scholarly journals Variability of Green Time to Discharge a Specified Number of Queued Vehicles at a Signalized Intersection

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yi Zhao ◽  
Yongfeng Ma ◽  
Jian Lu ◽  
Yankai Zong ◽  
Qian Wan
Keyword(s):  
Statistical Data ◽  
Mean Value ◽  
Signalized Intersections ◽  
Signal Timing ◽  
Passing Rate ◽  
Start Up ◽  
Headway Distribution ◽  
The Mean ◽  
New Perspective ◽  
The Ideal

The aim of this paper is to study the headway distribution of queued vehicles (less than 16 vehicles) at signalized intersections. Existing studies usually take the average statistics of headway at any queuing place. When different percentile points of statistical data are assigned to headway, the passing rate (the rate of all queued vehicles passing the stop line) under the ideal signal timing scheme varies. When selecting the mean value, the passing rate of a queue of fewer than 16 vehicles is no more than 65%. When selecting 75% as the percentile, the passing rate is up to 94%. The queue length also decides the assigned percentile of headway to ensure the passing rate reaches a certain level. The value assignation of headway directly affects lane capacity and start-up loss time. This paper provides a new perspective on parameter calibration and will make the signal timing algorithm method more effective.

scholarly journals Estimation of Saturation Flow Rate and Start-Up Lost Time for Signal Timing Based on Headway Distribution

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yi Zhao ◽  
Wenbo Zhang ◽  
Jian Lu ◽  
Wenjun Zhang ◽  
Yongfeng Ma
Keyword(s):  
Flow Rate ◽  
Queue Length ◽  
Signal Timing ◽  
Start Up ◽  
Adjustment Factors ◽  
Headway Distribution ◽  
Lost Time ◽  
Saturation Flow Rate ◽  
New Perspective ◽  
Saturation Flow

This study aimed to calibrate saturation flow rate (SFR) and start-up lost time (SLT) when developing signal timing. In current commonly used methods, SFR for one given lane is usually calibrated from many subjective adjustment factors and a fixed result. SLT is calculated based on the fixed SFR, which prevents local applications in China. Considering the importance of traffic behavior (headway) in determining SFR and SLT, this study started from headway distribution and attempted to specify the relationships between headway and vehicle position directly. A common intersection in Nanjing, China, was selected to implement field study and data from 920 queues was collected. Headway distribution was explored and the 78th percentile of headway at each position was selected to build model. Based on the developed relationships, SFR and SLT were calibrated. The results showed that SFR and SLT were correlated with queue length. Moreover, the results showed that it was difficult to reach saturated state even with a long queue length. This paper provides a new perspective on calibrating important parameters in signal timing, which will be useful for traffic agencies to complete signal timing by making the process simpler.

scholarly journals A Comparison of the Mean-Value and Initial-Value Solutions of the Ideal Resonance Problem with an Application in Rigid-Body Mechanics

1974 ◽  
Vol 62 ◽  
pp. 209-209
Author(s):  
A. H. Jupp
Keyword(s):  
Elliptic Functions ◽  
Mean Value ◽  
Resonance Problem ◽  
Ideal Resonance ◽  
Deep Circulation ◽  
Ideal Resonance Problem ◽  
Rigid Body Mechanics ◽  
The Mean ◽  
Mean Elements ◽  
The Ideal

A solution of the ideal resonance problem has already been exhibited (Jupp, 1972) explicitly in terms of the ‘mean’ elements; to second order in the small parameter in the case of libration, and to first order in the case of deep circulation. Both representations possess a singularity when the ‘mean’ modulus of the Jacobi elliptic functions is unity; this corresponds to motions on or close to the separatrix of the phase plane of the dynamical system.

scholarly journals A NEW PERSPECTIVE FOR PHYSICAL HEIGHTS IN BRAZIL

2019 ◽  
Vol 25 (1) ◽  
Author(s):  
Fabio Luiz Albarici ◽  
Ismael Foroughi ◽  
Gabriel do Nascimento Guimarães ◽  
Marcelo Santos ◽  
Jorge Trabanco
Keyword(s):  
Mass Density ◽  
Density Variation ◽  
Mean Value ◽  
South American ◽  
Normal Height ◽  
Rigorous Definition ◽  
The Mean ◽  
Orthometric Heights ◽  
New Perspective ◽  
Definition Of

Abstract The physical heights definition of heights, proposed by Helmert in 1890 is one of the commonly used heights systems in practice. In Helmert’s definition, the mean value of gravity along plumbline is computed by simplifying the topography with a Bouguer shell containing masses with mean density value. Although this approximation might be accurate enough many purposes, a more rigorous definition can be determined by considering the effects of terrain, topographic mass density variation, and masses contained in the geoid the mean gravity value along the plumbline. The purpose of this paper is to compute the corrections for the Helmert’s definition of the orthometric heights to obtain the rigorous orthometric heights in the state of São Paulo and adjacent states and to evaluate these corrections. The heights system used in Brazil (until July 2018) and some South American countries is normal-orthometric heights, therefore the corrections needs to be applied accordingly. Our numerical results show that there are significant differences between the normal-orthometric and rigorous orthometric heights, with maximum values of ~ 0.4 m, minimum of ~ -0.8 m and mean value of ~ -0.32 m. There are larger differences between normal-orthometric and normal height than the ones between normal and rigorous definition of orthometric heights.

scholarly journals Comparative analysis of maternal mortality indices in Perm Krai over the past 20 years

2018 ◽  
Vol 35 (5) ◽  
pp. 57-62
Author(s):  
M. M. Padrul ◽  
E. V. Cherkasova ◽  
V. V. Skryabina ◽  
S. N. Berseneva
Keyword(s):  
Comparative Analysis ◽  
Maternal Mortality ◽  
Statistical Data ◽  
Federal District ◽  
Mean Value ◽  
Data Intensive ◽  
The Past ◽  
Perm Krai ◽  
The Russian Federation ◽  
The Mean

Aim. To compare the maternal mortality (MM) indices in Perm Krai with MM indices in the Russian Federation (RF) and Privolzhskiy Federal District over the past 20 years. Materials and methods. On the basis of official statistical data, intensive indices and image indices, mean multiyear MM indices, 95 % confidence intervals, median, 25 and 75 percentile indices were calculated. The mean multiyear indices are presented as M (mean value) ± SD (standard deviation). Results. According to official statistical data, the mean multiyear (1997–2016) indices of MM coefficient in Perm Krai tend to decline, but they do not reliably differ from the analogous indices in RF. During the last 20 years, there was noted a steady and obvious decrease in MM index on the territory of Perm Krai, especially marked for the last 2 years (2015–2016) that resulted in appearance of statistically significant differences regarding this index in Perm Krai compared to these indices in RF as a whole. Conclusions. Perm Krai is a rather favorable region as far as rendering of medical aid to pregnant, parturient women and puerperas is concerned.

scholarly journals Start-up of horizontal anaerobic reactors with sludge blanket and fixed bed for wastewater treatment from coffee processing by wet method

2013 ◽  
Vol 33 (2) ◽  
pp. 353-366 ◽  
Author(s):  
Roberto A. de Oliveira ◽  
Natani M. N. Bruno
Keyword(s):  
Fixed Bed ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Mean Value ◽  
Treatment System ◽  
Anaerobic Sludge ◽  
Mean Values ◽  
Anaerobic Reactors ◽  
Start Up ◽  
The Mean

In this study it was evaluated the start-up procedures of anaerobic treatment system with three horizontal anaerobic reactors (R1, R2 and R3), installed in series, with volume of 1.2 L each. R1 had sludge blanket, and R2 and R3 had half supporter of bamboo and coconut fiber, respectively. As an affluent, it was synthesized wastewater from mechanical pulping of the coffee fruit by wet method, with a mean value of total chemical oxygen demand (CODtotal) of 16,003 mg L-1. The hydraulic retention time (HRT) in each reactor was 30 h. The volumetric organic loading (VOL) applied in R1 varied from 8.9 to 25.0 g of CODtotal (L d)-1. The mean removal efficiencies of CODtotal varied from 43 to 97% in the treatment system (R1+R2+R3), stabilizing above 80% after 30 days of operation. The mean content of methane in the biogas were of 70 to 76%, the mean volumetric production was 1.7 L CH4 (L reactor d)-1 in the system, and the higher conversions were around at 0.20 L CH4 (g CODremoved)-1 in R1 and R2. The mean values of pH in the effluents ranged from 6.8 to 8.3 and the mean values of total volatile acids remained below 200 mg L-1 in the effluent of R3. The concentrations of total phenols of the affluent ranged from 45 to 278 mg L-1, and the mean removal efficiency was of 52%. The start-up of the anaerobic treatment system occurred after 30 days of operation as a result of inoculation with anaerobic sludge with active microbiota.

Analyzing start-up time headway distribution characteristics at signalized intersections

2019 ◽  
Vol 535 ◽  
pp. 122348 ◽  
Author(s):  
Qiang Luo ◽  
Jie Yuan ◽  
Xinqiang Chen ◽  
Shubo Wu ◽  
Zhijian Qu ◽  
...  
Keyword(s):  
Signalized Intersections ◽  
Distribution Characteristics ◽  
Time Headway ◽  
Start Up ◽  
Headway Distribution

scholarly journals WORKING WITH DATA IN STATISTICAL RESEARCH

2021 ◽  
Vol 1 (7(71)) ◽  
pp. 36-39
Author(s):  
I. Kuzmin
Keyword(s):  
Null Hypothesis ◽  
Statistical Data ◽  
Extreme Values ◽  
Mean Value ◽  
Type I ◽  
Statistical Research ◽  
Independent Variable ◽  
The Mean ◽  
Range Of Values ◽  
Classical Hypothesis

Statistical data in most cases are described as an arithmetic mean value and a median depending on themselves, in the absence or presence of extreme values, respectively. Also, when using the classical hypothesis testing, errors of the type I (erroneous rejection of the null hypothesis of the absence of differences) and type II (erroneous acceptance of the null hypothesis) inevitably occur. Sometimes in the data, you can make the wrong choice when choosing the dependent and independent variable. The classical check does not give a complete picture of the data of the general population. Confidence intervals for a range of values for selection within a certain probability (95%). One of the modern methods for assessing the mean, mean and other measures is resampling, in particular, bootstrap (multiple generation of samples).

scholarly journals Research on Calculation Method of Mean in Sports Statistical Data with EXCEL

2020 ◽  
Vol 9 (3) ◽  
pp. 141-148
Author(s):  
Aining Li ◽  
◽  
Shiwei Zhang ◽  
Zhanbin Feng ◽  
Qiyuan Zhang
Keyword(s):  
Statistical Data ◽  
Statistical Processing ◽  
Mean Value ◽  
Descriptive Statistics ◽  
Central Tendency ◽  
Education Department ◽  
Statistical Indicator ◽  
Normal Mean ◽  
The Mean

The mean is the most commonly used statistical indicator to reflect the central tendency of data distribution, in this study, the mean was reclassified according to whether the effect of extreme value was considered or not. According to the definition and specific classification of mean value, We explain in detail how to calculate the normal mean by ways of "built-in function", "pivot table chart" and "descriptive statistics", symmetry trim mean by TRIMMEAN function and asymmetrical trim mean by ways of nested function and VBA self-built function with the date of the 10 referees' scores in the kindergarten gymnastics competition of normal education department of our college. If we fully exploit the powerful statistical function of Excel, we can better meet our sports practice of statistical processing needs.

Measured Distributions of Control Delay on Signalized Arterials

2003 ◽  
Vol 1852 (1) ◽  
pp. 1-9 ◽  
Author(s):  
James D. Colyar ◽  
Nagui M. Rouphail
Keyword(s):  
Real World ◽  
Standard Error ◽  
Mean Value ◽  
Signal Timing ◽  
Factors Affecting ◽  
Highway Capacity Manual ◽  
Control Delay ◽  
Signal Coordination ◽  
Before And After ◽  
The Mean

The Highway Capacity Manual and other traffic operations manuals give no guidance on the magnitude and factors affecting variability in control delay. However, knowing the variability in control delay has several useful applications, such as providing a more complete and statistically significant comparison of different signal timing or roadway geometric improvements. The objective of this research is to provide an exploratory analysis of the variability in signalized control delay using real-world measurements on an arterial corridor in Cary, North Carolina. Data were collected with a portable, onboard emissions and engine diagnostics measurement device, from which second-by-second speed data were recorded. A new method for estimating intersection control delay from second-by-second speed data is presented that attempts to take into account over-capacity conditions and closely spaced intersections. The data collection focused on recording a similar number of runs on a corridor before and after signal coordination was implemented. The results show that the distribution of control delay generally has a single, large peak at low delays, when the mean control delay was in the level-of-service A–B range, whereas the distribution becomes increasingly bimodal (two distinct peaks) as the mean control delay increases. Another finding is that there is a direct relationship between mean control delay and standard error of control delay, but there is still variability in the standard error that cannot be explained solely by the mean value. Finally, differences in the before and after runs showed that a real-world signal timing improvement can reduce both the mean and the standard error of control delay as well as alter the shape of the delay distribution.

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