Guided Image Filtering for Interactive High‐quality Global Illumination

Interactive computation of global illumination is a major challenge in current computer graphics research. Global illumination heavily affects the visual quality of generated images. It is therefore a key attribute for the perception of photo‐realistic images. Path tracing is able to simulate the physical behaviour of light using Monte Carlo techniques. However, the computational burden of this technique prohibits interactive rendering times on standard commodity hardware in high‐quality. Trying to solve the Monte Carlo integration with fewer samples results in characteristic noisy images. Global illumination filtering methods take advantage of the fact that the integral for neighbouring pixels may be very similar. Averaging samples of similar characteristics in screen‐space may approximate the correct integral, but may result in visible outliers. In this paper, we present a novel path tracing pipeline based on an edge‐aware filtering method for the indirect illumination which produces visually more pleasing results without noticeable outliers. The key idea is not to filter the noisy path traced images but to use it as a guidance to filter a second image composed from characteristic scene attributes that do not contain noise by default. We show that our approach better approximates the Monte Carlo integral compared to previous methods. Since the computation is carried out completely in screen‐space it is therefore applicable to fully dynamic scenes, arbitrary lighting and allows for high‐quality path tracing at interactive frame rates on commodity hardware.     

Designing for attention with sound: challenges and extensions to ecological interface design

OBJECTIVE: We explore whether ecological interface design (EID) principles can be applied to the design of an auditory display for anesthesia monitoring. BACKGROUND: EID examples focus almost exclusively on visual displays. In the anesthesia work environment, however, auditory displays may provide better individual and team awareness of patient state. METHOD: Using a work domain analysis of physiological monitoring in anesthesia, we identify information to display. Using the skills, rules, and knowledge distinction we identify cognitive control needed. Using semantic mapping we map physiological variables and constraints to auditory dimensions. RESULTS: EID principles do not address when information should be displayed and to whom. An attentional mapping stage helps to specify answers to these questions so that a workable auditory display for anesthesia monitoring is achieved. CONCLUSION: EID principles of representing work domain functional structure and minimizing resource-demanding cognitive control are necessary but insufficient to specify requirements for an effective auditory display. Also needed are analyses of control tasks, strategies, and the social organization of work. Such analyses are an integral part of the broader cognitive work analysis framework from which EID emerged. APPLICATION: Actual or potential uses of this research include the design of displays that support continuous peripheral awareness in collaborative multimodal work environments.     

Modeling expert problem solving in a game of chance: a Yahtzee© case study

Although developments on software agents have led to useful applications in automation of routine tasks such as electronic mail filtering, there is a scarcity of research that empirically evaluates the performance of a software agent versus that of a human reasoner, whose problem-solving capabilities the agent embodies. In the context of a game of a chance, namely Yahtzee©, we identified strategies deployed by expert human reasoners and developed a decision tree for agent development. This paper describes the computer implementation of the Yahtzee game as well as the software agent. It also presents a comparison of the performance of humans versus an automated agent. Results indicate that, in this context, the software agent embodies human expertise at a high level of fidelity.     

Organizational climate in air traffic control Innovative preparedness for implementation of new technology and organizational development in a rule governed organization

A positive and innovative organizational climate is of great importance in order to manage and adapt to change. Such a climate seldom evolves in organizations closely governed by rules and regulations. Because of ongoing organizational and technical changes within the Swedish Air Navigation Services Provider, a study concerning the organizational climate for changes and innovations was conducted to investigate the organization's capacity to cope with changes. Study locations were the two Swedish main air traffic control centers and parts of the civil aviation administration headquarters. In the study 390 subjects took part and the CCQ questionnaire was used to measure the organizational climate. The results show that the organizational climate is quite positive despite the rule-governed work. The results also show that administrative personnel assess the organizational climate as more positive than operative personnel. Comparisons between management positions did not result in any differences.     

The continuing dilemma concerning medical versus surgical management of patients with acute type B dissections

In the free-running circadian rhythms of 14 human subjects (4 females, 10 males) who lived singly in an isolation unit without temporal clues, locomotor activity was recorded by means of contact plates installed below the carpet in the main room. During sleep, movements in bed were picked up by spring contacts attached to the mattress. In all subjects, the hourly means of locomotion during wakefulness (alpha) were negatively correlated with the duration of alpha to such an extent that the total amount of locomotion per cycle remained constant when alpha varied from 14 to 23 hr. The hourly values of movements in bed were independent of the duration of sleep (rho), so that the total number of movements was almost proportional to rho. The "homeostatic control" of locomotion during wake time is considered as a means to conserve energy when the duration of wakefulness increases.     

Schools as healthful environments: prerequisite to comprehensive school health?

The development of healthy schools to support and nature the well-being of students, teachers, and staff is proposed as a first step toward the goal of comprehensive health education. A focus on healthy schools incorporates elements of an expanded concept of comprehensive health education that demands careful consideration of the physical, psychological, and social environment of the nation's schools--worksite to 51 million (students, teachers, and staff). The active participation of all stakeholders in environmental assessments, health and safety audits, and restructuring of schools is an essential part of the school reform movement. A healthy worksite concept supports the transformation of the school environment to increase "productivity" by enhancing the ability of teachers, staff, and students to function well.     

Steroid-responsive encephalomyelitis in childhood

The syndrome of parainfectious encephalomyelitis evolves from an antecedent infection. Several etiologic agents have been associated with this complication, although the pathogenesis in each instance may prove to be more uniform. Considerable evidence suggests that the syndrome is mediated immunologically. The seven cases reported here were clinically similar, although the infectious etiologies were diverse. Leptospirosis antedated the neurologic syndrome in two cases, and a "viral" illness preceded the other five cases. The evolution of the syndrome was slowly progressive in each case, and six patients had prominent involvement of rhombencephalic structures. The progressive course was reversed rapidly with eventual full recovery in each instance after initiation of corticosteroid therapy. Our experience with these cases coupled with a review of the literature suggests that corticosteroid therapy should be considered in the subacute or chronic cases of parainfectious encephalomyelitis.     

A new method for evaluating antiarrhythmic drug efficacy

To develop standards for distinguishing antiarrhythmic drug effect from spontaneous variability of premature ventricular complexes (PVCs), 21 males (mean age 56 +/- 8 years) with chronic ischemic heart disease and PVCs underwent symptom-limited treadmill exercise testing and 24-hour ambulatory monitoring before and after 2 weeks of placebo medication. Linear regression analysis was used to describe the relationship between baseline and placebo PVC frequency for various indexes of ventricular ectopic activity and to establish 95% and 99% one-tailed confidence intervals for this relationship within the group of 21 patients. The lower limit of baseline PVC frequency for which the procedure could distinguish a placebo from a true drug response, termed the "sensitivity threshold," was an average frequency of 2.2 PVCs/hour for ambulatory electrocardiographic monitoring and 1.2 PVCs/min for treadmill exercise testing. All patients exceeded the sensitivity threshold on baseline ambulatory ECGs, but only 38% of patients did so on baseline treadmill exercise tests. To establish antiarrhythmic efficacy with 95% confidence, the minimal percent reduction of PVCs between baseline and placebo visits was 68% for treadmill exercise testing and 65% for ambulatory electrocardiography. Although these standards were developed in patients with chronic ischemic heart disease, the model can be used to establish antiarrhythmic drug efficacy in any patient group.