title: Numerical calculation of series and shunt resistance of a photovoltaic cell using the Lambert W-function: Experimental evaluation

authors: Ghani, Faisal Abid

subjects: series resistance

abstract: The values of series and shunt resistances play an important role in the modelling behaviour of a photovoltaic cell. The authors proposed in earlier work a new method to determine these values numerically at maximum power point using the Newton-Raphson method and equations based on the Lambert W-function. Here, an experimental investigation has been carried out to further validate this method and observe its behaviour over the entire current voltage curve. Current voltage curves from a single multi-crystalline cell were obtained under outdoor testing in Hamilton, New Zealand under three levels of illumination (800, 900, and 1000 W/m(2)). In addition to the method of Ghani and Duke (2011), two other methods were also used to calculate series and shunt resistances based on the parameters extracted from the experimental data. A comparative study of each methods output current vector using a root mean square error analysis revealed that greatest accuracy was achieved with the proposed approach.

text: Numerical calculation of series and shunt resistance of a photovoltaic cell using the Lambert W-function: Experimental evaluation The values of series and shunt resistances play an important role in the modelling behaviour of a photovoltaic cell. The authors proposed in earlier work a new method to determine these values numerically at maximum power point using the Newton-Raphson method and equations based on the Lambert W-function. Here, an experimental investigation has been carried out to further validate this method and observe its behaviour over the entire current voltage curve. Current voltage curves from a single multi-crystalline cell were obtained under outdoor testing in Hamilton, New Zealand under three levels of illumination (800, 900, and 1000 W/m(2)). In addition to the method of Ghani and Duke (2011), two other methods were also used to calculate series and shunt resistances based on the parameters extracted from the experimental data. A comparative study of each methods output current vector using a root mean square error analysis revealed that greatest accuracy was achieved with the proposed approach.

year: 2013

title: The effects of reinforcer magnitude in the preceding and upcoming ratios on between-ratio pausing in multiple fixed-ratio schedules

authors: Young, Rachel

subjects: Reinforcer Magnitude

abstract: Experiment 1 examined the effects of reinforcer magnitude in the preceding and upcoming ratios on between-ratio pausing during a range of FR values in a multiple FR FR schedule of reinforcement. Two components which were associated with two different discriminative stimuli were used, where one component was associated with a small reinforcer (1-s) and the other component was associated with a large reinforcer (6-s). The longest between-ratio pauses were found when the upcoming reinforcer was small (S-S and L-S transition) than when the upcoming reinforcer was large (S-L and L-L transition). In addition, consistently longer between-ratio pauses occurred when the preceding reinforcer was large and the upcoming reinforcer was small (L-S transition). Experiment 2 examined the effects of the past reinforcer magnitude on the between-ratio pause when the discriminative stimuli to differentiate the preceding and upcoming reinforcer magnitude was removed, during a range of FR values on a multiple FR FR schedule of reinforcement. When the past reinforcer magnitude had been small and the upcoming reinforcer was small or large (S-S and S-L transition) consistently shorter between-ratio pauses occurred. In comparison, when the past reinforcer had been large and the upcoming reinforcer was small or large (L-L and L-S transition) consistently longer pause durations occurred across the two transitions. Overall and running response rates were analysed in Experiments 1 and 2 and it was found that overall and running response rates consistently decreased as the FR values were increased. Overall, these experiments showed that the preceding and upcoming reinforcer magnitudes have a direct effect on the length of the between-ratio pause where increasing the FR value was observed to consistently increase the length of the between-ratio pause, when also compared across the four transitions (Small-Small, Small-Large, Large-Large, and Large-Small).

text: The effects of reinforcer magnitude in the preceding and upcoming ratios on between-ratio pausing in multiple fixed-ratio schedules Experiment 1 examined the effects of reinforcer magnitude in the preceding and upcoming ratios on between-ratio pausing during a range of FR values in a multiple FR FR schedule of reinforcement. Two components which were associated with two different discriminative stimuli were used, where one component was associated with a small reinforcer (1-s) and the other component was associated with a large reinforcer (6-s). The longest between-ratio pauses were found when the upcoming reinforcer was small (S-S and L-S transition) than when the upcoming reinforcer was large (S-L and L-L transition). In addition, consistently longer between-ratio pauses occurred when the preceding reinforcer was large and the upcoming reinforcer was small (L-S transition). Experiment 2 examined the effects of the past reinforcer magnitude on the between-ratio pause when the discriminative stimuli to differentiate the preceding and upcoming reinforcer magnitude was removed, during a range of FR values on a multiple FR FR schedule of reinforcement. When the past reinforcer magnitude had been small and the upcoming reinforcer was small or large (S-S and S-L transition) consistently shorter between-ratio pauses occurred. In comparison, when the past reinforcer had been large and the upcoming reinforcer was small or large (L-L and L-S transition) consistently longer pause durations occurred across the two transitions. Overall and running response rates were analysed in Experiments 1 and 2 and it was found that overall and running response rates consistently decreased as the FR values were increased. Overall, these experiments showed that the preceding and upcoming reinforcer magnitudes have a direct effect on the length of the between-ratio pause where increasing the FR value was observed to consistently increase the length of the between-ratio pause, when also compared across the four transitions (Small-Small, Small-Large, Large-Large, and Large-Small).

year: 2015

title: Re-presenting Māori and Indigenous understandings of Being: Deconstructing the notion of mental illness

authors: Southey, Kim Marie

subjects: Maori

abstract: This thesis examines metaphysics in order to re-present Māori and indigenous understandings of Being and deconstruct the notion of mental illness.  A holistic understanding of Being is crucial to Māori and indigenous worldviews and takes priority as a focus for this thesis. Holistic notions of Being allow indigenous peoples to reimagine potentiality in general and the possibility of a renewed experience of being-in-the-world more specifically. Through an exploration of Māori and indigenous (complex) holism, I seek to re-turn to the influence of things in the world that exist outside of the self-contained individual - that is, beyond the cognitive rational agent.  Doing so shifts the concept of well-being to reside not simply within the person (or the individual’s reactions), but within the entire world in which we live.  

It is posited that a dominant Western metaphysics poses a fundamental risk to Māori and indigenous expressions of Being.  This deeper layer of influence – the metaphysics of presence - is examined to expose its structure – one that insists that things in the world will be represented as fully discernible objects.  The implications that a dominant Western metaphysics has for the notion of mental illness are explored within the context of the metaphysics of presence that sets up things in the world as Beings whose essential meaning is identified only through qualities that can be seen, measured, described and defined.  Within this view of the world, the notion of mental illness is solidified, reflected in a focus on the most discernible aspects of Being – the observable and physical parts of a person that can be examined through science.  To counter this, the more mysterious and unthinkable aspects of Being reflected in Māori and indigenous metaphysics are highlighted as a way of re-turning to holism, to the extent that they resist the expectation that things in the world will be reduced to fit the dominant (metaphysical) framework.  

I engage the relational holistic research approach of whaiwhakaaro (a non-method implicating the more-than-human entities that push thinking and characterised by a free-flowing style of reflection), to draw out the possibilities that exist for re-presenting Māori and indigenous metaphysics and the notion of mental illness.  Eleven interviews were conducted with participants from varying professional and community-based backgrounds.  While the participants represent different views on metaphysics and mental illness, each has a passion for exploring the philosophies that shape the experience of being-in-the-world and how we understand ourselves in relation to all other things.  Their responses provide important signals for how human nature, more-than-human nature, and (mental) well-being are re-conceptualised.  

The main ideas that emerged through the interviews and the process of reflecting on participant responses (whaiwhakaaro) provoked thinking about the possibilities of holism in reconsidering the notion of mental illness.  Māori and indigenous understandings of Being were used to re-turn to ideas of well-being as a collective experience. I posit that, if there is illness, then it resides in the world rather than being centred solely on the individual who experiences the world.  If there is a way to talk about illness and well-being, then it need not be restricted to assigned concepts or pre-determined categories that explain behaviour.  Through a re-turn to complex holism – to Māori and indigenous metaphysical premises – I suggest we can engage with people’s experiences on different terms.  These are the terms that carry excessive meaning, that allow for mystery – to break from conventions and categories. These terms support a different view of individualism where the person is free to express their experience of thorough interconnection – of whakapapa.  In its broadest sense, the re-turn to holism is an understanding of the self as part of a thoroughly connected whole.

text: Re-presenting Māori and Indigenous understandings of Being: Deconstructing the notion of mental illness This thesis examines metaphysics in order to re-present Māori and indigenous understandings of Being and deconstruct the notion of mental illness.  A holistic understanding of Being is crucial to Māori and indigenous worldviews and takes priority as a focus for this thesis. Holistic notions of Being allow indigenous peoples to reimagine potentiality in general and the possibility of a renewed experience of being-in-the-world more specifically. Through an exploration of Māori and indigenous (complex) holism, I seek to re-turn to the influence of things in the world that exist outside of the self-contained individual - that is, beyond the cognitive rational agent.  Doing so shifts the concept of well-being to reside not simply within the person (or the individual’s reactions), but within the entire world in which we live.  

It is posited that a dominant Western metaphysics poses a fundamental risk to Māori and indigenous expressions of Being.  This deeper layer of influence – the metaphysics of presence - is examined to expose its structure – one that insists that things in the world will be represented as fully discernible objects.  The implications that a dominant Western metaphysics has for the notion of mental illness are explored within the context of the metaphysics of presence that sets up things in the world as Beings whose essential meaning is identified only through qualities that can be seen, measured, described and defined.  Within this view of the world, the notion of mental illness is solidified, reflected in a focus on the most discernible aspects of Being – the observable and physical parts of a person that can be examined through science.  To counter this, the more mysterious and unthinkable aspects of Being reflected in Māori and indigenous metaphysics are highlighted as a way of re-turning to holism, to the extent that they resist the expectation that things in the world will be reduced to fit the dominant (metaphysical) framework.  

I engage the relational holistic research approach of whaiwhakaaro (a non-method implicating the more-than-human entities that push thinking and characterised by a free-flowing style of reflection), to draw out the possibilities that exist for re-presenting Māori and indigenous metaphysics and the notion of mental illness.  Eleven interviews were conducted with participants from varying professional and community-based backgrounds.  While the participants represent different views on metaphysics and mental illness, each has a passion for exploring the philosophies that shape the experience of being-in-the-world and how we understand ourselves in relation to all other things.  Their responses provide important signals for how human nature, more-than-human nature, and (mental) well-being are re-conceptualised.  

The main ideas that emerged through the interviews and the process of reflecting on participant responses (whaiwhakaaro) provoked thinking about the possibilities of holism in reconsidering the notion of mental illness.  Māori and indigenous understandings of Being were used to re-turn to ideas of well-being as a collective experience. I posit that, if there is illness, then it resides in the world rather than being centred solely on the individual who experiences the world.  If there is a way to talk about illness and well-being, then it need not be restricted to assigned concepts or pre-determined categories that explain behaviour.  Through a re-turn to complex holism – to Māori and indigenous metaphysical premises – I suggest we can engage with people’s experiences on different terms.  These are the terms that carry excessive meaning, that allow for mystery – to break from conventions and categories. These terms support a different view of individualism where the person is free to express their experience of thorough interconnection – of whakapapa.  In its broadest sense, the re-turn to holism is an understanding of the self as part of a thoroughly connected whole.

year: 2020