The contributions regarding the conception,designing, modelling and the implementation in a flexible cell of fabrication of a modular serial robot

The authors of the presented paper are propose to relief the calculus, modelling and construction of the translation module of an industrial robot which possess in his cinematic chain five degrees of freedom, type TTRTR. It is propose a choosing variant of the direct current driving engine of the translation module, knowing the output momentum and calculating the input momentum. This is realized by equalize of an equation which results from dynamic modeling of the robot with a designing equation which keep in view the component elements of the structure of the module. The robot is composed by: module of translation on horizontal to the base of the robot (MTB-Sil), module of translation on vertical (MTV-Sil), module of rotation round the vertical axis from the robot's arm, module of translation from the structure of the robot's arm (MT-Sil) and module of orientation assembled with clamping device. In the paper, also is presented an economic study regarding the implementation of the analyzed robot in a manufactural cell concerning the manufacturing and assembling of some types of car radiators. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A numerical study of the dynamics of elastic articulated systems in a fluid

We propose a method and an algorithm for computing the dynamics of elastic structures of articulated form in a fluid flow taking account of the weakening in certain structural elements. In describing the motion we use two sets of radius-vectors, which are approximated in the computations by parametric local splines of first degree. The possibilities of the proposed method are illustrated using the example of the study of the dynamics of transition processes in an articulated anchor-buoy structure, which arise when there is an abrupt change in the direction of the fluid flow velocity. We determine the kinematic and force characteristics of the structure under various changes in the direction of the flow velocity. We determine the structural elements in which the weakening occurs. Three figures. Bibliography: 7 titles. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 26, 1996, pp. 128–134.     

Managing a marketing reward policy: a study of an implementation in a computer firm

A firm selling office equipment is looking for the marketing strategy which allows it to maximize its turnover. The decision variable is the representative commission rate which, so far, has been determined in a non-satisfactory, and somewhat arbitrary way. The sequential and Markovian nature of the problem leads us to apply Bellman and Howard methods, in order to determine short-term and long-term optimal policies. This paper aims at showing that such methods give the firm better opportunity to determine its policy. Major assumptions and restrictions are discussed and potential extensions are evoked.     

A demonstrative study of a new SQC concept and procedure in the manufacturing industry

A review of the changes in the environment surrounding the manufacturing industry indicated an ever greater necessity for corporate efforts to amplify and capitalize upon the technical prowess of the engineering staff who bear the main burden of these times. In this study, we propose the establishment of a new technical method for conducting scientific SQC as a new concept and procedure that will improve the job quality of the engineering staff in each stage of the business process so as to contribute to production with excellent QCDS. We also try to evaluate and investigate its usefulness on the basis of an actual study example in Toyota.     

Modelling the cost of poor quality in a five-state part manufacturing operation: a case study

The quality history of individual parts from a critical operation can be modeled by a five-state Markov chain involving factory rework operation, customer inspection and field test, parts scrapped, parts defective but used-as-is by concession or re-graded for alternative applications, and defect-free parts satisfying customer requirements. We estimate total failure cost by a five-state Markov chain model and present a case study to demonstrate relationship of the total failure cost to appraisal and prevention costs.     

A numerical study of an MPI/OpenMP implementation based on asynchronous threads for a three-dimensional splitting scheme in heat transfer problems

We present the results of a study of the parallel algorithms based on MPI and OpenMP for vector splitting schemes in heat transfer problems. We compare the three parallel implementations: MPI, “simple” MPI/OpenMP (#pragma omp directives applied to MPI-based code), and MPI/OpenMP with “postman” threads. The main idea of the last algorithm is to assign one thread within each computational node to perform the data transfer. This approach allows us to implement overlapping of useful computations and data transfer. The results show that the introducing postman threads can significantly improve the performance of an MPI/OpenMP implementation; nevertheless, for the considered class of numerical algorithms, it is more reasonable to use an MPI implementation.     

Peristaltic flow of a micropolar fluid through a porous medium in the presence of an external magnetic field

This paper presents an analytical study of the MHD flow of a micropolar fluid through a porous medium induced by sinusoidal peristaltic waves traveling down the channel walls. Low Reynolds number and long wavelength approximations are applied to solve the non-linear problem in the closed form and expressions for axial velocity, pressure rise per wavelength, mechanical efficiency and stream function are obtained. The impacts of pertinent parameters on the aforementioned quantities are examined by plotting graphs on the basis of computational results. It is found that the pumping improves with Hartman number but degrades with permeability of the porous medium.     

An analysis of the swimming problem of a singly flagellated micro-organism in an MHD fluid flowing through a porous medium

The focus of the present work is concerned with the study of the swimming of microscopic organisms that use a single flagellum for propulsion in a magnetohydrodynamic (MHD) fluid flowing through a porous medium. The flow is modelled by appropriate equations and the organism is modelled by an infinite flexible but inextensible transversely waving sheet, which represents approximately the flagellum. The governing equations subject to appropriate boundary conditions are solved analytically. Expressions for the velocity of propulsion of the microscopic organism are obtained. We show that as the MHD character of the fluid is removed the results match those of an earlier analysed problem of propulsion through a fluid in a porous medium. In addition, in the final case of a simple viscous fluid (absence of magnetic field), we show that as the permeability becomes large the results reduce to the swimming of such organisms in a viscous fluid (discounting the pores and the MHD character).     

On a linearized system arising in the study of viscous surface flow down an inclined plane

We consider the linearized problem describing motion of a viscous incompressible fluid flow down an inclined plane under the effect of gravity. We formulate the problem for downward periodic disturbances from the laminar steady flow as an evolution equation in the product of Sobolev spaces \(H^{\frac{3}{2}}_0({\mathbb {T}}) \times {\mathbb {P}}^0H^0(\Omega ) \) . It is crucial to study qualitative behavior of solutions that the operator arising in the linearized problem has compact resolvent operators and generates an analytic semigroup in \(H^{\frac{3}{2}}_0({\mathbb {T}}) \times {\mathbb {P}}^0H^0(\Omega ) \) .     

Application of the matrix riemann problem to the study of excitation of natural waves in an acoustic waveguide by a piston radiator

Stationary excitation of natural waves in a flat acoustic waveguide with absolutely soft lateral walls by a piston radiator is investigated. In the case where the length of the radiator is equal to the halved width of the waveguide, the exact analytic solution is obtained. The representation of the acoustic field in the waveguide in the form of an expansion over the natural waves of the waveguide is provided.Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 239, 1997, pp. 129–132.     

Operational Research for informed innovation: <Emphasis Type="Italic">NHS Direct</Emphasis> as a case study in the design,implementation and evaluation of a new public service

Delivering modern and responsive public services requires informed innovation drawing on a combination of design, planning and evaluative skills. The development of the national 24-hour telephone helpline service NHS Direct provides a case study demonstrating how, through using these skills, OR has been instrumental in achieving public service innovation. Firstly, OR analysts led strategic design and scenario-planning work, assessing the evidence on the performance of ‘direct’ services here and around the world and developing scenarios of an NHS where much greater use was made of modern communication technology, such as telephone call centres, to provide services. Secondly, we did modelling work to help determine the size, distribution and staffing of the call centres required in England to meet the likely demand and satisfy service performance targets. Thirdly, we set out evaluation criteria and developed performance-monitoring systems. NHS Direct has been one of the best-received innovations in the history of the NHS and Operational Research has made a crucial contribution to its development.     

Mathematical study of the small oscillations of an incompressible and inviscid liquid under zero gravity in a container of revolution with elastic bottom and anchored edge

In this paper, the Authors study the small oscillations of an inviscid liquid under zero gravity in a container of revolution with elastic bottom, considered as a membrane or a plate, and anchored edge. They obtain the equations of the displacements of the free surface and the bottom and they reduce these equations to a functional equation in a suitable Hilbert space. By using the methods of Functional Analysis the Authors prove the existence of the small oscillations. Research partially supported by GNFM, MURST (Italy).