About the lab

The Pragmatics laboratory is a laboratory focused on computer science research and its applications. Concretely, we work on software development from programming languages and software engineering; in addition, we study real-world applications of computer science. If you are interested in knowing more about us, please visit research areas and publications Web pages.

Featured research (8)

Background: Twitter offers tools that facilitate the diffusion of information by which companies can engage consumers to share their messages. Literature review: Communication professionals are using platforms such as Twitter to disseminate information; however, the strategies that they should use to achieve high information diffusion are not clear. This article proposes message repetition as a strategy. Research questions: 1. What is the wear-out point of Twitter? 2. How many times should a company repeat a tweet written on its brand page to maximize the diffusion for seeds? 3. How many times should a company repeat a tweet written on its brand page to maximize the diffusion while minimizing the number of consumers reaching their wear-out point for seeds? 4. How many times should a company repeat a tweet written on its brand page to maximize the diffusion for nonseeds? 5. How many times should a company repeat a tweet written on its brand page to maximize the diffusion while minimizing the number of consumers reaching their wear-out point for both seeds and nonseeds? Research methodology: An agent-based simulation model for information diffusion is proposed as an approach to measure the diffusion of a tweet that has been repeated. The model considers that consumers can reach their wear-out point when they read a tweet several times. Results: The results of the model indicate the number of times a company should send the same tweet to achieve high information diffusion before this action has negative effects on consumers. Brand followers are key to achieving high information diffusion; however, consumers begin to feel bothered by the tweet by the sixth repetition. Conclusions: To the best of our knowledge, this is the first study to examine tweet repetition as a strategy to achieve higher information diffusion on Twitter. In addition, it extends the information diffusion literature by controlling the wear-out effect. It contributes to both communication and computational science literature by analyzing a communication problem using an agent-based approach. Finally, this article contributes to the field of technical and professional communication by testing a strategy to reach great information diffusion, and by creating a tool that any company can use to anticipate the results of a communication campaign created in Twitter before launching it.
Managing mobile ad hoc systems is a difficult task due to the high volatility of the systems' topology. Ad hoc systems are commonly defined by means of their constituent entities and the relationships between such entities, however, a formal specification and run-time execution model is missing. The benefit of a formal specification is that it can enable reasoning about local and global system properties, for example, determining whether the system can reach a given state. We propose a Petri net-based specification and execution model to manage ad hoc distributed systems. Our model enables spontaneous communication between previously unknown system components. The model is locally equivalent to standard Petri nets, and hence could be used for the verification of properties for system snapshots static with respect to connections and disconnection, in which it is possible to analyze liveness, reachability, or conflicts. We validate the usability of our distributed ad hoc Petri net model by modeling distributable systems as described by existing distributed Petri nets approaches. Additionally, we demonstrate the applicability and usability of the proposed model in distributed ad hoc networks by implementing the communication behavior of two prototypical ad hoc network applications, disaster and crisis management, and VANETs, successfully validating the appropriate behavior of the system in each case.
Spain ranks second in the world for the number of international tourists. These tourists have different preferences, which influence their choice of tourist routes depending on the activities offered by provinces. There are currently no routes customised according to the preferences of a travel party, which makes the supply of tourist packages complex. We propose an agent-based model, named ABM RoutePlanner, which simulates the behaviour of travel parties through provinces of Spain. The model is developed as an application of the ODD protocol. This paper makes two contributions. First, we describe a model applicable to the identification of appropriate routes for different combinations of tourists’ preferences in some (hypothetical) environments. Second, we present the actual routes that will allow tour operators to define strategic plans that motivate tourists to visit the provinces included in the routes. The simulation model was calibrated with data extracted from TripAdvisor and Spanish tourist surveys.
JavaScript is one of the main programming languages to develop highly rich responsive and interactive Web applications. In these kinds of applications, the use of asynchronous operations that execute callbacks is crucial. However, the dependency among nested callbacks, known as callback hell, can make it difficult to understand and maintain them, which will eventually mix concerns. Unfortunately, current solutions for JavaScript do not fully address the aforementioned issue. This paper presents Sync/cc, a JavaScript package that works on modern browsers. This package is a proof-of-concept that uses continuations and aspects that allow developers to write event handlers that need nested callbacks in a synchronous style, preventing callback hell. Unlike current solutions, Sync/cc is modular, succinct, and customizable because it does not require ad-hoc and scattered constructs, code refactoring, or adding ad-hoc implementations such as state machines. In practice, our proposal uses a) continuations to only suspend the current handler execution until the asynchronous operation is resolved, and b) aspects to apply continuations in a non-intrusive way. We test Sync/cc with a management information system that administers courses at a university in Chile.
Developing robot control software systems is difficult because of a wide variety of requirements, including hardware systems and sensors, even though robots are demanding nowadays. Middleware systems, such as Robot Operating System (ROS), are being developed and widely used to tackle this difficulty. Streaming data Sharing Manager (SSM) is one of such middleware systems that allow developers to write and read sensor data with timestamps using a Personal Computer (PC). The timestamp feature is essential for the robot control system because it usually uses multiple sensors with their own measurement cycles, meaning that measured sensor values with different timestamps become useless for the robot control. Using SSM allows developers to use measured sensor values with the same timestamps; however, SSM assumes that only one PC is used. Thereby, if one process consumes CPU resources intensively, other processes cannot finish their assumed deadlines, leading to the unexpected behavior of a robot. This paper proposes an SSM middleware, named Distributed Streaming data Sharing Manager (DSSM), that enables distributing processes on SSM to different PCs. We have developed a prototype of DSSM and confirmed its behavior so far. In addition, we apply DSSM to an existing real SSM based robot control system that autonomously controls an unmanned vehicle robot. We then reveal its advantages and disadvantages via several experiments by measuring resource usages.

Lab head

Paul Leger
  • Department of Civil Engineering
About Paul Leger
  • http://pleger.cl I am an associate professor at the Catholic University of the North (Chile). I am a Computer Science Engineer with a Ph.D. in Computer Science from the University of Chile. I have been visiting researchers at universities across the world: Tokyo Institute of Technology (Japan), Shibaura Institute of Technology (Japan), Cauca University (Colombia), and École des Mines de Nantes (France).

Members (4)

Hiroaki Fukuda
  • Shibaura Institute of Technology
Carmen Hidalgo-Alcázar
  • Universidad Miguel Hernández de Elche
Cecilia Camacho
  • Institución Universitaria Colegio Mayor del Cauca