128 research outputs found
How do Changes in Land Use Patterns Affect Species Diversity? an Approach for Optimizing Landscape Configuration
Get PDFHeterogeneity of agricultural landscapes is supposed to be of significant importance for species diversity in agroecosystems (Weibull et al. 2003). Thus it is necessary to account for structural aspects of landscapes in land management decision processes. Spatial optimization models of land use can serve as tools for decision support. These models can aim at various landscape functions like nutrient leaching and economical aspects (Seppelt and Voinov 2002), water quality (Randhir et al. 2000) or habitat suitability (Nevo and Garcia 1996). However neighbourhood effects stay unconsidered in these approaches. In this paper we present an optimization model concept that aims at maximizing habitat suitability of selected species by identifying optimum spatial configurations of agricultural land use patterns. Bird species with diverging habitat requirements were chosen as target species. Habitat suitability models for these species are used to set up the performance criterion. Landscape structure is quantified by landscape metrics (McGarigal et al. 2002) estimated within the species home range. Statistical significance of these metrics for species presence was proven by a logistic regression model (Fielding and Haworth 1995). The landscape is represented by a grid based data set. Based on a genetic algorithm the optimization task is to identify an optimum configuration of model units. These model units are defined by contiguous cells of identical land use. Within this concept we can study how optimum but possibly artificial landscapes vary in structure depending on the selected species for which habitat suitability is maximized.
Tahran Sefiri Ali Galib Bey’in merkezle muhâberât evrâkının (1893/ 1895) (transkripsiyon ve değerlendirilmesi)
Get PDFVIII ÖZET Ortadogu'nun en önemli uygarlık merkezlerinden birisini olusturan ran, son derece zengin bir kültüre sahip olup bu özelligini yüzyıllardır korumaktadır. Kaynaklardan Türklerle ilk münasebetlerinin Hunlar dönemine dayandıgını ögrendigimiz ranlıların Osmanlılarla iliskileri XIV. ve XVIII. Yüzyıllar arasında ran’a egemen olan Safevi Hanedanlıgı zamanında baslamıstır. Dönemin bu iki büyük gücü birbirlerine karsı denge politikası izleyerek Irak bölgesine hakim olmak istemis, söz konusu süreç XIX. Yüzyıla degin devam etmistir. XIX. Yüzyılda Osmanlı-ran münasebetleri yeni bir döneme girerek, bölge dısı devletler bölgede etkin bir rol oynamaya baslamıslardır. Söz konusu devletler, Osmanlı ve ran devletlerini siyasî, askeri ve ekonomik yönden etkilemis, ayrıca ekonomik yönden zayıf ran'ın yer altı kaynakları Avrupalı Devletlerin istahını kabartmıstır. Bu amaçla özellikle ngiltere ve Rusya'nın bölgede, nüfuzunu arttırmak için çesitli oyunlar oynadıgını görmekteyiz. Söyle ki: Rusların uzun zamandan beri kıskırttıgı Ermeni örgütlerinin faaliyetlerinin siddetini 1894-1896 yılları arasında arttırması; Ermeni ve Kürtlerin Osmanlı Devleti'ne karsı isyanları; iki devlet arasındaki “Sünni-Sii” zıtlasması; Dogu Anadolu'daki Osmanlı-ran sınırında yasayan bazı konar göçer asiretlerin sebep oldugu problemler; Nasıreddin Sah (1848-1896) döneminde ran’ın Irak Bölgesi’ne hakim olmak istemesi ayrıca bu bölge ile ngiltere ve Rusya’nın da ilgilenmesi iki devlet arasındaki barıs ortamının bozulmasına neden olmustur. XIX. Yüzyılın ikinci yarısında slam dünyasına karsı emperyalizm tehlikesinin belirmeye baslaması II. Abdülhamid'i birtakım tedbirler almaya sevk etmistir. Bu amaçla yani Osmanlı Devleti’nin bekasını saglamak ve idaresindeki Müslümanları emperyalizme karsı tek vücut haline getirmek için “ttihad-ı slam” politikasını izlemistir. ran ise sünnilerin egemenligine girip slam birligi içinde milli hüviyetini kaybetme korkusu gibi çekinceleri nedeniyle bu politikaya olumlu yaklasmamıstır. ste bu sıcak gelismelerin yasandıgı dönemde tezimizin ana kaynagını olusturan yazmanın müellifi Ali Galib Bey'in Tahran sefirligi esnasında (1893-1895) Osmanlı Devleti ile yaptıgı yazısmalar, önemli ayrıntı ve saptamaları içerdiginden dönemin siyasî ve sosyal ortamını birebir müsahede etmemizi saglamakta, Osmanlı-ran iliskilerine yeni bir bakıs açısı getirmektedir. Evrâkın baska bir nüshası bulunmamaktadır. IX Evrâkımız, müellif yazması olmakla birlikte diplomasi tarihi açısından da son derece önemlidir. Tezimiz, “Tahran Sefiri Ali Galib Bey’in Merkezle Muhaberât Evrâkı (1893-1895)” adlandırdıgımız evrâkın transkripsiyonu ve degerlendirilmesini ihtiva etmektedir. Evrâkın Latin alfabesi ile Türkçeye kazandırılması amaçlanmıstır. XConstituting one of the most important civilization centers in Middle East; Iran has an extremely rich culture and remains these properties for centuries. As from the sources we learned that their first contact with Turks dates back to Huns Era ,Iranians’ relations with Ottomans started with the Safavid Dynasty era which dominated Iran between XIV. and XVIII. centuries. The two superpower of this era followed a balancing policy against each other and tried to control Iraq region, and the said situation continued until XIX. century. In XIX. century Ottoman-Iran relations entered to a new phase and states outside the region have begun to play active role in the region. Said states influenced the Ottoman and Iran States’ political, military and economic aspects, beside, economically weak Iran’s natural resources has swelled the appetite of European States. Because of this reason, especially United Kingdom and Russia had played various games for increasing their influences. Such as: The increase in the intensity of the activies of the Armenian organizations between the years of 1894 to 1896; Armenian’s and Kurdish revolts against Ottoman State ;Sunni-Shiite confrontation between the two states; problems caused by nomadic tribes which was stating in Eastern Anatolia and on the Iranian- Ottoman border; Iran’s desire to control the Iraq region during Nasıreddin Sah era (1886-1896), and the United Kingdom’s and Russian interests on this region led to deterioration of the peace environment between the two states. The emerging of imperialistic threats on Islamic world at the second half of the XIX. century, has led to II.Abdülhamit to take some measures. For this purpose, means, for ensuring the survival of Ottoman State and for gathering the Muslims in its administration as one body against imperialism , had followed “ttihad- ı slam”[Union of Islam] policy. Iran did not have positive approach to this policy due to drawbacks such as afraid of loosing national identity by entering this Sunni dominated Islamic Union. As Ali Galip Bey’s, the author of writing of the developments took place in this warm period which constitutes the main source of our thesis, correspondences with Ottoman State during his ambassadorship in Tehran (1893-1895) includes important details and determinations, it is enabling us to observe the political social climate of the XI period exactly, and brings a new perspective to Ottaman-Iranian relations. The documents do not have another copy. Our documents, as being the writings of author, it is also extremely important in terms of history of diplomacy. Our thesis contains the transcription and assessment of the “Tehran Ambassador Ali Galip Bey’s correspondence documents with Head Office (1893-1895)”. It was intended to gain the documents into Turkish with Latin alphabet
Projeções de mudanças climáticas para o Pantanal - uma análise dos cenários do CMIP6.
Get PDFResumo. Alterações das médias e da variabilidade climática na temperatura do ar e, consequentemente, da evapotranspiração e da precipitação afetam o balanço hídrico dos ecossistemas agrícolas e naturais. A avaliação do balanço hídrico, em diferentes cenários de emissão de gases de efeito estufa, mais especificamente do déficit hídrico, está relacionada ao potencial de risco de fogo e às quedas na produção agrícola. Dada a dimensão de impactos e riscos nas áreas antrópicas e naturais, é essencial que as projeções sejam avaliadas para tomada de decisão tanto em relação ao manejo agrícola quanto à prevenção de incêndios florestais. Os cenários de mudanças climáticas do CMIP6 (Coupled Model Intercomparison Project Phase 6), principal conjunto internacional de projeções dos impactos das mudanças climáticas, indicam alterações significativas nos componentes do balanço hídrico, em especial do déficit hídrico. Especificamente para a região do Pantanal brasileiro, os cenários projetam o clima mais seco na primavera, o que pode favorecer, ainda mais, incêndios de grandes proporções e perdas significativas na produção agrícola regional. Consequentemente, faz-se necessário avaliar os impactos de maneira mais detalhada e propor alternativas de adaptação para as projeções futuras do clima no Pantanal.Geopantanal 2024
Otimização de controladores nebulosos e sistemas especialistas reativos utilizando algoritmos genéticos
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica.A RoboCup, ``Robot World Cup'' , é uma iniciativa de um grupo internacional de pesquisadores em Inteligência Artificial e Robótica que propõe um problema padrão a ser solucionado: uma partida de futebol de robôs. Esta iniciativa permite que diversas técnicas destas áreas sejam testadas e, principalmente, comparadas em termos de eficiência. Atualmente encontra-se em andamento a implementação de um time de futebol de robôs para a categoria simuladores da RoboCup - UFSC-Team - na qual cada sistema que implementa um dos jogadores do time é baseado em um modelo de agente autônomo concorrente. De acordo com este modelo cada um dos agentes apresenta um sistema decisório dividido em três níveis: reativo, instintivo e cognitivo. Estes níveis decisórios são implementados em três diferentes processos: Interface, Coordinator e Expert de acordo com a arquitetura do ambiente Expert-Coop. Este trabalho traz a implementação de uma ferramenta para a otimização de parâmetros de controladores nebulosos e de sistemas especialistas reativos utilizando algoritmos genéticos. Esta ferramenta permite a utilização de algoritmos genéticos para determinar os valores ótimos para os parâmetros dos controladores nebulosos e dos sistemas especialistas reativos, responsáveis respectivamente pelos comportamentos reativos, e pelos comportamentos instintivos dos agentes do UFSC-Team. Sendo assim, os controladores podem ser implementados intuitivamente e em seguida submetidos a um processo evolutivo utilizando algoritmos genéticos. Isso representa um ganho significativo, tanto no tempo de desenvolvimento quanto na eficiência, do processo de implementação destes controladores e sistemas especialistas
Computational studies of reaction channels for 3(RO…OR’) intermediates formed in peroxy radical self and cross-reactions
No full textGas phase accretion reactions (“dimer formation”) have recently received attention as a significant process in the atmosphere, because they can lead to the formation of very-low volatility highly oxygenated organic molecules (HOMs), which later form aerosol particles. On the other hand, organic peroxy radical (RO2) are key intermediates in the chemistry of the atmosphere. One of the main sink reactions of RO2 especially in clean conditions is the recombination reaction RO2 + R’O2. This reaction goes through an intermediate complex 1(RO…3O2…OR’). The 3O2 is very weakly bound, and evaporates from the system, giving a 3(RO…OR’) cluster. This complex cluster has three major reaction channels, leading to the following products: 1) R-H=O + R’OH, 2) ROOR’, and 3) RO + R’O. This thesis presents a series of quantum chemical studies on the properties and fates of the 3(RO…OR’) intermediate clusters. The starting point of the work is a systematic conformational search of the intermediate clusters on the triplet potential energy surface, using a cost-effective model based on a combination of multiple state-of-the-art quantum chemical methods. The next step is to calculate the reaction rate of the three channels: evaporation or dissociation to radical products RO + R’O, a hydrogen shift reaction forming carbonyl + alcohol products R-H=O + R’OH, and a “spin-flip” (intersystem crossing; ISC) leading to the formation of ROOR’ peroxide “dimer” accretion products. This work shows that for small and medium-sized RO2, all these channels are competitive with each other in the atmosphere, with typical rates greater than 106 s-1, and many rates exceeding 1010 s-1. However, for complex R or R’, the binding energy effect may render not only the dissociation channel, but also the H-shift channel, uncompetitive with the ISC. The overall results suggests that the computationally proposed novel RO2 + R’O2 reaction mechanism is qualitatively compatible with experimental results on accretion product formation and may thus play a key role in the formation of organic aerosols.Aiempi tutkimus on osoittautunut että molekyylien tiivistyminen aerosolihiukkasiksi on tärkeä prosessi ilmakehässä. Yksi erityisen mielenkiintoinen reaktioluokka on ns dimeerien muodostuminen, missä kahden molekyylin väliin muodostuu uusi kemiallinen sidos. Tämä johtaa monimutkaisten orgaanisten molekyylien syntyyn, jotka voivat myöhemmin muodostaa aerosolihiukkasia. Tässä väitöstutkimuksessa käytimme kehittyneitä tietokonemalleja ymmärtääksemme orgaanisten peroksiradikaalien (RO2) rekombinaatioreaktioiden yksityiskohtia. Peroksiradikaaleja muodostuu kaikkien orgaanisten yhdisteiden hapettumisessa ilmakehässä, ja niiden reaktioilla on keskeinen rooli ilmakehän kemiassa. Puhtaissa olosuhteissa peroksiradikaalit voivat reagoida keskenään, muodostaen monimutkaisia välituotteita. Nämä välituotteet hajoavat sitten eri tavoin, jolloin syntyy erilaisia tuotteita, mukaan lukien aerosolinmuodostusta edistäviä dimeerejä. Väitöstutkimuksessa selvitettiin, että eri tavat, joilla nämä välituotteet voivat hajota, tapahtuvat kaikki suunnilleen samalla nopeudella ilmakehässä. Tämä tarkoittaa, että peroksiradikaalien rekombinaatio voi olla merkittävä tekijä orgaanisten aerosolien muodostumisessa. Lopuksi tämä tutkimus auttaa meitä ymmärtämään, kuinka tietyt molekyylit liittyvät toisiinsa ilmassa, ja nämä prosessit voivat olla aiemmin luultua tärkeämpiä ilmakehässä.ei saavutettav
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Thermal Resistance of Graphene based Device
Get PDFThermal transport in low dimensional materials play a critical role in the functionality and reliability of modern electronics. In 2D material based device, interface between 2D materials and substrates often limit the heat flow through the device. This thesis discusses the experimental measurements and theoretical modeling of thermal resistances at 2D material based device. First, we measure thermal conductivity and thermal resistance of bulk substrate by three-omega method. Next, we model the interfacial thermal resistance between the 2D material and substrates with the aid of phonon mismatch modelling. Finally, we quantify the total thermal resistance of a graphene based device by series resistance model. Our analysis shows majority of the resistance comes from the interfaces, and material’s intrinsic resistance becomes less significant at nanoscale. We find that the thermal resistance at the interface of graphene and substrate contributes to more than 50% of the total resistance. We attribute this high resistance at interface to weak Van der Waals interactions at the interface and dissimilar phonon vibrational properties of the materials. Our results suggest that increasing bond strength at the interface is an effective way to reduce the overall thermal resistance of the device. We compare our results with commonly used materials and interfaces, demonstrating the role of interface as potential application for heat guide or block in 2D material based device. This study will provide guide into the energy-efficient design and thermal management of 2D material devices
Behaviour of quantum chromodynamics near an infrared fixed point.
Get PDFIn perturbation theory, the QCD running coupling depends on the renormalization scheme or is parameterised by a physical process. The problem is that artefacts of this ambiguity may upset physical conclusions outside the asymptotically free region, in particular near an infrared fixed point. Thus, a non-perturbative definition for the QCD running coupling is required that should be a monotonic and analytic function of the space-like energy scale Q². The most physical coupling is Grunberg's definition for the running coupling as an effective charge αɢ(Q²). However, we find that it works only for sufficiently high energy scales. At some finite values of the energy scale, near the top of the resonance region, the β-function associated with αɢ(Q²) has a false zero below which αɢ(Q²) decreases. We test this conclusion further by applying chiral perturbation theory to the running coupling based on the method of effective charges. We consider the Drell-Yan ratio R(q²) and Adlerfunction D(Q²) in the time-like and space-like domains, respectively. These quantities tend to a finite value in the both infrared and ultraviolet limits: R(0) = D(0) = 0:5 for π±; K± and R(∞) = D(∞) = 2 for the light quarks. This means that the running coupling becomes negative in the infrared limit. Therefore, neither the time-like nor the space-like effective charges is a monotonic function over the whole energy scale. We also try to cancel the space-like pole of the proposed exact β-function, using the property of renormalization scheme dependence. Our modified exact β-function is non-singular for all finite values of the running coupling α and has an infrared fixed point even for a small number of quark flavours.Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 201
Design optimisation of centrifugal pump impellers using parallel genetic algorithm
Get PDFComputational Fluid Dynamics (CFD) techniques have settled to a stage, where it is
possible to gain significant insight into fluid flow processes of turbomachinery.
However, the purpose of fluid dynamics naturally goes beyond improved understanding
to the aim of improving the performance of the engineering systems. Consequently, the
present thesis investigates the use of a automated design optimisation method using
CFD. This
presents a new design method for a important turbomachinery part, blade
profiles of centrifugal pump impellers, based on a shape optimisation algorithm in
combination with CFD. The use of
genetic algorithms in shape optimisation dose not
allow the
design engineer to use any derivative information on the evolution of the
shape, but only simple evaluation techniques. A optimisation library (GAlib), based on
a
genetic algorithm (GA), was used. GA controls the evolution of a population of
profiles towards an optimum design. The optimisation process can handle simple
objectives as well as conicting ones. The fitness value of each population element is
evaluated
using a CFD flow solver (Mac_LNS) based on nite-difference discretisation
of the
incompressible, Navier-Stokes (N-S) equations on structured polar-coordinate
meshes. A
number of design examples have been developed and the behaviour of the
genetic algorithm has been tested using different kinds of objective functions. I
addition, the algorithm was tested with a multi-objective mction. Bézier curves were
selected to
represent the impeller profile. A symmetric profile, identical profile for the
pressure side (PS) and suction side (SS), was used as a basic shape to generate the
population elements. GAlib was modified to run as a parallel algorithm using Message
Passing Interface (MPI). It is indicated that parallelisation using MPI is good technique
to overcome the time taken
by GA and CFD, and quite good optimisation convergence
criteria was obtained
by using parallelisation. The obtained results show that the genetic
algorithm is capable of achieving satisfactory designs of centrifugal impeller blade
profiles effectively and with a minimum amount of user expertise
A Design of an Autonomous Drone for Animal Recognition
No full textThe purpose of the research is to design a new drone architecture which will be capable
of moving autonomously through most of the environments by interacting with the server
itself. The main feature is that it will be able to move through air, land and water.
Nowadays various drones are available. But a drone which can move through any
environment is never seen before. The main motive is to use the drone in rescue mission
and get accuracy in rescue missions in the cases of environmental & natural calamities
and make it easier than previous times. Besides this drone will use the environmental data
and bio information as a method of communication while interacting with the
environment. Environmental data learning can be used to communicate with the nature
and gather bio-information and environmental data from the environment and living
beings. We hope this drone will be also able to move under water. For communicating
with the environment and learning about the environment this drone will use two kinds of
database: temporary database and online database. This research paper proposes a new
design and modest algorithm which will help to move the drone autonomously avoiding
most of the obstacles in its way. By gathering bio-information and environmental data the
proposed ALW (Air, Land, and Water) drone will be able to communicate with the
environment and adapt the changes in the environment and communicate with the server
to act properly to be successful in its rescue mission. In this paper we used R Studio & R
programming language to compare the accuracy results among several Machine Learning
algorithms for several datasets. Based on the simulation results we can say that the drone
will be able to predict the disaster accurately and recognize animal correctly
Pengaruh Lokasi, Promosi dan Pengetahuan Terhadap Minat Non-Muslim Menjadi Nasabah Bank Syariah di Kota Palu
Get PDFHasil penelitian menunjukkan bahwa secara parsial variabel faktor lokasi (X1) berpengaruh secara positif dan signifikan terhadap minat non-muslim menjadi nasabah Bank Syariah yang dibuktikan dengan hasil uji T, dimana pada variabel (X1) diperoleh Thitung 4,131 > Ttabel 1,986 dan nilai signifikansi (sig.) .000 < 0,05. Variabel faktor promosi tidak berpengaruh positif dan signifikan terhadap minat
non-muslim menjadi nasabah Bank Syariah yang dibuktikan dengan hasil uji T, dimana (X2) diperoleh Thitung -1.020 0,05.
Variabel faktor pengetahuan (X3) secara parsial berpengaruh positif dan signifikan
terhadap minat non-muslim menjadi nasabah Bank Syariah yang dibuktikan dengan hasil uji T, dimana pada variabel (X3) diperoleh Thitung 2,332 > Ttabel 1,986 dan nilai signifikansi (sig.) .022 < 0,05. Sementara hasil pengujian berdasarkan hipotesis F menunjukkan bahwa variabel faktor lokasi, promosi dan pengetahuan berpengaruh secara simultan terhadap minat non-muslim menjadi nasabah Bank Syariah di Kota Palu, serta hasil koefisien determinasi (Adjusted R Square) sebesar 67,9% sedangkan sisanya dipengaruhi oleh variabel yang tidak diteliti dalam penelitian ini
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