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关键词： Computer science  

摘要： The continually increasing size of data implies the need for better computing techniques. Modern computers are parallel architectures containing several processors. However, writing parallel programs is not an easy task. Some of the algorithms designed for sequential data structure can be parallelized using the skeletal parallelism approach. Algorithmic skeletons are patterns of parallel algorithms, often realized as high-order functions implemented in parallel, manipulating distributed data structures. This thesis presents first the Bird-Meertens Formalism, used as a foundation for parallel programming. Secondly, we present the design of PySke, a library of skeletons implementation in Python. To ensure correctness, some of these skeletons are formalized and proved correct in the proof assistant Coq. Correct parallel examples are written with Coq and extracted to be run with BSML, a functional parallel programming implementation of the bulk synchronous parallel model.

关键词： 车载激光点云   道路提取   法向量   区域生长   特征图像   Otsu  

摘要： 车载激光扫描系统能够快速获取目标表面三维坐标和反射强度等信息,并且具有实时性、高精度、高密度、非接触式以及自动化等特点,为道路信息的快速获取与实时更新提供了新的途径。但车载激光扫描系统获取的原始激光点云数据量大、杂乱无序、空间分布不均匀、包含的目标丰富多样。同时,道路环境场景复杂、道路形状多变,道路边界与路面上的交通标线等特征在原始点云中不够突出,且容易受到遮挡导致道路点云局部存在缺失,这些因素都给道路信息的自动提取造成了很大的困难。因此,如何准确、高效、完整地从大范围复杂环境下的车载激光点云中提取道路及其标线等特征信息,在当下具有十分重要的研究价值。本文的主要研究内容如下:(1)针对车载激光点云杂乱无序且存在噪声点与冗余数据的问题,总结与探讨了车载激光点云数据的常用预处理方法,主要包括点云空间索引建立、原始点云去噪和点云精简。(2)结合结构化道路点云法向量分布特征,提出了一种依据法向量相似度的路面点云提取方法。首先使用布料模拟算法对原始点云进行非地面点滤波,然后分别基于主成分分析法与曲面拟合法计算出各激光脚点的法向量与曲率值,最后依据点云法向量相似度作为约束条件,采用改进的区域生长分割算法提取出路面点云。(3)研究并改进了基于强度特征图像的道路标线点云提取方法。首先将路面点云投影转换成点云强度特征图像,并基于边缘检测与连通分析的方法得到道路标线位置,然后通过投影反变换从路面点云中初步得到道路标线点云,最后引入Otsu法进行点云强度滤波剔除路面噪声点,实现对道路标线的精确提取。(4)设计开发了具有点云显示、点云预处理、道路信息提取等功能的软件,并选取不同环境下的多组车载点云数据对本文提出的道路及标线提取方法进行了实验验证,对实验结果进行了分析与评价。

关键词： Computer science  

摘要： ADTools and TestGen are tools to simplify testing Data Structures assignments by automatically creating JUnit tests given test case specifications. However, instructors must still develop test case specifications for these assignments - a time intensive task. The purpose of this thesis is to automatically generate test cases to further reduce the instructor’s workload. This research developed a tool, CaseGen, that generates test cases by instantiating a correct implementation of an assignment, calling an assignment method on that instance, and recording the result and state of the instance after the call. Since these results are generated by a correct implementation, the resulting test case is correct. An evaluation of CaseGen showed that it was able to successfully generate test cases, thus eliminating a step in the ADTools test creation process.

关键词： 数据结构   经典算法   策略探究  

摘要： 数据结构、经典算法较难掌握,很多学生即便充分掌握了,在实践应用、自主创新等领域也往往很难取得较好的效果,需要教师改进课堂教学策略,调动学生学习动力、思索能力,引导学生多实践,为学生打造更好的学习环境。本文介于此,首先探究数据结构中经典算法教学活动中存在的不足,之后就如何有效改进进行策略探究。

关键词： 品牌营销   大数据   服务模型  

摘要： 本文介绍了一种利用农产品形成全流程数据,为农产品品质提供数据背书,进而为网络电商平台农产品品牌营销策略提供数据服务的方法,提出了数据服务平台结构与作用机理,给出了数据全集模型、数据全景模型、数据仓库模型、数据服务指针模型、品牌保护数据模型的结构与要素.本研究成果,为智慧农业大数据交易奠定了基础,其基于数据服务的平台化运营实现,特别适合农产品优势区区域品牌塑造、传播、提升与保护场景.

关键词： 应用性本科   数据结构   教学过程  

摘要： 该文主要针对应用型本科计算机专业的学生特点和数据结构课程的特点,通过有针对性的教学过程的把控,来提高数据结构课程的教学质量。

关键词： 应用型本科   数据结构   教学模式  

摘要： 该文主要探讨应用型本科《数据结构》课程的教学模式。提出要以适应就业市场为目标、以培养学生实践应用能力为主线来设计教学内容和培养方案。

摘要： The Bayesian parametric and semiparametric approaches are compared to recover the polynomial and nonpolynomial relationships among latent factors in the structural equation model (SEM). In earlier studies, the semiparametric approach has been demonstrated to be a more advanced approach to estimate the nonnormally distributed densities. However, its performance in recovering nonlinearity among factors has not been widely studied. The objectives of this dissertation are (1) to compare the recovery performances between the parametric and semiparametric approaches in capturing the polynomial and nonpolynomial relationships among latent factors in the structural model and (2) to investigate the recovery performance of the semiparametric approach in capturing the nonpolynomial relationships when the polynomial function is misspecified. The Bayesian semiparametric approach is applied using the truncated Dirichlet process with a stick-breaking prior to track the nonlinearity under different combinations of nonlinear functions (e. g., exponential, logarithmic, and sine) in the simulation study. Several important results were revealed. First, in study 1, both the parametric and semiparametric approaches achieved good convergence rates under the exponential and sine conditions. The polynomial conditions had greater difficulty in convergence due to the quadratic and interaction effects. Second, regarding the nonlinearity recoveries, the parametric approach performed similarly to the semiparametric approach at large truncation levels (200) in recovering the polynomial nonlinearity. The semiparametric approach had better recovery of nonpolynomial nonlinearity than the parametric approach. Third, in study 2, the semiparametric approach had a fairly good convergence rate at truncation level 5 under the exponential and sine conditions. Fourth, the semiparametric approach barely recovered the nonpolynomial nonlinearity with a misspecified polynomial function. A large truncation level