A Tale of Distributed Transparency and Partial Failures (Elisa Gonzalez Boix)
Partial failures are everyday reality when dealing with distributed systems. A partial failure occurs when one component of the distributed system fails, possibly affecting a number of other components. When designing a distributed system, an important goal is to ensure robustness against failures so that whenever they happen the system can recover and continue working to some extent. As such, building fault-tolerant distributed systems has been an active research topic for the last decades. The advances in mobile computing, however, have changed the set of basic assumptions about the network behaviour. Networks of wirelessly interconnected mobile devices are fragile and prone to fluctuations, and devices may appear and disappear from the environment at any moment in time. As a result masking network failures became dangerous and deceiving.
In this talk I reflect on my research exploring the trade-off between novel programming abstractions that aid with the difficulties of failure handling, on the one hand, and providing mechanisms that allow developers to be aware of their effects and take them into account in the design and construction of applications, on the other hand. Since my research was grounded in the ambient-oriented programming, a paradigm geared towards mobile computing, I will introduce its key programming characteristics and examine the past innovations in ambient-oriented languages. I will then describe how we are applying concepts developed within mobile computing to help the development of mobile cloud applications.
About the Speaker
Elisa Gonzalez Boix is Assistant Professor at the Software Languages Lab (SOFT) of the Vrije Universiteit Brussel (VUB), Belgium. She obtained her Master in Informatics Engineering in 2004 from the Universitat Politecnica de Catalunya (Spain) and her PhD in Sciences in 2012 from VUB on programming language abstractions and tools for handling partial failures in distributed applications running on mobile ad hoc networks. Her PhD heavily relied on reflection and meta-level programming. She has also been active in the design and development of the distributed actor-based AmbientTalk language, prototyping its first concurrency model based on active objects in 2003. Since 2008 she has also employed AmbientTalk to teach distributed and mobile programming to master level students. She serves on the PC of the Dynamic Languages Symposium (DLS) and co-organized the SCRIPT 2013 workshop (Secure Cloud and Reactive Internet Programming Technology) and the International Workshop on Programming based on Actors, Agents, and Decentralized Control (AGERE!) in 2014 and 2015. Her current research focuses on implementation technology to support the design of both programming languages and tools for mobile and cloud systems.
Crowdsourcing Mobile Media through Games (Dion H. Goh)
The popularity of social computing and proliferation of user-generated content have given rise to the crowdsourcing phenomenon. Despite the potential of crowdsourcing, a couple of conundrums exist. In particular, participants need to be motivated to perform their assigned tasks, which can be tedious, and thus dependent on individuals’ willingness to devote their time and effort to such endeavors. Other platforms such as the Amazon Mechanical Turk, offer monetary payments to participants but this limits crowdsourcing projects to those backed with adequate funding, and does not guarantee the accuracy and truthfulness of the generated outputs.
Games have thus been investigated as an alternative means to motivate people to participate in crowdsourcing. Known variously as crowdsourcing games, games with a purpose or human computation games, they generate useful outputs as by-products of gameplay. Such games are seen as promising approach to crowdsourcing because they capitalize on people's desire for entertainment. In other words, they make crowdsourcing more fun and engaging in order to attract participants.
This talk will introduce the concept of crowdsourcing games. A selection of typical game mechanics employed as well as examples of games in various domains will be provided. Following this, the talk will discuss the use crowdsourcing games in the creation and sharing of location-based mobile media. Applications that share location-based mobile media are fast becoming popular in part due to people’s increasing reliance on mobile phones, and the incorporation of game-based concepts provide further impetus to their adoption.
Although there are benefits to mobility and mobile media sharing, limitations of mobile devices such as difficult text input as well as the lack of sufficient incentives may make the creation and sharing of location-based content tedious, possibly resulting in decreased motivation for participation. By intertwining games with crowdsourcing of content, such applications provide entertainment and content is created as a result of gameplay. Nevertheless, there are challenges associated with designing crowdsourcing games since they have to meet the twin goals of entertaining users and producing quality outputs. Through various user studies that will be presented, issues in creating these games as well as design lessons are discussed.
About the Speaker
Dion Goh has a PhD in computer science. He is currently Associate Professor with Nanyang Technological University (Singapore) where is also the Director of the Masters of Information Systems program in the Wee Kim Wee School of Communication and Information. His major areas of research are in mobile information sharing and seeking, social media perceptions and practices, and gamification techniques for shaping user perceptions and motivating behavior. His work has been widely published in over 200 international journals and conference proceedings. Dion has led a number of funded projects in the use of gamification in mobile content sharing, the use of games for mental health interventions, human computation games for data analytics, mobile tagging, and collaborative querying.
Ad Hoc Vehicular Crowdsourcing for Urban Congestion Mitigation (Stephan Olariu)
Most traffic signals in the US run a set of predefined timing plans that set the signal's cycle length and green phase length based on the time of the day. In most cases, the optimization of the signal systems currently occurs off-line at either the isolated intersection or corridor level. One of the major disadvantages of this approach is that it requires data on traffic-turning movements be regularly collected to develop optimized traffic signal plans off-line. A second major disadvantage is that the time-of-day based signal timings do not adapt well to unexpected changes in traffic demand. For example, if an incident on the roadway network causes travel patters to change significantly, the signals often cannot fully accommodate the changes in flow, resulting in traffic buildup and congestion. In order to ensure that the signals function as well as possible, they have to be re-timed regularly to reflect current conditions. Unfortunately, due to budget or manpower limitations, transportation agencies often neglect to re-time signals resulting in unnecessary delays to the traveling public.
While the transportation agencies have devoted substantial effort to optimizing traffic signals at the corridor level, the problem of rescheduling the timing of traffic lights at the scale of a wider urban area is still very much uncharted territory. The principle reason behind this state of affairs is the combinatorial explosion inherent in the process of transiting from small-scale to large scale, complex problems. This is clearly the case when the traffic flows from several corridors compete for unshareable resources -- time and road bandwidth. In an ideal world, the municipal Traffic Management Center (TMC) would have at its disposal a number of supercomputers that could be used to compute in near real-time optimal timing plans for all the traffic signals under its jurisdiction. In reality, no municipality can afford the huge expenditure involved in purchasing and maintaining a computational resource solely dedicated to optimizing traffic flow. One alternative would be for the TMC to outsource this huge computational task to one of the existing cloud service providers. This approach, however, would be not only be costly but, due to the overheads involved, would not guarantee traffic signal re-timing in useful time, say, to mitigate the effects of a pop-up congestion event.
This keynote address introduces and develops a framework for harnessing the on-board computational resources in vehicles stuck in urban congestion in order to assist transportation agencies with dissipating congestion through large-scale signal re-timing. We refer to our framework as Ad Hoc Vehicular Crowdsourcing for Urban Congestion Mitigation. What makes this framework unique is that we suggest that in such situations the vehicles have the potential to cooperate with various transportation authorities to solve problems that otherwise would either take an inordinate amount of time to solve or cannot be solved for lack for adequate municipal resources.
About the Speaker
Professor Olariu has held many different roles and responsibilities as a member of numerous organizations and teams. Much of his experience has been with the design and implementation of robust protocols for various flavors of wireless networks and in particular vehicular networks and their applications. Professor Olariu is applying mathematical modeling and analytical frameworks to the resolution of problems ranging from securing communications, to predicting the behavior of complex systems, to evaluating performance of vehicular networks and vehicular clouds. His current research interests are in the area of modeling complex intelligent systems enabled by large-scale deployments of sensors and actors.
E-Commerce: Early Expectations vs. Current Situation (Hannes Werthner)
This talk takes a historic (and a little bit subjective) view confronting the current e-commerce situation with its initial expectations and promises. The talk will look at areas such as the structural development of the online market, the progress made w.r.t. user services or interoperability issues. At the end it will discuss a set of current challenges. The talk will use the online tourism industry as a special case.
About the Speaker
Hannes Werthner is a Professor for e-commerce , and previously Director of the Vienna PhD School of Informatics, at the Vienna University of Technology, Austria. Before that he was Professor at the University of Innsbruck; the Vienna University of Economics; and at the University of Trento, Italy. Besides being member in many editorial boards of journals, e.g., Communications of the ACM, International Journal of Electronic Markets, Information Systems and e-Business Management, or Information Technology and Tourism, he was also a member of ISTAG, a high level Advisory Group for the "Information Society Technologies" within the EU research programs. For his contributions in e-tourism, since 2011 the Hannes Werthner Lifetime Award is given to the highly recognized academic or business personalities in the e-tourism arena. His expertise covers fields such as e-commerce and e-tourism, recommender systems, network analysis.