Papers by Keyword: Regularity

Abstract: To reveal the fault occurrence regularity during actual operation of transport vehicle, based on reliability, maintainability and optimization theory and method, and by the the technical means such as large sample testing, mathematical modeling and multivariate data analysis, after several years of follow-up research, we found that the occurrence of vehicle failts obey Weibull distribution, and given specific failt rate functions. Accordingly, we established a corresponding optimal mathematical model of vehicle maintenance cycle, and got the optimal solution of the model. The results of special organized verify test shows that the model solution is accurate and reliable. If transport vehicles perform the optimal vehicle maintenance cycle, the lowest unit mileage cost of vehicle detection, diagnosis and maintenance would be got.

Abstract: Before the foundation of St. Petersburg in 1703, there had for centuries existed a developed system of rural settlements located on the flat valleys and areas along the Neva River and around the Ladoga Lake. Since 1703, under the leadership of Peter I and his followers, there was carried out a systematic creation of the capital St. Petersburg agglomeration (St. Petersburg and residential suburbs around it), which was done on the basis of purposefully introduced principles of regularity and harmony of architectural ensembles, by the methods of large-scale reconstruction of the previous irregular system of the population settlement distribution. The scale of this new agglomeration had no analogues in world town-planning practice of the XVIII century and united spaces with the total area over 200 square kilometers, which extended from the town of Sestroretsk in the North to the town of Novgorod in the South, from the town of Narva in the West to the Volkhov River in the East. The regularity and multi-center character of the central city formed according to the pattern of a mesh and cellular structure (with the dimensions of 10 km by 15 km), was supplemented with a regularity of suburban ensembles` layout and multi-kilometer rectilinear axes – roads connecting them. Some of the roads had the length of several hundred km (such as the road from Moscow to St. Petersburg built in 1706-1718, that was as long as nearly 700 km). Huge suburban forest-park and natural-landscape spaces between palace and park ensembles were united as star-patterned compositions. This historically created agglomeration is deservedly included in the List of Objects of the World Heritage, but so far it has not received a unambiguous understanding of its uniqueness and needs a considerable effort in searching new individual ways of the historical heritage preservation. On the basis of the archive records, the contribution presents an analysis of regularities of consecutive and purposeful transformation of the historical rural settlements system existing up to the foundation of St. Petersburg into the capital St. Petersburg agglomeration of regular type.

Abstract: In this article, 133 massive colliery blasting accidents were statistically analyzed in China after 2000, mainly from two aspects of the accident number and death number, three aspects such as the type of accidents, the time rule of accidents, and provincial were analyzed statistically; 72 massive colliery blasting accidents caused by blasters were analyzed statistically with regard to the unsafe act of blasters. The statistical results show that the accident and death number presents a downward opening parabolic trajectory by year; The time of the accident is more concentrated, and the fate casualties happened frequently around March, July, November and December, February is the least; Coal mine gas accident is the main type of blasting accidents, and the coal dust explosion accident causes most deaths averagely; The past statistical method seriously neglected the seriousness of blasting accidents; The coal mine underwent massive colliery blasting accidents distribute widely, but six provinces (Guizhou, Shanxi, Heilongjiang, Sichuan, Henan, Hunan, Liaoning) are the key places of blasting accidents; There are 22 species of unsafe act to blasters, the most common unsafe act is no working face environmental inspection, material and tools be used unsafely and improperly. Coal enterprises, government, and regulators should strengthen the prevention of the key time, accident style, region, and the common unsafe blasting act to the regularity of coal mine blasting accidents.

Abstract: The safe operation of canned motor in nuclear primary pump is very important for nuclear power station. Taken a 5500KW large canned motor of nuclear primary pump as an example, physical model of three dimensional fluid and temperature coupled field was established. The motor temperature distribution under nominal working condition was calculated by using finite volume method. By calculation, revealing the temperature distribution regularity of stator strands, rotor bars, stator core and rotor core, which have significant reference value to structure design of canned motor.

Abstract: Determining regularity and convexity of NURBS curves is necessary in computer aided geometric design. In this paper, the problems above are converted to the questions related to polynomials. Then based on properties of algebraic equations and isolation theorem of roots, a simple and practical method for determining those geometric properties of NURBS curves is put forward. Compared with traditional method it will save us much computation

Abstract: The paper gets the calculational method of check size in theory by discussing the effect factors of forming woven plaids. It realizes a calcuiation and design system of plaid by computer aided design. Meanwhile, by combining with the typical Tianzige and Jiugongge, the paper discusses the change regularity of check shaping parameters as a result of the change in check size and fabric density, and realizes a autogeneration system of the new check parameters.

Abstract: Regularity is one of important properties of curves in computer aided design. In this paper, we convert the problem of determining regularity of Bézier curves to that of detecting existence of zero points of polynomials. Based on the properties of algebraic equations and isolation theorem of roots, a simple and practical method is presented. Regularity of Bézier curves and number of singular points can be determined by easier computation.