Papers by Keyword: Isomorphism

Abstract: Isomorphism identification is a difficult problem in kinematic chains. There is number of method given by many researchers to detect the isomorphism and inversion of kinematic chain but each has its own shortcomings. Purpose of this paper is to give an efficient and reliable method. An attempt has been made to provide satisfactory solution to detection of isomorphism by using hamming method. The method is implemented on sewing machine, break drum; straight line motion mechanisms have six links kinematic chain.

Abstract: The present work is focused on the graph theory which is used for structural analysis of kinematic chain and identification of degree of freedom. A method based on graph theory is proposed in this paper to solve structural problems by using a suitable example of fourteen links kinematic chain. Purpose of this paper is to give an easy and reliable method for structural analysis of fourteen links kinematic chain. Here, a simple incidence matrix is used to represent the kinematic chain. The proposed method is applied for determining the characteristic polynomial equation of fourteen links kinematic chain. An algebraic test based on graph theory is also used for identifying degree of freedom of kinematic chain whether it is total, partial or fractionated degree of freedom.

Abstract: Kinematic chains differ due to the structural differences between them. The location of links, joints and loops differ in each kinematic chain to make it unique. Two similar kinematic chains will produce similar motion properties and hence are avoided. The performance of these kinematic chains also depends on the individual topology, i.e. the placement of its entities. In the present work an attempt has been made to compare a family of kinematic chains based on its structural properties. The method is based on identifying the chains structural property by using its JOINT LOOP connectivity table. Nomenclature J - Number of joints, F - Degree of freedom of the chain, N - Number of links, L - Number of basic loops (independent loops plus one peripheral loop).

Abstract: As an indispensable tool in cryptosystem design and analysis, Boolean function has always been one of important issues. Isomorphism decision of Boolean function has wide applications. However, how to determine the isomorphism of Boolean functions is NP-hard problem. In this paper, an algorithm of determining Boolean function Isomorphism based on ROBDD is presented, which can effectively solve problem of Boolean functions Isomorphism decision.

Abstract: Several methods have been adopted by different researchers to test for isomorphism in Planetary Gear Trains (PGT) and out of these isomorphic PGTs, one PGT is selected at random. There is no definite basis for selecting a particular PGT out of the isomorphic graphics for further generation process. Structural aspects and rating of the PGTs are useful in selecting one such PGT for further generation. Symmetry in PGTs is one such aspect. PGTs with symmetry generate more possible higher level graphs than PGTs with no symmetry.

Abstract: 10 pieces of yellowish green peridot from Jilin province with fine and pure texture were selected to analyze the relationship between frequency drift in middle-infrared band and color appearance, through the replacement of Fe²⁺. The actual crystal chemical formula of the samples calculated by Oxygen atom method is: (Mg_1.84,Fe_0.19)_2.04[(Si_0.982,Al_0.001)_0.983O₄], so prove that it is chrysolite [1] and the replacement of Fe²⁺ and Mg²⁺ in the position M, which led to the yellowish green appearance. With the help of Fourier infrared spectrometer TENSOR27 and One Way ANOVA analysis study the infrared spectra of 10 samples and analyze the impact Fe2+ had on frequency drift, getting the Correlation coefficient r between Fe²⁺ and the wave-number near 1040cm^-1, 622cm^-1, 522cm^-1, and the value of r are -0.896,-0.884,-0.903, therefore, with Fe²⁺ increasing ,three reflection peaks drift to the lower frequency. Compare the reflectivity in the visible area (360nm ~ 750nm) tested by colorimeter Color i5 with the mafic peridot end of forsterite solid solution, finding that with the reflectance peaks drift to low frequency, reflection of blue and purple light decrease, blue and purple tone in peridot decreasing; reflection of the red and orange light increases, red and orange tone increasing. It is concluded that in the transformation of mafic Peridot end to chrysolite peridot end, reflection peaks in infrared band drift to lower frequency, causing the increase of red and orange tone, decrease of blue and purple tone in Peridot.

Abstract: As well known, graph theory is a powerful tool for mechanism design. The enumeration of planet gear trains can be converted the synthesis of graphs while a planetary gear train is converted to a graph. During the enumeration of graphs, the problem of isomorphism should be solved. This paper proposes a novel algorithm used to generate non-isomorphism graphs and thereby omits the part of isomorphism detection. The vertex characteristic is firstly defined in this paper that is the core of the enumeration algorithm. This paper also gives an example of the application for the algorithm.

Abstract: In order to study the phase of Fe and Ti in a beach placer , different methods such as the X-ray diffraction analysis, chemical analysis, scanning electron microscopic , electron probe microanalysis are used to study the characteristics of the beach placer . The research results show the major metallic mineral in the beach placer is titanic magnetite, EDS and energy spectrum map features of which indicate that the vast majority of titanic magnetite contain a certain amount of Ti , the two elements of Fe and Ti take on closely symbiosis and distribute more evenly in titanic magnetite. The Ti exists in the Magnetite lattice in form of isomorphism. The theoretical highest grade of Fe and Ti in the separated Magnetic concentrate are 66.02per cent and 4.86 per cent respectively. In addition, the beach placer contains a small quantity of Ilmenite which is hysterogenic and exists in the form of fine solid solution separation structure in the titanic magnetite

Abstract: The Green’s functions technique suitable for broken symmetry structure analysis was developed. With the help of this new technique the phonon subsystem was analysed in ultrathin films and in cylindrical nanotubes with finite height. The most interesting results of mentioned analyses are spatial dependence of thermodynamical characteristics, existence of phonon gap and extremely low specific heat and thermal conductivity at low temperatures. This promises wide application of films and finite nanotubes in technology. The same technique was applied to investigate electron subsystems in rectangular nanostructures of all dimensions as well as in simple and full nanotubes. The most interesting conclusion of these analyses is the presence of autoreduction effect being the consequence of nonisomorphic transition configuration – momentum space. This effect represents a qualitative difference between nano and macroscopic structures. The skin effect is present in all types of nanostructures except nano-parallelepiped where antiskin effect takes place. The latter is quite understandable, since in nano-parallelepiped nodes are on boundaries.