基于乘员伤害分析的路侧行道树事故严重度评价

为了定量评估公路路侧行道树事故严重度,有针对性地提出安全改善措施,以减少车辆与路侧行道树碰撞的事故损失,分别引入加速度严重性指数(Acceleration Severity Index,ASI)、头部损伤判据(Head Injury Criteria,HIC)和胸部合成加速度(Chest Resultant Accel...     

基于深度相机的船舶小构件打磨装置视觉识别算法设计

基于深度相机,针对船舶小构件智能打磨装置的视觉识别系统进行算法模块设计,确定视觉识别系统的模块框架与模块功能,并基于OpenCV库与PCL库,利用C++程序语言对模块功能进行算法实现。同时搭建算法试验平台,对模块算法进行验证,完成包括相机位姿估计与坐标变换、工件点云分割、工件质心提取、工件边缘提取在内的算法功能实现,为船舶小构件智能打磨装备提供准确全面的视觉数据,保证智能打磨装备的上料及打磨作业顺利执行。     

航空货运客户细分与客户价值分析方法

为了航空货运企业保留和争取有价值客户,根据航空货运主要客户是货运代理的特点,采用价值与忠诚度2个维度,将航空货运客户细分为8类,提出了对8类货运代理客户的相关营销策略;在现有客户价值计算公式中加入了航班载运率的影响项,使之适合于航空货运业,为航空货运客户细分提供依据。计算结果表明：考虑和不考虑航班载运率的影响使客户价值相差近1／3,因此引进航班载运率的影响可更加正确地计算客户价值和正确地划分客户类型。     

基于潜在类别模型的高铁旅客市场细分

对高速铁路旅客市场进行细分是应用收益管理理论的重要环节.基于京沪高铁的客票数据,选取年龄、性别、出行日期、出行距离、购票方式和提前购票时间6类外显变量作为分类指标,采用潜在类别模型进行高速铁路旅客市场的细分.首先将外显变量概率参数化后代入模型进行建模并利用Mplus软件进行模型求解,模型拟合的AIC和BIC等指标表明,当潜在类别为3类时模型具有较好的效果.然后根据模型参数估计结果对所有数据进行潜在聚类分析,分类正确率达到93%左右,表明分类结果合理,3种类别的旅客在提前购票时间、出行距离等方面具有明显的差异.潜在类别模型的引入可以为我国高速铁路收益管理理论研究和实践应用提供参考借鉴.     

High speed rail passenger segmentation and ticketing channel preference

A multi-channel strategy for the purposes of marketing and ticketing has been widely employed in various fields, including the transportation industry, yet few transportation studies have investigated ticket channel-related issues. This study thus adopts Taiwan High Speed Rail (THSR) as a case study to identify passengers’ perceptions regarding key factors that affect the channel preference through which they receive their services, particularly across a four-stage ticket purchasing process, including information enquiry, booking, payment, and ticket pick-up. To investigate these key factors, we base the framework of our research model upon customers’ perceived value perspective, adopting a multinomial logit model to examine the influence of channel attributes on HSR passengers’ preferences. The relationship among the decisions made by these passengers at each ticket purchasing stage is also examined. The findings of our study demonstrate that perceived risk, perceived benefit, and perceived ease of use are critical factors influencing passengers’ channel preference throughout the ticket-purchasing process. Perceptual differences are proven to exist due to various demographic factors and trip characteristics. The conclusions of this study have implications for THSR management to design appropriate ticketing channel services for certain types of passengers and can also be generally applied to multiple distribution channels in conventional railway system and intercity bus services.     

Segmentation of paratransit users based on service quality and travel behaviour in Bandung,Indonesia

Using a data-set collected among paratransit users in Bandung, Indonesia, this paper explores the impacts of paratransit users' negative experiences and dissatisfactions with their paratransit usage pattern. Segmentation and ordered probit analyses are used to examine the impacts of users' opinions on service quality on their trip-making behaviour. The results indicate that users are divided into six segments – namely, the unlucky, the young user, the experienced, the adapter, the infrequent user and the captive. The results further indicate that paratransit users, especially women, perceive negative experiences related to on-time performance (departure and arrival time) and security issues related to vehicles. Despite these dissatisfactions and negative experiences, they are still likely to use paratransit as part of their daily life. Two paratransit market segments (the adapter and the captive) are also likely to result in more trips using paratransit. The study offers several strategies and recommendations that can improve the current paratransit system so that it can better serve local needs.     

Segmentation of complex objects＇ sonar images using parameter-fixed MRF model

The effective method of the recognition of underwater complex objects in sonar image is to segment sonar image into target, shadow and sea-bottom reverberation regions and then extract the edge of the object. Because of the time-varying and space-varying characters of underwater acoustics environment, the sonar images have poor quality and serious speckle noise, so traditional image segmentation is unable to achieve precise segmentation. In the paper, the image segmentation process based on MRF （Markov random field） model is studied, and a practical method of estimating model parameters is proposed. Through analyzing the impact of chosen model parameters, a sonar imagery segmentation algorithm based on fixed parameters＇ MRF model is proposed. Both of the segmentation effect and the low computing load are gained. By applying the algorithm to the synthesized texture image and actual side-scan sonar image, the algorithm can be achieved with precise segmentation result.     

合成孔径雷达图像船舶自动检测新方法

针对传统SAR图像船舶自动检测方法在检测近岸目标时存在的普适性不强、计算量大、自动识别差的缺陷,提出了一种新的迭代阈值分割算法,通过消除噪声、分离目标检测出船舶目标,对比验证该方法能自动、快速、准确地检测近岸船舶目标。     

基于云模糊理论的图像纹理分割

为了处理图像纹理的模糊性和随机性,基于云模糊理论提出了纹理特征矢量云模型,并成功地应用于纹理图像分割.该方法在对纹理统计描述符模糊化处理后,逆向生成纹理特征矢量云.矢量云模型的数字特征能够很好地表达纹理的模糊性和随机性,据此通过云距离计算及纹理特征矢量云生长,完成对图像纹理的分割.实验结果表明,该方法较经典的ISODATA算法和K-means簇算法的分割精度高,并且迭代收敛速度快.