Distributed manufacturing systems and the internet of things : a case study

In order to stay competitive in today's global market, manufacturing companies need to be flexible. To ensure flexible production, shorten processing times, and reduce time-tomarket, companies are utilizing the distributed manufacturing system paradigm, wherein geographically distributed, local resources are used for product development and production. In this context, the Internet of Things (IoT) has emerged as a concept which uses existing communication technologies, such as local wireless networks and the Internet to ensure visibility of anything from anywhere and at any time. In the paper, a case study of applying the IoT to the manufacturing domain is discussed. A distributed agent-based system for virtual monitoring and control of 3-axis CNC milling machine tools is designed and developed. The machines' 3D models and process states are shown through a web interface in real-time. The potential and challenges of implementing this system and the basic building blocks for decentralized value creation are discussed

Trace-Orthogonal PPM-Space Time Block Coding Under Rate Constraints for Visible Light Communication

Visible light communications (VLC) represents a new frontier of communications allowing high data-rate Internet access, specially in indoor environments, where the use of light emitting diodes (LEDs) is growing as a viable alternative to traditional illumination. As a result, LED output intensity can be varied faster than human eye can perceive, thus guaranteeing simultaneous wireless communications and illumination. One of the key challenges is the limited modulation bandwidth of sources that is typically around several MHz. The use of multiple input and multiple output (MIMO) techniques in optical wireless system helps to increase the capacity of the system and thus improve the system performance. In this paper, we investigate the use of an optical MIMO technique jointly with pulse position modulation (PPM) in order to improve the data rates without reducing the reliability of the link. PPM is known to be signal-to-noise ratio efficient modulation format, while it is bandwidth inefficient so the use of MIMO can compensate that drawback with reasonable complexity. Furthermore, an offline tool for VLC system planning, including error probability and transmission rate, has been proposed in order to solve the tradeoff between transmission rate and error rate. Finally, several numerical results and performance comparisons are reported

An Internet of Things approach for managing smart services provided by wearable devices.

The Internet of Things (IoT) is growing at a fast pace with new devices getting connected all the time. A new emerging group of these devices are the wearable devices, and Wireless Sensor Networks are a good way to integrate them in the IoT concept and bring new experiences to the daily life activities. In this paper we present an everyday life application involving a WSN as the base of a novel context-awareness sports scenario where physiological parameters are measured and sent to the WSN by wearable devices. Applications with several hardware components introduce the problem of heterogeneity in the network. In order to integrate different hardware platforms and to introduce a service-oriented semantic middleware solution into a single application, we propose the use of an Enterprise Service Bus (ESB) as a bridge for guaranteeing interoperability and integration of the different environments, thus introducing a semantic added value needed in the world of IoT-based systems. This approach places all the data acquired (e.g., via Internet data access) at application developers disposal, opening the system to new user applications. The user can then access the data through a wide variety of devices (smartphones, tablets, computers) and Operating Systems (Android, iOS, Windows, Linux, etc.)

Detecting ionospheric TEC perturbations caused by natural hazards using a global network of GPS receivers: The Tohoku case study

Recent advances in GPS data processing have demonstrated that ground-based GPS receivers are capable of detecting ionospheric TEC perturbations caused by surface-generated Rayleigh, acoustic and gravity waves. There have been a number of publications discussing TEC perturbations immediately following the M 9.0 Tohoku earthquake in Japan on March 11, 2011. Most investigators have focused on the ionospheric responses up to a few hours following the earthquake and tsunami. In our research, in addition to March 11, 2011 we investigate global ionospheric TEC perturbations a day before and after the event. We also compare indices of geomagnetic activity on all three days with perturbations in TEC, revealing strong geomagnetic storm conditions that are also apparent in processed GEONET TEC observations. In addition to the traveling ionospheric disturbances (TIDs)produced by the earthquake and tsunami, we also detect “regular” TIDs across Japan about 5 hours following the Tohoku event, concluding these are likely due to geomagnetic activity. The variety of observed TEC perturbations are consistent with tsunami-generated gravity waves, auroral activity, regular TIDs and equatorial fluctuations induced by increased geomagnetic activity. We demonstrate our capabilities to monitor TEC fluctuations using JPL’s real-time Global Assimilative Ionospheric Model (GAIM) system. We show that a real-time global TEC monitoring network is able to detect the acoustic and gravity waves generated by the earthquake and tsunami. With additional real-time stations deployed, this new capability has the potential to provide real-time monitoring of TEC perturbations that could potentially serve as a plug-in to enhance existing early warning systems

Ionospheric Signatures of Tohoku-Oki Tsunami of March 11, 2011: Model Comparisons Near the Epicenter

We observe ionospheric perturbations caused by the Tohoku earthquake and tsunami of March 11, 2011. Perturbations near the epicenter were found in measurements of ionospheric total electron content (TEC) from 1198 GPS receivers in the Japanese GEONET network. For the first time for this event, we compare these observations with the estimated magnitude and speed of a tsunami-driven atmospheric gravity wave, using an atmosphere-ionosphere-coupling model and a tsunami model of sea-surface height, respectively. Traveling ionospheric disturbances (TIDs) were observed moving away from the epicenter at approximate speeds of 3400 m/s, 1000 m/s and 200–300 m/s, consistent with Rayleigh waves, acoustic waves, and gravity waves, respectively. We focus our analysis on gravity waves moving south and east of the epicenter, since tsunamis propagating in the deep ocean have been shown to produce gravity waves detectable in ionospheric TEC in the past. Observed southeastward gravity wave perturbations, seen 60 min after the earthquake, are mostly between 0.5 to 1.5 TECU, representing up to 5% of the background vertical TEC (VTEC). Comparisons of observed TID gravity waves with the modeled tsunami speed in the ocean and the predicted VTEC perturbation amplitudes from an atmosphere-ionosphere-coupling model show the measurements and models to be in close agreement. Due to the dense GPS network and high earthquake magnitude, these are the clearest observations to date of the effect of a major earthquake and tsunami on the ionosphere near the epicenter. Such observations from a future real-time GPS receiver network could be used to validate tsunami models, confirm the existence of a tsunami, or track its motion where in situ buoy data is not available

Consensus Paper: Neurophysiological Assessments of Ataxias in Daily Practice

The purpose of this consensus paper is to review electrophysiological abnormalities and to provide a guideline of neurophysiological assessments in cerebellar ataxias. All authors agree that standard electrophysiological methods should be systematically applied in all cases of ataxia to reveal accompanying peripheral neuropathy, the involvement of the dorsal columns, pyramidal tracts and the brainstem. Electroencephalography should also be considered, although findings are frequently non-specific. Electrophysiology helps define the neuronal systems affected by the disease in an individual patient and to understand the phenotypes of the different types of ataxia on a more general level. As yet, there is no established electrophysiological measure which is sensitive and specific of cerebellar dysfunction in ataxias. The authors agree that cerebellar brain inhibition (CBI), which is based on a paired-pulse transcranial magnetic stimulation (TMS) paradigm assessing cerebellar-cortical connectivity, is likely a useful measure of cerebellar function. Although its role in the investigation and diagnoses of different types of ataxias is unclear, it will be of interest to study its utility in this type of conditions. The authors agree that detailed clinical examination reveals core features of ataxia (i.e., dysarthria, truncal, gait and limb ataxia, oculomotor dysfunction) and is sufficient for formulating a differential diagnosis. Clinical assessment of oculomotor function, especially saccades and the vestibulo-ocular reflex (VOR) which are most easily examined both at the bedside and with quantitative testing techniques, is of particular help for differential diagnosis in many cases. Pure clinical measures, however, are not sensitive enough to reveal minute fluctuations or early treatment response as most relevant for pre-clinical stages of disease which might be amenable to study in future intervention trials. The authors agree that quantitative measures of ataxia are desirable as biomarkers. Methods are discussed that allow quantification of ataxia in laboratory as well as in clinical and real-life settings, for instance at the patients' home. Future studies are needed to demonstrate their usefulness as biomarkers in pharmaceutical or rehabilitation trials

Interconversion between bound and free conformations of LexA orchestrates the bacterial SOS response

The bacterial SOS response is essential for the maintenance of genomes, and also modulates antibiotic resistance and controls multidrug tolerance in subpopulations of cells known as persisters. In Escherichia coli, the SOS system is controlled by the interplay of the dimeric LexA transcriptional repressor with an inducer, the active RecA filament, which forms at sites of DNA damage and activates LexA for self-cleavage. Our aim was to understand how RecA filament formation at any chromosomal location can induce the SOS system, which could explain the mechanism for precise timing of induction of SOS genes. Here, we show that stimulated self-cleavage of the LexA repressor is prevented by binding to specific DNA operator targets. Distance measurements using pulse electron paramagnetic resonance spectroscopy reveal that in unbound LexA, the DNA-binding domains sample different conformations. One of these conformations is captured when LexA is bound to operator targets and this precludes interaction by RecA. Hence, the conformational flexibility of unbound LexA is the key element in establishing a co-ordinated SOS response. We show that, while LexA exhibits diverse dissociation rates from operators, it interacts extremely rapidly with DNA target sites. Modulation of LexA activity changes the occurrence of persister cells in bacterial populations

Combined Epidural and General Anesthesia for Paediatric Renal Transplantation-A Single Center Experience

ABSTRACT Background. Appropriate anesthesia for pediatric renal transplantation requires stable intraoperative hemodynamics, optimal perfusion of the newly transplanted kidney and good analgesia during recovery. The aim of this study was to assess the preliminary application, success and safety of combined epidural and general anesthesia in pediatric renal transplantation in a small cohort

TomograPy: A Fast, Instrument-Independent, Solar Tomography Software

Solar tomography has progressed rapidly in recent years thanks to the development of robust algorithms and the availability of more powerful computers. It can today provide crucial insights in solving issues related to the line-of-sight integration present in the data of solar imagers and coronagraphs. However, there remain challenges such as the increase of the available volume of data, the handling of the temporal evolution of the observed structures, and the heterogeneity of the data in multi-spacecraft studies. We present a generic software package that can perform fast tomographic inversions that scales linearly with the number of measurements, linearly with the length of the reconstruction cube (and not the number of voxels) and linearly with the number of cores and can use data from different sources and with a variety of physical models: TomograPy (http://nbarbey.github.com/TomograPy/), an open-source software freely available on the Python Package Index. For performance, TomograPy uses a parallelized-projection algorithm. It relies on the World Coordinate System standard to manage various data sources. A variety of inversion algorithms are provided to perform the tomographic-map estimation. A test suite is provided along with the code to ensure software quality. Since it makes use of the Siddon algorithm it is restricted to rectangular parallelepiped voxels but the spherical geometry of the corona can be handled through proper use of priors. We describe the main features of the code and show three practical examples of multi-spacecraft tomographic inversions using STEREO/EUVI and STEREO/COR1 data. Static and smoothly varying temporal evolution models are presented.Comment: 21 pages, 6 figures, 5 table

Application of a portable coordinate measuring machine onto automotive door panel for quality inspection activity

An experimental investigation was conducted to explore the feasibility of replacing the current inspection method by a portable coordinate measuring machine (CMM) for daily quality inspection in automotive industry. The experiment focusses on inspecting stamped body parts due to the significant number of inspection points that could be time consuming for inspection activities. Two inspection methods were performed, i.e. the application of checking fixture (CF) which is the current method and the second method was using a portable CMM. Both inspections were performed onto the same loose freeform surface of an outer door panel. Factors related to inspection duration, economical and data reliability were all compared to understand the practicality of replacing the current inspection method with a portable CMM. It was found that a portable CMM provide a significant shorter inspection duration, more economical and better data reliability but at the same time is unable to match the performance of conventional inspection onto freeform surface. The conclusion was made that a portable CMM alone is not sufficient to replace the current inspection method thus require further study