Probability Of Noncompliance Research Articles

Reliability Analysis of Horizontal Curves Using Geometric Design Consistency Assessment Criterion

Road accidents have always been one of the important reasons for fatalities and financial losses. Since road accidents on rural highways cause more serious injuries than those on urban highways, providing a suitable method to increase safety in the curves can be a significant contributor to preventing these damages. Although speed is one of the most important variables affecting highway safety, numerous studies have been performed on the reliability analysis of horizontal curves without taking the speed variable into account. The aim of this research is reliability (probability of noncompliance) assessment in the horizontal curve design using geometric design consistency criteria. The radius, superelevation, and operating speed of 19 horizontal curves were collected by field research on the Mashhad‐Torbat Heydarieh highway in Iran. Three different approaches were defined based on the geometric design consistency criterion of a single horizontal curve, and consecutively, the probability of noncompliance was calculated using these approaches. According to the obtained results, this study showed that radius enhancement increases the probability of noncompliance and the consistency level of the geometric design. Finally, the high values of the probability of noncompliance (failure) indicate that the geometric design guidelines need calibration in the design of horizontal curves, especially for higher radii.

Expected Safety Performance of Different Freeway Merging Strategies in an Environment of Mixed Vehicle Technologies

This study evaluates different proposed merging solutions that reduce the conflict between merging vehicles and mainline traffic within a mixed traffic environment using a safety measure to see which strategy might work better than others under specific traffic conditions. The mixed traffic includes various percentages of driver-operated vehicles (DVs) and connected autonomous vehicles (CAVs). The probability of noncompliance (PNC) is selected as a surrogate safety measure to assess the strategies. A MATLAB program is developed to simulate various traffic conditions at a merging area and to calculate the PNC merging for the different merging strategies. In addition, to examine the relationship between PNC and collision frequency at the merging area, the collision data at 15 merging ramps in Ottawa were collected to examine the relationship between PNC values obtained from the simulation for the case of a full-DV vehicle fleet and no management strategy (current conditions) and actual safety performance. The results confirmed the validity of PNC as a surrogate safety measure that is correlated to expected collision frequency at merge areas. By simulating all proposed merging management strategies, the results of this study showed a general trend of decreasing PNC and, hence, improved safety performance since the CAV penetration rate increases even when no management strategy is used or under the do-nothing option. However, most merging strategies had better expected safety performance than the do-nothing option, which indicates the value of implementing a merging management strategy, especially during the period of transition from a full-DV to a full-CAV fleet.

Probability of non-compliance to the consumption of Iron Tablets in pregnant women in Indonesia.

The low non-compliance to the consumption of Iron Tablets in pregnant women is an obstacle in the implementation of government programs to prevent and overcome the anemia problems in pregnant women. This study was conducted to determine the probability of non-compliance of pregnant women in the consumption of iron tablets in Indonesia. A cross-sectional study using the 2017 IDHS data. The sample was 12,466 women of childbearing age 15-49 years in Indonesia who consumed Iron Tablets during their last pregnancy. Univariate analysis used proportion measure, the bivariate analysis using chi-square test and multivariate used binary logistic regression test. Statistical analysis using SPSS-26 software. The level of non-compliance to the consumption of Iron Tablets during pregnancy in Indonesia is only 48.47%. The risk factors for quantity (p = 0.000, OR 2.085), and quality (p = 0.000, OR 1.655) Antenatal Care (ANC) was not good, examiners were pregnancy not health workers (p = 0.000, OR 1.816), residence in rural areas (p = 0.000, OR 1.262), and very poor socioeconomic status (p value = 0.000, OR 2.041) were significantly related to non-compliance with Iron Tablets consumption. The probability of non-compliance to the consumption of Iron Tablets in pregnant women with risk factors is 88%. Quantity of ANC and socioeconomic have a high influence on compliance to consumption of iron tablets, so it is important to bring nutrition workers at ANC activities to educate pregnant women about the benefits, side effects, and ways of consumption of iron tablets, reactivate supervisors for consumption of iron tablets, increase access health services in rural areas and families with low socioeconomic status, as well as providing free health care programs for the poor.

Multivariate models to investigate the relationship between collision risk and reliability outcomes on horizontal curves

This paper proposes a reliability-based framework to address the risk associated with limitations in the Available Sight Distance (ASD) on curved highway segments considering a three-dimensional (3D) sight distance computation approach. To facilitate this assessment, the ASD on horizontal curves was evaluated and an accurate inventory of curve attribute information was generated using LiDAR (Light Detection and Ranging) data in an automated and efficient manner. These datasets were then used to estimate the risk (probability of noncompliance, Pnc) associated with sight distance insufficiencies. Full Bayes multivariate Poisson log-normal safety performance functions were developed to relate the Pnc to the expected number of collisions. The results show that there was a statistically significant relationship between Pnc and collision frequency. There was also a significant correlation of 0.444 to 0.452 across collision severity levels indicating that curves with high Property-Damage-Only (PDO) collisions could be associated with higher injury and fatal (I + F) collisions. It was also found that Pnc had a greater impact on increasing PDO collisions than I + F collisions, suggesting that collisions associated with insufficient sight distance are likely to be less severe. The results of this analysis are expected to improve our understanding of the risks associated with deviations from design guidelines and quantitatively assess the safety margins due to these variations. The framework presented in this paper can be used to compare different design alternatives and investigate the influence of design deficiencies on collision occurrence across various severity levels.

Fiscal risk and financial fragility

We propose a new methodology to evaluate the importance of fiscal risk to financial stability. We first develop a method to estimate the probability of non-compliance of public entities, which takes into account the strict legal framework that is mandatory for governments. While in our model the evolution of public entities' revenues is stochastic and heavily depends on expectations about macroeconomic risk factors, the evolution of their personnel expenses and debt is rather deterministic due to the stickiness of the regulation. We then estimate the resilience of the financial sector to the public sector by simulating bank credit defaults in a multilayer network with interacting agents comprising banks, firms, and the public entities. Using Brazilian data at the state level, we establish a statistical link between states' probability of non-compliance and probability of default, enabling us to estimate the expected impact of the public sector in terms of financial losses on the economy. We find that, while most Brazilian states are struggling to comply with budget legal constraints on personnel expenses, the richest states are more likely to not comply with limits on their consolidated debts. We show that financial contagion is small mostly because banks that are more exposed to the public sector are highly capitalized.

Probabilistic Geometric Design of Highways: A Review

The design input parameters such as vehicular operating speed, deceleration rate and driver’s perception reaction time considered in the geometric design of highways exhibit considerable uncertainty in practical scenario. As such, in this context, the probabilistic approach or reliability based approach is essential in highway geometric design which is capable of incorporating the factor of uncertainty of design input parameters. The objective of this paper is, therefore, to present a state of the art review on the works dealing with reliability based methodology in highway geometric design and discuss future scope of development. Prominently, in the present study, the process of probabilistic or reliability based design in the reference of sight distance considerations and horizontal alignment have been reviewed, and thereby, some recently developed parameters such as Lfront-eye (the distance from the front of the car to the driver’s eye) and considerations as reported in various literature are recommended to be introduced in the framework of reliability based highway geometric design practice. Further, it is recommended in line with the reliability based design practice to incorporate the methodology to establish the link between Probability of Noncompliance (Pnc) and collision frequency obtained from accident data. Also, it is recommended that a reliability based optimization technique can act as a viable tool for ensuring uniform level of safety on a reliability based designed road.

Reliability-Based Safety Evaluation of Headlight Sight Distance Applied to Road Sag Curve Standards

Sight distance is key to ensure safe road geometric design under all circumstances. Road design standards propose models simulating nighttime driving that contemplate the features of vehicle frontlighting systems to address the design of sag curves. These models are based on a deterministic approach, which is known to present a number of drawbacks. It neglects the stochastic nature of the variables involved and, therefore, no information is available about the safety margin of the design output. As opposed to design based on deterministic methods, probabilistic methods overcome these inconveniences providing a solid approach to broach the analysis of sag curves. This research study applied a probabilistic approach to evaluate the risk level (probability of noncompliance, Pnc) associated to sag curve designs, and assessed the effect of the variables involved in headlight sight distance (HSD) on the Pnc. The required stopping sight distance was considered not to be met when it exceeded the HSD. A total of 71,334 case studies were generated by combining the range of values of the variables involved in the HSD as per the Spanish geometric design standard. The risk level associated to each case was calculated by means of a Monte Carlo simulation. The results showed that variables modeling headlight features significantly affect the risk level. Moreover, the risk associated to design outputs that are considered equivalent by the standard varies significantly. Therefore, the use reliability theory in the development of standards and design guides is recommended.

System reliability as a surrogate measure of safety for horizontal curves: methodology and case studies

Reliability analysis has been advocated to account for the uncertainty in geometric design and to evaluate the risk associated with various design options. Most of the previous studies using reliability-analysis in highway design evaluated only one-mode of noncompliance. This study assesses the performance of horizontal curves using a system of multi-modal noncompliance (insufficient sight distance, vehicle skidding, and vehicle rollover). Five case studies of a highway in British Columbia are considered. Two approaches were used: (1) second-order reliability-bounds with FORM analysis (First-Order Reliability Method), (2) Monte-Carlo Simulation (MCS). A calibrated design chart that accommodates heavy-trucks on horizontal-curves with sharp-radii is provided. The results show that the differences in the system probability of noncompliance between one-mode and system of multi-modes of noncompliance are more pronounced for heavy-trucks. Results also show that the probability of noncompliance associated with vehicle rollover is significantly affected by the stability-ratio compared to height-ratio and roll-rate.

Author contributions to ecological publications: What does it mean to be an author in modern ecological research?

Authorship is a central element of scientific research carrying a variety of rewards and responsibilities, and while various guidelines exist, actual author contributions are often ambiguous. Inconsistent or limited contributions threaten to devalue authorship as intellectual currency and diminish authors’ responsibility for published content. Researchers have assessed author contributions in the medical literature and other research fields, but similar data for the field of ecological research are lacking. Authorship practices in ecological research are broadly representative of a variety of fields due to the cross-disciplinary nature of collaborations in ecological studies. To better understand author contributions to current research, we distributed a survey regarding co-author contributions to a random selection of 996 lead authors of manuscripts published in ecological journals in 2010. We obtained useable responses from 45% of surveyed authors. Reported lead author contributions in ecological research studies consistently included conception of the project idea, data collection, analysis, and writing. Middle and last author contributions instead showed a high level of individual variability. Lead authorship in ecology is well defined while secondary authorship is more ambiguous. Nearly half (48%) of all studies included in our survey had some level of non-compliance with Ecological Society of America (ESA) authorship guidelines and the majority of studies (78%) contained at least one co-author that did not meet International Committee of Medical Journal Editors (ICMJE) requirements. Incidence of non-compliance varied with lead author occupation and author position. The probability of a study including an author that was non-compliant with ESA guidelines was lowest for professor-led studies and highest for graduate student and post doctoral researcher-led studies. Among studies with > two co-authors, all lead authors met ESA guidelines and only 2% failed to meet ICMJE requirements. Middle (24% ESA, 63% ICMJE) and last (37% ESA, 60% ICMJE) authors had higher rates of non-compliance. The probability of a study containing a co-author that did not meet ESA or ICMJE requirements increased significantly with the number of co-authors per study although even studies with only two co-authors had a high probability of non-compliance of approximately 60% (ICMJE) and 15 to 40% (ESA). Given the variable and often limited contributions of authors in our survey and past studies of other research disciplines, institutions, journals, and scientific societies need to implement new approaches to instill meaning in authorship status. A byline approach may not alter author contributions but would better define individual contributions and reduce existing ambiguity regarding the meaning of authorship in modern ecological research.

Safety Evaluation and Adjustment of Superelevation Design Guides for Horizontal Curves Based on Reliability Analysis

In general, the use of superelevation and changes in a road’s transverse slope are typically based on the road’s design speed to provide safety and comfort for a vehicle driving on a horizontal curve. However, due to the difference between operating and design speeds, there has always been uncertainty in determining the margin of safety using superelevation. This paper discusses the assessment of the safety margins obtained from the application of superelevation in horizontal-curve design. The assessment uses geometric design guides and a reliability index to determine any uncertainties in the design parameters. In addition, adjusted design charts of superelevation values related to the radius of horizontal curves at various levels of probability of noncompliance are provided. The results show that the adjusted superelevation values are generally greater than those derived from current standards. The adjusted design charts can help designers select an appropriate superelevation value for a particular horizontal curve for highways that have geometric constraints. These adjusted charts may also aid designers in predicting the consequences and safety margins associated with the selection of superelevation alternatives required to approve geometric designs that involve violations of the standard requirements due to environmental constraints.

Reliability-Based Analysis of Sight Distance Modelling for Traffic Safety

Sight distance is of the utmost importance for traffic safety. The consideration of three-dimensional (3D) available sight distance (ASD) in geometric design has been supported by several researchers. However, existing ASD estimation methods are two-dimensional (2D) in nature, which do not evaluate varying visibility conditions. This paper compares different methodologies of modelling the ASD. The ASD of 402 horizontal curves, located in twelve in-service two-lane rural highways, was analyzed. Three ASD estimation methods were used which include a 2D method and two different 3D methods. The ASD results obtained through 2D and 3D methodologies are compared. Also, the different conditions of the existing roadside features or geometric elements, under which the 3D ASD estimation is important, were identified. Next, reliability theory is utilized to evaluate the risk level (probability of noncompliance,Pnc) associated with limited sight distance for each ASD modelling method. The results of the comparison emphasized the importance of considering the 3D modelled sight distance when evaluating the associated risk either in highway design or during the service life. In addition, the results indicated that the ASD modelling approach can have a significant impact on the estimation of the safety of highway design.

Noncompliance to smoke-free law: which hospitality premises are more prone?

ObjectivesIn Turkey, smoking has been banned in hospitality establishments since July 2009. The objective of this study was to determine noncompliance to the smoke-free law and its change in 2 consecutive years in enclosed spaces of hospitality venues and also to evaluate the factors associated with noncompliance. Study designThis is an observational study. MethodsHospitality venues in Istanbul were visited, and data were collected through direct observation and interviews. Observation of smoking, cigarette butts or existence of ashtrays were defined as noncompliance. The survey was repeated in 2 consecutive years; the venues were visited both in 2013 and 2014. Logistic regression was used to evaluate factors associated with noncompliance. ResultsIn 2013, 450 establishments were visited, and in the next year, 367 (81.6%) were revisited. Noncompliance for 2013 and 2014 were 49.0% and 29.7%, respectively. The highest violation was observed in bars and traditional coffeehouses. There was a significant decrease in noncompliance from 2013 to 2014 among restaurants and cafés, while such a change was not observed among bars and traditional coffeehouses. In the multivariate analysis, venues other than restaurants, venues that did not have no-smoking signs and venues which had been issued fines previously had increased probability of noncompliance. ConclusionsWhile compliance to smoke-free law had increased significantly within 1 year, almost one third of the venues were still violating the law in 2014. The venues which were issued fines continued to violate the law. There is a need to strengthen enforcement efforts and revise the methods of enforcement and penalties in hospitality establishments.

Multi-mode reliability-based design of horizontal curves

Recently, reliability analysis has been advocated as an effective approach to account for uncertainty in the geometric design process and to evaluate the risk associated with a particular design. In this approach, a risk measure (e.g. probability of noncompliance) is calculated to represent the probability that a specific design would not meet standard requirements. The majority of previous applications of reliability analysis in geometric design focused on evaluating the probability of noncompliance for only one mode of noncompliance such as insufficient sight distance. However, in many design situations, more than one mode of noncompliance may be present (e.g. insufficient sight distance and vehicle skidding at horizontal curves). In these situations, utilizing a multi-mode reliability approach that considers more than one failure (noncompliance) mode is required. The main objective of this paper is to demonstrate the application of multi-mode (system) reliability analysis to the design of horizontal curves. The process is demonstrated by a case study of Sea-to-Sky Highway located between Vancouver and Whistler, in southern British Columbia, Canada. Two noncompliance modes were considered: insufficient sight distance and vehicle skidding. The results show the importance of accounting for several noncompliance modes in the reliability model. The system reliability concept could be used in future studies to calibrate the design of various design elements in order to achieve consistent safety levels based on all possible modes of noncompliance.

Reliability-Based Design of Horizontal Curves on Two-Lane Rural Highways

Current design guides adopt a deterministic approach to the design of horizontal curves; each factor included in the design is represented by the near-worst-case value. In the context of horizontal curve design, the design procedure is based only on the driver comfort criterion, and data correspond to experiments conducted in the 1930s. Furthermore, current horizontal curve design procedures lack a quantitative evaluation for safety. To overcome those shortcomings, a new design framework is proposed to design horizontal curves; a probabilistic approach is adopted and two criteria are considered: vehicle dynamic stability and driver comfort. Reliability analysis was used to provide a quantitative evaluation for the design in regard to the probability of failure, probability of noncompliance, and reliability index. Outputs of simulation runs in a vehicle dynamics model were used to estimate demand lateral friction and lateral acceleration depending on the geometric characteristics of horizontal curves. In addition, data of an instrumented vehicle experiment were used to develop driver-level models for the distribution of the curve speed and driver comfort threshold. The first-order reliability method was used to estimate the probability of failure, probability of noncompliance, and reliability index. The proposed design framework and developed models were applied in an example to design a horizontal curve for a specific design speed.

Assessing risk factors in the organic control system: evidence from inspection data in Italy.

Certification is an essential feature in organic farming, and it is based on inspections to verify compliance with respect to European Council Regulation-EC Reg. No 834/2007. A risk-based approach to noncompliance that alerts the control bodies to activate planning inspections would contribute to a more efficient and cost-effective certification system. An analysis of factors that can affect the probability of noncompliance in organic farming has thus been developed. This article examines the application of zero-inflated count data models to farm-level panel data from inspection results and sanctions obtained from the Ethical and Environmental Certification Institute, one of the main control bodies in Italy. We tested many a priori hypotheses related to the risk of noncompliance. We find evidence of an important role for past noncompliant behavior in predicting future noncompliance, while farm size and the occurrence of livestock also have roles in an increased probability of noncompliance. We conclude the article proposing that an efficient risk-based inspection system should be designed, weighting up the known probability of occurrence of a given noncompliance according to the severity of its impact.

Sight Distance Standards Based on Observational Data Risk Evaluation of Passing

The paper presents an application of a reliability analysis for evaluating the risk associated with passing sight distance (PSD) standards in terms of the expected probability of noncompliance. Calculation of PSD is required to determine where drivers can safely execute passing maneuvers. Traditional PSD standards are based on deterministic, theoretical models, which are calibrated with conservative percentile values for uncertain design inputs to account for uncertainty. The PSD standards do not provide information about the risk of deviation from them. Reliability analysis is a technique that is based on limit state design and that accounts for the propagation of variability from input random parameters to the design outputs. A total of 1,098 passing maneuvers were observed on several two-lane highways in Spain; two data collection methodologies were used: external observations and an instrumented vehicle. The most significant factors affecting PSD were impeding-vehicle speed, passing-vehicle acceleration, and headways between impeding and passing vehicles. A uniform acceleration model described the passing-vehicle trajectory. The characterized input parameters and the passing model were used to perform a reliability analysis. The results showed the probability of noncompliance in different scenarios, defined as the proportion of cases in which the required PSD would exceed the available sight distance. American and Spanish PSD standards were evaluated. Geometric design standards presented a probability of noncompliance of about 0.15, whereas some marking standards had a probability of noncompliance exceeding 0.85. These standards may be associated with higher risk levels if they are followed by drivers. As well, PSD risk levels were not consistent for different design speeds, since they underestimated operating speed at some locations.

Probabilistic Analysis of Freeway Deceleration Speed-Change Lanes

The design of a freeway speed-change lane (SCL) depends mainly on the manner of deceleration, initial speed, and the speed to be approached at the SCL. The design SCL length should provide drivers with sufficient distance to diverge at a reasonable speed and to decelerate comfortably. In the design guides, recommended SCL lengths are based on a deterministic approach in which a single value is assumed for each design parameter. An alternative approach is presented: a probabilistic methodology is used to analyze SCL length. This reliability-based analysis allows for the calculation of the probability of noncompliance for any specific SCL length, which corresponds to the percentage of drivers who may not be able to decelerate comfortably. Models are developed with different analysis methodologies and are applied to estimate the probability of noncompliance at seven SCL sites on the basis of speed and deceleration field data collected at these sites.

Probabilistic Design of Freeway Entrance Speed-Change Lanes considering Acceleration and Gap Acceptance Behavior

An adequate length of entrance speed-change lanes (SCLs) is required for vehicles’ acceleration and gap-searching purposes so that vehicles can merge onto the freeway comfortably. The current design guides use a deterministic approach for the design of SCL length based only on the acceleration behavior of vehicles in the SCL. This study introduces a probabilistic approach for the design of the length of SCLs that considers both acceleration and gap acceptance behavior of drivers during the merging process. A microscopic simulation, coupled with a Monte Carlo simulation technique, is used to develop a probabilistic model to evaluate the probability of a forced merge by vehicles in the SCL, termed the probability of noncompliance (PNC). Reliability measures can be developed on the basis of the distribution of PNC values for all simulated SCL vehicles at a specific site. Several such measures are estimated for seven study sites and are shown to have high potential to indicate the safety performance at entrance SCL sites. As an example application of the developed model, the mean PNC is estimated to the SCL lengths recommended in North American design guides for a specific freeway design speed but different values of controlling curve design speed and traffic volume in the freeway right lane. The results indicate that the mean PNC may change with the change of either the design speed of the ramp controlling curve or the traffic volume on the freeway right lane.

Reliability of column capacity design in shear

The capacity design of shear forces is one of the special demands of EC8 by which the ductile behavior of structures is implemented. The aim of capacity design is the formation of plastic hinges without shear failure of the elements. This is achieved by deriving the design shear forces from equilibrium conditions, assuming that plastic hinges, with their possible over-strengths, have been formed in the adjacent joints of the elements. In this equilibrium situation, the parameters (dimensions, material properties, axial forces etc) are random variables. Therefore, the capacity design of shear forces is associated with a probability of non-compliance (probability of failure). In the present study the probability of non-compliance of the shear capacity design in columns is calculated by assuming the basic variables as random variables. Parameters affecting this probability are examined and a modification of the capacity design is proposed, in order to achieve uniformity of the safety level.

Factors Influencing Women’s Preference to Select a Combined Hormonal Contraceptive Method: A Cross-Sectional Survey in Lithuania

Effectiveness and side effects are the main concerns when selecting a contraceptive method. Therefore, the aim of this study was to identify the preference of a combined hormonal contraception method by Lithuanian women, the reasons for selecting one of them and rejecting other two methods, and the factors determining selection or rejection. A cross-sectional multicenter survey was performed by the Lithuanian Society of Private Obstetricians and Gynecologists. A total of 4134 women, aged 18-49, who visited their physician due to initiation or reinitiation of hormonal contraception completed self-administered questionnaires identifying the reasons to select one method and reject the two remaining ones. Descriptive and inferential statistics methods were used for data analysis. The vaginal ring was the most accepted contraception method (55.4%), followed by the pill (35.6%). The skin patch was least preferable (9%). The vaginal ring and the skin patch were mainly selected for the frequency of use (72.9% and 51.2%, respectively), convenience (48.5% and 71%, respectively), and lower probability of noncompliance (48.7% and 63.5%, respectively). The main reason for selecting the pill was familiarity with the method (50.7%). The acceptance of vaginal ring increased with age and was higher among women with higher education. The most important factors when selecting a contraceptive method among the methods with equal effectiveness and similar safety profile were convenience, frequency of use, and lower probability of noncompliance. Age, education, and employment status were found to be other reasons associated with the choice of contraceptive method.