Incremental design of scalable interconnection networks using basic building blocks

In this paper, we present an incremental design of scalable interconnection networks in multicomputer systems using basic building blocks. Both network topologies and routing algorithms are considered. We use wormhole-routed small-scale 2D meshes as basic building blocks. The minimum requirement to expand these networks is a single building block. This implies that the network does not have to maintain the regular 2D mesh topology. Some new topologies are introduced: incomplete meshes based on those adaptive routing algorithms designed from the turn model and extended incomplete meshes based on XY routing. We show that the original routing algorithm can be adopted to send a message between any source and destination without using store-and-forward and causing deadlock. The way that the network is constructed incrementally requires no or a very small amount of rewiring and keeps high bisection density and short diameter of the network. The design methods can be used to economically and incrementally build expandable and scalable parallel computers.     

Computational procedures for plastic shakedown design of structures

The minimum volume design problem of elastic perfectly plastic finite element structures subjected to a combination of fixed and perfect cyclic loads is studied. The design problem is formulated in such a way that incremental collapse is certainly prevented. The search for the structural design with the required limit behaviour is effected following two different formulations, both developed on the grounds of a statical approach: the first one operates below the elastic shakedown limit and is able to provide a suboptimal design; the second one operates above the elastic shakedown limit and is able to provide the/an optimal design. The Kuhn–Tucker conditions of the two problems provide useful information about the different behaviour of the obtained structures.An application concludes the paper; the comparison among the designs is effected, pointing out the different behaviour of the obtained structures as well as the required computational effort related to the numerical solutions.     

Computational methods for optimal shakedown design of FE structures

The paper concerns the optimal shakedown design of structures discretized by elastic perfectly plastic finite elements. The design problem is formulated in four alternative versions, i.e. as the search for the minimum volume design whose shakedown limit load multiplier is assigned or as the search for the maximum shakedown limit load multiplier design whose volume is assigned; both problems are approached on the grounds of the shakedown lower bound and upper bound theorems. Correspondingly four computational methods, one for each original problem, are presented. These methods consist in solving iteratively new problems which are simpler than the original ones, but expressed in such a way that the obtained design and behavioural variables fulfill the optimality conditions of the relevant original problems, and thus they provide the true optimal design. Finally, an alternative numerical approach devoted to obtaining the optimal shakedown design is presented. Several numerical examples confirm the theoretical results.     

Simulation aided design of organizational structures in manufacturing systems using structuring strategies

This paper presents a simulation aided approach for designing organizational structures in manufacturing systems. The approach is based on a detailed modeling and characterization of the forecasted order program, especially of elementary processes, activity networks and manufacturing orders. Under the use of the organization modeling system FORM, that has been developed at the ifab-Institute of Human and Industrial Engineering of the University of Karlsruhe, structuring strategies—e.g., a process-oriented strategy—can be applied in order to design organizational structures in manufacturing systems in a flexible and efficient way. Following that, a dynamical analysis of the created manufacturing structures can be carried out with the simulation tool FEMOS, that has also been developed at the ifab-Institute. The evaluation module of FEMOS enables to measure the designed solutions with the help of logistical—e.g., lead time degree—and organizational—e.g., degree of autonomy—key data. This evaluation is the basis for the identification of effective manufacturing systems and also of improvement potentialities. Finally, a case study is presented in this paper designing and analyzing different organizational structures of a manufacturing system where gear boxes and robot grip arms were manufactured.     

Parameterization and optimization strategies for the automated design of uPVC profile extrusion dies

Optimization strategies for use within an automated optimization framework for PVC profile extrusion dies are presented. The methods are designed to work in an industrial environment and must therefore account for the specific design and manufacturing techniques for these profile dies. The complex three-dimensional die geometry will be represented through a series of two-dimensional so-called die-slices. The purpose of the presented optimization cycle is to find the optimal shape of the die cross-section of the die-slices. Each die-slice geometry is optimized by a computerized optimization loop using a finite element (FE) analysis of the polymer flow through the die. Simple data representation of the complex die geometry allows an efficient parameterization. Several optimization strategies are compared regarding the achieved quality of the optimization, the computational costs, the required user interaction and the robustness in industrial applications. The strategies are (i) a global scheme in which all design variables (DVs) are dealt with simultaneously, (ii) a sequential optimization in which DVs are addressed one after each other, (iii) employing a height approximation type method in which the new values for the DVs are found using assumptions of the flow between two parallel plates, and (iv) a global scheme in which the DVs are decoupled taking advantage of the particular FE analysis applied.     

A controller design methodology for close headway spacing strategies for automated vehicles

An extended analysis of a vehicle following at close headway is carried out. A largely linear model of a vehicle is used to permit the computation of a large convoy. Vehicular interactions within a convoy in which each vehicle receives only information on the status of the preceding vehicle are analysed and a matrix representation of the set of interactions is developed, the main emphasis being on the propagation of spacing errors within the convoy. The conditions for positive impulse response, attenuation of error and stable, non-oscillatory response are identified in terms of both pole placement and volume space in which stable operating conditions may be located. The implications of the choice of controller parameters are studied with four examples and related to the information flow strategy and requirements within each convoy. The paper then presents the proposed short headway controller design methodology.     

Semantic schema modeling for genetic programming using clustering of building blocks

Semantic schema theory is a theoretical model used to describe the behavior of evolutionary algorithms. It partitions the search space to schemata, defined in semantic level, and studies their distribution during the evolution. Semantic schema theory has definite advantages over popular syntactic schema theories, for which the reliability and usefulness are criticized. Integrating semantic awareness in genetic programming (GP) in recent years sheds new light also on schema theory investigations. This paper extends the recent work in semantic schema theory of GP by utilizing information based clustering. To this end, we first define the notion of semantics for a tree based on the mutual information between its output vector and the target and introduce semantic building blocks to facilitate the modeling of semantic schema. Then, we propose information based clustering to cluster the building blocks. Trees are then represented in terms of the active occurrence of building block clusters and schema instances are characterized by an instantiation function over this representation. Finally, the expected number of schema samples is predicted by the suggested theory. In order to evaluate the suggested schema, several experiments were conducted and the generalization, diversity preserving capability and efficiency of the schema were investigated. The results are encouraging and remarkably promising compared with the existing semantic schema.     

Efficient strategies for reliability-based design optimization of variable stiffness composite structures

This study investigates efficient design optimization frameworks for composite structures with uncertainties related to material properties and loading. The integration of two decoupled reliability-based design optimization methodologies with a decoupled discrete material optimization is proposed to determine material and fiber orientation for three-dimensional composite structures. First, a deterministic and decoupled discrete material optimization is used for baseline comparison. The objective is to minimize the cost of composite structures with the design variables comprising of the piecewise patch orientations and material properties of the fiber reinforced composites. The reliability-based design optimization includes a hybrid method, and also the sequential optimization and reliability assessment method. In the sequential optimization and reliability assessment method, the inverse reliability analysis is evaluated using a stochastic response surface method and a first order reliability approach. Comparing the methods based on the optimal material and fiber orientations, the uncertainties in loads and material properties lead to different optimal layouts compared to the deterministic solutions. The numerical results also reveal that the hybrid method applied in reliability based designs results in negligible additional computational cost.     

一种新型智能大厦局域网中继器的设计

本文介绍了智能建筑通信系统对通信的要求,以RS485为例设计一种适用于智能建筑的新型中继器,它利用单片机外部中断检测串行通信的起始位,定时器定时控制数据收发周期,从而将数据按字节收发,实现中继器的功能.本方案以RS485通信方式为例,其思想亦适用于其他通信方式.     

一种新型智能大厦局域网中继器的设计

本文介绍了智能建筑通信系统对通信的要求,以RS485为例设计一种适用于智能建筑的新型中继器,它利用单片机外部中断检测串行通信的起始位,定时器定时控制数据收发周期,从而将数据按字节收发,实现中继器的功能。本方案以RS485通信方式为例,其思想亦适用于其他通信方式。     

Active control of building structures using piezoelectric actuators

Active control strategy is an innovative method for enhancing structural functionality against strong ground motions. In this paper the performance of piezoelectric actuators for active control of the seismic responses of tall buildings is investigated. Three-dimensional modeling of the building is considered where three degrees of freedom including displacements in two perpendicular horizontal directions and rotation about the vertical axis are corresponded to each floor. The piezoelectric actuators are hosted at the bottom of the columns and the controlling forces produced by actuators are considered in the equations of motion of the buildings. Linear quadratic regulator (LQR), supervisory fuzzy controller (SFC) and fuzzy logic controller (FLC) are applied in the control designs. For the numerical studies, a real 10 story building subjected to an ensemble of 20 worldwide acceleration records is considered. Since there are many possible positions for placement of piezoelectric actuators in the test building, genetic algorithm is used for finding the optimal arrangement of actuators in order to achieve maximum reduction in building responses. The comparison of the controlled and uncontrolled responses of the test building indicates that the piezoelectric actuators are able to provide considerable reductions in buildings’ seismic responses. Also the performance of the above three controllers reveals that the fuzzy controller is much more effective than the two others.     

Isogeometric design sensitivity analysis and experimental validation of nanoscale structures considering surface effects

A continuum-based design sensitivity analysis (DSA) method is developed for nanoscale structures with surface effects. To account for the effects of precise geometry in the response and the design sensitivity analyses, we employ an isogeometric approach which uses the same NURBS basis functions as used to describe the geometry of CAD. A direct differentiation method is employed to obtain the analytical design sensitivity using a generalized Young-Laplace equation with high-order surface effects. Effective material properties with the surface effects for silver nanowires are measured from a three-point bending test using atomic force microscopy (AFM). The diameter and the suspended length of silver nanowires are considered as sizing and shape design variables, respectively. The design sensitivity expressions are derived with respect to the design parameters and validated comparing with the experimental results from the AFM scanning, showing an acceptable agreement.     

Computational method for the design of ducts

This paper describes an inverse method that applies to two-dimensional, irrotational and incompressible flow, based on a transformation of variables from the physical plane defined by (x, y), to a computational plane defined by the stream function ψ, and the velocity potential, ?. In this new plane, the resulting differential equation describing the flow is relatively simple, and should be solved in a domain that presents always a rectangular shape, facilitating the generation of a numerical grid appropriate to the problem. The solution of this equation gives the distribution of the x coordinate throughout the flow field, while the values of the y coordinate are calculated by integration of the previous result. Some of the numerical details of the procedure will be discussed, with special emphasis on the numerical treatment of the boundary conditions. The application of the described method to the design of a curved duct with an overall deflection of around 90° will be presented, with the aim of showing the potentialities of the method, which is computationally quite simple.     

3D molecular assembling of B-DNA sequences using nucleotides as building blocks

Unlike the current atomistic DNA models, this paper proposes a new 3D space-filling model for sequences of DNA base pairs using nucleotides, instead of atoms, as building blocks of DNA molecules. This nucleotide-based model is more scalable than the traditional atomistic model, and has the advantage that easily adapts to any topological conformation of DNA. Interestingly, this model also allows the building of the molecular surface of the DNA, either partly or entirely, as needed for energy computations in molecular applications. Moreover, it allows us to grasp the DNA shape at different levels of shape composition: atom, nucleotide, and DNA macromolecule as a whole.     

Sculpturic design of structures using finite elements

A new philosphy of optimal structural design called ‘sculpturic design’ is introduced in this paper. A companion methodology is presented through which an optimal design is achieved using a systematic procedure. To illustrate this concept and methodology several examples are treated, and by using the finite-element method, certain structures which may be termed ‘sculpturic structures’ are obtained.     

Definition of standards-based building blocks for multimedia content management

The emergence of new ways of rendering multimedia content from a multiplicity of devices like tablets, smartphones, consoles or smart TVs, opens a complete set of new opportunities for multimedia services providers. It is important that the development of those disruptive services is done in an interoperable way. Existing service-oriented middleware platforms and recently developed standards devoted to the definition and implementation of complex multimedia services may speed up its development. In this context, the identification of different content management scenarios including the high-level functionalities they require is an important aspect to be able to implement services in a flexible and interoperable way. Use of standards and standards-based architectures will be a key aspect to combine services offered by different providers. In this paper, we propose the definition of standards-based building blocks based on the high-level functionalities required by content management and distribution scenarios. This will facilitate provision of complex new services specially focused, but not limited to, the management and distribution of multimedia content.     

Computational intelligence approach to PID controller design using the universal model

Despite the popularity of PID (Proportional-Integral-Derivative) controllers, their tuning aspect continues to present challenges for researches and plant operators. Various control design methodologies have been proposed in the literature, such as auto-tuning, self-tuning, and pattern recognition. The main drawback of these methodologies in the industrial environment is the number of tuning parameters to be selected. In this paper, the design of a PID controller, based on the universal model of the plant, is derived, in which there is only one parameter to be tuned. This is an attractive feature from the viewpoint of plant operators. Fuzzy and neural approaches - bio-inspired methods in the field of computational intelligence - are used to design and assess the efficiency of the PID controller design based on differential evolution optimization in nonlinear plants. The numerical results presented herein indicate that the proposed bio-inspired design is effective for the nonlinear control of nonlinear plants.     

Computational observer design techniques for linear systems withunknown inputs using the concept of transmission zeros

Computational observer design techniques for linear systems subject to unknown inputs are presented. Complete and intuitive geometric conditions for the solution of the problem which result in design matrix equations are provided. These design equations are solved in a computationally efficient way. The synthesis of the reduced-order observer takes full advantage of the concept of transmission zeros. In particular, the necessary and sufficient conditions obtained are given in terms of the transmission zeros of the triple (A,D, C)     

A strategy for automated modeling of frame structures

Structural analysis involves three main phases, namely, modeling, analysis, and results processing. Computer software exists in order to automate the analysis and results processing phases. However, modeling is still done largely by hand, especially for frame structures.This paper considers automated modeling of frame structures in the context of a computer integrated system for structural engineering design. In this system a structure is defined in terms of its components and connections, and it is necessary to create an analysis model in terms of nodes, elements, boundary conditions, and so on. The paper describes the logic of the modeling process, describes the output from the process, and shows how this output can be used as input data for a structural analysis program. The scope is limited to determination of the structure stiffness properties and assembly of the stiffness matrix.