174 research outputs found
Tuning of Nonlinear PID Controller for TRMS Using Evolutionary Computation Methods
In this paper, the Twin rotor MIMO system (TRMS) is tuned by Nonlinear PID controller using Evolutionary Computation methods. The proposed Nonlinear PID controller, used to tune TRMS, improves the system performance with additional degrees of freedom. Evolutionary Computation methods such as Differential Search Algorithm (DSA), real coded Genetic Algorithm (RGA) with simulated binary crossover (SBX) and Particle Swarm optimization (PSO) and Gravitational Search Algorithm (GSA) are used to determine the optimal parameters of the proposed controller by minimizing Integral Square Error (ISE) for rotor response of TRMS. SIMULINK MATLAB software is used for simulating the system. The statistical performance of the controller is analysed among twenty independent trials by taking best, worst, mean and standard deviations of ISE. Simulation results reveal that TRMS system tuned by nonlinear PID controller using Particle Swarm optimization (PSO) is better than the other methods
Bivalve resources and its exploitation in Malabar
The Malabar region of Kerala (Kozhikode, Kannur, Mahe, Kasargod) has significant bivalve resources contributing to subsistence fisheries of the local population. Clams and oysters form the major resources in the estuaries and backwaters. The clams, Meretrix casta, Meretrix meretrix, Villorita cyprinoides, Paphia malabarica and the edible oyster, Crassostrea madrasensis form the major exploited bivalve resources of commercial significance
Biology of Mactra violacea (Gmelin 1791) from Kerala, south-west coast of India
The surf clam Mactra violacea (commonly
known as violet trough shell), is distributed all along
the sandy beaches of north Kerala. It occurs in the
surf zone, upto 75-100 m depth. It is a large clam
(upto 80 mm) with high meat content and nutritive
value which is collected and consumed by the local
people. The biology of the surf clam was studied to
understand its growth, edibility and potential for
mariculture
Site selection for Mussel Culture
In India, most of the bivalves produced are fished from the natural stocks. At present
green mussels are cultivated mainly in the states of Kerala and Karnataka., Production o f bivalves
by mariciilture in India is very little compared to the rest o f the world. The major source for
collection o f the seeds of the bivalves is through wild collection or through laying of clutch material as in edible oysters
Growth and production of vertically and horizontally suspended mussel ropes in estuarine culture
An experiment to compare the growth and production of vertically and horizontally suspended mussel ropes was conducted in the CMFRI Demonstration cum Research Farm in Chaliyar Estuary, Karuvanthiruthy, Kozhikode. Approximately 13.5 m of vertically suspended and 24 m of horizontal ropes were set in the farm in January 2005. The growth in terms of length and weight was monitored at monthly intervals. A total harvest of 587.7 kg shell-on mussels were obtained of which 249 kg was from vertical and 339 kg from horizontally suspended ropes
Bivalve resources of Moorad Estuary, north Kerala
A bivalve resource survey of Moorad estuary in
Badagara District of north Kerala was carried out
during February 2004 to assess the bivalve species,
their distribution and potential stock.
Sampling sites were fixed within five main
zones of the Moorad estuary based on the clam
fishery activities and local enquiries. The bivalve
distribution in a unit area was taken by demarking
the area of clam bed with a quadrant. Observations
on the area of clam bed, water clarity, depth and
temperature were recorded at each site. Surface
and bottom water samples were collected and
hydrographic parameters like salinity, temperature,
pH and dissolved oxygen content, productivity,
nitrate, phosphate and silicate were recorded.
Sediment samples were collected to analyse the
grain size and organic content of the clam beds. All
samples were analysed within 24 h except sediment
samples. Average density of bivalve per square
metre area was analysed and the potential stock
was estimated for each bivalve species in the
estuary
Mussel seed prospecting along Malabar coast and the influence of rainfall
The green mussel Perna viridis forms a significant
fishery along the Malabar coast. The green mussel forms extensive beds on the laterite and granite formations along Kasargod to Kozhikode in the intertidal and subtidal
zones up to 15-20m depth.The mussel farming sector now faces twofold problem in acquiring seed for farming in the estuaries. a) Mussel spat settlement has been relatively poor and not available duringthe mussel farming season. b) The mussel pickers are unwilling to supply seed to the
mussel farmers
Fishery and biology of Meretrix casta (Chemnitz) in the Moorad estuary, Kerala
Meretrix casta forms an important fishery in the Moorad estuary. The average
annual landing for the period 2000-2004 was 426t, the average catch per effort
was 573 kg and total effort was 3182. Clams ranging from 28 to 32 mm size
contributed to the fishery. M casta is a continuous breeder with two peaks in
March-April and August-September. The precentage edibility ranged between
8 and 16. The standing stock biomass in the Moorad estuary was estimated at
2073 t with an average density of 1096 numbers per sq. m. The present status
and management options for this important fishery are discussed
Mussel culture in backwaters of Kasaragod district, Kerala
Mussel culture is increasingly getting
Popular in Padanna and Cheruvattur Panchayats
In Hosdurg Taluk of Kasaragod district in Kerala,
By virtue of the popularisation efforts made by the
CMFR Institute. Initially this low cost technology
Of farming was transferred to five groups with 15
To 21 farmers at Cheruvattur and Vallyaparamba,
Mostly women groups
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