1,034 research outputs found
Reduced-reference Video Quality Metric Using Spatio-temporal Activity Information
Monitoring and maintaining acceptable Quality of Experience is of great importance to video service providers. Perceived visual quality of transmitted video via wireless networks can be degraded by transmission errors. This paper presents a reduced-reference video quality metric of very low complexity and overhead that makes use of frame based spatial (SI) and temporal (TI) activity levels to monitor the effect of channel errors on video transmitted over error prone networks. The performance of the metric is evaluated relative to that of a number of full and reduced reference metrics. The proposed metric outperforms some of the most popular full reference metrics whilst requiring very little overhead
Dual Axes Solar Tracker
Photovoltaic (PV) is one of the most important sources of renewable energy in the world. Its current efficiency could be increased up to 60% by using dual axes solar tracker, which maximise PV exposure to sun. The most important component in dual axes solar tracker is sensing location of the sun. Four light dependent resistors (LDR) are used as the sensors, connected to potentiometers to increase their accuracy. Arduino UNO is used as the controller to control two stepper motors. Two experiments have been carried out, where the tolerance of the LDR has been found to be 0.05V and the calibration of the four LDRs to have the error of 0.03V. Both experiments proved the capability of LDR for dual axes solar tracker and potentiometer to increase their accuracy
RIS-aided Mixed RF-FSO Wireless Networks: Secrecy Performance Analysis with Simultaneous Eavesdropping
The appearance of sixth-generation networks has resulted in the proposal of
several solutions to tackle signal loss. One of these solutions is the
utilization of reconfigurable intelligent surfaces (RIS), which can reflect or
refract signals as required. This integration offers significant potential to
improve the coverage area from the sender to the receiver. In this paper, we
present a comprehensive framework for analyzing the secrecy performance of a
RIS-aided mixed radio frequency (RF)-free space optics (FSO) system, for the
first time. Our study assumes that a secure message is transmitted from a RF
transmitter to a FSO receiver through an intermediate relay. The RF link
experiences Rician fading while the FSO link experiences M\'alaga distributed
turbulence with pointing errors. We examine three scenarios: 1) RF-link
eavesdropping, 2) FSO-link eavesdropping, and 3) a simultaneous eavesdropping
attack on both RF and FSO links. We evaluate the secrecy performance using
analytical expressions to compute secrecy metrics such as the average secrecy
capacity, secrecy outage probability, strictly positive secrecy capacity,
effective secrecy throughput, and intercept probability. Our results are
confirmed via Monte-Carlo simulations and demonstrate that fading parameters,
atmospheric turbulence conditions, pointing errors, and detection techniques
play a crucial role in enhancing secrecy performance.Comment: No comment
Edge dissimilarity reduced-reference quality metric with low overhead bitrate
In multimedia transmission, it is important to rely on an objective quality metric which accurately represents the subjective quality of processed images and video sequences. Reduced-reference metrics make use of side-information that is transmitted to the receiver for estimating the quality of the received sequence with low complexity. In this paper, an Edge-based Dissimilarity Reduced-Reference video quality metric with low overhead bitrate is proposed. The metric is evaluated by finding the dissimilarity between the edge information of original and distorted sequences. The edge degradation can be detected in this manner as perceived video quality is highly associated with edge structural. Due to the high overhead using the Soergel distance, it is pertinent to find a way to reduce the overhead while maintaining the edge information that can convey the quality measure of the sequences. The effects of different edge detection operator, video resolution and file compressor are investigated. The aim of this paper is to significantly reduce the bitrate required in order to transmit the side information overhead as the reduced reference video quality metric. From the results obtained, the side information extracted using Sobel edge detector maintained consistency throughout the reduction of spatial and temporal down-sample
Simultaneous determination of domperidone and Itopride in pharmaceuticals and human plasma using RP-HPLC/UV detection : method development, validation and application of the method in in-vivo evaluation of fast dispersible tablets
Domperidone and Itopride are pro-kinetic agents, regulating the gastric motility and are commonly prescribed as anti emetic drugs. In the present study a simple, rapid and sensitive RP-HPLC/UV method was developed for simultaneous determination of Domperidone and Itopride in pharmaceutical samples and human plasma, using Tenofavir as internal standard. Experimental conditions were optimized and method was validated according to the standard guidelines. Combination of water (pH 3.0) and acetonitrile (65:35 v/v) was used as mobile phase, pumped at the flow rate of 1.5 ml/min. Detector wavelength was set at 210 nm and column oven temperature was 40oC. Unlike conventional liquid-liquid extraction, simple precipitation technique was applied for drug extraction from human plasma using acetonitrile for deprotienation.The method showed adequate separation of both the analytes and best resolution was achieved using Hypersil BDS C8 column (150 mm × 4.6 mm, 5 μm). The method was quite linear in the range of 20-600 ng/ml. Recovery of the method was 92.31% and 89.82% for Domperidone and Itopride, respectively. Retention time of both the analytes and internal standard was below 15 min. The lower limit of detection (LLOD) and lower limit of quantification (LLOQ) for Domperidone were 5 and 10 ng/ml while for Itopride was 12 and 15 ng/ml, respectively. The developed method was successfully applied for in-vivo analysis of fast dispersible tablets of Domperidone in healthy human volunteer. The proposed method was a part of formulation development study and was efficiently applied for determination of the two drugs in various pharmaceutical products and human plasma
Simulating Cotton Growth and Productivity Using AquaCrop Model under Deficit Irrigation in a Semi-Arid Climate
AquaCrop is a water-driven model that simulates the effect of environment and management on crop production under deficit irrigation. The model was calibrated and validated using three databases and four irrigation treatments (i.e., 100%ET, 80%ET, 70%ET, and 50%ET). Model performance was evaluated by simulating canopy cover (CC), biomass accumulation, and water productivity (WP). Statistics of root mean square error (RMSE) and Willmott’s index of agreement (d) showed that model predictions are suitable for non-stressed and moderate stressed conditions. The results showed that the simulated biomass and yield were consistent with the measured values with a coefficient of determination (R2) of 0.976 and 0.950, respectively. RMSE and d-index values for canopy cover (CC) were 2.67% to 4.47% and 0.991% to 0.998% and for biomass were 0.088 to 0.666 ton/ha and 0.991 to 0.999 ton/ha, respectively. Prediction of simulated and measured biomass and final yield was acceptable with deviation ˂10%. The overall value of R2 for WP in terms of yield was 0.943. Treatment with 80% ET consumed 20% less water than the treatment with 100%ET and resulted in high WP in terms of yield (0.6 kg/m3) and biomass (1.74 kg/m3), respectively. The deviations were in the range of −2% to 11% in yield and −2% to 4% in biomass. It was concluded that AquaCrop is a useful tool in predicting the productivity of cotton under different irrigation scenarios
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Effect of 1-Methyl Cyclopropane and Modified Atmosphere Packaging on the Storage of Okra (Abelmoschus esculentus L.) : Theory and Experiments
Okra possesses a short shelf-life which limits its marketability, thereby, the present study investigates the individual and combined effect of 1-methylcyclopropene (1-MCP) and modified atmosphere packaging (MAP) on the postharvest storage life of okra. The treated/ untreated okra samples were stored at ambient (i.e., 27 °C) and low (i.e., 7 °C) temperatures for eight and 20 days, respectively. Results revealed that the 1-MCP and/or MAP treatment successfully inhibited fruit softening, reduction in mucilage viscosity, and color degradation (hue angle, ∆E, and BI) in the product resulting in a longer period of shelf-life. However, MAP with or without 1-MCP was more effective to reduce weight loss in okra stored at both ambient and cold storage conditions. Additionally, ascorbic acid and total antioxidants were also retained in 1-MCP with MAP during cold storage. The 1-MCP in combination with MAP effectively suppressed respiration rate and ethylene production for four days and eight days at 27 °C and 7 °C temperature conditions, respectively. According to the results, relatively less chilling injury stress also resulted when 1-MCP combined with MAP. The combined treatment of okra pods with 1-MCP and MAP maintained the visual quality of the product in terms of overall acceptability for four days at 20 °C and 20 days at 7 °C
FREQUENCY OF NASOPHARYNGEAL ANGIOFIBROMA IN PATIENTS PRESENTING WITH RECURRENT EPISTAXIS
Objective: To determine the frequency of nasopharyngeal angiofibroma in patients presenting with recurrent epistaxis.
Study design: Cross sectional study.
Duration and setting: This study was carried out from July 2017 to July 2018 at ENT, Head & Neck Surgery department, Khyber teaching hospital, Peshawar.
Material and method: A total number of 93 patients were included in this study. Patients fulfilling the inclusion criteria were collected from the outdoor patient department (OPD) of ENT, head and neck surgery, Khyber teaching hospital, Peshawar. Informed consent for participating in the study was taken from all patients. The patients’ biodata along with hospital registration number were entered on proforma. The patients were assessed initially by history and nasal endoscopic. CT scan nose and PNS with contrast was done and patient admitted and operated for the suspected nasopharyngeal angiofibroma. Biopsy specimen was sent for histopathology to consultant histopathologist in the hospital’s pathology laboratory. Lab reports of the biopsy specimen showing histopathology of nasopharyngeal angiofibroma were reviewed and data entered in the proforma.
Results: Out of 93 patients, 32% patients were in age range 10-15 years, 68% patients were in age range 16-20 years. Mean age was 16 years with SD ± 1.26. Fifty seven percent patients had duration of symptoms <1 year while 43% patients had duration of symptoms > 1 year. The incidence of nasopharyngeal angiofibroma was 18%. Conclusion: Our study concludes that the incidence of nasopharyngeal angiofibroma in our setup is 18% which can be due to the increasing number of Afghan refugees.
Key words: nasopharyngeal angiofibroma, recurrent epistaxis
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