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Showing papers on "Modular design published in 2007"


01 Jan 2007
TL;DR: Some of the design aspects of the underlying architecture of the Konstanz Information Miner are described and briefly sketch how new nodes can be incorporated.
Abstract: The Konstanz Information Miner is a modular environment, which enables easy visual assembly and interactive execution of a data pipeline. It is designed as a teaching, research and collaboration platform, which enables simple integration of new algorithms and tools as well as data manipulation or visualization methods in the form of new modules or nodes. In this paper we describe some of the design aspects of the underlying architecture and briefly sketch how new nodes can be incorporated.

1,078 citations


Journal ArticleDOI
TL;DR: Although there is an emerging agreement that organisms have a modular organization, the main open problem is the question of whether modules arise through the action of natural selection or because of biased mutational mechanisms.
Abstract: A network of interactions is called modular if it is subdivided into relatively autonomous, internally highly connected components. Modularity has emerged as a rallying point for research in developmental and evolutionary biology (and specifically evo-devo), as well as in molecular systems biology. Here we review the evidence for modularity and models about its origin. Although there is an emerging agreement that organisms have a modular organization, the main open problem is the question of whether modules arise through the action of natural selection or because of biased mutational mechanisms.

922 citations


Journal ArticleDOI
TL;DR: Several of the key directions for the future of modular self-reconfigurable robotic systems, including the design, fabrication, motion planning, and control of autonomous kinematic machines with variable morphology are shown.
Abstract: The field of modular self-reconfigurable robotic systems addresses the design, fabrication, motion planning, and control of autonomous kinematic machines with variable morphology. Modular self-reconfigurable systems have the promise of making significant technological advances to the field of robotics in general. Their promise of high versatility, high value, and high robustness may lead to a radical change in automation. Currently, a number of researchers have been addressing many of the challenges. While some progress has been made, it is clear that many challenges still exist. By illustrating several of the outstanding issues as grand challenges that have been collaboratively written by a large number of researchers in this field, this article has shown several of the key directions for the future of this growing field

903 citations


Journal Article
TL;DR: Several of the key directions for the future of modular self-reconfigurable robotic systems, including the design, fabrication, motion planning, and control of autonomous kinematic machines with variable morphology are shown.
Abstract: The field of modular self-reconfigurable robotic systems addresses the design, fabrication, motion planning, and control of autonomous kinematic machines with variable morphology. Modular self-reconfigurable systems have the promise of making significant technological advances to the field of robotics in general. Their promise of high versatility, high value, and high robustness may lead to a radical change in automation. Currently, a number of researchers have been addressing many of the challenges. While some progress has been made, it is clear that many challenges still exist. By illustrating several of the outstanding issues as grand challenges that have been collaboratively written by a large number of researchers in this field, this article has shown several of the key directions for the future of this growing field

414 citations


Book
01 Jan 2007
TL;DR: Modular forms Modular forms of level $1$ Modular form of weight $2$ Dirichlet characters Eisenstein series and Bernoulli numbers Dimension formulas Linear algebra General modular symbols Computing with new forms Computing periods Solutions to selected exercises Appendix A: Computing in higher rank Bibliography Index.
Abstract: Modular forms Modular forms of level $1$ Modular forms of weight $2$ Dirichlet characters Eisenstein series and Bernoulli numbers Dimension formulas Linear algebra General modular symbols Computing with newforms Computing periods Solutions to selected exercises Appendix A: Computing in higher rank Bibliography Index.

357 citations


Proceedings ArticleDOI
10 Dec 2007
TL;DR: To create the Super Servo, the author has replaced the electronics in a hobby servo with such components as sensors to monitor current and temperature, a communications bus, and a programmable microcontroller, to create a robust and versatile robot.
Abstract: Many factors such as size, power, and weight constrain the design of modular snake robots. Meeting these constraints requires implementing a complex mechanical and electrical architecture. Here we present our solution, which involves the construction of sixteen aluminum modules and creation of the Super Servo, a modified hobby servo. To create the Super Servo, we have replaced the electronics in a hobby servo, adding such components as sensors to monitor current and temperature, a communications bus, and a programmable microcontroller. Any robust solution must also protect components from hazardous environments such as sand and brush. To resolve this problem we insert the robots into skins that cover their surface. Functions such as climbing the inside and outside of a pipe add a new dimension of interaction. Thus we attach a compliant, high-friction material to every module, which assists in tasks that require gripping. This combination of the mechanical and electrical architectures results in a robust and versatile robot.

268 citations


Patent
30 Nov 2007
TL;DR: The modular spinal prosthesis described in this article provides an artificial articular configuration to replace damaged, worn or otherwise removed spinal facet elements, which can replace damaged or worn spinal facet element elements.
Abstract: Modular spinal prosthesis having one of both of adaptable and configurable components are provided. The modular spinal prosthesis described herein provide an artificial articular configuration to replace damaged, worn or otherwise removed spinal facet elements.

264 citations


Journal ArticleDOI
TL;DR: This work defines three measures of component modularity based on the notion of centrality and calculates and interprets all three measures by studying the product architecture of a large commercial aircraft engine.
Abstract: Modularity has been defined at the product and system levels. However, little effort has gone into defining and quantifying modularity at the component level. We consider complex products as a network of components that share technical interfaces (or connections) in order to function as a whole and define component modularity based on the lack of connectivity among them. Building upon previous work in graph theory and social network analysis, we define three measures of component modularity based on the notion of centrality. Our measures consider how components share direct interfaces with adjacent components, how design interfaces may propagate to nonadjacent components in the product, and how components may act as bridges among other components through their interfaces. We calculate and interpret all three measures of component modularity by studying the product architecture of a large commercial aircraft engine. We illustrate the use of these measures to test the impact of modularity on component redesign. Our results show that the relationship between component modularity and component redesign depends on the type of interfaces connecting product components. We also discuss directions for future work. DOI: 10.1115/1.2771182

252 citations


Patent
24 Apr 2007
TL;DR: In this article, a backplane architecture, structure, and method that has no active components and separate power supply lines and protection to provide high reliability in server environment is presented for power management and workload management for multi-server environments.
Abstract: Network architecture, computer system and/or server, circuit, device, apparatus, method, and computer program and control mechanism for managing power consumption and workload in computer system and data and information servers. Further provides power and energy consumption and workload management and control systems and architectures for high-density and modular multi-server computer systems that maintain performance while conserving energy and method for power management and workload management. Dynamic server power management and optional dynamic workload management for multi-server environments is provided by aspects of the invention. Modular network devices and integrated server system, including modular servers, management units, switches and switching fabrics, modular power supplies and modular fans and a special backplane architecture are provided as well as dynamically reconfigurable multi-purpose modules and servers. Backplane architecture, structure, and method that has no active components and separate power supply lines and protection to provide high reliability in server environment.

248 citations


Journal ArticleDOI
TL;DR: Based on cluster desynchronization properties of phase oscillators, an efficient method is introduced for the detection and identification of modules in complex networks with a high level of precision.
Abstract: Based on cluster desynchronization properties of phase oscillators, we introduce an efficient method for the detection and identification of modules in complex networks. The performance of the algorithm is tested on computer generated and real-world networks whose modular structure is already known or has been studied by means of other methods. The algorithm attains a high level of precision, especially when the modular units are very mixed and hardly detectable by the other methods, with a computational effort O(KN) on a generic graph with N nodes and K links.

240 citations


Journal ArticleDOI
TL;DR: It is described how modular software design and well proven object oriented design patterns can help to implement a flexible software package for the efficient solution of partial differential equations.
Abstract: We describe how modular software design and well proven object oriented design patterns can help to implement a flexible software package for the efficient solution of partial differential equations. Today not only efficiency in the numerical solution is of utmost importance for practical use, efficiency in problem setup and interpretation of numerical results is of importance if modeling and computing comes closer and closer together. In order to demonstrate the possibilities of the software, we apply the tool to several non-standard problems.

Patent
20 Aug 2007
TL;DR: In this article, a prefabricated interconnectable modular building units, each unit comprising a frame shaped as a rectangular parallelopiped and comprised of framing members and a plurality of nodes, each node situated at a corner of said frame for selective interconnection with other units, the nodes and the exterior dimensions of the frame conforming to ISO shipping standards such that each unit is transportable using the ISO intermodal transportation system, and such that when the units are aggregated horizontally and vertically and adjacent units are interconnected, a building structure compnsing at least one habitable
Abstract: Construction systems for erecting building structures comprise a plurality of prefabricated interconnectable modular building units, each unit comprising a frame shaped as a rectangular parallelopiped and comprised of framing members and a plurality of nodes, each node situated at a corner of said frame for selective interconnection with other units, the nodes and the exterior dimensions of the frame conforming to ISO shipping standards such that each unit is transportable using the ISO intermodal transportation system, and such that when the units are aggregated horizontally and vertically and adjacent units are interconnected, a building structure compnsing at least one habitable space is formed The modular units are assembled in a factory remote from the job site, and are there constructed to a semi-finished state, including installation of one or more of interior fit-out systems and finishes, exterior envelope systems, plumbing systems, electrical systems, environmental systems, and fire protection systems.

01 Jan 2007
TL;DR: This article outlines some of this progress and identifies key challenges and opportunities that lay ahead in the field of modular self-reconfigurable robotic systems.
Abstract: T he field of modular self-reconfigurable robotic systems addresses the design, fabrication , motion planning, and control of autonomous kinematic machines with variable morphology. Beyond conventional actuation, sensing, and control typically found in fixed-morphology robots, self-reconfigurable robots are also able to deliberately change their own shape by rearranging the connectivity of their parts in order to adapt to new circumstances, perform new tasks, or recover from damage. Over the last two decades, the field of modular robotics has advanced from proof-of-concept systems to elaborate physical implementations and simulations. The goal of this article is to outline some of this progress and identify key challenges and opportunities that lay ahead. Modular robots are usually composed of multiple building blocks of a relatively small repertoire, with uniform docking interfaces that allow transfer of mechanical forces and moments, electrical power, and communication throughout the robot. The modular building blocks often consist of some primary structural actuated unit and potentially some additional specialized units such as grippers, feet, wheels, cameras, payload, and energy storage and generation units. Figure 1 illustrates such a system in the context of a potential application. Modular self-reconfigurable robotic systems can be generally classified into several architectural groups by the geometric arrangement of their units. Several systems exhibit hybrid properties. ◆ Lattice Architectures: Lattice architectures have units that are arranged and connected in some regular, three-dimensional pattern, such as a simple cubic or hexagonal grid. Control and motion can be executed in parallel. Lattice architectures usually offer simpler reconfiguration, as modules move to a discrete set of neighboring locations in which motions can be made open-loop. The computational representation can also be more easily scaled to more complex systems. ◆ Chain/Tree Architectures: Chain/tree architectures have units that are connected together in a string or tree topology. This chain or tree can fold up to become space filling, but the underlying architecture is serial. Through articulation, chain architectures can potentially reach any point or orientation in space, and are therefore more versatile but computationally more difficult to represent and analyze and more difficult to control. ◆ Mobile Architectures: Mobile architectures have units that use the environment to maneuver around and can either hook up to form complex chains or lattices or form a number of smaller robots that execute coordinated movements and together form a larger " virtual " network. Control of all three types of modular systems can be centralized …

Journal ArticleDOI
21 Jun 2007-Nature
TL;DR: Ionic liquids are generally regarded as solvents, but these modular, tunable compounds have far greater technological potential and with a coat of silver, they become ideal materials for the liquid mirror of a space telescope.
Abstract: Ionic liquids are generally regarded as solvents, but these modular, tunable compounds have far greater technological potential. With a coat of silver, they become ideal materials for the liquid mirror of a space telescope.

Proceedings ArticleDOI
12 Aug 2007
TL;DR: The theory and implementation of a highly scalable and modular convex solver which solves all these estimation problems, can be parallelized on a cluster of workstations, allows for data-locality, and can deal with regularizers such as l1 and l2 penalties.
Abstract: A wide variety of machine learning problems can be described as minimizing a regularized risk functional, with different algorithms using different notions of risk and different regularizers. Examples include linear Support Vector Machines (SVMs), Logistic Regression, Conditional Random Fields (CRFs), and Lasso amongst others. This paper describes the theory and implementation of a highly scalable and modular convex solver which solves all these estimation problems. It can be parallelized on a cluster of workstations, allows for data-locality, and can deal with regularizers such as l1 and l2 penalties. At present, our solver implements 20 different estimation problems, can be easily extended, scales to millions of observations, and is up to 10 times faster than specialized solvers for many applications. The open source code is freely available as part of the ELEFANT toolbox.

01 Oct 2007
TL;DR: This report is a Users Guide for the NASA-developed Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) software, which is a transient simulation of a large commercial turbofan engine with a realistic engine control system.
Abstract: This report is a Users Guide for the NASA-developed Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) software, which is a transient simulation of a large commercial turbofan engine (up to 90,000-lb thrust) with a realistic engine control system. The software supports easy access to health, control, and engine parameters through a graphical user interface (GUI). C-MAPSS provides the user with a graphical turbofan engine simulation environment in which advanced algorithms can be implemented and tested. C-MAPSS can run user-specified transient simulations, and it can generate state-space linear models of the nonlinear engine model at an operating point. The code has a number of GUI screens that allow point-and-click operation, and have editable fields for user-specified input. The software includes an atmospheric model which allows simulation of engine operation at altitudes from sea level to 40,000 ft, Mach numbers from 0 to 0.90, and ambient temperatures from -60 to 103 F. The package also includes a power-management system that allows the engine to be operated over a wide range of thrust levels throughout the full range of flight conditions.

Journal ArticleDOI
TL;DR: The design structure matrix (DSM) is used to visualize the product architecture and to develop the basic building blocks required for the identification of product modules, leading to a new clustering method based on the minimum description length (MDL) principle and a simple genetic algorithm.
Abstract: Designing modular products can result in many benefits to both manufacturers and consumers. The development of modular products requires the identification of highly interactive groups of elements and arranging (i.e., clustering) them into modules. However, no rigorous clustering technique can be found in engineering design literature. This paper uses the design structure matrix (DSM) to visualize the product architecture and to develop the basic building blocks required for the identification of product modules. The DSM architectural representation and building blocks are then used for the development of a new clustering method based on the minimum description length (MDL) principle and a simple genetic algorithm (GA). The new method is capable of partitioning the product architecture into a set of modules where interactions within modules are maximized and interactions outside modules are minimized. We demonstrate the proposed clustering method using several examples of real complex products and compare our results to clustering arrangements proposed by human experts. The proposed method is capable of mimicking the clustering preference of human experts and yields competitive clustering arrangements.

Journal ArticleDOI
TL;DR: A hierarchical software structure has been established to perform all data processing and the control of the hand and provides basic API functions and skills to access all hardware resources for data acquisition, computation and tele-operation.

Journal ArticleDOI
TL;DR: A large space of possible robots capable of autonomous self-reproduction is demonstrated, composed of actuated modules equipped with electromagnets to selectively control the morphology of the robotic assembly.
Abstract: Long-term physical survivability of most robotic systems today is achieved through durable hardware. In contrast, most biological systems are not made of robust materials; long-term sustainability and evolutionary adaptation in nature are provided through processes of self-repair and, ultimately, self-reproduction. Here we demonstrate a large space of possible robots capable of autonomous self-reproduction. These robots are composed of actuated modules equipped with electromagnets to selectively control the morphology of the robotic assembly. We show a variety of 2-D and 3-D machines from 3 to 2n modules, and two physical implementations that each achieves two generations of reproduction. We show both automatically generated and manually designed morphologies

Journal ArticleDOI
TL;DR: In this article, the authors present a review of the current developments in mechatronic systems for metal cutting and forming machine tools and their interaction with manufacturing processes, including active and passive damping of vibrations through piezo, magnetic and electro-hydraulic actuators.

Journal ArticleDOI
TL;DR: The JastAdd system enables modular specifications of extensible compiler tools and languages throughObject-orientation and static aspect-oriented programming are combined with declarative attributes and context-dependent rewrites to allow highly modular specifications.

Journal ArticleDOI
TL;DR: A novel distributed-arithmetic (DA)-based proportional-integral-derivative (PID) controller algorithm is proposed and integrated into a digital feedback control system, resulting in cost reduction, high speed, and low power consumption, which is desirable in embedded control applications.
Abstract: In this paper, modular design of embedded feedback controllers using field-programmable gate array (FPGA) technology is studied. To this end, a novel distributed-arithmetic (DA)-based proportional-integral-derivative (PID) controller algorithm is proposed and integrated into a digital feedback control system. The DA-based PID controller demonstrates 80% savings in hardware utilization and 40% savings in power consumption compared to the multiplier-based scheme. It also offers good closed-loop performance while using less resources, resulting in cost reduction, high speed, and low power consumption, which is desirable in embedded control applications. The complete digital control system is built using commercial FPGAs to demonstrate the efficiency. The design uses a modular approach, so that some modules can be reused in other applications. These reusable modules can be ported into Matlab/Simulink as Simulink blocks for hardware/software cosimulation or integrated into a larger design in the Matlab/Simulink environment to allow for rapid prototyping applications.

Journal ArticleDOI
TL;DR: The modular structure of the protein–protein interaction (PPI) networks during fruitfly and human brain aging and their relationships demonstrate that aging is largely associated with a small number, instead of many network modules, and that some modular changes might be reversible.
Abstract: Many fundamental questions on aging are still unanswered or are under intense debate. These questions are frequently not addressable by examining a single gene or a single pathway, but can best be addressed at the systems level. Here we examined the modular structure of the protein– protein interaction (PPI) networks during fruitfly and human brain aging. In both networks, there are two modules associated with the cellular proliferation to differentiation temporal switch that display opposite aging-related changes in expression. During fly aging, another couple of modules are associated with the oxidative–reductive metabolic temporal switch. These network modules and their relationships demonstrate (1) that aging is largely associated with a small number, instead of many network modules, (2) that some modular changes might be reversible and (3) that genes connecting different modules through PPIs are more likely to affect aging/longevity, a conclusion that is experimentally validated by Caenorhabditis elegans lifespan analysis. Network simulations further suggest that aging might preferentially attack key regulatory nodes that are important for the network stability, implicating a potential molecular basis for the stochastic nature of aging. Molecular Systems Biology 4 December 2007; doi:10.1038/msb4100189 Subject Categories: differentiation and death; molecular biology of disease

Journal ArticleDOI
TL;DR: MoNet provides an objective approach to understand the organization and interactions of biological processes in cellular systems by extending the concept of degree from the single vertex to the sub-graph, and a formal definition of module in a network is used.
Abstract: Motivation: Accumulating evidence suggests that biological systems are composed of interacting, separable, functional modules. Identifying these modules is essential to understand the organization of biological systems. Result: In this paper, we present a framework to identify modules within biological networks. In this approach, the concept of degree is extended from the single vertex to the sub-graph, and a formal definition of module in a network is used. A new agglomerative algorithm was developed to identify modules from the network by combining the new module definition with the relative edge order generated by the Girvan-Newman (G-N) algorithm. A JAVA program, MoNet, was developed to implement the algorithm. Applying MoNet to the yeast core protein interaction network from the database of interacting proteins (DIP) identified 86 simple modules with sizes larger than three proteins. The modules obtained are significantly enriched in proteins with related biological process Gene Ontology terms. A comparison between the MoNet modules and modules defined by Radicchi et al. (2004) indicates that MoNet modules show stronger co-clustering of related genes and are more robust to ties in betweenness values. Further, the MoNet output retains the adjacent relationships between modules and allows the construction of an interaction web of modules providing insight regarding the relationships between different functional modules. Thus, MoNet provides an objective approach to understand the organization and interactions of biological processes in cellular systems. Availability: MoNet is available upon request from the authors. Contact: luofeng@cs.clemson.edu Supplementary information: Supplementary Data are available at Bioinformatics online.

Journal ArticleDOI
TL;DR: A modular analog circuit fault- diagnostic system based on neural networks using wavelet decomposition, principal component analysis, and data normalization as preprocessors to identify faulty components or modules in an analog circuit by analyzing its impulse response.
Abstract: We have developed a modular analog circuit fault- diagnostic system based on neural networks using wavelet decomposition, principal component analysis, and data normalization as preprocessors. Our proposed system has the ability to identify faulty components or modules in an analog circuit by analyzing its impulse response. In this approach, the circuit is divided into modules, which, in turn, are divided into smaller submodules successively. At each level, where a module is divided into submodules, a neural network is trained to identify the submodule that inherits the fault of interest from the parent module. This procedure finds the faulty component or module of any desirable size in an analog circuit by consecutive divisions of modules as many times as necessary. Our proposed approach has three advantages over the traditional neural-network-based diagnostic systems, which directly look for faulty components in the entire circuit. First, the performance of the modular systems is reliable and robust independent of the circuit size and can successfully classify similar fault classes with a significant overlap in the feature space where the traditional approach completely fails. Second, the modular approach requires significantly smaller neural network architectures, leading to much more efficient training. Third, for large real circuit boards, our diagnostic system proceeds to systematically reduce the size of the faulty modules until it is feasible to replace it.

Proceedings ArticleDOI
04 Jun 2007
TL;DR: A design methodology for partitioning an NoC architecture into multiple VFIs and assigning supply and threshold voltage levels to each VFI Simulation results show about 40% savings for a real video application and demonstrate the effectiveness of the approach in reducing the overall system energy consumption.
Abstract: Due to high levels of integration and complexity, the design of multi-core SoCs has become increasingly challenging In particular, energy consumption and distributing a single global clock signal throughout a chip have become major design bottlenecks To deal with these issues, a globally asynchronous, locally synchronous (GALS) design is considered for achieving low power consumption and modular design Such a design style fits nicely with the concept of voltage-frequency islands (VFIs) which has been recently introduced for achieving fine-grain system-level power management This paper proposes a design methodology for partitioning an NoC architecture into multiple VFIs and assigning supply and threshold voltage levels to each VFI Simulation results show about 40% savings for a real video application and demonstrate the effectiveness of our approach in reducing the overall system energy consumption The results and functional correctness are validated using an FPGA prototype for an NoC with multiple VFIs

Journal ArticleDOI
TL;DR: By systematically altering the number and affinity of modular autoinhibitory interactions, this work shows that it can predictably convert a simple linear signaling protein into an ultrasensitive switch.
Abstract: Many signaling proteins are built from simple, modular components, yet display highly complex signal-processing behavior. Here we explore how modular domains can be used to build an ultrasensitive switch—a nonlinear input/output function that is central to many complex biological behaviors. By systematically altering the number and affinity of modular autoinhibitory interactions, we show that we can predictably convert a simple linear signaling protein into an ultrasensitive switch.

Journal ArticleDOI
TL;DR: A distributed fault diagnosis algorithm is presented which allows each module in the distributed system to diagnose its faults independently unless completion of a task requires the use of coupled components.
Abstract: This paper studies online fault detection and isolation of modular dynamic systems modeled as sets of place-bordered Petri nets. The common places among the set of Petri nets modeling a system capture coupling of various system components. The transitions are labeled by events, some of which are unobservable (i.e., not directly recorded by the sensors attached to the system). The events whose occurrence must be diagnosed have unobservable transition labels. These events model faults or other significant changes in the system state. The existing theory of diagnosis of discrete-event systems is extended in the context of the above model. The modular structure of the system is exploited by a distributed algorithm for fault diagnosis. A Petri net diagnoser is associated with every Petri net and the diagnosers communicate in real time during the diagnostic process when the token count of common places changes. A merge function is defined to combine the individual diagnoser states and recover the complete diagnoser state that would be obtained under a monolithic approach. Strategies that reduce the communication overhead are presented. The software implementation of the distributed algorithm is discussed. Note to Practitioners-In the last decade, monitoring, fault detection, and diagnosis methodologies based on the use of discrete-event models have been successfully used in a variety of technological systems ranging from document processing systems to intelligent transportation systems. This paper was motivated by the problem of fault diagnosis for modular (distributed) dynamic discrete-event systems (DES). As a DES modeling formalism, Petri nets offer potential advantages in terms of the distributed representation of the system and the ability to represent coupling of the system components. The systems studied in this paper are sets of modules coupled with each other through various system components and modeled using Petri nets. We present a distributed fault diagnosis algorithm which allows each module in the distributed system to diagnose its faults independently unless completion of a task requires the use of coupled components. In the case of coupling, modules communicate with each other to accurately diagnose the fault. The distributed fault diagnosis algorithm recovers the monolithic diagnosis information at the cost of communication and growing communication overhead. To mitigate that problem, we present an improved version of the algorithm that significantly reduces the communication overhead. Finally, we introduce the software toolbox (written in Matlab and integrated with AT&T Graphviz) and we present a case study of an example of a heating, ventilation, and air-conditioning system where we use the software tool for modeling and analyzing the system

Journal ArticleDOI
TL;DR: This paper presents a conceptual study of a wireless real-time system dedicated for remote sensor/actuator control in production automation based on user requirements and a market research.
Abstract: Modern factory facilities are characterized by highly flexible manufacturing cells and highly dynamic processes, where clusters of fixed or moving sensors and actuators have to be controlled in a limited space under stringent real-time and reliability constraints. In such demanding industrial environments, wireless systems can also be beneficial by improving flexibility, cutting cables, and enabling solutions, which are cumbersome or even not possible to realize with wireline systems, especially in controlling moving or rotating parts. In this paper, we present a conceptual study of a wireless real-time system dedicated for remote sensor/actuator control in production automation. System development is based on user requirements, which were extracted from customer interviews and a market research. Low level measurements of frequency- and space-selective wireless channels in a factory-like environment were carried out. System design aspects, i.e., network topology, multiple access schemes, and radio technologies, will be thoroughly reviewed. The performance of a first prototype implementation will be discussed with emphasis on timing behavior and power consumption, as sensors and actuators of the wireless system are intended to operate without power lines or batteries

Book
25 Jun 2007
TL;DR: The author explains methodology concepts for constructing testbenches that are modular and reusable and includes extensive coverage of the SystemVerilog 3.1a constructs such as classes, program blocks, randomization, assertions, and functional coverage.
Abstract: The updated second edition of this book provides practical information for hardware and software engineers using the SystemVerilog language to verify electronic designs. The author explains methodology concepts for constructing testbenches that are modular and reusable. The book includes extensive coverage of the SystemVerilog 3.1a constructs such as classes, program blocks, randomization, assertions, and functional coverage. This second edition contains a new chapter that covers programs and interfaces as well as chapters with updated information on directed testbench and OOP, layered, and random testbench for an ATM switch.