Content-based image retrieval in picture archiving and communications systems.
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We propose the concept of content-based image retrieval (CBIR) and demonstrate its potential use in picture archival and communication system (PACS). We address the importance of image retrieval in PACS and highlight the drawbacks existing in traditional textual-based retrieval. We use a digital mammogram database as our testing data to illustrate the idea of CBIR, where retrieval is carried out based on object shape, size, and brightness histogram. With a user-supplied query image, the system can find images with similar characteristics from the archive, and return them along with the corresponding ancillary data, which may provide a valuable reference for radiologists in a new case study. Furthermore, CBIR can perform like a consultant in emergencies when radiologists are not available. We also show that content-based retrieval is a more natural approach to man-machine communication. (+info)
Active manual control of object views facilitates visual recognition.
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Active exploration of large-scale environments leads to better learning of spatial layout than does passive observation [1] [2] [3]. But active exploration might also help us to remember the appearance of individual objects in a scene. In fact, when we encounter new objects, we often manipulate them so that they can be seen from a variety of perspectives. We present here the first evidence that active control of the visual input in this way facilitates later recognition of objects. Observers who actively rotated novel, three-dimensional objects on a computer screen later showed more efficient visual recognition than observers who passively viewed the exact same sequence of images of these virtual objects. During active exploration, the observers focused mainly on the 'side' or 'front' views of the objects (see also [4] [5] [6]). The results demonstrate that how an object is represented for later recognition is influenced by whether or not one controls the presentation of visual input during learning. (+info)
Experimental analysis of human vocal behavior: applications of speech-recognition technology.
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Recent developments in speech recognition make it feasible to apply the technology to study vocal behavior. The present study illustrates the use of this technology to establish functional stimulus classes. Eight students were taught to say nonsense words in the presence of arbitrarily assigned sets of symbols consistent with three three-member experimenter-defined stimulus classes. Computer-controlled speech-recognition software was used to record, analyze, and differentially reinforce vocal responses. When the stimulus classes were established, students were taught to say a new nonsense word in the presence of one member of each stimulus class. Transfer of function was tested subsequently to determine if the novel stimulus names transferred to the remaining stimulus class members. Most subjects required two iterations of the training and testing procedures before transfer occurred. The data illustrate the usefulness of recording vocal behavior during stimulus control procedures and demonstrate the use of speech-recognition technology. The paper also describes the current state of speech-recognition technology and suggests several other areas of research that might benefit from using vocal behavior as its primary datum. (+info)
Identification of driver model parameters.
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The paper presents a driver model, which can be used in a computer simulation of a curved ride of a car. The identification of the driver parameters consisted in a comparison of the results of computer calculations obtained for the driver-vehicle-environment model with different driver data sets with test results of the double lane-change manoeuvre (Standard No. ISO/TR 3888:1975, International Organization for Standardization [ISO], 1975) and the wind gust manoeuvre. The optimisation method allows to choose for each real driver a set of driver model parameters for which the differences between test and calculation results are smallest. The presented driver model can be used in investigating the driver-vehicle control system, which allows to adapt the car construction to the psychophysical characteristics of a driver. (+info)
The purpose of occupational medicine.
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The purposes of occupational medicine are described in terms of its clinical medical, environmental medical, research, and administrative content. Each of these components is essential in different proportions in comprehensive occupational health services for different industries, and can only be satisfactorily provided by occupational physicians and occupational health nurses who are an integral part of their organizations. Two-thirds of the working population in the United Kingdom are without the benefits of occupational medicine. The reorganization of the National Health Service and of local government presents the opportunity to extend occupational health services to many more workers who need them. It is suggested that area health authorities should provide occupational health services for all National Health Service staff and, on an agency basis, for local government and associated services, eventually extending to local industry. Such area health authority based services, merged with the Employment Medical Advisory Service, could conveniently then be part of the National Health Service, as recommended by the British Medical Association, the Society of Occupational Medicine, and the Medical Services Review Committee. (+info)
Comparison of one-, two-, and three-dimensional measurements of childhood brain tumors.
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BACKGROUND: End points for assessing drug activity in brain tumors are determined by measuring the change in tumor size by magnetic resonance imaging (MRI) relative to a pretreatment or best-response scan. Traditionally, two-dimensional (2D) tumor measurements have been used, but one-dimensional (1D) measurements have recently been proposed as an alternative. Because software to estimate three-dimensional (3D) tumor volume from digitized MRI images is available, we compared all three methods of tumor measurement for childhood brain tumors and clinical outcome. METHODS: Tumor size from 130 MRI scans from 32 patients (32 baseline and 98 follow-up scans, for a total of 130 scans; median, three scans per patient; range, two to 18 scans) was measured by each method. Tumor-response category (partial response, minor response, stable disease, or progressive disease) was determined from the percentage change in tumor size between the baseline or best-response scan and follow-up scans. Time to clinical progression was independently determined by chart review. All statistical tests were two-sided. RESULTS: Concordances between 1D and 2D, 1D and 3D, and 2D and 3D were 83% (95% confidence interval [CI] = 67% to 99%), 61% (95% CI = 47% to 75%), and 66% (95% CI = 52% to 80%), respectively, on follow-up scans. Concordances for 1D and 3D and for 2D and 3D were statistically significantly lower than the concordance for 1D and 2D (P< .001 and P = .003, respectively). Concordance among 1D, 2D, and 3D methods in detecting partial response was high; there was less concordance in classifying tumors in the minor response and progressive-disease categories. Median times to progression measured by the 1D, 2D, and 3D methods were 154, 105, and 112 days, respectively, compared with 114 days based on neurologic symptoms and signs (P = .09 for overall comparison). CONCLUSIONS: Detection of partial responses was not influenced by the measurement method, but estimating time to disease progression may be method dependent for childhood brain tumors. (+info)
Human performance cognitive-behavioral modeling: a benefit for occupational safety.
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Human Performance Modeling (HPM) is a computer-aided job analysis software methodology used to generate predictions of complex human-automation integration and system flow patterns with the goal of improving operator and system safety. The use of HPM tools has recently been increasing due to reductions in computational cost, augmentations in the tools' fidelity, and usefulness in the generated output. An examination of an Air Man-machine Integration Design and Analysis System (Air MIDAS) model evaluating complex human-automation integration currently underway at NASA Ames Research Center will highlight the importance to occupational safety of considering both cognitive and physical aspects of performance when researching human error. (+info)
A systematic procedure for modeling usability based on product design variables: a case study in audiovisual consumer electronic products.
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A systematic modeling approach to describing, prescribing, and predicting usability of a product has been presented. Given the evaluation results of the usability dimension (UD) and the measurement of the product's design variables, referred to as the human interface elements (HIEs), the approach enables one to systematically assess the relationship between the UD and HIEs. The assessed relationship is called a usability model. Once built, such a usability model can relate, in a quantitative manner, the HIEs directly to the UDs, and thus can serve as an effective aid to designers by evaluating and predicting the usability of an existing or hypothetical product. A usability model for elegance of audiovisual consumer electronic products has been demonstrated. (+info)