Podcasts about splines

Ben and Lee discuss "doing the right thing" and how to connect a nuclear base on the moon with Lee's house with Home Depot extension cables. Also we decide that this is now just a podcast about SimCity 2000

The Google hack keeping negative reviews at the top of your business listing. Is TikTok preparing a standalone messaging app? Chrome's ad privacy notice seems a little fishy. And the AI company that secretly uses humans instead of AI..

QUESTIONS ASKED ON THE SHOW Spark Plug Indexing is it worth it? Do you recommend low drag bearings on all 4 wheels or just the front? On the gen 2 bert transmissions is the Crate guys getting them ballspline or slip yoke? On a 602, is there an advantage to using a lightweight flexplate? What are your thoughts on lightweight balancers on a 602. Is it a bolt on or part of the engine? And, is there an advantage to a lightweight balancer? Were is the best location to install Coolant temp Sensor in a 602 engine? I've got a damaged rocker arm stud in a 602that makes it hard to get the valves set right. Any recommendations for a workaround until I can pull the engine for a refresh? I got a new set of schoenfeld headers for 604 crate late. Got extensions and mufflers. Do you recommend using the extensions? Are brisk spark plugs best for a 602 on gas? Each week, Kate Dillon from Crate Insider and Steve Hendren from Hendren Racing Engines go live on the Crate Insider Facebook page and Crate Insider YouTube Channel to chat about world events, random things, and to answer tech questions. To watch this podcast on Crate Insider's YouTube channel, click here.

[…] Fidèle au Ministère de l'Intérieur, la Salle 101 dénonce, dénonce et dénonce encore, toujours au service de la France. La preuve : Ymir, super roman du super Rich Larson que nous aimons d'amour. Splines, recueil chelou super de Luvan. Le cycle de Lyonesse, petits romans supers d'un inconnu nommé Jack Vance. Guedin, on te dit.  »Avoue c'est […]

We're digging deep into right brain / left brain communication! But metaphorically, not like...with a spoon. Want to get really into the weeds on this Brain Storm? Check out the PubMed.gov abstract: Running speed and REM sleep control two distinct modes of rapid interhemispheric communication

In this tutorial I walk through creating a curvy rectangular shape using the spline tool in Fusion 360. I show how to use symmetrical and equal sketch constraints to create a shape thats flexible and parametric. Whenever one side of the shape is effect, the other side is perfectly mirrored. One corner of the shape features a bezier handle with a sketch dimension (length and angle) making it easy to adjust a single corner and automatically update the other three. This technique was used in an upcoming project that uses spline curves to create a kitty paw shape. I personally have found the spline tool one of the more trickier to tame and this project has brought me more understanding of how to better manipulate and control splines in fusion 360. 3D Printing Projects Playlist: https://www.youtube.com/playlist?list=PLjF7R1fz_OOWD2dJNRIN46uhMCWvNOlbG 3D Hangout Show Playlist: https://www.youtube.com/playlist?list=PLjF7R1fz_OOVgpmWevin2slopw_A3-A8Y Layer by Layer CAD Tutorials Playlist: https://www.youtube.com/playlist?list=PLjF7R1fz_OOVsMp6nKnpjsXSQ45nxfORb Timelapse Tuesday Playlist: https://www.youtube.com/playlist?list=PLjF7R1fz_OOVagy3CktXsAAs4b153xpp_ Milling Monday https://www.youtube.com/playlist?list=PLjF7R1fz_OOVL48weqeHiu7aw-_sPhCSA Visit the Adafruit shop online - http://www.adafruit.com ----------------------------------------- LIVE CHAT IS HERE! http://adafru.it/discord Adafruit on Instagram: https://www.instagram.com/adafruit Subscribe to Adafruit on YouTube: http://adafru.it/subscribe New tutorials on the Adafruit Learning System: http://learn.adafruit.com/ -----------------------------------------

In this tutorial I walk through creating a curvy rectangular shape using the spline tool in Fusion 360. I show how to use symmetrical and equal sketch constraints to create a shape thats flexible and parametric. Whenever one side of the shape is effect, the other side is perfectly mirrored. One corner of the shape features a bezier handle with a sketch dimension (length and angle) making it easy to adjust a single corner and automatically update the other three. This technique was used in an upcoming project that uses spline curves to create a kitty paw shape. I personally have found the spline tool one of the more trickier to tame and this project has brought me more understanding of how to better manipulate and control splines in fusion 360. 3D Printing Projects Playlist: https://www.youtube.com/playlist?list=PLjF7R1fz_OOWD2dJNRIN46uhMCWvNOlbG 3D Hangout Show Playlist: https://www.youtube.com/playlist?list=PLjF7R1fz_OOVgpmWevin2slopw_A3-A8Y Layer by Layer CAD Tutorials Playlist: https://www.youtube.com/playlist?list=PLjF7R1fz_OOVsMp6nKnpjsXSQ45nxfORb Timelapse Tuesday Playlist: https://www.youtube.com/playlist?list=PLjF7R1fz_OOVagy3CktXsAAs4b153xpp_ Milling Monday https://www.youtube.com/playlist?list=PLjF7R1fz_OOVL48weqeHiu7aw-_sPhCSA Visit the Adafruit shop online - http://www.adafruit.com ----------------------------------------- LIVE CHAT IS HERE! http://adafru.it/discord Adafruit on Instagram: https://www.instagram.com/adafruit Subscribe to Adafruit on YouTube: http://adafru.it/subscribe New tutorials on the Adafruit Learning System: http://learn.adafruit.com/ -----------------------------------------

You can't cut back on funding!! 0:00 Intro 3:12 From The Archives: Castlevania 4:48 Music: 10000 6:46 News Of The Weird 16:59 Music: 10008 20:06 Review Review: Viewtiful Joe 43:18 Music: 10018 45:03 Outro LowBiasGaming - http://www.lowbiasgaming.net Patreon - http://www.patreon.com/jasonsgroovemachine Discord Chat! - https://discord.gg/4B4gUXw Twitter - http://www.twitter.com/jasongrvin YouTube - http://www.youtube.com/jasonsgroovemachine --- Send in a voice message: https://anchor.fm/electricleftovers/message

You can't cut back on funding!! 0:00 Intro 3:12 From The Archives: Castlevania 4:48 Music: 10000 6:46 News Of The Weird 16:59 Music: 10008 20:06 Review Review: Viewtiful Joe 43:18 Music: 10018 45:03 Outro LowBiasGaming - http://www.lowbiasgaming.net Patreon - http://www.patreon.com/jasonsgroovemachine Discord Chat! - https://discord.gg/4B4gUXw Twitter - http://www.twitter.com/jasongrvin YouTube - http://www.youtube.com/jasonsgroovemachine --- Send in a voice message: https://anchor.fm/electricleftovers/message

Ellie Murray and Lucy D'Agostino McGowan discuss Bayesian statistics, model validation, and more, with special guest Dr. Frank Harrell from the Department of Biostatistics at Vanderbilt University.

In our 222nd regular episode of Metagamers Anonymous, we gather in the aftermath of our most recent GameDay event to discuss the madness of the day’s adventures. Metagamers Anonymous is a podcast dedicated to tabletop roleplaying games and (mostly) related material. To join the conversation, drop us a line at feedback@prismatictsunami.com. Note: Some degree of […]

In our 222nd regular episode of Metagamers Anonymous, we gather in the aftermath of our most recent GameDay event to discuss the madness of the day’s adventures. Metagamers Anonymous is a podcast dedicated to tabletop roleplaying games and (mostly) related material. To join the conversation, drop us a line at feedback@prismatictsunami.com. Note: Some degree of […] The post MetAnon Ep222 - Reticulating Splines first appeared on Prismatic Tsunami.

Welcome to "In the Shade of the Sun", a new one-arc campaign from True Meta Inc.! Listen as Max, Eric, and temporarily-promoted Dungeon Master Victor begin weaving an urban fantasy adventure influenced by Monster of the Week. (We'll be releasing episodes of Shade weekly til the end of August and return to our Link Strike adventure in September!)

Arne Rick (@Couchsofa) war schon ein häufiger, aber ungenannter Gast im Modellansatz Podcast: Als DJ war er auf den Aufnahmen von der aktuellen und früheren Gulasch-Programmiernächten im Hintergrund zu hören. Außer für Musik hat Arne auch ein großes Faible für Mathematik und Informatik und befasst sich im Zuge seiner von Prof. Marcus Aberle betreuten Bachelorarbeit zum Bauingenieurwesen an der Hochschule Karlsruhe mit Bezierkurven für Stabwerke. Stabwerke sind Modelle für Strukturen in Bauwerken und eine Lösung für ein System von Stabwerken hilft im konstruktiven Bauingenieurwesen, die Aufbauten in ihren Bemessungen und Anforderungen auszulegen und erforderliche Eigenschaften festzulegen. Die Darstellung als Stabwerke ist im Sinne eines Fachwerks eng verknüpft mit dem Prinzip von Finite Elementen, da diese in gewissen Anwendungen als Stabwerke und umgekehrt interpretiert werden können. Weiterhin können Stabwerke mit Hilfe von finite Elementen innerhalb der Stäbe genauer bestimmt bzw. verfeinert werden. Die Betrachtung des Stabwerks beginnt mit der Struktur und den Einwirkungen: Hier ist spielt das Semiprobabilistische Teilsicherheitsbeiwerte-System eine besondere Rolle, da es die möglichen Einwirkungen auf die Bauteile und damit die Gesamtanalyse probabilistisch erfassbar macht. Man unterscheidet hier nicht mehr so stark zwischen dem Bauen im Bestand, wo viele Nebenbedingungen zwar bekannt, aber die Eigenschaften der verbleibenden Bestandteile unsicher sind, und dem Aufbau eines Neubaus, wo es jeweils für die Bauingenieure gilt, die Vorgaben aus der Architektur konstruktiv, berechnend, planend und organisatorisch unter Berücksichtigung des möglichen Zeit- und finanziellen Rahmens, verfügbarer Materialien, Technik, Mitarbeiter und Bauverfahren sicher umzusetzen. Speziell in der Betrachtung der Stabwerke können die Fälle der statistischen Über- und Unterbestimmung des Bauwerks auftreten, wo Überbestimmung grundsätzlich zu Verformungen führt, eine Unterbestimmung andererseits kein funktionsfähiges Bauwerk darstellt. Weiterhin ändert jede Anpassung von beispielsweise der Tragfähigkeit eines Bauteils auch gleich zur Änderung des gesamten Stabwerks, da ein stärkerer Stab oft auch mehr wiegt und sich eventuell auch weniger verformt. Außerdem ziehen in einem statisch überbestimmten System die steiferen Elemente die Lasten an. So ist es häufig, eher unintuitiv, von Vorteil Bauteile zu schwächen um eine Lastumlagerung zu erzwingen. Dies führt in der Auslegung oft zu einem iterativen Prozess. Die Darstellung eines Stabes oder Balkens ist dabei eine Reduzierung der Wirklichkeit auf ein lokal ein-dimensionales Problem, wobei die weiteren Einwirkungen aus der Umgebung durch Querschnittswerte abgebildet werden. Die Voute ist ein dabei oft auftretendes konstruktives Element in der baulichen Umsetzung eines Tragwerks, die in der Verbindung von Stäben eine biegesteife Ecke bewirkt und in vielen Gebäuden wie beispielsweise dem ZKM oder der Hochschule für Gestaltung in Karlsruhe zu sehen sind. In der Modellierung der einzelnen Stäbe können verschiedene Ansätze zum Tragen kommen. Ein Standardmodell ist der prismatische Bernoulli Biegestab, das mit Differentialgleichungen beschrieben und allgemein gelöst werden kann. Daraus entstehen Tabellenwerke, die eine Auslegung mit Hilfe dieses Modell ermöglichen, ohne weitere Differentialgleichungen lösen zu müssen. Eine häufige Vereinfachung ist die Reduzierung des Problems auf zwei-dimensionale planare Stabwerke, die in den meissten Anwendungsfällen die relevanten Anforderungen darstellen können. Die Stäbe in einem Stabwerk können nun unterschiedlich miteinander verbunden werden: Eine Möglichkeit ist hier ein Gelenk, oder in verschiedene Richtungen und Dimension festlegte oder freie Lager, also Festlager oder Loslager zwischen Stäben oder einem Stab und dem Boden. Je nach Wahl der Verbindung entstehen in diesem Punkt eine unterschiedliche Anzahl von Freiheitsgraden. Für die praktische Berechnung werden Lager oft auch verallgemeinert, in dem die Verbindung über eine Feder modelliert wird: Hier haben ideale Loslager eine Federkonstante von 0, während die Federkonstante von idealen Festlagern gegen unendlich geht. Mit allen Werten dazwischen können dann reelle Lager besser beschrieben werden. In vereinfachter Form führt die Berechnung eines Stabwerks mit idealisierten unbiegbaren Balken mit den Endpunkten der Balken als Variablen und den Verknüpfung der Balken als Gleichungen direkt auf ein relativ einfaches lineares Gleichungssystem. Da sich in Realität alle Balken unter Last merklich verbiegen (es sei denn, sie sind vollkommen überdimensioniert), müssen sie grundsätzlich mit Steifigkeit modelliert werden, um belastbare Ergebnisse zu erhalten. Aber auch im erweiterten Modell wird der Stab durch eine Matrix linear beschrieben, nur dass hier auch die Last eine Rolle spielt und über das Elastizitätsmodul, Fläche und Trägheitsmoment die Verbiegungen abbilden kann. So ergibt das erweiterte Modell ebenfalls ein lineares Gleichungssystem, nur mit mehr Variablen und Parametern, die das System beschreiben und Angaben zur Verbiegung und Lastverteilung machen. Nach der gewöhnlichen Berechnung des Stabwerks hat sich Arne nun mit der Frage beschäftigt, ob die Stäbe mit Biegezuständen mit Bezierkurven besonders sinnvoll dargestellt werden können. In der Konstruktion erfahren Bézierkurven eine große Beliebtheit, da sie über Start- und Endpunkt mit zwei Kontrollpunkten sehr intiutiv zu steuern sind. Oft kommen oft Non-Uniform Rational B-Splines (NURBS) zum Einsatz, die als verallgemeinerte Bézier-Splines aufgefasst werden können. Das Grundproblem besteht darin, dass die Stäbe im erweiterten Modell durch Einführung der Biegezustände und Elastizität weder ihre Länge behalten, noch eine eindeutige Ausrichtung durch unterschiedliche Winkel an den Enden erhalten. Einen solchen Widerspruch versucht man bei Finiten Elementen entweder durch eine feinere Diskretisierung und damit durch eine Abbildung durch Geradenstücke oder durch eine Abbildung mit Polynomen höherer Ordnung zu ermöglichen und das Problem auf dem verfeinerten Modell zu lösen. Der dritte Ansatz ist hier, die Ergebnisse durch die in der Konstruktion bewährte Darstellung über Bezier-Kurven qualitativ anzunähern, um die Modellerfahrung aus der Konstruktion in der Darstellung der Lösung zu nutzen. Die Umsetzung erfolgt in Python, das mit den Bibliotheken NumPy und SciPy eine Vielzahl hilfreicher und effizienter Funktionen besitzt. Literatur und weiterführende Informationen A. Rick: Structurana, Python, 2017. Friedrich U. Mathiak: Die Methode der finiten Elemente (FEM), Einführung und Grundlagen, Skript, Hochschule Neubrandenburg, 2010. Ch. Zhang, E. Perras: Geometrische Nichtlinearität, Steifigkeitsmatrix und Lastvektor, Vorlesung Baustatik (Master), Lehrstuhl Baustatik, Universität Siegen, 2015. Podcasts M. Bischoff: Baustatik und -dynamik, Gespräche mit Markus Völter & Nora Ludewig im omega tau Podcast, Episode 029, 2010. M. An: Topologieoptimierung, Gespräch mit G. Thäter im Modellansatz Podcast, Folge 125, Fakultät für Mathematik, Karlsruher Institut für Technologie (KIT), 2017. A. Rick: A Hackers Approach To Building Electric Guitars, Vortrag auf der GPN15, Karlsruhe, 2015. GPN17 Special Sibyllinische Neuigkeiten: GPN17, Folge 4 im Podcast des CCC Essen, 2017. M. Lösch: Smart Meter Gateway, Gespräch mit S. Ritterbusch im Modellansatz Podcast, Folge 135, Fakultät für Mathematik, Karlsruher Institut für Technologie (KIT), 2017. F. Magin: Automated Binary Analysis, Gespräch mit S. Ritterbusch im Modellansatz Podcast, Folge 137, Fakultät für Mathematik, Karlsruher Institut für Technologie (KIT), 2017. A. Rick: Bézier Stabwerke, Gespräch mit S. Ritterbusch im Modellansatz Podcast, Folge 141, Fakultät für Mathematik, Karlsruher Institut für Technologie (KIT), 2017.

Water shortage reported!

Favorite techniques, including Matt’s method of hiding splines in miters. What nail guns you need, fixing punky patches on spalted maple, and favorite furniture of all time... for this week.

Favorite techniques, including Matt’s method of hiding splines in miters. What nail guns you need, fixing punky patches on spalted maple, and favorite furniture of all time... for this week.

We record live at the University of Georgia School of Law at the invitation of the Georgia Law Review. The main topic is law journals, but we also give an update on Christian’s crumbling infrastructure, talk about gravitational waves, and introduce a new and complete system of citation. This show’s links: Baby Blue: web page and PDF The Bluebook David Post, The New (and Much Improved) ‘Bluebook’ Caught in the Copyright Cross-Hairs Links to correspondence between lawyers for The Bluebook and others and the Baby Blue team Oral Argument 73: Looking for the Splines B.P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration), Observation of Gravitational Waves from a Binary Black Hole Merger (and see the article and video at the Times: Dennis Overbye, Gravitational Waves Detected, Confirming Einstein’s Theory) David Foster Wallace, Tense Present (an earlier version of Authority and American Usage in Consider the Lobster and Other Essays) Robot or Not The Oyez podcast feed for 2015 Supreme Court oral argument and the collection of Oyez feeds in iTunes

We open the burgeoning mailbag. And oh what a bounty! Side A: 1. Georgia’s assertion of copyright over its annotated statutes. 2. Law school application, rankings, and preparation. 3. The utility for law of having a Ph.D. 4. Substantive due process and Lochner. 5. Would law school be better without the study of the Supreme Court or constitutional law? Side B: 6. Voting rights and proportional representation. 7. Whether we’ve had a fair discussion of the death penalty. 8. What makes legal writing good or bad? 9. Other podcasts. 10. Race and the law. 11. The utilitarian case for manual override of driverless cars. 12. Facebook’s ability to create “bad” desires and preferences. Drugs and entertainment. 13. The rogue Kentucky clerk and the difference between civil disobedience and sabotage or revolution. This show’s links: Oral Argument on Twitter and on Facebook About Carl Malamud Georgia Accuses Public Records Activist of Information “Terrorism” Episode 68: Listen to My Full Point and Episode 12: Heart of Darkness Episode 62: Viewer Mail Episode 30: A Filled Milk Caste Episode 66: You’re Never Going to Get It All Done (guest Kareem Creighton) and Kareem Creighton’s tweet to us about this question Chris Elmendorf, Making Sense of Section 2: Of Biased Votes, Unconstitutional Elections, and Common Law Statutes Episode 56: Cracking and Packing (guest Lori Ringhand) Episode 67: Monstrous Acts (guest Josh Lee) Callins v. Collins (Scalia’s concurrence citing the brutality of a murder in a case in which the defendant was later proved innocent) Danielle Allen, Our Declaration; Robert Cover, Violence and the Word ; Jedediah Purdy, After Nature: A Politics for the Anthropocene Undisclosed: The State v. Adnan Syed, a podcast recommended to us Episode 69: Contaminated Evidence (guest Brandon Garrett); see also Episode 45: Sacrifice, Episode 64: Protect and Serve (guest Seth Stoughton) The Our National Conversation about Conversations about Race podcast Episode 70: No Drones in the Park (guest Frank Pasquale) Episode 72: The Guinea Pig Problem (guest Michelle Meyer) A youtube of David Foster Wallace talking about drugs and entertainment in Infinite Jest (2m23s) Anthony Kreis’s tweet about civil disobedience

Elaboración de la tabla de diferencias divididas utilizando EXCEL y elaboración de Splines Lineales

Elaboración de las ecuaciones que permiten encontrar un spline cúbico

Klothoiden sind Kurven, die 1794 von Jakob I. Bernoulli zuerst beschrieben wurden. Er hatte die Form eines Metallstreifens untersucht, der von einem Gewicht an einem Ende verbogen wird, während das andere Ende eingespannt ist. Als Resultat des elastischen Verhaltens ist dann die Krümmung proportional zur Kurvenlänge. Viele weitere Eigenschaften von Kurven mit dIeser Eigenschaft wurden dann von Leonhard Euler über den Rahmen des Gedankenexperiments von Bernoulli hinaus bewiesen , wie zum Beispiel die Position der asymptotischen Endpunkte. Im Straßen- und Schienenbau sind Klothoiden ausgezeichnete Übergangsbögen zwischen geraden Strecken und Kurven, da diese Kurve die Krümmung zwischen den beiden Abschnitten gleichmäßig anpasst. Bei der Planung von Schienentrassen wurde diese Eigenschaft vor etwa 100 Jahren schon ausgenutzt. Eine aktuelle wichtige Anwendung ist die Abbildung der Straßen in Fahrassistenzsystemen, wo passend parametrisierte Klothoiden große Vorteile gegenüber Splines besitzen, wie Gotami Heller im Gespräch mit Gudrun Thäter erklärt. Um Klothoiden tatsächlich im Computermodell benutzen zu können, muss eine möglichst adäquate Approximation gesucht und implementiert werden, die die nötige Glattheit in der Kurve erhält. Literatur und Zusatzinformationen M. Bäumker: Rechenverfahren der Ingenieurvermessung http://www.eecs.berkeley.edu/Pubs/TechRpts/2008/EECS-2008-111.pdf: R. Levien: The Euler spiral, a mathematical history, Technical Report University of Carlifornia at Berkeley, UCB/EECS-2008-111, 2008. D. Khosla: Accurate estimation of forward path geometry using two-clothoid road model, Intelligent Vehicle Symposium, 2002. IEEE. Vol. 1. IEEE, 2002.

Wed, 5 Nov 2014 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/17600/ https://edoc.ub.uni-muenchen.de/17600/1/Bloechl_Andreas.pdf Blöchl, Andreas ddc:330, ddc:300, Volkswirtschaftliche Fakultät

This video shows you how to create 3D shapes using open mask splines. This includes using edge gradients as part of the workflow and the different options when using edge gradients.

This video show you how to manage edge gradients when working with closed splines forming a 3D shape. Create round edges on 3D shapes. Also a bit of fun with Replica nodes.

Penalized splines have become a popular tool to model the trend component in economic time series. The outcome of the spline predominantly depends on the choice of a penalization parameter that controls the smoothness of the trend. This paper derives the penalization of splines by frequency domain aspects and points out their link to rational square wave filters. As a novel contribution this paper focuses on the so called excess variability at the margins that describes the undesired increasing variability of the trend estimation to the ends of the series. It will be shown that the too high volatility at the margins can be reduced considerably by a time varying penalization, which yields more reliable estimations for the most recent periods.

This movie shows you how to create a new XGen description on top of an existing description, as well as how to use many of XGen's utilities and modifiers to create a mohawk hairstyle. It then shows you how to use groomable splines to create a beard.

On purpose to extract trend and cycle from a time series many competing techniques have been developed. The probably most prevalent is the Hodrick Prescott filter. However this filter suffers from diverse shortcomings, especially the subjective choice of its penalization parameter. To this point penalized splines within a mixed model framework offer the advantage of a data driven derivation of the penalization parameter. Nevertheless the Hodrick-Prescott filter as well as penalized splines fail to estimate trend and cycle when one deals with times series that contain structural breaks. This paper extends the technique of splines within a mixed model framework to account for break points in the data. It explains how penalized splines as mixed models can be used to avoid distortions caused by breaks and finally provides an empirical application to German data which exhibit structural breaks due to the reunification in 1990.

Have you always wanted to fly a plane? Drive a truck? Farm a farm? In this wondrous day and age, regardless of your experience or skill level, anyone can be or do anything they want!* Limited only by your imagination, drive to succeed and perseverance, you can reach the stars!* Episode 8 of Nugatory Quest is here to help you on this grand adventure of self-discovery, giving you the exclusive scoop on popular languages, super-old Olympic games and blood-sucking (drinking?) fiends. We’re here to help, and we know that you can accomplish anything you set your mind to.*   (*In video games.)   Course Materials: Much Good English, The Split Level, Portmanteau, Michael Jason Bateman, JimmiPods, Sweet Sweet Heinz

Who would have thought that simulating an ant farm would be so fun? Darren, Heath, and James discuss Maxis and the Sim Franchise in this episode of Nostalgiamatic. We'll fill you with more retro then you could buy for 500 simoleons.

Multivariate adaptive regression splines (MARS) are a useful tool to identify linear and nonlinear effects and interactions between two covariates. In this dissertation a new proposal to model survival type data with MARS is introduced. Martingale and deviance residuals of a Cox PH model are used as response in a common MARS approach to model functional forms of covariate effects as well as possible interactions in a data-driven way. Simulation studies prove that the new method yields a better fit to the data than the traditional Cox PH approach. The analysis of real data of the German Heart Center on survivors of an acute myocardial infarction also documents the good performance of the method.

We propose a novel method to model nonlinear regression problems by adapting the principle of penalization to Partial Least Squares (PLS). Starting with a generalized additive model, we expand the additive component of each variable in terms of a generous amount of B-Splines basis functions. In order to prevent overfitting and to obtain smooth functions, we estimate the regression model by applying a penalized version of PLS. Although our motivation for penalized PLS stems from its use for B-Splines transformed data, the proposed approach is very general and can be applied to other penalty terms or to other dimension reduction techniques. It turns out that penalized PLS can be computed virtually as fast as PLS. We prove a close connection of penalized PLS to the solutions of preconditioned linear systems. In the case of high-dimensional data, the new method is shown to be an attractive competitor to other techniques for estimating generalized additive models. If the number of predictor variables is high compared to the number of examples, traditional techniques often suffer from overfitting. We illustrate that penalized PLS performs well in these situations.

Tue, 10 May 2005 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/3942/ https://edoc.ub.uni-muenchen.de/3942/1/Brezger_Andreas.pdf Brezger, Andreas ddc:510, ddc:500, Fakultät für Mathematik, Informatik und Statistik

P-splines are a popular approach for fitting nonlinear effects of continuous covariates in semiparametric regression models. Recently, a Bayesian version for P-splines has been developed on the basis of Markov chain Monte Carlo simulation techniques for inference. In this work we adopt and generalize the concept of Bayesian contour probabilities to Bayesian P-splines within a generalized additive models framework. More specifically, we aim at computing the maximum credible level (sometimes called Bayesian p-value) for which a particular parameter vector of interest lies within the corresponding highest posterior density (HPD) region. We are particularly interested in parameter vectors that correspond to a constant, linear or more generally a polynomial fit. As an alternative to HPD regions simultaneous credible intervals could be used to define pseudo contour probabilities. Efficient algorithms for computing contour and pseudo contour probabilities are developed. The performance of the approach is assessed through simulation studies and applications to data for the Munich rental guide and on undernutrition in Zambia and Tanzania.

In many studies where it is known that one or more of the certain covariates have monotonic effect on the response variable, common fitting methods for generalized additive models (GAM) may be affected by a sparse design and often generate implausible results. A fitting procedure is proposed that incorporates the monotonicity assumptions on one or more smooth components within a GAM framework. The flexible likelihood based boosting algorithm uses the monotonicity restriction for B-spline coefficients and provides componentwise selection of smooth components. Stopping criteria and approximate pointwise confidence bands are derived. The method is applied to data from a study conducted in the metropolitan area of Sao Paulo, Brazil, where the influence of several air pollutants like SO_2 on respiratory mortality of children is investigated.

This paper aims at proposing suitable statistical tools to address heterogeneity in repeated measures, within a Multiple Sclerosis (MS) longitudinal study. Indeed, due to unobservable sources of heterogeneity, modelling the effect of covariates on MS severity evolves as a very difficult feature. Bayesian P-Splines are suggested for modelling non linear smooth effects of covariates within generalized additive models. Thus, based on a pooled MS data set, we show how extending Bayesian P-splines to mixed effects models (Lang and Brezger, 2001), represents an attractive statistical approach to investigate the role of prognostic factors in affecting individual change in disability.

Extensions of the traditional Cox proportional hazard model, concerning the following features are often desirable in applications: Simultaneous nonparametric estimation of baseline hazard and usual fixed covariate effects, modelling and detection of time-varying covariate effects and nonlinear functional forms of metrical covariates, and inclusion of frailty components. In this paper, we develop Bayesian multiplicative hazard rate models for survival and event history data that can deal with these issues in a flexible and unified framework. Some simpler models, such as piecewise exponential models with a smoothed baseline hazard, are covered as special cases. Embedded in the counting process approach, nonparametric estimation of unknown nonlinear functional effects of time or covariates is based on Bayesian penalized splines. Inference is fully Bayesian and uses recent MCMC sampling schemes. Smoothing parameters are an integral part of the model and are estimated automatically. We investigate performance of our approach through simulation studies, and illustrate it with a real data application.

Generalized additive models have become a widely used instrument for flexible regression analysis. In many practical situations, however, it is desirable to restrict the flexibility of nonparametric estimation in order to accommodate a presumed monotonic relationship between a covariate and the response variable. For example, consumers usually will buy less of a brand if its price increases, and therefore one expects a brand's unit sales to be a decreasing function in own price. We follow a Bayesian approach using penalized B-splines and incorporate the assumption of monotonicity in a natural way by an appropriate specification of the respective prior distributions. We illustrate the methodology in an empirical application modeling demand for a brand of orange juice and show that imposing monotonicity constraints for own- and cross-item price effects improves the predictive validity of the estimated sales response function considerably.

Generalized additive models (GAM) for modelling nonlinear effects of continuous covariates are now well established tools for the applied statistician. In this paper we develop Bayesian GAM's and extensions to generalized structured additive regression based on one or two dimensional P-splines as the main building block. The approach extends previous work by Lang und Brezger (2003) for Gaussian responses. Inference relies on Markov chain Monte Carlo (MCMC) simulation techniques, and is either based on iteratively weighted least squares (IWLS) proposals or on latent utility representations of (multi)categorical regression models. Our approach covers the most common univariate response distributions, e.g. the Binomial, Poisson or Gamma distribution, as well as multicategorical responses. For the first time, we present Bayesian semiparametric inference for the widely used multinomial logit models. As we will demonstrate through two applications on the forest health status of trees and a space-time analysis of health insurance data, the approach allows realistic modelling of complex problems. We consider the enormous flexibility and extendability of our approach as a main advantage of Bayesian inference based on MCMC techniques compared to more traditional approaches. Software for the methodology presented in the paper is provided within the public domain package BayesX.

Additive models of the type y=f_1(x_1)+...+f_p(x_p)+e where f_j,j=1,...,p, have unspecified functional form, are flexible statistical regression models which can be used to characterize nonlinear regression effects. The basic tools used for fitting the additive model are the expansion in B-splines and penalization which prevents the problem of overfitting. This penalized B-spline (called P-spline) approach strongly depends on the choice of the amount of smoothing used for components f_j. In this paper we treat the problem of choosing the smoothing parameters by genetic algorithms. In several simulation studies our approach of automatically calculation of the smoothing parameters is compared to alternative methods given in literature. In particular functions with different spatial variability are considered and the effect of constant respectively local adaptive smoothing parameters is evaluated.

Varying-coefficient models provide a flexible framework for semi- and nonparametric generalized regression analysis. We present a fully Bayesian B-spline basis function approach with adaptive knot selection. For each of the unknown regression functions or varying coefficients, the number and location of knots and the B-spline coefficients are estimated simultaneously using reversible jump Markov chain Monte Carlo sampling. The overall procedure can therefore be viewed as a kind of Bayesian model averaging. Although Gaussian responses are covered by the general framework, the method is particularly useful for fundamentally non-Gaussian responses, where less alternatives are available. We illustrate the approach with a thorough application to two data sets analysed previously in the literature: the kyphosis data set with a binary response and survival data from the Veteran’s Administration lung cancer trial.

P-splines are an attractive approach for modelling nonlinear smooth effects of covariates within the generalized additive and varying coefficient models framework. In this paper we propose a Bayesian version for P-splines and generalize the approach for one dimensional curves to two dimensional surface fitting for modelling interactions between metrical covariates. A Bayesian approach to P-splines has the advantage of allowing for simultaneous estimation of smooth functions and smoothing parameters. Moreover, it can easily be extended to more complex formulations, for example to mixed models with random effects for serially or spatially correlated response. Additionally, the assumption of constant smoothing parameters can be replaced by allowing the smoothing parameters to be locally adaptive. This is particularly useful in situations with changing curvature of the underlying smooth function or where the function is highly oscillating. Inference is fully Bayesian and uses recent MCMC techniques for drawing random samples from the posterior. In a couple of simulation studies the performance of Bayesian P-splines is studied and compared to other approaches in the literature. We illustrate the approach by a complex application on rents for flats in Munich.

Varying-coefficient models provide a flexible framework for semi- and nonparametric generalized regression analysis. We present a fully Bayesian B-spline basis function approach with adaptive knot selection. For each of the unknown regression functions or varying coefficients, the number and location of knots and the B-spline coefficients are estimated simultaneously using reversible jump Markov chain Monte Carlo sampling. The overall procedure can therefore be viewed as a kind of Bayesian model averaging. Although Gaussian responses are covered by the general framework, the method is particularly useful for fundamentally non-Gaussian responses, where less alternatives are available. We illustrate the approach with a thorough application to two data sets analyzed previously in the literature: the kyphosis data set with a binary response and survival data from the Veteran's Administration lung cancer trial.

This paper presents a fully Bayesian approach to regression splines with automatic knot selection in generalized semiparametric models for fundamentally non-Gaussian responses. In a basis function representation of the regression spline we use a B-spline basis. The reversible jump Markov chain Monte Carlo method allows for simultaneous estimation both of the number of knots and the knot placement, together with the unknown basis coefficients determining the shape of the spline. Since the spline can be represented as design matrix times unknown (basis) coefficients, it is straightforward to include additionally a vector of covariates with fixed effects, yielding a semiparametric model. The method is illustrated with data sets from the literature for curve estimation in generalized linear models, the Tokyo rainfall data and the coal mining disaster data, and by a credit-scoring problem for generalized semiparametric models.