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Hardware/Software Tradeoffs for Bitmap Graphics on the Blit
 SoftwarePractice and Experience
, 1985
"... The Blit is an experimental bitmap graphics terminal built for research into interactive computer graphics on the UNIX timesharing system. The hardware is inexpensive and the graphics functions are implemented entirely in software. Nevertheless, the graphics performance of the Blit is comparable ..."
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Cited by 39 (3 self)
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The Blit is an experimental bitmap graphics terminal built for research into interactive computer graphics on the UNIX timesharing system. The hardware is inexpensive and the graphics functions are implemented entirely in software. Nevertheless, the graphics performance of the Blit is comparable or superior to some displays with special purpose graphics hardware. This paper explains the paradox by referring to some principles of design: the hardware and software should be designed together to complement each other; carefully designed software can outperform infelicitous hardware; and simplicity of design leads to efficiency of execution. These principles are illustrated by examples from the Blit hardware and software and comparisons with other systems. March 30, 2000 _______________ * Current address: Bell Laboratories Murray Hill, New Jersey 07974 AT&T Bell Laboratories Holmdel, NJ 07733. Current address: Valid Logic Systems, Mountain View CA 94043 Hardware/Software Trad...
Capabilitybased Financial Instruments
 In Proc. Financial Cryptography 2000, Anguila, BWI
, 2000
"... Every novel cooperative arrangement of mutually suspicious parties interacting electronically  every smart contract  effectively requires a new cryptographic protocol. However, if every new contract requires new cryptographic protocol design, our dreams of cryptographically enabled electronic ..."
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Cited by 38 (6 self)
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Every novel cooperative arrangement of mutually suspicious parties interacting electronically  every smart contract  effectively requires a new cryptographic protocol. However, if every new contract requires new cryptographic protocol design, our dreams of cryptographically enabled electronic commerce would be unreachable. Cryptographic protocol design is too hard and expensive, given our unlimited need for new contracts.
Counting Lattice Paths By Narayana Polynomials
 J. Comb
, 2000
"... Let d(n) count the lattice paths from (0, 0) to (n, n) using the steps (0,1), (1,0), and (1,1). Let e(n) count the lattice paths from (0, 0) to (n, n) with permitted steps from the step set NN f(0; 0)g, where N denotes the nonnegative integers. We give a bijective proof of the identity e(n) = 2 n 1 ..."
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Cited by 26 (3 self)
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Let d(n) count the lattice paths from (0, 0) to (n, n) using the steps (0,1), (1,0), and (1,1). Let e(n) count the lattice paths from (0, 0) to (n, n) with permitted steps from the step set NN f(0; 0)g, where N denotes the nonnegative integers. We give a bijective proof of the identity e(n) = 2 n 1 d(n) for n 1. In giving perspective for our proof, we consider bijections between sets of lattice paths defined on various sets of permitted steps which yield path counts related to the Narayana polynomials.
Objects Counted By The Central Delannoy Numbers
 J. Int. Seq
"... The central Delannoy numbers, (d n ) n0 = 1; 3; 13; 63; 321; 1683; 8989; 48639; : : : (A001850 of The OnLine Encyclopedia of Integer Sequences) will be defined so that dn counts the lattice paths running from (0; 0) to (n; n) that use the steps (1; 0), (0; 1), and (1; 1). In a recreational spirit w ..."
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Cited by 11 (2 self)
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The central Delannoy numbers, (d n ) n0 = 1; 3; 13; 63; 321; 1683; 8989; 48639; : : : (A001850 of The OnLine Encyclopedia of Integer Sequences) will be defined so that dn counts the lattice paths running from (0; 0) to (n; n) that use the steps (1; 0), (0; 1), and (1; 1). In a recreational spirit we give a collection of 29 configurations that these numbers count.
A Metalevel Architecture for Prototyping Object Systems
, 1995
"... As applications become larger and more complex, it is frequently the case that system components require varying models of computation. The use of different computational models is not well supported by standard objectoriented mechanisms and systems. Typical mechanisms implicitly encapsulate metal ..."
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Cited by 4 (0 self)
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As applications become larger and more complex, it is frequently the case that system components require varying models of computation. The use of different computational models is not well supported by standard objectoriented mechanisms and systems. Typical mechanisms implicitly encapsulate metalevel (i.e., computational) semantics along with the baselevel (i.e., domain) behaviour. Objects defined using one model cannot easily be executed under another and so cannot be reused. A major problem is the inclusion of baselevel language constructs in the metalevel architecture design. Metalevels typically only facilitate concepts which are similar to those in the original baselevel language and so cannot describe widely differing models of execution. We present a metalevel architecture founded on the novel principle of finegrained, operational decomposition of the metalevel into objects. Unlike others, our approach bases the design of the architecture on the operations which occur during object execution (e.g., send, lookup) rather than the structural nature of an object’s representation (e.g., class, method). This clearly separates the elements of the metalevel from those of the baselevel language and so opens the metalevel to more radical change. The power of this approach is shown via several markedly different object
The excedances and descents of biincreasing permutations
, 2002
"... Abstract. Motivated by the relations between certain difference statistics and the classical permutation statistics we study permutations whose inversion number and excedance difference coincide. It turns out that these (socalled biincreasing) permutations are just the 321avoiding ones. The paper ..."
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Cited by 4 (3 self)
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Abstract. Motivated by the relations between certain difference statistics and the classical permutation statistics we study permutations whose inversion number and excedance difference coincide. It turns out that these (socalled biincreasing) permutations are just the 321avoiding ones. The paper investigates their excedance and descent structure. In particular, we give some combinatorial interpretations for the distribution coefficients of the numbers of excedances and descents and their difference analogues over biincreasing permutations in terms of parallelogram polyominoes and 2Motzkin paths. This yields a connection between restricted permutations, parallelogram polyominoes, and lattice paths that reveals the relations between several wellknown bijections involving these objects (e.g. by DelestViennot, BilleyJockuschStanley, FrançonViennot, and FoataZeilberger). Keywords permutation statistics, patternavoiding permutations, parallelogram polyominoes, lattice paths 1 Motivation and preliminaries Let Sn be the set of all permutations of [n]: = {1,..., n}. We write any permutation π ∈ Sn as a word π1 · · · πn where πi means the integer π(i). In this paper, we will mainly investigate certain permutations in view of the behaviour of their excedances and descents. First we recall the definitions and introduce some notations. For π ∈ Sn, an excedance of π is an integer i ∈ [n − 1] such that πi> i. Here the element πi is called an excedance letter. The set of excedances of π is denoted by E(π). By πe and πne we denote the restrictions of π to the excedances and nonexcedances, respectively. A descent of π is an integer i ∈ [n − 1] for which πi> πi+1. If i is a descent we call πi a descent top and πi+1 a descent bottom. The set of descents of π is denoted by D(π). We write πd to denote the subword consisting of all descent tops of π (in order of appearance). The subword formed from the remaining letters will be denoted by πnd. A pair (πi, πj) is called an inversion of π if i < j and πi> πj. The set consisting all inversions of π we denote by I(π). (Clearly, this definition can be adopted for arbitrary words.) Three of the four classical statistics, the excedance number, the descent number, and the inversion number, count the number of occurrences of these patterns in a permutation; the fourth one,
Towards Structured Blockbased PDF
 Electronic Publishing— Origination, Dissemination and Design
, 1995
"... Acrobat product range, is discussed in some detail. Particular emphasis is given to its flexible objectoriented structure, which has yet to be fully exploited. It is currently used to represent not logical structure but simply a series of pages and associated resources. A definition of an Encapsula ..."
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Cited by 1 (1 self)
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Acrobat product range, is discussed in some detail. Particular emphasis is given to its flexible objectoriented structure, which has yet to be fully exploited. It is currently used to represent not logical structure but simply a series of pages and associated resources. A definition of an Encapsulated PDF (EPDF) is presented, in which EPDF blocks carry with them their own resource requirements, together with geometrical and logical information. A block formatter called Juggler is described which can lay out EPDF blocks from various sources onto new pages. Future revisions of PDF supporting uniquelynamed EPDF blocks tagged with semantic information would assist in compositepage makeup and could even lead to fully revisable PDF. KEY WORDS PDF Objectoriented Blocks Structured documents Juggler 1
Polynomial Coefficient Enumeration
, 2008
"... Abstract Let f(x1,..., xk) be a polynomial over a field K. This paper considers such questions as the enumeration of the number of nonzero coefficients of f or of the number of coefficients equal to α ∈ K ∗. For instance, if K = Fq then a matrix formula is obtained for the number of coefficients of ..."
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Abstract Let f(x1,..., xk) be a polynomial over a field K. This paper considers such questions as the enumeration of the number of nonzero coefficients of f or of the number of coefficients equal to α ∈ K ∗. For instance, if K = Fq then a matrix formula is obtained for the number of coefficients of f n that are equal to α ∈ F ∗ q, as a function of n. Many additional results are obtained related to such areas as lattice path enumeration and the enumeration of integer points in convex polytopes. 1 Introduction. Given a polynomial f ∈ Z[x1,..., xn], how many coefficients of f are nonzero? For α ∈ Z and p prime, how many coefficients are congruent to α modulo p? In this paper we will investigate these and related questions. First let us review some known results that will suggest various generalizations.
Structural studies of human 7Gmyeloma proteins of different antigenic subgroups and genetic specificities
, 1966
"... In 1956 Grubb (1) discovered individual differences in human TGglobulins (7ST) detectable by a complex serologic reaction based on the ability of individual Tglobufins to inhibit the interaction of selected antiTglobulins with TGincomplete antiRh antibodies, coating Rh0+ erythrocytes. This fin ..."
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In 1956 Grubb (1) discovered individual differences in human TGglobulins (7ST) detectable by a complex serologic reaction based on the ability of individual Tglobufins to inhibit the interaction of selected antiTglobulins with TGincomplete antiRh antibodies, coating Rh0+ erythrocytes. This finding led to the subsequent delineation of several genetically controlled variants of human TGglobufins, collectively known as the Gm factors (2). ~ In spite of the complex assay system required for their detection, and as yet incomplete knowledge of their precise mode of inheritance (3, 4), a great deal is known about their molecular localization. The Gm factors are present only on certain types of heavy polypeptide chains of IgG (Tchains), and not found in the IgA and IgM fractions (58). The Gin(a) and Gin(b) factors are found in the Fe fragment of the Tchain (5, 6) while Gin(f) activity appears to be located in the Fd fragment (9). The precise mode of inheritance of the Gm factors is controversial. Population studies suggest that the Gm factors are determined by multiple codominant alleles at the Gin locus. They are phenotypically recognizable as a series of serologically detectable
SUGP92/24 Extremal variety as the foundation of a cosmological quantum theory
, 1992
"... Dynamical systems of a new kind are described. These are based on the extremization of a nonlocal and nonadditive quantity that we call the variety of a system. In these systems all dynamical quantities are relational, and particles have properties, and can be identified, only through the values o ..."
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Dynamical systems of a new kind are described. These are based on the extremization of a nonlocal and nonadditive quantity that we call the variety of a system. In these systems all dynamical quantities are relational, and particles have properties, and can be identified, only through the values of these relational quantities. The variety then measures how uniquely each of the elements of the system can be distinguished from the others in terms of the relational variables. Thus a system with extremal variety is one in which the parts are related to the whole in as distinct a way as possible. We study several dynamical systems which are defined by setting the action of the system equal to its variety, and find that they have the following characterstics: 1) The dynamics is deterministic globally, but stochastic on the smallest scales. 2) At an intermediate scale structures emerge which are stable under the stochastic perturbations at smaller scales. 3) In near to extermal configurations one sees the emergence of both short ranged repulsive forces and long ranged attractive forces, 4) The dynamics is invariant under permutations of the labels of the particles. For these reasons it seems possible that extremal variety models could provide a foundation for a new kind of nonlocal hidden variables theory, which could be applicable in a cosmological context. In addition, the mathematical definition of variety may provide a quantitative tool to study selforganizing systems, because it distinguishes highly structured, but asymmetric, configurations such as one finds in biological systems from both random configurations and configurations such as crystals which are highly ordered by virtue of having a large symmetry group. 1 1