title: Detecting replay attacks in audiovisual identity verification

authors: Bredin, Herve

subjects: computer science

abstract: We describe an algorithm that detects a lack of correspondence between speech and lip motion by detecting and monitoring the degree of synchrony between live audio and visual signals. It is simple, effective, and computationally inexpensive; providing a useful degree of robustness against basic replay attacks and against speech or image forgeries. The method is based on a cross-correlation analysis between two streams of features, one from the audio signal and the other from the image sequence. We argue that such an algorithm forms an effective first barrier against several kinds of replay attack that would defeat existing verification systems based on standard multimodal fusion techniques. In order to provide an evaluation mechanism for the new technique we have augmented the protocols that accompany the BANCA multimedia corpus by defining new scenarios. We obtain 0% equal-error rate (EER) on the simplest scenario and 35% on a more challenging one.

text: Detecting replay attacks in audiovisual identity verification We describe an algorithm that detects a lack of correspondence between speech and lip motion by detecting and monitoring the degree of synchrony between live audio and visual signals. It is simple, effective, and computationally inexpensive; providing a useful degree of robustness against basic replay attacks and against speech or image forgeries. The method is based on a cross-correlation analysis between two streams of features, one from the audio signal and the other from the image sequence. We argue that such an algorithm forms an effective first barrier against several kinds of replay attack that would defeat existing verification systems based on standard multimodal fusion techniques. In order to provide an evaluation mechanism for the new technique we have augmented the protocols that accompany the BANCA multimedia corpus by defining new scenarios. We obtain 0% equal-error rate (EER) on the simplest scenario and 35% on a more challenging one.

year: 2006

title: Workload categorization for hazardous industries: the semantic modelling of multi-modal physiological data

authors: König, Jemma Lynette

subjects: complex event processing

abstract: The forestry industry is one of the most hazardous industries in New Zealand, and the physical and cognitive fatigue of forestry workers has been shown to contribute to this. Physical and cognitive fatigue can be exacerbated by prolonged physical and cognitive workload. As such, we propose that the identification and mitigation of fatigue factors could reduce the risk of incidents and injuries in hazardous work environments. This paper introduces a semantic model for workload categorization. The model takes as input a set of multi-modal physiological measurements and uses parallel processing, complex event processing, and rule-based modeling to categorize a series of workloads (resting, cognitive workload, and physical workload). The model has undergone a set of evaluations, including categorization accuracy and performance. The model has been tested under three scenarios: when a participant is resting and refraining from any physically or mentally demanding tasks; when a participant is undertaking a cognitively intensive task; and when a participant is walking, jogging, and running. The study has been conducted with participants between the ages of 22 and 39 and has shown an average accuracy of 89% for resting workload, 76% for cognitive workload, and 97% for physical workload. Finally, in this paper, we discuss the application and extension of this model to predict fatigue in hazardous industries. The work described in this paper contributes to a larger research project centered on investigating technology uses in hazardous work environments.

text: Workload categorization for hazardous industries: the semantic modelling of multi-modal physiological data The forestry industry is one of the most hazardous industries in New Zealand, and the physical and cognitive fatigue of forestry workers has been shown to contribute to this. Physical and cognitive fatigue can be exacerbated by prolonged physical and cognitive workload. As such, we propose that the identification and mitigation of fatigue factors could reduce the risk of incidents and injuries in hazardous work environments. This paper introduces a semantic model for workload categorization. The model takes as input a set of multi-modal physiological measurements and uses parallel processing, complex event processing, and rule-based modeling to categorize a series of workloads (resting, cognitive workload, and physical workload). The model has undergone a set of evaluations, including categorization accuracy and performance. The model has been tested under three scenarios: when a participant is resting and refraining from any physically or mentally demanding tasks; when a participant is undertaking a cognitively intensive task; and when a participant is walking, jogging, and running. The study has been conducted with participants between the ages of 22 and 39 and has shown an average accuracy of 89% for resting workload, 76% for cognitive workload, and 97% for physical workload. Finally, in this paper, we discuss the application and extension of this model to predict fatigue in hazardous industries. The work described in this paper contributes to a larger research project centered on investigating technology uses in hazardous work environments.

year: 2022-04

title: Examining Culturally Responsive Leadership: An investigation into how one school leader, in a primary school setting, provides culturally responsive leadership that ensures Maori students achieve

authors: Ford, Therese

subjects: Culture

abstract: Addressing the achievement disparities that exist within New Zealand education between Maori and non-Maori is a major government priority and is identified by the Ministry of Education as being a critical challenge for school leadership (Ministry of Education, 2008a). Therefore, an important question for school leaders to contemplate is: How do we raise Maori student achievement and eliminate the ‘gap’, or more specifically, what are the teaching and leadership practices that will make a difference? The research project presented in this thesis examines how one school leader, in a mainstream primary school setting, provides culturally responsive leadership practice that ensures Maori students achieve. This case study was conducted within a kaupapa Maori theoretical framework and used a mixed methods approach that incorporated the triangulation of quantitative and qualitative data. Quantitative data included student achievement data in reading, while qualitative data collection and analysis included school documents, participant observations of the principal, a series of semi-structured interviews and a stimulated recall interview with the principal and focus group interviews with the school leadership team and a group of teachers. The literature reviewed highlighted the centrality of culture in education, the implications for relationships and interactions between teachers and students that are born out of cultural deficit theorising and the potential culturally responsive teaching practices hold for students from minority groups. It also identified a series of effective leadership practices that enable school leaders to influence classroom teaching and have a subsequent impact on student outcomes. The case study school reflects a mainstream primary school context where the majority of Maori students are achieving at or above national expectations in reading. The findings indicate that the principal is implementing many of the practices that characterise effective leadership in successful schools. The principal’s leadership practice is guided by her understandings of culturally responsive leadership, which emphasises the importance of developing quality relationships and quality teaching and learning. Consequently, she has focused her leadership practice on three interrelated strategies that reflect this theorising. The strategies include: prioritising the development of relationships with and between school stakeholders, establishing systems and structures to support the development of relationships and creating a school culture of learning where teachers reject deficit theorising, accept ownership for the performance of students, implement culturally responsive teaching practices and are critically reflective about their practice. This study suggests that further research examining culturally responsive leadership in mainstream education is needed to provide a more comprehensive profile of a culturally responsive leader in the New Zealand context. However, this report does provide an interesting point for reflection and discussion amongst school leaders who want to raise Maori student achievement and reduce disparities.

text: Examining Culturally Responsive Leadership: An investigation into how one school leader, in a primary school setting, provides culturally responsive leadership that ensures Maori students achieve Addressing the achievement disparities that exist within New Zealand education between Maori and non-Maori is a major government priority and is identified by the Ministry of Education as being a critical challenge for school leadership (Ministry of Education, 2008a). Therefore, an important question for school leaders to contemplate is: How do we raise Maori student achievement and eliminate the ‘gap’, or more specifically, what are the teaching and leadership practices that will make a difference? The research project presented in this thesis examines how one school leader, in a mainstream primary school setting, provides culturally responsive leadership practice that ensures Maori students achieve. This case study was conducted within a kaupapa Maori theoretical framework and used a mixed methods approach that incorporated the triangulation of quantitative and qualitative data. Quantitative data included student achievement data in reading, while qualitative data collection and analysis included school documents, participant observations of the principal, a series of semi-structured interviews and a stimulated recall interview with the principal and focus group interviews with the school leadership team and a group of teachers. The literature reviewed highlighted the centrality of culture in education, the implications for relationships and interactions between teachers and students that are born out of cultural deficit theorising and the potential culturally responsive teaching practices hold for students from minority groups. It also identified a series of effective leadership practices that enable school leaders to influence classroom teaching and have a subsequent impact on student outcomes. The case study school reflects a mainstream primary school context where the majority of Maori students are achieving at or above national expectations in reading. The findings indicate that the principal is implementing many of the practices that characterise effective leadership in successful schools. The principal’s leadership practice is guided by her understandings of culturally responsive leadership, which emphasises the importance of developing quality relationships and quality teaching and learning. Consequently, she has focused her leadership practice on three interrelated strategies that reflect this theorising. The strategies include: prioritising the development of relationships with and between school stakeholders, establishing systems and structures to support the development of relationships and creating a school culture of learning where teachers reject deficit theorising, accept ownership for the performance of students, implement culturally responsive teaching practices and are critically reflective about their practice. This study suggests that further research examining culturally responsive leadership in mainstream education is needed to provide a more comprehensive profile of a culturally responsive leader in the New Zealand context. However, this report does provide an interesting point for reflection and discussion amongst school leaders who want to raise Maori student achievement and reduce disparities.

year: 2010