Tensor reduction for user profiling in personalized recommender systems

User profiling is the process of constructing user models which represent personal characteristics and preferences of customers. User profiles play a central role in many recommender systems. Recommender systems recommend items to users based on user profiles, in which the items can be any objects which the users are interested in, such as documents, web pages, books, movies, etc. In recent years, multidimensional data are getting more and more attention for creating better recommender systems from both academia and industry. Additional metadata provides algorithms with more details for better understanding the interactions between users and items. However, most of the existing user/item profiling techniques for multidimensional data analyze data through splitting the multidimensional relations, which causes information loss of the multidimensionality. In this paper, we propose a user profiling approach using a tensor reduction algorithm, which we will show is based on a Tucker2 model. The proposed profiling approach incorporates latent interactions between all dimensions into user profiles, which significantly benefits the quality of neighborhood formation. We further propose to integrate the profiling approach into neighborhoodbased collaborative filtering recommender algorithms. Experimental results show significant improvements in terms of recommendation accuracy.

User perceived video quality modelling on mobile devices for Vp9 and H265 encoders

This study constructs performance prediction models to estimate the end-user perceived video quality on mobile devices for the latest video encoding techniques –VP9 and H.265. Both subjective and objective video quality assessments were carried out for collecting data and selecting the most desirable predictors. Using statistical regression, two models were generated to achieve 94.5% and 91.5% of prediction accuracies respectively, depending on whether the predictor derived from the objective assessment is involved. These proposed models can be directly used by media industries for video quality estimation, and will ultimately help them to ensure a positive end-user quality of experience on future mobile devices after the adaptation of the latest video encoding technologies.

Refining user and item profiles based on multidimensional data for top-n item recommendation

In recommender systems based on multidimensional data, additional metadata provides algorithms with more information for better understanding the interaction between users and items. However, most of the profiling approaches in neighbourhood-based recommendation approaches for multidimensional data merely split or project the dimensional data and lack the consideration of latent interaction between the dimensions of the data. In this paper, we propose a novel user/item profiling approach for Collaborative Filtering (CF) item recommendation on multidimensional data. We further present incremental profiling method for updating the profiles. For item recommendation, we seek to delve into different types of relations in data to understand the interaction between users and items more fully, and propose three multidimensional CF recommendation approaches for top-N item recommendations based on the proposed user/item profiles. The proposed multidimensional CF approaches are capable of incorporating not only localized relations of user-user and/or item-item neighbourhoods but also latent interaction between all dimensions of the data. Experimental results show significant improvements in terms of recommendation accuracy.

Using augmented video to test in-car user experiences of context analog HUDs

Automotive interactive technologies represent an exemplar challenge for user experience (UX) designers, as the concerns for aesthetics, functionality and usability add up to the compelling issues of safety and cognitive demand. This extended abstract presents a methodology for the user-centred creation and evaluation of novel in-car applications, involving real users in realistic use settings. As a case study, we present the methodologies of an ideation workshop in a simulated environment and the evaluation of six design idea prototypes for in-vehicle head up display (HUD) applications using a semi-naturalistic drive. Both methods rely on video recordings of real traffic situations that the users are familiar with and/or experienced themselves. The extended abstract presents experiences and results from the evaluation and reflection on our methods.

Cultural safety, diversity and the servicer user and carer movement in mental health research

This study will be of interest to anyone concerned with a critical appraisal of mental health service users’ and carers’ participation in research collaboration and with the potential of the postcolonial paradigm of cultural safety to contribute to the service user research (SUR) movement. The history and nature of the mental health field and its relationship to colonial processes provokes a consideration of whether cultural safety could focus attention on diversity, power imbalance, cultural dominance and structural inequality, identified as barriers and tensions in SUR. We consider these issues in the context of state-driven approaches towards SUR in planning and evaluation and the concurrent rise of the SUR movement in the UK and Australia, societies with an intimate involvement in processes of colonisation. We consider the principles and motivations underlying cultural safety and SUR in the context of the policy agenda informing SUR. We conclude that while both cultural safety and SUR are underpinned by social constructionism constituting similarities in principles and intent, cultural safety has additional dimensions. Hence, we call on researchers to use the explicitly political and self-reflective process of cultural safety to think about and address issues of diversity, power and social justice in research collaboration.

Driving toward user-centered engineering in automotive design

In an industry worth more than €500 billion annually, producing more than 80 million vehicles worldwide each year and consisting of over 50 major manufacturers worldwide, the automotive industry represents a lucrative but highly competitive manufacturing industry (Deloitte, 2009a; European Automobile Manufacturers Association, 2012). With sales falling in Europe in 2013 for the sixth consecutive year (Boston and Curtin, 2014), automotive manufacturers are increasingly turning to new strategies to retain their share of sales in a contracting market. Some strategies have focused on the industry approach to manufacturing, namely, a technically focused push for a build-toorder process rather than the current build-to-stock approach in order to reduce overall value-chain costs and to increase efficiency (Parry and Roehrich, 2013, p. 13). However, others stress a more customer-orientated approach, striving to develop products that meet customer requirements (Oliver Wyman Group, 2007).

Investigation of the effects of the fatty acid profile on fuel properties using a Multi-Criteria Decision Analysis

The structural features of fatty acids in biodiesel, including degree of unsaturation, percentage of saturated fatty acids and average chain length, influence important fuel properties such as cetane number, iodine value, density, kinematic viscosity, higher heating value and oxidation stability. The composition of fatty acid esters within the fuel should therefore be in the correct ratio to ensure fuel properties are within international biodiesel standards such as ASTM 6751 or EN 14214. This study scrutinises the influence of fatty acid composition and individual fatty acids on fuel properties. Fuel properties were estimated based on published equations, and measured according to standard procedure ASTM D6751 and EN 14214 to confirm the influences of the fatty acid profile. Based on fatty acid profile-derived calculations, the cetane number of the microalgal biodiesel was estimated to be 11.6, but measured 46.5, which emphasises the uncertainty of the method used for cetane number calculation. Multi-criteria decision analysis (MCDA), PROMETHEE-GAIA, was used to determine the influence of individual fatty acids on fuel properties in the GAIA plane. Polyunsaturated fatty acids increased the iodine value and had a negative influence on cetane number. Kinematic viscosity was negatively influenced by some long chain polyunsaturated fatty acids such as C20:5 and C22:6 and some of the more common saturated fatty acids C14:0 and C18:0. The positive impact of average chain length on higher heating value was also confirmed in the GAIA plane

Social networking sites and participatory reluctance: A case study of Gaydar, user resistance and interface rejection

This article conceptualises ‘participatory reluctance’ as a particular orientation to social media that problematises binarised notions of connection and disconnection in social networking sites. It qualitatively examines how the concept has functioned within gay men’s social networking service, Gaydar, among 18- to 28-year-old users of the site in Brisbane, Australia. Participatory reluctance is shown to be a central aspect of the culture of this space, fostered among the studied demographic by the convergence of the growing global push for marriage equality and increasing normalisation of the kinds of gay male identities commonly adopted among this group, with three key factors rooted primarily in Gaydar’s design: (1) young users’ perceptions of the site as a space for procuring casual sex; (2) their perceptions of the imagined user as embodying existing stereotypes of gay masculinity, and; (3) a lack of genuine alternatives in terms of niche digital spaces for gay men’s social networking.

User centred engineering in automotive design: A shift from technology-driven product development

The research assessed how best to transition engineering-based automotive firms towards more customer-orientated design and development approaches, whilst identifying the main barriers and concerns facing such a shift. The research investigates the ability of a firm to empower individual engineers with user centred design tools traditionally used by designers, whilst understanding the company-wide needs to facilitate their implementation.

The nutritional profile of baby and toddler food products sold in Australian supermarkets

Background/Aims To examine the nutritional profile of baby and toddler foods sold in Australia. Methods Nutrient information for baby and toddler foods available at Australian supermarkets was collected between August and December 2013. Levels of declared energy, total fat, saturated fat, total sugar, sodium and estimated added sugar were examined, as well as the presence of additional micronutrients on the label. The Health Star Rating (HSR) system was used to determine nutritional quality. The range of products on offer was also examined by product type and by the age category for which the product was marketed. Results Of the 309 products included, 29 % were fortified. On a per 100 g basis, these 309 products provided a mean (±SD) of 476 ± 486 kJ, 1.6 ± 2.4 g total fat, 10.7 ± 12.2 g total sugar, 2.7 ± 7.4 g added sugar, and 33.5 ± 66.5 mg sodium. Fruit-based products or products with fruit listed as an ingredient (58 %) were the predominant product type. On the nutrition label, 42 % displayed at least one additional micronutrient while 37 % did not display saturated fat. The most common HSR was four stars (45 %) and 6? months was the most commonly identified targeted age group (36 %). Conclusions The majority of baby and toddler foods sold in Australian supermarkets are ready-made fruit-based products aimed at children under 12 months of age. Baby and toddler foods are overlooked in public policy discussions pertaining to population nutrient intake but their relatively high sugar content deriving from fruits requires close attention to ensure these foods do not replace other more nutrient dense foods, given children have an innate preference for sweet tastes.

Introduction to the Proceedings of the Workshop on User-Focused Service Engineering, Consumption and Aggregation (USECA) 2011

The first User-Focused Service Engineering, Consumption and Aggregation workshop (USECA) in 2011 was held in conjunction with the WISE 2011 conference in Sydney, Australia. Web services and related technology are a widely accepted standard architectural paradigm for application development. The idea of reusing existing software components to build new applications has been well documented and supported for the world of enterprise computing and professional developers. However, this powerful idea has not been transferred to end-users who have limited or no computing knowledge. The current methodologies, models, languages and tools developed for Web service composition are suited to IT professionals and people with years of training in computing technologies. It is still hard to imagine any of these technologies being used by business professionals, as opposed to computing professionals. © 2013 Springer-Verlag.

Architecture for service profiling

Service oriented architecture is gaining momentum. However, in order to be successful, the proper and up-to-date description of services is required. Such a description may be provided by service profiling mechanisms, such as one presented in this article. Service profile can be defined as an up-to-date description of a subset of non-functional properties of a service. It allows for service comparison on the basis of non-functional parameters, and choosing the service which is most suited to the needs of a user. In this article the notion of a service profile along with service profiling mechanism is presented as well as the architecture of a profiling system. © 2006 IEEE.