Effect of tooth shape to size of contact stress noninvolute gearing

The article describes the effect of the tooth shape to the size of the contact stress. Using the geometrical parameters konex-concave gearing can change the tooth profile, which can be achieved by reducing the size of the contact stress. Important role played by reduced radii of curvature, which significantly affect to the size of these stress. Comparative two places around the beginning (point B) and end (point D) on the line of action.В статье описывается влияние формы зуба с размером контактного напряжения. В геометрических параметрах выпукло-вогнутой передачи можно изменить форму зубов, которая может быть достигнута за счет сокращения размеров контактных напряжений. Важную роль играет сокращение радиусов кривизны, которая существенно влияет на размер этих напряжений. Приравнивается два места вокруг самого начала (точка B) и конца (точка D) на линии зацепления, которые находится в непосредственной близости от этих точек представленых одно и двухпарным зацеплением

Comparison of biochemical response between the minimally invasive and standard open posterior lumbar interbody fusion

Background The mini-invasive open posterior lumbar fusion procedure (mini PLIF) procedure is an alternative to standard open procedure (open PLIF) and is intended to reduce surgery-related trauma. The measuring of suitable biochemical factors enables objective comparison of the invasiveness of spinal surgery procedures. Methods Prospectively collected data on myoglobin, creatine kinase, interleukin-6, C-reactive protein levels and intensity of low back pain and radicular pain in one-level mini PLIF and open PLIF procedures were analysed. The mini PLIF and the open PLIF groups included 27 and 23 patients, respectively. The collection of blood samples and clinical data were performed preoperatively and on postoperative days 1, 3 and 7. The non-paired t-test was used for statistical evaluation. Results We did not found any statistically significant differences of myoglobin and creatine kinase levels between the groups. In the open PLIF group the IL-6 levels were significantly higher than in the mini PLIF group on postoperative day 3. CRP levels showed significant lower stress response in favour of the mini PLIF group on postoperative days 3 and 7. Levels of post-op low back pain on day 3 were significantly lower in mini PLIF group. Also intensity of radicular pain on day 1 and 3 were lower also mini PLIF group. Conclusion The extent of myonecrosis was comparable in both techniques. The analysis of the IL-6 and CRP levels showed significantly lower systemic inflammatory response in mini PLIF technique. The mini PLIF technique provides transiently lower postoperative pain levels

Acceleration of Data Encryption Algorithms in FPGA

Tato práce se zabývá možností akcelerace šifrovacích algoritmů pomocí rekonfigurovatelných obvodů FPGA a zkoumáním rozdílu rychlosti implementace oproti implementaci softwarové. Práce popisuje základy šifrování a akcelerace algoritmů na FPGA. Dále se zabývá procesem návrhu, implementace, simulace a syntézy výsledné implementace. Provádí rozbor dosaženého řešení. Cílem projektu bylo vytvořit funkční řešení akcelerovaného algoritmu, tím umožnit jeho další použití v reálném provozu a dále vytvoření česky psaného materiálu o této problematice.This work deals with the possibility of acceleration algorithm using reconfigurable FPGA circuits and speed of implementation by examining the difference compared to software implementation. The work describes the basics of encryption and acceleration algorithms on the FPGA. It then addresses the process of design, implementation, simulation and synthesis of the resulting implementation. It made analysis of the achieved solution. The aim of the project was to create a functional solution of accelerated algorithm, thus enabling its use in the real application and, finally, establishment of czech written material on this issue.

A signal strength fluctuation prediction model based on the random forest algorithm

This article describes the effect of the weather on radio wave propagation in a mobile telecommunication network. The research is focused on urban and countryside environments where a correlation between the received signal power level and weather conditions is found using the Random Forest algorithm as a signal level approximator. The results achieved in this paper clearly indicate that it is possible to predict the behaviour of the received power level in relationship to atmospheric phenomena.Web of Science20512612