Development and Analysis of Deterministic Privacy-Preserving Policies Using Non-Stochastic Information Theory

A deterministic privacy metric using non-stochastic information theory is developed. Particularly, minimax information is used to construct a measure of information leakage, which is inversely proportional to the measure of privacy. Anyone can submit a query to a trusted agent with access to a non-stochastic uncertain private dataset. Optimal deterministic privacy-preserving policies for responding to the submitted query are computed by maximizing the measure of privacy subject to a constraint on the worst-case quality of the response (i.e., the worst-case difference between the response by the agent and the output of the query computed on the private dataset). The optimal privacy-preserving policy is proved to be a piecewise constant function in the form of a quantization operator applied on the output of the submitted query. The measure of privacy is also used to analyze the performance of $k$-anonymity methodology (a popular deterministic mechanism for privacy-preserving release of datasets using suppression and generalization techniques), proving that it is in fact not privacy-preserving.Comment: improved introduction and numerical exampl

On Known-Plaintext Attacks to a Compressed Sensing-based Encryption: A Quantitative Analysis

Despite the linearity of its encoding, compressed sensing may be used to provide a limited form of data protection when random encoding matrices are used to produce sets of low-dimensional measurements (ciphertexts). In this paper we quantify by theoretical means the resistance of the least complex form of this kind of encoding against known-plaintext attacks. For both standard compressed sensing with antipodal random matrices and recent multiclass encryption schemes based on it, we show how the number of candidate encoding matrices that match a typical plaintext-ciphertext pair is so large that the search for the true encoding matrix inconclusive. Such results on the practical ineffectiveness of known-plaintext attacks underlie the fact that even closely-related signal recovery under encoding matrix uncertainty is doomed to fail. Practical attacks are then exemplified by applying compressed sensing with antipodal random matrices as a multiclass encryption scheme to signals such as images and electrocardiographic tracks, showing that the extracted information on the true encoding matrix from a plaintext-ciphertext pair leads to no significant signal recovery quality increase. This theoretical and empirical evidence clarifies that, although not perfectly secure, both standard compressed sensing and multiclass encryption schemes feature a noteworthy level of security against known-plaintext attacks, therefore increasing its appeal as a negligible-cost encryption method for resource-limited sensing applications.Comment: IEEE Transactions on Information Forensics and Security, accepted for publication. Article in pres

Are we working towards global research priorities for management and conservation of sea turtles?

In 2010, an international group of 35 sea turtle researchers refined an initial list of more than 200 research questions into 20 metaquestions that were considered key for management and conservation of sea turtles. These were classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies. To obtain a picture of how research is being focused towards these key questions, we undertook a systematic review of the peer-reviewed literature (2014 and 2015) attributing papers to the original 20 questions. In total, we reviewed 605 articles in full and from these 355 (59%) were judged to substantively address the 20 key questions, with others focusing on basic science and monitoring. Progress to answering the 20 questions was not uniform, and there were biases regarding focal turtle species, geographic scope and publication outlet. Whilst it offers some meaningful indications as to effort, quantifying peer-reviewed literature output is ob viously not the only, and possibly not the best, metric for understanding progress towards informing key conservation and management goals. Along with the literature review, an international group based on the original project consortium was assigned to critically summarise recent progress towards answering each of the 20 questions. We found that significant research is being expended towards global priorities for management and conservation of sea turtles. Although highly variable, there has been significant progress in all the key questions identified in 2010. Undertaking this critical review has highlighted that it may be timely to undertake one or more new prioritizing exercises. For this to have maximal benefit we make a range of recommendations for its execution. These include a far greater engagement with social sciences, widening the pool of contributors and focussing the questions, perhaps disaggregating ecology and conservatio

Recognizing Affiliation: Using Behavioural Traces to Predict the Quality of Social Interactions in Online Games

Online social interactions in multiplayer games can be supportive and positive or toxic and harmful; however, few methods can easily assess interpersonal interaction quality in games. We use behavioural traces to predict affiliation between dyadic strangers, facilitated through their social interactions in an online gaming setting. We collected audio, video, in-game, and self-report data from 23 dyads, extracted 75 features, trained Random Forest and Support Vector Machine models, and evaluated their performance predicting binary (high/low) as well as continuous affiliation toward a partner. The models can predict both binary and continuous affiliation with up to 79.1% accuracy (F1) and 20.1% explained variance (R2) on unseen data, with features based on verbal communication demonstrating the highest potential. Our findings can inform the design of multiplayer games and game communities, and guide the development of systems for matchmaking and mitigating toxic behaviour in online games.Comment: CHI '2

An Integrative Study of Service and Safety Climate and Performance: Do Climates Compete?

Organizational scholars continue to expand our knowledge of the contextual forces influencing employee behavior in organizations. A notable stream in this research agenda includes organizational climate studies that describe the social processes guiding employee perceptions of their environment. These shared perceptions formulate climate constructs that have demonstrated through theorizing and empirical findings relationships with attitudinal, behavioral, and performance outcomes across multiple levels of analysis. Contemporary climate studies have focused on facet-specific climates, such as a service climate or safety climate, and have linked facet climates with the same facet related performance (e. g. safety climate predicts increased safety performance). Given these strong research programs in climate studies, it is surprising that few researchers have tested the notion of competing climates, despite several calls for such activity in recent climate reviews. The current study adopts a multiple climate perspective to address the differential performance effects given the existence of multiple, competing climates. Using Quinn & Rohrbaugh\u27s (1981) competing values framework, this project tests the notion of climate competition via meta-analysis

Are we working towards global research priorities for management and conservation of sea turtles?

This is the final version. Available from Inter Research via the DOI in this recordThere is another ORE record for this publication: http://hdl.handle.net/10871/24817In 2010, an international group of 35 sea turtle researchers refined an initial list of more than 200 research questions into 20 metaquestions that were considered key for management and conservation of sea turtles. These were classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies. To obtain a picture of how research is being focused towards these key questions, we undertook a systematic review of the peer-reviewed literature (2014 and 2015) attributing papers to the original 20 questions. In total, we reviewed 605 articles in full and from these 355 (59%) were judged to substantively address the 20 key questions, with others focusing on basic science and monitoring that may lead to innovations or inform subsequent interpretation of effectiveness of conservation interventions and/or severity of threats. Progress to answering the 20 questions was not uniform and there were biases regarding focal turtle species, geographic scope and publication outlet. Whilst it offers some meaningful indications as to effort, quantifying peer-reviewed literature output is obviously not the only, and possibly not the best, metric for understanding research progress towards informing key conservation and management goals. Along with the literature review, an international group based on the original project consortium, with additional members, were assigned in groups of two or three (based on core expertise) to critically summarise recent progress towards answering each of the 20 questions. We found that significant research is being expended towards global priorities for management and conservation of sea turtles. Although highly variable, there has been significant progress in all the key questions identified in 2010. Undertaking this critical review has highlighted that it may be timely to undertake one or more new prioritizing exercises. For this to have maximal benefit we make a range of recommendations for its execution. These include a far greater engagement with social sciences, widening the pool of contributors and focussing the questions, perhaps disaggregating ecology and conservation.K.R.W-S is supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-125252

Integrative study of service and safety climate and performance: Do climates compete?

Scope and Method of Study: Organizational work climate competition studied via meta-analytic path modeling.Findings and Conclusions: Safety climate is strongly related with safety performance and service climate is strongly related to performance. Although inconclusive test of climate competition, this project provided theoretical contribution of addressing competing climates and practical applications for managing conflicting climate perceptions

Community-Engaged Development of a Parent-Child Book Reading Wise Intervention

Children living in communities with high rates of poverty experience significant detriment to their academic skills and social, emotional, and behavioral health. Though a range of evidence-based interventions exist that aim to reduce these disparities, they face substantial barriers (e.g., related to financial and human resources, opportunity cost to target families, variable fit across the diverse populations in low-income households). In contrast, wise interventions use psychologically precise pathways to produce small, recursive changes that result in significant benefits. As such, they represent a resource efficient strategy with the potential for considerable impact with contextual adaptation. The current study utilized social marketing research strategies in the context of an academic-community partnership to design, iteratively refine, and examine an emotion-enhanced children’s book – or picture book infused with opportunities to label and explain character emotions – as a wise intervention based in parent-child book reading, an especially warm and nurturing form of parent-child interaction. We employed the Social Marketing Assessment and Response Tool (SMART Model) to guide intervention development and evaluation. In SMART Phases 2-4 (Formative Research), end-users (n=14) completed surveys on basic demographic information, mental health, current beliefs about joint book reading and ongoing practices, and perspectives and response styles to children’s emotions. We then engaged participants in focus groups and interviews to obtain insights regarding the perceived need and preferred characteristics of the proposed intervention. Feedback informed the design of prototype components (i.e., book characters and storylines) that we presented to both new and returning end-users (n=10) for feedback in SMART Phase 5 (Development) pre-testing. Stakeholders (i.e., end-users) again completed surveys on basic demographic information, mental health, current beliefs about joint book reading and ongoing practices, and perspectives and response styles to children’s emotions, and participated in interviews to provide additional feedback. Results from Phase 5 pre-testing informed iterative refinement, and a completed intervention was evaluated by a broad audience via an online survey (n=31) to examine acceptability, usability, and perceived effectiveness