Showing papers by "Hong Kong University of Science and Technology published in 1992"
TL;DR: Empirical results show that neural nets is a promising method of evaluating bank conditions in terms of predictive accuracy, adaptability, and robustness.
Abstract: This paper introduces a neural-net approach to perform discriminant analysis in business research. A neural net represents a nonlinear discriminant function as a pattern of connections between its processing units. Using bank default data, the neural-net approach is compared with linear classifier, logistic regression, kNN, and ID3. Empirical results show that neural nets is a promising method of evaluating bank conditions in terms of predictive accuracy, adaptability, and robustness. Limitations of using neural nets as a general modeling tool are also discussed.
1,141 citations
TL;DR: In this paper, a coding scheme designed for facility layout is presented, where a solution is represented by the postorder sequence of the nodes in a slicing tree, and new solutions are generated by applying the various genetic operators in each generation.
211 citations
TL;DR: In this paper, the authors present a procedure that can be used by facility designers to allocate space to manufacturing cells, taking into account the area and shape requirements of individual cells as well as any occupied regions on a floor plan.
Abstract: This paper describes a procedure that can be used by facility designers to allocate space to manufacturing cells. The procedure takes into consideration the area and shape requirements of individual cells as well as any occupied regions on a floor plan. A layout is represented as a collection of rectangular partitions organized as a slicing tree. The solution method involves searching through the space of all slicing trees of a given structure. An effective simulated annealing algorithm capable of minimizing inter-cell traffic flow and enforcing geometric constraints is presented. The algorithm is compared with two local search methods with encouraging results.
176 citations
Posted Content•
TL;DR: In this article, the conditional expected excess return on U.S. stocks is positively related to the conditional covariance of the return of these stocks with the return on a foreign index but is not related to its own conditional variance.
Abstract: We document that there is a significant foreign influence on the risk premium of U.S. assets. Using a bivariate GARCH-in-mean process for conditional expected excess returns, we find that the conditional expected excess return on U.S. stocks is positively related to the conditional covariance of the return of these stocks with the return on a foreign index but is not related to its own conditional variance. Further, we are unable to reject the international version of the CAPM. Evidence is presented for different model specifications, multiple-day returns and alternative proxies of foreign stock returns including the Nikkei 225 Stock Average, Morgan Stanley Japan and Morgan Stanley EAFE indices.
128 citations
TL;DR: In this article, the effects of exogenous carbon substrates on the removal of inorganic nitrogen and phosphorus by a simple nitrification-denitrification process were examined and the results showed that 94% of NH4+-N was removed at the end of the aeration period and 88% ortho-P was removed after the aerobic stage.
89 citations
TL;DR: In this paper, the authors analyze how depositors can employ both monitoring and capital requirements to control the risk of bank assets and how monitors should be compensated if their actions are not directly observable and if there are binding limits on their liability.
79 citations
TL;DR: Findings based on 134 senior MIS personnel and management executives indicate that capital budgeting has little impact on IS investment, and simple techniques such as payback period and cost benefit ratio are preferred over more sophisticated discount cash-flow models.
58 citations
TL;DR: The results of EBV genotyping support evidence that the EBV strains associated with NPC in the Southern Chinese population differ from those found in Caucasians.
Abstract: Using the polymerase chain reaction (PCR) to analyze paraffin sections from 12 Caucasian patients, we detected only the prototype F Epstein-Barr virus (EBV) in 10 specimens from patients with nasopharyngeal carcinoma (NPC). This is in contrast to the higher frequency of association of "f" variants in NPC biopsies from Southern Chinese. The results of EBV genotyping support evidence that the EBV strains associated with NPC in the Southern Chinese population differ from those found in Caucasians. DNA sequencing confirmed that a simple point mutation is responsible for the restriction-fragment-length polymorphism which distinguishes the prototype F virus from the "f" variant.
45 citations
TL;DR: In this paper, the effects of easily-biodegradable organic substances upon the nutrient removal by a simulated sequencing batch reactor (SBR) were examined. And the results showed that the concentration of NH 4 + -N dropped from its initial 50 to 18 mg l -1 (64 % removal) during the first aeration period, with the NO 3 − -N content increased from 2 to 33 mg l −1.
40 citations
TL;DR: In this article, the authors used the method of multiple scales for heterogeneous media to derive the constitutive equations on the meso-and macro-scales for composite materials consisting of fibers and a matrix material.
Abstract: This paper uses the method of multiple scales for heterogeneous media to derive the constitutive equations on the meso- and macro-scales for composite materials consisting of fibers and a matrix material. We have deduced the general theory for problems of three scales. The subscale solutions are obtained by numerical or analytical methods.
31 citations
TL;DR: In this article, the authors carried out numerical computations of water impact on a two-dimensional flat-bottomed body using a volume-of-fluid method based on a modified SOLA-VOF code.
TL;DR: In this paper, it was shown that the iron motion in a five-coordinated heme model is controlled mainly by the γ 9 out-of-plane vibration in which the iron atom and the axial ligand move like a rigid unit with respect to the rest of the heme.
Proceedings Article•
23 Aug 1992
TL;DR: An on-going project of devising a conceptual clustering model based on a comprehensive object database programming system, which is suitable and desirable for many applications whose objects can be classified statically.
Abstract: 1 Introduct ion In object-oriented database systems, it is assumed silently that fundamental object types and inter-object relationships can be classified statically, prescribing basic structural and behavioral properties for all the objects in the database. Such a classification-based approach falls short of supporting those data-intensive applications requiring more advanced dynamic functions. A particular kind of such advanced functions is “dynamic clustering” the ability to group/cluster existing objects to form typeless, ad-hoc collections (called “clusters”) which are directly denotable and employable. Such clusters can be formed by taking copies or by including the Oids of the input objects, and can be explicitly defined or indefinitely defined, exhibiting thus different impacts and characteristics, ranging from loosely-coupled to tightly-coupled ones. In this paper we describe an on-going project of devising a conceptual clustering model. A real life DB application is used as a basis for testing and evaluating the model. An implementation prototype has been implemented, based on a comprehensive object database programming system. *The work by this author was supported, in part, by the Commonwealth Scientific and Industrial Research Organization (CSIRO) under contract BT00825. Permissions to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantages, the VLDB copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Very Large Data Base Endowment. To copy otherwise, or to republish, requires a fee and/or special permission from the Endowment. Proceedings of the 18th VLDB Conference Vancouver, British Columbia, Canada 1992 Object-oriented languages and systems are becoming more and more popular for applications which model environments that lend themselves to extensive classifications, complex objects and inter-object relationships [KLE89, Mey88, ZMESO]. In a conventional object-oriented database, the conceptual structure (schema) is embodied by a collection of abstract data types (called “classes” in this paper) which, when defined, are organized into an inheritance (ISA) hierarchy. Objects can then be created within classes, instantiating and justifying these predefined data types. In this way, a class prescribes both structural and behavioral properties (attributes and methods) of its objects, and objects in the class can be stored efficiently through a shared representation. Further, setoriented access of class members can be applied efficiently, which is suitable and desirable for many applications whose objects can be classified statically (or at least to a large extent, with additional facilities for introducing/deriving new classes such as specialization and/or generalization [Sci89, SNSS]). Such a classification-based approach, however, falls short of supporting those applications involving objects and inter-object relationships that are by nature tentative, irregular, ill-structured, evolving, or simply unpredicatable. *In particular, certain objects may arise dynamically as “clusters” of existing objects in some ad hoc fashion. While it is always in theory possible to accommodate such new types of objects through introducing new classes accordingly, in practice there are several reasons against this obvious approach. First, the number of such ad hoc objects may not be large enough to warrant the introduction of new classes (e.g., we may end up with many ad hoc classes). Second, the evolving/uncertain nature of some objects implies the inappropriateness of using class structure (as the classes would have to undertake similar evolu-
01 Jun 1992
TL;DR: The system described in this paper is a programming tool for managing textual objects that provides a great deal of flexibility, giving access to very complex document structure, with a large number of constituent kinds of textual objects.
Abstract: Computer programs that access significant amounts of text usually include code that manipulates the textual objects that comprise it. Such programs include electronic mail readers, typesetters and, in particular, full-text information retrieval systems. Such code is often unsatisfying in that access to textual objects is either efficient, or flexible, but not both. A programming language like Awk or Perl provides very general facilities for describing textual objects, but at the cost of rescanning the text for every textual object. At the other extreme, full-text information retrieval systems usually offer access to a very limited number of kinds of textual objects, but this access is very efficient. The system described in this paper is a programming tool for managing textual objects. It provides a great deal of flexibility, giving access to very complex document structure, with a large number of constituent kinds of textual objects. Further, it provides access to these objects very efficiently, both in terms of time and auxiliary space, by being very careful to access secondary storage only when absolutely necessary.
TL;DR: This paper proposes an architecture for modelling intelligent information systems and discusses how this architecture supports the communication of knowledge in such information systems.
Abstract: An intelligent information system may be composed of hundreds or thousands of entities each of which may possess some part of the overall knowledge of an organization. In such an environment there is a need for these entities to communicate in order to share knowledge and to cooperate in accomplishing organizational activities. In this paper we propose an architecture for modelling intelligent information systems and discuss how this architecture supports the communication of knowledge in such information systems.
01 Oct 1992
TL;DR: The A la carte Framework provides a set of reusable, integrating components which integrate the major functional domains that could or should be integrated in heterogeneous systems and provides a mechanism for capturing key characteristics of the components and constraints which describe how the components can be mixed and interchanged, thereby helping to reduce the complexity of the integration process.
Abstract: The integration of heterogeneous database environments is a difficult and complex task. The A la carte Framework addresses this complexity by providing a reusable and extensible architecture in which a set of heterogeneous database management systems can be integrated. The goal is to support incremental integration of existing database facilities into heterogeneous, interoperative, distributed systems. The Framework addresses the three main issues in heterogeneous systems integration. First, it identifies the problems in integrating heterogeneous systems. Second, it identifies the key interfaces and parameters required for autonomous systems to interoperate correctly. Third, it demonstrates an approach to integrating these interfaces in an extensible and incremental way. The A la carte Framework provides a set of reusable, integrating components which integrate the major functional domains, such as transaction management, that could or should be integrated in heterogeneous systems. It also provides a mechanism for capturing key characteristics of the components and constraints which describe how the components can be mixed and interchanged, thereby helping to reduce the complexity of the integration process. Using this framework, we have implemented an experimental, heterogeneous configuration as part of the object management work in the software engineering research consortium, Arcadia.
TL;DR: In this article, the resonance energy, width and intensity of He-like Xe ions channeled along the 〈110〉 axis of a thin Si crystal has been investigated in measurements of charge state distributions and of the resulting X-ray production.
TL;DR: Techniques to study the weight space organization of neural networks optimizing different performance functions are introduced, by considering the total free energy in the joint weight space of two networks, and their correlation order parameter.
Abstract: We introduce techniques to study the weight space organization of neural networks optimizing different performance functions, by considering the total free energy in the joint weight space of two networks, and their correlation order parameter The example of training noise performance functions shows that Hebbian-like and MSN-like networks occupy different regions in the "world map" projection of the weight space (MSN meaning the maximally stable network) The lines of maximum latitude, minimum susceptibility and band splitting separate the regions of Hebbian-like and MSN-like networks in similar ways In the low storage limit, the differentiation of network behaviour is determined by the signal-to-noise ratio mt/√α (mt and α being the training overlap and the storage level, respectively) Possible applications of our technique are discussed
TL;DR: Observations ofPhason-strained octagonal quasicrystal phases of Mo-Cr-Ni are consistent with some of the results of the two-dimensional octagonal random tiling model of Li, Park, and Widom.
Abstract: Phason-strained octagonal quasicrystal phases of Mo-Cr-Ni have been studied by electron diffraction and dark-field imaging. Diffraction patterns of the twofold axes show that some spots are shifted and split along the fourfold axis. Discommensurations (DCs) observed in dark-field images of the split reflections are aligned perpendicular to the fourfold axis. The density of the DCs in widely separated and adjacent regions may vary by more than 1 order of magnitude. Our observations are consistent with some of the results of the two-dimensional octagonal random tiling model of Li, Park, and Widom.
16 Dec 1992
TL;DR: It is shown that for queueing networks with deterministic or discrete service time distributions the performance functions can be nondifferentiable at a dense subset of a given interval.
Abstract: It is shown that for queueing networks with deterministic or discrete service time distributions the performance functions can be nondifferentiable at a dense subset of a given interval. It is also shown that when the service time densities are supported on small intervals the performance function derivatives change rapidly. These phenomena have to be taken into consideration in gradient-based optimization. These results are proved for a two-server cyclic network, and a potential generality to other queueing networks is pointed out. >
TL;DR: In this paper, the authors describe the non-linear phenomena observed on polymer surfaces caused by excimer laser exposures, e.g., increased hydrophilicity of polymer surfaces, imagewise witting and metallization, and new metal compounds formed on laser-exposed polymer films.
Abstract: It is known that continuous wave photoexposures and excimer laser exposures have different effects on polymer sufaces ( e.g. the photosensitivity of inorganic resists) and new photochemistry is observed on excimer laser irradiation. This report describes the non-linear phenomena observed on polymer surfaces, caused by excimer laser exposures, e.g increased hydrophilicity of polymer surfaces, imagewise witting and metallization, and the new metal compounds formed on laser-exposed polymer films. Because these phenomena are limited to polymer films with a high glass transition temperature, such as polyimides and poly(phenylquinoxaline), the effects may be induced by photomechanical processes. In some cases, new interfacial reactions occur between the exposed polymer surfaces and the deposited metal films. The swelling of polyimide in pre-photoablation and the photoablation of doped Teflon AF films are also discussed.
TL;DR: In this article, a comprehensive and systematic study is presented to derive stability properties of various two-level, six-point finite difference schemes (in particular, difference schemes of Pade type) for the approximation to the constant coefficient convective-diffusion equation.
Abstract: A comprehensive and systematic study is presented to derive stability properties of various two-level, six-point finite difference schemes (in particular, difference schemes of Pade type) for the approximation to the constant coefficient convective-diffusion equation. First, the modified equivalent partial differential equation (MEPDE) for a general six-point difference scheme is derive. The MEPDE provides direct information on the order of accuracy of a difference scheme. The von Neumann and matrix methods are then employed to deduce the necessary and sufficient conditions for the numerical stability for the six-point difference schemes. An unified technique is developed to find the stability regions for the difference schemes. Some new second and third order six-point difference schemes for the approximation of the constant coefficient convective-diffusion equation are presented.
TL;DR: In this paper, a catalyst deactivation model for chemical poisoning was developed based on the concept that a poison influences more than the sites (s) it occupies when adsorbed on a catalyst surface, and a collection of these sites is termed an infected zone.
Abstract: In a previous paper, a catalyst deactivation model for chemical poisoning was developed based on the concept that a poison influences more than the site (s) it occupies when adsorbed on a catalyst surface. The sites which are influenced but not occupied are called infected sites, and a collection of these sites is termed an infected zone. The mathematical formulation of the Infected Zone Model takes into account all of the various sites on the surface: normal, completely deactivated, and infected. To describe the deactivation of a reactive system, material balances of the flow streams and kinetics data are also needed. In this work, published experimental data from three different sources were analyzed using the infected zone model equations. The results indicate that better fits can be obtained in some cases, and confirm that the number of sites affected by a poison is larger than the number of sites actually occupied.
TL;DR: With the widespread use of workstations and window systems, much better multi‐lingual processing environments can be provided.
Abstract: Computing involving data in a logo-syllabic oriental language like Chinese is more difficult than in English. Many attempts have been made to develop bilingual or multilingual processing systems.1–3 Most of them are based on microcomputers like the IBM-PC. With the widespread use of workstations and window systems, much better multi-lingual processing environments can be provided.
This paper describes the design and implementation of the program cxterm, a Chinese terminal emulator for the X Window System. We discuss the representation of multi-byte international characters, the problems of Chinese character input and output, the pros and cons of various approaches, and the design decisions for cxterm. A feature of cxterm is its independence of input methods. A user can incorporate new input methods into cxterm at run-time, without changing the program code. We also compare our approach with related work in multi-lingual input/output in X, and describe how cxterm performs better in terms of efficiency, flexibility, and user-friendliness.
TL;DR: In this article, an Infected Zone Model (IZM) was developed to correlate the decay in activity with the amount of poison covering a catalyst under conditions of chemical poisoning, which is based on the transformation of normal sites into completely deactivated and infected sites when poison interacts with sites.
Abstract: An Infected Zone Model (IZM) was developed to correlate the decay in activity with the amount of poison covering a catalyst under conditions of chemical poisoning. This model is based on the transformation of normal sites into completely deactivated and infected sites when poison interacts with sites. “Normal” sites are not under the influence of poison. “Completely deactivated” sites are those occupied by poison, while “infected” sites are those influenced but not occupied by poison; both contribute to the total loss in activity. The following equation, which is obtained through balancing the activities of these sites on a catalytic surface, correlates the normalized activity a of catalysts with poison coverage θ. a = I )[1−(1−θ) δo ] I is the average residual activity coefficient of infected sites, and δ o is the effective infected zone size.
01 Jul 1992
TL;DR: In this paper, the Volpe National Transportation Systems Center has supported the Federal Aviation Administration Technical Center on structural integrity research for the past two and half years, focusing on understanding the behavior of multiple site damage, detection of MSD during airframe inspection, and the avoidance of the MSD in future designs.
Abstract: Multiple site damage (MSD) is a type of cracking that may be found in aging airplanes and which may adversely affect their continuing airworthiness. The Volpe National Transportation Systems Center has supported the Federal Aviation Administration Technical Center on structural integrity research for the past two and half years. The work has focused on understanding the behavior of MSD, detection of MSD during airframe inspection, and the avoidance of MSD in future designs. These three elements of the MSD problem are addressed and a summary of the completed work, the current status, and requirements for future research is provided.
TL;DR: In this paper, Rao integrates a simple Sraffian production economy with an assets market and concludes that the central bank policy, via its influence on the profit rate, controls the long-run distribution of income and relative prices.
Abstract: Rejecting neoclassical notions of supply and demand, Sraffa demonstrated that relative prices are determined by the profit rate. However, a Sraffa model fails to explicitly describe the determination of output, growth, and accumulation. Rao closes this model with a monetary sector, and examines the effects in both a Sraffian and a Classical world. Rao integrates a two class, simple Sraffian production economy with an assets market. The produaion side yields capital and consumption goods using Sraffian technology, while assets consist of money (printed and distnbuted by the Central Bank) and the stock of capital. Different approaches to the labor market yield two distinct models: Sraffian and Classical. The principal conclusion is that, in a Sraffian world, Central Bank policy, via its influence on the profit rate, controls the long-run distribution of income and relative prices. In a Classical regime-in which the real wage (and so the profit rate) is exogenously driven the Central Bank controls long-run economic growth.
TL;DR: In this article, the growth of Au and Cu film on polyphenylquinoxaline (PPQ) surfaces has been studied by X-ray photoemission spectroscopy, scanning (SEM) and transmission (TEM) electron microscopy.
TL;DR: A series of optical and electrical measurements of a-SiC:H/c-Si heterojunctions prepared by a parallel-plate plasma-enhanced chemical vapor deposition system are reported in this paper.
Abstract: A series of optical and electrical measurements of a-SiC:H/c-Si heterojunctions prepared by a parallel-plate plasma-enhanced chemical vapor deposition system are reported. All the samples underwent various passivation processes. It is observed that in situ H/sub 2//Ar plasma prior cleaning and H/sub 2/ plasma annealing can reduce the dark current of the heterojunction by three orders of magnitude. Higher process pressure and lower power density also favour good interface properties. >