2,275 research outputs found
An Introduction to 3D User Interface Design
3D user interface design is a critical component of any virtual environment (VE) application. In this paper, we present a broad overview of three-dimensional (3D) interaction and user interfaces. We discuss the effect of common VE hardware devices on user interaction, as well as interaction techniques for generic 3D tasks and the use of traditional two-dimensional interaction styles in 3D environments. We divide most user interaction tasks into three categories: navigation, selection/manipulation, and system control. Throughout the paper, our focus is on presenting not only the available techniques, but also practical guidelines for 3D interaction design and widely held myths. Finally, we briefly discuss two approaches to 3D interaction design, and some example applications with complex 3D interaction requirements. We also present an annotated online bibliography as a reference companion to this article
The Bird-Shaped Finial on Islamic Royal Parasols: a Ghaznavid or Fatimid Innovation?
This paper aims at investigating when and why the bird-shaped finial made its appearance on Islamic parasols through the analysis of written sources and miniature paintings. Evidence attest to the trans-regional and diachronic use of the parasol as a royal insignia whose meaning and value grew wider to symbolise the seat of government, was it the royal tent, palace or throne
LNG as the future marine fuel, Waste Heat Recovery Systems & Cold Ironing solutions for eco-friendly maritime transport
Nowadays a regulatory framework regarding the pollutant emissions abatement, both at international
and local level, significantly interests the maritime sector. To comply with the latest environmental
rules, a new approach to ship design and a renewed way to operate the ship are need both in
navigation and in harbour. This PhD Thesis aims to investigate on the positive features offered by the
LNG fuel, more eco-friendly than the traditional marine fuel oils. In the first part of the research, the
performance comparison between two marine engines, fuelled by natural gas and diesel oil
respectively is reported. Two different simulation codes, one for each engine, validated by means of
geometrical and performance data provided by the manufacturer have been developed to extend the
comparison to the whole working area of the examined engines. In the second part of the research, a
LNG-repowering study of a cruise ferry is presented. The study is enhanced by the investigation on
possible Waste Heat Recovery (WHR) systems aiming at the reduction of Green House Gas (GHG),
pollution, and money saving. A computational code has been developed to carry out the sizing and to
analyse the energetic performance and economical aspects of the several examined WHR layout
systems. The more eco-friendly layout for the considered ship is proposed to comply with in force
rules. The third part of the PhD Thesis is focused on studying some maritime technical solutions for
the electric energy generation and delivery to ships moored in port, by means of LNG fuelled
generators installed on board a floating unit. Two different scenarios, regarding the LNG supply
chain, are considered and some options for producing cleaner electric energy are then investigated.
The reference area examined in this study is the old port of Genoa, where the traffic of both
passenger and cargo ships takes place. The analysis is carried out by means of a MATLAB numerical
code to calculate the most important features of the floating unit, as dimensions and weights and the
most significant characteristics of the electric generation equipment, as the average load factor, fuel
consumption and energy cost. From an economical point of view, the externalities costs abatement,
thanks to the technical solution proposed are investigated. The study also focuses on the estimation of
governmental incentives to promote and sustain the use of the proposed power supply barge, resulting
into a fully positive technical solution
Unpublished Islamic Bronze Cauldrons from Private Collections: Two Early and One Very Late Specimens
Islamic Metalwork From Afghanistan (9th-13th Century): The Documentation of the IsMEO Italian Archaeological Mission
[Italiano]:Il volume presenta le collezioni metallistiche documentate dalla Missione Archeologica Italiana IsMEO in Afghanistan (1957-1978), ad oggi ancora largamente inedite e purtroppo quasi del tutto scomparse. I circa 439 manufatti e frammenti, ascrivibili all’arco cronologico tra il IX e il XIII secolo, attestano una produzione ricca e variegata che merita di contributire alla discussione accademica sulla metallistica islamica medievale. Lo studio propone un catalogo articolato in 14 classi funzionali e un’analisi morfologica, decorativa ed epigrafica dei manufatti. Inoltre, l’analisi dei reperti emersi dagli scavi di Ghazni e di quelli presumibilmente provenienti dallo stesso sito conferma il ruolo della città quale importante centro produttivo
./[English]: The volume presents the Islamic metalwork collections documented by the IsMEO Italian Archaeological Mission in Afghanistan (1957-1978), largely still unpublished today and sadly lost for the majority. The approximately 439 artefacts and fragments, datable to the chronological range between the 9th and 13th century, attest to a rich and varied production that deserves to be part of the scholarly discussion on Islamic medieval metalwork. The study offers a catalogue organised in 14 functional classes as well as a morphological, decorative and epigraphic analysis of the artefacts. Moreover, the analysis of the finds emerged from the excavations in Ghazni and those allegedely coming from the same site confirms the role played by the city as an important production centre
Artistic syncretism between East and West in the roundels on the right door leaf of Bohemond I's mausoleum in Canosa (early 12th century)
Among the several examples of Islamic influences on the medieval art
and architecture of the southern Italy, the mausoleum of Bohemond I in
Canosa (Apulia) stands out for importance. Numerous studies have been
devoted to this monument, and in particular to its famous bronze door,
but still no attention has been paid to the decoration of its right leaf. A
mixture of Islamic and Byzantine elements can be found in its decorative
roundels, which betray the syncretic influences that built up the artistic
background of Bohemond I himself
Some Newly Discovered Islamic Buckets from Ghazni (Afghanistan)
In 2012 an unexpected discovery occurred in Ghazni, where many Islamic buckets were retrieved fortuitously at the feet of the citadel. Only sixteen of them are nowadays preserved in the Kabul National Museum. These new artefacts come as a chance to complete our knowledge of the metalwork production from medieval Afghanistan
Relação entre terceiros molares inferiores e nervo alveolar inferior (NAI): revisão de literatura
Exodontias de terceiros molares são procedimentos comuns realizados por médicos dentistas, e apesar de rotineiro podem causar transtornos ou complicações trans e/ou pós operatórias. Vários fatores estão ligados à s possÃveis complicações, como idade e o grau de impactação do dente, em casos de terceiros molares inferiores, a sua Ãntima relação com o nervo alveolar inferior. Existem exames imaginológicos como radiografias e tomografias computadorizadas que podem ser utilizadas no pré-operatório a fim de auxiliar o medico dentista a estabelecer a relação entre essas estruturas, evitando futuros transtornos como a parestesia. Algumas técnicas cirúrgicas vêm sendo discutidas como métodos alternativos em casos onde há a hipótese de lesão do nervo. Este trabalho realiza uma revisão de literatura sobre o tema terceiros molares inferiores e suas relações com o nervo alveolar inferior, a fim de relacionar os riscos cirúrgicos com posicionamento do terceiro molar associando exames complementares com técnicas cirúrgicas, com o fim de prever possÃveis complicações.Third molars extraction are common procedures performed by dentists, and despite frequency , it may cause trans and / or postoperative complications. Several factors are related to the possible complications, such as age and degree of impactation of the tooth, in cases of lower third molars, its intima relationship with the inferior alveolar nerve. There are imaging examinations such as x-rays and CT scans that can be used preoperatively to assist the dentist to establish the relationship between these structures, avoiding future disorders such as paresthesia. Some surgical techniques have been discussed as alternative methods in cases where there is a hypothesis of nerve damage. This paper presents a review of the literature on the third lower molar theme and its relationship with the inferior alveolar nerve, in order to relate the surgical risks with third molar positioning, associating complementary exams with surgical techniques, in order to predict possible complications
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