Yehia Khalil | University of Louisville, KY (original) (raw)

Papers by Yehia Khalil

ISCA 20th International Conference on Parallel …, 2007

Dried bittersweet root bark is combined with crystalline zinc chloride to form a salve which is t... more Dried bittersweet root bark is combined with crystalline zinc chloride to form a salve which is topically applied to remove unwanted growths from the skin. The salve comprises an admixture of a major volumetric proportion of root bark with a minor volumetric proportion of zinc chloride crystals.

More businesses are utilizing employee wellness programs to improve the health of their employees... more More businesses are utilizing employee wellness programs to improve the health of their employees (improve productivity levels, reduce absenteeism and reduce disability claims) while reducing health care costs. The success of any wellness program depends on three main rudiments: 1) identifying factors that driving up the healthcare cost within the organization such as: smoking, diabetes, back pain, or other chronic conditions. 2) Engagement level of employees in the wellness programs 3) Barriers to achieving expected engagement level. The real challenge for any wellness program is to incorporate data from different e.g. Health Risk Assessment (HRA), demographics, medical claims data, and qualitative input to build a comprehensive wellness program which incorporates the needs of the business population. Promoting health and wellness is a process, so it requires ongoing evaluation and monitoring to ensure employee satisfaction, and to ensure it is meeting the needs of employer along w...

Journal of Neurosurgery: Spine, 2021

OBJECTIVEIn the future, payers may not cover unplanned 90-day emergency room (ER) visits or readm... more OBJECTIVEIn the future, payers may not cover unplanned 90-day emergency room (ER) visits or readmissions after elective lumbar spine surgery. Prior studies using large administrative databases lack granularity and/or use a proxy for actual cost. The purpose of this study was to identify risk factors and subsequent costs associated with 90-day ER visits and readmissions after elective lumbar spine surgery.METHODSA prospective, multisurgeon, single-center electronic medical record was queried for elective lumbar spine fusion surgeries from 2013 to 2017. Predictive models were created for 90-day ER visits and readmissions.RESULTSOf 5444 patients, 729 (13%) returned to the ER, most often for pain (n = 213, 29%). Predictors of an ER visit were prior ER visit (OR 2.5), underserved zip code (OR 1.4), and number of chronic medical conditions (OR 1.4). In total, 421 (8%) patients were readmitted, most frequently for wound infection (n = 123, 2%), exacerbation of chronic obstructive pulmonary...

Journal of Hospital Administration, 2015

Objective: To describe the initial outcomes of an incentive driven medical home and navigation pr... more Objective: To describe the initial outcomes of an incentive driven medical home and navigation program on preventive services among healthcare system employees. Methods: Quasi-experimental design examining participation, use of preventive services and adherence to medical guidelines and emergency room use in a five hospital integrated health system. Employees were required to complete a health risk assessment (HRA), visit a Primary Care Provider (PCP) and submit PCP visit screening and biometric results in order to be eligible for the financial incentives. Subsidized lifestyle change intervention and navigation programs were also offered to participants. Descriptive statistics and Chi Square were used to analyze results for the 5,435 employee participants and 3,623 non-participants during thee 1-year intervention. Results: Preventive care visits for participants increased by 35% compared to an increase of 3% for non-participants. Nonadherence to medical guidelines decreased 7% for participants and increased 18% for non-participants. Inappropriate emergency room use overall decreased from 20% to 14%. Conclusions: One year after introduction of the wellness program, preventive visits increased, compliance with medical care increased and inappropriate emergency room visits were reduced.

ISSPIT 2007 - 2007 IEEE International Symposium on Signal Processing and Information Technology, 2007

The traffic behavior of the University of Louisville network with the interconnected backbone rou... more The traffic behavior of the University of Louisville network with the interconnected backbone routers and the number of Virtual Local Area Network (VLAN) subnets is investigated using the Random Matrix Theory (RMT) approach. We employ the system of equal interval time series of traffic counts at all router to router and router to subnet connections as a representation of the inter-domain traffic. The cross-correlation matrix C of the real and simulated traffic rate changes between different traffic time series is calculated and tested against null- hypothesis of random interactions. The majority of the eigenvalues lambdai of matrix C fall within the bounds predicted by the RMT for the eigenvalues of random correlation matrices. The inverse participation ratio (IPR) of congested traffic shows the higher level of localization (fewer number of randomly interacting network nodes). In other words, the IPR level signifies the start of congestion or correlated traffic. Hence, the RMT based model for multiple input multiple output (MIMO) system widely accepted in wireless communication domain is quite applicable for analysis and modeling of traffic dynamics of wired systems. In particular, the IPR of the RMT predicted boundaries in real traffic can be used as a congestion indicator in network congestion control mechanisms.

Conference Proceedings - IEEE SOUTHEASTCON, 2007

ABSTRACT

2010 IEEE International Symposium on Signal Processing and Information Technology, ISSPIT 2010, 2011

ABSTRACT

2008 IEEE Symposium on Computers and Communications, 2008

Data centers (DC) suffer from an increasing number of threats; these are exaggerated by the incre... more Data centers (DC) suffer from an increasing number of threats; these are exaggerated by the incredible growth of critical data volumes in addition to vulnerabilities in technologies used for distributed architectures. This paper demonstrates the need to define a new metric for ldquoresilience levelrdquo to complement other system metrics such as performance, availability, robustness and fault tolerance. In addition, ldquodata centerrdquo resiliencepsilas evaluation framework and its advantages are presented.

Disclosed herein is a molten metal sampler made from cast mold halves which are preassembled in a... more Disclosed herein is a molten metal sampler made from cast mold halves which are preassembled in a paperboard sleeve which is filled with sand-resin mix, which is then baked. The sampler is provided with windows on one sample cavity which are provided with metal plates which form the sides for sample mold and provide smooth sides for the sample. Various thickness plates can be employed to fit within the windows. The sampler is also provided with a bath thermocouple and a liquidus arrest thermocouple. The sample formed has a thick disc portion suitable for spectrographic analysis and a wafer portion suitable for punching for gas analysis.

The focus of this study is to develop predictive models to forecast future Asthma hospitalization... more The focus of this study is to develop predictive models to forecast future Asthma hospitalizations for patients diagnosed with Asthma. Using SAS® Software tools such as predictive models provides great benefit to insurance companies, hospitals, and pharmaceutical companies trying to manage their resources and define future plans and policies. The strength areas of predictive modeling are: a) an ability to incorporate any type of variable into the analysis, b) Dynamic, as they can easily accommodate any information as they become available to adjust the model accordingly. A recent study shows that around 21 million Americans are diagnosed with asthma, which represents a large section of the insurance and pharmaceutical patient population. Asthma patients are classified into two groups: Controlled vs. Uncontrolled asthma; however, during the year 2000, the national surveys show that there were nine million physician office visits and more than 900,000 hospitalization cases in addition...

Operational continuity of data centers faces * What is the status of the secondary data center ch... more Operational continuity of data centers faces * What is the status of the secondary data center challenges by experienced cyber attackers and occasional and its ability to maintain clients requests? natural disasters. Assessment of a data center's resilience for complex and realistic scenarios is very important for For test-bed designing and implementation, it is various reasons such as: system specification, design and important to have a clear image for data center enhancement. Yet data center resilience evaluation is a resilience evaluation process, which can be demanding process because of the complexity of its elucidating by using the graphical visualization systems and the multidimensional aspects required for a scheme for structuring and visualizing (Delta chart resilient system. This paper illustrates data center resilience template). [3] Figure one show implementation of evaluation test-bed and its monitoring system. This test-bed Delta chart on data center resilience. can provide a realistic testing environment and capable to implement multiple operating and attacking scenarios.

Current information systems face many challenges in terms of malicious activities, hacking threat... more Current information systems face many challenges in terms of malicious activities, hacking threats and natural disasters. A key challenge is to design a resilient communication networks that can provide high performance level with minimum disconnected points and delay. This paper presents a novel approach to discover the most critical network's nodes based on social network analysis (SNA) which have been used for social studies and recently have been widely used in many domains. The main focus of social network analysis is to study the "relations" between network nodes. In principle, critical network's nodes will be identified based on their magnitude for the network in terms of centrality: Degree, Betweens and Closeness. The results show that using social network analysis enhances computer network resilience by identifying the critical elements of communication network.

2008 IEEE Symposium on Computers and Communications, 2008

Data centers (DC) suffer from an increasing number of threats; these are exaggerated by the incre... more Data centers (DC) suffer from an increasing number of threats; these are exaggerated by the incredible growth of critical data volumes in addition to vulnerabilities in technologies used for distributed architectures. This paper demonstrates the need to define a new metric for ldquoresilience levelrdquo to complement other system metrics such as performance, availability, robustness and fault tolerance. In addition, ldquodata centerrdquo resiliencepsilas evaluation framework and its advantages are presented.

ISCA 20th International Conference on Parallel …, 2007

Dried bittersweet root bark is combined with crystalline zinc chloride to form a salve which is t... more Dried bittersweet root bark is combined with crystalline zinc chloride to form a salve which is topically applied to remove unwanted growths from the skin. The salve comprises an admixture of a major volumetric proportion of root bark with a minor volumetric proportion of zinc chloride crystals.

More businesses are utilizing employee wellness programs to improve the health of their employees... more More businesses are utilizing employee wellness programs to improve the health of their employees (improve productivity levels, reduce absenteeism and reduce disability claims) while reducing health care costs. The success of any wellness program depends on three main rudiments: 1) identifying factors that driving up the healthcare cost within the organization such as: smoking, diabetes, back pain, or other chronic conditions. 2) Engagement level of employees in the wellness programs 3) Barriers to achieving expected engagement level. The real challenge for any wellness program is to incorporate data from different e.g. Health Risk Assessment (HRA), demographics, medical claims data, and qualitative input to build a comprehensive wellness program which incorporates the needs of the business population. Promoting health and wellness is a process, so it requires ongoing evaluation and monitoring to ensure employee satisfaction, and to ensure it is meeting the needs of employer along w...

Journal of Neurosurgery: Spine, 2021

OBJECTIVEIn the future, payers may not cover unplanned 90-day emergency room (ER) visits or readm... more OBJECTIVEIn the future, payers may not cover unplanned 90-day emergency room (ER) visits or readmissions after elective lumbar spine surgery. Prior studies using large administrative databases lack granularity and/or use a proxy for actual cost. The purpose of this study was to identify risk factors and subsequent costs associated with 90-day ER visits and readmissions after elective lumbar spine surgery.METHODSA prospective, multisurgeon, single-center electronic medical record was queried for elective lumbar spine fusion surgeries from 2013 to 2017. Predictive models were created for 90-day ER visits and readmissions.RESULTSOf 5444 patients, 729 (13%) returned to the ER, most often for pain (n = 213, 29%). Predictors of an ER visit were prior ER visit (OR 2.5), underserved zip code (OR 1.4), and number of chronic medical conditions (OR 1.4). In total, 421 (8%) patients were readmitted, most frequently for wound infection (n = 123, 2%), exacerbation of chronic obstructive pulmonary...

Journal of Hospital Administration, 2015

Objective: To describe the initial outcomes of an incentive driven medical home and navigation pr... more Objective: To describe the initial outcomes of an incentive driven medical home and navigation program on preventive services among healthcare system employees. Methods: Quasi-experimental design examining participation, use of preventive services and adherence to medical guidelines and emergency room use in a five hospital integrated health system. Employees were required to complete a health risk assessment (HRA), visit a Primary Care Provider (PCP) and submit PCP visit screening and biometric results in order to be eligible for the financial incentives. Subsidized lifestyle change intervention and navigation programs were also offered to participants. Descriptive statistics and Chi Square were used to analyze results for the 5,435 employee participants and 3,623 non-participants during thee 1-year intervention. Results: Preventive care visits for participants increased by 35% compared to an increase of 3% for non-participants. Nonadherence to medical guidelines decreased 7% for participants and increased 18% for non-participants. Inappropriate emergency room use overall decreased from 20% to 14%. Conclusions: One year after introduction of the wellness program, preventive visits increased, compliance with medical care increased and inappropriate emergency room visits were reduced.

ISSPIT 2007 - 2007 IEEE International Symposium on Signal Processing and Information Technology, 2007

The traffic behavior of the University of Louisville network with the interconnected backbone rou... more The traffic behavior of the University of Louisville network with the interconnected backbone routers and the number of Virtual Local Area Network (VLAN) subnets is investigated using the Random Matrix Theory (RMT) approach. We employ the system of equal interval time series of traffic counts at all router to router and router to subnet connections as a representation of the inter-domain traffic. The cross-correlation matrix C of the real and simulated traffic rate changes between different traffic time series is calculated and tested against null- hypothesis of random interactions. The majority of the eigenvalues lambdai of matrix C fall within the bounds predicted by the RMT for the eigenvalues of random correlation matrices. The inverse participation ratio (IPR) of congested traffic shows the higher level of localization (fewer number of randomly interacting network nodes). In other words, the IPR level signifies the start of congestion or correlated traffic. Hence, the RMT based model for multiple input multiple output (MIMO) system widely accepted in wireless communication domain is quite applicable for analysis and modeling of traffic dynamics of wired systems. In particular, the IPR of the RMT predicted boundaries in real traffic can be used as a congestion indicator in network congestion control mechanisms.

Conference Proceedings - IEEE SOUTHEASTCON, 2007

ABSTRACT

2010 IEEE International Symposium on Signal Processing and Information Technology, ISSPIT 2010, 2011

ABSTRACT

2008 IEEE Symposium on Computers and Communications, 2008

Data centers (DC) suffer from an increasing number of threats; these are exaggerated by the incre... more Data centers (DC) suffer from an increasing number of threats; these are exaggerated by the incredible growth of critical data volumes in addition to vulnerabilities in technologies used for distributed architectures. This paper demonstrates the need to define a new metric for ldquoresilience levelrdquo to complement other system metrics such as performance, availability, robustness and fault tolerance. In addition, ldquodata centerrdquo resiliencepsilas evaluation framework and its advantages are presented.

Disclosed herein is a molten metal sampler made from cast mold halves which are preassembled in a... more Disclosed herein is a molten metal sampler made from cast mold halves which are preassembled in a paperboard sleeve which is filled with sand-resin mix, which is then baked. The sampler is provided with windows on one sample cavity which are provided with metal plates which form the sides for sample mold and provide smooth sides for the sample. Various thickness plates can be employed to fit within the windows. The sampler is also provided with a bath thermocouple and a liquidus arrest thermocouple. The sample formed has a thick disc portion suitable for spectrographic analysis and a wafer portion suitable for punching for gas analysis.

The focus of this study is to develop predictive models to forecast future Asthma hospitalization... more The focus of this study is to develop predictive models to forecast future Asthma hospitalizations for patients diagnosed with Asthma. Using SAS® Software tools such as predictive models provides great benefit to insurance companies, hospitals, and pharmaceutical companies trying to manage their resources and define future plans and policies. The strength areas of predictive modeling are: a) an ability to incorporate any type of variable into the analysis, b) Dynamic, as they can easily accommodate any information as they become available to adjust the model accordingly. A recent study shows that around 21 million Americans are diagnosed with asthma, which represents a large section of the insurance and pharmaceutical patient population. Asthma patients are classified into two groups: Controlled vs. Uncontrolled asthma; however, during the year 2000, the national surveys show that there were nine million physician office visits and more than 900,000 hospitalization cases in addition...

Operational continuity of data centers faces * What is the status of the secondary data center ch... more Operational continuity of data centers faces * What is the status of the secondary data center challenges by experienced cyber attackers and occasional and its ability to maintain clients requests? natural disasters. Assessment of a data center's resilience for complex and realistic scenarios is very important for For test-bed designing and implementation, it is various reasons such as: system specification, design and important to have a clear image for data center enhancement. Yet data center resilience evaluation is a resilience evaluation process, which can be demanding process because of the complexity of its elucidating by using the graphical visualization systems and the multidimensional aspects required for a scheme for structuring and visualizing (Delta chart resilient system. This paper illustrates data center resilience template). [3] Figure one show implementation of evaluation test-bed and its monitoring system. This test-bed Delta chart on data center resilience. can provide a realistic testing environment and capable to implement multiple operating and attacking scenarios.

Current information systems face many challenges in terms of malicious activities, hacking threat... more Current information systems face many challenges in terms of malicious activities, hacking threats and natural disasters. A key challenge is to design a resilient communication networks that can provide high performance level with minimum disconnected points and delay. This paper presents a novel approach to discover the most critical network's nodes based on social network analysis (SNA) which have been used for social studies and recently have been widely used in many domains. The main focus of social network analysis is to study the "relations" between network nodes. In principle, critical network's nodes will be identified based on their magnitude for the network in terms of centrality: Degree, Betweens and Closeness. The results show that using social network analysis enhances computer network resilience by identifying the critical elements of communication network.

2008 IEEE Symposium on Computers and Communications, 2008

Data centers (DC) suffer from an increasing number of threats; these are exaggerated by the incre... more Data centers (DC) suffer from an increasing number of threats; these are exaggerated by the incredible growth of critical data volumes in addition to vulnerabilities in technologies used for distributed architectures. This paper demonstrates the need to define a new metric for ldquoresilience levelrdquo to complement other system metrics such as performance, availability, robustness and fault tolerance. In addition, ldquodata centerrdquo resiliencepsilas evaluation framework and its advantages are presented.