A psychology literature study on modality related issues for multimodal presentation in crisis management

The motivation of this psychology literature study is to obtain modality related guidelines for real-time information presentation in crisis management environment. The crisis management task is usually companied by time urgency, risk, uncertainty, and high information density. Decision makers (crisis managers) might undergo cognitive overload and tend to show biases in their performances. Therefore, the on-going crisis event needs to be presented in a manner that enhances perception, assists diagnosis, and prevents cognitive overload. To this end, this study looked into the modality effects on perception, cognitive load, working memory, learning, and attention. Selected topics include working memory, dual-coding theory, cognitive load theory, multimedia learning, and attention. The findings are several modality usage guidelines which may lead to more efficient use of the user’s cognitive capacity and enhance the information perception

An information assistant system for the prevention of tunnel vision in crisis management

In the crisis management environment, tunnel vision is a set of bias in decision makers’ cognitive process which often leads to incorrect understanding of the real crisis situation, biased perception of information, and improper decisions. The tunnel vision phenomenon is a consequence of both the challenges in the task and the natural limitation in a human being’s cognitive process. An information assistant system is proposed with the purpose of preventing tunnel vision. The system serves as a platform for monitoring the on-going crisis event. All information goes through the system before arrives at the user. The system enhances the data quality, reduces the data quantity and presents the crisis information in a manner that prevents or repairs the user’s cognitive overload. While working with such a system, the users (crisis managers) are expected to be more likely to stay aware of the actual situation, stay open minded to possibilities, and make proper decisions

Multimodal information presentation for high-load human computer interaction

This dissertation addresses the question: given an application and an interaction context, how can interfaces present information to users in a way that improves the quality of interaction (e.g. a better user performance, a lower cognitive demand and a greater user satisfaction)? Information presentation is critical to the quality of interaction because it guides, constrains and even determines cognitive behavior. A good presentation is particularly desired in high-load human computer interactions, such as when users are under time pressure, stress, or are multi-tasking. Under a high mental workload, users may not have the spared cognitive capacity to cope with the unnecessary workload induced by a bad presentation. In this dissertation work, the major presentation factor of interest is modality. We have conducted theoretical studies in the cognitive psychology domain, in order to understand the role of presentation modality in different stages of human information processing. Based on the theoretical guidance, we have conducted a series of user studies investigating the effect of information presentation (modality and other factors) in several high-load task settings. The two task domains are crisis management and driving. Using crisis scenario, we investigated how to presentation information to facilitate time-limited visual search and time-limited decision making. In the driving domain, we investigated how to present highly-urgent danger warnings and how to present informative cues that help drivers manage their attention between multiple tasks. The outcomes of this dissertation work have useful implications to the design of cognitively-compatible user interfaces, and are not limited to high-load applications

Measuring stress and cognitive load effects on the perceived quality of a multimodal dialogue system

In this paper we present the results of a pilot study investigating the impact of stress and cognitive load on the perceived interaction quality of a multimodal dialogue system for crisis management. Four test subjects interacted with the system in four differently configured trials aiming to induce low/high levels of stress and cognitive load. To measure the level of stress and cognitive load physiological sensors and subjective ratings were collected. After each trial the subjects filled in an evaluation questionnaire regarding the system interaction quality. In the end we conducted an in-depth interview with each subject. The trials were recorded with a webcam to facilitate the behaviour analysis. Results showed that both factors have an influence on the way subjects perceived the interaction quality, whereas the cognitive load seems to have a higher impact. Further quantitative experiments are needed in order to validate the results and quantify the weight of each factor. \u

Robust multi-clue face tracking system

In this paper we present a multi-clue face tracking system, based on the combination of a face detector and two independent trackers. The detector, a variant of the Viola-Jones algorithm, is set to generate very low false positive error rate. It initiates the tracking system and updates its state. The trackers, based on 3DRS and optical flow respectively, have been chosen to complement each other in different conditions. The main focus of this work is the integration of the two trackers and the design of a closed loop detector-tracker system, aiming at achieving superior robustness at real-time operation on a PC platform. Tests were carried out to assess the actual performance of the system. With an average of about 95% correct face location rate and no significant false positives, the proposed approach appears to be particularly robust to complex backgrounds, ambient light variation, face orientation and scale changes, partial occlusions, different\ud facial expressions and presence of other unwanted faces

All-optical wavelength-tunable narrow-linewidth fiber laser

Parameter regulations of narrow-linewidth fiber lasers in frequency domain has drawn considerable interests for widespread applications in the light quantum computing, precise coherent detection, and generation of micro-waves. All-optical methods provide compact, precise and fast accesses to achieving these lasers with wavelength-tunability. Here, the optical-thermal effects of graphene is utilized to precisely control operations of free-running lasers with a tuning speed of 140 MHz/ms. Assisted by the single-longitude-mode operation and linewidth suppression of stimulated Brillouin backscattering, we obtain an optical-controllable ~750 Hz fiber laser with a wavelength-tuning range of 3.7 nm

Vacuum Filling Simulation with Combined Lagranian and VOF Method

Jetting succeeded by accumulation is the characteristic of the vacuum filling, which is different from the conventional pressure-driven flow. In order to simulate this kind of flow, a three-dimensional theoretical model in terms of incompressible and viscous flow is established, and an iterative method combined with finite element method (FEM) is proposed to solve the flow problem. The Lagranian-VOF method is constructed to trace the jetting and accumulated flow fronts. Based on the proposed model and algorithm, a simulation program is developed to predict the velocity, pressure, temperature, and advancement progress. To validate the model and algorithm, a visual experimental equipment for vacuum filling is designed and construted. The vacuum filling experiments with different viscous materials and negative pressures were conducted and compared the corresponding simulations. The results show the flow front shape closely depends on the fluid viscosity and less relates to the vacuum pressure

Optical polarization rogue waves from supercontinuum generation in zero dispersion fiber pumped by dissipative soliton

Optical rogue waves emerge in nonlinear optical systems with extremely large amplitudes, and leave without a trace. In this work, we reveal the emergence of optical polarization rogue waves in supercontinuum generation from a zero-dispersion fiber, pumped by a dissipative soliton laser. Flat spectral broadening is achieved by modulation instability, followed by cascaded four-wave-mixing. In this process, we identify the emergence of optical polarization rogue waves, based on the probability density function of the relative distance among polarization states. Experimental results show that optical polarization rogue waves originate from vector multi-wave-mixing. Besides, we observe double peaks, and even triple peaks in the histogram of the state of polarization. This is a new and intriguing property, never observed so far in optical rogue waves, for example those emerging in the statistics of pulse intensities. Our polarization domain statistical analysis provides a new insight into the still debated topic of the mechanism for rogue wave generation in optical supercontinuum