246 research outputs found

    ASETS: A SDN Empowered Task Scheduling System for HPCaaS on the Cloud

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    With increasing demands for High Performance Computing (HPC), new ideas and methods are emerged to utilize computing resources more efficiently. Cloud Computing appears to provide benefits such as resource pooling, broad network access and cost efficiency for the HPC applications. However, moving the HPC applications to the cloud can face several key challenges, primarily, the virtualization overhead, multi-tenancy and network latency. Software-Defined Networking (SDN) as an emerging technology appears to pave the road and provide dynamic manipulation of cloud networking such as topology, routing, and bandwidth allocation. This paper presents a new scheme called ASETS which targets dynamic configuration and monitoring of cloud networking using SDN to improve the performance of HPC applications and in particular task scheduling for HPC as a service on the cloud (HPCaaS). Further, SETSA, (SDN-Empowered Task Scheduler Algorithm) is proposed as a novel task scheduling algorithm for the offered ASETS architecture. SETSA monitors the network bandwidth to take advantage of its changes when submitting tasks to the virtual machines. Empirical analysis of the algorithm in different case scenarios show that SETSA has significant potentials to improve the performance of HPCaaS platforms by increasing the bandwidth efficiency and decreasing task turnaround time. In addition, SETSAW, (SETSA Window) is proposed as an improvement of the SETSA algorithm

    Modeling and Characterization of Lymphatic Vessels Using a Lumped Parameter Approach

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    The lymphatic system is responsible for several vital roles in human body, one of which is maintaining fluid and protein balance. There is no central pump in the lymphatic system and the transport of fluid against gravity and adverse pressure gradient is maintained by the extrinsic and intrinsic pumping mechanisms. Any disruption of the lymphatic system due to trauma or injury can lead to edema. There is no cure for lymphedema partly because the knowledge of the function of the lymphatic system is lacking. Thus, a well-developed model of the lymphatic system is crucial to improve our understanding of its function. Here we used a lumped parameter approach to model a chain of lymphangions in series. Equations of conservation of mass, conservation of momentum, and vessel wall force balance were solved for each lymphangion computationally. Due to the lack of knowledge of the parameters describing the system in the literature, more accurate measurements of these parameters should be pursued to advance the model. Because of the difficulty of the isolated vessel and in-situ experiments, we performed a parameter sensitivity analysis to determine the parameters that affect the system most strongly. Our results showed that more accurate estimations of active contractile force and physiologic features of lymphangions, such as length/diameter ratios, should be pursued in future experiments. Also further experiments are required to refine the valve behavior and valve parameters

    Modelling of Growth Profile of Three Probiotic Single Strain Starter Cultures (L.acidophilus (La-5), Bifidobacterium (BB-12), S.thermophilus (STB-01)) through Turbidity Measurement Technique

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    Probiotics are one or more mixture of viable microorganisms which have beneficial effects on animals and human beings through propagation gastrointestinal microflora. Some instances for health benefits of these products are: alleviating gastrointestinal disorders, diarrehea, food allergies, infection of Helicobacter pylori, lactose intolerance, candidiasis, serum cholesterol, and improving immune system balance, mineral uptake and protecting the consumer from different cancers such as colon, bladder and gastrointestinal cancers.To achieve these neutraceutical purposes, a large population of probiotics( 107- 108 cfu/g) should remain alive during storage of these products up to expiring date.In this research production of probiotic ABT yogurt is taken into consideration. Single strains of two probiotic starter cultures, Bifidobacterium( BB-12) and L. acidophilus(La-5), and one single strain of S. thermophilus (STB-01) for reducing the fermentation time are used. In probiotic products the method of counting probiotic bacteria have a significant effect. Traditional microbiological methods require wide range of time and a lots of facilities. Modelling of growth profile of bacteria with the data obtained from turbidity measurement would be a helpful method for fast counting of microbial communities. Keywords: analyze ; Broth media ; Colony Count Unit; Direct-Vat-Set(DVS); Durbin-Watson statistic

    A Hybrid Data Mining Method for Customer Churn Prediction

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    The expenses for attracting new customers are much higher compared to the ones needed to maintain old customers due to the increasing competition and business saturation. So customer retention is one of the leading factors in companies’ marketing. Customer retention requires a churn management, and an effective management requires an exact and effective model for churn prediction. A variety of techniques and methodologies have been used for churn prediction, such as logistic regression, neural networks, genetic algorithm, decision tree etc.. In this article, a hybrid method is presented that predicts customers churn more accurately, using data fusion and feature extraction techniques. After data preparation and feature selection, two algorithms, LOLIMOT and C5.0, were trained with different size of features and performed on test data. Then the outputs of the individual classifiers were combined with weighted voting. The results of applying this method on real data of a telecommunication company proved the effectiveness of the method

    Modeling the Number of Attacks in Multiple Sclerosis Patients Using Zero-Inflated Negative Binomial Model

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    Background and aims: Multiple sclerosis (MS) is an inflammatory disease of the central nervous system. The impact of the number of attacks on the disease is undeniable. The aim of this study was to analyze the number of attacks in these patients. Methods: In this descriptive-analytical study, the registered data of 1840 MS patients referred to the MS clinic of Ayatollah Kashani hospital in Isfahan were used. The number of attacks during the treatment period was defined as the response variable, age at diagnosis, sex, employment, level of education, marital status, family history, course of disease, and expanded disability as the explanatory variables. The analysis was performed using zero-inflated negative binomial model via Bayesian framework in OpenBUGS software. Results: Age at diagnosis (CI: -0.04, -0.20), marital status (CI: -0.56, 0.002), level of education (CI: -0.81, -0.26), Job (CIHousewives vs Employee=[0.04, 0.64], CIUnemployee vs Employee=[-1.10,0.008])), and course of disease (CI: -0.51, -0.08) had a significant effect on the number of attacks. In relapsing-remitting patients, the number of attacks was partial significantly affected by expanded disability status scale (EDSS) (CI: -0.019, 0.16). Conclusion: Aging, being single (never married), high education, and not having a job decrease the number of attacks; therefore, lower age, being married, primary education, and being a housewife increase the number of attacks. An interventional or educational program is suggested in order to prevent the occurrence of further attacks in high-risk groups of patients and to increase their chances of recovery. Keywords: Multiple sclerosis Attack Negative binomial Zero-inflated Markov chain Monte Carl

    The Effects of Hand Tracking on User Performance: an experimental study of an object selection based memory game

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    Until recently, Virtual Reality (VR) applications relied on controllers to enable user interaction in virtual environments. With advances in tracking technology, HMDs are now able to track the movements of users’ hands in real-time with significantly greater accuracy, allowing us to interact with the digital world directly with our hands. However, it is not entirely clear how hand tracking affects users’ performance. In this study, we investigate user performance using an in-game analytics-based assessment methodology for a VR memory puzzle task. We conducted a within-subjects experiment with 30 participants in three conditions: 1- Hand-tracking, 2- Controller Without Haptics, and 3- Controller With Haptics. In all our measurements (correct order and pattern, correct pattern only, and trial completion) except for the initial selection time, participants performed best with hand tracking. The use of controllers with haptics did not outperform controllers without haptics in most measures, possibly because other feedback cues compensated for the lack of haptics. This study helps us better understand the three selected interactivity methods when used in VR, as well as the importance of naturalistic experience in interaction design

    Our Nudges, Our Selves: Tailoring Mobile User Engagement Using Personality

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    To increase mobile user engagement, current apps employ a variety of behavioral nudges, but these engagement techniques are applied in a one-size-fits-all approach. Yet the very same techniques may be perceived differently by different individuals. To test this, we developed HarrySpotter, a location-based AR app that embedded six engagement techniques. We deployed it in a 2-week study involving 29 users who also took the Big-Five personality test. Preferences for specific engagement techniques are not only descriptive but also predictive of personality traits. The Adj. R2R^2 ranges from 0.16 for conscientious users (encouraged by competition) to 0.32 for neurotic users (self-centered and focused on their own achievements), and even up to 0.61 for extroverts (motivated by both exploration of objects and places). These findings suggest that these techniques need to be personalized in the future.Comment: 10 pages, 1 figure, 2 table

    Analyzing the Effect of COVID-19 on Education by Processing Users’ Sentiments

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    COVID-19 infection has been a major topic of discussion on social media platforms since its pandemic outbreak in the year 2020. From daily activities to direct health consequences, COVID-19 has undeniably affected lives significantly. In this paper, we especially analyze the effect of COVID-19 on education by examining social media statements made via Twitter. We first propose a lexicon related to education. Then, based on the proposed dictionary, we automatically extract the education-related tweets and also the educational parameters of learning and assessment. Afterwards, by analyzing the content of the tweets, we determine the location of each tweet. Then the sentiments of the tweets are analyzed and examined to extract the frequency trends of positive and negative tweets for the whole world, and especially for countries with a significant share of COVID-19 cases. According to the analysis of the trends, individuals were globally concerned about education after the COVID-19 outbreak. By comparing between the years 2020 and 2021, we discovered that due to the sudden shift from traditional to electronic education, people were significantly more concerned about education within the first year of the pandemic. However, these concerns decreased in 2021. The proposed methodology was evaluated using quantitative performance metrics, such as the F1-score, precision, and recall

    Quality of Randomization in Clinical Trials Published in Persian Journals of Medical Sciences Indexed in Scopus During 2013-2017

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    Background and Objectives Randomization is one of the principles of correct clinical trial. The aim of this study was to determine the quality of randomization in the published articles of clinical trials in the Persian-language journals indexed in Scopus. Methods In this cross-sectional study, all clinical trials published in Persian journals indexed in Scopus during 2013-2017 were evaluated in terms of randomization using the Jadad scale. The score of the randomization item of this scale ranges from 0 to 2, with 0, 1, and 2 indicating poor, moderate, and good quality. Results A total of 452 articles were evaluated. Random allocation was indicated in 423 articles (93.6%). Simple random assignment and blocked methods were used in 42.8% and 22% of randomizations, respectively. The randomization method was unknown in 34% and an incorrect method was used for randomization in 5.3% of the articles. According to the Jadad scale, 56.4% of the articles had good, 36.9% had moderate, and 6.6% had poor quality in terms of randomization. Methodologists were consulted in 40.7% of the articles, and their contributions led to increased transparency in the randomization report (P = 0.007). Conclusion The randomization method and its report are missing in many clinical trials. Therefore, considering the importance of randomization in validating the results of these studies, journals editors and researchers should pay attention to the quality of randomization and its report. Keywords: Clinical trial , Randomization , Scopus , Persian journals , Jadad scal
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