Gengen He - Academia.edu (original) (raw)

Papers by Gengen He

We are investigating a prototype virtual pinhole positron emission tomography (VP-PET) system for... more We are investigating a prototype virtual pinhole positron emission tomography (VP-PET) system for small animal imaging applications. The PET detector modules were made up of 1.3 mm lutetium-yttrium oxyorthosilicate (LYSO) arrays, and the insert detectors consists of 0.6 mm pixelated Cadmium Zinc Telluride (CdZnTe). To validate the imaging experiment, we conducted a Monte Carlo simulation for the VP-PET system in Geant4 Application for Emission Tomography (GATE). For a point source of Na-22 with 0.5 mm diameter, the filtered back-projection (FBP) algorithm reconstructed PET image shows a resolution of 0.7 mm full-width-at-half-maximum (FWHM). The system sensitivity is 0.46 cps/kBq at the center of field view (CFOV) of the PET system with a source activity of 0.925 MBq and an energy resolution of 350-650 keV. A rod source phantom and a Derenzo phantom with F-18 were also simulated to investigate the PET imaging capability. GATE simulation indicated that two point sources with 0.5 mm d...

This study will introduce a prototype design of indoor positioning system with the combination of... more This study will introduce a prototype design of indoor positioning system with the combination of vision-based pedestrian tracking and digital map information in WGS 1984 and in future will combine with INS. A trial has been finished for visual tracking with integration of digitized floor plan, taking place in PMB Building in University of Nottingham. The result is promising for future development of positioning system.

World Academy of Science, Engineering and Technology, International Journal of Cognitive and Language Sciences, 2020

2018 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), 2018

Vision-aided inertial navigation has become a very popular method for indoor navigation recently.... more Vision-aided inertial navigation has become a very popular method for indoor navigation recently. This popularity is basically due to the development of light-weighted and low-cost Micro Electro-Mechanical Systems (MEMS) as well as advancement and availability of Charged-Couple-Device (CCD) cameras in public indoor areas. While the use of inertial sensors and cameras are challenging due to drift accumulation and object detection in line of sight, respectively, the integration of these two sensors can compensate their drawbacks and provide more accurate positioning solutions. This study examines this hypothesis by evaluating the accuracy of the vision-aided systems for indoor positioning and tracking. The novel aspect of this study is to implement inertial and visual sensors in independent platforms other than attached together on the same platform. The other novelty is to integrate digitized floor plans for absolute position information. The mean accuracy of this positioning system ...

Autonomous vehicles (aka self-driving cars) and their equipped intelligent systems are among the ... more Autonomous vehicles (aka self-driving cars) and their equipped intelligent systems are among the most exciting and innovative technologies in transportation. In order to operate safely, autonomous vehicles require high-precision geospatial datasets and maps, which contain significantly more detailed road information (such as lanes and signs) and the true ground (absolute accuracy) than those found in conventional geospatial resources for driving and navigation. With the integration with artificial intelligence, machine learning, data mining, image processing and other technologies, novel intelligent applications are fast growing. This workshop aims to bring both academic researchers and geospatial industry engineers together to present, discuss, and share the state-of-the-art scientific research and technology advancement on related fields for autonomous vehicles. The workshop participants will also have an opportunity to share their latest research works and brainstorm their vision...

The design of a navigation system to support indoor fire evacuation depends not only on speed but... more The design of a navigation system to support indoor fire evacuation depends not only on speed but also a relatively thorough consideration of the cognition factors. This study has investigated potential cognition factors which can affect the human behaviours and decision making during fire evacuation by taking a survey among indoor occupants in age of 20s under designed virtual scenarios. It mainly focuses on two aspects of Fire Responses Performances (FRP), i.e. indoor familiarity (spatial cognition) and psychological stress (situ-ated cognition). The collected results have shown that these cognition factors can be affected by gender and user height and they are correlated with each other in certain ways. It has also investigated users‟ attitudes to the navigation services under risky and non-risky conditions. The collected answers are also found to be correlated with the selected FRP factors. These findings may help to further design of personalized indoor navigation support for f...

I dedicate this dissertation work to my parents, Paul Friday, Francis Ho, Yanyan Song, who inspir... more I dedicate this dissertation work to my parents, Paul Friday, Francis Ho, Yanyan Song, who inspired, supported me and encourage me through this long process. My grandparents would also have been very proud. First and foremost, I want thank my advisor, Dr. Shih-Lung Shaw. He gave me a new life direction, and guided me through this journey. I want to thank Dr. Toru Ishikawa at the University of Tokyo, he taught me many of the methods I used in my dissertation I hope to have many more collaborations with him in the future.

The vision-aided pedestrian dead reckoning (PDR) systems have become increasingly popular, thanks... more The vision-aided pedestrian dead reckoning (PDR) systems have become increasingly popular, thanks to the ubiquitous mobile phone embedded with several sensors. This is particularly important for indoor use, where other indoor positioning technologies require additional installation or body attachment of specific sensors. This paper proposes and develops a novel 3-D passive vision-aided PDR system that uses multiple surveillance cameras and smartphone-based PDR. The proposed system can continuously track users’ movement on different floors by integrating results of inertial navigation and Faster Region-Based Convolutional Neutral Network (Faster R-CNN)-based real-time pedestrian detection, while utilizing existing camera locations and embedded barometers to provide floor/height information to identify user positions in 3-D space. This novel system provides a relatively low-cost and user-friendly solution, which requires no modifications to currently available mobile devices and also ...

2018 Ubiquitous Positioning, Indoor Navigation and Location-Based Services (UPINLBS)

Currently, Pedestrian Dead Reckoning (PDR) systems are becoming more attractive in market of indo... more Currently, Pedestrian Dead Reckoning (PDR) systems are becoming more attractive in market of indoor positioning. This is mainly due to the development of cheap and light Micro Electro-Mechanical Systems (MEMS) on smartphones and less requirement of additional infrastructures in indoor areas. However, it still faces the problem of drift accumulation and needs the support from external positioning systems. Vision-aided inertial navigation, as one possible solution to that problem, has become very popular in indoor localization with satisfied performance than individual PDR system. In the literature however, previous studies use fixed platform and the visual tracking uses feature-extraction-based methods. This paper instead contributes a distributed implementation of positioning system and uses deep learning for visual tracking. Meanwhile, as both inertial navigation and optical system can only provide relative positioning information, this paper contributes a method to integrate digital map with real geographical coordinates to supply absolute location. This hybrid system has been tested on two common operation systems of smartphones as iOS and Android, based on corresponded data collection apps respectively, in order to test the robustness of method. It also uses two different ways for calibration, by time synchronization of positions and heading calibration based on time steps. According to the results, localization information collected from both operation systems has been significantly improved after integrating with visual tracking data.

Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems - GIS '15, 2015

Spatial Cognition & Computation

This study addressed the issue of collaborative navigation by examining the types of information ... more This study addressed the issue of collaborative navigation by examining the types of information communicated in the processes of direction giving and receiving between people who guided each other simultaneously to a destination over the cell phone in a novel environment. When paired with a partner whose sense of direction differed greatly from their own, people found the collaboration difficult and took a longer time to verbally direct the partner to the destination. Landmarks that people used in giving navigational instructions differed depending on sense of direction. People with a good sense of direction adjusted route directions to their partners' wayfinding ability. Results from a detailed qualitative analysis of participants' verbal protocols and implications for personalized navigation tools are discussed.

Talanta

A chemical potential driven micro-membrane sampler for enrichment of trace gaseous carbonyl compo... more A chemical potential driven micro-membrane sampler for enrichment of trace gaseous carbonyl compounds has been developed. The sampler is composed of exposed parts with membrane and analysis parts with polypropylene tube. The membrane acts as a barrier, through which the analytes dynamically diffuse and transfer from absorbents present outside to extract solvent inside through the difference of chemical potential. Formaldehyde and acetic acid were selected as verification samples. Quantification is achieved through high performance liquid chromatography (HPLC) analysis. The mass of analytes determined shows a linear correlation with concentration of the gaseous analytes. The limits of detection of formaldehyde and acetic acid after 8h sampling were 3.32 and 0.76 μg m(-3).

International Journal of Computational Biology and Drug Design

Using a unique combination of visual, statistical, and data mining methods, we tested the hypothe... more Using a unique combination of visual, statistical, and data mining methods, we tested the hypothesis that an immune cell's movement pattern can convey key information about the cell's function, antigen specificity, and environment. We applied clustering, statistical tests, and a support vector machine (SVM) to assess our ability to classify different datasets of imaged flouresently labelled T cells in mouse liver. We additionally saw clusters of different movement patterns of T cells of identical antigenic specificity. We found that the movement patterns of T cells specific and non-specific for malaria parasites are differentiable with 72% accuracy, and that specific cells have a higher tendency to move towards the parasite than non-specific cells. Movements of antigen-specific T cells in uninfected mice vs. infected mice were differentiable with 69.8% accuracy. We additionally saw clusters of different movement patterns of T cells of identical antigenic specificity. We conc...

We are investigating a prototype virtual pinhole positron emission tomography (VP-PET) system for... more We are investigating a prototype virtual pinhole positron emission tomography (VP-PET) system for small animal imaging applications. The PET detector modules were made up of 1.3 mm lutetium-yttrium oxyorthosilicate (LYSO) arrays, and the insert detectors consists of 0.6 mm pixelated Cadmium Zinc Telluride (CdZnTe). To validate the imaging experiment, we conducted a Monte Carlo simulation for the VP-PET system in Geant4 Application for Emission Tomography (GATE). For a point source of Na-22 with 0.5 mm diameter, the filtered back-projection (FBP) algorithm reconstructed PET image shows a resolution of 0.7 mm full-width-at-half-maximum (FWHM). The system sensitivity is 0.46 cps/kBq at the center of field view (CFOV) of the PET system with a source activity of 0.925 MBq and an energy resolution of 350-650 keV. A rod source phantom and a Derenzo phantom with F-18 were also simulated to investigate the PET imaging capability. GATE simulation indicated that two point sources with 0.5 mm d...

This study will introduce a prototype design of indoor positioning system with the combination of... more This study will introduce a prototype design of indoor positioning system with the combination of vision-based pedestrian tracking and digital map information in WGS 1984 and in future will combine with INS. A trial has been finished for visual tracking with integration of digitized floor plan, taking place in PMB Building in University of Nottingham. The result is promising for future development of positioning system.

World Academy of Science, Engineering and Technology, International Journal of Cognitive and Language Sciences, 2020

2018 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), 2018

Vision-aided inertial navigation has become a very popular method for indoor navigation recently.... more Vision-aided inertial navigation has become a very popular method for indoor navigation recently. This popularity is basically due to the development of light-weighted and low-cost Micro Electro-Mechanical Systems (MEMS) as well as advancement and availability of Charged-Couple-Device (CCD) cameras in public indoor areas. While the use of inertial sensors and cameras are challenging due to drift accumulation and object detection in line of sight, respectively, the integration of these two sensors can compensate their drawbacks and provide more accurate positioning solutions. This study examines this hypothesis by evaluating the accuracy of the vision-aided systems for indoor positioning and tracking. The novel aspect of this study is to implement inertial and visual sensors in independent platforms other than attached together on the same platform. The other novelty is to integrate digitized floor plans for absolute position information. The mean accuracy of this positioning system ...

Autonomous vehicles (aka self-driving cars) and their equipped intelligent systems are among the ... more Autonomous vehicles (aka self-driving cars) and their equipped intelligent systems are among the most exciting and innovative technologies in transportation. In order to operate safely, autonomous vehicles require high-precision geospatial datasets and maps, which contain significantly more detailed road information (such as lanes and signs) and the true ground (absolute accuracy) than those found in conventional geospatial resources for driving and navigation. With the integration with artificial intelligence, machine learning, data mining, image processing and other technologies, novel intelligent applications are fast growing. This workshop aims to bring both academic researchers and geospatial industry engineers together to present, discuss, and share the state-of-the-art scientific research and technology advancement on related fields for autonomous vehicles. The workshop participants will also have an opportunity to share their latest research works and brainstorm their vision...

The design of a navigation system to support indoor fire evacuation depends not only on speed but... more The design of a navigation system to support indoor fire evacuation depends not only on speed but also a relatively thorough consideration of the cognition factors. This study has investigated potential cognition factors which can affect the human behaviours and decision making during fire evacuation by taking a survey among indoor occupants in age of 20s under designed virtual scenarios. It mainly focuses on two aspects of Fire Responses Performances (FRP), i.e. indoor familiarity (spatial cognition) and psychological stress (situ-ated cognition). The collected results have shown that these cognition factors can be affected by gender and user height and they are correlated with each other in certain ways. It has also investigated users‟ attitudes to the navigation services under risky and non-risky conditions. The collected answers are also found to be correlated with the selected FRP factors. These findings may help to further design of personalized indoor navigation support for f...

I dedicate this dissertation work to my parents, Paul Friday, Francis Ho, Yanyan Song, who inspir... more I dedicate this dissertation work to my parents, Paul Friday, Francis Ho, Yanyan Song, who inspired, supported me and encourage me through this long process. My grandparents would also have been very proud. First and foremost, I want thank my advisor, Dr. Shih-Lung Shaw. He gave me a new life direction, and guided me through this journey. I want to thank Dr. Toru Ishikawa at the University of Tokyo, he taught me many of the methods I used in my dissertation I hope to have many more collaborations with him in the future.

The vision-aided pedestrian dead reckoning (PDR) systems have become increasingly popular, thanks... more The vision-aided pedestrian dead reckoning (PDR) systems have become increasingly popular, thanks to the ubiquitous mobile phone embedded with several sensors. This is particularly important for indoor use, where other indoor positioning technologies require additional installation or body attachment of specific sensors. This paper proposes and develops a novel 3-D passive vision-aided PDR system that uses multiple surveillance cameras and smartphone-based PDR. The proposed system can continuously track users’ movement on different floors by integrating results of inertial navigation and Faster Region-Based Convolutional Neutral Network (Faster R-CNN)-based real-time pedestrian detection, while utilizing existing camera locations and embedded barometers to provide floor/height information to identify user positions in 3-D space. This novel system provides a relatively low-cost and user-friendly solution, which requires no modifications to currently available mobile devices and also ...

2018 Ubiquitous Positioning, Indoor Navigation and Location-Based Services (UPINLBS)

Currently, Pedestrian Dead Reckoning (PDR) systems are becoming more attractive in market of indo... more Currently, Pedestrian Dead Reckoning (PDR) systems are becoming more attractive in market of indoor positioning. This is mainly due to the development of cheap and light Micro Electro-Mechanical Systems (MEMS) on smartphones and less requirement of additional infrastructures in indoor areas. However, it still faces the problem of drift accumulation and needs the support from external positioning systems. Vision-aided inertial navigation, as one possible solution to that problem, has become very popular in indoor localization with satisfied performance than individual PDR system. In the literature however, previous studies use fixed platform and the visual tracking uses feature-extraction-based methods. This paper instead contributes a distributed implementation of positioning system and uses deep learning for visual tracking. Meanwhile, as both inertial navigation and optical system can only provide relative positioning information, this paper contributes a method to integrate digital map with real geographical coordinates to supply absolute location. This hybrid system has been tested on two common operation systems of smartphones as iOS and Android, based on corresponded data collection apps respectively, in order to test the robustness of method. It also uses two different ways for calibration, by time synchronization of positions and heading calibration based on time steps. According to the results, localization information collected from both operation systems has been significantly improved after integrating with visual tracking data.

Proceedings of the 23rd SIGSPATIAL International Conference on Advances in Geographic Information Systems - GIS '15, 2015

Spatial Cognition & Computation

This study addressed the issue of collaborative navigation by examining the types of information ... more This study addressed the issue of collaborative navigation by examining the types of information communicated in the processes of direction giving and receiving between people who guided each other simultaneously to a destination over the cell phone in a novel environment. When paired with a partner whose sense of direction differed greatly from their own, people found the collaboration difficult and took a longer time to verbally direct the partner to the destination. Landmarks that people used in giving navigational instructions differed depending on sense of direction. People with a good sense of direction adjusted route directions to their partners' wayfinding ability. Results from a detailed qualitative analysis of participants' verbal protocols and implications for personalized navigation tools are discussed.

Talanta

A chemical potential driven micro-membrane sampler for enrichment of trace gaseous carbonyl compo... more A chemical potential driven micro-membrane sampler for enrichment of trace gaseous carbonyl compounds has been developed. The sampler is composed of exposed parts with membrane and analysis parts with polypropylene tube. The membrane acts as a barrier, through which the analytes dynamically diffuse and transfer from absorbents present outside to extract solvent inside through the difference of chemical potential. Formaldehyde and acetic acid were selected as verification samples. Quantification is achieved through high performance liquid chromatography (HPLC) analysis. The mass of analytes determined shows a linear correlation with concentration of the gaseous analytes. The limits of detection of formaldehyde and acetic acid after 8h sampling were 3.32 and 0.76 μg m(-3).

International Journal of Computational Biology and Drug Design

Using a unique combination of visual, statistical, and data mining methods, we tested the hypothe... more Using a unique combination of visual, statistical, and data mining methods, we tested the hypothesis that an immune cell's movement pattern can convey key information about the cell's function, antigen specificity, and environment. We applied clustering, statistical tests, and a support vector machine (SVM) to assess our ability to classify different datasets of imaged flouresently labelled T cells in mouse liver. We additionally saw clusters of different movement patterns of T cells of identical antigenic specificity. We found that the movement patterns of T cells specific and non-specific for malaria parasites are differentiable with 72% accuracy, and that specific cells have a higher tendency to move towards the parasite than non-specific cells. Movements of antigen-specific T cells in uninfected mice vs. infected mice were differentiable with 69.8% accuracy. We additionally saw clusters of different movement patterns of T cells of identical antigenic specificity. We conc...