90 research outputs found

    Chaotic Time Series Prediction using Spatio-Temporal RBF Neural Networks

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    Due to the dynamic nature, chaotic time series are difficult predict. In conventional signal processing approaches signals are treated either in time or in space domain only. Spatio-temporal analysis of signal provides more advantages over conventional uni-dimensional approaches by harnessing the information from both the temporal and spatial domains. Herein, we propose an spatio-temporal extension of RBF neural networks for the prediction of chaotic time series. The proposed algorithm utilizes the concept of time-space orthogonality and separately deals with the temporal dynamics and spatial non-linearity(complexity) of the chaotic series. The proposed RBF architecture is explored for the prediction of Mackey-Glass time series and results are compared with the standard RBF. The spatio-temporal RBF is shown to out perform the standard RBFNN by achieving significantly reduced estimation error.Comment: Published in: 2018 3rd International Conference on Emerging Trends in Engineering, Sciences and Technology (ICEEST). arXiv admin note: substantial text overlap with arXiv:1908.0132

    Genetic diversity in Balkhi, Hashtnagri and Michni sheep populations using SSR markers

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    Morphological and genetic diversity among the three neighboring sheep breeds native to Central valley of Khyber Pukhtunkhwa (KP, Pakistan) was investigated. A total number of 138 non relative individuals of Balkhi (46), Hashtnagri (44) and Michni (48) was sampled for morphological as well as molecular characters using 31 ovine specific SSR markers. Morphological observations and morphometric traits varied significantly among different sheep breeds. Balkhi having usually brown or white colour, with a tucked up fat tail was the larger breed. Hashtnagri is a medium sized breed; body covered with white wool, having long white tail, with a tail switch. The body colour of Michni sheep was usually brown or some times white. This breed is comparatively small in size with longer fat tail, hanging near  (33.3%) or below (66.7%) hock. Total number of 119 alleles was identified with mean number of 3.8 alleles per locus, ranging from 2 to 8. Twelve unique alleles  were identified in Michni population at different loci. Average gene diversity was higher in Michni (0.561). Inbreeding estimate (FIT) was significantly higher  (27.1%) among three breeds and was highest between Balkhi and Hashtnagri (31%), similarly highest gene flow (Nm = 60.4) and lowest population differentiation (FST = 4.3%) was estimated between these two  breeds. Maximum genetic distance was observed between Balkhi and Michni; however, Balkhi was genetically closed to Hashtnagri population. Balkhi and Michni were assigned at high accuracy to their respective population; however, the identity of Hashtnagri is obscure.Key words: Balkhi, Hashtnagri, Michni, simple sequence repeat (SSR) markers, morphological characteristics, genetic diversity

    DSLOT-NN: Digit-Serial Left-to-Right Neural Network Accelerator

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    We propose a Digit-Serial Left-tO-righT (DSLOT) arithmetic based processing technique called DSLOT-NN with aim to accelerate inference of the convolution operation in the deep neural networks (DNNs). The proposed work has the ability to assess and terminate the ineffective convolutions which results in massive power and energy savings. The processing engine is comprised of low-latency most-significant-digit-first (MSDF) (also called online) multipliers and adders that processes data from left-to-right, allowing the execution of subsequent operations in digit-pipelined manner. Use of online operators eliminates the need for the development of complex mechanism of identifying the negative activation, as the output with highest weight value is generated first, and the sign of the result can be identified as soon as first non-zero digit is generated. The precision of the online operators can be tuned at run-time, making them extremely useful in situations where accuracy can be compromised for power and energy savings. The proposed design has been implemented on Xilinx Virtex-7 FPGA and is compared with state-of-the-art Stripes on various performance metrics. The results show the proposed design presents power savings, has shorter cycle time, and approximately 50% higher OPS per watt.Comment: Presented at 2023 26th Euromicro Conference on Digital System Design (DSD

    Experimentation on Optimal Configuration and Size of Thin Cylinders in Natural Convection

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    In this paper, an experimental study of laminar, steady state natural convection heat transfer from heated thin cylinders in an infinite air medium has been reported. Two electrically heated cylinders having the same slenderness ratio (L/D) i.e. 6.1 but different diameters i.e. 3.8 cm and 5.08 cm were used. 105 experiments were carried out to study the effect of diameter and inclination angle of thin cylinder on natural convection heat transfer. After mandatory corrections of radiation and endcap heat losses, convective heat transfer results were presented in the form of local and average dimensionless numbers. For vertical configuration of thin cylinder, Nusselt number was varied from 52.99 to 95.10 corresponding to 1.28×108≤Ra*L≤1.08×1010. While for horizontal configuration,Nusselt number was varied from 10.74 to 17.78 corresponding to 9.42×104≤Ra*D≤8.17×106. Results were compared with the published data and found satisfactory as the maximum percentage difference was only 3.09%. The essence of research is that the heat transfer coefficient increases with decrease in diameter and increase in inclination angle. Smoke flow visualization was done to capture patterns of fluid flow. Finally, comparison was made to quantify increase in Nusselt number from slender cylinder as compared to the flat plate

    Convection Heat Transfer from Heated Thin Cylinders Inside a Ventilated Enclosure

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    Experimental study was conducted to determine the effect of velocity of axial fan, outlet vent height, position, area, and aspect ratio (h/w) of ventilated enclosure on convection heat transfer. Rectangular wooden ventilated enclosure having top and front transparent wall was made up of Perspex for visualization, and internal physical dimensions of box were 200 mm × 200 mm × 400 mm. Inlet vent was at bottom while outlet vents were at the side and top wall. Electrically heated cylindrical heat source having 6.1 slenderness ratio was fabricated and hanged at the centre of the enclosure. To calculate heat transfer rates, thermocouples were attached to the inner surface of heat source with silica gel. Heat source was operated at constant heat flux in order to quantify the effect of velocity of air on heat transfer. It was observed that average Nusselt number was increased from 68 to 216 by changing velocity from 0 to 3.34 m/s at constant modified Grashof number i.e. 5.67E+09. While variation in outlet height at the front wall did not affect heat transfer in forced convection region. However, Nusselt number decreased to 5% by changing the outlet position from top to the front wall or by 50% reduction in outlet area during forced convection. Mean rise in temperature of enclosure increased from 8.19 K to 9.40 K by increasing aspect ratio of enclosure from 1.5 to 2 by operating heat source at constant heat flux i.e. 541.20 w/m2

    Mabry syndrome in a child of South Asian descent

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    Mabry syndrome is the triad of seizures, hyperphosphatasia, and mental disability. It usually manifests in first year of life and has an autosomal recessive mode of inheritance. Besides the usual triad, other manifestations of Mabry syndrome include hypoplasia of distal phalanges, brachytelencepahly, gastrointestinal malformations and constipation, hypertelorism, short nose with a broad nasal bridge and dip, and thin upper lip with down turned corners of the mouth. More than 20 cases of Mabry syndrome have been reported in medical literature. Herein, we report the case of a six-month child with Mabry syndrome that presented with decreased neck holding, hypotonia and delayed motor milestones. The child also had a high-arched palate and hyperplastic malar eminences. Constipation was present but had a delayed onset, starting at 19 months of age. This is the first case of Mabry syndrome occurring in a child of South Asian descent

    Subacute sclerosing panencephalitis: clinical and demographic characteristics

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    Objective: To determine the clinical and demographic characteristics of children diagnosed with Subacute sclerosing panencephalitis (SSPE). Study Design: Case series. Place and Duration of Study: The Aga Khan University Hospital, Karachi, from January 2000 to June 2012. Methodology: A retrospective analysis was done, regarding medical charts of 43 children under the age of 16 years with a discharge diagnosis of SSPE. Demographic and clinical characteristics were recorded. Results were expressed as percentages. Results: Most of the 43 patients were male (72%). The average age at presentation was 8.7 years with average duration of symptoms being 100.6 days. History of measles was present in 17 patients (39.5%). All children had seizures at presentation and 65% had cognitive impairment. Most patients required poly therapy for control of seizures. Sodium valproate was the most commonly used anti-epileptic agent; Isoprinosine was tried in 22 (51%) patients. CSF for antimeasles antibodies was positive in approximately 86% of the 40 (93%) children. EEG showed burst suppression pattern in 36 (83.7%) cases. Forty-two patients (97.6%) were discharged home in a vegetative state. Conclusion: SSPE is progressive neurodegenerative disorder. It can be prevented by timely immunization against measles. Measles antibody in the CSF is diagnostic for SSPE and is helpful in early diagnosis. Most patients experience a gradual but progressive decline in motor and cognitive functions

    Patterns of Traumatic Brain Injuries in Patients Presenting at a Tertiary Care Unit

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    Objective: The purpose of this study was to evaluate the distribution of traumatic brain injuries.Patients and Methods: Questionnaire based data was collected from an inpatient population of patients who presented to the Neurosurgical Unit of Ayub Teaching Hospital with traumatic brain injuries. CAT scan (Computerized Automated Tomography scan) was used as the imaging modality for preliminary diagnosis. The data was collected over a period of three years. Non-probability purposive sampling was used as the sampling technique. Patients of both sexes and all ages were included in the study.Results: Out of a total of 1938 patients, 1470 (75.9%) were males and 468 (24.1%) were females. Patients from 20 to 40 years’ age group (38.1%) represented the greatest number. Fall (52.6%) was found to be the most common external cause of Traumatic brain injury, followed by Road Traffic Accidents (34.1%). Most of the patients (42.4%) had a GCS score falling between 8 and 12. No lesion was found at the initial CAT scan in most of the patients (27.2%). Depressed Skull Fracture (21.4%) was the most common abnormal finding in initial imaging. Conservative (78.3%) treatment was provided to most of the patients keeping in view the appropriate management requirements. 97.8% of the patients were treated successfully.Conclusion: The quality of care at Neurosurgery Ayub Teaching Hospital was found to be up to the mark for traumatic brain injuries patients. However, the standard of care at Kashmir and Balakot needs to be re-evaluated
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