902 resultados para dimension stone
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Since 1997 the Finnish Jabal Haroun Project (FJHP) has studied the ruins of the monastery and pilgrimage complex (Gr. oikos) of Aaron located on a plateau of the Mountain of Prophet Aaron, Jabal an-Nabi Harûn, ca. 5 km to the south-west of the UNESCO World Heritage site of Petra in Jordan. The state of conservation and the damaging processes affecting the stone structures of the site are studied in this M.A. thesis. The chapel was chosen as an example, as it represents the phasing and building materials of the entire site. The aim of this work is to act as a preliminary study with regards to the planning of long-term conservation at the site. The research is empirical in nature. The condition of the stones in the chapel walls was mapped using the Illustrated Glossary on Stone Deterioration, by the ICOMOS International Scientific Committee for Stone. This glossary combines several standards and systems of damage mapping used in the field. Climatic conditions (temperature and RH %) were monitored for one year (9/2005-8/2006) using a HOBO Microstation datalogger. The measurements were compared with contemporary measurements from the nearest weather station in Wadi Musa. Salts in the stones were studied by taking samples from the stone surfaces by scraping and with the “Paper Pulp”-method; with a poultice of wet cellulose fiber (Arbocel BC1000) and analyzing what main types of salts were to be found in the samples. The climatic conditions on the mountain were expected to be rapidly changing and to differ clearly from conditions in the neighboring areas. The rapid changes were confirmed, but the values did not differ as much as expected from those nearby: the 12 months monitored had average temperatures and were somewhat drier than average. Earlier research in the area has shown that the geological properties of the stone material influence its deterioration. The damage mapping showed clearly, that salts are also a major reason for stone weathering. The salt samples contained several salt combinations, whose behavior in the extremely unstable climatic conditions is difficult to predict. Detailed mapping and regular monitoring of especially the structures, that are going remain exposed, is recommended in this work.
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Tutkielmassa käsitellään kiviesineiden käytön jatkumista kivikauden jälkeen Itä-Afrikassa. Rautakauden alku Itä- ja Etelä-Afrikassa liitetään perinteisesti bantuheimojen migraatioon näille alueille. Tämä vallitseva teoria otettiin tässä tutkimuksessa lähtökohdaksi. Afrikasta tunnetaan runsaasti sekä etnografisia että arkeologisia esimerkkejä kiviteknologian säilymisestä paikoin 1900-luvun loppupuolelle. Nämä liittyvät usein perimätiedon perusteella "kivikautisten" metsästäjä-keräilijöiden ja rautakautisten maanviljelijä- ja karjanhoitajayhteisöjen rinnakkaiseloon. Tutkimuskysymystä lähestytään sekä julkaistun että primääriaineiston kautta. Alussa esitellään kirjallisuudesta löytyviä esimerkkejä myöhäisestä kiviesineiden käytöstä, minkä jälkeen käydään tarkemmin läpi Malawin alueelta julkaistu aiheeseen liitettävissä oleva arkeologinen aineisto. Tätä käytetään vertailuaineistona tutkimuksen pääasiallista tapaustutkimusta käsiteltäessä. Pääasiallisena tapaustutkimuksena toimii Viktoria-järven läheisyydessä sijaitsevan Wadh Lang'o:n asuinpaikan kiviesineistön analyysi. Wadh Lang'o:sta tunnetaan pitkä kulttuurisekvenssi, joka kattaa alueen myöhäiskivikautiset ja rautakautiset kulttuurivaiheet. Stratigrafisen aineiston perusteella kiviesineet ovat säilyneet asuinpaikalla käytössä ainakin keskisen rautakauden alkuun. Varhaisimmassa vaiheessa asuinpaikkaa on asuttanut Oltome-kulttuuriin kuuluva väestö. Suurimmat muutokset materiaalisessa kulttuurissa analyysin kattamana aikana ovat aiheutuneet seuraavan kulttuurivaiheen, Elmenteitan-kulttuurin, myötä. Kiviesineistön perusteella Elmenteitan-keramiikan ilmaantuminen asuinpaikalle on liitettävissä idästäpäin Itä-Afrikan hautavajoaman suunnalta tapahtuneeseen migraatioon. Jatkuvuuden puolesta puhuvat esimerkiksi tehdyt kiviraaka-aine valinnat. Vaikuttaa, että edeltänyt Oltome-keraaminen väestö on säilyttänyt vaikutuksensa asuinpaikalla vielä tänäkin aikana. Varhaisrautakautisen Urewe-keramiikan ilmestymiseen asuinpaikalle ei näyttäisi olevan liitettävissä mitään suurisuuntaista migraatiota, toisin kuin vallalla oleva teoria bantumigraatiosta antaisi olettaa. Mahdollisesti uusi keramiikka on omaksuttu spesialistien, esimerkiksi seppien, muuton myötä tai vaeltavien kauppiaiden vaikutuksesta. Kiviesineistö osoittaa jatkuvuutta esimerkiksi mikroliittien morfologisten piirteiden ja käytettyjen raaka-aineiden perusteella. Mahdollisesti Elmenteitan-kulttuurin karjanhoitoa harjoittanut väestö on kyennyt estämään bantusiirtolaisten muuton alueelleen. Rauta ei vaikuta olleen asuinpaikalla missään vaiheessa erityisen yleistä, eikä paikalta tunneta merkkejä raudanvalmistuksesta. Tutkielman lopussa esitellään kaksi vaihtoehtoista mallia, joiden pohjalta myöhäinen kiviesineiden käyttö voisi selittyä. Niistä ensimmäinen perustuu konventinaaliseen käsitykseen, jossa rautakauden alku nähdään bantumigraation seurauksena. Toinen malli perustuu varhaisrautakautisten kulttuuripiirteiden leviämiseen diffuusion avulla. Wadh Lang'o:n tapaustutkimus näyttäisi puhuvan diffuusion puolesta, mutta toisilla alueilla, esimerkiksi Malawissa, migraatio vaikuttaa olevan todennäköisin selitysmalli. Avainsanat: arkeologia, kiviteknologia, Itä-Afrikka, Oltome, Elmenteitan, Urewe, bantumigraatio, myöhäiskivikausi, rautakausi
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In this paper, we present an approach to estimate fractal complexity of discrete time signal waveforms based on computation of area bounded by sample points of the signal at different time resolutions. The slope of best straight line fit to the graph of log(A(rk)A / rk(2)) versus log(l/rk) is estimated, where A(rk) is the area computed at different time resolutions and rk time resolutions at which the area have been computed. The slope quantifies complexity of the signal and it is taken as an estimate of the fractal dimension (FD). The proposed approach is used to estimate the fractal dimension of parametric fractal signals with known fractal dimensions and the method has given accurate results. The estimation accuracy of the method is compared with that of Higuchi's and Sevcik's methods. The proposed method has given more accurate results when compared with that of Sevcik's method and the results are comparable to that of the Higuchi's method. The practical application of the complexity measure in detecting change in complexity of signals is discussed using real sleep electroencephalogram recordings from eight different subjects. The FD-based approach has shown good performance in discriminating different stages of sleep.
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Fractal Dimensions (FD) are popular metrics for characterizing signals. They are used as complexity measuresin signal analysis applications in various fields. However, proper interpretation of such analyses has not been thoroughly addressed. In this paper, we study the effect of various signal properties on FD and interpret results in terms of classical signal processing concepts such as amplitude, frequency,number of harmonics, noise power and signal bandwidth. We have used Higuchi’s method for estimating FDs. This study helps in gaining a better understanding of the FD complexity measure for various signal parameters. Our results indicate that FD is a useful metric in estimating various signal properties. As an application of the FD measure in real world scenario, the FD is used as a feature in discriminating seizures from seizure free intervals in intracranial EEG data recordings and the FD feature has given good discrimination performance.
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Consonance in urban form is contingent on the continuity of the fine grain architectural features that are imbued in the commodity of the evolved historic urban fabric. A city's past can be viewed therefore as a repository of urban form characteristics from which concise architectural responses can result in a congruent urban landscape. This thesis proposes new methods to evaluate the interplay of architectural elements that can be traced throughout the lifespan of the particular evolving urban areas under scrutiny, and postulates a theory of how the mapping of historical urban form can correlate with deriving parameters for new buildings.
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Unlike standard applications of transport theory, the transport of molecules and cells during embryonic development often takes place within growing multidimensional tissues. In this work, we consider a model of diffusion on uniformly growing lines, disks, and spheres. An exact solution of the partial differential equation governing the diffusion of a population of individuals on the growing domain is derived. Using this solution, we study the survival probability, S(t). For the standard nongrowing case with an absorbing boundary, we observe that S(t) decays to zero in the long time limit. In contrast, when the domain grows linearly or exponentially with time, we show that S(t) decays to a constant, positive value, indicating that a proportion of the diffusing substance remains on the growing domain indefinitely. Comparing S(t) for diffusion on lines, disks, and spheres indicates that there are minimal differences in S(t) in the limit of zero growth and minimal differences in S(t) in the limit of fast growth. In contrast, for intermediate growth rates, we observe modest differences in S(t) between different geometries. These differences can be quantified by evaluating the exact expressions derived and presented here.
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There are many reports of efficient embryo germination and the method has been optimized to suit subtropical low chill genotypes. However the subsequent growth, vigor, and ability of germinated embryos to develop and survive acclimatization is rarely reported. Many germinated embryos do not survive acclimatization, develop slowly, or fail to develop normally. Methods to improve plant development from in vitro embryo cultures are needed to improve the number of plants that survive to be useful in breeding programs. This paper describes an improved method of embryo rescue that significantly increases embryo shoot and root development that leads to increased plant survival. Four treatments: Woody Plant Media (WPM) solidified with agar, vermiculite with liquid WPM, vermiculite with WPM plus agar, and conventional stratification, were evaluated for embryo growth and subsequent plantlet development and survival for two low-chill peach and one low-chill nectarine cultivar. Highly significant improvements were found for shoot and root development of seedlings germinated in vermiculite based media compared to embryos germinated in conventional agar-based media. Vermiculite with WPM and agar improved plantlet growth subsequent to in vitro culture and significantly increased survival of germinated embryos resulting in more plants reaching the field.
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We computed Higuchi's fractal dimension (FD) of resting, eyes closed EEG recorded from 30 scalp locations in 18 male neuroleptic-naive, recent-onset schizophrenia (NRS) subjects and 15 male healthy control (HC) subjects, who were group-matched for age. Schizophrenia patients showed a diffuse reduction of FD except in the bilateral temporal and occipital regions, with the reduction being most prominent bifrontally. The positive symptom (PS) schizophrenia subjects showed FD values similar to or even higher than HC in the bilateral temporo-occipital regions, along with a co-existent bifrontal FD reduction as noted in the overall sample of NRS. In contrast, this increase in FD values in the bilateral temporo-occipital region was absent in the negative symptom (NS) subgroup. The regional differences in complexity suggested by these findings may reflect the aberrant brain dynamics underlying the pathophysiology of schizophrenia and its symptom dimensions. Higuchi's method of measuring FD directly in the time domain provides an alternative for the more computationally intensive nonlinear methods of estimating EEG complexity.
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Digital image
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Obverse: The emblem of the International Precious Stones Congress. Reverse: The twelve precious stones on the High Priest's breastplate and their Hebrew names.
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Contains papers and photos including correspondence and other materials relating to work as Chairman of the Jewish Agency for Palestine (and Israel), as National Chairman of the United Jewish Appeal, as a leading campaigner for Israel Bonds, and as co-founder of and Chairman of the Board of the Weizmann Institute of Science; 2 texts of radio broadcasts made in 1948 informing America about the Israeli war for independence and the new Israeli republic; a list of military equipment supplied by Mr. Stone to Israel in 1948; letters and biographical material relating both to pressure applied by Mr. Stone and others on Pres. Truman to recognize and support the new Jewish state and to Mr. Stone's financial support of Truman's campaign and the Democratic Party in 1948; materials on associations with Boston University (including the dedication of the Dewey D. and Harry K. Stone Science Building), and the Truman Library; tributes and awards; biographical material; memorials; misc. speeches, presentations, and essays; misc. press clippings; and various photographs. Among the correspondents are: Chaim Weizmann, Vera Weizmann, Abba Eban, David Ben Gurion, Harry S. Truman, John F. Kennedy, Lyndon Johnson, Richard Nixon, the Rothschilds, Hubert Humphrey, Adlai E. Stevenson II, Teddy Kollek, Golda Meir, Richard Cardinal Cushing, Jacob Fine, Henry Ford II, Solomon Goldman, John M. McCormack, Meyer Weisgal, and Stephen S. Wise.
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Collection contains materials pertaining to the life and work of Stone.
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Quasiconformal mappings are natural generalizations of conformal mappings. They are homeomorphisms with 'bounded distortion' of which there exist several approaches. In this work we study dimension distortion properties of quasiconformal mappings both in the plane and in higher dimensional Euclidean setting. The thesis consists of a summary and three research articles. A basic property of quasiconformal mappings is the local Hölder continuity. It has long been conjectured that this regularity holds at the Sobolev level (Gehring's higher integrabilty conjecture). Optimal regularity would also provide sharp bounds for the distortion of Hausdorff dimension. The higher integrability conjecture was solved in the plane by Astala in 1994 and it is still open in higher dimensions. Thus in the plane we have a precise description how Hausdorff dimension changes under quasiconformal deformations for general sets. The first two articles contribute to two remaining issues in the planar theory. The first one concerns distortion of more special sets, for rectifiable sets we expect improved bounds to hold. The second issue consists of understanding distortion of dimension on a finer level, namely on the level of Hausdorff measures. In the third article we study flatness properties of quasiconformal images of spheres in a quantitative way. These also lead to nontrivial bounds for their Hausdorff dimension even in the n-dimensional case.
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An axis-parallel k-dimensional box is a Cartesian product R-1 x R-2 x...x R-k where R-i (for 1 <= i <= k) is a closed interval of the form [a(i), b(i)] on the real line. For a graph G, its boxicity box(G) is the minimum dimension k, such that G is representable as the intersection graph of (axis-parallel) boxes in k-dimensional space. The concept of boxicity finds applications in various areas such as ecology, operations research etc. A number of NP-hard problems are either polynomial time solvable or have much better approximation ratio on low boxicity graphs. For example, the max-clique problem is polynomial time solvable on bounded boxicity graphs and the maximum independent set problem for boxicity d graphs, given a box representation, has a left perpendicular1 + 1/c log n right perpendicular(d-1) approximation ratio for any constant c >= 1 when d >= 2. In most cases, the first step usually is computing a low dimensional box representation of the given graph. Deciding whether the boxicity of a graph is at most 2 itself is NP-hard. We give an efficient randomized algorithm to construct a box representation of any graph G on n vertices in left perpendicular(Delta + 2) ln nright perpendicular dimensions, where Delta is the maximum degree of G. This algorithm implies that box(G) <= left perpendicular(Delta + 2) ln nright perpendicular for any graph G. Our bound is tight up to a factor of ln n. We also show that our randomized algorithm can be derandomized to get a polynomial time deterministic algorithm. Though our general upper bound is in terms of maximum degree Delta, we show that for almost all graphs on n vertices, their boxicity is O(d(av) ln n) where d(av) is the average degree.