13 research outputs found
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No full textNot AvailableMotivated by the computer search algorithms for constructing two-level supersaturated designs by Heavlin and Finnegan (1993), Li and Wu (1997), Nguyen (1996), Lejeune (2003) and Gupta, Parsad, Kole and Bhar (2008), this paper develops an algorithm to generate multi-level supersaturated designs. Popular E(fnod) and E(λ^2) criterion have been used as a measure of non-orthogonality for the designs generated. The algorithm also ensures that no two columns in the designs generated are fully aliased. A catalogue of 120 optimal supersaturated designs for different number of factors m, design runs n, with 5 ≤ n < 16 runs, and different number of factor levels q, with 3 < q < 6, has been prepared. All the designs generated are fnod-optimal; some designs are λ^2-optimal too.Not Availabl
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No full textNot AvailableMotivated by the computer search algorithms for constructing two-level supersaturated designs by Heavlin and Finnegan (1993), Li and Wu (1997), Nguyen (1996), Lejeune (2003) and Gupta, Parsad, Kole and Bhar (2008), this paper develops an algorithm to generate multi-level supersaturated designs. Popular E (f(NOD)) and E (chi(2)) criterion have been used as a measure of non-orthogonality for the designs generated. The algorithm also ensures that no two columns in the designs generated are fully aliased. A catalogue of 120 optimal supersaturated designs for different number of factors m, design runs n, with 5 <= n <= 16 runs, and different number of factor levels q, with 3 <= q <= 6, has been prepared. All the designs generated are f(NOD)-optimal; some designs are chi(2)-optimalNot Availabl
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No full textNot AvailableThis article describes a general method of construction of supersaturated designs for asymmetric factorials obtained by exploiting the concept of resolvable orthogonal arrays and Hadamard matrices. The supersaturated design constructed here has a restricted form of t.q^ξ // n, where ξ factors are at q-levels each and one factor is at t-levels and the number of runs is n. The designs obtained have the factor at t-levels always orthogonal to the ξ factors with q levels each in the symmetric design q^ξ // n. The method of construction is illustrated with the help of examples. A catalogue of designs obtained is prepared and f_NOD-efficiency and chi-square-efficiency of the designs are given. Many designs are optimal while other designs have high efficiencies. The efficiency of the resulting design is better than that of the symmetric design q^ξ // n.Not Availabl
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No full textNot AvailableThe purpose of this article is to generate mixed-level unbalanced or non-U-type supersaturated designs using computer intensive procedures. Lower bounds to modified E (f_UNOD) and Chi-square_U(D) criteria have been used to measure the efficiency of the generated non-U-type mixed-level supersaturated designs. The catalogue of unbalanced mixed-level supersaturated designs has been given. The designs generated are such that no two
columns are fully aliased.Not Availabl
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No full textNot AvailableSupersaturated Designs (SSDs) are fractional factorial designs in which the run size is not enough to estimate the main effects of all the factors in the experiment Two-level SSDs have been studied extensively in the literature. The thrust of research has been on obtaining lower bounds to the value of E(s^2), a measure of departure from orthogonality, and constructing designs that attain these lower bounds. The focus of this paper is to review the literature on two-level SSDs.Not Availabl
Computer-generated construction of efficient two level supersaturated designs
No full textNot AvailableThe co-ordinate column-wise exchange algorithms of Nguyen (1996) and Lejeune (2003) have been modified to generate efficient supersaturated designs (SSDs) for two-level factorial experiments. Designs have been generated for two different settings viz. (a) the design is balanced in the sense that for an n run design, the +1 and -1 levels appear n/2 times each for all the factors; (b) the design is balanced and there is a subset of factors that are mutually orthogonal. The upper bound on the number of active factors that are estimable through the design has also been obtained by computing the rank of design matrix X using the necessary condition of Srivastava (1975). Catalogues of efficient SSDs have been prepared for number of runs 10<=n<=20, n=2t in (a) and n=4t in (b) ,t a positive integer, and number of factors n+2<=m<=2n. A comparison of the designs generated has been made with the designs available in the literature.Not Availabl
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No full textNot AvailableThis article describes some methods of construction of mixed level fNOD-optimal supersaturated designs. The methods of construction exploit the layout and the property of Uniform designs and Hadamard matrices. Mathematical expression for E(fNOD) and E(Chi-square) criteria have been obtained for many designs constructed in this paper. Some examples are given to illustrate the methods of construction. A catalogue of 67 optimal mixed level supersaturated designs with at most 60 runs and 60 factors is prepared. Some other important features of the designs are also given in the catalogue. All designs are fNOD-optimal while some designs are Chi-square-optimal too.Not Availabl
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No full textNot AvailableThe purpose of this article is to introduce a new class of extended E(s^2)-optimal two level supersaturated designs obtained by adding runs to an existing E(s^2)-optimal two level supersaturated design. The extended design is a union of two optimal SSDs belonging to different classes. New lower bound to E(s^2) has been obtained for the extended supersaturated designs. Some examples and a small catalogue of E(s^2)-optimal SSDs are also included.Not Availabl
Research on Digital Preservation: An empirical analysis
No full textDigital preservation is an evolving area of research for libraries, archives, and museums across the globe over the last two decades. Due to the growing recognition of the need to address various issues dealt with digital preservation, this field of study has generated quite a range of scholarly communications on several aspects. The present paper aims to examine critically the extant literature on digital preservation and libraries for the period from 2001 to 2019 and to assess the evolving trajectory and trends. Out of a total of 1292 extracted records from the Scopus database, a total of 710 articles are considered for the study purpose after the exclusion of non-relevant articles. Employing bibliometric indicators the study primarily assessed the publication pattern, document types, the most prolific authors, most contributing institutions, and focus areas of study as well as the geographical distribution of publications. Along with this, the VOSviewer software is used for co-author network analysis. The findings of the current analysis reveal that the highest number of papers published in the source journal Lecture Notes in Computer Science while the U.S.A. is in the top spot among the countries and author Nelson, M. L. from the U.S.A. has published the maximum number of research papers. It also provides information on various forms of publication on digital preservation and the impactful papers. Though there are studies on the assessment of digital libraries and digital repositories, a bibliometric assessment of literature on digital preservation is a novel attempt. As a metric study, it reflects the relative position of a country, an institution, and a researcher
Distribution of Different forms of Aluminium (Al) under Tea Plantations of Different Age in Eastern Bihar of India
No full textOn average, aluminium makes up 7–8% of the earth\u27s crust, making it the most prevalent metal on the planet and the third most abundant element (after silicon and oxygen). Al is present and widespread throughout the plant life cycle, although it serves no particular biological purpose. Al is mostly present in soil as minerals (aluminosilicates and aluminium oxides) therefore, organisms are typically not exposed to significant quantities of it. The paper aims to distribute different forms of aluminium (Al) under different age tea plantation plantations in Eastern Bihar of India. The study was carried out in different age tea plantations in the eastern region of India with the objective to find out the different forms of Al in the plantation. A representative soil sample was taken from each of the three (3) tea plantations that were taken into consideration for each treatment. Free oxides of iron and aluminium were extracted using the citrate-dithionite-bicarbonate (CBD) method. Following the tea plantation age, treatments were taken into consideration, viz. (i) T1: < 10 years old, (ii) T2: 10–20 years old, (iii) 20–30 years old, (iv) 30–40 years old, and (v) > 40 years old tea gardens. Results found that all forms of Al, such as exchangeable Al, Extractable Al, Non-exchangeable Al, Oxide form of Al/CBD extractable-Al, and Amorphous Al/Oxalate extractable Al concentration, increased with increasing the age of the tea plantation. Furthermore, all forms of Al showed significant and positive correlation with each other. Concentration of various forms of Al in tea soils followed in the order of Oxalate-Al > CBD-Al > Exchangeable Al > Extractable Al > Non-exchangeable Al. Forms of Al concentration gradually increase during tea cultivation over the years, which must be the cause of lowering soil acidity and affect nutrient availability to tea plant growth at old age plantations. Clay content of these soils varied from 19.75 to 21.83%, with a mean content of 20.94%. Water holding capacity found to be low due to light-textured soil, having ranged between 27.00 and 35.67% with an average of 30.76%. All soils were found to be moderately acidic, with soil pH ranging between 4.65 and 5.48, with an average of 5.01. From this study, it may be concluded that the content of all fractions of aluminium concentration increases with increasing age of the tea plantation and all exists exist in equilibrium condition conditions in the soil solution
