Physics in the year 2006 is tightly constrained by experiment, observation, and mathematical consistency. The Standard Model provides a remarkably precise de- scription of particle physics, and general relativity is quite successful in describing gravitational phenomena. At the same time, it is clear that a more fundamental theory is needed for several distinct reasons. Here we consider a new approach, which begins with the unusually ambitious point of view that a truly fundamental theory should aspire to explaining the origins of Lorentz invariance, gravity, gauge fields and their symmetry, supersymmetry, fermionic fields, bosonic fields, quantum mechanics and spacetime. The present dissertation is organized so that it starts with the most conventional ideas for extending the Standard Model and ends with a microscopic statistical picture, which is actually the logical starting point of the theory, but which is also the most remote excursion from conventional physics. One motivation for the present work is the fact that a Euclidean path integral in quantum physics is equivalent to a partition function in statistical physics. This suggests that the most fundamental description of nature may be statistical. This dissertation may be regarded as an attempt to see how far one can go with this premise in explaining the observed phenomena, starting with the simplest statistical picture imaginable. It may be that nature is richer than the model assumed here, but the present results are quite suggestive, because, with a set of assumptions that are not unreasonable, one recovers the phenomena listed above. At the end, the present theory leads back to conventional physics, except that Lorentz invariance and supersymmetry are violated at extremely high energy. To be more specific, one obtains local Lorentz invariance (at low energy compared to the Planck scale), an SO(N) unified gauge theory (with N = 10 as the simplest possibility), supersymmetry of Standard Model fermions and their sfermion partners, and other familiar features of standard physics. Like other attempts at superunification, the present theory involves higher dimensions and topological defects.

銀行在面對借款人以不動產申請抵押貸款時，產生對住宅擔保品估價之需求，以為債權之確保。然銀行的估價過程與一般估價最大不同，肇因於其估價前，擔保品本身已先產生一組買賣契約價格。過去研究指出，估價會嘗試以某些較易取得的價格資訊作為定錨點(anchor)，藉以調整並成為最後的價格。而我國不動產交易價格資訊不透明，契約價格往往由借款人提供的情況下，銀行內部估價人員可能因資訊不易取得、定錨效果，在擔保品的鑑估結果上受到契約價格影響，倘有心人士欲藉此獲得高額貸款、牟取不法利益，將損及銀行債權，即使採用自動估價系統降低人為影響因素，因資料來源不佳，只會產生所謂「garbage in garbage out」的結果。據此，如何分辨契約價格是否具有參考力變成為關鍵，亦為本文欲補足的研究缺口。 本文採用國內某銀行臺北市不動產擔保品8,348筆估價資料為樣本，建立以挑選契約價格是否具有參考力的機率預測模型，尋求影響能判定契約價格是否具有參考力的主要因素，並研究在最適的機率界限下，篩選出具有參考力的契約價格樣本。而研究結果所建立的模型，其預測並篩選出的契約價格樣本均較未經模型篩選者，對擔保品價格之估計有顯著提升。因此本研究所建立的契約價格篩選模型確能提升銀行估價準確性，使不動產擔保品鑑估價格的形成過程中，獲得更多可靠的參考資訊，降低人為操縱的空間，並在成交價格資訊不足的情況下，提升估價人員對契約價格的辨識能力。 / In the face of the borrower to apply for a mortgage of real estate, financial institutions have estimated the price of the collateral requirements to protect the debt claim. However, the biggest difference with the general valuation and that of financial institutions, valuation of its causes before the collateral itself has produced a first sale contract price. In the past research that one attempts to estimate the price of some greater access to information act to anchor in order to adjust and become the final price. Because financial institutions are not easy to obtain price information on real estate transactions in Taiwan, price information is often provided by the borrower. A small number of loans borrower deliberate fraud to forgery or false irrigation Contract price sale and purchase agreement in order to obtain high credit. Even with the automatic valuation system to reduce the human impact factor, due to poor data sources, it will only produce so-called "garbage in garbage out" of the results. Accordingly, how to tell whether the contract price to a reference force becomes critical, and also in this article want to complement the research gap. We adopt 8,348 estate collateral valuation data in Taipei City of a domestic bank for the sample to establish a binary logistic regression model. And we try to seek the main factors that determine whether the contract price of the reference force, and find out the optimal cutoff point, filter out of a sample of the contract price of the reference force. The results confirm the model in this paper. The selected samples of the contract price is estimated that the price of collateral significantly improved compared with those without filtering. Therefore, the model established in this study can really improve the accuracy of bank valuation. Enhance the recognition ability of the bank's internal appraisers on the contract price in the lack of transaction price information.

Le but de cette thèse est d'étudier lagravité quantique bidimensionnelle. Nousnous intéressons plus particulièrement auxapproches dans le continu. Ces dernièresreposent principalement sur l'action deLiouville qui décrit le couplage entre théorieconforme et gravité. Si cette action, bienconnue, est très bien comprise, la mesure del'intégrale fonctionnelle sur l'espace desmétriques pose plus de problèmes. Toutefois,sous l'hypothèse simplificatrice d'une mesurede champ libre, la dépendance en l'aire de lafonction de partition de la gravité quantiqueen présence de matière conforme a pu êtreétablie. Malgré l'hypothèse assez forte sur lamesure d'intégration, cette formule (diteKPZ), a été confirmée par des calculs issusde méthodes discrètes, et ce dans plusieurscas particuliers. Grâce à une nouvelle méthode derégularisation spectrale en espace courbe,cette mesure d'intégration a récemment puêtre proprement définie. Dans cette thèse,un calcul perturbatif de la fonction departition à aire fixée est mené, jusqu'à troisboucles, en considérant l'action de Liouvilleet des surfaces de Kähler de genrequelconque (qui coïncident avec l'ensembledes surfaces à deux dimensions). Desdivergences apparaissant dans les calculs, ilest nécessaire de renormaliser les actions.Cette renormalisation peut être interprétéecomme une renormalisation de la mesured'intégration. Nos résultats à deux bouclessont finis, indépendants de la régularisationet compatibles avec le résultat KPZ, maisdépendent d'un paramètre libre. L'étude àtrois boucles suggère que la théorie resterenormalisable aux ordres supérieurs maisdépend de nouveaux paramètres à chaqueordre. Ces résultats ont été généralisé dansle cas du tore au couplage à de la matièrenon-conforme. / Nowadays, two-dimensional quantumgravity can be studied in two differentapproaches, one involving discrete theories(triangulation, matrix model...), the othercontinuous ones, mainly based on the socalled Liouville action which universallydescribes the coupling of any conformal fieldtheory to gravity. While the Liouville action isrelatively well understood, the appropriatefunctional integral measure is however rathercomplicated. Nevertheless, a formula for thearea dependence of the quantum gravitypartition function in the presence of conformalmatter has been obtained, under thesimplifying assumption of a free-fieldmeasure. Notwithstanding its non-rigorousderivation, this formula, often referred to asthe KPZ formula, has since been verified inmany instances and has scored manysuccesses. Recent developments of efficient multiloopregularization methods on curved spacetimesopened the way for a precise and welldefinedperturbative computation of the fixedareapartition function in the Kählerformalism. In this work, a first-principlescomputation of the fixed-area partitionfunction in the Liouville theory is performed,up to three loops. Among other things, therole of the non-trivial quantum gravityintegration measure is highlighted.Renormalization is required and may beinterpreted as a renormalization of theintegration measure. This leads to a finite andregularization-independent result at two loops,that is more general than the KPZ result,although compatible. Finiteness andregularization-independence seem alsopossible at three loops. These results aregeneralized to the coupling to non-conformalmatter on the torus.

The linear Barotropic Non-Divergent simulation of a vortex on a beta plane is consistent with Willoughby’s earlier shallow-water divergent results in that it produced an unbounded accelerating westward and poleward motion without an asymptotic limit. However, Montgomery’s work which yielded finite linear drift speeds for his completely cyclonic vortex was inconsistent with ours. The nonlinearly-forced streamfunction exhibited a beta-gyre like structure, but with opposite polarity phase to the linear gyres. Utilization of the linear model with time-dependent, but otherwise beta-like, forcing revealed increasing magnitude and phase reversal in the neighborhood of a low cyclonic frequency. Here, the mean bounded vortex has an outer waveguide that supports Vortex Rossby Wave propagation that is faster than the mean flow and confined to a very narrow band of frequencies between zero and the Vortex Rossby Wave cutoff. The low frequency waves constitute the beta-gyre mode described previously by Willoughby.

Orientador: Carola Dobrigkeit Chinellato / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-08T01:00:42Z (GMT). No. of bitstreams: 1 Rodrigues_JoaoPauloCaminhaCascudo_M.pdf: 7322384 bytes, checksum: e50136f5ec9d16fff8fd6a15ba64b5f0 (MD5) Previous issue date: 2007 / Resumo: Neste trabalho estuda-se a propagação pelo meio intergaláctico de raios cósmicos ultra-energéticos partindo de fontes com distribuição espacial uniforme, considerando as perdas de energia ocasionadas pela expansão adiabática do universo e pelas interações com a Radiação , Cósmica de Fundo (produção de pares e-e+ e fotoprodução de píons), o que resulta no aparecimento do corte GZK (Greisen-Zatsepin-Kuzmin). A degradação de energia no espectro primário da radiação cósmica que chega ao topo da atmosfera terrestre é então analisada para diferentes redshifts das fontes injetoras. São utilizadas simulações de Monte Carlo bem como uma abordagem analítica, com a posterior comparação dos resultados obtidos em cada método. Uma vez conhecido o fluxo propagado, é feita uma estimativa da forma da resolução de energia do Observatório Pierre Auger, com a decorrente convolução desta resolução com o fluxo propagado, novamente utilizando-se ambos os métodos. Os resultados mostram que o corte GZK pode se mostrar severamente atenuado no fluxo convoluído, o que dificulta a sua constatação experimental / Abstract: In this work, we study the propagation of Ultra-High Energy Cosmic Rays (UHECR) which are injected into the intergalactic medium by sources with flat spatial distribution for several redshifts. The energy spectrum of UHECR observed on the Earth is directly influenced by the energy losses due to both the adiabatic expansion of the universe and interactions with the Cosmic Microwave Background radiation (e-e+ pair production and photoproduction of pions), which cause the so-called Greisen-Zatsepin-Kuzmin (GZK) cutoff. We perform Monte Carlo simulations and also consider a semi-analytical approach and compare the results obtained by each method. Once the propagated primary flux is known, we make a simple estimate of the shape of the Pierre Auger Observatory energy resolution. This resolution is folded with the propagated primary flux again utilizing both methods. The results show the GZK cutoff may be severely smeared and might not be detected as sharp as predicted. / Mestrado / Teorias Especificas e Modelos de Interação ; Sistematica de Particulas ; Raios Cosmicos / Mestre em Física

The work deals with design of transformation cells suitable for realization of higher orders frequency filters with possibility of cutoff frequency control. At first, there is a common description of frequency filters and active elements like current and voltage conveyors. Furthermore assumptions of cutoff frequency control are defined which result in a convenient characteristical equation. Phylosophy of synthetic elements DP , EP , DS , ES including a possibility of change of cutoff frequency is next in line. By exploitation of synthetic elements theory new circuit’s schemes of transformation cells are searched. The work continues with the choice of appropriate transformation cells for resulting circuit’s solutions of frequency filters with possibility of cutoff frequency control by using transfer coefficients of active elements or with help of passive elements. The work concludes with verification of its proper function based on a simulation executed in OrCAD and with practical implementation of choosen circuit’s solution.

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住宅為兼具消費及投資之雙重功能財貨，因此若從購屋動機劃分購屋族群，可以分為自住者及投資者，近年來受到國內房市呈現生氣蓬勃之景象及利率持續走低等總體經濟因素影響之下，出現越來越多以投資為主要目的之投資型購屋者，對於金融機構之購屋貸款業務來說，投資者之還款行為相較於自住者是比較不穩定的。故本文之研究目的即藉由探討自住者及投資者之購屋特徵異同，建立投資者之機率預測模型，預測某購屋者成為投資者之機率，提供一較為客觀之機率預測模型，供作金融機構放貸參考準則。接著進一步探討在不同機率界限（cutoff point）下之預測準確率，找出預測準確率最高之機率界限值，提高本模型之預測準確度；並探討金融機構在不同經營方針下之較適機率界限值。 / 本文使用台灣住宅需求動向季報之已購屋者問卷，建立二元羅吉特模型。研究結果顯示，區位在中心都市、高單價、小面積產品及大面積產品、預售屋及拍賣屋市場屬於投資型產品，而搜尋時間短、搜尋間數少、年齡較長、男性、無固定職業及家庭平均月收入較高者成為投資者之機率較高。接著，運用貝氏定理計算出預測準確率最高之機率界限值，結果當機率界限值為0.70時預測準確率最高，投資者達72.22%，自住者達80.07%。此外，並使用2007Q4的資料作樣本外驗證，投資者命中率為65.52%，自住者命中率為84.51%。最後，為提供金融機構運用，本文模擬兩種預測誤差在不同權重下對於金融機構所造成的損失，找出損失最少的機率界限值，結果皆是以0.70為最適機率界限值。 / Housing is dual function goods, consumption and investment, so if we separate the home buyers by their motives, they can be defined as two groups, owner-occupiers and investors. Recently, because the housing market is vigorous inland and the rates are fairly low, there are more and more home buyers buying houses for investment. To financial institutions, their payment behaviors are more instable, compare to owner-occupiers. So this article is aim to build a probability predictive model of housing investors by discussing the different home buying characters between owner-occupiers and investors. Therefore we can provide financing institutions a more objective method evaluating if they should lend money to the home buyers. Then we discuss the predictive accuracy with different cutoff points, finding the cutoff point with highest predictive accuracy, therefore we can elevate the model`s predictive accuracy. Besides, we also discuss the most optimal cutoff point for financial institutions under different administration principles. / This article builds binary logit model by the data of “Housing Demand Survey in Taiwan”. Our results suggests that if the houses in downtown、high unit price、big and small acreage、presale and court auction housing market belong to investing houses. And short search duration、few search items、older、male、non-constant job、higher income are getting higher probability to be housing investors. Then, we use Bayesian Theorem to figure out the cutoff point with highest predictive accuracy, and Our results suggests that 0.70 cutoff point with highest predictive accuracy , at that time, investor predictive accuracy is 72.22%, owner-occupier is 80.07%. Besides, we also do the out-sample test by the 2007Q4 data, the investor`s hit-rate is65.52%, the owner-occupier`s hit-rate is 84.51%. At the end, in order to provide financial institution to use, we give two predictive deviation different weights, to find the smallest loss cutoff point, the result all suggest that 0.70 is the most optimal cutoff point.