Raghda Alqurashi | Umm Al-Qura University, Makkah, Saudi Arabia (original) (raw)
Papers by Raghda Alqurashi
The agent-based model is a well-established approach to carry out the simulation of crowd behavio... more The agent-based model is a well-established approach to carry out the simulation of crowd behavior under varying conditions and environments. However, this approach still lacks the ability to be fully automated and to take into account the agents' unfamiliarity and minimum awareness in an unknown environment. In this paper, we propose a multi-level multi-stage agent-based modeling framework that automates the decision-making processes during crowd evacuation in large-scale facilities. We demonstrate that crowd behaviors can be modeled at different stages and at several layers. We do this by integrating a probabilistic model with a dynamic generating process of intelligent guide agents to automatically generate decisions that are nearly optimal for neighboring agents. Specifically, we apply the framework to different evacuation scenarios and analyze its effectiveness in case of a high-density crowd. Our experimental results provide evidence that the hybrid multi-layered approach can be successfully applied to efficiently simulate agent behaviors in intensive crowd environments. The results show that employing our method, which is scalable, outperforms the standard conservative agent-based approaches.
It has been medically proven that one's sleep quality directly affects his or her personal health... more It has been medically proven that one's sleep quality directly affects his or her personal health, social behavior, and work effectiveness. Understanding sleep quality, hence, is an important topic and has been attracting a vast amount of research efforts. In addition, with the advent and ever-increasing number of mobile and wearable devices, many attempts have been made towards monitoring one's sleep using these ubiquitous devices. However, there were none on exploring the complex relationship between sleep quality and sleeping environment. In this paper, we propose mSleepWatcher as an ongoing attempt answer the question of "Why didn't I sleep well?". By mining the environmental sensing information collected by built-in sensors of off-the-shelf mobile and wearable devices in combination with the sleep quality sensing information, a set of causality analysis techniques is adopted and applied to exploit the existence of temporal dependencies between the environment during sleep and sleep quality. Resulted from mSleepWatcher system, latent relationships between the environment and sleep quality can be inferred which are then used to provide recommendation to users to suggest users adjusting their sleep environment for a better sleep. The proposed system is the first attempt to bring a fresh picture of sleep study associated with different scenarios of environmental variations. Derived from our preliminary work, both strength and limitations for developing the complete system in mobile devices are discussed in detail.
This paper introduces LIBS, a lightweight and inexpensive wearable sensing system, that can captu... more This paper introduces LIBS, a lightweight and inexpensive wearable sensing system, that can capture electrical activities of human brain, eyes, and facial muscles with two pairs of custom-built flexible electrodes each of which is embedded on an off-the-shelf foam earplug. A supervised nonnegative matrix factorization algorithm to adaptively analyze and extract these bioelectrical signals from a single mixed in-ear channel collected by the sensor is also proposed. While LIBS can enable a wide class of low-cost selfcare, human computer interaction, and health monitoring applications, we demonstrate its medical potential by developing an autonomous whole-night sleep staging system utilizing LIBS's outputs. We constructed a hardware prototype from off-the-shelf electronic components and used it to conduct 38 hours of sleep studies on 8 participants over a period of 30 days. Our evaluation results show that LIBS can monitor biosignals representing brain activities, eye movements, and muscle contractions with excellent fidelity such that it can be used for sleep stage classification with an average of more than 95% accuracy.
This paper describes a modified agent-based model (ABM) that simulates crowd behavior within dyna... more This paper describes a modified agent-based model (ABM) that simulates crowd behavior within dynamically changing environments. These include network topology changes, or external stimuli such as explosions, fires, earthquakes, just to name a few. In general, crowd dynamics simulation is relatively difficult to carry out because the behavior-influencing factors may come from within as well as outside of the system. The proposed modeling system employs a hybrid centralized approach (to assist the individual agents with their decision-making) that is based on both the local and/or incomplete/indirect global information.
We present a Virtual Ant Laboratory agent-based model, an interactive and prediction tool to simu... more We present a Virtual Ant Laboratory agent-based model, an interactive and prediction tool to simulate the ants' environment and their decisions making and foraging behaviors. The proposed simulation model provides the ability to generate customized complex ant environments and to explore the interaction between the environment features and ants' behavior.As expected, the results showed that the quality of the food and the distance between food sources and the nest have a significant impact on the ants' decisions. The model was partially validated via live-ants laboratory experiments and can easily be generalized to other environments/agents.
The purpose of this quantitative study was to identify significant factors that prevented teacher... more The purpose of this quantitative study was to identify significant factors that prevented teachers in Saudi Arabia from using video games in their classroom; and found differences in hindering factors between gender and level of teaching and teaching experience. The results showed that there were five factors that prevented Saudi teachers from using video games in their classroom among 25 categories of reasons. These five factors were "The impact of education video games on student and learning process", "Required times, cost, training, and technical issues of applying educational video games", "Characteristics of educational video games", "Harmonization between the educational video games and teaching", "Unawareness of educational video games".
Applied sciences, Oct 16, 2019
Agent-based model (ABM) simulation is a bottom-up approach that can describe the phenomena genera... more Agent-based model (ABM) simulation is a bottom-up approach that can describe the phenomena generated from actions and interactions within a multiagent system. An ABM is an improvement over model simulations which only describe the global behavior of a system. Therefore, it is an appropriate technology to analyze emergent phenomena in social sciences and complex adaptive systems such as vehicular traffic and pedestrian crowds. In this paper, a hybrid agent-based modeling framework designed to automate decision-making processes during traffic congestion is proposed. The model provides drivers with real-time alternative routes, computed via a decentralized multi-agent model, that tries to achieve a system-optimal traffic distribution within an entire system, thus reducing the total travel time of all the drivers. The presented work explores a decentralized ABM technique on an autonomous microgrid that is represented through cellular automata (CA). The proposed model was applied to high-density traffic congestion events such as car accidents or lane closures, and its effectiveness was analyzed. The experimental results confirm the efficiency of the proposed model in not only accurately simulating the driver behaviors and improving vehicular traffic flows during congestion but also by suggesting changes to traffic dynamics during the simulations, such as avoiding obstacles and high-density areas and then selecting the best alternative routes. The simulation results validate the ability of the proposed model and the included decision-making sub-models to both predict and improve the behaviors and intended actions of the agents.
Hyper-rings are a multi-machine organization that is, in a sense, a generalization of the standar... more Hyper-rings are a multi-machine organization that is, in a sense, a generalization of the standard hyper-cube architecture. One of the most powerful properties of the hyper-rings is that the node-connectivity of an N-HR has been proven to be equal to its degree. This paper discusses hyper-rings, their construction and properties, and an interactive software that allows the user to generate and display hyper-rings of arbitrary size and dimension. The algorithm also finds and displays, under 3D rotations, all node-disjoint shortest paths between any two user-specified nodes.
GetMobile, Nov 14, 2017
in 2009. Her primary research interests are in mobile systems, with emphasis on applying sensing ... more in 2009. Her primary research interests are in mobile systems, with emphasis on applying sensing techniques for mobile health care.
Journal of the American College of Cardiology, Sep 8, 2016
Representative. yWomenHeart Representative. zHealthcare Information and Management Systems Societ... more Representative. yWomenHeart Representative. zHealthcare Information and Management Systems Society (HIMSS) Representative during the writing effort, no longer employed by HIMSS. xHeart Rhythm Society Representative. kAmerican Society of Nuclear Cardiology Representative. {Society of Cardiovascular Angiography and Interventions Representative.
Abstract:A graph G= (V, E) is called a hyper-ring with N nodes (N-HR for short) if
ACM Transactions on Management Information Systems
We develop a similarity measure for medical event sequences (MESs) and empirically evaluate it us... more We develop a similarity measure for medical event sequences (MESs) and empirically evaluate it using U.S. Medicare claims data. Existing similarity measures do not use unique characteristics of MESs and have never been evaluated on real MESs. Our similarity measure, the Optimal Temporal Common Subsequence for Medical Event Sequences (OTCS-MES), provides a matching component that integrates event prevalence, event duplication, and hierarchical coding, important elements of MESs. The OTCS-MES also uses normalization to mitigate the impact of heavy positive skew of matching events and compact distribution of event prevalence. We empirically evaluate the OTCS-MES measure against two other measures specifically designed for MESs, the original OTCS and Artemis, a measure incorporating event alignment. Our evaluation uses two substantial data sets of Medicare claims data containing inpatient and outpatient sequences with different medical event coding. We find a small overlap in nearest neighbors among the three similarity measures, demonstrating the superior design of the OTCS-MES with its emphasis on unique aspects of MESs. The evaluation also provides evidence about the impact of component weights, neighborhood size, and sequence length.
2017 International Conference on Computational Science and Computational Intelligence (CSCI), 2017
The purpose of this quantitative study was to identify significant factors that prevented teacher... more The purpose of this quantitative study was to identify significant factors that prevented teachers in Saudi Arabia from using video games in their classroom; and found differences in hindering factors between gender and level of teaching and teaching experience. The results showed that there were five factors that prevented Saudi teachers from using video games in their classroom among 25 categories of reasons. These five factors were "The impact of education video games on student and learning process", "Required times, cost, training, and technical issues of applying educational video games", "Characteristics of educational video games", "Harmonization between the educational video games and teaching", "Unawareness of educational video games".
2017 International Conference on Computational Science and Computational Intelligence (CSCI), 2017
This paper describes a modified agent-based model (ABM) that simulates crowd behavior within dyna... more This paper describes a modified agent-based model (ABM) that simulates crowd behavior within dynamically changing environments. These include network topology changes, or external stimuli such as explosions, fires, earthquakes, just to name a few. In general, crowd dynamics simulation is relatively difficult to carry out because the behavior-influencing factors may come from within as well as outside of the system. The proposed modeling system employs a hybrid centralized approach (to assist the individual agents with their decision-making) that is based on both the local and/or incomplete/indirect global information.
ACM Transactions on Management Information Systems (TMIS), 2017
We develop a similarity measure for medical event sequences (MESs) and empirically evaluate it us... more We develop a similarity measure for medical event sequences (MESs) and empirically evaluate it using U.S. Medicare claims data. Existing similarity measures do not use unique characteristics of MESs and have never been evaluated on real MESs. Our similarity measure, the Optimal Temporal Common Subsequence for Medical Event Sequences (OTCS-MES), provides a matching component that integrates event prevalence, event duplication, and hierarchical coding, important elements of MESs. The OTCS-MES also uses normalization to mitigate the impact of heavy positive skew of matching events and compact distribution of event prevalence. We empirically evaluate the OTCS-MES measure against two other measures specifically designed for MESs, the original OTCS and Artemis, a measure incorporating event alignment. Our evaluation uses two substantial data sets of Medicare claims data containing inpatient and outpatient sequences with different medical event coding. We find a small overlap in nearest ne...
2017 International Conference on Computational Science and Computational Intelligence (CSCI), 2017
We present a Virtual Ant Laboratory agent-based model, an interactive and prediction tool to simu... more We present a Virtual Ant Laboratory agent-based model, an interactive and prediction tool to simulate the ants' environment and their decisions making and foraging behaviors. The proposed simulation model provides the ability to generate customized complex ant environments and to explore the interaction between the environment features and ants' behavior.As expected, the results showed that the quality of the food and the distance between food sources and the nest have a significant impact on the ants' decisions. The model was partially validated via live-ants laboratory experiments and can easily be generalized to other environments/agents.
A graph G= (V, E) is called a hyper-ring with N nodes (N-HR for short) if V = {0, ..., N-1} and E... more A graph G= (V, E) is called a hyper-ring with N nodes (N-HR for short) if V = {0, ..., N-1} and E = {(u,v)| v-u modulo N is a power of 2}. In other words, a hyper-ring with N nodes is a graph in which all of the edges connect nodes that are at distances of powers of 2 from each other. Hyper-rings are a multi-machine organization that is, in a sense, a generalization of the standard hyper-cube architecture. One of the most powerful properties of the hyper-rings is that the node-connectivity of an N-HR has been proven to be equal to its degree. This paper discusses hyper-rings, their construction and properties, and an interactive software that allows the user to generate and display hyper-rings of arbitrary size and dimension. The algorithm also finds and displays, under 3D rotations, all node-disjoint shortest paths between any two user-specified nodes.
It has been medically proven that one’s sleep quality directly affects his or her personal health... more It has been medically proven that one’s sleep quality directly affects his or her personal health, social behavior, and work effectiveness. Understanding sleep quality, hence, is an important topic and has been attracting a vast amount of research efforts. In addition, with the advent and ever-increasing number of mobile and wearable devices, many attempts have been made towards monitoring one’s sleep using these ubiquitous devices. However, there were none on exploring the complex relationship between sleep quality and sleeping environment. In this paper, we propose mSleepWatcher as an on-going attempt answer the question of "Why didn’t I sleep well?". By mining the environmental sensing information collected by built-in sensors of off-the-shelf mobile and wearable devices in combination with the sleep quality sensing information, a set of causality analysis techniques is adopted and applied to exploit the existence of temporal dependencies between the environment during ...
The agent-based model is a well-established approach to carry out the simulation of crowd behavio... more The agent-based model is a well-established approach to carry out the simulation of crowd behavior under varying conditions and environments. However, this approach still lacks the ability to be fully automated and to take into account the agents' unfamiliarity and minimum awareness in an unknown environment. In this paper, we propose a multi-level multi-stage agent-based modeling framework that automates the decision-making processes during crowd evacuation in large-scale facilities. We demonstrate that crowd behaviors can be modeled at different stages and at several layers. We do this by integrating a probabilistic model with a dynamic generating process of intelligent guide agents to automatically generate decisions that are nearly optimal for neighboring agents. Specifically, we apply the framework to different evacuation scenarios and analyze its effectiveness in case of a high-density crowd. Our experimental results provide evidence that the hybrid multi-layered approach ...
Communications of the ACM
The agent-based model is a well-established approach to carry out the simulation of crowd behavio... more The agent-based model is a well-established approach to carry out the simulation of crowd behavior under varying conditions and environments. However, this approach still lacks the ability to be fully automated and to take into account the agents' unfamiliarity and minimum awareness in an unknown environment. In this paper, we propose a multi-level multi-stage agent-based modeling framework that automates the decision-making processes during crowd evacuation in large-scale facilities. We demonstrate that crowd behaviors can be modeled at different stages and at several layers. We do this by integrating a probabilistic model with a dynamic generating process of intelligent guide agents to automatically generate decisions that are nearly optimal for neighboring agents. Specifically, we apply the framework to different evacuation scenarios and analyze its effectiveness in case of a high-density crowd. Our experimental results provide evidence that the hybrid multi-layered approach can be successfully applied to efficiently simulate agent behaviors in intensive crowd environments. The results show that employing our method, which is scalable, outperforms the standard conservative agent-based approaches.
It has been medically proven that one's sleep quality directly affects his or her personal health... more It has been medically proven that one's sleep quality directly affects his or her personal health, social behavior, and work effectiveness. Understanding sleep quality, hence, is an important topic and has been attracting a vast amount of research efforts. In addition, with the advent and ever-increasing number of mobile and wearable devices, many attempts have been made towards monitoring one's sleep using these ubiquitous devices. However, there were none on exploring the complex relationship between sleep quality and sleeping environment. In this paper, we propose mSleepWatcher as an ongoing attempt answer the question of "Why didn't I sleep well?". By mining the environmental sensing information collected by built-in sensors of off-the-shelf mobile and wearable devices in combination with the sleep quality sensing information, a set of causality analysis techniques is adopted and applied to exploit the existence of temporal dependencies between the environment during sleep and sleep quality. Resulted from mSleepWatcher system, latent relationships between the environment and sleep quality can be inferred which are then used to provide recommendation to users to suggest users adjusting their sleep environment for a better sleep. The proposed system is the first attempt to bring a fresh picture of sleep study associated with different scenarios of environmental variations. Derived from our preliminary work, both strength and limitations for developing the complete system in mobile devices are discussed in detail.
This paper introduces LIBS, a lightweight and inexpensive wearable sensing system, that can captu... more This paper introduces LIBS, a lightweight and inexpensive wearable sensing system, that can capture electrical activities of human brain, eyes, and facial muscles with two pairs of custom-built flexible electrodes each of which is embedded on an off-the-shelf foam earplug. A supervised nonnegative matrix factorization algorithm to adaptively analyze and extract these bioelectrical signals from a single mixed in-ear channel collected by the sensor is also proposed. While LIBS can enable a wide class of low-cost selfcare, human computer interaction, and health monitoring applications, we demonstrate its medical potential by developing an autonomous whole-night sleep staging system utilizing LIBS's outputs. We constructed a hardware prototype from off-the-shelf electronic components and used it to conduct 38 hours of sleep studies on 8 participants over a period of 30 days. Our evaluation results show that LIBS can monitor biosignals representing brain activities, eye movements, and muscle contractions with excellent fidelity such that it can be used for sleep stage classification with an average of more than 95% accuracy.
This paper describes a modified agent-based model (ABM) that simulates crowd behavior within dyna... more This paper describes a modified agent-based model (ABM) that simulates crowd behavior within dynamically changing environments. These include network topology changes, or external stimuli such as explosions, fires, earthquakes, just to name a few. In general, crowd dynamics simulation is relatively difficult to carry out because the behavior-influencing factors may come from within as well as outside of the system. The proposed modeling system employs a hybrid centralized approach (to assist the individual agents with their decision-making) that is based on both the local and/or incomplete/indirect global information.
We present a Virtual Ant Laboratory agent-based model, an interactive and prediction tool to simu... more We present a Virtual Ant Laboratory agent-based model, an interactive and prediction tool to simulate the ants' environment and their decisions making and foraging behaviors. The proposed simulation model provides the ability to generate customized complex ant environments and to explore the interaction between the environment features and ants' behavior.As expected, the results showed that the quality of the food and the distance between food sources and the nest have a significant impact on the ants' decisions. The model was partially validated via live-ants laboratory experiments and can easily be generalized to other environments/agents.
The purpose of this quantitative study was to identify significant factors that prevented teacher... more The purpose of this quantitative study was to identify significant factors that prevented teachers in Saudi Arabia from using video games in their classroom; and found differences in hindering factors between gender and level of teaching and teaching experience. The results showed that there were five factors that prevented Saudi teachers from using video games in their classroom among 25 categories of reasons. These five factors were "The impact of education video games on student and learning process", "Required times, cost, training, and technical issues of applying educational video games", "Characteristics of educational video games", "Harmonization between the educational video games and teaching", "Unawareness of educational video games".
Applied sciences, Oct 16, 2019
Agent-based model (ABM) simulation is a bottom-up approach that can describe the phenomena genera... more Agent-based model (ABM) simulation is a bottom-up approach that can describe the phenomena generated from actions and interactions within a multiagent system. An ABM is an improvement over model simulations which only describe the global behavior of a system. Therefore, it is an appropriate technology to analyze emergent phenomena in social sciences and complex adaptive systems such as vehicular traffic and pedestrian crowds. In this paper, a hybrid agent-based modeling framework designed to automate decision-making processes during traffic congestion is proposed. The model provides drivers with real-time alternative routes, computed via a decentralized multi-agent model, that tries to achieve a system-optimal traffic distribution within an entire system, thus reducing the total travel time of all the drivers. The presented work explores a decentralized ABM technique on an autonomous microgrid that is represented through cellular automata (CA). The proposed model was applied to high-density traffic congestion events such as car accidents or lane closures, and its effectiveness was analyzed. The experimental results confirm the efficiency of the proposed model in not only accurately simulating the driver behaviors and improving vehicular traffic flows during congestion but also by suggesting changes to traffic dynamics during the simulations, such as avoiding obstacles and high-density areas and then selecting the best alternative routes. The simulation results validate the ability of the proposed model and the included decision-making sub-models to both predict and improve the behaviors and intended actions of the agents.
Hyper-rings are a multi-machine organization that is, in a sense, a generalization of the standar... more Hyper-rings are a multi-machine organization that is, in a sense, a generalization of the standard hyper-cube architecture. One of the most powerful properties of the hyper-rings is that the node-connectivity of an N-HR has been proven to be equal to its degree. This paper discusses hyper-rings, their construction and properties, and an interactive software that allows the user to generate and display hyper-rings of arbitrary size and dimension. The algorithm also finds and displays, under 3D rotations, all node-disjoint shortest paths between any two user-specified nodes.
GetMobile, Nov 14, 2017
in 2009. Her primary research interests are in mobile systems, with emphasis on applying sensing ... more in 2009. Her primary research interests are in mobile systems, with emphasis on applying sensing techniques for mobile health care.
Journal of the American College of Cardiology, Sep 8, 2016
Representative. yWomenHeart Representative. zHealthcare Information and Management Systems Societ... more Representative. yWomenHeart Representative. zHealthcare Information and Management Systems Society (HIMSS) Representative during the writing effort, no longer employed by HIMSS. xHeart Rhythm Society Representative. kAmerican Society of Nuclear Cardiology Representative. {Society of Cardiovascular Angiography and Interventions Representative.
Abstract:A graph G= (V, E) is called a hyper-ring with N nodes (N-HR for short) if
ACM Transactions on Management Information Systems
We develop a similarity measure for medical event sequences (MESs) and empirically evaluate it us... more We develop a similarity measure for medical event sequences (MESs) and empirically evaluate it using U.S. Medicare claims data. Existing similarity measures do not use unique characteristics of MESs and have never been evaluated on real MESs. Our similarity measure, the Optimal Temporal Common Subsequence for Medical Event Sequences (OTCS-MES), provides a matching component that integrates event prevalence, event duplication, and hierarchical coding, important elements of MESs. The OTCS-MES also uses normalization to mitigate the impact of heavy positive skew of matching events and compact distribution of event prevalence. We empirically evaluate the OTCS-MES measure against two other measures specifically designed for MESs, the original OTCS and Artemis, a measure incorporating event alignment. Our evaluation uses two substantial data sets of Medicare claims data containing inpatient and outpatient sequences with different medical event coding. We find a small overlap in nearest neighbors among the three similarity measures, demonstrating the superior design of the OTCS-MES with its emphasis on unique aspects of MESs. The evaluation also provides evidence about the impact of component weights, neighborhood size, and sequence length.
2017 International Conference on Computational Science and Computational Intelligence (CSCI), 2017
The purpose of this quantitative study was to identify significant factors that prevented teacher... more The purpose of this quantitative study was to identify significant factors that prevented teachers in Saudi Arabia from using video games in their classroom; and found differences in hindering factors between gender and level of teaching and teaching experience. The results showed that there were five factors that prevented Saudi teachers from using video games in their classroom among 25 categories of reasons. These five factors were "The impact of education video games on student and learning process", "Required times, cost, training, and technical issues of applying educational video games", "Characteristics of educational video games", "Harmonization between the educational video games and teaching", "Unawareness of educational video games".
2017 International Conference on Computational Science and Computational Intelligence (CSCI), 2017
This paper describes a modified agent-based model (ABM) that simulates crowd behavior within dyna... more This paper describes a modified agent-based model (ABM) that simulates crowd behavior within dynamically changing environments. These include network topology changes, or external stimuli such as explosions, fires, earthquakes, just to name a few. In general, crowd dynamics simulation is relatively difficult to carry out because the behavior-influencing factors may come from within as well as outside of the system. The proposed modeling system employs a hybrid centralized approach (to assist the individual agents with their decision-making) that is based on both the local and/or incomplete/indirect global information.
ACM Transactions on Management Information Systems (TMIS), 2017
We develop a similarity measure for medical event sequences (MESs) and empirically evaluate it us... more We develop a similarity measure for medical event sequences (MESs) and empirically evaluate it using U.S. Medicare claims data. Existing similarity measures do not use unique characteristics of MESs and have never been evaluated on real MESs. Our similarity measure, the Optimal Temporal Common Subsequence for Medical Event Sequences (OTCS-MES), provides a matching component that integrates event prevalence, event duplication, and hierarchical coding, important elements of MESs. The OTCS-MES also uses normalization to mitigate the impact of heavy positive skew of matching events and compact distribution of event prevalence. We empirically evaluate the OTCS-MES measure against two other measures specifically designed for MESs, the original OTCS and Artemis, a measure incorporating event alignment. Our evaluation uses two substantial data sets of Medicare claims data containing inpatient and outpatient sequences with different medical event coding. We find a small overlap in nearest ne...
2017 International Conference on Computational Science and Computational Intelligence (CSCI), 2017
We present a Virtual Ant Laboratory agent-based model, an interactive and prediction tool to simu... more We present a Virtual Ant Laboratory agent-based model, an interactive and prediction tool to simulate the ants' environment and their decisions making and foraging behaviors. The proposed simulation model provides the ability to generate customized complex ant environments and to explore the interaction between the environment features and ants' behavior.As expected, the results showed that the quality of the food and the distance between food sources and the nest have a significant impact on the ants' decisions. The model was partially validated via live-ants laboratory experiments and can easily be generalized to other environments/agents.
A graph G= (V, E) is called a hyper-ring with N nodes (N-HR for short) if V = {0, ..., N-1} and E... more A graph G= (V, E) is called a hyper-ring with N nodes (N-HR for short) if V = {0, ..., N-1} and E = {(u,v)| v-u modulo N is a power of 2}. In other words, a hyper-ring with N nodes is a graph in which all of the edges connect nodes that are at distances of powers of 2 from each other. Hyper-rings are a multi-machine organization that is, in a sense, a generalization of the standard hyper-cube architecture. One of the most powerful properties of the hyper-rings is that the node-connectivity of an N-HR has been proven to be equal to its degree. This paper discusses hyper-rings, their construction and properties, and an interactive software that allows the user to generate and display hyper-rings of arbitrary size and dimension. The algorithm also finds and displays, under 3D rotations, all node-disjoint shortest paths between any two user-specified nodes.
It has been medically proven that one’s sleep quality directly affects his or her personal health... more It has been medically proven that one’s sleep quality directly affects his or her personal health, social behavior, and work effectiveness. Understanding sleep quality, hence, is an important topic and has been attracting a vast amount of research efforts. In addition, with the advent and ever-increasing number of mobile and wearable devices, many attempts have been made towards monitoring one’s sleep using these ubiquitous devices. However, there were none on exploring the complex relationship between sleep quality and sleeping environment. In this paper, we propose mSleepWatcher as an on-going attempt answer the question of "Why didn’t I sleep well?". By mining the environmental sensing information collected by built-in sensors of off-the-shelf mobile and wearable devices in combination with the sleep quality sensing information, a set of causality analysis techniques is adopted and applied to exploit the existence of temporal dependencies between the environment during ...
The agent-based model is a well-established approach to carry out the simulation of crowd behavio... more The agent-based model is a well-established approach to carry out the simulation of crowd behavior under varying conditions and environments. However, this approach still lacks the ability to be fully automated and to take into account the agents' unfamiliarity and minimum awareness in an unknown environment. In this paper, we propose a multi-level multi-stage agent-based modeling framework that automates the decision-making processes during crowd evacuation in large-scale facilities. We demonstrate that crowd behaviors can be modeled at different stages and at several layers. We do this by integrating a probabilistic model with a dynamic generating process of intelligent guide agents to automatically generate decisions that are nearly optimal for neighboring agents. Specifically, we apply the framework to different evacuation scenarios and analyze its effectiveness in case of a high-density crowd. Our experimental results provide evidence that the hybrid multi-layered approach ...
Communications of the ACM