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Topic Review
Applications of Unmanned Aerial Vehicles
Unmanned aerial vehicles (UAVs), also known as drones, have come in a great diversity of several applications such as military, construction, image and video mapping, medical, search and rescue, parcel delivery, hidden area exploration, oil rigs and power line monitoring, precision farming, wireless communication and aerial surveillance. The drone industry has been getting significant attention as a model of manufacturing, service and delivery convergence, introducing synergy with the coexistence of different emerging domains. 
  • 23.7K
  • 27 Jul 2022
Topic Review
Chronology of Jesus
A chronology of Jesus aims to establish a timeline for the events of the life of Jesus. Scholars have correlated Jewish and Greco-Roman documents and astronomical calendars with the New Testament accounts to estimate dates for the major events in Jesus's life. Two main approaches have been used to estimate the year of the birth of Jesus: one based on the accounts in the Gospels of his birth with reference to King Herod's reign, and the other by subtracting his stated age of "about 30 years" when he began preaching. Most scholars, on this basis, assume a date of birth between 6 and 4 BC. Three details have been used to estimate the year when Jesus began preaching: a mention of his age of "about 30 years" during "the fifteenth year" of the reign of Tiberius Caesar, another relating to the date of the building of the Temple in Jerusalem, and yet another concerning the death of John the Baptist. Hence, scholars estimate that Jesus began preaching and gathering followers around AD 28–29. According to the three synoptic gospels Jesus continued preaching for at least one year, and according to John the Evangelist for three years. Five methods have been used to estimate the date of the crucifixion of Jesus. One uses non-Christian sources such as Josephus and Tacitus. Another works backwards from the historically well-established trial of the Apostle Paul by the Roman proconsul Gallio in Corinth in AD 51/52 to estimate the date of Paul's conversion. Both methods result in AD 36 as an upper bound to the crucifixion. Thus, scholars generally agree that Jesus was crucified between AD 30 and AD 36. Isaac Newton's astronomical method calculates those ancient Passovers (always defined by a full moon) which are preceded by a Friday, as specified by all four Gospels; this leaves two potential crucifixion dates, 7 April AD 30 and 3 April AD 33. In the lunar eclipse method, the Apostle Peter's statement that the moon turned to blood at the crucifixion (Acts of the Apostles 2:14-21) is taken to refer to the lunar eclipse of 3 April AD 33; although astronomers are discussing whether the eclipse was visible as far west as Jerusalem. Recent astronomical research uses the contrast between the synoptic date of Jesus' last Passover on the one hand with John's date of the subsequent "Jewish Passover" on the other hand, to propose Jesus' Last Supper to have been on Wednesday, 1 April AD 33 and the crucifixion on Friday 3 April AD 33.
  • 23.6K
  • 09 Nov 2022
Topic Review
Inequalities in Sociology
The digital is increasingly present in everyday life, with a deep and growing social, political and economic impact, and society 5.0 is one of the possible attempts for this materialisation. However, the digital is not experienced by everyone in the same way, so this digitalisation of societies will have varied implications for individuals, namely the transformation of differences in access and digital literacy into new inequalities. Sociology – as the scientific knowledge of the reciprocal influence of interactions between individuals and the influence of the social context – will have a heuristic potential for understanding this reality. Sociology will, thus, take on, concurrently with other sciences, a relevant role concerning the subsequent development of a more balanced society in this digital dimension, increasingly important in defining the social position of the individual, and, thus, will add to a development that materialises the potential of this digital society.
  • 23.5K
  • 30 Oct 2020
Topic Review
Photo Manipulation
Photo manipulation involves transforming or altering a photograph using various methods and techniques to achieve desired results. Some photo manipulations are considered skillful artwork while others are frowned upon as unethical practices, especially when used to deceive the public. Other examples include being used for political propaganda, or to make a product or person look better, or simply for entertainment purposes or harmless pranks. Depending on the application and intent, some photo manipulations are considered an art form because it involves the creation of unique images and in some instances, signature expressions of art by photographic artists. For example, Ansel Adams employed some of the more common manipulations using darkroom exposure techniques, burning (darkening) and dodging (lightening) a photograph. Other examples of photo manipulation include retouching photographs using ink or paint, airbrushing, double exposure, piecing photos or negatives together in the darkroom, scratching instant films, or through the use of software-based manipulation tools applied to digital images. There are a number of software applications available for digital image manipulation, ranging from professional applications to very basic imaging software for casual users.
  • 23.4K
  • 24 Oct 2022
Topic Review
Parasitic Nutrition
Parasitic nutrition is a mode of heterotrophic nutrition where a parasitic organism lives on the body surface or inside the body of another type of organism (a host) and gets nutrition directly from the body of the host. Since these parasites derive nourishment from their host, this symbiotic interaction is often harmful to the host. Parasites depend on their host for survival, since the host provides nutrition and protection. As a result of this dependence, parasites have considerable modifications to optimise parasitic nutrition and therefore their survival. Parasites are divided into two groups: endoparasites and ectoparasites. Endoparasites are parasites that live inside the body of the host, whereas ectoparasites are parasites that live on the outer surface of the host and generally attach themselves during feeding. Due to the different strategies of endoparasites and ectoparasites, they require different adaptations to derive nutrients from their host. Parasites require nutrients to carry out essential functions including reproduction and growth. Essentially, the nutrients required from the host are carbohydrates, amino acids and lipids. Carbohydrates are utilised to generate energy, whilst amino acids and fatty acids are involved in the synthesis of macromolecules and the production of eggs. Most parasites are heterotrophs, so they therefore are unable to synthesise their own 'food' i.e. organic compounds and must acquire these from their host.
  • 23.4K
  • 29 Nov 2022
Topic Review
History of the Middle East
Home to the Cradle of Civilization, the Middle East (usually interchangeable with the Near East) has seen many of the world's oldest cultures and civilizations. This history started from the earliest human settlements, continuing through several major pre- and post-Islamic Empires through to the nation-states of the Middle East today. Template:Human history Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh. Mesopotamia was home to several powerful empires that came to rule almost the entire Middle East—particularly the Assyrian Empires of 1365–1076 BC and the Neo-Assyrian Empire of 911–609 BC. From the early 7th century BC and onwards, the Iranian Medes followed by Achaemenid Persia and other subsequent Iranian states empires dominated the region. In the 1st century BC, the expanding Roman Republic absorbed the whole Eastern Mediterranean, which included much of the Near East. The Eastern Roman Empire, today commonly known as the Byzantine Empire, ruling from the Balkans to the Euphrates, became increasingly defined by and dogmatic about Christianity, gradually creating religious rifts between the doctrines dictated by the establishment in Constantinople and believers in many parts of the Middle East. From the 3rd up to the course of the 7th century AD, the entire Middle East was dominated by the Byzantines and Sassanid Persia. From the 7th century, a new power was rising in the Middle East, that of Islam. The dominance of the Arabs came to a sudden end in the mid-11th century with the arrival of the Seljuq Turks. In the early 13th century, a new wave of invaders, the armies of the Mongol Empire, mainly Turkic, swept through the region. By the early 15th century, a new power had arisen in western Anatolia, the Ottoman emirs, linguistically Turkic and religiously Islamic, who in 1453 captured the Christian Byzantine capital of Constantinople and made themselves sultans. Large parts of the Middle East became a warground between the Ottomans and Iranian Safavids for centuries starting in the early 16th century. By 1700, the Ottomans had been driven out of Hungary and the balance of power along the frontier had shifted decisively in favor of the West. The British also established effective control of the Persian Gulf, and the French extended their influence into Lebanon and Syria. In 1912, the Italians seized Libya and the Dodecanese islands, just off the coast of the Ottoman heartland of Anatolia. In the late 19th and early 20th centuries, Middle Eastern rulers tried to modernize their states to compete more effectively with the European powers. A turning point in the history of the Middle East came when oil was discovered, first in Persia in 1908 and later in Saudi Arabia (in 1938) and the other Persian Gulf states, and also in Libya and Algeria. A Western dependence on Middle Eastern oil and the decline of British influence led to a growing American interest in the region. During the 1920s, 1930s, and 1940s, Syria and Egypt made moves towards independence. The British, the French, and the Soviets departed from many parts of the Middle East during and after World War II (1939–1945). The struggle between the Arabs and the Jews in Palestine culminated in the 1947 United Nations plan to partition Palestine. Later in the midst of Cold War tensions, the Arabic-speaking countries of Western Asia and Northern Africa saw the rise of pan-Arabism. The departure of the European powers from direct control of the region, the establishment of Israel, and the increasing importance of the oil industry, marked the creation of the modern Middle East. In most Middle Eastern countries, the growth of market economies was inhibited by political restrictions, corruption and cronyism, overspending on arms and prestige projects, and over-dependence on oil revenues. The wealthiest economies in the region per capita are the small oil-rich countries of Persian Gulf: Qatar, Kuwait, Bahrain, and the United Arab Emirates. A combination of factors—among them the 1967 Six-Day War, the 1970s energy crisis beginning with the 1973 OPEC oil embargo in response to U.S. support of Israel in the Yom Kippur War, the concurrent Saudi-led popularization of Salafism/Wahhabism, and the 1978-79 Iranian Revolution—promoted the increasing rise of Islamism and the ongoing Islamic revival (Tajdid). The Fall of the Soviet Union in 1991 brought a global security refocus from the Cold War to a War on Terror. Starting in the early 2010s, a revolutionary wave popularly known as the Arab Spring brought major protests, uprisings, and revolutions to several Middle Eastern and Maghreb countries. Clashes in western Iraq on 30 December 2013 were preliminary to the Sunni pan-Islamist ISIL uprising. The term Near East can be used interchangeably with Middle East, but in a different context, especially when discussing ancient times, it may have a limited meaning, namely the northern, historically Aramaic-speaking Semitic area and adjacent Anatolian territories, marked in the two maps below.
  • 23.2K
  • 27 Oct 2022
Topic Review
Northwestern European People
Northwestern European people are a pan-ethnic group, or multi-ethnic regional grouping, and the inhabitants of Northwestern Europe. Northwest or Northwestern Europeans can usually trace back full or partial heritage to Great Britain and Ireland, Northern Germany, Denmark , Sweden, Norway , the Netherlands, Northern France, Belgium, and other places connected to Northwestern Europe geographically or culturally. As the pan-ethnic group is also a cultural category, rather than exclusively geographical; it often can include peoples with ancestry from bordering regions such as Austria, Finland , Southern Germany, and Switzerland . There is a large Northwestern European diaspora, with significant numbers within North America (Northwestern European Americans and Northwestern European Canadians), and Northwestern European Australians in Oceania. Other subgroupings of Europeans include Eastern European people and Southern European people.
  • 23.1K
  • 28 Oct 2022
Topic Review
Grid Reference System
A grid reference system, also known as grid reference or grid system, is a geographic coordinate system that defines locations in maps using Cartesian coordinates based on a particular map projection. Grid lines on maps illustrate the underlying coordinate system. Such coordinate lines are numbered to provide a unique reference to each location on the map. Grid coordinates are normally eastings and northings.
  • 23.1K
  • 25 Oct 2022
Topic Review
List of Current Monarchies
This is a list of current monarchies. (As of 2019), there are 44 sovereign states in the world with a monarch as Head of state. 13 in Asia, 12 in Europe, 10 in North America, 6 in Oceania and 3 in Africa.
  • 23.0K
  • 28 Oct 2022
Topic Review Video
Modular Multilevel Converters
A modular multilevel converter (MMC) is an advanced voltage source converter applicable to a wide range of medium and high-voltage applications. It has competitive advantages such as quality output performance, high modularity, simple scalability, and low voltage and current rating demand for the power switches. The generalized configuration of a three-phase MMC is comprised of a DC terminal, an AC terminal, and a converting kernel involving three phase legs. Each leg/phase has two symmetric arms referred to as the upper arm and lower arm. The upper arm and lower arm contain a group of identical submodules connected in series together with a chock inductor to suppress high-frequency components in the arm current.  The research interests of MMCs are primarily associated with the topologies, mathematical modeling, output voltage and current control, submodule balancing control, circulating current control, and modulation methods. And the incorporation of wideband gap (WBG) semiconductors are prospected to facilitate the MMC application with further advantages of high-voltage and high-power operations, low power losses, high efficiency, improved reliability, and reduced module size and cooling system.
  • 22.8K
  • 18 Aug 2021
Topic Review
Chemtrail Conspiracy Theory
The chemtrail conspiracy theory posits the erroneous belief that long-lasting condensation trails are "chemtrails" consisting of chemical or biological agents left in the sky by high-flying aircraft, sprayed for nefarious purposes undisclosed to the general public. Believers in this conspiracy theory say that while normal contrails dissipate relatively quickly, contrails that linger must contain additional substances. Those who subscribe to the theory speculate that the purpose of the chemical release may be solar radiation management, weather modification, psychological manipulation, human population control, biological or chemical warfare, or testing of biological or chemical agents on a population, and that the trails are causing respiratory illnesses and other health problems. The claim has been dismissed by the scientific community. There is no evidence that purported chemtrails differ from normal water-based contrails routinely left by high-flying aircraft under certain atmospheric conditions. Although proponents have tried to prove that chemical spraying occurs, their analyses have been flawed or based on misconceptions. Because of the persistence of the conspiracy theory and questions about government involvement, scientists and government agencies around the world have repeatedly explained that the supposed chemtrails are in fact normal contrails. The term chemtrail is a portmanteau of the words chemical and trail, just as contrail is a portmanteau of condensation and trail.
  • 22.7K
  • 31 Oct 2022
Topic Review
The Shaping of Social Media Algorithms on User Behavior
Social media has thus become an integral part of daily life for over two billion people all over the world. Social media apps such as Facebook, Instagram, and TikTok remain at the center of our interactions, information, entertainment, and connections. This widespread adoption is strongly attributed to content curation and delivery through complex algorithms that lie beneath the surface of each platform. These algorithms decide the content users are exposed to and self-learn from the interactions of the users on large volumes of data. Such a system of personalization has transformed how users engage with these platforms and facilitated the growth of social media platforms. However, the impact of these algorithms has only started to unveil how deeply they influence society. We must enhance this knowledge to fully appreciate the role of social media in society. This covers how algorithms inform users’ information diet, interaction patterns, purchase choices and even well-being.
  • 22.5K
  • 31 Oct 2024
Topic Review
Sensors for Health Monitoring
The use of wearable equipment and sensing devices to monitor physical activities, whether for well-being, sports monitoring, or medical rehabilitation, has expanded rapidly due to the evolution of sensing techniques, cheaper integrated circuits, and the development of connectivity technologies. In this scenario, this paper presents a state-of-the-art review of sensors and systems for rehabilitation and health monitoring. Although we know the increasing importance of data processing techniques, our focus was on analyzing the implementation of sensors and biomedical applications. Although many themes overlap, we organized this review based on three groups: Sensors in Healthcare, Home Medical Assistance, and Continuous Health Monitoring; Systems and Sensors in Physical Rehabilitation; and Assistive Systems.
  • 22.5K
  • 19 Feb 2021
Topic Review
Gompertz Function with R
The Gompertz function is a sigmoid curve being a special case of a logistic curve. Although it was originally designed to describe mortality, it is now used in biology. For example, it is useful to describe many  phenomena such as the growth of a cancerous tumor confined to an organ without metastasis, the growth of the number of individuals in a population, e.g. prey in a Volterra-Lotka model, the germination of seeds, etc. It also models as the logistic function the growth of a colony of bacteria or in an epidemic the spread of the number of infected people. However, despite its many applications, in many cases the fitting of experimental data to the Gompertz function is not always straightforward. In this article we present a protocol that will be useful when performing the data regression to this curve using the statistical package R.
  • 22.3K
  • 07 Apr 2021
Topic Review
Digital Journalism
Digital journalism also known as online journalism is a contemporary form of journalism where editorial content is distributed via the Internet as opposed to publishing via print or broadcast. What constitutes 'digital journalism' is debated by scholars. However the primary product of journalism, which is news and features on current affairs, is presented solely or in combination as text, audio, video, or some interactive forms like newsgames, and disseminated through digital media technology. Fewer barriers to entry, lowered distribution costs, and diverse computer networking technologies have led to the widespread practice of digital journalism. It has democratized the flow of information that was previously controlled by traditional media including newspapers, magazines, radio, and television. Some have asserted that a greater degree of creativity can be exercised with digital journalism when compared to traditional journalism and traditional media. The digital aspect may be central to the journalistic message and remains, to some extent, within the creative control of the writer, editor, and/or publisher.
  • 22.1K
  • 02 Dec 2022
Topic Review
Online Shopping
Online shopping is a form of electronic commerce which allows consumers to directly buy goods or services from a seller over the Internet using a web browser. Consumers find a product of interest by visiting the website of the retailer directly or by searching among alternative vendors using a shopping search engine, which displays the same product's availability and pricing at different e-retailers. As of 2016, customers can shop online using a range of different computers and devices, including desktop computers, laptops, tablet computers and smartphones. An online shop evokes the physical analogy of buying products or services at a regular "bricks-and-mortar" retailer or shopping center; the process is called business-to-consumer (B2C) online shopping. When an online store is set up to enable businesses to buy from another businesses, the process is called business-to-business (B2B) online shopping. A typical online store enables the customer to browse the firm's range of products and services, view photos or images of the products, along with information about the product specifications, features and prices. Online stores typically enable shoppers to use "search" features to find specific models, brands or items. Online customers must have access to the Internet and a valid method of payment in order to complete a transaction, such as a credit card, an Interac-enabled debit card, or a service such as PayPal. For physical products (e.g., paperback books or clothes), the e-tailer ships the products to the customer; for digital products, such as digital audio files of songs or software, the e-tailer typically sends the file to the customer over the Internet. The largest of these online retailing corporations are Alibaba, Amazon.com, and eBay.
  • 21.8K
  • 12 Oct 2022
Topic Review
Structure and Properties of Gelatin
Gelatin is a natural biopolymer that is intrinsically biocompatible and biodegradable, has low immunogenicity, and is classified as Generally Recognized as Safe (GRAS) by the United States Food and Drug Administration (FDA). It consists of an amphoteric polymer that is derived from collagen by alkaline-, acid-, or heat-based hydrolysis.
  • 21.7K
  • 24 May 2023
Topic Review
Corporate Social Responsibility in the Banking Sector
The concept of corporate social responsibility (CSR) extends the responsibility of companies beyond the interest of their owners to other stakeholder groups (including employees, customers, regulators, and community), highlighting the necessity to internalize the impact of business activities on the natural environment and the society. CSR is inevitably becoming an increasingly important part of almost every business. This is particularly true for the banking industry, which suffered substantial losses in reputation and public trust in the aftermath of the global financial crisis. Not surprisingly therefore, banks around the world have visibly intensified their CSR efforts.
  • 21.7K
  • 17 Nov 2021
Topic Review
Close Quarters Combat
Close quarters combat (CQC) is a tactical concept that involves physical confrontation between several combatants. It can take place between military units, police/corrections and criminals, and other similar scenarios. In warfare, it usually consists of small units or teams engaging the enemy with personal weapons at very short range, up to 100 meters, from proximity hand-to-hand combat to close-quarter target negotiation with short-range firearms. In the typical close quarters combat scenario, the attackers try a very fast, violent takeover of a vehicle or structure controlled by the defenders, who usually have no easy way to withdraw. Because enemies, hostages/civilians, and fellow operators can be closely intermingled, close quarters combat demands a rapid assault and a precise application of lethal force. The operators need great proficiency with their weapons, and the ability to make split-second decisions in order to minimize accidental casualties. Criminals sometimes use close quarters combat techniques, such as in an armed robbery or jailbreak, but most of the terminology comes from training used to prepare soldiers, police/corrections, and other authorities. Therefore, much material relating to close quarters combat is written from the perspective of the authorities who must break into the stronghold where the opposing force has barricaded itself. Typical examples would be commando operations behind enemy lines and hostage rescues. Although there is considerable overlap, close quarters combat is not synonymous with urban warfare, now sometimes known by the military acronyms MOUT (military operations in urban terrain), FIBUA (fighting in built-up areas) or OBUA (Operations in Built Up Areas) in the West. Urban warfare is a much larger field, including logistics and the role of crew-served weapons like heavy machine guns, mortars, and mounted grenade launchers, as well as artillery, armor, and air support. In close quarters combat, the emphasis is on small infantry units using light, compact weapons that one person can carry and use easily in tight spaces, such as carbines, submachine guns, shotguns, pistols, knives, and bayonets. As such, close quarters combat is a tactical concept that forms a part of the strategic concept of urban warfare, but not every instance of close quarters combat is necessarily urban warfare—for example, a jungle is potentially a stage for close quarters combat.
  • 21.7K
  • 22 Nov 2022
Topic Review
MP3 Player
An MP3 player is an electronic device that can play MP3 digital audio files. It is a type of digital audio player (DAP), or portable media player. Most players play more than the MP3 file format, such as Windows Media Audio (WMA), Advanced Audio Coding (AAC), Vorbis, FLAC, Speex and Ogg.
  • 21.6K
  • 19 Oct 2022
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