Francisco Esquembre

Easy Java Simulations: a software tool to create scientific simulations in Java

Abstract We introduce Easy Java Simulations, Ejs, a tool created by science teachers to help teach and learn science. Ejs allows users to create simulations using their knowledge of the scientific model. The author needs to supply a small amount of code for the model; the tool provides a graphical drag-and-drop interface to build the program. The resulting Ejs generated program is an independent, high quality Java application or applet ready to be published on a Web server. Ejs can serve as an effective teaching and learning tool if used in an appropriate pedagogical setting; for instance, to help students create their own simulations in order to express their conceptions on how a given scientific process works. The Ejs program and documentation can be freely downloaded from the site http://fem.um.es/Ejs .

Development of a Web-Based Control Laboratory for Automation Technicians: The Three-Tank System

This paper introduces a Web-based control laboratory for experimentation on a nonlinear multiple-input-multiple-output (MIMO) system: the three-tank plant. Using this application, automation technician students can learn in a practical way many fundamental aspects of control processes. The client-side of the virtual laboratory has been developed using the programming support provided by Easy Java Simulations (EJS), an open-source tool for teachers with limited programming skills who want to create Java applications and applets. The lab has been integrated in the collaborative Web-based experimentation environment eMersion which provides more flexibility for the students performing the laboratory experiments.

Real-time collaboration of virtual laboratories through the Internet

Web-based learning environments are becoming increasingly popular in higher education. One of the most important web-learning resources is the virtual laboratory (VL), which gives students an easy way for training and learning through the Internet. Moreover, on-line collaborative communication represents a practical method to transmit the knowledge and experience from the teacher to students overcoming physical distance and isolation. Considering these facts, the authors of this document have developed a new dynamic collaborative e-learning system which combines the main advantages of virtual laboratories and collaborative learning practices. In this system, the virtual laboratories are based on Java applets which have embedded simulations developed in Easy Java Simulations (EJS), an open-source tool for teachers who do not need complex programming skills. The collaborative e-learning is based on a real-time synchronized communication among these Java applets. Therefore, this original approach provides a new tool which integrates virtual laboratories inside a synchronous collaborative e-learning framework. This paper describes the main features of this system and its successful application in a distance education environment among different universities from Spain.

Modeling Physics with Easy Java Simulations

Modeling has been shown to correct weaknesses of traditional instruction by engaging students in the design of physical models to describe, explain, and predict phenomena.1 Although the modeling method can be used without computers, the use of computers allows students to study problems that are difficult and time consuming, to visualize their results, and to communicate their results with others. This combination of computer modeling with theory and experiment can achieve insight and understanding that cannot be achieved with only one approach. This paper describes the Easy Java Simulations (Ejs) modeling and authoring tool and shows how it can be used to teach mechanics concepts with computer modeling.

The learning of control concepts using interactive tools

This paper discusses the creation of interactive computer simulations that implement virtual laboratories in the field of Control Engineering education. Easy Java Simulations (Ejs, http://fem.um.es/Ejs/), a Java‐based tool that helps create interactive dynamic simulations, is introduced. This tool can be used on its own, generating stand‐alone Java applications or applets, or in conjunction with Matlab/Simulink, using them as the internal engine that describes and solves the model. We describe in this paper this particular feature in detail, and provide some examples that show the advantages that this tool offers to the world‐wide engineering education community. Ejs is a freeware, open source, tool aimed for educators with low profile in programming but deep knowledge on certain technical and scientific fields. The tool allows to develop complete, interactive simulations in three steps: describing the mathematical model (optionally using Matlab/Simulink), building the user interface using off‐the‐shelf graphical elements, and connecting certain properties of these elements to the variables of the model. This last step is the key point to transform a classical simulation into a full interactive application.

Developing Networked Control Labs: A Matlab and Easy Java Simulations Approach

The new information technologies provide great opportunities in control education. One of them is the use of remote control labs to teach the behavior of control systems through a network. In this paper, a new approach to create interactive networked control labs is described. Two main software tools are used: Matlab and Easy Java Simulations. The first one is a widely used tool in the control community, whereas the second one is an authoring tool, designed to build interactive applications in Java without special programming skills. The remote labs created by this approach give to students the opportunity to face the effects of network delays on the controlled system and also to specify on the fly their own control algorithm.

Adding interactivity to existing Simulink models using Easy Java Simulations

This paper describes how to use Easy Java Simulations (Ejs for short), a software tool designed to create interactive simulations in Java, to turn existing models created using Simulink into really dynamic, interactive virtual labs. The user basically needs to connect variables in the Ejs model to variables in the Simulink model using an easy-to-use, very natural interface. Ejs takes then care of all the technical tasks required to keep a perfect synchronization between both tools. The main advantage is that existing Simulink models can benefit of the extended graphic capabilities of Ejs for a more realistic visualization and for enhanced interactive possibilities.

Web-Enabled Remote Scientific Environments

A new approach to developing Web-enabled environments for remote diagnostics, maintenance, and experimentation in engineering is based on a middleware layer that uses a Java-lntemet-Labview server to provide communication between Java programs and Labview virtual instruments. The authors illustrate their technique by applying it to the development of a complete Web-enabled application for remote control of a thermal process.

Synchronous collaboration of virtual and remote laboratories

Virtual and remote laboratories(VRLs) are e‐learning resources which enhance the accessibility of experimental setups providing a distance teaching framework which meets the students hands‐on learning needs. In addition, online collaborative communication represents a practical and a constructivist method to transmit the knowledge and experience from the teacher to students, overcoming physical distance and isolation. Thus, the integration of learning environments in the form of VRLs inside collaborative learning spaces is strongly desired. Considering these facts, the authors of this document present an original approach which enables user to share practical experiences while they work collaboratively through the Internet. This practical experimentation is based on VRLs, which have been integrated inside a synchronous collaborative e‐learning framework. This article describes the main features of this system and its successful application for science and engineering subjects.

A Systematic Two-Layer Approach to Develop Web-based Experimentation Environments for Control Engineering Education

This paper introduces the systematic approach currently used by the Department of Computer Science and Automatic Control of the Spanish University of Distance Learning (UNED) to develop Web-based laboratories for distance learning of topics with high technical contents such as control engineering. This approach differentiates two layers in the construction of web- based laboratories: the experimentation layer and the e-learning layer. For the experimentation layer, LabVIEW and data acquisition boards from National Instruments are used to create the server-side applications and Easy Java Simulations for the client-side interfaces. For the e-learning layer, the eMersion environment is used to support the required flexible educational scheme. This paper describes the programming techniques implemented and the design considerations that justify these particular choices. As an llustrative case-study, an example of development of a web-based application is discussed, in which an electrical drive servo-motor is introduced as a convenient setup to practice with motion control applications. Other significant examples of web-based experiments developed by the authors are also reported.