john joseph | Salem university lokoja (original) (raw)

Papers by john joseph

Ecological Modelling, 2022

Understanding the impacts of anthropogenic sound on marine mammals is important for effective mit... more Understanding the impacts of anthropogenic sound on marine mammals is important for effective mitigation and management. Sound impacts can cause behavioral changes that lead to displacement from preferred habitat and can have negative influence on vital rates. Here, we develop a movement model to better understand and simulate how whales respond to anthropogenic sound over ecologically meaningful space and time scales. The stochastic model is based on a sequential Monte Carlo sampler (a particle filter). The movement model takes account of vertical dive information and is influenced by the underwater soundscape and the historical whale distribution in the region. In the absence of noise disturbance, the simulator is shown to recover the historical whale distribution in the region. When noise disturbance is incorporated, the whale's behavioral response is determined through a dose-response function dependent on the received level of sound. The aggregate impact is assessed by considering both the duration of foraging loss and the spatial shift to alternate (and potentially less favorable) habitat. Persistence of the behavioral response in time is treated through a 'disruption' parameter. We apply the approach to a population of fin whales whose distribution overlaps naval sonar testing activities beside the Southern California range complex. The simulation shows the consequences of one year of naval sonar disturbance are a function of: i) how loud the sound source is, ii) where the disturbed whales are relative to preferred (high density) habitat, and iii) how long a whale takes before returning to a pre-disturbance state. The movement simulator developed here is a generic movement modeling tool that can be adapted for different species, different regions, and any acoustic disturbances with known impacts on animal populations.

Frontiers in Marine Science, 2021

Soundscapes offer rich descriptions of composite acoustic environments. Characterizing marine sou... more Soundscapes offer rich descriptions of composite acoustic environments. Characterizing marine soundscapes simply through sound levels results in incomplete descriptions, limits the understanding of unique features, and impedes meaningful comparisons. Sources that contribute to sound level metrics shift in time and space with changes in biological patterns, physical forces, and human activity. The presence of a constant or chronic source is often interwoven with episodic sounds. Further, the presence and intensity of sources can influence other sources, calling for a more integrated approach to characterizing soundscapes. Here, we illustrate this complexity using data from a national-scale effort, the Sanctuary Soundscape Monitoring Project (SanctSound), an initiative designed to support collection of biological, environmental, and human use data to compliment the interpretation of sound level measurements. Using nine examples from this diverse dataset we demonstrate the benefit of i...

Frontiers in Marine Science, 2021

Low-frequency sound from large vessels is a major, global source of ocean noise that can interfer... more Low-frequency sound from large vessels is a major, global source of ocean noise that can interfere with acoustic communication for a variety of marine animals. Changes in vessel activity provide opportunities to quantify relationships between vessel traffic levels and soundscape conditions in biologically important habitats. Using continuous deep-sea (890 m) recordings acquired ∼20 km (closest point of approach) from offshore shipping lanes, we observed reduction of low-frequency noise within Monterey Bay National Marine Sanctuary (California, United States) associated with changes in vessel traffic during the onset of the COVID-19 pandemic. Acoustic modeling shows that the recording site receives low-frequency vessel noise primarily from the regional shipping lanes rather than via the Sound Fixing and Ranging (SOFAR) channel. Monthly geometric means and percentiles of spectrum levels in the one-third octave band centered at 63 Hz during 2020 were compared with those from the same m...

Current Biology, 2020

Animal-Borne Metrics Enable Acoustic Detection of Blue Whale Migration Highlights d Acoustic moni... more Animal-Borne Metrics Enable Acoustic Detection of Blue Whale Migration Highlights d Acoustic monitoring reveals patterns in population-level blue whale song production d Tag-derived metrics provide behavioral context for distinct diel patterns in song d When integrated, tag and acoustic metrics reveal an acoustic signature of migration d Key to discerning timing, plasticity, and drivers of a dispersed migration

Frontiers in Marine Science, 2020

Anthropogenic noise has been recognized as a threat to marine mammals for decades, making it a ce... more Anthropogenic noise has been recognized as a threat to marine mammals for decades, making it a central issue for their conservation and management (Tougaard et al., 2015; National Marine Fisheries Service, 2016; Southall et al., 2019). For many marine mammals, hearing is the primary sensory modality, important for navigation, foraging, predator avoidance, and communication (Tyack, 1986). Noise can be considered as any sound that has the potential to interfere with normal functioning of auditory processes or cause harmful behavioral or physiological responses. Potential impacts of noise include interruption of essential behaviors (Wisniewska et al., 2018), masking

PLOS ONE, 2019

This study examines the occurrence of humpback whale (Megaptera novaeangliae) song in the northea... more This study examines the occurrence of humpback whale (Megaptera novaeangliae) song in the northeast Pacific from three years of continuous recordings off central California (36.713˚N, 122.186˚W). Song is prevalent in this feeding and migratory habitat, spanning nine months of the year (September-May), peaking in winter (November-January), and reaching a maximum of 86% temporal coverage (during November 2017). From the rise of song in fall through the end of peak occurrence in winter, song length increases significantly from month to month. The seasonal peak in song coincides with the seasonal trough in day length and sighting-based evidence of whales leaving Monterey Bay, consistent with seasonal migration. During the seasonal song peak, diel variation shows maximum occurrence at night (69% of the time), decreasing during dawn and dusk (52%), and further decreasing with increasing solar elevation during the day, reaching a minimum near solar noon (30%). Song occurrence increased 44% and 55% between successive years. Sighting data within the acoustic detection range of the hydrophone indicate that variation in local population density was an unlikely cause of this large interannual variation. Hydrographic data and modeling of acoustic transmission indicate that changes in neither habitat occupancy nor acoustic transmission were probable causes. Conversely, the positive interannual trend in song paralleled major ecosystem variations, including similarly large positive trends in winddriven upwelling, primary productivity, and krill abundance. Further, the lowest song occurrence during the first year coincided with anomalously warm ocean temperatures and an extremely toxic harmful algal bloom that affected whales and other marine mammals in the PLOS ONE |

Journal of Operational Oceanography, 2017

The structure and intensity of the intermediate wake generated by a submerged propagating body in... more The structure and intensity of the intermediate wake generated by a submerged propagating body in a stratified fluid was studied using a combination of (i) numerical simulations, (ii) field measurements, and (iii) laboratory experiments. The numerical component offered guidance for the field work performed in Monterey Bay (CA, USA) in the summer of 2015. The field work focused on subsurface thermal signatures of a submerged propagating object. Vertical temperature profiles suggested that long-term changes in thermal stratification can occur after the passage of a towed body. Horizontal temperature variability, measured by an autonomous underwater vehicle facilitated the identification of the wake using perturbation temperature variance as the key diagnostic variable. Analogous thermal signatures of stratified wakes were found in ocean observations and in modelling results. The influence of the tow ship on the wake was shown to be minimal. Laboratory experiments focused on the surface expression of stratified wakes were used to complement numerical simulations and field measurements. All three components of this project indicate that detection of the wake of a submerged object based on its thermal signatures is a viable and effective approach.

arXiv (Cornell University), May 19, 2023

We describe the development, operation, and application of the 4D Camera-a 576 by 576 pixel activ... more We describe the development, operation, and application of the 4D Camera-a 576 by 576 pixel active pixel sensor for scanning/transmission electron microscopy which operates at 87,000 Hz. The detector generates data at approximately 480 Gbit/s which is captured by dedicated receiver computers with a parallelized software infrastructure that has been implemented to process the resulting 10-700 Gigabyte-sized raw datasets. The back illuminated detector provides the ability to detect single electron events at accelerating voltages from 30-300 keV. Through electron counting, the resulting sparse data sets are reduced in size by 10 − 300× compared to the raw data, and open-source sparsity-based processing algorithms offer rapid data analysis. The high frame rate allows for large and complex 4D-STEM experiments to be accomplished with typical STEM scanning parameters.

Underwater soundscapes of coastal zones close to human settlements are heterogeneous in nature. M... more Underwater soundscapes of coastal zones close to human settlements are heterogeneous in nature. Multiple ships and biological sources are often simultaneously present in the passive sonar vicinity. Classification of such heterogeneous underwater soundscapes is a challenging task for humans as well as machine learning systems. In this work a Bayesian Deep Learning approach is proposed that can accurately classify multiple ships simultaneously present in the vicinity of the sensor (multi-label classification) and provide uncertainty in the classification. This is achieved by assuming a Bayesian formulation of standard convolutional neural network architectures to not only assign multi-labels per inference but also to provide per inference uncertainty. By utilizing almost 3,500 hours of passive sonar data (spanning more than a year of sensor deployment) labeled through automated fusion with automatic identification system information, both multi-class and multi-label classification tasks of shipgenerated noise are addressed. The best performing Bayesian architecture on the multi-label task achieves a weighted F 1 score of 0.84, where each prediction is accompanied by a measurement of uncertainty which is used to further enhance the understanding of model predictions.

2018 International CET Conference on Control, Communication, and Computing (IC4), 2018

Network File System is a widely used distributed file system that allows the user to access and m... more Network File System is a widely used distributed file system that allows the user to access and manipulate storage on remote computers, as if they were a part of the local machine. Network File System is notoriously slow in its default configuration and if more clients connects to the NFS environment, it merely accentuates the delay. When configured to deliver faster speeds, the system suffers from higher risk of data corruption and loss. This study proposes a number of modifications to the Network File System, enabling it to provide elevated system performance, while containing the risk of data loss and corruption. Further, the proposed system behaves better in congested networks by consuming less bandwidth, ensuring decent speeds, even during periods of heavy network traffic.

Citizens all over the world require certificates to prove their identity, qualifications, and ach... more Citizens all over the world require certificates to prove their identity, qualifications, and achievements. Issuing, verifying and maintaining these certificates remained a problem, as most certificates were available only as hard copy, until the advent of computers. Digitization of important certificates and documents can lead to potential security risks. Firstly, digitization makes it possible to easily forge counterfeit certificates, and further risks the privacy of documents. Moreover, individuals still have to be physically present at issuing offices to get hold of new certificates. This paper proposes a solution to these problems by employing cryptography and blockchain technology to securely issue, store and verify important certificates.

Linguistic Theory and Grammatical Description, 1991

International Journal of Performability Engineering, 2021

Frontiers in Communication, 2021

Insofar as linguists operate with a conception of languages as closed and self-contained systems,... more Insofar as linguists operate with a conception of languages as closed and self-contained systems, there should be no obstacle to comparing those systems in terms of simplicity and complexity. Even if complexity ‘trade-offs’ between sub-systems of phonology, morphology and syntax are considered, it ought to be relatively straightforward to quantify constitutive elements and rules, and assign each language system its place on a complexity scale. In practice, however, such attempts have turned up a series of problems and paradoxes, which can be seen in work by Peter Trudgill and Johanna Nichols; the latter has proposed an alternative means of measuring complexity which presents new problems of its own. This paper makes the case that overcoming the difficulty of measuring simplicity and complexity requires confronting the normative and interpretative judgments that enter into how language systems are conceived, identified and analysed.

Proceedings of Meetings on Acoustics, 2018

Nonlinear time-warping made simple: A step-by-step tutorial on underwater acoustic modal separati... more Nonlinear time-warping made simple: A step-by-step tutorial on underwater acoustic modal separation with a single hydrophone

OCEANS 2016 MTS/IEEE Monterey, 2016

a novel approach has been developed for detecting and classifying foraging calls of two mysticete... more a novel approach has been developed for detecting and classifying foraging calls of two mysticete species in passive acoustic recordings. This automated detector/classifier applies a computer-vision based technique, a pattern recognition method, to detect the foraging calls and remove ambient noise effects. The detected calls were then classified as blue whale D-calls [1] or fin whale 40-Hz calls [2] using a logistic regression classifier, a machine learning technique. The detector/classifier has been trained using the 2015 Detection, Classification, Localization and Density Estimation (DCLDE 2015, Scripps Institution of Oceanography UCSD [3]) low-frequency annotated set of passive acoustic data, collected in the Southern California Bight, and its out-of-sample performance was estimated by using a crossvalidation technique. The DCLDE 2015 scoring tool was used to estimate the detector/classifier performance in a standardized way. The pattern recognition algorithm's out-of-sample performance was scored as 96.68% recall with 92.03 % precision. The machine learning algorithm's out-of-sample prediction accuracy was 95.20%. The result indicated the potential of this detector/classifier on real-time passive acoustic marine mammal monitoring and bioacoustics signal processing.

Traditionally, pension funds have been relatively homogeneous in their real estate investment pra... more Traditionally, pension funds have been relatively homogeneous in their real estate investment practices. Today, however, pension funds as an investor group are quite diverse in their attitudes towards real estate. Our study shows that real estate strategies run the gamut from aggressively increasing total exposure to exiting the asset class altogether. Some look to real estate for its diversification and inflation hedging benefits, while others choose real estate strictly on a total risk/return basis. A growing number of funds are increasing their allocation to REIT stocks while many others own no public real estate securities. While there are no industry-wide constants that apply to all pension funds, this thesis explores the industry's current real estate investment options and identifies trends for the next five years.

2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), 2012

This paper describes the performance of a scalable readout system for high-speed CCD sensors base... more This paper describes the performance of a scalable readout system for high-speed CCD sensors based on the Advanced Telecommunication Computing Architecture specification. The paper reports the readout system performance tested with a IMPixel Frame Store CCD sensor for soft X-ray applications at synchrotron light sources. This camera is capable of producing image data at over 400 MB/s which must be processed in real-time and stored to disk. The high-level hardware architecture, signal processing data flow, and network protocol optimization are also be presented.

Ecological Modelling, 2022

Understanding the impacts of anthropogenic sound on marine mammals is important for effective mit... more Understanding the impacts of anthropogenic sound on marine mammals is important for effective mitigation and management. Sound impacts can cause behavioral changes that lead to displacement from preferred habitat and can have negative influence on vital rates. Here, we develop a movement model to better understand and simulate how whales respond to anthropogenic sound over ecologically meaningful space and time scales. The stochastic model is based on a sequential Monte Carlo sampler (a particle filter). The movement model takes account of vertical dive information and is influenced by the underwater soundscape and the historical whale distribution in the region. In the absence of noise disturbance, the simulator is shown to recover the historical whale distribution in the region. When noise disturbance is incorporated, the whale's behavioral response is determined through a dose-response function dependent on the received level of sound. The aggregate impact is assessed by considering both the duration of foraging loss and the spatial shift to alternate (and potentially less favorable) habitat. Persistence of the behavioral response in time is treated through a 'disruption' parameter. We apply the approach to a population of fin whales whose distribution overlaps naval sonar testing activities beside the Southern California range complex. The simulation shows the consequences of one year of naval sonar disturbance are a function of: i) how loud the sound source is, ii) where the disturbed whales are relative to preferred (high density) habitat, and iii) how long a whale takes before returning to a pre-disturbance state. The movement simulator developed here is a generic movement modeling tool that can be adapted for different species, different regions, and any acoustic disturbances with known impacts on animal populations.

Frontiers in Marine Science, 2021

Soundscapes offer rich descriptions of composite acoustic environments. Characterizing marine sou... more Soundscapes offer rich descriptions of composite acoustic environments. Characterizing marine soundscapes simply through sound levels results in incomplete descriptions, limits the understanding of unique features, and impedes meaningful comparisons. Sources that contribute to sound level metrics shift in time and space with changes in biological patterns, physical forces, and human activity. The presence of a constant or chronic source is often interwoven with episodic sounds. Further, the presence and intensity of sources can influence other sources, calling for a more integrated approach to characterizing soundscapes. Here, we illustrate this complexity using data from a national-scale effort, the Sanctuary Soundscape Monitoring Project (SanctSound), an initiative designed to support collection of biological, environmental, and human use data to compliment the interpretation of sound level measurements. Using nine examples from this diverse dataset we demonstrate the benefit of i...

Frontiers in Marine Science, 2021

Low-frequency sound from large vessels is a major, global source of ocean noise that can interfer... more Low-frequency sound from large vessels is a major, global source of ocean noise that can interfere with acoustic communication for a variety of marine animals. Changes in vessel activity provide opportunities to quantify relationships between vessel traffic levels and soundscape conditions in biologically important habitats. Using continuous deep-sea (890 m) recordings acquired ∼20 km (closest point of approach) from offshore shipping lanes, we observed reduction of low-frequency noise within Monterey Bay National Marine Sanctuary (California, United States) associated with changes in vessel traffic during the onset of the COVID-19 pandemic. Acoustic modeling shows that the recording site receives low-frequency vessel noise primarily from the regional shipping lanes rather than via the Sound Fixing and Ranging (SOFAR) channel. Monthly geometric means and percentiles of spectrum levels in the one-third octave band centered at 63 Hz during 2020 were compared with those from the same m...

Current Biology, 2020

Animal-Borne Metrics Enable Acoustic Detection of Blue Whale Migration Highlights d Acoustic moni... more Animal-Borne Metrics Enable Acoustic Detection of Blue Whale Migration Highlights d Acoustic monitoring reveals patterns in population-level blue whale song production d Tag-derived metrics provide behavioral context for distinct diel patterns in song d When integrated, tag and acoustic metrics reveal an acoustic signature of migration d Key to discerning timing, plasticity, and drivers of a dispersed migration

Frontiers in Marine Science, 2020

Anthropogenic noise has been recognized as a threat to marine mammals for decades, making it a ce... more Anthropogenic noise has been recognized as a threat to marine mammals for decades, making it a central issue for their conservation and management (Tougaard et al., 2015; National Marine Fisheries Service, 2016; Southall et al., 2019). For many marine mammals, hearing is the primary sensory modality, important for navigation, foraging, predator avoidance, and communication (Tyack, 1986). Noise can be considered as any sound that has the potential to interfere with normal functioning of auditory processes or cause harmful behavioral or physiological responses. Potential impacts of noise include interruption of essential behaviors (Wisniewska et al., 2018), masking

PLOS ONE, 2019

This study examines the occurrence of humpback whale (Megaptera novaeangliae) song in the northea... more This study examines the occurrence of humpback whale (Megaptera novaeangliae) song in the northeast Pacific from three years of continuous recordings off central California (36.713˚N, 122.186˚W). Song is prevalent in this feeding and migratory habitat, spanning nine months of the year (September-May), peaking in winter (November-January), and reaching a maximum of 86% temporal coverage (during November 2017). From the rise of song in fall through the end of peak occurrence in winter, song length increases significantly from month to month. The seasonal peak in song coincides with the seasonal trough in day length and sighting-based evidence of whales leaving Monterey Bay, consistent with seasonal migration. During the seasonal song peak, diel variation shows maximum occurrence at night (69% of the time), decreasing during dawn and dusk (52%), and further decreasing with increasing solar elevation during the day, reaching a minimum near solar noon (30%). Song occurrence increased 44% and 55% between successive years. Sighting data within the acoustic detection range of the hydrophone indicate that variation in local population density was an unlikely cause of this large interannual variation. Hydrographic data and modeling of acoustic transmission indicate that changes in neither habitat occupancy nor acoustic transmission were probable causes. Conversely, the positive interannual trend in song paralleled major ecosystem variations, including similarly large positive trends in winddriven upwelling, primary productivity, and krill abundance. Further, the lowest song occurrence during the first year coincided with anomalously warm ocean temperatures and an extremely toxic harmful algal bloom that affected whales and other marine mammals in the PLOS ONE |

Journal of Operational Oceanography, 2017

The structure and intensity of the intermediate wake generated by a submerged propagating body in... more The structure and intensity of the intermediate wake generated by a submerged propagating body in a stratified fluid was studied using a combination of (i) numerical simulations, (ii) field measurements, and (iii) laboratory experiments. The numerical component offered guidance for the field work performed in Monterey Bay (CA, USA) in the summer of 2015. The field work focused on subsurface thermal signatures of a submerged propagating object. Vertical temperature profiles suggested that long-term changes in thermal stratification can occur after the passage of a towed body. Horizontal temperature variability, measured by an autonomous underwater vehicle facilitated the identification of the wake using perturbation temperature variance as the key diagnostic variable. Analogous thermal signatures of stratified wakes were found in ocean observations and in modelling results. The influence of the tow ship on the wake was shown to be minimal. Laboratory experiments focused on the surface expression of stratified wakes were used to complement numerical simulations and field measurements. All three components of this project indicate that detection of the wake of a submerged object based on its thermal signatures is a viable and effective approach.

arXiv (Cornell University), May 19, 2023

We describe the development, operation, and application of the 4D Camera-a 576 by 576 pixel activ... more We describe the development, operation, and application of the 4D Camera-a 576 by 576 pixel active pixel sensor for scanning/transmission electron microscopy which operates at 87,000 Hz. The detector generates data at approximately 480 Gbit/s which is captured by dedicated receiver computers with a parallelized software infrastructure that has been implemented to process the resulting 10-700 Gigabyte-sized raw datasets. The back illuminated detector provides the ability to detect single electron events at accelerating voltages from 30-300 keV. Through electron counting, the resulting sparse data sets are reduced in size by 10 − 300× compared to the raw data, and open-source sparsity-based processing algorithms offer rapid data analysis. The high frame rate allows for large and complex 4D-STEM experiments to be accomplished with typical STEM scanning parameters.

Underwater soundscapes of coastal zones close to human settlements are heterogeneous in nature. M... more Underwater soundscapes of coastal zones close to human settlements are heterogeneous in nature. Multiple ships and biological sources are often simultaneously present in the passive sonar vicinity. Classification of such heterogeneous underwater soundscapes is a challenging task for humans as well as machine learning systems. In this work a Bayesian Deep Learning approach is proposed that can accurately classify multiple ships simultaneously present in the vicinity of the sensor (multi-label classification) and provide uncertainty in the classification. This is achieved by assuming a Bayesian formulation of standard convolutional neural network architectures to not only assign multi-labels per inference but also to provide per inference uncertainty. By utilizing almost 3,500 hours of passive sonar data (spanning more than a year of sensor deployment) labeled through automated fusion with automatic identification system information, both multi-class and multi-label classification tasks of shipgenerated noise are addressed. The best performing Bayesian architecture on the multi-label task achieves a weighted F 1 score of 0.84, where each prediction is accompanied by a measurement of uncertainty which is used to further enhance the understanding of model predictions.

2018 International CET Conference on Control, Communication, and Computing (IC4), 2018

Network File System is a widely used distributed file system that allows the user to access and m... more Network File System is a widely used distributed file system that allows the user to access and manipulate storage on remote computers, as if they were a part of the local machine. Network File System is notoriously slow in its default configuration and if more clients connects to the NFS environment, it merely accentuates the delay. When configured to deliver faster speeds, the system suffers from higher risk of data corruption and loss. This study proposes a number of modifications to the Network File System, enabling it to provide elevated system performance, while containing the risk of data loss and corruption. Further, the proposed system behaves better in congested networks by consuming less bandwidth, ensuring decent speeds, even during periods of heavy network traffic.

Citizens all over the world require certificates to prove their identity, qualifications, and ach... more Citizens all over the world require certificates to prove their identity, qualifications, and achievements. Issuing, verifying and maintaining these certificates remained a problem, as most certificates were available only as hard copy, until the advent of computers. Digitization of important certificates and documents can lead to potential security risks. Firstly, digitization makes it possible to easily forge counterfeit certificates, and further risks the privacy of documents. Moreover, individuals still have to be physically present at issuing offices to get hold of new certificates. This paper proposes a solution to these problems by employing cryptography and blockchain technology to securely issue, store and verify important certificates.

Linguistic Theory and Grammatical Description, 1991

International Journal of Performability Engineering, 2021

Frontiers in Communication, 2021

Insofar as linguists operate with a conception of languages as closed and self-contained systems,... more Insofar as linguists operate with a conception of languages as closed and self-contained systems, there should be no obstacle to comparing those systems in terms of simplicity and complexity. Even if complexity ‘trade-offs’ between sub-systems of phonology, morphology and syntax are considered, it ought to be relatively straightforward to quantify constitutive elements and rules, and assign each language system its place on a complexity scale. In practice, however, such attempts have turned up a series of problems and paradoxes, which can be seen in work by Peter Trudgill and Johanna Nichols; the latter has proposed an alternative means of measuring complexity which presents new problems of its own. This paper makes the case that overcoming the difficulty of measuring simplicity and complexity requires confronting the normative and interpretative judgments that enter into how language systems are conceived, identified and analysed.

Proceedings of Meetings on Acoustics, 2018

Nonlinear time-warping made simple: A step-by-step tutorial on underwater acoustic modal separati... more Nonlinear time-warping made simple: A step-by-step tutorial on underwater acoustic modal separation with a single hydrophone

OCEANS 2016 MTS/IEEE Monterey, 2016

a novel approach has been developed for detecting and classifying foraging calls of two mysticete... more a novel approach has been developed for detecting and classifying foraging calls of two mysticete species in passive acoustic recordings. This automated detector/classifier applies a computer-vision based technique, a pattern recognition method, to detect the foraging calls and remove ambient noise effects. The detected calls were then classified as blue whale D-calls [1] or fin whale 40-Hz calls [2] using a logistic regression classifier, a machine learning technique. The detector/classifier has been trained using the 2015 Detection, Classification, Localization and Density Estimation (DCLDE 2015, Scripps Institution of Oceanography UCSD [3]) low-frequency annotated set of passive acoustic data, collected in the Southern California Bight, and its out-of-sample performance was estimated by using a crossvalidation technique. The DCLDE 2015 scoring tool was used to estimate the detector/classifier performance in a standardized way. The pattern recognition algorithm's out-of-sample performance was scored as 96.68% recall with 92.03 % precision. The machine learning algorithm's out-of-sample prediction accuracy was 95.20%. The result indicated the potential of this detector/classifier on real-time passive acoustic marine mammal monitoring and bioacoustics signal processing.

Traditionally, pension funds have been relatively homogeneous in their real estate investment pra... more Traditionally, pension funds have been relatively homogeneous in their real estate investment practices. Today, however, pension funds as an investor group are quite diverse in their attitudes towards real estate. Our study shows that real estate strategies run the gamut from aggressively increasing total exposure to exiting the asset class altogether. Some look to real estate for its diversification and inflation hedging benefits, while others choose real estate strictly on a total risk/return basis. A growing number of funds are increasing their allocation to REIT stocks while many others own no public real estate securities. While there are no industry-wide constants that apply to all pension funds, this thesis explores the industry's current real estate investment options and identifies trends for the next five years.

2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), 2012

This paper describes the performance of a scalable readout system for high-speed CCD sensors base... more This paper describes the performance of a scalable readout system for high-speed CCD sensors based on the Advanced Telecommunication Computing Architecture specification. The paper reports the readout system performance tested with a IMPixel Frame Store CCD sensor for soft X-ray applications at synchrotron light sources. This camera is capable of producing image data at over 400 MB/s which must be processed in real-time and stored to disk. The high-level hardware architecture, signal processing data flow, and network protocol optimization are also be presented.