Quantum error-correcting codes

Dissertação de mestrado em Physics EngineeringQuantum computing is a new and exciting field of research that, using the properties of quantum mechanics, has the potential to be a disruptive technology, being able to per form certain computations faster than any classical computer, such as Shor’s factorization algorithm and Grover’s algorithm. Although there are several quantum computer with different underlying technologies, one of the main challenges of quantum computation is the occurence of errors, destroying the information and making computation impossible. Errors may have several different sources namely, thermal noise, faulty gates or incorrect measurements. The present dissertation aims to study and employ methods for reducing the effects of errors during quantum computation and correct them using Stabilizer Codes, which are a very powerful tool to produce circuit encoding networks that can, in theory, protect quantum systems from errors during transmission. A proof of concept algorithm was implemented using Qiskit, a Python based program development language for the IBM Q machines, and tested on both simulators and real systems. The algorithm is capable of, given any stabilizer in standard form, generate the circuit encoding network. Due to technological limitations associated with current quantum computers the results obtained in ibmq_guadalupe fail to show the efficacy of Stabilizer Codes.A computação quântica é uma área de investigação recente que, usando as propriedades da mecânica quântica, tem o potencial de ser uma tecnologia disruptiva, sendo capaz de realizar alguns tipos de computação de forma mais rápida do que qualquer outro computador clássico atual, tais como, o algoritmo de fatorização de Shor e o algoritmo de procura de Grover. Apesar de já existirem vários computadores quãnticos com tecnologias de diferentes modos de operação, um dos principais desafios que a computação quântica enfrenta é a existência de erros, destruindo a informação presente e impossibilitando a computação. Os erros podem ser de várias fontes, nomeadamente, ruido térmico, operações deficientes ou medidas incorrectas. Esta dissertação tem como objectivo estudar e aplicar métodos para reduzir os efeitos dos erros durante a computação quântica e corrigi-los usando códigos estabilizadores, que são uma ferramenta poderosa para produzir circuitos que podem, em teoria, proteger sistemas quânticos de erros ocorridos durante a transmissão. Foi implementado um algoritmo usando Qiskit, uma linguagem à base de Python usada para desenvolver programas nas máquinas da IBM, que foi testado em simuladores e em sistemas físicos. O algoritmo é capaz de, dado um estabilizador na sua forma standard, gerar o circuito codificador. Devido a limitações da tecnologia associadas aos atuais computadores quânticos, os resultados obtidos na máquina ibimq_guadalupe não demonstram a eficácia dos códigos estabilizadores

Method for resource control in parallel environments using program organization and run-time support

A system and method for dynamic scheduling and allocation of resources to parallel applications during the course of their execution. By establishing well-defined interactions between an executing job and the parallel system, the system and method support dynamic reconfiguration of processor partitions, dynamic distribution and redistribution of data, communication among cooperating applications, and various other monitoring actions. The interactions occur only at specific points in the execution of the program where the aforementioned operations can be performed efficiently

Method for resource control in parallel environments using program organization and run-time support

A system and method for dynamic scheduling and allocation of resources to parallel applications during the course of their execution. By establishing well-defined interactions between an executing job and the parallel system, the system and method support dynamic reconfiguration of processor partitions, dynamic distribution and redistribution of data, communication among cooperating applications, and various other monitoring actions. The interactions occur only at specific points in the execution of the program where the aforementioned operations can be performed efficiently

IMPACTOS DA RECOMPOSIÇÃO DA RESERVA LEGAL NAS RECEITAS TRIBUTÁRIAS ESTADUAIS E MUNICIPAIS

O trabalho analisa a determinação de recomposição da reserva legal nas propriedades rurais paulistas no cumprimento da atual legislação ambiental. Mostra que se aplicada tal como está desenhada haverá importantes impactos negativos na área agropecuária destinada a atividades econômicas e, por conseguinte, nas receitas estaduais e municipais, penalizando principalmente os municípios mais pobres. Dessa maneira tal medida se mostra inaplicável sem a adoção de medidas compensatórias.----------------------This article analyzes the legal act for individual farms’ environmental reserve restoration in São Paulo State in duty to the environmental statutes. It shows thai if it is applied as it is designed, there will be important negative impacts in the agricultural area used for economic activities, consequently, impacts in municipalities and states’ internal revenue, penalizing primarily the poorest municipalities. Therefore, this act in not applicable without the adoption of compensatory measures.reserva legal, agropecuária paulista, finanças públicas, área agropecuária, environmental reserve, Sao Paulo State agriculture, public finance, agricultural area, Environmental Economics and Policy,

Cable robot for non-standard architecture and construction: A dynamic positioning system

In the past few years, cable-driven robots have received some attention by the scientific community and the industry. They have special characteristics that made them very reliable to operate with the level of safeness that is required by different environments, such as, handling of hazardous materials in construction sites. This paper presents a cable-driven robot called SPIDERobot, that was developed for automated construction of architectural projects. This robot has a rotating claw and it is controlled by a set of 4 cables that allow 4 degrees of freedom. In addition to the robot, this paper introduces a Dynamic Control System (DCS) that controls the positioning of the robot and assures that the length of cables is always within a safe value. Results show that traditional force-feasible approaches are more influenced by the pulling forces or the geometric arrangement of all cables and their positioning is significantly less accurate than the DCS. Therefore, the architecture of the SPIDERobot is designed to enable an easily scaling up of the solution to higher dimensions for operating in realistic environments.This work is partly funded by the project PTDC/ATPAQI/ 5124/2012 - Robotic Technologies for Non-Standard Design and Construction in Architecture. This work is also financed by the ERDF European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT Portuguese Foundation for Science and Technology within project ”FCOMP - 01-0124-FEDER-022701”info:eu-repo/semantics/publishedVersio

Role of pressor mechanisms from the NTS and CVLM in control of arterial pressure

In the present study, we investigated the effects of inhibition of the caudal ventrolateral medulla (CVLM) with the GABA(A) agonist muscimol combined with the blockade of glutamatergic mechanism in the nucleus of the solitary tract (NTS) with kynurenic acid (kyn) on mean arterial pressure (MAP), heart rate (HR), and regional vascular resistances. in male Holtzman rats anesthetized intravenously with urethane/chloralose, bilateral injections of muscimol (120 pmol) into the CVLM or bilateral injections of kyn (2.7 nmol) into the NTS alone increased MAP to 186 +/- 11 and to 142 +/- 6 mmHg, respectively, vs. control: 105 +/- 4 mmHg; HR to 407 +/- 15 and to 412 +/- 18 beats per minute (bpm), respectively, vs. control: 352 +/- 12 bpm; and renal, mesenteric and hindquarter vascular resistances. However, in rats with the CVLM bilaterally blocked by muscimol, additional injections of kyn into the NTS reduced MAP to 88 +/- 5 mmHg and mesenteric and hindquarter vascular resistances below control baseline levels. Moreover, in rats with the glutamatergic mechanisms of the NTS blocked by bilateral injections of kyn, additional injections of muscimol into the CVLM also reduced MAP to 92 +/- 2 mmHg and mesenteric and hindquarter vascular resistances below control baseline levels. Simultaneous blockade of NTS and CVLM did not modify the increase in HR but also abolished the increase in renal vascular resistance produced by each treatment alone. the results suggest that important pressor mechanisms arise from the NTS and CVLM to control vascular resistance and arterial pressure under the conditions of the present study.Universidade Federal de São Paulo, Dept Physiol, EPM, São Paulo, BrazilUNESP, Fac Odontol, Dept Physiol & Pathol, Araraquara, BrazilABC, Fac Med, Dept Physiol, Santo Andre, BrazilUniversidade Federal de São Paulo, Dept Physiol, EPM, São Paulo, BrazilWeb of Scienc

Um relato de caso de síndrome de Cotard com sintoma catatoniformes

Federal University of São Paulo Psychiatry DepartamentUNIFESP, Psychiatry DepartamentSciEL