Evidences that demand a verdict: place-making battles in Asia’s world city

Parallel Session 1: 1.2 UrbanizationThis paper examines the history and politics of reclamation, a mechanism that has produced 25 percent of urban land from the sea, in Hong Kong. Through detailed review of historical records and documents, the eroic conquest of the sea by reclamation in Hong Kong in the past 168 years can be divided in four broad phases: a tug-of-war between the pro-reclamation colonial Government and the anti-reclamation British military force and the private sector in the first forty years in the City of Victoria; a prolonged period from the 1880s to the Second World War with Government-planned but private sector-driven reclamations spread to Kowloon, annexed in 1860; the post-war decades up to the 1990s when public-sector led reclamation had been instrumental in accommodating and fueling industrialization and urban growth spatially and financially; and finally in the last decade when the civil society groups have been proactive in arresting further Harbour reclamation and demanding a right to design an accessible, vibrant and sustainable Harbourfront. This historical review offers us a window to decipher the politics of place-making in an evolving open market economy facilitated by an executive-led government increasingly challenged by a developing post-colonial civil society.postprintThe 10th Asian Urbanization Conference, Hong Kong, 16-19 August 2009

Comments on 'Least squares restoration of multichannel images'

In this correspondence, we give the correct matrix formulation arising from the constrained optimization of the least squares restoration of multichannel images in the above paper.published_or_final_versio

Mathematical analysis of super-resolution methodology

The attainment of super resolution (SR) from a sequence of degraded undersampled images could be viewed as reconstruction of the high-resolution (HR) image from a finite set of its projections on a sampling lattice. This can then be formulated as an optimization problem whose solution is obtained by minimizing a cost function. The approaches adopted and their analysis to solve the formulated optimization problem are crucial, The image acquisition scheme is important in the modeling of the degradation process. The need for model accuracy is undeniable in the attainment of SR along with the design of the algorithm whose robust implementation will produce the desired quality in the presence of model parameter uncertainty. To keep the presentation focused and of reasonable size, data acquisition with multisensors instead of, say a video camera is considered.published_or_final_versio

Practice report: Sustainability impact assessment in Hong Kong and the Pearl River Delta: "Both necessary and impossible"?

Rapid economic integration of Hong Kong and the Pearl River Delta under the policy of "One Country Two Systems" and the consequent social and environmental degradation mean that assessment of sustainability impacts of development projects is essential. However, some fundamental problems are identified for the two systems to carry out SIA before embarking on development projects: minimal integration in terms of institutional set-up, strategies and policies concerning sustainable development; pre-set sustainability indicators rather than tailor-made ones to assess policies, programmes and projects of various nature; and rather different social, economic and environmental norms and development problems. In the short run, given these constraints, SIA in the region though "necessary" is rather "impossible". Nevertheless, recommendations are put forward to facilitate regional cooperation of SIA practices in the longer term. © IAIA 2007.published_or_final_versio

Extending the depth of field in a compound-eye imaging system with super-resolution reconstruction

Optical device miniaturization is highly desirable in many applications. Direct down-scaling of traditional imaging system is one approach, but the extent to which it can be minimized is limited by the effect of diffraction. Compound-eye imaging system, which utilizes multiple microlenses in image capture is a promising alternative. In this paper, we explore the possibility of an incorporation of phase masks in such a system to extend the depth of field. Simulation experiments are conducted to verify the feasibility of the system. © 2006 IEEE.published_or_final_versio

Iterative algorithms based on decoupling of deblurring and denoising for image restoration

In this paper, we propose iterative algorithms for solving image restoration problems. The iterative algorithms are based on decoupling of deblurring and denoising steps in the restoration process. In the deblurring step, an efficient deblurring method using fast transforms can be employed. In the denoising step, effective methods such as the wavelet shrinkage denoising method or the total variation denoising method can be used. The main advantage of this proposal is that the resulting algorithms can be very efficient and can produce better restored images in visual quality and signalto-noise ratio than those by the restoration methods using the combination of a data-fitting term and a regularization term. The convergence of the proposed algorithms is shown in the paper. Numerical examples are also given to demonstrate the effectiveness of these algorithms. © 2008 Society for Industrial and Applied Mathematics.published_or_final_versio

On discovery of extremely low-dimensional clusters using semi-supervised projected clustering

Recent studies suggest that projected clusters with extremely low dimensionality exist in many real datasets. A number of projected clustering algorithms have been proposed in the past several years, but few can identify clusters with dimensionality lower than 10% of the total number of dimensions, which are commonly found in some real datasets such as gene expression profiles. In this paper we propose a new algorithm that can accurately identify projected clusters with relevant dimensions as few as 5% of the total number of dimensions. It makes use of a robust objective function that combines object clustering and dimension selection into a single optimization problem. The algorithm can also utilize domain knowledge in the form of labeled objects and labeled dimensions to improve its clustering accuracy. We believe this is the first semi-supervised projected clustering algorithm. Both theoretical analysis and experimental results show that by using a small amount of input knowledge, possibly covering only a portion of the underlying classes, the new algorithm can be further improved to accurately detect clusters with only 1% of the dimensions being relevant. The algorithm is also useful in getting a target set of clusters when there are multiple possible groupings of the objects. © 2005 IEEE.published_or_final_versio

An empirical study on the visual cluster validation method with Fastmap

This paper presents an empirical study on the visual method for cluster validation based on the Fastmap projection. The visual cluster validation method attempts to tackle two clustering problems in data mining: to verify partitions of data created by a clustering algorithm; and to identify genuine clusters from data partitions. They are achieved through projecting objects and clusters by Fastmap to the 2D space and visually examining the results by humans. A Monte Carlo evaluation of the visual method was conducted. The validation results of the visual method were compared with the results of two internal statistical cluster validation indices, which shows that the visual method is in consistence with the statistical validation methods. This indicates that the visual cluster validation method is indeed effective and applicable to data mining applications.published_or_final_versio

Block diagonal and schur complement preconditioners for block-toeplitz systems with small size blocks

In this paper we consider the solution of Hermitian positive definite block-Toeplitz systems with small size blocks. We propose and study block diagonal and Schur complement preconditioners for such block-Toeplitz matrices. We show that for some block-Toeplitz matrices, the spectra of the preconditioned matrices are uniformly bounded except for a fixed number of outliers where this fixed number depends only on the size of the block. Hence, conjugate gradient type methods, when applied to solving these preconditioned block-Toeplitz systems with small size blocks, converge very fast. Recursive computation of such block diagonal and Schur complement preconditioners is considered by using the nice matrix representation of the inverse of a block-Toeplitz matrix. Applications to block-Toeplitz systems arising from least squares filtering problems and queueing networks are presented. Numerical examples are given to demonstrate the effectiveness of the proposed method. © 2007 Society for Industrial and Applied Mathematics.published_or_final_versio

HARP: A practical projected clustering algorithm

In high-dimensional data, clusters can exist in subspaces that hide themselves from traditional clustering methods. A number of algorithms have been proposed to Identify such projected clusters, but most of them rely on some user parameters to guide the clustering process. The clustering accuracy can be seriously degraded If incorrect values are used. Unfortunately, in real situations, it is rarely possible for users to supply the parameter values accurately, which causes practical difficulties in applying these algorithms to real data. In this paper, we analyze the major challenges of projected clustering and suggest why these algorithms need to depend heavily on user parameters. Based on the analysis, we propose a new algorithm that exploits the clustering status to adjust the internal thresholds dynamically without the assistance of user parameters. According to the results of extensive experiments on real and synthetic data, the new method has excellent accuracy and usability. It outperformed the other algorithms even when correct parameter values were artificially supplied to them. The encouraging results suggest that projected clustering can be a practical tool for various kinds of real applications.published_or_final_versio