Communications of the ACM

Concept-based multi-objective problems and their solution by EC

Recent studies on the support of engineers during conceptual design resulted in a non-traditional type of Multi-Objective Problems (MOPs), namely concept-based ones. In concept-based MOPs the focus is on conceptual solutions that are represented by sets of particular solutions. This means that a concept has a one-to-many relation with the objective space. Such a set-based concept representation is most suitable for human-computer interaction. In concept-based MOPs concept-related preferences could be easily incorporated with or without range-related preferences. This paper provides an overview of studies on concept-based problems, which have been conducted at Tel-Aviv University, and suggests some future research directions.

MACCS: enabling communications for mobile workers within healthcare environments

As wireless communications systems become more ubiquitous, enterprise workers are becoming more and more mobile. Addressing mobility in the enterprise has recently become a pressing concern for many corporations. In particular, there is a growing component of mobile workers whose job tasks require them to be mobile within their local workspace. These workers sometimes do not have a desk or phone and frequently use their hands in performing required tasks; they typically referred to as "corridor cruisers" or "campus roamers". One class of workers that fall under this category is healthcare professionals (e.g. nurses). Communication enabling these workers usually involves an expensive proposition: equipping them with a mobile/wireless phone, PDA or a paging device. Our goal was to see if we could address the communications needs of healthcare workers by using a small, inexpensive, wearable, hands-free audio device (a wireless headset) along with a speech interface to an intelligent agent. In this paper we present the results of an industrial user study in a real world healthcare environment of our Mobile Access to Converged Communications System (MACCS) which empowers mobile workers with a hands-free voice interface to manage their communications. In addition we also discuss the design, implementation and deployment of MACCS.

Collocated Interaction: New Challenges in 'Same Time, Same Place' Research

In the 25 years since Ellis, Gibbs, and Rein proposed the time-space taxonomy, research in the 'same time, same place' quadrant has diversified, perhaps even fragmented. The goal of this one-day workshop is to bring together researchers with diverse, yet convergent interests in tabletop, surface, mobile and wearable technologies, and those interested in the social aspects of interaction, such as conversation analysis and ethnomethodology. These communities have matured considerably, and produced significant exemplars of systems, methods, and studies concerned with collocated interactions. Yet, new challenges abound as people wear and carry more devices than ever, creating fragmented device ecologies at work, and changing the ways we socialise with each other. In this workshop we seek to start a dialogue to look back as well as forward, review best practices, discuss and design paper-prototypes using the collocated design framework, to consider how we might address new and future challenges through collocated design practice.

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.

REX—a VLSI parasitic extraction tool for electromigration and signal analysis