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Papers by duc giang Tran

Cureus

Background Since coronavirus disease 2019 (COVID-19) emerged, increasing cases have been identifi... more Background Since coronavirus disease 2019 (COVID-19) emerged, increasing cases have been identified worldwide. COVID-19 continues to lead to significant morbidity and mortality, despite developing a vaccination for the disease. While much has been studied regarding the initial presentation and treatment of patients with COVID-19, to our knowledge, no study has uncovered that COVID-19-positive patients with abdominal pain are at a higher risk of requiring intubation. Methodology In this retrospective cohort study, we identified 104 patients who presented to the emergency room of a single tertiary care center with laboratory-confirmed COVID-19 between February 1, 2020, and April 27, 2020, and collected data on reported pain complaints. Results In this retrospective cohort study, the most common pain complaints were chest pain (25.5%), myalgia (23.4%), and abdominal pain (17.0%). Less common pain complaints included headaches (14.9%) and neck/back pain (6.3%). Of these pain complaints, only patients who reported having abdominal pain were more likely to be intubated (37.5% of patients with abdominal pain were intubated compared to 8.3% of patients without abdominal pain, with a p-value of 0.001). Conclusions Abdominal pain in a patient with COVID-19 infection significantly increases their chances of requiring intubation based on the results of this study.

Foods, 2022

The growing concern for food safety and quality motivates governments and private sectors to impr... more The growing concern for food safety and quality motivates governments and private sectors to improve consumers’ confidence in food systems, such as through adopting certifications and traceability systems. The recent emergence of diverse food labelling schemes and the turbulence in food systems in emerging countries have sparked questions about consumers’ valuation of such labels. Nonetheless, little is known on how the familiarity with, trust in and knowledge of these food labelling schemes affect consumers’ willingness to pay for labelling schemes in emerging market contexts. This study aims to address these literature gaps by investigating consumers’ valuation of existing certifications, branding and traceability labelling schemes in Vietnam. A face-to-face survey was conducted, including a discrete choice experiment on water spinach in Ho Chi Minh City, Vietnam. The findings indicated that Vietnamese consumers are generally willing to pay price premia for food labelling schemes,...

This research is partially supported by Grantsin-Aid for Scientific Research No. 17K03692 from th... more This research is partially supported by Grantsin-Aid for Scientific Research No. 17K03692 from the Japan Society for the Promotion of Science.

Advances in Intelligent Systems and Computing, 2021

Recent research in biology has shifted the focus toward single-cell data analysis. The new single... more Recent research in biology has shifted the focus toward single-cell data analysis. The new single-cell technologies have allowed us to monitor and characterize cells in early embryonic stage and in heterogeneous tumor tissue. However, current single-cell RNA sequencing (scRNA-seq) technologies still need to overcome significant challenges to ensure accurate measurement of gene expression. One critical challenge is to address the dropout event. Due to the low amount of starting material, a large portion of expression values in scRNA-seq data is missing and reported as zeros. These missing values can greatly affect the accuracy of downstream analysis. Here we introduce scIRN, a neural network-based approach, that can reliably recover the missing values in single-cell data and thus can effectively improve the performance of downstream analyses. To impute the dropouts in single-cell data, we build a neural network that consists of two sub-networks: imputation sub-network and quality assessment sub-network. We compare scIRN with stateof-the-art imputation methods using 10 scRNA-seq datasets. In our extensive analysis, scIRN outperforms existing imputation methods in improving the identification of cell sub-populations and the quality of visualizing transcriptome landscape.

Open image in new window Rainfall and earthquakes are considered two of the major causes of lands... more Open image in new window Rainfall and earthquakes are considered two of the major causes of landslides worldwide. These landslides cause billions of dollars in property damage and revenue losses, as well as the deaths of thousands of people each year. While researchers have been examining the effect of either rainfall or earthquakes on the deformation and stability of slopes, the combined effect of rainfall and earthquakes on deformation and slope stability has not been evaluated systematically. In this study, a series of model slopes were constructed in a Plexiglas container placed on top of a shake table. The model slopes were prepared to have different initial void ratios of 0.89, 1.0 and 1.2 and various slope inclinations of 30°, 40°, and 45°. These slopes were instrumented with accelerometers, tensiometers and inclinometers and subjected to a number of sinusoidal seismic motions with different seismic accelerations from 0.1 to 0.3 g, with several frequencies ranging from 1 to 3...

Long term and high-frequency monitoring of water quality, particularly the suspended particulate ... more Long term and high-frequency monitoring of water quality, particularly the suspended particulate matter (SPM) concentration are crucial to decipher the health and sustainable development of marine ecosystems. However, in-situ measurements based on indirect optical or acoustic techniques are often associated with large uncertainties due to the dynamics of natural SPM, especially throughout the land-sea continuum. Therefore, this study aims to improve the accuracy of long term in-situ measurements by quantitatively elucidating the physical mechanisms by which sand and fine sediment respond to multi-wavelength optical and multi-frequency acoustic signals. We hypothesize that whilst fine sediment is very sensitive to optical signals, the coarser particles are more sensitive to acoustic signals, and vice versa. We further hypothesize that the SPM compositions and variability can be differentiated and derived based on such sensitivities and differences in behaviors of sand and fine sediment under different types of signals, i.e., optical and acoustic.

2019 11th International Conference on Knowledge and Systems Engineering (KSE), 2019

Advances in single-cell technologies have shifted genomics research from the analysis of bulk tis... more Advances in single-cell technologies have shifted genomics research from the analysis of bulk tissues toward a comprehensive characterization of individual cells. This holds enormous opportunities for both basic biology and clinical research. As such, identification and characterization of shortlived progenitors, stem cells, cancer stem cells, or circulating tumor cells are essential to better understand both normal and diseased tissue biology. However, quantifying gene expression in each cell remains a significant challenge due to the low amount of mRNA available within individual cells. This leads to the excess amount of zero counts caused by dropout events. Here we introduce RIA, a regression-based approach, that is able to reliably recover the missing values in single-cell data and thus can effectively improve the performance of downstream analyses. We compare RIA with state-of-the-art methods using five scRNA-seq datasets with a total of 3,535 cells. In each dataset analyzed, RIA outperforms existing approaches in improving the identification of cell populations while preserving the biological landscape. We also demonstrate that RIA is able to infer temporal trajectories of embryonic development stages.

This research employed a Participatory Action Research methodology to work with minority inter-pr... more This research employed a Participatory Action Research methodology to work with minority inter-provincial students and unearth their lived experiences at the University of Danang in Vietnam. It focused on examining the undervaluation of inter-provincial students’ voices in the university’s policies – and to a wider extent, in most Vietnamese universities – by facilitating a process in which their challenges and ideas for change at university could be heard. This research also sought to observe and analyse the influences of power dynamics within a Confucian-heritaged context on the participatory research process itself. Vietnam is believed to be a society in which hierarchical power takes its deepest roots due to the effects of Confucianism. By using Participatory Action Research with a variety of methods – photovoice, diagraming, group discussion, interviewing and exhibition – I sought to facilitate student voices and document some of the potential and constraints of the methodolog...

Advancing Culture of Living with Landslides, 2017

Landslides are the third largest disasters worldwide. In order to save innocent lives and propert... more Landslides are the third largest disasters worldwide. In order to save innocent lives and property damage, a system for understanding, assessment and early warning of the landslides is highly necessary. In this work, we have designed and developed an integrated wireless sensor network system for real-time monitoring and early warning of landslides. This paper will discuss the detailed requirements and design criteria considered in the design and development of the Intelligent Wireless Probe (IWP), to capture the relevant landslide triggering parameters. The network of IWPs is used to derive the local or regional contribution of geological, hydrological, and meteorological factors towards the initiation of a potentially imminent landslide. This heterogeneous sensor system provides the capability for gathering real-time context aware data to understand the dynamic variability in landslide risk. The data from these systems are continuously transmitted to our control center for real-time data analysis to derive the possibility of an imminent landslide. Based on the knowledge discovery from these analyses a three level warning system was developed to issue real-time landslide warnings. We have deployed the complete system in Western Ghats and North Eastern Himalayas in India. The system in Munnar has proven its validity by delivering real time warnings to the community in 2009, 2011, and 2013 and continues to monitor landslides even today for the tenth year in a row. The results from the experimentation shows this system has contributed in enhancing the reliability of landslide warning, reduced false alarm rate, and provides the capability to issue warnings in local, slope and regional levels. After the success of this work, Government of India has adopted the system nationally as a result of which we have carried out a second deployment in the North Eastern Himalayas.

Für eine Systematisierung der unterschiedlichen Untersuchungsdesigns vgl. Abschnitt 3.5 (Teil 2 d... more Für eine Systematisierung der unterschiedlichen Untersuchungsdesigns vgl. Abschnitt 3.5 (Teil 2 dieser Arbeit). Für empirische Studien vgl. etwa Ashbaugh-Skaife/Collins/LaFond (2004, 2006), Cheng/Collins/Huang (2006). 9 Wesentliche Impulse für den Literaturstrang um den Cash Flow-Effekt gingen von der Studie von Gompers/Ishii/Metrick (2003) aus, die, stellvertretend für die Machtverhältnisse zwischen Manager und Anteileigner in einem Unternehmen, einen Index konstruieren und diesen in Relation zu den besagten Erfolgsmaßen setzen. 10 hang 15 Darauf aufbauend werden zwei empirisch überprüfbare Generalhypothesen (als Alternativhypothesen) aufgestellt:  Hypothese 1: Corporate Governance hat einen Einfluss auf die Eigenkapitalkosten von Unternehmen und ist damit nicht diversifizierbar.  Hypothese 2: Fremdkapitalgeber haben im Vergleich zu Eigenkapitalgebern eine geringere Nachfrage nach Corporate Governance Mechanismen aufgrund ihrer institutionell besser geschützten Rechtsposition in Deutschland. Mithilfe von ökonometrischen Verfahren werden diese Hypothesen empirisch getestet. Im Hinblick auf das Untersuchungsdesign der empirischen Arbeit besteht ein wesentliches Problem in der Erfassung der Güte der Corporate Governance von Unternehmen (exogene Variablen). Zur Lösung dieses Problems wird auf ein Konzept von Standard & Poor's (2002) zurückgegriffen, das basierend auf den Befunden bisheriger Forschungsarbeiten die Eigentümerstruktur, Managementvergütung und Unternehmenstransparenz als wesentliche Dimensionen zur Sicherstellung einer "guten" Corporate Governance betrachtet. Diese Dimensionen werden im Rahmen der empirischen Arbeit durch verschiedene Stellvertretervariablen approximiert. Zur Schätzung der Eigen-bzw. Fremdkapitalkosten (endogene Variable) werden auf folgende in der Literatur etablierte Methoden zurückgegriffen: (1) Impliziter Eigenkapitalkostenansatz (PEG-Ratio 16), (2) Empirische Bestimmung des Beta-Faktors im Sinne des Capital Asset Pricing Model aus realisierten Kapitalmarktdaten und (3) Zinsaufwand bezogen auf verzinstes bilanzielles Fremdkapital als durchschnittliches Maß für den Fremdkapitalkostensatz. Die notwendigen Daten zur Erfassung dieser Dimensionen werden mehrheitlich per Hand aus verschiedenen Quellen (Geschäftsberichte, Hoppenstedt AG) bzw. professionellen Datenbankanbietern (Worldscope, Datastream, I/B/E/S) erhoben. 15 Zum theoretischen Link zwischen Corporate Governance und Kapitalkosten vgl. Abschnitt 3.4 des in Teil 2 präsentierten Beitrags dieser Arbeit. 16 Vgl. Easton (2004).

The present study examines the different ways in which language structure marks individuation and... more The present study examines the different ways in which language structure marks individuation and cue early attention in a novel noun generalization task. Results in the present study extends the Boundary Shift Hypothesis, suggesting that the linguistic boundary between individuals and nonindividuals influences the perceptual boundaries and the correlational patterns formed overtime between ontological kinds. The results provide a new perspective on the facilitative role of linguistic markers in category formations, rather than strictly in boundary formations. This demonstrates the potential degree of cognitive processing among different language learners and lends support towards a mechanistic explanation of the role of language in categorical formations.

Electronic Visualisation and the Arts (EVA 2015), 2015

Gilcrease on Wheels is an initiative designed to project the Gilcrease Museum's extraordinary Ame... more Gilcrease on Wheels is an initiative designed to project the Gilcrease Museum's extraordinary American collections in a multi-faceted educational package that includes on-site programming, pre-visit preparation, and post-visit activities and evaluation to rural school districts and underserved communities in Oklahoma. Gilcrease on Wheels utilises Gilcrease Museum's extensive collections of American (North America, Mesoamerica, and South America) art, archaeology, and historical documents to enliven the classroom experience while addressing appropriate teaching standards in social studies, art, and language arts to offer a well-rounded, complementary learning experience through exhibits on Oklahoma history and Native American cultures. By introducing Gilcrease collections, in-class enrichment, new activities, and incentives to explore local history, this program promotes critical thinking and encourages students to explore their part of the world. Gilcrease on Wheels incorporates electronic interactive experiences which are age-appropriate for each grade level. Gilcrease on Wheels was inaugurated at the Poteau Public Library on October 23rd, 2014 with successful programming for the third grade. By the end of 2014, over 2000 children in rural schools had participated in programs. The third grade interactive experience incorporates the use of sounds from nature to match to items in the exhibit. The first three years of Gilcrease on Wheels the program focuses on reaching children in rural southeast Oklahoma, including the counties of LeFlore, Haskell, Latimer and Sequoyah. Gilcrease on Wheels gradually will expand to additional grade levels and topics. Age-appropriate techniques and applicable learning standards for each grade will guide development of new curricula incorporating electron interactive experiences. By 2017, Gilcrease on Wheels will expand to cover other under-served, rural areas across Oklahoma Electronic interactive app. Travelling museum exhibit. Age-appropriate apps.

AIAA Modeling and Simulation Technologies Conference and Exhibit, 2004

As part of the investigation of the accident involving American Airlines Flight 587, the National... more As part of the investigation of the accident involving American Airlines Flight 587, the National Transportation Safety Board (NTSB), in cooperation with NASA Ames Research Center, proposed to conduct observations and tests using the Vertical Motion Simulator (VMS). The investigation was divided into two phases. Phase I consisted of evaluating the accelerations experienced during the accident event by back-driving the cockpit controls, displays, out-the-window scene, cockpit communications, and motion of the aircraft as recorded and derived from the aircraft's flight data recorder (FDR) and cockpit voice recorder (CVR). Phase II consisted of evaluating the effects of flight control characteristics and accelerations similar to those experienced during the accident event on pilot perception and performance using a tracking task. The tracking task consisted of pilots following an on-screen target with various flight control configurations, with both motion off and motion being back-driven using derived acceleration data from the FDR. This paper describes the work provided by the VMS in support of the investigation and does not include any conclusions drawn from the study.

2013 IEEE 9th International Colloquium on Signal Processing and its Applications, 2013

ABSTRACT Due to the importance of blood vessel detection in many medical tools and the increasing... more ABSTRACT Due to the importance of blood vessel detection in many medical tools and the increasing demand for portable diagnosis equipment, fast blood vessel detection algorithm in a standalone and portable device is very important. The optimization of a computationally intensive algorithm such as this on a mobile platform is challenging due to the limited resources available. In this paper, the blood vessel detection system is implemented and optimized in a portable device running Android OS on an ARM-based processor. The performance of Java programming model and native programming model are compared with respect to the execution time for blood vessel detection. The experimental results show that the blood vessel detection system has worked well in the ARM platform with the Android OS. Moreover, native programming platform is faster than Java programming with 75.91% better in terms of execution time on average. With multithreading, the performance gain in native programming is 92.77% faster than Java programming.

ALGAE, 2011

The physiology of the unicellular green alga Dunaliella salina in response to abiotic stress has ... more The physiology of the unicellular green alga Dunaliella salina in response to abiotic stress has been studied for several decades. Early D. salina research focused on its remarkable salinity tolerance and ability, upon exposure to various abiotic stresses, to accumulate high concentrations of β-carotene and other carotenoid pigments valued highly as nutraceuticals. The simple life cycle and growth requirements of D. salina make this organism one of the large-scale commercially exploited microalgae for natural carotenoids. Recent advances in genomics and proteomics now allow investigation of abiotic stress responses at the molecular level. Detailed knowledge of isoprenoid biosynthesis mechanisms and the development of molecular tools and techniques for D. salina will allow the improvement of physiological characteristics of algal strains and the use of transgenic algae in bioreactors. Here we review D. salina isoprenoid and carotenoid biosynthesis regulation, and also the biotechnological and genetic transformation procedures developed for this alga that set the stage for its future use as a production system.

Finite Elements: Techniques and Developments

This paper investigates various dynamic effects on the cushioning properties of corrugated fibre ... more This paper investigates various dynamic effects on the cushioning properties of corrugated fibre board (CFB) and the arse of finite element modelling (FEM) as an alternative to conventional experimental tests to evaluate the impact behavior of CFB It was found that the transient response under impact of CFB depends greatly on the compression speed, its mode of behavior can change from predominantly inelastic behavior to instability of the flute. The extent and shape of contact area between the impactor and the cushioning fibre board also affects the characteristics of the response. All these factors should be taken into account in the testing program for cushioning properties of fibre board. Finite element modeling of the corrugated fiber board structure using explicit dynamic software ABAQUS to simulate cushion tests yielded results which are in good agreement with the experimental results. The simulation technique based on FEM would serve as an alternative to obtain the cushion curves in practical packages, and would aid the design of packaging container and of packaging material made of CFB.

TENCON 2009 - 2009 IEEE Region 10 Conference, 2009

ABSTRACT Building a real system is one of the major challenges of privacy-preserving data mining ... more ABSTRACT Building a real system is one of the major challenges of privacy-preserving data mining (PPDM). In this paper, we propose CRYPPAR, a novel, full-fledged framework for privacy preserving association rule mining based on a cryptographic approach. We use secure scalar product protocols and public-key cryptosystems in CRYPPAR to efficiently mine association rules over vertically partitioned data. We also introduce a partial topology to lower communication cost as much as possible. Empirical results show that the framework is efficient in privacy-preserving association rules and may become a general framework for PPDM systems.

TENCON 2009 - 2009 IEEE Region 10 Conference, 2009

ABSTRACT As sensor nodes are powered by battery of limited lifespan, energy consumption has alway... more ABSTRACT As sensor nodes are powered by battery of limited lifespan, energy consumption has always been an important issue in sensor networks. New generation of sensor network technology bring about the possibility of constructing a spatial index over a sensor network such that sensor queries are forwarded only to the relevant nodes. Existing spatial indices share the common feature of using the same node path for propagating queries and routing back results. Hence, intermediate nodes along the path incur heavier workload than non-intermediate nodes and drain their battery more quickly. In this paper, we propose a multi-parent method to share the workload of intermediate nodes so that sensor results have alternative return paths to the sink node. As a result, the lifespan of the entire sensor network can be prolonged. We study the performance and effects of this method under three different kinds of spatial index structures. Our experiments show that the proposed approach is able to prolong the sensor network lifespan especially when the sensor network is dense. The experiments also yield various interesting information on the performance of the proposed approach under various conditions of the sensor network.

AIAA Atmospheric Flight Mechanics Conference, 2009

In the 1970's the role of the military helicopter evolved to encompass more demanding missions in... more In the 1970's the role of the military helicopter evolved to encompass more demanding missions including low-level nap-of-the-earth flight and operation in severely degraded visual environments. The Vertical Motion Simulator (VMS) at the NASA Ames Research Center was built to provide a high-fidelity simulation capability to research new rotorcraft concepts and technologies that could satisfy these mission requirements. The VMS combines a high-fidelity large amplitude motion system with an adaptable simulation environment including interchangeable and configurable cockpits. In almost 30 years of operation, rotorcraft research on the VMS has contributed significantly to the knowledgebase on rotorcraft performance, handling qualities, flight control, and guidance and displays. These contributions have directly benefited current rotorcraft programs and flight safety. The high fidelity motion system in the VMS was also used to research simulation fidelity. This research provided a fundamental understanding of pilot cueing modalities and their effect on simulation fidelity.

Cureus

Background Since coronavirus disease 2019 (COVID-19) emerged, increasing cases have been identifi... more Background Since coronavirus disease 2019 (COVID-19) emerged, increasing cases have been identified worldwide. COVID-19 continues to lead to significant morbidity and mortality, despite developing a vaccination for the disease. While much has been studied regarding the initial presentation and treatment of patients with COVID-19, to our knowledge, no study has uncovered that COVID-19-positive patients with abdominal pain are at a higher risk of requiring intubation. Methodology In this retrospective cohort study, we identified 104 patients who presented to the emergency room of a single tertiary care center with laboratory-confirmed COVID-19 between February 1, 2020, and April 27, 2020, and collected data on reported pain complaints. Results In this retrospective cohort study, the most common pain complaints were chest pain (25.5%), myalgia (23.4%), and abdominal pain (17.0%). Less common pain complaints included headaches (14.9%) and neck/back pain (6.3%). Of these pain complaints, only patients who reported having abdominal pain were more likely to be intubated (37.5% of patients with abdominal pain were intubated compared to 8.3% of patients without abdominal pain, with a p-value of 0.001). Conclusions Abdominal pain in a patient with COVID-19 infection significantly increases their chances of requiring intubation based on the results of this study.

Foods, 2022

The growing concern for food safety and quality motivates governments and private sectors to impr... more The growing concern for food safety and quality motivates governments and private sectors to improve consumers’ confidence in food systems, such as through adopting certifications and traceability systems. The recent emergence of diverse food labelling schemes and the turbulence in food systems in emerging countries have sparked questions about consumers’ valuation of such labels. Nonetheless, little is known on how the familiarity with, trust in and knowledge of these food labelling schemes affect consumers’ willingness to pay for labelling schemes in emerging market contexts. This study aims to address these literature gaps by investigating consumers’ valuation of existing certifications, branding and traceability labelling schemes in Vietnam. A face-to-face survey was conducted, including a discrete choice experiment on water spinach in Ho Chi Minh City, Vietnam. The findings indicated that Vietnamese consumers are generally willing to pay price premia for food labelling schemes,...

This research is partially supported by Grantsin-Aid for Scientific Research No. 17K03692 from th... more This research is partially supported by Grantsin-Aid for Scientific Research No. 17K03692 from the Japan Society for the Promotion of Science.

Advances in Intelligent Systems and Computing, 2021

Recent research in biology has shifted the focus toward single-cell data analysis. The new single... more Recent research in biology has shifted the focus toward single-cell data analysis. The new single-cell technologies have allowed us to monitor and characterize cells in early embryonic stage and in heterogeneous tumor tissue. However, current single-cell RNA sequencing (scRNA-seq) technologies still need to overcome significant challenges to ensure accurate measurement of gene expression. One critical challenge is to address the dropout event. Due to the low amount of starting material, a large portion of expression values in scRNA-seq data is missing and reported as zeros. These missing values can greatly affect the accuracy of downstream analysis. Here we introduce scIRN, a neural network-based approach, that can reliably recover the missing values in single-cell data and thus can effectively improve the performance of downstream analyses. To impute the dropouts in single-cell data, we build a neural network that consists of two sub-networks: imputation sub-network and quality assessment sub-network. We compare scIRN with stateof-the-art imputation methods using 10 scRNA-seq datasets. In our extensive analysis, scIRN outperforms existing imputation methods in improving the identification of cell sub-populations and the quality of visualizing transcriptome landscape.

Open image in new window Rainfall and earthquakes are considered two of the major causes of lands... more Open image in new window Rainfall and earthquakes are considered two of the major causes of landslides worldwide. These landslides cause billions of dollars in property damage and revenue losses, as well as the deaths of thousands of people each year. While researchers have been examining the effect of either rainfall or earthquakes on the deformation and stability of slopes, the combined effect of rainfall and earthquakes on deformation and slope stability has not been evaluated systematically. In this study, a series of model slopes were constructed in a Plexiglas container placed on top of a shake table. The model slopes were prepared to have different initial void ratios of 0.89, 1.0 and 1.2 and various slope inclinations of 30°, 40°, and 45°. These slopes were instrumented with accelerometers, tensiometers and inclinometers and subjected to a number of sinusoidal seismic motions with different seismic accelerations from 0.1 to 0.3 g, with several frequencies ranging from 1 to 3...

Long term and high-frequency monitoring of water quality, particularly the suspended particulate ... more Long term and high-frequency monitoring of water quality, particularly the suspended particulate matter (SPM) concentration are crucial to decipher the health and sustainable development of marine ecosystems. However, in-situ measurements based on indirect optical or acoustic techniques are often associated with large uncertainties due to the dynamics of natural SPM, especially throughout the land-sea continuum. Therefore, this study aims to improve the accuracy of long term in-situ measurements by quantitatively elucidating the physical mechanisms by which sand and fine sediment respond to multi-wavelength optical and multi-frequency acoustic signals. We hypothesize that whilst fine sediment is very sensitive to optical signals, the coarser particles are more sensitive to acoustic signals, and vice versa. We further hypothesize that the SPM compositions and variability can be differentiated and derived based on such sensitivities and differences in behaviors of sand and fine sediment under different types of signals, i.e., optical and acoustic.

2019 11th International Conference on Knowledge and Systems Engineering (KSE), 2019

Advances in single-cell technologies have shifted genomics research from the analysis of bulk tis... more Advances in single-cell technologies have shifted genomics research from the analysis of bulk tissues toward a comprehensive characterization of individual cells. This holds enormous opportunities for both basic biology and clinical research. As such, identification and characterization of shortlived progenitors, stem cells, cancer stem cells, or circulating tumor cells are essential to better understand both normal and diseased tissue biology. However, quantifying gene expression in each cell remains a significant challenge due to the low amount of mRNA available within individual cells. This leads to the excess amount of zero counts caused by dropout events. Here we introduce RIA, a regression-based approach, that is able to reliably recover the missing values in single-cell data and thus can effectively improve the performance of downstream analyses. We compare RIA with state-of-the-art methods using five scRNA-seq datasets with a total of 3,535 cells. In each dataset analyzed, RIA outperforms existing approaches in improving the identification of cell populations while preserving the biological landscape. We also demonstrate that RIA is able to infer temporal trajectories of embryonic development stages.

This research employed a Participatory Action Research methodology to work with minority inter-pr... more This research employed a Participatory Action Research methodology to work with minority inter-provincial students and unearth their lived experiences at the University of Danang in Vietnam. It focused on examining the undervaluation of inter-provincial students’ voices in the university’s policies – and to a wider extent, in most Vietnamese universities – by facilitating a process in which their challenges and ideas for change at university could be heard. This research also sought to observe and analyse the influences of power dynamics within a Confucian-heritaged context on the participatory research process itself. Vietnam is believed to be a society in which hierarchical power takes its deepest roots due to the effects of Confucianism. By using Participatory Action Research with a variety of methods – photovoice, diagraming, group discussion, interviewing and exhibition – I sought to facilitate student voices and document some of the potential and constraints of the methodolog...

Advancing Culture of Living with Landslides, 2017

Landslides are the third largest disasters worldwide. In order to save innocent lives and propert... more Landslides are the third largest disasters worldwide. In order to save innocent lives and property damage, a system for understanding, assessment and early warning of the landslides is highly necessary. In this work, we have designed and developed an integrated wireless sensor network system for real-time monitoring and early warning of landslides. This paper will discuss the detailed requirements and design criteria considered in the design and development of the Intelligent Wireless Probe (IWP), to capture the relevant landslide triggering parameters. The network of IWPs is used to derive the local or regional contribution of geological, hydrological, and meteorological factors towards the initiation of a potentially imminent landslide. This heterogeneous sensor system provides the capability for gathering real-time context aware data to understand the dynamic variability in landslide risk. The data from these systems are continuously transmitted to our control center for real-time data analysis to derive the possibility of an imminent landslide. Based on the knowledge discovery from these analyses a three level warning system was developed to issue real-time landslide warnings. We have deployed the complete system in Western Ghats and North Eastern Himalayas in India. The system in Munnar has proven its validity by delivering real time warnings to the community in 2009, 2011, and 2013 and continues to monitor landslides even today for the tenth year in a row. The results from the experimentation shows this system has contributed in enhancing the reliability of landslide warning, reduced false alarm rate, and provides the capability to issue warnings in local, slope and regional levels. After the success of this work, Government of India has adopted the system nationally as a result of which we have carried out a second deployment in the North Eastern Himalayas.

Für eine Systematisierung der unterschiedlichen Untersuchungsdesigns vgl. Abschnitt 3.5 (Teil 2 d... more Für eine Systematisierung der unterschiedlichen Untersuchungsdesigns vgl. Abschnitt 3.5 (Teil 2 dieser Arbeit). Für empirische Studien vgl. etwa Ashbaugh-Skaife/Collins/LaFond (2004, 2006), Cheng/Collins/Huang (2006). 9 Wesentliche Impulse für den Literaturstrang um den Cash Flow-Effekt gingen von der Studie von Gompers/Ishii/Metrick (2003) aus, die, stellvertretend für die Machtverhältnisse zwischen Manager und Anteileigner in einem Unternehmen, einen Index konstruieren und diesen in Relation zu den besagten Erfolgsmaßen setzen. 10 hang 15 Darauf aufbauend werden zwei empirisch überprüfbare Generalhypothesen (als Alternativhypothesen) aufgestellt:  Hypothese 1: Corporate Governance hat einen Einfluss auf die Eigenkapitalkosten von Unternehmen und ist damit nicht diversifizierbar.  Hypothese 2: Fremdkapitalgeber haben im Vergleich zu Eigenkapitalgebern eine geringere Nachfrage nach Corporate Governance Mechanismen aufgrund ihrer institutionell besser geschützten Rechtsposition in Deutschland. Mithilfe von ökonometrischen Verfahren werden diese Hypothesen empirisch getestet. Im Hinblick auf das Untersuchungsdesign der empirischen Arbeit besteht ein wesentliches Problem in der Erfassung der Güte der Corporate Governance von Unternehmen (exogene Variablen). Zur Lösung dieses Problems wird auf ein Konzept von Standard & Poor's (2002) zurückgegriffen, das basierend auf den Befunden bisheriger Forschungsarbeiten die Eigentümerstruktur, Managementvergütung und Unternehmenstransparenz als wesentliche Dimensionen zur Sicherstellung einer "guten" Corporate Governance betrachtet. Diese Dimensionen werden im Rahmen der empirischen Arbeit durch verschiedene Stellvertretervariablen approximiert. Zur Schätzung der Eigen-bzw. Fremdkapitalkosten (endogene Variable) werden auf folgende in der Literatur etablierte Methoden zurückgegriffen: (1) Impliziter Eigenkapitalkostenansatz (PEG-Ratio 16), (2) Empirische Bestimmung des Beta-Faktors im Sinne des Capital Asset Pricing Model aus realisierten Kapitalmarktdaten und (3) Zinsaufwand bezogen auf verzinstes bilanzielles Fremdkapital als durchschnittliches Maß für den Fremdkapitalkostensatz. Die notwendigen Daten zur Erfassung dieser Dimensionen werden mehrheitlich per Hand aus verschiedenen Quellen (Geschäftsberichte, Hoppenstedt AG) bzw. professionellen Datenbankanbietern (Worldscope, Datastream, I/B/E/S) erhoben. 15 Zum theoretischen Link zwischen Corporate Governance und Kapitalkosten vgl. Abschnitt 3.4 des in Teil 2 präsentierten Beitrags dieser Arbeit. 16 Vgl. Easton (2004).

The present study examines the different ways in which language structure marks individuation and... more The present study examines the different ways in which language structure marks individuation and cue early attention in a novel noun generalization task. Results in the present study extends the Boundary Shift Hypothesis, suggesting that the linguistic boundary between individuals and nonindividuals influences the perceptual boundaries and the correlational patterns formed overtime between ontological kinds. The results provide a new perspective on the facilitative role of linguistic markers in category formations, rather than strictly in boundary formations. This demonstrates the potential degree of cognitive processing among different language learners and lends support towards a mechanistic explanation of the role of language in categorical formations.

Electronic Visualisation and the Arts (EVA 2015), 2015

Gilcrease on Wheels is an initiative designed to project the Gilcrease Museum's extraordinary Ame... more Gilcrease on Wheels is an initiative designed to project the Gilcrease Museum's extraordinary American collections in a multi-faceted educational package that includes on-site programming, pre-visit preparation, and post-visit activities and evaluation to rural school districts and underserved communities in Oklahoma. Gilcrease on Wheels utilises Gilcrease Museum's extensive collections of American (North America, Mesoamerica, and South America) art, archaeology, and historical documents to enliven the classroom experience while addressing appropriate teaching standards in social studies, art, and language arts to offer a well-rounded, complementary learning experience through exhibits on Oklahoma history and Native American cultures. By introducing Gilcrease collections, in-class enrichment, new activities, and incentives to explore local history, this program promotes critical thinking and encourages students to explore their part of the world. Gilcrease on Wheels incorporates electronic interactive experiences which are age-appropriate for each grade level. Gilcrease on Wheels was inaugurated at the Poteau Public Library on October 23rd, 2014 with successful programming for the third grade. By the end of 2014, over 2000 children in rural schools had participated in programs. The third grade interactive experience incorporates the use of sounds from nature to match to items in the exhibit. The first three years of Gilcrease on Wheels the program focuses on reaching children in rural southeast Oklahoma, including the counties of LeFlore, Haskell, Latimer and Sequoyah. Gilcrease on Wheels gradually will expand to additional grade levels and topics. Age-appropriate techniques and applicable learning standards for each grade will guide development of new curricula incorporating electron interactive experiences. By 2017, Gilcrease on Wheels will expand to cover other under-served, rural areas across Oklahoma Electronic interactive app. Travelling museum exhibit. Age-appropriate apps.

AIAA Modeling and Simulation Technologies Conference and Exhibit, 2004

As part of the investigation of the accident involving American Airlines Flight 587, the National... more As part of the investigation of the accident involving American Airlines Flight 587, the National Transportation Safety Board (NTSB), in cooperation with NASA Ames Research Center, proposed to conduct observations and tests using the Vertical Motion Simulator (VMS). The investigation was divided into two phases. Phase I consisted of evaluating the accelerations experienced during the accident event by back-driving the cockpit controls, displays, out-the-window scene, cockpit communications, and motion of the aircraft as recorded and derived from the aircraft's flight data recorder (FDR) and cockpit voice recorder (CVR). Phase II consisted of evaluating the effects of flight control characteristics and accelerations similar to those experienced during the accident event on pilot perception and performance using a tracking task. The tracking task consisted of pilots following an on-screen target with various flight control configurations, with both motion off and motion being back-driven using derived acceleration data from the FDR. This paper describes the work provided by the VMS in support of the investigation and does not include any conclusions drawn from the study.

2013 IEEE 9th International Colloquium on Signal Processing and its Applications, 2013

ABSTRACT Due to the importance of blood vessel detection in many medical tools and the increasing... more ABSTRACT Due to the importance of blood vessel detection in many medical tools and the increasing demand for portable diagnosis equipment, fast blood vessel detection algorithm in a standalone and portable device is very important. The optimization of a computationally intensive algorithm such as this on a mobile platform is challenging due to the limited resources available. In this paper, the blood vessel detection system is implemented and optimized in a portable device running Android OS on an ARM-based processor. The performance of Java programming model and native programming model are compared with respect to the execution time for blood vessel detection. The experimental results show that the blood vessel detection system has worked well in the ARM platform with the Android OS. Moreover, native programming platform is faster than Java programming with 75.91% better in terms of execution time on average. With multithreading, the performance gain in native programming is 92.77% faster than Java programming.

ALGAE, 2011

The physiology of the unicellular green alga Dunaliella salina in response to abiotic stress has ... more The physiology of the unicellular green alga Dunaliella salina in response to abiotic stress has been studied for several decades. Early D. salina research focused on its remarkable salinity tolerance and ability, upon exposure to various abiotic stresses, to accumulate high concentrations of β-carotene and other carotenoid pigments valued highly as nutraceuticals. The simple life cycle and growth requirements of D. salina make this organism one of the large-scale commercially exploited microalgae for natural carotenoids. Recent advances in genomics and proteomics now allow investigation of abiotic stress responses at the molecular level. Detailed knowledge of isoprenoid biosynthesis mechanisms and the development of molecular tools and techniques for D. salina will allow the improvement of physiological characteristics of algal strains and the use of transgenic algae in bioreactors. Here we review D. salina isoprenoid and carotenoid biosynthesis regulation, and also the biotechnological and genetic transformation procedures developed for this alga that set the stage for its future use as a production system.

Finite Elements: Techniques and Developments

This paper investigates various dynamic effects on the cushioning properties of corrugated fibre ... more This paper investigates various dynamic effects on the cushioning properties of corrugated fibre board (CFB) and the arse of finite element modelling (FEM) as an alternative to conventional experimental tests to evaluate the impact behavior of CFB It was found that the transient response under impact of CFB depends greatly on the compression speed, its mode of behavior can change from predominantly inelastic behavior to instability of the flute. The extent and shape of contact area between the impactor and the cushioning fibre board also affects the characteristics of the response. All these factors should be taken into account in the testing program for cushioning properties of fibre board. Finite element modeling of the corrugated fiber board structure using explicit dynamic software ABAQUS to simulate cushion tests yielded results which are in good agreement with the experimental results. The simulation technique based on FEM would serve as an alternative to obtain the cushion curves in practical packages, and would aid the design of packaging container and of packaging material made of CFB.

TENCON 2009 - 2009 IEEE Region 10 Conference, 2009

ABSTRACT Building a real system is one of the major challenges of privacy-preserving data mining ... more ABSTRACT Building a real system is one of the major challenges of privacy-preserving data mining (PPDM). In this paper, we propose CRYPPAR, a novel, full-fledged framework for privacy preserving association rule mining based on a cryptographic approach. We use secure scalar product protocols and public-key cryptosystems in CRYPPAR to efficiently mine association rules over vertically partitioned data. We also introduce a partial topology to lower communication cost as much as possible. Empirical results show that the framework is efficient in privacy-preserving association rules and may become a general framework for PPDM systems.

TENCON 2009 - 2009 IEEE Region 10 Conference, 2009

ABSTRACT As sensor nodes are powered by battery of limited lifespan, energy consumption has alway... more ABSTRACT As sensor nodes are powered by battery of limited lifespan, energy consumption has always been an important issue in sensor networks. New generation of sensor network technology bring about the possibility of constructing a spatial index over a sensor network such that sensor queries are forwarded only to the relevant nodes. Existing spatial indices share the common feature of using the same node path for propagating queries and routing back results. Hence, intermediate nodes along the path incur heavier workload than non-intermediate nodes and drain their battery more quickly. In this paper, we propose a multi-parent method to share the workload of intermediate nodes so that sensor results have alternative return paths to the sink node. As a result, the lifespan of the entire sensor network can be prolonged. We study the performance and effects of this method under three different kinds of spatial index structures. Our experiments show that the proposed approach is able to prolong the sensor network lifespan especially when the sensor network is dense. The experiments also yield various interesting information on the performance of the proposed approach under various conditions of the sensor network.

AIAA Atmospheric Flight Mechanics Conference, 2009

In the 1970's the role of the military helicopter evolved to encompass more demanding missions in... more In the 1970's the role of the military helicopter evolved to encompass more demanding missions including low-level nap-of-the-earth flight and operation in severely degraded visual environments. The Vertical Motion Simulator (VMS) at the NASA Ames Research Center was built to provide a high-fidelity simulation capability to research new rotorcraft concepts and technologies that could satisfy these mission requirements. The VMS combines a high-fidelity large amplitude motion system with an adaptable simulation environment including interchangeable and configurable cockpits. In almost 30 years of operation, rotorcraft research on the VMS has contributed significantly to the knowledgebase on rotorcraft performance, handling qualities, flight control, and guidance and displays. These contributions have directly benefited current rotorcraft programs and flight safety. The high fidelity motion system in the VMS was also used to research simulation fidelity. This research provided a fundamental understanding of pilot cueing modalities and their effect on simulation fidelity.