University of New Brunswick

About: University of New Brunswick is a education organization based out in Fredericton, New Brunswick, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 10498 authors who have published 20654 publications receiving 474448 citations.

Quantum Circuit Simplification and Level Compaction

Abstract: Quantum circuits are time-dependent diagrams describing the process of quantum computation. Usually, a quantum algorithm must be mapped into a quantum circuit. Optimal synthesis of quantum circuits is intractable, and heuristic methods must be employed. With the use of heuristics, the optimality of circuits is no longer guaranteed. In this paper, we consider a local optimization technique based on templates to simplify and reduce the depth of nonoptimal quantum circuits. We present and analyze templates in the general case and provide particular details for the circuits composed of NOT, CNOT, and controlled-sqrt-of-NOT gates. We apply templates to optimize various common circuits implementing multiple control Toffoli gates and quantum Boolean arithmetic circuits. We also show how templates can be used to compact the number of levels of a quantum circuit. The runtime of our implementation is small, whereas the reduction in the number of quantum gates and number of levels is significant.

Passive hyperthermia reduces voluntary activation and isometric force production

Abstract: It has been suggested that a critically high body core temperature may impair central neuromuscular activation and cause fatigue. We investigated the effects of passive hyperthermia on maximal isometric force production (MVC) and voluntary activation (VA) to determine the relative roles of skin (T sk) and body core temperature (T c) on these factors. Twenty-two males [VO2max=64.2 (8.9) ml kg−1 min−1, body fat=8.2 (3.9)%] were seated in a knee-extension myograph, then passively heated from 37.4 to 39.4°C rectal temperature (T re) and then cooled back to 37.4oC using a liquid conditioning garment. Voluntary strength and VA (interpolated twitch) were examined during an isometric 10-s MVC at 0.5°C intervals during both heating and cooling. Passive heating to a T c of 39.4oC reduced VA by 11 (11)% and MVC by 13 (18)% (P<0.05), but rapid skin cooling, with a concomitant reduction in cardiovascular strain [percentage heart rate reserve decreased from 64 (11)% to 29 (11)%] and psychophysical strain did not restore either of these measures to baseline. Only when cooling lowered T c back to normal did VA and MVC return to baseline (P<0.05). We conclude that an elevated T c reduces VA during isometric MVC, and neither T sk nor cardiovascular or psychophysical strain modulates this response. Results are given as mean (SD) unless otherwise stated.