MULTI-CAMERA SURVEILLANCE SYSTEM FOR TIME AND MOTION STUDIES OF TIMBER HARVESTING OPERATIONS

Timber harvesting is an important activity in the state of Kentucky; however, there is still a lack of information about the procedure used by the local loggers. The stump to landing transport of logs with skidders is often the most expensive and time-consuming task in timber harvesting operations. This thesis evaluated the feasibility of using a multi-camera system for time and motion studies of timber harvesting operations. It was installed in 5 skidders in 3 different harvesting sites in Kentucky. The time stamped video provided accurate time consumption data for each work phase of the skidders, which was used to fit linear regressions and find the influence of skidding distance, skid-trail gradient, and load size on skidding time. The multi-camera systems were found to be a reliable tool for time and motion studies in timber harvesting sites. Six different time equations and two speed equations were fitted for skidding cycles and sections of skid-trails, for skidders that are both loaded and unloaded. Skid-trail gradient and load size did not have an influence on skidding time. There is a need for future studies of different variables that could affect skidding time and, consequently, cost

First-order methods for the convex hull membership problem

The convex hull membership problem (CHMP) consists in deciding whether a certain point belongs to the convex hull of a finite set of points, a decision problem with important applications in computational geometry and in foundations of linear programming. In this study, we review, compare and analyze first-order methods for CHMP, namely, Frank-Wolfe type methods, Projected Gradient methods and a recently introduced geometric algorithm, called Triangle Algorithm (TA). We discuss the connections between this algorithm and Frank-Wolfe, showing that TA can be interpreted as an inexact Frank-Wolfe. Despite this similarity, TA is strongly based on a theorem of alternatives known as distance duality. By using this theorem, we propose suitable stopping criteria for CHMP to be integrated into Frank-Wolfe type and Projected Gradient, specializing these methods to the membership decision problem. Interestingly, Frank-Wolfe integrated with such stopping criteria coincides with a greedy version of the Triangle Algorithm which is, in its turn, equivalent to an algorithm due to von Neumann. We report numerical experiments on random instances of CHMP, carefully designed to cover different scenarios, that indicate which algorithm is preferable according to the geometry of the convex hull and the relative position of the query point. Concerning potential applications, we present two illustrative examples, one related to linear programming feasibility problems and another related to image classification problems.Comment: 29 pages, 11 figure

Strategies for pests control : p-fuzzy systems with hybrid control

Orientador: Rodney Carlos BassaneziDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação CientificaResumo: O objetivo deste trabalho é propor um modelo utilizando Sistemas Baseados em Regras Fuzzy (SBRF) que possa controlar, do ponto de vista teórico, uma determinada espécie, considerada como praga em uma lavoura ou plantação. Faz-se primeiro uma introdução à Teoria dos Conjuntos Fuzzy, bem como aos sistemas especialistas fuzzy que utilizam regras de inferência, através do método de inferência de Mamdani e que utilizem o método de defuzzificação por centro de massa. Logo após, são abordados os conceitos de Sistemas Dinâmicos P-Fuzzy uni e bidimensionais desenvolvidos por Silva [24] e Cecconelo [7]. É proposto um novo tipo de Sistema Dinâmico P-fuzzy para modelar a dinâmica populacional, de uma espécie ou de um sistema presa-predador, que leve em conta fatores extrínsecos da(s) espécie(s) envolvida(s). Estes fatores são representados por uma Condição Ambiental, que é definida e acoplada aos Sistemas P-fuzzy usuais. Ainda, usando um controlador fuzzy propomos um sistema de controle híbrido com controladores biológicos e químicos (biocidas) em que as espécies que interagem estão sujeitas também às condições ambientais. Simulações e experimentos computacionais feitos com o auxílio da Fuzzy Logic Toolbox do software Matlab são realizados e seus resultados são comentados.Abstract: The aim of this work is to propose determined model, using Fuzzy Rule-based Systems (FRBS), wich can control, in a theoretical manner, a species considered a plage in a farming or plantation. An introduction to Fuzzy Sets is maded as well as maded to Fuzzy Systems wich uses inference mIes, through the Mamdani method of inference and that uses Centroid as defuzzification method. After this, the concepts of uni and bidimensional P-fuzzy Dynamic Systems are studied and approached, as developed by Silva [24] and Cecconelo [7]. We propose a new type of P-fuzzy Dynamic System, to model the population dynamics of one species system or of a prey-predator system, that takes into account extrinsic factors of the species involved. Such factores are represented by an Enviromental Condition wich is defined and connected to the usual P-fuzzy Systems. Finnaly, using a Fuzzy Controller, we propose a system for hybrid control with biological and chemical (biocides) controllers in wich the density of species are also influenced by enviromental conditions. Computational simulations and experiments are made with the aid of Matlab Fuzzy Logic Toolbox and its results are commented.MestradoBiomatematicaMestre em Matemática Aplicad

Chemical identification of chlorophenylpiperazine in seized tablets

Designer drug is a term used to describe psychoactive drugs of abuse which are usually synthesized by modifying the molecular structures of existing drugs of abuse. The term gained widespread popularity when MDMA (ecstasy) experienced a popularity boom in the mid 1980´s. In Brazil, designer drugs seizures have increased in the last few years, and actually tablets with unknown psychoactive compounds began to be forwarded to the Forensic Laboratories. This work describes the analytical assays that were performed to identify the chlorophenylpiperazine, a psychoactive substance first time identified in seized tablets in Sao Paulo state

Uso da tecnologia LoRa em robôs detectores de gases

Trabalho de Conclusão de Curso (Graduação)Os robôs móveis têm sido utilizados para garantir mais segurança, auxiliando humanos em tarefas perigosas. A segurança é algo primordial aos trabalhadores, principalmente em ambientes perigosos onde podem estar expostos a condições extremas, como em ambientes com presença de gases tóxicos e inflamáveis. Neste cenário, a tecnologia pode tornar o trabalho em locais de alta periculosidade mais seguros por meio de uma análise de risco contínua utilizando tecnologias como a Internet das Coisas e a robótica. Este monitoramento possibilita trazer alertas para o trabalhador, que pode se adequar a medidas de prevenção e tomar as devidas providências. Neste sentido, este trabalho tem como escopo o monitoramento remoto de emissão de gases, emulando de forma controlada a situação em indústrias, para auxiliar a segurança dos trabalhadores em ambientes com presença de gases perigosos utilizando robótica móvel e tecnologia LoRa como ferramentas, dado o desafio do uso de sensores de baixo custo e de interferências na comunicação. Dentre os fatores a serem averiguados neste trabalho está a adaptabilidade do robô no ambiente, o funcionamento da comunicação em uma certa distância e caracterização dos sensores na medição de gases. Ao final deste projeto foi obtido um protótipo inicial funcional capaz de se locomover de forma autônoma no ambiente enviando informações de sua geolocalização e dos gases a serem monitorados para o usuário, para que em um trabalho futuro o mesmo possa ser inserido e avaliado em um ambiente com características industriais

Perspectives of bilateral thoracic sympathectomy for treatment of heart failure

Surgical neuromodulation therapies are still considered a last resort when standard therapies have failed for patients with progressive heart failure (HF). Although a number of experimental studies have provided robust evidence of its effectiveness, the lack of strong clinical evidence discourages practitioners. Thoracic unilateral sympathectomy has been extensively studied and has failed to show significant clinical improvement in HF patients. Most recently, bilateral sympathectomy effect was associated with a high degree of success in HF models, opening the perspective to be investigated in randomized controlled clinical trials. In addition, a series of clinical trials showed that bilateral sympathectomy was associated with a decreased risk of sudden death, which is an important outcome in patients with HF. These aspects indicates that bilateral sympathectomy could be an important alternative in the treatment of HF wherein pharmacological treatment barely reaches the target dose