On the Area of Hypercube Layouts

This paper precisely analyzes the wire density and required area in standard layout styles for the hypercube. The most natural, regular layout of a hypercube of N^2 nodes in the plane, in a N x N grid arrangement, uses floor(2N/3)+1 horizontal wiring tracks for each row of nodes. (The number of tracks per row can be reduced by 1 with a less regular design.) This paper also gives a simple formula for the wire density at any cut position and a full characterization of all places where the wire density is maximized (which does not occur at the bisection).Comment: 8 pages, 4 figures, LaTe

Unified description of pairing, trionic and quarteting states for one-dimensional SU(4) attractive fermions

Paired states, trions and quarteting states in one-dimensional SU(4) attractive fermions are investigated via exact Bethe ansatz calculations. In particular, quantum phase transitions are identified and calculated from the quarteting phase into normal Fermi liquid, trionic states and spin-2 paired states which belong to the universality class of linear field-dependent magnetization in the vicinity of critical points. Moreover, unified exact results for the ground state energy, chemical potentials and complete phase diagrams for isospin $S=1/2, 1, 3/2$ attractive fermions with external fields are presented. Also identified are the magnetization plateaux of $m^z=M_s/3$ and $m^z=2M_s/3$, where $M_s$ is the magnetization saturation value. The universality of finite-size corrections and collective dispersion relations provides a further test ground for low energy effective field theory.Comment: 13 pages, 4 figure

Yang-Yang method for the thermodynamics of one-dimensional multi-component interacting fermions

Using Yang and Yang's particle-hole description, we present a thorough derivation of the thermodynamic Bethe ansatz equations for a general $SU(\kappa)$ fermionic system in one-dimension for both the repulsive and attractive regimes under the presence of an external magnetic field. These equations are derived from Sutherland's Bethe ansatz equations by using the spin-string hypothesis. The Bethe ansatz root patterns for the attractive case are discussed in detail. The relationship between the various phases of the magnetic phase diagrams and the external magnetic fields is given for the attractive case. We also give a quantitative description of the ground state energies for both strongly repulsive and strongly attractive regimes.Comment: 22 pages, 2 figures, slight improvements, some extra reference

Phase Transitions and Pairing Signature in Strongly Attractive Fermi Atomic Gases

We investigate pairing and quantum phase transitions in the one-dimensional two-component Fermi atomic gas in an external field. The phase diagram, critical fields, magnetization and local pairing correlation are obtained analytically via the exact thermodynamic Bethe ansatz solution. At zero temperature, bound pairs of fermions with opposite spin states form a singlet ground state when the external field $H < H_{c1}$. A completely ferromagnetic phase without pairing occurs when the external field $H > H_{c2}$. In the region $H_{c1} < H < H_{c2}$ we observe a mixed phase of matter in which paired and unpaired atoms coexist. The phase diagram is reminiscent of that of type II superconductors. For temperatures below the degenerate temperature and in the absence of an external field, the bound pairs of fermions form hard-core bosons obeying generalized exclusion statistics.Comment: 9 pages, 5 figures, expanded version with additional text, references and figure

The 1D interacting Bose gas in a hard wall box

We consider the integrable one-dimensional delta-function interacting Bose gas in a hard wall box which is exactly solved via the coordinate Bethe Ansatz. The ground state energy, including the surface energy, is derived from the Lieb-Liniger type integral equations. The leading and correction terms are obtained in the weak coupling and strong coupling regimes from both the discrete Bethe equations and the integral equations. This allows the investigation of both finite-size and boundary effects in the integrable model. We also study the Luttinger liquid behaviour by calculating Luttinger parameters and correlations. The hard wall boundary conditions are seen to have a strong effect on the ground state energy and phase correlations in the weak coupling regime. Enhancement of the local two-body correlations is shown by application of the Hellmann-Feynman theorem.Comment: 23 pages, 7 figures. Improved version. Extra figure added for the weak coupling regime. New expression for the interaction-dependent cloud size and additional reference

Guru Sebagai Penyelidik : Faktor-Faktor Yang Mempengaruhi Kekerapan Aktiviti Kajian Tindakan Di Sekolah

Action Research, a proven research methodology in the field of education, is still a new research topic in Malaysia. The purpose of this research project is to determine factors affecting the frequency of action research carried out in schools. The purposive sample for this research is a group of 32 teachers from throughout the state of Kedah; who have attended the 1996 Action Research Course, organized by the State’s Educational Resource Centre (SERC). This group of teachers' who have successfully completed at least one action research project are known as Action Researcher. Questionnaire for this survey is designed to measure the current status of Action Researcher in the following aspects: perception on Action Research, skills in carrying out Action Research, school climate condusiveness, and personal constraint. These factors are then correlated to the number of Action Research projects undertaken by each respondent. Results show that only skills factor has a positive correlation with the number of Action Research projects undertaken. Demographic comparison reveals that the most active Action Researcher are from secondary school, especially graduate teachers. Taking into account the conclusion derived from open-ended questions; this research project has come out with some recommendations to the relevant authorities, especially SERC on ways to realize the “Teacher As Researcher” movement

An Investigation of IBM PC Computer Viruses Infection Rates and Types in a Western Australian Environment

In recent years computer viruses have become increasingly significant as a form of computer abuse. By virtue of their reproductive capability, computer viruses can have cumulative and potentially catastrophic effects to the many people who use those affected computers. There is a growing concern in the computing community about these forms of electronic vandalism. This concern arises from the possible damage to stored information on which the work depends and the ensuing disruption of the work-place. Although the vandalism or purposeful abuse by introducing computer viruses to computer systems was originally mainly an American experience, research reports published by the Australian Computer Abuse Research Bureau (ACARB) support the claim that computer viruses have become increasingly significant as a form of computer abuse in Australia in recent years. Apart from ACARB\u27s figures, there is minimal empirical research of a similar nature being conducted to investigate computer viruses as a form of computer abuse in Australia. In this study, an attempt has been made to investigate the problem, albeit on a limited scope. In this study, the infection types and rates of IBM PC viruses in limited government IT organizations in Western Australia were investigated. In addition, this study has made an attempt to validate Spafford\u27s speculation that less than 10 viruses (out of a minimum of 374) account for 90% of infections in the Western Australian environment. This study was descriptive in nature in that a fact-finding survey based on questionnaires and standardized interviews was conducted in State Government IT organizations in Western Australia in order to obtain data on which the research findings can be based. The data gathering instrument for this study was a standardized questionnaire which comprised limited choice questions directed at obtaining such information as infection rates of various types of computer viruses. The questionnaire was field tested to eliminate ambiguous or biased items and to improve format, both for ease of understanding and facility in analyzing results. The questionnaire was used by the interviewer as a basis for the interview so that the potential for subjectivity and bias can be reduced. Before the commencement of this study, a letter of transmittal was sent to the prospective participants in order to request their participations. Confirmation of participation was sought through telephone calls. A very high response rate (87.5%, n = 42) for this study was achieved. This is taken as an assurance that reasonable representation of the state government sector for the study is achieved. Prior to commencement of this study, approval was sought from the University Committee for the Conduct of Ethical Research since this study will involve human subjects. During the interview, subjects were informed of the purpose of the study, that there will be no compulsion to participate in the study and that they will be free to withdraw from further participation in the study at any time they desire. The results of the survey and its implications are provided in chapters 5 and 6. In conclusion, the research ratifies the proposition that currently very few of the IBM PC viruses contribute to the vast majority of infections in the Western Australian work-place

Across-shelf sediment transport modeling and its application to storms at Duck, North Carolina

To understand the morphodynamics of the inner shelf, a benthic boundary layer tripod supporting 6 point-measuring current meters, an acoustic Doppler current profiler, and three near-bed profiling acoustic backscatter sensors documented storm and swell conditions during October, 1996, at a depth 13 in on the inner shelf off Duck, North Carolina. The relationship between eddy viscosity and eddy diffusivity during storm and swell conditions was examined using data collected in October 1996 on the inner shelf off Duck, NC. Sediment suspension models, including Rouse-type diffusion models, combined advection and diffusion models, and a Rouse model with a thickened wave boundary layer, were compared to determine which model best reproduces observed sediment concentration profiles. A physics-based morphodynamics model was then developed to determine which components of hydrodynamic forcing and resulting sediment transport are predicted to be most significant to morphological change outside the surf zone on the inner shelf of the Middle Atlantic Bight. The simplest possible analytical solutions were sought for depth-dependent currents driven by the along- and across-shelf components of the wind and by waves via Stokes return flow and boundary layer streaming. Predicted currents and sediment concentrations were compared with observations collected at 13 m depth off Duck, NC, during October, 1996. Sediment transport and morphologic change were modeled and the morphologic change model was applied to 24 significant storms, which were documented by before-and-after shoreface profiles collected by the Field Research Facility of the US Army Corps of Engineers at Duck, NC, between 1987 and 1993. Significant correlations were found between observed shoreface volume change between 600--800 in offshore and predicted depth change on the inner shelf due to across-shelf sediment flux. Overall, correlations between observed and predicted change were higher for wave-driven components of sediment flux than for wind-driven components