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Communications of the ACM

101 - 110 of 3,299 for bentley

On finding the closest bitwise matches in a fixed set

In a given large fixed table of bit-vectors, we would like to find, as rapidly as possible, those bit-vectors which have the least Hamming distances from a newly-presented arbitrary bit-vector.

A general approach to ethnographic analysis for systems design

An important aspect of designing for ubiquitous collaborating systems is addressing the needs of the culture in which the system is to be applied. The value of ethnographic analysis in this respect is gaining increasing acceptance. Such analysis provides a 'rich' and 'concrete' portrayal of the situation and thus helps systematic design of any system where collaboration and communication between actors is paramount. A discussion of these issues has recently been presented in [1]. This paper takes these issues further by considering 'EthnoModel' as an approach to generalisation of the method to any system demonstrating these features.

Evolving art with scalable vector graphics

In this paper we introduce the use of Scalable Vector Graphics (SVG) as a representation for evolutionary art. We describe the technical aspects of using SVG in evolutionary art, and explain the genetic operators mutation and crossover. Furthermore, we compare the use of SVG with existing representations in evolutionary art. We performed a number of experiments in an unsupervised evolutionary art system using two aesthetic measures as fitness functions, and compared the outcome of the different experiments with each other and with previous work with symbolic expressions as the representation. All images and SVG code examples in this paper are available at

Measuring, enabling and comparing modularity, regularity and hierarchy in evolutionary design

For computer-automated design systems to scale to complex designs they must be able to produce designs that exhibit the characteristics of modularity, regularity and hierarchy -- characteristics that are found both in man-made and natural designs. Here we claim that these characteristics are enabled by implementing the attributes of combination, control-flow and abstraction in the representation.To support this claim we use an evolutionary algorithm to evolve solutions to different sizes of a table design problem using five different representations, each with different combinations of modularity, regularity and hierarchy enabled and show that the best performance happens when all three of these attributes are enabled.We also define metrics for modularity, regularity and hierarchy in design encodings and demonstrate that high fitness values are achieved with high values of modularity, regularity and hierarchy and that there is a positive correlation between increases in fitness and increases in the measured values of modularity, regularity and hierarchy.

Exploring Challenges in Automated Just-In-Time Adaptive Food Choice Interventions

A healthy diet lowers the risk of developing diseases like diabetes, obesity and different types of cancers and cardiovascular conditions. Persuasive systems have already shown promise in changing user's nutrition through the strategy of monitoring and retrospectively visualizing (bad) eating behavior. In contrast emerged the idea of systems proactively offering help before such behavior even occurs, i.e. before a food choice has been made. Recent advances within the sensor-enrichment of smartphones and wearable technologies have made it possible to develop new behavior change intervention techniques, such as Just-In-Time Adaptive Interventions (JITAI). Within this work, we discuss challenges towards technology-supported, completely automated JITAIs to support healthy food choices. We derive the challenges based on existing literature, and discuss future research opportunities that would benefit users towards achieving a healthier eating behavior.

Brief Announcement: Parallel Dynamic Tree Contraction via Self-Adjusting Computation

Dynamic algorithms are used to compute a property of some data while the data undergoes changes over time. Many dynamic algorithms have been proposed but nearly all are sequential. In this paper, we present our ongoing work on designing a parallel algorithm for the dynamic trees problem, which requires computing a property of a forest as the forest undergoes changes. Our algorithm allows insertion and/or deletion of both vertices and edges anywhere in the input and performs updates in parallel. We obtain our algorithm by applying a dynamization technique called self-adjusting computation to the classic algorithm of Miller and Reif for tree contraction.

TVX '15: Proceedings of the ACM International Conference on Interactive Experiences for TV and Online Video

We are very pleased that we can present to you an exciting program for ACM TVX 2015, which has been put together based on many submissions from all around the globe.

As the leading international conference for presentation and discussion of research into interactive experiences for online video and TV, the conference brings together international researchers and practitioners from a wide range of disciplines, ranging from human-computer interaction, multimedia engineering and design to media studies, media psychology and sociology, to present and discuss the latest insights in the field. ACM TVX2015 presents research on content production, systems & architectures, interaction technologies & techniques, experience design & evaluation, media studies, empirical methods, data science, business models & marketing and innovation & visions.

The call for papers attracted submissions from Asia, Canada, Europe, the United States and South America. Fifty full and short papers were submitted and subjected to a thorough double-blind review process. Each paper was assigned to an Associate Chair (AC) who recruited at least three reviewers per paper and wrote a meta-review summarizing the main points of each review. The review process included a rebuttal period, giving authors the chance to respond to reviewers' comments. During the TPC meeting on March 6, 2015, in Leuven, Belgium, each paper was discussed in depth and the final decision of which papers to accept was made, resulting in a high-quality program of twelve accepted full and short papers and an acceptance rate of 24%. Work in Progress papers were also reviewed by at least three reviewers per paper, of which 13 were accepted (50% acceptance rate) and will be presented as a poster during the conference. Full papers, short papers and Works in Progress are part of the main proceedings and will be included in the ACM Digital Library.

In addition to these submissions, there were several other categories that received submissions, resulting in 3 workshops, 3 courses, 6 Doctoral Consortium papers, 9 TVX in Industry presentations, and 13 demos, which are all made available in the adjunct proceedings.

Finally, we also encourage attendees to attend the keynote: Empowering storytellers with social media, Jacob Shwirtz (Endemol Beyond USA).