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Open access

Yan-Yun Yu, Yan Lin and Kai Li


A new method for ship Inner Shell optimization, which is called Parametric Inner Shell Optimization Method (PISOM), is presented in this paper in order to improve both hull performance and design efficiency of transport ship. The foundation of PISOM is the parametric Inner Shell Plate (ISP) model, which is a fully-associative model driven by dimensions. A method to create parametric ISP model is proposed, including geometric primitives, geometric constraints, geometric constraint solving etc. The standard optimization procedure of ship ISP optimization based on parametric ISP model is put forward, and an efficient optimization approach for typical transport ship is developed based on this procedure. This approach takes the section area of ISP and the other dominant parameters as variables, while all the design requirements such as propeller immersion, fore bottom wave slap, bridge visibility, longitudinal strength etc, are made constraints. The optimization objective is maximum volume of cargo oil tanker/cargo hold, and the genetic algorithm is used to solve this optimization model. This method is applied to the optimization of a product oil tanker and a bulk carrier, and it is proved to be effective, highly efficient, and engineering practical.

Open access

Junjie Zhao, Xiquan Liang and Li Yan

Several Higher Differentiation Formulas of Special Functions

In this paper, we proved some basic properties of higher differentiation, and higher differentiation formulas of special functions [4].

MML identifier: HFDIFF 1, version: 7.8.10 4.100.1011

Open access

Bo Li, Yan Zhang and Artur Korniłowicz

Simple Continued Fractions and Their Convergents

The article introduces simple continued fractions. They are defined as an infinite sequence of integers. The characterization of rational numbers in terms of simple continued fractions is shown. We also give definitions of convergents of continued fractions, and several important properties of simple continued fractions and their convergents.

Open access

Bo Li, Yan Zhang and Xiquan Liang

Difference and Difference Quotient

In this article, we give the definitions of forward difference, backward difference, central difference and difference quotient, and some of their important properties.

Open access

Bo Li, Yan Zhang and Xiquan Liang

Several Differentiation Formulas of Special Functions. Part III

In this article, we give several differentiation formulas of special and composite functions including trigonometric function, inverse trigonometric function, polynomial function and logarithmic function.

Open access

Li Yan, Xiquan Liang and Junjie Zhao

Gauss Lemma and Law of Quadratic Reciprocity

In this paper, we defined the quadratic residue and proved its fundamental properties on the base of some useful theorems. Then we defined the Legendre symbol and proved its useful theorems [14], [12]. Finally, Gauss Lemma and Law of Quadratic Reciprocity are proven.

MML identifier: INT 5, version: 7.8.05 4.89.993

Open access

Xiquan Liang, Li Yan and Junjie Zhao

Linear Congruence Relation and Complete Residue Systems

In this paper, we defined the congruence relation and proved its fundamental properties on the base of some useful theorems. Then we proved the existence of solution and the number of incongruent solution to a linear congruence and the linear congruent equation class, in particular, we proved the Chinese Remainder Theorem. Finally, we defined the complete residue system and proved its fundamental properties.

Open access

Ping Du, Yan-Qiu Chen, Chang-Tian Li and Yu Li

Application of Random Amplified Polymorphic DNA Analysis in Identifying Phellinus Igniarius Strains

Described in this paper, the random amplified polymorphic DNA (RAPD) analysis was conducted with 20 random primers in various strains of Phellinus igniarius collected from different localities. The results showed that 17 of the 20 random primers were polymorphic ones. The DNA bands derived from each primer amplifying in tested strains ranged from 10 to 33. The size of the amplified DNA fragments ranged from 250 to 2000 base pairs. Of each test primer, a wide variation in banding profiles was observed among the 7 strains of P. igniarius. A total of 377 band positions were scored for all of the tested strains, which differed significantly among the bands from different primers. UPGMA cluster analysis subdivided the tested strains into two groups, which was helpful to find out the difference among the tested strains and to distinguish them directly.