Modeling and visualization for a pearl-quality evaluation simulator

Visual simulation using CG and VR has attracted wide attention in the machine vision field. This paper proposes a method of modeling and visualizing pearls that will be the central technique of a pearl-quality evaluation simulator. Pearls manifest a very specific optical phenomenon that is not dependent on the direction of the light source. To investigate this feature, we propose a physical model, called an illuminant model for multilayer film interference considering the multiple reflection in spherical bodies. The rendering algorithm has been configured from such representations of physical characteristics as interference, mirroring, and texture, which correspond, respectively, to the sense of depth, brightness, and grain that are the main evaluation factors obtained from psychological experiments. Further, portions of photos of real pearls and the images generated by the present method were evaluated based on a scale of psychological evaluations of pearl-like quality demonstrating, thereby, that not merely the generated images as a whole, but the respective parts of images can present such a pearl-like quality     

Biomechanical evaluation of scaffolding tasks

A field study was conducted to identify tasks and activities that increase the risk of overexertion injury associated with the erection and dismantling of frame scaffolds, and to determine strategies that would prevent or reduce the worker's risk of injury. Twelve construction sites involving 29 workers were visited. The investigation identified that lifting scaffold end frames, carrying end frames, handling scaffold planks, removing cross braces, and removing guardrails are activities that increase the risk of overexertion injuries during task performance. This paper has focused on end-frame handling problems. Although the techniques used to handle end frames varied among the construction sites and subjects, six lifting and five carrying strategies were commonly used. Computer simulations of these work techniques show that considerable biomechanical stress occurs to most of the workers at their shoulders, elbows, and hips. To reduce overexertion injuries during erection and dismantling of frame scaffolds, design of an assistive device to lift scaffold end frames and modifications to the end-frame fixtures are suggested. Future research areas for the prevention of injury during scaffolding work are also proposed.     

Knowledge visualization: A new framework for interactive graphic interface design

Diagrams communicate massive amounts of information at a glance. Complex domains can be simplified and extended with diagrammatic notations. Computational systems can certainly benefit from the use of diagrams. However, graphic interfaces are difficult and time consuming to write. We need a way of shortening the graphic-interface building cycle so that it is relatively easy and fast to add a graphic interface to any application that may benefit from it.A general-purpose, graphic-interface-building tool kit that a designer or user, not a programmer, can use to design and attach graphic interfaces to applications can greatly speed up and lower the costs of adding graphics to systems. In this paper, I describe a new framework for interactive graphic interface design. The framework will enable graphic-interface-building tools which are general purpose, inter-active, and application-specific.The framework consists of a taxonomy (ontology) of visual properties that span sub-object properties, full objects, and the relationships between objects. The taxonomy forms a skeleton on which to hang methods for manipulating these visual properties, objects, relations, and composites. The methods consist of the generation of prototypes, the recognition of properties in objects, and mouse manipulation functions for modifying properties in an object. Further characteristics of the framework are that the properties are composable, that objects can be explicitly, incrementally described through repeated composition and application of recognition methods, and that the composition of properties to form more fully described and more complex objects is recursive. This makes the framework and the objects within it quite flexible, incremental, uniform, and modular.     

An empirical evaluation of textual display configurations for supervisory tasks

There is often a need to display logged information textually for real-time event-based supervisory tasks. Textual display design can follow several directions that reflect a tradeoff between a visual load and an operational load. The study reported here was designed in order to examine this tradeoff and its implications for such display design. An event-based monitoring and handling task was used with different event types having either a high or a low handling priority. The events were presented in four different display configurations varying in their degree of visual and operational load. The specific performance indices were event dwelling times, event handling proportion, and handling errors. In general it was found that the high priority events were handled faster and more accurately than the low priority events. In addition, performance with the various display configurations was dependent upon event type. These findings are discussed in terms of visual vs. operational load tradeoff and its context-sensitivity. Some implications for display design and further research on event presentation approaches are discussed.     

An empirical evaluation of textual display configurations for supervisory tasks

There is often a need to display logged information textually for real-time event-based supervisory tasks. Textual display design can follow several directions that reflect a tradeoff between a visual load and an operational load. The study reported here was designed in order to examine this tradeoff and its implications for such display design. An event-based monitoring and handling task was used with different event types having either a high or a low handling priority. The events were presented in four different display configurations varying in their degree of visual and operational load. The specific performance indices were event dwelling times, event handling proportion, and handling errors. In general it was found that the high priority events were handled faster and more accurately than the low priority events. In addition, performance with the various display configurations was dependent upon event type. These findings are discussed in terms of visual vs. operational load tradeoff and its context-sensitivity. Some implications for display design and further research on event presentation approaches are discussed.     

Psychophysical evaluation of in-situ ultrasound visualization

We present a novel psychophysical method for evaluating ultrasonography based on real-time tomographic reflection (RTTR), in comparison to conventional ultrasound (CUS). The method measures the user's perception of the location of an ultrasound-imaged target independently from assessing the action employed to reach it. Three experiments were conducted with the sonic flashlight (SF), an RTTR device, and CUS. The first two experiments determined subjects' perception of target location with a triangulation-by-pointing task. Depth perception with the SF was comparable to direct vision, while CUS caused considerable underestimation of target depth. Binocular depth information in the SF was shown to significantly contribute to its superiority. The third experiment tested subjects in an ultrasound-guided needle insertion task. Because the SF provides visualization of the target at its actual location, subjects performed insertions faster and more accurately by using the SF rather than CUS. Furthermore, the trajectory analysis showed that insertions with the SF generally went directly to the target along the desired path, while CUS often led to a large deviation from the correct path consistent with the observed underestimation of target depth. These findings lend great promise to the use of RTTR-based imaging in clinical practice and provide precise means of assessing efficacy.     

Studying the effectiveness of multi-user immersive environments for collaborative evaluation tasks

Massively Multiuser On-line Learning (MMOL) Platforms, often called “virtual learning worlds”, constitute a still unexplored context for communication-enhanced learning, where synchronous communication skills in an explicit social setting enhance the potential of effective collaboration. In this paper, we report on an experimental study of collaborative evaluation in an MMOL setting with 21 graduate students enrolled in university courses in technology-mediated teaching and learning. This study was carried out using a prototype of a 3D MMOL platform built around an interactive space called “MadriPolis”. This space was used to recreate an adequate scenario for a collaborative experience about Learning Object evaluation using the mainstream Learning Object Review Instrument (LORI), which is based on a Convergent Participation Model (CPM). The same experience was carried out using a conventional LCMS (Learning Content Management System) platform with the aim of contrasting the outcomes and interaction patterns in the two settings. This study makes use of Social Network Analysis (SNA) measures to describe the interactions between tutors and learners. By dwelling on the advantages of immersive environments, SNA indexes revealed that these interactions were rather dense and that student participation was rather broad-based in the case of the MMOL. The results suggest that MMOL platforms could be used in collaborative evaluation tasks as a means to enhance both tutor interaction patterns and the strength of the group's relationship.     

Studying the effectiveness of multi-user immersive environments for collaborative evaluation tasks

Massively Multiuser On-line Learning (MMOL) Platforms, often called “virtual learning worlds”, constitute a still unexplored context for communication-enhanced learning, where synchronous communication skills in an explicit social setting enhance the potential of effective collaboration. In this paper, we report on an experimental study of collaborative evaluation in an MMOL setting with 21 graduate students enrolled in university courses in technology-mediated teaching and learning. This study was carried out using a prototype of a 3D MMOL platform built around an interactive space called “MadriPolis”. This space was used to recreate an adequate scenario for a collaborative experience about Learning Object evaluation using the mainstream Learning Object Review Instrument (LORI), which is based on a Convergent Participation Model (CPM). The same experience was carried out using a conventional LCMS (Learning Content Management System) platform with the aim of contrasting the outcomes and interaction patterns in the two settings. This study makes use of Social Network Analysis (SNA) measures to describe the interactions between tutors and learners. By dwelling on the advantages of immersive environments, SNA indexes revealed that these interactions were rather dense and that student participation was rather broad-based in the case of the MMOL. The results suggest that MMOL platforms could be used in collaborative evaluation tasks as a means to enhance both tutor interaction patterns and the strength of the group's relationship.     

基于网络的对称度误差评定及其可视化

以面对面对称度误差为例,讨论了网络环境下零件形位误差评定结果可视 化的具体方法,阐述了VRML 与Java 之间的通信机制与交互原理,并通过实例实现了以 VRML 作为三维展示平台、以Java Applet 作为控制核心的面对面对称度误差的评定及其结 果可视化。用户通过屏幕可直观观察到基准中心平面位置和各测点分布特征,为不合格零件 的修正和后续工艺的改进提供了依据。     

Binarised regression tasks: methods and evaluation metrics

Some supervised tasks are presented with a numerical output but decisions have to be made in a discrete, binarised, way, according to a particular cutoff. This binarised regression task is a very common situation that requires its own analysis, different from regression and classification—and ordinal regression. We first investigate the application cases in terms of the information about the distribution and range of the cutoffs and distinguish six possible scenarios, some of which are more common than others. Next, we study two basic approaches: the retraining approach, which discretises the training set whenever the cutoff is available and learns a new classifier from it, and the reframing approach, which learns a regression model and sets the cutoff when this is available during deployment. In order to assess the binarised regression task, we introduce context plots featuring error against cutoff. Two special cases are of interest, the \( UCE \) and \( OCE \) curves, showing that the area under the former is the mean absolute error and the latter is a new metric that is in between a ranking measure and a residual-based measure. A comprehensive evaluation of the retraining and reframing approaches is performed using a repository of binarised regression problems created on purpose, concluding that no method is clearly better than the other, except when the size of the training data is small.     

Mission evaluation: expert evaluation system for large-scale combat tasks of the weapon system of systems

Mission evaluation is a new requirement for capability evaluation of the weapon system of systems (WSOS) in the era of big data, and is based on evaluating large-scale tasks with similar attributes. The use of traditional methods by military experts to evaluate large scale tasks incurs significant time cost and results in low accuracy, and is caused by a variety of factors that cause confusion. Therefore, we developed a system to assist military personnel in improving the efficiency of mission evaluation; the main innovations of our work include the qualitative and quantitative visualization of complex information is realized in a three-pane interface. We also realize the iterative and interactive evaluation modes of large-scale tasks by using the active learning method; moreover, the overall display of large-scale task evaluation results is realized using statistical graphics. In practical application, the system not only improves the users’ efficiency and accuracy scores, but also helps to achieve the recognition evaluation for the overall scoring results.     

Development and evaluation of a microprocessor-based ergonomic dosimeter for evaluating carpentry tasks

This portable and self-contained lightweight microprocessor based Ergonomic Dosimeter is designed to collect continuously postural angles of the torso and the upper arm in the sagittal plane and the number of kneeling activities. Up to 4 h of task performance data can be stored in a non-volatile memory of the dosimeter, which can then be downloaded to a lap-top computer. The portable dosimeter was tested for test-retest reliability, compared with posture data obtained with a computer-based video analysis system and evaluated at a carpenter’s apprentices school and at a construction site. The dosimeter was shown to be suitable for collecting posture and kneeling data for a prolonged period at construction sites.     

Algorithms for implementing elastic tasks on multiprocessor platforms: a comparative evaluation

Real-Time Systems - The elastic task model enables the adaptation of systems of recurrent real-time tasks under uncertain or potentially overloaded conditions. A range of permissible periods is...     

Graphical histories for visualization: supporting analysis, communication, and evaluation

Interactive history tools, ranging from basic undo and redo to branching timelines of user actions, facilitate iterative forms of interaction. In this paper, we investigate the design of history mechanisms for information visualization. We present a design space analysis of both architectural and interface issues, identifying design decisions and associated trade-offs. Based on this analysis, we contribute a design study of graphical history tools for Tableau, a database visualization system. These tools record and visualize interaction histories, support data analysis and communication of findings, and contribute novel mechanisms for presenting, managing, and exporting histories. Furthermore, we have analyzed aggregated collections of history sessions to evaluate Tableau usage. We describe additional tools for analyzing users’ history logs and how they have been applied to study usage patterns in Tableau.     

Knowledge precepts for design and evaluation of information visualizations

The design and evaluation of most current information visualization systems descend from an emphasis on a user's ability to "unpack" the representations of data of interest and operate on them independently. Too often, successful decision-making and analysis are more a matter of serendipity and user experience than of intentional design and specific support for such tasks; although humans have considerable abilities in analyzing relationships from data, the utility of visualizations remains relatively variable across users, data sets, and domains. In this paper, we discuss the notion of analytic gaps, which represent obstacles faced by visualizations in facilitating higher-level analytic tasks, such as decision-making and learning. We discuss support for bridging these gaps, propose a framework for the design and evaluation of information visualization systems, and demonstrate its use.     

Performance evaluation of pure-motion tasks for mobile robots with respect to world models

The evaluation of the performance of robot motion methods and systems is still an open challenge, although substantial progress has been made in the field over the years. On the one hand, these techniques cannot be evaluated off-line, on the other hand, they are deeply influenced by the task, the environment and the specific representation chosen for it. In this paper we concentrate on “pure-motion tasks”: tasks that require to move the robot from one configuration to another, either being an independent sub-task of a more complex plan or representing a goal by itself. After characterizing the goals and the tasks, we describe the commonly-used problem decomposition and different kinds of modeling that can be used, from accurate metric maps to minimalistic representations. The contribution of this paper is an evaluation framework that we adopt in a set of experiments showing how the performance of the motion system can be affected by the use of different kinds of environment representations.     

Ergonomic evaluation of work table for waste sorting tasks using digital human modelling

Waste sorting facilities rely heavily on plentiful human labour, and the lack of adequately designed work systems leads to musculoskeletal disorders among the workers. The present research explores the ergonomic design aspects of a cost-effective intervention, a work table for waste sorting in developing countries. This study evaluates the appropriate range of work height for the sorting tasks and proper location of hoppers to drop the sorted items. The ergonomic assessment was conducted by simulating postures involved in sorting tasks in a virtual environment and performing a biomechanical evaluation of the static postures by digital human modelling. Thirty male subjects from Indian population simulated the postures of sorting tasks. The compressive force at L4/L5 intervertebral disc, shoulder flexion moment, shoulder abduction moment, and elbow flexion moment were taken as the indicative parameters of the subject's physical workload. The appropriate table height was marginally lower than the elbow height of the subject and within 4 cm. The preferred hopper position was on the floor adjacent to the worker compared with the hopper on the top of the table.     

Biomechanical evaluation of nursing tasks in a hospital setting

A field study was conducted to investigate spinal kinematics and loading in the nursing profession using objective and subjective measurements of selected nursing tasks observed in a hospital setting. Spinal loading was estimated using trunk motion dynamics measured by the lumbar motion monitor (LMM) and lower back compressive and shear forces were estimated using the three-dimensional (3D) Static Strength Prediction Program. Subjective measures included the rate of perceived physical effort and the perceived risk of low back pain. A multiple logistic regression model, reported in the literature for predicting low back injury based on defined risk groups, was tested. The study results concluded that the major risk factors for low back injury in nurses were the weight of patients handled, trunk moment, and trunk axial rotation. The activities that required long time exposure to awkward postures were perceived by nurses as a high physical effort. This study also concluded that self-reported perceived exertion could be used as a tool to identify nursing activities with a high risk of low-back injury.     

Biomechanical evaluation of lifting tasks: A microcomputer-based model

This paper discusses a static and dynamic biomechanical evaluation of sagittal lifting activities via a microcomputer model. The input to the developed model includes operator's anthropometric data, and sex. The model provides the reactive forces and torques at the various joints of the body expressed in both British and metric systems. Also, the model shows the calculated compressive force on the spine at the fifth lumber/first sacral joint (L5/S1), and both kinematic and kinetic informations are displayed. The model has a menu of five options: (1) to analyze stress imposed on the L5/S1 during a dynamic activity; (2) to determine maximum weight to be allowed during a dynamic motion; (3) to check stress on the spine (L5/S1) for specified static postures; (4) to determine maximum weight to be allowed for a static posture; or (5) to stimulate the lifting action and determine critical postures while performing lifting tasks based on static biochemical analysis.