title: Jitter measurement in digital signals by using software defined radio technology

authors: Anthonys, Gehan

abstract: Here, we propose a method using software defined radio (SDR) technology to measure periodic and random jitter in a digital signal. Conventional methods to measure jitter required expensive measurement equipment. We use a cheap (less than US $40) SDR USB dongle to expose random and periodic jitter in the amplitude modulated light source of a range camera. By using Fourier analysis we generate an ideal reference signal to enable to extract jitter at the zero crossings of the signal under test. We measure jitter with SDR receiver and more conventionally a real-time digital oscilloscope. From the SDR receiver, we find the periodic jitter at low frequency and compare to the oscilloscope results. We demonstrate that periodic and random jitter can be detected on a RF signal with consumer priced products provided that the jitter frequency less within the bandwidth of the receiver.

text: Jitter measurement in digital signals by using software defined radio technology Here, we propose a method using software defined radio (SDR) technology to measure periodic and random jitter in a digital signal. Conventional methods to measure jitter required expensive measurement equipment. We use a cheap (less than US $40) SDR USB dongle to expose random and periodic jitter in the amplitude modulated light source of a range camera. By using Fourier analysis we generate an ideal reference signal to enable to extract jitter at the zero crossings of the signal under test. We measure jitter with SDR receiver and more conventionally a real-time digital oscilloscope. From the SDR receiver, we find the periodic jitter at low frequency and compare to the oscilloscope results. We demonstrate that periodic and random jitter can be detected on a RF signal with consumer priced products provided that the jitter frequency less within the bandwidth of the receiver.

year: 2019

title: Using machine learning techniques to track individuals & their fitness activities

authors: Reichherzer, Thomas

subjects: wearable fitness device

abstract: The use of wearable devices for fitness and health tracking is on an upward curve with a range of devices now available from a number of manufacturers. The devices work with smart devices to exchange data via Bluetooth communication protocol. This paper presents the results of an initial study on the security and privacy weaknesses of wearable fitness devices. It discusses methods to 1) capture and process data sent from a wearable device to its paired smartphone during synchronization and 2) analyze the records to track individuals and make predictions. The data analysis methods use supervised machine-learning techniques to train a classifier for associating synchronization records with the individuals, their physical activities, and conditions under which they were performed. Results of the study show that the methods allow individuals and their activities to be tracked, both of which infringe on the privacy of the user. The paper also provides recommendations on improving the security of wearable devices based on the initial research results.

text: Using machine learning techniques to track individuals & their fitness activities The use of wearable devices for fitness and health tracking is on an upward curve with a range of devices now available from a number of manufacturers. The devices work with smart devices to exchange data via Bluetooth communication protocol. This paper presents the results of an initial study on the security and privacy weaknesses of wearable fitness devices. It discusses methods to 1) capture and process data sent from a wearable device to its paired smartphone during synchronization and 2) analyze the records to track individuals and make predictions. The data analysis methods use supervised machine-learning techniques to train a classifier for associating synchronization records with the individuals, their physical activities, and conditions under which they were performed. Results of the study show that the methods allow individuals and their activities to be tracked, both of which infringe on the privacy of the user. The paper also provides recommendations on improving the security of wearable devices based on the initial research results.

year: 2017

title: Fanning the divine spark: Gaining understandings of micro-interactions in New Zealand classrooms

authors: Eley, Elizabeth Martha Ann

subjects: micro-interactions

abstract: New Zealand’s Treaty of Waitangi was signed by representatives of Iwi Māori (Indigenous tribal groups) and the British Crown.  Inherent in the heritages of both signatory groups is the ontological positioning that children are born of greatness; carriers of the divine spark from Tama-nui-te-rā (the central sun) and created in the image of God.  Almost all New Zealand children attend school.  For some, their ongoing classroom experiences with educators fans their divine spark and works towards the realisation of their innate potential.  For others, schooling is not a positive experience and their divine spark may be neither recognised nor celebrated.  

This research explores the relationships and pedagogical practices that underpin the classroom micro-interactions experienced by children.  Children’s schooling experience is made up of small interactions in classrooms that are situated in the social, political and legal contexts of schooling.  Therefore, this research applies both a centripetal and a centrifugal examination of the macro and micro contexts of classroom interactions.  

In examining the macro-context, ontological views of the child and the theoretical frameworks that guide pedagogy are considered.  The Education Acts governing New Zealand schooling have successively contained an ontological contradiction that enforces both a factory model as the preferred means of schooling for New Zealand and a requirement to honour the Treaty of Waitangi, including the worldviews of both signatories.  I conclude that educators within the compulsory schooling sector are not provided with specific guidance on how to navigate these contradictory worldviews.  Neither ontological views of how children are perceived within the system, nor theoretical frameworks that could and should inform views of knowledge and how learning occurs, are made explicit for educators.  

At the micro-context level, relationships and pedagogical practices are explored through case studies in three different New Zealand classrooms.  In each case, from video-recordings of classroom interactions, critical incidents were extracted and used to support interviews with participating teachers, students, parents and members of the wider school community.  Employing culturally responsive research methodologies, the interactions with participants were relational and dialogic.  The research found that classroom micro-interactions are pervasive and complex.  All participants, students, teachers and whānau, draw from the knowledge, understandings and positionings of the individual’s own cultural toolkits in classroom interactions.  Their cultural toolkits contain a range of factors to support learning, all of which were necessary and interdependent.  

The thesis calls for all children to receive an education that fans their inherent divine spark.  While this experience is not yet the case for all, there is opportunity in the rhetoric and structures already within New Zealand’s education system for this to occur.  Some schools and communities have begun to successfully challenge and address the prevailing theoretical and pedagogical status quo.  Therefore, there is reason for radical hope for a system-wide fanning of the divine spark in every child.

text: Fanning the divine spark: Gaining understandings of micro-interactions in New Zealand classrooms New Zealand’s Treaty of Waitangi was signed by representatives of Iwi Māori (Indigenous tribal groups) and the British Crown.  Inherent in the heritages of both signatory groups is the ontological positioning that children are born of greatness; carriers of the divine spark from Tama-nui-te-rā (the central sun) and created in the image of God.  Almost all New Zealand children attend school.  For some, their ongoing classroom experiences with educators fans their divine spark and works towards the realisation of their innate potential.  For others, schooling is not a positive experience and their divine spark may be neither recognised nor celebrated.  

This research explores the relationships and pedagogical practices that underpin the classroom micro-interactions experienced by children.  Children’s schooling experience is made up of small interactions in classrooms that are situated in the social, political and legal contexts of schooling.  Therefore, this research applies both a centripetal and a centrifugal examination of the macro and micro contexts of classroom interactions.  

In examining the macro-context, ontological views of the child and the theoretical frameworks that guide pedagogy are considered.  The Education Acts governing New Zealand schooling have successively contained an ontological contradiction that enforces both a factory model as the preferred means of schooling for New Zealand and a requirement to honour the Treaty of Waitangi, including the worldviews of both signatories.  I conclude that educators within the compulsory schooling sector are not provided with specific guidance on how to navigate these contradictory worldviews.  Neither ontological views of how children are perceived within the system, nor theoretical frameworks that could and should inform views of knowledge and how learning occurs, are made explicit for educators.  

At the micro-context level, relationships and pedagogical practices are explored through case studies in three different New Zealand classrooms.  In each case, from video-recordings of classroom interactions, critical incidents were extracted and used to support interviews with participating teachers, students, parents and members of the wider school community.  Employing culturally responsive research methodologies, the interactions with participants were relational and dialogic.  The research found that classroom micro-interactions are pervasive and complex.  All participants, students, teachers and whānau, draw from the knowledge, understandings and positionings of the individual’s own cultural toolkits in classroom interactions.  Their cultural toolkits contain a range of factors to support learning, all of which were necessary and interdependent.  

The thesis calls for all children to receive an education that fans their inherent divine spark.  While this experience is not yet the case for all, there is opportunity in the rhetoric and structures already within New Zealand’s education system for this to occur.  Some schools and communities have begun to successfully challenge and address the prevailing theoretical and pedagogical status quo.  Therefore, there is reason for radical hope for a system-wide fanning of the divine spark in every child.

year: 2020