972 resultados para Demmon, Isaac Newton, 1842-1920.
Resumo:
The object of study in this thesis is Finnish skiing culture and Alpine skiing in particular from the point of view of ethnology. The objective is to clarify how, when, why and by what routes Alpine skiing found its way to Finland. What other phenomena did it bring forth? The objective is essentially linked to the diffusion of modern sports culture to Finland. The introduction of Alpine skiing to Finland took place at a time when skiing culture was changing: flat terrain skiing was abandoned in favour of cross-country skiing in the early decades of the 20th century, and new techniques and equipment made skiing a much more versatile sport. The time span of the study starts from the late 19th century and ends in the mid-20th century. The spatial focus is in Finland. People and communities formed through their actions are core elements in the study of sports and physical activity. Organizations tend to raise themselves into influential actors in the field of physical culture even if active individuals work in their background. Original archive documents and publications of sports organizations are central source material for this thesis, complemented by newspapers and sports magazines as well as photographs and films on early Alpine skiing in Finland. Ever since their beginning in the late 19th century skiing races in Finland had mostly taken place on flat terrain or sea ice. Skiing in broken cross-country terrain made its breakthrough in the 1920 s, at a time when modern skiing techniques were introduced in instruction manuals. In the late 1920 s the Finnish Women s Physical Education Association (SNLL) developed unconventional forms of pedagogical skiing instruction. They abandoned traditional Finnish flat terrain skiing and boldly looked for influences abroad, which caused friction between the leaders of the women s sports movement and the (male) leaders of the central skiing organization. SNLL was instrumental in launching winter tourism in Finnish Lapland in 1933. The Finnish Tourism Society, the State Railways and sports organizations worked in close co-operation to instigate a boom in tourism, which culminated in the inauguration of a tourist hotel at Pallastunturi hill in the winter of 1938. Following a Swedish model, fell-skiing was developed as a domestic counterpart to Alpine skiing as practiced in Central Europe. The first Finnish skiing resorts were built at sites of major cross-country skiing races. Inspired by the slope at Bad Grankulla health spa, the first slalom skiing races and fell-skiing, slalom enthusiasts began to look for purpose-built sites to practice turn technique. At first they would train in natural slopes but in the late 1930 s new slopes were cleared for slalom races and recreational skiing. The building of slopes and ski lifts and the emergence of organized slalom racing competitions gradually separated Alpine skiing from the old fell-skiing. After the Second World War fell-skiing was transformed into ski trekking on marked courses. At the same time Alpine skiing also parted ways with cross-country skiing to become a sport of its own. In the 1940 s and 1950 s Finnish Alpine skiing was almost exclusively a competitive sport. The specificity of Alpine skiing was enhanced by rapid development of equipment: the new skis, bindings and shoes could only be used going downhill.
Resumo:
Soon after the Bolshevik Revolution of 1917, a three-year civil war broke out in Russia. As in many other civil wars, foreign powers intervened in the conflict. Britain played a leading role in this intervention and had a significant effect on the course of the war. Without this intervention on the White side, the superiority of numbers in manpower and weaponry of the Bolsheviks would have quickly overwhelmed their opponents. The aim of this dissertation is to explain the nature and role of the British intervention on the southern, and most decisive, front of the Civil War. The political decision making in London is studied as a background, but the focus of the dissertation is on the actual implementation of the British policy in Russia. The British military mission arrived in South Russia in late 1918, and started to provide General Denikin s White army with ample supplies. General Denikin would have not been able to build his army of more than 200,000 men or to make his operation against Moscow without the British matériel. The British mission also organized the training and equipping of the Russian troops with British weapons. This made the material aid much more effective. Many of the British instructors took part in fighting the Bolsheviks despite the orders of their government. The study is based on primary sources produced by British departments of state and members of the British mission and military units in South Russia. Primary sources from the Whites, including the personal collections of several key figures of the White movement and official records of the Armed Forces of South Russia are also used to give a balanced picture of the course of events. It is possible to draw some general conclusions from the White movement and reasons for their defeat from the study of the British intervention. In purely material terms the British aid placed Denikin s army in a far more favourable position than the Bolsheviks in 1919, but other military defects in the White army were numerous. The White commanders were unimaginative, their military thinking was obsolete, and they were incapable of organizing the logistics of their army. There were also fundamental defects in the morale of the White troops. In addition to all political mistakes of Denikin s movement and a general inability to adjust to the complex situation in Revolutionary Russia, the Whites suffered a clear military defeat. In South Russia the Whites were defeated not because of the lack of British aid, but rather in spite of it.
Resumo:
A key problem in helicopter aeroelastic analysis is the enormous computational time required for a numerical solution of the nonlinear system of algebraic equations required for trim, particularly when free wake models are used. Trim requires calculation of the main rotor and tail rotor controls and the vehicle attitude which leads to the six steady forces and moments about the helicopter center of gravity to be zero. An appropriate initial estimate of the trim state is needed for successful helicopter trim. This study aims to determine the control inputs that can have considerable effect on the convergence of trim solution in the aeroelastic analysis of helicopter rotors by investigating the basin of attraction of the nonlinear equations (set of initial guess points from which the nonlinear equations converge). It is illustrated that the three main rotor pitch controls of collective pitch, longitudinal cyclic pitch and lateral cyclic pitch have a significant contribution to the convergence of the trim solution. Trajectories of the Newton iterates are shown and some ideas for accelerating the convergence of a trim solution in the aeroelastic analysis of helicopters are proposed. It is found that the basins of attraction can have fractal boundaries. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
Tässä pro gradu -tutkimuksessa tutkin kätilötyön rakentumista Suomessa vuosina 1879 - 1920 Hämeenlinnan lääkäripiirin näkökulmasta. Analysoin vuoden 1879 kätilöohjesäännön tuomien muutosten sekä valtion organisaatioiden, lääkäreiden ja kunnallistason määräysten merkitystä kätilötoiminnalle ja kätilöille. Tutkimuksen ajallinen rajaus, 1879 - 1920, juontuu Keisarillisen Majesteetin vuonna 1879 antamasta kätilöohjesäännöstä, joka oli toimintaa ohjaavana lainsäädäntönä voimassa vuoteen 1920. Tutkin tässä työssä kätilötyötä kahdessa tasossa, mikrohistoriallisesti ja yleisellä tasolla. Tutkimusmenetelmänä sovellan kvalitatiivista ja kvantitatiivista menetelmää. Tutkimuksen teoreettisena kehyksenä toimii soveltavin osin Michel Foucault'n teoria biovallasta. Kätilöiden puutteeseen maalaiskunnissa oli pyritty vaikuttamaan vuoden 1859 kätilöohjesäännöllä. Käytännön muutoksia ei tapahtunut ja vuonna 1879 hyväksyttiin uusi kätilöohjesääntö. Uusi ohjesääntö oli valtion hallinnon ja lääkäreiden yhteistoiminnan tulos. Sen sanoma oli ohjaavaa, mutta ei pakottavaa. Lakiuudistuksella pyrittiin vaikuttamaan kuntiin ja kuntien kautta kansalaisten toimintaan. Haluttiin muokata ihmisten käyttäytymistapoja normalisoimalla kätilöhoitoinen synnytys. Kätilöohjesäännön voimaantulo ja vuodet 1879 - 1920 voidaan nähdä käännekohtana kätilötyössä. Tutkimusperiodin aikana kätilötyö alkoi saada itsenäisen ammattikunnan piirteitä selvemmin. Rahan rooli oli monessa suhteessa merkittävä, sillä elatuksen lisäksi raha vaikutti kätilön asemaan ja arvostukseen. Kunnan päättäjät olivat merkittävässä valtaapitävässä asemassa, koska heillä oli päätösvalta kätilön palkkaamisessa ja työn ehdoissa. Kunnissa, joissa kätilöä arvostettiin, maksettiin paremmin ja kuntalaiset tukeutuivat koulutettuun apuun enemmän. Tutkimusaikana kätilöiden olosuhteet kunnissa olivat haasteelliset eikä laki rajoittanut synnytyksen avustajaa, joten kätilöhoitoisissa synnytyksissä tapahtunut kasvu oli kätilöiden melko pyytettömän työn tulosta. Haluttiin muutakin kun käyttää valtaa.
Resumo:
Tutkimus käsittelee kotitalouksien sisäistä resurssienjakoa suomalaisissa kotitalouksissa 1920-luvulla. Kiinnostuksen kohteena ovat investoinnit tyttö- ja poikalasten inhimilliseen pääomaan: erityisesti koulutukseen, mutta myös terveydenhoitoon ja ravintoon. Tutkimuksessa pyritään selvittämään, suosittiinko toista sukupuolta resurssienjaossa. Tutkimus lainaa menetelmiä ja kysymyksenasetteluja kehitystaloustieteestä, jossa kotitalouksien sisäinen toiminta on noussut keskeiseksi tutkimussuunnaksi ”kadonneiden naisten ongelman” myötä. Useat kehitystaloustieteelliset sekä talous- ja sosiaalihistorialliset tutkimukset ovat havainneet kotitalouksien syrjivän tyttöjä resurssienjaossa, minkä kumulatiiviset vaikutukset ovat johtaneet pahimmillaan naisten kuolleisuuden kasvuun. Useimmissa tapauksissa resurssienjaon on havaittu liittyvän lasten taloudelliseen arvostukseen. Vanhemmat panostavat niihin lapsiin, joiden tulevan ansiotason odotetaan olevan suurin. Tärkein tulevaan ansiotason vaikuttava tekijä ovat tavoitettavissa olevat työmarkkinat. Tutkimuksen keskeisimpänä aineistona hyödynnetään vuonna 1928 Suomessa suoritetun elinkustannustutkimuksen vuosikortteja. Aineisto sisältää 954 kotitalouden kulutustiedot 15 kaupungista ja 14 teollisuuspaikkakunnalta. Aineistoa analysoidaan ekonometrisin menetelmin regressioanalyysin avulla. Engelin lain mukaan kotitalouden tulojen noustessa ruokamenojen osuus kulutuksesta pienenee. Erilaisten Engel-mallin variaatioiden avulla voidaan tutkia epäsuorasti, miten kotitalouden demografinen rakenne vaikuttaa erilaisten hyödykkeiden kulutukseen. Tässä tutkimuksessa sovelletaan Engel-malliin perustuvaa Working-mallia, jonka avulla on mahdollista tarkastella, miten eri sukupuoli-ikäryhmien läsnäolo vaikuttaa koulutus- terveydenhoito- ja ruokamenoihin aineiston kotitalouksissa. Tämän lisäksi tutkimuksessa selvitetään, miten lapsiin kohdistuviin investointeihin vaikuttivat kotitalouksien sosiaaliluokka, asuinpaikan perifeerisyys, paikalliset työmarkkinat ja vanhempien inhimillisen pääoman määrä. Tutkimustulokset paljastavat, että lapsiin kohdistuvia investointeja aineisto kotitalouksissa selitti ensisijaisesti näiden reagoiminen taloudellisiin kannustimiin. Sosiaaliryhmien käyttäytymismalleissa oli kuitenkin eroja: työläisperheissä panostettiin tyttölasten koulutukseen, mutta toimenhaltijaperheissä suosittiin poikia. Tässä tutkimuksessa selityksiä epätasaiselle resurssienjaolle etsitään koulutuksen tuotosta. Vaikuttaa siltä, että vuosi oppikoulussa oli työläistytöille kannattavampaa kuin työläispojille, joille sosiaalisesti hyväksyttyjä ja riittävän hyvin palkattuja töitä löytyi myös ilman muodollista koulutusta. Toimenhaltijaperheissä kouluttautuminen oli puolestaan kannattavampaa pojille, sillä työelämän lasikatot ja sosiaaliset normit rajoittivat tyttöjen mahdollisuuksia työelämässä. Vaikka tutkimustulokset viittaavat siihen, että kotitaloudet pyrkivät tekemään taloudellisesti rationaalisia valintoja, vaikuttivat näihin valintoihin yhteiskunnan sukupuolihierarkiat. Koska tyttöjen ja poikien ”mahdolliset tulevaisuudet” olivat erilaiset, kannatti heidän inhimilliseen pääomaansa investoida eri tavoin. Tutkimuksen johtopäätökset antavat tukea useissa empiirisissä tutkimuksissa esiintyneelle havainnolle siitä, että lapsen asemaan perheen sisällä vaikuttaa hänen ansiomahdollisuutensa kodin ulkopuolella. Tutkimus pohtii myös koulutuksen vaikutusta laajemmassa rakennemuutoksessa. Koulutuksen voi perustellusti olettaa parantaneen työläistyttöjen sosiaalista liikkuvuutta työläispoikiin nähden. Koska naisten on todistettu siirtävän inhimillistä pääomaa lapsilleen miehiä tehokkaammin, oli tällä myös todennäköisesti ylisukupolvisia vaikutuksia suomalaiselle yhteiskunnalle. Kansainvälisessä kehitystaloustieteellisessä tutkimuksessa naisten koulutuksen on todettu liittyvän positiivisesti talouskasvuun ja koko yhteiskunnan sosiaaliseen hyvinvointiin. Vaikka tässä tutkimuksessa tutkitaan ensisijaisesti mikrotaloushistoriallisesti kotitalouksien käyttäytymistä, osallistuu se myös tähän koulutuksen laajempia vaikutuksia käsittelevään keskusteluun.
Resumo:
Due to its wide applicability, semi-supervised learning is an attractive method for using unlabeled data in classification. In this work, we present a semi-supervised support vector classifier that is designed using quasi-Newton method for nonsmooth convex functions. The proposed algorithm is suitable in dealing with very large number of examples and features. Numerical experiments on various benchmark datasets showed that the proposed algorithm is fast and gives improved generalization performance over the existing methods. Further, a non-linear semi-supervised SVM has been proposed based on a multiple label switching scheme. This non-linear semi-supervised SVM is found to converge faster and it is found to improve generalization performance on several benchmark datasets. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
Nonlinear equations in mathematical physics and engineering are solved by linearizing the equations and forming various iterative procedures, then executing the numerical simulation. For strongly nonlinear problems, the solution obtained in the iterative process can diverge due to numerical instability. As a result, the application of numerical simulation for strongly nonlinear problems is limited. Helicopter aeroelasticity involves the solution of systems of nonlinear equations in a computationally expensive environment. Reliable solution methods which do not need Jacobian calculation at each iteration are needed for this problem. In this paper, a comparative study is done by incorporating different methods for solving the nonlinear equations in helicopter trim. Three different methods based on calculating the Jacobian at the initial guess are investigated. (C) 2011 Elsevier Masson SAS. All rights reserved.
Resumo:
We consider the problem of optimal routing in a multi-stage network of queues with constraints on queue lengths. We develop three algorithms for probabilistic routing for this problem using only the total end-to-end delays. These algorithms use the smoothed functional (SF) approach to optimize the routing probabilities. In our model all the queues are assumed to have constraints on the average queue length. We also propose a novel quasi-Newton based SF algorithm. Policies like Join Shortest Queue or Least Work Left work only for unconstrained routing. Besides assuming knowledge of the queue length at all the queues. If the only information available is the expected end-to-end delay as with our case such policies cannot be used. We also give simulation results showing the performance of the SF algorithms for this problem.
Resumo:
A micro-newton static force sensor is presented here as a packaged product. The sensor, which is based on the mechanics of deformable objects, consists of a compliant mechanism that amplifies the displacement caused by the force that is to be measured. The output displacement, captured using a digital microscope and analyzed using image processing techniques, is used to calculate the force using precalibrated force-displacement curve. Images are scanned in real time at a frequency of 15 frames per second and sampled at around half the scanning frequency. The sensor was built, packaged, calibrated, and tested. It has simulated and measured stiffness values of 2.60N/m and 2.57N/m, respectively. The smallest force it can reliably measure in the presence of noise is about 2 mu N over a range of 1.4mN. The off-the-shelf digital microscope aside, all of its other components are purely mechanical; they are inexpensive and can be easily made using simple machines. Another highlight of the sensor is that its movable and delicate components are easily replaceable. The sensor can be used in aqueous environment as it does not use electric, magnetic, thermal, or any other fields. Currently, it can only measure static forces or forces that vary at less than 1Hz because its response time and bandwidth are limited by the speed of imaging with a camera. With a universal serial bus (USB) connection of its digital microscope, custom-developed graphical user interface (GUI), and related software, the sensor is fully developed as a readily usable product.
Resumo:
We present the first q-Gaussian smoothed functional (SF) estimator of the Hessian and the first Newton-based stochastic optimization algorithm that estimates both the Hessian and the gradient of the objective function using q-Gaussian perturbations. Our algorithm requires only two system simulations (regardless of the parameter dimension) and estimates both the gradient and the Hessian at each update epoch using these. We also present a proof of convergence of the proposed algorithm. In a related recent work (Ghoshdastidar, Dukkipati, & Bhatnagar, 2014), we presented gradient SF algorithms based on the q-Gaussian perturbations. Our work extends prior work on SF algorithms by generalizing the class of perturbation distributions as most distributions reported in the literature for which SF algorithms are known to work turn out to be special cases of the q-Gaussian distribution. Besides studying the convergence properties of our algorithm analytically, we also show the results of numerical simulations on a model of a queuing network, that illustrate the significance of the proposed method. In particular, we observe that our algorithm performs better in most cases, over a wide range of q-values, in comparison to Newton SF algorithms with the Gaussian and Cauchy perturbations, as well as the gradient q-Gaussian SF algorithms. (C) 2014 Elsevier Ltd. All rights reserved.
Resumo:
We present a new Hessian estimator based on the simultaneous perturbation procedure, that requires three system simulations regardless of the parameter dimension. We then present two Newton-based simulation optimization algorithms that incorporate this Hessian estimator. The two algorithms differ primarily in the manner in which the Hessian estimate is used. Both our algorithms do not compute the inverse Hessian explicitly, thereby saving on computational effort. While our first algorithm directly obtains the product of the inverse Hessian with the gradient of the objective, our second algorithm makes use of the Sherman-Morrison matrix inversion lemma to recursively estimate the inverse Hessian. We provide proofs of convergence for both our algorithms. Next, we consider an interesting application of our algorithms on a problem of road traffic control. Our algorithms are seen to exhibit better performance than two Newton algorithms from a recent prior work.
Resumo:
Air exploratory discussion of an ancient Chinese algorithm, the Ying Buzu Shu, in about 2nd century BC, known as the rule of double false position in the West is given. In addition to pointing out that the rule of double false position is actually a translation version of the ancient Chinese algorithm, a comparison with well-known Newton iteration method is also made. If derivative is introduced, the ancient Chinese algorithm reduces to the Newton method. A modification of the ancient Chinese algorithm is also proposed, and some of applications to nonlinear oscillators are illustrated.