Electrical And Electronic Engineering

Most of the non-linear transceivers, which are based on Tomlinson Harashima (TH) precoding and have been proposed in the literature for two-way relay networks, assume perfect channel state information (CSI). In this paper, we propose a novel and robust TH precoding scheme for two-way relay networks with multiple antennas at the transceiver and the relay nodes. We assume imperfect CSI and that the channel uncertainty is bounded by a spherical region. Furthermore, we consider the sum of the mean square error as the objective function, under a limited power constraint for transceiver and relay nodes. Simulations are provided to evaluate the performance and to validate the efficiency of the proposed scheme.

The face gear is used in the spinning machine to lift the spindle mechanism. The face gear are attach with the heart cam for spinning the yarn about spindle. During the working, the tangential force is acting on face gear, which may cause to break the teeth. The tangential load which is acting on the gear is from pinion. The face gear are working similar to the bevel gear and transmitting the power. The intersection axis of both the pinion and gear at right angle to each other. The failure of the gear is due to low strength of the gear material. The beam strength of the face gear is low as compare to the tangential load that why the face gear fail. By changing the material of gear we can prevent the gear from failure. The redesign involve to change the material or to chance the dimension. But in that case, by changing the dimension likes to change the module and thickness which may affect the working of machines. Similarly to change in the setup of machine, in that case it is desira...

The purpose of incorporating an ejector into vapour compression cycle is to improve the COP by reducing the throttling loss associated with the expansion device. A computer simulation of the improved cycle is carried out using a one-dimensional model based on mass, momentum and energy balances. Refrigerant characteristics were evaluated using NIST subroutines for equations of state solutions. According to the results of simulation of the improved cycle, it has been shown that the geometric parameters of the ejector design have considerable effects on the system's performance. The maximum COP is obtained for F opt whose value is around 10. Several refrigerants are considered; it has been observed, at F opt and for given operating conditions, that the best performances are obtained with R141b. Compared with the standard cycle the COP of the improved cycle shows an increase of about 22%.

In this paper, a new generator for converting of sea wave energy to electrical energy is proposed. At the beginning, analytical model of generator is extracted and then 3-D and 2-D finite element analysis (FEA) have been developed and implemented on the dodecahedron tubular linear induction motor/generator. The generator have been studied in normal and heavy weather condition in Persian Gulf and sensitivity analysis of the generator against sea wave period and height on the voltage, efficiency and thrust is studied. The results verify the accuracy of self-excited tubular linear induction generator (SETLIG) model and show that tubular linear induction generator can be used as a powerful tool for converting of wave energy to electrical energy.

A novel class of bit-flipping (BF) algorithms for decoding low-density parity-check (LDPC) codes is presented. The proposed algorithms, which are called gradient descent bit flipping (GDBF) algorithms, can be regarded as simplified gradient descent algorithms. Based on gradient descent formulation, the proposed algorithms are naturally derived from a simple non-linear objective function.

The paper is focused on the structuring of glass wafers to obtain high aspect ratio glass columns with high vertical profile for Micro Electro Mechanical Systems (MEMS). The technique proposed is to pattern columns by mechanical sawing. The sawing parameters have been optimised to achieve a high yield. Different dimensions of the column have been tested and glass columns down to 150 m × 150 m of cross-section and 700 m height have been obtained. They present high aspect ratio (>100) and very good vertical profile (88-90 • ). Hoya SD-2 and Corning Pyrex #7740 glass wafers have been processed with similar results. Different cleaning procedures have been tested to improve the anodic bondability of the samples after sawing. Machined glass columns have also been structured by commercial sand blasting technique and the results are also compared to the sawed samples. The glass wafers with machined columns have been anodically bonded to silicon. Anodic bonding characterisation of glass columns of different sections is also presented. Pull tests confirmed the good bondability of the glass columns.

L’articolo presenta i principali risultati di esperimenti eseguiti su nodi trave-pilastro innovativi realizzati con struttura composta acciaio e calcestruzzo. Trattasi di cinque prove in cui altrettanti nodi a due vie in scala reale sono sottoposti a spostamenti pseudo-statici di tipo ciclico tali da indurre una condizione di sollecitazione di tipo sismico. Quattro nodi hanno le travi di tipologia mista acciaio e calcestruzzo ed un nodo e interamente in calcestruzzo armato normale per stabilire utili confronti. Per quanto riguarda i primi quattro, due nodi hanno i pilastri in c.a., un nodo e realizzato con pilastro con camicia di acciaio di sezione quadrata ed infine un nodo ha anche i pilastri in struttura reticolare mista. I risultati ottenuti sono analizzati criticamente e confrontati tra loro per poter trarre utili conclusioni sulla duttilita e sulla resistenza dei nodi innovativi nei confronti delle sollecitazioni di natura sismica.

We discuss a prototypical reaction-diffusion-flow problem in saturated/unsaturated porous media. The special features of our problem are: the reaction produces water and therefore the flow and transport are coupled in both directions and moreover, the reaction may alter the microstructure. This means we have a variable porosity in our model. For the spatial discretization we propose a mass conservative scheme based on the mixed finite element method (MFEM). The scheme is semiimplicit in time. Error estimates are obtained for some particular cases. We apply our finite element methodology for the case of concrete carbonation -one of the most important physico-chemical processes affecting the durability of concrete.

The Global Random Walk algorithm (GRW) performs a simultaneous tracking on a fixed grid of huge numbers of particles at costs comparable to those of a single-trajectory simulation by the traditional Particle Tracking (PT) approach. Statistical ensembles of GRW simulations of a typical advection-dispersion process in groundwater systems with randomly distributed spatial parameters are used to obtain reliable estimations of the input parameters for the upscaled transport model and of their correlations, input-output correlations, as well as full probability distributions of the input and output parameters.

We identify sufficient conditions under which evolution equations for probability density functions (PDF) of random concentrations are equivalent to Fokker-Planck equations. The novelty of our approach is that it allows consistent PDF approximations by densities of computational particles governed by Itô processes in concentration-position spaces. Accurate numerical solutions are obtained with a global random walk (GRW) algorithm, stable, free of numerical diffusion, and insensitive to the increase of the total number of computational particles. The system of Itô equations is specified by drift and diffusion coefficients describing the PDF transport in the physical space, provided by up-scaling procedures, as well as by drift and mixing coefficients describing the PDF transport in concentration spaces. Mixing models can be obtained similarly to classical PDF approaches or, alternatively, from measured or simulated concentration time series. We compare their performance for a GRW-PDF numerical solution to a problem of contaminant transport in heterogeneous groundwater systems.

The adequacy of the model is evaluated by R-squared . Two-night recordings of the 45 subjects and segmented two-night recordings of 13 subjects, who are selected among the 45 subjects, are utilized for the validation of the second hypothesis. Training and evaluation of the trained classifier is performed using Leave-One-Out Cross-Validation (LOOCV) . The classification performance is evaluated using the area under the Precision-Recall curve, which is a metric more suitable than the area under the ROC curve in the case where class-imbalance problem exists. Partial data and ground-truths of the test subject/cycle are used for the construction of personalized classifier. The performance of the personalized classifier is compared to that of a subject-independent classifier. Chapter 2 gives an overview of the sleep physiology. It also summarizes the past work on unobtrusive sleep staging. The classification framework is introduced in detail as well. Furthermore, the result of an early investigation on deep sleep classification is explained in this chapter. In the end of Chapter 2, the two hypotheses that need to be validated are presented. Chapter 3 describes the methods and procedures of the validation of the two hypotheses. The description of the experiment setup and dataset employed in this research are also introduced. The result of validations and detailed discussion are presented in Chapter 4. Chapter 5 and Chapter 6 describe the conclusions and future work respectively.

Music is traditionally considered as a temporal art. At the same time, a musical work supposes organisation, unity, continuity. These are attributes of spatiality. By consequence, we are talking in music about a special kind of space -not surfaces or volumes, but a metaphorical one, which we call here the virtual musical space. It is important not only to admit its presence among the musical language elements, but especially to comprehend its structure, and its influence in the modern forms of art.

An essential generalization of the Lebedev index transform with the square of the Macdonald function is investigated. Namely, we consider a family of integral operators with the positive kernel K (iτ+α)/2 (x) 2 , α ≥ 0, x > 0, τ ∈ R, where K µ (z) is the Macdonald function and i is the imaginary unit. Mapping properties such as the boundedness, compactness, invertibility are investigated for these operators and their adjoints in the Lebesgue weighted spaces. Inversion theorems are proved. Important particular cases are exhibited. As an interesting application, a solution of the initial value problem for the second order differential difference equation, involving the Laplacian, is obtained.

In this work, we present a fractional model of Cahn-Allen equation associated with newly introduced Atangana-Baleanu (AB) derivative of fractional order which uses Mittag-Leffler function as the nonsingular and non-local kernel. The existence and uniqueness of this modified fractional model are discussed by employing the fixed-point postulate. An efficient scheme homotopy perturbation transform technique (HPTT) which is an amalgamation of homotopy perturbation technique with Laplace transform is used to examine this time-fractional phase-field model numerically. Also, convergence and error analysis of the proposed technique is presented. The numerical simulations are analyzed graphically as well as in tabulated form.

Simultaneous imaging of a three-dimensional distribution of point sources is presented. In a two-lens microscope, the point-spreads on the quasi-image plane, which is located between the Fourier and image planes, are spatially distinct, so a set of Fresnel lenslets can perform individual wave-front shaping for axial and lateral rearrangements of the images. In experiments performed with single atoms and holographically programmed lenslets, various three-dimensional arrangements of point sources, including axially aligned atoms, are successfully refocused on the screen, demonstrating the simultaneous and time-efficient detection of the three-dimensional holographic imaging. We expect that non-sequential real-time measurements of three-dimensional point sources shall be in particular useful for quantum correlation measurements and in situ tracking of dynamic particles.

Simultaneous imaging of a three-dimensional distribution of point sources is presented. In a two-lens microscope, the point-spreads on the quasi-image plane, which is located between the Fourier and image planes, are spatially distinct, so a set of Fresnel lenslets can perform individual wave-front shaping for axial and lateral rearrangements of the images. In experiments performed with single atoms and holographically programmed lenslets, various three-dimensional arrangements of point sources, including axially aligned atoms, are successfully refocused on the screen, demonstrating the simultaneous and time-efficient detection of the three-dimensional holographic imaging. We expect that non-sequential real-time measurements of three-dimensional point sources shall be in particular useful for quantum correlation measurements and in situ tracking of dynamic particles.

We theoretically study the stacked optical transients generated from a series of square pulses passing through a cold atomic ensemble. Using the hybrid analysis and fast Fourier transform, we identify the stacked coherent transients [Europhys. Lett. 4, 47 (1987)] as optical precursors. With slow-light and electromagnetically induced transparency, we obtain nearly 700% transmitted intensity at the transient spikes resulting from the interference between the delayed main field and the stacked optical precursors.

The description of the precursor fields in a single-resonance Lorentz model dielectric is considered in the singular and weak dispersion limits. The singular dispersion limit is obtained as the damping approaches zero and the material dispersion becomes increasingly concentrated about the resonance frequency. The algebraic peak amplitude decay of the Brillouin precursor with propagation distance z Ͼ 0 then changes from a z -1/2 to a z -1/3 behavior. The weak dispersion limit is obtained as the material density decreases to zero. The material dispersion then becomes vanishingly small everywhere and the precursors become increasingly compressed in the space-time domain immediately following the speed-of-light point ͑z , t͒ = ͑z , z / c͒. In order to circumvent the numerical difficulties introduced in this case, an approximate equivalence relation is derived that allows the propagated field evolution due to an ultrawideband signal to be calculated in an equivalent dispersive medium that is highly absorptive.

We discuss the transient effects associated with short-pulse propagation in a linearly dispersive medium by comparing optical precursors with 0 pulses. The classical and quantum effects were, in the past, treated independently due to the different time scales. Using results from recent studies [Phys. Rev. Lett. 96, 143901 (2006)] as well as the discussions by Varoquaux et al. [Phys. Rev. B. 34, 7617 (1989)] and Bürck [Hyperfine Interact. 123, 483 (1999)], we show analytically that precursors and 0 pulses describe the same physical phenomenon. We also show that most published results of transient pulse propagation can be expressed using one overarching equation. Finally, we give a physical interpretation of the analogy between precursors and 0 pulses as a medium-impulse response using a Green's function.

The Johnson graph J(v, k) has, as vertices, the k-subsets of a v-set V and as edges the pairs of k-subsets with intersection of size k -1. We introduce the notion of a neighbour-transitive code in J(v, k). This is a vertex subset Γ such that the subgroup G of graph automorphisms leaving Γ invariant is transitive on both the set Γ of 'codewords' and also the set of 'neighbours' of Γ, which are the non-codewords joined by an edge to some codeword. We classify all examples where the group G is a subgroup of the symmetric group Sym (V) and is intransitive or imprimitive on the underlying v-set V. In the remaining case where G ≤ Sym (V) and G is primitive on V, we prove that, provided distinct codewords are at distance at least 3, then G is 2-transitive on V. We examine many of the infinite families of finite 2-transitive permutation groups and construct surprisingly rich families of examples of neighbour-transitive codes. A major unresolved case remains.

In this paper we complete a classification of finite linear spaces S with line size at most 12 admitting a line-transitive point-imprimitive subgroup of automorphisms. The examples are the Desarguesian projective planes of orders 4, 7, 9 and 11, two designs on 91 points with line size 6, and 467 designs on 729 points with line size 8.

We consider a code to be a subset of the vertex set of a Hamming graph. The set of s-neighbours of a code is the set of vertices, not in the code, at distance s from some codeword, but not distance less than s from any codeword. A 2-neighbour transitive code is a code which admits a group X of automorphisms which is transitive on the s-neighbours, for s = 1, 2, and transitive on the code itself. We give a classification of 2-neighbour transitive codes, with minimum distance δ 5, for which X acts faithfully on the set of entries of the Hamming graph.

El presente estudio, tiene por objeto desarrollar un sistema de Telefonía IP para el Reitero mi agradecimiento a todos los excelentes profesores, que durante toda mi carrera universitaria en la Escuela Politécnica del Ejercito, me han preparado exitosamente para afrontar los retos profesionales, que el mundo actual exige. Agradezco y resalto el apoyo que recibí por parte de los funcionarios del Ilustre Municipio de Ambato, sobre todo del Departamento de Sistemas dirigido por el Ing. Xavier Francisco López, quien junto a su selecto grupo de colaboradores, me brindaron total apertura para poder desarrollar mi proyecto de grado, demostrando siempre un elevado espíritu de colaboración digno de destacar, agradezco también a mi buen amigo Marco Castillo, quien colaboró desinteresada y pro-activamente brindando asistencia en el desarrollo del monitoreo de la red.

Graphene is an important nano-material with extraordinary properties. An established PVD based Graphene synthesis method is engineered in order to demonstrate the versatility of the growth method with respect to the quality and number of layers of synthesized Graphene. A statistical method known as Factorial Design-of-Experiments (DoE) is demonstrated in this work to determine key factors for synthesis of Graphene on Copper (Cu) using amorphous carbon (a-C) as the solid carbon source. Both Qualitative and Quantitative analysis are performed to determine a suitable recipe. Carbon source thickness (which is a-C), annealing temperature and annealing duration are varied to study their effect on the growth. Annealing temperature and a-C thickness are found to be significant factors for growth feasibility in a PVD based growth whereas annealing time is found to play a crucial role in growing different number of layers of Graphene with different quality. The quality and number of layers of Graphene are verified by Raman characterization.

We report studies on the dc magnetization of YBCO thin ®lms in simultanously applied dc and ac ®elds. The eect of the ac ®elds is to decrease the irreversible magnetization drastically leading to complete collapse of the hysteresis loops for relatively small ac ®elds (25 Oe). The magnitude of the decrease depends on the component of the ac ®eld parallel to the c-axis. The decrease is non-linear with ac amplitude and is explained in the framework of the critical state response of ultrathin ®lms in perpendicular geometry. The ac ®elds increase the relaxation rapidly at short times while the long time response appears unaected.

We have investigated the hysteresis in the AC susceptibility of granular YBCO superconductors when the DC field is cycled. A crossover point is observed where the susceptibility X' in decreasing fields becomes more diamagnetic than for increasing fields, and this is investigated as a function of temperature, AC field amplitude and frequency. The behavior is consistent with the variation of the AC penetration depth with these variables and with a reduced flux density of the intergrain regions on field reversal. The zero field cooled behavior of the second harmonic X2 as well as the behavior of X' in field cooled conditions, are also reported. The DC field dependence of X' is analyzed using the low amplitude, linear response region approximations.

Instrumentation is a technique frequently used in software engineering for several different purposes, e.g. program and/or specification execution trace, testing criteria coverage analy- sis, and reverse engineering. Instrumenting a software product can be divided into two main tasks: (i) deriving the software product structure and (ii) inserting statements for collecting runtime/simulation information. Most instrumentation approaches are specific to a given domain or language. Thus, it is very difficult to reuse the effort expended in developing an instrumenter, even if the target languages are quite similar. To tackle this problem, in this paper, we propose an instrumentation-oriented meta-language, named IDeL, designed to support the description of both main tasks of instru- mentation process, namely: (i) the product structure derivation and (ii) the insertion of the instrumentation statements. In order to apply IDeL to a specific language L, it should be in- stantiated with a co...

This paper presents novel results for the high order capacity statistics (HOS) of equal gain combining (EGC) diversity receivers. The proposed methodology to obtain these results includes in the analysis the study of generalized fading channels and arbitrary number of receiving antennas. Analytical expressions for the n-th order capacity statistics as well as for the amount of dispersion (AoD), the reliability of the signal throughput, the kurtosis and the skewness of the channel capacity distribution have been derived. The validity of the proposed methodology has been verified by means of Monte Carlo computer simulations. Furthermore, it has been shown that previously published results for the first order capacity statistics are included in the analysis as special cases.

Long Range (LoRa) systems have recently attracted significant attention within the research community as well as for commercial use due to their ability to transmit data over long distances at a relatively low energy cost. In this study, new results for the bit error rate performance of Long Range (LoRa) systems operating in the presence of Rayleigh, Rice, Nakagami-m, Hoyt, η-μ and generalized fading channels are presented. Specifically, we propose novel exact single integral expressions as well as simple, accurate expressions that yield tight results in the entire signal-to-noise ratio (SNR) region. The validity of our newly derived formulas is substantiated by comparing numerically evaluated results with equivalent ones, obtained using Monte-Carlo simulations and exact analytical expressions.

The frequency scarcity imposed by fast growing demand for mobile data service requires promising spectrum aggregation systems. The so-called higher-order statistics (HOS) of the channel capacity is a suitable metric on the system performance. While prior relevant works have improved our knowledge on the HOS characterization of spectrum aggregation systems, an analytical framework encompassing generalized fading models of interest is not yet available. In this paper, we pursue a detailed HOS analysis of κ-µ and κ-µ shadowed fading channels by deriving novel and exact expressions. Furthermore, the simplified HOS expressions for the asymptotically low and high signal-to-noise regimes are derived. Several important statistical measures, such as amount of fading, amount of dispersion, reliability, skewness, and kurtosis, are obtained by using the HOS results. More importantly, the useful implications of system and fading parameters on spectrum aggregation systems are investigated for channel selection. Finally, all derived expressions are validated via Monte-Carlo simulations.

The use of optical spatial modulation (OSM), which has been recently emerged as a power and bandwidth efficient pulsed modulation technique for indoor optical wireless communication, is proposed as a simple, low-complexity means of achieving spatial diversity in coherent free space optical (FSO) communication systems. In doing so, this paper makes several novel contributions as follows. It presents a generic analytical framework for obtaining the Average Bit Error Probability (ABEP) of uncoded OSM with coherent detection in the presence of turbulence-induced fading. Although the framework is general enough to accommodate any type of models based on turbulence scattering, the focus in this paper is the H-K distribution. Although this distribution represents a very general scattering model valid over a wide range of atmospheric conditions, it is has not been considered in the past in conjunction with FSO systems possibly because of its mathematical complexity. The proposed analytical framework yields exact performance evaluation results for MIMO systems with two transmit and an arbitrary number of receive apertures. In addition, tight upper bounds are derived for the error probability for OSM systems with an arbitrary number of transmit apertures as well as for convolutionally encoded signals. The performance of OSM is compared to that of well established coherent FSO schemes, employing spatial diversity at the transmitter or the receiver only. Specifically, it is shown that OSM can offer comparable performance with conventional coherent FSO schemes while outperforming the latter in terms of spectral efficiency and hardware complexity. Various numerical performance evaluation results are also presented and compared with equivalent results obtained by Monte Carlo simulations which verify the accuracy of the derived analytical expressions.

ABSTRACTIn this paper, a study on the end‐to‐end performance of multi‐hop non‐regenerative relaying networks over independent generalized‐gamma (GG) fading channels is presented. Using an upper bound for the end‐to‐end signal‐to‐noise ratio (SNR), novel closed‐form expressions for the probability density function, the moments, and the moments‐generating function of the end‐to‐end SNR are presented. Based on these derived formulas, lower bounds for the outage and the average bit error probability (ABEP) are derived in closed form. Special attention is given to the low‐ and high‐SNR regions having practical interest as well as to the Nakagami fading scenario. Moreover, the performance of the considered system when employing adaptive square‐quadrature amplitude modulation is further analyzed in terms of the average spectral efficiency, the bit error outage, and the ABEP. Computer simulation results verify the tightness and the accuracy of the proposed bounds. Copyright © 2011 John Wile...

Hierarchical Multilevel Space-Shift Keying Modulation is proposed for Unequal Error Protection under Line-Of Sight conditions in Rician fading channels. The High Priority (HP) information is conveyed via the number of active antennas employed to transmit a codeword. The Low Priority (LP) information is transmitted employing Generalized Space Shift Keying (GSSK) in the codeword subsets corresponding to the transmission of the HP symbols. Hierarchical modulation is accomplished by associating phase shifts with every transmit antenna and adjusting these phase shifts to achieve different levels of Unequal Error Protection. The simulations demonstrate the performance and design options offered by the proposed scheme.

A reconfigurable space-time coding technique is investigated, for a high-speed downlink packet access multiple-antenna network, which combats the effects of antenna correlation. Reconfigurability is achieved at the link level by introducing a linear precoder in a space-time block coded system. The technique assumes knowledge of the long-term characteristics of the channel, namely the channel correlation matrix at the transmitter. The benefits of the proposed reconfigurable technique as compared to the conventional non-reconfigurable versions are evaluated via system-level simulations. In order to characterize the system-level performance accurately and, at the same time, use a feasible approach in terms of computational complexity, a suitable linkto-system interface has been developed. The average system throughput and the number of satisfied users are the performance metrics of interest. Simulation results demonstrate the performance enhancements achieved by the application of reconfigurable techniques as compared to their conventional counterparts.

We present a study of changes in the laycr morphology of tensilely straincd GalnAs/InP multiple quantum well (MQW) structurcs in dcpcndcn~Sc on strain and substrate off-orientation. Growth was perfonncd by chemical beam cpitax'y (CBE). For high tensile strain (xc;~-0.77) latcral thickncss fluctuations evolving into facets of the (411)A type are obscrvcd in cross-scctional transntission electron microscopy (TEM). Thcsc undulations arc parallel to [01 i] and present for samplcs grown on both cxactly oricntcd and off-oricntcd (100) InP substrates. For off-oriented substratcs thc strain induced generation of macrostcps parallel to the surface steps is dctcctcd for xc;~-0.65 and x(;,~=O.77. The distance and height of thc macrostcps directly correspond to the substrate off-orientation anglc. While the macrostep generation is a dircct conscqucncc of surface steps in combination with strain, the occurrcncc of the undulations might bc connccted with the (2x4) surfacc reconstruction during CBE growth. Both mechanisms arc discussed with rcspect to experimcntal and theoretical litcraturc data. % 1997 Elscvicr Scicncc Ltd.

Goal-Our objective is to provide a framework for extracting signals of interest from the wearable seismocardiogram (SCG) measured during walking at normal (subject's preferred pace) and moderately-fast (1.34 -1.45 m/s) speeds. Methods-We demonstrate, using empirical mode decomposition (EMD) and feature tracking algorithms, that the pre-ejection period (PEP) can be accurately estimated from a wearable patch that simultaneously measures electrocardiogram (ECG) and sternal acceleration signals. We also The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Pneumonia causes the deaths of over a million people worldwide each year, with most occurring in countries with limited access to expensive but effective diagnostic methods, e.g., chest X-rays. Physical examination, the other major established method of diagnosis, suffers from several drawbacks, most notably low accuracy and high interobserver error. We sought to address this diagnostic gap by developing a proof-of-concept non-invasive device to identify the accumulation of fluid in the lungs (consolidation) characteristic of pneumonia. This device, named Tabla after the percussive instrument of the same name, utilizes the technique of auscultatory percussion; a percussive input sound is sent through the chest and recorded with a digital stethoscope for analysis. Tabla analyzes differences in sound transmission through the chest at audible frequencies as a marker for lung consolidation. This paper presents preliminary data from five pneumonia patients and eight healthy subjects. We demonstrate 92.3% accuracy in distinguishing between healthy subjects and patients with pneumonia after data analysis with a K-nearest neighbors algorithm. This prototype device is low cost and simple to implement and may offer a rapid and inexpensive method for pneumonia diagnosis appropriate for general use and in areas with limited medical infrastructure.

Passive implantable sensors have received considerable attention for wireless in vivo measurement of physiological parameters in challenging locations of the human body. They are considered promising alternatives to the existing catheterbased biomedical transducers and battery powered implants. In this paper, we report a novel planar reader antenna for wireless interrogation of LC-based passive implantable sensors. The antenna utilizes two planar, electromagnetically isolated loops for wireless detection of the resonance frequency of the LC sensors. 2-D and 3-D versions of the antenna with the identical geometry were developed for a comparative study. A comprehensive analysis of the antenna together with in vitro evaluation of the antenna performance is presented. With the proposed antenna topology, the isolation level of 58 dB within the frequency range of 1-50 MHz, and at least 37 dB up to 100 MHz was achieved. The 3-D version of the antenna demonstrated improved performance by the T/R isolation of at least 64 and 44 dB within the frequency bands of 1-50 and 50-100 MHz, respectively.

Pneumonia causes the deaths of over a million people worldwide each year, with most occurring in countries with limited access to expensive but effective diagnostic methods, e.g., chest X-rays. Physical examination, the other major established method of diagnosis, suffers from several drawbacks, most notably low accuracy and high interobserver error. We sought to address this diagnostic gap by developing a proof-of-concept non-invasive device to identify the accumulation of fluid in the lungs (consolidation) characteristic of pneumonia. This device, named Tabla after the percussive instrument of the same name, utilizes the technique of auscultatory percussion; a percussive input sound is sent through the chest and recorded with a digital stethoscope for analysis. Tabla analyzes differences in sound transmission through the chest at audible frequencies as a marker for lung consolidation. This paper presents preliminary data from five pneumonia patients and eight healthy subjects. We ...