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Analysis of time delays in projects - application to Iran and emerging countries
, Article 2006 IEEE International Conference on Management of Innovation and Technology, ICMIT 2006, Singapore, 21 June 2006 through 23 June 2006 ; Volume 2 , 2006 , Pages 681-684 ; 1424401488 (ISBN); 9781424401482 (ISBN) ; Sharif University of Technology
2006
Abstract
Numerous projects are underway in emerging countries, such as Iran, where technology transfer and economic expansion are the primary national objectives. However, majority of these projects either fall, according to world class standards, or faced with significant time delays. An Initial analysis of selected projects reveals that over 60% of causes belong to organization factors, while environment and personal causes are less than 40%. The overwhelming evidence points of lack of proper project management and education within organization factors. Some prescriptive interventions are proposed to counter organization deficiencies and overcome consistent time delays. A planning stage using...
Practical next bit test for evaluating pseudorandom sequences
, Article Scientia Iranica ; Volume 16, Issue 1 D , 2009 , Pages 19-33 ; 10263098 (ISSN) ; Eghlidos, T ; Sharif University of Technology
2009
Abstract
The Next Bit Test briefly states that a sequence is random if and only if, given any i bits of the sequence, it is not possible to predict the next bit of the sequence with a probability of success significantly greater than 1/2. In 1996, Sadeghiyan and Mohajeri proposed a so-called "new universal test for bit strings", based on the theoretical next bit test. In this paper, we study different aspects of this test and show its weakness. Then, we improve it both theoretically and practically for better classification of the sequences. As a result, a Practical Next Bit (PNB) test is introduced in two Global and Local versions and a histogram, which gives an impression of the global evaluation...
Modelling and forecasting of signal-to-interference plus noise ratio in femtocellular networks using logistic smooth threshold autoregressive model
, Article IET Signal Processing ; Volume 9, Issue 1 , 1 February 2015 , Pages 48-59 ; Lotfollahzadeh, T ; Shayesteh, M. G ; Kalbkhani, H ; Sharif University of Technology
Abstract
The aim of this paper is to present a non-linear statistical model to fit and forecast the signal-to-interference plus noise ratio (SINR) in two-tier heterogeneous cellular networks which consist of macrocells and femtocells. Since in these networks the number and locations of femtocell base stations (FBS) are variable, SINR forecasting can be useful in some areas such as power control and handover management. So far, linear autoregressive (AR)models have commonly been used in forecasting the received signal strength (rss) inmacrocellular networks.However,ARmodelling results in highmean square error (MSE)when data are non-linear. This paper focuses on SINR which takes into account signal...
Predicting atrial fibrillation termination using ECG features, a comparison
, Article 2008 1st International Symposium on Applied Sciences in Biomedical and Communication Technologies, ISABEL 2008, Aalborg, 25 October 2008 through 28 October 2008 ; 2008 ; 9781424426478 (ISBN) ; Esmaeili, V ; Towhidkhah, F ; Moradi, M. H ; Sharif University of Technology
2008
Abstract
In this study, surface ECG recordings have been used to accomplish a non-invasive method which can predict spontaneous termination of Atrial Fibrillation (AF) and discriminate terminating (T) and non-terminating (N) AF episodes. The data set was provided by Physionet including holter recordings of 50 patients (20 training and 30 test sets). Concerning that most relevant information about the AF exists in the atrial fibrillatory wave, Several spectral and time-frequency parameters were extracted from the ECG signal after canceling the QRST complex. Also a temporal feature, RR interval variation, representing the ventricular activity was calculated. These parameters were evaluated using a...
A proper transform for satisfying benford's law and its application to double JPEG image forensics
, Article 2012 IEEE International Symposium on Signal Processing and Information Technology, ISSPIT 2012, 12 December 2012 through 15 December 2012 ; 2012 , Pages 240-244 ; 9781467356060 (ISBN) ; Razzazi, F ; Behrad, A ; Ahmadi, A ; Babaie-Zadeh, M ; Sharif University of Technology
2012
Abstract
This paper presents a new transform domain to evaluate the goodness of fit of natural image data to the common Benford's Law. The evaluation is made by three statistical fitness criteria including Pearson's chi-square test statistic, normalized cross correlation and a distance measure based on symmetrized Kullback-Leibler divergence. It is shown that the serial combination of variance filtering and block 2-D discrete cosine transform reveals the best goodness of fit for the first significant digit. We also show that the proposed transform domain brings reasonable fit for the second, third and fourth significant digits. As an application, the proposed transform domain is utilized to detect...
Analysis and modeling time headway distributions under heavy traffic flow conditions in the urban highways: Case of Isfahan
, Article Transport ; Volume 26, Issue 4 , 2011 , Pages 375-382 ; 16484142 (ISSN) ; Tamannaei, M ; Haghshenash, H ; Sharif University of Technology
Abstract
The time headway of vehicles is an importan microscopic traffic flow parameter which affects the safety and capacity of highway facilities such as freeways and multi-lane highways. The present paper intends to provide a report on the results of a study aimed at investigating the effect of the lane position on time headway distributions within the high levels of traffic flow. The main issue of this study is to assess the driver's behavior at different highway lanes based on a headway distribution analysis. The study was conducted in the city of Isfahan, Iran. Shahid Kharrazi six-lane highway was selected for collecting the field headway data. The under-study lanes consisted of passing and...
Intelligent classification of web pages using contextual and visual features
, Article Applied Soft Computing Journal ; Volume 11, Issue 2 , 2011 , Pages 1638-1647 ; 15684946 (ISSN) ; Fotouhi, M ; Khaleghi, M ; Sharif University of Technology
Abstract
In this paper we address classification of Web content and in particular its application in the detection of pornographic Web pages. Filtering of undesirable Web content is mainly achieved based on blocking a specific Web address via searching it in a reference list of black URLs or doing a plain contextual analysis on the page by searching special keywords in the text. The main problem with current filtering methods is the requirement for instantly update of the URL list and also the high rate of over-blocking the usual pages. In this paper, we propose an intelligent approach which is based on using textual, profile, and visual features in a hierarchical structure classifier. Textual...
Distributed binary majority voting via exponential distribution
, Article IET Signal Processing ; Volume 10, Issue 5 , 2016 , Pages 532-542 ; 17519675 (ISSN) ; Golestani, S. J ; Sharif University of Technology
Institution of Engineering and Technology
Abstract
In the binary majority voting problem, each node initially chooses between two alternative choices. The goal is to design a distributed algorithm that informs nodes which choice is in majority. In this study, the authors formulate this problem as a hypothesis testing problem and propose fixed-size and sequential solutions using classical and Bayesian approaches. In the sequential version, the proposed mechanism enables nodes to test which choice is in majority, successively in time. Hence, termination of the algorithm is embedded within it, contrary to the existing approaches which require a monitoring algorithm to indicate the termination. This property makes the algorithm more efficient in...
Time-invariant 3d human action recognition with positive and negative movement memory using convolutional neural networks
, Article 4th International Conference on Pattern Recognition and Image Analysis, IPRIA 2019, 6 March 2019 through 7 March 2019 ; 2019 , Pages 26-31 ; 9781728116211 (ISBN) ; Mohammadzade, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Developing time-invariant solutions for recognition of human action is still an important and open challenge. Three issues make time-invariant solutions so important: different speed of performing the same action by different people, latency in doing the actions and the existence of redundant frames in the recorded video. To overcome these problems, we propose a method based on the so-called memory of the joints to remember only the cumulative positive and negative movement of each joint. Hence, we transform action recognition from time-space to shape-space and the action recognition becomes the problem of shape classification. These shape features contain highly discriminative information...
Optimizing multi-response statistical problems using a genetic algorithm
, Article Scientia Iranica ; Volume 13, Issue 1 , 2006 , Pages 50-59 ; 10263098 (ISSN) ; Akhavan Niaki, S. T ; Sharif University of Technology
Sharif University of Technology
2006
Abstract
In this paper, two methods to solve multi-response statistical problems are presented. In these methods, desirability function, genetic algorithm and simulation methodology are applied. The desirability function is responsible for modeling the multi-response statistical problem, the genetic algorithm tries to optimize the model and, finally, the simulation approach generates the required input data from a simulated system. The methods differ from each other in controlling the randomness of the problem. In the first method, replications control this randomness, while, in the second method, the randomness is controlled by a statistical test. Furthermore, these methods are compared by designed...
Feature-based no-reference video quality assessment using Extra Trees
, Article IET Image Processing ; Volume 16, Issue 6 , 2022 , Pages 1531-1543 ; 17519659 (ISSN) ; Amini, A ; Behroozi, H ; Sharif University of Technology
John Wiley and Sons Inc
2022
Abstract
With the emergence of social networks and improvements in the internet speed, the video data has become an ever-increasing portion of the global internet traffic. Besides the content, the quality of a video sequence is an important issue at the user end which is often affected by various factors such as compression. Therefore, monitoring the quality is crucial for the video content and service providers. A simple monitoring approach is to compare the raw video content (uncompressed) with the received data at the receiver. In most practical scenarios, however, the reference video sequence is not available. Consequently, it is desirable to have a general reference-less method for assessing the...
The most descriptive surprise definition for brain's EEG response to visual and auditory oddball tasks
, Article 30th International Conference on Electrical Engineering, ICEE 2022, 17 May 2022 through 19 May 2022 ; 2022 , Pages 267-271 ; 9781665480871 (ISBN) ; Mousavi, Z ; Aghajan, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
The human brain continuously tries to predict sensory input in order to prepare for responding to new events. The brain develops a model for the incoming sensory information and updates it as new inputs arrive. It is hypothesized that the brain deduces a distribution for the input which is made more accurate with new observations. A notable question is how the brain perceives and reacts to new information. The oddball paradigm task is a simple experiment that can reveal the brain's ability in predicting the incoming input. We analyzed the EEG response of the brain recorded during oddball visual and auditory tasks in order to characterize its response to surprising instances embedded in a...
An efficient and practically robust hybrid metaheuristic algorithm for solving fuzzy bus terminal location problems
, Article Asia-Pacific Journal of Operational Research ; Volume 29, Issue 2 , April , 2012 ; 02175959 (ISSN) ; Ghanbari, R ; Mahdavi Amiri, N ; Sharif University of Technology
2012
Abstract
Bus network design is an important problem in public transportation. In practice, some parameters of this problem are uncertain. We propose two models for the bus terminal location problem with fuzzy parameters. In the first formulation, the number of passengers corresponding to each node is a fuzzy number. In the second formulation, an additional assumption of fuzzy neighborhood is considered. These problems being NP-hard, we use a genetic algorithm (GA) and a simulated annealing (SA) algorithm for solving them. We also propose an idea to hybridize these algorithms. In our hybrid algorithm, SA is applied as a neighborhood search procedure of GA on the best individual of the population,...
Ranking of technology transfer barriers in developing countries; case study of Iran's biotechnology industry
, Article IEEE International Conference on Industrial Engineering and Engineering Management, 6 December 2011 through 9 December 2011, Singapore ; 2011 , Pages 1602-1606 ; 21573611 (ISSN) ; 9781457707391 (ISBN) ; Rashvanlouei, K. Y ; Ismail, K ; Sharif University of Technology
Abstract
In this paper, first we shall define a list of technology transfer barriers in the biotechnology field through interviews and literature reviews. Next, we shall categorize them into four major categories of technology, and at last introduce all of the hypotheses on the existence of relationship between each part of technology and failure in the technology transfer process. Questionnaires consisting of two parts were created and handed out to all of the specialists and biotechnology idea-holders in the Iranian National Research center of Biotechnology, Lidco Co, Iran Pastor Institute, Biotechnology Department of University of Tehran, etc. Going on, we've evaluated the factors' validity...
Multiple-chi-square tests and their application on distinguishing attacks
, Article 2011 8th International ISC Conference on Information Security and Cryptology, ISCISC 2011, 14 September 2011 through 15 September 2011, Mashhad ; 2011 , Pages 55-60 ; 9781467300773 (ISBN) ; Salmasizadeh, M ; Mohajeri, J ; Sharif University of Technology
2011
Abstract
Chi-square tests are vastly used for distinguishing random distributions, but extra care must be taken when using them on several independent variables. We noticed, the chisquare statistics, in some previous works, was computed half of its real value. Thus, to avoid possible future confusions, we formulize multiple-chi-square tests. To show the application of multiple-chi-square tests, we introduce two new tests and apply them to Trivium as a special case. These tests are modifications of ANF monomial test and, when applied to Trivium with the same number of rounds, the data complexity of them is roughly 24 times smaller than that of previous ANF monomial test
Linear discourse segmentation of multi-party meetings based on local and global information
, Article IEEE/ACM Transactions on Speech and Language Processing ; Volume 23, Issue 11 , July , 2015 , Pages 1879-1891 ; 23299290 (ISSN) ; Sameti, H ; Liu, Y ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
Linear segmentation of a meeting conversation is beneficial as a stand-alone system (to organize a meeting and make it easier to access) or as a preprocessing step for many other meeting related tasks. Such segmentation can be done according to two different criteria: topic in which a meeting is segmented according to the different items in its agenda, and function in which the segmentation is done according to the meeting's different events (like discussion, monologue). In this article we concentrate on the function segmentation task and propose new unsupervised methods to segment a meeting into functionally coherent parts. The first proposed method assigns a score to each possible boundary...
A change point method for monitoring generalized linear profiles in phase I
, Article Quality and Reliability Engineering International ; Volume 31, Issue 8 , 2015 , Pages 1367-1381 ; 07488017 (ISSN) ; Mahlooji, H ; Yeh, A. B ; Zou, C ; Sharif University of Technology
Abstract
The Phase I applications of the statistical profile monitoring have recently been extended to the case when the response variable is binary. We are motivated to undertake the current research in an attempt to try to provide a unified framework for the Phase I control in the context of statistical profile monitoring that can be used to tackle a large class of response variables, such as continuous, count, or categorical response variables. The unified framework is essentially based on applying the change point model to the class of generalized linear models. The proposed Phase I control chart is assessed and compared with the existing charts under binomial and Poisson profiles. Some...
Localized discriminative Gaussian process latent variable model for text-dependent speaker verification
, Article 24th European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning, ESANN 2016, 27 April 2016 through 29 April 2016 ; 2016 , Pages 183-188 ; 9782875870278 (ISBN) ; Sameti, H ; Zeinali, H ; Sharif University of Technology
i6doc.com publication
2016
Abstract
The duration of utterances is one of the effective factors on the performance of speaker verification systems. Text dependent speaker verification suffers from both short duration and unmatched content between enrollment and test segments. In this paper, we use Discriminative Gaussian Process Latent Variable Model (DGPLVM) to deal with the uncertainty caused by short duration. This is the first attempt to utilize Gaussian Process for speaker verification. Also, to manage the unmatched content between enrollment and test segments we proposed the localized-DGPLVM that trains DGPLVM for each phrase in dataset. Experiments show the relative improvement of 27.4% in EER on RSR2015
A comprehensive statistical study on daytime surface urban heat island during summer in urban areas, case study: Cairo and its new towns
, Article Remote Sensing ; Volume 8, Issue 8 , 2016 ; 20724292 (ISSN) ; Sodoudi, S ; El Zafarany, A ; Abou El Seoud, T ; Ashraf, H ; Krone, K ; Sharif University of Technology
MDPI AG
2016
Abstract
Surface urban heat island (SUHI) is defined as the elevated land surface temperature (LST) in urban area in comparison with non-urban areas, and it can influence the energy consumption, comfort and health of urban residents. In this study, the existence of daytime SUHI, in Cairo and its new towns during the summer, is investigated using three different approaches; (1) utilization of pre-urbanization observations as LST references; (2) utilization of rural observations as LST references (urban-rural difference); and (3) utilization of the SIUHI (Surface Intra Urban Heat Island) approach. A time series of Landsat TM & ETM+ data (46 images) from 1984 to 2015 was employed in this study for...
Efficient fuzzy Bayesian inference algorithms for incorporating expert knowledge in parameter estimation
, Article Journal of Hydrology ; Volume 536 , 2016 , Pages 255-272 ; 00221694 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
Elsevier
Abstract
Bayesian inference has traditionally been conceived as the proper framework for the formal incorporation of expert knowledge in parameter estimation of groundwater models. However, conventional Bayesian inference is incapable of taking into account the imprecision essentially embedded in expert provided information. In order to solve this problem, a number of extensions to conventional Bayesian inference have been introduced in recent years. One of these extensions is 'fuzzy Bayesian inference' which is the result of integrating fuzzy techniques into Bayesian statistics. Fuzzy Bayesian inference has a number of desirable features which makes it an attractive approach for incorporating expert...