Computer-aided Design Activities Research Articles

EEG-BASED COGNITIVE LOAD INDICATORS IN CAD MODELLING TASKS OF VARYING COMPLEXITY

AbstractAs an initial step towards a better understanding of cognitive load in computer-aided design (CAD), the herein presented study investigated cognitive load imposed on 24 mechanical engineers during two CAD modelling tasks of intentionally different complexity levels. The cognitive load has been rarely studied in the CAD context, which resulted in the lack of understanding if and how the EEG-based indicators available from the literature reflect the changes in cognitive load imposed on engineering designers in CAD activities. Therefore, cognitive load was measured and analysed using three EEG-based indicators to explore insights that might be obtained from them. The initial analysis revealed different cognitive load results from the employed indicators for the same EEG data. In addition, the study implies that the cognitive load results obtained through the used indicators are only partially coherent with the CAD modelling task complexity. Hence, the results imply that the chosen EEG-based indicator matters when measuring and analysing cognitive load in CAD modelling tasks and that its adjustment for CAD context might be needed.

A Silent Revolution: From Sketching to Coding – A Case Study on Code-based Design Tool Learning

Along with the information technology rising, Computer Aided Design activities are becoming more modern and more complex. But learning how to operation these new design tools has become the main problem lying in front of each designer. This study was purpose on finding problems encountered during code-based design tools learning period of designers, especially those influential factors. The research was based on two design protocol analysis studies. A pilot study was performed for research details adjustment. Three selected participants have been told to complete one sketching work with two different digital design tools. A 30 minutes teaching was performed on each participant. Processing was introduced for data analysis. We found digital methods can be used to performing design process analyzing. We construct a multi-scale analyzing structure for design process and we demonstrate the possibility of pure quantitative study of the design process.

Role of graphics tools in the learning design process

This paper discusses the design activities of students in secondary school in France. Graphics tools are now part of the capacity of design professionals. It is therefore apt to reflect on their integration into the technological education. Has the use of intermediate graphical tools changed students’ performance, and if so in what direction, in phase of seeking solutions through a design activity in a situation of teaching and learning? The influence of computer aided design (CAD) tools on design professional activities has been the subject of much research, but little has focused on student activity. Thus, analysing student work through an experimental device, we ask that students produce more solutions without using CAD tools. Do CAD activities encourage the modelling of a particular solution? Does drawing by hand before CAD activities support the production of various solutions and define them more precisely? Through the analysis of solutions developed by students, including traces of their activity (sketches, digital files), we test our hypotheses.

A fuzzy psycho-physiological approach to enable the understanding of an engineer’s affect status during CAD activities

Affective computing involves human–computer interaction (HCI) where an interface can detect and respond in context to a user’s emotions. Emotions play an essential role in the daily activities of a human during work and, as a consequence, can critically affect their decision-making. Recent research on affective computing opens the door to exploring the emotional aspects of computer aided tasks and HCI; however, there is little research in this area related to computer aided design (CAD). There is an established connection between emotional and cognitive processes and without these emotional markers decision-making in humans is almost non-existent.The holy grail of engineering design is for a concept to be ‘right-first-time’ and only by delving into the affect-cognitive domain will insights in terms of the associability of critical decision-making and the underlying intent of engineering decisions and tasks be better understood. Work in this field aims to recognize, interpret and process human emotions in order to support and adapt computer-based systems and their associated interfaces to user behaviors and to elicit appropriate system responses. This is a very contemporary area in engineering design research. One key aspect of provisioning CAD systems with the capability to detect the emotional state of the engineer is to lessen the chance of distorted reasoning as a result of irrational judgements. Work in this area can potentially identify emotional markers that influence the coherence/incoherence of reasoning against knowledge as well as the potential quality and suitability of a specific engineering solution or approach.This paper proposes and investigates a methodology to determine the emotional aspects attributed to a set of CAD design tasks by analyzing the CAD operators’ psycho-physiological signals. Two sets of experiments were conducted. A pilot case study focused on modeling tasks carried out in Solid Edge™ was run to prove the validity of the methodology, the tools applied and subsequent analysis. The main case study extended this to more wide-ranging user logging, incorporating a series of configuration and optimization tasks in Siemens NX™ for a real design task. Psycho-physiological signals of electroencephalography (EEG) and galvanic skin resistance (GSR)/electrocardiography (ECG) were recorded along with a log of CAD system user interactions. A fuzzy logic model was established to map the psycho-physiological signals to a set of key emotions, namely frustration, satisfaction, engagement and challenge and the results analyzed.The methodology and subsequent analysis applied was found to be repeatable. Over the various task action-chains the elicitation and interpretation of each participant’s emotions were successfully carried out with significant correlations demonstrated between the associated engineers’ CAD activities and their reported emotional states.

Towards a Knowledge-Based Model for the Computer Aided Design Process

We propose in this paper a model for an elementary activity of the computer aided design (CAD) process, taking into account the specificity of the utilization of a computer: its capability to manipulate a relatively high volume of data and to explore alternatives quickly and systematically. The CAD activity is defined according to a given expertise domain (functionality, assembly, manufacturing, etc.) which is examined with respect to two inter-related subtasks: knowledge processing and data processing. Knowledge processing manipulates the knowledge model which represents an expert's point of view on the domain. Four things determine the knowledge model: a typology of combinable elements, a typology of possible relations between elements, an expert rule base for the creation of problem models (translation of problem data in elements and relations), and a set of criteria to evaluate the quality of solutions. Data processing manipulates the computational model which represents the computing point of view of the domain. We use the constraint satisfaction problem (CSP) model as the computational model. The relationship between subtasks is done according to the manner in which the knowledge model is translated in to the computational model. The proposed model of the CAD process allows an adaptive man-machine task sharing by allocating the user interaction to the knowledge model while the computer interacts with the computational model. An example from the assembly planning domain illustrates the model. Once the different CAD activities are determined, they can be combined to form a CAD process. The activities are coordinated by exchanging partial solutions (which can be done during knowledge processing and/or data processing), rules and evaluation criteria (during knowledge processing). Such kinds of CAD processes can also be used to define recursively the CAD activity of higher levels of abstraction.

A historical review of circuit simulation

Within the Circuits and Systems (CAS) Society, developments in computer-aided circuit analysis and circuit design commenced in the early 1950's using the earliest digital computers. Initially, computer-aided circuit analysis of linear circuits was used in design optimization, design centering, and in determining the effects of parasitics on circuit performance. Although this use of computer-aided circuit analysis has continued, computer-aided design (CAD) and circuit design automation within the CAS Society are now principally concerned with problems associated with the overall design and evaluation of very large circuits and systems. This paper is a review of a major thread of CAD activity which has occurred within CAS from the earliest and remains of major interest. This thread involves computer-aided circuit analysis (circuit simulation) and its use in CAD systems. Fortunately, several excellent review papers have appeared within the past year or two to document well the technical milestones, as well as the problems of interest at the present time. It is possible then, in this paper, to concentrate on the developments in our present capability of circuit simulators, stressing the significant trends, noting some early developments which did not become major aspects, and observing the interchange between theory and practice.

Computer-aided design in the U.S.A

During the summer of 1968 Dr. Radley visited the U.S.A. with the specific aim of investigating and reporting on computer-aided design activities there. This paper is his report on the state of the art as he found it. He visited universities as well as commercial organisations and attended both the 5th Annual Design Automation Workshop, held in Washington, and WESCON 68.

Wet tantalytic capacitor seals

During the summer of 1968 Dr. Radley visited the U.S.A. with the specific aim of investigating and reporting on computer-aided design activities there. This paper is his report on the state of the art as he found it.He visited universities as well as commercial organisations and attended both the 5th Annual Design Automation Workshop, held in Washington, and WESCON 68.