AKH-NFIS: Adaptive Krill Herd Network Fuzzy Inference System for Mobile Robot Navigation

Wireless Personal Communications - Mobile robot navigation has been a current issue in the most recent two decades. Mobile robots are necessary to explore in obscure and dynamic situations. To...     

Mechanical and tribological properties of silicon carbide coating on Inconel alloy from liquid pre-ceramic precursor

Liquid polycarbosilane (LPCS) derived hard coatings of silicon carbide (SiC) were deposited on Inconel alloy at three different moderately high temperatures by chemical vapour deposition. The deposited films were characterized by X-ray diffractometry and Field emission scanning electron microscopy. Liquid PCS yielded a mixture of α-SiC and β-SiC during decomposition having uniform round-shaped particles of dimension around 200–300 nm without extensive cracking and few discrete shaped particles were also found to form at higher temperature (i.e. 1100 °C and 1200 °C) deposited films. The coated samples showed substantial increment in hardness and fracture toughness as compared to the uncoated sample. The fracture toughness (K_IC) values of the deposited films were in the range of 6.7–10.7 MPa(m)^1/2. The tribological properties and hardness of the films were also found to vary with deposition temperature. The scratch tracks of the films revealed that brittle failures occurred in all SiC coated substrates.     

A simulation‐based algorithm for optimal pricing policy under demand uncertainty

We propose a simulation‐based algorithm for computing the optimal pricing policy for a product under uncertain demand dynamics. We consider a parameterized stochastic differential equation (SDE) model for the uncertain demand dynamics of the product over the planning horizon. In particular, we consider a dynamic model that is an extension of the Bass model. The performance of our algorithm is compared to that of a myopic pricing policy and is shown to give better results. Two significant advantages with our algorithm are as follows: (a) it does not require information on the system model parameters if the SDE system state is known via either a simulation device or real data, and (b) as it works efficiently even for high‐dimensional parameters, it uses the efficient smoothed functional gradient estimator.     

Profit margin,process improvement and capacity decisions in global manufacturing

We study two strategies that a company may employ for competing in global markets: high profit margin; and investment in process improvements. The strategy of high profit margin is associated with aggressive investment in new plants worldwide; and the strategy of process improvements is associated with increasing the effective capacity of existing plants, reducing manufacturing cost and increasing the plant's life cycle. Such plant decisions are complicated by country-specific parameters, e.g. tariff rate, tax rate, transportation cost and economic growth rate, which may vary widely from one country to another. We construct a simulation model that uses non-linear relationships among decision variables to explore insights, e.g.: (i) global conditions that would be synergistic with each of the two strategies; (ii) level of investment that would be justified in newly industrialized countries, in relation to the industrially mature countries; and (iii) shifts in investment in time and their relationship to the competitive strategies.     

Spectral derivative feature coding for hyperspectral signature analysis

This paper presents a new approach to hyperspectral signature analysis, called spectral derivative feature coding (SDFC). It is derived from texture features used in texture classification to dictate gradient changes among adjacent bands in characterizing spectral variations so as to improve better spectral discrimination and classification. In order to evaluate its performance, two known binary coding methods, spectral analysis manager (SPAM) and spectral feature-based binary coding (SFBC) are used to conduct comparative analysis. Experimental results demonstrate that the proposed SDFC performs more effectively in capturing spectral characteristics than do SPAM and SFBC.     

Application of electromagnetic impact technique for welding copper-to-stainless steel sheets

The ability to manufacture a product using different metal combinations greatly increases flexibility in design and production. Joining of dissimilar metal combinations like Copper-to-Stainless Steel (Cu-to-SS) is, however, a challenging task owing to the large differences in physical and chemical properties. The application of electromagnetic (EM) impact technique is demonstrated for welding copper (Cu) to stainless steel (SS) sheets. The welding Cu-to-SS is accomplished by using Al drivers to accelerate Cu and SS work sheets. The tensile shear strength test and the metallographic studies are carried out for Cu-to-SS EM welds.     

Linearizer for pulse-shaping of received pulse in ultra-wideband radio systems

This paper presents a novel concept of pulse-shaping in an ultra-wide band radio system. Instead of attempting to design an antenna with flat group delay, the emphasis has been shifted to the signal processing aspect of pulse shaping. The received pulse which has broadened due to non-linear phase response of the propagating channel is shaped back closer to the ideal pulse using a linearizer. The block schematic of the linearizer is presented along with simulated results. Though only a Rayleigh first order pulse has been used for simulation purpose, the method can easily be generalized to incorporate other pulse shapes.     

Distribution of mineral species in different coal seams of Talcher coalfield and its transformation behavior at varying temperatures

International Journal of Coal Science & Technology - Mineral phase characterization and thorough understanding of its transformation behavior during combustion are imperative to know the...     

Discrete element approach for mine dump stability analysis

Mine overburden dumps have posed significant safety issues in the operations of various unit operations of open pit min-ing especially the external dumps. The external dumps are composed of a mixture of fragmented rocks and loose soil. Their charac-teristic is comparable to heavily discontinuous solid mass. The conventional approach of limit equilibrium methods provide safety factors for the slope but nothing about the stress-strain characteristics of the large dump mass. The designs of dump location and their respective geometry are integrated for the know-how of the stability characteristics of these dumps. The discrete element method uses a circular disk to represent the granular solid mass and their interactions are described by the Newton's third law of motion. The displacement is described by the sliding of the circular disk. This work is focused on the modeling efficiency of the discrete element methods to represent the behaviour of mine dump masses with the specified joint plane for the limit equilibrium method. The advantage of the work lies on the ease of information retrieval at any point at the dump mass concerning the stress and strain histories, displacement, failures etc. which when integrated produces a better understanding of the stability of the dump masses.