Improving Dynamic Characteristics of Open-loop Controlled Log Crane

The improvement of the dynamics of flexible manipulators like log cranes often requires advanced control methods. This thesis discusses the vibration problems in the cranes used in commercial forestry machines. Two control methods, adaptive filtering and semi-active damping, are presented. The adaptive filter uses a part of the lowest natural frequency of the crane as a filtering frequency. The payload estimation algorithm, filtering of control signal and algorithm for calculation of the lowest natural frequency of the crane are presented. The semi-active damping method is basedon pressure feedback. The pressure vibration, scaled with suitable gain, is added to the control signal of the valve of the lift cylinder to suppress vibrations. The adaptive filter cuts off high frequency impulses coming from the operatorand semi-active damping suppresses the crane?s oscillation, which is often caused by some external disturbance. In field tests performed on the crane, a correctly tuned (25 % tuning) adaptive filter reduced pressure vibration by 14-17 % and semi-active damping correspondingly by 21-43%. Applying of these methods require auxiliary transducers, installed in specific points in the crane, and electronically controlled directional control valves.

Gridifying IBM's Generic Log Adapter to Speed-Up the Processing of Log Data

Peer-reviewed

Visual SLAM for underwater vehicles using video velocity log and natural landmarks

A visual SLAM system has been implemented and optimised for real-time deployment on an AUV equipped with calibrated stereo cameras. The system incorporates a novel approach to landmark description in which landmarks are local sub maps that consist of a cloud of 3D points and their associated SIFT/SURF descriptors. Landmarks are also sparsely distributed which simplifies and accelerates data association and map updates. In addition to landmark-based localisation the system utilises visual odometry to estimate the pose of the vehicle in 6 degrees of freedom by identifying temporal matches between consecutive local sub maps and computing the motion. Both the extended Kalman filter and unscented Kalman filter have been considered for filtering the observations. The output of the filter is also smoothed using the Rauch-Tung-Striebel (RTS) method to obtain a better alignment of the sequence of local sub maps and to deliver a large-scale 3D acquisition of the surveyed area. Synthetic experiments have been performed using a simulation environment in which ray tracing is used to generate synthetic images for the stereo system

Cómo mejorar la efectividad en un jugador de tenis: Modelos de regresión log-lineales

La efectividad en el deporte hace referencia al impacto alcanzado por una acción llevada a cabo en condiciones habituales, estando presente en la ejecución de cualquier actividad física, referida a la capacidad para producir el efecto deseado, y está relacionada con la e$cacia, entendida como el efecto de una acción llevada a cabo en las mejores condiciones posibles, y que tiene como objetivo, lograr la meta, o conseguir el triunfo. El objetivo de este trabajo consistió en identificar la relación entre la zona y el tipo de golpe, desde la cual el tenista presenta mayor y menor efectividad en el juego. Para ello se observó a un tenista durante 12 entrenamientos con un rival de nivel equivalente, según la ATP, durante la temporada 2012-2013, registrando su situación en la cancha y el tipo de golpe de todas las devoluciones con éxito, entendido como obtención del punto o recuperación del saque. Se crearon tres criterios categóricos que constituyen un instrumento de observación para registrar el juego del tenista en la zona horizontal, y la zona vertical de la pista, además del tipo de golpe que realiza en términos de drive, revés, smash y dejada. Utilizando la técnica de regresión log-lineal, se obtuvieron resultados que indican que el jugador presenta una menor efectividad en los golpes realizados desde el lado izquierdo, y muestra una mayor efectividad en el drive y revés ejecutados desde media pista o fondo del lado derecho. La interpretación de los resultados aporta información sobre las localizaciones en la pista y los golpes, relacionados con su mayor y menor efectividad.

Trolley R&D project for a small portal log yard crane

This master’s thesis was done for Andritz Inc. Atlanta Georgia. The purpose of the thesis was to develop a new trolley for a small portal log yard crane. In the beginning of the thesis the basic principles of the systematic design processes have been described, along which the design work of the trolley has proceeded. The second literature part consists of the design and dimensioning of the welded steel structures under fatigue loading. The design work of the trolley consists of the engineering and the selection of the mechanical components and the design of the load carrying structure for the trolley. The realization of the steel structure of the trolley is based on the fatigue and static dimensioning. The fatigue dimensioning is grounded in the life expectations estimated for the trolley and the static dimensioning is based on the CMAA guidelines. The computer aided element method was utilized in the design of the steel structure. The effective notch method and the hot spot method were used in the fatigue calculations. The trolley structure was carried out by using the sheet metal parts in order to manufacture the structure as effective and low cost way as possible. The corner stone of the dimensioning of the trolley structure was the utilization of the open profiles made of welded or cold formed sheet metals, which provide better weldability, weld inspection, access for repairs and corrosion protection. As a last part of the thesis a new trolley traveling system was developed. The distribution of the wheel loads of the trolley bogies on the main girder was also studied, which led to an innovative suspension arrangement between the trolley leg and the bogie. The new bogie solution increases the service life of the main girder of the crane and improves the stability of the bogies. The outcome of the thesis is an excellent trolley structure from the weight and the service life point of view.

ANÁLISE DA FUNÇÃO LOG-LOGÍSTICA PARA MODELAGEM DA DISTRIBUIÇÃO DE DIÂMETROS1

RESUMO Objetivou-se neste estudo avaliar a eficiência da função log-logística com dois e três parâmetros, γ = dapmin e truncada à direita para a descrição da estrutura diamétrica de povoamentos equiâneos, bem como ajustar um modelo de distribuição diamétrica utilizando as funções. A modelagem realizada pela função log-logística foi comparada com a modelagem realizada com a função Weibull. Para isso, utilizaram-se dados de parcelas permanentes de clones de Eucalyptus, mensuradas em seis ocasiões. A aderência das funções aos dados foi comprovada pela aplicação do teste de Kolmogorov-Smirnov (K-S). Os valores médios da estatística do teste K-S foram 0,0901; 0,0997; 0,1297; e 0,0616 para a função com 2P, 3P, α = dapmin e truncada à direita, respectivamente. Para a função Weibull, obteve-se a média de 0,0638 para a estatística do teste K-S. A função log-logística de dois parâmetros pode ser utilizada na modelagem da estrutura diamétrica de povoamentos de eucalipto.

Summa rerum genera esse tantum duo: substantiam nimirum & accidens, ex suffragio ampliss. facult. philos. in florentissimo ad Auram Athenaeo, sub umbone ... dn. mag. Simonis Tålpo, met & log. professoris famigeratissimi, consistorii Acad. assessoris gravissimi nec non annexae Pijkensis pastoris longe fidelissimi. Summos in philosophia honores aditurus dissertatione philosophica ad sobrie philosophantium examen modeste delata statuere conabitur Jeremias Wallenius J. f. Tavastensis. Ad diem 21. Nov. anni redempti orbis M. DC. XC. IV. Horis pomeridianis in auditorio maximo

Invokaatio: A.J.

Compendium metaphysicae, juxta ductum & akribeian clarissimorum in hoc genere philosophorum concinnatum, & tam disputando quàm legendo studiosae juventuti propositum, in Regiâ Academiâ Aboënsi, ab Andrea Thuronio, phys. & log. prof. ordinario. Nunc primâ vice ad usum discentium in lucem prodiens

Dedikaatio: Petrus Brahe.

Photograph - Log cutting

A photograph with a male dressed in a shirt and bow-tie cutting a log and two other men in suits standing on either side of the log. They are surrounded by a large crowd.

Third Annual All-Women's International Air Race Flight Log, 1951

A chart of Dorothy Rungeling's flight landings and departures during the Third Annual All-Women's International Air Race in 1951.

Photograph - Elderly Woman at Log House

A photograph of an elderly female standing on the porch of a log house. A handwritten note is on the reverse.

Reglamento para el régimen interior de la Resp.: Log.: Probidadnum. 76

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Memorias presentadas por el Gr.: Maes.: de la Res.: Gr.: Log.: de Estado del Valle de México y por el G.: Ora.: de la Resp.: Gr.:Log.: de Estado L.: H.: D.: L.: V.: del O.: de Toluca en la fiesta

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