r-循环矩阵求逆与相乘的一种算法

不通过特征值的计算，直接给出了n阶γ-循环矩阵求逆与相乘的一种算法．推广了现有的结果。若用FFT计算，其计算复杂性为O(nlog2n)。     

Planning readings: a comparative exploration of basic algorithms

Conventional introduction to computer science presents individual algorithmic paradigms in the context of specific, prototypical problems. To complement this algorithm-centric instruction, this study additionally advocates problem-centric instruction. I present an original problem drawn from students' life that is simply stated but provides rich discussions of different approaches. It lends itself to a wide range of didactic means from individual or group study to whole class discussions under various levels of guidance by the instructor. I suggest diverse algorithms for solving it, covering some of the most important algorithmic paradigms. Some of these algorithms (greedy, divide-and-conquer) do not produce optimal solutions but may nevertheless have their merits in practice. The best algorithms are illustrative instances of some of the most sophisticated paradigms introduced in undergraduate curricula (dynamic programming, graphs).     

The relationship between bowling action classification and three-dimensional lower trunk motion in fast bowlers in cricket

Abstract

Lower back injuries, specifically lumbar stress fractures, account for the most lost playing time in professional cricket. The aims of this study were to quantify the proportion of lower trunk motion used during the delivery stride of fast bowling and to examine the relationship between the current fast bowling action classification system and potentially injurious kinematics of the lower trunk. Three-dimensional kinematic data were collected from 50 male professional fast bowlers during a standing active range of motion trial and three fast bowling trials. A high percentage of the fast bowlers used a mixed bowling action attributable to having shoulder counter-rotation greater than 30°. The greatest proportion of lower trunk extension (26%), contralateral side-flexion (129%), and ipsilateral rotation (79%) was used during the front foot contact phase of the fast bowling delivery stride. There was no significant difference in the proportions of available lower trunk extension, contralateral side-flexion, and ipsilateral rotation range of motion used during fast bowling by mixed and non-mixed action bowlers. Motion of the lower trunk, particularly side-flexion, during front foot contact, in addition to variables previously known to be related to back injury (e.g. shoulder counter-rotation), should be examined in future cross-sectional and prospective studies examining the fast bowling action and low back injury.     

The effect of coaching intervention on elite fast bowling technique over a two year period

Fast bowling in cricket is an activity that is well recognised as having high injury prevalence and there has been debate regarding the most effective fast bowling technique. The aim of this study was to determine whether two-year coaching interventions conducted in a group of elite young fast bowlers resulted in fast bowling technique alteration. Selected kinematics of the bowling action of 14 elite young fast bowlers were measured using an 18 camera Vicon Motion Analysis system before and after two-year coaching interventions that addressed specific elements of fast bowling technique. Mann-Whitney tests were used to determine whether any changes in kinematic variables occurred pre- and post-intervention between those who had the coaching interventions and those who didn't. The coaching interventions, when applied, resulted in a more side-on shoulder alignment at back foot contact (BFC) (p = 0.002) and decreased shoulder counter-rotation (p = 0.001) however, there was no difference in the degree of change in back and front knee flexion angles or lower trunk side-flexion. This study has clearly shown that specific aspects of fast bowling technique are changeable over a two-year period in elite level fast bowlers and this may be attributed to coaching intervention.     

Quantification of the manifestations of fatigue during treadmill running

Abstract

During whole-body exercise, fatigue is difficult to quantify; however, changes to mechanical, physiological and psychological systems during exercise are associated with the development of fatigue. To quantify fatigue, one must therefore assess changes occurring in these variables. The purpose of this study was to demonstrate a method to assign weightings to selected variables and to combine them into a single value quantifying changes occurring during exercise. Twelve female recreational runners performed one hour of treadmill running, during which heart rate, respiration rate, stride frequency and six selected psychological variables were collected at defined intervals throughout the run. Data were normalised and a principle component analysis was performed. The resulting first eigenvector was termed the “contribution vector” and indicated the weighting of each variable towards the global exercise-induced changes in the body. The projection of data onto the contribution vector resulted in a value described as the “fatigue index”. An assessment of the generalisation of the method to new data was performed using a leave-one-out cross-validation procedure and indicated that the index is accurate to within 3.01% of the maximum index value measured. The method developed here has the advantage over current methods due to its multifactorial, causal and customisable nature.     

网络舆情突发异常识别及关键算法研究

本研究采用实验法,利用三个可衡量关注度的变量设计规则算法,以每天和每小时作为检测周期,对逸仙时空BBS中的主题帖进行筛选并预警,达到实时监控网络舆情突发异常的效果。     

快速解决高校计算机联合考试管理难题

文章阐述了高校计算机联合考试管理中存在的各种问题,并针对问题介绍了一种快速有效、安全可靠的解决方案.实践证明,该方案能够满足高校计算机联合考试的需要,希望能给各高校在计算机联合考试管理工作中提供一些帮助.     

基于差别矩阵的启发式粗糙集属性约简算法研究

提出基于差别矩阵的改进启发式粗糙集属性约简算法,降低算法的时间复杂度及空间复杂度。针对相关实际案例数据。以学生考试成绩为分析对象,应用改进后的约简算法,设计相应的评价指标,分析学生成绩的潜在影响因素,再次验证了本文提出算法的可行性和高效性。     

g-循环矩阵相乘的一种快速算法

利用快速离散傅立叶变换（DFT）给出了n阶g-循环矩阵相乘的快速算法,它的时间复杂性是O（nlog2n）。     

正确分类标引 避免错误加“0”——兼与于新国先生商榷

于新国先生所举的加“0”例证存在着许多错误,其错误不在加“0”技术上,而在如何分 类上,应避免产生这样的错误。