Stefano Tranquillini

From people to services to UI: distributed orchestration of user interfaces

Traditionally, workflow management systems aim at alleviating peoples burden of coordinating repetitive business procedures, i.e., they coordinate people. Web service orchestration approaches, instead, coordinate pieces of software (the web services), hiding the human aspects that are intrinsically present in any business process behind the services. The recent emergence of technologies like BPEL4People and WS-HumanTask, which introduce human actors into service compositions, manifest that taking into account the people involved in business processes is however important. Yet, none of these approaches allow one to also develop the user interfaces (UIs) the users need to concretely participate in a business process. With this paper, we want to go one step beyond state-of-the-art workflow management and service composition and propose an original model, language and running system for the composition of distributed UIs, an approach that allows us to bring together UIs, web services and people in a single orchestration logic and tool. To demonstrate the effectiveness of the idea, we apply the approach to a real-world home assistance scenario.

Process-based design and integration of wireless sensor network applications

Wireless Sensor and Actuator Networks (WSNs) are distributed sensor and actuator networks that monitor and control real-world phenomena, enabling the integration of the physical with the virtual world. They are used in domains like building automation, control systems, remote healthcare, etc., which are all highly process-driven. Today, tools and insights of Business Process Modeling (BPM) are not used to model WSN logic, as BPM focuses mostly on the coordination of people and IT systems and neglects the integration of embedded IT. WSN development still requires significant special-purpose, low-level, and manual coding of process logic. By exploiting similarities between WSN applications and business processes, this work aims to create a holistic system enabling the modeling and execution of executable processes that integrate, coordinate, and control WSNs. Concretely, we present a WSN-specific extension for Business Process Modeling Notation (BPMN) and a compiler that transforms the extended BPMN models into WSN-specific code to distribute process execution over both a WSN and a standard business process engine. The developed tool-chain allows modeling of an independent control loop for the WSN.

Modeling, Enacting, and Integrating Custom Crowdsourcing Processes

Crowdsourcing (CS) is the outsourcing of a unit of work to a crowd of people via an open call for contributions. Thanks to the availability of online CS platforms, such as Amazon Mechanical Turk or CrowdFlower, the practice has experienced a tremendous growth over the past few years and demonstrated its viability in a variety of fields, such as data collection and analysis or human computation. Yet it is also increasingly struggling with the inherent limitations of these platforms: each platform has its own logic of how to crowdsource work (e.g., marketplace or contest), there is only very little support for structured work (work that requires the coordination of multiple tasks), and it is hard to integrate crowdsourced tasks into state-of-the-art business process management (BPM) or information systems. We attack these three shortcomings by (1) developing a flexible CS platform (we call it Crowd Computer, or CC) that allows one to program custom CS logics for individual and structured tasks, (2) devising a BPMN--based modeling language that allows one to program CC intuitively, (3) equipping the language with a dedicated visual editor, and (4) implementing CC on top of standard BPM technology that can easily be integrated into existing software and processes. We demonstrate the effectiveness of the approach with a case study on the crowd-based mining of mashup model patterns.

Business Processes for the Crowd Computer

Social networks and crowdsourcing platforms provide powerful means to execute tasks that require human intelligence instead of just machine computation power. Especially crowdsourcing has demonstrated its applicability in many fields, and a variety of platforms have been created for delegating small tasks to human solvers on the Web. However, creating applications that are structured, thus applications that combine more than a single task, is a complex and typically manual endeavor that requires many different interactions with crowdsourcing platforms. In this paper, we introduce the idea of a crowd computer, discuss its properties, and propose a programming paradigm for the development of crowdsourcing applications. In particular, we argue in favor of business processes as formalism to program the crowd computer and show how they enable the reuse of intricate crowdsourcing practices.

Towards business processes orchestrating the physical enterprise with wireless sensor networks

The industrial adoption of wireless sensor networks (WSNs) is hampered by two main factors. First, there is a lack of integration of WSNs with business process modeling languages and back-ends. Second, programming WSNs is still challenging as it is mainly performed at the operating system level. To this end, we provide makeSense: a unified programming framework and a compilation chain that, from high-level business process specifications, generates code ready for deployment on WSN nodes.

Crowdsourcing Processes: A Survey of Approaches and Opportunities

This article makes a case for crowdsourcing approaches that are able to manage crowdsourcing processes -- that is, crowdsourcing scenarios that go beyond the mere outsourcing of multiple instances of a micro-task and instead require the coordination of multiple different crowd and machine tasks. It introduces the necessary background and terminology, identifies a set of analysis dimensions, and surveys state-of-the-art tools, highlighting strong and weak aspects and promising future research and development directions.

Distributed orchestration of user interfaces

Workflow management systems focus on the coordination of people and work items, service composition approaches on the coordination of service invocations, and, recently, web mashups have started focusing on the integration and coordination of pieces of user interfaces (UIs), e.g., a Google map, inside simple web pages. While these three approaches have evolved in a rather isolated fashion - although they can be seen as evolution of the componentization and coordination idea from people to services to UIs - in this paper we describe a component-based development paradigm that conciliates the core strengths of these three approaches inside a single model and language. We call this new paradigm distributed UI orchestration, so as to reflect the mashup-like and process-based nature of our target applications. In order to aid developers in implementing UI orchestrations, we equip the described model and language with suitable design, deployment, and runtime instruments, covering the whole life cycle of distributed UI orchestrations.

The interplay of physical and social wellbeing in older adults: investigating the relationship between physical training and social interactions with virtual social environments

Background. Regular physical activity can substantially improve the physical wellbeing of older adults, preventing several chronic diseases and increasing cognitive performance and mood. However, research has shown that older adults are the most sedentary segment of society, spending much of their time seated or inactive. A variety of barriers make it difficult for older adults to maintain an active lifestyle, including logistical difficulties in going to a gym (for some adults, leaving home can be challenging), reduced functional abilities, and lack of motivation. In this paper, we report on the design and evaluation of Gymcentral. A training application running on tablet was designed to allow older adults to follow a personalized home-based exercise program while being remotely assisted by a coach. The objective of the study was to assess if a virtual gym that enables virtual presence and social interaction is more motivating for training than the same virtual gym without social interaction. Methods. A total of 37 adults aged between 65 and 87 years old (28 females and 9 males, mean age = 71, sd = 5.8) followed a personalized home-based strength and balance training plan for eight weeks. The participants performed the exercises autonomously at home using the Gymcentral application. Participants were assigned to two training groups: the Social group used an application with persuasive and social functionalities, while the Control group used a basic version of the service with no persuasive and social features. We further explored the effects of social facilitation, and in particular of virtual social presence, in user participation to training sessions. Outcome measures were adherence, persistence and co-presence rate. Results. Participants in the Social group attended significantly more exercise sessions than the Control group, providing evidence of a better engagement in the training program. Besides the focus on social persuasion measures, the study also confirms that a virtual gym service is effective for supporting individually tailored home-based physical training for older adults. The study also confirms that social facilitation tools motivate users to train together in a virtual fitness environment. Discussion. The study confirms that Gymcentral increases the participation of older adults in physical training compare to a similar version of the application without How to cite this article Khaghani Far et al. (2015), The interplay of physical and social wellbeing in older adults: investigating the relationship between physical training and social interactions with virtual social environments. PeerJ Comput. Sci. 1:e30; DOI 10.7717/peerjcs.30 social and persuasive features. In addition, a significant increase in the co-presence of the Social group indicates that social presence motivates the participants to join training sessions at the same time with the other participants. These results are encouraging, as they motivate further research into using home-based training programs as an opportunity to stay physically and socially active, especially for those who for various reasons are bound to stay at home. Subjects Human–Computer Interaction, Emerging Technologies, Mobile and Ubiquitous Computing, Network Science and Online Social Networks

ReLauncher: Crowdsourcing Micro-Tasks Runtime Controller

Task execution timeliness, i.e., the completion of a task within a given time frame, is a known open issue in crowdsourcing. While running tasks on crowdsourcing platforms a requester experiences long tails in execution caused by abandoned assignments (those left by workers unfinished), which become available for other workers only after some expiration time (e.g., 30 minutes in CrowdFlower). These abandoned assignments result in significant delays and a poor predictability of the overall task execution time. In this paper, we propose an approach and an implementation called ReLauncher to identify such abandoned assignments and relaunch them for other workers. We evaluate our implementation with an experiment on CrowdFlower that provides substantive evidence for a significant execution speed improvement with an average extra cost of about 10%.

BPMN Task Instance Streaming for Efficient Micro-task Crowdsourcing Processes

The Business Process Model and Notation BPMN is a standard for modeling and executing business processes with human or machine tasks. The semantics of tasks is usually discrete: a task has exactly one start event and one end event; for multi-instance tasks, all instances must complete before an end event is emitted. We propose a new task type and streaming connector for crowdsourcing able to run hundreds or thousands of micro-task instances in parallel. The two constructs provide for task streaming semantics that is new to BPMN, enable the modeling and efficient enactment of complex crowdsourcing scenarios, and are applicable also beyond the special case of crowdsourcing. We implement the necessary design and runtime support on top of CrowdFlower, demonstrate the viability of the approach via a case study, and report on a set of runtime performance experiments.