Pacific Science Review A: Natural Science and Engineering最新文献

A novel coupled-line-free wideband bandpass/bandstop filter configuration is designed and tested. The filter is based on a reentrant structure with unequal dielectric constants for the internal and external fillings. As a result, additional symmetrical transmission zeros are generated in the lower and upper stop bands of the bandpass filter; this leads to an elliptic function response and improvement of the pass band and selectivity. Similar conclusions are made about the bandstop filter in terms of the return loss. The general TEM circuit model, in terms of the two-port series connection, is presented for the proposed filters, and then, it is used to determine its electrical parameters. The experimental prototype was fabricated using conventional printed circuit board technology. The measured S-parameters show acceptable agreement with the analytical and full-wave simulations, showing promising potential for different applications.

In this paper, we propose a 4D chaotic image encryption technique based on a dynamic state variables selection mechanism to improve the effectiveness and security of chaos-based image cryptosystems. Experimental outcomes of our scheme demonstrate better security against many known attacks, as well as high efficiency.

The impact of elevation on climate change is a well-established research agenda. In the present era of climate change, it is necessary to understand the local impacts of such relationships. In this study, we attempted to portray local climate change using its altitudinal factor and fifteen years (2000–2014) of daily diurnal data from 20 stations in West Bengal, India that experienced increasing summer temperatures over the last several years. The study region is a combined zone of the plateau and plain region where there are variations in altitude. Further, the study used the ARMA model to forecast future climatic conditions of the region. The results demonstrate that climate change is playing an active role in the region, although there was not a convincing relationship between elevation and climate change. The low-lying counterparts of the study area were influenced by climate change. As per the forecast, the gap between the daily maximum and minimum temperatures will generally remain similar to or slightly less than the present conditions, while there is a high possibility of a more prominent decrease in the diurnal temperature range (DTR) over time.

In this paper, a competition of selling two substitutable products and one complementary product has been studied in two-echelon supply chain systems in which one of these three products is produced by one manufacturer separately, and all produced items are sold through a common retailer in the market. The demand of each product depends linearly on prices of these three products as per their nature. In this study, four different decision scenarios are developed mathematically under the game theory framework to maximize the profit function of each participant of the supply chain, and a number of pricing strategies are subsequently worked out for manufacturers and retailer. Finally, the model under different scenarios is illustrated with numerical data to study the feasibility of the model exploring the managerial insights, as well. Different marketing policies are predicted for maximum individual and system profits.

The paper is devoted to the theory for the interaction of an electromagnetic field with one-particle quantum-confined states of charge carriers in semiconductor quantum dots. It is demonstrated that the oscillator strengths and dipole moments of the transitions for one-particle states in quantum dots are large parameters, exceeding the corresponding typical parameters for bulk semiconductor materials. In the context of the dipole approximation, it is demonstrated that the large optical absorption cross sections in the quasi-zero-dimensional systems enable the use of such systems as efficient absorbing materials.

Type-2 intuitionistic fuzzy sets possess many advantages over type-1 fuzzy sets because their membership functions are themselves fuzzy, making it possible to model and minimize the effects of uncertainty in type-1 intuitionistic fuzzy logic systems. This paper presents generalized type-2 intuitionistic fuzzy numbers and its different arithmetic operations with several graphical representations. Basic generalized trapezoidal intuitionistic fuzzy numbers considered for these arithmetic operations are formulated on the basis of $\left(\alpha ,\beta \right)$-cut methods. The ranking function of the generalized trapezoidal intuitionistic fuzzy number has been successively calculated. To validate the proposed arithmetic operations, we solved a type-2 intuitionistic fuzzy transportation problem by the ranking function for mean interval method. Transportation costs, supplies and demands of the homogeneous product are type-2 intuitionistic fuzzy in nature. A numerical example is presented to illustrate the proposed model.

In this work, a new similarity measure was proposed based on the heights and areas of interval-valued trapezoidal fuzzy numbers. Some properties corresponding to the proposed similarity measure were illustrated. A comparison with the different existing similarity-measurement techniques demonstrated that the proposed method gave better results, overcoming the drawbacks of the existing methods. The proposed similarity-measurement technique was applied to the prediction of risk in the burning problem of Familial Breast Cancer (FBC). Finally, a numerical illustration for FBC was given using interval-valued trapezoidal fuzzy numbers.

CdO nanopowders were synthesized by a simple soft chemical method using cadmium acetate as the precursor salt. The as-synthesized nanopowders were characterized by XRD, SEM, EDX and TEM analysis. Polycrystalline nature with a (1 1 1) preferential orientation is revealed by the XRD analysis, which was confirmed from the SAED pattern. The presence of Cd and O in the nanopowders is confirmed from the EDX spectrum. The presence of peaks at 417, 499, 620 and 669 cm⁻¹ observed in the FTIR spectrum corresponds to the bonding between Cd and O. Antimicrobial activities were performed against three bacteria and fungi strains by the agar well diffusion method, and from the observed zones of inhibition, it is confirmed that the as-synthesized CdO nanopowders act as an effective antimicrobial agent against pathogenic microorganisms.