Injury Risk Posed by Side Impact of Nontracking Vehicles into Guardrails

Author(s):  
Nicholas S. Johnson ◽  
Hampton C. Gabler

Side impact is one of the most dangerous types of guardrail crashes. Of particular concern is a nontracking vehicle sliding sideways into a guardrail end treatment. This study investigated the issue of end terminal-side crashes with the use of a data set of 142 guardrail crashes extracted from the National Automotive Sampling System–Crashworthiness Data System. Side crashes involving an end terminal were substantially over-represented in driver injuries. End terminal contact occurred in about 25% of all guardrail-side crashes but represented almost 70% of driver injuries. Terminals that were noncompliant with NCHRP Report 350 were roughly five times as likely as compliant designs to cause serious crash injury. Collisions with terminals were also about twice as likely to initiate rollover compared with collisions with the length-of-need section of the guardrail. When injuries caused by rollovers, unbelted drivers, and driver ejections were accounted for, the risk presented by terminal contact was accentuated, as was the difference between cars, light trucks, and vans in terminal impacts.

Author(s):  
Jules S. Jaffe ◽  
Robert M. Glaeser

Although difference Fourier techniques are standard in X-ray crystallography it has only been very recently that electron crystallographers have been able to take advantage of this method. We have combined a high resolution data set for frozen glucose embedded Purple Membrane (PM) with a data set collected from PM prepared in the frozen hydrated state in order to visualize any differences in structure due to the different methods of preparation. The increased contrast between protein-ice versus protein-glucose may prove to be an advantage of the frozen hydrated technique for visualizing those parts of bacteriorhodopsin that are embedded in glucose. In addition, surface groups of the protein may be disordered in glucose and ordered in the frozen state. The sensitivity of the difference Fourier technique to small changes in structure provides an ideal method for testing this hypothesis.


2021 ◽  
pp. 1-11
Author(s):  
Yanan Huang ◽  
Yuji Miao ◽  
Zhenjing Da

The methods of multi-modal English event detection under a single data source and isomorphic event detection of different English data sources based on transfer learning still need to be improved. In order to improve the efficiency of English and data source time detection, based on the transfer learning algorithm, this paper proposes multi-modal event detection under a single data source and isomorphic event detection based on transfer learning for different data sources. Moreover, by stacking multiple classification models, this paper makes each feature merge with each other, and conducts confrontation training through the difference between the two classifiers to further make the distribution of different source data similar. In addition, in order to verify the algorithm proposed in this paper, a multi-source English event detection data set is collected through a data collection method. Finally, this paper uses the data set to verify the method proposed in this paper and compare it with the current most mainstream transfer learning methods. Through experimental analysis, convergence analysis, visual analysis and parameter evaluation, the effectiveness of the algorithm proposed in this paper is demonstrated.


2021 ◽  
Vol 9 (1) ◽  
pp. 232596712097399
Author(s):  
Markus Geßlein ◽  
Johannes Rüther ◽  
Michael Millrose ◽  
Hermann Josef Bail ◽  
Robin Martin ◽  
...  

Background: Hand and wrist injuries are a common but underestimated issue in taekwondo. Detailed data on injury risk, patterns, and mechanism are missing. Purpose: To evaluate (1) the fight time exposure-adjusted injury incidence rate (IIR) and clinical incidence and (2) injury site, type, sport-specific mechanism, and time loss in taekwondo. Study Design: Descriptive epidemiology study. Methods: Athletes from a single national Olympic taekwondo training center were investigated prospectively for hand and wrist injuries during training and competition over 5 years. The Orchard Sports Injury Classification System Version 10 was used to classify injury type, and analysis of the anatomic injury site was performed. The mechanism of injury was classified as due to either striking or blocking techniques. Results: From a total of 107 athletes, 79 athletes (73.8%) with a total exposure time of 8495 hours were included in the final data set. During the study period, 75 injuries of the hand and wrist region were recorded despite the athletes using protective hand gear. The IIR was 13.9 (95% CI, 10.5-17.5) and was significantly higher during competition. The clinical incidence as an indicator for risk of injury was 60.7% (95% CI, 50.9-70.5). Finger rays were the most affected location (68%), and fractures (43%) and joint ligament injuries (35%) were the most common type of injury. Significantly more injuries were found on the dominant hand side ( P < .001). Comparison of injury mechanisms demonstrated significantly more injuries at the finger rays deriving from blocking techniques ( P = .0104). The mean time loss for all hand and wrist injuries was 15.7 ± 13.5 days (range, 3-45 days) and was highest for distal radial fractures, with a mean of 39.7 ± 4.8 days (range, 32-45 days). Conclusion: There was a significantly higher IIR for acute hand and wrist injuries in elite taekwondo athletes during competition, which resulted in considerable time loss, especially when fractures or dislocations occurred. Significantly more injuries to the finger rays were found during blocking despite the use of protective hand gear. Improvement of tactical skills and blocking techniques during training and improved protective gear appear to be essential for injury prevention.


Geophysics ◽  
2007 ◽  
Vol 72 (1) ◽  
pp. F25-F34 ◽  
Author(s):  
Benoit Tournerie ◽  
Michel Chouteau ◽  
Denis Marcotte

We present and test a new method to correct for the static shift affecting magnetotelluric (MT) apparent resistivity sounding curves. We use geostatistical analysis of apparent resistivity and phase data for selected periods. For each period, we first estimate and model the experimental variograms and cross variogram between phase and apparent resistivity. We then use the geostatistical model to estimate, by cokriging, the corrected apparent resistivities using the measured phases and apparent resistivities. The static shift factor is obtained as the difference between the logarithm of the corrected and measured apparent resistivities. We retain as final static shift estimates the ones for the period displaying the best correlation with the estimates at all periods. We present a 3D synthetic case study showing that the static shift is retrieved quite precisely when the static shift factors are uniformly distributed around zero. If the static shift distribution has a nonzero mean, we obtained best results when an apparent resistivity data subset can be identified a priori as unaffected by static shift and cokriging is done using only this subset. The method has been successfully tested on the synthetic COPROD-2S2 2D MT data set and on a 3D-survey data set from Las Cañadas Caldera (Tenerife, Canary Islands) severely affected by static shift.


Author(s):  
Alexander Baturo ◽  
Johan A. Elkink

Abstract How can one assess which countries select more experienced leaders for the highest office? There is wide variation in prior career paths of national leaders within, and even more so between, regime types. It is therefore challenging to obtain a truly comparative measure of political experience; empirical studies have to rely on proxies instead. This article proposes PolEx, a measure of political experience that abstracts away from the details of career paths and generalizes based on the duration, quality and breadth of an individual's experience in politics. The analysis draws on a novel data set of around 2,000 leaders from 1950 to 2017 and uses a Bayesian latent variable model to estimate PolEx. The article illustrates how the new measure can be used comparatively to assess whether democracies select more experienced leaders. The authors find that while on average they do, the difference with non-democracies has declined dramatically since the early 2000s. Future research may leverage PolEx to investigate the role of prior political experience in, for example, policy making and crisis management.


2021 ◽  
pp. 014544552110540
Author(s):  
Nihal Sen

The purpose of this study is to provide a brief introduction to effect size calculation in single-subject design studies, including a description of nonparametric and regression-based effect sizes. We then focus the rest of the tutorial on common regression-based methods used to calculate effect size in single-subject experimental studies. We start by first describing the difference between five regression-based methods (Gorsuch, White et al., Center et al., Allison and Gorman, Huitema and McKean). This is followed by an example using the five regression-based effect size methods and a demonstration how these methods can be applied using a sample data set. In this way, the question of how the values obtained from different effect size methods differ was answered. The specific regression models used in these five regression-based methods and how these models can be obtained from the SPSS program were shown. R2 values obtained from these five methods were converted to Cohen’s d value and compared in this study. The d values obtained from the same data set were estimated as 0.003, 0.357, 2.180, 3.470, and 2.108 for the Allison and Gorman, Gorsuch, White et al., Center et al., as well as for Huitema and McKean methods, respectively. A brief description of selected statistical programs available to conduct regression-based methods was given.


AERA Open ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 233285841986729 ◽  
Author(s):  
Eunice S. Han

This article examines how teachers unions affect teachers’ well-being under various legal institutions. Using a district–teacher matched data set, this study identifies the union effects by three approaches. First, I contrast teacher outcomes across different state laws toward unions. Second, I compare the union–nonunion differentials within the same legal environment, using multilevel models and propensity score matching. Finally, unexpected legal changes restricting the collective bargaining of teachers in four states form a natural experiment, allowing me to use the difference-in-difference estimation to identify the causal effect of weakening unionism on teacher outcomes. I find that (a) many teachers join unions even when bargaining is rarely or never available, and meet-and-confer or union membership rate affects teachers’ lives in the absence of a bargaining contract; (b) how unions influence teacher outcomes vary greatly by different legal environment; and (c) the changes in public policy limiting teachers’ bargaining rights significantly decrease teacher compensation.


Author(s):  
Jerry S. Ogden

Analysis of vehicle deformation from impacts largely relies upon A and B stiffness coefficients for vehicle structures in order to approximate the velocity change and accelerations produced by an impact. While frontal impact stiffness factors for passenger vehicles, light trucks, vans, and sport utility vehicles are relatively prevalent for modern vehicles, stiffness factors for rear and side structures, as well as heavy vehicles, buses, recreational vehicles, trailers, motorcycles, and even objects, are essentially non-existent. This paper presents the application of the Generalized Deformation and Total Velocity Change Analysis to real-world collision events (G-DaTA?V™ System of Equations) as developed by this author. The focus of this paper addresses the relative precision and accuracy of the G-DaTA?V™ System of Equations for determining the total velocity change for oblique and/or offset vehicle-to-vehicle collisions involving light trucks and sport utility vehicles, which are largely under-represented with modern vehicle A and B stiffness values for side and rear surfaces. The previous paper presented by this author to the Academy addressed the relative accuracy and precision of the G-DaTA?V™ System of Equations as they relate to a first validation using the RICSAC-staged collision database. As a secondary and more comprehensive validation process, the G-DaTA?V™ System of Equations will be applied to real-world collision data obtained through the National Automotive Sampling System (NASS), which provides the National Highway Traffic Safety Administration (NHTSA) with a comprehensive compilation of real-world collision events representing a broad-based collection of collision configurations from across the country. This data represents a reusable source of information that was collected using standardized field techniques implemented by NASS-trained field technicians. Through using a “core set of crash data components,” NASS has demonstrated its utility and applicability to a vast array of statistical and analytical studies regarding traffic safety and vehicle collision dynamics.


2021 ◽  
Vol 2 (1) ◽  
pp. 30-45
Author(s):  
BK Mahalder ◽  
◽  
MB Ahmed ◽  
H Bhandari ◽  
MU Salam ◽  
...  

Quantifying knowledge on agriculture can have many benefits to stakeholders. While many knowledge-based systems exist in modern days for farmers’ decision support, specific models are lacking on how knowledge traits can impact on agricultural production systems. This study employed modelling technique, supported by field data, to provide a clear understanding and quantifying how knowledge management in production practices can contribute to rice productivity in the environmentally stressed southwest Bangladesh. This research accounted for ‘Boro’ rice as the target crop and ‘BRRI dhan28’ as the test variety. The ‘B-M Model’ was developed following the principle and procedure from published literature, ‘brainstorming’ and data from field surveys. Three knowledge management traits (KMT) were defined and quantified as the inputs of the model. Those are: self-experience and observation (SEO), extension advisory services (EAS) and accessed information sources (AIS). The yield influencing process (YIP), the intermediate state variable of the model, was deduced by accounting for the two dominant agronomic practices, seedling age for transplanting and triple superphosphate (TSP) application. ‘Knowledge drives farmers’ practice change which in turn influences yield’ was composed as the theoretical framework of the ‘B-M Model’. The model performed strongly against an independently collected field data set. Across the 180 farmers’ data, the average relative rice yield (RRY) predicted by the model (0.705) and observed in the field (0.716) was close (root mean squared deviation (RMSD) = 0.018). The difference between predicted and observed RRY was not statistically different (LSD = 0.03), indicating the model fully captured the field data. A regression of predicted and observed RRY explained 96% variance in observation, further proving the model’s strength in estimating RRY in a wider range of farmers’ rice yield. In a normative analysis, the practicality and usefulness of the model to stakeholders were simulated for the understanding of how much achievable yield could be expected by changing farmers’ knowledge pool (the sum of three KMT) on rice production practices, and at what combination(s) of KMT to be considered at strategic hierarchy to materialize a targeted achievable yield. To the best of the knowledge, a model quantifying rice yield in relation to knowledge management trait does not exist in literature. Upon successful testing under diverse yield scenarios using multiple and sophisticated statistical tools that enhanced the credibility of the model, it is concluded that the model has the potential to be used for identifying quantitative pathways of farmers’ knowledge acquisition for practice change leading to improved productivity of rice in the southwest region of Bangladesh.


Sign in / Sign up

Export Citation Format

Share Document