Asian Journal of Applied Science and Engineering

17-26

Authors: Áurea Sousa, Helena Bacelar-Nicolau, Fernando C. Nicolau, Osvaldo Silva

Symbolic Data Analysis can be defined as the extension of standard data analysis to more complex data tables. We illustrate the application of the Ascendant Hierarchical Cluster Analysis (AHCA) to a symbolic data set (with a known structure) in the field of the automobile industry (car data set), in which objects are described by variables whose values are intervals of the real data set (interval variables). The AHCA of thirty-three car models, described by eight interval variables (with different scales of measure), was based on the standardized weighted generalized affinity coefficient, by the method of Wald and Wolfowitz. We applied three probabilistic aggregation criteria in the scope of the VL methodology (V for Validity, L for Linkage). Moreover, we compare the achieved results with those obtained by other authors, and with a priori partition into four clusters defined by the category (Utilitarian, Berlina, Sporting and Luxury) to which the car belong. We used the global statistics of levels (STAT) to evaluate the obtained partitions.

38-47

Authors: Ajay Pandey, R. K. Mandloi

Liquefied petroleum gas (hereafter LPG), with an Octane Number of ~105, was looked upon and used as a viable vehicle - fuel option as early as 1912. However, its usage gained significant momentum with the advent of dual – fuel technology in the mid 1950s. This technology made it possible for LPG to be used in parallel with another fuel – Gasoline or Diesel. Though the LPG fuel system has become far more sophisticated while moving from 1st generation of technology development to the 5th one, most passenger car engines running on LPG are still not specially designed to operate on LPG. It is a very common practice in many developing countries, including India, to use retrofitted gasoline engines that operate on a dual – fuel mode: LPG and petrol. The extreme temperature conditions in LPG - run retrofitted gasoline engines result in considerable changes in the microstructure and wear growth patterns for both inlet and exhaust valves. This investigation focused on analysis of valve wear using a Pin – on – Disc (POD) wear tester. The characterization of wear was done by wear rate, analyses of worn surfaces, wear debris structure and sub – surfaces. The precipitation characteristics and behavior of secondary particles like carbides, oxides, silicates, etc., was also studied. The microstructure analysis and quantitative metallography of inlet and exhaust valve specimens was carried out by employing Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) techniques. The images thus obtained were utilized for microstructural characterization of the valve specimens. The surface morphology of the valve material was studied and AFM measurements were used for quantitative characterization of the structure as also to gain useful information about crystallographic orientation of individual grains, the formation of cracks, identification of potential crack initiation and fracture sites, etc. A comparative evaluation of microstructure of worn - out valves with new valves was also carried out.

62-68

Authors: Taposh Kumar Das

In this article we adopted the Mathematical model of solution of the Boltz-mann Transport equation (BTE) for photons. For the dose calculation of radiotherapy for cancer treatment we need the number of electrons which we get from the Boltzmann Transport equation for electrons. To solve this BTE for electrons we need the number of photons which we get by solving the Boltzmann Transport equation for photons.

79-81

Authors: Bahare Hajirostamlo, Narges Mirsaeedghazi, Mostafa Arefnia, Mohammad Ali Shariati, Esmail Alimohammadi Fard

Increasing of agriculture products is of importance so that research and development in this branch considers as one of the most important infrastructure which develops production growth. Agriculture provides new and improved findings regarding inputs and production methods hence R&D efficiency increases and leads to potential creation in increasing of agriculture products and reduces pressure on natural resources. In most developing countries agriculture products has increased per farmers which exhibits the efficiency of novel technology application thus basic practicing of R&D in the field of agriculture is really important.