Toward a User-Centered Method for Studying CVEs for Learning

2005 ◽  
pp. 269-301 ◽  
Author(s):  
Daphne Economou ◽  
Steve Pettifer
Keyword(s):  
Interaction Analysis ◽  
Systems Design ◽  
Design Guidelines ◽  
Research Community ◽  
Collaborative Virtual Environments ◽  
Rigorous Approach ◽  
Third Phase ◽  
Virtual Actors ◽  
Design Factors ◽  
Grid Based

This chapter addresses one of the challenges the collaborative virtual environments (CVEs) research community faces which is the lack of a systematic approach to study social interaction in CVEs, determine requirements for CVE systems design, and inform the CVE systems design. It does this by presenting a method for studying multi-user systems in an educational context. The method has been developed as part of the Senet project, which is investigating the use of virtual actors in CVEs for learning. Groupware prototypes are studied in order to identify requirements and design factors for CVEs. The method adopts a rigorous approach for organizing experimental settings, collecting and analysing data, and informing CVE systems design. The analysis part of the method shares many of the Interaction Analysis foci and expands on it by providing a grid-based method of transforming rich qualitative data in a quantitative form. The outcome of this analysis is used for the derivation of design guidelines that can inform the construction of CVEs for learning. The method is described by a third phase of work in the Senet project.

The Effect of Scale on Fluid-Filled Flexible Composite Actuators

2011 ◽  
Author(s):  
Larry D. Peel ◽  
Luis Muratalla ◽  
Jeff Baur ◽  
Dean Foster
Keyword(s):  
Incompressible Fluid ◽  
Mechanical Energy ◽  
Systems Design ◽  
Critical Length ◽  
Variable Stiffness ◽  
Micro Air Vehicles ◽  
Design Guidelines ◽  
Segment Length ◽  
Actuation Force ◽  
Opening And Closing

Morphing aircraft and other shape-changing structures are well suited to McKibben-like flexible composite actuators. These actuators, made from fiber-reinforced elastomeric composites, are extremely efficient in converting potential energy (pressurized air) into mechanical energy. Such actuators are promising for use in micro air vehicles, prosthetics and robotics because they offer excellent force-to-weight ratios and behave similar to biological muscle. Use of an incompressible pressurizing fluid instead of compressible air may also offer higher actuator stiffness, better control, and compatibility with existing actuation systems. Using incompressible fluids also allows the actuator to serve as a variable stiffness element which can be modulated by opening and closing valves that constrain or allow fluid flow. The effect of an incompressible fluid (water) on the performance of Rubber Muscle Actuators (RMA), with varying diameters, lengths and segment lengths, was experimentally investigated in the current work. Upon pressurization with air or water, past an activation threshold, overall force and stroke increased with increasing actuation length and diameter. Actuation force when pressurized with water is slightly greater than with air. Both air and water-pressurized actuation force and strain decrease significantly when segment length is less than a minimum critical length. Closed valve actuator stiffness (modulus) of actuators at full length, when pressurized with an incompressible fluid is up to 60× greater than the open valve stiffness of the same actuator. Air-filled RMAs with equal parameters only see a 10× increase. Incompressible fluid-filled RMAs have great potential to provide needed high actuation forces within adaptive material systems. Design guidelines are given to aid additional RMA use.

scholarly journals Design of a Solid-State Circuit Breaker for a DC Grid-Based Vessel Power System

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 953 ◽  
Author(s):  
Lukas Tapia ◽  
Igor Baraia-Etxaburu ◽  
Juan José Valera ◽  
Alain Sanchez-Ruiz ◽  
Gonzalo Abad
Keyword(s):  
Solid State ◽  
Power System ◽  
Electric Propulsion ◽  
Circuit Breaker ◽  
Design Guidelines ◽  
Zero Crossing ◽  
Solid State Circuit ◽  
Dc Breaker ◽  
Solid State Circuit Breaker ◽  
Grid Based

Electric propulsion and integrated hybrid power systems can improve the energy efficiency and fuel consumption of different kinds of vessels. If the vessel power system is based on DC grid distribution, some benefits such as higher generator efficiency and lower volume and cost can be achieved. However, some challenges remain in terms of protection devices for this kind of DC grid-based power system. The absence of natural zero crossing in the DC current together with the fast and programmable breaking times required make it challenging. There are several papers related to DC breaker topologies and their role in DC grids; however, it is not easy to find comprehensive information about the design process of the DC breaker itself. In this paper, the basis for the design of a DC solid-state circuit breaker (SSCB) for low voltage vessel DC grids is presented. The proposed SSCB full-scale prototype detects and opens the fault in less than 3 µs. This paper includes theoretical analyses, design guidelines, modeling and simulation, and experimental results.

Macroergonomic Work Systems' Design Factors and Elements

2016 ◽  
pp. 116-136 ◽  
Author(s):  
Arturo Realyvásquez ◽  
Aidé Aracely Maldonado-Macías ◽  
Jaime Romero-González
Keyword(s):  
Systems Design ◽  
Literature Survey ◽  
Manufacturing Technology ◽  
Sociotechnical Systems ◽  
Advanced Manufacturing Technology ◽  
Advanced Manufacturing ◽  
Work Systems ◽  
Manual Search ◽  
Environment Factor ◽  
Design Factors

Currently there is no a literature survey which evaluates and classifies the papers according to the macroergonomic factors and elements that authors consider needed to work systems' design. For that reason, this chapter offers a review to identify the most frequent macroergonomic work systems' design factors and elements enounced in literature and propose a classification for them. A manual search was performed in seven databases by using keywords such as sociotechnical systems, macroergonomics, and work systems design. Bibliographical sources were classified into five main groups, corresponding to the factors of work systems' design, named Peron factor, Organization factor, factor of Tools and Technology, Tasks factor, and Environment factor, and their corresponding subgroups (elements). The macroergonomic Organization factor presented the highest frequency, while the macroergonomic factor of Tools and Technology presented the lowest frequency. Regarding the elements, Teamwork was the most frequent, while Advanced Manufacturing technology and Work Schedules were the less frequent.

An Information Systems Design Framework for Facilitating TQM Implementation

2002 ◽  
pp. 174-193
Author(s):  
Nazim U. Ahmed ◽  
Ramarathnam Ravichandran
Keyword(s):  
Information Systems ◽  
Continuous Improvement ◽  
Systems Design ◽  
Second Phase ◽  
Communication Effectiveness ◽  
Manufacturing Firm ◽  
The Third ◽  
Third Phase ◽  
Firm Response ◽  
Is Design

This paper provides a framework for information systems (IS) design for TQM implementation. The framework consists of three main phases. In the first, TQM implementation tasks are established. These tasks include identifying customer satisfaction variables (CSV), translation of CSV to firm response variables (FRV), benchmarking, and continuous improvement. The second phase includes analyses of communication effectiveness requirements between the organizational entities such as sales/marketing, top management, operations, accounting/finance and also with the customers. In the third phase, appropriate IS component inventories for different communication interfaces are generated. This was accomplished by first mapping the TQM implementation tasks for the communication interfaces. Then appropriate IS/IT solution was recommended for each interface. The final IS design is achieved by integrating IS components at technological, functional, and strategic levels. Finally, a hypothetical example for a large manufacturing firm is provided.

Systematic Usability Evaluation and Design Issues for Collaborative Virtual Environments

2003 ◽  
Vol 12 (3) ◽  
pp. 241-267 ◽  
Author(s):  
Jolanda G. Tromp ◽  
Anthony Steed ◽  
John R. Wilson
Keyword(s):  
Longitudinal Studies ◽  
Virtual Environments ◽  
User Behavior ◽  
Usability Evaluation ◽  
Design Guidelines ◽  
Social Acceptability ◽  
Design Issues ◽  
Collaborative Virtual Environments ◽  
Consumer Evaluations ◽  
The Future

This paper presents results of the longitudinal usability and network trials that took place throughout the COVEN (COllaborative Virtual ENvironments) Project. To address the lack of understanding about usability design and evaluation for collaborative virtual environments (CVEs), a deductive analysis was used to systematically identify areas of inquiry. We present a summary of the analysis and the resulting framework through which various complementary methods were utilized during our studies. The objective of these studies was to gain a better understanding about design, usability, and utility for CVEs in a multidisciplinary setting. During the studies, which span four years, we undertook longitudinal studies of user behavior and computational demands during network trials, usability inspections of each iteration of the project demonstrators, consumer evaluations to assess social acceptability and utility of our demonstrators, and continuous preparations of design guidelines for future developers of CVEs. In this paper, we discuss the need for such activities, give an overview of our development of methods and adaptation of existing methods, give a number of explanatory examples, and review the future requirements in this area.

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