Here we formulate second-order cone programs (SOCPs) for synthesizing complex weights for far-field directional (single-point mainbeam) patterns for narrowband arrays. These formulations, while constructed here with the uniform circular array (UCA) in mind, are actually quite general in that they control the arbitrary-pol sidelobe level (SLL) and co-pol SNR loss relative to ideal by minimizing ...

This paper presents an active resonant conductance method (ARCM) for the design of large traveling-wave-fed SIW linear slot arrays. Two key slot parameters, slot offsets and lengths, are derived from excitation coefficients with intermediary active resonant conductance. In this method, both dominant mode mutual coupling which includes external & internal and higher order modes mutual coupling a...

Projects scheduling by the project portfolio selection, something that has its own complexity and its flexibility, can create different composition of the project portfolio. An integer programming model is formulated for the project portfolio selection and scheduling.Two heuristic algorithms, genetic algorithm (GA) and simulated annealing (SA), are presented to solve the problem. Results of cal...

this paper presents a new mathematical model for a hybrid flow shop scheduling problem with multiprocessor tasks in which sequence dependent set up times and preemption are considered. the objective is to minimize the weighted sum of makespan and maximum tardiness. three meta-heuristic methods based on genetic algorithm (ga), imperialist competitive algorithm (ica) and a hybrid approach of ga a...

Lens antennas are a promising device for realizing the anti-collision radars needed in intelligent transport systems (ITS) and multibeam antennas for satellite communication. They have simple structure, high gain and no feed blockage. Especially if the operating frequencies are above the microwave band, the resulting apertures with several tens of wavelengths, become practical. In advance ITS a...

In this study, a new concept for Ka-band 5G communication tunable reflector metasurface (MS) beam steering at 28 GHz is proposed. Varactor diodes are used as the tunability component of each unit cell MS. Significant improvements in and bandwidth performance were achieved using referred to stripes configuration. Several different geometries cells arranged designed achieve better directionality,...

this study is focused on the development of a systematic computational approach which implements genetic algorithm (ga) to find the optimal rigorous kinetic models.a general kinetic model for hydrogenolysis of dibenzothiophene (dbt) based on langmuir-hinshelwood type has been obtained from open literature. this model consists of eight continuous parameters(e.g., arrhenus  and van't hoff paramet...

in this paper, we consider a flow shop scheduling problem with availability constraints (fsspac) for the objective of minimizing the makespan. in such a problem, machines are not continuously available for processing jobs due to preventive maintenance activities. we proposed a mixed-integer linear programming (milp) model for this problem which can generate non-permutation schedules. furthermor...

Assembly plays an important role in any production system as it constitutes a significant portion of the lead time and cost of a product. Virtual computer-integrated manufacturing (VCIM) system is a modern production system being conceptually developed to extend the application of traditional computer-integrated manufacturing (CIM) system to global level. Assembly scheduling in VCIM systems is ...