Connectivity and coverage in machine-type communications

Machine-type communication (MTC) provides a potential playground for deploying machine-to-machine (M2M), IP-enabled 'things' and wireless sensor networks (WSNs) that support modern, added-value services and applications. 4G/5G technology can facilitate the connectivity and the coverage of the MTC entities and elements by providing M2M-enabled gateways and base stations for carrying traffic streams to/from the backbone network. For example, the latest releases of long-term evolution (LTE) such as LTE-Advanced (LTE-A) are being transformed to support the migration of M2M devices. MTC-oriented technical definitions and requirements are defined to support the emerging M2M proliferation. ETSI describes three types of MTC access methods, namely a) the direct access, b) the gateway access and c) the coordinator access. This work is focused on studying coverage aspects when a gateway access takes place. A deployment planar field is considered where a number of M2M devices are randomly deployed, e.g., a hospital where body sensor networks form a M2M infrastructure. An analytical framework is devised that computes the average number of connected M2M devices when a M2C gateway is randomly placed for supporting connectivity access to the M2M devices. The introduced analytical framework is verified by simulation and numerical results

Connectivity and coverage in machine-type communications

Machine-type communication (MTC) provides a potential playground for deploying machine-to-machine (M2M), IP-enabled 'things' and wireless sensor networks (WSNs) that support modern, added-value services and applications. 4G/5G technology can facilitate the connectivity and the coverage of the MTC entities and elements by providing M2M-enabled gateways and base stations for carrying traffic streams to/from the backbone network. For example, the latest releases of long-term evolution (LTE) such as LTE-Advanced (LTE-A) are being transformed to support the migration of M2M devices. MTC-oriented technical definitions and requirements are defined to support the emerging M2M proliferation. ETSI describes three types of MTC access methods, namely a) the direct access, b) the gateway access and c) the coordinator access. This work is focused on studying coverage aspects when a gateway access takes place. A deployment planar field is considered where a number of M2M devices are randomly deployed, e.g., a hospital where body sensor networks form a M2M infrastructure. An analytical framework is devised that computes the average number of connected M2M devices when a M2C gateway is randomly placed for supporting connectivity access to the M2M devices. The introduced analytical framework is verified by simulation and numerical results

Wide-angle absorption of visible light from simple bilayers

Color-selective absorption of light is a very significant operation used in numerous applications, from photonic sensing and switching to optical signal modulation and energy harnessing. We demonstrate angle-insensitive and polarization-independent absorption by thin bilayers comprising ordinary bulk media: dielectrics, semiconductors, and metals. Several highly efficient designs for each color of the visible spectrum are reported, and their internal fields’ distributions reveal the resonance mechanism of absorption. The proposed bilayer components are realizable, since various physical or chemical deposition methods can be used for their effective fabrication. The absorption process is found to exhibit endurance with respect to the longitudinal dimension of the planar structure, which means that the same designs could be successfully utilized in non-planar configurations composed of arbitrary shapes

Automatic 3D Reconstruction of Coronary Artery Centerlines from Monoplane X-ray Angiogram Images

We present a new method for the fully automatic 3D reconstruction of the coronary artery centerlines, using two X-ray angiogram projection images from a single rotating monoplane acquisition system. During the first stage, the input images are smoothed using curve evolution techniques. Next, a simple yet efficient multiscale method, based on the information of the Hessian matrix, for the enhancement of the vascular structure is introduced. Hysteresis thresholding using different image quantiles, is used to threshold the arteries. This stage is followed by a thinning procedure to extract the centerlines. The resulting skeleton image is then pruned using morphological and pattern recognition techniques to remove non-vessel like structures. Finally, edge-based stereo correspondence is solved using a parallel evolutionary optimization method based on f symbiosis. The detected 2D centerlines combined with disparity map information allow the reconstruction of the 3D vessel centerlines. The proposed method has been evaluated on patient data sets for evaluation purposes

A standardized scoring method for the copy of cube test, developed to be suitable for use in psychiatric populations

BACKGROUND: Although the 'copy of cube test', a version of which is included in the Short Test of Mental Status (STMS), has existed for years, little has been done to standardize it in detail. The aim of the current study was to develop a novel and detailed standardized method of administration and scoring this test. METHODS: The study sample included 93 healthy control subjects (53 women and 40 men) aged 35.87 ± 12.62 and 127 patients suffering from schizophrenia (54 women and 73 men) aged 34.07 ± 9.83 years. The psychometric assessment included the Positive and Negative Symptoms Scale (PANSS) the Young Mania Rating Scale (YMRS), and the Montgomery-Åsberg Depression Rating Scale (MADRS). RESULTS: A scoring method was developed based on the frequencies of responses of healthy controls. Cronbach's α was equal to 0.75 and inter-rater reliability was 0.90. Three indices and five subscales of the Standardized Copy of the Cube Test (SCCT) were eventually developed. They included the Deficit Index (DcI), which includes the Missing Elements (ME) Mirror Image (M) subscales, the Deformation Index (DfI) which includes the Deformation (D) and the Rotation (R) subscales and the Closing-In Index (CiI). DISCUSSION: The SCCT seems to be a reliable, valid and sensitive to change instrument for the testing of psychiatric patients. The great advantage of this instrument is the fact that it only requires paper and a pencil, and is this easily administered and brief. Further research is necessary to test its usefulness as a neuropsychological test

The standardised copy of pentagons test

<p>Abstract</p> <p>Background</p> <p>The 'double-diamond copy' task is a simple paper and pencil test part of the Bender-Gestalt Test and the Mini Mental State Examination (MMSE). Although it is a widely used test, its method of scoring is crude and its psychometric properties are not adequately known. The aim of the present study was to develop a sensitive and reliable method of administration and scoring.</p> <p>Methods</p> <p>The study sample included 93 normal control subjects (53 women and 40 men) aged 35.87 ± 12.62 and 127 patients suffering from schizophrenia (54 women and 73 men) aged 34.07 ± 9.83.</p> <p>Results</p> <p>The scoring method was based on the frequencies of responses of healthy controls and proved to be relatively reliable with Cronbach's α equal to 0.61, test-retest correlation coefficient equal to 0.41 and inter-rater reliability equal to 0.52. The factor analysis produced two indices and six subscales of the Standardised Copy of Pentagons Test (SCPT). The total score as well as most of the individual items and subscales distinguished between controls and patients. The discriminant function correctly classified 63.44% of controls and 75.59% of patients.</p> <p>Discussion</p> <p>The SCPT seems to be a satisfactory, reliable and valid instrument, which is easy to administer, suitable for use in non-organic psychiatric patients and demands minimal time. Further research is necessary to test its psychometric properties and its usefulness and applications as a neuropsychological test.</p

Multi-functional metasurface architecture for amplitude, polarization and wavefront control

Metasurfaces (MSs) have been utilized to manipulate different properties of electromagnetic waves. By combining local control over the wave amplitude, phase, and polarization into a single tunable structure, a multi-functional and reconfigurable metasurface can be realized, capable of full control over incident radiation. Here, we experimentally validate a multi-functional metasurface architecture for the microwave regime, where in principle variable loads are connected behind the backplane to reconfigurably shape the complex surface impedance. As a proof-of-concept step, we fabricate several metasurface instances with static loads in different configurations (surface mount capacitors and resistors of different values in different connection topologies) to validate the approach and showcase the different achievable functionalities. Specifically, we show perfect absorption for oblique incidence (both polarizations), broadband linear polarization conversion, and beam splitting, demonstrating control over the amplitude, polarization state, and wavefront, respectively. Measurements are performed in the 4-18 GHz range inside an anechoic chamber and show good agreement with theoretically-anticipated results. Our results clearly demonstrate the practical potential of the proposed architecture for reconfigurable electromagnetic wave manipulation.Comment: 6 pages, 5 figure

ABSense: Sensing Electromagnetic Waves on Metasurfaces via Ambient Compilation of Full Absorption

Metasurfaces constitute effective media for manipulating and transforming impinging EM waves. Related studies have explored a series of impactful MS capabilities and applications in sectors such as wireless communications, medical imaging and energy harvesting. A key-gap in the existing body of work is that the attributes of the EM waves to-be-controlled (e.g., direction, polarity, phase) are known in advance. The present work proposes a practical solution to the EM wave sensing problem using the intelligent and networked MS counterparts-the HyperSurfaces (HSFs), without requiring dedicated field sensors. An nano-network embedded within the HSF iterates over the possible MS configurations, finding the one that fully absorbs the impinging EM wave, hence maximizing the energy distribution within the HSF. Using a distributed consensus approach, the nano-network then matches the found configuration to the most probable EM wave traits, via a static lookup table that can be created during the HSF manufacturing. Realistic simulations demonstrate the potential of the proposed scheme. Moreover, we show that the proposed workflow is the first-of-its-kind embedded EM compiler, i.e., an autonomic HSF that can translate high-level EM behavior objectives to the corresponding, low-level EM actuation commands.Comment: Publication: Proceedings of ACM NANOCOM 2019. This work was funded by the European Union via the Horizon 2020: Future Emerging Topics call (FETOPEN), grant EU736876, project VISORSURF (http://www.visorsurf.eu

Participatory citizenship: critical perspectives on client-centred occupational therapy

Background/aims: This article aims to discuss client-centred practice, the current dominant approach within occupational therapy, in relation to participatory citizenship. Occupational therapists work within structures and policies that set boundaries on their engagement with clients, while working with complex, multidimensional social realities. Methods: The authors present a critical discussion shaped by their research, including a survey, discussions at workshops at international conferences, and critical engagement with the literature on occupational therapy, occupation, and citizenship. Conclusion: A focus on citizenship suggests reframing professional development based on the participation in public life of people as citizens of their society. While occupational therapists often refer to clients in the context of communities, groups, families, and wider society, the term client centred practice typically represents a particular view of the individual and may sometimes be too limited in application for a more systemic and societal approach. Significance: The authors question the individual focus which has, until recently, been typical of client-centred occupational therapy. Placing citizenship at the core of intervention is a transformative process that assumes all people are citizens and conceives of health as a collective issue, influencing the way we educate, do research, and practise. Key words: Collective, dis-citizenship, inequalities, professional development, participation, paradigms, occupational justice</p