title: Impedance measurement of batteries under load

authors: Hasan, Rahat

abstract: The impedance of a lithium battery at a single state-of-charge (SoC) is obtained from the current and voltage response of the cell. Making this measurement is important in order to understand cell characteristics. There exist some impedance analysers which can make suitable measurements at a single SoC. Measuring this impedance at multiple SoC is slow and tedious especially at lower frequencies. We present a new method which computes the impedance over a range of SoC while simultaneously varying the SoC. The proposed method produces reliable data even when the device under test is behaving non-linearly. The data obtained from this measurement is validated by comparing impedance data obtained at different SoC from a cell under no load.

text: Impedance measurement of batteries under load The impedance of a lithium battery at a single state-of-charge (SoC) is obtained from the current and voltage response of the cell. Making this measurement is important in order to understand cell characteristics. There exist some impedance analysers which can make suitable measurements at a single SoC. Measuring this impedance at multiple SoC is slow and tedious especially at lower frequencies. We present a new method which computes the impedance over a range of SoC while simultaneously varying the SoC. The proposed method produces reliable data even when the device under test is behaving non-linearly. The data obtained from this measurement is validated by comparing impedance data obtained at different SoC from a cell under no load.

year: 2019

title: Lower bounds on the sizes of defining sets in full n-Latin squares and full designs

authors: Cavenagh, Nicholas J.

subjects: Science & Technology

abstract: The full n-Latin square is the n×n array with symbols 1, 2, . . . , n in each cell. In this paper we show, as part of a more general result,that any defining set for the full n-Latin square has size n³(1 − o(1)). The full design N(v, k) is the unique simple design with parameters (v,k,{v-2 \atopwithdelims ()k-2}); that is, the design consisting of all subsets of size k from a set of size v. We show that any defining set for the full design N(v, k) has size {v\atopwithdelims ()k}(1-o(1)) (as v-k becomes large). These results improve existing results and are asymptotically optimal. In particular, the latter result solves an open problem given in (Donovan, Lefevre, et al, 2009), in which it is conjectured that the proportion of blocks in the complement of a full design will asymptotically approach zero.

text: Lower bounds on the sizes of defining sets in full n-Latin squares and full designs The full n-Latin square is the n×n array with symbols 1, 2, . . . , n in each cell. In this paper we show, as part of a more general result,that any defining set for the full n-Latin square has size n³(1 − o(1)). The full design N(v, k) is the unique simple design with parameters (v,k,{v-2 \atopwithdelims ()k-2}); that is, the design consisting of all subsets of size k from a set of size v. We show that any defining set for the full design N(v, k) has size {v\atopwithdelims ()k}(1-o(1)) (as v-k becomes large). These results improve existing results and are asymptotically optimal. In particular, the latter result solves an open problem given in (Donovan, Lefevre, et al, 2009), in which it is conjectured that the proportion of blocks in the complement of a full design will asymptotically approach zero.

year: 2018

title: Understanding the construction of belonging in a for-profit ECE centre: An ethnographic study

authors: Westerbeke, Lynley Ann

subjects: Belonging

abstract: Participation in high quality early childhood education [ECE] is recognised as having long ranging academic and social benefits for children, especially those from disadvantaged backgrounds (Mitchell, Wylie & Carr, 2008).   In 2010 the ECE Participation Programme was successfully introduced to increase enrolment in ECE for targeted groups, such as Māori, Pasifika, and low income families.  I argue that focusing on increased participation alone is limiting and participation requires being viewed alongside the notion of belonging.  With the majority of children participating in for-profit ECE centres in Aotearoa New Zealand (Ministry of Education, 2015) I suggest that what children are participating in merits greater investigation.    
In this thesis belonging is positioned as not simply obtaining membership, but utilising Rogoff’s (2003) understanding of participation, it is viewed as something which is highly influential, where core values are transmitted and transformed.
The research questions guiding this thesis are:
1.	What affordances and challenges to belonging are identified by stakeholders participating in a privately owned, for-profit, ECE centre?
2.	How is the ethical stewardship of Te Whāriki reflected in the leadership’s decision making?
This thesis used a critical ethnographic methodology, and was conducted over a nine month period in a for-profit ECE centre, with the researcher in the role of participant observer.  The centre is located in a lower socio-economic area of an inner city suburb and is accessed by families who at the time of the study had only 30% of its parents in paid employment.  The majority of children identified as Māori and lived in close proximity to the centre, and all teachers at the centre identified as Pākehā.  The stakeholders identified for this study were the children, their parents and the teachers.  Three teachers participated in the study and four children were selected for case study, aged between two and four and a half years.  Data was generated primarily through semi-structured interviews with the children, their parents and the teachers, and observation of the setting.  The data was viewed utilising Rogoff’s (2003) three foci of analysis, with three contributing factors to belonging identified by participants; values, relationships and leadership.
The thesis argues that belonging is complex and participation in for-profit ECE services is an ethical concern, not only for the children and their families but also for teachers.  To make sense of the aligned yet often contradicting perspectives of the stakeholders I propose a belonging framework, conceptualised to bring understanding to the construction of belonging within the centre.  It suggests that belonging to the centre can be viewed from three distinct viewpoints; it can be observed, lived, and framed.   The study evidenced that the day-to-day lived experiences of the children are not fully known by parents and, while also lived, belonging is primarily observed for this cohort.  Within the context of lived belonging the teachers’ and leadership’s philosophical and pedagogical approaches meet, and often collide.  The child is placed at the heart of the framework where belonging is lived and it is here that meaning for this group is primarily created, and cultural values are transmitted and transformed.  The third perspective is how belonging is framed, with the leaders’ operational decision making setting the parameters for the stakeholders’ participation.  It is in this space that the actual values guiding the setting are revealed.
My thesis aims to explain the impact on the stakeholders’ sense of belonging when a government funded centre is driven by agendas not fully aligned with the intentions of the democratic and bicultural curriculum, Te Whāriki.  This study adds to the literature on for-profit ECE services, participation in ECE in Aotearoa New Zealand, and leadership in ECE.

text: Understanding the construction of belonging in a for-profit ECE centre: An ethnographic study Participation in high quality early childhood education [ECE] is recognised as having long ranging academic and social benefits for children, especially those from disadvantaged backgrounds (Mitchell, Wylie & Carr, 2008).   In 2010 the ECE Participation Programme was successfully introduced to increase enrolment in ECE for targeted groups, such as Māori, Pasifika, and low income families.  I argue that focusing on increased participation alone is limiting and participation requires being viewed alongside the notion of belonging.  With the majority of children participating in for-profit ECE centres in Aotearoa New Zealand (Ministry of Education, 2015) I suggest that what children are participating in merits greater investigation.    
In this thesis belonging is positioned as not simply obtaining membership, but utilising Rogoff’s (2003) understanding of participation, it is viewed as something which is highly influential, where core values are transmitted and transformed.
The research questions guiding this thesis are:
1.	What affordances and challenges to belonging are identified by stakeholders participating in a privately owned, for-profit, ECE centre?
2.	How is the ethical stewardship of Te Whāriki reflected in the leadership’s decision making?
This thesis used a critical ethnographic methodology, and was conducted over a nine month period in a for-profit ECE centre, with the researcher in the role of participant observer.  The centre is located in a lower socio-economic area of an inner city suburb and is accessed by families who at the time of the study had only 30% of its parents in paid employment.  The majority of children identified as Māori and lived in close proximity to the centre, and all teachers at the centre identified as Pākehā.  The stakeholders identified for this study were the children, their parents and the teachers.  Three teachers participated in the study and four children were selected for case study, aged between two and four and a half years.  Data was generated primarily through semi-structured interviews with the children, their parents and the teachers, and observation of the setting.  The data was viewed utilising Rogoff’s (2003) three foci of analysis, with three contributing factors to belonging identified by participants; values, relationships and leadership.
The thesis argues that belonging is complex and participation in for-profit ECE services is an ethical concern, not only for the children and their families but also for teachers.  To make sense of the aligned yet often contradicting perspectives of the stakeholders I propose a belonging framework, conceptualised to bring understanding to the construction of belonging within the centre.  It suggests that belonging to the centre can be viewed from three distinct viewpoints; it can be observed, lived, and framed.   The study evidenced that the day-to-day lived experiences of the children are not fully known by parents and, while also lived, belonging is primarily observed for this cohort.  Within the context of lived belonging the teachers’ and leadership’s philosophical and pedagogical approaches meet, and often collide.  The child is placed at the heart of the framework where belonging is lived and it is here that meaning for this group is primarily created, and cultural values are transmitted and transformed.  The third perspective is how belonging is framed, with the leaders’ operational decision making setting the parameters for the stakeholders’ participation.  It is in this space that the actual values guiding the setting are revealed.
My thesis aims to explain the impact on the stakeholders’ sense of belonging when a government funded centre is driven by agendas not fully aligned with the intentions of the democratic and bicultural curriculum, Te Whāriki.  This study adds to the literature on for-profit ECE services, participation in ECE in Aotearoa New Zealand, and leadership in ECE.

year: 2016