scispace - formally typeset
Search or ask a question

Showing papers by "University of Wollongong published in 1972"



Journal ArticleDOI
01 Jul 1972-Fuel
TL;DR: In this paper, the authors show that the maximum reflectivity of coalified anthracites tends to be higher in sections parallel to the plane of the bedding than in sections perpendicular to it.

44 citations


Journal ArticleDOI
TL;DR: The existence of skew-Hadamard matrices of order 8(4f+1) when f is odd and 8f + 1 is a prime power was shown in this paper.
Abstract: The concepts of circulant and backcirculant matrices are generalized to obtain incidence matrices of subsets of finite additive abelian groups. These results are then used to show the existence of skew-Hadamard matrices of order 8(4f+1) when f is odd and 8f + 1 is a prime power. This shows the existence of skew-Hadamard matrices of orders 296, 592, 1184, 1640, 2280, 2368 which were previously unknown.A construction is given for regular symmetric Hadamard matrices with constant diagonal of order 4(2m + 1)2 when a symmetric conference matrix of order 4m + 2 exists and there are Szekeres difference sets, X and Y, of size m satisfying x є X ⇒ −xє X, y є Y ⇒ −y єY.

34 citations


Journal ArticleDOI
TL;DR: Biographical data describing suicide attempts were obtained from a large hospital in the Illawarra region on the south coast of New South Wales, Australia and each admission day was assigned to a moon phase.
Abstract: Some recent studies have indicated that meteorological and climatic variables may be related to the incidence of suicide. Pokorny (1964) and Lester, et al. (1969) have investigated the possibility that completed suicides are related to moon phases. Both authors have found that except in one isolated instance, there does not appear to be a significant association between moon phase and the incidence of completed suicide. However, no data were presented by these authors regarding attempted suicide and moon phases. This report examined the possible association between moon phases and attempted suicide. The Australian suicide rate has been examined by Heczel (1971) who described a striking rise in the rate over the past 20 yr. Oliver, et ul. (1971) described the sharp increase in numbers of patients presenting at the casualty depactment of a large Melbourne hospital after suicidal acts. In the present study biographical data describing suicide attempts were obtained from a large hospital in the Illawarra region on the south coast of New South Wales, Australia. Ss were 84 males and females who had been treated in the casualty department between June 1, 1970, and July 31, 1971. Each admission day was assigned to a moon phase (full moon, third quarter, new moon and first quarter). Suicide attempts were tabulated by sex and moon phase (Table 1 ) .

34 citations


01 Jan 1972
TL;DR: Wallis as mentioned in this paper proved the conjecture for 4, 8, 12, 16, 20, 24, 28, 32, 40 and gave partial results for 36, 44, 52, 56.
Abstract: We study the conjecture: There exists a square (0,l,-l)-matrix W = W(w,k) of order w satisfying WWT= kIw for all k = 0, 1,..., w when w = 0 (mod 4). We prove the conjecture is true for 4, 8, 12, 16, 20, 24, 28, 32, 40 and give partial results for 36, 44, 52, 56. Disciplines Physical Sciences and Mathematics Publication Details Jennifer Seberry Wallis, Orthogonal (0,1,-1) matrices, Proceedings of First Australian Conference on Combinatorial Mathematics, TUNRA, Newcastle, (1972), 61-84. This conference paper is available at Research Online: http://ro.uow.edu.au/infopapers/945 ORTHOGONAL (O,l,-l)-MATRICES Jenn ifer I~a 11 is University of Newcastle, N.S.H., 2308, Australia ABSTRACT We study the conjecture: There exists a square (O,l,-l)-matrix W = W(w,k) of order w 8ati~fying = kI w for aZZ k = 0, 1, ..• , w when w = ° (mod 4). We prove the conjecture is true for 4, 8, 12, 16, 20, 24, 28, 32, 40 and give partial results for 36, 44, 52, 56.We study the conjecture: There exists a square (O,l,-l)-matrix W = W(w,k) of order w 8ati~fying = kI w for aZZ k = 0, 1, ..• , w when w = ° (mod 4). We prove the conjecture is true for 4, 8, 12, 16, 20, 24, 28, 32, 40 and give partial results for 36, 44, 52, 56. One generalization of Hadamard matrices is to weighing matrices (see Olga Taussky [3J), that is square (O,l,-l)-matrices, 1-1, of order n satisfying W1t? = kI n' k ~ n, (1) where I is the identity matrix of order T denotes W transposed. n, W n Clearly WWT = WTW = kI . (2) n These matrices have application both in design of weighing experiments (see Raghavarao [2]) and in coding theory. Write'W(w,k) for a weighing matrix satisfying (1). RELEVANT MATRICES Clearly (O,l,-l)-matrices satisfying WWT = 0 and 11, always exist. Matrices satisfying wwT = nI , n n == O(mod 4) are Hadamard matriqes and if U = I + W is a 8kew ... Hadamal'd matrix = (n l)I • n / For up-to-date results about these matrices we refer the reader to [1, 4, 5]. These matrices exist for 2 and all n _ O(mod 4), n ~ 100. If n 2(mod 4) a matrix satisfying U = I + W with T WW = (n l)I , n is ,called a symmetric conference matrix and these can only exist if a,b integer (see Raghavarao [2]). These matrices exist for ' n = 2(mod 4), n 1 a prime power for n < 100. Write H for the Hadamard matrix of order n, J for the matn n rix of order n of all ones, S for the matrix of order n with zero n diagonal and other elements ±l satisfying SST n n = (n l)I • n The symbol x denotes the Kronecker product and the orders of all matrices are assumed to be compatible under binary operations. SOME CONSTRUCTIONS . T T T T CONSTRUCTION 1. Prov~ded AA + BE + CC + DD = mI and for any X, n Y e: {A, B, c, D}, X and Yare (O,l,-l)-matrices and XyT = yXT, then

24 citations


01 Jan 1972
TL;DR: Hunt et al. as mentioned in this paper used cyclotomy to construct a 4n x 4n Hadamard array, a square matrix of order 4n with elements ± A, ± B, ± C, ± D each repeated n times in each row and column, assuming the indeterminates A, B, C, D commute.
Abstract: A 4n x 4n Hadamard array, H, is a square matrix of order 4n with elements ± A, ± B, ± C, ± D each repeated n times in each row and column. Assuming the indeterminates A, B, C, D commute, the row vectors of H must be orthogonal. These arrays have been found for n = 1 (Williamson, 1944), n = 3 (Baumert-Hall, 1965), n = 5 (Welch, 1971), and some other odd n < 43 (Cooper, Hunt, Wallis). The results for n = 25, 31, 37, 41 are presented here, as is a result for n = 9 not based on supplementary difference sets. This gives the following new orders for Hadamard matrices < 4000: 1804, 3404, 3596, 3772. These results were obtained by using an adaption of cyclotomy which allows the product of incidence matrices to be easily derived. This adaption is developed and the constructions shown for some families of supplementary difference sets. Disciplines Physical Sciences and Mathematics Publication Details David C. Hunt and Jennifer Seberry Wallis, Cyclotomy, Hadamard arrays and supplementary difference sets, Proceedings of the Second Manitoba Conference on Numerical Mathematics. Congressus Numerantium, 7, (1972), 351-381. This conference paper is available at Research Online: http://ro.uow.edu.au/infopapers/944 CYCLOTOMY, HADAMARD ARRAYS AND SUPPLEMENTARY DIFFERENCE SETS • David C. Hunt and Jennifer Wallis University of New South Wales, Kensington, N.S.W., 2033, Australia ond University of Newcastle, N.S.W., 2308, Australia

13 citations


Journal ArticleDOI
TL;DR: Some of the main constituents of Marsdenia rostrata, originating from two localities, were isolated and identified in this article, and two new steroidal ester alkaloids, rostratine and dihydrorostratine, were identified.

12 citations


01 Jan 1972
TL;DR: In this paper, a finite abelian group V and subsets S1, S2,..., Sn of V, write Ti for the totality of all possible differences between elements of Si (with repetitions counted multiply) and T for the whole of members of all the Ti.
Abstract: Given a finite abelian group V and subsets S1, S2, ... ,Sn of V, write Ti for the totality of all the possible differences between elements of Si (with repetitions counted multiply) and T for the totality of members of all the Ti. If T contains each non-zero element of V the same number of times, then the sets S1, S2,...,Sn will be called supplementary difference sets. We discuss some properties for such sets, give some existence theorems and observe their use in the construction of Hadamard matrices and balanced incomplete block designs. Disciplines Physical Sciences and Mathematics Publication Details Jennifer Seberry Wallis, On supplementary difference sets, Aequationes Mathematicae, 8, (1972), 242-257. This journal article is available at Research Online: http://ro.uow.edu.au/infopapers/943 Vol. 8, fase. 3, 1972 Reprint from aequationes mathematicae BIRKHAUSER VERLAG BASEL On Supplementary Difference Sets JENNIFER WALLIS (New South Wales, Australia) pages 242-257 Given a finite abelian group V and subsets S1, S2, ... , Sn of V, write Ti for the totality of all the possible differences between elements of Si (with repetitions counted multiply) and T for the totality of members of all the T i• If T contains each non-zero dement of V the same number of times, then the sets S1> S2,"" Sn will be called supplementary difference sets. We discuss some properties for such sets, give some existence theorems and observe their use in the construction of Hadamard matrices and balanced incomplete block designs.

11 citations


Journal ArticleDOI
TL;DR: The authors assesses the reliability of the peabody picture vocabulary test and conclude that the test is unreliable, but does not consider the use of picture vocabulary tests in the test itself.
Abstract: (1972). An assessment of the reliability of the peabody picture vocabulary test. Australian Psychologist: Vol. 7, No. 3, pp. 167-169.

11 citations




Journal ArticleDOI
TL;DR: A new unsaturated α-amino acid identified as L -2-amINO-4-methyl-5-hexenoic Acid has been isolated from a New Guinea fungus, tentatively identified as Boletus.

Journal ArticleDOI
TL;DR: The mise en correlation des resultats a ces deux genres de mesure a montre une relation directe entre le degre D'enrichissement de l'envitonnement and l'ampleur de la correlation obtenue as discussed by the authors.
Abstract: Cent septante-deux enfants australiens provenant de cinq milieux differents ont ete soumis a un test D'intelligence verbale et a deux epreuves de classification de type piagetien. La mise en correlation des resultats a ces deux genres de mesure a montre une relation directe entre le degre D'enrichissement de l'envitonnement et l'ampleur de la correlation obtenue.


Journal ArticleDOI
TL;DR: Bhattacharyya et al. as mentioned in this paper proposed a method to solve the problem of gender discrimination in the context of gender reassignment, which is based on the Bhattacharya method.
Abstract: For reference to original article by Bhattacharyya, see this Bibliography Vol. 36, No. 2, 09 E72-05525

Journal ArticleDOI
TL;DR: In this paper, the shape strain associated with the formation of two orthorhombic martensite plates in Cu-15 at.% Sn was examined using the double shear theory of martensitic transformations and it was shown that for this transformation the hypothesis that the complementary strain is composed of two strains, appears to be untenable.


Journal ArticleDOI
TL;DR: In this article, the problem of finding the required shape of gravity flow discharge chutes to achieve minimum transit time is formulated as a classical optimization problem using Pontryagin's minimum principle.

Journal ArticleDOI
01 Nov 1972-Politics






01 Jan 1972
TL;DR: In this paper, the authors present a survey of the various linear operators used in this connection, e.g. Bernstein, Szasz, Baskakov, Meyer-Konig and Zeller as well as those of Shah and Suryanarayana.
Abstract: The uniform approximation of continuous functions of a real variable on intervals, through positive linear operators J is an active field of research at present. This study first surveys the various linear operators used in this connection, e.g. Operators of Bernstein, Szasz, Baskakov, Meyer-Konig and Zeller as well as those of Shah and Suryanarayana and the various results obtained from them. The asymptotic form of most of these approximating operators has been studied. These results are ?malogous to those obtained by Sikkema with regards to the Meyer-Konig and Zeller operator. Using the method of Shisha and Mond a quantitative estimation of the closeness of approximation of these operators is then obtained. Finally it is examined whether the derivatives of these operators approximate uniformly the corresponding derivatives of the function. It has been shown that for the Meyer-Konig and Zeller, Baskakov and Szasz operators, they have the property that the v^ derivative of a function can be approximated uniformly by the v derivative of the operator.

01 Jan 1972
TL;DR: One of the major constituents of the free amino acid pool in this Boletus was found to be a new unsaturated α-amino acid, the structure of which has been elucidated as 2(S)-amino-4-methylhex-5-enoic acid.
Abstract: The constituents of the bark and leaves of Schefferomitra subaequalis belonging to the family Annonaceae and those of an allegedly hallucinogenic Boletus species, section Ixocomus, group Nudi, both originating from New Guinea, were investigated. Eight alkaloids were isolated from the bark of Sch. subaegualis. Two of these: liriodenine and anonaine, were already known to be present in Sch. subaegualis. In this investigation three other aporphine alkaloids, asimilobine, isoboldine and anolobine were isolated and identified. In addition two new tetrahydroprotoberberine type alkaloids, aequaline and schefferine and a third new alkaloid, described as alkaloid "Y" have been isolated. The structures of aequaline and schefferine were elucidated as L-3, 9-dihydroxy-2, 10-dimethoxy tetrahydroprotoberberine and L-9-hydroxy-2,3,10-trimethoxy tetrahydroprotoberberine respectively, and their absolute configurations established as S. The structure of the alkaloid "Y" is not yet known. From the leaves of Sch. subaequalis six of the above eight alkaloids viz. anonaine, asimilobine, isoboldine, anolobine, aequaline and schefferine were isolated. Only the two coloured alkaloids: liriodenine and alkaloid "Y" were absent. From the Boletus species there were isolated mannitol and ergosterol and the known amino acids: leucine, isoleucine, valine, methionine, tyrosine, alanine, threonine, glycine, arginine, lysine and histidine. One of the major constituents of the free amino acid pool in this Boletus was found to be a new unsaturated α-amino acid, the structure of which has been elucidated as 2(S)-amino-4-methylhex-5-enoic acid. In addition two apparently new steroids have been isolated and characterised but due to shortage of available material no structural assignments have been made for these compounds.


01 Jan 1972
TL;DR: In this paper, the authors consider testing procedures, equipment, and techniques with recommendations where possible for relevant tests on ferro cement products and present results normally to be expected in practice.
Abstract: At the present time there does not appear to be any standard methods of testing for ferro cement products used in the Boat Industry anywhere in the world. Throughout the literature many tests are suggested, but, in general, are not definitive nor specified in detail. This work considers testing procedures, equipment, and techniques with recommendations where possible for relevant tests on ferro cement products. Also included are results normally to be expected in practice.