http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Deepak Patel,Prasenjit Biswas,Anil Kumar,Hiren R. Kotadia,Archana Mallik,Sanjeev Das 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7
The present investigation focuses on grain refinement in pure aluminum and its alloy under mechanical stirring with a verylow degree of forced convection of 800 rpm as compared to reported values of up to 8000 rpm during direct chill castingprocess (DC). Commercially pure aluminum (99.7%) and Al6082 alloy billets were fabricated in an in-house designed DCcasting simulator. Mechanical forced convection (MFC) was applied to the melt during casting by a common four-bladedimpeller. The microstructural properties of the as-cast billets have been analysed to study the effect of MFC during casting andsolidification. The structure of both Al and its alloy is found to be refined in presence of MFC as compared to conventionalDC. A combination of simulation, experimental and theoretical approaches has been used to determine the effect of MFCin melt-temperature distribution to propose the mechanism of grain refinement. It has been observed that MFC prominentlyreduces the temperature gradient and extends undercooling time, resulting in fine grain structure.
Coupled fixed point theorems for rational inequality in generalized metric spaces
Deepak Singh,Surjeet Singh Tomar,M.S.Rathore,Varsha Chauhan 영남수학회 2015 East Asian mathematical journal Vol.31 No.1
In modern times, coupled fixed point theorems have been rigorously studied by many researchers in the milieu of partially ordered G- metric spaces using different contractive conditions. In this note, some coupled fixed point theorems using mixed monotone property in partially ordered G-metric spaces are obtained. Furthermore some theorems by omitting the completeness on the space and continuity conditions on function, are obtained. Our results partially generalize some existing results in the present literature. To exemplify our results and to distinguish them from the existing ones, we equip the article with suitable examples.
Deepak Sharma 한양대학교 세라믹연구소 2015 Journal of Ceramic Processing Research Vol.16 No.6
In recent years, colloidal processing of advanced ceramics has received an increasing amount of attention in high-tech structural materials for their excellent mechanical properties. Rheological measurements are widely used to identify the nature and behavior of the dispersions, both as a means of studying their fundamental properties and as assessment of their suitability for particular technological purposes. Knowledge of their rheological behavior is essential for almost all dispersion in order to handle them satisfactorily. In this paper, we reviewed comprehensively those parameters which influence the rheological properties and the final assessment of the colloidal dispersion. These parameters allow a wide understanding of colloidal treatment for the process of disspersibility, which is useful way to predict and control a host of product properties, material behavior and end use performance.
Hazardous Air Pollutants Emission Characteristics from Cement Kilns Co-burning Wastes
Deepak Pudasainee,Jeong Hun Kim,Sang Hyeob Lee,Sung Jin Cho,Geum Ju Song,Yong Chil Seo 대한환경공학회 2009 Environmental Engineering Research Vol.14 No.4
Emission characteristics of air pollutants from three commercially operating cement kilns co-burning waste were investigated. The major heavy metals emitted were mercury (Hg), zinc (Zn), nickel (Ni), chromium (Cr), lead (Pb), cadmium (Cd), and arsenic (As) Removal efficiency of the bag filter was above 98.5% for heavy metals (except Hg), and above 60% for Hg. Higher fractions of heavy metals entering the bag filter were speciated to cement kiln dust. On average, 3.3% of the -heavy metals of medium and low toxicity (Pb, Ni, and Cr) entering the bag filter were released into the atmosphere. Among highly toxic heavy metals, 0.14% of Cd, 0.01% of As, and 40% of Hg entering the bag filter were released into the atmosphere. In passing through the bag filter, the proportion of oxidized Hg in all cases increased. Emission variations of hazardous air pollutants in cement kilns tested were related to raw materials, fuel, waste feed and operating conditions. Volatile organic compounds detected in gas emissions were toluene, acrylonitrile benzene, styrene, 1,3-butadiene, and methylene chloride. Although hazardous air pollutants in emissions from cement kilns co-burning waste were within the existing emission limit, efforts are required to minimize their levels.
On the Distribution of a Statistic Used for Detecting First-Order Serial Correlation
Deepak Sanjel,하형태,Serge B. Provost 한국자료분석학회 2008 Journal of the Korean Data Analysis Society Vol.10 No.1
This paper provides a simple methodology for approximating the distribution of a test statistic proposed by J. Durbin and G. S. Watson. After expressing the statistic as a ratio of quadratic forms, its exact moments are evaluated by making use of a recursive formula. Its density function is then approximated by a beta density function multiplied by a linear combination of Jacobi orthogonal polynomials. The coefficients of the linear combination are determined by making use of a moment-based methodology. An integral representation of the moments of the statistic under the alternative hypothesis is also provided. As verified by a simulation study, the approach used in this paper, which takes into account the observation matrix of explanatory variables associated with the assumed regression model, yields very accurate critical values for testing independence versus first-order serial correlation.
H.264/AVC Video Encryption Technique with Different Level of Security
Deepak Kafle,Kyung-Hyune Rhee 한국멀티미디어학회 2008 한국멀티미디어학회 학술발표논문집 Vol.2008 No.1
The H.264/AVC video coding scheme consists of a Video Coding Layer (VCL) and a Network Abstraction Layer (NAL). VCL is mainly responsible for coding video efficiently and the NAL supports video specific transport features for a variety of networks and bitstreams. This paper describes the H.264/AVC NAL in general and proposes to partially encrypt encoded slices without compromising network friendliness and compression efficiency. VCL NAL units are classified into three groups: headers, IDR pictures and non-IDR pictures. We propose a graded security scheme which fully encrypts the IDR pictures and partially encrypts non-IDR pictures. Our experimental results show that the proposed scheme is secure, flexible and have low computational cost.