Grid

Nigeria is a country faced with great challenges in the power sector. This is as a result of inadequate administrative and technical efforts in handling issues in this sector. Aforetime, the country has solely depended on grid electricity generation which has proven to be unstable for several decades. These and others, has made it imperative to introduce the use of renewable energy in addressing some of the electricity challenges facing the country. The sources of renewable energy which could serve as an alternative source of power include wind, solar, and biogas. These can also be combined together as an entity to form a hybrid renewable energy source. In this paper, a solar tree was designed and constructed to provide an alternative supply of electricity to farm settlements in Nigeria. This is achieved by generating electricity from a single or multiple number of solar panels connected with a charge controller, a battery bank for storage and an inverter circuit to supply electrical power. Depending on the electrical load demand and the applications coverage area, the solar tree rating and specification can be a single-phase or three-phase AC output.

This paper proposes an Energy Management System (EMS) of an off-grid residential microgrid comprised of a solar photovoltaic array, wind turbine, and a battery-based energy storage system for a residential building in a remote area. The aim is to design a less complex energy management system that addresses energy resources dispatch challenge in a hybrid residential microgrid. It equitably dispatches resources and manages the generated energy to meet the residential load. The management control system algorithm is implemented using the state machine and simulated in MATLAB/Simulink environment for validation. Three scenarios are simulated, they emulate various contingencies scenarios that might rise due to the intermittency nature of the renewable resources. Simulation results show that the proposed energy management system achieves its design objectives. It maintains the power supply and demand balance, through an appropriate scheduling of resources even during contingency due to t...

Real-time surveillance systems, network and telecommunication systems, and other dynamic processes often generate tremendous (potentially infinite) volume of stream data. Effective analysis of such stream data poses great challenges to database and data mining researchers, due to its unique features, such as single-scan algorithm, multi-dimensional online analysis, fast response time, etc.

Abstract. Developing e-Learning applications concerns issues of human communication and facilitating technology. One of the key research issues in Computer-Mediated Communication (CMC) is the participation of remote audience in a communicative activity. This is particularly important in learning contexts. In the two studies reported here, we discuss systems infrastructure by presenting the concept of the Virtual Observatory through the AstroGrid project. We explore how such a Grid can be used in the future as an e- ...

This paper represents the modeling and simulation of 2 MW Direct Drive permanent magnet synchronous generator (PMSG) Wind energy conversion system (WECS). The modeling of wind turbine and PMSG is carried out in simulink to determine its parameter. WECS consists different components namely Wind turbine, Generator, rectifier-inverter, controller system including transformer, grid etc. The PMSG and converter model are established in the d-q model. Renewable energy technologies offers clean, abundant energy gathered from self-renewing resources such as the sun, wind etc. As the power demand increases, power failure also increases. So, renewable energy sources can be used to provide constant loads. A new converter topology for hybrid wind/photovoltaic energy system is proposed. Hybridizing solar and wind power sources provide a realistic form of power generation. Simulation is carried out in MATLAB/ SIMULINK software and the results of the Cuk converter, SEPIC converter and the hybridize...

The problem of constructing a tight isothetic outer (or inner) polygon covering an arbitrarily shaped 2D object on a background grid, is addressed in this paper, and a novel algorithm is proposed. Such covers have many applications to image mining, rough sets, computational geometry, and robotics. Designing efficient algorithms for these cover problems was an open problem in the literature.

L’origine di questo saggio sorge dalla domanda se le città siano mai state moderne; e in particolare, che tipo di modernità le riguardi. In modo simile al noto saggio di Latour, la risposta viene cercata in due dimensioni: nel rapporto tra spazio e natura, e in quello tra cittadinanza e società. Lo sfondo di questo interrogativo riguarda la critica al programma di ‘purificazione’ che il modernismo – sia in urbanistica che in architettura – ha interpretato con convinzione, quasi con ferocia, nei riguardi appunto della natura e della società.
Questa domanda è trattata esaminando Buenos Aires, città moderna spesso presa ad esempio di come il modello moderno della città europea sia stato capace di riprodursi in altre condizioni. L’angolatura che si utilizza, a fronte della vastità del tema, è invece volutamente ristretta al ruolo che la ‘forma’ della città esercita sulle condizioni sociali; ancora in modo più ristretto, alla forma della pianta urbana disegnata dalle strade che fonda la distinzione tra spazio pubblico e privato, un’ulteriore ma non arbitraria semplificazione. Inutile ricordare quanto la forma della città sia di interesse per chi si occupa di storia urbana. La preoccupazione qui è più limitata e riguarda quali effetti politici risultino dalle diverse forme assunte dall’organizzazione dello spazio3. Anche questo, non sorprende, è un costante interrogativo dell’urbanistica e delle scienze sociali, al quale sono state date nel tempo risposte molto diverse.
Apparentemente, come molte altre città, Buenos Aires è organizzata in modo regolare, razionale, intorno ad una griglia ortogonale. Particolarità della città è che questo elemento formale e spaziale sembra attraversare quasi indenne fasi molto diverse della storia urbana, tutte caratterizzate da richiami al modernismo probabilmente tra loro inconciliabili. Ammesso che sia mai stato possibile, Buenos Aires non ha di certo costruito un ordine funzionale su questa nitida organizzazione spaziale: il formalismo apparente si coniuga con una gran varietà di forme sociali. In altre parole, l’organizzazione
spaziale della città ha resistito alla zonizzazione funzionale che avrebbe dovuto far corrispondere spazi, luoghi e comportamenti. Anzi, la griglia ha operato come elemento di connessione, se non come meccanismo generativo, che ha consentito il radicamento di tante forme di urbanità diverse, soprattutto nello spazio della strada. Questo processo è conseguenza della particolare marginalità della città rispetto al solco della modernità; e della compresenza tra ibridi assemblage di attori e forme culturali.
Quest’ultimo aspetto sembra costituire un elemento di riflessione più
vasta e offrire uno spunto di risposta alla domanda di apertura. Buenos
Aires illustra bene due casi diversi di processi di ibridazione, separatamente elaborati da Latour e Canclini ma ambedue cruciali nel comprendere la nozione di modernità: la tenace contaminazione di natura e società nelle reti concrete che organizzano gli spazi; la commistione delle diverse temporalità culturali.

Abstract—With the proliferation of international standards for grid-enabled databases, the need for data loading and data mapping in a large integrated environment of heterogeneous databases highlights issues of consistency and integrity. We discuss methods for providing semi-...

This paper presents a modification to conventional magnetron sputtering systems. The introduction of a grid in front of the target increases the metal ion ratio. Using OES and observing both Ti neutrals and ions, it was confirmed that the relative ionization could be qualitatively extended with grid-attached magnetron sputtering compared with a conventional magnetron system. On the other hand, the relative ionization of Ar decreased. Our results also show that the Ti films deposited by conventional magnetron exhibit (100) preferred orientation as the bias voltage increased. On the other hand, in the case of the grid-attached magnetron, the Ti films exhibit highly preferred (002) orientation with increasing bias voltage. The experiments clearly demonstrated that a dense Ti film with a smooth, specular reflecting surface can be produced using the grid-attached magnetron with increased Ti ion flux compared to the conventional magnetron.

Bu yazıda Peter Eisenman'ın daha ismi bile yok iken başlattığı mimari yapısökümün ken-disinin mitsel bir yapıya sahip olduğu savunulmuş ve mimarın mitsellikle olan ilişkisini nasıl gözden geçirdiği açıklanmaya çalışılmıştır. Eisenman henüz tam anlamıyla gerçekleşmemiş olduğuna inandığı Modernizme taze bir yol açmak için yeni bir tarihsel kırılma arayışını kariye-rinin başlıca amacı haline getirmişti. Eisenman'ın tarihselciliği çözmek için kullandığı yöntem, biçim ve anlam arasında kurulmuş olan tarihsel ilişkileri " mitsel " kabul etmekti. Farklı zaman-larda Yapısalcılık, avangard sanat, Kavramsal Sanat, psikanaliz ve Yapısöküm gibi farklı etkilere maruz kalan kuramsal gelişiminde hiç kaybolmayan ama giderek belirginleşen bir şey, ızgara, uzun kariyeri boyunca mimarın sentetik ve eklektik kuramından kaynaklanan çelişkileri çözmek için kullandığı başlıca araç olmuştur. Başlangıçta mimarlıkta rasyonellik mitosunu sağlayan ızgara gerekmedikçe ortaya çıkmayan soyut bir yapı iken, daha sonra Eisenman'ın, kendi mi-marlığının mitselliğinin varlığını ve yokluğunu aynı anda ima eden ve üslupsal diyebileceğimiz bir temaya dönüşmüştür.

... 693 to develop custom Grid portal web applications. ... The File Browser Port-let also supports the ability to create new directories, delete files and directories, edit text files online, upload files to remote file systems and download files to a user's local host, so long as the files ...

This chapter looks at teletext from the perspective of an artist and of its artistic value. It is argued that teletext is not just news on demand provided by television networks or a character set, and that it is about much more than nostalgia, profit, constraints, domesticity or zombie technology stored in a garage, because teletext performs in ways we have not fully designed it for and not yet fully understood. Teletext is compared to brutalist architecture with which it shares many similarities: text is used unadorned and roughcast, like concrete. Brutalism has an unfortunate reputation of evoking a raw dystopia and teletext evokes an “object of nostalgia,” It is a challenge and has the universal language of silence. The text further argues that using old technologies, like teletext, is a commitment that is at the same time a risk because it does not seek to forge a self-identity. It is a dialogue of possibilities rather than an ego-trip monologue with technology. And these possibilities are irrelevant to the individual’s self-identity and pursuits. Finally, the chapter also explores how teletext is not a physical object; it is the dark band dividing pictures horizontally on the television screen, used by the PAL system. Vertical-blanking-interval lines like REM (rapid eye movement) sleep intervals. A door to unlock the Imagination.

This paper represents the modeling and simulation of 2 MW Direct Drive permanent magnet synchronous generator (PMSG) Wind energy conversion system (WECS). The modeling of wind turbine and PMSG is carried out in simulink to determine its parameter. WECS consists different components namely Wind turbine, Generator, rectifier-inverter, controller system including transformer, grid etc. The PMSG and converter model are established in the d-q model. Renewable energy technologies offers clean, abundant energy gathered from self-renewing resources such as the sun, wind etc. As the power demand increases, power failure also increases. So, renewable energy sources can be used to provide constant loads. A new converter topology for hybrid wind/photovoltaic energy system is proposed. Hybridizing solar and wind power sources provide a realistic form of power generation. Simulation is carried out in MATLAB/ SIMULINK software and the results of the Cuk converter, SEPIC converter and the hybridized converter are presented.

Abstract- Mobile ad hoc networks (MANETs) can be defined as a collection of large number of mobile nodes that form temporary network without aid of any existing network infrastructure or central access point. Due to the nature of MANETs to design and maintaining security is challenging task for researcher in an open and distributed communication environment. This paper we proposed security architecture for MANET grid and optimal key management by combines symmetric key technique and elliptic curve public key technique. The proposed architecture and optimal key management eliminates threats including the man-in-the-middle attack and the Black hole attack can be effectively eliminated under the proposed scheme. The core advantages of the proposed scheme include strong security, scalability, fault-tolerance, accessibility, and efficiency.

A bulk of research states that witchcraft is an antithesis to development. This thesis finds that that is an assumption, which cannot explain the case of the Giriama. The results of this thesis has the implications that witchcraft may indeed exist in a modern developed setting, that people in the West/North could have witchcraft beliefs as well, and that witchcraft does not have to be valued negatively. To arrive at this conclusion, witchcraft as a personal and social phenomenon was plucked apart, and then juxtaposed against different concepts of development. Combining Lucien Levy-Bruhl’s theory of Mystical Participation with Mary Douglas’ theories on Grid and Group, witchcraft rationality is stated to be indicative of a category of worldview. This categorisation helps the reader to better recognise cultures with this particular rationality, and to understand the nature and consequences of the rationality. Throughout the text, the witchcraft rationality worldview is contrasted with ...