Knowledge-Based Approach Using Support Vector Machine for Transmission Line Distance Relay Co-ordination

In this paper, knowledge-based approach using Support Vector Machines (SVMs) are used for estimating the coordinated zonal settings of a distance relay. The approach depends on the detailed simulation studies of apparent impedance loci as seen by distance relay during disturbance, considering various operating conditions including fault resistance. In a distance relay, the impedance loci given at the relay location is obtained from extensive transient stability studies. SVMs are used as a pattern classifier for obtaining distance relay co-ordination. The scheme utilizes the apparent impedance values observed during a fault as inputs. An improved performance with the use of SVMs, keeping the reach when faced with different fault conditions as well as system power flow changes, are illustrated with an equivalent 265 bus system of a practical Indian Western Grid.

Nature of Quiet Sun Oscillations Using Data from the Hinode, TRACE, and SOHO Spacecraft

We study the nature of quiet-Sun oscillations using multi-wavelength observations from TRACE, Hinode, and SOHO. The aim is to investigate the existence of propagating waves in the solar chromosphere and the transition region by analyzing the statistical distribution of power in different locations, e.g. in bright magnetic (network), bright non-magnetic and dark non-magnetic (inter-network) regions, separately. We use Fourier power and phase-difference techniques combined with a wavelet analysis. Two-dimensional Fourier power maps were constructed in the period bands 2 -aEuro parts per thousand 4 minutes, 4 -aEuro parts per thousand 6 minutes, 6 -aEuro parts per thousand 15 minutes, and beyond 15 minutes. We detect the presence of long-period oscillations with periods between 15 and 30 minutes in bright magnetic regions. These oscillations were detected from the chromosphere to the transition region. The Fourier power maps show that short-period powers are mainly concentrated in dark regions whereas long-period powers are concentrated in bright magnetic regions. This is the first report of long-period waves in quiet-Sun network regions. We suggest that the observed propagating oscillations are due to magnetoacoustic waves, which can be important for the heating of the solar atmosphere.

Average Modelling of a Voltage Source Inverter with Dead-Time in a Synchronous Reference Frame

Voltage source inverters are an integral part of renewable power sources and smart grid systems. Computationally efficient and fairly accurate models for the voltage source inverter are required to carry out extensive simulation studies on complex power networks. Accuracy requires that the effect of dead-time be incorporated in the inverter model. The dead-time is essentially a short delay introduced between the gating pulses to the complementary switches in an inverter leg for the safety of power devices. As the modern voltage source inverters switch at fairly high frequencies, the dead-time significantly influences the output fundamental voltage. Dead-time also causes low-frequency harmonic distortion and is hence important from a power quality perspective. This paper studies the dead-time effect in a synchronous dq reference frame, since dynamic studies and controller design are typically carried out in this frame of reference. For the sake of computational efficiency, average models are derived, incorporating the dead-time effect, in both RYB and dq reference frames. The average models are shown to consume less computation time than their corresponding switching models, the accuracies of the models being comparable. The proposed average synchronous reference frame model, including effect of dead-time, is validated through experimental results.

The role of agricultural co-operatives in the development of fisheries in Nigeria

Problems faced by the fishery sector in Nigeria are examined and the role that agricultural cooperatives play in fishery development considered. The importance of improving the marketing and distribution system through fishermen cooperatives is stressed. It is concluded that for the successful implementation of fishery products, there is need for regular communication, cooperation and collaboration among relative agencies

Artisanal containers and transportation for smoke-dried fish in Nigeria

The packaging containers and means of transportation for Nigerian smoke-dried fish from harvesting all through the post-harvest chain were described. Sacks, paper cartons, wooden rackets, cane and bamboo baskets were predominantly used packaging containers. Means of transportation ranged from wheelbarrows, motorcycle, lorries, to pick-up vehicles and trucks. The major area of improvement is seen in packaging at the wholesale level. To overcome the constraints within the system, both the public and private sectors must provide effective services that benefit fishermen, processors, wholesalers, retailers, organisation and other key participants that make the work. Suggestions for reducing post harvest losses and improving the efficiency of the existing distribution system, based on the various need of the stake holders and the socio-cultural settings of the application were proffered

Geometric discretization through primal-dual meshes

This thesis introduces new tools for geometric discretization in computer graphics and computational physics. Our work builds upon the duality between weighted triangulations and power diagrams to provide concise, yet expressive discretization of manifolds and differential operators. Our exposition begins with a review of the construction of power diagrams, followed by novel optimization procedures to fully control the local volume and spatial distribution of power cells. Based on this power diagram framework, we develop a new family of discrete differential operators, an effective stippling algorithm, as well as a new fluid solver for Lagrangian particles. We then turn our attention to applications in geometry processing. We show that orthogonal primal-dual meshes augment the notion of local metric in non-flat discrete surfaces. In particular, we introduce a reduced set of coordinates for the construction of orthogonal primal-dual structures of arbitrary topology, and provide alternative metric characterizations through convex optimizations. We finally leverage these novel theoretical contributions to generate well-centered primal-dual meshes, sphere packing on surfaces, and self-supporting triangulations.

Ausência de correlação entre a penetração do cimento AH Plus nos túbulos dentinários e a qualidade do selamento

O presente estudo objetivou testar experimentalmente a existência da possível correlação entre a penetração de cimento nos túbulos dentinários e a qualidade do selamento. Foram utilizados 60 incisivos centrais superiores humanos que formaram um único grupo experimental. Após a eliminação das porções coronárias, as raízes foram padronizadas em 13 mm de comprimento. A instrumentação dos canais foi realizada no sentido coroa-ápice, e o comprimento de trabalho estabelecido a 1 mm aquém do forame apical. Como solução irrigadora foi empregado o NaOCl a 5,25% e ao final, EDTA a 17%. Em seguida, todos os canais foram obturados com guta-percha e cimento AH Plus marcado com um corante fluorescente. Para determinar a qualidade do selamento das obturações endodônticas, as amostras foram submetidas ao modelo de infiltração de glicose sob pressão. As raízes foram montadas em um dispositivo de dupla-câmara selada para permitir a infiltração da glicose. Como controle negativo foram utilizados 4 dentes hígidos, e como controle positivo, 2 dentes instrumentados porém, não obturados. Foram utilizados 0,75 mL de solução de glicose a 1 mol/L na câmara superior e 0,75 mL de água deionizada na câmara inferior. Os dispositivos foram conectados a um sistema de distribuição de pressão desenvolvido com o objetivo de permitir a infiltração de 32 amostras em uma mesma etapa. A solução de glicose foi forçada apicalmente sob uma pressão de 15 psi durante 1 hora. Uma alíquota de 50 L foi coletada da câmara inferior para quantificar a glicose infiltrada. A concentração de glicose foi determinada através de um método enzimático com o auxílio do Kit Glucose HK e de um espectrofotômetro em um comprimento de onda de 340 nm. Na sequência, as amostras foram desacopladas dos corpos de prova, embutidas em resina epóxi e cortadas em 3 secções transversais. Uma sequência de preparação metalográfica padrão foi realizada para permitir a observação da penetração de cimento nos túbulos dentinários por meio de microscopia confocal e óptica. Os dados obtidos nos 2 experimentos foram cruzados pelo teste de correlação de Spearman, o qual revelou a inexistência de qualquer possibilidade de correlação (r = 0,12). Com base nesses resultados, o presente trabalho concluiu que, dentro das condições experimentais usadas, a quantidade de cimento presente dentro dos túbulos dentinários não teve relação com a qualidade do selamento produzido.

基于向量变换的包裹相位场预处理与信息完整性探讨

针对包裹相位场在消除噪声的特别要求,提出了对包裹相位场预处理的向量滤波方法。理论分析了功率谱密度和向量变换的滤波思想。仿真实验研究了滤波模板的大小对滤波效果的影响,比较了在同样模板的选取下向量滤波方法与二次均值滤波法的滤波效果,分析了向量滤波方法与二次均值滤波法的功率谱密度分布。结果表明,相比二次均值滤波法,向量滤波法在降噪的同时,相位图依然清晰,它的功率谱密度分布没有明显变化,预处理后频谱信息的丢失远小于二次均值滤波。向量滤波法在提高信噪比的同时,信息的完整性得到较好保证。

Erretiroaren pentsioa eta adinez langile nagusien lan-bizitzaren luzamena

[Pentsio-sistema honela antolatzen da: lehen maila, kotizaziopeko pentsioak jasotzen ez dituztenei pentsioak ordaintzera bideratzen da; bigarren maila, Gizarte Segurantza edo kotizaziopeko pentsioena da; hirugarren maila, borondatezko gizarte-aurreikuspen osagarriari dagokio Euskal Autonomia Erkidegoan eta pentsio-planei Espainian. Bigarren mailan, Gizarte Segurantza banaketa-sisteman oinarritzen da. 2050ean erretiro-pentsioak finantzatzeko arazoak egotea espero da. Etorkizuneko egoerari aurre egiteko, 27/2011 Legearen eta 5/2013 Errege Lege Dekretuaren bitartez, erreformak burutu dira. Hirugarren mailan, Euskal Autonomia Erkidegoan gizarte-aurreikuspen osagarria Eusko Jaurlaritzaren esku dago eta Borondatezko Aurreikuspen Sozialeko Erakundeen (BASE) aurreikuspen-planak bertako pentsio-plan propioak dira. Lan honetan, batez ere, pentsio-sistemaren bigarren eta hirugarren mailak aztertuko ditut. Lehenengo marko teorikoa, ondoren alde praktikoa, eta azkenean datuetan oinarrituz proposamen batzuk eman eta ondorioak aterako ditut.]

Algumas Contribuições para Algoritmos de Controle de Filtros Ativos e Híbridos Conectados em Paralelo com Redes Elétricas Trifásicas a 3 ou a 4 Fios.

Este trabalho apresenta contribuições para algoritmos de controle utilizados em filtros ativos e híbridos conectados em redes elétricas trifásicas a 3 ou a 4 fios. Em relação aos algoritmos de controle para filtros ativos, a contribuição consiste em estender o conceito da filtragem harmônica seletiva para compensação de correntes harmônicas e desequilibradas em uma rede trifásica a 4 fios. Esses algoritmos derivam dos conceitos utilizados na teoria da potência instantânea (teoria pq), em conjunto com um circuito de sincronismo PLL. É importante ressaltar que estes algoritmos não utilizam as correntes consumidas pelas cargas, ou seja, apenas as tensões no ponto da rede onde o filtro está conectado são utilizadas para determinação das correntes harmônicas de referência. Apenas as correntes na saída do conversor são utilizadas como realimentação do controle PWM. Estes algoritmos também foram utilizados no filtro híbrido para compensação de correntes harmônicas em uma rede trifásica a 3 fios. Por fim foi feito uma alteração nesses algoritmos de controle que permite eliminar as correntes utilizadas na realimentação do controle PWM. Resultados de simulação são apresentados com objetivo de observar o comportamento desses algoritmos tanto no filtro ativo quanto no híbrido nas condições mencionadas.

Visual survey of exposed riverine sediments (Ers) in the Dane, Weaver and Bollin catchments

This is the Visual survey ERS Dane, Weaver & Bollin Catchments produced by the Environment Agency in 2005. Visual surveys of the River Dane downstream of the confluence with the Swettenham Brook, the River Weaver, and the River Bollin catchment in the EA Northwest South area of England were undertaken between 3rd and 9th February 2005 with the aim of identifying the spatial distribution and relative quality of exposed Riverine sediments (ERS). The potential value of these ERS in terms of likely habitat quality for ERS invertebrate communities was determined by recording a suite of appropriate environmental variables. Following an initial cartographical analysis of reaches likely to contain ERS, tens of kilometres of riverbank were inspected and 67 areas of ERS were selected for detailed visual survey. Site characteristics ranged widely both between and within catchments, with habitat quality ranging from poor to very high.

Central Area Fisheries Advisory Committee 1st April, 1981

This is the report from the Central Area Fisheries Advisory Committee meeting, which was held on the 1st April, 1981. It covers information on Rivers Leven and Kent fish distribution and water quality surveys 1980, authority works on Headwater Beck of the River Hodder and the River Douglas, the annual report on match fishing at Skerton and Mitton fisheries and the report by the area fisheries officer on fisheries activities. This comments on river conditions and fishing, migratory fish movement,an update on Middleton hatchery, salmon cages in Dalton-in-Furness, and Langcliffe hatchery. Finally the report adds about stockings by the authority, fish mortalities, fish disease and the monthy catches of salmon and sea trout for the 1980 season. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

Antibunching and blinking from a single colloidal CdSe quantum dot

We have investigated the optical properties of single CdSe/ZnS nanocrystals by conducting combinations of experiments on antibunching and photoluminescence intermittence under different experimental conditions. Based on photoluminescence in an antibunching experiment, we analyzed the emission lifetime of QDs by using stretched exponentials. The difference between the parameters obtained from average lifetimes and stretched exponents were analyzed by considering the effect of nonradiative emission. An Auger-assisted tunneling model was used to explain the power law exponents of off time distribution. The power law exponent under high excitation power was correlated with a higher Auger ionization rate. Using the parameters obtained from stretched exponential function and power law, the antibunching phenomena at different time and under different excitation intensity were analyzed.

GSMBE growth and PL investigation of lattice-matched InGaAs/InP quantum wells

Using a home-made gas-source molecular beam epitaxy system, high quality InGaAs quantum wells with different well widths lattice-matched to a (001) InP substrate have been obtained. Sharp and intense peaks for each well can be well resolved in the PL spectra for the sample. For well widths larger than similar to 60 Angstrom, the exciton energies are in good agreement with those of calculation. For wells narrower than 40 Angstrom, our line widths are below the theoretical values of line width broadening due to one monolayer interface fluctuation, showing that the interface fluctuation of our sample is within one monolayer.

Ultrasound-promoted chiral fluorescent organogel

In this paper, we have described a chiral binaphthyl-based fluorescent organogel. Very interestingly, similar to sonocrystallisation of organics, ultrasound can promote the gelation while it cannot occur spontaneously at relatively high temperature or low concentration. The fluorescence enhancement of the gel obtained via ultrasound irradiation is observed. In solution there exist rapid dynamic equilibria between (S)-1 oligomers. The association interactions both between gelator molecules and between solvent and gelator molecules could together effect the helical growth of distorted (S)-1 nanocrystals.