基于电功率的HEV动力电池能量的监控方法

针对目前用于混合动力电动汽车动力电池能量管理的荷电状态法存在的“定义与结果难相一致”的问题,针对基于电功率的混合动力汽车动力电池能量的动态监控方法,建立了相应的数学模型,利用计算机仿真分析和实验来验证该方法的可行性和实用性。     

1+X证书制度在汽车专业领域试点案例

文章针对1+X证书制度在高职汽车专业领域在人才培养模式创新、课证融通、推进“三教改革”、实训室和考核站点建设介绍了自己的实践经验和取得的阶段性成果,对高职汽车专业领域1+X试点具有一定借鉴意义。     

铁含量对AlSi10Mg(Cu)合金断屑性能影响的研究

为改善AlSi10Mg(Cu)五阀缸盖毛坯的切削加工性能,对合金中的Fe含量进行了分析、试验研究。试验结果表明,铁含量在0.45%～0.55%时,AlSi10Mg(Cu)五阀缸盖毛坯的综合性能和加工性能最为适宜;在保证合金成分要求的前提下,应尽可能地提高铁元素的含量,以提高合金的加工性能。     

A New Arithmetic Coding System Combining Source Channel Coding and MAP Decoding

A new arithmetic coding system combining source channel coding and maximum a posteriori decoding were proposed. It combines source coding and error correction tasks into one unified process by introducing an adaptive forbidden symbol. The proposed system achieves fixed length code words by adaptively adjusting the probability of the forbidden symbol and adding tail digits of variable length. The corresponding improved MAP decoding metric was derived. The proposed system can improve the performance. Simulations were performed on AWGN channels with various noise levels by using both hard and soft decision with BPSK modulation.The results show its performance is slightly better than that of our adaptive arithmetic error correcting coding system using a forbidden symbol.     

Nonlinear Statistical Process Monitoring Based on Control Charts with Memory Effect and Kernel Independent Component Analysis

A novel nonlinear combination process monitoring method was proposed based on techniques with memory effect (multivariate exponentially weighted moving average (MEWMA)) and kernel independent component analysis (KICA). The method was developed for dealing with nonlinear issues and detecting small or moderate drifts in one or more process variables with autocorrelation. MEWMA charts use additional information from the past history of the process for keeping the memory effect of the process behavior trend. KICA is a recently developed statistical technique for revealing hidden, nonlinear statistically independent factors that underlie sets of measurements and it is a two-phase algorithm: whitened kernel principal component analysis (KPCA) plus independent component analysis (ICA). The application to the fluid catalytic cracking unit (FCCU) simulated process indicates that the proposed combined method based on MEWMA and KICA can effectively capture the nonlinear relationship and detect small drifts in process variables. Its performance significantly outperforms monitoring method based on ICA, MEWMA-ICA and KICA, especially for long-term performance deterioration.     

Efficient Accurate Context-Sensitive Anomaly Detection

For program behavior-based anomaly detection, the only way to ensure accurate monitoring is to construct an efficient and precise program behavior model. A new program behavior-based anomaly detection model, called combined pushdown automaton （CPDA） model was proposed, which is based on static binary executable analysis. The CPDA model incorporates the optimized call stack walk and code instrumentation technique to gain complete context information. Thereby the proposed method can detect more attacks, while retaining good performance.     

沥青混合料抗拉性能试验研究及力学特性分析

沥青混合料的抗拉性能是表征其低温与疲劳性能的重要指标。本文针对半圆弯曲试验(SCB)与劈裂试验(IDT)建立三维非线性有限元模型,对两种试验方法的受力特点与破坏模式进行数值模拟,并利用室内试验进行验证。结果表明:两试验中试件的力学响应规律明显不同;半圆弯曲试验试件主要承受拉应力,劈裂试验试件内出现压缩、拉伸、剪切多种受力模式交织现象;非轴对称受力时,劈裂试件的应力响应更为复杂,不能充分体现间接拉伸的目的。相比较而言,半圆弯曲试验更能模拟沥青混凝土路面的层底受拉状况。     

连续小箱梁桥地震响应分析

以太原市南沙河高架桥工程为例,简要介绍了连续小箱梁桥抗震分析在实际工程设计中的应用,以供今后类似工程计算参考。     

The environmental impact of distribution to retail channels: A case study on packaged beverages

This study aims to quantify the environmental impact of two retail distribution networks and offer consumers a channel that is more beneficial to the environment. The environmental impact of replenishing the packaged beverages sold in convenience stores (CVSs) and hypermarkets is assessed using the streamlined life-cycle assessment (LCA) approach. In this study, the life-cycle impact assessment (LCIA) for packaged beverages up to the point of sale illustrates the distribution-level environmental impacts of truck transportation. The matched-pair t-test shows that the environmental impacts of transporting 1800 cartons of 24-pack/10 oz. beverages to be sold in Carrefour and 7-11 stores is different at a significance level of 0.1. The transport-focused LCA is used to improve the understanding and compare the environmental characteristics of the two distribution and retail systems. This study constitutes a vehicle for communicating to both internal and external stakeholders the environmental profiles of distributing the same product sold through two retail channels.     

Forecasting short-term subway passenger flow under special events scenarios using multiscale radial basis function networks

Reliable and accurate short-term subway passenger flow prediction is important for passengers, transit operators, and public agencies. Traditional studies focus on regular demand forecasting and have inherent disadvantages in predicting passenger flows under special events scenarios. These special events may have a disruptive impact on public transportation systems, and should thus be given more attention for proactive management and timely information dissemination. This study proposes a novel multiscale radial basis function (MSRBF) network for forecasting the irregular fluctuation of subway passenger flows. This model is simplified using a matching pursuit orthogonal least squares algorithm through the selection of significant model terms to produce a parsimonious MSRBF model. Combined with transit smart card data, this approach not only exhibits superior predictive performance over prevailing computational intelligence methods for non-regular demand forecasting at least 30 min prior, but also leverages network knowledge to enhance prediction capability and pinpoint vulnerable subway stations for crowd control measures. Three empirical studies with special events in Beijing demonstrate that the proposed algorithm can effectively predict the emergence of passenger flow bursts.