Non-Fermi Liquid behavior at the Orbital Ordering Quantum Critical Point in the Two-Orbital Model

The critical behavior of a two-orbital model with degenerate $d_{xz}$ and $d_{yz}$ orbitals is investigated by multidimensional bosonization. We find that the corresponding bosonic theory has an overdamped collective mode with dynamical exponent $z=3$, which appears to be a general feature of a two-orbital model and becomes the dominant fluctuation in the vicinity of the orbital-ordering quantum critical point. Since the very existence of this $z=3$ overdamped collective mode induces non-Fermi liquid behavior near the quantum critical point, we conclude that a two-orbital model generally has a sizable area in the phase diagram showing non-Fermi liquid behavior. Furthermore, we show that the bosonic theory resembles the continuous model near the d-wave Pomeranchuk instability, suggesting that orbital order in a two-orbital model is identical to nematic order in a continuous model. Our results can be applied to systems with degenerate $d_{xz}$ and $d_{yz}$ orbitals such as iron-based superconductors and bilayer strontium ruthenates Sr$_3$Ru$_2$O$_7$.Comment: 5 pages, 2 figure

Pomeranchuk Instability in a non-Fermi Liquid from Holography

The Pomeranchuk instability, in which an isotropic Fermi surface distorts and becomes anisotropic due to strong interactions, is a possible mechanism for the growing number of experimental systems which display transport properties that differ along the $x$ and $y$ axes. We show here that the gauge-gravity duality can be used to describe such an instability in fermionic systems. Our holographic model consists of fermions in a background which describes the causal propagation of a massive neutral spin-two field in an asymptotically AdS spacetime. The Fermi surfaces in the boundary theory distort spontaneously and become anisotropic once the neutral massive spin-two field develops a normalizable mode in the bulk. Analysis of the fermionic correlators reveals that the low-lying fermionic excitations are non-Fermi liquid-like both before and after the Fermi surface shape distortion. Further, the spectral weight along the Fermi surface is angularly dependent and can be made to vanish along certain directions.Comment: Updated version to appear in PRD. New version has WKB analysis of spectral intensity in ordered phas

Tonal perception in Cantonese-speaking aphasics

Also available in print.A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), University of Hong Kong, April 30, 1992.Thesis (B.Sc)--University of Hong Kong, 1992published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Feature extraction for range image interpretation using local topology statistics

This thesis presents an approach for interpreting range images of known subject matter, such as the human face, based on the extraction and matching of local features from the images. In recent years, approaches to interpret two-dimensional (2D) images based on local feature extraction have advanced greatly, for example, systems such as Scale Invariant Feature Transform (SIFT) can detect and describe the local features in the 2D images effectively. With the aid of rapidly advancing three-dimensional (3D) imaging technology, in particular, the advent of commercially available surface scanning systems based on photogrammetry, image representation has been able to extend into the third dimension. Moreover, range images confer a number of advantages over conventional 2D images, for instance, the properties of being invariant to lighting, pose and viewpoint changes. As a result, an attempt has been made in this work to establish how best to represent the local range surface with a feature descriptor, thereby developing a matching system that takes advantages of the third dimension present in the range images and casting this in the framework of an existing scale and rotational invariance recognition technology: SIFT. By exploring the statistical representations of the local variation, it is possible to represent and match range images of human faces. This can be achieved by extracting unique mathematical keys known as feature descriptors, from the various automatically generated stable keypoint locations of the range images, thereby capturing the local information of the distributions of the mixes of surface types and their orientations simultaneously. Keypoints are generated through scale-space approach, where the (x,y) location and the appropriate scale (sigma) are detected. In order to achieve invariance to in-plane viewpoint rotational changes, a consistent canonical orientation is assigned to each keypoint and the sampling patch is rotated to this canonical orientation. The mixes of surface types, derived using the shape index, and the image gradient orientations are extracted from each sampling patch by placing nine overlapping Gaussian sub-regions over the measurement aperture. Each of the nine regions is overlapped by one standard deviation in order to minimise the occurrence of spatial aliasing during the sampling stages and to provide a better continuity within the descriptor. Moreover, surface normals can be computed from each of the keypoint location, allowing the local 3D pose to be estimated and corrected within the feature descriptors since the orientations in which the images were captured are unknown a priori. As a result, the formulated feature descriptors have strong discriminative power and are stable to rotational changes

Towards governmentality with Chinese characteristics: higher education policy discourses in post-colonial Hong Kong and Macao

This article examines the intertwining and evolution of neoliberal and nationalist discourses in post-colonial Hong Kong and Macao, arguing that their combination reveals the dual layers of political rationality in the dynamics of higher education policymaking. It suggests a move towards governmentality with Chinese characteristics, marked by gradual and continuous shifts towards decolonisation and re-Sinicisation within the ‘One Country, Two Systems’ framework. This perspective contrasts with existing literature on Hong Kong that emphasises the maintenance of the colonial status quo and points out abrupt changes due to the 2019 protests and the 2020 National Security Law. By analysing the reconfiguration of governmentality in the higher education systems of these post-colonial Chinese societies amid changing political landscapes, the article sheds light on both the incremental changes and significant moments influencing the trajectory of higher education development in Hong Kong and Macao.摘要本文檢視新自由主義和民族主義論述在後殖民時代香港和澳門的交織與演變，認為它們的結合揭示了高等教育政策制定動態中政治理性的雙重性。研究表明，具有中國特色的治理性得以發展，其標誌是在「一國兩制」的框架內逐步、持續地向去殖民化和再中國化轉變。這一觀點與強調維持香港殖民現狀，並指出了2019年的抗議活動和2020年的《國家安全法》所帶來的劇變的現有文獻形成鮮明對比。本文透過分析這些中國後殖民地社會不斷變化的政治格局中高等教育體系治理性的重構，揭示了影響香港和澳門高等教育發展軌蹟的漸進變化和重要時刻

International transfer pricing in a developing economy context : perspectives from the taxpayers and the tax authorities

Since the 1979 economic reforms, China has been characterized by a rapid increase in international trade and an inflow of foreign direct investment. Foreign investment enterprises (FIEs) play an increasing important role in the Chinese economy and are substantially engaged in transactions with affiliates outside China. Therefore, international transfer pricing in China has become a significant issue. Empirical research on international transfer pricing has focused on multinational corporations (MNCs) operating in developed countries. However, it is difficult to generalize their findings to MNCs operating in developing countries as the business environment of developing countries is quite different from that of developed countries. Existing literature identifies that due to differences in the business environment between developed and developing countries, the tax factors which are important in developed countries should not be over-emphasized in developing countries. Some nontax factors such as foreign exchange control and restrictions on profit repatriation which may not be important in developed countries are nevertheless important in developing countries. However, empirical studies on international transfer pricing in developing countries are relatively scare. Furthermore, there have been no empirical studies that examine the relationships between management’s perception of the importance of environmental variables and management’s choice of international transfer pricing methods in developing countries, or which analyze the tax and nontax cost trade-off for tax evasion via international transfer pricing in developed or developing countries. The objective of this thesis is to provide a comprehensive empirical study on international transfer pricing in China from the perspectives of both taxpayer and the tax authority. The results of this thesis indicate that the more important the management perceives the interest of local partners and the maintenance of a good relationship with host government to be, the more likely it is that the FIE will adopt a market-based transfer pricing method. On the other hand, the more important the management perceives foreign exchange controls in transfer pricing decisions to be, the more likely it is that the FIE will choose a cost-based transfer pricing method. The research results also reveal that based on a tax and non-tax cost trade-off analysis, wholly foreign-owned enterprises, cooperative joint ventures and exportoriented FIEs are more likely to be selected for transfer pricing audits in China than equity joint ventures and domestic -market oriented enterprises. Some explanations for this result are the lack of monitoring by Chinese local partners in certain FIEs and the opportunity for transfer pricing manipulations. The results of this thesis have important policy implications for foreign investors carrying on business in China, the Chinese tax authorities as well as academic researchers. My research results should help foreign investors to have a better understanding of the tax and the nontax factors in formulating transfer pricing policies in China. The results should also help tax authorities tackle tax audit problems more effectively and in setting tax audit guidelines on related party transactions. Further, this thesis should contribute to the establishment of a more comprehensive theoretical framework of international transfer pricing in developing countries. It also empirically demonstrates the applicability of the tax and nontax cost theory in the context of international transfer pricing

Responses of Mammalian Cells to Membrane-Disrupting Peptides.

Responses of cultured mouse fibroblasts, human erythrocytes, bovine erythrocytes, and liposomes with different phosphatidylcholine (PC) and sphingomyelin (SPM) ratios to both natural and synthetic lytic peptides were characterized. Peptide-induced morphological alterations of the plasma membrane of cells were examined by various light microscopic techniques and scanning electron microscopy (SEM). The ability of natural and synthetic peptides to kill cells and cause increased permeability of liposomes was evaluated using Trypan Blue (TB) dye exclusion assay and fluorescent dye leakage assay, respectively. Differential interference contrast microscopy, SEM, and fluorescence studies revealed characteristic structural and lipid changes in the plasma membrane of lytic peptide-treated fibroblasts, and these alterations were accompanied by simultaneous changes in the cell permeability as indicated by the uptake of TB. Formation of membrane vesicles, composed primarily of lipids, was demonstrated in cells treated with a low lethal dose of melittin and eventually resulted in the liberation of membrane lipids. SEM revealed that much of the plasma membrane was lost by 5 minutes following peptide exposure. Confocal microscopy confirmed the translocation of membrane proteins from the cell surface to cytoplasmic areas in peptide-treated cells. A fluorescently labeled peptide was used to demonstrate the reaction of the peptides with the plasma membrane. The measurements of the ability of natural and synthetic peptides to kill fibroblasts allowed classification of these peptides into four groups. The results also suggested that peptide length and substitution of glycine for alanine affected the potency of synthetic peptides. Differential susceptibility of different cell types to destruction by the same peptides was demonstrated in mouse fibroblasts and human and bovine erythrocytes. These peptides were less efficient in lysing erythrocytes than in destroying fibroblasts. This difference in activity was possibly due to the higher content of membrane SPM in the resistant RBCs. Lytic peptides demonstrated less ability to permeate liposomes composed of 70% SPM. Synergistic effects were demonstrated in mammalian cells using weak lytic peptides and exogenous phospholipases. The effect was dependant upon the phospholipid composition of the target cells. Cell susceptibility and synergy between peptides and membrane reactive enzymes are important factors in the selection of therapeutic peptides

The role of university leaders in a political crisis: Students' perspectives from Hong Kong

University students actively participated in the 2019 Hong Kong protests. In this context, the students expected that their universities would support their political stance. Drawing on data from interviews with student leaders, this article documents and examines students' expectations for their university heads, how they interacted and negotiated with university management and how university leaders variously responded to the students' expectations during the social movement. Noting the difficulties in reconciling conflicts over the positioning of the university amid strong political polarisation and social divisions in the society, this article argues that university leaders can only passively adapt to political unrest, and that such passive adaptation exemplifies university's vulnerability to political crises

IS accreditation in AACSB colleges via ABET

The development of ABET/CAC accreditation standards for IS programs presents an excellent opportunity for IS programs in AACSB-accredited business schools to improve their perceived quality and credibility. We argue that neglect by AACSB of IS/IT content has prompted this preemptive move on the part of ABET/CAC. A comparison of AACSB and ABET/CAC accreditation standards finds them to be generally quite compatible. Ironically, our survey of IS program leaders in AACSB-accredited business schools found familiarity with and interest in ABET/CAC standards to be just emerging. Although compliance with the ABET/CAC standards is evidently relatively high among most programs, understanding of potential benefits of accreditation is quite low. Also quite low is understanding of how colleagues might react to accreditation efforts