Traffic crashes tend to be more serious when commercial trucks are involved. And an increasing number of commercial vehicles are equipped with advanced driver assistance systems (ADAS) for traffic safety improvement. ...
详细信息
Traffic crashes tend to be more serious when commercial trucks are involved. And an increasing number of commercial vehicles are equipped with advanced driver assistance systems (ADAS) for traffic safety improvement. To this end, this study investigated the impacts of ADAS with respect to forward collision warning (FCW), urban forward collision warning (UFCW), lane departure warning (LDW), headway monitoring and warning (HMW), and speed limit indicator (SLI) on commercial truck drivers' behaviours using naturalistic data. Participants experienced two different test scenarios with two different ADAS warning configurations: Visual and audio alerts in the inactive state and in the active state. After activating alerts, 62%, 35%, 69%, 81% and 73% of drivers received less warnings in terms of FCW, UFCW, LDW, HMW and SLI respectively;the average of FCW, UFCW, LDW, HMW and SLI respectively declined 22%, 13%, 28%, 45% and 15%, but median changed little except for LDW and HMW. Then, the further analysis results by the one-way analysis of variance (ANOVA) method revealed that all warnings except UFCW had positive effect on commercial truck drivers' behaviour performance. The findings provide important references for commercial truck driver training and supervision in the age of advanced technology.
Triangle approximate counting has emerged as a prominent issue in graph stream research in the past few years, with applications ranging from social network analy-sis to web topic mining and motif detection in informa...
详细信息
Triangle approximate counting has emerged as a prominent issue in graph stream research in the past few years, with applications ranging from social network analy-sis to web topic mining and motif detection in informatics. Many graph stream sam-pling and triangle approximate counting algorithms have been proposed, with the majority of them guaranteeing unbiased estimation. However, they either cannot ensure that the memory overhead or the result's uncertainty is too great due to the use of an excessively large sampling space. In this article, we propose RFES, a set of one-pass stream algorithms for counting the global number of triangles in a fully dynamic graph stream in an unbiased, low-variance, and high-precision manner. RFES has three algorithms: RFESBASE, RFES-IMPR, and RFES-FD, which rep-resent the basic, improved, and complete dynamic versions, respectively. Each algo-rithm is based on our proposed first-edge reservoir sampling method, which shrinks the sampling space while increasing the uncertainty of triangles in the sample. It can deal with fully dynamic data with a lower theoretical estimation variance than state-of-the-art algorithms. A significant number of experimental results demonstrated that our RFES algorithm is more accurate and takes less time. The source codes of RFES can be downloaded from the website: https://***/BioLab310/RFES.
Due to the randomness and complexity of the discontinuity distribution, it is always complicated to analyse the three-dimensional stability problem of discontinuity-controlled rock slope in the field of engineering ge...
详细信息
Due to the randomness and complexity of the discontinuity distribution, it is always complicated to analyse the three-dimensional stability problem of discontinuity-controlled rock slope in the field of engineering geology. Specifically, when restricted by poor sampling conditions, the discontinuity data obtained are very limited. To solve this problem, we propose a stochastic kinematic method to estimate the slope failure angle based on limited data. Taking the high-steep rock slope on the right bank of a proposed bridge as an example, the stochastic kinematic method based on multiple algorithms (Monte Carlo simulation, Latin hypercube, and Bayesian estimation) is used to analyse the failure angles of potentially unstable blocks in two modes of plane and wedge failure. After statistical optimisation, the slope failure angles are determined to be 65.69 degrees (plane failure) and 58.65 degrees (wedge failure);this approach is more objective than the empirical formula method and can be used as the basis for judging the slope stability. The method proposed in this study fully considers the randomness of discontinuity distribution and combination, and can use limited sample data to realise failure angle analysis and stability judgement. The result is important as a reference of significance for engineering construction and disaster prevention.
Touch voltages are more likely to appear on long-distance pipelines that lie in shared corridors with transmission lines. The touch voltage level varies with soil resistivity and can become hazardous while maintenance...
详细信息
Touch voltages are more likely to appear on long-distance pipelines that lie in shared corridors with transmission lines. The touch voltage level varies with soil resistivity and can become hazardous while maintenance is being undertaken, necessitating risk assessment. Therefore, a novel approach is proposed that achieves better accuracy in the risk assessment of hazardous touch voltages appearing on pipelines than current approaches. The proposed approach incorporates soil resistivity measurements taken over a 1-year period, allowing for the derivation of soil models, touch voltage hazard profiles versus time and, thus, a probability reduction factor that can be integrated into a probabilistic risk calculation. Using a probability reduction factor is a key aspect to improving the accuracy of risk assessment, allowing pipeline asset operators to clearly identify whether or not, risk mitigation action is required. Further, the proposed approach allows appropriate risk mitigation actions to be identified. The efficacy and significance of the proposed approach are demonstrated through a case study on an area of land near a shared gas pipeline and transmission line corridor. The case study results show how appropriate safety levels can be achieved by adjusting the number of work day per year and temporary protection settings.
Security patterns can help organizations develop secure software. While it is typical to encounter isolated applications of one or more software patterns in practice, effectively responding to security threats demands...
详细信息
ISBN:
(纸本)9798400716836
Security patterns can help organizations develop secure software. While it is typical to encounter isolated applications of one or more software patterns in practice, effectively responding to security threats demands a comprehensive grasp and utilization of an entire pattern language or catalog, comprising numerous intricately interconnected patterns. The composition of software patterns makes them more efficient. Solutions for establishing sequences of software patterns are often found documented in plain text through explicit pattern relationships. This article presents two experiments of establishing pattern sequences using stochastic processes, one based on stochastic trees and the other, based on Bayesian belief network to establish meaningful pattern sequences. We used stochastic trees and Bayesian belief networks to find conditionally dependent patterns between which we tried to find the most expected combinations in pattern sequences. By employing these two processes, we established four envisioned sequences of patterns from the security pattern catalog. The pattern stories based around these pattern sequences demonstrate their meaningfulness. These two processes are not exclusively relevant to security patterns. We consider applying them to the patterns for engineering software for the cloud.
Our topic is performance differences between using random and chaos for particle swarm optimization (PSO). We take random sequences with different probability distributions and compare them to chaotic sequences with d...
详细信息
ISBN:
(纸本)9798400701207
Our topic is performance differences between using random and chaos for particle swarm optimization (PSO). We take random sequences with different probability distributions and compare them to chaotic sequences with different but also with same density functions. This enables us to differentiate between differences in the origin of the sequences (random number generator or chaotic nonlinear system) and statistical differences expressed by the underlying distributions. Our findings (obtained by evaluating the PSO performance for various benchmark problems using statistical hypothesis testing) cast considerable doubt on previous results which compared random to chaos and suggested that the choice leads to intrinsic differences in performance.
CDMA communication system has a certain anti-interference performance, but when the interference is stronger, the performance and stability of system will descend obviously. In this paper, narrow-band interference sup...
详细信息
ISBN:
(纸本)9781479928767
CDMA communication system has a certain anti-interference performance, but when the interference is stronger, the performance and stability of system will descend obviously. In this paper, narrow-band interference suppression based on FFT transform is adopted to improving anti-interference performance of CDMA communication systems significantly. probability and statistics search for interference signal is used in frequency domain, which increases the stability of anti-interference. This paper describes Matlab simulation and FPGA implementation of the algorithm. Hardware experiments show that the algorithm can improve the performance of narrow-band interference suppression for the ordinary CDMA mobile phone about 25dB.
A recent theoretical framework using power-law functions was proposed to model scattering from biological tissues in ultrasound and optical coherence tomography. Multi-scale scattering sites such as the fractal branch...
详细信息
ISBN:
(纸本)9781510648203;9781510648197
A recent theoretical framework using power-law functions was proposed to model scattering from biological tissues in ultrasound and optical coherence tomography. Multi-scale scattering sites such as the fractal branching vasculature will then contribute to power-law based probability distributions of speckle statistics. These distributions are the Burr type XII distribution, the Lomax distribution, and the generalized logistic distribution for speckle amplitude, intensity, and log amplitude, respectively. Previous experiments with ultrasound and optical coherence tomography demonstrate that these distributions are better fits to image histogram data of various biological tissues when compared with classical models (e.g., Rayleigh, K, and gamma distributions). Of critical importance is that this framework provides novel parameters, most notably the power-law exponent parameter, for characterizing the physics of scattering from soft tissue. The typical range for the exponent parameter in other normal tissues is approximately 3 to 6. The aim is for this parameter to be used as a new biomarker for diagnostic imaging, sensitive to changes in tissue structures. Here, we demonstrate a specific application to mouse brain tissue, in which the exponent parameter is used to characterize mouse cortical brain under various conditions including ex vivo and in vivo using optical coherence tomography.
The generalized Box-Muller algorithm provides a methodology for generating q-Gaussian random variates, which generalizes the Gaussian (q = 1). The parameter -infinity < q <= 3 is related to the shape of the tail...
详细信息
The generalized Box-Muller algorithm provides a methodology for generating q-Gaussian random variates, which generalizes the Gaussian (q = 1). The parameter -infinity < q <= 3 is related to the shape of the tail decay;q < 1 for compact-support including parabola (q = 0);1 < q <= 3 for heavy-tail including Cauchy (q = 2). This addendum clarifies the transformation q' = 3q-1/q+1 within the algorithm is due to a difference in the dimensions d of the generalized logarithm and the generalized distribution. The transformation is clarified by the decomposition of q = 1 + 2 kappa/1+d kappa, where the shape parameter -1 < kappa <= infinity quantifies the magnitude of the deformation from exponential. A simpler specification for the generalized Box-Muller algorithm is provided using the shape of the tail decay.
Geological models are mainly obtained via interpolation of simulations using geostatistical algorithms, and the simulation results are highly uncertain. In this paper, several factors that have great influences on mod...
详细信息
Geological models are mainly obtained via interpolation of simulations using geostatistical algorithms, and the simulation results are highly uncertain. In this paper, several factors that have great influences on model results are analyzed. Through an analysis of the sensitive uncertain factors, it is found that the uncertainty of the lithofacies model has the greatest influence on the geological model, and the variogram has the second greatest influence. Therefore, ensuring the rationality of lithologic model can effectively reduce the uncertainty of the model. It is found that using seismic impedance as constraints can effectively improve the accuracy of the lithofacies model, and one can use the seismic impedance to obtain a reasonable variogram (effectively overcoming the shortage of well data), thus reducing the uncertainty of the model. Although the stochastic simulation technology used in geological modeling can yield many simulation results, only a limited number of models can be applied in practical work. In this paper, a probabilistic analysis method is proposed to optimize the model, which can provide a reference for business decision-making and risk assessment of oil and gas companies. Reserve uncertainty analysis in the exploration stage can determine the most probable reserve of the reservoir through the probabilistic characteristics of the reserve so as to determine the next exploration target. In the development stage, probabilistic analyses of the porosity, remaining oil saturation and other parameters related to oil field production can maximize the development of remaining oil. The idea of model optimization based on sensitivity analysis of model uncertainties proposed in this paper can effectively reduce the uncertainty of the model, improve the accuracy of the geological model and meet the needs of different research stages and levels.
暂无评论