RedirectedDoors+: Door-Opening Redirection with Dynamic Haptics in Room-Scale VR.

RedirectedDoors is a visuo-haptic door-opening redirection technique in VR, and it has shown promise in its ability to efficiently compress the physical space required for a room-scale VR experience. However, its previous implementation has only supported laboratory experiments with a single door opening at a fixed location. To significantly expand this technique for room-scale VR, we have developed RedirectedDoors+, a robot-based system that permits consecutive door-opening redirection with haptics. Specifically, our system is mainly achieved with the use of three components: (1) door robots, a small number of wheeled robots equipped with a doorknob-like prop, (2) a robot-positioning algorithm that arbitrarily positions the door robots to provide the user with just-in-time haptic feedback during door opening, and (3) a user-steering algorithm that determines the redirection gain for every instance of door opening to keep the user away from the boundary of the play area. Results of simulated VR exploration in six virtual environments reveal our system's performance relative to user walking speed, paths, and number of door robots, from which we derive its usage guidelines. We then conduct a user study ($N=12$) in which participants experience a walkthrough application using the actual system. The results demonstrate that the system is able to provide haptic feedback while redirecting the user within a limited play area.

Monitoring and Visualization of Crystallization Processes Using Electrical Resistance Tomography: CaCO3 and Sucrose Crystallization Case Studies.

In the current research work, electrical resistance tomography (ERT) was employed for monitoring and visualization of crystallization processes. A first-of-its-kind MATLAB-based interactive GUI application "ERT-Vis" is presented. Two case studies involving varied crystallization methods were undertaken. The experiments were designed and performed involving calcium carbonate reactive (precipitative) crystallization for the high conductivity solution-solute media, and the cooling crystallization of sucrose representing the lower conductivity solution-solute combination. The software successfully provided key insights regarding the process in both crystallization systems. It could detect and separate the solid concentration distributions in the low as well as high conductivity solutions using the visual analytics tools provided. The performance and utility of the software were studied using a software evaluation case study involving domain experts. Participant feedback indicated that ERT-Vis software helps by reconstructing images instantaneously, interactively visualizing, and evaluating the output of the crystallization process monitoring data.

Supporting Visualization Analysis in Industrial Process Tomography by Using Augmented Reality-A Case Study of an Industrial Microwave Drying System.

Industrial process tomography (IPT) based process control is an advisable approach in industrial heating processes for improving system efficiency and quality. When using it, appropriate dataflow pipelines and visualizations are key for domain users to implement precise data acquisition and analysis. In this article, we propose a complete data processing and visualizing workflow regarding a specific case-microwave tomography (MWT) controlled industrial microwave drying system. Furthermore, we present the up-to-date augmented reality (AR) technique to support the corresponding data visualization and on-site analysis. As a pioneering study of using AR to benefit IPT systems, the proposed AR module provides straightforward and comprehensible visualizations pertaining to the process data to the related users. Inside the dataflow of the case, a time reversal imaging algorithm, a post-imaging segmentation, and a volumetric visualization module are included. For the time reversal algorithm, we exhaustively introduce each step for MWT image reconstruction and then present the simulated results. For the post-imaging segmentation, an automatic tomographic segmentation algorithm is utilized to reveal the significant information contained in the reconstructed images. For volumetric visualization, the 3D generated information is displayed. Finally, the proposed AR system is integrated with the on-going process data, including reconstructed, segmented, and volumetric images, which are used for facilitating interactive on-site data analysis for domain users. The central part of the AR system is implemented by a mobile app that is currently supported on iOS/Android platforms.

Affective Colormap Design for Accurate Visual Comprehension in Industrial Tomography.

The design of colormaps can help tomography operators obtain accurate visual comprehension, thereby assisting safety-critical decisions. The research presented here is about deploying colormaps that promote the best affective responses for industrial microwave tomography (MWT). To answer the two research questions related to our study, we firstly conducted a quantitative analysis of 11 frequently-used colormaps on a segmentation task. Secondly, we presented the same colormaps within a crowdsourced study comprising two parts to verify the quantitative outcomes. The first part encoded affective responses from participants into a prevailing four-quadrant valence-arousal grid; the second part recorded participant ratings towards the accuracy of each colormap on MWT segmentation. We concluded that three colormaps are the best suited in the context of MWT tasks. We also found that the colormaps triggering emotions in the positive-exciting quadrant can facilitate more accurate visual comprehension than other affect-related quadrants. A synthetic colormap design guideline was consequently proposed.

A comparative study of input devices for digital slide navigation.

This paper describes work presented at the Nordic Symposium on Digital Pathology 2014, Linköping, Sweden. Quick and seamless integration between input devices and the navigation of digital slides remains a key barrier for many pathologists to "go digital." To better understand this integration, three different input device implementations were compared in terms of time to diagnose, perceived workload and users' preferences. Six pathologists reviewed in total nine cases with a computer mouse, a 6 degrees-of-freedom (6DOF) navigator and a touchpad. The participants perceived significantly less workload (P < 0.05) with the computer mouse and the 6DOF navigator, than with the touchpad, while no effect of the input device used on the time to diagnose was observed. Five out of six pathologists preferred the 6DOF navigator, while the touchpad was the least preferred device. While digital slide navigation is often designed to mimic microscope interaction, the results of this study demonstrate that in order to minimize workload there is reason to let the digital interaction move beyond the familiar microscope tradition.

Slide navigation patterns among pathologists with long experience of digital review.

AIMS: In order to develop efficient digital pathology workstations, we studied the navigation patterns of pathologists diagnosing whole-slide images. To gain a better understanding of these patterns, we built a conceptual model based on observations. We also determined whether or not new navigation patterns have emerged among pathologists with extensive digital experience. METHODS AND RESULTS: Five pathologists were asked to diagnose a set of four cases while thinking out loud. The navigation within the digital slides was recorded and divided into re-occurring navigation actions. The pathologists reused the same type of actions, but their occurrence differed. The most common action was a slow panning that followed an edge structure or covered an area systematically, which accounted for 30.2% of all actions and had a median duration of 7.2 s. Of all the actions, 49% were carried out within the navigation overview and 38% of the actions could not have been performed with a conventional microscope. CONCLUSIONS: The new navigation possibilities in the digital workstation were used to a large extent. The division of actions into different concepts can be used to find and prioritize between existing user interface designs as well as to understand the different navigation styles used by different pathologists.

Epistemic action: a measure for cognitive support in tangible user interfaces?

The quality of user interfaces is often measured in terms of efficiency, effectiveness, and satisfaction. In the area of tangible user interfaces, epistemic--or exploratory--action has been suggested as a fourth measure of quality. In computer game studies (Kirsh & Maglio, 1992, 1994), players used epistemic actions to modify the environment, which helped them determine the correct position of blocks with less mental effort. There, the researchers found that it might be easier to physically modify the external world and then interpret it than to compute and interpret a new state mentally. Specifically, epistemic action may be a relevant concept when researching tangible user interfaces incorporating physical handles. This article examines the potential relations between the three traditional measures of usability and epistemic actions using three spatial planning tools with different degrees of physicality. The results indicate that epistemic action is a measure that is independent of the three traditional usability measures: efficiency, effectiveness, and satisfaction. However, epistemic action does not increase linearly with the physicality of a user interface, and it probably is a more complex measure that is also related to the reusability of the interface. Further research is needed to fully understand the potential of this measure.

Average craniofacial development from 6 to 35 years of age in a mixed group of patients with juvenile idiopathic arthritis.

OBJECTIVE: To investigate long term the average changes in craniofacial morphology in a group of Norwegian juvenile idiopathic arthritis (JIA) patients with mixed diagnosis from 6 to 35 years of age. A matched group of healthy individuals was included as controls. MATERIAL AND METHODS: Craniofacial development in 38 females and 16 males with JIA was followed on lateral cephalograms from childhood for 23-31 years. The patients were compared with the healthy individuals at the ages of 6, 9, 12, and 35 years. RESULTS: At 6 and 9 years of age, the average craniofacial morphology in the JIA patients was similar to that of the control subjects. At 12 years of age, significant craniofacial morphological differences between the JIA and the control subjects appeared. These included a steeper mandibular plane angle and a more retrognathic position of the mandible. The length of the mandible (ar-gn), the height of the ramus (ar-tgo), and the length of the corpus (tgo-gn) were significantly smaller in the JIA patients. The average growth direction of the chin was more downward in the JIA patients. A smaller posterior facial height and a higher ratio between the anterior and posterior facial heights were also observed. The differences in craniofacial morphology between the patients and the control group were more pronounced at 35 years of age than at earlier ages. CONCLUSION: The typical craniofacial morphological pattern in JIA patients was established between 9 and 12 years of age. From the age of 12 until the age of 35, this morphological pattern remained relatively stable, in contrast to the pattern in the healthy control subjects.

Scanning electron microscopic evaluation of enamel surfaces exposed to 3 orthodontic bonding systems.

INTRODUCTION: This in-vitro study investigated the effects of conventional etching with a 35% phosphoric etching gel and priming/bonding with Transbond XT primer/adhesive (3M Unitek, Monrovia, Calif), conditioning with 10% polyacrylic acid and bonding with a resin-modified glass ionomer cement (Fuji ORTHO LC, GC Corporation, Tokyo Japan) or using a self-etching bonding system (Transbond Plus) and bonding with Transbond XT adhesive on the surface morphology of the enamel. The study was conducted at the Faculty of Dentistry, University of Oslo, in Norway, 2004. METHODS: The enamel surfaces of extracted premolars where conditioned with 1 of the 3 systems and evaluated with environmental scanning electron microscope. Brackets were then bonded with 1 of 3 bonding agents and examined with a conventional scanning electron microscope. RESULTS: The bonding systems induced different effects on the enamel structure. Phosphoric acid etching produced a rough, etched surface with the typical honeycomb pattern. Bonding brackets to such a surface resulted in thick resin tags relatively deep into the enamel. Less pronounced etching of the surface enamel was obtained by the self-etching primer system, and bonding resulted in smaller and fewer resin tags. The resin-modified glass ionomer bonded after conditioning the enamel with polyacrylic acid showed no resin tags. CONCLUSIONS: Bonding systems with self-etching primers or conditioners with polyacrylic acid might offer potential benefits compared with conventional acid etching and priming because of fewer irreversible changes to the enamel surface.