Hon Wai Leong

Simulated annealing for VLSI design

1. Introduction.- 1.1. Combinatorial Optimization.- 1.2. The Method of Simulated Annealing.- 1.3. Remarks.- 2. Placement.- 2.1. Introduction.- 2.2. Gate-Array Placement.- 2.2.1. The K-G-V Algorithm.- 2.2.2. TimberWolf.- 2.3. Standard-Cell Placement.- 2.3.1. TimberWolf.- 2.3.2. Another Approach.- 2.4. Macro/Custom-Cell Placement.- 2.4.1. Jespen and Gelatts Algorithm.- 2.4.2. TimberWolf.- 2.5. Other Stochastic Algorithms.- 2.5.1. Genetic Placement.- 2.5.2. Simulated Evolution Placement.- 2.6. Concluding Remarks.- 3. Floorplan Design.- 3.1. Introduction.- 3.2. Part 1: Rectangular Modules.- 3.2.1. Slicing Floorplans.- 3.2.2. Solution Space.- 3.2.3. Neighboring Solutions.- 3.2.4. Cost Function.- 3.2.5. Annealing Schedule.- 3.2.6. Experimental Results.- 3.3. Part 2: Rectangular and L-Shaped Modules.- 3.3.1. Geometric Figures.- 3.3.2. The Operators.- 3.3.3. Floorplan Representation.- 3.3.4. The Algorithm.- 3.3.5. Experimental Results.- 3.4. Concluding Remarks.- 4. Channel Routing.- 4.1. Introduction.- 4.2. The Channel Routing Problem.- 4.3. The Channel Router SACR.- 4.3.1. Solution Space.- 4.3.2. Neighboring Solutions.- 4.3.3. Cost Function.- 4.3.4. Annealing Schedule.- 4.3.5. Fast Approximation Scheme.- 4.4. The Channel Router SACR2.- 4.5. Experimental Results and Discussion.- 4.6. Concluding Remarks.- 5. Permutation Channel Routing.- 5.1. Introduction.- 5.2. Motivation and Applications.- 5.3. NP-Completeness Results.- 5.4. First Method - Simulated Annealing.- 5.4.1. Neighboring Solutions.- 5.4.2. Cost Function.- 5.4.3. Annealing Schedule.- 5.5. Second Method - Iterative Improvement.- 5.5.1. The Iterative Improvement Scheme.- 5.5.2. Version-D.- 5.5.3. Version-C.- 5.5.4. Choice of Initial Solution.- 5.6. Experimental Results.- 5.7. Concluding Remarks.- 6. PLA Folding.- 6.1. Introduction.- 6.2. The PLA Folding Problem.- 6.3. The PLA Folding Algorithm.- 6.3.1. Solution Space.- 6.3.2. Neighboring Solutions.- 6.3.3. Cost Function.- 6.3.4. Annealing Schedule.- 6.4. Multiple-Folded PLA Realization.- 6.5. Constrained Multiple Folding.- 6.6. Simple Folding.- 6.7. Experimental Results and Discussions.- 6.8. Concluding Remarks.- 7. Gate Matrix Layout.- 7.1. Introduction.- 7.2. Problem Formulation.- 7.3. Generalized Problem Formulation.- 7.4. Advantages of the Generalized Formulation.- 7.5. The Simulated Annealing Method.- 7.5.1. Solution Space.- 7.5.2. Neighboring Solutions.- 7.5.3. Cost Function.- 7.5.4. Annealing Schedule.- 7.6. Experimental Results.- 7.7. Concluding Remarks.- 8. Array Optimization.- 8.1. Introduction.- 8.2. The Array Optimization Problem.- 8.3. Definitions.- 8.4. The Array Optimization Algorithm.- 8.4.1. The Algorithm Column-Fold.- 8.4.2. The Algorithm Row-Fold.- 8.4.3. The Solution Space.- 8.4.4. The Main Folding Algorithm.- 8.5. Experimental Results.- 8.6. Concluding Remarks.- References.

Trajectory-based ball detection and tracking with applications to semantic analysis of broadcast soccer video

This paper first presents an improved trajectory-based algorithm for automatically detecting and tracking the ball in broadcast soccer video. Unlike the object-based algorithms, our algorithm does not evaluate whether a sole object is a ball. Instead, it evaluates whether a candidate trajectory, which is generated from the candidate feature image by a candidate verification procedure based on Kalman filter,, which is generated from the candidate feature image by a candidate verification procedure based on Kalman filter, is a ball trajectory. Secondly, a new approach for automatically analyzing broadcast soccer video is proposed, which is based on the ball trajectory. The algorithms in this approach not only improve play-break analysis and high-level semantic event detection, but also detect the basic actions and analyze team ball possession, which may not be analyzed based only on the low-level feature. Moreover, experimental results show that our ball detection and tracking algorithm can achieve above 96% accuracy for the video segments with the soccer field. Compared with the existing methods, a higher accuracy is achieved on goal detection and play-break segmentation. To the best of our knowledge, we present the first solution in detecting the basic actions such as touching and passing, and analyzing the team ball possession in broadcast soccer video.

On the reconfiguration of degradable VLSI/WSI arrays

This paper consider the problem of reconfiguring two dimensional very large scale integration (VLSI/WSI) arrays via the degradation approach. In this approach, all elements are treated uniformly and no elements are dedicated as spares. The goal is to derive a fault-free subarray T from the defective host array such that the dimensions of T are larger than some specified minimum. This problem has been shown to be NP-complete under various switching and routing constraints. However, we show that a special case of the reconfiguration problem with row bypass and column rerouting capabilities is optimally solvable in linear time. Using this result, a new fast and efficient reconfiguration algorithm is proposed. Empirical study shows that the new algorithm indeed produces good results in terms of the percentages of harvest and degradation of VLSI/WSI arrays.

A ball tracking framework for broadcast soccer video

It is challenging to detect and track the ball from the broadcast soccer video. The feature-based tracking method to judge if a sole object is a target are inadequate because the features of the balls change fast over frames and we cannot differ the ball from other objects by them. This paper proposes a new framework to find the ball position by creating and analyzing the trajectory. The ball trajectory is obtained from the candidate collection by use of the heuristic false candidate reduction, the Kalman filter-based trajectory mining, and the trajectory evaluation. The ball trajectory is extended via a localized Kalman filter-based model matching procedure. The experimental results on two consecutive 1000-frame sequences illustrate that the proposed framework is very effective and can obtain a very high accuracy that is much better than existing methods.

Automatic camera calibration of broadcast tennis video with applications to 3D virtual content insertion and ball detection and tracking

This paper presents an original algorithm to automatically acquire accurate camera calibration from broadcast tennis video (BTV) as well as demonstrates two of its many applications. Accurate camera calibration from BTV is challenging because the frame-data of BTV is often heavily distorted and full of errors, resulting in wildly fluctuating camera parameters. To meet this challenge, we propose a frame grouping technique, which is based on the observation that many frames in BTV possess the same camera viewpoint. Leveraging on this fact, our algorithm groups frames according to the camera viewpoints. We then perform a group-wise data analysis to obtain a more stable estimate of the camera parameters. Recognizing the fact that some of these parameters do vary somewhat even if they have similar camera viewpoint, we further employ a Hough-like search to tune such parameters, minimizing the reprojection disparity. This two-tiered process gains stability in the estimates of the camera parameters, and yet ensures good match between the model and the reprojected camera view via the tuning step. To demonstrate the utility of such stable calibration, we apply the camera matrix acquired to two applications: (a) 3D virtual content insertion; and (b) tennis-ball detection and tracking. The experimental results show that our algorithm is able to acquire accurate camera matrix and the two applications have very good performances.

A new class of efficient algorithms for reconfiguration of memory arrays

In this paper, we present a new class of linear time heuristic algorithms for reconfiguring RRAMs. One novel feature of our algorithms is that we are able to derive new bounds on the fault counts for fast detection of reparable and irreparable RRAMs. Another novel feature is that, based on our algorithms, we are able to identify a new polynomial time solvable instance of the reconfiguration problem. Empirical results indicate that our new class of algorithms is indeed fast and effective.

A gridding Hough transform for detecting the straight lines in sports video

A gridding Hough transform (GHT) is proposed to detect the straight lines in sports video, which is much faster and requires much less memory than the previous Hough transforms. The GHT uses the active gridding to replace the random point selection in the random Hough transforms because forming the linelets from the actively selected points is easier than from the randomly selected points. Existing straight-line Hough transforms require a lot of resources because they were designed for all kinds of straight lines. Considering the fact that the straight lines interested in sports video are long and sparse, this paper proposes two techniques: the active gridding and linelets process. On account of these two techniques, the proposed GHT is fast and uses little memory. The experimental results show that the proposed GHT is faster than the random Hough transform (RHT) and the standard Hough transform (SHT) by 30% and 700% respectively and achieves a 97.5% recall, higher than those achieved by either the SHT or the RHT.

3D reconstruction and enrichment of broadcast soccer video

Recently, it has become a new trend to reconstruct sports video for various purposes. This paper presents a 3D reconstruction and enrichment system that not only reconstructs broadcast soccer video but also enriches reconstructed video with music and illustrations of the video contents. The system can reconstruct not only the goalmouth scene but also the midfield scene, which cannot be reconstructed by the existing systems. To quickly find the feature points for calibrating the camera, we propose a fast algorithm to detect the lines in the goalmouth scene and use the algorithm proposed in our previous papers to detect the partial ellipses in the midfield scene. The reconstruction is conducted on several video sequences of two scenes. The reconstructed videos eliminate the ball deformation and unnecessary camera changes through smoothing the camera parameters. This system also serves as an experimental system for our project that reconstructs the on-going soccer game in real time.

Permutation Channel Routing

Most of the channel routing algorithms in the literature [Deut76, YoKu82, RiFi82, BuPe83, ReSS85] including the simulated annealing channel routers studied in Chapter 4 assume a model in which the pins on the two sides of the channel are fixed (both physically and logically.) Other models that reflect less stringent physical constraints have also been studied. In [GoCW83], it was assumed that only the relative ordering of the pins is fixed. The pins are allowed to “shift” horizontally. This model captures the possibility of expanding or contracting the dimensions of a cell. In [LeLi83] and [Leon86a], the discretionary channel routing problem in which only some of the pins in a given net need to be interconnected was studied. This model captures the possibility of having physically equivalent pins or duplicated pins in a cell. As expected, such flexibilities lead to better routing results, namely, fewer tracks are required for interconnection.

Accurate cylindricity evaluation with axis-estimation preprocessing

Evaluating cylindricity is a very important application in metrology. In this paper, we focus on cylindricity evaluation based on radial form measurements. The standard characterization of cylindricity is the notion of zone cylinder, i.e. the cylindrical crown contained between two coaxial cylinders with minimum radial separation and containing all the data points. Unfortunately, the construction of the zone cylinder is a very complex geometric problem, which can be formulated as a nonlinear optimization. Recently a new method (referred to here as the hyperboloid method) has been discussed, which avoids the direct construction of the zone cylinder of a point set, but approximates it with guaranteed accuracy through a computationally very efficient iterative process based on a linearization of the underlying problem. The iterations can be viewed as the construction of a sequence of “zone hyperboloids” tending to the desired “zone cylinder.” An important requirement of the method, however, is that the initial position of the cylindrical specimen axis be nearly vertical, since significant deviations from this condition essentially invalidate the process. It is the purpose of this paper to remove this shortcoming of the hyperboloid technique by providing a simple procedure for appropriately initializing the data (axis estimation). Axis estimation and the hyperboloid technique constitute an integrated methodology for cylindricity evaluation, which is currently the most effective. The theoretical foundations of the method are reviewed from a viewpoint that highlights its essential features and intuitively explains its effectiveness. The analytical discussion is complemented by experimental data concerning a few significant samples.