Dimensional Cues Research Articles

FOODCAM: A Novel Structured Light-Stereo Imaging System for Food Portion Size Estimation.

Imaging-based methods of food portion size estimation (FPSE) promise higher accuracies compared to traditional methods. Many FPSE methods require dimensional cues (fiducial markers, finger-references, object-references) in the scene of interest and/or manual human input (wireframes, virtual models). This paper proposes a novel passive, standalone, multispectral, motion-activated, structured light-supplemented, stereo camera for food intake monitoring (FOODCAM) and an associated methodology for FPSE that does not need a dimensional reference given a fixed setup. The proposed device integrated a switchable band (visible/infrared) stereo camera with a structured light emitter. The volume estimation methodology focused on the 3-D reconstruction of food items based on the stereo image pairs captured by the device. The FOODCAM device and the methodology were validated using five food models with complex shapes (banana, brownie, chickpeas, French fries, and popcorn). Results showed that the FOODCAM was able to estimate food portion sizes with an average accuracy of 94.4%, which suggests that the FOODCAM can potentially be used as an instrument in diet and eating behavior studies.

Control of Cricket System Using LQR Controller Optimized by Particle Swarm Optimization

The cricket system, as a strongly coupled, nonlinear and multivariable two dimensional cue system, is a typical representative of unstable and underactuated system. In this paper, the system is analyzed by modeling based on the cricket experimental platform, and while designing the LQR controller, the particle swarm algorithm is introduced to optimize the controller parameters to determine the optimal weight matrix Q in order to solve the difficult problem of controller parameter rectification. The simulation results show that the PSO-LQR can restore the balance of the system in a shorter period of time with enhanced stability compared to a single LQR controller, which exhibits good control performance.

Perception of Ambiguous Motion Biased by Dimensional Cues

Perception of Ambiguous Motion Biased by Dimensional Cues

Heterogeneity in voter perceptions of party competition in multidimensional space: Evidence from Japan

On the question of how voters perceive party positions, much of the existing literature has not adequately considered the case of a multidimensional policy space. Since the ideological cues related to each issue differ in a policy space of multiple dimensions, it is possible that each individual favors different dimensional cues. To test this hypothesis, this paper focuses on Japan’s 2012 Lower House election, which took place in a two-dimensional policy space. An analysis of how voters position the three major parties relative to each other reveals that there is actually heterogeneity in the voter perception of the policy space. Further, using a mixed logit model, we find that demographic factors and political attitudes explain this heterogeneity.

The Impact of Servicescape Cues on Consumer Prepurchase Authenticity Assessment and Patronage Intentions to Ethnic Restaurants

In the context of ethnic dining services, authenticity is the key ingredient. This study aims to investigate the impact of servicescape dimensions on consumers’ prepurchase authenticity perceptions and patronage intentions to ethnic restaurants. The authors propose that three key dimensions of the servicescape—the physical setting, service providers, and other customers—provide ethnic-associated cues for consumers to assess authenticity in the preconsumption stage. Empirical results from a between-subject experimental design suggest that servicescape dimensions can induce preconsumption authenticity perceptions of ethnic restaurants and that the dimensional cues interplay to affect authenticity assessments. Furthermore, a customer’s ethnicity (referent ethnic vs. mainstream) affects how she/he interprets servicescape cues and, therefore, his/her authenticity assessment. The perceived authenticity, together with a consumer’s trait of cosmopolitanism and his/her familiarity with such ethnic restaurants, consequently affect consumers’ patronage intentions. These findings contribute to hospitality research on consumers’ authenticity assessments of ethnic restaurants. Furthermore, managerial implications for ethnic restaurants in terms of marketing strategies will be discussed.

Contextual influences of dimension, speed, and direction of motion on subjective time perception

Research has indicated that the direction of motion and the speed of motion can influence the subjective estimates of temporal duration of two-dimensional (2-D) stimuli expanding and contracting within the picture plane. In this study, we investigated whether the contextual cues of stimulus/movement-plane dimensionality (2-D stimuli with implied movement in the picture plane or depth-rendered "3-D" stimuli with implied movement in the depth plane) influence and interact with speed and implied movement direction during interval estimation. Participants viewed a series of standard stimulus durations followed by a test stimulus duration and determined whether the test and standard durations differed. The results indicated that moving stimuli were overestimated relative to stationary stimuli, regardless of the direction of motion or dimensionality. Also, faster-moving stimuli were overestimated relative to slower-moving stimuli. Importantly, an interaction between movement direction and dimensional cues indicated that the loom/recede distinction occurs for 2-D but not for 3-D stimuli. It is possible that the loom/recede distinction for the 2-D condition may be an artifact arising from reduced or from a lack of perceived motion in 2-D "recede" conditions, rather than a specific overestimation for looming stimuli.

View-invariant motion trajectory-based activity classification and recognition

Motion trajectories provide rich spatio-temporal information about an object's activity. The trajectory information can be obtained using a tracking algorithm on data streams available from a range of devices including motion sensors, video cameras, haptic devices, etc. Developing view-invariant activity recognition algorithms based on this high dimensional cue is an extremely challenging task. This paper presents efficient activity recognition algorithms using novel view-invariant representation of trajectories. Towards this end, we derive two Affine-invariant representations for motion trajectories based on curvature scale space (CSS) and centroid distance function (CDF). The properties of these schemes facilitate the design of efficient recognition algorithms based on hidden Markov models (HMMs). In the CSS-based representation, maxima of curvature zero crossings at increasing levels of smoothness are extracted to mark the location and extent of concavities in the curvature. The sequences of these CSS maxima are then modeled by continuous density (HMMs). For the case of CDF, we first segment the trajectory into subtrajectories using CDF-based representation. These subtrajectories are then represented by their Principal Component Analysis (PCA) coefficients. The sequences of these PCA coefficients from subtrajectories are then modeled by continuous density hidden Markov models (HMMs). Different classes of object motions are modeled by one Continuous HMM per class where state PDFs are represented by GMMs. Experiments using a database of around 1750 complex trajectories (obtained from UCI-KDD data archives) subdivided into five different classes are reported.

Integrating Novel Dimensions to Eliminate Category Exceptions: When More Is Less.

Category learning can be characterized as a process of discovering the dimensions that represent stimuli efficiently and effectively. Categories that are overlapping when represented in 1 dimensionality may be separate in a higher dimensional cue set. The authors report 2 experiments in which participants were shown an additional cue after learning to use 2 imperfect cues. The results revealed that participants can integrate new information into their categorization cue set. The authors discovered wide individual differences, however, with many participants favoring simpler, but less accurate, cue sets. Some participants demonstrated the ability to discard information previously used when new, more accurate information was introduced. The categorization model RASHNL (J. K. Kruschke & M. K. Johansen, 1999) gave qualitatively accurate fits of the data.

Use of Visual and Tactual Cues in Learning of Simultaneous Shape Discriminations by Albino and Pigmented Rats (<em>Rattus Norvegicus</em>)

Albino Wistar, pigmented DA and crossbred (F1) rats were compared in learning of 4 versions of a simultaneous circle-triangle discrimination. On tasks with 3 dimensional shapes, either with both visual and tactual cues available, or without the tactual cues, albino rats performed as well as the pigmented rats. On tasks with reduction of visual cues, (one task with 2 dimensional cues, the other with tactual cues, and reduced 3 dimensional visual cues), the albino group's performance was significantly inferior to that of the pigmented rats. The two types of pigmented rats did not differ in learning on any task.

Effect of cue salience on discrimination learning

Salience for specific dimensional cues was assessed in second-grade children immediately prior to a two-choice discrimination learning task. The cue reinforced in the learning task was either the salient cue (learned fastest), the alternate cue of the salient cue’s dimension, or a cue from a dimension not salient (learned slowest). Children without specifically salient cues learned in approximately as many trials as did the children who were reinforced for choices of the salient cue or dimension. The results indicated that specific cue salience did not have a general facilitative effect, but that it was related to discrimination learning in a logical and predictable manner.

Retrieval of attribute information as a function of processing depth

The effects of processing depth on retrieval of attribute information was investigated using a modified probe-recognition procedure. Subjects decided whether a probe word was a synonym, a homonym, identical to, or not related to any word of a previously presented three-word set. Depth of processing was manipulated by priming with a dimensional cue prior to the presentation of the study set. The dimensional cue specified the relation in question between probes and potential target words in each study set. Effects were assessed relative to unprimed conditions where subjects had the dimensional relation specified during probe presentation. The probe word followed the three-word set by a 0-, 10-, or 30-sec filled or unfilled delay. Priming effects were reflected in reaction time but not recognition accuracy, with degree of effect related to level of processing. Synonyms were affected most, homonyms next, identity least.

ASYMMETRIC SYNTACTIC RECOGNITION MATRICES: A CHOICE ANALYSIS AS EVIDENCE FOR A HYPOTHETICAL STIMULUS‐SAMPLING PROCESS1,2

ABSTRACTAn extension of Luce's choice analysis of recognition experiments has been made so as to predict quantitatively the syntactic confusions that occur among simple syntactically related sentences which are heard at several times normal conversation rate (speeded speech). Two states are assumed to account for the pattern of asymmetric confusions: (a) a dimensional loss state wherein dimensional cues of the stimulus sentence are lost on a certain proportion of trials, and (b) a nonloss state wherein all relevant syntactic cues are assumed to be sampled but where confusions among stimuli are still assumed to occur in a predictable manner. Some relationships between the present model and Chomsky's distinction between competence and performance are discussed.

Intradimensional and extradimensional shift performance of children in a differential conditioning task

The intradimensional and extradimensional shift performance of preschool children was compared with that of second graders in a differential conditioning (single cue presentation) situation. The younger children showed better ID than ED shift performance and their ID-ED difference was greater than that of the older children despite the fact that the differential conditioning paradigm prevents simultaneous comparison of dimensional cue values.