In this thesis, we construct a mathematical model for Sectorized FFR Networks (SFN). In SFN, frequency allocation adopts FFR (Fractional Frequency Reuse), which divides the frequency into two parts: the super group (Sup-G) and the regular group (Reg-G). Since the frequency allocations of Sup-G and sectors overlaps each other, and the same frequency band is used by two Sup-G in two different BS, when the radius of Sup-G is too large, interferences will occur among the adjacent BS. In our mathematical model, given different environmental parameters (number of sector, number of MS, strength of power), we can compute the system capacity by varying the radius of Sup-G and the various environmental parameters. In practical applications, since the number of MS becomes smaller in the cellular edge and it increases rapidly in the cellular center, Gaussian distribution is more adequate to model the distribution of MS. Thus, in the calculation of interference, we take the integration of the path loss multiplied by the transmission power and the MS density. Finally, through the SINR and Shannon Capacity formula, we can derive the overall system capacity. From the mathematical model, we can achieve a ratio of Sup-G radius and cellular radius. With this radius ratio, an MS can have about the same capacity regardless of the position in the FFR network. Otherwise, an MS may get very different capacity when it moves to the cellular edge or sometimes it appears in the cellular center. Additionally, from the mathematical model, we can analyze the interferences and system capacity for different numbers of sectors.

No description available.

In this thesis a distributed, dynamic, load aware, joint power and frequency allocation protocol for 4G networks along with system-level simulated results are presented. In all cellular networks, a key limiting factor for throughput is inter-cell interference, especially at the cell edges. Several methods have been proposed and adopted in each mobile network generation to cancel or suppress its effects, whereas each method has its drawbacks in terms of receiver complexity or additional control nodes. However, the proposed protocol presented here does not impose any architectural changes.  In 4G networks such as LTE, the choice of OFDMA for the air interface has paved the way for selective frequency and power allocation in the available spectrum. Taking advantage of this opportunity, fractional frequency reuse (FFR) has been proposed in OFDMA based mobile networks in order to reduce the throughput loss at the cell edges due to inter-cell interference. In FFR, center users lose part of available spectrum that is dedicated to the edge users.  Our protocol aims to minimize this loss of center users incurred by FFR, at the cost of minimal degradation at the edges. An eNodeB, only when overloaded, requests its neighbours’ edge band to be used for its center users at a reduced power level. This is done via small message exchange between the eNodeBs. The neighbors of the overloaded eNodeBs solve a small local knapsack problem to decide whether band lending is feasible or not. A distinguishing feature of this protocol is the power level adjustment for the borrowed band, which is mutually decided by the borrower and lender. The band is released when it is not needed or it is causing unacceptable loss to the lender. The implementation is done in a Matlab based LTE system level simulator. For the implementation of our protocol in the simulator, starting point was implementation of FFR-3 functionality, a prerequisite and a baseline for comparison with our protocol. Results are compared among three different setups of re-use1, FFR-3 and our protocol by varying number of overloaded eNodeBs for various numbers of scenarios and the comparison is made based on the center users’ throughput, edge users’ throughput. An estimation of time and protocol overhead is also presented. We have observed center users’ throughput gain up to 46%, at the cost of 9% edge users’ throughput loss, when compared to the classic FFR-3 scheme. The overall system throughput goes up to 26 % in heavily loaded scenario.   The utility of the protocol for an LTE system is evident from the results, which is supported by the dynamic and decentralized nature of the protocol. This ensures better utilization of spectrum, by temporarily allocating more bandwidth where it is needed more.

Purpose of Review: Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) have emerged as the invasive diagnostic tools of choice for hemodynamic assessment of the severity of CAD (coronary artery disease). We sought to comprehensively review the evidence on the utility of hemodynamic assessment of the coronary stenoses after percutaneous coronary intervention (PCI) using FFR/iFR, mechanisms of positive post-PCI iFR/FFR, and the clinical impact of significant residual ischemia. Recent Findings: The evidence on the utility of the post-PCI hemodynamic assessment has accumulated over the last few years. The post hoc analysis from the FAME 1 and FAME 2 data shows that higher post-PCI FFR is associated with better symptomatic improvement and lower event rate with larger increase in delta FFR (∆ FFR: post-PCI FFR – pre-PCI FFR). Unlike pre-PCI FFR, a consensus has not been established on the optimal value of post-PCI FFR, though multiple studies point toward better clinical outcomes with higher post-PCI FFR and larger ∆ FFR. Summary: Visual assessment of adequate stent apposition by coronary angiography is insufficient in evaluating for residual ischemia. The hemodynamic evaluation of residual ischemia by post-PCI FFR/iFR yields clinically relevant data and allows for appropriate post PCI optimization.

No

No description available.

No description available.

Taxonomic delimitation of rare species is vital for accurate assessments of diversity and for their conservation. Cycladenia humilis, the sole species of Cycladenia, is an enigmatic perennial widely dispersed across the western United States. Within this species there are three currently recognized varieties: C. humilis var. humilis in Northern California, C. humilis var. venusta in Southern California, and C. humilis var. jonesii in Utah and Northern Arizona. Some populations occur geographically in areas between the typical distribution of each variety and the presently accepted taxonomy inadequately addresses these populations. Using five nDNA regions, we seek to clarify relationships between current varieties and assess the pattern of variation throughout the species. Analyses including K-means clustering, principle component analysis, fields for recombination, AMOVA, and ecological niche modeling were applied. Results indicate significant genetic structure between varieties and supports recognition of C. jonesii at the species level as distinct from C. humilis. Well defined intraspecific groupings are evident in the data, with evidence supporting the recognition of an additional variety in C. humilis, and two varieties in C. jonesii. Haplotype diversity and relationships between metapopulation clusters inform conservation efforts regarding diversity within Cycladenia and offer insights into the historical demography of this genus.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-07-17T13:25:04Z No. of bitstreams: 1 RaphaelBenderChagasLeite_TESE.pdf: 4093723 bytes, checksum: 021488e56c69aed1d15a27179827dc0a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-07-19T14:08:37Z (GMT) No. of bitstreams: 1 RaphaelBenderChagasLeite_TESE.pdf: 4093723 bytes, checksum: 021488e56c69aed1d15a27179827dc0a (MD5) / Made available in DSpace on 2017-07-19T14:08:37Z (GMT). No. of bitstreams: 1 RaphaelBenderChagasLeite_TESE.pdf: 4093723 bytes, checksum: 021488e56c69aed1d15a27179827dc0a (MD5) Previous issue date: 2017-02-23 / Nos seres humanos, o processamento da informa??o sonora possibilitou o aparecimento da linguagem oral e da m?sica. A altura sonora (do ingl?s, pitch), que permite a constru??o da melodia de uma m?sica e da pros?dia no discurso falado, ? um desses atributos. A percep??o da altura ? uma habilidade universal, contudo alguns indiv?duos se destacam por serem capazes de identificar ou produzir um tom em uma altura particular sem o uso de uma refer?ncia externa. Essa habilidade ? popularmente conhecida por ?Ouvido Absoluto? (em ingl?s, absolute pitch ou perfect pitch). No entanto, os mecanismos neurais respons?veis por tal habilidade ainda n?o s?o totalmente conhecidos. O presente trabalho tem o objetivo de contribuir para o entendimento dos processos neurais envolvidos na percep??o de alturas em indiv?duos com a habilidade de Ouvido Absoluto (OA). No nosso primeiro estudo, avaliamos a preval?ncia do OA em uma popula??o local de m?sicos (Escola de M?sica, UFRN). Para isso, utilizamos de ferramentas psicof?sicas e um question?rio. Nesse trabalho inicial, observamos que a habilidade do OA n?o se apresenta como um processo do tipo "tudo-ounada", mas sim com diferentes n?veis de desempenho: desde as pessoas que acertam abaixo do acaso, aumentando gradativamente a performance at? chegar aos 100%. Enquanto limiares tradicionais (~85%) mostraram uma preval?ncia de OA similar ?quela observada em m?sicos da Europa e Estados Unidos, a aplica??o de um limiar estat?stico resultou na detec??o de um n?mero maior de indiv?duos com algum grau de OA. Al?m disso, mostramos que indiv?duos com OA tem maior prefer?ncia de acerto para as chamadas notas naturais (aquelas relacionadas ?s teclas brancas no piano) em compara??o com as notas de teclas pretas (que s?o as notas sustenidas ou bem?is). Encontramos tamb?m que indiv?duos com OA apresentam in?cio mais precoce do treinamento musical. Finalmente, mostramos que quanto maior a profici?ncia musical, maior a preval?ncia dessa habilidade. Num segundo estudo, utilizamos potenciais evocados auditivos do tronco encef?lico (PEATE) para quantificar a ativa??o de n?cleos do tronco encef?lico no processamento de alturas de indiv?duos com OA. Nesse trabalho, mostramos a presen?a de respostas sustentadas (mas n?o transientes) com maior energia em indiv?duos com OA do que em m?sicos sem essa habilidade. Observamos tamb?m que a amplitude dessa resposta sustentada correlaciona-se com o tempo de rea??o em um teste de nomea??o de alturas. Esses resultados sugerem que indiv?duos com OA possuem maior refinamento no processamento da informa??o ac?stica nos primeiros est?gios do processamento auditivo, contribuindo assim para uma maior automatiza??o da identifica??o de alturas. Acreditamos que esses resultados, como um todo, poder?o facilitar entendimento das rela??es entre o desenvolvimento do sistema nervoso e o aprendizado musical, contribuindo assim para a elabora??o de novas t?cnicas de ensino de m?sica e programas de treinamento. / In humans, the processing of sound information allowed the appearance of speech and music. The pitch - which allows the melody of a song and prosody in spoken discourse - is one of these attributes. Pitch perception is a universal skill, however, just a few individuals are able to identify or produce a tone at a particular pitch without an external tonal reference, an ability known as the Absolute Pitch (AP). However, the neural mechanisms responsible for such ability are not yet fully understood. The present work has the objective to contribute to the understanding of the neural processes involved in the perception of pitch in AP possessors. In the first study, we evaluated AP prevalence in a local population of musicians (School of Music, UFRN). For this, we used psychophysical tools and a questionnaire. This first work showed that AP is not an "all-or-nothing" process, but rather that it has different levels of performance: from people that perform below chance, until it increases gradually to 100% of correct answers. While traditional thresholds (~85%) showed a prevalence of AP similar to that observed in musicians in Europe and the United States, the application of a statistical threshold resulted in the detection of a greater number of individuals with some degree of AP. In addition, we showed that AP possessors hit more the natural notes (those with the whitekeys of the piano) than those that are accidental (flat or sharp, i.e. the black keys of the piano). We also observed that AP possessors present an earlier onset of musical training. Finally, we showed that AP was more prevalent in a high proficiency group in comparison to the average proficiency group. In a second study, we used the auditory brainstem evoked potentials (ABR) to quantify the activation of brainstem nuclei in the processing of heights of individuals with OA. In this work, we showed that sustained responses (but not the transient ones) present a higher energy in individuals with AP than in control musicians. We also found that the amplitude of this sustained response correlates with the reaction time in a pitch naming test. These results suggest that individuals with AP have an increased refinement in the processing of acoustic information in the early stages of auditory processing, which would thus contribute to a greater automation of pitch identification. We believe that this thesis will contribute to the understanding of the relationship between nervous system development and musical learning, thus contributing to the development of new music teaching techniques and training programs.

How long would modern society cope with a power outage, what would happen to vital systems that we today take for granted in modern society. The Nordic electricity grid is facing a major shift where electricity production from non-renewable sources are to be replaced increasingly by renewable sources. By increasing the penetration of wind and solar power the electric power system might be exposed to disturbances due to decreasing inertia as a result of the electricity transition. Currently the electric power system has different reserves to use to maintain frequency stability but there are other reserves that could help further in the fight for the balance between electricity production and consumption. This project examines whether the new reserve service, fast frequency reserve (FFR), can help the existing frequency containment reserve for disturbed (FCR-D) operation. Therefore, two experiments were conducted using the simulation tool ARISTO, addressing relevant issues involving frequency stability. Motivation for the hypothesis was to investigate if FFR could reduce the frequency transients and improve frequency variations by developing various setups and cases when inertia was retained and when the system inertia was reduced at different stages. The results of the experiments showed that the global minimum frequency, nadir, had increased for all test cases compared to the reference case when using FFR, this proved that the FFR in fact help reducing frequency transients. The results showed furthermore that when the FFR had a duration time of 30 seconds compared to only 5 seconds, the frequency variations could be improved for certain setups for experiment 2.