title: Preliminary experiments quantifying the arcing process in a DC circuit breaker development project

authors: Dassanayake, Chamara

subjects: industries

abstract: AC circuit breakers are well-established technology today. However, DC circuit breakers (DCCB) are not easy to design and build since there are no zero crossings in a DC power supply. Mechanical and semiconductor switches are the key elements considered under various circuit topologies to design DCCBs. However, mass-produced commercial DCCBs are designed by modifying AC breakers by connecting multiple poles in series and/or using permanent magnets inside the breaker to lower the cost of DCCBs except for special applications such as in the military industry. Some of the major issues behind the DCCB design are fundamentally explained in this research with simple experimental results based on DC arc characteristics. We intend using these experimental observations in a new design approach for DC circuit breakers using supercapacitor energy absorption.

text: Preliminary experiments quantifying the arcing process in a DC circuit breaker development project AC circuit breakers are well-established technology today. However, DC circuit breakers (DCCB) are not easy to design and build since there are no zero crossings in a DC power supply. Mechanical and semiconductor switches are the key elements considered under various circuit topologies to design DCCBs. However, mass-produced commercial DCCBs are designed by modifying AC breakers by connecting multiple poles in series and/or using permanent magnets inside the breaker to lower the cost of DCCBs except for special applications such as in the military industry. Some of the major issues behind the DCCB design are fundamentally explained in this research with simple experimental results based on DC arc characteristics. We intend using these experimental observations in a new design approach for DC circuit breakers using supercapacitor energy absorption.

year: 2024

title: An analytical framework for joint vs separate decisions by couples in choice experiments: The case of coastal water quality in Tobago

authors: Beharry-Borg, Nesha

subjects: choice experiments

abstract: This paper offers an analytical framework for analyzing joint and separate decisions by couples in the context of choice experiments for nonmarket valuation. It reports results from an attribute-based stated preference study in which members of couples are asked to conduct a choice-experiment first individually and then jointly. The choice context was the selection of which beach to visit while on vacation in Tobago. Available alternatives differed in attributes related to coastal water and beach quality such as level of coastal development and fish abundance. Tests of preference equality are reported and structured so as to identify the intra-couple decision-making patterns under taste heterogeneity with both finite and continuous mixed logit. Results from the latter suggest that women’s preferences are found to be predominant in the joint choice-experiment. Results suggest caution in using individual choice rather than joint couple choice when valuing quality changes impacting on couple activities, such as water and beach quality in Tobago, and call for further research on the topic.

text: An analytical framework for joint vs separate decisions by couples in choice experiments: The case of coastal water quality in Tobago This paper offers an analytical framework for analyzing joint and separate decisions by couples in the context of choice experiments for nonmarket valuation. It reports results from an attribute-based stated preference study in which members of couples are asked to conduct a choice-experiment first individually and then jointly. The choice context was the selection of which beach to visit while on vacation in Tobago. Available alternatives differed in attributes related to coastal water and beach quality such as level of coastal development and fish abundance. Tests of preference equality are reported and structured so as to identify the intra-couple decision-making patterns under taste heterogeneity with both finite and continuous mixed logit. Results from the latter suggest that women’s preferences are found to be predominant in the joint choice-experiment. Results suggest caution in using individual choice rather than joint couple choice when valuing quality changes impacting on couple activities, such as water and beach quality in Tobago, and call for further research on the topic.

year: 2009

title: Indigenous peoples, data, and the coloniality of surveillance

authors: Cormack, Donna

abstract: In Aotearoa New Zealand (Aotearoa NZ), Māori (the Indigenous peoples of New Zealand) have long been objects of surveillance by state institutions and agents. State representations have centred on constructions of difference and deviance, on understandings of Indigenous peoples as dangerous, and on the management of Indigenous resistance to colonialism. This chapter considers how contemporary state surveillance practices in Aotearoa NZ, enabled by the expanded use of big data and linked government datasets, function to regulate and manage Māori. Through this lens, we explore continuities of current data practices for Indigenous peoples with the racialised logics and social orders set in place as part of global systems of imperialism and colonialism. Recognising that resistance has always been a part of Indigenous responses to colonialism, we also explore how Māori Data Sovereignty (MDSov), as part of broader Indigenous Data Sovereignty (IDS) movements globally, provides opportunities to counter and disrupt prevailing data relations and to imagine alternative futures.

text: Indigenous peoples, data, and the coloniality of surveillance In Aotearoa New Zealand (Aotearoa NZ), Māori (the Indigenous peoples of New Zealand) have long been objects of surveillance by state institutions and agents. State representations have centred on constructions of difference and deviance, on understandings of Indigenous peoples as dangerous, and on the management of Indigenous resistance to colonialism. This chapter considers how contemporary state surveillance practices in Aotearoa NZ, enabled by the expanded use of big data and linked government datasets, function to regulate and manage Māori. Through this lens, we explore continuities of current data practices for Indigenous peoples with the racialised logics and social orders set in place as part of global systems of imperialism and colonialism. Recognising that resistance has always been a part of Indigenous responses to colonialism, we also explore how Māori Data Sovereignty (MDSov), as part of broader Indigenous Data Sovereignty (IDS) movements globally, provides opportunities to counter and disrupt prevailing data relations and to imagine alternative futures.

year: 2022