جستجوی مقالات مرتبط با کلیدواژه "probabilistic model" در نشریات گروه "برق"
تکرار جستجوی کلیدواژه «probabilistic model» در نشریات گروه «فنی و مهندسی»-
Journal of Electrical and Computer Engineering Innovations, Volume:12 Issue: 1, Winter-Spring 2024, PP 247 -258Background and ObjectivesThe detection of community in networks is an important tool for revealing hidden data in network analysis. One of the signs that the community exists in the network is the neighborhood density between nodes. Also, the existence of a concept called a motif indicates that a community with a high edge density has a correlation between nodes that go beyond their close neighbors. Motifs are repetitive edge patterns that are frequently seen in the network.MethodsBy estimating the triangular motif in the network, our proposed probabilistic motif-based community detection model (PMCD) helps to find the communities in the network. The idea of the proposed model is network analysis based on structural density between nodes and detecting communities by estimating motifs using probabilistic methods.ResultsThe suggested model's output is the strength of each node's affiliation to the communities and detecting overlaps in communities. To evaluate the performance and accuracy of the proposed method, experiments are done on real-world and synthetic networks. The findings show that, compared to other algorithms, the proposed method is acting more accurately and densely in detecting communities.ConclusionThe advantage of PMCD in using the probabilistic generative model is speeding up the computation of the hidden parameters and establishing the community based on the likelihood of triangular motifs. In fact, the proposed method proves there is a probabilistic correlation between the observation of two node pairs in different communities and the increased existence of motif structure in the network.Keywords: community detection, Motif, Complex Networks, Probabilistic Model
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متون کوتاه رسانه های اجتماعی مانند توییتر اطلاعات زیادی در مورد موضوع های داغ و افکار عمومی ارائه می دهند. برای درک بهتر اطلاعات دریافتی از شبکه های اجتماعی، شناسایی و ردیابی موضوع امری ضروری است. در بسیاری از روش های ارائه شده در این زمینه، تعداد موضوع ها باید از پیش مشخص باشد و نمی تواند در طول زمان تغییر کند. از این منظر، این روش ها برای داده های در حال افزایش و پویا مناسب نیستند. همچنین مدل های تکاملی موضوعی غیر پارامتری به دلیل مشکل کمبود داده ها، بر روی متون کوتاه عملکرد مناسبی ندارند. در این مقاله، یک مدل خوشه بندی تکاملی جدید ارائه کرده ایم که به طور ضمنی از فرایند رستوران چینی وابسته به فاصله (dd-CRP) الهام گرفته است. در روش ارائه شده برای حل مشکل کمبود داده ها، از اطلاعات شبکه اجتماعی در کنار شباهت متنی، برای بهبود ارزیابی شباهت بین توییت ها استفاده شده است. همچنین در روش پیشنهادی، برخلاف اکثر روش های مطرح شده در این زمینه، تعداد خوشه ها به صورت خودکار محاسبه می شود. در واقع در این روش، توییت ها با احتمالی متناسب با شباهتشان به هم متصل می شوند و مجموعه ای از این اتصال ها یک موضوع را تشکیل می دهد. برای افزایش سرعت اجرای الگوریتم، از یک روش خلاصه سازی مبتنی بر خوشه بندی استفاده نموده ایم. ارزیابی روش بر روی مجموعه داده واقعی که در طول دو ماه و نیم از شبکه اجتماعی توییتر جمع آوری شده است، انجام می شود. ارزیابی به صورت خوشه بندی متون و مقایسه بین آنها می باشد. نتایج ارزیابی نشان می دهد که روش پیشنهادی نسبت به روش های مقایسه شده دارای انسجام موضوعی بهتری بوده و می تواند به طور موثر برای تشخیص موضوع بر روی متون کوتاه رسانه های اجتماعی استفاده گردد.
کلید واژگان: تشخیص موضوع, خوشه بندی تکاملی, شبکه اجتماعی, مدل احتمالاتیShort texts of social media like Twitter provide a lot of information about hot topics and public opinions. For better understanding of such information, topic detection and tracking is essential. In many of the available studies in this field, the number of topics must be specified beforehand and cannot be changed during time. From this perspective, these methods are not suitable for increasing and dynamic data. In addition, non-parametric topic evolution models lack appropriate performance on short texts due to the lack of sufficient data. In this paper, we present a new evolutionary clustering algorithm, which is implicitly inspired by the distance-dependent Chinese Restaurant Process (dd-CRP). In the proposed method, to solve the data sparsity problem, social networking information along with textual similarity has been used to improve the similarity evaluation between the tweets. In addition, in the proposed method, unlike most methods in this field, the number of clusters is calculated automatically. In fact, in this method, the tweets are connected with a probability proportional to their similarity, and a collection of these connections constitutes a topic. To speed up the implementation of the algorithm, we use a cluster-based summarization method. The method is evaluated on a real data set collected over two and a half months from the Twitter social network. Evaluation is performed by clustering the texts and comparing the clusters. The results of the evaluations show that the proposed method has a better coherence compared to other methods, and can be effectively used for topic detection from social media short texts.
Keywords: Topic detection, evolutionary clustering, social networks, probabilistic model -
Scientia Iranica, Volume:25 Issue: 4, 2018 Jul-Aug, PP 2039 -2050Many soil slopes are unsaturated and failure of them can be a major cause of damage to structures. Apart from soil properties, the Soil-Water Characteristic Curve (SWCC) is the backbone of any unsaturated slope analysis. Uncertainties of these effective parameters of unsaturated slopes cause the probabilistic analysis to be more realistic rather than deterministic. In this research, the stochastic analysis of unsaturated slope stability is carried out based on simplified Bishops method. The stochastic parameters are the input parameters of SWCC in addition to effective internal angle of friction, effective cohesion and unit weight of soil. Based on the collected results from hundreds of stochastic analyses, the probability of failure is presented as a three dimensional surface. Finally, probabilistic model is developed to model this surface and evaluate the probability of failure as function of safety factor and its correlation of variation.Keywords: Unsaturated soils, slope stability, Soil-water characteristic curve, artificial intelligence, Probabilistic model
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The Probabilistic Seismic Hazard Analysis (PSHA), by considering uncertainties in the input parameters (e.g. magnitude, location, wave path way ), aims to compute annual rate of exceeding various ground motions at a site or a map of sites given all anticipated earthquakes. Uncertainties may be originated due to inherent randomness of the phenomena or variability in the mean values of different models parameters which is mainly due to use of finite-sample size of observations. The first, in literatures, is commonly named aleatory uncertainty but the second is known as epistemic uncertainty. The total probability numerical integration, generally employed to calculate PSHA, only considers aleatory uncertainties, and variability in the models parameters is neglected to simplify calculation. In this paper, as an alternate of the total probability numerical integration, matured and standard reliability methods tailor to effortlessly consider both type of uncertainties are put-forward to compute site-specific PSHA. Then, as an application study, thepeak ground acceleration hazard curve for the site at which a historical bridge is located is developed and compare with those obtained from total probability numerical integration.Keywords: Seismic hazard analysis, Reliability methods, Probabilistic model, Epistemic, aleatory uncertainties
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This paper puts forward a framework for optimal mitigation of regional risk to enhance the resilience of civil infrastructure. To meet this objective, probabilistic models, methods, and software are developed and applied. The work is conducted within a new reliability-based approach, in which reliability methods compute risk. This contrasts several contemporary approaches for risk analysis. Risk, in this context, denotes the probability of exceeding monetary loss. Evaluating such probabilities requires probabilistic models for hazards, response, damage, and loss. This motivates the following contributions in this paper. First, a new computer program is developed that is tailored to conduct reliability analysis with many interconnected probabilistic models. It orchestrates the interaction of models through an object-oriented architecture. Second, a library of probabilistic models for regional seismic risk analysis are developed. The library includes new models for earthquake location and magnitude and building response, damage, and loss. Third, probabilistic methods for multi-hazard risk analysis are developed and applied in a large-scale regional analysis. The results are cost exceedance probabilities and insights into the seismic risk of the region. Finally, sensitivity measures are developed to identify the buildings whose retrofit yields the most reduction in regional risk, i.e., the most resilience of the region.Keywords: Risk mitigation, Infrastructure, Resilience, Seismic risk, Reliability method, Probabilistic model, Sensitivity
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