Leaky Wave-Guide Based Dielectric Resonator Antenna for Millimeter-Wave Applications

Sovan Mohanty,Baibaswata Mohapatra 한국전기전자재료학회 2021 Transactions on Electrical and Electronic Material Vol.22 No.3

In this paper, a leaky wave antenna based on the parallel non-radiative dielectric guide (NRD) has been proposed. This novel design uses two parallel dielectric strip waveguides having a dielectric constant of 2.2 are placed over a substrate of the dielectric constant of 2.55 and both are separated by a ground plane. The upper structure is bounded by defl ating conducting strip having distance less than λ 0 /2. The leakage from this antenna is in the form of surface wave concentrated more in the broadside direction rather than usual endfire or off broadside direction. It has been observed the proposed radiating structure has radiation effi ciency of 82%, the peak gain of 5.94 dB with narrow impedance bandwidth, and the resonating frequency at 13.59 GHz, 13.43 GHz, and 13.93 GHz. A comparative analysis is made by increasing the height of the dielectric strip to increase the number of modes. This leaky-wave structure based on a non-radiative dielectric (NRD) guide can be a suitable candidate for the device to device (D2D) communication in the millimeter-wave band.

Evaluation of Environmental Factors to Determine the Distribution of Functional Feeding Groups of Benthic Macroinvertebrates Using an Artificial Neural Network

박영석,Sovan Lek,전태수,Piet F.M. Verdonschot 한국생태학회 2008 Journal of Ecology and Environment Vol.31 No.3

Functional feeding groups (FFGs) of benthic macroinvertebrates are guilds of invertebrate taxa that obtain food in similar ways, regardless of their taxonomic affinities. They can represent a heterogeneous assemblage of benthic fauna and may indicate disturbances of their habitats. The proportion of different groups can change in response to disturbances that affect the food base of the system, thereby offering a means of assessing disruption of ecosystem functioning. In this study, we used benthic macroinvertebrate communities collected at 650 sites of 23 different water types in the province of Overijssel, The Netherlands. Physical and chemical environmental factors were measured at each sampling site. Each taxon was assigned to its corresponding FFG based on its food resources. A multilayer perceptron (MLP) using a backpropagation algorithm, a supervised artificial neural network, was applied to evaluate the influence of environmental variables to the FFGs of benthic macroinvertebrates through a sensitivity analysis. In the evaluation of input variables, the sensitivity analysis with partial derivatives demonstrates the relative importance of influential environmental variables on the FFG, showing that different variables influence the FFG in various ways. Collector-filterers and shredders were mainly influenced by Ca²+ and width of the streams, and scrapers were influenced mostly with Ca²+ and depth, and predators were by depth and pH. Ca²+ and depth displayed relatively high influence on all four FFGs, while some variables such as pH, %gravel, %silt, and %bank affected specific groups. This approach can help to characterize community structure and to ecologically assess target ecosystems. Functional feeding groups (FFGs) of benthic macroinvertebrates are guilds of invertebrate taxa that obtain food in similar ways, regardless of their taxonomic affinities. They can represent a heterogeneous assemblage of benthic fauna and may indicate disturbances of their habitats. The proportion of different groups can change in response to disturbances that affect the food base of the system, thereby offering a means of assessing disruption of ecosystem functioning. In this study, we used benthic macroinvertebrate communities collected at 650 sites of 23 different water types in the province of Overijssel, The Netherlands. Physical and chemical environmental factors were measured at each sampling site. Each taxon was assigned to its corresponding FFG based on its food resources. A multilayer perceptron (MLP) using a backpropagation algorithm, a supervised artificial neural network, was applied to evaluate the influence of environmental variables to the FFGs of benthic macroinvertebrates through a sensitivity analysis. In the evaluation of input variables, the sensitivity analysis with partial derivatives demonstrates the relative importance of influential environmental variables on the FFG, showing that different variables influence the FFG in various ways. Collector-filterers and shredders were mainly influenced by Ca²+ and width of the streams, and scrapers were influenced mostly with Ca²+ and depth, and predators were by depth and pH. Ca²+ and depth displayed relatively high influence on all four FFGs, while some variables such as pH, %gravel, %silt, and %bank affected specific groups. This approach can help to characterize community structure and to ecologically assess target ecosystems.

Development of sustainable elastomeric engineering nanocomposites from linseed oil with improved mechanical stability and thermally induced shape memory properties

Rakesh Das,Sovan Lal Banerjee,Rajesh Kumar,P.P. Kundu 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.35 No.-

The elastomeric nanocomposites having high mechanical stability and shape memory property werefabricated via in situ cationic polymerization of vegetable oil (linseed oil) in the presence of nano fly ash(NFA). The enhanced dynamic moduli and Young’s modulus of nanocomposites with respect to matrixelastomers were witnessed. The vibration damping behavior of nanocomposites in wide frequencyregion, observed under a laboratory fabricated machine reveals their effectiveness to attenuatehazardous vibration in broad application regions. Under thermally stimulated shape memory test, thenanocomposites exhibit 100% shape recovery, and the shape recovery time improves when the contentof NFA filler increases.

Interval-Valued Fuzzy Graphs

Tarasankar Pramanik,Sovan Samanta,Madhumangal Pal 한국지능시스템학회 2020 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.20 No.4

Interval-valued fuzzy graphs (IVFGs) are a generalization of fuzzy graphs. In this article, the sum distance between vertices in an IVFG is introduced. This definition satisfies the metric properties. In addition, some important aspects related to eccentricity, radius, and diameter are proved. The necessary and sufficient conditions for a vertex to be eccentric are established. The relationship between eccentricities and the sum distance between two vertices is derived. An algorithm is presented to determine the sum distance between two vertices in interval-valued fuzzy graphs. Furthermore, some related theorems for the complete IVFG are deduced.

Fuzzy $$\phi $$ ϕ -tolerance competition graphs

Pramanik, Tarasankar,Samanta, Sovan,Sarkar, Biswajit,Pal, Madhumangal Springer-Verlag 2017 SOFT COMPUTING Vol.21 No.13

Felodipine loaded PLGA nanoparticles: preparation, physicochemical characterization and in vivo toxicity study

Jana Utpal,Mohanty Anjan Kumar,Pal Sovan Lal,Manna Prabal Kumar,Mohanta Guru Prasad 나노기술연구협의회 2014 Nano Convergence Vol.1 No.31

Felodipine, a calcium channel blocker has been widely used for the treatment of hypertension and cardiovascular diseases; but the frequent dosing is needed for its poor solubility and variable bioavailability. In present study an attempt has been made to overcome the problems through nanoparticulate delivery system using poly (D, L-lactic-co-glycolic acid) polymer keeping in the view to get better sustainability of the formulation. The nanoparticles were prepared by single emulsion solvent evaporation technique and the physico-chemical characterization of prepared nanoparticles confirmed the particles were nanosize range with smooth and spherical morphology. Further, the compatibility of drug-polymer combination was analyzed by FTIR and DSC study. The in vitro drug release study of PLGA nanoparticles showed longer duration of drug release with reduced burst release compared with pure felodipine. The in vitro drug release data were fitted with various mathematical models to establish the drug release mechanism from the nanoparticles and found to follow mixed order kinetics. The in vivo toxicity study in albino mice showed no noticeable change in biochemical parameters and histopathology of organs. Hence, the developed felodipine nanoparticles were prepared, characterized and could possibly be advantageous for prolonged drug release and improving the antihypertensive effect.

Green computing: Practice of Efficient and Eco-Friendly Computing Resources

Parichay Chakraborty,Debnath Bhattacharyya,Sattarova Nargiza Y,Sovan Bedajna 보안공학연구지원센터(IJGDC) 2009 International Journal of Grid and Distributed Comp Vol.2 No.3

Relational Patterning on Different Hierarchical Levels in Communities of Benthic Macroinvertebrates in an Urbanized Stream Using an Artificial Neural Network

Park, Young-Seuk,Kwak, Inn-Sil,Cha, Eui-Young,Sovan Lek,Chon, Tae-Soo Korean Society of Applied Entomology 2001 Journal of Asia-Pacific Entomology Vol.4 No.2

Relations between different hierarchical levels in communities of benthic macroinvertebrates were patterned by using the counterpropagation neural network. Two data sets in densities of different level in taxonomy (e. g., Family and Genus/Species) and functional groups were provided concurrently as input and output to the neural network. A "cross-training" by the counterpropagation network was conducted between two sets of data. In the trained patterns, abundant groups appeared more consistently while the groups in low densities tended to disappear. The patterned relationships between the hierarchical levels reflected the variation of community groupings and the "two-way" patterning between input and output data was possible. Through the recognition process the trained network was further able to forecast the densities at the other hierarchical layer in a time-delayed manner if previous community data were given as input.were given as input.