Morphological filtering on hypergraphs

The focus of this article is to develop computationally efficient mathematical morphology operators on hypergraphs. To this aim we consider lattice structures on hypergraphs on which we build morphological operators. We develop a pair of dual adjunctions between the vertex set and the hyper edge set of a hypergraph H, by defining a vertex-hyperedge correspondence. This allows us to recover the classical notion of a dilation/erosion of a subset of vertices and to extend it to subhypergraphs of H. Afterward, we propose several new openings, closings, granulometries and alternate sequential filters acting (i) on the subsets of the vertex and hyperedge set of H and (ii) on the subhypergraphs of a hypergraph

पिंजऱ्यातील मत्स्यशोति विषयक व्यापार आणि आर्थिक सुसाध्यता/शक्यता

India is one of the largest fish producers in the world and contributes 5.43% to global fish production. India ranks second in fish production from aquaculture sector following China at top. Total fish production of India during 2010-11 was 8.42 million metric tones. Inland sector contributes about 5.2 million metric tones, whereas marine sector contributes 3.22 million metric tones. India has a long coastline of about 8,129 km and continental shelf area of 0.5 million km2. Declining catch rates in marine capture fisheries consequently created serious unemployment issues in rural coastal areas. Issues faced by marine fisheries sector in India have focused the attention of policy makers and rural fishers towards development of mariculture and coastal aquaculture activities as alternative livelihood option

Gravity waves observed from the Equatorial Wave Studies (EWS) campaign during 1999 and 2000 and their role in the generation of stratospheric semiannual oscillations

International audienceThe altitude profiles of temperature fluctuations in the stratosphere and mesosphere observed with the Rayleigh Lidar at Gadanki (13.5° N, 79.2° E) on 30 nights during January to March 1999 and 21 nights during February to April 2000 were analysed to bring out the temporal and vertical propagation characteristics of gravity wave perturbations. The gravity wave perturbations showed periodicities in the 0.5?3-h range and attained large amplitudes (4?5 K) in the mesosphere. The phase propagation characteristics of gravity waves with different periods showed upward wave propagation with a vertical wavelength of 5?7 km. The mean flow acceleration computed from the divergence of momentum flux of gravity waves is compared with that calculated from monthly values of zonal wind obtained from RH-200 rockets flights. Thus, the contribution of gravity waves towards the generation of Stratospheric Semi Annual Oscillation (SSAO) is estimated

Turtle conservation activities in Tambaldeg village, Sindhudurg district, Maharashtra

Tambaldeg village in Devgad taluka is a famous tourist place in the Sindhudurg district. During a field visit to Tambaldeg beach on 24th April 2017, six carcasses of adult olive ridley turtle Lepidochelys olivacea and one of green turtle Chelonia mydas were observed in decomposed state. This beach is a turtle nesting site and the Forest department of Maharashtra with the support of local fishers is undertaking awareness programs for turtle conservation including hoardings displayed on conservation of turtles along the beach. Protection of nesting turtles and eggs is also undertaken by the local communities

First results from the CAWSES-India Tidal Campaign

The first CAWSES-India Tidal Campaign was conducted by the Indian scientific community during March–April 2006. The objectives of this campaign were: (1) To determine the characteristics of tides in the troposphere and lower stratosphere (0–20 km) and mesosphere and lower thermosphere (MLT) region (80–100 km), (2) to explore and identify what lower atmospheric processes drive middle atmospheric tides in the Indian continental region and (3) to provide information on those short-term variabilities of MLT tides that are likely to have an impact on the ionospheric variabilities and contribute to the upper atmospheric weather. Data sets from experiments conducted at the three low latitude radar sites, namely, Trivandrum (8.5° N, 76.9° E), Tirunelveli (8.7° N, 77.8° E) and Gadanki (13.5° N, 79.2° E) and fortnightly rocket launches from Thumba were made use of in this study. An important observational finding reported in this work is that the radar observations at Tirunelveli/Trivandrum indicate the presence of 15–20 day modulation of diurnal tide activity at MLT heights during the February–March period. A similar variation in the OLR fields in the western Pacific (120–160° longitude region) suggests a possible link between the observed tidal variabilities and the variations in the deep tropical convection through the nonmigrating tides it generates

भारतातील आणि महाराष्ट्रातील पिंजऱ्यातील मत्स्यपैदास : सद्य आणि भविष्यातील प्रगतीच्या संधी

Sea farming is a popular area of aquaculture practice throughout the world. In Asian countries, it is rapidly growing to meet the increasing demand of high value marine fishes. Although India has a tradition of aquaculture, sea farming ventures on commercial scale were lacking. In this context, Central Marine Fisheries Research Institute started open sea floating cage culture activities in 2006-07 with Department of Animal Husbandry, Dairying and Fisheries (DAHD&F), Government of India assistance. Indigenous cage of 15 m diameter was fabricated following Norwegian open sea floating cage design and launched at Visakhapatnam. There was a technical setback with the design of cage, and consultation with Indian Institute of Technology, West Bengal helped to overcome technical issues with the cage structure. Open sea floating cage diameter was reduced to 6 m and 14 new open sea floating cages were launched at Sutrapada (Gujarat), Vasai (Maharashtra), Mangalore (Karnataka), Cochin (Kerala), Pulicat (Tamil Nadu), Nellore, Kakinada, Baruva (Andhra Pradesh) and Balasore (Odisha) in participation with National Fisheries Development Board (NFDB)

Vertical propagation characteristics and seasonal variability of tidal wind oscillations in the MLT region over Trivandrum (8.5° N, 77° E): first results from SKiYMET Meteor Radar

Tidal activity in the Mesospheric Lower Thermosphere (MLT) region over Trivandrum (8.5° N, 77° E) is investigated using the observations from newly installed SKiYMET Meteor Radar. The seasonal variability and vertical propagation characteristics of atmospheric tides in the MLT region are addressed in the present communication. The observations revealed that the diurnal tide is more prominent than the semi/terdiurnal components over this latitude. It is also observed that the amplitudes of meridional components are stronger than that of zonal ones. The amplitude and phase structure shows the vertical propagation of diurnal tides with vertical wavelength of ~25 km. However, the vertical wavelength of the semidiurnal tide showed considerable variations. The vertical propagation characteristics of the terdiurnal tide showed some indications of their generating mechanisms. The observed features of tidal components are compared with Global Scale Wave Model (GSWM02) values and they showed a similar amplitude and phase structure for diurnal tides. Month-to-month variations in the tidal amplitudes have shown significant seasonal variation. The observed seasonal variation is discussed in light of the variation in tidal forcing and dissipation