•Sensor-packed manufacturing systems will become ubiquitous.•Cybersecurity aspects are gaining importance within the manufacturing domain.•Manufacturing cyber-physical systems are expected to follow ...the trend set by other domains that benefited from the Internet of Things, Cloud Computing, and Big Data.•Outcomes of the implementation of manufacturing cyber-physical systems could be transformative to the extent that predictive manufacturing systems can become a reality.
The recent advances in sensor and communication technologies can provide the foundations for linking the physical manufacturing facility and machine world to the cyber world of Internet applications. The coupled manufacturing cyber-physical system is envisioned to handle the actual operations in the physical world while simultaneously monitor them in the cyber world with the help of advanced data processing and simulation models at both the manufacturing process and system operational levels. Moreover, a sensor-packed manufacturing system in which each process or piece of equipment makes available event and status information, coupled with market research for true advanced Big Data analytics, seem to be the right ingredients for event response selection and operation virtualization. As a drawback, the resulting manufacturing cyber-physical system will be vulnerable to the inevitable cyber-attacks, unfortunately, so common for the software and Internet-based systems. This reality makes cybersecurity penetration within the manufacturing domain a need that goes uncontested across researchers and practitioners. This work provides a review of the current status of virtualization and cloud-based services for manufacturing systems and of the use of Big Data analytics for planning and control of manufacturing operations. Building on already developed cloud business solutions, cloud manufacturing is expected to offer improved enterprise manufacturing and business decision support. Based on the current state-of-the-art cloud manufacturing solutions and Big Data applications, this work also proposes a framework for the development of predictive manufacturing cyber-physical systems that include capabilities for attaching to the Internet of Things, and capabilities for complex event processing and Big Data algorithmic analytics.
Polyimides (PIs) represent a benchmark for high-performance polymers on the basis of a remarkable collection of valuable traits and accessible production pathways and therefore have incited serious ...attention from the ever-demanding medical field. Their characteristics make them suitable for service in hostile environments and purification or sterilization by robust methods, as requested by most biomedical applications. Even if PIs are generally regarded as “biocompatible”, proper analysis and understanding of their biocompatibility and safe use in biological systems deeply needed. This mini-review is designed to encompass some of the most robust available research on the biocompatibility of various commercial or noncommercial PIs and to comprehend their potential in the biomedical area. Therefore, it considers (i) the newest concepts in the field, (ii) the chemical, (iii) physical, or (iv) manufacturing elements of PIs that could affect the subsequent biocompatibility, and, last but not least, (v) in vitro and in vivo biocompatibility assessment and (vi) reachable clinical trials involving defined polyimide structures. The main conclusion is that various PIs have the capacity to accommodate in vivo conditions in which they are able to function for a long time and can be judiciously certified as biocompatible.
•Transportation of perishable products imposes a series of challenges to cold supply chain operations.•Forty percent of the food in the United States is wasted every year.•Transportation ...decision-making is performed by temporary virtual machines associated with every shipment.•Stopping and rerouting transportation mathematical models.•Simulated implementation considers shipments of fresh produce across the continental United States.
Transportation of perishable products is critical and imposes a series of challenges to the cold supply chain and logistics operations. The specific challenge to be addressed is the strict monitoring of transportation conditions. This paper provides insights in the logistics decision models associated with the cold supply chain of perishable products. The decision-making is performed in the cloud by temporary virtual machines (VMs) associated with every shipment or series of shipments. The VMs make operational decisions based on evaluating actual transportation conditions and location of shipped products against requirements and initial route and terminal market geographical location. The physical part of the logistics cyber-physical monitoring and control system is represented by integrated RFID-WSN sensor devices traveling with the product and reader checkpoints distributed along the transportation routes. Two types of decisions are considered in the proposed models: stopping transportation and/or rerouting the shipments to a closer location. The implementation of the optimization models for an actual case study, which considers shipments of fresh produce across the continental United States, shows significant savings that could be obtained if producers or third party logistics companies adopt the methodology.
•Manufacturing cybersecurity is becoming of utmost importance due to the increasingly use of cyber-physical systems.•Software-defined networks are a promising solution for addressing the security ...needs of distributed applications.•System resilience to disruptive events is necessary such that operations are not interrupted for long periods.•Cyber-resilience must be addressed for industrial/manufacturing systems.
In addition to productivity and quality output, for many years, manufacturing systems were also designed with reliability and safety requirements in mind. In the recent decade or so, the approach seems not adequate anymore. The current manufacturing global operations ask for more stringent requirements than ever before, which include privacy and security of transactions, among others. Manufacturing control is not new, but the use of cloud environments to integrate distributed manufacturing facilities and entirely control the production processes across those facilities is an active research area denoted in terms such as: virtual factory, cloud manufacturing, Industry 4.0, Industrial Internet of Things (IIoT), and more recently, software-defined networking-based (SDN-based) manufacturing. In computer networking domain, SDN is known as a network architecture that decouples the network data and control mechanisms. SDN architecture assigns the entire data control to a logically centralized control plane that can be software-programmed based on specific application needs. From the security point of view, this translates in the fact that anyone with access to the computers that run the network control software could potentially get control over the entire network. This paper proposes an integrated modeling environment that addresses the virtual manufacturing system assurance through cybersecurity and resilience mechanisms for SDN applications. First, the paper proposes a SDN-based manufacturing testbed and a combined cybersecurity-resilience ontology to be used for the requirements capture of the virtual manufacturing network design stages. Then, the paper outlines the framework for SDN-based cybersecurity-resilience protection mechanisms for virtual manufacturing applications, and ends with the envisioned future research needed for implementing the proposed framework.
The exchange bias effect refers to the shift of the hysteresis loop of a ferromagnet in direct contact to an antiferromagnet. For applications in spintronics a robust and tunable exchange bias is ...required. Here we show experimental evidence for a perpendicular exchange bias in a prototypical ferrimagnetic spin valve consisting of DyCo(5)/Ta/Fe(76)Gd(24), where the DyCo(5) alloy has the role of a hard ferrimagnet and Fe(76)Gd(24) is a soft ferrimagnet. Taking advantage of the tunability of the exchange coupling between the ferrimagnetic layers by means of thickness variation of an interlayer spacer, we demonstrate that perpendicular unidirectional anisotropy can be induced with desirable absolute values at room temperature, without making use of a field-cooling procedure. Moreover, the shift of the hysteresis loop can be reversed with relatively low magnetic fields of several hundred Oersteds. This flexibility in controlling a robust perpendicular exchange bias at room temperature may be of crucial importance for applications.
A fast dual mode-locked akinetic optical swept source at 850-nm central wavelength is presented using a dispersive cavity. We demonstrate that single mode fiber can be successfully used as dispersive ...element to induce mode locking. A first locking condition is imposed by driving the optical gain at a high frequency, to induce mode locking, while a second locking condition involves sweeping at a rate close to resonance value. In this regime, using the same fiber length in the loop, sweeping rates of 0.5 and 1 MHz are demonstrated with proportional reduction in the tuning bandwidth. The axial range of the swept source was evaluated by scanning through the channeled spectrum of a Michelson interferometer.
Multiferroic materials possess two or more ferroic orders but have not been exploited in devices owing to the scarcity of room-temperature examples. Those that are ferromagnetic and ferroelectric ...have potential applications in multi-state data storage if the ferroic orders switch independently, or in electric-field controlled spintronics if the magnetoelectric coupling is strong. Future applications could also exploit toroidal moments and optical effects that arise from the simultaneous breaking of time-reversal and space-inversion symmetries. Here, we use soft X-ray resonant magnetic scattering and piezoresponse force microscopy to reveal that, at the interface with Fe or Co, ultrathin films of the archetypal ferroelectric BaTiO simultaneously possess a magnetization and a polarization that are both spontaneous and hysteretic at room temperature. Ab initio calculations of realistic interface structures provide insight into the origin of the induced moments and bring support to this new approach for creating room-temperature multiferroics. PUBLICATION ABSTRACT
In this paper we describe the OpenGeoSys (OGS) project, which is a scientific open-source initiative for numerical simulation of thermo-hydro-mechanical-chemical processes in porous media. The basic ...concept is to provide a flexible numerical framework (using primarily the Finite Element Method (FEM)) for solving multifield problems in porous and fractured media for applications in geoscience and hydrology. To this purpose OGS is based on an object-oriented FEM concept including a broad spectrum of interfaces for pre- and postprocessing. The OGS idea has been in development since the mid-eighties. We provide a short historical note about the continuous process of concept and software development having evolved through Fortran, C, and C++ implementations. The idea behind OGS is to provide an open platform to the community, outfitted with professional software-engineering tools such as platform-independent compiling and automated benchmarking. A comprehensive benchmarking book has been prepared for publication. Benchmarking has been proven to be a valuable tool for cooperation between different developer teams, for example, for code comparison and validation purposes (DEVOVALEX and CO
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BENCH projects). On one hand, object-orientation (OO) provides a suitable framework for distributed code development; however, the parallelization of OO codes still lacks efficiency. High-performance-computing efficiency of OO codes is subject to future research.
We analyze an optimized artificial fixed-stress iterative scheme for a space–time finite element approximation of the Biot system modeling fluid flow in deformable porous media. The iteration is ...based on a prescribed constant artificial volumetric mean total stress in the first half step. The optimization comes through the adaptation of a numerical stabilization or tuning parameter and aims at an acceleration of the iterations. The separated subproblems of fluid flow, written as a mixed first order in space system, and mechanical deformation are discretized by space–time finite element methods of arbitrary order. Continuous and discontinuous Galerkin discretizations of the time variable are encountered. The convergence of the iterative schemes is proved for the continuous and fully discrete case. The choice of the optimization parameter is identified in the proofs of convergence of the iterations. The analyses are illustrated and confirmed by numerical experiments.
•A fixed-stress iterative coupling scheme for the Biot system is analyzed.•The subproblems are discretized by families of space–time finite element methods.•The convergence of the iteration is proved on the continuous and discrete level.•The theoretical results are illustrated and confirmed by numerical tests.
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