
Bahram Sadeghi BighamAlzahra University · Department of Mathematics
Bahram Sadeghi Bigham
PhD
About
100
Publications
31,115
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338
Citations
Introduction
Robotics
Algorithms and Computational Geometry
Data Science (Trajectory Data Set)
AI (medical applications)
Additional affiliations
September 2007 - present
Publications
Publications (100)
In today’s competitive and rapidly changing business landscape, organizations face significant challenges such as resource limitations, fluctuating demand, and evolving customer needs. Addressing these challenges requires effective strategies, with supplier selection playing a vital role in building resilient and efficient supply chains. This study...
This paper introduces a novel method for automatically classifying questions with multiple labels, using data specifically sourced from Stack Overflow. Traditional tagging methods frequently face challenges due to the complexity and semantic diversity of these questions, resulting in inconsistent and sometimes inaccurate results. The process starts...
The rapid growth of image data has led to the development of advanced image processing and computer vision techniques, which are crucial in various applications such as image classification, image segmentation, and pattern recognition. Texture is an important feature that has been widely used in many image processing tasks. Therefore, analyzing and...
We study the problem of perfect tiling in the plane and explore the possibility of tiling a rectangle using integral distinct squares. Assume a set of distinguishable squares (or equivalently a set of distinct natural numbers) is given, and one has to decide whether it can tile the plane or a rectangle or not. Previously, it has been proved that ti...
This paper presents an approach for optimizing the oil recovery factor by determining initial oil production rates. The proposed method utilizes the Q-learning method and the reservoir simulator (Eclipse 100) to achieve the desired objective. The system identifies the most efficient initial oil production rates by conducting a sufficient number of...
Accurate prediction and forecasting of industrial products’ consumption, enables up-to-date and efficient supply, replacement of worn-out items, and prevention of resource wastage. Planning and forecasting the usage of industrial products can help often based on historical years’ performance and environmental factors, using either traditional metho...
With the advent of the Internet of Things (IoT) and GPS-enabled smartphones, a large volume of historical travel data has been collected. Having access to this type of big data made the Point of Interest (POI) recommendation feasible. Given the variety of available locations and the sparsity of users’ check-ins, the problem of recommending location...
The turning function is a tool in image processing that measures the difference between two polygonal shapes. We propose a localization algorithm for the optimal pose estimation of autonomous mobile robots using the scan-matching method based on the turning function algorithm. There are several methodologies aimed at moving the robots in the right...
The purpose of the current study is to investigate a special case of art gallery problem, namely a sculpture garden problem. In this problem, for a given polygon P, the ultimate goal is to place the minimum number of guards (landmarks) to define the interior polygon P by applying a monotone Boolean formula composed of the guards. Using this problem...
In today's world, everything is connected via the Internet. Smart cities are one application of the Internet of Things (IoT) that is aimed at making city management more efficient and effective. However, IoT devices within a smart city may collect sensitive information. Protecting sensitive information requires maintaining privacy. Existing smart c...
We consider a variant of the k-center clustering problem in IRd, where the centers can be divided into two subsets—one, the red centers of size p, and the other, the blue centers of size q, such that p+q=k, and each red center and each blue center must be a distance of at least some given α≥0 apart. The aim is to minimize the covering radius. We pr...
Fingerprint, as one of the most popular and robust biometric traits, can be used in automatic identification and verification systems to identify individuals. Fingerprint matching is a vital and challenging issue in fingerprint recognition systems. Most fingerprint matching algorithms are minutiae-based. The minutiae points are the ways that the fi...
Network‐on‐Chip (NoC) is a key component in chip multiprocessors (CMPs) as it supports communication between many cores. NoC is a network‐based communication subsystem on an integrated circuit, most typically between modules in a system on a chip (SoC). Designing a reliable NoC against failures that can prevent failure using some measures or preven...
In the minimum constraint removal ([Formula: see text]), there is no feasible path to move from a starting point towards the goal, and the minimum constraints should be removed in order to find a collision-free path. It has been proved that [Formula: see text] problem is NP-hard when constraints have arbitrary shapes or even they are in shape of co...
According to the characteristics of art, art education according to Bloom's classification, should take place at high and close to the level of creativity. E-learning related to the subject of art is different from ordinary E-learning. In this paper, a general circular model for E-learning for art education is presented, a case study which has been...
Fingerprint, as one of the most popular and robust biometric traits, can be used in automatic identification and verification systems to identify individuals. Fingerprint matching is a vital and challenging issue in fingerprint recognition systems. Most fingerprint matching algorithms are minutiae-based. The minutiae in fingerprints can be determin...
We study the problem of perfect tiling in the plane and exploring the possibility of tiling a rectangle using integral distinct squares. Assume a set of distinguishable squares (or equivalently a set of distinct natural numbers) is given, and one has to decide whether it can tile the plane or a rectangle or not. Previously, it has been proved that...
The purpose of the current study is to investigate a special case of art gallery problem, namely Sculpture Garden Problem. In the said problem, for a given polygon $P$, the ultimate goal is to place the minimum number of guards to define the interior polygon $P$ by applying a monotone Boolean formula composed of the guards. As the findings indicate...
In the minimum constraint removal ($MCR$), there is no feasible path to move from the starting point towards the goal and, the minimum constraints should be removed in order to find a collision-free path. It has been proved that $MCR$ problem is $NP-hard$ when constraints have arbitrary shapes or even they are in shape of convex polygons. However,...
In the problem "Localization and trilateration with the minimum number of landmarks", we faced
the 3-Guard and classic Art Gallery Problems. The goal of the art gallery problem is to find the
minimum number of guards within a simple polygon to observe and protect its entirety. It has many
applications in robotics, telecommunications, etc. There are...
Skin color detection is an essential required step in various applications related to computer vision. These applications will include face detection, finding pornographic images in movies and photos, finding ethnicity, age, diagnosis, and so on. Therefore, proposing a proper skin detection method can provide solution to several problems. In this s...
In this study, a geometric version of an NP-hard problem ("Almost $2-SAT$" problem) is introduced which has potential applications in clustering, separation axis, binary sensor networks, shape separation, image processing, etc. Furthermore, it has been illustrated that the new problem known as "Two Disjoint Convex Hulls" can be solved in polynomial...
Robot localization is one of the most fundamental problems in motion planing, with many important applications in tracking vehicles and router systems. One way for localizing the robot is trilateration, which is used in the environments without GPS antenna by using a number of signals that can be measure their distance to robot at any time. It has...
Breast cancer is the second main cause of death in women of western countries, so early detection and prevention is crucial. Early detection increases the likelihood of treatment as well as patient resistance. Among breast cancer detection methods, mammography is the most effective diagnostic method. For radiologists, diagnosing a cancerous mass on...
Purpose
In this paper, an attempt has been made to develop an algorithm equipped with geometric pattern registration techniques to perform exact, robust and fast robot localization purely based on laser range data.
Design/methodology/approach
The expected pose of the robot on a pre-calculated map is in the form of simulated sensor readings. To obt...
The minimum constraint removal (MCR) is one of the most important problems in motion planning and computational geometry. In this problem, there is no feasible path for a robot to move from the starting point towards the goal. Therefore, in order to find a collision-free path, the minimum constraints should be removed. The MCR problem is NP-hard wh...
Measuring difference or similarity between data is one of the most fundamental steps in data science. This topic is of the utmost importance in many artificial intelligent systems, machine learning and any data mining and knowledge extraction. There are several applications in image processing, map analysis, self-driving cars, GIS, etc., when data...
This book presents outstanding theoretical and practical findings in data science and associated interdisciplinary areas. Its main goal is to explore how data science research can revolutionize society and industries in a positive way, drawing on pure research to do so. The topics covered range from pure data science to fake news detection, as well...
One of the most important steps which is used in every data mining projects is searching an object or some similar objects in a data set. For geometric data, there are some methods that measure the difference between two objects. In recent years, researchers have focused on these types of metrics and used them in different applications (e.g., shape...
One of the most important questions for managers of corporations is how they select a smart strategy for their corporations. To answer this question, Managers should consider some dimensions witch impact on the future of the corporation, and then they select a suitable strategy for their corporations. This paper presents a novel model (FASE model)...
Purpose – Robot localization in dynamic, cluttered environments is a challenging problem because it is
impractical to have enough knowledge to be able to accurately model the robot’s environment in such a manner. This
study aims to develop a novel probabilistic method equipped with function approximation techniques which is able
to appropriately mo...
The quality of recommendations based on any class of recommender systems may become poor if no or low quality data has been provided by users. This is a situation known as Cold Start problem, which typically happens when a new user registers to the system and no preference data is available for that user. Trust-Aware Recommendation Systems can be c...
We present a simple, robust and efficient harmony search algorithm for the Hop Constrained Connected Facility Location problem (HCConFL). The HCConFL problem is NP-hard that models the design of data-management and telecommunication networks in a manner of reliability. In this paper, we customize harmony search algorithm to solve the HCConFL proble...
The Hop-Constrained Steiner Tree problem (HCST) is challenging NP-hard problem arising in the design of centralized telecommunication networks where the reliability constraints matter. In this paper three iterative greedy algorithms are described to find efficient optimized solution to solve HCST on both sparse and dense graphs. In the third algori...
Proximity problems is a class of important problems
which involve estimation of distances between geometric objects. The nearest neighbor search which is a subset of proximity problems, arises in numerous fields of
applications, including Pattern Recognition, Statistical classification, Computer vision and etc. In this study, a nearest neighbor searc...
Smart grids, to facilitate the electricity production, distribution, and consumption, employ information and communication technologies simultaneously. Electricity markets, through stabilizing the electricity prices, attempt to alleviate the challenges of power exchange. On one hand, buyers, by considering their full demand satisfaction, endeavor t...
Parallel data are an important part of a reliable Statistical Machine Translation (SMT) system. The more of these data are available, the better the quality of the SMT system. However, for some language pairs such as Persian-English, parallel sources of this kind are scarce. In this paper, a bidirectional method is proposed to extract parallel sent...
Although mammography is typically the best method to detect breast cancer, it does not recognize 3–20% of the cancer cases. Mammography has established itself as the most efficient technique for detecting tiny cancerous tumor and micro-calcifications are the most difficult to detect since they are very small (0.1–1.0 mm) and they are almost contras...
Disease diagnosis, like cancer, is including challenging tasks that require a lot of attention. However data mining methods may not provide enough information to disease diagnose, but they are very effective to control and predict for an illness treatment or surgery. Because biomedical imaging and medical equipment are costly, computational algorit...
With the development of Internet communications, the security of message sending on the Internet has become very important. This article proposes a new adaptive data hiding method with a large data-embedding capacity for gray-scale images to raise the security of sending a message between sender and receiver in networks. At first, the image is divi...
Elimination of redundancies in the memory representation is necessary for fast and efficient analysis of large sets of fuzzy data. In this work, we use MTBDDs as the underlying data-structure to represent fuzzy sets and binary fuzzy relations. This leads to elimination of redundancies in the representation, less computations, and faster analyses. W...
Background and Objective: Endometriosis is a prevalent disease in women which may lead to infertility or low fertility. Grasping the genetic grounds for the disease may contribute to its treatment because it is presumed that genetic factors predispose to endometriosis risk factors. Materials and Methods: 9 genes involved in endometriosis in patient...
Elimination of redundancies in the memory representation is necessary for fast and efficient analysis of large sets of
fuzzy data. In this work, we use MTBDDs as the underlying
data
-
structure to represent fuzzy sets and binary fuzzy
relations. This leads to elimination of redundancies in the representation, less computations, and faster analys...
Classification of imbalanced data sets is an important challenge in machine learning. Whenever the size of one of the classes is very smaller than others, it is called as imbalanced data sets. In these types of data sets, all the algorithms and efficiency criteria care the majority class and ignore the minority class. But sometimes these minority c...
The smart grid makes use of two-way streams of electricity and information to constitute an automated and distributed energy delivery network. Coming up with multi-agent systems for resource allocation, chiefly comprises the design of local capabilities of single agents, and therefore, the interaction and decision-making mechanisms that make them c...
Today, traffic safety is one of the main priorities of governments. Considering the importance of topic, identifying the
causes of road accidents has become the main aim to reduce the damage caused by traffic accidents. On the other hand,
because of the exponential growth of data volume, analysis of the factors in this regard is impractical. In thi...
For fast and efficient analysis of large sets of fuzzy data, elimination of
redundancies in the memory representation is needed. We used MTBDDs as the
underlying data-structure to represent fuzzy sets and binary fuzzy relations.
This leads to elimination of redundancies in the representation, less
computations, and faster analyses. We have also ext...
تکنولوژی ریزآرایه به عنوان ابزار قدرتمندی جهت تحلیل و بررسی رفتار هزاران ژن، نقش به سزایی در تشخیص، کشف و بررسی روشهای درمان در انواع بیماریها به خصوص سرطان دارد. در ساخت ریزآرایه از پروبهایی استفاده میشود که هرکدام شامل چندین باز متصل و یا ژن میباشد. هر باز طولی به اندازه ۰.۳۳ نانومتر دارد. این پروبها توسط روباتهای مخصوصی در ریزآرایه قرار م...
The smart grid makes use of two-way streams of electricity and information to constitute an automated and distributed energy delivery network. Coming up with multi-agent systems for resource allocation, chiefly comprises the design of local capabilities of single agents, and therefore, the interaction and decision-making mechanisms that make them c...
A set of natural numbers tiles the plane if a square tiling of the plane exists using exactly one square of side length n for every n in the set. From [2] we know that N itself tiles the plane. From that and [3] we know that the set of even numbers tiles the plane while the set of odd numbers does not.
According to [1] it is possible to tile the pl...
In software rating area, it is necessary to apply a measurement reference model to evaluate the quality of software. The standard 25030 is an example of an evaluation system which is based on stakeholders' requirements. In this study, an attempt has been made to establish a model in which all implicit and explicit requirements of stakeholders, user...
In this paper, we introduce a novel class of facility location problems, and propose solutions based on Voronoi diagrams. Our solutions locate a set of facilities on a two dimensional space, with respect to a set of dynamic demand. The information about this demand is gathered through modifications of the overall system, into a central decision uni...
Presenting an efficient general feature selection method for the problem of the curse of dimensionality is still an open problem in pattern recognition, and, considering the cooperation among features through search processes, it is the most important challenge. In this paper, a combinatorial approach has been proposed, which consists of three feat...
The very rapid change in the entire life influences the systems that control our behavior, skills and
knowledge. The evolution of our education methods is one of the main indicators in this change. The educational systems have been influenced by these rapid changes over the time and technology is increasingly used in learning settings. Assessment a...
J2ME is a development platform for mobile devices and has been introduced by Sun Micro-Systems Inc. In 1999 for programming limited devices such as phones, PDAs and other small devices. But this architecture does not support APIs for data persistence management and relational database because of its limitations. This paper presents a base for local...
The polar diagram of a set of points in a plane and its extracted dual EDPD were recently introduced for static and dynamic cases. In this paper, the near-pole polar diagram NPPD for a set of points is presented. This new diagram can be considered as a generalization of the polar diagram and has applications in several communication systems and rob...
The purpose of this paper is to investigate and study Electronic Problem-Based Learning (e-PBL) systems as well as proposing a method of learning which involves deeper understanding and comprehension in terms of Bloom’s Taxonomy. The PBL system allows students to become self-directed and self-disciplined and simplifies elimination of lecturers’ phy...
A set of natural numbers tiles the plane if a square-tiling of the plane exists using exactly one square of side length n for every n in the set. From we know that N itself tiles the plane. From that and we know that the set of even numbers tiles the plane while the set of odd numbers does not. According to it is possible to tile the plane using on...
Voronoi game is a simple geometric model for competitive facility location problem that is done between two players in continues space. In some previous researches the problem has been studied with Euclidean distance. In this paper a new version of one-round Voronoi game is presented in which multiplicatively weighted Voronoi diagram is used. It is...
The 2012 International Conference on Contemporary Issues in Computer and Information Science (CICIS 2012) is a conference where new advances and research results in the fields of computer science and information technology are presented. CICIS 2012 brought together leading researchers, engineers and scientists from around the world engaged in compu...
In recent years, recommendation systems based on Collaborative Filtering have been able to gain great success. But these systems have some problems confronting with Cold Start users who have not rated enough items. In such cases, we can use Trust networks between users, in order to overcome the " Cold start " problem. But these methods also do not...
Nowadays, number of products that are sold or bought through Internet by e-commerce websites such as eBay and Amazon are increasing rapidly. In other words, people prefer to buy or sell their requirements from Internet. The factors such trust, security and availability play important roles in these transactions. So, companies try to improve quality...
Nowadays, communication devices are widespread exponentially. People use some of these devices in daily life like as using mobile to access for shopping from Internet and pay by credit cards or student email their homework to their teacher. In other words, Internet network plays significant roles in people’s life. Therefore, some features such as a...