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Topic Review
Pan-Tompkins Algorithm
The Pan-Tompkins algorithm is commonly used to detect QRS complexes in electrocardiographic signals (ECG). The QRS complex represents the ventricular depolarization and the main spike visible in an ECG signal (see figure). This feature makes it particularly suitable for measuring heart rate, the first way to assess the heart health state. In the first derivation of Einthoven of a physiological heart, the QRS complex is composed by a downward deflection (Q wave), an high upward deflection (R wave) and a final downward deflection (S wave). The Pan-Tompkins algorithm applies a series of filters to highlight the frequency content of this rapid heart depolarization and removes the background noise. Then, it squares the signal to amplify the QRS contribute. Finally, it applies adaptive thresholds to detect the peaks of the filtered signal. The algorithm was proposed by Jiapu Pan and Willis J. Tompkins in 1985, in the journal IEEE Transactions on Biomedical Engineering . The performance of the method was tested on an annotated arrhythmia database (MIT/BIH) and evaluated also in presence of noise. Pan and Tompkins reported that the 99.3 percent of QRS complexes was correctly detected.
  • 6.6K
  • 24 Oct 2022
Topic Review
Advantages and Disadvantages of Hydrogen Trains
Hydrogen and electric drives used in various means of transport is a leading topic in many respects.
  • 6.6K
  • 20 Jun 2025
Topic Review
Yao's Millionaires' Problem
Yao's Millionaires' problem is a secure multi-party computation problem which was introduced in 1982 by computer scientist and computational theorist Andrew Yao. The problem discusses two millionaires, Alice and Bob, who are interested in knowing which of them is richer without revealing their actual wealth. This problem is analogous to a more general problem where there are two numbers [math]\displaystyle{ a }[/math] and [math]\displaystyle{ b }[/math] and the goal is to determine whether the inequality [math]\displaystyle{ a \geq b }[/math] is true or false without revealing the actual values of [math]\displaystyle{ a }[/math] and [math]\displaystyle{ b }[/math]. The Millionaires' Problem is an important problem in cryptography, the solution of which is used in e-commerce and data mining. Commercial applications sometimes have to compare numbers which are confidential and whose security is important. Many solutions have been introduced for the problem, among which the first solution, presented by Yao himself, was exponential in time and space.
  • 6.6K
  • 15 Nov 2022
Topic Review
Cardiff
Cardiff (/ˈkɑːrdɪf/ (listen); Welsh: Caerdydd [kairˈdiːð, kɑːɨrˈdɨːð] (listen)) is the capital of Wales, and its largest city. The eleventh-largest city in the United Kingdom , it is Wales's chief commercial centre, the base for most national cultural institutions and Welsh media, and the seat of the National Assembly for Wales. The unitary authority area's 2017 population was estimated to be 362,756. Cardiff is a significant tourist centre and the most popular visitor destination in Wales with 21.3 million visitors in 2017. In 2011, Cardiff was ranked sixth in the world in National Geographic's alternative tourist destinations. Cardiff is the county town of the historic county of Glamorgan (and later South Glamorgan). Cardiff is part of the Eurocities network of the largest European cities. A small town until the early 19th century, its prominence as a major port for the transport of coal following the arrival of industry in the region contributed to its rise as a major city. The Cardiff Built-up Area covers a slightly larger area outside the county boundary and includes the towns of Dinas Powys and Penarth. In 1905, Cardiff was made a city and proclaimed the capital of Wales in 1955. Since the 1980s, Cardiff has seen significant development. A new waterfront area at Cardiff Bay contains the Senedd building, home to the Welsh Assembly and the Wales Millennium Centre arts complex. Current developments include the continuation of the redevelopment of the Cardiff Bay and city centre areas with projects such as the Cardiff International Sports Village, a BBC drama village, and a new business district in the city centre. Sporting venues in the city include the Principality Stadium—the national stadium and the home of the Wales national rugby union team—Sophia Gardens (the home of Glamorgan County Cricket Club), Cardiff City Stadium (the home of Cardiff City football team and the Wales football team), Cardiff International Sports Stadium (the home of Cardiff Amateur Athletic Club), Cardiff Arms Park (the home of Cardiff Blues and Cardiff RFC rugby union teams) and Ice Arena Wales (the home of Cardiff Devils ice hockey team). The city hosted the 1958 British Empire and Commonwealth Games. The city was awarded the title of European City of Sport twice, due to its role in hosting major international sporting events: first in 2009 and again in 2014. The Principality Stadium hosted 11 football matches as part of the 2012 Summer Olympics, including the games' opening event and the men's bronze medal match.
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  • 18 Oct 2022
Biography
William Boeing
William Edward Boeing (/ˈboʊɪŋ/; October 1, 1881 – September 28, 1956) was an United States aviation pioneer who founded The Boeing Company in 1916. Boeing was born in Detroit, Michigan to Marie M. Ortmann, from Vienna, Austria, and Wilhelm Böing (1846–1890) from Hagen-Hohenlimburg, Germany.[1] From a successful family, Wilhelm Böing emigrated to the United States in 1868 and initia
  • 6.6K
  • 05 Dec 2022
Topic Review
Innovative Technologies for Polyphenol Oxidase Inactivation
Polyphenol oxidase (PPO) catalyses the browning reaction during fruit processing and storage. It is considered a threat to clean labels and minimally processed fruit products. Unwanted changes in fruits’ appearance and quality represent a cost to the industry. High pressure and ultrasound, in addition to thermal treatment, are effective in reducing PPO activity and producing high-quality products. PPO from different fruit cultivars behaves differently when submitted to different treatments.
  • 6.6K
  • 24 Mar 2022
Topic Review
Early Flood Warning System
The early-warning model for flash floods is based on a hydrological and geomorphological concept connected to the river basin, with the principle that flash floods will only occur where there is a high potential risk and when rainfall exceeds the threshold. In the model used to build flash-floods risk maps, the parameters of the basin are analyzed and evaluated and the weight is determined using Thomas Saaty’s analytic hierarchy process (AHP). The flash-floods early-warning software is built using open source programming tools. With the spatial module and online processing, a predicted precipitation of one to six days in advance for iMETOS (AgriMedia—Vietnam) automatic meteorological stations is interpolated and then processed with the potential risk maps (iMETOS is a weather-environment monitoring system comprising a wide range of equipment and an online platform and can be used in various fields such as agriculture, tourism and services). The results determine the locations of flash floods at several risk levels corresponding to the predicted rainfall values at the meteorological stations. The system was constructed and applied to flash floods disaster early warning for Thuan Chau in Son La province when the rainfall exceeded the 150 mm/d threshold. The system initially supported positive decision-making to prevent and minimize damage caused by flash floods.
  • 6.6K
  • 27 Jan 2022
Topic Review
Energy Resources in Algeria
Algeria is a wealthy country with natural resources, namely, nuclear, renewable, and non-renewable sources. The non-renewable energy sources are considered the lion’s share for energy production (98%). Algeria’s efforts to ensure and strengthen its energy security will take an important step in the coming decades by commissioning new energy infrastructure based on intensive use of water, coal, nuclear, non-renewable, and renewable sources.
  • 6.6K
  • 06 Jul 2022
Topic Review
Chemical Extraction of Chitosan from Shrimp Shells
The extraction of chitin and chitosan from raw shrimp wastes through three major processes: demineralization, deproteinization, and deacetylation. Chitin can be recovered from shrimp shells by removing minerals and proteins under diluted acidic and alkaline treatment, followed by a concentrated alkaline treatment to remove acetyl groups and obtain chitosan.
  • 6.5K
  • 01 Nov 2022
Topic Review
Sine
In mathematics, the sine is a trigonometric function of an angle. The sine of an acute angle is defined in the context of a right triangle: for the specified angle, it is the ratio of the length of the side that is opposite that angle, to the length of the longest side of the triangle (the hypotenuse). For an angle [math]\displaystyle{ x }[/math], the sine function is denoted simply as [math]\displaystyle{ \sin x }[/math]. More generally, the definition of sine (and other trigonometric functions) can be extended to any real value in terms of the length of a certain line segment in a unit circle. More modern definitions express the sine as an infinite series, or as the solution of certain differential equations, allowing their extension to arbitrary positive and negative values and even to complex numbers. The sine function is commonly used to model periodic phenomena such as sound and light waves, the position and velocity of harmonic oscillators, sunlight intensity and day length, and average temperature variations throughout the year. The function sine can be traced to the jyā and koṭi-jyā functions used in Gupta period Indian astronomy (Aryabhatiya, Surya Siddhanta), via translation from Sanskrit to Arabic, and then from Arabic to Latin. The word "sine" (Latin "sinus") comes from a Latin mistranslation by Robert of Chester of the Arabic jiba, which is a transliteration of the Sanskrit word for half the chord, jya-ardha.
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  • 11 Oct 2022
Topic Review
Composite Structures
Common types of engineering materials include metals, polymers, ceramics, and composites. Among these, composite materials are often a better alternative for traditional materials, such as metals, ceramics, and polymers due to their light weight, corrosion resistance, high strength and stiffness, ability to withstand high temperatures, and simple manufacturing process. Composite structures are used in a range of different industries from aerospace, marine, aviation, transport, and sports/leisure to civil engineering. For example, advanced composite materials have been used in different structures regarding the above industries, such as rotor blades, aircraft main body, and wing skins.
  • 6.5K
  • 28 Mar 2022
Topic Review
Moral Insanity
Moral insanity referred to a type of mental disorder consisting of abnormal emotions and behaviours in the apparent absence of intellectual impairments, delusions, or hallucinations. It was an accepted diagnosis in Europe and America through the second half of the 19th century. The physician James Cowles Prichard first used the phrase to describe a mental disorder in 1835 in his Treatise on insanity and other disorders affecting the mind. He defined moral insanity as: "madness consisting in a morbid perversion of the natural feelings, affections, inclinations, temper, habits, moral dispositions, and natural impulses, without any remarkable disorder or defect of the interest or knowing and reasoning faculties, and particularly without any insane illusion or hallucinations." The concept of moral insanity was indebted to the work of physician Philippe Pinel, which was acknowledged by Prichard. Pinel had described mental diseases of only partial, affective, insanity. His concept Manie sans délire (Latin – mania sine delirio; French – folie raisonnante or folie lucide raisonnante, monomanie affective; German – Moralisches Irresein) referred to insanity without delusion. That is, the sufferer was thought to be mad in one area only and thus the personality of the individual might be distorted but his or her intellectual faculties were unimpaired. The term 'moral', at that time and taken originally from French, could mean emotional rather than necessarily referring to ethics.
  • 6.5K
  • 28 Oct 2022
Topic Review
Bodhi
The English term enlightenment is the western translation of the abstract noun bodhi, (/ˈboʊdi/; Sanskrit: बोधि; Pali: bodhi), the knowledge or wisdom, or awakened intellect, of a Buddha. The verbal root budh- means "to awaken," and its literal meaning is closer to "awakening." Although the term buddhi is also used in other Indian philosophies and traditions, its most common usage is in the context of Buddhism. The term "enlightenment" was popularised in the Western world through the 19th century translations of Max Müller. It has the western connotation of general insight into transcendental truth or reality. The term is also being used to translate several other Buddhist terms and concepts, which are used to denote (initial) insight (prajna (Sanskrit), wu (Chinese), kensho and satori(Japanese)); knowledge (vidhya); the "blowing out" (Nirvana) of disturbing emotions and desires and the subsequent freedom or release (vimukti); and the attainment of supreme Buddhahood (samyak sam bodhi), as exemplified by Gautama Buddha. What exactly constituted the Buddha's awakening is unknown. It may probably have involved the knowledge that liberation was attained by the combination of mindfulness and dhyāna, applied to the understanding of the arising and ceasing of craving. The relation between dhyana and insight is a core problem in the study of Buddhism, and is one of the fundamentals of Buddhist practice. In the western world the concept of (spiritual) enlightenment has taken on a romantic meaning. It has become synonymous with self-realization and the true self and false self, being regarded as a substantial essence being covered over by social conditioning.
  • 6.5K
  • 22 Nov 2022
Topic Review
Artificial Island
An artificial island or man-made island is an island that has been constructed by people rather than formed by natural means. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure, to those that support entire communities and cities. Early artificial islands included floating structures in still waters, or wooden or megalithic structures erected in shallow waters (e.g. crannógs and Nan Madol discussed below). In modern times artificial islands are usually formed by land reclamation, but some are formed by the incidental isolation of an existing piece of land during canal construction (e.g. Donauinsel, Ko Kret, and much of Door County), or flooding of valleys resulting in the tops of former knolls getting isolated by water (e.g. Barro Colorado Island). One of the world's largest artificial islands, René-Levasseur Island, was formed by the flooding of two adjacent reservoirs.
  • 6.5K
  • 11 Oct 2022
Topic Review
Honda Ridgeline (2006–2014)
{{Infobox automobile | name = Honda Ridgeline (YK1) | image = 2012 Honda Ridgeline Mexican RTL.jpg | caption = 2012 Honda Ridgeline RTL (Mexico) | production = Late 2004 – early 2015 | model_years = 2006–2014 | assembly = Alliston, Ontario, Canada (HCM) (2004–2009)Lincoln, Alabama, United States (HMA) (2008–2015) | body_style = 4-door pickup | layout = Front-engine, four-wheel drive | class = Mid-size pickup truck | related = | engine = 3.5 L J35A9 V6 (2006–2008)3.5 L J35Z5 V6 (2009–2014) | transmission = H5 BJFA 5-speed automatic | wheelbase = 122 in (3,099 mm) | length = 2006–2008: 206.8 in (5,253 mm)2009–2011: 207 in (5,258 mm)2012–2014: 206.9 in (5,255 mm) | width = 77.8 in (1,976 mm) | height = 70.3 in (1,786 mm)2012–2014 RTL: 71.2 in (1,808 mm) | weight = 2006–2008: 4,491–4,552 lb (2,037–2,065 kg)2009–2011: 4,504–4,564 lb (2,043–2,070 kg)2012–2014: 4,491–4,575 lb (2,037–2,075 kg) | successor = Honda Ridgeline (second generation) | manufacturer = Honda Contrary to some media reporting, Honda's publications state that the first generation Ridgeline was a uniquely engineered vehicle with only 7% of its components shared with other Honda vehicles. Its powertrain resembled the one used in the first generation Acura MDX but was "extensively calibrated and strengthened" for heavier hauling and towing duties. The first generation Ridgeline went on sale in March 2005 as a 2006 model year vehicle. Production of the first generation Ridgeline ended in early 2015. According to Honda, the Ridgeline was not designed to steal sales from the more traditional trucks sold in North America, but was developed to "give the 18% of Honda owners who also own pickups a chance to make their garages a Honda-only parking area." Despite the first generation Ridgeline's poor sales, according to the author of Driving Honda, this mid-size pickup was one of the more profitable vehicles for Honda with reported sales in over 20 countries.
  • 6.5K
  • 26 Oct 2022
Topic Review
Major Applications of Smart Agriculture
With the rise of new technologies, such as the Internet of Things, raising the productivity of agricultural and farming activities is critical to improving yields and cost-effectiveness. IoT, in particular, can improve the efficiency of agriculture and farming processes by eliminating human intervention through automation. The fast rise of Internet of Things (IoT)-based tools has changed nearly all life sectors, including business, agriculture, surveillance, etc. These radical developments are upending traditional agricultural practices and presenting new options in the face of various obstacles.
  • 6.5K
  • 24 Jan 2022
Topic Review
Clays and the Origin of Life
Clays are able to replicate and drive the evolution of metabolism; they have the catalytic ability to synthesize monomers (amino acids, nucleotides and so on) and polymerize them, resulting in RNA–peptide worlds in which RNA replicates (genes) and, in cooperation with coded peptides, drives the evolution of the cell. 
  • 6.5K
  • 25 Feb 2022
Topic Review
Salvia divinorum
Salvia divinorum Epling and Játiva is a psychoactive Mexican mint used for centuries by Mazatec Indian shamans or curanderos of north-eastern Oaxaca, Mexico, for divinatory and religious purposes and physical healing.
  • 6.5K
  • 18 Mar 2021
Topic Review
Battery Energy Storage Systems Ancillary Services
The battery energy storage system (BESS) is significant in providing ancillary services to the grid. The BESS plays a crucial role in facilitating the integration of renewable energy sources (RESs) into the grid by compensating for the fluctuations produced by RESs as intermittent resources. Ancillary services encompass all the services necessary for the grid operator (transmission and distribution operator) to maintain the system’s integrity, stability, and power quality. Grid operators ensure a reliable power supply, frequency, voltage, and power load within certain limits. 
  • 6.5K
  • 28 Feb 2024
Topic Review Peer Reviewed
Social, Cultural, and Economic Determinants of Well-Being
Individual well-being is influenced by a number of economic and social factors that include income, mental health, physical health, education, social relationships, employment, discrimination, government policies, and neighborhood conditions. Well-being involves both physical and mental health as part of a holistic approach to health promotion and disease prevention. The well-being of a society’s people has the potential to impact the well-being and productivity of the society as a whole. Though it may be assessed at the individual level, well-being becomes an important population outcome at the macro level and therefore represents a public health issue. 
  • 6.5K
  • 27 Jun 2022
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