集装箱多式联运协调计划的分级优化

为更好地实现集装箱多式联运的综合效益,针对多式联运协调计划的复杂性,通过分析多式联运计划的层次,建立多式联运计划的分级优化概念模型;针对模型中核心内容的海上班轮运输计划和内陆集疏运计划,建立任务分配的优化模型;设计相应的遗传算法,对优化模型进行求解.仿真试验验证模型和算法的有效性.     

数控车床中的椭圆宏程序

对于数控专业的初学者学习数控编程,特别是宏程序的编程是比较困难.通过分析数控车床中的椭圆宏程序和论述坐标法,让初学者能够以此作为宏程序学习的一个入门,掌握各种不同曲线宏程序的编辑方法.     

探讨中高职教育协调发展中的几个核心问题

中高职衔接与职业技术教育协调发展有几个核心问题需要注意。我国中职教育和高职教育的发展和特点显示我国职业技术教育经过多年的摸索之后终于步入正轨,中高职衔接的时机已成熟。目前中高职衔接只是搭建职业技术教育立交桥的近期目标,中远期的目标是打造具有经济造血功能的职业一体化教育实体。     

Kinematic analysis of the backstroke start: differences between backstroke specialists and non-specialists

Abstract

The purpose of this study was to clarify factors to perform the hole-entry technique in the backstroke start. A total of 16 well-trained Japanese competitive swimmers were divided into two groups (backstroke specialists and non-specialists) to compare their backstroke start motions. Their backstroke motions were videotaped, and two-dimensional co-ordinates for the swimmers were obtained from the video images using direct linear transformation methods. A non-paired t-test and Mann–Whitney U-test were used to analyse the statistical difference of the kinematic variables between the groups. Backstroke specialists showed a significantly shorter 5 m time (P = 0.009, effect size = –1.54), a significantly higher position of the toe (P = 0.010, effect size = 1.47) at signal and of the hip at toe-off (P = 0.002, effect size = 1.94), a significantly larger hip joint angle at toe-off (P = 0.007, effect size = 1.60) and a significantly higher angular velocities of the hip joints (45–85%; P < 0.05) for the normalised time as compared to that of non-specialists. An earlier initiation of the extension and the maintenance of a higher extension speed at the hip joints were important factors in achieving an arched-back posture, which facilitated and water entrance with a small entry range.     

Development and Validation of a Method for Determining Tridimensional Angular Displacements with Special Applications to Ice Hockey Motions

Abstract

Tridimensional angular displacements of the skates were determined with a single cinecamera used in conjunction with two orthogonal rods attached to the rear part of the skater's boots. The method was based on the commutative law with the imposed restrictions that two of the angles were small in relation to the other one, and that a sequence of angular displacements was defined. This approach required the sole determinations of the planar coordinates of the three points delimiting the orthogonal rods. An experimental setup was designed to validate the method: the criterion angles were approximated with less than 2 degrees of error. Subsequently, the method was applied to a practical situation: the two-legged stop in ice hockey. The combination of this tridimensional method with instrumented strain gauge skates for the measurement of forces provides a new and powerful tool for performing kinetic analyses in tridimensional skating activities.     

互成角度的两平面镜成像问题的讨论

夹角为θ的平面镜M和N之间放置一物点P,由反射所成的虚像设为K个,这些像均分布在同一个圆周上,像的总数K=[(180°-α)/θ]+[(180°-β)/θ]。当180°/θ为整数时,K个虚像中有两个像重合,故只有K-1个虚像能被看到;当180°/θ不为整数时,K的值既取决于平面镜M和N之间的夹角,还与物点P所放位置有关。     

Periodic table of human civilization process

Abstract

In case of that human civilization was viewed as an integrated organism, the Periodic Table of the Civilizations (PTOC in short) has been formulated and recommended based on the development level and periodicity of core elements of human civilization. It divides the frontier process of the human civilization from the birth of humankind to the end of twenty-first century into 4 periods and 16 stages, and in which four periods include that of primitive culture, agricultural civilization, industrial civilization and knowledge civilization orderly, and each period includes four stages, that is, start, developing, maturing and transition stages sequentially. There are three approaches for the arrangements of the PTOC, that is, simple, vertical and horizontal tables. The big period of earth civilization refers to that from the primitive culture to the knowledge civilization, and then big period of space civilization will begin with the astronautic civilization. The first modernization witnesses the great changes and transformation from the traditional agricultural to the modern industrial civilization, and then second modernization from the modern industrial to the higher modern knowledge civilization. The periodic table, coordinate system and roadmap of human civilization and world modernization have been formulated to describe the relationship between them.     

科学发展观是与时俱进的马克思主义发展观

科学发展观是对马克思主义关于发展理论的继承与发展,是与时俱进的马克思主义发展观.这一发展观是以邓小平理论和“三个代表”重要思想为指导、从新世纪新阶段我国的发展全局出发而提出的重大战略思想,是我们党对社会主义现代化建设指导思想的新发展,标志着我们党执政理念的新飞跃.     

关于旋转体体积的研究

阐述了平面图形绕坐标轴旋转产生的旋转体体积与形心坐标之间的联系。在此基础上把它推广到绕任意直线旋转的情况。并得出求旋转体体积的一般，公式。