Granular segregation studies for the development of a radar-based three-dimensional sensing system

The behavior of dense granular materials is difficult to measure in three-dimensions due to the opacity of the materials. We present a new radar-based sensing system that has the capability of measuring three-dimensional particle movement throughout the bulk of high solids fraction granular systems. A key component of the new system involves retroreflectors imbedded in objects resembling the particles in the bulk granular systems. These embedded retroreflectors may be used as tracers in systems comprised of relatively large particles. However, in systems of smaller particles the most versatile use of this new sensing system requires an understanding of the details of relative particle movement based on particle size and other particle properties. Towards this, we present new ongoing experimental and computational results toward building a versatile sensing system for high solids fraction granular systems. We then comment on additional research needed on the behavior of the components in granular mixtures for a fully versatile sensing system.     

Speculations on the future practice of architecture

The future of professional design practice is discussed, using architectural practice as an example throughout the paper. A brief history of the development of the architectural profession leads to a discussion of problems in contemporary conditions. There follows a survey of probable conditions in the near future (up to the year 2000) which will provide the context of future practice. Interdisciplinary practices and design cooperatives are identified as appropriate responses to current and future problems. The potential contribution of computer-aided techniques in design is examined, and the concept of the computer aided interdisciplinary cooperative is introduced.     

Understanding granular media: from fundamentals and simulations to industrial application

Academic and industrial research on the behaviour of granular material is increasingly supported by numerical simulations. Such simulation environments are not only a vital tool in design and analysis, but also a key link between physicists and engineers. This Topical Collection includes a range of papers that use simulation to study granular matter from the micro- and macroscopic behaviour of particles to the behaviour of large industrial or geomechanical systems. These contributions enhance our understanding of basic physical effects and processes such as heat transfer, agglomeration and screening but also give essential parameters for the simulation of industrial systems, or, at least, guide the strategies required to provide realistic simulation results. The collection focuses on the presentation of (a) new coupled simulation methods to consider the interaction of granular bodies with structural or fluid systems (b) new findings for the consideration of particle shape and particle size distributions within simulations, (c) acoustic wake agglomeration, and (d) gravitational flow in geomechanics.     

A critical framework for methodological research in architecture

This paper reviews a cross-section of methodological studies undertaken in architecture since the Second World War. Despite a variety of orientations, technically, conceptually and philosophically, most studies reflect an understanding of people and objects as discrete entities interacting in an passive and unilateral manner. This dominant dualist understanding is concluded to be the essential cause of the ‘implementation gap' between architectural research and practice. For the gap to close, the development and institution of a critical framework is needed which encourages researchers to acknowledge explicitly the ontological and epistomological issues associated with architectural practice, education and research. Underlying this recommendation is a dialectic appreciation of person-world interaction; one which accepts as a holistic theme for inquiry, the experiential and interpretative quality of human thinking, feeling and action.     

A RISC architecture for high-speed data acquisition

A RISC architecture specifically designed for selective storage of high-speed digital words is presented. A specialized instruction set is created to allow programmable control of trigger conditions and storage memory. A RISC architecture is required to execute the instruction set and maintain a 10-MHz sample rate. The utility of the RISC system is illustrated by implementing both analog and digital data acquisitions. A prototype system was designed and fabricated for evaluation. Features of this design are presented     

Network architecture test-beds as platforms for ubiquitous computing

Distributed systems research, and in particular ubiquitous computing, has traditionally assumed the Internet as a basic underlying communications substrate. Recently, however, the networking research community has come to question the fundamental design or 'architecture' of the Internet. This has been led by two observations: first, that the Internet as it stands is now almost impossible to evolve to support new functionality; and second, that modern applications of all kinds now use the Internet rather differently, and frequently implement their own 'overlay' networks above it to work around its perceived deficiencies. In this paper, I discuss recent academic projects to allow disruptive change to the Internet architecture, and also outline a radically different view of networking for ubiquitous computing that such proposals might facilitate.     

Effects of Material Properties on Granular Flow in a Silo Using DEM Simulation

In order to test the effect of material properties on flowability of particulate materials, discharge procedures of spherical particles within a flat-bottomed model silo with three sets of material properties, i.e., soft and hard without adhesion and adhesive hard, were simulated using the Discrete Element Method. For each system, three particles on the center line were selected and their instant vertical velocity components were traced. In addition, both discharge and the rate were recorded throughout the procedure. The predicted results show that, for both the systems without adhesion, though the soft has a material modulus only 1/1000 of the hard, there are no significant differences in f low pattern and discharge rate. This suggests that a soft system can be used to predict the behavior of a hard one to save CPU time in a gravity-driven granular flow. On the other hand, comparison between both hard systems shows that adhesion can significantly reduce the flowability in granular flow. By analyzing the velocity plot for the traced particles, free fall was clearly detected above the decompression zone, indicating the motion of a particle in a granular flow can be resolved as free fall together with the movement due to particle collision. In addition, select dynamic behavior related to the kinetic fluctuations affecting flow was observed. discrete element method silo granule flow particulate material     

Effects of Material Properties on Granular Flow in a Silo Using DEM Simulation

In order to test the effect of material properties on flowability of particulate materials, discharge procedures of spherical particles within a flat-bottomed model silo with three sets of material properties, i.e., soft and hard without adhesion and adhesive hard, were simulated using the Discrete Element Method. For each system, three particles on the center line were selected and their instant vertical velocity components were traced. In addition, both discharge and the rate were recorded throughout the procedure. The predicted results show that, for both the systems without adhesion, though the soft has a material modulus only 1/1000 of the hard, there are no significant differences in f low pattern and discharge rate. This suggests that a soft system can be used to predict the behavior of a hard one to save CPU time in a gravity-driven granular flow. On the other hand, comparison between both hard systems shows that adhesion can significantly reduce the flowability in granular flow. By analyzing the velocity plot for the traced particles, free fall was clearly detected above the decompression zone, indicating the motion of a particle in a granular flow can be resolved as free fall together with the movement due to particle collision. In addition, select dynamic behavior related to the kinetic fluctuations affecting flow was observed.

discrete element method silo granule flow particulate material     

Examining the architecture of cellular computing through a comparative study with a computer.

The computer and the cell both use information embedded in simple coding, the binary software code and the quadruple genomic code, respectively, to support system operations. A comparative examination of their system architecture as well as their information storage and utilization schemes is performed. On top of the code, both systems display a modular, multi-layered architecture, which, in the case of a computer, arises from human engineering efforts through a combination of hardware implementation and software abstraction. Using the computer as a reference system, a simplistic mapping of the architectural components between the two is easily detected. This comparison also reveals that a cell abolishes the software-hardware barrier through genomic encoding for the constituents of the biochemical network, a cell's "hardware" equivalent to the computer central processing unit (CPU). The information loading (gene expression) process acts as a major determinant of the encoded constituent's abundance, which, in turn, often determines the "bandwidth" of a biochemical pathway. Cellular processes are implemented in biochemical pathways in parallel manners. In a computer, on the other hand, the software provides only instructions and data for the CPU. A process represents just sequentially ordered actions by the CPU and only virtual parallelism can be implemented through CPU time-sharing. Whereas process management in a computer may simply mean job scheduling, coordinating pathway bandwidth through the gene expression machinery represents a major process management scheme in a cell. In summary, a cell can be viewed as a super-parallel computer, which computes through controlled hardware composition. While we have, at best, a very fragmented understanding of cellular operation, we have a thorough understanding of the computer throughout the engineering process. The potential utilization of this knowledge to the benefit of systems biology is discussed.     

A conceptual approach for an architecture of distributed objects for the integration of heterogeneous data processing systems in manufacturing companies

A new integration concept for heterogeneous legacy systems is developed. The concept consists of a model (business object model), an implementation of business objects (Internet or Java/CORBA) and an information structure (structure of the graphical user interface). The architecture separates the dialog level from a logical application level, the business objects. Legacy systems should be integrated into a company-wide IT (Information Technology) architecture. This can be done through the encapsulation of these systems into several business objects. The IT implementation of the encapsulation will be implemented on the one hand using internet standards, and on the other hand using Java and CORBA. Information transparency for all users in a corporate and user-friendly way is developed and described in an information structure. Within the information structure the software engineer creates new applications using business objects as well as encapsulated legacy systems and applications. These legacy systems are integrated in the new architecture of distributed objects, and will be re-used, encapsulated and transformed into an object-oriented architecture.     

Aleatory architectures

We discuss new approaches and concepts at the intersection of granular materials research and architecture/structural engineering that are based on stochastic (re-) configuration of individual structural elements. These approaches, which we term aleatory architectures, suggest that building materials and components can have their own ‘agency’—that they can be designed to adapt and to find their own responses to structural or spatial contexts. Here we introduce some of the key ideas and ask: Can there be design by disorder? What are the possibilities of material agency? Can we develop a vocabulary of concepts to interpret various orderings of chance? Several papers in this Topical Collection then investigate these questions in more detail from a range of different scientific and architectural perspectives.     

Specific structural mechanics that underpinned the construction of Venice and dictated Venetian architecture

This paper demonstrates that Venetian architecture was the result of specifically conceived structural mechanics, novel failure analysis, and specially devised construction techniques, which allowed structural design to take full advantage of materials. Venice witnessed the creation of ‘structural art’ that drastically reduced the incidences of failure caused by extremely soft soils and aggressive environment, which extended the operating horizons of masonry and timber structural materials to the extent that very bold structures were obtained also before the pre-eminent materials of modern structures.A further aim of this paper is to promote a greater knowledge and understanding of the attributes and capabilities of traditional engineering materials in the context of structural design, thereby contributing to the prevention of failures of cultural buildings in the future.While normal masonry constructions can be governed by Euclidean geometry, Venetian buildings are far more complex and elusive in form. Venice and its architecture can be interpreted and comprehended only in the remit of structural engineering, which played a central role in enabling the construction of the city. The fundamental determinants of Venetian building morphology — the underlying logic of form in architecture — entailed a tectonic form midway between the masonry construction and the skeletal structure.     

Failure of cemented granular materials under simple compression: experiments and numerical simulations

We investigate the strength and failure properties of a model cemented granular material under simple compressive deformation. The particles are lightweight expanded clay aggregate beads coated by a controlled volume fraction of silicone. The beads are mixed with a joint seal paste (the matrix) and molded to obtain dense cemented granular samples of cylindrical shape. Several samples are prepared for different volume fractions of the matrix, controlling the porosity, and silicone coating upon which depends the effective particle–matrix adhesion. Interestingly, the compressive strength is found to be an affine function of the product of the matrix volume fraction and effective particle–matrix adhesion. On the other hand, it is shown that particle damage occurs beyond a critical value of the contact debonding energy. The experiments suggest three regimes of crack propagation corresponding to no particle damage, particle abrasion and particle fragmentation, respectively, depending on the matrix volume fraction and effective particle–matrix adhesion. We also use a sub-particle lattice discretization method to simulate cemented granular materials in two dimensions. The numerical results for crack regimes and the compressive strength are in excellent agreement with the experiments.     

Functional characterisation of mechanical joints to facilitate its selection during the design of open architecture products

New trends in product design require the use of modularity as key feature aimed to improve functional performance and the generation of open architecture products. For mechanical systems, one of the challenges during early design stages of these products involves the proper selection of joining methods among their constructive components. A robust joint selection process must consider product requirements, life cycle analysis and eventual procedures for assembly and disassembly. However, the general approach towards a Design-for-Assembly (DFA)/Design-for-Disassembly (DFD) only considers design, manufacturing and in some cases final disposal stage. Additionally, most of the works found in the literature are merely focused on assembly operations, disregarding economic and environmental benefits from optimising disassembly complexity. Herein, a functional characterisation of mechanical joint methods for the assembly and disassembly activities that take place throughout the product life cycle is proposed, focusing on open architecture products. Additionally, a classification of joining methods, a joint complexity metric valuation and a selection process are proposed for the conceptual design stage. The approach integrates both DFA and DFD principles in a formal methodology. The proposed selection roadmap can be implemented to increase product sustainability positively regarding resources optimisation, operational time and costs in reuse, remanufacturing and recycling tasks.     

Architectural design and reliability analysis of a fail-operational brake-by-wire system from ISO 26262 perspectives

Next generation drive-by-wire automotive systems enabling autonomous driving will build on the fail-operational capabilities of electronics, control and software (ECS) architectural solutions. Developing such architectural designs that would meet dependability requirements and satisfy other system constraints is a challenging task and will possibly lead to a paradigm shift in automotive ECS architecture design and development activities. This aspect is becoming quite relevant while designing battery-driven electric vehicles with integrated in-wheel drive-train and chassis subsystems.In such highly integrated dependable systems, many of the primary features and functions are attributed to the highest safety critical ratings. Brake-by-wire is one such system that interfaces with active safety features built into an automobile, and which in turn is expected to provide fail-operational capabilities. In this paper, building up on the basic concepts of fail-silent and fail-operational systems design we propose a system-architecture for a brake-by-wire system with fail-operational capabilities. The design choices are supported with proper rationale and design trade-offs. Safety and reliability analysis of the proposed system architecture is performed as per the ISO 26262 standard for functional safety of electrical/electronic systems in road vehicles.     

Product architecture design of multi-modal products

Incorporating multiple modes enables a product to change between different configurations, such as hybrid electric vehicles and washing machines. This paper investigates how multiple modes are constructed in modular product architecture—especially, how multi-modal modules are designed and used to construct overall product modality. The authors argue that product modality becomes viable by undertaking two strategies: temporal clustering, which activates and organizes different groups of modules in different modes, and modality propagation, which relies on modality of the product’s subordinate modules. A solution that successfully incorporates modality enables the system to achieve functions with minimal system resources; however, it also introduces extra complexity to the design process. In the final section, the authors propose two techniques that promote multi-modal modules in design processes. This research work provokes the considerations of modality in product architecture. It claims modality is an important factor that leads to innovative design solutions. To emphasize the importance of modality, the authors present a case study of two pasta machines and compare the radical differences in their modular design solutions.     

Smart,connected open architecture product: an IT-driven co-creation paradigm with lifecycle personalization concerns

Nowadays, the emphasis on manufacturing has shifted from a manufacturer-dominating to a customer-centric manner by actively involving users into the co-creation process to realise individual satisfaction. In such era, the rapid development of information and communication technology (e.g. wireless sensor network, and cyber-physical systems) enables a promising market of IT-driven product, i.e. smart, connected product, and also changes the way of user–manufacturer interaction in the product development process. However, to the best of authors’ knowledge, co-creation manner in such context is scarcely reported. Meanwhile, there is a lack of any paradigms given to enable such product open innovation along the lifecycle for personalisation concerns. Aiming to fill this gap, this paper, as an explorative research, proposes a new product development paradigm, i.e. smart, connected open architecture product (SCOAP). It follows the adaptable design principles for product extendibility and lifecycle consideration. Moreover, it enlarges the scope of existing open architecture product by involving IT-driven innovation consideration as well. Hence, the definitions, characteristics, evaluation criteria, development method, and lifecycle co-creation context of SCOAP are presented in details. To make it more concrete, a demo project of a smart, connected open architecture bicycle is given at last.     

Improve Computer Visualization of Architecture Based on the Bayesian Network

Computer visualization has marvelous effects when it is applied in various fields, especially in architectural design. As an emerging force in the innovation industry, architects and design agencies have already demonstrated the value of architectural visual products in actual application projects. Based on the digital image technology, virtual presentation of future scenes simulates architecture design, architectural renderings and multimedia videos. Therefore, it can help design agencies transform the theoretical design concept into a lively and realistic visual which can provide the audience with a clearer understanding of the engineering and construction projects. However, it is challenging for designers to produce satisfactory renderings due to the frequent fault data during rendering. In this paper, we use the 3Ds MAX as the operating platform and we present an algorithm based on the Bayesian network to construct a vector representation of the fault data. On this basis, a case study of 3D Max’ application has also been presented.     

A functional failure reasoning methodology for evaluation of conceptual system architectures

In this paper, we introduce a new methodology for reasoning about the functional failures during early design of complex systems. The proposed approach is based on the notion that a failure happens when a functional element in the system does not perform its intended task. Accordingly, a functional criticality is defined depending on the role of functionality in accomplishing designed tasks. A simulation-based failure analysis tool is then used to analyze functional failures and reason about their impact on overall system functionality. The analysis results are then integrated into an early stage system architecture analysis framework that analyzes the impact of functional failures and their propagation to guide system-level architectural design decisions. With this method, a multitude of failure scenarios can be quickly analyzed to determine the effects of architectural design decisions on overall system functionality. Using this framework, design teams can systematically explore risks and vulnerabilities during the early (functional design) stage of system development prior to the selection of specific components. Application of the presented method to the design of a representative aerospace electrical power system (EPS) testbed demonstrates these capabilities.