共查询到20条相似文献,搜索用时 15 毫秒
1.
OBJECTIVE: This study was conducted to assess dynamic visual acuity (DVA) under pupil dilation. BACKGROUND: Pupil dilation may negatively affect driving performance. METHODS: Thirty healthy young adults (mean age 29.4 years) with pupil dilation participated in this study as the Mydrin P group. In addition to them, 15 healthy young adults (mean age 28.5 years) without pupil dilation were enrolled as the control group. DVA was measured binocularly with free-head viewing at 0, 30, 60, 120, and 360 min after mydriatic drop instillation in both eyes. Pupil size was measured at each time. RESULTS: In the Mydrin P group, DVA significantly improved at 30, 60, and 120 min (ANOVA; p < .01) but returned to the predilation level at 360 min (ANOVA; p = .61). Pupil size changed from 4.1 to 7.8 mm (ANOVA; p < .01) at 30 min after the instillation, and this level was maintained up to 120 min but returned to normal within 360 min. In the control group, DVA did not significantly change at all measured times (ANOVA; p > .9). DVA was significantly (p < .05) correlated with the pupil size at all measured times. CONCLUSION: The improvement in DVA was related to the enlargement of the pupil. This study suggests that the pupil size is one factor that may affect DVA. APPLICATION: Potential applications of this study include useful information to assess the effect of pupil dilation on driving performance. 相似文献
2.
A process-oriented approach by systematically studying driver performance, distraction, and workload is the way to go for assessing safety effects of new telematics applications in vehicles. These systems may strive for drivers' attention and possibly lead to distraction from the primary task. Visual occlusion techniques appear to be an effective means of studying drivers' visual information processing performance. Studies to illustrate this include identifying the minimum visual information drivers need for driving (asking for visual information) and the evaluation of driver support systems such as heading control and adaptive cruise control with respect to visual workload. In other applications the occlusion technique is used to exclude 'visual array' information from the optic flow field. The temporary exclusion of part of the visual field of view was applied in evaluating the effects of different types of driver's side rearview mirrors. 相似文献
3.
In this paper we propose a new way to achieve a navigation task (visual path following) for a non-holonomic vehicle. We consider an image-based navigation process. We show that it is possible to navigate along a visual path without relying on the extraction, matching and tracking of geometric visual features such as keypoint. The new proposed approach relies directly on the information (entropy) contained in the image signal. We show that it is possible to build a control law directly from the maximization of the shared information between the current image and the next key image in the visual path. The shared information between those two images is obtained using mutual information that is known to be robust to illumination variations and occlusions. Moreover the generally complex task of features extraction and matching is avoided. Both simulations and experiments on a real vehicle are presented and show the possibilities and advantages offered by the proposed method. 相似文献
4.
In this paper a methodology is proposed for the integration of IDEFI with IDEF0, allowing an IDEFI model to be generated easily from the corresponding IDEFO model. The methodology involves: (1) the principle for the integration of IDEFI with IDEFO based on the concepts of IDEF methods; (2) the new requirements for IDEFO diagrams at the relative bottom levels to meet the prerequisites for the integration of IDEF models; (3) the development of a knowledge-based system (KBIDEF) for the integration of the IDEFI model with its corresponding IDEFO model; (4) the design of two databases: object-oriented IDEF0 and IDEFI databases, three libraries: Entity Class Library, Relation Class Library and Domain Relation Class Library and two knowledge bases: Relation Analysis Knowledge Base and Domain Knowledge Base for CIM information system design. Finally, the paper suggests some areas for future work. 相似文献
5.
Most past car pooling studies have focused on the to-work problem (from different origins to a common destination) or the return-from-work problem (from the same origin to different destinations). Pre-matching information, including the carpool partners and the route/schedule for each previously participating vehicle, have rarely been considered. As a result, there has not yet been a suitable method/model developed for solving practical many-to-many car pooling problem with multiple vehicle and person types, as well as pre-matching information, that occur in real-world. In this study we strive to make up this lack by employing a time–space network flow technique to develop a model for this type of car pooling problem with pre-matching information (CPPPMI). The model is formulated as an integer multiple commodity network flow problem. A solution algorithm, based on Lagrangian relaxation and a heuristic for the upper bound solution, is developed to solve the model. To test how well the model and the solution algorithm may be applied to real-world, numerical tests are performed with several problem instances randomly generated based upon data reported from a past study carried out in northern Taiwan. The test results show the effectiveness of the proposed model and solution algorithm. 相似文献
6.
This paper examines the potential to distinguish land cover types in digital images acquired at several different sensor view angles with respect to a fixed area on the Earth's surface. Images recorded by an airborne multispectral scanner over an area of arable farmland are used to generate four such multipleview-angle (MVA) datasets: each consists of data obtained at six sensor view angles in a single spectral waveband: green (0.52-0.605 mu m), red (0.63-0.69 mu m), near-infrared (0.76-0.90 mu m), and middle infrared (1.55-1.75 mu m), respectively.The data are initially presented in the form of single-band MVA false-colour composite images. These are used to illustrate the extent to which different surface materials can be distinguished visually in MVA data. The concept of MVA (cf.,multispectral) feature space is then introduced and the separability of different land cover types within it is explored. It is suggested that single-band MVA data contain two main components of statistical variance directional and spectral . Their relative contributions to the total statistical variance in single-band MVA data is assessed using linear correlation analysis and principal components analysis (PCA). It is shown that while the spectral component tends to dominate in all wavebands, particularly in the near-infrared, the directional component nevertheless provides an important means of distinguishing certain cover types. The implications of these findings are discussed in relation to the parameters used in current bidirectional reflectance distribution function (BDRF) models and the development of 'angular indices' for vegetation monitoring (cf., traditional multispectral vegetation indices). 相似文献
7.
When a database increases in size, retrieving the data becomes a major problem. An approach based on data visualization and visual reasoning is described. The main idea is to transform the data objects and present sample data objects in a visual space. The user can use a visual language to incrementally formulate the information retrieval request in the visual space. A prototype system is described with the following features: (1) it is built on top of the SIL-ICON visual language compiler and therefore can be customized for different application domains; (2) it supports a fuzzy icon grammar to define reasonable visual sentences; (3) it incorporates a semantic model of the database for fuzzy visual query translation; and (4) it incorporates a VisualNet which stores the knowledge learned by the system in its interaction with the user so that the VisualReasoner can adapt its behavior 相似文献
8.
A review of hardware for visual purposes, which is broadly classified into light emitters (CRTs, alphanumeric VDUs and television displays) and light controllers (eidophors, cathodochromic tubes, photochromatic displays and liquid crystals), is presented. It includes sections on constrained-format, head-mounted and solid-state displays, soft and hard copy, including printers and plotters, and interaction methods. 相似文献
10.
In this paper we present Top Tom, a digital platform whose goal is to provide analytical and visual solutions for the exploration of a dynamic corpus of user‐generated messages and media articles, with the aim of i) distilling the information from thousands of documents in a low‐dimensional space of explainable topics, ii) cluster them in a hierarchical fashion while allowing to drill down to details and stories as constituents of the topics, iii) spotting trends and anomalies. Top Tom implements a batch processing pipeline able to run both in near‐real time with time stamped data from streaming sources and on historical data with a temporal dimension in a cold start mode. The resulting output unfolds along three main axes: time, volume and semantic similarity (i.e. topic hierarchical aggregation). To allow the browsing of data in a multiscale fashion and the identification of anomalous behaviors, three visual metaphors were adopted from biological and medical fields to design visualizations, i.e. the flowing of particles in a coherent stream, tomographic cross sectioning and contrast‐like analysis of biological tissues. The platform interface is composed by three main visualizations with coherent and smooth navigation interactions: calendar view, flow view, and temporal cut view. The integration of these three visual models with the multiscale analytic pipeline proposes a novel system for the identification and exploration of topics from unstructured texts. We evaluated the system using a collection of documents about the emerging opioid epidemics in the United States. 相似文献
11.
This study explores the relationship between job salisfaction and the daily usage of visual display units (VDUs). A negative correlation is found to exist between job satisfaction and utilization of the VDU. Workers who have utilized the VDU alone for data entry were more satisfied with their jobs than those workers who had used the key punch for data entry and then switched to the VDU, although they said they preferred the VDU over the key punch. The following model was found to be statistically significant:
Job satisfaction =f(-VDU Usage + Supervisor intervention+ Team membership+ job utility—performance of the task) 相似文献
12.
Abstract This study explores the relationship between job salisfaction and the daily usage of visual display units (VDUs). A negative correlation is found to exist between job satisfaction and utilization of the VDU. Workers who have utilized the VDU alone for data entry were more satisfied with their jobs than those workers who had used the key punch for data entry and then switched to the VDU, although they said they preferred the VDU over the key punch. The following model was found to be statistically significant: Job satisfaction =f(-VDU Usage + Supervisor intervention+ Team membership+ job utility—performance of the task) 相似文献
13.
OBJECTIVE: This study investigates the effect of cognitive load on guidance of visual attention. BACKGROUND: Previous studies have shown that cognitive load can undermine driving performance, particularly drivers' ability to detect safety-critical events. Cognitive load combined with the loss of exogenous cues, which can occur when the driver briefly glances away from the roadway, may be particularly detrimental. METHOD: In each of two experiments, twelve participants engaged in an auditory task while performing a change detection task. A change blindness paradigm was implemented to mask exogenous cues by periodically blanking the screen in a driving simulator while a change occurred. Performance measures included participants' sensitivity to vehicle changes and confidence in detecting them. RESULTS: Cognitive load uniformly diminished participants' sensitivity and confidence, independent of safety relevance or lack of exogenous cues. Periodic blanking, which simulated glances away from the road-way, undermined change detection to a greater degree than did cognitive load; however, drivers' confidence in their ability to detect changes was diminished more by cognitive load than by periodic blanking. CONCLUSION: Cognitive load and short glances away from the road are additive in their tendency to increase the likelihood of drivers missing safety-critical events. APPLICATION: This study demonstrates the need to consider the combined consequence of cognitive load and brief glances away from the road in the design of emerging in-vehicle devices and the need to provide drivers with better feedback regarding these consequences. 相似文献
14.
This paper identifies correlations of design intent and user response to stylistic recognition of 23 car brands, with an emphasis on visual aesthetics. By evaluating car exterior designs based on shape similarities, it is possible to find the distributions of the typical design elements and novel design elements. These can then be compared with looking probabilities on design elements observed from eye tracking experiments to conduct a Design Intent Analysis. We have identified that the participants’ viewing patterns are related to the degree of shape similarities of particular design elements such as the front bumper, side silhouette, and side front fender. We observed no significance in regard to subjects’ looking probabilities in relation to design intent of the other 16 design elements. Thus, the design intent of the car brands does not correlate with the user responses. The contribution of this paper is twofold: providing systematic measures and promoting practical possibilities for design quantification. The design field relies heavily on expert knowledge; an empirical understanding of designer intent and user response therefore can provide quantifiable insight to automobile companies. Based on our findings, companies could investigate how creating unique designs may not always be good strategies for improving design qualities, brand recognition or even purchase intent. Companies can efficiently and strategically manage design costs, which are directly related to the manufacturing cost. 相似文献
15.
This paper surveys research in developing computational models for integrating linguistic and visual information. It begins with a discussion of systems which have been actually implemented and continues with computationally motivated theories of human cognition. Since existing research spans several disciplines (e.g., natural language understanding, computer vision, knowledge representation), as well as several application areas, an important contribution of this paper is to categorize existing research based on inputs and objectives. Finally, some key issues related to integrating information from two such diverse sources are outlined and related to existing research. Throughout, the key issue addressed is the correspondence problem, namely how to associate visual events with words and vice versa. 相似文献
16.
A graph of neural output as a function of the logarithm of stimulus intensity often produces an S-shaped function, which is frequently modeled by the hyperbolic ratio equation. The response of neurons in early vision to stimuli of varying contrast is an important example of this. Here, the hyperbolic ratio equation with a response exponent of two is derived exactly by considering the balance between information rate and the neural costs of making that information available, where neural costs are a function of synaptic strength and spike rate. The maximal response and semisaturation constant of the neuron can be related to the stimulus ensemble and therefore shift accordingly to exhibit contrast gain control and normalization. 相似文献
17.
The complex nature of two-dimensional image data has presented problems for traditional information systems designed strictly for alphanumeric data. Systems aimed at effectively managing image data have generally approached the problem from two different views: They either possess a strong database component with little image understanding, or they serve as an image repository for computer vision applications, with little emphasis on the image retrieval process. A general architecture for visual information-management systems (VIMS), which combine the strengths of both approaches, is presented. The system utilizes computer vision routines for both insertion and retrieval and allows easy query-by-example specifications. The vision routines are used to segment and evaluate objects based on domain-knowledge describing the objects and their attributes. The vision system can then assign feature values to be used for similarity-measures and image retrieval. A VIMS developed for face-image retrieval is presented to demonstrate these ideas 相似文献
18.
The data from a former experiment with a serial responding task were analysed to throw light on some issues connected with the ‘ blocking ’ phenomenon. The task consisted of pushing one of four keys in response to the appearance of four figures on a numerical indicator. It was self-paced. Thirty-five subjects worked on it uninterruptedly for 30 min. It is shown that: 1. The main change which occurs in the distribution of reaction times during the session is the appearance of a tail of long times: this is in agreement with the blocking hypothesis, i.e. with the hypothesis that an extra delay is sometimes added to the normal reaction time. 2. The increase in number of long reaction times takes place in the first five minutes of work. 3. Long reaction times are preceded by an increase in mean reaction time and in percentage of errors, which take place over four or five preceding responses, and are followed by a return of both variables to normal level ; this is in agreement with the hypothesis that blocks allow fatigue to dissipate. 相似文献
19.
Telematics systems are increasingly prevalent, but how safe are they to use? Designers have the challenge of designing systems that are suitable for usage within vehicles--systems that do not excessively distract the driver from the primary task of driving. This investigation addressed the requirements of telematics system design by evaluating an existing telematics device in the context of its everyday use. The system evaluated was the Mobile Data Terminal, a device used by the Sussex Police Force to assist officers in their duties whilst out on patrol. The investigation involved interviewing officers, working alongside officers in real-world situations, and assessing the system through implementation of a telematics safety checklist. The findings showed that the Mobile Data Terminal improved the productivity of double-crewed patrol cars, but was less effective, and potentially compromised road safety when patrol cars were single-crewed. The central conclusion was that telematics systems, which are considered to be incompatible with driving, should not be accessible whilst a vehicle is in motion. 相似文献
20.
Saliency prediction models provide a probabilistic map of relative likelihood of an image or video region to attract the attention of the human visual system. Over the past decade, many computational saliency prediction models have been proposed for 2D images and videos. Considering that the human visual system has evolved in a natural 3D environment, it is only natural to want to design visual attention models for 3D content. Existing monocular saliency models are not able to accurately predict the attentive regions when applied to 3D image/video content, as they do not incorporate depth information. This paper explores stereoscopic video saliency prediction by exploiting both low-level attributes such as brightness, color, texture, orientation, motion, and depth, as well as high-level cues such as face, person, vehicle, animal, text, and horizon. Our model starts with a rough segmentation and quantifies several intuitive observations such as the effects of visual discomfort level, depth abruptness, motion acceleration, elements of surprise, size and compactness of the salient regions, and emphasizing only a few salient objects in a scene. A new fovea-based model of spatial distance between the image regions is adopted for considering local and global feature calculations. To efficiently fuse the conspicuity maps generated by our method to one single saliency map that is highly correlated with the eye-fixation data, a random forest based algorithm is utilized. The performance of the proposed saliency model is evaluated against the results of an eye-tracking experiment, which involved 24 subjects and an in-house database of 61 captured stereoscopic videos. Our stereo video database as well as the eye-tracking data are publicly available along with this paper. Experiment results show that the proposed saliency prediction method achieves competitive performance compared to the state-of-the-art approaches. 相似文献
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