3,563 research outputs found
ISODATA: Thresholds for splitting clusters
The author has identified the following significant results. The parameter AD (average distance) as used in the ISODATA program was critically examined. Thresholds of AD to decide on the splitting of clusters were obtained. For the univariate case, 0.84 was established as a sound choice, after examining several simple, as well as composite, distributions and also after investigating the probability of misclassification when points have to be reassigned to the newly identified clusters. For the multivariate case, the empirical threshold (N-0.16)/square root of N was extrapolated. A final criticism on AD was that AD would lose its effectiveness as a discriminative measure for the present purpose when N was large
Keepers of the sacred flame: Patriotism, politics and the Chinese history subject community in Hong Kong
Chinese history (a subject entirely separate and distinct from 'history') has long been the most politically sensitive subject in Hong Kong's school curriculum. Previous studies have analysed the policies of the colonial and postcolonial Governments towards this subject. Here, we examine the role played by the Chinese history subject community (comprising teachers, academics and officials in the Government's educational bureaucracy), and look at the way in which this has operated as an autonomous interest group. We conclude that the influence of this subject community has been a key factor limiting the extent to which the local educational authorities have been able to develop a coherent policy in relation to history education in general, and the teaching of national history in particular. Specifically, advocates of the maintenance of Chinese history as a separate subject within the school curriculum have been able, by associating themselves with the post-1997 agenda of 'patriotic education', to effectively hoist the local educational bureaucracy with its own petard.postprin
Keepers of the sacred flame: Patriotism, politics and the Chinese history subject community in Hong Kong
Chinese history (a subject entirely separate and distinct from 'history') has long been the most politically sensitive subject in Hong Kong's school curriculum. Previous studies have analysed the policies of the colonial and postcolonial Governments towards this subject. Here, we examine the role played by the Chinese history subject community (comprising teachers, academics and officials in the Government's educational bureaucracy), and look at the way in which this has operated as an autonomous interest group. We conclude that the influence of this subject community has been a key factor limiting the extent to which the local educational authorities have been able to develop a coherent policy in relation to history education in general, and the teaching of national history in particular. Specifically, advocates of the maintenance of Chinese history as a separate subject within the school curriculum have been able, by associating themselves with the post-1997 agenda of 'patriotic education', to effectively hoist the local educational bureaucracy with its own petard.postprin
Kondo Effect in Fermi Systems with a Gap: A Renormalization Group Study
We present the results of a Wilson Renormalization Group study of the
single-impurity Kondo and Anderson models in a system with a gap in the
conduction electron spectrum. The behavior of the impurity susceptibility and
the zero-frequency response function, are discussed in the
cases with and without particle-hole symmetry. In addition, for the asymmetric
Anderson model the correlation functions, , are computed.Comment: 10 pages, 10 figure
Data resolution versus forestry classification
There are no author-identified significant results in this report
Phase Coexistence Near a Morphotropic Phase Boundary in Sm-doped BiFeO3 Films
We have investigated heteroepitaxial films of Sm-doped BiFeO3 with a
Sm-concentration near a morphotropic phase boundary. Our high-resolution
synchrotron X-ray diffraction, carried out in a temperature range of 25C to
700C, reveals substantial phase coexistence as one changes temperature to
crossover from a low-temperature PbZrO3-like phase to a high-temperature
orthorhombic phase. We also examine changes due to strain for films greater or
less than the critical thickness for misfit dislocation formation.
Particularly, we note that thicker films exhibit a substantial volume collapse
associated with the structural transition that is suppressed in strained thin
films
Out of plane analysis for composite structures
Simple two dimensional analysis techniques were developed to aid in the design of strong joints for integrally stiffened/bonded composite structures subjected to out of plane loads. It was found that most out of plane failures were due to induced stresses arising from rapid changes in load path direction or geometry, induced stresses due to changes in geometry caused by buckling, or direct stresses produced by fuel pressure or bearing loads. While the analysis techniques were developed to address a great variety of out of plane loading conditions, they were primarily derived to address the conditions described above. The methods were developed and verified using existing element test data. The methods were demonstrated using the data from a test failure of a high strain wingbox that was designed, built, and tested under a previous program. Subsequently, a set of design guidelines were assembled to assist in the design of safe, strong integral composite structures using the analysis techniques developed
A general framework for improving electrocardiography monitoring system with machine learning
As one of the most important health monitoring systems, electrocardiography (ECG) is used to obtain information about the structure and functions of the human heart for detecting and preventing cardiovascular disease. Given its important role, it is vital that the ECG monitoring system provides relevant and accurate information about the heart. Over the years, numerous attempts were made to design and develop more effective ECG monitoring system. Nonetheless, the literature reveals not only several limitations in conventional ECG monitoring system but also emphasizes on the need to adopt new technology such as machine learning to improve the monitoring system as well as its medical applications. This paper reviews previous works on machine learning to explain its key features, capabilities as well as presents a general framework for improving ECG monitoring system
Theories for multiple resonances
Two microscopic theories for multiple resonances in nuclei are compared,
n-particle-hole RPA and quantized Time-Dependent Hartree-Fock (TDHF). The
Lipkin-Meshkov-Glick model is used as test case. We find that quantized TDHF is
superior in many respects, except for very small systems.Comment: 14 Pages, 3 figures available upon request
Scale Dependent Dimension of Luminous Matter in the Universe
We present a geometrical model of the distribution of luminous matter in the
universe, derived from a very simple reaction-diffusion model of turbulent
phenomena. The apparent dimension of luminous matter, , depends linearly
on the logarithm of the scale under which the universe is viewed: , where is a correlation length.
Comparison with data from the SARS red-shift catalogue, and the LEDA database
provides a good fit with a correlation length Mpc. The
geometrical interpretation is clear: At small distances, the universe is
zero-dimensional and point-like. At distances of the order of 1 Mpc the
dimension is unity, indicating a filamentary, string-like structure; when
viewed at larger scales it gradually becomes 2-dimensional wall-like, and
finally, at and beyond the correlation length, it becomes uniform.Comment: 6 pages, 2 figure
- …