We present some basic facts concerning simultaneity in both special and general relativity. We discuss Weyl’s proof of the consistence of Einstein’s synchronization convention and consider the general relativistic problem of assigning a time function to a congruence of timelike curves. 1 Simultaneity in special relativity In special relativity the possibility of synchronizing distant clocks so ...

Clock distribution network consumes a significant portion of the total chip power since the clock signal has the highest activity factor and drives the largest capacitive load in a synchronous integrated circuit. A new methodology is proposed in this paper for buffer insertion and sizing in an H-tree clock distribution network. The objective of the algorithm is to minimize the total power consu...

Reducing Power dissipation is one of the crucial problems in today’s scenario. So this dissipation has become a bottleneck in the design of high speed synchronous systems which are operating at high frequency. Clock signals have been a great source of Power. Design can be made on the basis of Clock gating approach to reduce the consumption of clock’s signal switching power which is the foremost...

The circadian clock regulates diverse aspects of plant growth and development and promotes plant fitness. Molecular identification of clock components, primarily in Arabidopsis, has led to recent rapid progress in our understanding of the clock mechanism in higher plants. Using mathematical modeling and experimental approaches, workers in the field have developed a model of the clock that incor...

This study investigates differences in expression of clock and clock-controlled genes (CCGs) between human breast epithelial and breast cancer cells and breast tumor xenografts in circadian intact rats and examines if the pineal hormone melatonin influences clock gene and CCG expression. Oscillation of clock gene expression was not observed under standard growth conditions in vitro, however, se...

Implementation of vector clock is a fundamental problem in distributed system algorithms. Vector clock is strongly consistent, thus gives a total ordering of processes in terms of causality. But, state forward implementation of vector clock is not scalable. This paper studies Singhal-Kshemkalyani’s implementation of vector clock. Our analysis dictates that Singhal-Kshemkalyani’s implementation ...

Circadian clocks in mammals are built on a negative feedback loop in which the heterodimeric transcription factor circadian locomotor output cycles kaput (CLOCK)-brain, muscle Arnt-like 1 (BMAL1) drives the expression of its own inhibitors, the PERIOD and CRYPTOCHROME proteins. Reactivation of CLOCK-BMAL1 occurs at a specific time several hours after PERIOD and CRYPTOCHROME protein turnover, bu...

Mammals have developed an endogenous circadian clock located in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus that responds to the environmental light-dark cycle. Similar clocks are found in peripheral tissues, such as the liver and adipose tissue, regulating cellular and physiological functions. The circadian clock has been reported to regulate metabolism and energy homeostasis...

We present on-chip oscillator arrays synchronized by random noises, aiming at skew-free clock distribution on synchronous digital systems. Nakao et al. recently reported that independent neural oscillators can be synchronized by applying temporal random impulses to the oscillators [1], [2]. We regard neural oscillators as independent clock sources on LSIs; i.e., clock sources are distributed on...