Michael Feng - Academia.edu (original) (raw)

Papers by Michael Feng

Research paper thumbnail of Long-term bowel dysfunction and decision regret in diverticulitis: A mixed methods study

Surgery

Background: This study had aimed to describe long-term decision regret, bowel dysfunction, and th... more Background: This study had aimed to describe long-term decision regret, bowel dysfunction, and the overall quality of life in patients with diverticulitis, and to determine if elective colectomy was associated with these patient-reported outcome measures. Methods: This mixed-methods, survey-based study was administered to a national cohort of patients in the United States with diverticulitis. We measured decision regret (Brehaut Decision Regret), bowel dysfunction (Low Anterior Resection Syndrome score), and the overall quality of life (EuroQol 5 Dimension) in this population. We asked open-ended questions to elucidate factors that influenced patients' choices between elective colectomy and observation. Results: Among the 614 respondents, 294 (48%) chose between colectomy and observational management, 94 (15%) had surgery, and 157 (26%) had major Low Anterior Resection Syndrome. Of the 294 that chose between colectomy and observational management, 51 (17%) experienced decision regret. Colectomy was associated with an average decrease in the Brehaut Decision Regret score by 6 points but was not associated with a categorical measure of decision regret (Brehaut Score ≥50). Bowel dysfunction and overall quality of life were not significantly associated with colectomy. Disease-related factors, psychosocial factors, and interactions with physicians were commonly cited as reasons for pursuing colectomy or observational management. Conclusion: Patients with self-reported diverticulitis describe high levels of decision regret and bowel dysfunction regardless of chosen management strategy. Physicians should be aware that psychosocial factors can strongly influence a patient's choice between colectomy and observational management. We advocated for future prospective studies using patient reported outcome metrics to improve outcomes in diverticulitis.

Research paper thumbnail of Approved drugs ezetimibe and disulfiram enhance mitochondrial Ca 2+ uptake and suppress cardiac arrhythmogenesis

British Journal of Pharmacology, 2021

Treatment of cardiac arrhythmia remains challenging due to severe side effects of common anti‐arr... more Treatment of cardiac arrhythmia remains challenging due to severe side effects of common anti‐arrhythmic drugs. We previously demonstrated that mitochondrial Ca2+ uptake in cardiomyocytes represents a promising new candidate structure for safer drug therapy. However, druggable agonists of mitochondrial Ca2+ uptake suitable for preclinical and clinical studies are still missing.

Research paper thumbnail of Visual Discovery at Pinterest

Proceedings of the 26th International Conference on World Wide Web Companion - WWW '17 Companion, 2017

Over the past three years Pinterest has experimented with several visual search and recommendatio... more Over the past three years Pinterest has experimented with several visual search and recommendation services, including Related Pins (2014), Similar Looks (2015), Flashlight (2016) and Lens (2017). This paper presents an overview of our visual discovery engine powering these services, and shares the rationales behind our technical and product decisions such as the use of object detection and interactive user interfaces. We conclude that this visual discovery engine significantly improves engagement in both search and recommendation tasks.

Research paper thumbnail of Evaluation of Wound Photography for Remote Postoperative Assessment of Surgical Site Infections

JAMA surgery, Jan 24, 2018

Surgeons are increasingly interested in using mobile and online applications with wound photograp... more Surgeons are increasingly interested in using mobile and online applications with wound photography to monitor patients after surgery. Early work using remote care to diagnose surgical site infections (SSIs) demonstrated improved diagnostic accuracy using wound photographs to augment patients' electronic reports of symptoms, but it is unclear whether these findings are reproducible in real-world practice. To determine how wound photography affects surgeons' abilities to diagnose SSIs in a pragmatic setting. This prospective study compared surgeons' paired assessments of postabdominal surgery case vignettes with vs without wound photography for detection of SSIs. Data for case vignettes were collected prospectively from May 1, 2007, to January 31, 2009, at Erasmus University Medical Center, Rotterdam, the Netherlands, and from July 1, 2015, to February 29, 2016, at Vanderbilt University Medical Center, Nashville, Tennessee. The surgeons were members of the American Medica...

Research paper thumbnail of Ethyl 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-1,2,3,4-tetrahydro-2-isoquinolinecarboxylate

Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 1981

The compound is related to papaverine, a major alkaloid of Papaver somniferum.

Research paper thumbnail of Using Quality Improvement Principles to Enhance Long-Term Completion of Patient Reported Outcomes after Ventral Hernia Repair

Journal of the American College of Surgeons, Jan 20, 2016

Ventral hernia repair (VHR) is a commonly performed surgical procedure. Unfortunately, long term ... more Ventral hernia repair (VHR) is a commonly performed surgical procedure. Unfortunately, long term prospective information about quality of life and outcomes after VHR has been challenging to obtain. Decoupling follow up from clinical visits via patient reported outcomes (PROs) has been proposed as a means of achieving better long term assessments after VHR. The Americas Hernia Society Quality Collaborative (AHSQC) is a national quality improvement (QI) effort in hernia repair which uses PROs to obtain long term follow up. However, the modality of PRO engagement to maximize participation has not been well established. A formal QI initiative was undertaken to determine if long term PRO follow up could be increased at a single AHSQC site by adding telephone communication to email communication for long term postoperative VHR assessment. Between September 2015 and July 2016, the long term (greater than 1 year) AHSQC PRO completion rates after VHR at our institution were analyzed using Pl...

Research paper thumbnail of Interpreting site survey data in a 3D world

Offshore, 2011

Properly interpreting site survey data prior to deploying an offshore oil rig always has been cru... more Properly interpreting site survey data prior to deploying an offshore oil rig always has been crucial to drilling exploration or production wells.

Research paper thumbnail of Robotic-Assisted Simultaneous Repair of Bilateral Inguinal Hernias During Robotic Prostatectomy: A Case Report

American Journal of Robotic Surgery, 2015

Robotic surgery has been implemented worldwide in general surgery, urology surgery, and gynecolog... more Robotic surgery has been implemented worldwide in general surgery, urology surgery, and gynecology surgery. However, the high cost and longer surgical times have deterred many surgeons from the utilization of this platform for shorter, routine cases, such as cholecystectomy, appendectomy and inguinal hernia repair. While performing a robotic assisted laparoscopic prostatectomy (RALP) on a patient with concurrent symptomatic bilateral inguinal hernia, it was determined it would be more efficient to approach this problem robotically rather than laparoscopically. It would have been an inefficient use of time to undock the robot and convert to a conventional laparoscopic approach. When compared to traditional laparoscopy, the learning curve for robotic assisted laparoscopy is much flatter making it much easier to adopt this technology for a concurrent procedure with urology, both prostate and inguinal hernia repair.

Research paper thumbnail of Hierarchical pipelined distributed scheduling traffic manager

Research paper thumbnail of Dynamic Behavior of Electronic Module Spring Clips, Retention Bar, and Backplane Connector: Modeling and Testing

Volume 5: Electronics and Photonics, 2009

Electronic modules for a guidance system are mounted in a rack with spring clips resisting motion... more Electronic modules for a guidance system are mounted in a rack with spring clips resisting motion normal to the printed wiring board (PWB) and an aluminum bar with an elastomer pad keeping the module connected to a backplane. The elastomer pad also resists motion normal to the board. The proper boundary conditions for the spring clips, retention bar, and connector are needed in a finite element model in order to evaluate the shock and vibration transmitted to the module’s electrical components. The finite element model of the module was assembled, and an actual module was tested under random vibration and a 1g sine sweep. The printed wiring board elastic modulus was artificially set higher in the FEM than a measured value to account for the stiffening effect of board components which were omitted from the model. By also choosing the proper boundary conditions to represent the spring clips, retention bars, and backplane connection, the finite element model was able to match the first...

Research paper thumbnail of The Energy Impact of Faults in U.S. Commercial Buildings

Many buildings have a wide range of faults that increase energy consumption, but the national ene... more Many buildings have a wide range of faults that increase energy consumption, but the national energy impact of specific faults has yet to be quantified. This paper reports the preliminary results of a study to quantify the national energy impact of building faults. Based on a detailed literature review, the authors identified thirteen key faults and developed bottom-up energy impact ranges for each. The key faults are estimated to increase commercial building annual energy consumption by between 0.35 and 1.7 quads (0.4 and 1.8 Exajoules [EJ]). This equals between 4% and 18% of the sum of commercial building HVAC, lighting, and refrigeration energy consumption and is consistent with the typical range of energy waste reported in building commissioning studies. Two faults, "Lights or HVAC Left on When Space Unoccupied" and "Duct Leakage", account for at least half of the estimated energy impact. Due to data limitations, the faults have large energy impact ranges, particularly controls-related faults.

Research paper thumbnail of Experimental evaluation of an adaptive tomographic inversion method

38th Aerospace Sciences Meeting and Exhibit, 2000

Research paper thumbnail of Evaluation of new tomographic inversion method applied to jet flows

36th AIAA Aerospace Sciences Meeting and Exhibit, 1998

Tomographic reconstruction using a KarhunenLoeve basis(termed TRKB) is being performed on three n... more Tomographic reconstruction using a KarhunenLoeve basis(termed TRKB) is being performed on three non-reacting, methane-argon jets surrounded by a co-flow of air. The Karhunen-Loeve(K-L) procedure uses a training set, several scalar distributions obtained prior to employing TRKB, to produce basis functions. These basis functions are ideally suited for a finite series solution of the distribution to be reconstructed because for a specified number of terms in the series solution they give the most accurate reconstruction than any other set of basis functions. The jets are located at different heights from each other and are arbitrarily placed in the measurement plane. This represents an increase in flow complexity from previous research at Cornell University. The objective is to attempt tomographic reconstructions on methane concentration distributions with significant gradients. The training set necessary for the TRKB method is created with probe sampling measurements. The resultant K-L basis functions are efficient in reconstructin g distributions in the training set, i.e. as few as 42 line-of-sight laser absorption measurements and six K-L basis functions are required for adequate reconstruction. Problems that were encountered are nonlinear optical instrumentation and low measurement resolution. The reconstructed distributions show the robustness of the TRKB method and its usefulness in diagnostic or monitoring applications.

Research paper thumbnail of Energy Efficiency in Optical IP Networks with Multi-Layer Switching

Optical Fiber Communication Conference/National Fiber Optic Engineers Conference 2011, 2011

With the continuous growth of traffic in Internet Protocol (IP) networks, the issue of energy con... more With the continuous growth of traffic in Internet Protocol (IP) networks, the issue of energy consumption in these networks has been growing in importance. A number of papers in the literature have focused on developing estimates for energy consumption in IP networks and proposing ...

Research paper thumbnail of Dynamic Analysis to Confirm Lead Failure of a 352-Pin CQFP Under Shock

Volume 5: Electronics and Photonics, 2009

During qualification testing of an electronics module, several leads in one corner of a 352 pin c... more During qualification testing of an electronics module, several leads in one corner of a 352 pin ceramic quad flat pack (CQFP) component failed. The module was exposed to several different environments including sine vibration, thermal cycling, random vibration, and shock. The last test environment applied was seven consecutive shocks normal to the printed wiring board. Given the severity of the shock response spectrum, it was believed that the shocks normal to the board were the culprit. Therefore, a finite element model (FEM) was created of the module to diagnose the cause of the failure. The FEM modeled all 352 CQFP leads using quadratic beam elements. Besides the CQFP, the FEM also included the aluminum frame, the printed wiring board, and several adjacent components. It was validated by comparing the board’s mode frequencies and shapes computed in ANSYS to those imaged by optoelectronic holography on the test hardware. ANSYS was also used to rule out sine vibration, random vibra...

Research paper thumbnail of Electronics Packaging to Isolate MEMS Sensors From Thermal Transients

Volume 4: Electronics and Photonics, 2010

This paper describes a methodology for passive thermal management of a microelectromechanical sys... more This paper describes a methodology for passive thermal management of a microelectromechanical system (MEMS) sensor. The MEMS sensor has a temperature rate dependence that must be minimized while the system containing the sensor experiences thermal transients from a cold power-up. A multi-step packaging concept has been developed to manage the thermal transient at the MEMS sensor. The strategy minimizes heat flow to the sensor through use of thin, high thermal resistance kovar leads and an insulating air gap between sensor and electronics. The thermal mass of the sensor assembly is increased with minimal increases in weight and volume by mounting the sensor on a high heat capacity beryllium block. Lastly, a commercial off-the-shelf (COTS) heat sink diverts as much of the heat dissipation into the ambient air as possible. This paper describes the practical implementation of these concepts. This includes the soldering of the leads to the board, the mounting of the component onto the block, and the positioning of the block relative to the frame. This paper also presents a lumped parameter thermal analysis of the packaging. The analysis predicted a maximum dT/dt of 0.4K/minute where dT/dt is the temporal derivative of the MEMS sensor temperature. Test data validating the model is also presented.Copyright © 2010 by ASME

Research paper thumbnail of Energy efficiency of optical IP protocol suites

National Fiber Optic Engineers Conference, 2012

ABSTRACT An energy efficiency metric is defined for network node protocol suites. The metric is u... more ABSTRACT An energy efficiency metric is defined for network node protocol suites. The metric is used to provide a comparison of several common suites. Certain protocol suite implementations incur a significant energy efficiency penalty.

Research paper thumbnail of A Self Configuring and Self Administrating Name System with Dynamic Address Assignment

SSRN Electronic Journal, 2001

A distributed system that stores name-to-address bindings and provides name resolution to a netwo... more A distributed system that stores name-to-address bindings and provides name resolution to a network of computers is presented in this paper. This name system consists of a network of name services that are individually self-configuring and self-administering. The name service consists of an agent program that works in conjunction with the current implementation of the Domain Name System (DNS). The DNS agent program automatically configures a Berkeley Internet Name Domain (BIND) process during start up and dynamically reconfigures and administers the BIND process based on the changing state of the network. The proposed name system offers high scalability and fault-tolerance capabilities and communicates using standard Internet protocols.

Research paper thumbnail of Laser tomographic reconstruction in a complex concentration flow field

37th Aerospace Sciences Meeting and Exhibit, 1999

Research paper thumbnail of Middle States Geographer - Vol. 28. 1995 Spatial Statistical Modeling of Explicit and Implicit Determinants of Regional Fertility Rates - a Case Study of He-Nan Province, China

This paper attempts to use spatial statistical techniques to simultaneously model effects of expl... more This paper attempts to use spatial statistical techniques to simultaneously model effects of explicit and implicit fertility determinant variables. Explicit variables refer to those whose values may be measured and indeed are computed at various levels of surveys, and implicit variables refer to those whose values may not be collected in such a manner. I contend that implicit variables may be analyzed by spatial statistical methods when they possess three characteristics: tll The causal relationship between such implicit variables and their response variable is established through theory; [2] the objects these implicit variables act on may be collectively measured as relatively homogeneous areal units, and their effects are generally measurable, although it may not be immediately separable from the effects of explicit variables; and, [3] the mechanism by which these variables take effect consists of either human groups responding simultaneously to a common source, or interacting with each other. In other words, the effects of such variables may be found either as a spatial trend, or as spatial correlation and autocorrelation.

Research paper thumbnail of Long-term bowel dysfunction and decision regret in diverticulitis: A mixed methods study

Surgery

Background: This study had aimed to describe long-term decision regret, bowel dysfunction, and th... more Background: This study had aimed to describe long-term decision regret, bowel dysfunction, and the overall quality of life in patients with diverticulitis, and to determine if elective colectomy was associated with these patient-reported outcome measures. Methods: This mixed-methods, survey-based study was administered to a national cohort of patients in the United States with diverticulitis. We measured decision regret (Brehaut Decision Regret), bowel dysfunction (Low Anterior Resection Syndrome score), and the overall quality of life (EuroQol 5 Dimension) in this population. We asked open-ended questions to elucidate factors that influenced patients' choices between elective colectomy and observation. Results: Among the 614 respondents, 294 (48%) chose between colectomy and observational management, 94 (15%) had surgery, and 157 (26%) had major Low Anterior Resection Syndrome. Of the 294 that chose between colectomy and observational management, 51 (17%) experienced decision regret. Colectomy was associated with an average decrease in the Brehaut Decision Regret score by 6 points but was not associated with a categorical measure of decision regret (Brehaut Score ≥50). Bowel dysfunction and overall quality of life were not significantly associated with colectomy. Disease-related factors, psychosocial factors, and interactions with physicians were commonly cited as reasons for pursuing colectomy or observational management. Conclusion: Patients with self-reported diverticulitis describe high levels of decision regret and bowel dysfunction regardless of chosen management strategy. Physicians should be aware that psychosocial factors can strongly influence a patient's choice between colectomy and observational management. We advocated for future prospective studies using patient reported outcome metrics to improve outcomes in diverticulitis.

Research paper thumbnail of Approved drugs ezetimibe and disulfiram enhance mitochondrial Ca 2+ uptake and suppress cardiac arrhythmogenesis

British Journal of Pharmacology, 2021

Treatment of cardiac arrhythmia remains challenging due to severe side effects of common anti‐arr... more Treatment of cardiac arrhythmia remains challenging due to severe side effects of common anti‐arrhythmic drugs. We previously demonstrated that mitochondrial Ca2+ uptake in cardiomyocytes represents a promising new candidate structure for safer drug therapy. However, druggable agonists of mitochondrial Ca2+ uptake suitable for preclinical and clinical studies are still missing.

Research paper thumbnail of Visual Discovery at Pinterest

Proceedings of the 26th International Conference on World Wide Web Companion - WWW '17 Companion, 2017

Over the past three years Pinterest has experimented with several visual search and recommendatio... more Over the past three years Pinterest has experimented with several visual search and recommendation services, including Related Pins (2014), Similar Looks (2015), Flashlight (2016) and Lens (2017). This paper presents an overview of our visual discovery engine powering these services, and shares the rationales behind our technical and product decisions such as the use of object detection and interactive user interfaces. We conclude that this visual discovery engine significantly improves engagement in both search and recommendation tasks.

Research paper thumbnail of Evaluation of Wound Photography for Remote Postoperative Assessment of Surgical Site Infections

JAMA surgery, Jan 24, 2018

Surgeons are increasingly interested in using mobile and online applications with wound photograp... more Surgeons are increasingly interested in using mobile and online applications with wound photography to monitor patients after surgery. Early work using remote care to diagnose surgical site infections (SSIs) demonstrated improved diagnostic accuracy using wound photographs to augment patients' electronic reports of symptoms, but it is unclear whether these findings are reproducible in real-world practice. To determine how wound photography affects surgeons' abilities to diagnose SSIs in a pragmatic setting. This prospective study compared surgeons' paired assessments of postabdominal surgery case vignettes with vs without wound photography for detection of SSIs. Data for case vignettes were collected prospectively from May 1, 2007, to January 31, 2009, at Erasmus University Medical Center, Rotterdam, the Netherlands, and from July 1, 2015, to February 29, 2016, at Vanderbilt University Medical Center, Nashville, Tennessee. The surgeons were members of the American Medica...

Research paper thumbnail of Ethyl 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-1,2,3,4-tetrahydro-2-isoquinolinecarboxylate

Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 1981

The compound is related to papaverine, a major alkaloid of Papaver somniferum.

Research paper thumbnail of Using Quality Improvement Principles to Enhance Long-Term Completion of Patient Reported Outcomes after Ventral Hernia Repair

Journal of the American College of Surgeons, Jan 20, 2016

Ventral hernia repair (VHR) is a commonly performed surgical procedure. Unfortunately, long term ... more Ventral hernia repair (VHR) is a commonly performed surgical procedure. Unfortunately, long term prospective information about quality of life and outcomes after VHR has been challenging to obtain. Decoupling follow up from clinical visits via patient reported outcomes (PROs) has been proposed as a means of achieving better long term assessments after VHR. The Americas Hernia Society Quality Collaborative (AHSQC) is a national quality improvement (QI) effort in hernia repair which uses PROs to obtain long term follow up. However, the modality of PRO engagement to maximize participation has not been well established. A formal QI initiative was undertaken to determine if long term PRO follow up could be increased at a single AHSQC site by adding telephone communication to email communication for long term postoperative VHR assessment. Between September 2015 and July 2016, the long term (greater than 1 year) AHSQC PRO completion rates after VHR at our institution were analyzed using Pl...

Research paper thumbnail of Interpreting site survey data in a 3D world

Offshore, 2011

Properly interpreting site survey data prior to deploying an offshore oil rig always has been cru... more Properly interpreting site survey data prior to deploying an offshore oil rig always has been crucial to drilling exploration or production wells.

Research paper thumbnail of Robotic-Assisted Simultaneous Repair of Bilateral Inguinal Hernias During Robotic Prostatectomy: A Case Report

American Journal of Robotic Surgery, 2015

Robotic surgery has been implemented worldwide in general surgery, urology surgery, and gynecolog... more Robotic surgery has been implemented worldwide in general surgery, urology surgery, and gynecology surgery. However, the high cost and longer surgical times have deterred many surgeons from the utilization of this platform for shorter, routine cases, such as cholecystectomy, appendectomy and inguinal hernia repair. While performing a robotic assisted laparoscopic prostatectomy (RALP) on a patient with concurrent symptomatic bilateral inguinal hernia, it was determined it would be more efficient to approach this problem robotically rather than laparoscopically. It would have been an inefficient use of time to undock the robot and convert to a conventional laparoscopic approach. When compared to traditional laparoscopy, the learning curve for robotic assisted laparoscopy is much flatter making it much easier to adopt this technology for a concurrent procedure with urology, both prostate and inguinal hernia repair.

Research paper thumbnail of Hierarchical pipelined distributed scheduling traffic manager

Research paper thumbnail of Dynamic Behavior of Electronic Module Spring Clips, Retention Bar, and Backplane Connector: Modeling and Testing

Volume 5: Electronics and Photonics, 2009

Electronic modules for a guidance system are mounted in a rack with spring clips resisting motion... more Electronic modules for a guidance system are mounted in a rack with spring clips resisting motion normal to the printed wiring board (PWB) and an aluminum bar with an elastomer pad keeping the module connected to a backplane. The elastomer pad also resists motion normal to the board. The proper boundary conditions for the spring clips, retention bar, and connector are needed in a finite element model in order to evaluate the shock and vibration transmitted to the module’s electrical components. The finite element model of the module was assembled, and an actual module was tested under random vibration and a 1g sine sweep. The printed wiring board elastic modulus was artificially set higher in the FEM than a measured value to account for the stiffening effect of board components which were omitted from the model. By also choosing the proper boundary conditions to represent the spring clips, retention bars, and backplane connection, the finite element model was able to match the first...

Research paper thumbnail of The Energy Impact of Faults in U.S. Commercial Buildings

Many buildings have a wide range of faults that increase energy consumption, but the national ene... more Many buildings have a wide range of faults that increase energy consumption, but the national energy impact of specific faults has yet to be quantified. This paper reports the preliminary results of a study to quantify the national energy impact of building faults. Based on a detailed literature review, the authors identified thirteen key faults and developed bottom-up energy impact ranges for each. The key faults are estimated to increase commercial building annual energy consumption by between 0.35 and 1.7 quads (0.4 and 1.8 Exajoules [EJ]). This equals between 4% and 18% of the sum of commercial building HVAC, lighting, and refrigeration energy consumption and is consistent with the typical range of energy waste reported in building commissioning studies. Two faults, "Lights or HVAC Left on When Space Unoccupied" and "Duct Leakage", account for at least half of the estimated energy impact. Due to data limitations, the faults have large energy impact ranges, particularly controls-related faults.

Research paper thumbnail of Experimental evaluation of an adaptive tomographic inversion method

38th Aerospace Sciences Meeting and Exhibit, 2000

Research paper thumbnail of Evaluation of new tomographic inversion method applied to jet flows

36th AIAA Aerospace Sciences Meeting and Exhibit, 1998

Tomographic reconstruction using a KarhunenLoeve basis(termed TRKB) is being performed on three n... more Tomographic reconstruction using a KarhunenLoeve basis(termed TRKB) is being performed on three non-reacting, methane-argon jets surrounded by a co-flow of air. The Karhunen-Loeve(K-L) procedure uses a training set, several scalar distributions obtained prior to employing TRKB, to produce basis functions. These basis functions are ideally suited for a finite series solution of the distribution to be reconstructed because for a specified number of terms in the series solution they give the most accurate reconstruction than any other set of basis functions. The jets are located at different heights from each other and are arbitrarily placed in the measurement plane. This represents an increase in flow complexity from previous research at Cornell University. The objective is to attempt tomographic reconstructions on methane concentration distributions with significant gradients. The training set necessary for the TRKB method is created with probe sampling measurements. The resultant K-L basis functions are efficient in reconstructin g distributions in the training set, i.e. as few as 42 line-of-sight laser absorption measurements and six K-L basis functions are required for adequate reconstruction. Problems that were encountered are nonlinear optical instrumentation and low measurement resolution. The reconstructed distributions show the robustness of the TRKB method and its usefulness in diagnostic or monitoring applications.

Research paper thumbnail of Energy Efficiency in Optical IP Networks with Multi-Layer Switching

Optical Fiber Communication Conference/National Fiber Optic Engineers Conference 2011, 2011

With the continuous growth of traffic in Internet Protocol (IP) networks, the issue of energy con... more With the continuous growth of traffic in Internet Protocol (IP) networks, the issue of energy consumption in these networks has been growing in importance. A number of papers in the literature have focused on developing estimates for energy consumption in IP networks and proposing ...

Research paper thumbnail of Dynamic Analysis to Confirm Lead Failure of a 352-Pin CQFP Under Shock

Volume 5: Electronics and Photonics, 2009

During qualification testing of an electronics module, several leads in one corner of a 352 pin c... more During qualification testing of an electronics module, several leads in one corner of a 352 pin ceramic quad flat pack (CQFP) component failed. The module was exposed to several different environments including sine vibration, thermal cycling, random vibration, and shock. The last test environment applied was seven consecutive shocks normal to the printed wiring board. Given the severity of the shock response spectrum, it was believed that the shocks normal to the board were the culprit. Therefore, a finite element model (FEM) was created of the module to diagnose the cause of the failure. The FEM modeled all 352 CQFP leads using quadratic beam elements. Besides the CQFP, the FEM also included the aluminum frame, the printed wiring board, and several adjacent components. It was validated by comparing the board’s mode frequencies and shapes computed in ANSYS to those imaged by optoelectronic holography on the test hardware. ANSYS was also used to rule out sine vibration, random vibra...

Research paper thumbnail of Electronics Packaging to Isolate MEMS Sensors From Thermal Transients

Volume 4: Electronics and Photonics, 2010

This paper describes a methodology for passive thermal management of a microelectromechanical sys... more This paper describes a methodology for passive thermal management of a microelectromechanical system (MEMS) sensor. The MEMS sensor has a temperature rate dependence that must be minimized while the system containing the sensor experiences thermal transients from a cold power-up. A multi-step packaging concept has been developed to manage the thermal transient at the MEMS sensor. The strategy minimizes heat flow to the sensor through use of thin, high thermal resistance kovar leads and an insulating air gap between sensor and electronics. The thermal mass of the sensor assembly is increased with minimal increases in weight and volume by mounting the sensor on a high heat capacity beryllium block. Lastly, a commercial off-the-shelf (COTS) heat sink diverts as much of the heat dissipation into the ambient air as possible. This paper describes the practical implementation of these concepts. This includes the soldering of the leads to the board, the mounting of the component onto the block, and the positioning of the block relative to the frame. This paper also presents a lumped parameter thermal analysis of the packaging. The analysis predicted a maximum dT/dt of 0.4K/minute where dT/dt is the temporal derivative of the MEMS sensor temperature. Test data validating the model is also presented.Copyright © 2010 by ASME

Research paper thumbnail of Energy efficiency of optical IP protocol suites

National Fiber Optic Engineers Conference, 2012

ABSTRACT An energy efficiency metric is defined for network node protocol suites. The metric is u... more ABSTRACT An energy efficiency metric is defined for network node protocol suites. The metric is used to provide a comparison of several common suites. Certain protocol suite implementations incur a significant energy efficiency penalty.

Research paper thumbnail of A Self Configuring and Self Administrating Name System with Dynamic Address Assignment

SSRN Electronic Journal, 2001

A distributed system that stores name-to-address bindings and provides name resolution to a netwo... more A distributed system that stores name-to-address bindings and provides name resolution to a network of computers is presented in this paper. This name system consists of a network of name services that are individually self-configuring and self-administering. The name service consists of an agent program that works in conjunction with the current implementation of the Domain Name System (DNS). The DNS agent program automatically configures a Berkeley Internet Name Domain (BIND) process during start up and dynamically reconfigures and administers the BIND process based on the changing state of the network. The proposed name system offers high scalability and fault-tolerance capabilities and communicates using standard Internet protocols.

Research paper thumbnail of Laser tomographic reconstruction in a complex concentration flow field

37th Aerospace Sciences Meeting and Exhibit, 1999

Research paper thumbnail of Middle States Geographer - Vol. 28. 1995 Spatial Statistical Modeling of Explicit and Implicit Determinants of Regional Fertility Rates - a Case Study of He-Nan Province, China

This paper attempts to use spatial statistical techniques to simultaneously model effects of expl... more This paper attempts to use spatial statistical techniques to simultaneously model effects of explicit and implicit fertility determinant variables. Explicit variables refer to those whose values may be measured and indeed are computed at various levels of surveys, and implicit variables refer to those whose values may not be collected in such a manner. I contend that implicit variables may be analyzed by spatial statistical methods when they possess three characteristics: tll The causal relationship between such implicit variables and their response variable is established through theory; [2] the objects these implicit variables act on may be collectively measured as relatively homogeneous areal units, and their effects are generally measurable, although it may not be immediately separable from the effects of explicit variables; and, [3] the mechanism by which these variables take effect consists of either human groups responding simultaneously to a common source, or interacting with each other. In other words, the effects of such variables may be found either as a spatial trend, or as spatial correlation and autocorrelation.