Is pupil diameter influenced by refractive error?

Purpose: To investigate the relationship between pupil diameter and refractive error and how refractive correction, target luminance, and accommodation modulate this relationship. Methods: Sixty emmetropic, myopic, and hyperopic subjects (age range, 18 to 35 years) viewed an illuminated target (luminance: 10, 100, 200, 400, 1000, 2000, and 4100 cd/m2) within a Badal optical system, at 0 diopters (D) and −3 D vergence, with and without refractive correction. Refractive error was corrected using daily disposable contact lenses. Pupil diameter and accommodation were recorded continuously using a commercially available photorefractor. Results: No significant difference in pupil diameter was found between the refractive groups at 0 D or −3 D target vergence, in the corrected or uncorrected conditions. As expected, pupil diameter decreased with increasing luminance. Target vergence had no significant influence on pupil diameter. In the corrected condition, at 0 D target vergence, the accommodation response was similar in all refractive groups. At −3 D target vergence, the emmetropic and myopic groups accommodated significantly more than the hyperopic group at all luminance levels. There was no correlation between accommodation response and pupil diameter or refractive error in any refractive group. In the uncorrected condition, the accommodation response was significantly greater in the hyperopic group than in the myopic group at all luminance levels, particularly for near viewing. In the hyperopic group, the accommodation response was significantly correlated with refractive error but not pupil diameter. In the myopic group, accommodation response level was not correlated with refractive error or pupil diameter. Conclusions: Refractive error has no influence on pupil diameter, irrespective of refractive correction or accommodative demand. This suggests that the pupil is controlled by the pupillary light reflex and is not driven by retinal blur.

Probabilistic Models in Cryptography, Coding Theory and Tests for PRNG

2000 Mathematics Subject Classification: 94A29, 94B70

Space time coding for polynomial phase modulated signals

Polynomial phase modulated (PPM) signals have been shown to provide improved error rate performance with respect to conventional modulation formats under additive white Gaussian noise and fading channels in single-input single-output (SISO) communication systems. In this dissertation, systems with two and four transmit antennas using PPM signals were presented. In both cases we employed full-rate space-time block codes in order to take advantage of the multipath channel. For two transmit antennas, we used the orthogonal space-time block code (OSTBC) proposed by Alamouti and performed symbol-wise decoding by estimating the phase coefficients of the PPM signal using three different methods: maximum-likelihood (ML), sub-optimal ML (S-ML) and the high-order ambiguity function (HAF). In the case of four transmit antennas, we used the full-rate quasi-OSTBC (QOSTBC) proposed by Jafarkhani. However, in order to ensure the best error rate performance, PPM signals were selected such as to maximize the QOSTBC’s minimum coding gain distance (CGD). Since this method does not always provide a unique solution, an additional criterion known as maximum channel interference coefficient (CIC) was proposed. Through Monte Carlo simulations it was shown that by using QOSTBCs along with the properly selected PPM constellations based on the CGD and CIC criteria, full diversity in flat fading channels and thus, low BER at high signal-to-noise ratios (SNR) can be ensured. Lastly, the performance of symbol-wise decoding for QOSTBCs was evaluated. In this case a quasi zero-forcing method was used to decouple the received signal and it was shown that although this technique reduces the decoding complexity of the system, there is a penalty to be paid in terms of error rate performance at high SNRs.

Quasi-Orthogonal Space-Time Block Coding Using Polynomial Phase Modulation

Recently, polynomial phase modulation (PPM) was shown to be a power- and bandwidth-efficient modulation format. These two characteristics are in high demand nowadays specially in mobile applications, where devices with size, weight, and power (SWaP) constraints are common. In this paper, we propose implementing a full-diversity quasiorthogonal space-time block code (QOSTBC) using polynomial phase signals as modulation format. QOSTBCs along with PPM are used in order to improve the power efficiency of communication systems with four transmit antennas. We obtain the optimal PPM constellations that ensure full diversity and maximize the QOSTBC's minimum coding gain distance. Simulation results show that by using QOSTBCs along with a properly selected PPM constellation, full diversity in flat fading channels and thus low BER at high signal-to-noise ratios (SNR) can be ensured. More importantly, it is also shown that QOSTBCs using PPM achieve a better error performance than those using conventional modulation formats.

Correction to “Reminder and 2AFC tasks provide similar estimates of the difference limen: A reanalysis of data from Lapid, Ulrich, and Rammsayer (2008) and a discussion of Ulrich and Vorberg (2009)”

We recently published an article (García-Pérez & Alcalá- Quintana, 2010) reanalyzing data presented by Lapid, Ulrich, and Rammsayer (2008) and discussing a theoretical argument developed by Ulrich and Vorberg (2009). The purpose of this note is to correct an error in our study that has some theoretical importance, although it does not affect the conclusion that was raised. The error lies in that asymptote parameters reflecting lapses or finger errors should not enter the constraint relating the psychometric functions that describe performance when the comparison stimulus in a two-alternative forced choice (2AFC) discrimination task is presented in the first or second interval.

Algorithmes de construction et correction d'arbres de gènes par la réconciliation

Les gènes, qui servent à encoder les fonctions biologiques des êtres vivants, forment l'unité moléculaire de base de l'hérédité. Afin d'expliquer la diversité des espèces que l'on peut observer aujourd'hui, il est essentiel de comprendre comment les gènes évoluent. Pour ce faire, on doit recréer le passé en inférant leur phylogénie, c'est-à-dire un arbre de gènes qui représente les liens de parenté des régions codantes des vivants. Les méthodes classiques d'inférence phylogénétique ont été élaborées principalement pour construire des arbres d'espèces et ne se basent que sur les séquences d'ADN. Les gènes sont toutefois riches en information, et on commence à peine à voir apparaître des méthodes de reconstruction qui utilisent leurs propriétés spécifiques. Notamment, l'histoire d'une famille de gènes en terme de duplications et de pertes, obtenue par la réconciliation d'un arbre de gènes avec un arbre d'espèces, peut nous permettre de détecter des faiblesses au sein d'un arbre et de l'améliorer. Dans cette thèse, la réconciliation est appliquée à la construction et la correction d'arbres de gènes sous trois angles différents: 1) Nous abordons la problématique de résoudre un arbre de gènes non-binaire. En particulier, nous présentons un algorithme en temps linéaire qui résout une polytomie en se basant sur la réconciliation. 2) Nous proposons une nouvelle approche de correction d'arbres de gènes par les relations d'orthologie et paralogie. Des algorithmes en temps polynomial sont présentés pour les problèmes suivants: corriger un arbre de gènes afin qu'il contienne un ensemble d'orthologues donné, et valider un ensemble de relations partielles d'orthologie et paralogie. 3) Nous montrons comment la réconciliation peut servir à "combiner'' plusieurs arbres de gènes. Plus précisément, nous étudions le problème de choisir un superarbre de gènes selon son coût de réconciliation.

Modelling and Verification of a Correction Factor to Evaluate the Efficiency of Solar Thermal Collectors with the Rapid Test Method

A new method for the evaluation of the efficiency of parabolic trough collectors, called Rapid Test Method, is investigated at the Solar Institut Jülich. The basic concept is to carry out measurements under stagnation conditions. This allows a fast and inexpensive process due to the fact that no working fluid is required. With this approach, the temperature reached by the inner wall of the receiver is assumed to be the stagnation temperature and hence the average temperature inside the collector. This leads to a systematic error which can be rectified through the introduction of a correction factor. A model of the collector is simulated with COMSOL Multipyisics to study the size of the correction factor depending on collector geometry and working conditions. The resulting values are compared with experimental data obtained at a test rig at the Solar Institut Jülich. These results do not match with the simulated ones. Consequentially, it was not pos-sible to verify the model. The reliability of both the model with COMSOL Multiphysics and of the measurements are analysed. The influence of the correction factor on the rapid test method is also studied, as well as the possibility of neglecting it by measuring the receiver’s inner wall temperature where it receives the least amount of solar rays. The last two chapters analyse the specific heat capacity as a function of pressure and tem-perature and present some considerations about the uncertainties on the efficiency curve obtained with the Rapid Test Method.

Algorithmes de construction et correction d'arbres de gènes par la réconciliation

Les gènes, qui servent à encoder les fonctions biologiques des êtres vivants, forment l'unité moléculaire de base de l'hérédité. Afin d'expliquer la diversité des espèces que l'on peut observer aujourd'hui, il est essentiel de comprendre comment les gènes évoluent. Pour ce faire, on doit recréer le passé en inférant leur phylogénie, c'est-à-dire un arbre de gènes qui représente les liens de parenté des régions codantes des vivants. Les méthodes classiques d'inférence phylogénétique ont été élaborées principalement pour construire des arbres d'espèces et ne se basent que sur les séquences d'ADN. Les gènes sont toutefois riches en information, et on commence à peine à voir apparaître des méthodes de reconstruction qui utilisent leurs propriétés spécifiques. Notamment, l'histoire d'une famille de gènes en terme de duplications et de pertes, obtenue par la réconciliation d'un arbre de gènes avec un arbre d'espèces, peut nous permettre de détecter des faiblesses au sein d'un arbre et de l'améliorer. Dans cette thèse, la réconciliation est appliquée à la construction et la correction d'arbres de gènes sous trois angles différents: 1) Nous abordons la problématique de résoudre un arbre de gènes non-binaire. En particulier, nous présentons un algorithme en temps linéaire qui résout une polytomie en se basant sur la réconciliation. 2) Nous proposons une nouvelle approche de correction d'arbres de gènes par les relations d'orthologie et paralogie. Des algorithmes en temps polynomial sont présentés pour les problèmes suivants: corriger un arbre de gènes afin qu'il contienne un ensemble d'orthologues donné, et valider un ensemble de relations partielles d'orthologie et paralogie. 3) Nous montrons comment la réconciliation peut servir à "combiner'' plusieurs arbres de gènes. Plus précisément, nous étudions le problème de choisir un superarbre de gènes selon son coût de réconciliation.

General ledger account coding

The Supplier-Relationship Management system is used by SC Department of Motor Vehicles personnel to requisition most purchases of services and materials for DMV purposes. General ledger account codes are first assigned by the shopping cart preparer. Administrative departments such as procurement, payables and budget regularly correct general ledger codes during the purchasing cycle to ensure proper reporting. DMV goals are consistent with accurate reporting of expenditures by general ledger account code. Incorrect reporting would be contrary to DMV' s vision of promoting effective and efficient business processes. Journal entries increased from 34 to 66 in FY2014 and FY20152 ; with a notable amount correcting the general ledger code. This project examines the assignment or correction of general ledger account codes for DMV's planned purchases for the purpose of process improvement.

Improving Bangla ocr output through correction algorithms

Bangla OCR (Optical Character Recognition) is a long deserving software for Bengali community all over the world. Numerous e efforts suggest that due to the inherent complex nature of Bangla alphabet and its word formation process development of high fidelity OCR producing a reasonably acceptable output still remains a challenge. One possible way of improvement is by using post processing of OCR’s output; algorithms such as Edit Distance and the use of n-grams statistical information have been used to rectify misspelled words in language processing. This work presents the first known approach to use these algorithms to replace misrecognized words produced by Bangla OCR. The assessment is made on a set of fifty documents written in Bangla script and uses a dictionary of 541,167 words. The proposed correction model can correct several words lowering the recognition error rate by 2.87% and 3.18% for the character based n- gram and edit distance algorithms respectively. The developed system suggests a list of 5 (five) alternatives for a misspelled word. It is found that in 33.82% cases, the correct word is the topmost suggestion of 5 words list for n-gram algorithm while using Edit distance algorithm the first word in the suggestion properly matches 36.31% of the cases. This work will ignite rooms of thoughts for possible improvements in character recognition endeavour.

Transmission Of Intra-cellular Genetic Information: A System Proposal.

One of the great challenges of the scientific community on theories of genetic information, genetic communication and genetic coding is to determine a mathematical structure related to DNA sequences. In this paper we propose a model of an intra-cellular transmission system of genetic information similar to a model of a power and bandwidth efficient digital communication system in order to identify a mathematical structure in DNA sequences where such sequences are biologically relevant. The model of a transmission system of genetic information is concerned with the identification, reproduction and mathematical classification of the nucleotide sequence of single stranded DNA by the genetic encoder. Hence, a genetic encoder is devised where labelings and cyclic codes are established. The establishment of the algebraic structure of the corresponding codes alphabets, mappings, labelings, primitive polynomials (p(x)) and code generator polynomials (g(x)) are quite important in characterizing error-correcting codes subclasses of G-linear codes. These latter codes are useful for the identification, reproduction and mathematical classification of DNA sequences. The characterization of this model may contribute to the development of a methodology that can be applied in mutational analysis and polymorphisms, production of new drugs and genetic improvement, among other things, resulting in the reduction of time and laboratory costs.

Refractive Error In School Children In Campinas, Brazil.

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Determinação de açúcar total em café cru por espectroscopia no infravermelho próximo e regressão por mínimos quadrados parciais

In this work a fast method for the determination of the total sugar levels in samples of raw coffee was developed using the near infrared spectroscopy technique and multivariate regression. The sugar levels were initially obtained using gravimety as the reference method. Later on, the regression models were built from the near infrared spectra of the coffee samples. The original spectra were pre-treated according to the Kubelka-Munk transformation and multiplicative signal correction. The proposed analytical method made possible the direct determination of the total sugar levels in the samples with an error lower by 8% with respect to the conventional methodology.

Metodologia para analise cinematica de volumes respiratorios parciais de nadadores

Universidade Estadual de Campinas . Faculdade de Educação Física

Calibração de câmeras para análises subaquáticas de movimentos = : Cameras calibration for underwater motion analysis

Universidade Estadual de Campinas . Faculdade de Educação Física