Historically, a typical embedded system has been designed as a control-dominated system using only a state-oriented model, such as FSMs. However, the trend in embedded systems design in recent years has been towards highly distributed architectures with support for concurrency, data and control flow, and scalable distributed computations. This implies that a different approach is necessary. We propose to use some dataflow computational model views to specify embedded systems, because it is a notation that covers the most relevant aspects of distributed computing. In this paper, we introduce a new computational model, known as OAA (Object-Attribute Architecture) and present the general characteristics of an OA-methodology to support the design and simulation of distributed computing systems. The matrix multiplication algorithm in the object-attribute distributed computing environment has been used to validate our methodology. The preliminary evaluation results show the feasibility of the OA approach.
Exponential growth in data production and a prominent trend in data center design architecture – a shift from expensive hardware towards a multitude of simple servers – pose new tasks and demand the use of different strategies for data center architects. In this work, a new solutions to distributed systems design are discussed, which are based on Plan9 operating system model. We first overview application and research projects including project of porting Plan9 to the IBM Blue Gene/L supercomputer, project of the Plan9 use in data centers and cloud systems, and projects aimed at distributed embedded systems. Then we introduce a Cloud/IX operating system for the ARM-based server platforms that also follows the Plan9 model and is implemented on top of one of Plan 9 derivatives called 9front - a free software distributed operating system. We also present the experimental testbed setup and results of experimental study of the Cloud/IX on multi-computer server farm in actual data center environment.
Filtering the suspension in a porous soil is important for long-term evaluation of soil strength in the construction of underground and hydrotechnical structures. A size-exclusion model of solid particle capture for a flow of suspension in a porous media is considered: particles pass freely through the large pores and get stuck at the inlet of small pores whose diameter is less than the particle size. The asymptotic solution for the concentrations of suspended and retained particles is constructed under the assumption that the limit deposit is small.
A research project on dataflow automation system architecture is presented exploring the research and engineering issues related to the development of computer architecture for the next generation distributed supervision and control systems that exploits and leverages dataflow computation model. Major focus of research is on new object-attribute architecture of dataflow computing environment which is particularly suitable for the design and implementation of reconfigurable scalable heterogeneous distributed applications in industrial automation area. The state-ofthe- art in the application of the dataflow model of computation is accompanied with description of software tools developed for programming, simulation, debugging and test of automation applications that follow the object-attribute dataflow model.
Problems of deep bed filtration of the suspension in a porous soil are important for the design and construction of tunnels and hydrotechnical structures. A size-exclusion model of solid particle capture in a porous media is considered. For deep bed filtration equations an asymptotic solution for the concentrations of suspended and retained particles is constructed at the filter inlet. The asymptotics is compared with numerical solution. A new condition on equation coefficients is obtained.
This study proposes a method for determining the material constitutive equations and optimal forming conditions on the basis of free bulging tests. The blow-forming tests were carried out at the temperature of 420 °C using aluminum alloy (AMg-6) sheets of a 1 mm thickness. Each test was performed at constant pressure. For each fixed value of the pressure, a series of experiments was carried out with different forming times to obtain evolutions of dome height H and thickness s. These data were processed by the proposed method to obtain the flow stress dependence on the effective strain rate. The constitutive equations were obtained by least squares minimization of deviations between the experimental variations of H and s and ones predicted by a simplified engineering model. On the basis of the obtained data, the optimum strain rate for AMg-6 processing was determined as one corresponding to the maximum strain rate sensitivity.
Work solutions are proposed for problems of leader definition and role distribution in homogeneous groups of robots. It is shown that transition from a swarm to a collective of robots with hierarchical organization is possible using exclusively local interaction. The local revoting algorithm is central to the procedure for choice of leader while redistribution of roles can be achieved by a wave method. The basis for this approach is the static swarm model, which is characterized by the absence of a set control center and represents the network fixed at some time interval as a set of locally interacting agents.
In this work, a new experimental-numerical technique is developed in order to investigate the constitutive behaviour of a sheet material in conditions of superplastic forming. The principal feature of this technique is that unlike classical tensile testing it allows one to obtain stress-strain curves for a material formed in biaxial tension conditions produced by free bulging process. These conditions are much closer to the ones that the material undergoes during the superplastic forming process. Consequently, they give more accurate information about the material behaviour than the ones coming from tensile tests data. The drawback is that the strain (and similarly its time derivative) cannot be directly measured and controlled during free bulging test but its value has to be derived from other macroscopic measurement. Towards this end, a blow forming machine was equipped with a position transducer for the measurement of the dome height during the test. In order to control the stress in the dome apex at a predetermined level the applied pressure was continuously adjusted to current dome height using a special algorithm. After the test, the dome height data were processed to obtain the evolution of stress, strain and strain rate at the dome apex as well as the stress strain curves for constant referenced strain rates. The tests were performed on superplastic aluminium alloy (ALNOVI-U) sheets of 1.35 mm initial thickness at 500 °C. Using the data from two tests with different strain rate paths the stress-strain curves and the strain rate sensitivity index evolution were calculated for two constant referenced strain rates. The obtained constitutive data were verified by finite element simulation of a blow forming.
This paper outlines the principles of modelling and designing a laboratory for ideas, an innovative solution dedicated to the development of creativity and creative problem solving skills in an engineering context. Reflecting the objectives, this paper defines the connection between creativity and engineering, adopting them as a single mindset, and describes how creativity should be taught, having in mind new education models at leading engineering schools. It highlights five factors which have a significant impact on creativity of individuals - motivation, environment, knowledge and domain skills, openness to other domains, and open ended problems in assignments. As a co-creative and supportive environment, laboratory for ideas covers these factors and encompasses different groups of actors and activities. By encouraging students' entrepreneurial intentions and practical innovativeness, it is described how it should systematically strengthen both their creativity and engineering mindset.
The paper investigates into allocation of treasury funds when major repairs are being funded. Slum clearance is part of major repairs costs. It is shown that mortgage lending can be used to reduce loading on treasury funds and make slum clearance quicker. The world experience in mortgage lending improvement is studied. In particular, mortgage securitization effect is looked into. A model of government co-financing of mortgage lending is proposed. The effect on economic performances due to application of this model is assessed. Guidelines are suggested in order to maintain high quality of the mortgage portfolio.
Focusing on the characteristics of different thinking styles and different product development project types, we suggest that people should adapt their thinking strategies according to the challenge they face and choose a thinking style that is a best match for the type of project they are working on. Even though people can perform well in more than one thinking style, they can be more successful if they adequately choose the most appropriate one for solving the problem in front of them. Considering that different thinking styles have different ideas and conclusions as results, we propose how to match them to a specific product development project type that has a certain degree of change in the product as a deliverable. For further research, these findings open the possibility to define the most appropriate creative problem solving methods and techniques that spur and support a specific style of thinking.