Constantin Chassapis

Constructing reality: A study of remote, hands-on, and simulated laboratories

Laboratories play a crucial role in the education of future scientists and engineers, yet there is disagreement among science and engineering educators about whether and which types of technology-enabled labs should be used. This debate could be advanced by large-scale randomized studies addressing the critical issue of whether remotely operated or simulation-based labs are as effective as the traditional hands-on lab format. The present article describes the results of a large-scale (N = 306) study comparing learning outcomes and student preferences for several different lab formats in an undergraduate engineering course. The lab formats that were evaluated included traditional hands-on labs, remotely operated labs, and simulations. Learning outcomes were assessed by a test of the specific concepts taught in each lab. These knowledge scores were as high or higher (depending on topic) after performing remote and simulated laboratories versus performing hands-on laboratories. In their responses to survey items, many students saw advantages to technology-enabled lab formats in terms of such attributes as convenience and reliability, but still expressed preference for hands-on labs. Also, differences in lab formats led to changes in group functions across the plan-experiment-analyze process: For example, students did less face-to-face work when engaged in remote or simulated laboratories, as opposed to hands-on laboratories.

Remote versus hands-on labs: a comparative study

Advocates of hands-on laboratories and advocates of simulation have debated for years. Proponents of hands-on laboratories argue that student engineers need to be exposed to the physical experiences-and the uncertainties-of real environments. Advocates of simulation argue that physical labs are wasteful-they tie up badly needed space, and consume students time in menial set-up and tear-down procedures. Now remote laboratories have appeared as a third option. These laboratories are similar to simulation techniques in that they require minimal space and time, because the experiments can be rapidly configured and run over the Internet. But unlike simulations, they provide real data. It is unknown what the relative effectiveness of hands-on, simulated, and remote laboratories is. This paper presents a model for testing this relative effectiveness, and discusses the results of a preliminary assessment study comparing versions of remote labs versus hands-on labs in a junior-level mechanical engineering course on machine dynamics and mechanisms.

An IT view on perspectives of computer aided process planning research

Abstract This paper presents current research perspectives on Computer Aided Process Planning (CAPP) and it covers articles and other related publications that appeared especially in the last seven years. It aims to provide a clear understanding of the directions and challenges in the field. The current research efforts on CAPP systems focus on both variant as well as generative and hybrid systems. A majority of these systems apply expert system or artificial intelligence based techniques. At the same time a strong emphasis is placed on integrating CAPP and its related activities into one system. As a bridge between Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) CAPP relies on good interfaces between these systems. Automatic feature recognition systems can be used to interface CAD and CAPP. Various methods are available to perform feature recognition using solid model of the part. This paper first provides a general introduction to CAPP along with its background. It also gives an overview of manufacturing features and feature recognition research. Recent CAPP research and systems are discussed in terms of their general characteristics. Finally, shortcomings of current systems and expected future developments are considered.

The elastic behavior of linkages: An update

Abstract With the ever increasing speed requirements of machines, a thorough understanding of their elastic behavior becomes important. Because of this need, the number of publications which deal with linkage elasticity has increased considerably in the past few years. This paper updates previous literature surveys in this field by reviewing this recent work.

Optimal cooling system design for multi-cavity injection molding

Abstract The objective of this paper is to present a methodology for optimal design of cooling systems for multi-cavity injection mold tooling. After the part layout and the injection mold are designed, the methodology optimizes cooling system layout in terms of cooling channel size, locations, and coolant flow rate. The mold cooling design is modeled as a non-linear constrained optimization problem. The objective function for the constrained optimization problem is stated as minimization of both a function related to part average temperature and temperature gradients throughout all the cavities. The constrained optimal design problem is solved using Powells conjugate direction with the penalty function method. The objective function is evaluated using finite element analysis solving the transient heat conduction problem. A matrix-free Jacobi conjugate gradient algorithm of Galerkin finite element method is utilized to simulate transient heat conduction.

Content-rich interactive online laboratory systems

Online learning environments are rapidly becoming viable options for offering students a bridge from theoretical concepts to practical engineering applications. They represent collections of integrated tools that provide a delivery mechanism for rich learning content, advanced assessment capabilities as well as affordable access to a wide range of educational resources. Such online learning environments have been used at Stevens Institute of Technology (SIT) for a number of years to provide undergraduate engineering students with a comprehensive laboratory experience based on content‐rich and flexible remote and virtual laboratory experiments. These Web‐based educational tools were developed using various open source programming languages and free software applications. As discussed in this article, these open source components form a powerful combination for the cost‐efficient development, implementation and sharing of Web‐based virtual experimentation systems. This article describes the delivery methods for online experiments and the corresponding software modules implemented, which were integrated into a comprehensive student laboratory experience currently being used at SIT in a sophomore‐level core undergraduate course on solid mechanics taken by all undergraduate engineering majors as well as in a junior‐level course on mechanisms and machine dynamics for mechanical engineering majors. Furthermore, some results of the learning outcomes assessment for online experiments conducted over several years at SIT are summarized.

Multi criteria preventive maintenance scheduling through arena based simulation modeling

Line performance and equipment utilization have been major points of interest for many companies due to their direct impact on productivity. Achieving the highest possible utilization while maximizing throughput will improve the line performance; will also show significant increase on the line productivity. There are many variables that affect the line utilization and performance and preventive maintenance schedule is one of them. In this paper a multi criteria decision making approach will be implemented to select the preventive maintenance schedule that gives the best utility and performance values. To demonstrate the selection process a bread packaging line is used as a case study. Environmental conditions and line behavior are developed and simulated by using an Arena-based simulation model. The Arena model is to be used as a support tool for the multi criteria decision making process.

A Computer-Aided Optimization Approach for the Design of Injection Mold Cooling Systems

A methodology is presented for the design of optimal cooling systems for injection mold tooling which models the mold cooling as a nonlinear constrained optimization problem. The design constraints and objective function are evaluated using Finite Element Analysis (FEA). The objective function for the constrained optimization problem is stated as minimization of both a function related to part average temperature and temperature gradients throughout the polymeric part. The goal of this minimization problem is to achieve reduction of undesired defects as sink marks, differential shrinkage, thermal residual stress built-up, and part warpage primarily due to non-uniform temperature distribution in the part. The cooling channel size, locations, and coolant flow rate are chosen as the design variables. The constrained optimal design problem is solved using Powells conjugate direction method using penalty function. The cooling cycle time and temperature gradients are evaluated using transient heat conduction simulation. A matrix-free algorithm of the Galerkin Finite Element Method (FEM) with the Jacobi Conjugate Gradient (JCG) scheme is utilized to perform the cooling simulation. The optimal design methodology is illustrated using a case study.

A review of applications of computer games in education and training

Scientists, engineers and educators are increasingly using environments enabled by advanced cyberinfrastructure tools for their research, formal and informal education and training, career development and life-long learning. For instance, academic institutions as well as private training and education companies have recently started to explore the potential of commercially available multi-player computer game engines for the development of virtual environments for instructional purposes. Most of these developments are still in their early stages and are focused mainly on investigating the suitability of interactive games for remote user interaction, content distribution and collaborative activities. Some of the ongoing projects have additional research objectives, such as the analysis of patterns of human behavior and the study of the collaboration between users and their interaction with virtual environments. A few other developments are aimed at utilizing computer game technologies as a platform for personnel training and educational laboratory simulations. This paper provides a review of the current state of computer game applications, with a special focus on education and training implementations.

A scenario for collaborative learning in virtual engineering laboratories

The feasibility of developing interactive collaborative virtual environments for undergraduate student laboratory experiments is currently being explored at various institutions. Such environments can be implemented using commercial multiplayer game engines together with the associated software development kits. Such immersive environments are expected to provide students with an opportunity for exercising their problem solving skills by collaboratively interacting with each other and the virtual laboratory exercises. This paper discusses the requirements for designing game-based virtual laboratory environments from pedagogical as well as technical point of view. Also, the practical implementation of these design requirements in a prototype system is discussed and a sample scenario for a virtual laboratory based on an existing laboratory exercise from a junior- level mechanical engineering course on mechanisms and machine dynamics is presented. The described virtual laboratory environment represents an attempt to mimic important aspects of the learning experience gained through conventional hands-on experiments and even augment this experience by certain features that are not achievable in the traditional hands-on laboratory setting.