Manufacturing datatypes

2001 ◽  
Vol 11 (5) ◽  
pp. 493-524 ◽  
Author(s):  
RALF HINZE
Keyword(s):  
General Framework ◽  
Main Idea ◽  
Second Step ◽  
Structural Constraints ◽  
Usual Representation

This article describes a general framework for designing purely functional datatypes that automatically satisfy given size or structural constraints. Using the framework we develop implementations of different matrix types (for example, square matrices) and implementations of several tree types (for example, Braun trees and 2-3 trees). Consider representing square n×n matrices. The usual representation using lists of lists fails to meet the structural constraints: there is no way to ensure that the outer list and the inner lists have the same length. The main idea of our approach is to solve in a first step a related, but simpler problem, namely to generate the multiset of all square numbers. To describe this multiset we employ recursion equations involving finite multisets, multiset union, addition and multiplication lifted to multisets. In a second step we mechanically derive from these recursion equations datatype definitions that enforce the ‘squareness’ constraint. The transformation makes essential use of parameterized types.

scholarly journals Degeneration at E2 of certain spectral sequences

2016 ◽  
Vol 27 (14) ◽  
pp. 1650111 ◽  
Author(s):  
Dan Popovici
Keyword(s):  
Spectral Sequence ◽  
Differential Operators ◽  
Spectral Gap ◽  
Sufficient Conditions ◽  
Main Idea ◽  
Second Step ◽  
Compact Complex Manifold ◽  
Frölicher Spectral Sequence ◽  
Foliated Structure ◽  
Laplace Type

We propose a Hodge theory for the spaces [Formula: see text] featuring at the second step either in the Frölicher spectral sequence of an arbitrary compact complex manifold [Formula: see text] or in the spectral sequence associated with a pair [Formula: see text] of complementary regular holomorphic foliations on such a manifold. The main idea is to introduce a Laplace-type operator associated with a given Hermitian metric on [Formula: see text] whose kernel in every bidegree [Formula: see text] is isomorphic to [Formula: see text] in either of the two situations discussed. The surprising aspect is that this operator is not a differential operator since it involves a harmonic projection, although it depends on certain differential operators. We then use this Hodge isomorphism for [Formula: see text] to give sufficient conditions for the degeneration at [Formula: see text] of the spectral sequence considered in each of the two cases in terms of the existence of certain metrics on [Formula: see text]. For example, in the Frölicher case, we prove degeneration at [Formula: see text] if there exists an SKT metric [Formula: see text] (i.e. such that [Formula: see text]) whose torsion is small compared to the spectral gap of the elliptic operator [Formula: see text] defined by [Formula: see text]. In the foliated case, we obtain degeneration at [Formula: see text] under a hypothesis involving the Laplacians [Formula: see text] and [Formula: see text] associated with the splitting [Formula: see text] induced by the foliated structure.

Introduce an Evolutionary Programming Model - A Simulation of the Evolution of DNA Code

2013 ◽  
Vol 680 ◽  
pp. 559-564
Author(s):  
Mei Fan ◽  
Jun Ma
Keyword(s):  
Programming Model ◽  
Main Idea ◽  
Evolutionary Programming ◽  
Code Sequence ◽  
Second Step ◽  
Program Code ◽  
Engineering Technology ◽  
Modern Computer ◽  
Evolution Of Life ◽  
Robotic Evolution

Via examining the evolutionary phenomena in biology, it is known that the evolution of life is based on the fact the variation of species is caused by the alteration of the DNA code sequence. If we assume the DNA molecular chain is a program code sequence, similar to the modern computer program code sequence, then the evolutionary phenomenon in biology can be simulated and it will be bring out an Evolutionary Programming Model (EPM). The main idea of this model lies in the two key conception: First is that two copies of the program code sequence in memory were loaded, then put one in the running status and the other in non-running status. Second step, use the reflection calculation to perceive the environment and adjust its functions in the running one. Then use Bytecode Engineering Technology to locate and modify the corresponding code segment of the non-running one, and consequently generate the next version program. This process can be repeated as needed, similar to the evolution of the DNA sequence in Nature. EPM enables the program to "sense" the running environment, to make corresponding adjustments in order to accommodate the running environment, and to generate the new version program at the same time. The EPM model will have widely application prospects in the field of artificial intelligence and is extremely important in guiding the future automatic program design and robotic evolution design.

scholarly journals Transfer Entropy Approach for Portfolio Optimization: An Empirical Approach for CESEE Markets

2021 ◽  
Vol 14 (8) ◽  
pp. 369
Author(s):  
Tihana Škrinjarić ◽  
Derick Quintino ◽  
Paulo Ferreira
Keyword(s):  
Portfolio Optimization ◽  
Main Idea ◽  
Second Step ◽  
Portfolio Performance ◽  
Portfolio Strategies ◽  
Dynamic Portfolio ◽  
Using Data ◽  
Methodological Aspects ◽  
Dynamic Portfolio Optimization ◽  
Over Time

In this paper, we deal with the possibility of using econophysics concepts in dynamic portfolio optimization. The main idea of the research is that combining different methodological aspects in portfolio selection can enhance portfolio performance over time. Using data on CESEE stock market indices, we model the dynamics of entropy transfers from one return series to others. In the second step, the results are utilized in simulating the portfolio strategies that take into account the previous results. Here, the main results indicate that using entropy transfers in portfolio construction and rebalancing has the potential to achieve better portfolio value over time when compared to benchmark strategies.

scholarly journals Equivariant Embeddings into Smooth Toric Varieties

2002 ◽  
Vol 54 (3) ◽  
pp. 554-570 ◽  
Author(s):  
Jürgen Hausen
Keyword(s):  
General Framework ◽  
Toric Varieties ◽  
Main Idea ◽  
Embedding Theorem ◽  
Embedding Problem ◽  
Algebraic Varieties ◽  
Affine Cone

AbstractWe characterize embeddability of algebraic varieties into smooth toric varieties and prevarieties. Our embedding results hold also in an equivariant context and thus generalize a well-known embedding theorem of Sumihiro on quasiprojectiveG-varieties. The main idea is to reduce the embedding problem to the affine case. This is done by constructing equivariant affine conoids, a tool which extends the concept of an equivariant affine cone over a projectiveG-variety to a more general framework.

On the string matching with k differences in DNA databases

2021 ◽  
Vol 14 (6) ◽  
pp. 903-915
Author(s):  
Yangjun Chen ◽  
Hoang Hai Nguyen
Keyword(s):  
Time Complexity ◽  
String Matching ◽  
Main Idea ◽  
Second Step ◽  
Working Process ◽  
Typical Application ◽  
Average Value ◽  
Dna Database ◽  
A Genome ◽  
Better Than

In this paper, we discuss an efficient and effective index mechanism for the string matching with k differences, by which we will find all the substrings of a target string y of length n that align with a pattern string x of length m with not more than k insertions, deletions, and mismatches. A typical application is the searching of a DNA database, where the size of a genome sequence in the database is much larger than that of a pattern. For example, n is often on the order of millions or billions while m is just a hundred or a thousand. The main idea of our method is to transform y to a BWT-array as an index, denoted as BWT ( y ), and search x against it. The time complexity of our method is bounded by O( k · | T |), where T is a tree structure dynamically generated during a search of BWT ( y ). The average value of | T | is bounded by O(|Σ| 2 k ), where Σ is an alphabet from which we take symbols to make up target and pattern strings. This time complexity is better than previous strategies when k ≤ O(log |Σ| n ). The general working process consists of two steps. In the first step, x is decomposed into a series of l small subpatterns, and BWT ( y ) is utilized to speedup the process to figure out all the occurrences of such subpatterns with ⌊ k/l ⌋ differences. In the second step, all the found occurrences in the first step will be rechecked to see whether they really match x , but with k differences. Extensive experiments have been conducted, which show that our method for this problem is promising.

scholarly journals PRE-MULTISYMPLECTIC CONSTRAINT ALGORITHM FOR FIELD THEORIES

2005 ◽  
Vol 02 (05) ◽  
pp. 839-871 ◽  
Author(s):  
MANUEL DE LEÓN ◽  
JESÚS MARÍN-SOLANO ◽  
JUAN CARLOS MARRERO ◽  
MIGUEL C. MUÑOZ-LECANDA ◽  
NARCISO ROMÁN-ROY
Keyword(s):  
Fiber Bundle ◽  
General Framework ◽  
Vector Fields ◽  
Classical Field ◽  
Field Theories ◽  
Second Step ◽  
Field Equations ◽  
Jet Bundle ◽  
First Order ◽  
Classical Field Theories

We present a geometric algorithm for obtaining consistent solutions to systems of partial differential equations, mainly arising from singular covariant first-order classical field theories. This algorithm gives an intrinsic description of all the constraint submanifolds. The field equations are stated geometrically, either representing their solutions by integrable connections or, what is equivalent, by certain kinds of integrable m-vector fields. First, we consider the problem of finding connections or multivector fields solutions to the field equations in a general framework: a pre-multisymplectic fiber bundle (which will be identified with the first-order jet bundle and the multi-momentum bundle when Lagrangian and Hamiltonian field theories are considered). Then, the problem is stated and solved in a linear context, and a pointwise application of the results leads to the algorithm for the general case. In a second step, the integrability of the solutions is also studied. Finally, the method is applied to Lagrangian and Hamiltonian field theories and, for the former, the problem of finding holonomic solutions is also analyzed.

scholarly journals General Framework for Tracking Neural Activity Over Long-Term Extracellular Recordings

2020 ◽  
Author(s):  
Fernando Julian Chaure ◽  
Hernan Gonzalo Rey
Keyword(s):  
General Framework ◽  
Concept Drift ◽  
Class Imbalance ◽  
Main Idea ◽  
Superior Performance ◽  
Temporary Increase ◽  
Spike Sorting ◽  
Sorting Algorithms ◽  
Block Based

AbstractThe recent advances in the chronic implantation of electrodes have allowed the collection of extracellular activity from neurons over long periods of time. To fully take advantage of these recordings, it is necessary to track single neurons continuously, particularly when their associated waveform changes with time. Multiple spike sorting algorithms can track drifting neurons but they do not perform well in conditions like a temporary increase in the noise level, sparsely firing neurons, and changes in the number of detectable neurons. In this work, we present Spikes_Link, a general framework to track neurons under these conditions. Spikes_Link can be implemented with different spike sorting algorithms, allowing the experimenter to use the algorithm best fitted to their recording setup. The main idea behind Spikes_Link is the blockwise analysis of the recording using overlapping sets of spikes to equally represent all the putative neurons being tracked on a given block. This way, we can link classes with clusters obtained in a new block based on an overlapping metric. Moreover, the algorithm can fix temporary sorting errors (splits and merges). We compared an implementation of Spikes_Link with other algorithms using long-term simulations and obtained superior performance in all the metrics. In general, the Spikes_Link framework could be used for other clustering problems with concept drift and class imbalance.

Temperature Dependence of the Critical Electron Dose for Fatty Acid Monolayers

1982 ◽  
Vol 40 ◽  
pp. 78-79
Author(s):  
Kenneth H. Downing ◽  
Robert M. Glaeser
Keyword(s):  
Electron Beam ◽  
Fatty Acid ◽  
Inelastic Scattering ◽  
Temperature Dependence ◽  
Structural Damage ◽  
Direct Result ◽  
Second Step ◽  
Strong Temperature Dependence ◽  
Electron Dose ◽  
Covalent Bonds

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.

The Application of Protein A-Gold Immunocytochemistry to Studies of Protein Secretion

1985 ◽  
Vol 43 ◽  
pp. 426-429
Author(s):  
George H. Herbener ◽  
Antonio Nanci ◽  
Moise Bendayan
Keyword(s):  
Tissue Section ◽  
Colloidal Gold ◽  
Unit Area ◽  
Protein A ◽  
Extracellular Proteins ◽  
Gold Complex ◽  
Second Step ◽  
Igg Antibodies ◽  
Tissue Sections ◽  
Antigenic Sites

Protein A-gold immunocytochemistry is a two-step, post-embedding labeling procedure which may be applied to tissue sections to localize intra- and extracellular proteins. The key requisite for immunocytochemistry is the availability of the appropriate antibody to react in an immune response with the antigenic sites on the protein of interest. During the second step, protein A-gold complex is reacted with the antibody. This is a non- specific reaction in that protein A will combine with most IgG antibodies. The ‘label’ visualized in the electron microscope is colloidal gold. Since labeling is restricted to the surface of the tissue section and since colloidal gold is particulate, labeling density, i.e., the number of gold particles per unit area of tissue section, may be quantitated with ease and accuracy.

STRUCTURAL CONSTRAINTS ON COGNITIVE THEORY

1980 ◽  
Vol 25 (2) ◽  
pp. 203-204
Author(s):  
JOSEPH M. SCANDURA
Keyword(s):  
Cognitive Theory ◽  
Structural Constraints
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