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Topic Review
Abrasive Water-Jet Machining
Abrasive water jet machining (AWJM) is a very useful non-conventional machining for the cutting of dissimilar materials at once. It is a flexible process that generates low thermal damage to the machined surface as there is no continuous tool-material con- tact along the machining process. Compared to conventional processes such as milling, abrasive particles are used in water jet machining. These particles have cutting edges that allow the machining of the material by overlapping of small impacts that deform the material. At each instant, a quantity of abrasive particles travels in the water jet in order to perform the cut.
  • 10.7K
  • 24 Feb 2021
Topic Review
Data Envelopment Analysis (DEA)
Data Envelopment Analysis (DEA) is a non-parametric methodology for measuring the efficiency of Decision Making Units (DMUs) using multiple inputs to outputs configurations. This is the most commonly used tool for frontier estimations in assessments of productivity and efficiency applied to all fields of economic activities.
  • 10.7K
  • 28 Jan 2022
Topic Review
VANETs
A Vehicular Ad-hoc Network (VANET) comprises a group of moving or stationary vehicles connected by a wireless network. VANETs play a vital role in providing safety and comfort to drivers in vehicular environments. They provide smart traffic control and real-time information, event allocation.           
  • 10.7K
  • 16 Apr 2021
Topic Review
Subject–Verb–Object
In linguistic typology, subject–verb–object (SVO) is a sentence structure where the subject comes first, the verb second, and the object third. Languages may be classified according to the dominant sequence of these elements in unmarked sentences (i.e., sentences in which an unusual word order is not used for emphasis). English is included in this group. An example is "Sam ate oranges." The label often includes ergative languages that do not have subjects, but have an agent–verb–object (AVO) order. SVO is the second-most common order by number of known languages, after SOV. Together, SVO and SOV account for more than 75% of the world's languages. It is also the most common order developed in Creole languages, suggesting that it may be somehow more initially "obvious" to human psychology. Languages regarded as SVO include: All Bantu languages, Albanian, Arabic dialects, Assyrian, Bosnian, Bulgarian,[a 1] Chinese, English, Estonian, Finnish (but see below), French, Greek, Hausa, Icelandic (with the V2 restriction), Igbo, Italian, Javanese, Khmer, Latvian, Macedonian, Malay (Indonesian, Malaysian), Modern Hebrew, Norwegian (with the V2 restriction), Polish, Portuguese, Quiché, Reo Rapa, Romanian, Russian (but see below), Slovene, Spanish, Swedish (with the V2 restriction), Thai and Lao, Ukrainian (but see below), Vietnamese and Yoruba. Ancient Greek has free syntactic order, though Classical Greeks tended to favor SOV. Many famous phrases are SVO, however.
  • 10.7K
  • 29 Nov 2022
Topic Review
Fuel Economy in Aircraft
The fuel economy in aircraft is the measure of the transport energy efficiency of aircraft. Efficiency is increased with better aerodynamics and by reducing weight, and with improved engine BSFC and propulsive efficiency or TSFC. Endurance and range can be maximized with the optimum airspeed, and economy is better at optimum altitudes, usually higher. An airline efficiency depends on its fleet fuel burn, seating density, air cargo and passenger load factor, while operational procedures like maintenance and routing can save fuel. Average fuel burn of new aircraft fell 45% from 1968 to 2014, a compounded annual reduction 1.3% with a variable reduction rate. In 2018, CO₂ emissions totalled 747 million tonnes for passenger transport, for 8.5 trillion revenue passenger kilometres (RPK), giving an average of 88 gram CO₂ per RPK. A 88 gCO₂/km represents 28 g of fuel per km, or a 3.5 L/100 km (67 mpg‑US) fuel consumption. New technology can reduce engine fuel consumption, like higher pressure and bypass ratios, geared turbofans, open rotors, hybrid electric or fully electric propulsion; and airframe efficiency with retrofits, better materials and systems and advanced aerodynamics.
  • 10.6K
  • 01 Nov 2022
Topic Review
Philippine Hokkien
Philippine Hokkien (Chinese: 咱儂話; Pe̍h-ōe-jī: Lán-lâng-ōe; literally: 'our people's language'), is the variant of Hokkien as spoken by about 98.7% of the ethnic Chinese population of the Philippines. A mixed version that involves this language with Tagalog and English is Hokaglish.
  • 10.6K
  • 06 Oct 2022
Topic Review
World Index of Moral Freedom
{{Multiple issues| The World Index of Moral Freedom is sponsored and published by the Foundation for the Advancement of Liberty, a libertarian think tank based in Madrid, Spain . The Index is an international index ranking one hundred and sixty countries on their performance on five categories of indicators: The WIMF's first edition was published on 2 April 2016, co-authored by Foundation researchers Andreas Kohl and Juan Pina. A second edition was published by the same foundation in July 2018, this time authored by Juan Pina and Emma Watson.
  • 10.5K
  • 29 Sep 2022
Topic Review
Mobile Technology in Tourism
The influence of mobile technology on tourism is very significant. With the support of mobile-related devices (smartphones, glasses, or other wearable devices), technology, data and services, multiple travel concepts, and travel modes including mobile tourism, smart tourism, e-tourism, and sustainable tourism have emerged or developed further. Mobile technology is touted as the next technology wave that can fundamentally change tourism and hotels. Moreover, mobile technology is playing an increasing role in the travel experience, and increasing travel research is concentrated in this field. Research findings show that, first, the research of mobile technology in tourism can be divided into three phases and to a certain extent is synchronized with the development of mobile technology. Second, in the area of social sciences, the research of mobile technology in tourism needs further exploration, which must refer to related research in the areas of Transportation and IT to expand the perspective of research. Top journal analysis, journal co-citation analysis, author co-citation analysis, and collaboration network analysis reveal the most representative journals, authors, institutions, and countries/regions in this research field. This finding provides a valuable reference for scholars in this field. Additionally, this research also grasped the hot and cutting-edge topics in this field through the analysis of keywords in this field. Finally, the clustering of co-citation references presents the knowledge base of mobile technology research in the tourism field: mobile technology, travel mode, mobile instrument, travel behavior research, mobile applications, and geo-based technology.
  • 10.5K
  • 28 Sep 2020
Topic Review
Astronomy in the Medieval Islamic World
Islamic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age (9th–13th centuries), and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and later in the Far East and India. It closely parallels the genesis of other Islamic sciences in its assimilation of foreign material and the amalgamation of the disparate elements of that material to create a science with Islamic characteristics. These included Greek, Sassanid, and Indian works in particular, which were translated and built upon. Islamic astronomy played a significant role in the revival of Byzantine and European astronomy following the loss of knowledge during the early medieval period, notably with the production of Latin translations of Arabic works during the 12th century. Islamic astronomy also had an influence on Chinese astronomy and Malian astronomy. A significant number of stars in the sky, such as Aldebaran, Altair and Deneb, and astronomical terms such as alidade, azimuth, and nadir, are still referred to by their Arabic names. A large corpus of literature from Islamic astronomy remains today, numbering approximately 10,000 manuscripts scattered throughout the world, many of which have not been read or catalogued. Even so, a reasonably accurate picture of Islamic activity in the field of astronomy can be reconstructed.
  • 10.5K
  • 24 Nov 2022
Topic Review
V-twin Engine
A V-twin engine, also called a V2 engine, is a two-cylinder piston engine where the cylinders share a common crankshaft and are arranged in a V configuration. Although widely associated with motorcycles (installed either transversely or longitudinally), V-twin engines have also been used for industrial engines and in several small cars. The V-twin design dates back to the late 1880s.
  • 10.5K
  • 21 Oct 2022
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