Operating Speed on Crest Vertical Curves with Limited Stopping Sight Distance

2000 ◽  
Vol 1701 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Daniel B. Fambro ◽  
Kay Fitzpatrick ◽  
Charles W. Russell
Keyword(s):  
Operating Speed ◽  
Design Elements ◽  
Geometric Data ◽  
A Value ◽  
Sight Distance ◽  
The Mean ◽  
The Difference ◽  
Design Speed ◽  
Stopping Sight Distance ◽  
The Relationship

Horizontal and vertical elements of a highway are designed based on an assumed design speed. This concept was developed in the 1930s as a mechanism for designing rural alignments to permit most drivers to operate uniformly at their desired speed. In 1938, AASHO recognized that drivers select a speed influenced by the roadway environment instead of an assumed design speed. Recent research suggests that design speed is no longer the speed adopted by the faster group of drivers but that it has become a value used to establish the sharpness of horizontal and vertical design elements. The objective of this study was to establish the relationship between design and operating speeds for crest vertical curves with limited sight distance. Geometric data and 3,500 paired speeds (speeds at control and crest sections) were collected at 36 sites in 3 states. The results indicated that both the 85th percentile and the mean operating speeds were well above the inferred design speeds of the crest vertical curves for the range of conditions studied and that the lower the design speed the larger the difference between the 85th percentile speed and the design speed. The mean reductions in speed between the control and crest sections tend to increase as available sight distance is decreased; however, the reduction in speed is less than that suggested by current AASHTO criteria.

scholarly journals Building an Integrated Database of Road Design Elements

2020 ◽  
Author(s):  
Ali Dhafer Abed
Keyword(s):  
Road Network ◽  
Design Elements ◽  
Northern Iraq ◽  
The Road ◽  
Sight Distance ◽  
Sensing Technology ◽  
Design Speed ◽  
Stopping Sight Distance ◽  
City Structure ◽  
The City

The road network is the main artery within the city structure, which requires designing of routes and classification within the standards. Hence, the importance of this chapter, which will focus on the standards and design elements of the engineering design of road in terms of road type system, functional classification system, traffic volume system, number of traffic lane system, road width design, side slopes and elevations of road layers, super elevation, design speed, overtaking and stopping sight distance, longitudinal and cross sections of the road path, design elements of horizontal and vertical curves, and intersections. The Civil 3D Land Desktop, GIS programs, and remote sensing technology will be used to design the path of major highway linking two urban areas in Mosul (Northern Iraq), which will be considered a case study. The path of the road and its elements will be designed according to special criteria that are compatible with the topography and nature of the area. The geometric data of the road will then be exported with all the design elements to the GIS program to build an integrated road database. The database is capable of spatial analysis and connectivity with other parts of the road network in the city.

scholarly journals Perbandingan efektivitas penggunaan audio visual terhadap penurunan kecemasan anak selama perawatan gigi di TK Pertiwi dan TK Raudhatul Jannah Banda Aceh

2020 ◽  
Vol 2 (1) ◽  
pp. 108
Author(s):  
M. Erfin Febrian ◽  
Aulina Adami ◽  
Asnawi Abdullah
Keyword(s):  
Dental Care ◽  
Dental Treatment ◽  
Intervention Group ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Test Analysis ◽  
A Value ◽  
The Mean ◽  
The Difference ◽  
The Relationship

Background: Anxiety in children about dental care is a problem that arises in children. This is because the dentist's perception and introduction to children does not start early.Objectives: This study aims to compare the effectiveness of the use of audio visuals on reducing children's anxiety during dental treatment at Pertiwi and Raudhatul Jannah Kindergarten in Banda Aceh.Methods: This study uses a cross-sectional study design which is a study conducted to find the relationship between the independent variables (risk factors) and the dependent variable anxiety in dental care. Sampling was done by purposive sampling with the criteria of children aged 5-6 old. The number of samples is 100 samples. Test analysis using the dependent t-test and was analyzed using the stata 14.Results: The results showed, the comparison between the first day and the second day showed a difference in the decrease in anxiety level with the child's anxiety score with intervention of 2.78 with a deviation of 1.379 while the second group without intervention had a decrease in the mean score of anxiety, which was 2.48 with a deviation of 1.455. The difference in the decrease in anxiety scores in children is 0.30. The results of the T-Dependent statistical test obtained a value of p= 0.001Conclusion: In other words, the results of this study can show differences in the level of anxiety in the intervention group with the group that did not use the audio visual intervention.

scholarly journals Review of Academic Dishonesty among College Students

2016 ◽  
Vol 8 (4) ◽  
pp. 158
Author(s):  
Abolfazl Zolfaghari
Keyword(s):  
Academic Dishonesty ◽  
English Language ◽  
Academic Environment ◽  
Language Test ◽  
Chi Square ◽  
Quasi Experimental ◽  
The Mean ◽  
The Difference ◽  
Basic English ◽  
The Relationship

<p>Cheating and academic dishonesty is a moral anomaly in the field of scientific research and reflecting, i.e., academic environment and studies show that this phenomenon in many of the worlds is important problem.</p><p>This study measured the dishonesty of students in a quasi-experimental design. For this purpose, features lack of integrity by manipulating the facts were examined and meanwhile first, basic English language test coordination between the strict terms of the 280 students come to practice and after correction of examination papers by teachers, without leaving any traces on them instead, the plates are returned to students and provide them with answers to their paper to correct their score Master announced. The difference between the actual score (score of master) and score of the students to have their own, amount of honesty or lack of integrity appointed them and its relationship with some demographic and socio-ethical characteristics have been studied.</p><p>The results showed that more than 62 percent of the students in your grade to master completely honest with 26.6 percent have low honesty and the rest did not have the necessary integrity and the mean difference of scores announced by the professors and students have been about two score. Also results of chi-square tests and gamma, about the relationship between students’ evaluation of amount of sincerity with sincerity in the declared objective amount of the master score was not significant, this finding means that between demonstrators and people of integrity and honesty in practice, there are gaps.</p>

scholarly journals Urine CA-2 as a biomarker for diagnosis urinary stone and prediction of its complications

2020 ◽  
Author(s):  
Yuan-jing Leng ◽  
Hai-bin Zhou ◽  
Jiang-ling Fu ◽  
Wen-juan Wang
Keyword(s):  
Healthy Subjects ◽  
Characteristic Curve ◽  
Urinary Stone ◽  
Urinary Stones ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Healthy Control ◽  
The Mean ◽  
The Difference ◽  
The Relationship

Abstract PURPOSECarbonic anhydrase-2 (CA-2) plays a role in mineralization and calcification in organism. Strong evidence suggests that CA-2 is associated with urolithiasis. However, the relationship between CA-2 and urinary stone remains unclear. The study aimed to assess the association of urine CA-2 (uCA-2) level and the potential risk of urinary stone.METHODSFrom March 2017 to November 2019, a prospective cohort study was conducted on patients with urinary stones and healthy subjects to determine the pretreatment uCA-2 level detection by Enzyme linked immunosorbent assay (ELISA). The difference of uCA-2 level between patients with urinary stones and healthy subjects was compared. Then comparison between stone patients with complications and without complications was carried out as well as correlation analysis to detect factors associated with biomarker expression.RESULTS118 patients with urinary stones were into urinary stones group and 42 healthy subjects were into healthy control group. The mean pretreatment uCA-2 level was significantly higher in patients with urinary stones group than healthy controls group (P=0.028). Furthermore, The uCA-2 level was positive correlation with urinary stones complications (R=0.379, P=0.000), especially pain complications (R=0.524, P=0.000) and hematuria complications (R=0.374, P=0.000). Receiver operating characteristic curve (ROC) analysis that a uCA-2 level threshold of 10.94 ng/mL had 83.67% sensitivity and 68.12% specificity for predicting urinary stones complications. CONCLUSIONSExcessive uCA-2 excretion is a major risk factor for urinary stone. Our findings suggested that uCA-2 may be used as an unappreciated biomarker for the diagnosis urinary stone in patients and to predict its complications.

scholarly journals Hubungan antara Kedalaman Permukaan Air Tanah dengan Salinitas di Pesisir Pantai Kungkai Baru serta Penggunaan Model Discovery Learning

2018 ◽  
Vol 2 (2) ◽  
pp. 178-182
Author(s):  
Sutijo Joko Sudiro ◽  
Muchammad Farid ◽  
Eko Swistoro
Keyword(s):  
Learning Outcomes ◽  
Learning Model ◽  
Discovery Learning ◽  
High Ability ◽  
Significance Level ◽  
Average Value ◽  
A Value ◽  
Quasi Experimental ◽  
The Difference ◽  
The Relationship

ABSTRACT [Relationship between Groundwater Surface Depth with Salinity at the Coast of New Kungkai Beach and its Implementation on Discovery Learning Model]. The aims of this study were 1) to describe the relationship between groundwater surface depth with salinity in the coastal areas of new kungkai beach of Seluma, and 2) to determine the improvement of learning outcomes (cognitive) of high ability students, moderate and low by using discovery learning model on the concept of static fluid in class X computer and network engineering at SMK Negeri 3 Seluma. This research was a quasi experimental research with one groups pretest-posttest design. The results showed: 1) The relationship between depth with salinity has a value of 0.6478 with a significance level of 0.001 (<0.05); 2) Learning with discovery learning model can improve student learning outcomes on cognitive aspects (knowledge). Increased cognitive results can be seen from the average value of the initial test, the final test and the average value of gain in the class x Tkj is high-ability groups are at high criteria with a value of 0.75 gain in the group is in the criteria medium with the value of gain 0,52 and in the low group were in moderate criteria with a gain value of 0.44. There is a difference in learning outcomes between the high, medium and low groups. The difference is shown by Fcount > Ftable (4.04 > 3.35) with a significance level of 5%. Keywords: Groundwater surface depth; salinity; discovery learning model; SMKN 3 Seluma.

scholarly journals An Initial Investigation of the Effects of a Fully Automated Vehicle Fleet on Geometric Design

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
John Khoury ◽  
Kamar Amine ◽  
Rima Abi Saad
Keyword(s):  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Real Life ◽  
Geometric Design ◽  
Design Elements ◽  
Sight Distance ◽  
Human Driver ◽  
Projected Change ◽  
Vehicle Fleet ◽  
Stopping Sight Distance

This paper investigates the potential changes in the geometric design elements in response to a fully autonomous vehicle fleet. When autonomous vehicles completely replace conventional vehicles, the human driver will no longer be a concern. Currently, and for safety reasons, the human driver plays an inherent role in designing highway elements, which depend on the driver’s perception-reaction time, driver’s eye height, and other driver related parameters. This study focuses on the geometric design elements that will directly be affected by the replacement of the human driver with fully autonomous vehicles. Stopping sight distance, decision sight distance, and length of sag and crest vertical curves are geometric design elements directly affected by the projected change. Revised values for these design elements are presented and their effects are quantified using a real-life scenario. An existing roadway designed using current AASHTO standards has been redesigned with the revised values. Compared with the existing design, the proposed design shows significant economic and environmental improvements, given the elimination of the human driver.

scholarly journals Three-dimensional analysis of acetabular cup orientation and an evaluation of the relationship with pelvic sagittal parameters

2019 ◽  
Vol 27 (2) ◽  
pp. 230949901986122
Author(s):  
Ali Sahin ◽  
Mehmet Emin Simsek ◽  
Safa Gursoy ◽  
Mustafa Akkaya ◽  
Cetin Isik ◽  
...  
Keyword(s):  
Pelvic Tilt ◽  
Three Dimensional ◽  
Preoperative Assessment ◽  
Statistical Correlation ◽  
Acetabular Cup ◽  
Pelvic Parameters ◽  
Sagittal Parameters ◽  
The Mean ◽  
The Difference ◽  
The Relationship

Background: This study aimed to evaluate the effect of total hip arthroplasty (THA) on sagittal pelvic parameters and to evaluate the effect of sagittal pelvic parameters on acetabular cup orientation. Methods: The study included 86 patients who underwent THA for a diagnosis of unilateral coxarthrosis between 2011 and 2015. Measurements were taken of the preoperative and postoperative acetabular cup inclination (ACI), anteversion, and sagittal pelvic parameters. The effect of THA on sagittal pelvic parameters and the effects of the sagittal pelvic parameters on acetabular cup orientation were investigated. Results: The sagittal pelvic tilt values calculated were mean 9.7° ± 6.3° (2°; 23°) preoperatively and 11.0° ± 6.1° (2°; 25°) postoperatively. The increase in postoperative pelvic incidence (PI) values was determined to be statistically significant ( p < 0.05). The preoperative PI values had no significant effect on ACI, but in cases with high preoperative PI values, a tendency to high anteversion values was determined. The mean inclination values were found to be 40.2° ± 11.0° in the low PI group, 41.7° ± 7.4° in the normal PI group, and 44.1° ± 8.3° in the high PI group. As no increase in inclination values was observed with an increase in PI values, no statistical correlation was determined ( p = 0.343). Average of anteversion values in the low PI group was 9.2° ± 13.7°, in the normal PI group 19.3° ± 10.5°, and in the high PI group 21.1° ± 12.5°. The difference between the groups was statistically significant ( p = 0.001). Conclusion: Evaluating the results of this study, it can be concluded that varying PI values do affect the acetabular cup anterversion in THA. So, preoperative assessment of PI values is important in preventing postoperative acetabular cup malposition.

scholarly journals The Relationship Between Digital Egg Coloration and Egg Survival in Landlocked Fall Chinook

2018 ◽  
Vol 7 (1) ◽  
pp. 31
Author(s):  
Holiday Robley ◽  
Michael E. Barnes
Keyword(s):  
South Dakota ◽  
Chinook Salmon ◽  
Color Index ◽  
Oncorhynchus Tshawytscha ◽  
Egg Survival ◽  
A Value ◽  
The Mean ◽  
The Relationship ◽  
Egg Coloration

Digital color values were collected from the eggs of 128 spawns from individual landlocked fall Chinook salmon Oncorhynchus tshawytscha females from Lake Oahe, South Dakota, USA, in 2008, 2009, 2015 and 2016. For all spawns, the mean (SE) a* value, a measure of red-green chromaticness, was 10.99 (0.27), and ranged from 3.98 to 18.71. Mean (SE) b* (yellow-green) was 20.27 (0.32), and ranged from 9.28 to 28.50. Mean (SE) L* (white-black) was 20.73 (0.48), and ranged from 3.98 to 18.71. Egg total color index also showed considerable variation, with a mean (SE) of 23.05 (0.37) and range from 11.70 to 31.64. Egg survival to the eyed-stage was weakly, but significantly, correlated to b* (r = 0.206), L* (r = 0.185), Chroma (r = 0.211), and Entire Color Index (r = 0.211). Spawns with no egg survival had eggs with significantly lower a* values compared to spawns where at least some of the eggs survived to the eyed stage. L*, a*, b*, Chroma, and Entire Color Index varied significantly among the years, but Hue and egg survival to the eyed stage did not. The results of this study indicate a possible link between egg color and landlocked fall Chinook salmon egg survival, possibly due to differences in the diets of feral broodstock females or their ability to deposit bodily carotenoids in the developing eggs.

The Effect of Waking Suggestion on Post-Hypnotic Amnesia

1981 ◽  
Vol 11 (1) ◽  
pp. 44-46 ◽  
Author(s):  
D.P. Fourie
Keyword(s):  
Point Of View ◽  
The Other ◽  
Hypnotic Susceptibility ◽  
The Subject ◽  
The Mean ◽  
The Difference ◽  
The One ◽  
The Relationship ◽  
Female Subjects

It is increasingly realized that hypnosis may be seen from an interpersonal point of view, meaning that it forms part of the relationship between the hypnotist and the subject. From this premise it follows that what goes on in the relationship prior to hypnosis probably has an influence on the hypnosis. Certain of these prior occurences can then be seen as waking suggestionns (however implicitly given) that the subject should behave in a certain way with regard to the subsequent hypnosis. A study was conducted to test the hypothesis that waking suggestions regarding post-hypnotic amnesia are effective. Eighteen female subjects were randomly divided into two groups. The groups listened to a tape-recorded talk on hypnosis in which for the one group amnesia for the subsequent hypnotic experience and for the other group no such amnesia was suggested. Thereafter the Stanford Hypnotic Susceptibility Scale was administered to all subjects. Only the interrogation part of the amnesia item of the scale was administered. The subjects to whom post-hypnotic amnesia was suggested tended to score lower on the amnesia item than the other subjects, as was expected, but the difference between the mean amnesia scores of the two groups was not significant.

Driver Perception–Brake Response in Stopping Sight Distance Situations

1998 ◽  
Vol 1628 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Daniel B. Fambro ◽  
Rodger J. Koppa ◽  
Dale L. Picha ◽  
Kay Fitzpatrick
Keyword(s):  
Response Time ◽  
Performance Studies ◽  
Response Times ◽  
Highway Design ◽  
Braking Performance ◽  
Reaction Distance ◽  
State Highway ◽  
Sight Distance ◽  
Design Speed ◽  
Stopping Sight Distance

One of the most important requirements in highway design is the provision of adequate stopping sight distance at every point along the roadway. At a minimum, this sight distance should be long enough to enable a vehicle traveling at or near the design speed to stop before reaching a stationary object in its path. Stopping sight distance is the sum of two components–brake reaction distance and braking distance. Brake reaction distance is based on the vehicle’s speed and the driver’s perception–brake reaction time (PBRT). Four separate, but coordinated, driver braking performance studies measured driver perception–brake response to several different stopping sight distance situations. The results from the driver braking performance studies suggest that the mean perception–brake response time to an unexpected object scenario under controlled and open road conditions is about 1.1 s. The 95th percentile perception–brake response times for these same conditions was 2.0 s. The findings from these studies are consistent with those in the literature: that is, most drivers are capable of responding to an unexpected hazard in the roadway in 2.0 s or less. Thus, the American Association of State Highway and Transportation Officials’ perception–brake response time of 2.5 s encompasses most of the driving population and is an appropriate value for highway design.

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