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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Scanning behaviour and pattern recognition

Lishman, John Rowland January 1976 (has links)
Two basic models of human pattern recognition have been advanced: feature analysis and hypothesis testing. These can only be discriminated by looking at behaviour before recognition. This is studied here by having the subject scan with a pen that writes only where the (invisible) picture is black. Although a computer simulation shows that it is possible and efficient, subjects scanning capital letters and simple shapes with this technique rarely use hypothesis testing.
52

Computer recognition of occluded curved line drawings

Adler, Mark Ronald January 1978 (has links)
A computer program has been designed to interpret scenes from PEANUTS cartoons, viewing each scene as a two-dimensional representation of an event in the three-dimensional world. Characters are identified by name, their orientation and body position is described, and their relationship to other objects in the scene is indicated. This research is seen as an investigation of the problems in recognising flexible non-geometric objects which are subject to self-occlusion as well as occlusion by other objects. A hierarchy of models containing both shape and relational information has been developed to deal with the flexible cartoon bodies. Although the region is the basic unit used in the analysis, the hierarchy makes use of intermediate models to group individual regions into larger more meaningful functional units. These structures may be shared at a higher level in the hierarchy. Knowledge of model similarities may be applied to select alternative models and conserve some results of an incorrect model application. The various groupings account for differences among the characters or modifications in appearance due to changes in attitude. Context information plays a key role in the selection of models to deal with ambiguous shapes. By emphasising relationships between regions, the need for a precise description of shape is reduced. Occlusion interferes with the model-based analysis by obscuring the essential features required by the models. Both the perceived shape of the regions and the inter-relationships between them are altered. An heuristic based on the analysis of line junctions is used to confirm occlusion as the cause of the failure of a model-to-region match. This heuristic, an extension of the T-joint techniques of polyhedral domains, deals with "curved" junctions and can be applied to cases of multi-layered occlusion. The heuristic was found to be most effective in dealing with occlusion between separate objects; standard instances of self-occlusion were more effectively handled at the model level. This thesis describes the development of the program, structuring the discussion around three main problem areas: models, occlusion, and the control aspects of the system. Relevant portions of the programs analyses are used to illustrate each problem area.
53

Pattern recognition in the case of strong background noise

Wang, Xingmei January 2001 (has links)
Dissertation submitted in compliance with the requirements for Maters Degree in Technology: Mechanical Engineering, Technikon Natal, 2001. / This study presents a development of a method for recognition of a class of patterns in signals contaminated by strong noise. The class of signals considered is described by a finite alphabet. The target class of patterns is assumed to have specific statistical properties that can be conveniently captured by the position weight matrices (PWM) description. Itis also assumed thatthe 'signals: contain numerous patterns si~ilar to the patterns of the target class, but which belong to different classes. These other patterns represent the noise in the signals. The method for-improved recogrrition of the target class of patterns is based on clustering of the target motifs with regard to distance form the reference point (event) in the signal. This positional clustering enables more precise description of the target class of patterns by means of the PWMs. However, it requires the use of as many PWMs as there are clusters of the target class. The method developed is of general nature, applicable to the situations described. It is however, applied to the recognition of the specific short motifs in DNA sequences. The short motif considered is the TATA-box,one of the most important docking sites for proteins in Eukaryotic polymerase II promoter regions. The reference point in the singals obtained form DNA sequences the transcription .start site (TSS). Thus the positional dustering of the TATA-box motif resulted in 20 different PWMs, instead of only one that describes the whole TATA motif class. This however, resulted in more discriminative PWMs and the recognition accuracy has increased by about a factor of two when compared to the recognition of the TATA moti f based on the original PWM. / M
54

Computer recognition of partially-occluded objects.

January 1986 (has links)
by Chan Ming-hong. / Bibliography: leaves 67-68 / Thesis (M.Ph.)--Chinese University of Hong Kong, 1986
55

A syntactic method of weather pattern recognition.

January 1977 (has links)
Thesis (M.Phil.)--Chinese University of Hong Kong. / Bibliography: leaves 122-126.
56

Perception-based image similarity metrics. / 基於知覺的圖像相似性度量準則 / CUHK electronic theses & dissertations collection / Ji yu zhi jue de tu xiang xiang si xing du liang zhun ze

January 2012 (has links)
圖像相似性度量準則是一個傳統的研究領域。大量經典的圖像處理技術被用來為各種類型的圖像設計相似性度量準則,這些圖像包括了線條圖,灰度圖,彩圖以及高動態範圍圖像。儘管已有的度量準則在指定的條件下可以實現優良的圖像相似度比較,這些度量準則極少系統地考慮或檢驗自身與人類視覺感知之間的一致性。而與人類知覺的一致性是由大量實際應用提出的共同需求。隨著三維立體設備的廣泛應用,圖像的相似性已經不只是傳統的可視差別,更包括了人眼利用三維立體設備同時觀看兩張不同的圖片時的視覺可接受度。 / 非嚴謹對準形狀相似性度量準則(AISS)可以比較兩幅具有固定尺寸的線條圖的形狀相似度。對於該度量準則,兩幅待比較圖像的形狀不要求完全對齊,同時,又會考慮到圖像的形變,例如位置,方向和縮放上的變化。 / 雙目觀看舒適度預測器(BVCP)是另一個度量準則。當人的雙眼同時觀看兩幅不同的圖像時,該準則可用以預測視覺的舒適度。根據著名的双眼單视理論,人的視覺可以將兩幅具有細節、對比度以及亮度差別的圖像合成一幅圖像,只要這些差別在限定的程度之內。在計算機圖形學領域,BVCP 首次嘗試去預測雙目的圖像差別會否引起觀看的不舒適。 / 在本論文中,實用的應用程序也被提出用以衡量AISS 和BVCP。AISS 被用在了一個名為“基於結構的ASCII 藝術的應用程序中,該應用程序可以利用ASCII 字符的形狀近似地表現參考圖像的線條結構信息。而BVCP 則被用在一個創新地應用框架中,該框架可以從單幅高動態範圍圖像中生成一組(兩幅)低動態範圍圖像。當這一組低動態範圍圖像組被人的雙眼同時觀看時,可以比傳統的單幅低動態範圍圖像保留更多的人類可感知視覺信息。可信的結果和使用者研究也用來證明SSIM 和BVCP 的有效性以及與人類知覺的一致性。 / Image similarity metric is a traditional research field. Classical image processing techniques are used to design similarity metrics for all kinds of images, such as line drawings, gray or color image and even high-dynamic range (HDR) images. While existing metrics perform well for the tasks of comparing images in specified situations, few of them have systematically considered or examined the consistency with human perception required by practical applications. With the blooming of stereo devices, the similarity to be measured is not only the traditional visual difference between two images, but also the visual acceptance of two images when they are viewed simultaneously with 3D devices. This thesis presents two image similarity metrics motivated by perceptual principles, also with applications to demonstrate their novelty and practical values. / Alignment-Insensitive Shape Similarity Metric (AISS) measures shape similarity of line drawings. This metric can tolerate misalignment between two shapes and, simultaneously, accounts for the differences in transformation such as, position, orientation and scaling. / Binocular Viewing Comfort Predictor (BVCP) is another metric proposed to measure visual discomfort when human's two eyes view two different images simultaneously. According to a human vision phenomenon - binocular single vision, human vision is able tofuse two images with differences in detail, contrast and luminance, up to a certain limit. BVCP makes a first attempt in computer graphics to predict such visual comfort limit. / Applications are also proposed to evaluate AISS and BVCP. AISS is utilized in an application of Structure-based ASCII Art, which approximates line structure of the reference image content with the shapes of ASCII characters. BVCP is utilized in a novel framework - Binocular Tone Mapping which generates a binocular low-dynamic range (LDR) image pair from one HDR image. Such binocular LDR pair can be viewed with stereo devices and can preserve more human-perceivable visual content than traditional one single LDR image. Convincing results and user studies are also shown to demonstrate that both AISS and BVCP are consistent with human perception and effective in practical usage. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Zhang, Linling. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 122-132). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / Acknowledgement --- p.v / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Alignment-Insensitive Shape Similarity Metric --- p.8 / Chapter 2.1 --- Related Work --- p.10 / Chapter 2.2 --- Design of AISS --- p.13 / Chapter 2.2.1 --- Misalignment Tolerance --- p.14 / Chapter 2.2.2 --- Transformation Awareness --- p.16 / Chapter 2.2.3 --- Parameter Setting --- p.17 / Chapter 2.3 --- Results and Discussion --- p.18 / Chapter 2.4 --- Discussion --- p.20 / Chapter 3 --- Application for AISS: Structure-based ASCII Art --- p.21 / Chapter 3.1 --- Overview --- p.24 / Chapter 3.2 --- Optimization --- p.28 / Chapter 3.3 --- User Study and Discussion --- p.35 / Chapter 3.3.1 --- Metrics Comparison --- p.35 / Chapter 3.3.2 --- Comparison to Existing Work --- p.38 / Chapter 3.3.3 --- User Study --- p.40 / Chapter 3.4 --- Summary --- p.44 / Chapter 4 --- Binocular Viewing Comfort Predictor --- p.48 / Chapter 4.1 --- Background --- p.51 / Chapter 4.2 --- Design of BVCP --- p.54 / Chapter 4.2.1 --- Fusional Area --- p.55 / Chapter 4.2.2 --- Contour Fusion --- p.58 / Chapter 4.2.3 --- Contour and Regional Contrasts --- p.68 / Chapter 4.2.4 --- Failure of Rivalry --- p.70 / Chapter 4.2.5 --- The Overall Fusion Predictor --- p.74 / Chapter 4.3 --- User Study --- p.77 / Chapter 4.4 --- Discussion and Limitations --- p.84 / Chapter 5 --- Application for BVCP: Binocular Tone Mapping --- p.86 / Chapter 5.1 --- Framework --- p.90 / Chapter 5.1.1 --- Overview --- p.90 / Chapter 5.1.2 --- Optimization --- p.93 / Chapter 5.2 --- Results and Discussion --- p.96 / Chapter 5.2.1 --- Results --- p.96 / Chapter 5.2.2 --- User Study --- p.103 / Chapter 5.2.3 --- Incorporating Stereopsis --- p.106 / Chapter 5.2.4 --- Limitations --- p.109 / Chapter 5.3 --- Summary --- p.112 / Chapter 6 --- Conclusion --- p.113 / Chapter A --- User Study for ASCII art --- p.117 / Bibliography --- p.122
57

Applications of neural networks in the binary classification problem.

January 1997 (has links)
by Chan Pak Kei, Bernard. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 125-127). / Chapter 1 --- Introduction --- p.10 / Chapter 1.1 --- Overview --- p.10 / Chapter 1.2 --- Classification Approaches --- p.11 / Chapter 1.3 --- The Use of Neural Network --- p.12 / Chapter 1.4 --- Motivations --- p.14 / Chapter 1.5 --- Organization of Thesis --- p.16 / Chapter 2 --- Related Work --- p.19 / Chapter 2.1 --- Overview --- p.19 / Chapter 2.2 --- Neural Network --- p.20 / Chapter 2.2.1 --- Backpropagation Feedforward Neural Network --- p.20 / Chapter 2.2.2 --- Training of a Backpropagation Feedforward Neural Network --- p.22 / Chapter 2.2.3 --- Single Hidden-layer Model --- p.27 / Chapter 2.2.4 --- Data Preprocessing --- p.27 / Chapter 2.3 --- Fuzzy Sets --- p.29 / Chapter 2.3.1 --- Fuzzy Linear Regression Analysis --- p.29 / Chapter 2.4 --- Network Architecture Altering Algorithms --- p.31 / Chapter 2.4.1 --- Pruning Algorithms --- p.32 / Chapter 2.4.2 --- Constructive/Growing Algorithms --- p.35 / Chapter 2.5 --- Summary --- p.38 / Chapter 3 --- Hybrid Classification Systems --- p.39 / Chapter 3.1 --- Overview --- p.39 / Chapter 3.2 --- Literature Review --- p.41 / Chapter 3.2.1 --- Fuzzy Linear Regression(FLR) with Fuzzy Interval Analysis --- p.41 / Chapter 3.3 --- Data Sample and Methodology --- p.44 / Chapter 3.4 --- Hybrid Model --- p.46 / Chapter 3.4.1 --- Construction of Model --- p.46 / Chapter 3.5 --- Experimental Results --- p.50 / Chapter 3.5.1 --- Experimental Results on Breast Cancer Database --- p.50 / Chapter 3.5.2 --- Experimental Results on Synthetic Data --- p.53 / Chapter 3.6 --- Conclusion --- p.55 / Chapter 4 --- Searching for Suitable Network Size Automatically --- p.59 / Chapter 4.1 --- Overview --- p.59 / Chapter 4.2 --- Literature Review --- p.61 / Chapter 4.2.1 --- Pruning Algorithm --- p.61 / Chapter 4.2.2 --- Constructive Algorithms (Growing) --- p.66 / Chapter 4.2.3 --- Integration of methods --- p.67 / Chapter 4.3 --- Methodology and Approaches --- p.68 / Chapter 4.3.1 --- Growing --- p.68 / Chapter 4.3.2 --- Combinations of Growing and Pruning --- p.69 / Chapter 4.4 --- Experimental Results --- p.75 / Chapter 4.4.1 --- Breast-Cancer Cytology Database --- p.76 / Chapter 4.4.2 --- Tic-Tac-Toe Database --- p.82 / Chapter 4.5 --- Conclusion --- p.89 / Chapter 5 --- Conclusion --- p.91 / Chapter 5.1 --- Recall of Thesis Objectives --- p.91 / Chapter 5.2 --- Summary of Achievements --- p.92 / Chapter 5.2.1 --- Data Preprocessing --- p.92 / Chapter 5.2.2 --- Network Size --- p.93 / Chapter 5.3 --- Future Works --- p.94 / Chapter A --- Experimental Results of Ch3 --- p.95 / Chapter B --- Experimental Results of Ch4 --- p.112 / Bibliography --- p.125
58

Kernel based learning methods for pattern and feature analysis

Wu, Zhili 01 January 2004 (has links)
No description available.
59

New Statistical Methods to Get the Fractal Dimension of Bright Galaxies Distribution from the Sloan Digital Sky Survey Data

Wu, Yongfeng January 2007 (has links) (PDF)
No description available.
60

Learnable similarity functions and their application to record linkage and clustering

Bilenko, Mikhail Yuryevich, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

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