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Search Results: 1 - 10 of 668 matches for " Debasish Majumder "
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Value-at-Risk Based on Time-Varying Risk Tolerance Level  [PDF]
Debasish Majumder
Theoretical Economics Letters (TEL) , 2018, DOI: 10.4236/tel.2018.81007
Abstract: The conventional judgement-based method for fixing the risk tolerance level in the Value-at-Risk (VaR) model might be a suboptimal method, because the procedure induces the possibility of bias in risk measurement. Conversely, a superior risk management practice might be one, where input parameters are determined by a quantitative process which is non-subjective to the risk modeller’s preferences. Based on this insight, we have improved on the VaR model. Our model allows time variation of the risk tolerance level and so is suitable for scenario-wise risk analysis.
Genetic Algorithm Based Hybrid Fuzzy System for Assessing Morningness
Animesh Biswas,Debasish Majumder
Advances in Fuzzy Systems , 2014, DOI: 10.1155/2014/732831
Abstract: This paper describes a real life case example on the assessment process of morningness of individuals using genetic algorithm based hybrid fuzzy system. It is observed that physical and mental performance of human beings in different time slots of a day are majorly influenced by morningness orientation of those individuals. To measure the morningness of people various self-reported questionnaires were developed by different researchers in the past. Among them reduced version of Morningness-Eveningness Questionnaire is mostly accepted. Almost all of the linguistic terms used in questionnaires are fuzzily defined. So, assessing them in crisp environments with their responses does not seem to be justifiable. Fuzzy approach based research works for assessing morningness of people are very few in the literature. In this paper, genetic algorithm is used to tune the parameters of a Mamdani fuzzy inference model to minimize error with their predicted outputs for assessing morningness of people. 1. Introduction With the preference of people to perform activities at early hours of a day or later hours or in night, the circadian rhythm of individuals differs. This difference is known as morning versus evening orientation or more simply morningness. These individual differences have greater impact in circadian phase positions on physiological and psychological variables which are controlling them [1]. It is related to the ease of an adjustment to and tolerance of the night or rotating shifts [2] and influences athletic [3] and academic performance [4] at different times of the day. Several self-reporting questionnaires have been developed to measure diurnal type or distinction between “Larks” and “Owls” [5–8]. The assumption guiding these questionnaires is that people who express preference for activities at the extremes of the 24 hours of the day perform physiologic and cognitive tasks in accord with the preference [9]. Factors modulating circadian preference are increasing interest in researchers [10] and these questionnaire techniques have increasing importance in preselection, placement, and counseling of personnel engaged in rotating shift work or night work. Morningness scales, especially the Horne and Ostberg’s [5] Questionnaire (MEQ) is considered as the most popular and standardized for use in various countries and translated version like Posey and Ford [11] validated it in USA; Macacci and Zani [12] in Italy and Kerkhof [13] carried out a validation study of Dutch questionnaire; Ishihara et al., [14] validated in Japanese version; Benedito-Silva et al.,
Heavy Minerals in Sands along Brahmaputra (Jamuna) River of Bangladesh  [PDF]
Md. Ibrahim Khalil, Md. Nazrul Islam Khan, Md. Zafrul Kabir, Ratan Kumar Majumder, Md. Idris Ali, Debasish Paul, Syed Mohammad Azharul Islam
International Journal of Geosciences (IJG) , 2016, DOI: 10.4236/ijg.2016.71005
Abstract: Sands along Brahmaputra River of Bangladesh have long been considered to be a source of heavy minerals (HMs) since it traversed a long way through various terrains. An attempt has been made under this research work to determine the kinds and amounts of heavy minerals in the sands sourced from the river system. Samples from 14 locations along Brahmaputra River covering 30 km distance from upstream to downstream of the river are found to contain different heavy minerals concentration with a range of 7.92 - 25.16 weight% with the remaining of the sample comprising silicate and aluminosilicates. Mineral characterization from peak positions in diffractogram of X-ray Diffraction (XRD) evaluate quartz, feldspar and mica are major categories light mineral while rutile, magnetite, illmenite, zircon, monazite, garnet, uranium arsenide and uranium fluoride are the major types heavy minerals. Ilmenite and rutile are main contributors of total heavy mineral (THM). Titanium bearing minerals ilmenite and rutile contributes 26.22% - 31.01% and 14.57% - 23.50% of THM. In the present study area, most of the sands are found to be fine and medium grained as obtained from the particle sizes analysis using 18- to 230-mesh.
Astrophysical Constraints on the Scale of Left-Right Symmetry in Inverse Seesaw Models  [PDF]
Debasish Borah
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.329144
Abstract: We revisit the recently studied supersymmetric gauged inverse seesaw model [1] to incorporate astrophysical constraints on lightest supersymmetric particle (LSP) lifetime such that LSP constitutes the dark matter of the Universe. The authors in [1] considered light sneutrino LSP that can play the role of inelastic dark matter (iDM) such that desired iDM mass splitting and tiny Majorana masses of neutrinos can have a common origin. Here we consider a generalized version of this model without any additional discrete symmetry. We point out that due to spontaneous R-parity(Rp=(-1)3(B-L)+2s) breaking in such generic supersymmetric gauged inverse seesaw models, LSP can not be perfectly stable but decays to standard model particles after non-renormalizable operators allowed by the gauge symmetry are introduced. We show that strong astrophysical constraints on LSP lifetime makes sneutrino dark matter more natural than standard neutralino dark matter. We also show that long-livedness of sneutrino dark matter constrains the left right symmetry breaking scale MR<104 GeV.
Possible Involvement of Nuclear Factor Kappa B in Rapid Disease Progression in ART Naive HIV-1 Infected Remunerated Blood Donors with History of Oral Iron Intake  [PDF]
Debasish Chattopadhya
Journal of Biosciences and Medicines (JBM) , 2018, DOI: 10.4236/jbm.2018.67006
Abstract: A retrospective analysis on the assessment of the level of p65 component of the transcription factor Nuclear Factor Kappa B (NF-kB p65) in the nuclear extract of lipopolysaccharide stimulated peripheral blood mon-onuclear cells (PBMCs) of remunerated blood donors with HIV-1 infection revealed NF-kB p65 to be significantly higher in the subgroup with history of oral iron intake compared to the HIV-1 infected subgroup without such history. The level of NF-kB p65 in iron consuming subgroup of HIV-1 positive donors showed positive correlation with the serum ferritin level and with the rate of increase in viral load. The NF-kB p65 level also showed positive correlation with the level of superoxide produced by cultured Monocyte derived macrophages (MDMs) as well as with the levels of the immune activation markers viz. Tumour necrosis factor alpha (TNF-α) and two of its soluble markers i.e. Tumour necrosis factor receptor types one and two (TNFRI and TNFRII) reported in earlier studies in the same subgroup. The opposing roles of NF-kB in situation of iron overload in HIV-1 infection i.e. disease enhancement on one hand and facilitation of effective antiretroviral therapy through activation of HIV-1 in the latently infected cells on other hand suggest the need for further research to weigh benefits and risks of iron therapy in situations where iron deficiency in HIV-1 infection may be a serious consideration.
Processing and Material Characteristics of a reclaimed Ground Rubber Tire Reinforced Styrene Butadiene Rubber  [PDF]
Debapriya De, Debasish De
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.25066
Abstract: Mechanochemically partially devulcanized ground rubber tire (GRT) was revulcanized in composition with virgin styrene butadiene rubber (SBR). Reclaiming of GRT was carried out by tetra methyl thiuram disulfide (TMTD) in presence of spindle oil. The cure characteristics and tensile properties of SBR compounds were investigated. Results indicate that the minimum torque and Mooney viscosity of the SBR compounds increase with increasing reclaim rubber (RR) loading whereas the scorch time remain unaltered but optimum cure time exhibit a decreasing trend. Increasing RR loading also gives SBR compounds better resistance towards swelling but the 100% modulus, 200% modulus tensile strength, and the elongation at break increases. Thermogravimetric analysis of SBR/RR vulcanizates was carried out in order to get thermal stability of the vulcanizates. Scanning electron microscopy (SEM) studies further indicate the coherency and homogeneity in the SBR/RR vulcanizates.
Adsorptive Mass Transport of Dye on Rice Husk Ash  [PDF]
Debasish Sarkar, Amitava Bandyopadhyay
Journal of Water Resource and Protection (JWARP) , 2010, DOI: 10.4236/jwarp.2010.25049
Abstract: Experimentations have been carried out to characterize the adsorption of Methylene Blue (MB) and Congo Red (CR) dyes in the aqueous phase onto Rice Husk Ash (RHA). Theoretically analyses are also made for describing the sorption and diffusion processes. The effective pore diffusivities of the dye molecules studied in RHA are determined by a suitable global optimization technique. The depth of penetration, on the other hand, has been estimated for various initial concentrations of dyes. Theoretically predicted concentration pro-files are compared with the experimental values at different initial concentrations of these dyes. Such com-parative studies indicate that the predicted values are in excellent agreement with the experimental values.
High Incidence of Pulmonary Tuberculosis in ART Naive Remunerated Blood Donors with Human Immunodeficiency Virus Type-1 Infection: Possible Role of Iron Overload  [PDF]
Debasish Chattopadhya, Usha Baveja
Journal of Biosciences and Medicines (JBM) , 2018, DOI: 10.4236/jbm.2018.62006
Abstract: Iron overload is reported to be associated with immune alterations and increased susceptibility to infections. HIV infection is characterized by progressive immunodeficiency leading to invasion by opportunistic pathogens. It was of interest to find out if disease course in HIV type-1 infection could have any relation with alteration in body iron status among individuals with history of oral iron intake. A follow-up study of immunologic and virologic markers in relation to disease progression was undertaken on asymptomatic HIV-1 positive blood donors with history of oral iron intake (subgroup I) compared to those without such history (subgroup II). High serum iron was associated with elevated levels of Th2 category of cytokines, heightened immune activation, faster decline in CD4 + T lymphocyte count and higher viral set point. Pulmonary tuberculosis (PT) was the most common AIDS related illness (ARI) (>70%) recorded among subgroup I compared to non-PT category of ARI. Median ARI free duration (months) was shorter among those who developed PT compared to those developing non-PT category of ARI i.e. 30 (95% CI as 26,32) versus 67(95% CI as 60,71) in subgroup I and 47 (95% CI as 42,49) versus 80 (95% CI as 72,87) in subgroup II (P < 0.001 for PT versus non-PT in both subgroups). Median survival duration (months) in the PT versus non-PT categories of ARI was 47 (95% CI as 42,48) versus 95 (95% CI as 90,100) in subgroup I and 71 (95% CI as 65,76) versus 107 (95% CI as 102,112) in subgroup II (P < 0.001 for PT versus non-PT in both subgroups). The present study indicates that body iron overload resulting from excess intake of iron may be associated with qualitative defects in cell mediated immunity at early stage of HIV-1 infection that may facilitate subsequent acquisition of pulmonary tuberculosis, shorter ARI free duration and reduced survival.
Impaired in Vitro Macrophage Function in HIV-1 Infected Remunerated Blood Donors with History of Oral Iron Intake  [PDF]
Debasish Chattopadhya, Alice Verghese
Journal of Biosciences and Medicines (JBM) , 2018, DOI: 10.4236/jbm.2018.64001
Abstract: Both HIV-1 infection and iron overload are independently associated with infection by Mycobacterium tuberculosis due to impaired macrophage function. A prospective study of in vitro assessment of macrophage function was undertaken in a group of asymptomatic HIV-1 infected remunerated (professional) blood donors with (n = 54) or without (n = 54) prevalent practice of oral iron intake (subgroups I and II respectively). The assessment was carried out at enrolment as well as at the point of development of AIDS related illness (ARI). The subgroup I showed higher levels of pro-inflammatory cytokines viz. IL-1β, IL-6 and IL-8, but lowered levels of IL-12p70 in serum as well as in supernatant of monocyte derived macrophage (MDM) cultures both at enrolment and at the point of development of ARI in the subset of cases that developed pulmonary tuberculosis (PT) on follow up compared to the subset that developed categories of ARI other than pulmonary tuberculosis (non-PT) on follow up. The subgroup II of HIV-1 positive donors did not show any such alterations at enrolment or at the point of development of PT or non-PT categories of ARI on follow up. There was significant depression of nitrite level in serum as well as that produced by MDM culture at enrolment in subgroup I regardless of category of ARI developed on follow up while in subgroup II there was significant elevation in these levels at enrolment, more among cases developing PT than those developing non-PT category of ARI. The subgroup I demonstrated increased production of superoxide at enrolment. The present study suggested that depressed production of nitrite and IL-12p70 by macrophages induced by iron overload may be responsible for greater susceptibility of HIV-1 positive donors to M. tuberculosis while superoxide may be a less powerful anti-mycobacterial tool.
Effect of Road Traffic Noise Pollution on Human Work Efficiency in Government Offices, Private Organizations, and Commercial Business Centres in Agartala City Using Fuzzy Expert System: A Case Study
Debasish Pal,Debasish Bhattacharya
Advances in Fuzzy Systems , 2012, DOI: 10.1155/2012/828593
Abstract:
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