Recommending packages with validity constraints to groups of users

The success of recommender systems has made them the focus of a massive research effort in both industry and academia. Recent work has generalized recommendations to suggest packages of items to single users, or single items to groups of users. However, to the best of our knowledge, the interesting problem of recommending a package to a group of users (P2G) has not been studied to date. This is a problem with several practical applications, such as recommending vacation packages to tourist groups, entertainment packages to groups of friends or sets of courses to groups of students. In this paper, we formulate the P2G problem, and we propose probabilistic models that capture the preference of a group toward a package, incorporating factors such as user impact and package viability. We also investigate the issue of recommendation fairness. This is a novel consideration that arises in our setting, where we require that no user is consistently slighted by the item selection in the package. In addition, we study a special case of the P2G problem, where the recommended items are places and the recommendation should consider the current locations of the users in the group. We present aggregation algorithms for finding the best packages and compare our suggested models with baseline approaches stemming from previous work. The results show that our models find packages of high quality which consider all special requirements of P2G recommendation.     

Audio recording of rock/metal music using personal computers

Personal computers and their relevant technologies have been widely used by artists and musicians to create and record their own music and electroacoustic compositions. ＂Laptoppers＂ are famous for using their laptops for their dance/electronic beats and music. A genre that has not relied on the use of PCs for the production of its music is rock/heavy metal, since bands of these genres usually book recording studio time where professionals take on the task of the production using expensive equipment. This study shows that in today＇s day and age, and with the software and hardware currently available, it is possible for rock/metal artists to use their PC to record and produce their own CD successfully and at an extremely competitive cost. The effort＇s of a rock band that does just this is followed from the beginning and the results of their CD production and song successes is presented. The article also serves as a ＂HowTo＂ guide that bands on a low budget can follow to make good quality demo CDs and enter the music business industry.     

Categorization Constructionist Assessment with Software-Based Affinity Diagramming

Affinity diagramming is a cheap and widely used knowledge elicitation technique in human–computer interaction (HCI). However, empirical methods for evaluating user performance in conducting affinity diagrams have remained relatively static. Despite the fact that often the main value of such affinity diagramming sessions lies in the group-based discussions and debates that take place during their construction, what is being captured is often only the final categorizations (the affinity diagram) rather than the process of constructing them. In this article, we propose the concept of categorization constructionism, which we describe as optimized when affinity diagrams are facilitated in groups that have a considerate input of activity in categorization decision-making. We describe how we used this rule to model the temporal nature found within affinity diagram categorizations as they are constructed. To help us test our approach, we utilized participatory design (PD) sessions in developing three TabletPC-based software tools (CATERINE, SAW, and MATE) that would record, allow manipulation of, and evaluate the organization of affinity constructs over time programmatically with digital inking processes. We then used these tools to conduct an experiment that would explore our concept of measuring constructionistic activity over time in practice through the use of our tools.     

Rethinking HCI Education for Design: Problem-Based Learning and Virtual Worlds at an HCI Design Studio

The practice of teaching and learning human–computer interaction (HCI) design has to develop its own approaches that balance method and technology use with reflective and situated practice. This article presents our HCI design studio course that makes a combined use of constructivist pedagogies and virtual worlds aiming to aid students critically review and reflect on the use of related methods and technologies in design and to cultivate more general skills like self-directed learning, intrinsic motivation, and critical thinking. Our HCI design studio course can be thought of as an iterative and incremental teaching and learning process that blends HCI methods, design practice, and technology between a real and a virtual design studio. The course introduces problem-based learning to the pedagogies of project-based learning and studio-based learning currently employed in most HCI design studios. The positive student responses and our reflection and experiences focusing on a number of challenges for further implementation are also outlined.     

Interaction design studio learning in virtual worlds

The paper suggests that virtual worlds (VWs) have many unique advantages for supporting interaction design studio activities, provided that they are designed to include appropriate workplaces and interactive tools to foster collaboration and creativity. We present an approach for employing VWs that proposes the use of prospective tools and workplaces throughout the following key activities of interaction design studio courses: design brief, design thinking, design practice (conceptual and detailed), the desk crit, design review and user evaluation. Then, we describe a blended interaction design studio course on the basis of this approach, which ran through a whole semester. We found that the VW design studio is an engaging and constructive experience for students: In the VW environment, students and tutors held many online meetings, and students constructed several models about their design project, developed a digital prototype and conducted a remote usability evaluation. In addition, the persistence of the environment and the developed VW tools helped students and tutors to achieve careful feedback and reflection during the design project lifetime. Nevertheless, a number of challenges remain for wider implementation: the refinement of the instructional design approach, the usability of VW tools, further integration of VWs to professional design tools and the conduction of other full-scale VW design studio courses.     

Kinesthetic interactions in museums: conveying cultural heritage by making use of ancient tools and (re-) constructing artworks

Kinesthetic interactions allow users to interact with 3D applications through their body movements and hand gestures. When kinesthetic applications are introduced in museums and heritage institutions, they add embodiment to visitor experience. An appropriate fit for kinesthetic technology in museums rests on visitors engaging in purposeful body movements and hand gestures that convey meanings about both intangible and tangible heritage. This paper presents the design, development and evaluation of a kinesthetic application of sculpturing Cycladic figurines, which places the user at the role of an ancient craftsman who creates a figurine with bare-hand movements (translated by Leap Motion to respective sculpting actions) in a simplified virtual environment. The Cycladic sculpture application has been evaluated in laboratory and field testing (as part of a wider educational activity in the museum) with positive results on usability, fun and learning. We identify several benefits as well as challenges of designing kinesthetic interactions in museums and we report on design issues that need to be taken into account in similar applications.     

On surface growth of actin networks

A continuum theory of surface growth is applied to the mechanical modeling of cell motility. The theory relies on a decomposition of the motion into deformation- and growth-inducing parts. A non-dissipative constitutive relation is adopted and expressed exclusively in terms of the current configuration. The resulting model is used in the simulation of a network of actin filaments, and a simple one-dimensional example is included to showcase its predictive capacity.     

Specifying the dynamics of social technologies as social microworlds

This paper explores the affordances of social technologies for supporting the construction of a shareable artefact by a group of learners. A qualitative study that captures the use of five different types of social technologies (Facebook, blogs, wikis, Google Documents and Dropbox) in three different classroom settings sheds light on the potentials and challenges of these tools for supporting material exploration, artefact construction and evaluation. Qualitative content analysis of instructors’ field notes, students’ and instructors’ reflections, interviews and focus groups sheds light on the potential of social technologies to transform the activity of learning across a new culture of computational tools. The affordances of social technologies are discussed as well as design principles that need to be followed in these new arenas.     

Approach to Separate Sand from Gravel for Bed-Load Transport Calculations in Streams with Bimodal Sediment

The bed material found in gravel-bed streams is nonuniform in terms of grain size and can typically be classified as unimodal or bimodal. The latter type of sediment distribution is usually represented by two modes, one of sand size and another of gravel. For this case, the movement of one mode becomes nonlinearly influenced by the other. As a result, the presence of the two modes in a bimodal material complicates the calculation of bed-load transport rates. The present study proposes an approach to separate the calculation of bed-load transport rates for bimodal materials into two independent fractions of sand and gravel, thereby rendering the bed sediment into two unimodal components. This approach is accomplished by decoupling the two fractions through scaling the reference Shields stresses of the sand and gravel modes to match the value of the mode of unimodal materials. Consequently, the contribution of each fraction to bed load can be estimated using a suitable relation derived for unimodal materials. Laboratory and field bed-load data available in the literature are used to examine the validity of the overall approach.