Integration of inverter constraints in geometrical quantification of the optimal solution to an MPC controller

Published Conference ProceedingsThis paper considers a model predictive controller with reference tracking that manipulates the integer switch positions of a power converter. It can be shown that the optimal switch position can be computed without solving an optimization problem. Specifically, in a new coordinate system, the optimization problem can be solved offline, leading to a polyhedral partition of the solution space. The optimal switch position can then be found using a binary search tree. This concept is exemplified for a three-level single-phase converter with an RL load

The development of a computer driver jigsaw

With a jigsaw, sharp inside corners can only be sawn out if the blade of the jigsaw is lifted out of the material and the corner is approached from two different sides. For the blade to be able to re-enter the material no material must be present at the entry point. The most important feature of an automated jigsaw is that it should be able to round off inside corners on a contour and automatically return to these corners to remove material left between the round off and the contour. With this development project an automated jigsaw machine was designed, built and tested. Emphasis fell on the development of software that enables one to draw contours that need to be sawn out, change these contours into cutter paths for the jigsaw and transform the cutter paths into digital format necessary to control the jigsaw machine via the parallel port of a personal computer.‘n Figuursaag kan slegs skerp binnehoeke saag as die lem uit die materiaal uitgelig word en die hoek van twee kante af gesaag word. Waar die lem weer in die materiaal ingaan, mag geen materiaal aanwesig wees nie. Die belangrikste eienskap van ‘n ge-outomatiseerde figuursaag is dat kontoere so gesaag moet word dat binnehoeke afgerond kan word en die materiaal tussen die afronding en die gewensde kontoer outomaties verwyder moet word. Met hierdie ontwikkelingsprojek, is ‘n ge-outomatiseerde figuursaag ontwerp, gebou en getoets. Die klem van die projek val op die ontwikkeling van sagteware waarmee kontoere wat uitgesaag moet word, geteken kan word, omgeskakel kan word in ‘n snyerpad vir die saaglem en gebruik kan word vir digitale beheer van die saagmasjien deur gebruik te maak van die parallelpoort van ‘n persoonlike rekenaar.http://sajie.journals.ac.z

Effect of Weld Schedule on the Residual Stress Distribution of Boron Steel Spot Welds

Press-hardened boron steel has been utilized in anti-intrusion systems in automobiles, providing high strength and weight-saving potential through gage reduction. Boron steel spot welds exhibit a soft heat-affected zone which is surrounded by a hard nugget and outlying base material. This soft zone reduces the strength of the weld and makes it susceptible to failure. Additionally, different welding regimes lead to significantly different hardness distributions, making failure prediction difficult. Boron steel sheets, welded with fixed and adaptive schedules, were characterized. These are the first experimentally determined residual stress distributions for boron steel resistance spot welds which have been reported. Residual strains were measured using neutron diffraction, and the hardness distributions were measured on the same welds. Additionally, similar measurements were performed on spot welded DP600 steel as a reference material. A correspondence between residual stress and hardness profiles was observed for all welds. A significant difference in material properties was observed between the fixed schedule and adaptively welded boron steel samples, which could potentially lead to a difference in failure loads between the two boron steel welds

Braincase of panphagia protos (dinosauria, sauropodomorpha)

We describe a partial braincase of the basal sauropodomorph Panphagia protos from the Upper Triassic (midCarnian) horizons of the Ischigualasto Formation. The disarticulated braincase from a subadult individual includes one frontal, both parietals, one prootic, and the supraoccipital. The frontal is longer anteroposteriorly than it is wide transversely, has a small anterolateral process, and an elongate oval depression for the olfactory bulb. The supraoccipital is broader transversely than it is deep dorsoventrally and lacks a pronounced median nuchal eminence. Some braincase features that characterize more derived basal sauropodomorphs are not present in Panphagia, including a broader frontal and reduced anterior tympanic and floccular recesses. Panphagia appears to represent an early stage in the evolution of sauropodomorph dinosaurs.Describimos la caja craneana parcial del sauropodomorfo basal Panphagia protos proveniente de horizontes del Triásico superior (Carniano medio) de la Formación Ischigualasto. La caja craneana desarticulada es de un individuo sub-adulto e incluye un frontal, dos parietales, un proótico y el supraoccipital. El frontal es más largo anteroposteriormente que ancho transversalmente, tiene un pequeño proceso anterolateral y una depresión alargada oval para el bulbo olfatorio. El supraoccipital es transversalmente más ancho que dorsoventralmente alto y carece de una eminencia nucal media pronunciada. Algunas de las características que caracterizan los neurocráneos de sauropodomorfos basales más derivados no están presentes en Panphagia, incluyendo el frontal ancho y la reducción de las cavidades timpánica anterior y flocular. Panphagia parece representar una etapa temprana en la evolución de los dinosaurios sauropodomorfos.Fil: Martínez, Ricardo Néstor. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Fisicas y Naturales. Instituto y Museo de Ciencias Naturales; ArgentinaFil: Haro, Jose Augusto. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Fisicas y Naturales. Instituto y Museo de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Apaldetti, Graciela Cecilia. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Fisicas y Naturales. Instituto y Museo de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A Basal Sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic, Carnian) and the Early Evolution of Sauropodomorpha

BACKGROUND: The earliest dinosaurs are from the early Late Triassic (Carnian) of South America. By the Carnian the main clades Saurischia and Ornithischia were already established, and the presence of the most primitive known sauropodomorph Saturnalia suggests also that Saurischia had already diverged into Theropoda and Sauropodomorpha. Knowledge of Carnian sauropodomorphs has been restricted to this single species. METHODOLOGY/PRINCIPAL FINDINGS: We describe a new small sauropodomorph dinosaur from the Ischigualsto Formation (Carnian) in northwest Argentina, Panphagia protos gen. et sp. nov., on the basis of a partial skeleton. The genus and species are characterized by an anteroposteriorly elongated fossa on the base of the anteroventral process of the nasal; wide lateral flange on the quadrate with a large foramen; deep groove on the lateral surface of the lower jaw surrounded by prominent dorsal and ventral ridges; bifurcated posteroventral process of the dentary; long retroarticular process transversally wider than the articular area for the quadrate; oval scars on the lateral surface of the posterior border of the centra of cervical vertebrae; distinct prominences on the neural arc of the anterior cervical vertebra; distal end of the scapular blade nearly three times wider than the neck; scapular blade with an expanded posterodistal corner; and medial lamina of brevis fossa twice as wide as the iliac spine. CONCLUSIONS/SIGNIFICANCE: We regard Panphagia as the most basal sauropodomorph, which shares the following apomorphies with Saturnalia and more derived sauropodomorphs: basally constricted crowns; lanceolate crowns; teeth of the anterior quarter of the dentary higher than the others; and short posterolateral flange of distal tibia. The presence of Panphagia at the base of the early Carnian Ischigualasto Formation suggests an earlier origin of Sauropodomorpha during the Middle Triassic

A New Basal Sauropod Dinosaur from the Middle Jurassic of Niger and the Early Evolution of Sauropoda

The early evolution of sauropod dinosaurs is poorly understood because of a highly incomplete fossil record. New discoveries of Early and Middle Jurassic sauropods have a great potential to lead to a better understanding of early sauropod evolution and to reevaluate the patterns of sauropod diversification.A new sauropod from the Middle Jurassic of Niger, Spinophorosaurus nigerensis n. gen. et sp., is the most complete basal sauropod currently known. The taxon shares many anatomical characters with Middle Jurassic East Asian sauropods, while it is strongly dissimilar to Lower and Middle Jurassic South American and Indian forms. A possible explanation for this pattern is a separation of Laurasian and South Gondwanan Middle Jurassic sauropod faunas by geographic barriers. Integration of phylogenetic analyses and paleogeographic data reveals congruence between early sauropod evolution and hypotheses about Jurassic paleoclimate and phytogeography.Spinophorosaurus demonstrates that many putatively derived characters of Middle Jurassic East Asian sauropods are plesiomorphic for eusauropods, while South Gondwanan eusauropods may represent a specialized line. The anatomy of Spinophorosaurus indicates that key innovations in Jurassic sauropod evolution might have taken place in North Africa, an area close to the equator with summer-wet climate at that time. Jurassic climatic zones and phytogeography possibly controlled early sauropod diversification

THE DEVELOPMENT OF A COMPUTER DRIVEN JIGSAW

<P>ENGLISH ABSTRACT: With a jigsaw, sharp inside corners can only be sawn out if the blade of the jigsaw is lifted out of the material and the corner is approached from two different sides. For the blade to be able to re-enter the material no material must be present at the entry point. The most important feature of an automated jigsaw is that it should be able to round off inside corners on a contour and automatically return to these corners to remove material left between the round off and the contour. With this development project an automated jigsaw machine was designed, built and tested. Emphasis fell on the development of software that enables one to draw contours that need to be sawn out, change these contours into cutter paths for the jigsaw and transform the cutter paths into digital format necessary to control the jigsaw machine via the parallel port of a personal computer.</P><P>AFRIKAANSE OPSOMMING: ‘n Figuursaag kan slegs skerp binnehoeke saag as die lem uit die materiaal uitgelig word en die hoek van twee kante af gesaag word. Waar die lem weer in die materiaal ingaan, mag geen materiaal aanwesig wees nie. Die belangrikste eienskap van ‘n ge-outomatiseerde figuursaag is dat kontoere so gesaag moet word dat binnehoeke afgerond kan word en die materiaal tussen die afronding en die gewensde kontoer outomaties verwyder moet word. Met hierdie ontwikkelingsprojek, is ‘n ge-outomatiseerde figuursaag ontwerp, gebou en getoets. Die klem van die projek val op die ontwikkeling van sagteware waarmee kontoere wat uitgesaag moet word, geteken kan word, omgeskakel kan word in ‘n snyerpad vir die saaglem en gebruik kan word vir digitale beheer van die saagmasjien deur gebruik te maak van die parallelpoort van ‘n persoonlike rekenaar.</P&gt

ITERATIVE SLICING AS SOLUTION TO THE MODEL PREDIC- TIVE CONTROL PROBLEM OF A THREE-LEVEL INVERTER

Conference ProceedingsThis paper considers a model predictive controller with reference tracking that manipulates the integer switch positions of a power converter. It can be shown that the optimal switch position can be computed in a new coordinate system by solving the closest vector problem in a lattice by iterative slicing. A list of Voronoi relevant vectors defining the basic Voronoi cell of a lattice is used to find the Voronoi cell containing the unconstrained optimum in an iterative manner. This concept is exemplified for a three-level single-phase converter with an RL load

Development of a core outcome domain set for clinical research on capillary malformations (the COSCAM project)

BACKGROUND: Due to a large variety in treatment outcomes reported in therapeutic trials and lacking patient‐relevant outcomes, it is hard to adequately compare and improve current therapies for patients with capillary malformations (CMs). The Core Outcome Set for Capillary Malformations (COSCAM) project aims to develop a core outcome set (COS) for use in future CM trials, in which we will first develop a core outcome (sub)domain set (CDS). Here, we describe the methods for the development of a CDS and present the results of the first development stage. METHODS: The COSCAM project is carried out according to the recommendations of the Cochrane Skin Core OUtcomes Set INitiative (CS‐COUSIN) and the Core Outcome Measures in Effectiveness Trials (COMET) initiative. During the first stage, we identified all potentially relevant outcome subdomains based on a systematic review, two focus group sessions and input from patient representatives of Dutch patient organizations and the COSCAM‐founding group. In stage two, we will present the subdomains in a three‐round e‐Delphi study and online consensus meeting, in which CM patients, parents/caregivers and CM experts worldwide rate the importance of the proposed subdomains, hereby finalizing the core outcome (sub)domains of the CDS. RESULTS: A total of 67 potential outcome subdomains were included; sixteen were previously used in the literature, 20 were proposed by Dutch patients and their parents/caregivers (n = 13) in focus group sessions and 38 were suggested by the experts of the COSCAM‐founding group. Seven were excluded because of overlap. CONCLUSION: The final CDS may serve as a minimum standard in future CM trials, thereby facilitating adequate comparison of treatment outcomes. After this CDS development, we will select appropriate outcome measurement instruments to measure the core outcome subdomains