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the concept of cloud computing is actually implemented in order to provide a mechanism which makes data truly available and mobile in nature. The availability of the information which resides in the cloud computing environment is designed in such a manner such that the data is accessible and available to all the devices on demand. The best practice of implementation of cloud-based application is to integrate at lower levels, network intrusion detection system. These systems are actually artificially intelligent in nature to decide which application has to be given permission and which has to be blocked. In this paper we are proposing a very user-friendly and fast with high productivity, network intrusion detection system. This system works at the application layer, and it is artificially intelligent that is applicable on the Cloud architecture for the prevention of the spamming of the web forms.

A metamaterial-based wideband circularly polarized (CP) phased array antenna is developed. An 8×8 antenna array prototype using 5-bit RF phase shifter demonstrates a scan angle of ±30°, scan resolution of 3.5°, scan loss of 1.5 dB, boresight gain of 22 dBic, active reflection coefficient less than −9 dB, axial ratio less than 3 dB, and side-lobe levels less than −10 dB from 27 GHz to 30 GHz.

Design of a multi-port compact antenna for RF energy harvesting systems is presented in this paper. It consists of an E-shaped coaxial-fed microstrip antennas operating at 958MHz and 2.35GHz each placed on all sides of a cube. The advantage of this approach is that power can be received from all directions and at different polarizations, thereby enhancing the total harvested power. The overall size of the antenna is only 60mm x 60mm x 50mm. The isolation between various ports is below −30 dB ensuring minimum interference between them.

A novel, fast, and accurate analytical method based on input impedance is proposed for antenna directivity determination. The detailed theoretical expressions are examined and presented to determine the directivity of the wire-dipole and biconical antennas. The proposed analytical directivity results of the antennas are compared with conventional methods and measurements as well as a commercial electromagnetic (EM) simulator. A good correlation is achieved between the proposed method, the CST full-wave EM simulator, and the measurements. Additionally, the proposed method can be used to determine the antenna directivity in complicated environments, i.e., large array, for which the antenna characteristics may be deviated under coupling effects.

In this work the design, analysis and characterisation of a novel backward to forward scanning substrate integrated waveguide (SIW) leaky wave antenna with consistently high gain over the entire field of view is proposed. The leaky wave antenna (LWA) achieves beamforming from the backward to forward direction with change in frequency. The antenna measures 5.64λ 0 × 1.5λ 0 × 0.0294λ 0 at the centre frequency of 60 GHz and has an operating frequency range from 56 to 70 GHz with a gain > 9.5 dBi throughout the operating frequency range. The main beam direction changes from -53° to 50° as the frequency varies from 56 to 70 GHz. The designed leaky wave antenna is integrated with a mm-wave transceiver that is designed as a System-In-Package (SiP) and the complete system is used to carry out measurements to validate non-destructive testing (NDT) for metallic structures with defects under insulating materials such as foam, laminated plastic, composites and ceramics. The designed SiP measures 100 mm × 60 mm. The measured results demonstrate that the developed system is capable NDT and scanning of metallic structures under multilayered composites.

Surgical Safety Checklists are valuable tools for use by oral and maxillofacial surgeons. However, dentists occasionally join their maxillofacial surgery colleagues in theatre for specific dental procedures during major maxillofacial surgery, and surgical checklists do not address crucial dental steps. Not detecting a small dental instrument poses an aspiration hazard. We address this gap in safety with a single modification when adapting the WHO Surgical Safety Checklist to Oral and Maxillofacial Surgery procedures specifically for cases when dental colleagues are required to join their surgical colleagues in theatre.

A generalised stubs-integrated-microstrip (SIM) antenna with wide coverage circularly polarised (CP) radiation is proposed for radio-frequency energy harvesting applications. The antenna consists of a microstrip patch radiator with four integrated asymmetric/symmetric-stubs and a coaxial feed. Four stubs are integrated at the corners of a square microstrip radiator. The stub lengths or stub gaps from the microstrip radiator are optimised for wide-beam CP radiation. Four different combinations of asymmetric/symmetric based SIM antennas are designed, fabricated, and tested. The proposed antennas are able to cover upper-half area with CP radiation across the 3-dB axial ratio bandwidth.

The paradigm of wellness consists of both physical and mental wellness. One important parameter of physical wellness in the monitoring of cardiac health during activity, which requires measurement of ambulatory heart rate (HR). With the advent of smart wearable devices, measurement of heart-rate using Photoplethysmogram (PPG) has become a commodity. However, arriving at a reliable heart-rate measurement in real-time during daily activities is an open research problem. In this paper, we propose a method based on Weiner Filter, to estimate the correct HR values in the presence of motion, while being computationally efficient to be run on-device. Results are presented on a public data-set which prove the efficacy and efficiency of the proposed method.

Wearable health monitoring has become a very familiar term in today'sworld. One of the most popular means ofwearable sensing is photoplethysmogram (PPG). Due to its unobtrusive and ubiquitous nature, it is gaining popularity among people everywhere. Due to the ease of use, the utility of such technology is increasing day by day. However, in theworld of researchers, the accurate estimation of heart rate (HR) in presence of motion artefacts remains an unsolved problem due to the susceptibility of PPG signals to corruption by motion artefacts. The way in which a person fastens the device on the wrist plays an important role in the acquisition of signal from the device. While there are various research works going on in this field, there is always a trade-off between accuracy and complexity of algorithm and hardware resources. Also, in such scenarios where the sensor gets misplaced due to movements, there might be no PPG signal component available in the acquired signal data. In such cases the sophisticated denoising algorithms make no sense.

Background. Bacterial characterization is important in clinical and epidemiological studies. We herein report the first case of gas-producing Vibrio cholera gastroenteritis with acute kidney injury. Case presentation. A 30-year-old female presented to the emergency department with complaints of about ten episodes of watery diarrhea, four episodes of vomiting and elevated serum urea/creatinine levels. Although the bacteria were first misidentified as Vibrio furnissii by gas production on carbohydrate fermentation and triple sugar iron agar, it was later confirmed as Vibrio cholerae by 16 S rRNA gene sequencing and specific PCR. The treatment regimen was followed as for Vibrio species with intravenous fluids, ciprofloxacin and doxycycline. The patient recovered without relapse. Conclusions. Literature survey from the PubMed database shows no gas-producing Vibrio cholerae isolate being reported in the world. Further, genotype studies are warranted to look into the gas production of Vibrio cholerae .

Wrist based devices, like smart-watches, fitness bands and health monitors all provide a common sensor called Photoplethysmography (PPG) to measure optical pulse signal. This is usually used to derive the instantaneous heart-rate (HR), which is useful while doing any exercise or to monitor on a regular basis for chronic patients. However, one major issue with the signal is that it is easily corrupted by ambulatory motion generated by hand movements of the subject. Since, these devices also come equipped with an independent motion sensor, namely a tri-axes accelerometer, researchers have taken interest in trying to correct the motion artifact in PPG using the accelerometer as a reference noise signal. However, it is not a trivial problem and hence, even after a substantial body of research, the problem remains unsolved, especially when considering on-premise estimation due to the resource-constrained nature of wearable devices. In this paper, we aim to solve this problem using subspace based learning approach. Though this approach has been utilized before, we have added some novel steps to the algorithm pipeline and also made modifications so that the algorithm can be possibly run on a typical wearable device. Our preliminary results show efficacy and promise of our proposed approach.

A tapered-slit-patch antenna with wide-angle circularly polarized (CP) radiation and a compact rectifier was investigated for energy-harvesting systems. A tapered-slit octagonal-shaped patch radiator was implemented to realize the CP microstrip antenna with wide-angle radiation using a proximity-coupled feed. Eight tapered slits with length difference of 1.3% were embedded along the octagonal directions symmetrically on the microstrip radiator from the patch's center. The antenna prototype showed a gain of more than 5.8 dBic across the CP bandwidth of 7 MHz (894-901 MHz) with a 3-dB axial ratio (AR) beamwidth of more than 180°. A compact composite right/left-handed (CRLH)-based rectifier operating at 900 MHz was designed to be used along with the antenna for radio-frequency (RF) energy-harvesting system. A microstrip line forms the righthanded part of the CRLH transmission line (TL), and the lumped components form the left-handed part of the CRLH TL. The proposed rectifier was compact with size of 0.18λ 0 × 0.075λ 0 × 0.0002λ 0 at 900 MHz with a high RF-dc conversion efficiency of 43%.

In this work, a novel backward-to-forward scanning leaky-wave antenna is characterized and validated for non-destructive testing (NDT) of cracks and corrosion in metallic structures under multilayer composites. Beamforming systems play a major role in NDT applications that involve scanning of a large target. Leaky-wave antennas are capable of scanning their main beam from backward to forward direction with change in input frequency. They are less complex to realize compared to other conventional beamforming systems that involve mechanical scanning or electronic beamforming. The proposed leaky-wave antenna that measures $7.51\lambda_{\mathrm{g}}\times0.8\lambda_{\mathrm{g}}\times0.036\lambda_{\mathrm{g}}$ with operating bandwidth extending from 8.0 to 12.5 GHz is reported in this work. The coverage of the leaky-wave antenna extends from −63° to 64°. The antenna is validated to be used for NDT application with simulation results indicating the scanning capability of the leaky-wave antenna.

RF energy harvesting is the process of acquiring ambient RF energy and converting it into a suitable form for storage for powering low power devices. This paper describes a low cost rectifier operating at 1.8 GHz for energy harvesting applications. Rectifier is fabricated on lossy FR4 substrate and better impedance matching is achieved by incorporating a short stub and two open stubs. It has an efficiency of 63% and an output voltage of 0.8V at 0dBm input power. Source pulling technique is used to optimize the design. Compactness as well as low cost make this rectifier attractive for RF energy harvesting

A novel frequency scanning leaky wave antenna with consistently high gain across the entire operating frequency range for portable low-profile beamforming applications is reported. The leaky wave antenna is composed of fifteen unit cells having an overall size of $\mathbf{5.15}\lambda_{0}\times \text{0.66}\lambda_{0}\times \mathbf{0.03}\lambda_{0}$ at l0GHz. Each unit cell is composed of a SIW structure with a diagonal slot on the top metalized surface that acts as an aperture to feed three square metal rings on top of a superstrate. This structure helps to achieve a uniform gain of higher than 11dBi in the entire operating frequency range that extends from 8 to 12GHz with a continuous beam scanning angle from −60° to 60°. The unit cell design and the simulation results of the antenna have been presented in detail.

A circularly polarized (CP) microstrip antenna over an asymmetric-metasurface using a coaxial probe is presented in this paper. An asymmetric-metasurface is placed below a square radiating patch to achieve CP radiation (axial ratio less than 3 dB at around 1.6 GHz) at the L-band. The measured performance of the prototype antenna achieves an impedance bandwidth of 3.45% (1.598 GHz - 1.658 GHz) with gain of larger than 5.5 dBic.

Wireless systems manufacturers desire a low-profile, wideband, circularly polarized (CP) antenna. Generally, a single-feed CP microstrip antenna (CPMA) has a simple configuration but is hindered by a narrow, 3-dB axial ratio (AR) bandwidth. The bandwidth of a multiple-feed CPMA can be enhanced but requires a complicated and larger feeding network. Many techniques have been employed to improve AR bandwidth, such as using dual-feed, network-based structures [1], stacked patches [2]?[3], array antennas with sequential feeding network [4], and multilayered structures [5]. However, these CP antennas are based on multiradiating patches or complicated feeding structures.

A circularly polarized (CP) microstrip antenna with four strips is proposed for wide beamwidth and RF energy harvesting applications. Four strips along the diagonal directions are integrated symmetrically onto a square patch radiator for CP radiation with wide beamwidth. To improve the impedance matching of the antenna, a stub is integrated along the orthogonal direction of the patch radiator. The antenna is designed on FR4 substrate and an antenna prototype shows a measured 10-dB return loss bandwidth of 120 MHz (2.53–2.65 GHz) with a maximum gain of 4.6 dBic. The measured 3-dB axial ratio (AR) bandwidth is 65 MHz (2.540–2.605 GHz) with a 3-dB AR beamwidth of around 180° across the band. Overall antenna volume is 0.475λo× 0.475λo × 0.013λo at 2.5 GHz. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1044–1049, 2016

An e-shaped slotted-circular-patch antenna is proposed for circularly polarized (CP) radiation and RF energy harvesting. The proposed antenna consists of an e-shaped slotted-circular-patch radiator and a coaxial feed. An e-shaped slot is cut along the orthogonal axis of a circular-patch with a coaxial feed along the diagonal axis to generate CP radiation with compact antenna size of 45 × 45 × 1.6 mm. The prototype antenna shows the measured gain more than 5 dBic at 2.4 GHz with 3 dB axial ratio beamwidth more than 140°. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:868–875, 2016

An asymmetric-metasurface based wideband circularly polarized (CP) microstrip antenna using a coaxial probe is proposed for L-band applications. The antenna involves a stacked asymmetric-metasurface, a radiating rectangular-patch and a coaxial feed. An asymmetric-metasurface is designed using rectangular unit cells and smaller size unit cells along one of the diagonal lines. The asymmetric-metasurface is placed above a radiating rectangular-patch with support of foam layer to achieve a wideband CP radiation. The measured performance of the prototype antenna achieves an impedance bandwidth (−10 dB return loss bandwidth) of 15.7% (1.58-1.85 GHz) with CP bandwidth (3-dB axial ratio) of 13% (1.58-1.80 GHz) and gain of ≥9 dBic.

Introduction: Dengue fever is a common mosquito-borne viral disease which has reached alarming size in the past few years. It is endemic in more than 100 countries and significant differences were found in clinical profile and atypical manifestation. Aim of the Study: A retrospective observational study of clinical profile and atypical manifestations in patients with dengue fever. Materials and Methods: Serum samples were collected from clinically suspected cases of dengue fever and it was confirmed by NS1 antigen, IgM, and IgG antibody by ELISA. Clinical details and atypical manifestations were recorded. Observation: During the study period, a total of 2502 patients were suspected to have dengue infection, of which 464 (18.5%) samples were found to be positive for dengue viral infection. A majority of the cases were males [268 (57%)] when compared with females [196 (42%)]. Fever was the most common clinical presentation seen in all the patients, followed by headache (78.4%), myalgia (61%), body pain (49.3%), vomiting (40%), joint pain (31.5%), dry cough (19%), nausea (14%), abdominal pain (8%), diarrhea (5.6%), retro-orbital pain (04%), burning micturition (2.4%), and rashes (0.6%). Among atypical manifestations, hepatomegaly [32 (7%)] was the most common, followed by splenomegaly [23 (5%)], bradycardia [18 (4%)], meningitis [6 (1.2%)], hemoptysis [5 (1%)], acalculous cholecystitis [4 (0.8%)], and acute pancreatitis [2 (0.4%)]. The study of hematological parameters showed thrombocytopenia was present in 179 (38.5%) patients, followed by leukopenia [77 (17%)] and raised hematocrit [29 (6.2%)]. Conclusion: During ongoing epidemics, the clinical profile and atypical manifestations in clinically suspected dengue patients should be investigated early so that severe forms can be treated promptly.

A wideband circularly polarized (CP) stacked square-patch antenna using single-feed is proposed for ultra-high frequency (UHF) radio frequency identification (RFID) readers. The proposed wideband CP antenna comprises of a main radiating patch, a parasitic patch, and a probe. A cross-shaped slot and a square-ring-shaped slot are cut into the radiating square-patch and the parasitic square-patch, respectively. The CP radiation is generated by the embedded cross-shaped slot in radiating square-patch along the diagonal line. The area and location of the embedded slots as well as the separation between the patches are optimized for a wideband CP radiation. The measured impedance (greater than 10 dB return loss) and CP radiation (3 dB axial ratio) bandwidths of an antenna prototype are 18.0%, or 165 MHz (0.840 GHz – 1.005 GHz) and 11.6%, or 105 MHz (0.855 GHz – 0.960 GHz), respectively. The measured gain is greater than 7 dBic across the 3 dB axial ratio frequency range, while the antenna dimension is 0.54λ o ×0.54λ o ×0.087λ o (λ o is free-space wavelength at 0.9 GHz).

A rectangular dielectric resonator antenna (DRA) is proposed over a metasurface for achieving wideband circularly polarized radiation. The antenna consists of a rectangular DR, a metasurface, and a coaxial probe. The metasurface-based ground plane has improved the 3-dB axial ratio bandwidth and gain of the rectangular DRA. This DRA over the metasurface, which consists of an array of “+” shaped unit cells, exhibits a wideband 3-dB axial ratio bandwidth of 19% (4.45 GHz-5.39 GHz) with less than 2-VSWR and a realized gain of more than 6.0 dBic across a frequency range from 4 GHz to 5. 25 GHz.

The paper presents an overview of compact microstrip antennas for RF energy harvesting systems. A detailed literature review of several compact antennas suitable for energy harvesting systems is discussed along with different antenna polarizations. Various size reduction techniques for antennas along with trade-offs are summarized and compared

This paper proposes a planar grid array antenna (GAA) at 93 GHz on low cost printed circuit board (PCB). The switched beams can be realized in a very simple and elegant way by positioning the feeding points properly. With substrate integrated waveguide (SIW) feeding structure, the antenna is able to generate 3 beams with a specific coverage of ±19° and a peak realized gain of 18.7 dBi.

A substrate integrated waveguide based leaky-wave antenna with composite right-left-handed tapered slot unit cells is studied for a wideband radiation at the boresight. The antenna consists of a number of slotted-unit cells with varying slot lengths but the unchanged slot widths and the identical embedded rectangular patches. The measured gain at the boresight of the tapered LWA is greater than 9dBi across a wide bandwidth of 4.4% (8.80 GHz–9.20 GHz).

In this work, a novel compact 4×4 butler matrix is proposed for power transfer to aid electromagnetic energy harvesting for sensors. The butler matrix is designed to operate at 2.4 GHz. The butler matrix is composed of miniaturized couplers and a crossover. The coupler achieves a miniaturization of 14% and the crossover size is reduced by 17.5% when compared to a conventional crossover. An array of patch antenna is designed along with the butler matrix and the beam scanning capability of over 1000 is validated by simulation and measurement results.

A compact dual-band circularly polarized (CP) slotted patch antenna is proposed for global navigation satellite systems (GNSSs). The antenna consists of a main patch radiator, a parasitic patch radiator, and a coaxial feeding probe. Four circular-ring slots are cut onto the circular patch radiators respectively for CP radiation and antenna miniaturization. The parasitic patch radiator is connected to ground using four vias to further reduce the size of the antenna. The compact antenna prototype with an overall size of 0.306λ 0 ×0.306λ 0 ×0.02λ 0 (λ 0 is the free space wavelength at 1.227 GHz) achieves desired measured performance at L1/L2 bands: −10 dB reflection coefficient bandwidth of 2.0% (1.221 GHz–1.246 GHz) and 2.5% (1.533 GHz–1.572 GHz), 3-dB axial ratio (AR) bandwidth of 1.0% (1.22– GHz 1.231 GHz) and 0.84% (1.552 GHz–1.565 GHz); maximum gain of 4.0 dBic at 1.227 GHz and 5.6 dBic at 1.555 GHz. The 3-dB AR beamwidth is more than 145° across the 3-dB AR bandwidth for both bands.

In this paper, a simple, low cost, compact, portable and automatic measurement system is proposed for radiation patterns of antenna. Proposed system consists of a designed rotary stage, an USB signal generator and a spectrum analyzer. A stepper motor based rotary stage is employed to control automatically the 3600 rotation of the receiving antenna using LABVIEW software and Arduino hardware control system. The receiving antenna is then connected to the spectrum analyzer via GPIB interface. The radiation pattern is then plotted in real time on GUI interface developed based LABVIEW software. The proposed system is verified by comparing the results taken of this system with other existed results. A good agreement is obtained between them which enable this portable system can be utilized for both commercial and educational purposes.