Departure tooth profile arched gear of involute in the shaping of butt-end chisel heads

В статті розглянуто формоутворення циліндричних арочних зубчастих коліс торцевими різцевими головками. Виведено аналітичні залежності для розрахунку профілю западини зуба в перерізах перпендикулярних осі зубчастого колеса і визначені похибки профілю при нарізанні арочних коліс різцевими головками методом копіювання. Показано вплив параметрів зубчастого колеса і резцової головки на похибки профілю. Досліджено зачеплення арочних коліс нарізаних торцевою різцевою головкою методом копіювання.Purpose. Determination of rejections of tooth profile of the arched gear-wheels from involute at their cutting by butt-end heads by the method of copying in different cuts, perpendicular to axis of wheel. Approach. At shaping of the cylindrical arched gear-wheels by butt-end chisel heads by a method a copying involute profile will get only in a central cut on the width of wheel. In other cuts, perpendicular to axis of wheel, a profile will be different from involute. The shown out analytical dependences for the calculation of type of hollow of tooth in any crossing, perpendicular to axis of gear-wheel, enable to define the errors of profile at cutting of these wheels. On the basis of the conducted calculations influence of parameters of gear-wheel and chisel head is shown on the errors of profile. Hooking of the arched gear-wheels, cut by a butt-end chisel head by the method of copying and solution of problem of the mutual crossing of profiles of two gear-wheels is offered is investigational. Conclusion. Profile of tooth of the arched gear-wheel at his shaping by a butt-end chisel head in cuts, perpendicular to axis of wheel(except for middle), characterized by the rejection of profile (by a certain error). It is in-process shown that the size of error of profile depends on the radius of chisel head, distance from a middle cut, module, amount of teeth, corner of hooking and offset ratio. Importance. The shown out analytical dependences enable to forecast the size of error of profile of the arched wheels at cutting butt-end chisel heads.В статье рассмотрены формообразования цилиндрических арочных зубчатых колес торцовыми резцовыми головками. Выведены аналитические зависимости для расчета профиля впадины зуба в сечениях перпендикулярных оси зубчатого колеса и определены погрешности профиля при нарезании арочных колес резцовой головкой методом копирования. Показано влияние параметров зубчатого колеса и резцовой головки на погрешности профиля. Исследовано зацепление арочных колес нарезанных торцовой резцовой головкой методом копирования

VEHICLE IDENTIFICATION TASK SOLUTION BY WINDSCREEN MARKING WITH A BARCODE

The vehicle identification means are considered and the present-day traffic requirements are set. The vehicle automatic identification method concerned with barcode use is proposed and described

An Effective Object Detection Algorithm for High Resolution Video by Using Convolutional Neural Network

In this paper, an algorithm to detect small objects more accurately in high resolution video is proposed. For this task, an analysis of state-of-the-art algorithms in application to high resolution video processing, which can be implemented into modern surveillance systems is performed. The algorithm is based on CNN in application to high resolution video processing and it consists of the following steps: each video frame is divided into overlapping blocks; object detection in each block with CNN YOLO is performed; post processing for extracted objects in each block is done and merging neighbor regions with the same class probabilities is performed. The proposed algorithm shows better results in application to small objects detection on high resolution video than famous YOLO algorithm

Results from a blind and a non-blind randomised trial run in parallel: experience from the Estonian Postmenopausal Hormone Therapy (EPHT) Trial

<p>Abstract</p> <p>Background</p> <p>The Estonian Postmenopausal Hormone Therapy (EPHT) Trial assigned 4170 potential participants prior to recruitment to blind or non-blind hormone therapy (HT), with placebo or non-treatment the respective alternatives. Before having to decide on participation, women were told whether they had been randomised to the blind or non-blind trial. Eligible women who were still willing to join the trial were recruited. After recruitment participants in the non-blind trial (N = 1001) received open-label HT or no treatment, participants in the blind trial (N = 777) remained blinded until the end of the trial. The aim of this paper is to analyse the effect of blinding on internal and external validity of trial outcomes.</p> <p>Methods</p> <p>Effect of blinding was calculated as the hazard ratio of selected chronic diseases, total mortality and all outcomes. For analysing the effect of blinding on external validity, the hazard ratios from women recruited to the placebo arm and to the non-treatment arm were compared with those not recruited; for analysing the effect of blinding on internal validity, the hazard ratios from the blind trial were compared with those from the non-blind trial.</p> <p>Results</p> <p>The women recruited to the placebo arm had less cerebrovascular disease events (HR 0.43; 95% CI: 0.26-0.71) and all outcomes combined (HR 0.76; 95% CI: 0.63-0.91) than those who were not recruited. Among women recruited or not recruited to the non-treatment arm, no differences were observed for any of the outcomes studied.</p> <p>Among women recruited to the trial, the risk for coronary heart disease events (HR 0.77; 95% CI: 0.64-0.93), cerebrovascular disease events (HR 0.66; 95%CI: 0.47-0.92), and all outcomes combined (HR 0.82; 95% CI: 0.72-0.94) was smaller among participants in the blind trial than in the non-blind trial. There was no difference between the blind and the non-blind trial for total cancer (HR 0.95; 95% CI: 0.64-1.42), bone fractures (0.93; 95% CI: 0.74-1.16), and total mortality (HR 1.03; 95% CI: 0.53-1.98).</p> <p>Conclusions</p> <p>The results from blind and non-blind trials may differ, even if the target population is the same. Blinding may influence both internal and external validity. The effect of blinding may vary for different outcome events.</p> <p>Trial registration</p> <p>[<a href="http://www.controlled-trials.com/ISRCTN35338757">ISRCTN35338757</a>]</p

Recent advances in real geometric reasoning

In the 1930s Tarski showed that real quantifier elimination was possible, and in 1975 Collins gave a remotely practicable method, albeit with doubly-exponential complexity, which was later shown to be inherent. We discuss some of the recent major advances in Collins method: such as an alternative approach based on passing via the complexes, and advances which come closer to "solving the question asked" rather than "solving all problems to do with these polynomials"