we investigate the problem of the existence of a frame forright ideals of a c*-algebra a, without the use of the kasparov stabilizationtheorem. we show that this property can not characterize a as a c*-algebraof compact operators.

the main objective of this study is to swing krull intersection theorem in primary decomposition of rings and modules to the primary decomposition of soft rings and soft modules. to fulfill this aim several notions like soft prime ideals, soft maximal ideals, soft primary ideals, and soft radical ideals are introduced for a soft ring over a given unitary commutative ring. consequently, the p...

Defective droppers pose a significant threat to the performance of contact between train pantograph and railway catenary. In this paper, impact damaged on pantograph–catenary interaction behaviour is analysed, varying degrees damage each dropper labelled. To improve classification accuracy when both degree position are considered, model integrating multiple 1D CNNs proposed. Approaches includin...

With the increasing speed of urban rail trains, vibration between pantograph collector strip and contact wire intensifies, pantograph-catenary arc occurs frequently, which severely wear surface materials pantograph-catenary. The burning strength extinguishing characteristics are affected by temperature parameters. Based on theory magnetohydrodynamics, this paper establishes a mathematical model...

We show that group algebras kG of polycyclic-by-finite groups G, where k is a field, are catenary: If P = I0 I1 · · · Im = P ′ and P = J0 J2 · · · Jn = P ′ are both saturated chains of prime ideals of kG, then m = n.

When a train runs at high speed, affected by the structural characteristics of catenary, contact force changes periodically with span and dropper spacing. However, as running speed increases, periodic signal owing to fluctuation catenary vibration pantograph, which directly affects stable between pantograph catenary. Therefore, based on simulation research method, this study uses time–frequency...