Static Version Research Articles

Physician Recommendation on Healthcare Appointment Platforms Considering Patient Choice

In recent years, web-based appointment platforms develop rapidly, and many of them provide physician recommendation services to patients. Considering patients’ heterogeneity in both illness and behavior, it is a great challenge to deliver personalized recommendations. Motivated by this healthcare application, this study incorporates patient choices and focuses on optimizing real-time personalized recommendation of physician assortment with limited resources, in order to satisfy patients’ varying demands and improve the resource allocation efficiency. This work considers not only the influence of physician assortment to patient choice but also how physicians in the assortment are displayed on the webpage, i.e., the order of physicians. We adopt the location-based two-stage choice model to capture the patient behavior, in which patients randomly view the top physicians and then choose one among them. The recommendation problem is studied in both static and dynamic environments. In the static environment, we ignore resource capacities and optimize the recommendation of physician assortment as well as the displayed ranking. We propose a heuristic algorithm SORT for this static version of the problem and prove the lower bound of algorithm performance, along with the numerical performance validation. In the dynamic environment, we optimize the physician recommendations for a sequence of randomly arriving patients considering patients’ heterogeneity in both matching degrees and choice probabilities. We propose a dynamic algorithm Adjust-exponential inventory balancing (Adjust-EIB) by incorporating our static algorithm SORT in the improved existing algorithm, which makes recommendation decisions based on the real-time remaining resources. We conduct a series of numerical experiments to compare our algorithm with several benchmarks. The numerical results show that Adjust-EIB outperforms the benchmark algorithms, especially in congested systems. We also conduct a case study with real-world data and verify the capability of our algorithm in improving real-world system efficiency. Note to Practitioners —This work is motivated by the increasing popularity of web-based appointment platforms. Considering the fact of limited physician resources, we address the issue of how to recommend physicians for patients in a personalized and real-time way on web-based appointment platform, in order to improve the matching degree between physicians and patients as well as the resource allocation efficiency. To the best of our knowledge, we propose one of the initial methods to recommend personalized physician rankings in dynamic environments with limited resources. We construct a specific model and propose algorithms to make physician recommendation decision, which performs better than other benchmark approaches based on the numerical analysis, and the case study with real-world system data indicates our method’s capability of solving the practical problem. Our method is robust enough for the reason that the model allows arbitrary arrival pattern. The model and methods are specifically designed for the web-based appointment platforms, but it can also be easily applied in other application scenarios based on visual web pages, such as e-commerce.

The odonate phenotypic database, a new open data resource for comparative studies of an old insect order

We present The Odonate Phenotypic Database (OPD): an online data resource of dragonfly and damselfly phenotypes (Insecta: Odonata). Odonata is a relatively small insect order that currently consists of about 6400 species belonging to 32 families. The database consists of multiple morphological, life-history and behavioral traits, and biogeographical information collected from literature sources. We see taxon-specific phenotypic databases from Odonata and other organismal groups as becoming an increasing valuable resource in comparative studies. Our database has phenotypic records for 1011 of all 6400 known odonate species. The database is accessible at http://www.odonatephenotypicdatabase.org/, and a static version with an information file about the variables in the database is archived at Dryad.

On the problem of version selection to create a graph for the ant colony optimization algorithm

The article considers various graph creation methods for presenting the structure of a multiversion software package in solving its optimization problem by the ant colony optimization algorithm. The paper presents a method for calculating the weights of arcs for a static version of the graph and the reliability characteristics of the software package, taking into account its architecture. The version of creating a dynamic version of the graph is considered. A comparative analysis of these versions is conducted. The conclusions about the preferred application of the static version of the graph are made.

Convergence and divergence to radial optic flow in infancy.

Research finds a relationship between the development of depth perception and ocular motion functions including smooth pursuit and ocular following response. Infants' reactions to looming stimuli also suggest sensitivity to optic flow information that specifies relative distance. With radial optic flow, an expanding flow field elicits involuntary convergent eye movements while a contracting one elicits involuntary divergent eye movements. This response suggests the visual system is interpreting the radial flow as a change in relative depth. We measured the oculomotor response to radial optic flow in infants aged two to five months. The stimulus comprised a radial optic flow pattern that expanded or contracted across eight 400 ms trials while eye position was monitored with a Tobii X120 eye tracker. A subset of infants also viewed trials of a static version of the stimulus. On average, most infants in each age group demonstrated convergence to the expanding pattern and divergence to the contracting one. Moreover, the difference in gain between the convergence and divergence eye movements was significant. The presence of correct-direction vergence eye movements in response to expansion and contraction provides further evidence that infants are sensitive to information that specifies relative motion in depth.

Результаты использования альтернирующего предъявления различных стереостимулов для исследования способности к стереовосприятию у детей с послеоперационной остаточной микродевиацией

Purpose. To study abilities to stereo-perception in children with postoperative residual micro-deviation via alternating presentation of different stereo stimuli. Material and methods. The study included 30 children aged 8 to 16 years (average 12.5 years) with operated strabismus who have postoperative residual micro-deviation (mean 6.8±0.4 pr.D) at the time of the observation. Residual esotropia was observed in 21 children (5 of them had also a vertical micro-deviation), exotropia – 9 children. Along with the usual ophthalmic examination and evaluation of stereovision by means of classical Lang-test and Fly-test we used our own stereo-tests developed on the basis of stereo images created by J. Ninio. Our stereo-tests included stimuli: 1) with a central location of vertical or horizontal stripes with a successful fusion and an ability to stereo perception of tilt relative to the horizontal axis (vertical strip) or turn around the vertical axis (horizontal strip); 2) with a peripheral location of vertical or horizontal stripes creating respectively the effect of tilt or reversal turn; 3) randomly-point stereo-grams, creating the impression of a successful fusion of vertical or horizont al cylinder. The subject observed the images shown on the monitor screen from a distance of 50 cm from the eyes through the red-blue light filters in conditions of full prismatic compensation of the angle of strabismus and optimal spectacle or contact correction of ametropia. The stimuli were presented both in the static version and in the modes of alternation via a computer pr ogram developed by M. V. Zhmurov. Three modes of alternative presentation of stimuli were used: 1) the mode with a consecutive monocular presentation of visual stimuli corresponding to the right and left eyes 2) the mode with the presence of an empty interval between monocular phases; 3) the mode with the presence of a binocular phase between monocular phases. Results. In all patients, the results of the study of stereovision with Lang-test, Fly-test and static version of our stereo-tests used in this work were negative. In eight children of the general group, the stereo effect appears only with stereo-images with a peripheral arrangement of vertical or horizontal stripes in all three modes of the alternating presentation. In 22 children, the stereo effect appears with stimuli both with peripheral and with the central location of the stripes in all three modes of their alternating presentation. The volume effect with random-dot stereo-stimuli occurred in only nine children, with a stable bifoveal fusion, and only in the mode of alternating presentation with an empty interval between monocular phases. Thus, in this mode of alternating presentation it was possible to perceive not only linear, but also random-dot stereo-images. Comparing the maximum durations of monocular phases for different images in this mode, a significant difference was found between the mean values for stimuli with peripheral vertical stripes (57±2.3 ms) and with central vertical stripes (43.2±2.6 ms; p<0.001), as well as between the mean values for stimuli with peripheral horizontal stripes (56±2.1 ms) and central horizontal stripes (43.6±3.4 ms; p<0.002). The maximum duration of monocular phases for random-dot stereo-images producing the effect of a vertical cylinder (32.2±5.8 ms) and a horizontal cylinder (31.1±6.7 ms) was significantly lower than the maximum duration for stimuli with peripheral vertical and horizontal stripes (p<0.001). The same regularities were observed for the maximum dur ation of the empty i nterval. Conclusion. The stereo-perception is possible in children with residual postoperative micro-deviation. At the same time, the most effective of the images we used are stimuli with a peripheral arrangement of elements that create a stereo effect in condition of a successful fusion. The mode of alternating presentation of stimuli with the presence of an empty interval between monocular phases creates more favorable conditions for the appearance of a stereo effect in comparison with the mode of alternating presentation of stimuli with the presence of a binocular phase between monocular phases and in comparison with the mode of alternating monocular phases. Stereovision with random-dot stereograms causes serious difficulties in most children with postoperative microdeviation, however, it is possible in some cases in the mode of alternating presentation of stimuli with the presence of an empty i nterval between monocular phases.

KinBot: Automated stationary point search on potential energy surfaces

KinBot is a Python code that automatically characterizes kinetically important stationary points on reactive potential energy surfaces and arranges the results into a form that lends itself easily to master equation calculations. This version of KinBot tackles C, H, O and S atom containing species and unimolecular (isomerization or dissociation) reactions. KinBot iteratively changes the geometry of the reactant to obtain initial guesses for reactive saddle points defined by KinBot’s reaction types, which are then optimized by a third-party quantum chemistry package. KinBot verifies the connectivity of the saddle points with the reactant and identifies the products through intrinsic reaction coordinate calculations. New calculations can be automatically spawned from the products to obtain complete potential energy surfaces. The utilities of KinBot include conformer searches, projected frequency and hindered rotor calculations, and the automatic determination of the rotational symmetry numbers. Input files for popular RRKM master equation codes are automatically built, enabling an automated workflow all the way to the calculation of pressure and temperature dependent rate coefficients. Four examples are included. (i) [1,3]-sigmatropic H-migration reactions of unsaturated hydrocarbons and oxygenates are calculated to assess the relative importance of suprafacial and antrafacial reactions. (ii) Saddle points on three products of gamma-valerolactone thermal decomposition are studied and compared to literature potential energy surfaces. (iii) The previously published propene+OH reaction is reproduced to show the capability of building an entire potential energy surface. (iv) All species up to C4 in the Aramco Mech 2.0 are subjected to a KinBot search. Program summaryProgram title: KinBotProgram files doi:http://dx.doi.org/10.17632/hsh6dvv2zj.1Licensing provisions: BSD 3-ClauseProgramming language: PythonSupplementary material:1. A static version of the source code (KinBot.tar),2. The manual for the static version (KinBot_Manual.pdf)3. Geometries and energies of the stationary points on the potential energy surface of the sigmatropic reaction search (sigmatropic_H_shift.out)4. Geometries and energies of the stationary points on the potential energy surface of the propene+ OH central and terminal addition reaction (propene+oh central addition.out, propene+oh terminal addition.out)5. Geometries and energies of the stationary points on the potential energy surface of gamma valerolactone, 4-pentenoic acid and 3-pentenoic acid (GVL energies and geometries.out, 4PA energies and geometries.out, 3PA energies and geometries.out)6. Example runs including all input and output files for a one-well search for propanol radical, full PES search for the n-pentyl radical, a search for all homolytic scission in propanol, and the reaction searches for GVL (output.zip)7. Results of symmetry calculations for a literature benchmark dataset (Symmetry_correct.pdf, Symmetry_wrong.pdf)Nature of problem: Automatic discovery of unimolecular reaction pathways (isomerization and dissociation) for molecules and radicals relevant in gas-phase combustion and atmospheric chemistry, including oxidation and pyrolytic processes for structures including carbon, oxygen, sulfur and hydrogen atoms. The reactants, products, and transition states are characterized using a suite of tools coupled to electronic structure codes, and the results are provided in a format that lends itself easily to calculating rate coefficients based on statistical rate theories with other external codes.Solution method: Reaction pathways are identified using heuristic searches starting from a reactant by iteratively altering its geometry toward a good guess for a transition state for reactions with barriers. The transition state is identified as a first-order saddle point on the potential energy surface, which is located using local optimization methods of third-party quantum chemistry codes. We use intrinsic reaction coordinate calculations to verify the direct connectivity of the saddle point to the reactant and to identify the product species. Conformational searches, hindered rotor potentials, frequency calculations, and high-level optimizations yield the necessary data for RRKM master equation calculations.Additional comments including restrictions and unusual features: KinBot is designed to run on Unix clusters, and is written in Python, compatible with versions 2.7 and 3. It communicates with a PBS or SLURM workload manager to submit quantum chemistry calculations to third-party software. It makes use of a modified fork of ASE for the input writing, calling and output parsing of the quantum chemistry software which has been tested with Gaussian (G09RevD.01). OpenBabel (2.4.1) and RDKit (2018.09.01) are used to convert smiles to internal species representations and for species comparison and results visualization. The output of KinBot can be visualized with the PESViewer script, and graph structures are drawn using NetworkX. The master equation solvers MESS or MESMER are needed to calculate rate coefficients at the end of a given run. This version of KinBot can handle H, C, S, and O atom-containing molecules, and searches for isomerization and dissociation pathways.

Cheating as a dynamic marketing strategy in monopoly, cartel and duopoly

In 2015 it was discovered that Volkswagen had manipulated the exhaust emissions of its (diesel) cars. Since then, numerous other automotive car manufacturers were strongly suspected to violate against the same emission standards. This paper investigates how and why firms (monopoly, cartel and duopoly) engage in cheating, more precisely, promising attributes that are actually not part of the product. Firms make claims in order to better market their product but risk damaging their future reputation. The upshot of the paper is the stark difference between open loop and Markov perfect oligopolistic equilibrium outcomes. More precisely, the latter mitigates cheating substantially even below the levels attained by monopolies and cartels (unless consumers have a very short memory), which is contrary to the outcome in the limiting static version of the game. Therefore, revealing the true state (e.g., by mandating strict inspections) could force firms to use this information and play in Markov instead of open loop strategies.

Incorporation of air pollution dispersion principals into regression models - how far can we take it?

TPS 652: Air pollution exposure modeling 2, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background: Regression modelling is the most commonly used method for personalised air pollution exposure assessment. These models often incorporate a large number of land-use variables for which the causal relationship to air pollution is not clear. Moreover, it has been challenging to apply them to exposure assessment at a high temporal resolution. Formulating a regression model which takes into account well-established dispersion principals may improve previous capabilities. Methods: we designed a non-linear regression model which is based on traditional Gaussian dispersion. This model has 9 regression parameters which were optimised to provide the best fit between modelled and observed nitrogen oxides concentrations at the 39 regulatory air quality monitoring locations in our study area. Results: Using a single representative wind direction for the entire study area, the new model performed better than Inverse-Distance-Weighing (IDW) and a simpler regression model (TI-ODM). In particular, the cross-validated Mean Spatial Pearson Correlation (MSPC) was 0.23 over a dataset of 3500 unique half-hourly time-points, versus 0.19 for TI-ODM and 0.14 of IDW. The MSPC is particularly interesting when considering the epidemiological applications of exposure models. It was striking that all models performed much worse in predicting total nitrogen oxides than the nitrogen dioxide predictions shown in previous studies over the same area. A heterogeneous wind field was incorporated through a puff-like regression model. This model was applied both dynamically (i.e. having memory terms that propagate from each half-hourly time-point to the next) and statically (each time-point modelled separately as a “clean slate”). The static version performed much better (Nash-Sutcliffe efficiency=0.3 in the static version vs. -537.9 in the dynamic version). However, the static version could be run only in cross-validation mode due to computational limitations. Conclusions: In future work, this model must be qualitatively validated. If successful, it can be applied to epidemiological studies.

Static analysis of laminated reinforced composite plates using a simple first-order shear deformation theory

This paper aims to present an analytical model to predict the static analysis of laminated reinforced composite plates subjected to sinusoidal and uniform loads by using a simple first-order shear deformation theory (SFSDT). The most important aspect of the present theory is that unlike the conventional FSDT, the proposed model contains only four unknown variables. This is due to the fact that the inplane displacement field is selected according to an undetermined integral component in order to reduce the number of unknowns. The governing differential equations are derived by employing the static version of principle of virtual work and solved by applying Navier\'s solution procedure. The non-dimensional displacements and stresses of simply supported antisymmetric cross-ply and angle-ply laminated plates are presented and compared with the exact 3D solutions and those computed using other plate theories to demonstrate the accuracy and efficiency of the present theory. It is found from these comparisons that the numerical results provided by the present model are in close agreement with those obtained by using the conventional FSDT.

A Reactive-Darwinian Model for the ultimatum game: On the dominance of moderation in high diffusion

We consider a version of the ultimatum game which simultaneously combines reactive and Darwinian aspects with offers in [0,1]. By reactive aspects, we consider the effects that lead the player to change their offer given the previous result. On the other hand, Darwinian aspects correspond to copying a better strategy according to best game payoff when the current player compares with one of their neighbours. Therefore, we consider three different strategies, which govern how the players change their offers: greedy, moderate, and conservative. First, we provide an analytic study of a static version of game, where Darwinian aspects are not considered. Then, by using numerical simulations of a detailed and complete multi-agent system on a two dimensional lattice, we add an extra feature, in which players probabilistically escape from extreme offers (those close to 0 or 1) for obvious reasons. The players are also endowed reciprocity on their gains as proposers, which is reflected on their gains as responders. We also analyse the influence of the player’s mobility effects. An analysis of the emergence of coexistence of strategies and changes on the dominant strategies are observed, which in turn depends on the player’s mobility rate.

Scaffolding student teachers' information‐seeking behaviours with a network‐based tutoring system

AbstractStudent teachers' instructional planning requires them to regulate certain aspects of their own learning while designing lessons. The aim of this study is to support student teachers' self‐regulated learning through the convergence effect, where network‐based tutors are designed to optimize system recommendations of online resources based on information‐seeking behaviours. A total of 68 student teachers were randomly assigned to either a dynamic or static version of nBrowser, which converged a network or not towards an optimal configuration. The structural equation model suggests that student teachers spent less time during the learning session using the dynamic version of nBrowser. Although student teachers were found to be more efficient in seeking and acquiring information and reported knowledge gains, they failed to perform better than those assigned to the static condition on the lesson plan design task. We discuss the implications for the convergence effect in the context of network‐based tutors.

On Imaginary Content Analogies in Musico-Literary Imitation

In his article "On Imaginary Content Analogies in Musico-Literary Imitation,” Rodrigo Guijarro Lasheras analyzes "imaginary content analogy," a term often used in musico-literary studies to describe a type of imitation of music in literature. His paper aims to examine and characterize this important concept, establishing several of its features that musico-literary criticism has not normally paid attention to, such as its static or dynamic character, its implicit or explicit musical correlate, and its relation to vocal music. He argues that all imaginary content analogies must have a correlate, and that, despite the fact that we normally think of them as dynamic, there is also a static version of this phenomenon. This may open up a set of questions eventually leading to a better understanding of many musical novels, including works by Huxley, Joyce, Proust, Mann and Forster.

Sensory product characterisations based on check-all-that-apply questions: Further insights on how the static (CATA) and dynamic (TCATA) approaches perform.

Check-all-that-apply (CATA) questions have become one of the most popular methods for sensory characterisation with consumers. Temporal CATA (TCATA) is an extension of the former that takes into account the dynamic nature of sensory perception. The aim of the present work was to expand the methodological comparison of CATA and TCATA questions, considering the characterisation of solid products that undergo substantial oral processing when consumed. Five studies involving a total of 731 consumers were conducted with different product categories: dried apricots, peas, cheese, bread and milk chocolate. A between-subjects experimental design was used to compare the static and dynamic versions of CATA questions. For comparison purposes, TCATA data were analysed as CATA by collapsing the data into four fixed time intervals (quarters). The four quarters of TCATA were compared to results from CATA considering the frequency of use of the terms, sample discrimination, and product configurations. The temporal aspect of TCATA did not largely modify the average citation proportion of terms or the maximum citation proportion for individual terms. Significant differences among samples were established for most of the terms in both CATA and TCATA evaluations, albeit some subtle differences between the two methods were found. These differences were dependent on the product category and the specific sensory characteristics that were relevant for describing the focal samples. The largest differences were found for Study 5 (milk chocolate), for which TCATA identified a few additional insights on the evolution of similarities and differences among samples. However, in most cases general findings were virtually identical for both methodological approaches. In light of these results, the extra effort of using a dynamic sensory characterisation method compared to a static one, may, in many instances, not be warranted.

Critical wind speeds suggest wind could be an important disturbance agent in Amazonian forests

Abstract Recent research in the central Amazon suggests that wind is a major agent of disturbance, however, a mechanistic understanding of how wind may lead to tree mortality in Amazonian forests remains unclear. Here we estimated wind speeds necessary to topple central Amazon trees by linking both static and dynamic versions of two wind speed estimation methods (four methods total) to field data on tree failure derived from a static winching study. Static versions of these methods assumed invariant wind characteristics as more trees failed, while dynamic versions updated tree spacing, leaf area index and wind profiles progressively after each tree failure. First, we used a profile method which estimates wind force on individual trees by segments. We calculated drag on each segment and converted drag into basal turning moment, and compared the summed turning moments to the critical turning moment measured in the winching study. Estimated critical wind speeds from the static profile method varied greatly, from 10.75 m s−1 to &amp;gt;120.0 m s−1 with a mean of 45.70 m s−1. Critical wind speeds estimated with static approaches decreased with tree size but were not significantly different between two focal genera. Primary drivers of variation in critical wind speed were tree height and crown size. Second, we used the turning moment coefficient method of Hale, S.E., Gardiner, B., Peace, A., Nicoll, B., Taylor, P. and Pizzirani, S. 2015 Comparison and validation of three versions of a forest wind risk model. Environ. Model. Softw.68, 27–41. doi:10.1016/j.envsoft.2015.01.016.; the static version of this method yielded less-variable estimates, ranging from 18.98 to 52.01 m s−1, with a mean of 30.88 m s−1. Notably, the two static methods for estimating critical wind speeds differed in the trees they identified as having the highest and lowest critical wind speeds. Dynamic variants of the above two methods produced greatly reduced ranges in CWS estimates for our study trees, because after the early tree failures, remaining trees were subject to greater wind penetration into the stand and thus greater loading for a given above-canopy wind speed. CWS estimated with dynamic approaches differed significantly between the focal taxa. Nevertheless, both estimates suggest that wind speeds commonly observed during Amazon storms are sufficient to produce widespread tree damage and mortality.

Minimising the expected commute time

Motivated in part by a problem in simulated tempering (a form of Markov chain Monte Carlo) we seek to minimise, in a suitable sense, the time it takes a (regular) diffusion with instantaneous reflection at 0 and 1 to travel from the origin to 1 and then return (the so-called commute time from 0 to 1). We consider the static and dynamic versions of this problem where the control mechanism is related to the diffusion’s drift via the corresponding scale function. In the static version the diffusion’s drift can be chosen at each point in [0,1], whereas in the dynamic version we are only able to choose the drift at each point at the time of first visiting that point. The dynamic version leads to a novel type of stochastic control problem.

Predicting and containing epidemic risk using on-line friendship networks.

To what extent can online social networks predict who is at risk of an infection? Many infections are transmitted through physical encounter between humans, but collecting detailed information about it can be expensive, might invade privacy, or might not even be possible. In this paper, we ask whether online social networks help predict and contain epidemic risk. Using a dataset from a popular online review service which includes over 100 thousand users and spans 4 years of activity, we build a time-varying network that is a proxy of physical encounter between its users (the encounter network) and a static network based on their reported online friendship (the friendship With computer simulations, we compare stochastic infection processes on the two networks, considering infections on the encounter network as the benchmark. First, we show that the friendship network is useful to identify the individuals at risk of infection, despite providing lower accuracy than the ideal case in which the encounters are known. This limited prediction accuracy is not only due to the static nature of the friendship network because a static version of the encounter network provides more accurate prediction of risk than the friendship network. Then, we show that periodical monitoring of the infection spreading on the encounter network allows to correct the infection predicted by a process spreading on the friendly staff ndship network, and achieves high prediction accuracy. Finally, we show that the friendship network contains valuable information to effectively contain epidemic outbreaks even when a limited budget is available for immunization. In particular, a strategy that immunizes random friends of random individuals achieves the same performance as knowing individuals’ encounters at a small additional cost, even if the infection spreads on the encounter network.

A similarity hybrid harmony search algorithm for the Team Orienteering Problem

The Harmony Search (HS) is a metaheuristic algorithm, which is inspired from the composition of music harmonies. The functionality and flexibility of HS contribute to the development of successful methodologies for different kind of scientific problems. The aim of this paper is to propose a variant of the classic HS algorithm in order to provide competitive solutions for the Team Orienteering Problem (TOP). We introduce the Similarity Hybrid Harmony Search (SHHS) algorithm as an alternative and innovative optimization method. The SHHS follows the standard procedure of HS with some modifications and includes a new strategy called “similarity process”. Two versions of the proposed method have been developed, the static version with predefined values for the parameters of the method and the dynamic one with dynamic adjustment of the parameters. The SHHS algorithm is applied to the known benchmark instances of TOP. The dynamic of the algorithm is tested through a complete solution analysis which gives the superiority of the dynamic version compared to the static one. The results of both versions of the proposed algorithm indicate the positive performance against other effective and robust optimization algorithms from the literature.

Differences in Stereoscopic Luster Evoked by Static and Dynamic Stimuli.

We compared the classic static stereoscopic luster phenomenon with a recently described dynamic variant (“counter modulation”) to investigate whether they are related to the same or different processes. In the experiments, we presented pairs of center-surround stimuli haploscopically and measured the effect of the contrast between center colors on perceived luster. The center colors were either static or temporally modulated. In addition, we examined five color conditions (one achromatic, two equiluminant, and two mixed conditions) and three background conditions that influence the channel-wise polarities of the contrast of the two centers to the common surround. The results for static and dynamic stimuli differed in several ways, suggesting that they depend on different mechanisms: Compared with the static version, in dynamic stimuli, luster was perceived at markedly lower contrasts, did not depend on the sign of the contrast polarities, and appeared more steady. However, both phenomena seem also similar in some respects: In both cases, equiluminant stimuli led to lustrous impressions that were considerably less strong than those evoked by stimuli containing luminance variation, and the strength of the perceived luster was generally boosted with reversed contrast polarities.

A Novel Dynamic Morphed Stimuli Set to Assess Sensitivity to Identity and Emotion Attributes in Faces.

Face-based tasks are used ubiquitously in the study of human perception and cognition. Video-based (dynamic) face stimuli are increasingly utilized by researchers because they have higher ecological validity than static images. However, there are few ready-to-use dynamic stimulus sets currently available to researchers that include non-emotional and non-face control stimuli. This paper outlines the development of three original dynamic stimulus sets: a set of emotional faces (fear and disgust), a set of non-emotional faces, and a set of car animations. Morphing software was employed to vary the intensity of the expression shown and to vary the similarity between actors. Manipulating these dimensions permits us to create tasks of varying difficulty that can be optimized to detect more subtle differences in face-processing ability. Using these new stimuli, two preliminary experiments were conducted to evaluate different aspects of facial identity recognition, emotion recognition, and non-face object discrimination. Results suggest that these five different tasks successfully avoided floor and ceiling effects in a healthy sample. A second experiment found that dynamic versions of the emotional stimuli were recognized more accurately than static versions, both for labeling, and discrimination paradigms. This indicates that, like previous emotion-only stimuli sets, the use of dynamic stimuli confers an advantage over image-based stimuli. These stimuli therefore provide a useful resource for researchers looking to investigate both emotional and non-emotional face-processing using dynamic stimuli. Moreover, these stimuli vary across crucial dimensions (i.e., face similarity and intensity of emotion) which allows researchers to modify task difficulty as required.

Static traffic assignment with residual queues and spillback

In this paper we propose a novel static traffic assignment model where the network loading component accounts for non-stationary residual queues as well as spillback effects by explicitly adding capacity and storage constraints. This is achieved by deriving a static version of the dynamic general link transmission model that describes average link inflow and outflow rates during a given time period under simplified temporal assumptions. The resulting model adopts the same concave fundamental diagram and first order node model used in state-of-the-art macroscopic dynamic network loading without the need to explicitly describe time. We show that our mathematical problem formulation is an extension of several other models described in the literature, including the traditional capacity restrained static modelling paradigm. The equilibrium problem is formulated as a variational inequality problem while the network loading problem can be formulated as a fixed point problem. We prove that a solution exists to each problem as long as all traffic is loaded onto the network (i.e., no queue spillback into an origin). The model is illustrated via numerical examples on several hypothetical transport networks.