA) performs organ dosimetry and risk assessment for astronauts using model-normalized measurements of the radiation fields encountered in space. To determine the radiation fields in an organ or tissue of interest, particle transport calculations are performed using self-shielding distributions generated with the computer program CAMERA to represent the human body. CAMERA mathematically traces linear rays (or path lengths) through the computerized anatomical man (CAM) phantom, a computational stylized model developed in the early 1970s with organ and body profiles modeled using solid shapes and scaled to represent the body morphometry of the 1950 50th percentile (PCTL) Air Force male. With the increasing use of voxel phantoms in medical and health physics, a conversion from a mathematical-based to a voxel-based ray-tracing algorithm is warranted. In this study, the voxel-based ray tracer (VoBRaT) is introduced to ray trace voxel phantoms using a modified version of the algorithm first proposed by Siddon (1985 Med. Phys. 12 252-5). After validation, VoBRAT is used to evaluate variations in body self-shielding distributions for NASA phantoms and six University of Florida (UF) hybrid phantoms, scaled to represent the 5th, 50th, and 95th PCTL male and female astronaut body morphometries, which have changed considerably since the inception of CAM. These body self-shielding distributions are used to generate organ dose equivalents and effective doses for five commonly evaluated space radiation environments. It is found that dosimetric differences among the phantoms are greatest for soft radiation spectra and light vehicular shielding.

  4. 76 FR 8917 - Special Conditions: Gulfstream Model GVI Airplane; Automatic Speed Protection for Design Dive Speed

    2011-02-16

    ...; Automatic Speed Protection for Design Dive Speed AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... design features include a high speed protection system. These proposed special conditions contain the... Design Features The GVI is equipped with a high speed protection system that limits nose down...

  5. High-speed data search

    Driscoll, James N.

    1994-01-01

    The high-speed data search system developed for KSC incorporates existing and emerging information retrieval technology to help a user intelligently and rapidly locate information found in large textual databases. This technology includes: natural language input; statistical ranking of retrieved information; an artificial intelligence concept called semantics, where 'surface level' knowledge found in text is used to improve the ranking of retrieved information; and relevance feedback, where user judgements about viewed information are used to automatically modify the search for further information. Semantics and relevance feedback are features of the system which are not available commercially. The system further demonstrates focus on paragraphs of information to decide relevance; and it can be used (without modification) to intelligently search all kinds of document collections, such as collections of legal documents medical documents, news stories, patents, and so forth. The purpose of this paper is to demonstrate the usefulness of statistical ranking, our semantic improvement, and relevance feedback.

  6. 'PATRE': High speed concrete scabbling

    The decommissioning of a nuclear installation requires the complete and thorough decontamination of the buildings before dismantling to green field. This decontamination generally consists in cleaning and scabbling when necessary the concrete walls and floors. Up to now these works were often performed with hand-held machines, with limited power, and therefore were very long and had a high man-power content. PATRE is a concept which mechanizes the process, and allows the use of high power scabbling machines, thus allowing to reach much higher speed than with manual operations. The first tests with PATRE showed the following results: - 10 mm scabbling at a rate of 8 to 10 m2/h, - 45 mm scabbling, with 4 passes at a global rate of 1.5 m2/h

  7. Matter Flashed at Ultra Speed

    2007-06-01

    Using a robotic telescope at the ESO La Silla Observatory, astronomers have for the first time measured the velocity of the explosions known as gamma-ray bursts. The material is travelling at the extraordinary speed of more than 99.999% of the velocity of light, the maximum speed limit in the Universe. ESO PR Photo 26a/07 ESO PR Photo 26a/07 The REM Telescope "With the development of fast-slewing ground-based telescopes such as the 0.6-m REM telescope at ESO La Silla, we can now study in great detail the very first moments following these cosmic catastrophes," says Emilio Molinari, leader of the team that made the discovery. Gamma-ray bursts (GRBs) are powerful explosions occurring in distant galaxies, that often signal the death of stars. They are so bright that, for a brief moment, they almost rival the whole Universe in luminosity. They last, however, for only a very short time, from less than a second to a few minutes. Astronomers have long known that, in order to emit such incredible power in so little time, the exploding material must be moving at a speed comparable with that of light, namely 300 000 km per second. By studying the temporal evolution of the burst luminosity, it has now been possible for the first time to precisely measure this velocity. Gamma-ray bursts, which are unseen by our eyes, are discovered by artificial satellites. The collision of the gamma-ray burst jets into the surrounding gas generates an afterglow visible in the optical and near-infrared that can radiate for several weeks. An array of robotic telescopes were built on the ground, ready to catch this vanishing emission (see e.g. ESO 17/07). On 18 April and 7 June 2006, the NASA/PPARC/ASI Swift satellite detected two bright gamma-ray bursts. In a matter of a few seconds, their position was transmitted to the ground, and the REM telescope began automatically to observe the two GRB fields, detecting the near-infrared afterglows, and monitored the evolution of their luminosity as a

  8. Development of variable-shaft-speed alternator

    Rothbart, G.; Fullwood, R.

    1982-02-01

    A variable shaft speed alternator (VSSA) consists of an ordinary unmodified 1-1/2 Hp wound-rotor motor, with polyphase excitation controlled by solid state switching and a hybrid of analog and digital circuitry. This circuitry senses both shaft speed and line phase resulting in logic levels which control the current flow in each rotor coil. A first order polynomial was found using the least-squares regression method which accurately expressed the relationship among shaft speed, excitation power, and output power, VSSA torque was inferred from observations to be proportional to output power. Efficiency for converting mechanical power to electrical was inferred over a range of shaft speeds. A break-even speed below which no net power is produced was observed to be 0.375 of the synchronous speed for all output power levels. Similar behavior was observed with power fed to the power network (grid). Additional measurements involved VSSA performance at various power factors.

  9. Visual processing speed in old age

    Habekost, Thomas; vogel, asmus; Rostrup, Egill;

    2013-01-01

    speed of a particular psychological process that are not confounded by the speed of other processes. We used Bundesen's (1990) Theory of Visual Attention (TVA) to obtain specific estimates of processing speed in the visual system controlled for the influence of response latency and individual variations......Habekost, T., Vogel, A., Rostrup, E., Bundesen, C., Kyllingsbaek, S., Garde, E., Ryberg, C. & Waldemar, G. (2012). Visual processing speed in old age. Scandinavian Journal of Psychology. Mental speed is a common concept in theories of cognitive aging, but it is difficult to get measures of the...... of the perception threshold. A total of 33 non-demented old people (69-87 years) were tested for the ability to recognize briefly presented letters. Performance was analyzed by the TVA model. Visual processing speed decreased approximately linearly with age and was on average halved from 70 to 85...

  10. The effect of obesity on adverse outcomes and metabolism in pediatric burn patients

    Kraft, Robert; Herndon, David N.; Williams, Felicia N.; Al-Mousawi, Ahmed M; Finnerty, Celeste C.; Jeschke, Marc G

    2011-01-01

    Hypothesis Obesity influences metabolism and increases the incidence of clinical complications and worsens outcomes in pediatric burn patients. Design Retrospective, single-center study. Subjects Five hundred ninety-two severely burned pediatric patients who had burns covering more than 30% of the total body surface area and who were treated between 2001 and 2008 were enrolled in this study. Patients were divided into ≥ 85th percentile (n = 277) and normal (n = 315) weight groups based on body mass index percentiles. Results Patients stratified below (normal) and ≥ 85th percentile had similar age, gender distribution, and total burn size. No significant differences were detected in the incidence of sepsis (11% for obese vs. 10% for normal), the incidence of multiple organ failure (21% for obese and 16% for normal), or mortality (11% for obese vs. 8% for normal). Compared to the normal group, the ≥ 85th percentile group had low levels of constitutive proteins (α2macroglobulin and Apolipoprotein A-1) (p < 0.05 for both) as well as high levels of triglycerides and the acute-phase protein, C-reactive protein (p < 0.05 for both) up to 60 days after injury. Patients ≥ 85th percentile showed a significant higher loss of bone mineral density and lipolysis compared to normal individuals. Stepwise logistic regression analysis revealed that body mass index had a positive predictive value towards the maximum DENVER2 score, an index of organ failure (p < 0.001). Conclusions BMI ≥ 85th percentile altered the post-burn acute phase and catabolic response but did not increase the incidence of sepsis, multiple organ failure, or mortality in pediatric burn patients. Our results suggest that impaired metabolism and an altered inflammatory response occurs already in patients starting at the 85th percentile BMI. PMID:22143622

  11. Speed Control of Separately Excited DC Motor

    Moleykutty George

    2008-01-01

    This paper proposes the speed control of a separately excited dc motor (SEDM) by varying armature voltage. The novelty of this paper lies in the application of nonlinear autoregressive-moving average (NARMA)L2 controller for the speed control of SEDM. This paper also discusses speed control of a SEDM using chopper circuit. The performance of the proposed system has been compared with the traditional one using conventional controllers. The entire system has been modeled using MATLAB 7.0 toolbo...

  12. Review of high speed communications photomultiplier detectors

    Enck, R. S.; Abraham, W. G.

    1978-01-01

    Four types of newly developed high speed photomultipliers are discussed: all electrostatic; static crossed field; dynamic crossed field; and hybrid (EBS). Design, construction, and performance parameters of each class are presented along with limitations of each class of device and prognosis for its future in high speed light detection. The particular advantage of these devices lies in high speed applications using low photon flux, large cathode areas, and broadband optical detection.

  13. Induction Machine Speed Control with Flux Optimization

    Ouadi, Hamid; Giri, Fouad; Elfadili, Abderrahim; Dugard, Luc

    2010-01-01

    A new speed control strategy is developed, based on a machine model that accounts for the magnetic characteristic saturation. The control strategy includes a flux reference generator designed to meet optimal operational conditions, and a speed controller designed using nonlinear techniques. Both flux generation and speed control laws involve the machine state variables. The performances of the proposed control strategy are formally analysed and its supremacy with respect to standard control s...

  14. Speed stress and the aircraft pilot

    W.T.V. Adiseshiah

    1958-07-01

    Full Text Available When the human component in a man-machine system of pushed beyond the limits of human capacity in grasping information presented to senses or in executing a series of actions correctly, a condition of "speed stress" may be said to occur. Conditions encountered by aircraft at high speeds, make a consideration of the forms of speed stress, and of the measures to alleviate them, extremely important.

  15. Speed checks on the CERN site

    2007-01-01

    In view of the significant number of speeding incidents that have been reported, CERN will shortly start to carry out speed checks on the site. The radar used for this purpose will show drivers the speed measured. The disciplinary measures taken against those exceeding the authorised limit (generally 50 k.p.h.) will include a ban from driving on the site for a minimum of one month. Maximilian Metzger
Secretary-General

  16. Towards high-speed scanning tunneling microscopy

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices is shown using finite-element simulations, combined with measurements of their resonance frequency and actuation range. Tip deposition was done using EBID (Electron-Beam Induced Deposition) which a...

  17. Towards high cutting speed in wood milling

    COSTES, Jean-Philippe; Larricq, Pierre

    2002-01-01

    International audience High cutting speed machining processes have been used for about 10 years for metals. This technology presents many advantages related to output and surface quality. For timber machining, commonly used velocities are already high. However, literature about cutting velocity function during a machining process is rare. Nevertheless, some published results have shown the effect of speed on chip formation. In order to perform experiments at high cutting speeds, we used a ...

  18. Visual scale factor for speed perception

    Colombet, Florent; Paillot, Damien; Merienne, Frédéric; KEMENY, Andras

    2011-01-01

    Speed perception is an important task depending mainly on optic flow that the driver must perform continuously to control his/her vehicle. Unfortunately it appears that in some driving simulators speed perception is under estimated, leading into speed production higher than in real conditions. Perceptual validity is then not good enough to study driver's behavior. To solve this problem, a technique has recently seen the light, which consists of modifying the geometric field of view (GFOV) whi...

  19. Measurement of the absolute speed is possible?

    Sergey V. Shevchenko; Tokarevsky, Vladimir V.

    2016-01-01

    One of popular problems, which  are experimentally studied in physics in a long time, is the testing of the special relativity theory, first of all – measurements of isotropy and constancy of light speed; as well as attempts to determine so called “absolute speed”, i.e. the Earth speed in the absolute spacetime (absolute reference frame), if this spacetime (ARF) exists.  Corresponding experiments aimed at the measuring of proper speed of some reference frame in oth...

  20. Distraction as a Determinant of Processing Speed

    Lustig, Cindy; Hasher, Lynn; Tonev, Simon T.

    2006-01-01

    Processing speed is often described as a fundamental resource determining individual (e.g., I.Q.) and group (e.g., developmental) differences in cognition. However, most tests that measure speed present many items on a single page. Because many groups with slowed responding are also distractible, we compared younger and older adults on high- (i.e., standard) versus low-distraction versions of two classic speed tasks. Reducing distraction improved the performance of older adults while having l...

  1. Pedestrian Crossing Speed: The Case of Malaysia

    Boon Hoe Goh; Kulanthayan Subramaniam; Yeong Tuck Wai; Abdullahi Ali Mohamed

    2012-01-01

    Pedestrians are vulnerable road users, and they are always at risk when making their daily trips. Hence, roadway design and traffic control devices need to consider pedestrians’ safety. Pedestrian walking speed is fundamental to any roadway and traffic control design. Unfortunately, no specific guidelines exist for pedestrian crossing speed in Malaysia. The ultimate goals of this research are to establish the local pedestrian crossing speed and to identify the contributing factors. A total of...

  2. High speed all optical networks

    Chlamtac, Imrich; Ganz, Aura

    1990-01-01

    An inherent problem of conventional point-to-point wide area network (WAN) architectures is that they cannot translate optical transmission bandwidth into comparable user available throughput due to the limiting electronic processing speed of the switching nodes. The first solution to wavelength division multiplexing (WDM) based WAN networks that overcomes this limitation is presented. The proposed Lightnet architecture takes into account the idiosyncrasies of WDM switching/transmission leading to an efficient and pragmatic solution. The Lightnet architecture trades the ample WDM bandwidth for a reduction in the number of processing stages and a simplification of each switching stage, leading to drastically increased effective network throughputs. The principle of the Lightnet architecture is the construction and use of virtual topology networks, embedded in the original network in the wavelength domain. For this construction Lightnets utilize the new concept of lightpaths which constitute the links of the virtual topology. Lightpaths are all-optical, multihop, paths in the network that allow data to be switched through intermediate nodes using high throughput passive optical switches. The use of the virtual topologies and the associated switching design introduce a number of new ideas, which are discussed in detail.

  3. High speed rails. Fatigue behaviour

    In recent years, passenger train speed and freight train load have increased to enhance efficiency of rail road transportation. These trends have increased the severity of rail service conditions, calling for rails with greater wear resistance, strength and fatigue behaviour. In the United Stated and Europe, track site weld rails are made entirely by aluminothermic process. This work describes the results of experimental study conducted on bending fatigue strength of plain rails and aluminothermic welded rails with preheating procedures (oxipropane and air-induced propane) approved by railways authorities. Compliance with the required fatigue strength shall be ascertained by 4 point pulsating bending test in accordance with European standards by aluminothermic welding in rails. The locati method, based in the empirical Miner's law about the cumulative damage on a fatigue tested material, allows, once known the Wohler curve of the welding process in use to settle the fatigue tensile limit at 50% with only one test. The values obtained at 2.10''6 cycles for plain rails (Sf=353 MPa), oxipropane preheated aluminothermic weld rails (Sf=225 MPa), and propane-air induced aluminothermic weld rails (Sf=210 MPa) are very similar to those resulting from test method stated in the European Standard. From our point of view and due to its ease, speediness and savings, this is the most suitable test to check the quality and compare the aluminothermic processes in use. (Author) 15 refs

  4. Torque Control for Variable Speed Wind Turbines

    Schaak, P.; Van Engelen, T.G. [ECN Wind Energy, Petten (Netherlands)

    2004-11-01

    An advanced generator control algorithm has been developed and implemented in ECN's control design tool for wind turbines. For wind speeds above nominal the algorithm limits power and rotor speed to the common bounds of constant power control in variable speed turbines, while the electromagnetic torque varies half as much as found in literature. Simultaneously production dips at above nominal wind speeds are avoided. The algorithm has been examined by the aero-elastic wind turbine code Phatas. Application on a commercial wind turbine is in preparation.

  5. Pedestrian Crossing Speed: The Case of Malaysia

    Boon Hoe Goh

    2012-12-01

    Full Text Available Pedestrians are vulnerable road users, and they are always at risk when making their daily trips. Hence, roadway design and traffic’ control devices need to consider pedestrians’ safety. Pedestrian walking speed is fundamental to any roadway and traffic’ control design. Unfortunately, no specific guidelines exist for pedestrian crossing speed in Malaysia. The ultimate goals of this research are to establish the local pedestrian crossing speed and to identify the contributing factors. A total of 1579 samples on pedestrian crossing speed were collected at signalized and non-signalized crosswalks. The Bi-variate analysis (chi-square test was carried out to study statistically the association of the contributing factors. The Bi-variate analysis shows that crosswalk type, age and gender significantly contribute to pedestrian speed in Malaysia. However, lighting (daytime and night-time and race are not contributing to the pedestrians’ speed. Besides, pedestrians at non-signalized crosswalk have significantly faster crossing speed than at signalized crosswalk. Chi-square test also showed that children pedestrians are the fastest group, and elderly pedestrians are the slowest group in terms of pedestrian crossing speed. Moreover, male pedestrians have significantly faster crossing speed than female pedestrians do.

  6. High Speed On-Wafer Characterization Laboratory

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  7. Green maritime transportation: Speed and route optimization

    Psaraftis, Harilaos N.; Kontovas, Christos A.

    2015-01-01

    Among the spectrum of logistics-based measures for green maritime transportation, this chapter focuses on speed optimization. This involves the selection of an appropriate speed by the vessel, so as to optimize a certain objective. As ship speed is not fixed, depressed shipping markets and/or high...... necessarily be possible. The chapter presents some basics, discusses the main trade-offs and also examines combined speed and route optimization problems. Some examples are finally presented so as to highlight the main issues that are at play....

  8. High-speed Stochastic Fatigue Testing

    Brincker, Rune; Sørensen, John Dalsgaard

    1990-01-01

    Good stochastic fatigue tests are difficult to perform. One of the major reasons is that ordinary servohydraulic loading systems realize the prescribed load history accurately at very low testing speeds only. If the speeds used for constant amplitude testing are applied to stochastic fatigue...... testing, quite unacceptable errors are introduced. Usually this problem is solved by running the tests at very low speeds and by editing the load history in order to reduce the duration of the test. In this paper a new method for control of stochastic fatigue tests is proposed. It is based on letting the...... allowable speed by a factor from 10 to 30....

  9. Vehicle speed control transition module and method

    Mangan, E.L.; Conklin, B.

    1986-12-16

    An apparatus is described for automatically controlling the speed of a driverless vehicle comprising a stationary frame supporting first, second and third aligned drive tubes between tracks on the frame and which are adapted to support a driverless vehicle. A means is included for independently driving the first, second and third drive tubes such that each tube, when driven, rotates about its longitudinal axis, sensor means disposed along the frame for actuation by a driverless vehicle. The means for independently driving the drive tubes includes variable speed drive means responsive to the sensor means fro driving the second tube between first and second speeds. A method is described of automatically controlling the speed of a driverless vehicle which travels along first, second and third aligned drive tubes by frictional contact therewith. It maintains the first, second, and third drive tubes out of mechanical engagement with each other at all times, sensing the location of the driverless vehicle, driving the first drive tube at a first speed, driving the third drive tube at a second at a second speed. It also varies the speed of the second drive tube from the first speed to the second speed based on the sensed location of the driverless vehicle while the vehicle is driven by contact with the second drive tube.

  10. Movement speed is biased by prior experience

    Yousif, Nada; Greenwood, Richard; Rothwell, John C.; Diedrichsen, Jörn

    2013-01-01

    How does the motor system choose the speed for any given movement? Many current models assume a process that finds the optimal balance between the costs of moving fast and the rewards of achieving the goal. Here, we show that such models also need to take into account a prior representation of preferred movement speed, which can be changed by prolonged practice. In a time-constrained reaching task, human participants made 25-cm reaching movements within 300, 500, 700, or 900 ms. They were then trained for 3 days to execute the movement at either the slowest (900-ms) or fastest (300-ms) speed. When retested on the 4th day, movements executed under all four time constraints were biased toward the speed of the trained movement. In addition, trial-to-trial variation in speed of the trained movement was significantly reduced. These findings are indicative of a use-dependent mechanism that biases the selection of speed. Reduced speed variability was also associated with reduced errors in movement amplitude for the fast training group, which generalized nearly fully to a new movement direction. In contrast, changes in perpendicular error were specific to the trained direction. In sum, our results suggest the existence of a relatively stable but modifiable prior of preferred movement speed that influences the choice of movement speed under a range of task constraints. PMID:24133220

  11. Comparison of High Speed Congestion Control Protocols

    Jawhar Ben Abed

    2012-10-01

    Full Text Available Congestion control limits the quantity of information input at a rate less important than that of thetransmission one to ensure good performance as well as protect against overload and blocking of thenetwork. Researchers have done a great deal of work on improving congestion control protocols,especially on high speed networks.In this paper, we will be studying the congestion control alongside low and high speed congestion controlprotocols. We will be also simulating, evaluating, and comparing eight of high speed congestion controlprotocols : Bic TCP, Cubic TCP, Hamilton TCP, HighSpeed TCP, Illinois TCP, Scalable TCP,Compound TCP and YeAH TCP, with multiple flows.

  12. Rotor Speed Detection Method for Vector Control of Induction Motor without Speed Sensor Utilizing Slot Harmonics

    Kiyotake, Hirofumi; Shinohara, Katsuji; Yamamoto, Kichiro

    Speed sensorless vector controlled induction motor drives are the standard choice in many industrial applications, but this can hardly control torque and rotor speed at low speed. Recently, a method based on the high-frequency signal injection has been studied. This paper presents a method for suppressing the effects of the saturation saliency by using high pass filter, and a new approach to estimate the rotor speed. The effectiveness of these methods are demonstrated through experimental results showing both good suppression of saturation harmonics and good sensorless speed control at low speed.

  13. A study of speed limits and speed control measures for the urban arterial road

    Wichuda Satiennam

    2015-06-01

    Full Text Available Speed limits in accordance with environment and road functions have been used as a fundamental tool for speed management and road safety. This paper presents literatures review of speed limits measure and results from the study on speed limits problem and driver attitude toward the speed limit and speed control measure. Area of study is on the arterial road where the Mittaprab Highway passed through Khon Kaen City. The study found that improper designation of road functions is the main cause of complexity and difficulty on safety management. It suggests more researches on speed limit setting methods to accommodate the road conditions of the country. In order to increase effectiveness of speed limits measure, this paper suggests transportation-related authorities to classify this area to be the urban arterial road, to set proper speed limits, and to modify the road environment in accordance with its function. More measures to enhance speed limit effectiveness and to reduce accident are included automatic speed control devices, speed limits warning signs, and advertisement signs to use the bypass route. These could enhance the effective speed management program.

  14. Probability distributions for offshore wind speeds

    In planning offshore wind farms, short-term wind speeds play a central role in estimating various engineering parameters, such as power output, extreme wind load, and fatigue load. Lacking wind speed time series of sufficient length, the probability distribution of wind speed serves as the primary substitute for data when estimating design parameters. It is common practice to model short-term wind speeds with the Weibull distribution. Using 10-min wind speed time series at 178 ocean buoy stations ranging from 1 month to 20 years in duration, we show that the widely-accepted Weibull distribution provides a poor fit to the distribution of wind speeds when compared with more complicated models. We compare distributions in terms of three different metrics: probability plot R2, estimates of average turbine power output, and estimates of extreme wind speed. While the Weibull model generally gives larger R2 than any other 2-parameter distribution, the bimodal Weibull, Kappa, and Wakeby models all show R2 values significantly closer to 1 than the other distributions considered (including the Weibull), with the bimodal Weibull giving the best fits. The Kappa and Wakeby distributions fit the upper tail (higher wind speeds) of a sample better than the bimodal Weibull, but may drastically over-estimate the frequency of lower wind speeds. Because the average turbine power is controlled by high wind speeds, the Kappa and Wakeby estimate average turbine power output very well, with the Kappa giving the least bias and mean square error out of all the distributions. The 2-parameter Lognormal distribution performs best for estimating extreme wind speeds, but still gives estimates with significant error. The fact that different distributions excel under different applications motivates further research on model selection based upon the engineering parameter of interest.

  15. Speed of evolution on graphs

    Sui, Xiukai; Wu, Bin; Wang, Long

    2015-12-01

    The likelihood that a mutant fixates in the wild population, i.e., fixation probability, has been intensively studied in evolutionary game theory, where individuals' fitness is frequency dependent. However, it is of limited interest when it takes long to take over. Thus the speed of evolution becomes an important issue. In general, it is still unclear how fixation times are affected by the population structure, although the fixation times have already been addressed in the well-mixed populations. Here we theoretically address this issue by pair approximation and diffusion approximation on regular graphs. It is shown (i) that under neutral selection, both unconditional and conditional fixation time are shortened by increasing the number of neighbors; (ii) that under weak selection, for the simplified prisoner's dilemma game, if benefit-to-cost ratio exceeds the degree of the graph, then the unconditional fixation time of a single cooperator is slower than that in the neutral case; and (iii) that under weak selection, for the conditional fixation time, limited neighbor size dilutes the counterintuitive stochastic slowdown which was found in well-mixed populations. Interestingly, we find that all of our results can be interpreted as that in the well-mixed population with a transformed payoff matrix. This interpretation is also valid for both death-birth and birth-death processes on graphs. This interpretation bridges the fixation time in the structured population and that in the well-mixed population. Thus it opens the avenue to investigate the challenging fixation time in structured populations by the known results in well-mixed populations.

  16. Occupant kinematics in low-speed frontal sled tests: Human volunteers, Hybrid III ATD, and PMHS.

    Beeman, Stephanie M; Kemper, Andrew R; Madigan, Michael L; Franck, Christopher T; Loftus, Stephen C

    2012-07-01

    A total of 34 dynamic matched frontal sled tests were performed, 17 low (2.5g, Δv=4.8kph) and 17 medium (5.0g, Δv=9.7kph), with five male human volunteers of approximately 50th percentile height and weight, a Hybrid III 50th percentile male ATD, and three male PMHS. Each volunteer was exposed to two impulses at each severity, one relaxed and one braced prior to the impulse. A total of four tests were performed at each severity with the ATD and one trial was performed at each severity with each PMHS. A Vicon motion analysis system, 12 MX-T20 2 megapixel cameras, was used to quantify subject 3D kinematics (±1mm) (1kHz). Excursions of select anatomical regions were normalized to their respective initial positions and compared by test condition and between subject types. The forward excursions of the select anatomical regions generally increased with increasing severity. The forward excursions of relaxed human volunteers were significantly larger than those of the ATD for nearly every region at both severities. The forward excursions of the upper body regions of the braced volunteers were generally significantly smaller than those of the ATD at both severities. Forward excursions of the relaxed human volunteers and PMHSs were fairly similar except the head CG response at both severities and the right knee and C7 at the medium severity. The forward excursions of the upper body of the PMHS were generally significantly larger than those of the braced volunteers at both severities. Forward excursions of the PMHSs exceeded those of the ATD for all regions at both severities with significant differences within the upper body regions. Overall human volunteers, ATD, and PMHSs do not have identical biomechanical responses in low-speed frontal sled tests but all contribute valuable data that can be used to refine and validate computational models and ATDs used to assess injury risk in automotive collisions. PMID:22342960

  17. A Simplified Relativity Expression for Speeds Approaching the Speed of Light.

    Rowell, Neal P.

    1984-01-01

    Describes a simplified method of calculating the speeds necessary to cause large relativistic changes and to determine the magnitudes of physical quantities as an object approaches the speed of light. Provides equations and two completed example problems. (JM)

  18. 32 CFR 935.132 - Speed limits.

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on Wake Island shall operate it at a speed— (a) That is reasonable, safe, and proper, considering time...

  19. Speed Management Strategies; A Systematic Review

    Homayoun Sadeghi-Bazargani

    2016-07-01

    Full Text Available Objective: To systematically identify the various methods of speed management and their effects. Methods: A systematic search was performed in Science Direct, Ovid Medline, Scopus, PubMed and ProQuest databases from April to June 2015. Hand searching and reference of selected articles were used to improve article identification. Articles published after 1990 which had reported on efficacy/effectiveness of speed management strategies were included. Data were extracted using pre-defined extraction table. Results: Of the 803 retrieved articles, 22 articles were included in this review. Most of the included articles (63% had before-after design and were done in European countries. Speed cameras, engineering schemes, intelligent speed adaption (ISA, speed limits and zones, vehicle activated sign and integrated strategies were the most common strategies reported in the literature. Various strategies had different effects on mean speed of the vehicles ranging from 1.6 to 10 km/h. Moreover, 8-65% and 11-71% reduction was reported in person injured accidents and fatal accidents, respectively as a result of employing various strategies. Conclusion: Literature revealed positive effects of various speed management strategies. Using various strategies was mostly dependent on road characteristics, driver’s attitude about the strategy as well as economic and technological capabilities of the country. Political support is considered as a main determinant in selecting speed management strategies.

  20. On the constancy of light speed

    Rouf, Abdul

    2009-01-01

    Method given for intuitively visualizing constancy of light speed. Using mass-energy equivalence, we can show with the help of simple thought experiments, that velocity time dilation and gravitational time dilation are a necessary consequence of principle of relativity. Speed of light is discussed in the context of each kind of time dilation.

  1. Speed Management Strategies; A Systematic Review

    Sadeghi-Bazargani, Homayoun; Saadati, Mohammad

    2016-01-01

    Objective: To systematically identify the various methods of speed management and their effects. Methods: A systematic search was performed in Science Direct, Ovid Medline, Scopus, PubMed and ProQuest databases from April to June 2015. Hand searching and reference of selected articles were used to improve article identification. Articles published after 1990 which had reported on efficacy/effectiveness of speed management strategies were included. Data were extracted using pre-defined extraction table. Results: Of the 803 retrieved articles, 22 articles were included in this review. Most of the included articles (63%) had before-after design and were done in European countries. Speed cameras, engineering schemes, intelligent speed adaption (ISA), speed limits and zones, vehicle activated sign and integrated strategies were the most common strategies reported in the literature. Various strategies had different effects on mean speed of the vehicles ranging from 1.6 to 10 km/h. Moreover, 8-65% and 11-71% reduction was reported in person injured accidents and fatal accidents, respectively as a result of employing various strategies. Conclusion: Literature revealed positive effects of various speed management strategies. Using various strategies was mostly dependent on road characteristics, driver’s attitude about the strategy as well as economic and technological capabilities of the country. Political support is considered as a main determinant in selecting speed management strategies.

  2. Does Extensive Reading Promote Reading Speed?

    He, Mu

    2014-01-01

    Research has shown a wide range of learning benefits accruing from extensive reading. Not only is there improvement in reading, but also in a wide range of language uses and areas of language knowledge. However, few research studies have examined reading speed. The existing literature on reading speed focused on students' reading speed…

  3. The Design of Sport Bicycle Speed Odometer

    Dongbing Liu

    2013-04-01

    Full Text Available As bicycle sport equipment, a sport bike needs a speed and distance measuring device, due to the characteristic of road cycling, thereby mastering the state of motion. According to external conditions such as temperature, wind speed, the bike can make the appropriate adjustment to achieve the best movement effect. The bicycle speed odometer is a major accessibility tool that satisfies with needs of the people with fast development. This study elaborated a bike speed odometer design based on Hall element, taking AT89C52 single chip as the core, measuring speed with A44E Hall sensor, to finish the bike mileage/speed measurement and statistics by displaying bike mileage and speed in real time. By using the Hall elements, the hardware of speed odometer input the number of pulse of per circle into the single-chip computer system. Then the signal processed by the single-chip computer displays. The software is programmed with assembly language and modular design idea. The design of the hardware circuit is simple and the subroutine has universal property, which fully meet the design requirements and possess a wide range of application and dissemination value.

  4. Contrast affects flicker and speed perception differently

    Thompson, P.; Stone, L. S.

    1997-01-01

    We have previously shown that contrast affects speed perception, with lower-contrast, drifting gratings perceived as moving slower. In a recent study, we examined the implications of this result on models of speed perception that use the amplitude of the response of linear spatio-temporal filters to determine speed. In this study, we investigate whether the contrast dependence of speed can be understood within the context of models in which speed estimation is made using the temporal frequency of the response of linear spatio-temporal filters. We measured the effect of contrast on flicker perception and found that contrast manipulations produce opposite effects on perceived drift rate and perceived flicker rate, i.e., reducing contrast increases the apparent temporal frequency of counterphase modulated gratings. This finding argues that, if a temporal frequency-based algorithm underlies speed perception, either flicker and speed perception must not be based on the output of the same mechanism or contrast effects on perceived spatial frequency reconcile the disparate effects observed for perceived temporal frequency and speed.

  5. Reducing Heating In High-Speed Cinematography

    Slater, Howard A.

    1989-01-01

    Infrared-absorbing and infrared-reflecting glass filters simple and effective means for reducing rise in temperature during high-speed motion-picture photography. "Hot-mirror" and "cold-mirror" configurations, employed in projection of images, helps prevent excessive heating of scenes by powerful lamps used in high-speed photography.

  6. Perceived visual speed constrained by image segmentation

    Verghese, P.; Stone, L. S.

    1996-01-01

    Little is known about how or where the visual system parses the visual scene into objects or surfaces. However, it is generally assumed that the segmentation and grouping of pieces of the image into discrete entities is due to 'later' processing stages, after the 'early' processing of the visual image by local mechanisms selective for attributes such as colour, orientation, depth, and motion. Speed perception is also thought to be mediated by early mechanisms tuned for speed. Here we show that manipulating the way in which an image is parsed changes the way in which local speed information is processed. Manipulations that cause multiple stimuli to appear as parts of a single patch degrade speed discrimination, whereas manipulations that perceptually divide a single large stimulus into parts improve discrimination. These results indicate that processes as early as speed perception may be constrained by the parsing of the visual image into discrete entities.

  7. Study of speed endurance middle distance runners

    Golovaschenko R.V.

    2013-12-01

    Full Text Available Purpose : To investigate the boost performance speed endurance runners who specialize in middle-distance running . Material and methods : The study involved team members Vinnytsia region in an amount of 44 people, whose average age was 20,2 ± 2,1 years. Classes are held during the 21-day mesocycle, 5 times a week, twice a day. Things were aimed at enhancing the development of indicators of special speed endurance. Results : The dynamics of the running speed of the model segments that characterize speed endurance athletes. Proved that the improved running 400 meter intervals helps reduce travel time competitive distance of 1500 meters. Conclusion : The use of the program contributes to higher speed endurance, which determines the result in the women's 1,500 meters.

  8. Dynamically possible pattern speeds of double bars

    Maciejewski, Witold

    2009-01-01

    The method to study oscillating potentials of double bars, based on invariant loops, is introduced here in a new way, intended to be more intelligible. Using this method, I show how the orbital structure of a double-barred galaxy (nested bars) changes with the variation of nuclear bar's pattern speed. Not all pattern speeds are allowed when the inner bar rotates in the same direction as the outer bar. Below certain minimum pattern speed orbital support for the inner bar abruptly disappears, while high values of this speed lead to loops that are increasingly round. For values between these two extremes, loops supporting the inner bar extend further out as its pattern speed decreases, and they become more eccentric and pulsate more. These findings do not apply to counter-rotating inner bars.

  9. "Defining Computer 'Speed': An Unsolved Challenge"

    CERN. Geneva

    2012-01-01

    Abstract: The reason we use computers is their speed, and the reason we use parallel computers is that they're faster than single-processor computers. Yet, after 70 years of electronic digital computing, we still do not have a solid definition of what computer 'speed' means, or even what it means to be 'faster'. Unlike measures in physics, where the definition of speed is rigorous and unequivocal, in computing there is no definition of speed that is universally accepted. As a result, computer customers have made purchases misguided by dubious information, computer designers have optimized their designs for the wrong goals, and computer programmers have chosen methods that optimize the wrong things. This talk describes why some of the obvious and historical ways of defining 'speed' haven't served us well, and the things we've learned in the struggle to find a definition that works. Biography: Dr. John Gustafson is a Director ...

  10. Sensorless Speed Control including zero speed of Non Salient PM Synchronous Drives

    Rasmussen, Henrik

    2005-01-01

    including the rotor speed. Assuming motor parameters known the design achieves stability with guaranteed region of attraction even at zero speed. The control method is made robust at zero and low speed by changing the direct vector current component to a value different from zero. In order to verify the...

  11. Using a High-Speed Camera to Measure the Speed of Sound

    Hack, William Nathan; Baird, William H.

    2012-01-01

    The speed of sound is a physical property that can be measured easily in the lab. However, finding an inexpensive and intuitive way for students to determine this speed has been more involved. The introduction of affordable consumer-grade high-speed cameras (such as the Exilim EX-FC100) makes conceptually simple experiments feasible. Since the…

  12. 76 FR 31454 - Special Conditions: Gulfstream Model GVI Airplane; Automatic Speed Protection for Design Dive Speed

    2011-06-01

    ... for Gulfstream GVI airplanes was published in the Federal Register on February 16, 2011 (76 FR 8917...; Automatic Speed Protection for Design Dive Speed AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... high speed protection system. These special conditions contain the additional safety standards that...

  13. The Effects of a Speed Reading Course and Speed Transfer to Other Types of Texts

    Yen, Tran Thi Ngoc

    2012-01-01

    Reading fluency plays an important part in academic achievement at colleges and universities. Speed reading courses, along with repeated reading and extensive reading, are popularly used methods to help students increase their reading speed. Several studies have shown the positive influence of a speed reading course in L2/FL on students' reading…

  14. Wildlife speed cameras: measuring animal travel speed and day range using camera traps

    Rowcliffe, J.M.; Jansen, P.A.; Kays, R.; Kranstauber, B.; Carbone, C.

    2016-01-01

    Travel speed (average speed of travel while active) and day range (average speed over the daily activity cycle) are behavioural metrics that influence processes including energy use, foraging success, disease transmission and human-wildlife interactions, and which can therefore be applied to a range

  15. Mini barge shuttle speeds in ice

    Bronson, M. [BP Exploration Alaska Inc., Anchorage, AK (United States); McAdams, F.; McHale, J. [Alaska Clean Seas, Prudhoe Bay, AK (United States)

    2002-07-01

    The oil response capabilities in the nearshore waters of the Alaska North Slope are equally important to the oil industry and government regulators. Alaska Clean Seas has developed a way to store recovered oil in small tank barges in order to meet the challenge of cleaning up oil spills in drift ice. Workboats are used to take mini barges loaded with recovered oil to a nearby barge or shore facility for off-loading. In July 2000, after spring break-up, the mini barges were tested by Alaska Clean Seas. The test was designed to measure the speeds of the oil spill response workboats. Mini barges with a capacity of 249 barrels were tested along with 500 and 900 horsepower workboats. The workboats moved the mini barges by towing, on-hip, and by pushing. Transit in low ice concentrations had a mean speed of more than 5 knots. Transits in higher ice concentrations had a mean speed of 3 knots. It was noted that transit speeds of the mini barges did not vary much with other measured factors. The speed for towing, pushing and in-hip were the same. The two classes of towing vessels moved at the same speed regardless of the weight they carried. However, the difference between speeds in the two ice concentrations is statistically significant, according to the Wilcoxon rank test. 1 tab., 1 fig.

  16. Wake flow characteristics at high wind speed

    Aagaard Madsen, Helge; Larsen, Torben J.; Larsen, Gunner Chr.;

    2016-01-01

    Wake flow characteristic at high wind speeds is the main subject of this paper. Although the wake losses decrease at high wind speeds it has been found in a recent study that for multiple wake inflow the increase in loading due to wake effects are substantial even at wind speeds well above rated...... first flow regime comprising the first turbines in a row the local mean wind speed over the rotor disc is found to decrease linearly from turbine to turbine for the turbines operating at maximum power but also to some extend extend below rated power. The second flow regime is characterized by a constant...... local equilibrium wind speed. Based on the present results the equilibrium wind speed normalized with the inflow wind speed varies from about 0.4 for a spacing of 3D to slightly above 0.6 for a 9D spacing at an ambient turbulence intensity equal 6%. It is also found that for a turbine in the...

  17. Perceptual distortions of speed at low luminance: evidence inconsistent with a Bayesian account of speed encoding.

    Hammett, Stephen T; Champion, Rebecca A; Thompson, Peter G; Morland, Antony B

    2007-02-01

    Our perception of speed has been shown to be distorted under a number of viewing conditions. Recently the well-known reduction of perceived speed at low contrast has led to Bayesian models of speed perception that account for these distortions with a slow speed 'prior'. To test the predictive, rather than the descriptive, power of the Bayesian approach we have investigated perceived speed at low luminance. Our results indicate that, for the mesopic and photopic range (0.13-30 cd m(-2)) the perceived speed of lower luminance patterns is virtually unaffected at low speeds (4 deg s(-1)). We show here that the results can be accounted for by an extension to a simple ratio model of speed encoding [Hammett, S. T., Champion, R. A., Morland, A. & Thompson, P. G. (2005). A ratio model of perceived speed in the human visual system. Proceedings of Royal Society B, 262, 2351-2356.] that takes account of known changes in neural responses as a function of luminance, contrast and temporal frequency. The results are not consistent with current Bayesian approaches to modelling speed encoding that postulate a slow speed prior. PMID:17011014

  18. The Effect of Speed Camera Warning Sign on Vehicle Speed in School Zones

    M.M. Rohani

    2014-12-01

    Full Text Available Driving too fast is one of the most prevalent factors that contribute to traffic crashes. In school zones, staying alert and obeying the posted speed limit especially during the school period are imperative for public safety, particularly involving children. Encouraging motorists to travel at safe speeds through the installation of yellow transverse bars at Seri Sabak Uni School and Pintas Puding School was found to be ineffective. Drivers were observed to have violated the 30 km/h speed limit and more seriously, driven over the speed limits of adjoining roads. Consequently, speed camera warning signs were erected as a pre-emptive measure to curtail speeding problems in the school zones. From impact studies carried out to measure the effectiveness of these signs, it was found that the speed camera warning signs were also not able to change driver behavior.

  19. Handbook of asynchronous machines with variable speed

    Razik, Hubert

    2013-01-01

    This handbook deals with the asynchronous machine in its close environment. It was born from a reflection on this electromagnetic converter whose integration in industrial environments takes a wide part. Previously this type of motor operated at fixed speed, from now on it has been integrated more and more in processes at variable speed. For this reason it seemed useful, or necessary, to write a handbook on the various aspects from the motor in itself, via the control and while finishing by the diagnosis aspect. Indeed, an asynchronous motor is used nowadays in industry where variation speed a

  20. Speed Control of Separately Excited DC Motor

    Moleykutty George

    2008-01-01

    Full Text Available This paper proposes the speed control of a separately excited dc motor (SEDM by varying armature voltage. The novelty of this paper lies in the application of nonlinear autoregressive-moving average (NARMA–L2 controller for the speed control of SEDM. This paper also discusses speed control of a SEDM using chopper circuit. The performance of the proposed system has been compared with the traditional one using conventional controllers. The entire system has been modeled using MATLAB 7.0 toolbox. It has been found that both PI and hysteresis current controllers could be eliminated by the use of NARMA-L2 controller.

  1. Cascade Speed Control Of Dc Motor

    Anagha, Ranjith K; Anand C.P; Rahul Das; Anusha A.S

    2014-01-01

    Abstract: This paper presents a MATLAB aided Cascade designed controller to control and monitor the DC motor speed. First, design the driver circuit of the DC motor and use the microcontroller PIC16F877A to collect the feedback signals from the current sensor and optical encoder. The measured speed and current are serially transmitted to PC using RS232. By the MATLAB aided cascade controller, where inner loop is the current loop and outer loop is the speed loop, the parameters are adjusted to...

  2. Designing for High-Speed Ships

    Røed, Bjarte Knappen

    2007-01-01

    Fast patrol boats are high-speed vessels operated by the Royal Norwegian Navy (RNoN). These ships are 36,5 meters long, have a beam of 6,2 meters and operate at high speed (32 knots – 16,5 meters per second) in very restricted waters. The fast patrol boats are war ships and navigation tasks performed by the crews are different from those in civilian high-speed craft. A team of five persons navigate the fast patrol boats, and navigation is based on traditional means such as visual observations...

  3. Map Matching for Intelligent Speed Adaptation

    Tradisauskas, Nerius; Juhl, Jens; Lahrmann, Harry;

    2007-01-01

    The availability of Global Navigation Satellite Systems enables sophisticated vehicle guidance and advisory systems such as Intelligent Speed Adaptation (ISA) systems. In ISA systems, it is essential to be able to position vehicles within a road network. Because digital road networks as well as GPS...... positioning are often inaccurate, a technique known as map matching is needed that aims to use this inaccurate data for determining a vehicle's real road-network position. Then, knowing this position, an ISA system can compare the vehicle's speed with the speed limit in effect and react appropriately. This...

  4. Fiber Laser for Wind Speed Measurements

    Olesen, Anders Sig

    This PhD thesis evaluates the practical construction and use of a Frequency Stepped Pulse Train modulated coherent Doppler wind lidar (FSPT lidar) for wind speed measurement. The concept of Doppler lidar is introduced as a means to measure line of sight wind speed by the Doppler shift of reflected...... concept wind speed measurements obtained with the FSPT lidar are shown. This is followed by a discussion of the advantages and disadvantages of a FSPT lidar compared to a CW and a pulsed lidar system, and further avenues for evolving the concepts....

  5. Advanced nonlinear engine speed control systems

    Vesterholm, Thomas; Hendricks, Elbert

    1994-01-01

    Several subsidiary control problems have turned out to be important for improving driveability and fuel consumption in modern spark ignition (SI) engine cars. Among these are idle speed control and cruise control. In this paper the idle speed and cruise control problems will be treated as one......: accurately tracking of a desired engine speed in the presence of model uncertainties and severe load disturbances. This is accomplished by using advanced nonlinear control techniques such as input/output-linearization and sliding mode control. These techniques take advantage of a nonlinear model of the...

  6. Optimal speed of hypersonic cruise flight

    2011-01-01

    A coupling frame of speed gain and maintain was suggested to assess the flight performance of hypersonic cruise vehicles(HCV).The optimal cruise speed was obtained by analyzing the flight performance measured by the ratio of initial boost mass to generalized payload.The performance of HCVs based on rockets and air-breathing ramjets was studied and compared to that of a minimum-energy ballistic trajectory under a certain flight distance.It is concluded that rocket-based HCVs flying at the optimal speed ar...

  7. A Novel Motor-Speed-Regulation Method

    Huang Zhou

    2016-01-01

    Full Text Available The traditional doubly-fed motor has less reliability because it needs carbon brushes and sliding rings which are not highly reliable. The brushless doubly-fed machine costs a lot for its framework requires special designing and processing. To overcome the disadvantages of the two kinds of motors, this paper focuses on a novel method of motor speed regulation which is based on rotating feeding. The motor speed changing around its rated speed can be realized based on the method without any carbon brush or sliding ring on the prosaic electrical motors. On the basis of the full controlled thyristor rectifying bridge structure, the basic idea is introduced; the advantages and disadvantages of this method are analyzed. This kind of systems can replace the brushed or brushless double-fed systems. They are very suitable for driving fans or pumps, or power-generating systems with variable speed constant frequency such as wind power or water power generating systems.

  8. The Trachtenberg Speed System of Basic Mathematics

    Trachtenberg, Jakob

    2011-01-01

    Jakow Trachtenberg believed that everyone is born with phenomenal abilities to calculate, he devised a set of rules that allows every child to make multiplication, division, addition, subtraction and square-root calculations with unerring accuracy and at remarkable speed.

  9. On China's High-Speed Railway Technology

    You-tong FANG

    2011-01-01

    Energy and environmental issues have become increasingly prominent in matters of transportation.Compared with road,air,and sea transportation,railway transportation has the advantages of a large transmission capacity,with rapid,safe,and on-time travel,requiring less land resources,with lower energy consumption,less environmental pollution,and the capacity to operate under most weather conditions.In particular,high-speed railway technology has been growing rapidly.Since the world's first high-speed railway was built in Japan in 1964,more than ten countries and regions have developed high-speed railways,operating over a total of more than 10000 km.High-speed railways not only provide the public with a new type of rapid,convenient,safe,and comfortable travel,but also greatly boost the socio-economic development of the country.

  10. Point Measurement of Detonation Wave Speed

    Lu, F. K.; Gupta, N. K. M.; Wilson, D. R.

    Accurate determination of the speed of a detonation wave is important for studies of detonation phenomena. Different types of sensors that measure pressure, ion and flame have been used for this purpose.

  11. Ultrahigh-Speed Optical Transmission Technology

    Weber, Hans-Georg

    2007-01-01

    Ultrahigh-speed optical transmission technology is a key technology for increasing the communication capacity. In optical fibre networks, the number of wavelength channels and the bit rate per wavelength channel, i.e. the TDM (Time Division Multiplexing) bit rate, determine the transmission capacity. Currently, TDM bit rates of more than 40 Gbit/s require optical signal processing (Optical Time Division Multiplexing, OTDM). OTDM bit rates of up to 1.2 Tbit/s have already been reported. The devices developed for ultrahigh-speed optical transmission are not limited to communication applications only. They are key devices for high-speed optical signal processing, i.e. monitoring, measurement and control, and will thus give a wide technological basis for innovative science and technology. All these aspects of ultrahigh-speed optical transmission technology are described in detail in this book.

  12. SSC high speed communication channel and interconnects

    This paper investigates potential metallic and optical technology applications in SSC high speed interconnects and/or communication channels. Primary focus will be placed on evaluating several metallic and optical interconnect structures. 7 refs., 3 figs

  13. Speed of vision depends on temporal expectancy

    Vangkilde, Signe Allerup; Bundesen, Claus

    2009-01-01

    Temporal expectations play an important role in optimizing future perception and behavior, but the nature of the attentional processes affected by our expectations is still widely debated. To investigate effects of expectations on the speed of visual processing, we employed a cued single-letter r......Temporal expectations play an important role in optimizing future perception and behavior, but the nature of the attentional processes affected by our expectations is still widely debated. To investigate effects of expectations on the speed of visual processing, we employed a cued single......-letter recognition task with stimuli of varied durations terminated by pattern masks. To obtain an estimate of processing speed unconfounded by motor components, we used accuracy-based measures rather than reaction times. Eight healthy young subjects completed a total of 4,000 trials each. A symbolic cue at the...... measured the processing speed at times t [[gt

  14. Study of Movement Speeds Down Stairs

    Hoskins, Bryan L

    2013-01-01

    The Study of Movement Speeds Down Stairs closely examines forty-three unique case studies on movement patterns down stairwells. These studies include observations made during evacuation drills, others made during normal usage, interviews with people after fire evacuations, recommendations made from compiled studies, and detailed results from laboratory studies. The methodology used in each study for calculating density and movement speed, when known, are also presented, and this book identifies an additional seventeen variables linked to altering movement speeds. The Study of Movement Speeds Down Stairs is intended for researchers as a reference guide for evaluating pedestrian evacuation dynamics down stairwells. Practitioners working in a related field may also find this book invaluable.

  15. Low Speed Wind Tunnel Facility (LSWTF)

    Federal Laboratory Consortium — Description: This facility consists of a large-scale, low-speed open-loop induction wind tunnel which has been modified to house a linear turbine cascade. A 125-hp...

  16. Speed of adjustment: Evidence from Borsa Istanbul

    Emrah Arioglu

    2014-06-01

    Full Text Available In this study, we investigate the speed of adjustment for leverage ratios of firms listed on Borsa Istanbul, in order to investigate the prediction of the trade-off theory, regarding capital structure rebalancing. For this purpose, we estimate the speed of adjustment by using Generalized Method of Moments system estimation technique. The results of this estimation suggest the speed of adjustment as approximately 29%. This significant speed of adjustment is consistent with the prediction of trade-off theory, which suggests that firms follow target capital structures and when the firms' leverage ratios deviate from these targets; they make financial decisions with the goal of closing the gap between the previous year's leverage and target leverage of the current period.

  17. The elite weightlifter's strength and speed qualities

    Yukhno Y.O.

    2010-01-01

    Full Text Available The problems of estimation of power and speed possibilities of skilled weightlifter's are considered. In an experiment used complex REV 9000. The method of biomechanics control is developed. It allows in optimum terms to estimate the level of development of separate biolinks of body of sportsman. Speed power possibilities of right extensor higher on the average on 13%. Razgibatel' has large readiness to active reduction in the conditions of considerable tensions.

  18. Speed control system for an access gate

    Bzorgi, Fariborz M.

    2012-03-20

    An access control apparatus for an access gate. The access gate typically has a rotator that is configured to rotate around a rotator axis at a first variable speed in a forward direction. The access control apparatus may include a transmission that typically has an input element that is operatively connected to the rotator. The input element is generally configured to rotate at an input speed that is proportional to the first variable speed. The transmission typically also has an output element that has an output speed that is higher than the input speed. The input element and the output element may rotate around a common transmission axis. A retardation mechanism may be employed. The retardation mechanism is typically configured to rotate around a retardation mechanism axis. Generally the retardation mechanism is operatively connected to the output element of the transmission and is configured to retard motion of the access gate in the forward direction when the first variable speed is above a control-limit speed. In many embodiments the transmission axis and the retardation mechanism axis are substantially co-axial. Some embodiments include a freewheel/catch mechanism that has an input connection that is operatively connected to the rotator. The input connection may be configured to engage an output connection when the rotator is rotated at the first variable speed in a forward direction and configured for substantially unrestricted rotation when the rotator is rotated in a reverse direction opposite the forward direction. The input element of the transmission is typically operatively connected to the output connection of the freewheel/catch mechanism.

  19. Towards a Speed of Light Internet

    Singla, Ankit; Chandrasekaran, Balakrishnan; Godfrey, P. Brighten; Maggs, Bruce

    2015-01-01

    In principle, a network can transfer data at nearly the speed of light. Today's Internet, however, is much slower: our measurements show that latencies are typically more than one, and often more than two orders of magnitude larger than the lower bound implied by the speed of light. Closing this gap would not only add value to today's Internet applications, but might also open the door to exciting new applications. Thus, we propose a grand challenge for the networking research community: buil...

  20. Speed Measurements of Residential Internet Access

    Goga, Oana; Teixeira, Renata

    2012-01-01

    The spread of residential broadband Internet access is raising the question of how to measure Internet speed. We argue that available bandwidth is a key metric of access link speed. Unfortunately, the performance of available bandwidth estimation tools has rarely been tested from hosts connected to residential networks. This paper compares the accuracy and overhead of state-of-the-art available bandwidth estimation tools from hosts connected to commercial ADSL and cable networks. Our results ...

  1. Thermophysical properties from the speed of sound

    Goodwin, A. R. H.

    1988-01-01

    The speed of sound in various gases between 250 and 350 K has been obtained from measurements of the frequencies of the radial modes of spherical acoustic resonators; two resonators were used and both apparatus are described. The radius of each resonator was obtained from the speed of sound in argon. Measurements with the 60 mm radius resonator were made below 115 kPa on the six substances: n-butane; methyipropane; n-pentane; methylbutane; dimethylpropane; and, methano...

  2. Compressibility, turbulence and high speed flow

    Gatski, Thomas B

    2013-01-01

    Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and

  3. Speed-Selector Guard For Machine Tool

    Shakhshir, Roda J.; Valentine, Richard L.

    1992-01-01

    Simple guardplate prevents accidental reversal of direction of rotation or sudden change of speed of lathe, milling machine, or other machine tool. Custom-made for specific machine and control settings. Allows control lever to be placed at only one setting. Operator uses handle to slide guard to engage or disengage control lever. Protects personnel from injury and equipment from damage occurring if speed- or direction-control lever inadvertently placed in wrong position.

  4. Wind speed estimation using multilayer perceptron

    Highlights: • We present a method for determining the average wind speed using neural networks. • We use data from that site in the short term and data from other nearby stations. • The inputs used in the ANN were wind speed and direction data from a station. • The method allows knowing the wind speed without topographical data. - Abstract: Wind speed knowledge is prerequisite in the siting of wind turbines. In consequence the wind energy use requires meticulous and specified knowledge of the wind characteristics at a location. This paper presents a method for determining the annual average wind speed at a complex terrain site by using neural networks, when only short term data are available for that site. This information is useful for preliminary calculations of the wind resource at a remote area having only a short time period of wind measurements measurement in a site. Artificial neural networks are useful for implementing non-linear process variables over time, and therefore are a useful tool for estimating the wind speed. The neural network used is multilayer perceptron with three layers and the supervised learning algorithm used is backpropagation. The inputs used in the neural network were wind speed and direction data from a single station, and the training patterns used correspond to sixty days data. The results obtained by simulating the annual average wind speed at the selected site based on data from nearby stations with correlation coefficients above 0.5 were satisfactory, compared with actual values. Reliable estimations were obtained, with errors below 6%

  5. Influence of Speed Governors of Hydropower Stations on Frequency Stabilization of Fixed-Speed Wind Farm

    AL Jowder, Fawzi A. Rahman

    2013-05-01

    This paper uses a small power system, consisting of two hydropower stations and a fixed-speed wind farm as sources of power, to study the influence of type of speed governor of hydropower stations on the frequency stabilization of the fixed-speed wind farm. As an example, two types of speed governors are selected which are (1) mechanical-hydraulic speed governor and (2) electrical-hydraulic speed governor. Rest of the speed governors can be also examined following the same methodology presented in the research. Two transfer functions, which correspond to the two speed governors, are developed for each hydropower station. The overall transfer function of the test power system is developed, and different study cases are presented. The frequency response analysis of the different transfer functions is used to compare the two speed governors based on their ability to stabilize the frequency deviation of the fixed-speed wind resulting from electrical or mechanical disturbances in the power systems. Time-domain simulations under a mechanical disturbance, represented by a wind gust, and an electrical disturbance, represented by three-phase to ground fault, are performed to validate the results of the frequency response analysis.

  6. 14 CFR 25.1515 - Landing gear speeds.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear,...

  7. Comment on Goldhammer's "Measuring Ability, Speed, or Both"

    Davison, Mark L.

    2016-01-01

    The answer to the question, "Ability, speed, or both?" may be "both at once" if speed is simply a manifestation of ability. If differences in speed are manifestations of differences in ability, then both speed and ability may reflect a single dimension best characterized by a single score. While measurement of speed has proven…

  8. Acquisition speed comparison of microscope software programs.

    Biehlmaier, Oliver; Hehl, Joachim; Csucs, Gabor

    2011-06-01

    Reliable software is a prerequisite for successful operation of a modern wide field fluorescence microscope. When used for live cell imaging, acquisition speed is of particular interest. This is both because biological processes can be highly-dynamic, and to avoid unnecessary photobleaching and phototoxicity of living samples. This article shows that besides the hardware (microscope) components themselves, the acquisition control software is an important influencing factor of speed performance. We tested and compared the speed performance of five different generic applications (Image-Pro Plus, MetaMorph, Micro-Manager, SlideBook, and Volocity) using typical experimental setups involving a single specific state-of-the-art fluorescence microscope configuration. The test measurements included multichannel experiments, z-stacking, burst acquisition, as well as combinations of these measurements with time-lapse acquisitions. The measured data provided values for guiding the testing and analysis of other microscope systems with similar configurations. Despite the identical hardware settings, significant and surprisingly large speed differences were evident among the various software applications. Additionally, no application was identifiable as the fastest in all tests. Our work pinpoints the importance of the control software in determining a system's "real" maximal imaging speed. The study could serve as basis for further tests, eventually influencing the system selection criteria for speed-sensitive applications. PMID:21604324

  9. Sound speed in downhole flow measurement.

    Ünalmis, Ö Haldun

    2016-07-01

    This paper describes the use of sound speed in flow measurement applications in the high-pressure/high-temperature downhole environment. The propagation speed of a sound wave is a powerful tool to extract useful information from a flowing fluid medium in pipe whether the medium consists of a single-phase or multiphase flow. Considering the complex nature of the flow patterns and changing phase fractions from reservoir to surface, utilizing the propagation speed of sound of a fluid mixture is not a trivial task, especially if the interest is real-time flow measurement. The demanding applications span a wide spectrum from noisy medium originating from fast-moving gas/liquid flows to quiet medium originating from slow-moving liquid/liquid flows. In the current work, multiple flow loop tests are conducted in different facilities to evaluate the direct use of sound speed in flow rate measurement and the results are associated with real-life field examples. A tool analysis map is developed that addresses the use of sound speed for flow measurement under different scenarios. Although most examples are based on strain-based local sensing of the flow, the use of sound speed is independent of the methodology and can be implemented by other methods such as acoustic-based distributed sensing. PMID:27475167

  10. Optimum Speed Calculation for Electrical Machine Optimization in Variable Speed Applications

    A.A. Nasiri

    2014-01-01

    Full Text Available Electro-Mechanical Batteries have important advantages compared with chemical batteries, especially in Low Earth Orbit satellites applications. High speed, slot-less, external rotor, permanent magnet machines are used in these systems as Motor/Generator. Commonly, optimizations of electrical machines are done in constant, nominal speed. But Electro-Mechanical Batteries are variable speed system. The efficiency is variable versus time, so, optimization in each single speed cannot necessarily cause the overall efficiency optimization. In this study, iron and copper losses are formulated versus speed variations of rotor. Then, for energy optimization, the optimization speed is achieved by equalizing the average iron loss and copper loss over a period of charge and discharge.

  11. Experimental determination of the critical welding speed in high speed MAG welding

    Hu Zhikun; Wu Chuansong

    2008-01-01

    In high speed MAG welding process, some weld formation defects may be encountered. To get good weld quality, the critical welding speed beyond which humping or undercutting weld bead can occur must be known for different conditions. In this research, high speed MAG welding tests were carried out to check out the effects of different factors on the critical welding speed. Through observing the weld bead profiles and the macrographs of the transverse sections of MAG welds, the occurrence tendency of humping weld was analyzed, and the values of critical welding speed were determined under different levels of welding current or voltage, and the effect of shielding gas compositions on the critical welding speed was also investigated.

  12. Wildlife speed cameras: measuring animal travel speed and day range using camera traps

    Rowcliffe, J. M.; Jansen, P A; Kays, R.; Kranstauber, B.; C. Carbone

    2016-01-01

    Travel speed (average speed of travel while active) and day range (average speed over the daily activity cycle) are behavioural metrics that influence processes including energy use, foraging success, disease transmission and human-wildlife interactions, and which can therefore be applied to a range of questions in ecology and conservation. These metrics are usually derived from telemetry or direct observations. Here, we describe and validate an entirely new alternative approach, using camera...

  13. Optimal swimming speeds reflect preferred swimming speeds of brook charr (Salvelinus fontinalis Mitchill, 1874)

    Tudorache, Christian; O’Keefe, Robyn A.; Benfey, Tillmann J.

    2011-01-01

    Several measures have been developed to quantify swimming performance to understand various aspects of ecology and behaviour, as well as to help design functional applications for fishways and aquaculture. One of those measures, the optimal swimming speed, is the speed at which the cost of transport (COT) is minimal, where COT is defined as the cost of moving unit mass over unit distance. The experimental protocol to determine the optimal swimming speed involves forced-swimming in a flume or ...

  14. 77 FR 24760 - Safety Advisory 2012-02; Restricted Speed

    2012-04-25

    ... Federal Railroad Administration Safety Advisory 2012-02; Restricted Speed AGENCY: Federal Railroad... speed. This safety advisory contains a preliminary discussion of recent train accidents involving a failure to operate at restricted speed and makes recommendations to railroads to ensure...

  15. Is the speed of light invariant or covariant?

    Sasso, Daniele

    2010-01-01

    According to the theory of ether light propagates with constant speed c with respect to the absolute reference frame and with respect to any other reference frame the speed of light is covariant. According to the theory of special relativity the speed of light is invariant with respect to any reference frame. The new theory of reference frames gives a different answer to this question with the consideration of two speeds of light: the physical speed and the relativistic speed. After consideri...

  16. SpeedUptrademark ion exchange column model

    The Savannah River Site (SRS) is studying non-elutable ion exchange using crystalline silicotitanate (CST) as a potential replacement for the In-Tank Precipitation process to remove Cesium from SRS soluble radioactive waste. A transient model to describe the process of loading Cesium onto the granular fixed bed in an ion exchange (IX) column has been developed using the SpeedUp software package. SpeedUp offers the advantage of smooth integration into other existing SpeedUp flowsheet models. The mathematical algorithm of a porous particle diffusion model was adopted to account for convection, axial dispersion, film mass transfer, and pore diffusion. The method of orthogonal collocation on finite elements was employed to solve the governing transport equations. The model allows the use of a non-linear Langmuir isotherm based on an ''effective'' binary ionic exchange process. The SpeedUp IX column model was tested by comparison with the analytical solutions of transport problems from the ion exchange literature. In addition, a sample calculation of a train of three CST IX columns was made using both the SpeedUp model and Purdue University's VERSE-LC code. This paper summarizes the model development and verification assessment

  17. Quantum speed limit for arbitrary initial states.

    Zhang, Ying-Jie; Han, Wei; Xia, Yun-Jie; Cao, Jun-Peng; Fan, Heng

    2014-01-01

    The minimal time a system needs to evolve from an initial state to its one orthogonal state is defined as the quantum speed limit time, which can be used to characterize the maximal speed of evolution of a quantum system. This is a fundamental question of quantum physics. We investigate the generic bound on the minimal evolution time of the open dynamical quantum system. This quantum speed limit time is applicable to both mixed and pure initial states. We then apply this result to the damped Jaynes-Cummings model and the Ohimc-like dephasing model starting from a general time-evolution state. The bound of this time-dependent state at any point in time can be found. For the damped Jaynes-Cummings model, when the system starts from the excited state, the corresponding bound first decreases and then increases in the Markovian dynamics. While in the non-Markovian regime, the speed limit time shows an interesting periodic oscillatory behavior. For the case of Ohimc-like dephasing model, this bound would be gradually trapped to a fixed value. In addition, the roles of the relativistic effects on the speed limit time for the observer in non-inertial frames are discussed. PMID:24809395

  18. Improved Algorithms Speed It Up for Codes

    Hazi, A

    2005-09-20

    Huge computers, huge codes, complex problems to solve. The longer it takes to run a code, the more it costs. One way to speed things up and save time and money is through hardware improvements--faster processors, different system designs, bigger computers. But another side of supercomputing can reap savings in time and speed: software improvements to make codes--particularly the mathematical algorithms that form them--run faster and more efficiently. Speed up math? Is that really possible? According to Livermore physicist Eugene Brooks, the answer is a resounding yes. ''Sure, you get great speed-ups by improving hardware,'' says Brooks, the deputy leader for Computational Physics in N Division, which is part of Livermore's Physics and Advanced Technologies (PAT) Directorate. ''But the real bonus comes on the software side, where improvements in software can lead to orders of magnitude improvement in run times.'' Brooks knows whereof he speaks. Working with Laboratory physicist Abraham Szoeke and others, he has been instrumental in devising ways to shrink the running time of what has, historically, been a tough computational nut to crack: radiation transport codes based on the statistical or Monte Carlo method of calculation. And Brooks is not the only one. Others around the Laboratory, including physicists Andrew Williamson, Randolph Hood, and Jeff Grossman, have come up with innovative ways to speed up Monte Carlo calculations using pure mathematics.

  19. Landscape structure and the speed of adaptation

    The role of fragmentation in the adaptive process is addressed. We investigate how landscape structure affects the speed of adaptation in a spatially structured population model. As models of fragmented landscapes, here we simulate the percolation maps and the fractal landscapes. In the latter the degree of spatial autocorrelation can be suited. We verified that fragmentation can effectively affect the adaptive process. The examination of the fixation rates and speed of adaptation discloses the dichotomy exhibited by percolation maps and fractal landscapes. In the latter, there is a smooth change in the pace of the adaptation process, as the landscapes become more aggregated higher fixation rates and speed of adaptation are obtained. On the other hand, in random percolation the geometry of the percolating cluster matters. Thus, the scenario depends on whether the system is below or above the percolation threshold. - Highlights: • The role of fragmentation on the adaptive process is addressed. • Our approach makes the linkage between population genetics and landscape ecology. • Fragmentation affects gene flow and thus influences the speed of adaptation. • The level of clumping determines how the speed of adaptation is influenced

  20. Mycielski approach for wind speed prediction

    Hocaoglu, Fatih O. [Afyon Kocatepe University, Department of Electronics and Communication Engineering, 03200 Afyonkarahisar (Turkey); Fidan, Mehmet; Gerek, Oemer N. [Anadolu University, Department of Electrical and Electronics Engineering, 26555 Eskisehir (Turkey)

    2009-06-15

    Wind speed modeling and prediction plays a critical role in wind related engineering studies. However, since the data have random behavior, it is difficult to apply statistical approaches with apriori and deterministic parameters. On the other hand, wind speed data have an important feature; extreme transitions from a wind state to a far different one are rare. Therefore, behavioral modeling is possible. Although several studies focus on global parametrization of wind data behavior, the literature in time-wise modeling and prediction is relatively small. In this study, a novel approach for wind speed modeling using the Mycielski algorithm is demonstrated. The algorithm accurately predicts the time variations of wind speed data in the sense of forecasting future values of wind data by analyzing the repeatedness in the history of the data. The prediction precision of the procedure is tested using wind speed data obtained from three different locations of Turkey (Kayseri, izmir and Antalya). Prediction results with high accuracy are obtained and presented. (author)

  1. Aerodynamic design on high-speed trains

    Ding, San-San; Li, Qiang; Tian, Ai-Qin; Du, Jian; Liu, Jia-Li

    2016-04-01

    Compared with the traditional train, the operational speed of the high-speed train has largely improved, and the dynamic environment of the train has changed from one of mechanical domination to one of aerodynamic domination. The aerodynamic problem has become the key technological challenge of high-speed trains and significantly affects the economy, environment, safety, and comfort. In this paper, the relationships among the aerodynamic design principle, aerodynamic performance indexes, and design variables are first studied, and the research methods of train aerodynamics are proposed, including numerical simulation, a reduced-scale test, and a full-scale test. Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface. Optimization design of the streamlined head includes conception design, project design, numerical simulation, and a reduced-scale test. Smooth design of the body surface is mainly used for the key parts, such as electric-current collecting system, wheel truck compartment, and windshield. The aerodynamic design method established in this paper has been successfully applied to various high-speed trains (CRH380A, CRH380AM, CRH6, CRH2G, and the Standard electric multiple unit (EMU)) that have met expected design objectives. The research results can provide an effective guideline for the aerodynamic design of high-speed trains.

  2. Sensor study for high speed autonomous operations

    Schneider, Anne; La Celle, Zachary; Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Close, Ryan

    2015-06-01

    As robotic ground systems advance in capabilities and begin to fulfill new roles in both civilian and military life, the limitation of slow operational speed has become a hindrance to the wide-spread adoption of these systems. For example, military convoys are reluctant to employ autonomous vehicles when these systems slow their movement from 60 miles per hour down to 40. However, these autonomous systems must operate at these lower speeds due to the limitations of the sensors they employ. Robotic Research, with its extensive experience in ground autonomy and associated problems therein, in conjunction with CERDEC/Night Vision and Electronic Sensors Directorate (NVESD), has performed a study to specify system and detection requirements; determined how current autonomy sensors perform in various scenarios; and analyzed how sensors should be employed to increase operational speeds of ground vehicles. The sensors evaluated in this study include the state of the art in LADAR/LIDAR, Radar, Electro-Optical, and Infrared sensors, and have been analyzed at high speeds to study their effectiveness in detecting and accounting for obstacles and other perception challenges. By creating a common set of testing benchmarks, and by testing in a wide range of real-world conditions, Robotic Research has evaluated where sensors can be successfully employed today; where sensors fall short; and which technologies should be examined and developed further. This study is the first step to achieve the overarching goal of doubling ground vehicle speeds on any given terrain.

  3. Improved Algorithms Speed It Up for Codes

    Huge computers, huge codes, complex problems to solve. The longer it takes to run a code, the more it costs. One way to speed things up and save time and money is through hardware improvements--faster processors, different system designs, bigger computers. But another side of supercomputing can reap savings in time and speed: software improvements to make codes--particularly the mathematical algorithms that form them--run faster and more efficiently. Speed up math? Is that really possible? According to Livermore physicist Eugene Brooks, the answer is a resounding yes. ''Sure, you get great speed-ups by improving hardware,'' says Brooks, the deputy leader for Computational Physics in N Division, which is part of Livermore's Physics and Advanced Technologies (PAT) Directorate. ''But the real bonus comes on the software side, where improvements in software can lead to orders of magnitude improvement in run times.'' Brooks knows whereof he speaks. Working with Laboratory physicist Abraham Szoeke and others, he has been instrumental in devising ways to shrink the running time of what has, historically, been a tough computational nut to crack: radiation transport codes based on the statistical or Monte Carlo method of calculation. And Brooks is not the only one. Others around the Laboratory, including physicists Andrew Williamson, Randolph Hood, and Jeff Grossman, have come up with innovative ways to speed up Monte Carlo calculations using pure mathematics

  4. Speed controller for an alternating - current motor

    A controller for a multi-phase ac motor that is subject to a large inertial load, e.g. an induction motor driving a heavy spinning rotor of a neutron chopper that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal Esub(L) having a meandering line frequency, includes a sensor which provides a feedback pulse train representative of the actual speed of the motor which is compared (by counting clock pulses between feedback pulses) with a reference clock signal in a computing unit to provide a motor control signal Esub(c). The motor control signal is a weighted linear sum of a speed error signal, a phase error signal, and a drift error signal, the magnitudes of which are recalculated and updated with each revolution of the motor shaft. The speed error signal is constant for large speed errors but highly sensitive to small speed errors. The stator windings of the motor are driven by variable-frequency power amplifiers which are controlled by the motor control signal Esub(c) via PROMs which store digital representations of sine and cosine waveforms in quadrature. (author)

  5. Plasma arc cutting: speed and cut quality

    When cutting metal with plasma arc cutting, the walls of the cut are narrower at the bottom than at the top. This lack of squareness increases as the cutting speed increases. A model of this phenomenon, affecting cut quality, is suggested. A thin liquid layer, which separates the plasma from the solid metal to be melted, plays a key role in the suggested model. This layer decreases heat transfer from the plasma to the solid metal; the decrease is more pronounced the higher the speed and the thicker the liquid metal layer. Since the layer is thicker at the bottom of the cut, the heat transfer effectiveness is lower at the bottom. The decrease in heat transfer effectiveness is compensated by the narrowness of the cut. The suggested model allows one to calculate the profile of the cut. The result of the calculations of the cutting speeds for plates of various thicknesses, at which the squareness of the cut is acceptable, agrees well with the speeds recommended by manufacturers. The second effect considered in the paper is the deflection of the plasma jet from the vertical at a high cutting speed. A qualitative explanation of this phenomenon is given. We believe the considerations of this paper are pertinent to other types of cutting with moving heat sources.

  6. WIND SPEED AND ENERGY POTENTIAL ANALYSES

    A. TOKGÖZLÜ

    2013-01-01

    Full Text Available This paper provides a case study on application of wavelet techniques to analyze wind speed and energy (renewable and environmental friendly energy. Solar and wind are main sources of energy that allows farmers to have the potential for transferring kinetic energy captured by the wind mill for pumping water, drying crops, heating systems of green houses, rural electrification's or cooking. Larger wind turbines (over 1 MW can pump enough water for small-scale irrigation. This study tried to initiate data gathering process for wavelet analyses, different scale effects and their role on wind speed and direction variations. The wind data gathering system is mounted at latitudes: 37° 50" N; longitude 30° 33" E and height: 1200 m above mean sea level at a hill near Süleyman Demirel University campus. 10 minutes average values of two levels wind speed and direction (10m and 30m above ground level have been recorded by a data logger between July 2001 and February 2002. Wind speed values changed between the range of 0 m/s and 54 m/s. Annual mean speed value is 4.5 m/s at 10 m ground level. Prevalent wind

  7. Fast thought speed induces risk taking.

    Chandler, Jesse J; Pronin, Emily

    2012-04-01

    In two experiments, we tested for a causal link between thought speed and risk taking. In Experiment 1, we manipulated thought speed by presenting neutral-content text at either a fast or a slow pace and having participants read the text aloud. In Experiment 2, we manipulated thought speed by presenting fast-, medium-, or slow-paced movie clips that contained similar content. Participants who were induced to think more quickly took more risks with actual money in Experiment 1 and reported greater intentions to engage in real-world risky behaviors, such as unprotected sex and illegal drug use, in Experiment 2. These experiments provide evidence that faster thinking induces greater risk taking. PMID:22395129

  8. Maximum speed of dewetting on a fiber

    Chan, Tak Shing; Snoeijer, Jacco H

    2011-01-01

    A solid object can be coated by a nonwetting liquid since a receding contact line cannot exceed a critical speed. We theoretically investigate this forced wetting transition for axisymmetric menisci on fibers of varying radii. First, we use a matched asymptotic expansion and derive the maximum speed of dewetting. For all radii we find the maximum speed occurs at vanishing apparent contact angle. To further investigate the transition we numerically determine the bifurcation diagram for steady menisci. It is found that the meniscus profiles on thick fibers are smooth, even when there is a film deposited between the bath and the contact line, while profiles on thin fibers exhibit strong oscillations. We discuss how this could lead to different experimental scenarios of film deposition.

  9. DAC 22 High Speed Civil Transport Model

    1992-01-01

    Between tests, NASA research engineer Dave Hahne inspects a tenth-scale model of a supersonic transport model in the 30- by 60-Foot Tunnel at NASA Langley Research Center, Hampton, Virginia. The model is being used in support of NASA's High-Speed Research (HSR) program. Langley researchers are applying advance aerodynamic design methods to develop a wing leading-edge flap system which significantly improves low-speed fuel efficiency and reduces noise generated during takeoff operation. Langley is NASA's lead center for the agency's HSR program, aimed at developing technology to help U.S. industry compete in the rapidly expanding trans-oceanic transport market. A U.S. high-speed civil transport is expected to fly in about the year 2010. As envisioned, it would fly 300 passengers across the Pacific in about four hours at Mach 2.4 (approximately 1,600 mph/1950 kph) for a modest increase over business class fares.

  10. Virtual inertia for variable speed wind turbines

    Zeni, Lorenzo; Rudolph, Andreas Jakob; Münster-Swendsen, Janus;

    2013-01-01

    Inertia provision for frequency control is among the ancillary services that different national grid codes will likely require to be provided by future wind turbines. The aim of this paper is analysing how the inertia response support from a variable speed wind turbine (VSWT) to the primary...... frequency control of a power system can be enhanced. Unlike fixed speed wind turbines, VSWTs do not inherently contribute to system inertia, as they are decoupled from the power system through electronic converters. Emphasis in this paper is on how to emulate VSWTs inertia using control of the power...... conventional generation. The range of wind speeds near the power limitation zone seems to be the most critical from a primary response point of view. The theoretical reasons behind this are elucidated in the paper. Copyright © 2012 John Wiley & Sons, Ltd....

  11. Theory-based categorization under speeded conditions

    Luhmann, Christian C.; Ahn, Woo-Kyoung; Palmeri, Thomas J.

    2009-01-01

    It is widely accepted that similarity influences rapid categorization, whereas theories can influence only more leisurely category judgments. In contrast, we argue that it is not the type of knowledge used that determines categorization speed, but rather the complexity of the categorization processes. In two experiments, participants learned four categories of items, each consisting of three causally related features. Participants gave more weight to cause features than to effect features, even under speeded response conditions. Furthermore, the time required to make judgments was equivalent, regardless of whether participants were using causal knowledge or base-rate information. We argue that both causal knowledge and base-rate information, once precompiled during learning, can be used at roughly the same speeds during categorization, thus demonstrating an important parallel between these two types of knowledge. PMID:17128608

  12. Miniature, Variable-Speed Control Moment Gyroscope

    Bilski, Steve; Kline-Schoder, Robert; Sorensen, Paul

    2011-01-01

    The Miniature Variable-Speed Control Moment Gyroscope (MVS-CMG) was designed for small satellites (mass from less than 1 kg up to 500 kg). Currently available CMGs are too large and heavy, and available miniature CMGs do not provide sufficient control authority for use on practical satellites. This primarily results from the need to greatly increase the speed of rotation of the flywheel in order to reduce the flywheel size and mass. This goal was achieved by making use of a proprietary, space-qualified, high-speed (100,000 rpm) motor technology to spin the flywheel at a speed ten times faster than other known miniature CMGs under development. NASA is supporting innovations in propulsion, power, and guidance and navigation systems for low-cost small spacecraft. One of the key enabling technologies is attitude control mechanisms. CMGs are particularly attractive for spacecraft attitude control since they can achieve higher torques with lower mass and power than reaction wheels, and they provide continuous torque capability that enables precision pointing (in contrast to on-off thruster control). The aim of this work was to develop a miniature, variable-speed CMG that is sized for use on small satellites. To achieve improved agility, these spacecraft must be able to slew at high rate, which requires attitude control actuators that can apply torques on the order of 5 N-m. The MVS-CMG is specifically designed to achieve a high-torque output with a minimum flywheel and system mass. The flywheel can be run over a wide range of speeds, which is important to help reduce/eliminate potential gimbal lock, and can be used to optimize the operational envelope of the CMG.

  13. Modifications in Wheelchair Propulsion Technique with Speed

    Ian Miles Russell

    2015-10-01

    Full Text Available Objective: Repetitive loading of the upper limb joints during manual wheelchair propulsion has been identified a factor that contributes to shoulder pain, leading to loss of independence and decreased quality of life. The purpose of this study was to determine how individual manual wheelchair users with paraplegia modify propulsion mechanics to accommodate expected increases in reaction forces generated at the pushrim with self-selected increases in wheelchair propulsion (WCP speed.Methods: Upper extremity kinematics and pushrim reaction forces were measured for 40 experienced manual wheelchair users with paraplegia while propelling on a stationary ergometer at self-selected free and fast propulsion speeds. Upper extremity kinematics and kinetics were compared within-subject between propulsion speeds. Between group and within subject differences were determined (α =0.05.Results: Increased propulsion speed was accompanied by increases in Reaction Force (RF magnitude (22 of 40, >10N and shoulder Net Joint Moment (NJM, 15 of 40, >10Nm and decreases in pushrim contact duration. Within-subject comparison indicated that 27% of participants modified their WCP mechanics with increases in speed by regulating RF orientation relative to the upper extremity segments.Conclusions: Reorientation of the RF relative to the upper extremity segments can be used as an effective strategy for mitigating rotational demands (NJM imposed on the shoulder at increased propulsion speeds. Identification of propulsion strategies that individuals can use to effectively accommodate for increases in RFs is an important step towards preserving musculoskeletal health of the shoulder and improving health-related quality of life.

  14. Measure Guideline: Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings

    Hunt, A.; Easley, S.

    2012-05-01

    The report evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provide a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

  15. Measure Guideline. Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings

    Hunt, A. [Building Media and the Building America Retrofit Alliance (BARA), Wilmington, DE (United States); Easley, S. [Building Media and the Building America Retrofit Alliance (BARA), Wilmington, DE (United States)

    2012-05-01

    This measure guideline evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provides a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

  16. Speed estimator for induction motor drive based on synchronous speed tracking

    S B Bodkhe; M V Aware; J G Chaudhari; J G Agrawal

    2015-06-01

    This paper presents a new open-loop speed estimation method for a three-phase induction motor drive. The open-loop speed estimators available in literature have the advantage of reduced computational stress over the observers but they share a common limitation of being largely dependent on flux and machine parameters. They involve integrations and differentiation in the algorithm that leads to serious error in estimation when subject to different operating conditions. The proposed estimator is based on synchronous speed tracking and is cost-effective. It is immune to any variation in machine parameters and noise. The synchronous speed is computed from stator frequency which is estimated on-line using the stator current signals. A unique, non-adaptive method for estimation of stator frequency within one-sixteenth of time period is also proposed to enhance the speed of estimation. Computer simulation and experimentation on a 2.2 kW Field oriented controlled induction motor drive is carried out to verify the performance of proposed speed estimator. The results show excellent response over a wide range of rotor speed in both directions including low speed and under different operating conditions. This confirms the effectiveness of the proposed method.

  17. Differential Effects of Intelligence, Perceptual Speed and Age on Growth in Attentional Speed and Accuracy

    Goldhammer, Frank; Rauch, Wolfgang A.; Schweizer, Karl; Moosbrugger, Helfried

    2010-01-01

    The study investigates the effects of intelligence, perceptual speed and age on intraindividual growth in attentional speed and attentional accuracy over the course of a 6-minute testing session. A sample of 193 subjects completed the Advanced Progressive Matrices and the Vienna Matrices Test representing intelligence, the tests Alertness and…

  18. Theme II. Speed limits and the driver. Advisory speed limits: Should they be expanded or not?

    Wegman, F.C.M.

    1985-01-01

    According to Dutch legislation, advisory speed limits should only be used on curves with a small radius, although there has been an increasing demand in recent years for w wider application of advisory speed limits. The behaviour of drivers on curves and the forces working on the vehicle and its occ

  19. Shadows over the speed of light

    Mares, J J; Spicka, V; Stavek, J; Sestak, J; Kristofik, J

    2016-01-01

    In this paper, we discuss some of the consequences of the CGPM (1983) definition of meter and, in particular, we discuss giving the speed of light an exact value. It is shown that this act touches the fundamental paradigms, such as the second postulate of the special theory of relativity (STR), the c-equivalence principle and the method of time synchronization. In order to fill the arising logical gaps, we suggest, among others, to weaken the second postulate of STR to a form directly confirmed by experiments and make new measurements of Maxwell's constant with accuracy comparable with that of the speed of light.

  20. Power, speed & automation with Adobe Photoshop

    Scott, Geoff

    2012-01-01

    This is a must for the serious Photoshop user! Power, Speed & Automation explores how to customize and automate Photoshop to increase your speed and productivity.  With numerous step-by-step instructions, the authors-two of Adobe's own software developers!- walk you through the steps to best tailor Photoshop's interface to your personal workflow; write and apply Actions; and use batching and scripts to process large numbers of images quickly and automatically.  You will learn how to build your own dialogs and panels to improve your production workflows in Photoshop, the secrets of changing

  1. High Speed SPM of Functional Materials

    Huey, Bryan D. [Univ. of Connecticut, Storrs, CT (United States)

    2015-08-14

    The development and optimization of applications comprising functional materials necessitates a thorough understanding of their static and dynamic properties and performance at the nanoscale. Leveraging High Speed SPM and concepts enabled by it, efficient measurements and maps with nanoscale and nanosecond temporal resolution are uniquely feasible. This includes recent enhancements for topographic, conductivity, ferroelectric, and piezoelectric properties as originally proposed, as well as newly developed methods or improvements to AFM-based mechanical, friction, thermal, and photoconductivity measurements. The results of this work reveal fundamental mechanisms of operation, and suggest new approaches for improving the ultimate speed and/or efficiency, of data storage systems, magnetic-electric sensors, and solar cells.

  2. Pulse speed on a plucked wire

    Odekirk, Tristan; Slaton, William V.

    2012-04-01

    This paper serves to update an elegant experiment published in The Physics Teacher to measure the speed of a pulse on a taut metal wire. Unfortunately, commercially available units2 that serve the same purpose are priced outside the range of most high school or college physics teaching laboratories. Wakeland et al. show how an affordable adaptation of the traditional standing wave apparatus using taut metal wire and horseshoe magnets can be used to measure the speed of a pulse by using an oscilloscope to measure an induced voltage in the wire as the pulse transverses the middle of the magnets, which are a known distance apart.

  3. Event alignment, warping between running speeds

    Pontoppidan, Niels Henrik; Douglas, Ryan

    2004-01-01

    We are pursuing a system that monitors the engine condition under multiple load settings, i.e. under non-stationary operating conditions. We have obtained data from the electronically controlled 2-stroke engine at MAN B&w research copenhagen. the running speed when data acquired under simulated...... marine conditions (different load settings on the propeller curve) was in the range from 60 to 120 rotations per minute; furthermore the running speed was stable within periods of fixed load. Electronically controlled engines can change the angular timing of certain events, such as fuel injection in...

  4. Speeding Up Neighbour-Joining Tree Construction

    Brodal, Gerth Stølting; Fagerberg, Rolf; Mailund, Thomas;

    A widely used method for constructing phylogenetic trees is the neighbour-joining method of Saitou and Nei. We develope heuristics for speeding up the neighbour-joining method which generate the same phylogenetic trees as the original method. All heuristics are based on using a quad-tree to guide...... of alignments, and compare the running time with that of the QuickTree tool, a well-known and widely used implementation of the standard neighbour-joining method. The results show that the presented heuristics can give a significant speed-up over the standard neighbour-joining method, already for...

  5. High Speed Wireless Signal Generation and Demodulation

    Caballero Jambrina, Antonio; Sambaraju, Rakesh; Zibar, Darko;

    We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation.......We present the experimental demonstration of high speed wireless generation, up to 40 Gb/s, in the 75-110 GHz wireless band. All-optical OFDM and photonic up-conversion are used for generation and single side-band modulation with digital coherent detection for demodulation....

  6. Adjustable Speed Drives - Future Challenges and Applications

    Blaabjerg, Frede; Thoegersen, Paul

    2004-01-01

    The main trends within Adjustable Drives in industrial and appliance applications for the next decade are discussed based on the newest developments seen on the market and a few historical trends. Different drive configurations are presented and the general demands to adjustable speed drives are...... specified. Further on power architectures and motor types are discussed in a short term and long-term view. Possible drivers of the future development are identified, and the concept of an ?Electronic Motor? is discussed. A number of applications are presented where variable speed is attractive....

  7. Congestion control of high-speed networks

    1993-06-01

    We report on four areas of activity in the past six months. These areas include the following: (1) work on the control of integrated video and image traffic, both at the access to a network and within a high-speed network; (2) more general/game theoretic models for flow control in networks; (3) work on fault management for high-speed heterogeneous networks to improve survivability; and (4) work on all-optical (lightwave) networks of the future, designed to take advantage of the enormous bandwidth capability available at optical frequencies.

  8. Torque observer for the control of variable speed wind turbines operating below rated wind speed

    Cardenas-Dobson, R.; Asher, G.M. [Universidad de Magallanes, Punta Arenas (Chile); Asher, G. [Nottingham Univ. (United Kingdom). Dept. of Electrical Engineering

    1996-12-31

    This paper gives a formal analysis and design of a combined mechanical torque observer and direct speed control strategy for the tracking of the optimal speed in a variable wind speed turbine-generator system. An analysis of the control structure linearized about the optimal tracking point is derived and forms the basis for analytic comparisons with the more common indirect tracking control. The linearized structure is used for a formal design of an interacting speed controller and torque observer system. Simulation results relating to tracking accuracy and energy capture for a 7.5kW system are presented and discussed. Finally, the controller-observer structure is implemented on a 7.5kW experimental rig using a Switched Reluctance generator and verifies the good performance of the design approach. The application of a torque for wind speed estimation is also discussed. (author)

  9. SPEED COMPLIANCE IN FREEWAY VARIABLE SPEED LIMIT SYSTEM – CASE STUDY OF THE PRAGUE CITY RING

    Michał MATOWICKI

    2016-03-01

    Full Text Available Many previous studies have confirmed the strong relationship between speed compliance and the frequency and severity of traffic accidents. Variable speed limit (VSL system as a measure to improve traffic safety enables the freeway system to change its posted speed limit based on various traffic and environmental conditions. Such system helps drivers to recognize the upcoming events, to adjust their driving style and in such way to address speed variation of the traffic flow. This is called speed harmonization. Although many studies researching the effect of VSL system on the traffic stream can be found, there are only few addressing its influence on the drivers behavior, particularly focusing on their tolerance limit and compliance, which has crucial meaning for future design of controlling algorithms. This study was prepared to inspect this grey area by studying the data from the VSL system at Prague city ring, describing the influence of the highway management system and its influence on drivers.

  10. A speed auto-adaptable system for high speed inspection of rail-track defects

    Ge, Jia; Luo, Yunhan; Zhang, Jun; Guo, Long; Sun, Liang; Chen, Zhe

    2012-11-01

    High quality images play a key role in inspecting surface defect of rail track. However, image distortion is frequently occurred in traditional detection systems in which exposure frequency of camera are fixed as constant. The system studied in this paper improves traditional systems by combining a speed auto-adaptable (SAA) system, to adjust proper exposure frequency and uniform image quality all the time according to vehicle riding speed. The system mainly consists of a high-speed external controlled camera, a rotary encoder and a signal processing card, with this system, performance in avoiding image distortion both in laboratory test and practical application can be achieved with minimum detection precision of 0.2 mm at relative low speed and theoretically maximum detection speed of approximate 489 km/h.

  11. Optimal time of phototherapy for newborns whose total bilirubin ranges from 75 th to 95th percentile in the hour - specific serum bilirubin nomogram%对总胆红素位于小时胆红素第75-95百分位的新生儿光疗时机的研究

    韩金粉; 彭艳松; 刘学工

    2012-01-01

    Objective To study the optimal time of phototherapy for newborns (gestational age≥36 weeks and birth weight≥2500 g) whose total bilirubin ranges from 75th to 95th percentile in the hour - specific serum bilirubin nomogram.Methods The hour - specific serum bilirubin nomogram recommended by America in 2004 was used in this study.Newborns total serum bilirubin (TSB) values from 75th to 95th percentile were divided into 2 groups based on high -risk factors of jaundice inside 72 hours after birth:the observed group with high - risk factors of jaundice and the CK group without them.The number of TSB of the newborns TSB beyond 95th percentile outside 72 h after birth was researched in the two groups.Results Before discharge,total serum bilirubin (TSB) values of 12.8% (5/39) infants were in the high risk zone ( >95th percentile) in the CK group and of 32.2% (10/31) were in that zone in the observed group.The difference was significant ( x2 =3.876,P < 0.05 ).Conclusions Phototherapy should begin inside 72 hours after birth for the newborns with high - risk factors of jaundice and (TSB) values from 75 th to 95 th percentile,and the primary diseases should be treated actively.%目的 探讨胎龄≥36周、体质量≥2500 g、总胆红素值位于小时胆红素百分位值列线图第75~95百分位的新生儿合理光疗时机.方法 利用美国2004年推荐使用的小时胆红素百分位值列线图,将生后72 h内总胆红素值位于第75 ~95百分位的新生儿,分为有黄疸高危因素的研究组及无黄疸高危因素的对照组,比较两组新生儿生后72 h后胆红素上升至第95百分位病例数的统计学差异.结果 对照组39倒,生后72 h后总胆红素上升至第95百分位5倒,发生率为12.8% (5/39);研究组31例,生后72 h后总胆红素上升至第95百分位10例,发生率为32.2%( 10/31),差异有统计学意义(x2=3.876,P< 0.05).结论 对生后72 h内总胆红素值位于小时胆

  12. About Variable Speed Heating and Cooling Pumps

    Cătălin Popovici; Jan Ignat

    2009-01-01

    The present work has the purpose of underlying the advantages of variable speed heating and cooling pumps use for the perspective of general and particular pumping costs and efficiency. The study approaches comparisons between constant flow pumps and variable flow pumps in different given situations and comparatively analyses the pumping costs.

  13. Airfoil shape for flight at subsonic speeds

    Whitcomb, Richard T.

    1976-01-01

    An airfoil having an upper surface shaped to control flow accelerations and pressure distribution over the upper surface and to prevent separation of the boundary layer due to shock wave formulation at high subsonic speeds well above the critical Mach number. A highly cambered trailing edge section improves overall airfoil lifting efficiency.

  14. Errors in equations for galaxy rotation speeds

    Nicholson, Kenneth F.

    2003-01-01

    Shown are the errors and difficulties of the equations used for galaxy rotation speeds in the book "Galactic Dynamics" (Binney and Tremaine). A usable and accurate set of equations is then presented. The new equations allow easy determination of galaxy mass distribution from the rotation profile with no need for dark matter or any knowledge of galaxy surface light.

  15. Keeping Rural Schools up to Full Speed

    Beesley, Andrea

    2011-01-01

    Rural schools are long accustomed to meeting challenges in innovative ways. For them, the challenge is not so much a lack of technology as it is adequate internet access, which affects both teachers and students. In this article, the author discusses how to keep rural schools up to full speed. The author suggests that the best approach when…

  16. Approaching the Speed of Light with Class.

    Dance, Rosalie A.; Sandefur, James T.

    1997-01-01

    Describes an experimental approach to determining the speed of light in water using some simple observations and Fermat's principle. Enables students to integrate mathematical techniques and encourages mathematical exploration in which the students have control over what mathematics and technology to use and when to use them. Presents extensions…

  17. The Speed of Light in Different Media.

    Feldman, Allan

    1991-01-01

    A procedure for measuring the speed of light using the assumption that the frequency of light remains unchanged as it moves from one medium to another is presented. A laser with a known wavelength and frequency in air was used as a light source. (KR)

  18. Power of a Finite Speed Carnot Engine

    Agrawal, D. C.; Menon, V. J.

    2009-01-01

    A model of an endoreversible Carnot engine is considered where the piston moves with a constant speed "u." Expressions for the cycle time [tau] for the four branches, as well as output power, P[subscript W], are derived and the optimized root for maximum power is obtained in closed form. Our results are discussed in terms of the isothermal…

  19. A Finite Speed Curzon-Ahlborn Engine

    Agrawal, D. C.

    2009-01-01

    Curzon and Ahlborn achieved finite power output by introducing the concept of finite rate of heat transfer in a Carnot engine. The finite power can also be achieved through a finite speed of the piston on the four branches of the Carnot cycle. The present paper combines these two approaches to study the behaviour of output power in terms of…

  20. CMOS Image Sensors for High Speed Applications

    M. Jamal Deen

    2009-01-01

    Full Text Available Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps.

  1. Regulating vacuum pump speed with feedback control

    Considerable energy is wasted by the vacuum pump/motor on dairy farms. The output capacity (m3/min or cfm) of the vacuum pump always exceeds the capacity needed to milk cows and wash pipelines. Vacuum pumps run at full speed and load regardless of actual need for air. Excess air is admitted through a controller. Energy can be saved from electrical demand reduced by regulating vacuum pump speed according to air based on air usage. An adjustable speed drive (ASD) on the motor and controlled based upon air usage, can reduce the energy used by the vacuum pump. However, the ASD unit tested could not maintain vacuum levels within generally accepted guidelines when air usage changed. Adding a high vacuum reserve and a dual vacuum controller between the vacuum pump and the milking pipeline brought vacuum stability within guidelines. The ASD/dual vacuum system can reduce energy consumption and demand by at least 50 percent during milking and provide better vacuum stability than conventional systems. Tests were not run during washing cycles. Using 1990 costs and only the energy saved during milking, the simple payback on investment in new equipment for a 5 hp motor, speed controller and vacuum regulator would be about 5 years

  2. Speed trends in male distance running.

    Kruse, Timothy N; Carter, Rickey E; Rosedahl, Jordan K; Joyner, Michael J

    2014-01-01

    The major cycling "Grand Tours" have shown an attenuation of performance over the last decade. This has been interpreted as circumstantial evidence that newer anti-doping strategies have reduced the use of performance-enhancing drugs. To examine this idea under more controlled conditions, speed trends for world class 5000 m, 10000 m, and marathon performances by men from 1980 to 2013 were analyzed. We obtained comprehensive records from the International Association of Athletics Federations, Association of Road Racing Statisticians, and the Track and Field All-time Performances database webpages. The top 40 performances for each event and year were selected for regression analysis. For the three distances, we noted cumulative performance improvements in the 1990s thru the mid-2000s. After the peak speed years of the mid 2000 s, there has been limited improvement in the 5000 m and 10,000 m and world records set during that time remain in place today, marking the longest period of time between new records since the early 1940s. By contrast marathon speed continues to increase and the world record has been lowered four times since 2007, including in 2013. While the speed trends for 5000 m and 10000 m track results parallel those seen in elite cycling, the marathon trends do not. We discuss a number of explanations other than improved anti-doping strategies that might account for these divergent findings. PMID:25409192

  3. Speed trends in male distance running.

    Timothy N Kruse

    Full Text Available The major cycling "Grand Tours" have shown an attenuation of performance over the last decade. This has been interpreted as circumstantial evidence that newer anti-doping strategies have reduced the use of performance-enhancing drugs. To examine this idea under more controlled conditions, speed trends for world class 5000 m, 10000 m, and marathon performances by men from 1980 to 2013 were analyzed. We obtained comprehensive records from the International Association of Athletics Federations, Association of Road Racing Statisticians, and the Track and Field All-time Performances database webpages. The top 40 performances for each event and year were selected for regression analysis. For the three distances, we noted cumulative performance improvements in the 1990s thru the mid-2000s. After the peak speed years of the mid 2000 s, there has been limited improvement in the 5000 m and 10,000 m and world records set during that time remain in place today, marking the longest period of time between new records since the early 1940s. By contrast marathon speed continues to increase and the world record has been lowered four times since 2007, including in 2013. While the speed trends for 5000 m and 10000 m track results parallel those seen in elite cycling, the marathon trends do not. We discuss a number of explanations other than improved anti-doping strategies that might account for these divergent findings.

  4. High-speed fiber grating pressure sensors

    Udd, Eric; Rodriguez, George; Sandberg, Richard L.

    2014-06-01

    Fiber grating pressure sensors have been used to support pressure measurements associated with burn, deflagration and detonation of energetic materials. This paper provides an overview of this technology and serves as a companion paper to the application of this technology to measuring pressure during high speed impacts.

  5. High-Speed Rail & Air Transport Competition

    Adler, Nicole; Nash, Chris; Pels, Eric

    2008-01-01

    This paper develops a methodology to assess transport infrastructure investments and their effects on a Nash equilibria taking into account competition between multiple privatized transport operator types. The operators, including high-speed rail, hub and spoke legacy airlines and low cost carriers,

  6. Separating Fact from Fiction: Increasing Running Speed

    Murgia, Carla

    2008-01-01

    From a biomechanical point of view, this article explores the common belief that one must increase stride length and frequency in order to increase running speed. The limb length, explosive power, and anaerobic capacity of the athlete, as well as the type of running (sprinting vs. long distance) must be considered before making such a…

  7. Speed enhancement in VCSELs employing grating mirrors

    Chung, Il-Sug; Mørk, Jesper

    2013-01-01

    In recent years, various approaches to improve the speed of directly modulated vertical-cavity surface-emitting lasers (VCSELs) have been reported and demonstrated good improvement. In this paper, we propose and numerically investigate a new possibility of using high-index-contrast grating (HCG) as...

  8. Adjustable Speed Drives and Power Quality

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    This paper provides an overview and proposes cost-effective and efficient opportunities in improving power quality in Adjustable Speed Drive (ASD) systems. In particular, an Electronic Inductor (EI) technique has been used in single drives to overcome the existing challenges in conventional...

  9. High-speed milling of light metals

    F. Cus

    2007-01-01

    Full Text Available Purpose: Purpose of this paper: Introduction applicability of high-speed cutting of light metals is presented inthis paper.Design/methodology/approach:HSC is the result of numerous technical advances ensuring that milling hasbecome faster than conventional milling and has gained importance as a cutting process. The advantages ofthe HSC milling are higher productivity owing to the reduction of machining times increase of the flow timeof production, reduction of the number of technological operations, increase of the surface quality and longerservice life of tools. The machining conditions for execution of the HSC (36000min-1 and feeding 20m/minrequire modernly built machine tools to meet those machining conditions.Findings: Continuous development of new materials is more and more dynamical, particularly, in theautomobile, aircraft and electronic industry and in the manufacture of various mechanical parts. Also theachievements in the area of building of machines and tools, ensuring high cutting speeds (highly efficientmachining have contributed to development of the process.Research limitations/implications: High quality of the surfaces, the quality of this so-called HSC milling canbe compared to grinding.Practical implications: High-speed milling of light metals from aluminium and magnesium is more and morefrequently used in practice. This result is high quality of the surface and shorter machining times. In some caseswhen machining by grinding is specified, the latter is omitted.Originality/value: The applicability of high-speed milling has proved to be successful, when aluminum andmagnesium alloying materials are machined.

  10. Intelligent Speed Adaptation for involuntary drivers

    Agerholm, Niels; Tradisauskas, Nerius; Juhl, Jens; Berthelsen, Kasper Klitgaard; Lahrmann, Harry

    2012-01-01

    The Danish Intelligent Speed Adaptation (ISA) trial ISA C included 26 commercial cars and 51 drivers a number of whom were involuntary. After a baseline period, ISA was activated for one year. The drivers should identify themselves with a personal key ID before driving. As well as being informative...

  11. Shadows over the speed of light

    Mareš, Jiří J.; Hubík, Pavel; Špička, Václav; Stávek, J.; Šesták, Jaroslav; Krištofik, Jozef

    T151, č. 1 (2012), s. 1-7. ISSN 0031-8949 Institutional research plan: CEZ:AV0Z10100521 Keywords : speed of light * special relativity * Maxwell’s constant Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.032, year: 2012

  12. High-speed Power Line Communications

    Matthew N. O. Sadiku,

    2015-11-01

    Full Text Available This is the idea of using existing power lines for communication purposes. Power line communications (PLC enables network communication of voice, data, and video over direct power lines. High-speed PLC involves data rates in excess of 10 Mbps. PLC has attracted a lot of attention and has become an interesting subject of research lately.

  13. 14 CFR 23.1507 - Operating maneuvering speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Operating maneuvering speed. 23.1507... Limitations and Information § 23.1507 Operating maneuvering speed. The maximum operating maneuvering speed, VO, must be established as an operating limitation. VO is a selected speed that is not greater than...

  14. 14 CFR 25.149 - Minimum control speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum control speed. 25.149 Section 25... Minimum control speed. (a) In establishing the minimum control speeds required by this section, the method... prevent a heading change of more than 20 degrees. (e) VMCG, the minimum control speed on the ground,...

  15. 14 CFR 25.1505 - Maximum operating limit speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maximum operating limit speed. 25.1505... Operating Limitations § 25.1505 Maximum operating limit speed. The maximum operating limit speed (V MO/M MO airspeed or Mach Number, whichever is critical at a particular altitude) is a speed that may not...

  16. 14 CFR 29.931 - Shafting critical speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Shafting critical speed. 29.931 Section 29... speed. (a) The critical speeds of any shafting must be determined by demonstration except that...) If any critical speed lies within, or close to, the operating ranges for idling, power-on,...

  17. 14 CFR 25.1517 - Rough air speed, VRA.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rough air speed, VRA. 25.1517 Section 25... Limitations § 25.1517 Rough air speed, VRA. A rough air speed, VRA, for use as the recommended turbulence... specified in § 25.335(d); and (3) Is sufficiently less than VMO to ensure that likely speed variation...

  18. 14 CFR 27.931 - Shafting critical speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Shafting critical speed. 27.931 Section 27... speed. (a) The critical speeds of any shafting must be determined by demonstration except that...) If any critical speed lies within, or close to, the operating ranges for idling, power on,...

  19. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (85th, Miami, Florida, August 5-8, 2002). Media Ethics Division.

    2002

    The Media Ethics division of the proceedings contains the following 6 papers: "A Masochist's Teapot: Where to Put the Handle in Media Ethics" (Thomas W. Hickey); "Stalker-razzi and Sump-pump Hoses: The Role of the Media in the Death of Princess Diana" (Elizabeth Blanks Hindman); "The Promise and Peril of Anecdotes in News Coverage: An Ethical…

  20. Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (85th, Miami, Florida, August 5-8, 2002). Advertising Division.

    2002

    The Advertising Division of the proceedings contains the following 20 papers: "Business and Communication Programs' Contribution in Advertising Education and Research: A Comparison" (Tien-tsung Lee); "Attributions of Advertising Influence Via Third-Person Perceptions: A Review and Synthesis" (Don Umphrey); "Advertising Agency Web Sites: Presence…

  1. On the Maximum Speed of Matter

    Raftopoulos, Dionysios G.

    2013-09-01

    In this paper we examine the analytical production of the Lorentz Transformation regarding its fundamental conclusion i.e. that the speed of Light in vacuum is the uppermost limit for the speed of matter, hence superluminal speeds are unattainable. This examination covers the four most prominent relevant sources of bibliography: Albert Einstein's historic paper (1905) titled: "On the Electrodynamics of moving Bodies" on which his Special Relativity Theory is founded. His famous textbook titled: "Relativity, The Special and General Theory", A. P. French's textbook titled "Special Relativity", Wolfgang Rindler's textbook titled: "Essential Relativity". Special emphasis is placed on the critical analysis of Einstein's gedanken experiment as it is presented in his original paper, where he considers a moving, straight, rigid rod at the ends of which there are two clocks, whose synchronization is checked according to his own definition as given in part 1 of his paper. By applying the second fundamental hypothesis (principle) of SRT, we arrive at the conclusion that this noetic experiment can be concluded only if the rod's speed V with regards the stationary system and measured from it, is less than the speed of light C also with regards the stationary system and measured from it. In the opposite case, said noetic experiment would be meaningless as it could never be concluded for the Observer of the stationary system, at least in the Euclidean Space. Finally, we show that in all four cases under examination the relationship v < c is not a conclusion of the Lorentz Transformation, but rather a hidden pre-condition of its analytical production, in other words, the LT can only be valid for v < c Consequently, there doesn't exist a definite and rigid law of Physics forbidding matter to travel with superluminal velocity in vacuum.

  2. Indigenously developed large pumping speed cryoadsorption cryopump

    Indigenous cryoadsorption cryopump with large pumping speeds for fusion reactor application has been developed at the Institute for Plasma Research (IPR). Towards its successful realization, technological bottlenecks were identified, studied and resolved. Hydroformed cryopanels were developed from concept leading to the design and product realization with successful technology transfer to the industry. This has led to the expertise for developing hydroformed panels for any desired shape, geometry and welding pattern. Activated sorbents were developed, characterized using an experimental set up which measures adsorption isotherms down to 4K for hydrogen and helium. Special techniques were evolved for coating sorbents on hydroformed cryopanels with suitable cryo-adhesives. Various arrangements of cryopanels at 4 K surrounded by 80 K shields and baffles (which are also hydroformed) were studied and optimized by transmission probability analysis using Monte Carlo techniques. CFD analysis was used to study the temperature distribution and flow analysis during the cryogen flow through the panels. Integration of the developed technologies to arrive at the final product was a challenging task and this was meticulously planned and executed. This resulted in a cryoadsorption cryopump offering pumping speeds as high as 50,000 to 70,000 1/s for helium and 1,50,000 1/s for hydrogen with a 3.2 m2 of sorbent panel area. The first laboratory scale pump integrating the developed technologies was a Small Scale CryoPump (SSCP-01) with a pumping speed of 2,000 1/s for helium. Subsequently, Single Panel CryoPump (SPCP-01) with pumping speed 10,000 1/s for helium and a Multiple Panel CryoPump (MPCP-08) with a pumping speed of 70,000 1/s for helium and 1,50,000 1/s for hydrogen respectively were developed. This paper describes the efforts in realizing these products from laboratory to industrial scales. (author)

  3. Architectures and applications of high-speed vision

    Watanabe, Yoshihiro; Oku, Hiromasa; Ishikawa, Masatoshi

    2014-11-01

    With the progress made in high-speed imaging technology, image processing systems that can process images at high frame rates, as well as their applications, are expected. In this article, we examine architectures for high-speed vision systems, and also dynamic image control, which can realize high-speed active optical systems. In addition, we also give an overview of some applications in which high-speed vision is used, including man-machine interfaces, image sensing, interactive displays, high-speed three-dimensional sensing, high-speed digital archiving, microvisual feedback, and high-speed intelligent robots.

  4. Speed Control Of Induction Motor Using Dspic30f2023

    M. S. Aspalli; Laxmi

    2013-01-01

    AC motor drives are widely used to control the speed of conveyor systems, blower speeds, pump speeds, machine tool speeds and other applications that require variable speed with variable torque. The main aim of the work is to design and develop an electronic system that can be used to control the speed of a three phase induction motor.The speed of the three phase induction motor can be controlled by various methods. The stator frequency control is one of the simplest methods to control the sp...

  5. Temperature distribution of high speed tool steel rod during high speed hot rolling procedure

    Jeong, Hyo Tae; Lee, Soo Yeon; Ha, Tae Kwon [Kangnung National University, Gangneung (Korea, Republic of); Jung, Jae Young [Research Institute of Inderstrial Science and Technology, Pohang (Korea, Republic of)

    2008-03-15

    The temperature distribution of high speed tool steel rod has been studied during high speed hot rolling procedures. The tool steel rod shows severe temperature gradient during rolling procedures and the temperature at the center of rod are much higher than that at the surface of rod. This temperature gradient accumulated after every rolling procedure and the center of rolled rod could be remelt in some procedures to cause inside defects. In this study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, have been discussed to prevent the temperature increases at the center of rod.

  6. Temperature distribution of high speed tool steel rod during high speed hot rolling procedure

    The temperature distribution of high speed tool steel rod has been studied during high speed hot rolling procedures. The tool steel rod shows severe temperature gradient during rolling procedures and the temperature at the center of rod are much higher than that at the surface of rod. This temperature gradient accumulated after every rolling procedure and the center of rolled rod could be remelt in some procedures to cause inside defects. In this study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, have been discussed to prevent the temperature increases at the center of rod

  7. Universal one-way light speed from a universal light speed over closed paths

    Minguzzi, E.; MacDonald, A

    2002-01-01

    This paper gives two complete and elementary proofs that if the speed of light over closed paths has a universal value $c$, then it is possible to synchronize clocks in such a way that the one-way speed of light is c. The first proof is an elementary version of a recent proof. The second provides high precision experimental evidence that it is possible to synchronize clocks in such a way that the one-way speed of light has a universal value. We also discuss an old incomplete proof by Weyl whi...

  8. Effect of welding current and speed on occurrence of humping bead in high-speed GMAW

    Chen Ji; Wu Chuansong

    2009-01-01

    The developed mathematical model of humping formation mechanism in high-speed gas metal arc welding (GMAW) is used to analyze the effects of welding current and welding speed on the occurrence of humping bead. It considers both the momentum and heat content of backward flowing molten jet inside weld pool. Three-dimensional geometry of weld pool, the spacing between two adjacent humps and hump height along humping weld bead are calculated under different levels of welding current and welding speed. It shows that wire feeding rate, power intensity and the moment of backward flowing molten jet are the major factors on humping bead formation.

  9. Ship speed optimization: Concepts, models and combined speed-routing scenarios

    Psaraftis, Harilaos N.; Kontovas, Christos A.

    2014-01-01

    The purpose of this paper is to clarify some important issues as regards ship speed optimization at the operational level and develop models that optimize ship speed for a spectrum of routing scenarios in a single ship setting. The paper's main contribution is the incorporation of those fundamental...... parameters and other considerations that weigh heavily in a ship owner's or charterer's speed decision and in his routing decision, wherever relevant. Various examples are given so as to illustrate the properties of the optimal solution and the various trade-offs that are involved....

  10. A MHz speed wavelength sweeping for ultra-high speed FBG interrogation

    Kim, Gyeong Hun; Lee, Hwi Don; Eom, Tae Joong; Jeong, Myung Yung; Kim, Chang-Seok

    2015-09-01

    We demonstrated a MHz speed wavelength-swept fiber laser based on the active mode locking (AML) technique and applied to interrogation system of an array of fiber Bragg grating (FBG) sensors. MHz speed wavelength sweeping of wavelength-swept fiber laser can be obtained by programmable frequency modulation of the semiconductor optical amplifier (SOA) without any wavelength tunable filter. Both static and dynamic strain measurement of FBG sensors were successfully characterized with high linearity of an R-square value of 0.9999 at sweeping speed of 50 kHz.

  11. Virtual speed sensors based algorithm for expressway traffic state estimation

    XU DongWei; DONG HongHui; JIA LiMin; QIN Yong

    2012-01-01

    The accurate estimation of expressway traffic state can provide decision-making for both travelers and traffic managers.The speed is one of the most representative parameter of the traffic state.So the expressway speed spatial distribution can be taken as the expressway traffic state equivalent.In this paper,an algorithm based on virtual speed sensors (VSS) is presented to estimate the expressway traffic state (the speed spatial distribution).To gain the spatial distribution of expressway traffic state,virtual speed sensors are defined between adjacent traffic flow sensors.Then,the speed data extracted from traffic flow sensors in time series are mapped to space series to design virtual speed sensors.Then the speed of virtual speed sensors can be calculated with the weight matrix which is related with the speed of virtual speed sensors and the speed data extracted from traffic flow sensors and the speed data extracted from traffic flow sensors in time series.Finally,the expressway traffic state (the speed spatial distribution) can be gained.The acquisition of average travel speed of the expressway is taken for application of this traffic state estimation algorithm.One typical expressway in Beijing is adopted for the experiment analysis.The results prove that this traffic state estimation approach based on VSS is feasible and can achieve a high accuracy.

  12. Surface grinding characteristics of ferrous metals under high-speed and speed-stroke grinding conditions

    Some ferrous metals have been ground under different conditions with high-speed and speed-stroke in surface grinding operation. The paper describes experimental investigation of grinding forces in grinding some ferrous metals with the application of cutting fluids. Grinding tests have been carried out on mild steel, assab steel and stainless steel with different combinations of down feed and cross feed. The wheel speed was 27 m/sec while the table speed was maintained at the maximum possible 25 m/min. The grindability has been evaluated by measuring the grinding forces, grinding ratio, and surface finish. Grinding forces have been plotted against down feed of the grinding wheel and cross feed of the table. It has been observed that the radial and tangential grinding forces in stainless steel were higher than those in assab steel and mild steel

  13. Aerodynamic Separability in Tip Speed Ratio and Separability in Wind Speed- a Comparison

    From extensive application over a number of years, it has been established that the nonlinear rotor aerodynamics of typical medium and large wind turbines exhibit an effectively global separability property, in other words the aerodynamic torque of the machine can be defined by two independent additive functions. Two versions of the separability of aerodynamic torque for variable speed wind turbines are investigated here; the separated function, related to wind speed, in the first version is only dependent on that variable and not rotor speed and in the second version is only dependent on tip speed ratio. Both provide very good approximations to the aerodynamic torque over extensive neighbourhoods of T0, at least from 0 to 2T0

  14. Pulse Detonation Engines for High Speed Flight

    Povinelli, Louis A.

    2002-01-01

    Revolutionary concepts in propulsion are required in order to achieve high-speed cruise capability in the atmosphere and for low cost reliable systems for earth to orbit missions. One of the advanced concepts under study is the air-breathing pulse detonation engine. Additional work remains in order to establish the role and performance of a PDE in flight applications, either as a stand-alone device or as part of a combined cycle system. In this paper, we shall offer a few remarks on some of these remaining issues, i.e., combined cycle systems, nozzles and exhaust systems and thrust per unit frontal area limitations. Currently, an intensive experimental and numerical effort is underway in order to quantify the propulsion performance characteristics of this device. In this paper, we shall highlight our recent efforts to elucidate the propulsion potential of pulse detonation engines and their possible application to high-speed or hypersonic systems.

  15. Multiple architecture system for wind speed prediction

    A new approach based on multiple architecture system (MAS) for the prediction of wind speed is proposed. The motivation behind the proposed approach is to combine the complementary predictive powers of multiple models in order to improve the performance of the prediction process. The proposed MAS can be implemented by associating the predictions obtained from the different regression algorithms (MLR, MLP, RBF and SVM) making up the ensemble by three fusion strategies (simple, weighted and non-linear). The efficiency of the proposed approach has been assessed on a real data set recorded from seven locations in Algeria during a period of 10 years. The experimental results point out that the proposed MAS approach is capable of improving the precision of the wind speed prediction compared to the traditional prediction methods.

  16. High speed functional magnetic resonance imaging

    Gibson, A M

    2002-01-01

    The work in this thesis has been undertaken by the except where indicated by reference, within the Magnetic Resonance Centre at the University of Nottingham during the period from October 1998 to October 2001. This thesis documents the implementation and application of a novel high-speed imaging technique, the multi-slice, echo shifted, echo planar imaging technique. This was implemented on the Nottingham 3 T imaging system, for functional magnetic resonance imaging. The technique uses echo shifting over the slices in a multi-slice echo planar imaging acquisition scheme, making the echo time longer than the repetition time per slice. This allows for rapid volumar sampling of the blood oxygen level dependent effect in the human brain. The new high-speed technique was used to investigate the variability of measuring the timing differences between haemodynamic responses, at the same cortical location, to simple cued motor tasks. The technique was also used in an investigation into motor cortex functional connect...

  17. A high-speed avalanche photodiode

    High-speed avalanche photodiodes are widely used in optical communication systems. Nowadays, separate absorption charge and multiplication structure is widely adopted. In this article, a structure with higher speed than separate absorption charge and multiplication structure is reported. Besides the traditional absorption layer, charge layer and multiplication layer, this structure introduces an additional charge layer and transit layer and thus can be referred to as separate absorption, charge, multiplication, charge and transit structure. The introduction of the new charge layer and transit layer brings additional freedom in device structure design. The benefit of this structure is that the carrier transit time and device capacitance can be reduced independently, thus the 3 dB bandwidth could be improved by more than 50% in contrast to the separate absorption charge and multiplication structure with the same size. (semiconductor devices)

  18. Tornado-borne missile speeds. Final report

    An investigation of the question of tornado-borne missile speeds was carried out, with a view to identify pertinent areas of uncertainty and to estimate credible tornado-borne missile speeds - within the limitations inherent in the present state of the art. The investigation consists of two parts: (1) a study in which a rational model for the missile motion is proposed, and numerical experiments are carried out corresponding to various assumptions on the initial conditions of the missile motion, the structure of the tornado flow, and the aerodynamic properties of the missile; (2) a theoretical and experimental study of tornado-borne missile aerodynamics, conducted by Colorado State Univ. (CSU) to be covered in a separate report by CSU. In the present report, the factors affecting missile motion and their influence upon such motion are examined

  19. Time optimal paths for high speed maneuvering

    Reister, D.B.; Lenhart, S.M.

    1993-01-01

    Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

  20. Safety issues in high speed machining

    1994-05-01

    There are several risks related to High-Speed Milling, but they have not been systematically determined or studied so far. Increased loads by high centrifugal forces may result in dramatic hazards. Flying tools or fragments from a tool with high kinetic energy may damage surrounding people, machines and devices. In the project, mechanical risks were evaluated, theoretic values for kinetic energies of rotating tools were calculated, possible damages of the flying objects were determined and terms to eliminate the risks were considered. The noise levels of the High-Speed Machining center owned by the Helsinki University of Technology (HUT) and the Technical Research Center of Finland (VTT) in practical machining situation were measured and the results were compared to those after basic preventive measures were taken.

  1. Network Based High Speed Product Innovation

    Lindgren, Peter

    In the first decade of the 21st century, New Product Development has undergone major changes in the way NPD is managed and organised. This is due to changes in technology, market demands, and in the competencies of companies. As a result NPD organised in different forms of networks is predicted to...... be of ever-increasing importance to many different kinds of companies. This happens at the same times as the share of new products of total turnover and earnings is increasing at unprecedented speed in many firms and industries. The latter results in the need for very fast innovation and product...... development - a need that can almost only be resolved by organising NPD in some form of network configuration. The work of Peter Lindgren is on several aspects of network based high speed product innovation and contributes to a descriptive understanding of this phenomenon as well as with normative theory on...

  2. High speed printing with polygon scan heads

    Stutz, Glenn

    2016-03-01

    To reduce and in many cases eliminate the costs associated with high volume printing of consumer and industrial products, this paper investigates and validates the use of the new generation of high speed pulse on demand (POD) lasers in concert with high speed (HS) polygon scan heads (PSH). Associated costs include consumables such as printing ink and nozzles, provisioning labor, maintenance and repair expense as well as reduction of printing lines due to high through put. Targets that are applicable and investigated include direct printing on plastics, printing on paper/cardboard as well as printing on labels. Market segments would include consumer products (CPG), medical and pharmaceutical products, universal ID (UID), and industrial products. In regards to the POD lasers employed, the wavelengths include UV(355nm), Green (532nm) and IR (1064nm) operating within the repetition range of 180 to 250 KHz.

  3. High-speed massively parallel scanning

    Decker, Derek E.

    2010-07-06

    A new technique for recording a series of images of a high-speed event (such as, but not limited to: ballistics, explosives, laser induced changes in materials, etc.) is presented. Such technique(s) makes use of a lenslet array to take image picture elements (pixels) and concentrate light from each pixel into a spot that is much smaller than the pixel. This array of spots illuminates a detector region (e.g., film, as one embodiment) which is scanned transverse to the light, creating tracks of exposed regions. Each track is a time history of the light intensity for a single pixel. By appropriately configuring the array of concentrated spots with respect to the scanning direction of the detection material, different tracks fit between pixels and sufficient lengths are possible which can be of interest in several high-speed imaging applications.

  4. Nanometer lapping technology at high speed

    YANG JianDong; TIAN ChunLin; WANG ChangXing

    2007-01-01

    In floating lapping with solid abrasives, the workpiece is taken as an isolated body. The forces that act on it are analyzed. A differential equation about the forces that act on it is set up, so the forces that act on it and its motion rule are received. Combining it with known lapping tool motion, the relative motion rule between the lapping tool and workpiece is determined too. According to the relative motion, the distribution of abrasives density is designed reasonably, which makes the lapping tool wear uniformly, which, in turn, avoids redressing the lapping tool, saves abrasives, and increases machining accuracy. Combining it with advantages in high speed lapping with solid abrasives, the low cost, high efficiency nanometer lapping at high speed is realized.

  5. Improving the critical speeds of high-speed trains using magnetorheological technology

    With the rapid development of high-speed railways, vibration control for maintaining stability, passenger comfort, and safety has become an important area of research. In order to investigate the mechanism of train vibration, the critical speeds of various DOFs with respect to suspension stiffness and damping are first calculated and analyzed based on its dynamic equations. Then, the sensitivity of the critical speed is studied by analyzing the influence of different suspension parameters. On the basis of these analyses, a conclusion is drawn that secondary lateral damping is the most sensitive suspension damper. Subsequently, the secondary lateral dampers are replaced with magnetorheological fluid (MRF) dampers. Finally, a high-speed train model with MRF dampers is simulated by a combined ADAMS and MATLAB simulation and tested in a roller rig test platform to investigate the mechanism of how the MRF damper affects the train’s stability and critical speed. The results show that the semi-active suspension installed with MRF dampers substantially improves the stability and critical speed of the train. (paper)

  6. Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator Variable-Speed Wind Turbines

    Yanting Hu

    2013-07-01

    Full Text Available Grid-connected wind turbines are fluctuating power sources that may produce flicker during continuous operation. This paper presents a simulation model of a MW-level variable speed wind turbine with a full-scale back-to-back power converter and permanent magnet synchronous generator (PMSG developed in the simulation tool of PSCAD/EMTDC. Flicker emission of this system is investigated. The 3p (three times per revolution power oscillation due to wind shear and tower shadow effects is the significant part in the flicker emission of variable speed wind turbines with PMSG during continuous operation. A new method of flicker mitigation by controlling the rotational speed is proposed. It smoothes the 3p active power oscillations from wind shear and tower shadow effects of the wind turbine by varying the rotational speed of the PMSG. Simulation results show that damping the 3p active power oscillation by using the flicker mitigation speed controller is an effective means for flicker mitigation of variable speed wind turbines with full-scale back-to-back power converters and PMSG during continuous operation.

  7. High-speed milling of light metals

    F. Cus; U. Zuperl; V. Gecevska

    2007-01-01

    Purpose: of this paper: Introduction applicability of high-speed cutting of light metals is presented in this paper.Design/methodology/approach: HSC is the result of numerous technical advances ensuring that milling has become faster than conventional milling and has gained importance as a cutting process. The advantages of the HSC milling are higher productivity owing to the reduction of machining times increase of the flow time of production, reduction of the number of technological operati...

  8. WIND SPEED AND ENERGY POTENTIAL ANALYSES

    A. TOKGÖZLÜ; O. KAYNAR; M. ALTUNÇ; M.ZONTUL; Z. ASLAN

    2013-01-01

    This paper provides a case study on application of wavelet techniques to analyze wind speed and energy (renewable and environmental friendly energy). Solar and wind are main sources of energy that allows farmers to have the potential for transferring kinetic energy captured by the wind mill for pumping water, drying crops, heating systems of green houses, rural electrification's or cooking. Larger wind turbines (over 1 MW) can pump enough water for small-scale irrigation. This study tried to ...

  9. SPEED COMMUTER-URBAN RAIL TRANSPORT

    SHABAROVA ELEONORA

    2014-01-01

    Transport crisis in the cities has become a ubiquitous problem. In Russia, the situation is deteriorated by the absence of the methodology of conceptual design of integrated transport systems in general, and the city-street-speed railway as part of the system. To mitigate this situation, two methodological tasks have been proposed: 1) the relevance of the use of the existing rail network in the city in order to solve the transport crisis and provide the simultaneous increase of its efficiency...

  10. Resonant speed meter for gravitational wave detection

    Nishizawa, Atsushi; Sakagami, Masa-aki

    2008-01-01

    Gravitational-wave detectors have been well developed and operated with high sensitivity. However, they still suffer from mirror displacement noise. In this paper, we propose a resonant speed meter, as a displacement noise-canceled configuration based on a ring-shaped synchronous recycling interferometer. The remarkable feature of this interferometer is that, at certain frequencies, gravitational-wave signals are amplified, while displacement noises are not.

  11. Intrusion Detection in High-Speed Networks

    Riegel, Martin; Walsø, Claes Lyth

    2007-01-01

    This thesis investigates methods for implementing an intrusion detection system (IDS) in a high-speed backbone network. The work presented in this report is run in cooperation with Kripos and Uninett. The popular IDS software, Snort, is deployed and tested in Uninett's backbone network. In addition, the monitoring API (MAPI) is considered as a possible IDS implementation in the same environment. The experiments conducted in this report make use of the programmable DAG card, which is a passive...

  12. A High-Speed Information Retrieval System

    SHI Shu-dong; LI Zhi-tang

    2004-01-01

    We cleveloped a high-speed information retrieval system. The system hased on the IXP 2800 is one of the dedicute device. The velocily of the information retrieval is 6.8 Gb/s. The protocol support Telnet, FTP, SMTP, POP3 etc. various networks protocols. The information retrieval supports the key word and the natural language process. This paper explains the hardware system, software system and the index of the performance.

  13. Processing at the Speed of Light

    2003-01-01

    Spatial Light Modulators (SLMs) are critical elements in optical processing systems used for imaging, displaying, data storage, communications, and other applications. By taking advantage of the natural properties of light beams, the devices process information at speeds unattainable by human operators and most machines, with high-resolution results.Boulder Nonlinear Systems, Inc., is one of the world s foremost SLM manufacturers. Applications of this technology are briefly described.

  14. Eating the competition speeds up invasions

    Hall, Richard J.

    2010-01-01

    Many introduced species engage in intraguild predation (IGP), the consumption of species with which they compete for shared resources. While the factors influencing local persistence of IG predator and prey species are well-understood, using these factors to predict the invasion speed of an introduced IG predator has received less attention. Existing theory predicts that native competitors slow invasions via depletion of shared resources, but this fails to account for additional resources acq...

  15. Power of a finite speed Carnot engine

    A model of an endoreversible Carnot engine is considered where the piston moves with a constant speed u. Expressions for the cycle time τ for the four branches, as well as output power, PW, are derived and the optimized root for maximum power is obtained in closed form. Our results are discussed in terms of the isothermal expansion ratio V*2 and temperature ratio a in a manner accessible to students

  16. Speed of Adjustment in Cointegrated Systems

    Fanelli, Luca; Paruolo, Paolo

    2007-01-01

    This paper considers the speed of adjustment to long-run equilibria, in the context of cointegrated Vector Autoregressive Processes (VAR). We discuss the definition of multivariate p-lives for any indicator of predictive ability, concentrating on cumulated interim multipliers which converge to impact factor for increasing forecasting horizon. Interim multipliers are related to autoregressive Granger-causality coefficients, structural or generalized cumulative impulse responses. We discuss the...

  17. Low Speed Energy Conversion from Marine Currents

    Thomas, Karin

    2007-01-01

    The focus of this thesis is research on the performance of very low speed direct drive permanent magnet generators for energy conversion from marine and tidal currents. Various aspects involved in the design of these generators and their electromagnetic modelling using the finite element simulations are presented. For a detailed study, a 5 kW prototype generator has been designed and constructed based on finite element based simulations. Several experiments were conducted on the prototype gen...

  18. Size as a determinant of reading speed

    Bailey, I.; Clear, R.; Berman, S.

    1992-03-01

    The speed of reading unrelated words as a function of luminance, size, and contrast, was measured with an eye movement monitor for fifteen young adults. Subjects read up to 5,000 words in a test session, with the exact number depending upon their acuity. The size of the smallest legible print at a given luminance and contrast for these subjects was found to fit well to the Blackwell-Taylor detection threshold data above about 1 minute of arc. At lower sizes inclusion of a resolution size term provided an excellent fit. Reading speed was fit to a number of visual performance models. It was found that for most subjects that a ratio of the print size to an estimate of the threshold print size (a VL[sub size]) gave the best fits to the data. The threshold size was computed with a fit to the Blackwell-Taylor detection threshold data, modified to include a resolution size term as above. For the sole remaining subject a slightly better fit was obtained with a VL[sub contrast] model, where again the thresholds were modified by a limiting size term. The implication of these results for visual performance modeling is discussed. The reading speed for all subjects varied rapidly with size near the acuity limit, but became almost independent of visibility parameters as long as size is two times the acuity limit. These results show that size is a powerful determinant of reading speed, and suggest that minification of about 1/2 power could be used as a field test for adequate visibility.

  19. Size as a determinant of reading speed

    Bailey, I.; Clear, R.; Berman, S.

    1992-03-01

    The speed of reading unrelated words as a function of luminance, size, and contrast, was measured with an eye movement monitor for fifteen young adults. Subjects read up to 5,000 words in a test session, with the exact number depending upon their acuity. The size of the smallest legible print at a given luminance and contrast for these subjects was found to fit well to the Blackwell-Taylor detection threshold data above about 1 minute of arc. At lower sizes inclusion of a resolution size term provided an excellent fit. Reading speed was fit to a number of visual performance models. It was found that for most subjects that a ratio of the print size to an estimate of the threshold print size (a VL{sub size}) gave the best fits to the data. The threshold size was computed with a fit to the Blackwell-Taylor detection threshold data, modified to include a resolution size term as above. For the sole remaining subject a slightly better fit was obtained with a VL{sub contrast} model, where again the thresholds were modified by a limiting size term. The implication of these results for visual performance modeling is discussed. The reading speed for all subjects varied rapidly with size near the acuity limit, but became almost independent of visibility parameters as long as size is two times the acuity limit. These results show that size is a powerful determinant of reading speed, and suggest that minification of about 1/2 power could be used as a field test for adequate visibility.

  20. Wind speed forecasting for wind energy applications

    Liu, Hong

    With more wind energy being integrated into our grid systems, forecasting wind energy has become a necessity for all market participants. Recognizing the market demands, a physical approach to site-specific hub-height wind speed forecasting system has been developed. This system is driven by the outputs from the Canadian Global Environmental Multiscale (GEM) model. A simple interpolation approach benchmarks the forecasting accuracy inherited from GEM. Local, site specific winds are affected on a local scale by a variety of factors including representation of the land surface and local boundary-layer process over heterogeneous terrain which have been a continuing challenge in NWP models like GEM with typical horizontal resolution of order 15-km. In order to resolve these small scale effects, a wind energy industry standard model, WAsP, is coupled with GEM to improve the forecast. Coupling the WAsP model with GEM improves the overall forecasts, but remains unsatisfactory for forecasting winds with abrupt surface condition changes. Subsequently in this study, a new coupler that uses a 2-D RANS model of boundary-layer flow over surface condition changes with improved physics has been developed to further improve the forecasts when winds coming from a water surface to land experience abrupt changes in surface conditions. It has been demonstrated that using vertically averaged wind speeds to represent geostrophic winds for input into the micro-scale models could reduce forecast errors. The hub-height wind speed forecasts could be further improved using a linear MOS approach. The forecasting system has been evaluated, using a wind energy standard evaluation matrix, against data from an 80-m mast located near the north shore of Lake Erie. Coupling with GEM-LAM and a power conversion model using a theoretical power curve have also been investigated. For hub-height wind speeds GEM appears to perform better with a 15-Ian grid than the high resolution GEM-2.5Ian version at the

  1. Modernizing Newton, to work at any speed

    Fraundorf, P B

    2001-01-01

    Modification of three ideas underlying Newton's original world view, with only minor changes in context, might offer two advantages to introductory physics students. First, the students will experience less cognitive dissonance when they encounter relativistic effects. Secondly, the map-based Newtonian tools that they spend so much time learning about can be extended to high speeds, non-inertial frames, and even (locally, of course) to curved-spacetime.

  2. Speed Trends in Male Distance Running

    Kruse, Timothy N.; Carter, Rickey E.; Rosedahl, Jordan K.; Joyner, Michael J.

    2014-01-01

    The major cycling "Grand Tours" have shown an attenuation of performance over the last decade. This has been interpreted as circumstantial evidence that newer anti-doping strategies have reduced the use of performance-enhancing drugs. To examine this idea under more controlled conditions, speed trends for world class 5000 m, 10000 m, and marathon performances by men from 1980 to 2013 were analyzed. We obtained comprehensive records from the International Association of Athletics Federations, ...

  3. High-speed milling of light metals

    F. Cus

    2007-09-01

    Full Text Available Purpose: of this paper: Introduction applicability of high-speed cutting of light metals is presented in this paper.Design/methodology/approach: HSC is the result of numerous technical advances ensuring that milling has become faster than conventional milling and has gained importance as a cutting process. The advantages of the HSC milling are higher productivity owing to the reduction of machining times increase of the flow time of production, reduction of the number of technological operations, increase of the surface quality and longer service life of tools. The machining conditions for execution of the HSC (36000min-1 and feeding 20m/min require modernly built machine tools to meet those machining conditions.Findings: Continuous development of new materials is more and more dynamical, particularly, in the automobile, aircraft and electronic industry and in the manufacture of various mechanical parts. Also the achievements in the area of building of machines and tools, ensuring high cutting speeds (highly efficient machining have contributed to development of the process.Research limitations/implications: High quality of the surfaces, the quality of this so-called HSC milling can be compared to grinding.Practical implications: High-speed milling of light metals from aluminium and magnesium is more and more frequently used in practice. This result is high quality of the surface and shorter machining times. In some cases when machining by grinding is specified, the latter is omitted.Originality/value: The applicability of high-speed milling has proved to be successful, when aluminum and magnesium alloying materials are machined.

  4. Speed and position sensors for electric motors

    Lyyjynen, M. [Helsinki University of Technology, Otaniemi (Finland). Institute of Intelligent Power Electronics

    1997-12-31

    This paper gives an overview of speed and position measuring instruments for electric motors. The emphasis is on sensors that are designed to operate at industrial environment. In addition to that, some other, mostly magnetic sensors which are used, e.g., in automotive applications, are presented. Some of them are already applied in induction motors and some might be worth a try remembering the limitations. Automotive sensors are very cost-effective due to high production volumes. (orig.) 22 refs.

  5. High-Speed Multiprocessing For Engine Simulation

    Milner, Edward J.; Arpasi, Dale J.

    1988-01-01

    Parallel microprocessors have computational power and speed for realistic simulations. Interactive information bus links front-end processor and computational processors. Real-time information bus links real-time extension processor and pre-processors. Computational processor and preprocessor communicate through shared memory. System used to simulate small turboshaft engine to demonstrate potential of multiprocessing in such applications. Real-time simulations aid development of new digital engine controls enabling testing of hardware and software under realistic conditions.

  6. A study of anthropometric measurements and prevalence of overweight amongst school girls in an urban school

    Sukhmeet Minhas,Priyanshi Chaudhary,Harinder Sekhon George Koshy,Vandana Gangadharan

    2013-01-01

    Background: Individuals whose Body Mass Index exceeds the age-gender-specific 95th percentile are overweight; while those with BMI between the 85th and 95th percentiles are at risk of overweight. The prevalence of obesity is increasing worldwide. Children are becoming overweight at younger age. Currently 10% of children worldwide are either overweight or obese. The present study was undertaken to study the anthropometric measurements and determine the prevalence of overweight amongst school g...

  7. Design of very high speed electric generators

    This work approaches the design process of an electric generator suitable for running efficiently at high speed, driven by a turbo shaft.The axial flux concept was used.For the mechanical design of the prototype, cooling capacity and mounting method were considered, looking for simplicity of the parts evolved. Neodymium-iron-boron permanent magnets were used as magnetic source.For the electrical design, a calculation tool was developed in order to predict the prototype electrical parameters and optimize its geometry.The goal was to obtain 1 kW of electric power at a speed of 100,000 rpm.The efficiency and electrical behaviour of the prototype were characterized at speeds between 2,000 rpm and 30,000 rpm and then the behaviour at the design condition was predicted by obtaining an equivalent electric circuit.The estimated load voltage was 237 V as well as an electrical efficiency of 95%.Eddy current effects were not recognized. Increase of the internal resistance and decree of inductance were observed while raising the electric frequency.Finally, an electronic system was developed in order to use the prototype as a c.c. motor. Global performance was measured according to different supply characteristic. An optimum supply voltage was found.A maximum efficiency of 63% was reached.

  8. Quantum speed limits, coherence, and asymmetry

    Marvian, Iman; Spekkens, Robert W.; Zanardi, Paolo

    2016-05-01

    The resource theory of asymmetry is a framework for classifying and quantifying the symmetry-breaking properties of both states and operations relative to a given symmetry. In the special case where the symmetry is the set of translations generated by a fixed observable, asymmetry can be interpreted as coherence relative to the observable eigenbasis, and the resource theory of asymmetry provides a framework to study this notion of coherence. We here show that this notion of coherence naturally arises in the context of quantum speed limits. Indeed, the very concept of speed of evolution, i.e., the inverse of the minimum time it takes the system to evolve to another (partially) distinguishable state, is a measure of asymmetry relative to the time translations generated by the system Hamiltonian. Furthermore, the celebrated Mandelstam-Tamm and Margolus-Levitin speed limits can be interpreted as upper bounds on this measure of asymmetry by functions which are themselves measures of asymmetry in the special case of pure states. Using measures of asymmetry that are not restricted to pure states, such as the Wigner-Yanase skew information, we obtain extensions of the Mandelstam-Tamm bound which are significantly tighter in the case of mixed states. We also clarify some confusions in the literature about coherence and asymmetry, and show that measures of coherence are a proper subset of measures of asymmetry.

  9. Exhaust emissions from high speed passenger ferries

    Cooper, D. A.

    Exhaust emission measurements have been carried out on-board three high-speed passenger ferries (A, B and C) during normal service routes. Ship A was powered by conventional, medium-speed, marine diesel engines, Ship B by gas turbine engines and Ship C conventional, medium-speed, marine diesel engines equipped with selective catalytic reduction (SCR) systems for NO x abatement. All ships had similar auxiliary engines (marine diesels) for generating electric power on-board. Real-world emission factors of NOx, SO2, CO, CO 2, NMVOC, CH4, N2O, NH3, PM and PAH at steady-state engine loads and for complete voyages were determined together with an estimate of annual emissions. In general, Ship B using gas turbines showed favourable NO x, PM and PAH emissions but at the expense of higher fuel consumption and CO 2 emissions. Ship C with the SCR had the lowest NO x emissions but highest NH 3 emissions especially during harbour approaches and stops. The greatest PM and PAH specific emissions were measured from auxiliary engines operating at low engine loads during harbour stops. Since all ships used a low-sulphur gas oil, SO 2 emissions were relatively low in all cases.

  10. Speed Control of BLDC Motor Using DSP

    G.MadhusudhanaRao

    2010-03-01

    Full Text Available This paper proposed the speed control of brushless dc motor drive employing PWM technique using TMS320F240 digital signal processor. BLDC is widely used because of its high mechanical power density, simplicity and cost effectiveness. The complete controller for BLDC is developed using TMS 320F240 digital signal processor, which has thespecial features for digital motor control. A mathematical model of the drive system is developed to analyze the performance of the proposed drive. The hall sensor signals are used to sense the rotor position. A shunt resistor is used to sense the actual current entering into the motor. These hall signals, phase current sensing signal and the speed command are the input to the DSP. Both the outer velocity control loop and inner current control loop uses PI controller that has been implemented by programming in TMS320F240 DSP processor [8]. According to the input command, feedback command andcontrol algorithm, the PWM pulses for each phase generated by the DSP is given to IGBT driver. The output of the driver is 6 independent PWM pulses that have to be given to the corresponding gate of the six IGBTs power switches used in the three-phase bridge inverter whose output is given to the stator of the BLDC motor. The drive performance is studied for starting, speed reversal and load perturbation.

  11. Monetary reward speeds up voluntary conditional saccades

    Lewis L Chen

    2014-06-01

    Full Text Available Past studies have shown that reward contingency is critical for sensorimotor learning, and reward expectation speeds up saccades in animals. Whether monetary reward speeds up saccades in human remains unknown. Here we addressed this issue by employing a conditional saccade task, in which human subjects performed a series of non-reflexive, visually-guided horizontal saccades. The subjects were (or were not financially compensated for making a saccade in response to a centrally-displayed visual congruent (or incongruent stimulus. Reward modulation of saccadic velocities was quantified independently of the amplitude-velocity coupling. We found that reward expectation significantly sped up voluntary saccades up to 30°/s, and the reward modulation was consistent across tests. These findings suggest that monetary reward speeds up saccades in human in a fashion analogous to how juice reward sped up saccades in monkeys. We further noticed that the idiosyncratic nasal-temporal velocity asymmetry was highly consistent regardless of test order, and its magnitude was not correlated with the magnitude of reward modulation. This suggests that reward modulation and the intrinsic velocity asymmetry may be governed by separate mechanisms that regulate saccade generation.

  12. New varying speed of light theories

    Magueijo, J

    2003-01-01

    We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying $c$, dispelling the myth that the constancy of $c$ is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally Lorentz invariant VSL theories; theories exhibiting a color dependent speed of light; varying $c$ induced by extra dimensions (e.g. in the brane-world scenario); and field theories where VSL results from vacuum polarization or CPT violation. We show how VSL scenarios may solve the cosmological problems usually tackled by inflation, and also how they may produce a scale-invariant spectrum of Gaussian fluctuations, capable of explaining the WMAP data. We then review the connection between VSL and theories of quantum gravity, showing how ``doubly special'' relativity has emerged as a VSL effective model of quantum space...

  13. Second-generation speed limit map updating applications

    Tradisauskas, Nerius; Agerholm, Niels; Juhl, Jens;

    2011-01-01

    Intelligent Speed Adaptation is an Intelligent Transport System developed to significantly improve road safety in helping car drivers maintain appropriate driving behaviour. The system works in connection with the speed limits on the road network. It is thus essential to keep the speed limit map...... used in the Intelligent Speed Adaptation scheme updated. The traditional method of updating speed limit maps on the basis of long time interval observations needed to be replaced by a more efficient speed limit updating tool. In a Danish Intelligent Speed Adaptation trial a web-based tool was therefore...... developed to give road authorities the opportunity to keep the speed limit map updated. However, the feedback from road authorities was insufficient. Hence a new web application based on Google Maps was made to provide easier speed limit updates for road authorities. The lessons learnt were that tools for...

  14. Robust Underestimation of Speed During Driving: A Field Study.

    Schütz, Alexander C; Billino, Jutta; Bodrogi, Peter; Polin, Dmitrij; Khanh, Tran Q; Gegenfurtner, Karl R

    2015-12-01

    Traffic reports consistently identify speeding as a substantial source of accidents. Adequate driving speeds require reliable speed estimation; however, there is still a lack of understanding how speed perception is biased during driving. Therefore, we ran three experiments measuring speed estimation under controlled driving and lighting conditions. In the first experiment, participants had to produce target speeds as drivers or had to judge driven speed as passengers. Measurements were performed at daylight and at night. In the second experiment, participants were required to produce target speeds at dusk, under rapidly changing lighting conditions. In the third experiment, we let two cars approach and pass each other. Drivers were instructed to produce target speeds as well as to judge the speed of the oncoming vehicle. Here measurements were performed at daylight and at night, with full or dipped headlights. We found that passengers underestimated driven speed by about 20% and drivers went over the instructed speed by roughly the same amount. Interestingly, the underestimation of speed extended to oncoming cars. All of these effects were independent of lighting conditions. The consistent underestimation of speed could lead to potentially fatal situations where drivers go faster than intended and judge oncoming traffic to approach slower than it actually is. PMID:26562855

  15. A New Method to Measure the Speed of Gravitation

    Rabounski D.

    2005-04-01

    Full Text Available According to the standard viewpoint the speed of gravitation is the speed of weak waves of the metrics. This study proposes a new approach, defining the speed as the speed of travelling waves in the field of gravitational inertial force. D’Alembert’s equations of the field show that this speed is equal to the velocity of light corrected by gravitational potential. The approach leads to a new experiment to measure the speed of gravitation, which, using “detectors” such as planets and their satellites, is not linked to deviation of geodesic lines and quadrupole mass-detectors with their specific technical problems.

  16. Tectonic speed limits from plate kinematic reconstructions

    Zahirovic, Sabin; Müller, R. Dietmar; Seton, Maria; Flament, Nicolas

    2015-05-01

    The motion of plates and continents on the planet's surface are a manifestation of long-term mantle convection and plate tectonics. Present-day plate velocities provide a snapshot of this ongoing process, and have been used to infer controlling factors on the speeds of plates and continents. However, present-day velocities do not capture plate behaviour over geologically representative periods of time. To address this shortcoming, we use a plate tectonic reconstruction approach to extract time-dependent plate velocities and geometries from which root mean square (RMS) velocities are computed, resulting in a median RMS plate speed of ∼ 4 cm /yr over 200 Myr. Linking tectonothermal ages of continental lithosphere to the RMS plate velocity analysis, we find that the increasing portions of plate area composed of continental and/or cratonic lithosphere significantly reduces plate speeds. Plates with any cratonic portion have a median RMS velocity of ∼ 5.8 cm /yr, while plates with more than 25% of cratonic area have a median RMS speed of ∼ 2.8 cm /yr. The fastest plates (∼ 8.5 cm /yr RMS speed) have little continental fraction and tend to be bounded by subduction zones, while the slowest plates (∼ 2.6- 2.8 cm /yr RMS speed) have large continental fractions and usually have little to no subducting part of plate perimeter. More generally, oceanic plates tend to move 2-3 times faster than continental plates, consistent with predictions of numerical models of mantle convection. The slower motion of continental plates is compatible with deep keels impinging on asthenospheric flow and increasing shear traction, thus anchoring the plate in the more viscous mantle transition zone. We also find that short-lived (up to ∼ 10 Myr) rapid accelerations of Africa (∼100 and 65 Ma), North America (∼100 and 55 Ma) and India (∼ 130 , 80 and 65 Ma) appear to be correlated with plume head arrivals as recorded by large igneous province (LIPs) emplacement. By evaluating

  17. Cardiovascular effects of 3 months of football training in overweight children examined by comprehensive echocardiography

    Hansen, Peter Riis; Andersen, Lars Juel; Rebelo, António Natal;

    2013-01-01

    Abstract We examined effects of a 3-month football training programme in overweight children using comprehensive echocardiography and peripheral arterial tonometry. Twenty preadolescent overweight children (17 boys, 3 girls aged 8-12 yrs; body mass index [BMI] ≥ 85(th) percentile) participated in...

  18. Childhood environment and obesity

    US children are at risk for developing childhood obesity. Currently, 23% of children ages 2–5 are overweight or obese, i.e., at or above the 85th percentile. This prevalence becomes even higher as children age, with 34% of children ages 6–11 being overweight or obese. Ethnic minority children are at...

  19. Effects of Aerobic Exercise on Overweight Children's Cognitive Functioning: A Randomized Controlled Trial

    Davis, Catherine L.; Tomporowski, Phillip D.; Boyle, Colleen A.; Waller, Jennifer L.; Miller, Patricia H.; Naglieri, Jack A.; Gregoski, Mathew

    2007-01-01

    The study tested the effect of aerobic exercise training on executive function in overweight children. Ninety-four sedentary, overweight but otherwise healthy children (mean age = 9.2 years, body mass index [greater than or equal to] 85th percentile) were randomized to a low-dose (20 min/day exercise), high-dose (40 min/day exercise), or control…

  20. Two laboratory methods for the calibration of GPS speed meters

    The set-ups of two calibration systems are presented to investigate calibration methods of GPS speed meters. The GPS speed meter calibrated is a special type of high accuracy speed meter for vehicles which uses Doppler demodulation of GPS signals to calculate the measured speed of a moving target. Three experiments are performed: including simulated calibration, field-test signal replay calibration, and in-field test comparison with an optical speed meter. The experiments are conducted at specific speeds in the range of 40–180 km h−1 with the same GPS speed meter as the device under calibration. The evaluation of measurement results validates both methods for calibrating GPS speed meters. The relative deviations between the measurement results of the GPS-based high accuracy speed meter and those of the optical speed meter are analyzed, and the equivalent uncertainty of the comparison is evaluated. The comparison results justify the utilization of GPS speed meters as reference equipment if no fewer than seven satellites are available. This study contributes to the widespread use of GPS-based high accuracy speed meters as legal reference equipment in traffic speed metrology. (paper)

  1. Design of A Novel High Speed Dynamic Comparator with Low Power Dissipation for High Speed ADCs

    Sougata Ghosh

    2013-01-01

    Full Text Available A new CMOS dynamic comparator using dual input single output differential amplifier as latch stage suitable for high speed analog-to-digital converters with High Speed, low power dissipation and immune to noise than the previous reported work is proposed. Back to-back inverter in the latch stage is replaced with dual-input single output differential amplifier. This topology completely removes the noise that is present in the input. The structure shows lower power dissipation and higher speed than the conventional comparators. The circuit is simulated with 1V DC supply voltage and 250 MHz clock frequency. The proposed topology is based on two cross coupled differential pairs positive feedback and switchable current sources, has a lower power dissipation, higher speed, less area, and it is shown to be very robust against transistor mismatch, noise immunity. Previous reported comparators are designed and simulated their DC response and Transient response in Cadence®Virtuoso Analog Design Environment using GPDK 90nm technology. Layouts of the proposed comparator have been done in Cadence® Virtuoso Layout XL Design Environment. DRC and LVS has been checked and compared with the corresponding circuits and RC extracted diagram has been generated. After that post layout simulation with 1V supply voltage has been done and compared the speed, power dissipation, Area, delay with the results before layout and the superior features of the proposed comparator are established

  2. Control of Variable Speed Variable Pitch Wind Turbine at Above and Below Rated Wind Speed

    Saravanakumar Rajendran

    2014-01-01

    Full Text Available The paper presents a nonlinear approach to wind turbine (WT using two-mass model. The main aim of the controller in the WT is to maximize the energy output at varying wind speed. In this work, a combination of linear and nonlinear controllers is adapted to variable speed variable pitch wind turbines (VSVPWT system. The major operating regions of the WT are below (region 2 and above rated (region 3 wind speed. In these regions, generator torque control (region 2 and pitch control (region 3 are used. The controllers in WT are tested for below and above rated wind speed for step and vertical wind speed profile. The performances of the controllers are analyzed with nonlinear FAST (Fatigue, Aerodynamics, Structures, and Turbulence WT dynamic simulation. In this paper, two nonlinear controllers, that is, sliding mode control (SMC and integral sliding mode control (ISMC, have been applied for region 2, whereas for pitch control in region 3 conventional PI control is used. In ISMC, the sliding manifold makes use of an integral action to show effective qualities of control in terms of the control level reduction and sliding mode switching control minimization.

  3. HIGH SPEED INJECTION MOLDING OF HIGH DENSITY POLYETHYLENE - EFFECTS OF INJECTION SPEED ON STRUCTURE AND PROPERTIES

    Kun Jiang; Feng Chen; Qiang Fu; Fei-long Yu; Run Su; Jing-hui Yang; Tian-nan Zhou; Jian Gao; Hua Deng; Ke Wang; Qin Zhang

    2011-01-01

    Thin wall samples of high density polyethylene (HDPE) were prepared via injection molding with differentinjection speeds ranging from 100 mm/s to 1200 mm/s. A significant decrease in the tensile strength and Young's moduluswas observed with increasing injection speed. In order to investigate the mechanism behind this decrease, the orientation,molecular weight, molecular weight distribution, melt flow rate, crystallinity and crystal morphology of HDPE werecharacterized using two-dimensional wide-angle X-ray diffraction (2D-WAXD), gel permeation chromatography (GPC),capillary rheometry and differential scanning calorimetry (DSC), respectively. It is demonstrated that the orientation,molecular weight, molecular weight distribution, melt flow rate and crystallinity have no obvious change with increasinginjection speed. Nevertheless, the content of extended chain crystals or large folded chain crystals was found to decreasewith increasing injection speed. Therefore, it is concluded that the decrease in tensile properties is mainly contributed by the reduced content of extended chain crystals or large folded chain crystals. This study provides industry with valuableinformation for the application of high speed injection molding.

  4. Wireless Reporting System for Accident Detection at Higher Speeds u

    Peddi Anudeep

    2014-09-01

    Full Text Available Speed is one of the basic reasons for vehicle accident. Many lives could have been saved if emergency service could get accident information and reach in time. Nowadays, GPS has become an integral part of a vehicle system. This paper proposes to utilize the capability of a GPS receiver to monitor speed of a vehicle and detect accident basing on monitored speed and send accident location to an Alert Service Center. The GPS will monitor speed of a vehicle and compare with the previous speed in every second through a Microcontroller Unit. Whenever the speed will be below the specified speed, it will assume that an accident has occurred. The system will then send the accident location acquired from the GPS along with the time and the speed by utilizing the GSM network. This will help to reach the rescue service in time and save the valuable human life.

  5. Torque- and Speed Control of a Pitch Regulated Wind Turbine

    Rasila, Mika

    2003-07-01

    Variable speed operated wind turbines has the potential to reduce fatigue loads, compared to fixed speed wind turbines. With pitch controllable rotor blades limitation of the power at high wind speeds is obtained. The thesis describes different controlling aspects concerning wind turbines and how these together can be used to optimize the system's performance. Torque control is used in order to achieve reduction on the mechanical loads on the drive-train for low wind speeds and limitation of power output for high wind speeds. In the high wind speed interval torque control is effective in order to limit the output power if a sufficiently fast pitch actuator is used. In the middle wind speed interval filter utilization can be used to give a reference signal to the controller in order to reduce speed and torque variations.

  6. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    National Aeronautics and Space Administration — We propose to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight, low voltage beam...

  7. Speed and automaticity of word recognition - inseparable twins?

    Poulsen, Mads; Asmussen, Vibeke; Elbro, Carsten

    'Speed and automaticity' of word recognition is a standard collocation. However, it is not clear whether speed and automaticity (i.e., effortlessness) make independent contributions to reading comprehension. In theory, both speed and automaticity may save cognitive resources for comprehension...... processes. Hence, the aim of the present study was to assess the unique contributions of word recognition speed and automaticity to reading comprehension while controlling for decoding speed and accuracy. Method: 139 Grade 5 students completed tests of reading comprehension and computer-based tests of speed...... shared developmental sources. However, multiple regression analyses indicated that both automaticity (effortlessness) and speed of word recognition (word-specific orthographic knowledge) contributed unique variance to reading comprehension when word decoding accuracy and speed was controlled. Conclusion...

  8. High Speed Magnetostrictive MEMS Actuated Mirror Deflectors Project

    National Aeronautics and Space Administration — The main goal of this proposal is to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight,...

  9. Small variable speed hermetic reciprocating compressors for domestic refrigerators

    Rasmussen, Bjarne D.

    1996-01-01

    This paper contains both a theoretical and experimental investigation of some of the fundamental characteristics of a smal variable speed hermetic reciprocating compressor intended for application in domestic refrigeration. The results of a previously published simulation model for variable speed...

  10. Multiple Running Speed Signals in Medial Entorhinal Cortex.

    Hinman, James R; Brandon, Mark P; Climer, Jason R; Chapman, G William; Hasselmo, Michael E

    2016-08-01

    Grid cells in medial entorhinal cortex (MEC) can be modeled using oscillatory interference or attractor dynamic mechanisms that perform path integration, a computation requiring information about running direction and speed. The two classes of computational models often use either an oscillatory frequency or a firing rate that increases as a function of running speed. Yet it is currently not known whether these are two manifestations of the same speed signal or dissociable signals with potentially different anatomical substrates. We examined coding of running speed in MEC and identified these two speed signals to be independent of each other within individual neurons. The medial septum (MS) is strongly linked to locomotor behavior, and removal of MS input resulted in strengthening of the firing rate speed signal, while decreasing the strength of the oscillatory speed signal. Thus, two speed signals are present in MEC that are differentially affected by disrupted MS input. PMID:27427460

  11. Speed control of diesel generator sets

    In some marine and stationary power plants, it is often of interest to be able to give some information about the dynamic behaviour of the engine when it is loaded according to a given programme: How well it reacts to the application of a step load and to a load rejection. What is the best speed governor type and its optimum parameter adjustment in order to satisfy the requested specification of maximum speed engine deviation and recovery time. How great is the influence of turbocharger options such as jet assist or waste gate on the dynamic behaviour of the plant. Such kinds of questions occur for all stand-by power stations and in marine installations where the engine is submitted to very large load variations in the form of steps, ramps or any other load programme. The computer program GENERAT fully fulfils the aims described above. The comparison of measurements and simulation is good enough to allow us to use simulation as a means of predicting the dynamic behaviour of stationary power plant with four-stroke engines submitted to a given load programme. This program allows us also to determine the optimum generator inertia and to find the optimum governor parameters. The next step of development will be to model the turbocharger and supercharging method for two-stroke engines and some new digital speed controls and to rewrite the program with the help of the simulation package ACSL. This last point presents some advantages, as for example in large reduction of program maintenance and higher flexibility

  12. New varying speed of light theories

    Magueijo, Joao [Blackett Laboratory, Imperial College of Science, Technology and Medicine, South Kensington, London SW7 2BZ (United Kingdom)

    2003-11-01

    We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying-c, dispelling the myth that the constancy of c is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally Lorentz invariant VSL theories; theories exhibiting a colour-dependent speed of light; varying-c induced by extra dimensions (e.g. in the brane-world scenario); and field theories where VSL results from vacuum polarization or CPT violation. We show how VSL scenarios may solve the cosmological problems usually tackled by inflation, and also how they may produce a scale-invariant spectrum of Gaussian fluctuations, capable of explaining the WMAP data. We then review the connection between VSL and theories of quantum gravity, showing how 'doubly special' relativity has emerged as a VSL effective model of quantum space-time, with observational implications for ultra-high energy cosmic rays (UHECRs) and gamma ray bursts. Some recent work on the physics of 'black' holes and other compact objects in VSL theories is also described, highlighting phenomena associated with spatial (as opposed to temporal) variations in c. Finally, we describe the observational status of the theory. The evidence is currently slim-redshift dependence in the atomic fine structure, anomalies with UHECRs, and (to a much lesser extent) the acceleration of the universe and the WMAP data. The constraints (e.g. those arising from nucleosynthesis or geological bounds) are tight but not insurmountable. We conclude with the observational predictions of the theory and the prospects for its refutation or vindication.

  13. High speed UNIBUS-VME interface

    An interface between VME an the UNIBUS of PDP or VAX computer is presented. The system supports high speed parallel communication (up to 1MB/S) and is composed of two modules. One of these is a commercial DR11M board which performs DMA transfers between UNIBUS and the external word. The other is a VME module specifically developed for this application. The interface has been tested under VMS operating system in VAX and VALET-PLUS system for the VME Bus. We describe in detail the VME module and its connection with the DR11M. Software, both in WMS and VALET, is also described. (Author) 7 refs

  14. Accident Safety Design for High Speed Elevator

    Tawiwat Veeraklaew

    2012-12-01

    Full Text Available There have been many elevators exist in buildings for such a long time; however, an accident might happen as a free fall due to lacks of maintenance or some other accident such as firing. Although this situation is rarely occurred, many people are still concerned about it. The question here is how to make passengers to feel safe and confident when they are using an elevator, especially, high speed elevator. This problem is studied here in this paper as a free fall spring-mass-damper system with the stiffness and damping coefficient can be computed as minimum jerk of the system with given constraints on trajectories.

  15. High Speed Solid State Circuit Breaker

    Podlesak, Thomas F.

    1993-01-01

    The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

  16. High Speed Laser 3D Measurement System

    SONG Yuan-he; FAN Chang-zhou; GUO Ying; LI Hong-wei; ZHAO Hong

    2003-01-01

    Using the method of line structure light produced by a laser diode,three dimensional profile measurement is deeply researched.A hardware circuit developed is used to get the center position of light section for the improvement of the measurement speed.A double CCD compensation technology is used to improve the measurement precision. An easy and effective calibration method of the least squares to fit the parameter of system structure is used to get the relative coordinate relationship of objects and images of light section in the directions of height and axis. Sensor scanning segment by segment and layer by layer makes the measurement range expand greatly.

  17. χVariable-speed-of-light cosmologies

    Variable-speed-of-light (VSL) cosmologies are currently attracting much interest as a possible alternative to cosmological inflation. We discuss the fundamental geometrodynamic aspects of VSL cosmologies, and provide several alternative implementations. These implementations provide a large class of VSL cosmologies that pass the zeroth-order consistency tests of being compatible with both classical Einstein gravity and low-energy particle physics. While they solve the 'kinematic' puzzles as well as inflation does, VSL cosmologies typically do not solve the flatness problem since in their purest form no violation of the strong energy condition occurs. Nevertheless, these models are easy to unify with inflation

  18. Surface Treatment of High Speed Steel Tools

    タカハシ, ヒサオ; Hisao, TAKAHAASHI

    1997-01-01

    This paper reveals to cutting performance on 3 kinds of high speed steels throw away tips (including made by powder metallurgical process), which are compared surface treated tips by means of the coating process PVD-TiN (physical vapor deposition by the arc ion plating method) with untreated conventional tips. The results are as follows: "X"tips by name have the highest hardness and performance on continuous cutting than the others, but they have the lowest toughness and larger chipping on in...

  19. A finite speed Curzon-Ahlborn engine

    Curzon and Ahlborn achieved finite power output by introducing the concept of finite rate of heat transfer in a Carnot engine. The finite power can also be achieved through a finite speed of the piston on the four branches of the Carnot cycle. The present paper combines these two approaches to study the behaviour of output power in terms of isothermal expansion ratio V*2 and the temperature differences x and y present at the hot source and cold sink branches, respectively, for the benefit of undergraduate students

  20. High speed drying of saturated steam

    This paper describes the development of the drying process for the saturated steam used in the PWR nuclear plant turbines in order to prevent negative effects of water on turbine efficiency, maintenance costs and equipment lifetime. The high speed drying concept is based on rotating the incoming saturated steam in order to separate water which is more denser than the steam; the water film is then extracted through an annular slot. A multicellular modular equipment has been tested. Applications on high and low pressure extraction of various PWR plants are described (Bugey, Loviisa)

  1. High-Speed Images of Bubble Formation

    Bunganič, Radovan; Růžička, Marek; Drahoš, Jiří

    Praha : Process Engineering Publisher, 2004, s. 922. ISBN 80-86059-40-5. [International Congress of Chemical and Process Engineering CHISA 2004 /16./. Praha (CZ), 22.08.2004-26.08.2004] R&D Projects: GA ČR GA104/04/0827; GA ČR GD104/03/H141 Grant ostatní: BEMUSAC(XE) G1MA/CT/2002/04019 Institutional research plan: CEZ:AV0Z4072921 Keywords : bubble formation * high-speed image Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  2. Speed Money: Time, Corruption, and Trade

    Shepherd, Ben

    2009-01-01

    This paper shows that longer trade times are associated with higher levels of trade-related corruption, consistent with a theoretical framework in which “fast” producers earn higher profits than “slow” ones, but may have to pay “speed money” to possibly corrupt customs officials. This finding is robust to the use of corruption measures based on perceptions and reported behavior, the inclusion of a wide range of control variables from the previous literature, and estimation by a variety of met...

  3. Wind speed prediction using different computing techniques

    Nayak, Munir Ahmad; Deo, M. C.

    2014-01-01

    Wind is slated to become one of the most sought after source of energy in future. Both onshore as well as offshore wind farms are getting deployed rapidly over the world. This paper evaluates a neural network based time series approach to predict wind speed in real time over shorter duration of up to 12 hr based on analysis of three hourly wind data collected through a wave rider buoy deployed off Goa in deep water and far away from the shore. The data were collected for 4 years from February...

  4. Speed mathematics secrets skills for quick calculation

    Handley, Bill

    2011-01-01

    Using this book will improve your understanding of math and haveyou performing like a genius!People who excel at mathematics use better strategies than the restof us; they are not necessarily more intelligent.Speed Mathematics teaches simple methods that will enable you tomake lightning calculations in your head-including multiplication,division, addition, and subtraction, as well as working withfractions, squaring numbers, and extracting square and cube roots.Here's just one example of this revolutionary approach to basicmathematics:96 x 97 =Subtract each number from 100.96 x 97 =4 3Subtract

  5. High Speed, Low Weight Momentum/Reaction Wheels

    Wilhide, Larry; Brothers, Louis; Breyer, Eugene

    1999-01-01

    Advancements in several critical areas have made possible lightweight, strong and highly reliable momentum / reaction wheels. The development of reliable bearings with design features that allow high speed operation for space flight applications has significantly altered the weight / speed / wheel design considerations. Current designs typically operate at speeds at or below 6,000 RPM The new retainerless can achieve speeds 10 times that and meet or improve all other significant bearing opera...

  6. 14 CFR 25.1511 - Flap extended speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for...

  7. Ion-swimming speed variation of Vibrio cholerae cells

    Anindito Sen; Ranjan K Nandi; Amar N Ghosh

    2005-09-01

    In the present work we report the variation in swimming speed of Vibrio cholerae with respect to the change in concentration of sodium ions in the medium. We have also studied the variation in swimming speed with respect to temperature. We find that the swimming speed initially shows a linear increase with the increase of the sodium ions in the medium and then plateaus. The range within which the swimming speed attains saturation is approximately the same at different temperatures.

  8. Speed limitation based on an advanced curve warning system

    Glaser, Sébastien; Nouveliere, Lydie; Lusetti, Benoît

    2007-01-01

    This paper presents an integrated system to prevent driver from taking a curve with a dangerous speed. The integrated system underlines three functions developed as follows : the first function consists in knowing the geometry characteristics of the coming road ; the second function has to compute a safe speed according to the road section, the vehicle and the driver ; the last function must impose the speed control of the vehicle in order to achieve a safe speed in the case that the dr...

  9. Speed Regulator for Permanent Magnet DC Boring Machine

    2000-01-01

    In this paper a variable-speed system for a loaded permanent magnet direct current boring machine (PMDCBM) is described in details. The voltage adjustment of PMDCBM is accomplished by means of solid state switch with a high gain Darlington transistor. The device designed possesses good variable speed characteristic and Iow loss at low speed. The speed can be regulated automatically to hold at an ideal value according to the load.

  10. Speed regulating Effects of Incentive-based Intelligent Speed Adaptation in the short and medium term

    Agerholm, Niels

    Speed regulating Effects of Incentive-based Intelligent Speed Adaptation in the short and medium term Despite massive improvements in vehicles’ safety equipment, more information and safer road network, inappropriate road safety is still causing that more than 250 people are killed and several...... fewer speed limit violations. Estimation of safety effects showed various results and the reduction in the number of fatalities was estimated to be as high as 37 to 42% if ISA was fully implemented. Despite convincing effects of ISA in short term, it was found that the effect of ISA decreased over time...... activation of ISA. The effect was studied on the basis of the Danish ISA trial PAYS. Short term means 0-1.5 months after ISA activation, while medium-term means 3-4.5 months after ISA activation. Regarding short-term effects, it was found that the combination of informative and incentive ISA resulted in...

  11. EXPERIMENTAL INVESTIGATION ON SOUND SPEED PROPAGATING THROUGH HIGH SPEED AERATED FLOW IN OPEN CHANNEL

    2002-01-01

    An experiment concerning the sound propaga-tion in aerated open channel flow was designed and conductedin a variable slope chute. The acquisition of sound data wasdone by the hydro-phones installed into the bottom wall of thechute. The data were analyzed and processed by the tape re-corder and a 3562A analyzer. The primary experimetal resultsindicated that the sound speed in aerated flow is varied with the air concentration and highly lower than each of the soundspeed in pure water or air. As released by the derived theoryformula, the minimum sound of 24m/s in aerated flow hap-pened when the air concentration achieved to 50%. This resultshows that the compressibility of high speed aerated flowshould be considered when the air concentration is near to50%. A criterion of compressibility of high speed aerated flowwas also giv. En in this paper.

  12. HDR {sup 192}Ir source speed measurements using a high speed video camera

    Fonseca, Gabriel P. [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Viana, Rodrigo S. S.; Yoriyaz, Hélio [Instituto de Pesquisas Energéticas e Nucleares—IPEN-CNEN/SP, São Paulo 05508-000 (Brazil); Podesta, Mark [Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Rubo, Rodrigo A.; Sales, Camila P. de [Hospital das Clínicas da Universidade de São Paulo—HC/FMUSP, São Paulo 05508-000 (Brazil); Reniers, Brigitte [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Research Group NuTeC, CMK, Hasselt University, Agoralaan Gebouw H, Diepenbeek B-3590 (Belgium); Verhaegen, Frank, E-mail: frank.verhaegen@maastro.nl [Department of Radiation Oncology - MAASTRO, GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec H3G 1A4 (Canada)

    2015-01-15

    Purpose: The dose delivered with a HDR {sup 192}Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a {sup 192}Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases.

  13. HDR 192Ir source speed measurements using a high speed video camera

    Purpose: The dose delivered with a HDR 192Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a 192Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases

  14. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  15. Intelligent speed control and effects on driving behaviour

    Horst, A.R.A. van der; Hogema, J.H.

    1999-01-01

    Supporting the driver in conducting his nowadays demanding task is a promising means to get the maximum out of the road system with respect to both efficiency and safety. With respect to safety, speed management is a main issue. Police enforcement of speeding is one approach, preventing high speeds

  16. 14 CFR 25.1513 - Minimum control speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum control speed. 25.1513 Section 25.1513 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Limitations § 25.1513 Minimum control speed. The minimum control speed V MC determined under § 25.149 must...

  17. 14 CFR 23.1513 - Minimum control speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum control speed. 23.1513 Section 23.1513 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Information § 23.1513 Minimum control speed. The minimum control speed V MC, determined under § 23.149,...

  18. 14 CFR 29.49 - Performance at minimum operating speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Performance at minimum operating speed. 29... minimum operating speed. (a) For each Category A helicopter, the hovering performance must be determined... than helicopters, the steady rate of climb at the minimum operating speed must be determined over...

  19. 14 CFR 23.1511 - Flap extended speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap extended speed. 23.1511 Section 23.1511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Information § 23.1511 Flap extended speed. (a) The flap extended speed V FE must be established so that it...

  20. 14 CFR 23.73 - Reference landing approach speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Reference landing approach speed. 23.73... Reference landing approach speed. (a) For normal, utility, and acrobatic category reciprocating engine-powered airplanes of 6,000 pounds or less maximum weight, the reference landing approach speed, VREF,...

  1. 14 CFR 27.49 - Performance at minimum operating speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Performance at minimum operating speed. 27... minimum operating speed. (a) For helicopters— (1) The hovering ceiling must be determined over the ranges... climb at the minimum operating speed must be determined over the ranges of weight, altitude,...

  2. 49 CFR 174.86 - Maximum allowable operating speed.

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15...

  3. 14 CFR 23.149 - Minimum control speed.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Minimum control speed. 23.149 Section 23... Maneuverability § 23.149 Minimum control speed. (a) VMC is the calibrated airspeed at which, when the critical... still inoperative, and thereafter maintain straight flight at the same speed with an angle of bank...

  4. Gender Differences in Processing Speed: A Review of Recent Research

    Roivainen, Eka

    2011-01-01

    A review of recent large-scale studies on gender differences in processing speed and on the cognitive factors assumed to affect processing speed was performed. It was found that females have an advantage in processing speed tasks involving digits and alphabets as well as in rapid naming tasks while males are faster on reaction time tests and…

  5. Spreading speeds in a lattice differential equation with distributed delay

    Niu, Hui-Ling

    2015-01-01

    This paper studies the spreading speed for a lattice differential equation with infinite distributed delay and we find that the spreading speed coincides with the minimal wave speed of traveling waves. Here the model has been proposed to describe a single species living in a 1D patch environment with infinite number of patches connected locally by diffusion.

  6. Improved road traffic emission inventories by adding mean speed distributions

    Smit, R.; Poelman, M.; Schrijver, J.

    2008-01-01

    Does consideration of average speed distributions on roads-as compared to single mean speed-lead to different results in emission modelling of large road networks? To address this question, a post-processing method is developed to predict mean speed distributions using available traffic data from a

  7. Differential Response Speed: Is It Really a Nuisance?

    Jeon, Minjeong

    2015-01-01

    It is commonly acknowledged that ability and speed are not separate constructs but interact with each other. Traditionally, the ability-speed interplay has been seen as a problem to be conquered and a number of psychometric methods have been developed to deal with the interplay between ability and speed and to obtain more pure ability measures.…

  8. Electric motor drive with infinitely variable speed transmission

    Tibbals, E.C. Jr.

    1983-07-05

    A drive system adapted for use in motor vehicles comprises an infinitely variable speed drive transmission coupled to a DC motor, and the speed ratio of the transmission is controlled by a speed-responsive flyweight or governor so as to maintain the DC motor at its most efficient operating level.

  9. 14 CFR 25.33 - Propeller speed and pitch limits.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller speed and pitch limits. 25.33 Section 25.33 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight General § 25.33 Propeller speed and pitch limits. (a) The propeller speed and...

  10. Naturalistic speeding data: Drivers aged 75 years and older.

    Chevalier, Anna; Chevalier, Aran John; Clarke, Elizabeth; Wall, John; Coxon, Kristy; Brown, Julie; Ivers, Rebecca; Keay, Lisa

    2016-09-01

    The data presented in this article are related to the research article entitled "A longitudinal investigation of the predictors of older drivers׳ speeding behavior" (Chevalier et al., 2016) [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75-94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS) data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control. PMID:27294182

  11. Logic design and implementation on high speed data converting

    A kind of high speed data converter was discussed in this paper. Structure of the system, implementation of the design and memory in the system were introduced in details. Such data converters are important units in high speed routers, and this design is a good reference for high speed router designing

  12. Lorentz transformation directly from the invariance of the speed of light via the addition law of parallel speeds

    Rothenstein, Bernhard

    2007-01-01

    We show that starting with the addition law of parallel speeds derived as a consequence of the invariance of the speed of light, the Lorentz transformations for the space-time coordinates can be derived.

  13. Interconnection of speed, power and speed-power abilities of professional hockey players on ice and out of ice

    Zankovets V.E.

    2015-09-01

    Full Text Available Purpose: determination of correlation’s degree between speed, power and speed-power abilities of professional hockey players on ice and out of ice. Material: 65 professional hockey players of age from 16 to 33 years old were tested. 75 highly qualified coaches were questioned. Results: The found out interconnections between 11 indicators of speed, power and speed power qualities supplement knowledge about transfer physical qualities. We detected high interconnection between speed and speed-power abilities, manifested by sportsmen in exercises on ice and on land. We registered moderate level of interconnection between static (absolute power and speed abilities of hockey players. We proved hypothesis about possibility of start speed (power transfer in different conditions of its manifestation. Conclusions: the received data permit to correct hockey players’ training program, considering new knowledge about transfer of one or the other physical qualities on sportsmen’s training.

  14. High-speed motion neutron radiography

    A system has been developed to perform neutron radiographic analysis of dynamic events having a duration of several milliseconds. The system has been operated in the range of 2000 to 10,000 frames. Synchronization has provided high-speed motion neutron radiographs for evaluation of the firing cycles of 7.62-mm munition rounds within a thick steel rifle barrel. The system has also been used to demonstrate its ability to produce neutron radiographic movies of two-phase flow. The equipment includes a TRIGA reactor capable of pulsing to a peak power of 3000 MW, a neutron beam collimator, a scintillator neutron conversion screen coupled to an image intensifier, and a 16-mm high-speed movie camera. The peak neutron flux incident at the object position is about 4 X 1011 n/cm2 X s with a pulse, full-width at half-maximum, of 9 ms. Modulation transfer function techniques have been used to assist optimization of the system performance. Special studies have been performed on the scintillator conversion screens and on the effects of statistical limitations on information availability

  15. Impact of stimulus uncanniness on speeded response

    Kohske eTakahashi

    2015-05-01

    Full Text Available In the uncanny valley phenomenon, the causes of the feeling of uncanniness as well as the impact of the uncanniness on behavioral performances still remain open. The present study investigated the behavioral effects of stimulus uncanniness, particularly with respect to speeded response. Pictures of fish were used as visual stimuli. Participants engaged in direction discrimination, spatial cueing, and dot-probe tasks. The results showed that pictures rated as strongly uncanny delayed speeded response in the discrimination of the direction of the fish. In the cueing experiment, where a fish served as a task-irrelevant and unpredictable cue for a peripheral target, we again observed that the detection of a target was slowed when the cue was an uncanny fish. Conversely, the dot-probe task suggested that uncanny fish, unlike threatening stimulus, did not capture visual spatial attention. These results suggested that stimulus uncanniness resulted in the delayed response, and importantly this modulation was not mediated by the feelings of threat.

  16. Analysis of motion in speed skating

    Koga, Yuzo; Nishimura, Tetsu; Watanabe, Naoki; Okamoto, Kousuke; Wada, Yuhei

    1997-03-01

    A motion on sports has been studied by many researchers from the view of the medical, psychological and mechanical fields. Here, we try to analyze a speed skating motion dynamically for an aim of performing the best record. As an official competition of speed skating is performed on the round rink, the skating motion must be studied on the three phases, that is, starting phase, straight and curved course skating phase. It is indispensable to have a visual data of a skating motion in order to analyze kinematically. So we took a several subject's skating motion by 8 mm video cameras in order to obtain three dimensional data. As the first step, the movement of the center of gravity of skater (abbreviate to C. G.) is discussed in this paper, because a skating motion is very complicated. The movement of C. G. will give an information of the reaction force to a skate blade from the surface of ice. We discuss the discrepancy of several skating motion by studied subjects. Our final goal is to suggest the best skating form for getting the finest record.

  17. High-speed cameras at Los Alamos

    Brixner, Berlyn

    1997-05-01

    In 1943, there was no camera with the microsecond resolution needed for research in Atomic Bomb development. We had the Mitchell camera (100 fps), the Fastax (10 000), the Marley (100 000), the drum streak (moving slit image) 10-5 s resolution, and electro-optical shutters for 10-6 s. Julian Mack invented a rotating-mirror camera for 10-7 s, which was in use by 1944. Small rotating mirror changes secured a resolution of 10-8 s. Photography of oscilloscope traces soon recorded 10-6 resolution, which was later improved to 10-8 s. Mack also invented two time resolving spectrographs for studying the radiation of the first atomic explosion. Much later, he made a large aperture spectrograph for shock wave spectra. An image dissecting drum camera running at 107 frames per second (fps) was used for studying high velocity jets. Brixner invented a simple streak camera which gave 10-8 s resolution. Using a moving film camera, an interferometer pressure gauge was developed for measuring shock-front pressures up to 100 000 psi. An existing Bowen 76-lens frame camera was speeded up by our turbine driven mirror to make 1 500 000 fps. Several streak cameras were made with writing arms from 4 1/2 to 40 in. and apertures from f/2.5 to f/20. We made framing cameras with top speeds of 50 000, 1 000 000, 3 500 000, and 14 000 000 fps.

  18. High-speed optogenetic circuit mapping

    Augustine, George J.; Chen, Susu; Gill, Harin; Katarya, Malvika; Kim, Jinsook; Kudolo, John; Lee, Li M.; Lee, Hyunjeong; Lo, Shun Qiang; Nakajima, Ryuichi; Park, Min-Yoon; Tan, Gregory; Tang, Yanxia; Teo, Peggy; Tsuda, Sachiko; Wen, Lei; Yoon, Su-In

    2013-03-01

    Scanning small spots of laser light allows mapping of synaptic circuits in brain slices from transgenic mice expressing channelrhodopsin-2 (ChR2). These light spots photostimulate presynaptic neurons expressing ChR2, while postsynaptic responses can be monitored in neurons that do not express ChR2. Correlating the location of the light spot with the amplitude of the postsynaptic response elicited at that location yields maps of the spatial organization of the synaptic circuits. This approach yields maps within minutes, which is several orders of magnitude faster than can be achieved with conventional paired electrophysiological methods. We have applied this high-speed technique to map local circuits in many brain regions. In cerebral cortex, we observed that maps of excitatory inputs to pyramidal cells were qualitatively different from those measured for interneurons within the same layers of the cortex. In cerebellum, we have used this approach to quantify the convergence of molecular layer interneurons on to Purkinje cells. The number of converging interneurons is reduced by treatment with gap junction blockers, indicating that electrical synapses between interneurons contribute substantially to the spatial convergence. Remarkably, gap junction blockers affect convergence in sagittal cerebellar slices but not in coronal slices, indicating sagittal polarization of electrical coupling between interneurons. By measuring limb movement or other forms of behavioral output, this approach also can be used in vivo to map brain circuits non-invasively. In summary, ChR2-mediated high-speed mapping promises to revolutionize our understanding of brain circuitry.

  19. A high speed magnetostrictive mirror deflector

    This paper discusses the development of a high speed magnetostrictive mirror deflector that is compact, power efficient, and requires only low voltage for excitation. The magnetostrictive mirror deflector was designed and fabricated, and its performance tested. Three kinds of experiments were conducted to evaluate the performance, namely, identification of resonance frequencies, measurement of the angle of deflection, and study of the stability of the actuator under continuous use. The measurements were made using a high speed charge coupled device camera integrated with a PC using a custom made data acquisition and analysis program. The deflector was able to produce more than 6.1 mrad at 5.28 kHz with a minimal power of 0.8 W. Experiments conducted to test the repeatability of the measurements made have shown that the device is suitable for continuous duty operation. The results obtained in this study showed that the magnetostrictive mirror deflector is a good candidate for lidar and rapidly tunable laser system use

  20. Reduced particle settling speed in turbulence

    Fornari, Walter; Sardina, Gaetano; Brandt, Luca

    2016-01-01

    We study the settling of finite-size rigid spheres in sustained homogeneous isotropic turbulence (HIT) using Direct Numerical Simulations. In particular, an immersed boundary method is used to account for the dispersed solid phase. We study semi-dilute suspensions of spheres at different Galileo numbers, Ga. The Galileo number is the ratio between buoyancy and viscous forces, and is here varied via the solid-to-fluid density ratio. The focus is on particles that are slightly heavier than the fluid. We find that in HIT, the mean settling speed is less than in quiescent fluid and it reduces by 6 to 60\\% with respect to the terminal velocity of an isolated sphere in quiescent fluid "Vt", as the ratio between "Vt" and the turbulent velocity fluctuations u' is decreased. Analysing the fluid-particle relative motion, we find that the mean settling speed is progressively reduced while reducing due to the increase of the vertical drag induced by the particle cross-flow velocity. Unsteady effects contribute to the mea...

  1. Persistent pattern speeds in Saturn's D ring

    Chancia, Robert; Hedman, Matthew M.

    2016-05-01

    Saturn's D ring is the innermost part of Saturn's ring system. Due to its close proximity to the planet, it is sensitive to perturbing forces caused by asymmetries in Saturn's interior and magnetic field. Using high-phase-angle images obtained by the Imaging Science Subsystem (ISS) over the course of the entire Cassini mission we investigate the region between 71000-73000 km from Saturn's center. Previous studies have shown that this region contains azimuthal brightness variations generated by periodic perturbing forces with frequencies close to Saturn's rotation rate (nearly twice the local orbital period). These structures are not due to a single resonance, but instead involve a complex network of patterns drifting past one another over time. Some of these could be caused by asymmetries in Saturn's magnetosphere, which have rotation rates that have been observed to change over the course of the Cassini mission. However, some patterns may be generated by perturbations from long-lived gravitational anomalies inside the planet that move at speeds comparable to Saturn's winds. By comparing observations taken over several years we can distinguish the patterns caused by each phenomenon. We identify multiple structures with nearly constant pattern speeds that would appear to be due to persistent structures inside the planet. Strangely, the rotation rates required to produce these D ring structures are different from those responsible for generating waves in the C ring (where the local orbital rate is roughly 3/2 Saturn's rotation rate).

  2. Nonparametric analysis of high wind speed data

    Francisco-Fernández, Mario; Quintela-del-Río, Alejandro

    2013-01-01

    In this paper, nonparametric curve estimation methods are applied to analyze time series of wind speeds, focusing on the extreme events exceeding a chosen threshold. Classical parametric statistical approaches in this context consist in fitting a generalized Pareto distribution (GPD) to the tail of the empirical cumulative distribution, using maximum likelihood or the method of the moments to estimate the parameters of this distribution. Additionally, confidence intervals are usually computed to assess the uncertainty of the estimates. Nonparametric methods to estimate directly some quantities of interest, such as the probability of exceedance, the quantiles or return levels, or the return periods, are proposed. Moreover, bootstrap techniques are used to develop pointwise and simultaneous confidence intervals for these functions. The proposed models are applied to wind speed data in the Gulf Coast of US, comparing the results with those using the GPD approach, by means of a split-sample test. Results show that nonparametric methods are competitive with respect to the standard GPD approximations. The study is completed generating synthetic data sets and comparing the behavior of the parametric and the nonparametric estimates in this framework.

  3. Scaling for speed on the water

    McCauley, Joseph L

    2016-01-01

    Hydrodynamic scaling laws and extensive experimental data for the performance of fully submerged propellers have existed and have been used to advantage since the 1950s and earlier. Modern high performance boats require surface piercing propellers. I present three new hydrodynamic scale-free predictions for the relative performance of both submerged and surface-piercing propellers and boats. For the surface piercing case I compare my scaling predictions with official APBA OPC kilo records, using a single class record in each case as a baseline for my predictions. One scaling law allows propeller diameter to be predicted from an established baseline where shaft hp and shaft RPM are the variables. The second scaling law accurately predicts the speed loss when the gear ratio is lowered. The third scale-free prediction is inferred from Froude nr. scaling and allows boat speed to be predicted based on shaft hp and weight, given a known baseline in the same class of drag coefficient and submerged depth of boat. I a...

  4. Speed Adaptation in Urban Road Network Management

    Raiyn Jamal

    2016-06-01

    Full Text Available Various forecasting schemes have been proposed to manage traffic data, which is collected by videos cameras, sensors, and mobile phone services. However, these are not sufficient for collecting data because of their limited coverage and high costs for installation and maintenance. To overcome the limitations of these tools, we introduce a hybrid scheme based on intelligent transportation system (ITS and global navigation satellite system (GNSS. Applying the GNSS to calculate travel time has proven efficient in terms of accuracy. In this case, GNSS data is managed to reduce traffic congestion and road accidents. This paper introduces a short-time forecasting model based on real-time travel time for urban heterogeneous road networks. Travel time forecasting has been achieved by predicting travel speeds using an optimized exponential moving Average (EMA model. Furthermore for speed adaptation in heterogeneous road networks, it is necessary to introduce asuitable control strategy for longitude, based on the GNSS. GNSS products provide worldwide and real-time services using precise timing information and, positioning technologies.

  5. Social Environment Shapes the Speed of Cooperation

    Nishi, Akihiro; Christakis, Nicholas A.; Evans, Anthony M.; O’Malley, A. James; Rand, David G.

    2016-01-01

    Are cooperative decisions typically made more quickly or slowly than non-cooperative decisions? While this question has attracted considerable attention in recent years, most research has focused on one-shot interactions. Yet it is repeated interactions that characterize most important real-world social interactions. In repeated interactions, the cooperativeness of one’s interaction partners (the “social environment”) should affect the speed of cooperation. Specifically, we propose that reciprocal decisions (choices that mirror behavior observed in the social environment), rather than cooperative decisions per se, occur more quickly. We test this hypothesis by examining four independent decision time datasets with a total of 2,088 subjects making 55,968 decisions. We show that reciprocal decisions are consistently faster than non-reciprocal decisions: cooperation is faster than defection in cooperative environments, while defection is faster than cooperation in non-cooperative environments. These differences are further enhanced by subjects’ previous behavior – reciprocal decisions are faster when they are consistent with the subject’s previous choices. Finally, mediation analyses of a fifth dataset suggest that the speed of reciprocal decisions is explained, in part, by feelings of conflict – reciprocal decisions are less conflicted than non-reciprocal decisions, and less decision conflict appears to lead to shorter decision times. PMID:27435940

  6. The sound speed anomaly of Baltic seawater

    von Rohden, C.; Weinreben, S.; Fehres, F.

    2016-02-01

    The effect of the anomalous chemical composition of Baltic seawater on the speed of sound relative to seawater with quasi-standard composition was quantified at atmospheric pressure and temperatures of 1 to 46 °C. Three modern oceanographic time-of-flight sensors were applied in a laboratory setup for measuring the speed-of-sound difference δw in a pure water diluted sample of North Atlantic seawater and a sample of Baltic seawater of the same conductivity, i.e., the same practical salinity (SP = 7.766). The average δw amounts to 0.069 ± 0.014 m s-1, which is significantly larger than the resolution and reproducibility of the sensors and independent of temperature. This magnitude for the anomaly effect was verified with offshore measurements conducted at different sites in the Baltic Sea using one of the sensors. The results from both measurements show values up to 1 order of magnitude smaller than existing predictions based on chemical models.

  7. Influence of impact speed on head and brain injury outcome in vulnerable road user impacts to the car hood.

    Fredriksson, Rikard; Zhang, Liying; Boström, Ola; Yang, King

    2007-10-01

    EuroNCAP and regulations in Europe and Japan evaluate the pedestrian protection performance of cars. The test methods are similar and they all have requirements for the passive protection of the hood area at a pedestrian to car impact speed of 40 km/h. In Europe, a proposal for a second phase of the regulation mandates a brake-assist system along with passive requirements. The system assists the driver in optimizing the braking performance during panic braking, resulting in activation only when the driver brakes sufficiently. In a European study this was estimated to occur in about 50% of pedestrian accidents. A future system for brake assistance will likely include automatic braking, in response to a pre-crash sensor, to avoid or mitigate injuries of vulnerable road users. An important question is whether these systems will provide sufficient protection, or if a parallel, passive pedestrian protection system will be necessary. This study investigated the influence of impact speed on head and brain injury risk, in impacts to the carhood. One car model was chosen and a rigid adjustable plate was mounted under the hood. Free-flying headform impacts were carried out at 20 and 30 km/h head impact velocities at different under-hood distances, 20 to 100 mm; and were compared to earlier tests at 40 km/h. The EEVC WG17 adult pedestrian headform was used for non-rotating tests and a Hybrid III adult 50th percentile head was used for rotational tests where linear and rotational acceleration was measured. Data from the rotational tests was used as input to a validated finite element model of the human head, the Wayne State University Head Injury Model (WSUHIM). The model was utilized to assess brain injury risk and potential injury mechanism in a pedestrian-hood impact. Although this study showed that it was not necessarily true that a lower HIC value reduced the risk for brain injury, it appeared, for the tested car model, under-hood distances of 60 mm in 20 km/h and 80 mm

  8. 78 FR 31836 - Special Conditions: Embraer S.A., Model EMB-550 Airplane, Dive Speed Definition With Speed...

    2013-05-28

    ... in the Federal Register on January 24, 2013 (78 FR 5146). We received no substantive comments, and..., Dive Speed Definition With Speed Protection System AGENCY: Federal Aviation Administration (FAA), DOT... design features include a high-speed protection system. The applicable airworthiness regulations do...

  9. 78 FR 5146 - Special Conditions: Embraer S.A., Model EMB-550 Airplane, Dive Speed Definition With Speed...

    2013-01-24

    ... Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477 19478), as well as...., Model EMB-550 Airplane, Dive Speed Definition With Speed Protection System AGENCY: Federal Aviation... category airplanes. These design features include a high-speed protection system. The...

  10. New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

    Nazim Mir-Nasiri; Sulaiman Hussaini

    2006-01-01

    This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use ...

  11. Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator Variable-Speed Wind Turbines

    Hu, Weihao; Zhang, Yunqian; Chen, Zhe;

    2013-01-01

    Grid-connected wind turbines are fluctuating power sources that may produce flicker during continuous operation. This paper presents a simulation model of a MW-level variable speed wind turbine with a full-scale back-to-back power converter and permanent magnet synchronous generator (PMSG...

  12. Speed Kills, Speed Thrills: Constraining and Enabling Accelerations in Academic Work-Life

    Vostal, Filip

    2015-01-01

    Intensification, speed of change and faster pace of life have recently emerged as significant issues in studies analysing the current academic climate. This article takes up the "social acceleration thesis" as a conceptual resource for capturing the relationship between the individual experience of time and the changing structure and…

  13. Comparison of NWP wind speeds and directions to measured wind speeds and directions

    Astrup, Poul; Mikkelsen, Torben

    Numerical Weather Predictions (NWP) of wind speed and direction has been compared to measurements for seven German sites for nuclear power plants, and for Risø, the site of the Danish nuclear research reactors now being decommissioned . For the German sites the data cover approximately three month...

  14. Propagation speed of gamma radiation in brass

    Cavalcante, Jose T.P.D.; Silva, Paulo R.J.; Saitovich, Henrique

    2009-07-01

    The propagation speed (PS) of visible light -represented by a short frequency range in the large frame of electromagnetic radiations (ER) frequencies- in air was measured during the last century, using a great deal of different methods, with high precision results being achieved. Presently, a well accepted value, with very small uncertainty, is c= 299,792.458 Km/s) (c reporting to the Latin word celeritas: 'speed swiftness'). When propagating in denser material media (MM), such value is always lower when compared to the air value, with the propagating MM density playing an important role. Until present, such studies focusing propagation speeds, refractive indexes, dispersions were specially related to visible light, or to ER in wavelengths ranges dose to it, and with a transparent MM. A first incursion in this subject dealing with {gamma}-rays was performed using an electronic coincidence counting system, when the value of it's PS was measured in air, C{sub {gamma}}{sub (air)}298,300.15 Km/s; a method that went on with later electronic improvements. always in air. To perform such measurements the availability of a {gamma}-radiation source in which two {gamma}-rays are emitted simultaneously in opposite directions -as already used as well as applied in the present case- turns out to be essential to the feasibility of the experiment, as far as no reflection techniques could be used. Such a suitable source was the positron emitter {sup 22}Na placed in a thin wall metal container in which the positrons are stopped and annihilated when reacting with the medium electrons, in such way originating -as it is very well established from momentum/energy conservation laws - two gamma-rays, energy 511 KeV each, both emitted simultaneously in opposite directions. In all the previous experiments were used photomultiplier detectors coupled to NaI(Tl) crystal scintillators, which have a good energy resolution but a deficient time resolution for such purposes

  15. A Sequential Shifting Algorithm for Variable Rotor Speed Control

    Litt, Jonathan S.; Edwards, Jason M.; DeCastro, Jonathan A.

    2007-01-01

    A proof of concept of a continuously variable rotor speed control methodology for rotorcraft is described. Variable rotor speed is desirable for several reasons including improved maneuverability, agility, and noise reduction. However, it has been difficult to implement because turboshaft engines are designed to operate within a narrow speed band, and a reliable drive train that can provide continuous power over a wide speed range does not exist. The new methodology proposed here is a sequential shifting control for twin-engine rotorcraft that coordinates the disengagement and engagement of the two turboshaft engines in such a way that the rotor speed may vary over a wide range, but the engines remain within their prescribed speed bands and provide continuous torque to the rotor; two multi-speed gearboxes facilitate the wide rotor speed variation. The shifting process begins when one engine slows down and disengages from the transmission by way of a standard freewheeling clutch mechanism; the other engine continues to apply torque to the rotor. Once one engine disengages, its gear shifts, the multi-speed gearbox output shaft speed resynchronizes and it re-engages. This process is then repeated with the other engine. By tailoring the sequential shifting, the rotor may perform large, rapid speed changes smoothly, as demonstrated in several examples. The emphasis of this effort is on the coordination and control aspects for proof of concept. The engines, rotor, and transmission are all simplified linear models, integrated to capture the basic dynamics of the problem.

  16. Wind speed change regionalization in China (1961–2012

    Pei-Jun Shi

    2015-06-01

    Full Text Available This research quantitatively recognized the wind speed change using wind speed trend and trend of wind speed variability from 1961 to 2012 and regionalized the wind speed change on a county-level basis. The mean wind speed observation data and linear fitting method were used. The findings suggested that level-I regionalization includes six zones according to wind speed trend value in different regions, viz. Northeast China–North China substantial declining zone, East–Central China declining zone, Southeast China slightly declining zone, Southwest China very slightly declining zone, Northwest China declining zone, and Qinghai–Tibetan Plateau slightly declining zone. Level-II regionalization divides China into twelve regions based on trend of wind speed variability and the level-I regionalization results.

  17. Perceived speed in peripheral vision can go up or down.

    Hassan, Omar; Thompson, Peter; Hammett, Stephen T

    2016-04-01

    We measured the perceived speed and contrast of patterns in peripheral vision relative to foveal patterns for a range of eccentricities at both mesopic and photopic levels. The results indicate that perceived speed varies with eccentricity, speed, and luminance. At high (photopic) luminance, patterns appear slower when viewed peripherally rather than foveally, but at low (mesopic) luminance fast-moving patterns can appear faster when viewed peripherally. When perceived contrast is equated, perceived speed reduces as a function of eccentricity in a speed-independent manner. Peripheral stimuli appear faster or slower than foveal stimuli depending upon luminance-an image parameter known to influence the gain of magno and parvocellular cells. We conclude that speed encoding in the periphery is consistent with a ratio-type speed code that is weighted by ganglion cell density. PMID:27128323

  18. Wind speed change regionalization in China(1961-2012)

    SHI; Pei-Jun; ZHANG; Gang-Feng; KONG; Feng; YE; Qian

    2015-01-01

    This research quantitatively recognized the wind speed change using wind speed trend and trend of wind speed variability from 1961 to 2012 and regionalized the wind speed change on a county-level basis.The mean wind speed observation data and linear fitting method were used.The findings suggested that level-I regionalization includes six zones according to wind speed trend value in different regions,viz.Northeast ChinaeNorth China substantial declining zone,EasteCentral China declining zone,Southeast China slightly declining zone,Southwest China very slightly declining zone,Northwest China declining zone,and QinghaieTibetan Plateau slightly declining zone.Level-II regionalization divides China into twelve regions based on trend of wind speed variability and the level-I regionalization results.

  19. The Silicon Photomultiplier for High Speed Photometry

    Vander Haagen, Gary A.

    2011-05-01

    The Silicon Photomultiplier (SPM) offers sensitivity comparable to conventional photomultipliers with the added advantage of small size, low operating voltages, and robust tolerance to excess/ambient light. A Peltier cooled SPM running at -30°C was used in conjunction with wideband electronics and a 17-inch Astrograph to collect photometric data without a reference star. High speed photometric trials were conducted on eclipsing binary AW UMa demonstrating fast data rate capability. Data shows the SPM exhibits excellent sensitivity, acceptable signal to noise, and bandwidth with sampling times as short as 1 millisecond for brighter targets. Automated digital data acquisition is discussed along with digital signal processing techniques for noise reduction, spectral analysis, and data mining. The SPM demonstrated acceptable signal to noise for fast photometric studies for 8-10th magnitude targets depending on scintillation and background conditions. Future SPM study topics are also discussed.

  20. Evaporation of high speed sporadic meteors

    E. Murad

    2004-01-01

    Full Text Available Recent measurements conducted at the Arecibo Observatory report high-speed sporadic meteors having velocities near 50 km/s. The results seem to indicate a bimodal velocity distribution in the sporadic meteors (maxima at ~20 km/s and ~50 km/s. The particles have a maximum mass of ~1µg. This paper will present an analysis of the ablation of 1µg meteoroids having velocities of 20, 30, 50, and 70 km/s. The calculations show that there is fractionation even for the fast meteoroids, the effect being particularly noticeable for the 1µg sporadic particles, and less so for the heavier particles. The relevance of the calculations to the radar observations of the sporadic meteors will be discussed.