in this paper, we consider a cooperative cognitive radio network in which there is an ofdm primary link and multiple single carrier secondary links.the primary link is required to maintain its secrecy rate above a predefined threshold. if the secrecy rate requirement is not satisfied, the secondary system help primary link to maintain its secrecy rate requirement. in doing so, the secondary trans...

This paper proposes an improved direct active and reactive power control (DPC) strategy for a grid-connected doubly fed induction generator (DFIG) based wind-turbine system under unbalanced grid voltage condition. The method produces required rotor voltage references based on the sliding mode control (SMC) approach in stationary reference frame, without the requirement of synchronous coordinate...

This review basically provided a conceptual framework for sample size calculation in epidemiologic studies with various designs and outcomes. The formula requirement of sample size was drawn based on statistical principles for both descriptive and comparative studies. The required sample size was estimated and presented graphically with different effect sizes and power of statistical test at 95...

The efficiency of agricultural tractor transmission has been improved over the years, with new concepts such as Continuously Variable Transmission (CVT) and Full Powershift (FPS) evolving in advanced technologies. Both options seek to offer farmer greater operational results lower energy expenditure, necessitating studies assess effectiveness these technologies define best choice for each purpo...

The optimization of energy input on agricultural farms, such as through improved fuel consumption, is currently under investigation in mechanization research with the aim achieving economic and environmental goals. In previous research, we developed a simplified algorithm focused defining most efficient tractor–implement combination considering factors that influence this aspect. ASABE (America...

Soil-cutting forces are key indicators of root-tuber harvesters and other soil-engaging tools’ performance. To improve operational efficiency, minimise soil disturbance, reduce fuel consumption, the draught vertical involved in root tuber crop harvesting must be minimised. Two field experiments assessed harvester’s performance at a depth 200 mm, varying frequencies, travel speeds on clay sandy ...

This paper assesses the performance of dual header pulse interval modulation (DH-PIM) over indoor optical wireless systems. DH-PIM being anisochronous scheme offers a built-in symbol synchronization capability. Theoretical and simulation results demonstrate that DH-PIM offers shorter symbol length, improved transmission rate and bandwidth requirement and a comparable power spectral density prof...