544 research outputs found
Wireless model-based predictive networked control system over cooperative wireless network
Owing to their distributed architecture, networked control systems (NCSs) are proven to be feasible in scenarios where a spatially distributed feedback control system is required. Traditionally, such NCSs operate over real-time wired networks. Recently, in order to achieve the utmost flexibility, scalability, ease of deployment, and maintainability, wireless networks such as IEEE 802.11 wireless local area networks (LANs) are being preferred over dedicated wired networks. However, conventional NCSs with event-triggered controllers and actuators cannot operate over such general purpose wireless networks since the stability of the system is compromised due to unbounded delays and unpredictable packet losses that are typical in the wireless medium. Approaching the wireless networked control problem from two perspectives, this work introduces a practical wireless NCS and an implementation of a cooperative medium access control protocol that work jointly to achieve decent control under severe impairments, such as unbounded delay, bursts of packet loss and ambient wireless traffic. The proposed system is evaluated on a dedicated test platform under numerous scenarios and significant performance gains are observed, making cooperative communications a strong candidate for improving the reliability of industrial wireless networks
A girl with a torticollis without trauma: Grisel’s syndrome
A 7 year-old girl patient was referred from pediatric emergency department (ED) to our emergency department due to cervical pain and neck stiffness. On her physical examination, torticollis was found in the neck. There was no history of trauma. Physical examination showed no focal neurological deficits. On further anamnestic evaluation the patient's parents revealed that she had presented to paediatric ED due to throat and neck pain and put on antibiotics therapy for 5 days. A computed tomography (CT) scan of the patient's neck was performed. A cervical lymphadenopathy associated with atlanto-axial subluxation shadow. The atlas was rotated on one articular process with 3-5 mm anterior displacement, compatible with Type II subluxation. Non-traumatic or inflammatory atlanto-axial subluxation is known as Grisel's syndrome. The subluxation was stabilized with external stabilization (rigid cervical collar). Skeletal muscle relaxants, antibiotics and nonsteroidal anti-inflammatory medications with bed rest were given for further treatment. Early diagnosis of Grisel's syndrome is of crucial importance due to the neurological deficits suc as recurrence or permanent neck deformity. CT, magnetic resonance imaging (MRI) or other imaging tests are required to demonstrate fractures and displaced bone fragments (ie., atlanto-axial subluxation). The primary treatment of early detected Grisel's syndrome is conservative including antibiotic therapy, bed rest, muscle relaxants, external fixation and anti-inflammatory therapy
Design of a self-aligned, wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with 10 nm magnetic force microscope resolution
We describe the design of a wide temperature range (300 mK-300 K) atomic force microscope/magnetic force microscope with a self-aligned fibre-cantilever mechanism. An alignment chip with alignment groves and a special mechanical design are used to eliminate tedious and time consuming fibre-cantilever alignment procedure for the entire temperature range. A low noise, Michelson fibre interferometer was integrated into the system for measuring deflection of the cantilever. The spectral noise density of the system was measured to be similar to 12 fm/root Hz at 4.2 K at 3 mW incident optical power. Abrikosov vortices in BSCCO(2212) single crystal sample and a high density hard disk sample were imaged at 10 nm resolution to demonstrate the performance of the system. (C) 2014 AIP Publishing LLC
Noncontact lateral-force gradient measurement on Si(111)-7×7 surface with small-amplitude off-resonance atomic force microscopy
In this work, the authors report on a quantitative investigation of lateral-force gradient and lateral force between a tungsten tip and Si(111)-(7×7) surface using combined noncontact lateral-force microscopy and scanning tunneling microscopy. Simultaneous lateral-force gradient and scanning tunneling microscopy images of single and multiatomic step are obtained. In our measurement, tunnel current is used as feedback. The lateral-stiffness contrast has been observed to be 2.5 N/m at a single atomic step, in contrast to 13 N/m at a multiatomic step on Si (111) surface. They also carried out a series of lateral stiffness-distance spectroscopy, which show a sharp increase in tip-surface interaction stiffness as the sample is approached toward the surface
A study on technology management process: the parts and components suppliers in the Turkish automotive industry
This paper summarizes part of an empirical study on technology management process in the Turkish automotive parts and components industry. In this study, technology management practices in the Turkish automotive parts and components suppliers' sector are described and evaluated. Practices, techniques, and approaches are proposed to improve the level of technology management so as to turn technology into a competitive weapon. The investigation is organized within the framework of a process model for technology management that consists of technology identification, selection, acquisition, exploitation, protection, and abandonment. A comprehensive questionnaire addressing all phases of this process is developed and the results of 21 companies are presented
Turkish version of the pediatric quality of life inventory (PedsQL) 3.0 arthritis module: a reliability and validity study
LFM-Pro: a tool for detecting significant local structural sites in proteins
Motivation: The rapidly growing protein structure repositories have opened up new opportunities for discovery and analysis of functional and evolutionary relationships among proteins. Detecting conserved structural sites that are unique to a protein family is of great value in identification of functionally important atoms and residues. Currently available methods are computationally expensive and fail to detect biologically significant local features
Improving Disaster Resilience Using Mobile Based Disaster Management System
AbstractThe use of ICTs can help to produce information and make better decisions for effective disaster management system. ICT is considered to necessary enhance adaptation capacity and supports feedback, ensure information access, enables active participation, reduces vulnerability. Mobile technologies are appropriate for providing these needs to improving resilience. Nowadays with the widespread use of mobile devices, benefiting as an information sharing environment after disaster is inevitable. The use of mobile technologies by citizens after a disaster increases resilience against disasters. The aim of the study is to increase disaster resilience by using mobile technologies to ensure citizens play an active role in disaster management
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