title: Measuring electrical properties of batteries at ultra-long timescales

authors: Wilson, Marcus T.

abstract: Quantifying battery behavior is critical to development of new battery technologies and energy storage systems. While it is straightforward to measure properties such as impedance at short timescales (i.e. frequencies larger than ~1 Hz) the relevance of this is questionable since rechargeable batteries in normal usage are often cycled on timescales of hours or days. Making measurements at these timescales, for example impedance measurements below ~1 mHz, is more challenging. In this paper we discuss approaches to quantifying battery behavior at timescales from hours to weeks (frequency scales of ~0.1 mHz down to ~1 μHz). We present frequency domain measurements and time domain measurements, achieved through four-point measurements with a Keysight 66332A at around 100 mA RMS. At low frequencies significant charge is shifted in a measurement cycle, complicating interpretation. The digitization of a sine-wave may introduce errors such as constant current offsets that build in significance with time. The operating point (DC voltage level) of the battery should be controlled since it influences impedance at the lowest frequencies as a result of the voltage-dependent nature of different electrochemical processes. We relate the voltage-dependent effects to time-domain measurements such as cyclic voltammetry and incremental capacity analysis.

text: Measuring electrical properties of batteries at ultra-long timescales Quantifying battery behavior is critical to development of new battery technologies and energy storage systems. While it is straightforward to measure properties such as impedance at short timescales (i.e. frequencies larger than ~1 Hz) the relevance of this is questionable since rechargeable batteries in normal usage are often cycled on timescales of hours or days. Making measurements at these timescales, for example impedance measurements below ~1 mHz, is more challenging. In this paper we discuss approaches to quantifying battery behavior at timescales from hours to weeks (frequency scales of ~0.1 mHz down to ~1 μHz). We present frequency domain measurements and time domain measurements, achieved through four-point measurements with a Keysight 66332A at around 100 mA RMS. At low frequencies significant charge is shifted in a measurement cycle, complicating interpretation. The digitization of a sine-wave may introduce errors such as constant current offsets that build in significance with time. The operating point (DC voltage level) of the battery should be controlled since it influences impedance at the lowest frequencies as a result of the voltage-dependent nature of different electrochemical processes. We relate the voltage-dependent effects to time-domain measurements such as cyclic voltammetry and incremental capacity analysis.

year: 2023

title: Cyber security visualization effectiveness

authors: Garae, Jeffery

subjects: Cyber Security

abstract: Security visualization utilises predefined data attributes and translates them into visual nodes to form images for the purpose of communicating critical security information to targeted audiences. It is commonly used for two reasons: exploring and reporting purposes thus, sharing insights on suspected security events. However, the challenge of selecting the best visualization out of two or more visualization samples, regardless of existing limitations such as screen dimensions and visual complexities, required users to utilise certain measurement criteria. These criteria urge security visualization researchers, developers and users (viewers) to ask themselves the following two questions: What makes a security visualization effective? How do we measure visualization effectiveness in the context of investigating, analysing, understanding and reporting cyber security incidents?

This thesis explores a range of effectiveness measurement techniques for web and mobile platforms. We investigated existing effectiveness methods for the design, implementation and user observation phases in security visualizations. Consequently, we identified effectiveness criteria and metrics in applications include visual clarity, visibility, distortion rates and user cognitive response (viewing) times. With the goal of aiding decision making in cyber security operations, we provided a distinctive security visualization paradigm of a full-scale effectiveness measurement (SvEm framework) approach for both theoretical and user-centric visualization techniques. Our framework facilitates effectiveness through our SvEm algorithm thus, providing various interactive three-dimensional (3D) visualization applications to enhance both single and multi-user collaboration.

The SvEm framework involves several key components: (1) web/mobile display dimensions and resolution, (2) security incident entities, (3) user cognitive activators and alerts, (4) working memory load, (5) threat scoring system and (6) the colour usage management. To evaluate effectiveness in our framework, we developed several use cases: (1) VisualProgger - a real-time security visualization analytic application (web and mobile platforms), (2) a security visualization with augmented reality and (3) a security visualization for intelligence tracking and monitoring. In addition, we developed and documented a new security visualization guideline (a SCeeVis pre-standard) as part of the SvEm framework to aid with the design, implementation and observation environments.

This pre-standard further allowed us to develop our SCeeVis colour chaining standard and a new cognition and working memory (SvEm-CWML) instruction set to enhance the user’s cognition and perception process for security visualizations. As a result, our visualization application outputs effectiveness measurement by capturing and increasing the user's attention span through the process of reducing cognitive load, while increasing the viewer’s memory efficiency. Thus, users have a high potential to gain security insights from a given visualization. Our evaluation shows that, viewers perform better with the existence of prior knowledge of security events and if they operate in a comfortable visual environment. It has also indicated that circular visualization designs attracted and maintained the viewer’s attention. Finally, these discoveries have revealed new research directions for future work relating to effectiveness measurement in security visualization.

text: Cyber security visualization effectiveness Security visualization utilises predefined data attributes and translates them into visual nodes to form images for the purpose of communicating critical security information to targeted audiences. It is commonly used for two reasons: exploring and reporting purposes thus, sharing insights on suspected security events. However, the challenge of selecting the best visualization out of two or more visualization samples, regardless of existing limitations such as screen dimensions and visual complexities, required users to utilise certain measurement criteria. These criteria urge security visualization researchers, developers and users (viewers) to ask themselves the following two questions: What makes a security visualization effective? How do we measure visualization effectiveness in the context of investigating, analysing, understanding and reporting cyber security incidents?

This thesis explores a range of effectiveness measurement techniques for web and mobile platforms. We investigated existing effectiveness methods for the design, implementation and user observation phases in security visualizations. Consequently, we identified effectiveness criteria and metrics in applications include visual clarity, visibility, distortion rates and user cognitive response (viewing) times. With the goal of aiding decision making in cyber security operations, we provided a distinctive security visualization paradigm of a full-scale effectiveness measurement (SvEm framework) approach for both theoretical and user-centric visualization techniques. Our framework facilitates effectiveness through our SvEm algorithm thus, providing various interactive three-dimensional (3D) visualization applications to enhance both single and multi-user collaboration.

The SvEm framework involves several key components: (1) web/mobile display dimensions and resolution, (2) security incident entities, (3) user cognitive activators and alerts, (4) working memory load, (5) threat scoring system and (6) the colour usage management. To evaluate effectiveness in our framework, we developed several use cases: (1) VisualProgger - a real-time security visualization analytic application (web and mobile platforms), (2) a security visualization with augmented reality and (3) a security visualization for intelligence tracking and monitoring. In addition, we developed and documented a new security visualization guideline (a SCeeVis pre-standard) as part of the SvEm framework to aid with the design, implementation and observation environments.

This pre-standard further allowed us to develop our SCeeVis colour chaining standard and a new cognition and working memory (SvEm-CWML) instruction set to enhance the user’s cognition and perception process for security visualizations. As a result, our visualization application outputs effectiveness measurement by capturing and increasing the user's attention span through the process of reducing cognitive load, while increasing the viewer’s memory efficiency. Thus, users have a high potential to gain security insights from a given visualization. Our evaluation shows that, viewers perform better with the existence of prior knowledge of security events and if they operate in a comfortable visual environment. It has also indicated that circular visualization designs attracted and maintained the viewer’s attention. Finally, these discoveries have revealed new research directions for future work relating to effectiveness measurement in security visualization.

year: 2019

title: Indigenous human rights and knowledge in archives, museums, and libraries: Some international perspectives with specific reference to New Zealand and Canada

authors: Morse, Bradford W.

subjects: indigenous records

abstract: This article highlights the extent to which international law has changed rapidly in recent years in relation to the rights of Indigenous peoples generally and in particular how this impacts upon the legal status of traditional knowledge and culture. It reviews the recognition of the unique legal status of Māori in Aotearoa and Aboriginal peoples in Canada in relation to self-determination and how their changing place within these nations are affecting the operations of museums, libraries, and archives as case studies, illustrating some of the key legal and practical challenges that now impinge upon the work of archivists and related professionals in many countries.

text: Indigenous human rights and knowledge in archives, museums, and libraries: Some international perspectives with specific reference to New Zealand and Canada This article highlights the extent to which international law has changed rapidly in recent years in relation to the rights of Indigenous peoples generally and in particular how this impacts upon the legal status of traditional knowledge and culture. It reviews the recognition of the unique legal status of Māori in Aotearoa and Aboriginal peoples in Canada in relation to self-determination and how their changing place within these nations are affecting the operations of museums, libraries, and archives as case studies, illustrating some of the key legal and practical challenges that now impinge upon the work of archivists and related professionals in many countries.

year: 2012