title: Controlling test case explosion in test generation for B formal models: Research Articles

authors: Legeard, Bruno

subjects: computer science

abstract: BZ-TESTING-TOOLS (BZ-TT) is a tool set for automated test case generation from B and Z specifications. BZ-TT uses boundary and cause–effect testing on the basis of the formal model. It has been used and validated on several industrial applications in the domain of critical software, particularly smart card and transport systems. This paper presents the test coverage criteria supported by BZ-TT. On the one hand, these correspond to various classical structural coverage criteria, but specialized to the case of B abstract machines. The paper gives algorithms for these in Prolog. On the other hand, BZ-TT introduces new coverage criteria for complex data structures, based on boundary analysis: this paper defines weak and strong state-boundary coverage, input-boundary coverage and output-boundary coverage. Finally, the paper describes how BZ-TT presents a unified view of these criteria to the validation engineer, and allows him or her to control the test case explosion on a coarse basis (choosing from a range of coverage criteria) as well as a fine basis (selecting options for each state or input variable).

text: Controlling test case explosion in test generation for B formal models: Research Articles BZ-TESTING-TOOLS (BZ-TT) is a tool set for automated test case generation from B and Z specifications. BZ-TT uses boundary and cause–effect testing on the basis of the formal model. It has been used and validated on several industrial applications in the domain of critical software, particularly smart card and transport systems. This paper presents the test coverage criteria supported by BZ-TT. On the one hand, these correspond to various classical structural coverage criteria, but specialized to the case of B abstract machines. The paper gives algorithms for these in Prolog. On the other hand, BZ-TT introduces new coverage criteria for complex data structures, based on boundary analysis: this paper defines weak and strong state-boundary coverage, input-boundary coverage and output-boundary coverage. Finally, the paper describes how BZ-TT presents a unified view of these criteria to the validation engineer, and allows him or her to control the test case explosion on a coarse basis (choosing from a range of coverage criteria) as well as a fine basis (selecting options for each state or input variable).

year: 2004

title: Supercapacitor-based pulse generator with waveform adjustment capability for small animal transcranial magnetic stimulation

authors: Raju, Soniya

subjects: Pulse circuits

abstract: In transcranial magnetic stimulation (TMS), pulsed magnetic fields are applied to the brain, typically requiring high-power stimulators with high voltages and low series impedance. TMS pulse generators for small animal coils, are underexplored, with limited dedicated circuits and simulation models. Here, we present a new design for a high-power TMS pulse generator for small animals, utilizing a pre-charged supercapacitor that is sufficient to produce repeated pulses for TMS applications without the need for recharging. This approach eliminates the need for expensive high-voltage components and a high-voltage power supply. In this paper, we detail the design approach and basic block diagrams of a supercapacitor (SC) based TMS pulse generator, along with its experimental results. The findings indicate that the new circuit enables a complete test using just a single charge of an SC module. The proposed circuit functions as a versatile pulse-shaping device, where the MOSFET is treated as a dynamically varying resistor element rather than a traditional switch; allowing pulse parameter variations. We analyze a novel circuit for generating and controlling TMS pulses in small animal coils, and demonstrate its effectiveness through experimental results.

text: Supercapacitor-based pulse generator with waveform adjustment capability for small animal transcranial magnetic stimulation In transcranial magnetic stimulation (TMS), pulsed magnetic fields are applied to the brain, typically requiring high-power stimulators with high voltages and low series impedance. TMS pulse generators for small animal coils, are underexplored, with limited dedicated circuits and simulation models. Here, we present a new design for a high-power TMS pulse generator for small animals, utilizing a pre-charged supercapacitor that is sufficient to produce repeated pulses for TMS applications without the need for recharging. This approach eliminates the need for expensive high-voltage components and a high-voltage power supply. In this paper, we detail the design approach and basic block diagrams of a supercapacitor (SC) based TMS pulse generator, along with its experimental results. The findings indicate that the new circuit enables a complete test using just a single charge of an SC module. The proposed circuit functions as a versatile pulse-shaping device, where the MOSFET is treated as a dynamically varying resistor element rather than a traditional switch; allowing pulse parameter variations. We analyze a novel circuit for generating and controlling TMS pulses in small animal coils, and demonstrate its effectiveness through experimental results.

year: 2024

title: Insecure, unpredictable, hoping to survive: Four cases of Māori people living precariously in Hamilton, Aotearoa New Zealand

authors: Uerata, Lynley Moana

subjects: Māori

abstract: A conceptualisation of precarity is introduced and adopted. A critique of contemporary conceptualisations of precarity is presented, drawing especially on Stuart Hall’s interpretation of articulation and Marx’s concept of relative surplus population. Much of the literature on precarity focusses on the neoliberal mode of contemporary capitalism originating in the late 1970s. However, there is limited literature which explores precarity as a way of life. A precarious way of life is characterised by interacting forms of precarity which embed insecurity, instability, and unpredictability in the everyday lives of real people. An account of the Māori experience of precarity since the pre-colonial era to the present-day is presented. Māori are the indigenous people of Aotearoa New Zealand who were colonised by the British Empire in the 1800s. 
The main research questions addressed in my thesis are: What forms of precarity are present in the everyday context? How do forms of precarity relate to each other? How do forms of precarity relate to being Māori? What kinds of support do those living with precarity gain from social structures, institutions, and social actors? What is the role of culture in the way Māori experience and mediate precarity? An analysis of semi-structured in-depth engagements with Māori people living precariously in Hamilton, Aotearoa New Zealand in 2016, based on four case studies, shows the character and significance of forms, sources, and effects of precarity in everyday life. As historical processes continue to overdetermine experiences of social structures and institutions in the present, in a contemporary capitalist context precarity arises from a wide range of interacting sources, forms, and effects of precarity. Among the different kinds of actors and organisations which comprise the support systems constructed to mediate precarity in the everyday context, cultural practices and resources can play a significant role for people who are culturally connected. When people are integrated into their local and cultural communities, they can cope better with a precarious way of life.

text: Insecure, unpredictable, hoping to survive: Four cases of Māori people living precariously in Hamilton, Aotearoa New Zealand A conceptualisation of precarity is introduced and adopted. A critique of contemporary conceptualisations of precarity is presented, drawing especially on Stuart Hall’s interpretation of articulation and Marx’s concept of relative surplus population. Much of the literature on precarity focusses on the neoliberal mode of contemporary capitalism originating in the late 1970s. However, there is limited literature which explores precarity as a way of life. A precarious way of life is characterised by interacting forms of precarity which embed insecurity, instability, and unpredictability in the everyday lives of real people. An account of the Māori experience of precarity since the pre-colonial era to the present-day is presented. Māori are the indigenous people of Aotearoa New Zealand who were colonised by the British Empire in the 1800s. 
The main research questions addressed in my thesis are: What forms of precarity are present in the everyday context? How do forms of precarity relate to each other? How do forms of precarity relate to being Māori? What kinds of support do those living with precarity gain from social structures, institutions, and social actors? What is the role of culture in the way Māori experience and mediate precarity? An analysis of semi-structured in-depth engagements with Māori people living precariously in Hamilton, Aotearoa New Zealand in 2016, based on four case studies, shows the character and significance of forms, sources, and effects of precarity in everyday life. As historical processes continue to overdetermine experiences of social structures and institutions in the present, in a contemporary capitalist context precarity arises from a wide range of interacting sources, forms, and effects of precarity. Among the different kinds of actors and organisations which comprise the support systems constructed to mediate precarity in the everyday context, cultural practices and resources can play a significant role for people who are culturally connected. When people are integrated into their local and cultural communities, they can cope better with a precarious way of life.

year: 2021