• Title/Summary/Keyword: VARMA

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MORE EXPANSION FORMULAS FOR q, 𝜔-APOSTOL BERNOULLI AND EULER POLYNOMIALS

  • Ernst, Thomas
    • Communications of the Korean Mathematical Society
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    • v.35 no.2
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    • pp.417-445
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    • 2020
  • The purpose of this article is to continue the study of q, 𝜔-special functions in the spirit of Wolfgang Hahn from the previous papers by Annaby et al. and Varma et al., with emphasis on q, 𝜔-Apostol Bernoulli and Euler polynomials, Ward-𝜔 numbers and multiple q, 𝜔power sums. Like before, the q, 𝜔-module for the alphabet of q, 𝜔-real numbers plays a crucial role, as well as the q, 𝜔-rational numbers and the Ward-𝜔 numbers. There are many more formulas of this type, and the deep symmetric structure of these formulas is described in detail.

Analysis of Multivariate Financial Time Series Using Cointegration : Case Study

  • Choi, M.S.;Park, J.A.;Hwang, S.Y.
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.1
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    • pp.73-80
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    • 2007
  • Cointegration(together with VARMA(vector ARMA)) has been proven to be useful for analyzing multivariate non-stationary data in the field of financial time series. It provides a linear combination (which turns out to be stationary series) of non-stationary component series. This linear combination equation is referred to as long term equilibrium between the component series. We consider two sets of Korean bivariate financial time series and then illustrate cointegration analysis. Specifically estimated VAR(vector AR) and VECM(vector error correction model) are obtained and CV(cointegrating vector) is found for each data sets.

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Dynamic Session Key based Pairwise Key Management Scheme for Wireless Sensor Networks

  • Premamayudu, B;Rao, Koduganti Venkata;Varma, P. Suresh
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.12
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    • pp.5596-5615
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    • 2016
  • Security is one of the major challenges in the Wireless Sensor Networks (WSNs). WSNs are more vulnerable to adversarial activities. All cryptographic security services indirectly depend on key management. Symmetric key management is the best key establishment process for WSNs due to the resource constraints of the sensors. In this paper, we proposed dynamic session key establishment scheme based on randomly generated nonce value and sensor node identity, in which each sensor node is equipped with session key on expire basis. The proposed scheme is compare with five popular existing key management systems. Our scheme is simulated in OMNET++ with MixiM and presented experimental results. The analytical study and experimental results show the superiority of the proposed scheme over the existing schemes in terms of energy, storage, resilience and communication overhead.

Assessment of Post-Earthquake Fire Behavior of a Steel MRF Building in a Low Seismic Region

  • Chicchi, Rachel;Varma, Amit
    • International journal of steel structures
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    • v.18 no.4
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    • pp.1470-1481
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    • 2018
  • Building-level response to post-earthquake fire hazards in steel buildings has been assessed using primarily two-dimensional analyses of the lateral force resisting system. This approach may not adequately consider potential vulnerabilities in the gravity framing system. For this reason, three-dimensional (3D) finite element models of a 10-story case study building with perimeter moment resisting frames were developed to analyze post-earthquake fire events and better understand building response. Earthquakes are simulated using ground motion time histories, while Eurocode parametric time-temperature curves are used to represent compartment fires. Incremental dynamic analysis and incremental fire analysis procedures capture a range of hazard intensities. Findings show that the structural response due to earthquake and fire hazards are somewhat decoupled from one another. Regardless of the level of plastic hinging present in the moment framing system due to a seismic event, gravity column failure is the initiating failure mode in a fire event.

Experimental investigation of wind flow characteristics over hills and escarpments - A review

  • Wani, Abdul Haseeb;Varma, Rajendra K.;Ahuja, Ashok K.
    • Wind and Structures
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    • v.32 no.4
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    • pp.393-403
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    • 2021
  • A comprehensive knowledge of the wind flow in hilly terrains is of great interest in many engineering applications, be it wind energy distribution for suitable site selection for wind farms, pollution dispersion, forest fire propagation or agrometerological studies. Several researchers have shown that wind flow over a hilly terrain may be significantly different when compared with the wind flow over a flat terrain. Complex hilly terrains may alter the wind speed to a great extent. Therefore, this effect of terrain must be properly assessed by designers and planners to arrive at a proper wind flow distribution. This paper reviews the work done in this area over the past three decades. Wind flow over two-dimensional hills and two-dimensional escarpments investigated in wind tunnels by various researchers is presented in this paper.

Genetic Studies and Development of Prediction Equations in Jersey${\times}$Sahiwal and Holstein-Friesian${\times}$Sahiwal Half Breds

  • Singh, P.K.;Kumar, Dhirendra;Varma, S.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.2
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    • pp.179-184
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    • 2005
  • First lactation records (174) of Jersey${\times}$Sahiwal and Holstein Friesian${\times}$Sahiwal half breds under 9 sires maintained at Chandra Shekher Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, India from 1975-1983, were used to estimate the genetic parameters and to predict herd life milk yield and average milk yield per day of herd life from first lactation traits. The traits included were: age at first calving, first service period, first lactation period, first calving interval, first lactation milk yield, milk yield per day of first calving interval, herd life milk yield, herd life and average milk yield per day of herd life. Most of the production and reproduction traits were found to have positive and significant correlations between them on genetic as well as phenotypic scales. Total twelve regression equations were fitted. The prediction equation of herd life milk yield in both the genetic groups showed linear relationship with AFC, FSP, FLP, FLMY and MY/DCI and was apparent and significant. Similarly, polynomials for milk yield per day of herd life for J${\times}$S and HF${\times}$S half breds also showed linear trend, which was found highly significant. The highest and lowest $R^2$ values were found for FCI and AFC, respectively.

Dilemma of gonial angle measurement: Panoramic radiograph or lateral cephalogram

  • Radhakrishnan, Pillai Devu;Varma, Nilambur Kovilakam Sapna;Ajith, Vallikat Velath
    • Imaging Science in Dentistry
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    • v.47 no.2
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    • pp.93-97
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    • 2017
  • Purpose: The purpose of this study was to evaluate the accuracy of panoramic imaging in measuring the right and left gonial angles by comparing the measured angles with the angles determined using a lateral cephalogram of adult patients with class I malocclusion. Materials and Methods: The gonial angles of 50 class I malocclusion patients (25 males and 25 females; mean age: 23 years) were measured using both a lateral cephalogram and a panoramic radiograph. In the lateral cephalograms, the gonial angle was measured at the point of intersection of the ramus plane and the mandibular plane. In the panoramic radiographs, the gonial angle was measured by drawing a line tangent to the lower border of the mandible and another line tangent to the distal border of the ascending ramus and the condyle on both sides. The data obtained from both radiographs were statistically compared. Results: No statistically significant difference was observed between the gonial angle measured using the lateral cephalograms and that determined using the panoramic radiographs. Further, there was no statistically significant difference in the measured gonial angle with respect to gender. The results also showed a statistically insignificant difference in the mean of the right and the left gonial angles measured using the panoramic radiographs. Conclusion: As the gonial angle measurements using panoramic radiographs and lateral cephalograms showed no statistically significant difference, panoramic radiography can be considered in orthodontics for measuring the gonial angle without any interference due to superimposed images.

Fundamental behavior of CFT beam-columns under fire loading

  • Varma, Amit H.;Hong, Sangdo;Choe, Lisa
    • Steel and Composite Structures
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    • v.15 no.6
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    • pp.679-703
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    • 2013
  • This paper presents experimental investigations of the fundamental behavior of concrete filled steel tube (CFT) beam-columns under fire loading. A total of thirteen specimens were tested to determine the axial force-moment-curvature-temperature behavior of CFT beam-columns. The experimental approach involved the use of: (a) innovative heating and control equipment to apply thermal loading and (b) digital image correlation with close-range photogrammetry to measure the deformations (e.g., curvature) of the heated region. Each specimen was sequentially subjected to: (i) constant axial loading; (ii) thermal loading in the expected plastic hinge region following the ASTM E119 temperature-time T-t curve; and (iii) monotonically increasing flexural loading. The effects of various parameters on the strength and stiffness of CFT beam-columns were evaluated. The parameters considered were the steel tube width, width-tothickness ratio, concrete strength, maximum surface temperature of the steel tube, and the axial load level on the composite CFT section. The experimental results provide knowledge of the fundamental behavior of composite CFT beam-columns, and can be used to calibrate analytical models or macro finite element models developed for predicting behavior of CFT members and frames under fire loading.

Equilibrium and kinetic studies on the adsorption of copper onto carica papaya leaf powder

  • Varma V., Geetha;Misra, Anil Kumar
    • Membrane and Water Treatment
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    • v.7 no.5
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    • pp.403-416
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    • 2016
  • The possibility of using carica papaya leaf powder for removal of copper from wastewater as a low cost adsorbent was explored. Different parameters that affect the adsorption process like initial concentration of metal ion, time of contact, adsorbent quantity and pH were evaluated and the outcome of the study was tested using adsorption isotherm models. A maximum of 90%-94.1% copper removal was possible from wastewater having low concentration of the metal using papaya leaf powder under optimum conditions by conducting experimental studies. The biosorption of copper ion was influenced by pH and outcome of experimental results indicate the optimum pH as 7.0 for maximum copper removal. Copper distribution between the solid and liquid phases in batch studies was described by isotherms like Langmuir adsorption and Freundlich models. The adsorption process was better represented by the Freundlich isotherm model. The maximum adsorption capacity of copper was measured to be 24.51 mg/g through the Langmuir model. Pseudo-second order rate equation was better suited for the adsorption process. A dynamic mode study was also conducted to analyse the ability of papaya leaf powder to remove copper (II) ions from aqueous solution and the breakthrough curve was described by an S profile. Present study revealed that papaya leaf powder can be used for the removal of copper from the wastewater and low cost water treatment techniques can be developed using this adsorbent.

Effects of Leachate during Vegetable Waste Composting using Rotary Drum Composter

  • Varma, V. Sudharsan;Kalamdhad, Ajay S.
    • Environmental Engineering Research
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    • v.19 no.1
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    • pp.67-73
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    • 2014
  • In India, disposal of vegetable market waste along with municipal solid waste in landfills or dumpsites is creating much nuisance in terms of odor nuisance, leachate production, and greenhouse gas emission into the atmosphere. Therefore, vegetable waste with high biodegradable and nutrient content is composted in a 550-L batch scale rotary drum composter to study the degradation process and its compost properties for its potential reuse as high quality compost. A total 150 kg of working volume was fixed for composting studies with two different ratios, trial A (6:3:1) of C/N 24 and trial B (8:1:1) of C/N 30, respectively. A maximum of $63.5^{\circ}C$ and $61.2^{\circ}C$ was observed in trials A and B; an average of $55^{\circ}C$ for more than 5 days, which helped in the degradation of organic matter and reduction of total and fecal coliform. The temperature dropped suddenly after the thermophilic stage in trial B, and leachate was observed due to insufficient amount of bulking agent. Mesophilic bacteria dominated during the initial stages of composting, and reduced considerably during the thermophilic stage. During the thermophilic stage, the rise in spore-forming organisms, including spore-forming bacteria, fungi, actinomycetes and streptomycetes, increased and these were predominant until the end of the composting process. By examination, it was observed that moisture and leachate production had adverse effects on the compost parameters with higher loss of micronutrients and heavy metals.