Edmund M Lai | Auckland University of Technology (original) (raw)

Papers by Edmund M Lai

Research paper thumbnail of Editorial: 5G-and-Beyond Communications for Smart Cities: Networks, Systems and Applications

School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, China, Schoo... more School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, China, School of Engineering, Computer and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand, School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, China, College of Information Engineering (College of Artificial Intelligence), Yangzhou University, Yangzhou, China, School of Computer Science and Electronic Engineering, University of Essex, Colchester, United Kingdom, Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ, United States, Department of Electronics and Communication Engineering, Institute of Information Technology (IIIT-Delhi), New Delhi, India, Department of Computer and Communication Systems Engineering, Putra Malaysia University, Selangor Darul Ehsan, Malaysia

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Research paper thumbnail of Effects of Similarity Score Functions in Attention Mechanisms on the Performance of Neural Question Answering Systems

Neural Processing Letters, 2022

Attention mechanisms have been incorporated into many neural network-based natural language proce... more Attention mechanisms have been incorporated into many neural network-based natural language processing (NLP) models. They enhance the ability of these models to learn and reason with long input texts. A critical part of such mechanisms is the computation of attention similarity scores between two elements of the texts using a similarity score function. Given that these models have different architectures, it is difficult to comparatively evaluate the effectiveness of different similarity score functions. In this paper, we proposed a baseline model that captures the common components of recurrent neural network-based Question Answering (QA) systems found in the literature. By isolating the attention function, this baseline model allows us to study the effects of different similarity score functions on the performance of such systems. Experimental results show that a trilinear function produced the best results among the commonly used functions. Based on these insights, a new T-trilin...

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Research paper thumbnail of PPDTSA: Privacy-preserving Deep Transformation Self-attention Framework For Object Detection

2021 IEEE Global Communications Conference (GLOBECOM), 2021

In order to perform competitive privacy-guaranteed object detection, we propose an end-to-end mod... more In order to perform competitive privacy-guaranteed object detection, we propose an end-to-end model called Privacy-preserving Deep Transformation Self-attention (PPDTSA). This model ensures the privacy of the inference results. It has a low-complexity hierarchical structure with a relatively small number of hyper-parameters. Consistency of prediction is achieved through the encoding and decoding blocks of the self-attention mechanism which enables points of interest to be located. Focus loss is estimated based on foreground-background imbalance. The remaining dense blocks enable image details to be retained and the Region Of Interest to be expanded. At the same time, the objects detected in the image are protected through the privacy noise volume which is specified by the user. Experimental results demonstrate that PPDTSA achieves superior performance on the MOT20 dataset compared with three other state-of-the-art object detection models.

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Research paper thumbnail of Practical digital signal processing for engineers and technicians

Practical Digital Signal Processing for Engineers and Technicians Edmund Lai PhD, BEng; Lai and A... more Practical Digital Signal Processing for Engineers and Technicians Edmund Lai PhD, BEng; Lai and Associates, Singapore . ... Newnes An imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP 200 Wheeler Road, Burlington, MA 01803 First published 2003 Copyright  ...

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Research paper thumbnail of Kohonen's algorithm for the parametr&ation of manifolds

The analytic process of parametrising manifolds is well known to Mathematicians and Physicists, [... more The analytic process of parametrising manifolds is well known to Mathematicians and Physicists, [1] and is becoming increasingly familiar to Engi-neers concerned with, for example, robot manip-ulator trajectories [2]. The numerical equivalent does not appear to ...

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Research paper thumbnail of Practical Digital Signal Processing

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Research paper thumbnail of Do RSSI values reliably map to RSS in a localization system?

2017 2nd Workshop on Recent Trends in Telecommunications Research (RTTR), 2017

In recent years, research into localization systems has become more popular as the proliferation ... more In recent years, research into localization systems has become more popular as the proliferation of Wireless Sensor Networks (WSNs) grows. Wireless Localization can refer to either an “Active” system which tracks a mobile transceiver, or “Passive” localization which tracks a transceiver free entity by measuring the changes it makes to the surrounding wireless environment. Recent work has seen both of these systems implemented with Received Signal Strength Indication (RSSI) values from transceivers. Many algorithms and channel models have been presented to increase the accuracy of a Received Signal Strength (RSS) based system. In this paper we experimentally check whether RSSI values map to the expected RSS values within an IEEE 802.15.4 network. Indoor experiments are repeated within an ideal outdoor environment, with multiple device platforms, to eliminate indoor multipath propagation as the cause for inconsistent behavior of RSSI. We identify 3 key issues with raw RSSI values and present either a possible solution or a mitigation strategy to reduce their effect. We conclude that using raw RSSI values is flawed, as the premise that they uniquely map to the distance between transceivers is incorrect. However they may be calibrated to increase their accuracy, and therefore viability.

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Research paper thumbnail of SpringLoc: A Device-Free Localization Technique for Indoor Positioning and Tracking Using Adaptive RSSI Spring Relaxation

IEEE Access, 2019

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Research paper thumbnail of Device-Free Localization Systems Utilizing Wireless RSSI: A Comparative Practical Investigation

IEEE Sensors Journal, 2019

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Research paper thumbnail of Design of variable linear phase FIR filters based on second order frequency transformations and coefficient decimation

2012 IEEE International Symposium on Circuits and Systems, 2012

This paper presents the design of a variable linear phase finite impulse response filter based on... more This paper presents the design of a variable linear phase finite impulse response filter based on second order frequency transformations and coefficient decimation. The design of variable digital filters (VDFs) using first and second order frequency transformations have been proposed in literature. The VDF using second order transformation has better cut-off slope characteristics compared to the VDF using first order transformation. However, the former has the drawback of limited range (approximately 25% of the half of the sampling frequency) over which the cut-off frequency, fc, can be varied. It also fails to provide variable lowpass, highpass, bandpass or bandstop responses from a fixed-coefficient lowpass filter using the same architecture. The architecture proposed here overcomes the above mentioned disadvantages using coefficient decimation technique. The design example shows that the range over which fc can be varied is 2.65 times wider in the proposed VDF than the VDF in [7] and for a given frequency range, the proposed VDF offers a total gate count saving of 33% and 41% over the VDF in [11] and [7] respectively. Also, the proposed architecture provides variable lowpass, highpass, bandpass or bandstop responses from a fixed coefficient lowpass filter.

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Research paper thumbnail of Linear Phase VDF Design with Unabridged Bandwidth Control over the Nyquist Band

IEEE Transactions on Circuits and Systems II: Express Briefs, 2014

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Research paper thumbnail of On Minimum Sampling Rates for Signals in Shift Invariant Spaces

Edmund MK. Lai, 2007

Page 1. On Minimum Sampling Rates for Signals in Shift Invariant Spaces Beilei Huang, Edmund MK. ... more Page 1. On Minimum Sampling Rates for Signals in Shift Invariant Spaces Beilei Huang, Edmund MK. Lai Institute of Information Sciences & Technology Massey University, Wellington, New Zealand AP Vinod School of Computer ...

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Research paper thumbnail of Transformer With Bidirectional GRU for Nonintrusive, Sensor-Based Activity Recognition in a Multiresident Environment

IEEE Internet of Things Journal

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Research paper thumbnail of A sustainable vehicular based energy efficient data dissemination approach

2017 27th International Telecommunication Networks and Applications Conference (ITNAC), 2017

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Research paper thumbnail of Cucker-smale flocking under asynchronous update dynamics

2017 IEEE International Conference on Agents (ICA)

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Research paper thumbnail of Gain-Some-Lose-Some: Reliable Quantification Under General Dataset Shift

2021 IEEE International Conference on Data Mining (ICDM), 2021

When applying supervised learning to estimate class distributions of unlabelled samples (so-calle... more When applying supervised learning to estimate class distributions of unlabelled samples (so-called quantification), dataset shift is an expected yet challenging problem. Existing quantification methods make strong assumptions on the nature of dataset shift that often will not hold in practice. We propose a novel Gain-Some-Lose-Some (GSLS) model that accounts for more general conditions of dataset shift. We present a method for fitting the GSLS model without any labelled instances from the target sample, and experimentally demonstrate that GSLS can produce reliable quantification prediction intervals under broader conditions of shift than existing quantification methods.

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Research paper thumbnail of Locally Weighted Ensemble-Detection-Based Adaptive Random Forest Classifier for Sensor-Based Online Activity Recognition for Multiple Residents

IEEE Internet of Things Journal, 2021

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Research paper thumbnail of Traffic Scenarios for Automated Vehicle Testing: A Review of Description Languages and Systems

Machines, 2021

Testing and validation of the functionalities and safety of automated vehicles shifted from a dis... more Testing and validation of the functionalities and safety of automated vehicles shifted from a distance-based to a scenario-based method in the past decade. A number of domain-specific languages and systems were developed to support scenario-based testing. The aim of this paper is to review and compare the features and characteristics of the major scenario description languages and systems (SDLS). Each of them is designed for different purposes and with different goals; therefore, they have their strengths and weaknesses. Their characteristics are highlighted with an example nontrivial traffic scenario that we designed. We also discuss some directions for further development and research of these SDLS.

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Research paper thumbnail of A New Noise Generating Method Based on Gaussian Sampling for Privacy Preservation

Geometry and Vision, 2021

Centralised machine learning brings in side effect pertaining to privacy preservation, most of ma... more Centralised machine learning brings in side effect pertaining to privacy preservation, most of machine learning methods prone to using the frameworks without privacy protection, as current methods for privacy preservation will slow down model training and testing. In order to resolve this problem, we develop a new noise generating method based on information entropy by using differential privacy for betterment the privacy protection which owns the architecture of federated machine learning. Our experiments unveil that this solution effectively preserves privacy in the vein of centralized federated learning. The gained accuracy is promising which has a room to be uplifted.

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Research paper thumbnail of A Sustainable Marriage of Telcos and Transp in the Era of Big Data: Are We Ready?

The emerging smart city paradigm e.g., intelligent transport, smart grid and participatory sensin... more The emerging smart city paradigm e.g., intelligent transport, smart grid and participatory sensing etc. is to advance the quality, performance and experience of urban citizten services through greater connectivity. This paradigm needs to collect data from citizens, various devices and assets that could be monitored, processed and analysed for the city governers to make better decision and also more efficiently manage those assests and resources. While the telecommunication and Internet are progressively being over-burdened and congested by the growing data transmission demands. To keep expanding the telecommunications and Internet infrastructures to accomodate these intensive data demands is costly and also the associated energy consumptions and carbon emissions could at long last wind up genuinely hurting the environment. To face this issue in the coming era of big data, we envision it will be best to utilize the established urban transport and road infrastructure and existing dail...

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Research paper thumbnail of Editorial: 5G-and-Beyond Communications for Smart Cities: Networks, Systems and Applications

School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, China, Schoo... more School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, China, School of Engineering, Computer and Mathematical Sciences, Auckland University of Technology, Auckland, New Zealand, School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu, China, College of Information Engineering (College of Artificial Intelligence), Yangzhou University, Yangzhou, China, School of Computer Science and Electronic Engineering, University of Essex, Colchester, United Kingdom, Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ, United States, Department of Electronics and Communication Engineering, Institute of Information Technology (IIIT-Delhi), New Delhi, India, Department of Computer and Communication Systems Engineering, Putra Malaysia University, Selangor Darul Ehsan, Malaysia

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Research paper thumbnail of Effects of Similarity Score Functions in Attention Mechanisms on the Performance of Neural Question Answering Systems

Neural Processing Letters, 2022

Attention mechanisms have been incorporated into many neural network-based natural language proce... more Attention mechanisms have been incorporated into many neural network-based natural language processing (NLP) models. They enhance the ability of these models to learn and reason with long input texts. A critical part of such mechanisms is the computation of attention similarity scores between two elements of the texts using a similarity score function. Given that these models have different architectures, it is difficult to comparatively evaluate the effectiveness of different similarity score functions. In this paper, we proposed a baseline model that captures the common components of recurrent neural network-based Question Answering (QA) systems found in the literature. By isolating the attention function, this baseline model allows us to study the effects of different similarity score functions on the performance of such systems. Experimental results show that a trilinear function produced the best results among the commonly used functions. Based on these insights, a new T-trilin...

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Research paper thumbnail of PPDTSA: Privacy-preserving Deep Transformation Self-attention Framework For Object Detection

2021 IEEE Global Communications Conference (GLOBECOM), 2021

In order to perform competitive privacy-guaranteed object detection, we propose an end-to-end mod... more In order to perform competitive privacy-guaranteed object detection, we propose an end-to-end model called Privacy-preserving Deep Transformation Self-attention (PPDTSA). This model ensures the privacy of the inference results. It has a low-complexity hierarchical structure with a relatively small number of hyper-parameters. Consistency of prediction is achieved through the encoding and decoding blocks of the self-attention mechanism which enables points of interest to be located. Focus loss is estimated based on foreground-background imbalance. The remaining dense blocks enable image details to be retained and the Region Of Interest to be expanded. At the same time, the objects detected in the image are protected through the privacy noise volume which is specified by the user. Experimental results demonstrate that PPDTSA achieves superior performance on the MOT20 dataset compared with three other state-of-the-art object detection models.

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Research paper thumbnail of Practical digital signal processing for engineers and technicians

Practical Digital Signal Processing for Engineers and Technicians Edmund Lai PhD, BEng; Lai and A... more Practical Digital Signal Processing for Engineers and Technicians Edmund Lai PhD, BEng; Lai and Associates, Singapore . ... Newnes An imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP 200 Wheeler Road, Burlington, MA 01803 First published 2003 Copyright  ...

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Research paper thumbnail of Kohonen's algorithm for the parametr&ation of manifolds

The analytic process of parametrising manifolds is well known to Mathematicians and Physicists, [... more The analytic process of parametrising manifolds is well known to Mathematicians and Physicists, [1] and is becoming increasingly familiar to Engi-neers concerned with, for example, robot manip-ulator trajectories [2]. The numerical equivalent does not appear to ...

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Research paper thumbnail of Practical Digital Signal Processing

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Research paper thumbnail of Do RSSI values reliably map to RSS in a localization system?

2017 2nd Workshop on Recent Trends in Telecommunications Research (RTTR), 2017

In recent years, research into localization systems has become more popular as the proliferation ... more In recent years, research into localization systems has become more popular as the proliferation of Wireless Sensor Networks (WSNs) grows. Wireless Localization can refer to either an “Active” system which tracks a mobile transceiver, or “Passive” localization which tracks a transceiver free entity by measuring the changes it makes to the surrounding wireless environment. Recent work has seen both of these systems implemented with Received Signal Strength Indication (RSSI) values from transceivers. Many algorithms and channel models have been presented to increase the accuracy of a Received Signal Strength (RSS) based system. In this paper we experimentally check whether RSSI values map to the expected RSS values within an IEEE 802.15.4 network. Indoor experiments are repeated within an ideal outdoor environment, with multiple device platforms, to eliminate indoor multipath propagation as the cause for inconsistent behavior of RSSI. We identify 3 key issues with raw RSSI values and present either a possible solution or a mitigation strategy to reduce their effect. We conclude that using raw RSSI values is flawed, as the premise that they uniquely map to the distance between transceivers is incorrect. However they may be calibrated to increase their accuracy, and therefore viability.

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Research paper thumbnail of SpringLoc: A Device-Free Localization Technique for Indoor Positioning and Tracking Using Adaptive RSSI Spring Relaxation

IEEE Access, 2019

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Research paper thumbnail of Device-Free Localization Systems Utilizing Wireless RSSI: A Comparative Practical Investigation

IEEE Sensors Journal, 2019

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Research paper thumbnail of Design of variable linear phase FIR filters based on second order frequency transformations and coefficient decimation

2012 IEEE International Symposium on Circuits and Systems, 2012

This paper presents the design of a variable linear phase finite impulse response filter based on... more This paper presents the design of a variable linear phase finite impulse response filter based on second order frequency transformations and coefficient decimation. The design of variable digital filters (VDFs) using first and second order frequency transformations have been proposed in literature. The VDF using second order transformation has better cut-off slope characteristics compared to the VDF using first order transformation. However, the former has the drawback of limited range (approximately 25% of the half of the sampling frequency) over which the cut-off frequency, fc, can be varied. It also fails to provide variable lowpass, highpass, bandpass or bandstop responses from a fixed-coefficient lowpass filter using the same architecture. The architecture proposed here overcomes the above mentioned disadvantages using coefficient decimation technique. The design example shows that the range over which fc can be varied is 2.65 times wider in the proposed VDF than the VDF in [7] and for a given frequency range, the proposed VDF offers a total gate count saving of 33% and 41% over the VDF in [11] and [7] respectively. Also, the proposed architecture provides variable lowpass, highpass, bandpass or bandstop responses from a fixed coefficient lowpass filter.

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Research paper thumbnail of Linear Phase VDF Design with Unabridged Bandwidth Control over the Nyquist Band

IEEE Transactions on Circuits and Systems II: Express Briefs, 2014

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Research paper thumbnail of On Minimum Sampling Rates for Signals in Shift Invariant Spaces

Edmund MK. Lai, 2007

Page 1. On Minimum Sampling Rates for Signals in Shift Invariant Spaces Beilei Huang, Edmund MK. ... more Page 1. On Minimum Sampling Rates for Signals in Shift Invariant Spaces Beilei Huang, Edmund MK. Lai Institute of Information Sciences & Technology Massey University, Wellington, New Zealand AP Vinod School of Computer ...

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Research paper thumbnail of Transformer With Bidirectional GRU for Nonintrusive, Sensor-Based Activity Recognition in a Multiresident Environment

IEEE Internet of Things Journal

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Research paper thumbnail of A sustainable vehicular based energy efficient data dissemination approach

2017 27th International Telecommunication Networks and Applications Conference (ITNAC), 2017

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Research paper thumbnail of Cucker-smale flocking under asynchronous update dynamics

2017 IEEE International Conference on Agents (ICA)

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Gain-Some-Lose-Some: Reliable Quantification Under General Dataset Shift

2021 IEEE International Conference on Data Mining (ICDM), 2021

When applying supervised learning to estimate class distributions of unlabelled samples (so-calle... more When applying supervised learning to estimate class distributions of unlabelled samples (so-called quantification), dataset shift is an expected yet challenging problem. Existing quantification methods make strong assumptions on the nature of dataset shift that often will not hold in practice. We propose a novel Gain-Some-Lose-Some (GSLS) model that accounts for more general conditions of dataset shift. We present a method for fitting the GSLS model without any labelled instances from the target sample, and experimentally demonstrate that GSLS can produce reliable quantification prediction intervals under broader conditions of shift than existing quantification methods.

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Research paper thumbnail of Locally Weighted Ensemble-Detection-Based Adaptive Random Forest Classifier for Sensor-Based Online Activity Recognition for Multiple Residents

IEEE Internet of Things Journal, 2021

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Research paper thumbnail of Traffic Scenarios for Automated Vehicle Testing: A Review of Description Languages and Systems

Machines, 2021

Testing and validation of the functionalities and safety of automated vehicles shifted from a dis... more Testing and validation of the functionalities and safety of automated vehicles shifted from a distance-based to a scenario-based method in the past decade. A number of domain-specific languages and systems were developed to support scenario-based testing. The aim of this paper is to review and compare the features and characteristics of the major scenario description languages and systems (SDLS). Each of them is designed for different purposes and with different goals; therefore, they have their strengths and weaknesses. Their characteristics are highlighted with an example nontrivial traffic scenario that we designed. We also discuss some directions for further development and research of these SDLS.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A New Noise Generating Method Based on Gaussian Sampling for Privacy Preservation

Geometry and Vision, 2021

Centralised machine learning brings in side effect pertaining to privacy preservation, most of ma... more Centralised machine learning brings in side effect pertaining to privacy preservation, most of machine learning methods prone to using the frameworks without privacy protection, as current methods for privacy preservation will slow down model training and testing. In order to resolve this problem, we develop a new noise generating method based on information entropy by using differential privacy for betterment the privacy protection which owns the architecture of federated machine learning. Our experiments unveil that this solution effectively preserves privacy in the vein of centralized federated learning. The gained accuracy is promising which has a room to be uplifted.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A Sustainable Marriage of Telcos and Transp in the Era of Big Data: Are We Ready?

The emerging smart city paradigm e.g., intelligent transport, smart grid and participatory sensin... more The emerging smart city paradigm e.g., intelligent transport, smart grid and participatory sensing etc. is to advance the quality, performance and experience of urban citizten services through greater connectivity. This paradigm needs to collect data from citizens, various devices and assets that could be monitored, processed and analysed for the city governers to make better decision and also more efficiently manage those assests and resources. While the telecommunication and Internet are progressively being over-burdened and congested by the growing data transmission demands. To keep expanding the telecommunications and Internet infrastructures to accomodate these intensive data demands is costly and also the associated energy consumptions and carbon emissions could at long last wind up genuinely hurting the environment. To face this issue in the coming era of big data, we envision it will be best to utilize the established urban transport and road infrastructure and existing dail...

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