Coskun Bayrak | University of Arkansas at Little Rock (original) (raw)

Papers by Coskun Bayrak

Background This paper presents the Generative Anatomy Modeling Language (GAML) for generating var... more Background This paper presents the Generative Anatomy Modeling Language (GAML) for generating variation of 3D virtual human anatomy in real‐time. This framework provides a set of operators for modification of a reference base 3D anatomy. The perturbation of the 3D models
is satisfied with nonlinear geometry constraints to create an authentic human anatomy.
Methods GAML was used to create 3D difficult anatomical scenarios for virtual simulation of airway management techniques such as Endotracheal Intubation (ETI) and Cricothyroidotomy
(CCT). Difficult scenarios for each technique were defined and the model variations procedurally created with GAML.
Conclusion This study presents details of the GAML design, set of operators, types of constraints.
Cases of CCT and ETI difficulty were generated and confirmed by expert surgeons. Execution performance pertaining to an increasing complexity of constraints using nonlinear programming was in real‐time execution.

Recent studies support the theory that the brain is composed of modules and certain nodes establi... more Recent studies support the theory that the brain is composed of modules and certain nodes establish connections between the modules (Chen et al. , 2008; Ferri et al. , 2008; Meunier et al. , 2009). We provide a new mathematical model for exchange of information between the neural modules at the highest spatial and hierarchical level of bottom-up processes using EEG (ElectroEncephaloGraphy) (Niedermeyer & da Silva , 2005). Borsuk-Ulam's antipodal symmetry theorem is adapted to establish the mathematical model and a comprehensive algorithm called PNT (Transformation, Normaliza-tion, Projection) was developed. EEG data collected from a total of 49 experiments with the participation of 18 different test subjects was used to validate the effectiveness and accuracy of PNT method. Antipodal Con-nector Nodes (ACNs) were defined and compared for resting and active stages of the brain based on the PNT method.

This volume contains the proceedings of the Fourth Colloquium on International Engineering Educat... more This volume contains the proceedings of the Fourth Colloquium on International Engineering Education, which took place in May 20, 2009 at San Diego State University, California. The transatlantic consortium “International Cooperation in Ambient Computing Education”(ICACE) organized the colloquium. More information about ICACE can be obtained from http://icace. dvt. fernuni-hagen. de/.

Data matching rules are normally the result of collective experiences and judgments of subject ma... more Data matching rules are normally the result of collective experiences and judgments of subject matter experts (SMEs). Data matching requires a clearly defined set of rules to both determine a match as well as provide a "usable" ranking between potential matches. The main objectives here are to determine the feasibility of building a trainable matching engine that can help mimic SME behaviors and to assess alternate approaches in terms of ease-of-use, accuracy, and performance. This research attempts to minimize the effort required to develop and test SME-developed rules, thereby eliminating the implementation costs associated with developing products for newer markets.

Information Technology Based Higher Education and Training, 2004

Course management systems (CMS) are an increasingly important part of academic systems in higher ... more Course management systems (CMS) are an increasingly important part of academic systems in higher education. However, they introduce challenges in their deployment especially when the budgets are constrained, and their use becomes more confusing as the numbers of users increases rapidly. Due to the inherent difficulties, these tools, which were once considered to be the promising environments, are entering a

ACM SIGSOFT Software Engineering Notes, 2005

Grid technology is increasingly being looked upon as a natural extension of the internet for enga... more Grid technology is increasingly being looked upon as a natural extension of the internet for engaging in complex data processing tasks over resources which are distributed across the world. Architects and developers employing grid systems must take into consideration security implications. Dynamic generation of virtual organizations leads to a synergistic picture which has to address security requirements never encountered before. Globus toolkit has devised a framework for making secure use of grid resource components which has been proved to be a feasible solution by a number of academic and scientific organizations. This paper is an attempt to identify and discern mechanisms proposed by Globus security model with certain test scenarios [1] .

Open source development (OSD) is a revolutionary new model for software development. Or at least ... more Open source development (OSD) is a revolutionary
new model for software development. Or at least
that’s what many people want us to think. Most of
the growing open source community, which now boasts several corporate sponsored projects such as Netscape’s Mozilla, cites Linux operating system developer Linus Torvalds
as the messiah of this new model. Eric Raymond, in his important paper, “The Cathedral and the Bazaar,” claims that Torvalds’ cleverest and most consequential hack was not the construction of the Linux kernel itself, but rather his quasi-guidance of the Linux development model—a best practice
extraordinaire of OSD [7]. But what is this model
and why does it work? Here, we explore these
questions by examining the OSD model as a classically
defined distributed system.

The development of the World Wide Web over the course of the past ten years has run rampant. The ... more The development of the World Wide Web over the course of the
past ten years has run rampant. The course it has taken has been
both swift and unpredictable. The largest distributed system in the
world began as a utopian notion of an interconnected and open
web of information, the dream of the academic and intellectual
alike. Today it is indeed a massive interconnected web of
communication and content, but the content, largely on the more
popular, if not pornographic, end of the mass media spectrum, is
not what the founders intended.
Coinciding with the rapid growth of the web has been the equally
speedy rise of the open source development community, which
can best be understood as a distributed system in its own right.
Indeed, the development of the web has been, outside of the Linux
project, the largest arena for open source development. And
current trends, witnessed by such significant open source projects
as Mozilla and Apache, seem to suggest that the open source way
of doing things is quickly becoming the web way of doing things.
However, there is a certain tension growing between those who
would like to control, for economic profit or for the gratification of
control itself, the direction of the web's development and those
open source developers who are responsible for a large portion of
that growth. This paper explores the natural relationship, as well
as the growing tension within this relationship, between the open
source development community and the World Wide Web.

Objective: The diagnosis of labor is currently one of the most difficult problems encountered by ... more Objective: The diagnosis of labor is currently one of the most difficult problems encountered by obstetrical healthcare providers. A major
health problem is the increase in the rate of preterm delivery, which is responsible for 75% of all deaths in newborns. In addition, preterm
delivery is associated with several cognitive and health problems in later life and enormous costs for the health system. A better understanding
of myometrial activities could help to reduce preterm deliveries and the costs associated with prematurity in the following years.
Therefore, the objective of this study was to determine whether using the Hilbert–Huang transform (HHT) to analyze the uterine contraction
data would help us gain a better insight of the myometrial activities of the human uterus during pregnancy.
Material and Methods: Uterine magnetomyographic (MMG) signals were recorded from pregnant patients at gestational ages of 32–38
weeks. The study was approved by the Human Research Advisory Board of the University of Arkansas for Medical Sciences (UAMS) and
performed after obtaining written consent from each patient. The recording of transabdominal MMG signals was conducted with the
SQUID Array for Reproductive Assessment (SARA, VSM MedTech Inc; Coquitlam, BC, Canada) system, which has 151 primary magnetic
sensors allocated approximately 3 cm apart over an area of 850 cm2. The arrangement of sensors is concave in nature and, in a similar
lateral distance, spans the maternal abdomen longitudinally from the symphysis pubis to the uterine fundus. The recording times ranged
from 12 to 28 min, and the sampling rate was 250 Hz. The data were down-sampled to 25 Hz to reduce the computational complexity
and post-processed with a bandpass filter (0.05–1 Hz) because the uterine contraction activity is a band-limited process (0.05–1 Hz). The
recordings of one intrauterine pressure catheter (IUPC) dataset and two mother-perceived contraction datasets were compared with the
HHT results, and HHT’s potential was explored through the development of a module and a series of experiments. The local energy and
the instantaneous frequency derived from the intrinsic mode functions (IMFs) through HHT provide a full energy-frequency-time distribution
of the data. Our objective was to determine whether HHT for each channel can help identify and localize contractions in the uterus.
Human studies have been reviewed by the appropriate ethics committee and have therefore been performed in accordance with the
ethical standards described in an appropriate version of the 1975 Declaration of Helsinki, as revised in 2000.
Results: After comparing the IUPC and other mother-perceived contraction (STIM) datasets with HHT results, we were able to visually detect
contraction locations in the HHT-processed uterine signals. For verification and validation purposes, when we further analyzed the delay time
between two signals, the mechanical activity (i.e., IUPC) following the electrical activity (i.e., magnetic signal) was observed. In conclusion, our
experimentations using the method introduced here revealed that there is a 75% correlation between the results obtained by HHT and IUPC data.
Conclusion: This study compared uterine contractions and changes in the intrauterine pressure with results obtained by HHT. In addition,
using IUPC data as a validation guide, we showed that the HHT approach can be used for noise removal. There is a need for time-saving
and non-subjective automatic contraction detection in the field of prenatal examination. (J Turk Ger Gynecol Assoc 2015; 16: 195-202)
Keywords: Uterine contraction, myometrium, magnetomyographic activity, Hilbert–Huang transform, empirical mode decomposition,
contraction analysis

Objective: The diagnosis of labor is currently one of the most difficult problems encountered by ... more Objective: The diagnosis of labor is currently one of the most difficult problems encountered by obstetrical healthcare providers. A major
health problem is the increase in the rate of preterm delivery, which is responsible for 75% of all deaths in newborns. In addition, preterm
delivery is associated with several cognitive and health problems in later life and enormous costs for the health system. A better understanding
of myometrial activities could help to reduce preterm deliveries and the costs associated with prematurity in the following years.
Therefore, the objective of this study was to determine whether using the Hilbert–Huang transform (HHT) to analyze the uterine contraction
data would help us gain a better insight of the myometrial activities of the human uterus during pregnancy.
Material and Methods: Uterine magnetomyographic (MMG) signals were recorded from pregnant patients at gestational ages of 32–38
weeks. The study was approved by the Human Research Advisory Board of the University of Arkansas for Medical Sciences (UAMS) and
performed after obtaining written consent from each patient. The recording of transabdominal MMG signals was conducted with the
SQUID Array for Reproductive Assessment (SARA, VSM MedTech Inc; Coquitlam, BC, Canada) system, which has 151 primary magnetic
sensors allocated approximately 3 cm apart over an area of 850 cm2. The arrangement of sensors is concave in nature and, in a similar
lateral distance, spans the maternal abdomen longitudinally from the symphysis pubis to the uterine fundus. The recording times ranged
from 12 to 28 min, and the sampling rate was 250 Hz. The data were down-sampled to 25 Hz to reduce the computational complexity
and post-processed with a bandpass filter (0.05–1 Hz) because the uterine contraction activity is a band-limited process (0.05–1 Hz). The
recordings of one intrauterine pressure catheter (IUPC) dataset and two mother-perceived contraction datasets were compared with the
HHT results, and HHT’s potential was explored through the development of a module and a series of experiments. The local energy and
the instantaneous frequency derived from the intrinsic mode functions (IMFs) through HHT provide a full energy-frequency-time distribution
of the data. Our objective was to determine whether HHT for each channel can help identify and localize contractions in the uterus.
Human studies have been reviewed by the appropriate ethics committee and have therefore been performed in accordance with the
ethical standards described in an appropriate version of the 1975 Declaration of Helsinki, as revised in 2000.
Results: After comparing the IUPC and other mother-perceived contraction (STIM) datasets with HHT results, we were able to visually detect
contraction locations in the HHT-processed uterine signals. For verification and validation purposes, when we further analyzed the delay time
between two signals, the mechanical activity (i.e., IUPC) following the electrical activity (i.e., magnetic signal) was observed. In conclusion, our
experimentations using the method introduced here revealed that there is a 75% correlation between the results obtained by HHT and IUPC data.
Conclusion: This study compared uterine contractions and changes in the intrauterine pressure with results obtained by HHT. In addition,
using IUPC data as a validation guide, we showed that the HHT approach can be used for noise removal. There is a need for time-saving
and non-subjective automatic contraction detection in the field of prenatal examination. (J Turk Ger Gynecol Assoc 2015; 16: 195-202)
Keywords: Uterine contraction, myometrium, magnetomyographic activity, Hilbert–Huang transform, empirical mode decomposition,
contraction analysis

Efficient utilization of resources has always been a challenge. Especially in a grid infrastructu... more Efficient utilization of resources has always been a challenge. Especially in a grid infrastructure where the number of nodes is comparably higher than a regular network, the status of the resources is continuously changing and hard to keep track of. A predictive approach, where resources’ status is forecasted based on their historical performances, can adapt the dynamicity of the environment. In this study, such an enhancement to the scheduling mechanism is analyzed: the utilization of the various kinds of resources, such as, memory, CPU, network, and IO are periodically monitored and future utilization of resources are predicted based on this historical information. The system employs a feature extraction and neural network combined approach: features are extracted for better accuracy and faster results. Linear, feed-forward, and recurrent networks are analyzed for time series prediction of resource’s performances. Recurrent networks combined with DWT feature extraction process resulted best predictions with good generalization.

Computer Methods and Programs in Biomedicine, 2013

ECoG Granger causality Multi-dimensional Hilbert transformation a b s t r a c t Analysis of direc... more ECoG Granger causality Multi-dimensional Hilbert transformation a b s t r a c t Analysis of directional information flow patterns among different regions of the brain is important for investigating the relation between ECoG (electrocorticographic) and mental activity. The objective is to study and evaluate the information flow activity at different frequencies in the primary motor cortex. We employed Granger causality for capturing the future state of the propagation path and direction between recording electrode sites on the cerebral cortex. A grid covered the right motor cortex completely due to its size (approx. 8 cm × 8 cm) but grid area extends to the surrounding cortex areas. During the experiment, a subject was asked to imagine performing two activities: movement of the left small finger and/or movement of the tongue. The time series of the electrical brain activity was recorded during these trials using an 8 × 8 (0.016-300 Hz band with) ECoG platinum electrode grid, which was placed on the contralateral motor cortex. For detection of information flow activity and communication frequencies among the electrodes, we have proposed a method based on following steps: (i) calculation of analytical time series such as amplitude and phase difference acquired from Hilbert transformation, (ii) selection of frequency having highest interdependence for the electrode pairs for the concerned time series over a sliding window in which we assumed time series were stationary, (iii) calculation of Granger causality values for each pair with selected frequency. The information flow (causal influence) activity and communication frequencies between the electrodes in grid were determined and shown successfully. It is supposed that information flow activity and communication frequencies between the electrodes in the grid are approximately the same for the same pattern. The successful employment of Granger causality and Hilbert transformation for the detection of the propagation path and direction of each component of ECoG among different subcortex areas were capable of determining the information flow (causal influence) activity and communication frequencies between the populations of neurons successfully. 2 c o m p u t e r m e t h o d s a n d p r o g r a m s i n b i o m e d i c i n e x x x ( 2 0 1 3 ) xxx-xxx 1. Please cite this article in press as: R.M. Demirer, et al., Determination of ECoG information flow activity based on Granger causality and Hilbert transformation, Comput. Methods Programs Biomed. (2013), http://dx.-3647; No. of Pages 9 c o m p u t e r m e t h o d s a n d p r o g r a m s i n b i o m e d i c i n e x x x ( 2 0 1 3 ) xxx-xxx Please cite this article in press as: R.M. Demirer, et al., Determination of ECoG information flow activity based on Granger causality and Hilbert transformation, Comput. Methods Programs Biomed. (2013), http://dx.-3647; No. of Pages 9 c o m p u t e r m e t h o d s a n d p r o g r a m s i n b i o m e d i c i n e x x x ( 2 0 1 3 ) xxx-xxx 9 A.3. Choice of model order

Journal of Neuroscience Methods, 2009

The study presented in this paper shows that electrocorticographic (ECoG) signals can be classifi... more The study presented in this paper shows that electrocorticographic (ECoG) signals can be classified for making use of a human brain-computer interface (BCI) field. The results show that certain invariant phase transition features can be reliably used to classify two types of imagined movements accurately. Those are the left small-finger and tongue movements. Our approach consists of two main parts: channel selection based on Tsallis entropy in Hilbert domain and the nonlinear classification of motor imagery with support vector machines (SVMs). The new approach, based on Hilbert and statistical/entropy measurements, were combined with SVMs based on admissible kernels for classification purposes. The classification accuracy rates were 95% (264/278) and 73% (73/100) for training and testing sets, respectively. The results support the use of classification methods for ECoG-based BCIs.

Proceedings of the 46th Annual Southeast Regional Conference on XX - ACM-SE 46, 2008

The vast accumulation of unstructured data within various types of documents in recent years has ... more The vast accumulation of unstructured data within various types of documents in recent years has escalated the need for more efficient and effective management of available data. An effective tool for unstructured data management can vastly benefit business enterprises as well as support the understanding of volumes of scientific data in academic and scholarly works. This paper presents a simple

Journal of Integrated Design and Process Science

ABSTRACT

In general, monitoring is an essential process to observe and improve the reliability and perform... more In general, monitoring is an essential process to observe and improve the reliability and performance of a system. The same hypothesis is also true for a specific distributed system introduced in this study in the form of monitoring and control.

Journal of Integrated Design and Process Science

ABSTRACT

Internet technology allows companies and individuals to overcome many of the physical constraints... more Internet technology allows companies and individuals to overcome many of the physical constraints that often prevent them interacting from a distant. In the past several years, communication using data, audio, and video applications has become increasingly popular to overcome this burden. These applications help people to control/view their remote systems and to share ideas between employees and colleagues as if being in the same environment. In this study, an environment composed of video streaming, audio/text conferencing, and the local to remote user data transfer is implemented. This java based environment is capable of handling the text messaging, data transmission, and audio session initiation (ASI) that launches Robust Audio Tool (RAT) for audio conferencing between selected users. In order to stream video, a video capture card with two cameras is used.

Background This paper presents the Generative Anatomy Modeling Language (GAML) for generating var... more Background This paper presents the Generative Anatomy Modeling Language (GAML) for generating variation of 3D virtual human anatomy in real‐time. This framework provides a set of operators for modification of a reference base 3D anatomy. The perturbation of the 3D models
is satisfied with nonlinear geometry constraints to create an authentic human anatomy.
Methods GAML was used to create 3D difficult anatomical scenarios for virtual simulation of airway management techniques such as Endotracheal Intubation (ETI) and Cricothyroidotomy
(CCT). Difficult scenarios for each technique were defined and the model variations procedurally created with GAML.
Conclusion This study presents details of the GAML design, set of operators, types of constraints.
Cases of CCT and ETI difficulty were generated and confirmed by expert surgeons. Execution performance pertaining to an increasing complexity of constraints using nonlinear programming was in real‐time execution.

Recent studies support the theory that the brain is composed of modules and certain nodes establi... more Recent studies support the theory that the brain is composed of modules and certain nodes establish connections between the modules (Chen et al. , 2008; Ferri et al. , 2008; Meunier et al. , 2009). We provide a new mathematical model for exchange of information between the neural modules at the highest spatial and hierarchical level of bottom-up processes using EEG (ElectroEncephaloGraphy) (Niedermeyer & da Silva , 2005). Borsuk-Ulam's antipodal symmetry theorem is adapted to establish the mathematical model and a comprehensive algorithm called PNT (Transformation, Normaliza-tion, Projection) was developed. EEG data collected from a total of 49 experiments with the participation of 18 different test subjects was used to validate the effectiveness and accuracy of PNT method. Antipodal Con-nector Nodes (ACNs) were defined and compared for resting and active stages of the brain based on the PNT method.

This volume contains the proceedings of the Fourth Colloquium on International Engineering Educat... more This volume contains the proceedings of the Fourth Colloquium on International Engineering Education, which took place in May 20, 2009 at San Diego State University, California. The transatlantic consortium “International Cooperation in Ambient Computing Education”(ICACE) organized the colloquium. More information about ICACE can be obtained from http://icace. dvt. fernuni-hagen. de/.

Data matching rules are normally the result of collective experiences and judgments of subject ma... more Data matching rules are normally the result of collective experiences and judgments of subject matter experts (SMEs). Data matching requires a clearly defined set of rules to both determine a match as well as provide a "usable" ranking between potential matches. The main objectives here are to determine the feasibility of building a trainable matching engine that can help mimic SME behaviors and to assess alternate approaches in terms of ease-of-use, accuracy, and performance. This research attempts to minimize the effort required to develop and test SME-developed rules, thereby eliminating the implementation costs associated with developing products for newer markets.

Information Technology Based Higher Education and Training, 2004

Course management systems (CMS) are an increasingly important part of academic systems in higher ... more Course management systems (CMS) are an increasingly important part of academic systems in higher education. However, they introduce challenges in their deployment especially when the budgets are constrained, and their use becomes more confusing as the numbers of users increases rapidly. Due to the inherent difficulties, these tools, which were once considered to be the promising environments, are entering a

ACM SIGSOFT Software Engineering Notes, 2005

Grid technology is increasingly being looked upon as a natural extension of the internet for enga... more Grid technology is increasingly being looked upon as a natural extension of the internet for engaging in complex data processing tasks over resources which are distributed across the world. Architects and developers employing grid systems must take into consideration security implications. Dynamic generation of virtual organizations leads to a synergistic picture which has to address security requirements never encountered before. Globus toolkit has devised a framework for making secure use of grid resource components which has been proved to be a feasible solution by a number of academic and scientific organizations. This paper is an attempt to identify and discern mechanisms proposed by Globus security model with certain test scenarios [1] .

Open source development (OSD) is a revolutionary new model for software development. Or at least ... more Open source development (OSD) is a revolutionary
new model for software development. Or at least
that’s what many people want us to think. Most of
the growing open source community, which now boasts several corporate sponsored projects such as Netscape’s Mozilla, cites Linux operating system developer Linus Torvalds
as the messiah of this new model. Eric Raymond, in his important paper, “The Cathedral and the Bazaar,” claims that Torvalds’ cleverest and most consequential hack was not the construction of the Linux kernel itself, but rather his quasi-guidance of the Linux development model—a best practice
extraordinaire of OSD [7]. But what is this model
and why does it work? Here, we explore these
questions by examining the OSD model as a classically
defined distributed system.

The development of the World Wide Web over the course of the past ten years has run rampant. The ... more The development of the World Wide Web over the course of the
past ten years has run rampant. The course it has taken has been
both swift and unpredictable. The largest distributed system in the
world began as a utopian notion of an interconnected and open
web of information, the dream of the academic and intellectual
alike. Today it is indeed a massive interconnected web of
communication and content, but the content, largely on the more
popular, if not pornographic, end of the mass media spectrum, is
not what the founders intended.
Coinciding with the rapid growth of the web has been the equally
speedy rise of the open source development community, which
can best be understood as a distributed system in its own right.
Indeed, the development of the web has been, outside of the Linux
project, the largest arena for open source development. And
current trends, witnessed by such significant open source projects
as Mozilla and Apache, seem to suggest that the open source way
of doing things is quickly becoming the web way of doing things.
However, there is a certain tension growing between those who
would like to control, for economic profit or for the gratification of
control itself, the direction of the web's development and those
open source developers who are responsible for a large portion of
that growth. This paper explores the natural relationship, as well
as the growing tension within this relationship, between the open
source development community and the World Wide Web.

Objective: The diagnosis of labor is currently one of the most difficult problems encountered by ... more Objective: The diagnosis of labor is currently one of the most difficult problems encountered by obstetrical healthcare providers. A major
health problem is the increase in the rate of preterm delivery, which is responsible for 75% of all deaths in newborns. In addition, preterm
delivery is associated with several cognitive and health problems in later life and enormous costs for the health system. A better understanding
of myometrial activities could help to reduce preterm deliveries and the costs associated with prematurity in the following years.
Therefore, the objective of this study was to determine whether using the Hilbert–Huang transform (HHT) to analyze the uterine contraction
data would help us gain a better insight of the myometrial activities of the human uterus during pregnancy.
Material and Methods: Uterine magnetomyographic (MMG) signals were recorded from pregnant patients at gestational ages of 32–38
weeks. The study was approved by the Human Research Advisory Board of the University of Arkansas for Medical Sciences (UAMS) and
performed after obtaining written consent from each patient. The recording of transabdominal MMG signals was conducted with the
SQUID Array for Reproductive Assessment (SARA, VSM MedTech Inc; Coquitlam, BC, Canada) system, which has 151 primary magnetic
sensors allocated approximately 3 cm apart over an area of 850 cm2. The arrangement of sensors is concave in nature and, in a similar
lateral distance, spans the maternal abdomen longitudinally from the symphysis pubis to the uterine fundus. The recording times ranged
from 12 to 28 min, and the sampling rate was 250 Hz. The data were down-sampled to 25 Hz to reduce the computational complexity
and post-processed with a bandpass filter (0.05–1 Hz) because the uterine contraction activity is a band-limited process (0.05–1 Hz). The
recordings of one intrauterine pressure catheter (IUPC) dataset and two mother-perceived contraction datasets were compared with the
HHT results, and HHT’s potential was explored through the development of a module and a series of experiments. The local energy and
the instantaneous frequency derived from the intrinsic mode functions (IMFs) through HHT provide a full energy-frequency-time distribution
of the data. Our objective was to determine whether HHT for each channel can help identify and localize contractions in the uterus.
Human studies have been reviewed by the appropriate ethics committee and have therefore been performed in accordance with the
ethical standards described in an appropriate version of the 1975 Declaration of Helsinki, as revised in 2000.
Results: After comparing the IUPC and other mother-perceived contraction (STIM) datasets with HHT results, we were able to visually detect
contraction locations in the HHT-processed uterine signals. For verification and validation purposes, when we further analyzed the delay time
between two signals, the mechanical activity (i.e., IUPC) following the electrical activity (i.e., magnetic signal) was observed. In conclusion, our
experimentations using the method introduced here revealed that there is a 75% correlation between the results obtained by HHT and IUPC data.
Conclusion: This study compared uterine contractions and changes in the intrauterine pressure with results obtained by HHT. In addition,
using IUPC data as a validation guide, we showed that the HHT approach can be used for noise removal. There is a need for time-saving
and non-subjective automatic contraction detection in the field of prenatal examination. (J Turk Ger Gynecol Assoc 2015; 16: 195-202)
Keywords: Uterine contraction, myometrium, magnetomyographic activity, Hilbert–Huang transform, empirical mode decomposition,
contraction analysis

Objective: The diagnosis of labor is currently one of the most difficult problems encountered by ... more Objective: The diagnosis of labor is currently one of the most difficult problems encountered by obstetrical healthcare providers. A major
health problem is the increase in the rate of preterm delivery, which is responsible for 75% of all deaths in newborns. In addition, preterm
delivery is associated with several cognitive and health problems in later life and enormous costs for the health system. A better understanding
of myometrial activities could help to reduce preterm deliveries and the costs associated with prematurity in the following years.
Therefore, the objective of this study was to determine whether using the Hilbert–Huang transform (HHT) to analyze the uterine contraction
data would help us gain a better insight of the myometrial activities of the human uterus during pregnancy.
Material and Methods: Uterine magnetomyographic (MMG) signals were recorded from pregnant patients at gestational ages of 32–38
weeks. The study was approved by the Human Research Advisory Board of the University of Arkansas for Medical Sciences (UAMS) and
performed after obtaining written consent from each patient. The recording of transabdominal MMG signals was conducted with the
SQUID Array for Reproductive Assessment (SARA, VSM MedTech Inc; Coquitlam, BC, Canada) system, which has 151 primary magnetic
sensors allocated approximately 3 cm apart over an area of 850 cm2. The arrangement of sensors is concave in nature and, in a similar
lateral distance, spans the maternal abdomen longitudinally from the symphysis pubis to the uterine fundus. The recording times ranged
from 12 to 28 min, and the sampling rate was 250 Hz. The data were down-sampled to 25 Hz to reduce the computational complexity
and post-processed with a bandpass filter (0.05–1 Hz) because the uterine contraction activity is a band-limited process (0.05–1 Hz). The
recordings of one intrauterine pressure catheter (IUPC) dataset and two mother-perceived contraction datasets were compared with the
HHT results, and HHT’s potential was explored through the development of a module and a series of experiments. The local energy and
the instantaneous frequency derived from the intrinsic mode functions (IMFs) through HHT provide a full energy-frequency-time distribution
of the data. Our objective was to determine whether HHT for each channel can help identify and localize contractions in the uterus.
Human studies have been reviewed by the appropriate ethics committee and have therefore been performed in accordance with the
ethical standards described in an appropriate version of the 1975 Declaration of Helsinki, as revised in 2000.
Results: After comparing the IUPC and other mother-perceived contraction (STIM) datasets with HHT results, we were able to visually detect
contraction locations in the HHT-processed uterine signals. For verification and validation purposes, when we further analyzed the delay time
between two signals, the mechanical activity (i.e., IUPC) following the electrical activity (i.e., magnetic signal) was observed. In conclusion, our
experimentations using the method introduced here revealed that there is a 75% correlation between the results obtained by HHT and IUPC data.
Conclusion: This study compared uterine contractions and changes in the intrauterine pressure with results obtained by HHT. In addition,
using IUPC data as a validation guide, we showed that the HHT approach can be used for noise removal. There is a need for time-saving
and non-subjective automatic contraction detection in the field of prenatal examination. (J Turk Ger Gynecol Assoc 2015; 16: 195-202)
Keywords: Uterine contraction, myometrium, magnetomyographic activity, Hilbert–Huang transform, empirical mode decomposition,
contraction analysis

Efficient utilization of resources has always been a challenge. Especially in a grid infrastructu... more Efficient utilization of resources has always been a challenge. Especially in a grid infrastructure where the number of nodes is comparably higher than a regular network, the status of the resources is continuously changing and hard to keep track of. A predictive approach, where resources’ status is forecasted based on their historical performances, can adapt the dynamicity of the environment. In this study, such an enhancement to the scheduling mechanism is analyzed: the utilization of the various kinds of resources, such as, memory, CPU, network, and IO are periodically monitored and future utilization of resources are predicted based on this historical information. The system employs a feature extraction and neural network combined approach: features are extracted for better accuracy and faster results. Linear, feed-forward, and recurrent networks are analyzed for time series prediction of resource’s performances. Recurrent networks combined with DWT feature extraction process resulted best predictions with good generalization.

Computer Methods and Programs in Biomedicine, 2013

ECoG Granger causality Multi-dimensional Hilbert transformation a b s t r a c t Analysis of direc... more ECoG Granger causality Multi-dimensional Hilbert transformation a b s t r a c t Analysis of directional information flow patterns among different regions of the brain is important for investigating the relation between ECoG (electrocorticographic) and mental activity. The objective is to study and evaluate the information flow activity at different frequencies in the primary motor cortex. We employed Granger causality for capturing the future state of the propagation path and direction between recording electrode sites on the cerebral cortex. A grid covered the right motor cortex completely due to its size (approx. 8 cm × 8 cm) but grid area extends to the surrounding cortex areas. During the experiment, a subject was asked to imagine performing two activities: movement of the left small finger and/or movement of the tongue. The time series of the electrical brain activity was recorded during these trials using an 8 × 8 (0.016-300 Hz band with) ECoG platinum electrode grid, which was placed on the contralateral motor cortex. For detection of information flow activity and communication frequencies among the electrodes, we have proposed a method based on following steps: (i) calculation of analytical time series such as amplitude and phase difference acquired from Hilbert transformation, (ii) selection of frequency having highest interdependence for the electrode pairs for the concerned time series over a sliding window in which we assumed time series were stationary, (iii) calculation of Granger causality values for each pair with selected frequency. The information flow (causal influence) activity and communication frequencies between the electrodes in grid were determined and shown successfully. It is supposed that information flow activity and communication frequencies between the electrodes in the grid are approximately the same for the same pattern. The successful employment of Granger causality and Hilbert transformation for the detection of the propagation path and direction of each component of ECoG among different subcortex areas were capable of determining the information flow (causal influence) activity and communication frequencies between the populations of neurons successfully. 2 c o m p u t e r m e t h o d s a n d p r o g r a m s i n b i o m e d i c i n e x x x ( 2 0 1 3 ) xxx-xxx 1. Please cite this article in press as: R.M. Demirer, et al., Determination of ECoG information flow activity based on Granger causality and Hilbert transformation, Comput. Methods Programs Biomed. (2013), http://dx.-3647; No. of Pages 9 c o m p u t e r m e t h o d s a n d p r o g r a m s i n b i o m e d i c i n e x x x ( 2 0 1 3 ) xxx-xxx Please cite this article in press as: R.M. Demirer, et al., Determination of ECoG information flow activity based on Granger causality and Hilbert transformation, Comput. Methods Programs Biomed. (2013), http://dx.-3647; No. of Pages 9 c o m p u t e r m e t h o d s a n d p r o g r a m s i n b i o m e d i c i n e x x x ( 2 0 1 3 ) xxx-xxx 9 A.3. Choice of model order

Journal of Neuroscience Methods, 2009

The study presented in this paper shows that electrocorticographic (ECoG) signals can be classifi... more The study presented in this paper shows that electrocorticographic (ECoG) signals can be classified for making use of a human brain-computer interface (BCI) field. The results show that certain invariant phase transition features can be reliably used to classify two types of imagined movements accurately. Those are the left small-finger and tongue movements. Our approach consists of two main parts: channel selection based on Tsallis entropy in Hilbert domain and the nonlinear classification of motor imagery with support vector machines (SVMs). The new approach, based on Hilbert and statistical/entropy measurements, were combined with SVMs based on admissible kernels for classification purposes. The classification accuracy rates were 95% (264/278) and 73% (73/100) for training and testing sets, respectively. The results support the use of classification methods for ECoG-based BCIs.

Proceedings of the 46th Annual Southeast Regional Conference on XX - ACM-SE 46, 2008

The vast accumulation of unstructured data within various types of documents in recent years has ... more The vast accumulation of unstructured data within various types of documents in recent years has escalated the need for more efficient and effective management of available data. An effective tool for unstructured data management can vastly benefit business enterprises as well as support the understanding of volumes of scientific data in academic and scholarly works. This paper presents a simple

Journal of Integrated Design and Process Science

ABSTRACT

In general, monitoring is an essential process to observe and improve the reliability and perform... more In general, monitoring is an essential process to observe and improve the reliability and performance of a system. The same hypothesis is also true for a specific distributed system introduced in this study in the form of monitoring and control.

Journal of Integrated Design and Process Science

ABSTRACT

Internet technology allows companies and individuals to overcome many of the physical constraints... more Internet technology allows companies and individuals to overcome many of the physical constraints that often prevent them interacting from a distant. In the past several years, communication using data, audio, and video applications has become increasingly popular to overcome this burden. These applications help people to control/view their remote systems and to share ideas between employees and colleagues as if being in the same environment. In this study, an environment composed of video streaming, audio/text conferencing, and the local to remote user data transfer is implemented. This java based environment is capable of handling the text messaging, data transmission, and audio session initiation (ASI) that launches Robust Audio Tool (RAT) for audio conferencing between selected users. In order to stream video, a video capture card with two cameras is used.