243 research outputs found
Social network sites as educational factors
Background: In this present era, the technology development has established certain type of communication. Nowadays education as the fundamental principle in transferring cognition to the learners has found various methods. Recently the concept that social networks could be effective tool in easing the achievement to the educational goals has been under attention. Therefore, this investigation is trying to find out whether, the social networks could play role on the process of education among students? Materials and Methods: This cross sectional descriptive study was performed on 1000 students from 7 medical universities in 2015. The data collection tool was questionnaire that was approved Cronbach's alpha was 0.85. Meanwhile its validity was confirmed too. The obtained data were analyzed by the descriptive statistic, ANOVA, Turkey and used X2 SPSS-19. Results: In this investigation, 940 subjects were under study. 85 used daily the social network. The highest usage was attributed to the Telegram. 52 preferred image suitable for transferring of information. Even though, 73 believed that these networks have significant effects on coordinating of students with in university charges. Conclusion: Considering the findings of the present study, it is proposed that the universities integrate the social networks in the education programs and recognize it as the awareness factor, therefore benefit it in the educational affairs. Ă© 2016 Alireza Ebrahimpour, Farnaz Rajabali, Fatemeh Yazdanfar, Reza Azarbad, Majid Rezaei Nodeh, Hasan Siamian, Mohammad Vahedi
Blood vessels extraction from fundus fluorescein angiogram in Curvelet domain
Abstract:
This paper proposes a new method for blood vessel segmentation and extraction based on Curvelet domain and Hough transform. Diabetic retiopathy is an important human visual disease which leads blindness. Fluorescein angiography has become indispensable in the diagnosis and evaluation of many retinal conditions. Here, we introduced a novel and efficient algorithm for automated retinal blood vessels segmentation in fluorescein angiography images. The proposed method in this paper consists of three main steps that in the first step, the input image to create an image with high contrast and uniform background by becoming curvelet transform under processing. Then, in the next step Kirschs templates are used for edge detection in retinal images and arithmetic mean filter is applied to the image. Finally, Hough transform is applied to the image obtained from the previous step to remove non-information parts. Experimental results show the superiority of the proposed method against competing approaches.
Keywords:
Transforms,Diabetes,Image edge detection,Biomedical imaging,Retinopathy,Blood vessels,Retin
Isolated Persian/Arabic handwriting characters: Derivative projection profile features, implemented on GPUs
For many years, researchers have studied high accuracy methods for recognizing the handwriting and achieved many significant improvements. However, an issue that has rarely been studied is the speed of these methods. Considering the computer hardware limitations, it is necessary for these methods to run in high speed. One of the methods to increase the processing speed is to use the computer parallel processing power. This paper introduces one of the best feature extraction methods for the handwritten recognition, called DPP (Derivative Projection Profile), which is employed for isolated Persian handwritten recognition. In addition to achieving good results, this (computationally) light feature can easily be processed. Moreover, Hamming Neural Network is used to classify this system. To increase the speed, some part of the recognition method is executed on GPU (graphic processing unit) cores implemented by CUDA platform. HADAF database (Biggest isolated Persian character database) is utilized to evaluate the system. The results show 94.5% accuracy. We also achieved about 5.5 times speed-up using GPU
Parallel Spatial Pyramid Match Kernel Algorithm for Object Recognition using a Cluster of Computers
This paper parallelizes the spatial pyramid match kernel (SPK) implementation. SPK is one of the most usable kernel methods, along with support vector machine classifier, with high accuracy in object recognition. MATLAB parallel computing toolbox has been used to parallelize SPK. In this implementation, MATLAB Message Passing Interface (MPI) functions and features included in the toolbox help us obtain good performance by two schemes of task-parallelization and dataparallelization models. Parallel SPK algorithm ran over a cluster of computers and achieved less run time. A speedup value equal to 13 is obtained for a configuration with up to 5 Quad processors
Evaluating cognitive load of multimedia learning by eye-tracking data analysis
Background and Objectives: Today, it is common to use multimedia in foreign language teaching. There are some principles for designing multimedia that would reduce task cognitive load. These principles are based on the cognitive load theory. The methods of cognitive load measurement are divided into two categories, namely the subjective and objective measurements. NASA-TLX is an example of the subjective measurements; methods such as electroencephalography and eye-tracking are among the objective measurements. Due to the advantages of objective measurements, using these methods is common in cognitive studies. Eye-tracking technology can record different eye-movements of humans such as pupil dilation, saccades, fixations, blinks and microsaccades with a high sampling rate. These measurements are being widely used in cognitive and mental workload studies. In this paper, the cognitive load in multimedia language learning has been evaluated, using eye-tracking data analysis. Methods: Two multimedia versions for teaching English were produced with the same narration and the length of 342s. In one version, the principles in designing multimedia were applied whereas in the other version, they were violated so that more cognitive load in comparison to the former version could be imposed. Ten subjects whose English listening comprehension was assessed with a simulation of the International English Language Testing System (IELTS) participated in the experiment and were randomly divided into two equal groups of five. The two groups were homogeneous with respect to their listening proficiency. One group watched the multimedia without principles while the other group watched the multimedia with principles. Then, each individual answered 12 multiple choice questions about the concepts presented in the multimedia as a performance test. During watching the multimedia and taking the performance test, the participantsâ eye movement data were recorded. Then, each person filled out the NASA-TLX Questionnaire. Based on the results of the performance test and the NASA-TLX, the difficulty level of the multimedia without principles as compared to its version with principles was evaluated. The collected data were divided into blocks of 30 seconds. Findings: Based on the NASA-TLX, the group who watched multimedia without principles experienced more cognitive load in comparison to the group who watched multimedia with principles, which approved our assumption about the higher load of the multimedia without principles. However, no significant difference was found in the results of the performance test between the two groups. According to statistical analyses, the pupil diameter, saccade length, saccade velocity, blink latency, and microsaccade amplitude in the multimedia blocks of both groups were significantly different. Nevertheless, no significant difference was found between the two groups in terms of the fixation time, the fixation rate, and the microsaccade rate. Conclusion: Based on the findings of this study, pupil dilation, saccade length, saccade velocity, blink latency, and microsaccade amplitude have a significant relationship with the amount of the load imposed by the instructional multimedia which corresponds to the literature review of the study. Based on the results of this study, along with the subjective methods, eye movement data can also be considered as an appropriate tool for assessing the cognitive load imposed by multimedia learning and qualifying the multimedia instructional content. A significant difference was also found between the two groups in the study in terms of their blinking rate. More investigation and different experiments are needed for examining other eye movement criteria that have been investigated in this study, including fixation time, fixation rate, and microsaccade rate so that a more definitive conclusion would be reached regarding a significant relationship between these parameters and the mental load imposed by the multimedia English teaching.   ===================================================================================== COPYRIGHTS ©2021 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers. ====================================================================================
Management of spine trauma in COVID-19 pandemic: A preliminary report
Background: COVID-19 was first identified in Iran in February 2020 and since then it spread rapidly through all over the country and soon after that it was reported as a pandemic. The current study presents a preliminary report of spine trauma management during COVID-19 pandemic. Methods: A cross sectional study was designed to evaluate patients admitted for vertebral fractures with diagnosis of COVID-19 infection on February and March 2020. Analysis was made based on clinical and laboratory data along with the imaging findings from chest HRCT. Results: Seven patients with spine trauma including five males and two females ranging from 14 to 59 years were diagnosed for COVID-19 infection through CT-scan findings. Except one, all other patients were asymptomatic for COVID-19 at the time of admission. In three cases the COVID diagnosis was made the day after arrival and in others after 10, 14 and 35 days. Five patients were treated surgically among whom four were admitted to ICU soon after the surgery. The mean ICU stay for operated patients were eight days and the mean hospital stay was 22.6 days. Conclusion: Proper diagnosis of COVID-19 is the keystone to protect both patients and health care providers. During the pandemic all admitted patients should be screened for COVID-19 infection. Unnecessary procedures for spine trauma patients should be avoided in order to reduce complications related to surgery and to preserve ICU beds. Ă© 2020 BY THE ARCHIVES OF BONE AND JOINT SURGERY
Genetics of intellectual disability in consanguineous families
Autosomal recessive (AR) gene defects are the leading genetic cause of intellectual disability (ID) in countries with frequent parental consanguinity, which account for about 1/7th of the world population. Yet, compared to autosomal dominant de novo mutations, which are the predominant cause of ID in Western countries, the identification of AR-ID genes has lagged behind. Here, we report on whole exome and whole genome sequencing in 404 consanguineous predominantly Iranian families with two or more affected offspring. In 219 of these, we found likely causative variants, involving 77 known and 77 novel AR-ID (candidate) genes, 21 X-linked genes, as well as 9 genes previously implicated in diseases other than ID. This study, the largest of its kind published to date, illustrates that high-throughput DNA sequencing in consanguineous families is a superior strategy for elucidating the thousands of hitherto unknown gene defects underlying AR-ID, and it sheds light on their prevalence
Risk factors for moderate and severe persistent pain in patients undergoing total knee and hip arthroplasty : a prospective predictive study
Persistent post-surgical pain (PPSP) is a major clinical problem with significant individual, social and health care costs. The aim of this study was to examine the joint role of demographic, clinical and psychological risk factors in the development of moderate and severe PPSP after Total Knee and Hip Arthroplasty (TKA and THA, respectively). This was a prospective study wherein a consecutive sample of 92 patients were assessed 24 hours before (T1), 48 hours after (T2) and 4-6 months (T3) after surgery. Hierarchical logistic regression analyses were performed to identify predictors of moderate and severe levels of PPSP. Four to six months after TKA and THA, 54 patients (58.7%) reported none or mild pain (Numerical Rating Scale: NRS 3). In the final multivariate hierarchical logistic regression analyses, illness representations concerning the condition leading to surgery (osteoarthritis), such as a chronic timeline perception of the disease, emerged as a significant predictor of PPSP. Additionally, post-surgical anxiety also showed a predictive role in the development of PPSP. Pre-surgical pain was the most significant clinical predictive factor and, as expected, undergoing TKA was associated with greater odds of PPSP development than THA. The findings on PPSP predictors after major joint arthroplasties can guide clinical practice in terms of considering cognitive and emotional factors, together with clinical factors, in planning acute pain management before and after surgery.This work was supported by a Project grant (PTDC/SAU-NEU/108557/2008) and by a PhD grant (SFRH/BD/36368/2007) from the Portuguese Foundation of Science and Technology, COMPETE and FEDER. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
How Can Selection of Biologically Inspired Features Improve the Performance of a Robust Object Recognition Model?
Humans can effectively and swiftly recognize objects in complex natural scenes. This outstanding ability has motivated many computational object recognition models. Most of these models try to emulate the behavior of this remarkable system. The human visual system hierarchically recognizes objects in several processing stages. Along these stages a set of features with increasing complexity is extracted by different parts of visual system. Elementary features like bars and edges are processed in earlier levels of visual pathway and as far as one goes upper in this pathway more complex features will be spotted. It is an important interrogation in the field of visual processing to see which features of an object are selected and represented by the visual cortex. To address this issue, we extended a hierarchical model, which is motivated by biology, for different object recognition tasks. In this model, a set of object parts, named patches, extracted in the intermediate stages. These object parts are used for training procedure in the model and have an important role in object recognition. These patches are selected indiscriminately from different positions of an image and this can lead to the extraction of non-discriminating patches which eventually may reduce the performance. In the proposed model we used an evolutionary algorithm approach to select a set of informative patches. Our reported results indicate that these patches are more informative than usual random patches. We demonstrate the strength of the proposed model on a range of object recognition tasks. The proposed model outperforms the original model in diverse object recognition tasks. It can be seen from the experiments that selected features are generally particular parts of target images. Our results suggest that selected features which are parts of target objects provide an efficient set for robust object recognition
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