Aid Of Representations Research Articles

Dorello's Canal for Laymen: A Lego-Like Presentation

Objective Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students.

Building block method: a bottom-up modular synthesis methodology for distributed compliant mechanisms

Abstract. Synthesizing topologies of compliant mechanisms are based on rigid-link kinematic designs or completely automated optimization techniques. These designs yield mechanisms that match the kinematic specifications as a whole, but seldom yield user insight on how each constituent member contributes towards the overall mechanism performance. This paper reviews recent developments in building block based design of compliant mechanisms. A key aspect of such a methodology is formulating a representation of compliance at a (i) single unique point of interest in terms of geometric quantities such as ellipses and vectors, and (ii) relative compliance between distinct input(s) and output(s) in terms of load flow. This geometric representation provides a direct mapping between the mechanism geometry and their behavior, and is used to characterize simple deformable members that form a library of building blocks. The design space spanned by the building block library guides the decomposition of a given problem specification into tractable sub-problems that can be each solved from an entry in the library. The effectiveness of this geometric representation aids user insight in design, and enables discovery of trends and guidelines to obtain practical conceptual designs.

A New Mathematical Approach for Pattern Generation

CAD systems are still monolithic and are based on complex geometrical models. Our aim is to implement a new mathematical approach based on fractal geometry integrating the advantage of web technology and providing a novice end-user with an easy- to-use system. In order to get the same performances as a local system, it is necessary to provide our system with adequate data representation aid architecture. This paper presents a framework of web-based system to generate the patterns for ornamental objects. The emphasis of this paper is to outline of methodology and architecture to develop the system, which depends on classifying the elements influenced in the conceptual design stage. The proposed system provides as tool for customer to generate design alternatives according to designers preferences. Thus the customer can directly explore more alternatives and generate designs with his/her styles from predefined images in the data base of system . Accordingly, to the requirement of customer , the whole system regenerate the designs using the power of macro programming. This whole system will use the power of Web technology and macro programming to generalize the designs.

Modern Teaching Methods in Physics with the Aid of Original Computer Codes and Graphical Representations

This study describes the possibility and advantages of utilizing simple computer codes to complement the teaching techniques for high school physics. The authors have begun working on a collection of open source programs which allow students to compare the results and graphics from classroom exercises with the correct solutions and further more to be able to easily interact with the source code in order to modify and create their own software. We believe that teaching and learning physics needs to benefit from the modern developments in computer sciences, thus creating a connection between textbook exercises and the use of computers is desirable. The personal experience of the authors suggests that solving a physics problem with the aid of a computer leads to a better understanding of the physical properties of the systems involved in the exercise.

Use of focus groups to develop methods to communicate cardiovascular disease risk and potential for risk reduction to people with type 2 diabetes

People need to perceive a risk in order to build an intention-to-change behaviour yet our ability to interpret information about risk is highly variable. We aimed to use a user-centred design process to develop an animated interface for the UK Prospective Diabetes Study (UKPDS) Risk Engine to illustrate cardiovascular disease (CVD) risk and the potential to reduce this risk. In addition, we sought to use the same approach to develop a brief lifestyle advice intervention. Three focus groups were held. Participants were provided with examples of materials used to communicate CVD risk and a leaflet containing a draft brief lifestyle advice intervention and considered their potential to increase motivation-to-change behaviours including diet, physical activity, and smoking in order to reduce CVD risk. Discussions were tape-recorded, transcribed and coded and recurring themes sought. Sixty-two percent of participants were male, mean age was 66 years (range = 47-76 years) and median age at leaving full-time education was 18 years (range = 15-40 years). Sixteen had type 2 diabetes and none had a prior history of CVD. Recurring themes from focus group discussions included the following: being less numerate is common, CVD risk reduction is important and a clear visual representation aids comprehension. A simple animated interface of the UKPDS Risk Engine to illustrate CVD risk and the potential for reducing this risk has been developed for use as a motivational tool, along with a brief lifestyle advice intervention. Future work will investigate whether use of this interactive version of the UKPDS Risk Engine and brief lifestyle advice is associated with increased behavioural intentions and changes in health behaviours designed to reduce CVD risk.

Numerical Models in Representation Design: Computing Seawater Properties in an Ecological Interface

The contribution of cognitive engineering in complex systems is often limited by the availability of information to populate advanced representational forms, such as those characterized by the Ecological Interface Design framework. We suggest the application of numerical models to derive required information, supplementing the analytical methods that are commonly used in computational aiding. We demonstrate the approach by presenting a solution combining numerical and analytical methods to the problem of determining seawater properties in a nuclear power plant. The example demonstrates that numerical approaches can expand the range of possible applications of representation aiding in complex systems.

Representation Aiding to Support Performance on Problem-Solving Tasks

A substantial literature has been developed that deals with the use of visual displays to support human problem solving. In particular, the cognitive systems engineering literature has emphasized the use of visual displays to improve performance on complex real-world tasks such as process control with the labels direct perception, ecological interface design, representational design, and semantic mapping, focusing on the use of representations that take advantage of powerful perceptual processes to support problem solving. Although the theoretical orientations and details of each approach are slightly different, they all share a fundamental core belief: The effectiveness of a graphical decision aid depends on relationships between the representation, the domain and associated task(s), and the characteristics of the agent (person). This review begins with a discussion of strategies for representation aiding, assuming that the appropriate domain semantics have been determined. It then discusses a core assumption in this literature that, in the design of complex real-world systems, designers cannot anticipate all the possible scenarios that could arise and must therefore design displays that support effective problem solving even when novel or unanticipated scenarios are encountered. Finally, the results of empirical studies of designs based on representation aiding are reviewed.

Design sketches and sketch design tools

In early stages of design architects often use sketching and diagramming to perform formal and functional reasoning. Design sketches are an external representation aid for visualization and evaluation of the spatial arrangements of artifacts. Symbols and configurations are used in design sketches to define context and object arrangements. This paper argues the need to study design drawing, reports the findings from empirical studies of design drawings, and describes the software systems implemented to support intention inference and automated activation of knowledge-based design tools to support design.

Objects and Mappings: Incompatible Principles of Display Design --- A Critique of Marino and Mahan

Representation aiding (and similar approaches that share the general orientation) has a great deal of utility, predictive ability, and explanatory power. Marino and Mahan (2005) discuss principles that are critical to the RA approach (configurality, emergent features, and mappings) in a reasonable fashion. However, the application of these principles is far from reasonable. The authors explicitly realize the potential for interactions between nutrients: "The nutritional quality of a food product is a multidimensional concept, and higher order interactions between nutrients may exist" (p. 126). However, they made no effort to discover the nature of these interactions: "No attempt was made to identify contingent interactions between nutrients" (p. 126). Despite not knowing the nature of the interactions between nutrients, they purposely chose a highly configural display that produced numerous emergent features dependent upon these interactions: "A radial spoke display was selected because of the strong configural properties of such display formats (Bennett & Flach, 1992)" (p. 124). Finally, the authors show apparent disdain for the specific mappings among domain, agent, and display that are fundamental to the RA approach: "[O]ther configural display formats could have been used" (p. 124). It is impossible to reconcile these statements and the RA approach to display design. However, these statements make perfect sense if a perceptual object is a guiding principle in one's approach to display design. Marino and Mahan (2005) draw heavily upon the principle of a perceptual object in their design justifications, experimental predictions, and interpretations of results. As we have indicated here and elsewhere (Bennett & Flach, 1992), we believe that these two sets of organizing principles for display design (i.e., objects and mappings) are incompatible. Display design will never be an exact science; there will always be elements of art and creativity. However, the guiding principles have moved well beyond the simple strategy of throwing variables into a geometric object format and relying upon the human agent's powerful perceptual systems to carry the design.

An Experimental Study of the Effects of Representational Guidance on Collaborative Learning Processes

The importance of both social processes and of representational aids for learning is well-established, yet few experimental studies have addressed the combination of these factors. The research reported in this article evaluates the influence of tools for constructing representations of evidential models on collaborative learning processes and outcomes. Pairs of participants worked with 1 of 3 representations (Graph, Matrix, Text) while investigating complex science and public health problems. Dependent measures included (a) the content of participants' utterances and representational actions and the timing of these utterances and actions with respect to the availability of information; (b) a multiple choice test of the ability to recall the data, hypotheses, and evidential relations explored; and (c) the contents of a written essay. The results show that representational notations can have significant effects on learners' interactions, and may differ in their influence on subsequent collaborative use of the knowledge being manipulated. For example, Graph and Matrix users elaborated on previously represented information more than Text users. Representation and discussion of evidential relations was quantitatively greatest for Matrix users as predicted, yet this came at the cost of excessive consideration and revision of unimportant relations. Graph users may have been more focused in their consideration of evidence, and the work done in the Graph representation had the greatest impact on the contents of the essays. Although limited to initial use of representations in a laboratory setting, the work demonstrates that representational guidance of collaborative learning is worthy of study and suggests several lines of further investigation.

The MPC elucidator: a case study in the design for human-automation interaction

In this paper, we describe the design of a decision support system for operators of model-based predictive controllers (MPC). MPC is a form of advanced automatic control that is increasingly common in process operations due to its ability to control and optimize large sections of a process. A cognitive task analysis revealed that current operating displays, which rely on displaying tables of numeric information across several display pages, do not effectively support human operator monitoring, diagnosis, and control of MPC. This case study shows how we applied representation aiding and workspace management design principles to better support the human-automation interaction requirements of monitoring, understanding, and adjusting these complex, semi-autonomous; process controllers. We show how effective user interface design can significantly reduce the complexity of operating with advanced automation, and can lead to improved understanding of how the automation works.

Testbed for Evaluating Tactical Situation Awareness and Decision Making

The next generation cruise missile, the Tactical Tomahawk, improves upon current versions by its ability to be retargeted in flight against targets of opportunity. We have developed a testbed for evaluating alternative display concepts and decision support features on the effect of an operator's ability to maintain situation awareness and make appropriate time-critical decisions. This user interface design was based on an analysis of critical operator tasks, and the concepts of representation aiding and limited workspace management. The testbed was developed with Macromedia Director, allowing it to be run cross-platform (Windows, Macintosh, and the Internet). One set of studies has been conducted so far with this system, to compare alternative display features on the effect of subject situation awareness and decision making.

An Empirical Evaluation of Interfaces for Army Tactical Operations

Timely and accurate decisions in the Army domain are directly linked to the commander's ability to assess the battlefield. We reviewed both existing and proposed Army interfaces and applied a Cognitive Systems Engineering (CSE) approach to the development of an alternative interface: the RAPTOR interface (Representation Aiding Portrayal of Tactical Operations Resources). This interface and a version of the Army's recently-implemented digital interface (the Force XXI Battle Command Brigade and Below — FBCB2) were evaluated using a simulated offensive scenario and domain experts from an active Army unit. The results indicate that the RAPTOR interface produced significantly better performance for quantitative, categorical and needs assessments. It is concluded that the RAPTOR interface summarizes critical information for Army units at all levels and makes this information easily accessible through effective graphical formats and interaction style.

Vortex Breakdown-Edge Interaction: Consequence of Edge Oscillations

High-image-density particle image velocimetry is employed to determine the instantaneous and averaged features of distortion of vortex breakdown incident on a stationary and an oscillating leading edge. It is demonstrated that the onset of vortex breakdown can be advanced or retarded substantially, depending on the period of the edge oscillation relative to the inherent frequency of vortex breakdown. These features are interpreted with the aid of global representations of averaged and rms distributions of velocity, vorticity, and Reynolds stress, as well as a cinema sequence of instantaneous patterns of velocity and vorticity. Moreover, instantaneous, whole-field images in a cinema sequence allow evaluation of global representations of spectra and cross spectra, providing further insight into the central mechanisms that dictate the surface loading of the edge

How Do We Understand a System with (So) Many Diagrams? Cognitive Integration Processes in Diagrammatic Reasoning

In order to understand diagrammatic reasoning with multiple diagrams, this study proposes a theoretical framework that focuses on the cognitive processes of perceptual and conceptual integration. The perceptual integration process involves establishing interdependence between relevant system elements that have been dispersed across multiple diagrams, while the conceptual integration process involves generating and refining hypotheses about a system by combining higher-level information inferred from the diagrams. This study applies a diagrammatic reasoning framework of a single diagram to assess the usability of multiple diagrams as an integral part of a system development methodology. Our experiment evaluated the effectiveness and usability of design guidelines to aid problem solving with multiple diagrams. The results of our experiment revealed that understanding a system represented by multiple diagrams involves a process of searching for related information and of developing hypotheses about the target system. The results also showed that these perceptual and conceptual integration processes were facilitated by incorporating visual cues and contextual information in the multiple diagrams as representation aids. Visual cues indicate which elements in a diagram are related to elements in other diagrams; the contextual information indicates how the individual datum in one diagram is related to the overall hypothesis about the entire system.

Vibrational eigenstates of four-atom molecules: a parallel strategy employing the implicitly restarted Lanczos method

We present an approach for determining the vibrational eigenstates of four-atom molecules. The primary representation of the (six-dimensional) eigenstates involves a finite basis or quantum number representation, whereas Hamiltonian matrix-vector products are evaluated with the aid of certain grid or discrete variable representations. This approach leads to computational and memory demands that are within acceptable limits. The implicitly restarted Lanczos method, as implemented in the ARPACK suites of codes, is then applied to determine some of the corresponding vibrational eigenstates. A distributed-memory parallel implementation of the method allows very large symmetric matrix eigenvalue problems — on the order of N = 2 × 10 6 — to be tackled. The lowest fifty vibrational states of the HOCO molecule, with zero total angular momentum and even parity, are accurately computed on Argonne National Laboratory's IBM SP computer.

Understanding and facilitating group problem structuring and formulation: Mental representations, interaction, and representation aids

Many issues facing the organizations of today are complex and ill-structured. The complexity of these issues do not lend themselves to structuring and formulation by quantitative models, nor simple intuitive problem solving. Rather, making sense of these situations necessitates considering and oftentimes negotiating alternative models of the ill-structured situation. The use of groups is one way to gain access to alternative perspectives. In this paper, we argue that individual mental representations are the underlying basis of group interaction and communication. And, that these internal representations can be formalized in external representations that may be useful to facilitate interaction and communication as a group strives to create a shared problem perspective. Based on this theoretical foundation, we explored these ideas by examining small groups using representational aids during the process of structuring and formulating a problem. While descriptive in nature, this study provides insights on the successful use of representational aids and suggests that these aids can positively impact problem structuring and formulation by facilitating the sharing of alternative perspectives.

Approximate entropy (ApEn) as a complexity measure.

Approximate entropy (ApEn) is a recently developed statistic quantifying regularity and complexity, which appears to have potential application to a wide variety of relatively short (greater than 100 points) and noisy time-series data. The development of ApEn was motivated by data length constraints commonly encountered, e.g., in heart rate, EEG, and endocrine hormone secretion data sets. We describe ApEn implementation and interpretation, indicating its utility to distinguish correlated stochastic processes, and composite deterministic/ stochastic models. We discuss the key technical idea that motivates ApEn, that one need not fully reconstruct an attractor to discriminate in a statistically valid manner-marginal probability distributions often suffice for this purpose. Finally, we discuss why algorithms to compute, e.g., correlation dimension and the Kolmogorov-Sinai (KS) entropy, often work well for true dynamical systems, yet sometimes operationally confound for general models, with the aid of visual representations of reconstructed dynamics for two contrasting processes. (c) 1995 American Institute of Physics.

Interactive multimedia planning support: moving from stand-alone systems to the World Wide Web

In city planning contexts, hypermedia systems have been demonstrated to be engaging tools that make complex information understandable to those who are not technically sophisticated. This is accomplished through the use of multimedia interfaces that use images, motion, and sound as representational aids. Hypermedia also affords associative linking which allows one to organize and browse related information in a manner similar to encyclopedic cross-referencing. Many of the early applications of these systems have been hampered by computing platform dependence and an inability to form associative links with remotely accessible information. The issue of connectivity with remotely accessible information has recently been addressed through the maturation of the Internet and the World Wide Web (WWW). This makes it possible for the globally networked community to access this information in an associative manner. In this paper I will reflect on the relevance of the WWW to multimedia-based collaborative planning s...

Representation aiding: complementary decision support for a complex, dynamic control task

Representation aiding, a form of decision support that relies heavily, although not exclusively, on computer graphics is discussed. The design of successful representation aids depends on the tasks to be performed and characteristics of human cognition and perception. Issues in design are discussed with reference to a set of representation aids that were developed for a particularly difficult task involving the manual start-up of a nuclear reactor. The results of a research program to evaluate these representation aids are described. Representation aiding is contrasted to complementary forms of decision support. >