3,841 research outputs found
On structuring the rules of a fuzzy controller
Since the pioneering work of Zadeh and Mamdani and Assilian, fuzzy logic control has emerged as one of the most active and fruitful research areas. The applications of fuzzy logic control can be found in many fields such as control of stream generators, automatic train operation systems, elevator control, nuclear reactor control, automobile transmission control, etc. In this paper, two new structures of hierarchical fuzzy rule-based controller are proposed to reduce the number of rules in a complete rule set of a controller. In one approach, the overall system is split into sub-systems which are treated independently in parallel. A coordinator is then used to take into account the interactions. This is done via an iterating information exchange between the lower level and the coordinator level. From the point of view of information used, this structure is very similar to central structure in that the coordinator can have at least in principle, all the information that the local controllers have
A new look at numerical analyses of free-edge stresses in composite laminates
The edge stress problem for a + or - 45 deg graphite/epoxy laminate was examined. The reliability of the displacement formulated finite element method in analyzing the edge stress problem was investigated. Analyses of two well known elasticity problems, one involving a stress discontinuity and one a singularity, showed that the finite element analysis yields accurate stress distributions everywhere except in two elements closest to the stress discontinuity of singularity. Stress distributions for a + or - 45 deg laminate showed the same behavior near the singularity found in the well known problems with exact solutions. The displacement formulated finite element method appears to be a highly accurate technique for calculating interlaminar stress in composite laminates. The disagreement among the numerical methods was attributed to the unsymmetric stress tensor at the singularity
Automatic test and planning procedures for navigation and air traffic control satellites Bibliography
Automatic test and planning procedures bibliography for navigation and air traffic control satellite
Preliminary Phytochemical Analysis of \u3cem\u3eDiospyros\u3c/em\u3e Species
Diospyros species are valuable traditional medicines of Chinese herbal medicine, Tibetan medicine, and Ayurvedic medicine. Extractive values and qualitative identification of phytochemicals constituents of 29 Diospyros species was carried out. The methanolic fruit extract yielded maximum percentage of Diospyros malabarica (5.61%), and minimum percentage of Diospyros foliosa (1.25%). Fruits of Diospyros species showed the presence of bioactive constituents of alkaloids (82%), flavonoids (68.97%), tannin (55.17%), terpenoids (100%), and essential oils (100%) were detected in 29 Diospyros species
On the transition from complex to real scalar fields in modern cosmology
We study some problems arising from the introduction of a complex scalar
field in cosmology, modelling its possible behaviors in both the inflationary
and dark energy stages of the universe. Such examples contribute to show that,
while the complex nature of the scalar field can be indeed important during
inflation, it loses its meaning in the later dark-energy dominated era of
cosmology, when the phase of the complex field is practically constant, and
there is indeed a transition from complex to real scalar field. In our
considerations, the Noether symmetry approach turns out to be a useful tool
once again. We arrive eventually at a potential containing the sixth and fourth
powers of the scalar field, and the resulting semiclassical quantum cosmology
is studied to gain a better understanding of the inflationary stage.Comment: 21 pages, 6 figures. In the new version, sections I, IV and VI have
been improved, and two words have been added at the beginning of the titl
PERFORMANCE STUDY OF FLEXIBLE PAVEMENTS ON NON EXPANSIVE SOILS
As part of infrastructure development huge investment is being made on expansion of National highways and important roads across the country. For improvement of Highways two types of Pavements are commonly used in India viz., Flexible Pavements (Bituminous) and rigid pavements (Concrete). Flexible pavements are widely used in this country from the considerations of economy The performance of Flexible pavements depends largely on properties of original ground on which the pavement rests, the quality of materials used in the construction of various layers of pavement and quality assurance as per relevant specifications. In general any road after construction is basically evaluated by the performance in terms of unevenness index and structural stability over a period of time. The evaluation of these two important parameters will facilitate the clear understanding of performance of various materials used in the construction and to undertake suitable rehabilitation measures if necessary. Keywords: Expansive Soil, Flexible Pavement
Development of indigenous column flotation technology at NML for the beneficiation of low-grade ores
NML Madras Centre has designed and developed indigenous automated flotation columns as part of its long term R&D program on the utilization of low-grade ores of India. Both laboratory size and semi-commercial flotation columns were extensively field tested in different mineral processing plants owned by Hindustan Copper Limited, Hindustan Zinc Limited, Kudremukh Iron Ore Company Limited, Sociedade De Fomento Industrial Limited, Bharat Gold Mines Limited, Gujarat Mineral Development Corporation Limited and Indian Rare Earths Limited for the beneficiation of copper, lead and zinc, iron, gold, fluorspar and sillimanite. State-of-the-art equipment was incorporated in both laboratory and semi-commercial flotation columns. Advantages of column flotation technology over conventional flotation machines and salient features of the NML flotation column were
discussed in the present paper. Flotation test results obtained both by flotation column and conventional cells were compared. The paper also highlights the potential of column flotation technology in achieving better metallurgical results
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