scholarly journals Conspicuity Research on the Highway Roadside Objects: A Simulator Study

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Xuemei Chen ◽  
Zhonghua Wei ◽  
Xia Zhao ◽  
Mingyang Hao ◽  
Tongyang Zhang

In a monotonous travelling environment, the single-vehicle run-off-roadside accidents occur easily. The injuries and fatalities caused by those accidents are significant components of the annual road casualties. The causation is the complex interaction of the visual effects on the roadside objects’ conspicuity. So the conspicuity enhancement needs to be considered in the roadside objects design to provide a temporary restoration of alertness and vigilance to drivers. Factors contributing to the conspicuity of the roadside objects were analyzed in this paper. A driving simulator study was conducted in order to extrapolate the relationship between the legibility distances and the objects and to quantify the conspicuity of the roadside objects different in basic features. The conclusions of this paper were firstly, a significant correlation existed between the mean legibility distance and the object’s size. The mean legibility distance was in a significant exponential proportion to the object’s size. Secondly, the triangle’s legibility was better than that of the rectangle and round contours. Only when the roadside object was combined with the suitable contour and size did the best visual quality come. To some extent, the conclusions could provide theoretical tools and strategies to optimize the dimensional design of the roadside objects in order to maintain the roadside safety.

Phytotaxa ◽  
2016 ◽  
Vol 268 (3) ◽  
pp. 209 ◽  
Author(s):  
SHUANG-XI YAN ◽  
HUI-JIE LIU ◽  
LE-LE LIN ◽  
SHUAI LIAO ◽  
JIN-YU LI ◽  
...  

The morphologically based taxonomic status of Clematis acerifolia var. elobata has been controversial. This study used two nuclear (ITS and ETS) and six plastid (rps16, rpl16, accD, trnS-trnG, atpB-rbcL, and trnV-atpE) molecular markers, and a DNA barcoding analysis to address the taxonomic status of C. acerifolia var. elobata and the relationship among other Clematis species. Our results showed that the discrimination power of ITS, ETS, and atpB-rbcL was better than that of the other tested DNA regions. When all tested sequences combined, most of the sampled taxa were resolved. Though the two taxa are closely related, they have differentiated clearly and formed two clades respectively. The mean divergence of the two taxa was 0.78%, which was higher than closely related Clematis species such as C. heracleifolia and C. pinnata (0.50 %). Considering molecular divergence, morphological differences, and distribution area, we raised C. acerifolia var. elobata to species level.


Author(s):  
Scott Himes ◽  
Eric Donnell

Recent advancements in analytical processes have used probabilistic approaches to examine the efficacy of the point mass model (and other Green Book models) to develop reliability-based approaches for geometric design. However, there has been minimal research establishing the link between reliability measures and substantive safety (expressed through crash frequency). The objective of this paper is to use empirical data supporting the calculation of reliability index for existing horizontal curves and to estimate the relationship between reliability index and crash frequency. Other horizontal curve-related characteristics that may have an impact on crash frequency on horizontal curves for rural two-lane highways and rural freeway facilities are controlled for in the evaluation. The safety analysis showed that the wet pavement reliability index was significantly associated with crash frequency for total curve-related crashes, single-vehicle run-off-road crashes, rollover crashes, truck-related crashes, and weather-related crashes. The relationship was strongest for the reliability index in its continuous form, meaning that the effect is continuous across the range of wet pavement reliability that was observed.


Author(s):  
Shaw-Pin Miaou

Crash-prediction models in the current edition of the Highway Safety Manual (HSM) have been developed to predict crash frequency by collision type and severity level for specific types of roadways and sites. Each model is made up of three major components: safety performance functions (SPFs), crash modification factors, and calibration factors. The objective of this study was to identify the limitations of the prediction models in estimating single-vehicle, run-off-road (SVROR) crashes for roadside safety analyses and suggest needed changes and developments. The paper presents a review of the state of the models in HSM and focuses on SPFs. Data from FHWA's safety effects of cross-section design for two-lane roads database were used to gain insight about the characteristics of SVROR crashes and total crashes, and to identify the limitations of the current models in predicting the frequency, type, and severity of SVROR crashes. Three major areas of limitations of SPFs are discussed: (a) assumptions involved in development, (b) variables that are potentially important to roadside design but not considered, and (c) statistical bias and uncertainty of the model equations.


2020 ◽  
Vol 24 (5) ◽  
pp. 207-216
Author(s):  
Chamroeun Se ◽  
Thanapong Champahom ◽  
Sajjakaj Jomnonkwao ◽  
Vatanavongs Ratanavaraha

Single-Vehicle Run Off Road (ROR) crash has been the leading crash type in terms of frequency and severity in Thailand. In this study, multinomial logit analysis was applied to identify the risk factors potentially influencing driver injury severity of single-vehicle ROR crash using accident records between 2011 and 2017 which were extracted from Highway Accident Information Management System (HAIMS) database. The analysis results show that the age of driver older than 55 years old, male driver, driver under influence of alcohol, drowsiness, ROR to left/right on straight roadway increase the probability of fatal crash, while other factors are found to mitigate severity such as the age of driver between 26-35 years old, using seatbelt, ROR and hit fixed object on straight and curve segment of roadway, mounted traffic island, intersection-related and accident in April. This study recommends the need to improve road safety campaign, law enforcement, and roadside safety features that potentially reduce level of severity of driver involving in single-vehicle ROR crash.


2021 ◽  
Author(s):  
Meng Yan ◽  
Wenying Wang ◽  
Zhaoxia Zheng ◽  
Lu Li ◽  
Duo Zhang ◽  
...  

Abstract Introduction. To investigate the association between OCT biomarkers and visual prognosis, based on TCED-HFV,and to explore whether these biomarkers have predictive value in visual prognosis of DME patients.Methods. The retrospective study included 166 eyes from 122 DME patients, who received 3 initial monthly intravitreal injections followed by PRN dosing. Results. The significant improvement of BCVA, as well as statistical decrement of CMT and HF, could be observed(p < 0.001, P=0.023, P=0.002, respectively). The BCVA in early and advanced DME is significantly better than that in severe DME in baseline (P=0.027, P=0.009, respectively) and 1 year (P=0.017, P=0.030, respectively). The broken EZ/ELM was generally accompanied by the existence of SF (P=0.032). The presence of DRIL and persistence SF were associated with negative visual effects (P<0.001, P=0.045, respectively). At month 12 the mean BCVA was significantly improved in both intact and disrupted EZ/ELM groups (P=0.023, P=0.033, respectively). The number of the DME patients with ERM increases after treatment (P<0.001).Conclusions. Intact EZ/ELM, the absence of DRIL and ERM might contribute to better response in patients. The persistence SF was a negative factor. Intravitreal anti-VEGF therapy was associated with ERM development and progression. It is not objective to consider only the OCT biomarkers but not the stages, and the indicators of different stages should be studied separately.


Genetics ◽  
1988 ◽  
Vol 119 (1) ◽  
pp. 213-221
Author(s):  
R J Redfield

Abstract Computer simulations of bacterial transformation are used to show that, under a wide range of biologically reasonable assumptions, transforming populations undergoing deleterious mutation and selection have a higher mean fitness at equilibrium than asexual populations. The source of transforming DNA, the amount of DNA taken up by each transforming cell, and the relationship between number of mutations and cell viability (the fitness function) are important factors. When the DNA source is living cells, transformation resembles meiotic sex. When the DNA source is cells killed by selection against mutations, transformation increases the average number of mutations per genome but can nevertheless increase the mean fitness of the population at equilibrium. In a model of regulated transformation, in which the most fit cells of a transforming population do not transform, transforming populations are always fitter at equilibrium than asexual populations. These results show that transformation can reduce mutation load.


2016 ◽  
Vol 7 (2) ◽  
pp. 59-63
Author(s):  
Abdullah A Al Nazeh

ABSTRACT Aims The aim of this study was to investigate the relationship between personality profiles and perception of maxillary midline diastema (MMD) among laypeople. Materials and methods Hundred total of 200 laypeople (100 females and 100 males, mean age = 28.8 ± 5.5 years) were recruited in this cross-sectional study. They were asked to rate the attractiveness of two digital photographs of ideal smile with 1 and 2 mm MMD on a visual analog scale (VAS) from 0 to 10. Participants' personality and psychological profiles were assessed via neuroticism.extraversion.openness five-factor inventory. The statistically significant levels were set at p ≤ 0.05. Results The mean VAS scores were 5.7 (± 2.1) and 4.3 (± 2.0) for 1 and 2 mm MMD respectively. The participants rated the attractiveness of 1 mm diastema better than the attractiveness of 2 mm diastema (p < 0.001). Females showed no difference in rating diastema attractiveness in comparison with males (p > 0.05). Participants (from both genders) with higher neuroticism scores rated 1 and 2 mm diastemas as less attractive than those with lower neuroticism scores (p ≤ 0.001). Conclusion Psychological profiles (high neuroticism) might be associated with negative perceptions of attractiveness of MMD. How to cite this article Al Nazeh AA. Relationship between Perception of Maxillary Midline Diastema and Personality Profiles. World J Dent 2016;7(2):59-63.


Author(s):  
Kathryn Wochinger ◽  
Brian Philips

This study investigated the relationship among spatial scanning ability, perceptual speed, and navigation performance in older and younger drivers. Fifty-six drivers performed a navigation task in a part-task driving simulator using: 1) text directions, 2) a standard paper map, 3) an enlarged paper map, and 4) a turn-by-turn display. Measures included navigation error rate and decision time, and spatial scanning and perceptual speed scores. Younger drivers performed better than the older drivers in error rate and decision time, and the turn-by-turn display improved performance compared to either map. Spatial scanning ability was a stronger predictor of error rate, while perceptual speed was a stronger predictor of decision time. The results suggest that navigation aids requiring minimal spatial and perceptual processing can improve navigation performance.


1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.


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