10 research outputs found

    Determination of car run up – braking and manoeuvring parameters in an emergency situation in the case of limited road segment

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    As the traffic intensity on roads increases, the number of road accidents also increases and the situations become more and more complicated. The presented method of reconstruction of preaccidental situations with the purpose of examination of road accident mechanisms can be widely used for the investigation of road accidents of different nature and for the determination of their reasons, the distance run by a car, the time of its run and speed which can be reached during the run up and followed by braking in road segments between two manoeuvres in a road segment of limited length. This method is being widely used in Lithuania for the investigation of accidental situations and for the assurance of law and order

    A mathematical model of the vibrating system equivalent to the vehicle in the mode of emergency braking

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    A mathematical model of the vibrating system equivalent to the vehicle in the mode of emergency braking is developed and the solution is offered. The problem associated with the comparison of the vibrations of the braking vehicle with the oscillations of a uniformly translating vehicle is considered. On the basis of the analysis of the available research data some assumptions and constraints are introduced, allowing the vibrating system equivalent to the condition of the vehicle in the mode of emergency braking to be developed. The system obtained differs from the data found in the theory of the vehicle in the description of the applied tangential forces caused by the force of inertia applied to the center of gravity. Based on the equivalent system developed, the differential equations describing the displacements of masses of the above system are derived and solved

    Comparative research of a motor car motion in the case of the loss of contact with the road surface

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    The paper describes the car motion when the contact between its wheels and the road surface is lost. A simulation of such car motion was carried out using a mathematical package "Maple 6" for the two cases: 1) The car flies off a horizontal surface; 2) The car runs over a springboard. The dependencies of the main parameters of motion (velocity and distance) upon the height of the horizontal road step or upon the springboard height and its inclination angle (in the second case) were found. The work presents the graphs of these motion parameters and evaluates the influence of air resistance in both cases

    Analiza wpływu stanu technicznego resora pneumatycznego autobusu na sygnały drgań w ramie autobusu

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    The paper analyses the spread of vibration intensity through the bus frame mechanical structure. The research has been completed upon application of the theory of covariance functions. Results of measuring the intensity of vibrations at fixed bus framepoints were recorded on the time scale in the form of data arrays (matrixes). The authors have completed the estimation of covariance functions by measuring the intensity of vibrations between the arrays of digital results and auto-covariance functions of single arrays upon changing the quantization interval on the time scale. The research results enable to define if the solidity of bus frame is disordered and to assess the technical condition of pneumatic suspension considering the vibration of frame points. Dangerous zones of bus suspension and reliability level of bus exploitation can be determined by application of these results.W pracy przeprowadzono analizę rozkładu intensywności drgań w mechanicznej konstrukcji ramy autobusu. Badania prowadzono z zastosowaniem teorii funkcji kowariancji. Wyniki pomiaru intensywności drgań w ustalonych punktach ramy autobusu rejestrowano na skali czasu, w postaci tablic danych (matryc). Funkcje kowariancji obliczano porównując natężenie drgań pomiędzy tablicami wyników cyfrowych, zaś funkcje auto-kowariancji pojedynczych tablic obliczano po zmianie przedziału kwantyzacji w skali czasowej. Wyniki badań pozwalają na określenie, czy zaburzona została stabilność struktury ramy autobusowej oraz umożliwiają ocenę stanu technicznego zawieszenia pneumatycznego na podstawie drgań w określonych punktach ramy. Wyniki te można wykorzystać do określenia niebezpiecznych stref zawieszenia autobusowego oraz poziomu niezawodności pracy autobusu

    The influence of coolant scale deposit inside the internal combustion engine on the piston and cylinder deformations

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    This paper presents the analysis of the influence of engine coolant scale deposits on the deformations in the piston – cylinder pair. The results of carried out calculations enable to make more precise evaluation of cylinder repair dimensions. The aim of calculations was to establish how the thermal gap between the piston and cylinder varies in accordance with variations of heat transfer conditions, i.e. when on the outer surface of the cylinder a layer of scale deposits is formed

    Analysis of calculation methods used for accuracy evaluation of the results of road accident examination

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    For examination of road accidents often calculations are being performed according to mathematical equations having many variables, real values of which are of stochastic nature and they depend on many accident factors. Therefore it is important to know limits of determination of final values of every being analysed parameter of car movement and their probabilistic characteristics. This paper presents some cases of simulation of some road situations by mathematical methods of calculations, which now are widely used for evaluation of accuracy of values of the calculated parameter (in this paper – the braking distance). Also here is presented some analysis of these methods. The paper presents the following cases of car braking: braking with making attempts to prevent a collision with another car, braking through impact-to-pedestrian prevention and conventional (rectilinear) car braking. The main attention in the analysis of the mentioned road situations is paid to veracity of the car braking distance, i.e. to limits of variation of values of this parameter and also to influence of accidental factors on the final result which is being looked for. Some conclusions on the expediency of application of the described methods of calculations to analysis of road accidents are present

    Multiple Myeloma Treatment in Real-world Clinical Practice: Results of a Prospective, Multinational, Noninterventional Study

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    Multiple myeloma (MM) remains an incurable disease, with little information available on its management in real-world clinical practice. The results of the present prospective, noninterventional observational study revealed great diversity in the treatment regimens used to treat MM. Our results also provide data to inform health economic, pharmacoepidemiologic, and outcomes research, providing a framework for the design of protocols to improve the outcomes of patients with MM. Background: The present prospective, multinational, noninterventional study aimed to document and describe real-world treatment regimens and disease progression in multiple myeloma (MM) patients. Patients and Methods: Adult patients initiating any new MM therapy from October 2010 to October 2012 were eligible. A multistage patient/site recruitment model was applied to minimize the selection bias; enrollment was stratified by country, region, and practice type. The patient medical and disease features, treatment history, and remission status were recorded at baseline, and prospective data on treatment, efficacy, and safety were collected electronically every 3 months. Results: A total of 2358 patients were enrolled. Of these patients, 775 and 1583 did and did not undergo stem cell transplantation (SCT) at any time during treatment, respectively. Of the patients in the SCT and non-SCT groups, 49%, 21%, 14%, and 15% and 57%, 20%, 12% and 10% were enrolled at treatment line 1, 2, 3, and ≥ 4, respectively. In the SCT and non-SCT groups, 45% and 54% of the patients had received bortezomib-based therapy without thalidomide/lenalidomide, 12% and 18% had received thalidomide/lenalidomide-based therapy without bortezomib, and 30% and 4% had received bortezomib plus thalidomide/lenalidomide-based therapy as frontline treatment, respectively. The corresponding proportions of SCT and non-SCT patients in lines 2, 3, and ≥ 4 were 45% and 37%, 30% and 37%, and 12% and 3%, 33% and 27%, 35% and 32%, and 8% and 2%, and 27% and 27%, 27% and 23%, and 6% and 4%, respectively. In the SCT and non-SCT patients, the overall response rate was 86% to 97% and 64% to 85% in line 1, 74% to 78% and 59% to 68% in line 2, 55% to 83% and 48% to 60% in line 3, and 49% to 65% and 36% and 45% in line 4, respectively, for regimens that included bortezomib and/or thalidomide/lenalidomide. Conclusion: The results of our prospective study have revealed great diversity in the treatment regimens used to manage MM in real-life practice. This diversity was linked to factors such as novel agent accessibility and evolving treatment recommendations. Our results provide insight into associated clinical benefits. © 2018 The Author
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