Communications of the ACM

Why computer science students need language

Many students enter the field of computer science with misconceptions about the importance of communication skills. They often choose this field, thinking they will end up with jobs working alone or with other "techies" developing computer games, and not having to deal with people. These students often do not realize the significance of reading, writing, and speaking skills in computer science. This paper discusses several relevant areas of computer science, and explains why computer science students need skills covered in English, speech, technical writing, and even foreign language courses in order to achieve success as a computing professional.

Automated awareness and visualization of online presence

We propose a novel framework for facilitating awareness of people's contactability in a networked environment. Image analysis on periodically captured photo bursts estimates a user's presence and activity levels. A graphical mapping combines these two parameters to represent how contactable the user is. A Visualization conveys the contactability of multiple users to their contacts on the network. An interaction strategy combines the above with the ability to actively seek for awareness of contactability. We describe the current status of implementing this framework, and report intermediate results.

On-line Steiner trees in the Euclidean plane

Suppose we are given a sequence of n points v1,…,vn in the Euclidean plane, and our objective is to construct, on-line, a connected graph that connects all of them, trying to minimize the total sum of lengths of its edges. We assume that the points appear one at a time, vi arriving at step i. At the end of step i, the on-line algorithm must construct a connected graph Ti-1. This can be done by joining vi (not necessarily by a straight line) to any point of Ti-1, which need not necessarily be one of the previously given points vj. The performance of our algorithm is measured by its competitive ratio: the supremum, over all sequences v1,…,vn as above, of the ratio between the total length of the graph constructed by our algorithm and the total length of the best Steiner tree that connects all the points v1,…, vn. There are known on-line algorithms whose competitive ratio is O(log n), but there is no known nontrivial lower bound for the best possible competitive ratio. Here we prove that the upper bound is almost tight by establishing an &OHgr;(log n/log log n) lower bound for the competitive ratio of any on-line algorithm. The lower bound holds for deterministic algorithms as well as for randomized ones, and obviously holds in any Euclidean space of dimension greater than 2 as well.

A flexible hybrid concurrency control model for collaborative applications in large scale settings

Large-scale collaborative applications are difficult to build because of their high concurrency control needs and the heterogeneity of the underlying architecture. Due to these difficulties, only a few large-scale applications have been developed, such as Usenet or irc. To facilitate the realisation of such applications, we propose a more precise definition of the application's needs, in order to provide a good "quality" of cooperation when it is needed, and cheaper cooperation when it is acceptable. The model of LaSCoW (Large Scale Collaborative Work) allows the applications to be partitioned into separate consistency domains, each domain implementing its own collaboration policy.

Use of domain information to improve the performance of an evolutionary algorithm

The main goal of this thesis work is to explore the capacities of cultural algorithms to add domain knowledge in evolutionary computation. Within our objectives is to develop a cultural algorithm for constrained optimization, and other for multiobjective optimization. With a proper desing of the belief space we expect to obtain competitive results compared with other state-of-the-art evolutionary algorithms, but reducing the number of fitness function evaluations needed. In this paper we focus in the algorithm for constrained optimization, because the development of the algorithm for multiobjective optimzation is an early stage.

Interpersonal interaction for pleasurable service experience

The importance of the quality of user experience in service encounter has been acknowledged in different disciplines, including Service Management, Marketing, and Design. However, the focus has been on tangible elements of a service, such as touchpoints, service evidence [21], servicescapes [4]. This paper argues that interpersonal interaction in service encounter plays a significant role in the quality of user experience, therefore should be taken into account into service design process. In particular, this paper pays attention on collaborative services where final users are actively involved, and assume the role of service co-producers.

To examine elements that facilitate interpersonal interaction in service, case studies on carpooling service were carried out. Based on a framework for sociability developed in interaction design discipline, 12 carpooling services in Europe and United States were analyzed. As opposed to managerial perspective, this paper suggests that the heterogeneity in the service performance, caused by the interaction between participants, is not a threat to the quality of user experience, but an opportunity to make the experience more unique, and special.

Getting sidetracked: display design and occasioning photo-talk with the photohelix

In this paper we discuss some of our recent research work designing tabletop interfaces for co-located photo sharing. We draw particular attention to a specific feature of an interface design, which we have observed over an extensive number of uses, as facilitating an under-reported but none-the-less intriguing aspect of the photo-sharing experience - namely the process of 'getting sidetracked'. Through a series of vignettes of interaction during photo-sharing sessions we demonstrate how users of our tabletop photoware system used peripheral presentation of topically incoherent photos to artfully initiate new photo-talk sequences in on-going discourse. From this we draw implications for the design of tabletop photo applications, and for the experiential analysis of such devices.

Benefits and Challenges for Social Media Users on the Autism Spectrum

Individuals with Autism Spectrum Disorder (ASD) often face difficulties creating and maintaining social connections with others, which has been shown to negatively affect their well-being. Some researchers have investigated whether social media use can lead to social benefits, but with mixed results. To better understand how social media use can be beneficial and what challenges it poses, we conducted an interview study with eight adults on the Autism Spectrum. We report on the perceived benefits and real challenges participants faced when trying to engage with others through social media. Often the benefits users hope for are overshadowed by negative ramifications and safety risks that accompany their social media use. We conclude with recommendations for designing social media for neurodiverse users.

Solusforge: controlling the generation of the 3D models with spatial relation graphs

In this paper, we propose Solusforge, a system for automatically generating Lego models from a graph of the components' spatial relationships. The system uses a two step constraint solving approach in which the spatial layout is solved for first, followed by the specific pieces that make up the model, thereby allowing us to explore two separate solution spaces independently. This technology has many uses, including in games featuring a system of snap-together pieces, including Kerbal Space Program, Beseiged, and Spore. While many of these games involve procedurally augmenting human generated design, none of them feature a fully procedural system for generating the artifacts within that space.

A building automation case study setup and challenges

Smart buildings will play a fundamental role in ensuring comfort while reducing the energy required. However, due to the lack of knowledge about the operation of the smart controllers, the occupants can unintentionally increase the energy spent. Nevertheless, there is evidence that the informed and motivated user will actually cooperate with the system.

Some of the issues associated with researching control systems in the context of building automation are difficult to address, because of the chronic lack of effective laboratory settings for experimentation. In this paper, we describe a system representative of the usual complexity found in cyber-physical systems, whose purpose is to address the needs for experimenting with building automation, with a focus on control systems and gamification. Designed with pragmatic concerns, this system presents a unique set of challenges and opportunities to research a new generation of software control systems, and supporting interfaces, that leverage the occupants' behaviour.