Some active stars show a so-called flip-flop phenomenon in which the main spot activity periodically switches between two active longitudes that are 180◦ apart. In this paper we study the flip-flop phenomenon by converting results from dynamo calculations into long-term synthetic photometric observations, which are then compared to the real stellar observations. We show that similar activity pa...

We present Flip-Flop Spectrum-Revealing QR (Flip-Flop SRQR) factorization, a significantly faster and more reliable variant of the QLP factorization of Stewart, for low-rank matrix approximations. Flip-Flop SRQR uses SRQR factorization to initialize a partial column pivoted QR factorization and then compute a partial LQ factorization. As observed by Stewart in his original QLP work, Flip-Flop S...

complementary metal-oxide semiconductor (cmos) technology has been the industry standard to implement very large scale integrated (vlsi) devices for the last two decades. due to the consequences of miniaturization of such devices (i.e. increasing switching speeds, increasing complexity and decreasing power consumption), it is essential to replace them with a new technology. quantum-dot cellular...

Delay faults are frequently encountered in nanometer technologies. Therefore, it is critical to detect these faults during factory test. Testing for a delay fault requires the application of a pair of test vectors in an at-speed manner. To maximize the delay fault detection capability, it is desired that the vectors in this pair are independent. Independent vector pairs cannot always be applied...

In this paper, a preprocessing circuit for ISFETs (Ion-sensitive field-effect transistors) to measure hydrogen-ion concentration in electrolyte is presented. A modified flip-flop is the main part of the circuit. The modification consists in replacing the standard transistors by ISFETs and periodically switching the supply voltage on and off. Concentration of hydrogen ions to be measured discont...

Providing resistance against side channel attacks especially differential power analysis (DPA) attacks, which aim at disclosing the secret key of cryptographic algorithm is one of the biggest challenges of designers of cryptographic devices. In this paper design of novel data flip-flop compatible with three-phase dual-rail logic (TDPL), called Charge recycling TDPL flip-flop is investigated. Th...

Activating a flip-flop circuit by a current fast-rising slope impulse, the circuit occupies one of the two stable states, the stable state ‘one‘ or ‘zero‘. In case of a perfect flip-flop symmetry over a large number of cycles, a noise causes the ratio of ‘ones‘ and ‘ zeros‘ is equal to one – 50% position of a flip-flop. However, any imbalance in the system changes the probability of taking a ‘o...

Clustered voltage scaling scheme is an effective method of power consumption reduction without performance degradation. One of the main issues in this scheme is performance and power penalties due to insertion of level converting flip-flops at the interface from low-supply to high supply clusters to simultaneously perform latching and level converting functions. A new level converting flip-flop...

Ultrahigh-speed circuit applications of resonant-tunneling diodes (RTDs) have been developed. The key points are the utilization of the edge-triggered and latching properties arising from negative differential resistance of the RTD, and the combination of RTDs and high electron mobility transistors (HEMTs). High-speed and low power operation of various flip-flop (FF) circuits monolithically int...