http://nopr.niscpr.res.in/handle/123456789/58543 Sun, 11 Oct 2026 23:19:00 GMT 2026-10-11T23:19:00Z https://http://nopr.niscpr.res.in:443/retrieve/181849/ijms2.jpg http://nopr.niscpr.res.in/handle/123456789/58543 http://nopr.niscpr.res.in/handle/123456789/58553 Title: Improved Collaborative Spectrum Sensing Scheme for Maritime Cognitive Radio Authors: Kailasam, M; Sankararajan, R; Rajendran, H Abstract: Expeditious growth in wireless networks for numerous wireless services and applications lead to the increase in demand for radio spectrum in both terrestrial and marine wireless communications. Radio spectrum is scarce as the available spectrum is already been allocated to various applications. Cognitive radio technology is an optimistic solution for the spectral scarcity. In Cognitive Radio Networks (CRN), the unused licensed bands are dynamically accessed by the unlicensed secondary users for data transmission. Spectrum Sensing (SS) is the key technique to detect the presence or absence of the primary users. SS for terrestrial wireless communication have been studied vastly. This paper is aimed to study SS for Maritime Cognitive Radio Networks (MCRN) which is daunting as SS in MCRN depends on the sea state. Existing work on SS in MCRN deals with Classical Energy Detection (CED) which is a straight forward procedure with low complexity and can be applied generally to any signal irrespective of its format. Here we intend to perform SS in MCRN using Improved Energy Detection (IED) which surpasses the performance of CED without ruining its general attributes. Evaluations and analysis are carried out using detection probability performance metric for both CED and IED, simulated and compared for different sea states. Page(s): 603-612 Sun, 01 Aug 2021 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/58553 2021-08-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/58552 Title: Comparing performance of inter-sensor NDVI for the detection of floating macroalgal blooms in the Yellow Sea Authors: Sakib, M H; Rashid, A H A; Yang, C-S Abstract: There are many complains against macroalgal bloom (MAB) from all over the world for its high negative economic impacts. Early and precise detection of MAB occurance can reduce huge economic loss in tourism and marine business. Thus, this study aims to detect the MAB in the Yellow Sea (YS) by comparing performance of Normalized Difference Vegetation Index (NDVI) between Geostationary Ocean Color Imager (GOCI) and Landsat-8 sensors from 2014 to 2019. The largest MAB during this period was identified from Landsat-8 sensors along the coast of Sheyang and Qingdao of China in 2018. The locations of MABs were almost nearby areas during the begining phase of MABs in consecutive years. In successive years huge and dense MABs reached the brink of shoreline of Qingdao. In Landsat-8 images in most cases larger total areas of MABs were detected including very small pathches which could not be detected from GOCI due to low spatial resolution. The findings of this study will be helpful for scientists to choose between GOCI and Landsat-8 based on the objectives of their study. Page(s): 613-619 Sun, 01 Aug 2021 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/58552 2021-08-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/58551 Title: Characterization and antibacterial activity of violacein producing deep purple pigmented bacterium Pseudoalteromonas luteoviolacea (Gauthier, 1982) isolated from coral reef ecosystems Authors: Jayasree, V S; Sobhana, K S; Priyanka, P; Keerthi, K R; Jasmine, S; Ranjith, L; Ramkumar, S; Saravanan, R; Kingsley, H J; Sreenath, K R; George, R M; Joshi, K K; Gopalakrishnan, A Abstract: The present study describes the isolation, characterization and antibacterial activity of two strains of the deep purple pigmented bacterium Pseudoalteromonas luteoviolacea designated P42 (Accession no. MN647538) and M64 (Accession no. MN647537), isolated from two coral reef regions viz. Minicoy Lagoon in the Lakshadweep Sea and Palk Bay, off Olaikuda village in Tamil Nadu, India. Ultrastructural examinations were done using scanning and transmission electron microscopy. Presence of violacein pigment was qualitatively analysed by chemical methods; UV-VIS spectrophotometry and FTIR spectroscopy. The strains, P42 and M64 were found to have antibacterial activity against 13 out of the 36 marine bacterial species tested. Antibiogram analysis revealed the sensitivity of both the strains to all the antibiotics tested, except for the resistance of P42 to Penicillin G and Trimethoprim. This study reports the isolation and characterization of P. luteoviolacea for the first time from India. Since both the isolated strains have shown clear evidence for the presence of violacein as well as antibacterial activity against selected marine bacteria, both P42 and M64 can be suggested as potent antibacterial agents. Page(s): 620-634 Sun, 01 Aug 2021 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/58551 2021-08-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/58550 Title: Redescription of poorly known neustonic calanoid copepod Pontella andersoni Sewell, 1912 (Family: Pontellidae) from the Bay of Bengal, Indian Ocean Authors: Francis, S V; Purushothaman, J; Siddique, A; Bhowal, A; Nandan, S B Abstract: The neustonic calanoid copepod of family Pontellidae Pontella andersoni Sewell, 1912 was originally described from the Bay of Bengal based on a single male and a damaged female with a description of copepodid stage III. Later, this species was described from Gulf of Mannar (based on a male specimen) and from West Java (based on immature specimens). In the present study, adult female and male specimens were collected from the coastal waters of northern Bay of Bengal. The species was easily distinguished from its congeners by a barrel shaped first urosomal somite in female, and two subequal spines with two knot-like projections in the first exopodal segment of right fifth leg, serrated spine and three processes in the second exopodal segment of left leg in male. The present note is an updated illustrative description of P. andersoni, since the previous descriptions were lacking the taxonomic resolution. Page(s): 635-640 Sun, 01 Aug 2021 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/58550 2021-08-01T00:00:00Z