检索结果-内蒙古大学图书馆

International Conference on Microelectronics for neural Networks

作者： G. Indiveri J. Kramer C. Koch Computation and Neural Systems Program California California Institute of Technology Pasadena CA USA

We present three different architectures that make use of analog VLSI velocity sensors for detecting the focus of expansion, time to contact and motion discontinuities respectively. For each of the architectures proposed we describe the functionality of their component modules and their principles of operation. Data measurements obtained from the VLSI chips developed demonstrate their correct performance and their limits of operation.

关键词： Very large scale integration Sensor systems Optical sensors Image motion analysis Sensor arrays Motion detection Focusing Vehicles Computer architecture Image sensors

来源：评论

学校读者我要写书评

暂无评论

A silicon model of the auditory neural perception of frequency modulated tones

A silicon model of the auditory neural perception of frequen...

引用

IEEE International Symposium on Circuits and systems (ISCAS)

作者： B.J. Arthur Computation and Neural Systems Program California Institute of Technology Pasadena CA USA

Frequency modulations in acoustic communication signals are thought to encode meaning in many animal species. Recent physiological experiments have elucidated possible neural mechanisms underlying their perception. The system described here attempts to model such mechanisms using subthreshold analog circuitry. It is built with a silicon cochlea and a unidirectional velocity-tuned delay line. Taps from the cochlea couple into the delay line. If the input frequency is modulated in the appropriate direction and right speed, the inputs to the delay line will coincide in time and summate. A similar design was recently used to detect motion in a vision chip.

关键词： Silicon Frequency modulation Delay lines Speech recognition Flexible manufacturing systems Circuits Motion detection Humans Filters Modulation coding

来源：评论

学校读者我要写书评

暂无评论

Analog VLSI circuits for visual motion-based adaptation of post-saccadic drift

Analog VLSI circuits for visual motion-based adaptation of p...

引用

International Conference on Microelectronics for neural Networks

作者： T.K. Horiuchi C. Koch Computation and Neural Systems Program California Institute of Technology Pasadena CA USA

Using the analog VLSI-based saccadic eye movement system previously developed we investigate the use of biologically realistic error signals to calibrate the system in a manner similar to the primate oculomotor system. In this paper we introduce two new circuit components which are used to perform this task, a resettable-integrator model of the burst generator with a floating-gate structure to provide on-chip storage of analog parameters and a directionally-selective motion detector for detecting post-saccadic drift.

关键词： Very large scale integration Circuits Motion detection Muscles Detectors Eyes Humans Sockets Retina Biology computing

来源：评论

学校读者我要写书评

暂无评论

Stimulating brain but not mind

引用

Nature 1996年第6598期383卷 301-303页

作者： C. Koch R. B. H. Tootell Computation and Neural Systems Program California Institute of Technology Pasadena USA Massachusetts General Hospital NMR Center Charlestown USA

来源：评论

学校读者我要写书评

暂无评论

Control of Selective Visual Attention: Modeling the "Where" Pathway 8

Control of Selective Visual Attention: Modeling the "Where" ...

引用

8th International Conference on neural Information Processing systems, NIPS 1995

作者： Niebur, Ernst Koch, Christof Computation and Neural Systems 139-74 California Institute of Technology United States

Intermediate and higher vision processes require selection of a subset of the available sensory information before further processing. Usually, this selection is implemented in the form of a spatially circumscribed region of the visual field, the so-called "focus of attention" which scans the visual scene dependent on the input and on the attentional state of the subject. We here present a model for the control of the focus of attention in primates, based on a saliency map. This mechanism is not only expected to model the functionality of biological vision but also to be essential for the understanding of complex scenes in machine vision. © NIPS 1995: Proceedings of the 8th International Conference on neural Information Processing systems. All rights reserved.

关键词： Mammals

来源：评论

学校读者我要写书评

暂无评论

Adaptive Retina with Center-Surround Receptive Field 8

Adaptive Retina with Center-Surround Receptive Field

引用

8th International Conference on neural Information Processing systems, NIPS 1995

作者： Liu, Shih-Chii Boahen, Kwabena Computation and Neural Systems 139-74 California Institute of Technology PasadenaCA91125 United States

Both vertebrate and invertebrate retinas are highly efficient in extracting contrast independent of the background intensity over five or more decades. This efficiency has been rendered possible by the adaptation of the DC operating point to the background intensity while maintaining high gain transient responses. The centersurround properties of the retina allows the system to extract information at the edges in the image. This silicon retina models the adaptation properties of the receptors and the antagonistic centersurround properties of the laminar cells of the invertebrate retina and the outer-plexiform layer of the vertebrate retina. We also illustrate the spatio-temporal responses of the silicon retina on moving bars. The chip has 59x64 pixels on a 6.9x6.8mm'2 die and it is fabricated in 2 μm n-well technology. © NIPS 1995: Proceedings of the 8th International Conference on neural Information Processing systems. All rights reserved.

关键词： Transient analysis

来源：评论

学校读者我要写书评

暂无评论

An analog VLSI velocity sensor

An analog VLSI velocity sensor

引用

IEEE International Symposium on Circuits and systems (ISCAS)

作者： J. Kramer R. Sarpeshkar C. Koch Computation and Neural Systems 139-74 California Institute of Technology Pasadena CA USA

An integrated circuit that computes the velocity vector of a visual stimulus in one dimension is presented. The circuit combines optical sensors and associated electronics on a single silicon chip, processed with standard CMOS technology. The velocity is inferred from the time delay of the appearance of an image feature at two fixed locations on the chip. The circuit operates quite robustly for high-contrast stimuli over considerable irradiance and velocity ranges. With lower-contrast stimuli the output signal for a given velocity tends to decrease, while the direction selectivity is still maintained. The individual motion-sensing cells are compact, and they are therefore suited for use in dense 1D or 2D imaging arrays.

关键词： Very large scale integration CMOS technology Optical sensors Silicon CMOS image sensors CMOS process Integrated circuit technology Delay effects Robustness Optical imaging

来源：评论

学校读者我要写书评

暂无评论

TOWARD COLOR IMAGE SEGMENTATION IN ANALOG VLSI - ALGORITHM AND HARDWARE

引用

INTERNATIONAL JOURNAL OF COMPUTER VISION 1994年第1期12卷 17-42页

作者： PEREZ, F KOCH, C 1. Computation and Neural Systems Program 216-76 California Institute of Technology 91125 Pasadena CA

Standard techniques for segmenting color images are based on finding normalized RGB discontinuities, color histogramming, or clustering techniques in RGB or CIE color spaces. The use of the psychophysical variable hue in HSI space has not been popular due to its numerical instability at low saturations. In this article, we propose the use of a simplified hue description suitable for implementation in analog VLSI. We demonstrate that if the integrated white condition holds, hue is invariant to certain types of highlights, shading, and shadows. This is due to the additive/shift invariance property, a property that other color variables lack. The more restrictive uniformly varying lighting model associated with the multiplicative/scale invariance property shared by both hue and normalized RGB allows invariance to transparencies, and to simple models of shading and shadows. Using binary hue discontinuities in conjunction with first-order type of surface interpolation, we demonstrate these invariant properties and compare them against the performance of RGB, normalized RGB, and CIE color spaces. We argue that working in HSI space offers an effective method for segmenting scenes in the presence of confounding cues due to shading, transparency, highlights, and shadows. Based on this work, we designed and fabricated for the first time an analog CMOS VLSI circuit with on-board phototransistor input that computes normalized color and hue.

关键词： Color image processing

来源：评论

学校读者我要写书评

暂无评论

Distinct rhythmic locomotor patterns can be generated by a simple adaptive neural circuit: Biology, simulation, and VLSI implementation

引用

Journal of computational Neuroscience 1994年第4期1卷 339-358页

作者： Ryckebusch, Sylvie Wehr, Mike Laurent, Gilles California Institute ofTechnology Biology Division Computation and Neural Systems Program Pasadena 91125 CA Mail Code 139-74 United States

Rhythmic motor patterns can be induced in leg motor neurons of isolated locust thoracic ganglia by bath application of pilocarpine. We observed that the relative phases of levators and depressors differed in the three thoracic ganglia. Assuming that the central pattern generating circuits underlying these three segmental rhythms are probably very similar, we developed a simple model circuit that can produce any one of the three activity patterns and characteristic phase relationships by modifying a single synaptic weight. We show results of a computer simulation of this circuit using the neuronal simulator neuralOG/Spike. We built and tested an analog VLSI circuit implementation of this model circuit that exhibits the same range of "behaviors" as the computer simulation. This multidisciplinary strategy will be useful to explore the dynamics of central pattern generating networks coupled to physical actuators, and ultimately should allow the design of biologically realistic walking robots. © 1994 Kluwer Academic Publishers.

关键词：

来源：评论

学校读者我要写书评

暂无评论

BAYESIAN MODELING AND CLASSIFICATION OF neural SIGNALS

引用

neural computation 1994年第5期6卷 1005-1030页

作者： LEWICKI, MS Computation Neural Systems Program California Institute of Technology 216-76 Pasadena CA 91125 USA

Identifying and classifying action potential shapes in extracellular neural waveforms have long been the subject of research, and although several algorithms for this purpose have been successfully applied, their use has been limited by some outstanding problems. The first is how to determine shapes of the action potentials in the waveform and, second, how to decide how many shapes are distinct. A harder problem is that action potentials frequently overlap making difficult both the determination of the shapes and the classification of the spikes. In this report, a solution to each of these problems is obtained by applying Bayesian probability theory. By defining a probabilistic model of the waveform, the probability of both the form and number of spike shapes can be quantified. In addition, this framework is used to obtain an efficient algorithm for the decomposition of arbitrarily complex overlap sequences. This algorithm can extract many times more information than previous methods and facilitates the extracellular investigation of neuronal classes and of interactions within neuronal circuits.

关键词：

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：