Sheikh Bahaei University
  • Najafābād, Esfahan, Iran
Recent publications
Lesion segmentation is a challenging task in computer-aided diagnosis (CAD) systems. In this paper, an automatic segmentation and diagnosis algorithm is proposed for Breast Ultrasound (BUS) images. Among imaging methods, ultrasound is used as an appropriate tool in the diagnosis of breast cancer owing to its advantages, including real-timeliness, low cost, no use of ionizing radiation, and high sensitivity in dense tissues. For this task, the main focus is to provide an efficient and automatic method to segment the region of interest (ROI), as well as to use morphological and texture-based features for diagnostic purposes. Two texture-based feature extraction methods, i.e. “estimation of Gabor filter coefficients by an autoregressive model” and “using statistical features in image visibility graph”, have been introduced after the automatic development of ROI. These features together with morphological features are classified by the Support Vector Machine (SVM) classifier to identify lesion type. After the selection of superior features by the recursive feature elimination algorithm, the proposed method is tested on a database with 163 images; the obtained results confirm the image segmentation ability and the feature separation ability.
Gait is one of the most frequently used forms of human movement during daily activities. The majority of works focus on exploring the dynamic factors during gait. Different from previous works, we adapt an image prediction task for anticipating the next frame in process of gait. In this work, we present a novel framework for human gait plantar pressure prediction using Spatio-temporal Transformer. We train the model to predict the next plantar pressure image in an image series while also learning frame feature encoders that predict the features of subsequent frames in the sequence. We proposed two new components in our loss function for considering temporality as well as smaller values in the image. Our model achieves superior results over several competitive baselines on the CAD WALK database. Clinical Relevance- This work can be used in robotic exoskeleton devices which are intelligent systems designed to improve gait performance and quality of life for the wearer that are being used to assist the recovery of walking ability for patients with disorders.
This paper presents a new circuit structure of a multi-mode active filter, using only 16 transistors and 2 grounded capacitors in carbon nanotube field-effect transistor (CNFET) technology which is biased at [Formula: see text][Formula: see text]V supply. The proposed multi-input, single-output (MISO) filter has the capability of working as low-pass, band-pass, high-pass, band-stop and all-pass filters in all the operating modes (voltage, current, transconductance and transresistance). In addition, the quality factor ([Formula: see text]) parameter can be tuned electronically independent of the center frequency ([Formula: see text]). The HSPICE simulation results show that the proposed filter consumes only 971[Formula: see text][Formula: see text]W at 1[Formula: see text]GHz center frequency, assuming [Formula: see text][Formula: see text]pF and the nanotube pitch parameter of ([Formula: see text] nm) and the chiral vector of (22,0), while the number of nanotubes is considered as [Formula: see text] for all the transistors. Moreover, the main circuit performances such as the center frequency and the power consumption of the circuit vary by 5.4% and 11.6%, respectively, for the standard temperature variation.
This study aims to evaluate the cause-and-effect relationships of potential PMO functions at project-oriented organizations. In this research, the Delphi technique was first employed to identify the potential PMO functions, and DEMATEL technique was conducted to evaluate the cause-and-effect relationships. According to the research findings, structure determination and project organization were the most effective PMO functions, whereas counseling and training through PMO was identified as the most important function. Moreover, participation in project implementation through PMO was the most affected function. To improve the PMO performance, project-oriented organizations can focus on effective functions and causes in order to modify and improve them.
This study aims to investigate the relationship between local host-tourist interaction, perceived service quality (PSQ), relationship quality (RQ), memorable tourism experience (MTE), and revisit intention in ecotourism based on social exchange theory. A questionnaire was sent through an online survey to the Iranian tourists who had chosen local accommodations in Iran, Iraq, and Turkey during the 2019–2020 and included both domestic and international destinations. A total of 406 valid questionnaires were obtained, and the proposed research model was tested using partial least squares structural equation modeling (PLS-SEM). The results indicate that hedonic and functional interactions have a positive impact on RQ and PSQ. On the other hand, RQ and PSQ contribute significantly to memorable experiences and revisit intention. Drawing on a large sample of eco lodging guests, this paper sheds light on the relationships between host-tourist interaction and RQ and PSQ for motivating behavioral intentions like visiting again and memorable experience.
An important class of fluids commonly used in industries is non-Newtonian fluids. In this paper, two numerical techniques based on rational Legendre functions and Chebyshev polynomials are presented for solving the flow of a third-grade fluid in a porous half space. This problem can be reduced to a nonlinear two-point boundary value problem on semi-infinite interval. Our methods are utilized to reduce the computation of this problem to some algebraic equations. The comparison of the results with the other methods and residual norm show very good accuracy and rate of convergence of our approach.
Estimating arithmetic deals with trading accuracy for speed, silicon area, and/or power consumption. Truncated parallel multipliers, which reduce power and area approximately by half, are very important units in estimating arithmetic. An n-bit unsigned truncated sequential multiplier with new approaches that compensate for the truncation error is proposed in this article. These compensating approaches improve the result accuracy using the ( )-th or n-th columns of the partial product matrix dynamically. By introducing a small circuit into the original sequential multiplier, these approaches compensate for the error resulting from removing the carry bits of the least significant parts of the partial product matrix. The maximum relative error of the new truncated multiplier is approximately 2.03%, thus it is only slightly different from that of the precise counterpart in terms of accuracy. A timing evaluation is conducted for the critical path of the proposed multiplier, applying a pre-layout logical synthesis. The evaluation reveals that depending on the operands length, this proposed multiplier is approximately 2.5% to 26.6% faster than the precise multiplier.
Mass market strategy does not have a big chance for success in a competitive market. Therefore, by segmenting a heterogeneous market in to some smaller and homogenous markets in which customers have similar characteristics, it is expected that the resources can be more efficiently utilised. The purpose of this study was a mathematical modelling of market segmentation of an Iranian steel-making company using value proposition elements. The model mentioned was used for the analysis of data related to six value proposition elements from 129 major customers of the company. This model was solved using GAMS software and the optimal number of segments was 9. In this study, the results obtained were compared with those achieved by the conventional segmentation methods such as K-means and SOM and two-step clustering. Further, for the validation of the mathematical model used, discriminant analysis of research data was done after segmentation and the success percentage of the ranking rule was found to be 95.3%. Also, the similarity criterion was computed for each potentially new customer.
The current research aims at examining the difference between the trip-related motivations held by those tourists who choose recreational destinations and those who choose cultural ones. To do so, in August 2013, 401 questionnaires were handed to Iranian tourists planning to take a trip to Istanbul and Antalya, Turkey. The results of the t-tests demonstrated that those tourists considering escape to be their major motivation for the trip tended to travel to tourist resorts more, and the recreational goal of the destination played the most significant role for them. On the other hand, those who travel for ego-enhancement try to practice more cultural destinations and place great value on tourist attractions.
This study addresses semi-global practical asymptotic stabilisation and performance recovery of a class of sampled-data non-linear systems using a time-scale separation redesign. In particular, a high-gain filter is designed to estimate uncertainties in continuous-time and a fast variable coming from the filter is used to cancel the effect of the uncertainty, then the controller including the filter is descritised in Euler method. The authors provide conditions relating the sampling time and the filter gain, with which the results for the sampled-data system are the same as those that have been developed for the continuous-time system. As a verification of results, numerical simulations are given.
This paper addresses input-to-state stability (ISS) analysis for discrete-time systems using the notion of finite-step ISS Lyapunov functions. Here, finite-step Lyapunov functions are energy functions that decay after a fixed but finite number of steps, rather than at every time step. We establish non-conservative dissipativity and small-gain conditions for ISS of networks of discrete-time systems, by generalizing results in [1] and [2] to the case of ISS. The effectiveness of the results is illustrated through two examples.
We study the life distribution of an operating device through the notion of mean residual life. The device is experiencing a random number of shocks governed by a homogeneous Poisson process, and a new U-statistic test procedure is introduced to test the hypothesis of that the life is exponentially distributed against the alternative that the life distribution is the life distribution has renewal increasing mean residual property.
Human beings have interactional nature, and with the passage of time, always try to present their ideas, expectations, and worldviews to the humanity. In the past, since the mass media was not easily accessible to everyone, graffiti was considered a powerful tool for transmitting thoughts and inclinations. In other words, as graffiti is affected by a specific line of thinking, it is possible to follow linguistic and cultural patterns. The current paper tries to investigate the existing common linguistic patterns in English and Persian graffiti in order to understand their social and behavioral patterns better. The research findings show that graffiti follow a distinguished linguistic pattern and are systematic, in a way that they can be compared with seven linguistic functions of Halliday. By systematic, it means that the graffiti can be analyzed through linguistic and cultural frameworks. However, the results showed that there are some differences in English and Persian graffiti. In Persian graffiti, instrumental, imaginative, and interactional designs are frequent. The research analysis that has been conducted in the social domain verifies the existence of such features in the East. In English graffiti, too, personal and regulatory functions more frequent than the Persian ones and these differences are also related to cultural indices of the two languages.
We present a detailed stratigraphic and structural study of the Kopeh Dagh fold-and-thrust belt in NE Iran, which is an investigation of the complex polyphased tectonic history of this belt and its links with the adjacent South Caspian Sea and Amu Darya basins. Based on numerous field surveys, a large amount of 2D and 3D seismic data, borehole data and more than 150 new biostratigaphic datings, a new detailed biostratigraphic chart and 4 main regional cross-sections illustrate the importance of lateral facies variations and structural inheritance in the present-day structure of the belt.
The present study aims at investigating the convergence to the target language culture. It seeks to discover if being exposed to the target culture may affect EFL learning. The 98 participants were randomly divided into two experimental and two control groups, the latter groups being just exposed to the foreign language elements, while the former groups being exposed additionally to the target culture. The findings revealed that the learners’ language proficiency in the experimental groups changed significantly in comparison with that of their counterparts in the control groups. The effect was stronger for the female students.
The present research is an attempt to identify the effect of ego identity types on the language proficiency of the learners. In other words, it is trying to answer the question which identity types achieve higher levels of proficiency in terms of language learning. The results revealed that the achieved ego identity types were better language learners in comparison with foreclosed and diffused types. The results obtained in terms of the effect of gender on language proficiency led the researchers to believe that the significant difference found in this regard was not caused due to such differences.
Background: Retinoblastoma is a rare malignant intraocular neoplasm. About 90% of cases feature a germline mutation in the RB1 gene and these will develop retinoblastoma during their early childhood. An association between mutations in germline cells and aging has been demonstrated. This suggests a higher incidence of childhood cancer including retinoblastoma among children of older parents. Materials and methods: In the present study we aimed to determine the association of paternal and maternal age with an increased risk of retinoblastoma in a case-control study in Iranian population. The study was carried out on 240 persons who were born during 1984-2012 in Mahak and Mofid hospitals in Tehran, Iran. The statistical analysis included studying the mean age of parents and in order to know whether parental age of patients is different from parental age of control group, (t-test) compare averages test is used perfectly. By binary logistic regression, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Results: The results of statistical analysis including the study of mean parental age by the use of (t-test) compare averages test showed a significant difference between parental ages of patients and controls. Logistic regression showed that coefficients were significant for maternal but not paternal age. Conclusions: Our findings indicate that advanced maternal age can increase the risk of retinoblastoma in offspring, but the paternal age has no significant effect.
Hammams, or public baths, are an essential part of the social life in urban Islam. Often, they have a rich and inspiring architecture. In Iran and, in particular, in Isfahan – a large and historic city in central of Iran – numerous hammams were built since the Safavid dynasty (1501–1722). Social and urban changes have resulted in a significant decline in the number of hammams over the years. This paper starts by describing the multiple dimensions of hammams, such as their main architecture features, their role in health, society and culture. This is followed by an analysis of hammams in Isfahan, using a modified version of Büyükdigan categories for Ottoman baths: (i) ‘baths in ruins’; (ii) ‘baths continuing their original functions’; and (iii) ‘baths readjusted for new uses’. Anecdotal evidence from a survey conducted in 15 hammams is used throughout this paper. The main conclusions relate to the rapid deterioration of hammams in daily life, coupled with the lack of detailed documentation, which would allow proper planning and development, and the deficient use of some of these magnificent buildings and places for tourism development.
Emotional intelligence is the ability to process information about one’s own emotions and the emotions of others. It involves perceiving emotions, understanding emotions, managing emotions and using emotions in thought processes and in other activities. Emotion understanding is the cognitive activity of using emotions to infer why an agent is in an emotional state and which actions are associated with the emotional state. For humans, knowledge about emotions includes, in part, emotional experiences (episodic memory) and abstract knowledge about emotions (semantic memory). In accordance with the need for more sophisticated agents, the current research aims to increase the emotional intelligence of software agents by introducing and evaluating an emotion understanding framework for intelligent agents. The framework organizes the knowledge about emotions using episodic memory and semantic memory. Its episodic memory learns by storing specific details of emotional events experienced firsthand or observed. Its semantic memory is a lookup table of emotion-related facts combined with semantic graphs that learn through abstraction of additional relationships among emotions and actions from episodic memory. The framework is simulated in a multi-agent system in which agents attempt to elicit target emotions in other agents. They learn what events elicit emotions in other agents through interaction and observation. To evaluate the importance of different memory components, we run simulations with components “lesioned”. We show that our framework outperformed Q-learning, a standard method for machine learning.
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60 members
Arash Ahmadi Esfahani
  • Department of Information Technology
Sahar Atarzadeh
  • Department of Computer Science
Mostafa Movahedi
  • Department of Information Technology
Ahmad Reza Akhavan Sarraf
  • Department of Management
Mahsa Tabaeian
  • Department of English Language and Literature
031, Najafābād, Esfahan, Iran
Head of institution
Jafar Zafarani