You're using an outdated browser. Please upgrade to a modern browser for the best experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Threat (Computer)
In computer security, a threat is a potential negative action or event facilitated by a vulnerability that results in an unwanted impact to a computer system or application. A threat can be either a negative "intentional" event (i.e. hacking: an individual cracker or a criminal organization) or an "accidental" negative event (e.g. the possibility of a computer malfunctioning, or the possibility of a natural disaster event such as an earthquake, a fire, or a tornado) or otherwise a circumstance, capability, action, or event. This is differentiated from a threat actor who is an individual or group that can perform the threat action, such as exploiting a vulnerability to actualise a negative impact. A more comprehensive definition, tied to an Information assurance point of view, can be found in "Federal Information Processing Standards (FIPS) 200, Minimum Security Requirements for Federal Information and Information Systems" by NIST of United States Any circumstance or event with the potential to adversely impact organizational operations (including mission, functions, image, or reputation), organizational assets, or individuals through an information system via unauthorized access, destruction, disclosure, modification of information, and/or denial of service. Also, the potential for a threat-source to successfully exploit a particular information system vulnerability. National Information Assurance Glossary defines threat as: Any circumstance or event with the potential to adversely impact an IS through unauthorized access, destruction, disclosure, modification of data, and/or denial of service. ENISA gives a similar definition: Any circumstance or event with the potential to adversely impact an asset [G.3] through unauthorized access, destruction, disclosure, modification of data, and/or denial of service. The Open Group defines threat as: Anything that is capable of acting in a manner resulting in harm to an asset and/or organization; for example, acts of God (weather, geological events,etc.); malicious actors; errors; failures. Factor analysis of information risk defines threat as: threats are anything (e.g., object, substance, human, etc.) that are capable of acting against an asset in a manner that can result in harm. A tornado is a threat, as is a flood, as is a hacker. The key consideration is that threats apply the force (water, wind, exploit code, etc.) against an asset that can cause a loss event to occur. National Information Assurance Training and Education Center gives a more articulated definition of threat: The means through which the ability or intent of a threat agent to adversely affect an automated system, facility, or operation can be manifest. Categorize and classify threats as follows: Categories Classes Human Intentional Unintentional Environmental Natural Fabricated 2. Any circumstance or event with the potential to cause harm to a system in the form of destruction, disclosure, modification or data, and/or denial of service. 3. Any circumstance or event with the potential to cause harm to the ADP system or activity in the form of destruction, disclosure, and modification of data, or denial of service. A threat is a potential for harm. The presence of a threat does not mean that it will necessarily cause actual harm. Threats exist because of the very existence of the system or activity and not because of any specific weakness. For example, the threat of fire exists at all facilities regardless of the amount of fire protection available. 4. Types of computer systems related adverse events (i. e. , perils) that may result in losses. Examples are flooding, sabotage and fraud. 5. An assertion primarily concerning entities of the external environment (agents); we say that an agent (or class of agents) poses a threat to one or more assets; we write: T(e;i) where: e is an external entity; i is an internal entity or an empty set. 6. An undesirable occurrence that might be anticipated but is not the result of a conscious act or decision. In threat analysis, a threat is defined as an ordered pair, <peril; asset category>, suggesting the nature of these occurrences but not the details (details are specific to events). 7. The potential violation of security. 8. A set of properties of a specific external entity (which may be either an individual or class of entities) that, in union with a set of properties of a specific internal entity, implies a risk (according to a body of knowledge).
  • 2.7K
  • 02 Nov 2022
Topic Review
Technology Tree
In strategy games, a technology, tech, or research tree is a hierarchical visual representation of the possible sequences of upgrades a player can take (most often through the act of research). Because these trees are technically directed and acyclic, they can more accurately be described as a technology directed acyclic graph. The diagram is tree-shaped in the sense that it branches between each 'level', allowing the player to choose one sequence or another. Each level is called a tier and is often used to describe the technological strength of a player. Typically, at the beginning of a session of a strategy game, a player will start at tier 1, and will only have a few options for technologies to research. Each technology that a player researches will open up one or more new options, but may or may not, depending on the computer game, close off the paths to other options. The tech tree is the representation of all possible paths of research a player can take, up to the culmination of said sequence. A player who is engaged in research activities is said to be "teching up", "going up the tech tree", or "moving up the tech tree". Analysis of a tech tree can lead players to memorize and use specific build orders.
  • 2.7K
  • 26 Oct 2022
Topic Review
Properties of Polynomial Roots
In mathematics, a univariate polynomial is an expression of the form where the ai belong to some field, which, in this article, is always the field [math]\displaystyle{ \mathbb C }[/math] of the complex numbers. The natural number n is known as the degree of the polynomial. In the following, p will be used to represent the polynomial, so we have A root of the polynomial p is a solution of the equation p = 0: that is, a complex number a such that p(a) = 0. The fundamental theorem of algebra combined with the factor theorem states that the polynomial p has n roots in the complex plane, if they are counted with their multiplicities. This article concerns various properties of the roots of p, including their location in the complex plane.
  • 2.7K
  • 21 Nov 2022
Topic Review
Requirements Engineering in OTF-Computing
The idea of On-The-Fly (OTF) Computing is to compose and provide software services ad hoc, based on requirement descriptions in natural language. Since non-technical users write  their software requirements themselves and in unrestricted natural language, deficits occur such as inaccuracy and incompleteness. These deficits are usually tackled by natural language processing methods, which have to face specific challenges in OTF Computing because maximum automation is the goal there. In the following, we present current automatic approaches for solving inaccuracies and incompleteness in natural language requirement descriptions.
  • 2.7K
  • 30 Oct 2020
Topic Review
BBM
BBM, also known by its full name BlackBerry Messenger, was a proprietary mobile instant messenger and videotelephony application included on BlackBerry devices that allows messaging and voice calls between BlackBerry OS, BlackBerry 10, iOS, Android, and Windows Mobile users. The consumer edition for iOS and Android, BBM Consumer, was developed by Indonesian company Emtek under licence from BlackBerry Limited (formerly known as Research In Motion). The consumer edition for BlackBerry OS and BlackBerry 10, as well as the paid enterprise edition, called BBM Enterprise (BBMe, formerly known as BBM Protected), were developed fully by BlackBerry Limited and continue to function. BBM Consumer for Android and iOS was shut down on 31 May 2019, however the paid enterprise version of the software, BBMe, is still supported on these platforms. Messages sent via BBM were sent over the Internet and used the BlackBerry PIN system. In the past, many service providers allowed sign-in to BBM using a dedicated BlackBerry data plan. Exchanging messages was possible to a single person or via dedicated discussion or chat groups, which allowed multiple BlackBerry devices to communicate in a single session. In addition to offering text-based instant messages, BBM also allowed users to send pictures, voicenotes (audio recordings), files (up to 16 MB), share real time location on a map, stickers and a wide selection of emojis. Communication was possible only among BlackBerry devices, until late 2013 when BBM was released on iOS and Android systems. Over 300 million Stickers were shared. Daily, approximately 150,000 BBM Voice Calls were placed. There were more than 190 million BBM users worldwide as of 2015, and BlackBerry infrastructure handled 30 petabytes of data traffic each month by early 2013. BBM was the original "mobile-first" messaging service, and was popular for a while before it started to lose out to rivals. As of April 2016, Indonesia was the only country where BBM was the most popular messaging app – installed on 87.5% of Android devices in the country.
  • 2.7K
  • 24 Nov 2022
Topic Review
Intel Active Management Technology
Intel Active Management Technology (AMT) is hardware and firmware for remote out-of-band management of select business computers, running on the Intel Management Engine, a microprocessor subsystem not exposed to the user, in order to monitor, maintain, update, upgrade and repair them. Out-of-band (OOB) or hardware-based management is different from software-based (or in-band) management and software management agents. Hardware-based management works at a different level from software applications, and uses a communication channel (through the TCP/IP stack) that is different from software-based communication (which is through the software stack in the operating system). Hardware-based management does not depend on the presence of an OS or locally installed management agent. Hardware-based management has been available on Intel/AMD based computers in the past, but it has largely been limited to auto-configuration using DHCP or BOOTP for dynamic IP address allocation and diskless workstations, as well as wake-on-LAN (WOL) for remotely powering on systems. AMT is not intended to be used by itself; it is intended to be used with a software management application. It gives a management application (and thus, the system administrator who uses it) access to the PC down the wire, in order to remotely do tasks that are difficult or sometimes impossible when working on a PC that does not have remote functionalities built into it. AMT is designed into a service processor located on the motherboard, and uses TLS-secured communication and strong encryption to provide additional security. AMT is built into PCs with Intel vPro technology and is based on the Intel Management Engine (ME). AMT has moved towards increasing support for DMTF Desktop and mobile Architecture for System Hardware (DASH) standards and AMT Release 5.1 and later releases are an implementation of DASH version 1.0/1.1 standards for out-of-band management. AMT provides similar functionality to IPMI, although AMT is designed for client computing systems as compared with the typically server-based IPMI. Currently, AMT is available in desktops, servers, ultrabooks, tablets, and laptops with Intel Core vPro processor family, including Intel Core i5, Core i7, Core i9 and Intel Xeon E3-1000, Xeon E, Xeon W-1000 product family. Intel confirmed a Remote Elevation of Privilege bug (CVE-2017-5689, SA-00075) in its Management Technology on May 1, 2017. Every Intel platform with either Intel Standard Manageability, Active Management Technology, or Small Business Technology, from Nehalem in 2008 to Kaby Lake in 2017 has a remotely exploitable security hole in the ME. Some manufacturers, like Purism and System76 are already selling hardware with Intel Management Engine disabled to prevent the remote exploit. Additional major security flaws in the ME affecting a very large number of computers incorporating Management Engine, Trusted Execution Engine, and Server Platform Services firmware, from Skylake in 2015 to Coffee Lake in 2017, were confirmed by Intel on November 20, 2017 (SA-00086).
  • 2.7K
  • 31 Oct 2022
Topic Review
Caduceus as a Symbol of Medicine
The caduceus is the traditional symbol of Hermes and features two snakes winding around an often winged staff. It is often used as a symbol of medicine, especially in the United States, despite its ancient and consistent associations with trade, liars, thieves, eloquence, negotiation, alchemy, and wisdom. The modern use of the caduceus as a symbol of medicine became established in the United States in the late 19th and early 20th century as a result of well-documented mistakes, misunderstandings of symbology and classical culture. The correct symbol for medicine is the Rod of Asclepius, which has only one snake and no wings.
  • 2.7K
  • 02 Nov 2022
Topic Review
Deep Packet Inspection
Deep packet inspection (DPI) is a type of data processing that inspects in detail the data being sent over a computer network, and may take actions such as alerting, blocking, re-routing, or logging it accordingly. Deep packet inspection is often used to baseline application behavior, analyze network usage, troubleshoot network performance, ensure that data is in the correct format, check for malicious code, eavesdropping, and internet censorship, among other purposes. There are multiple headers for IP packets; network equipment only needs to use the first of these (the IP header) for normal operation, but use of the second header (such as TCP or UDP) is normally considered to be shallow packet inspection (usually called stateful packet inspection) despite this definition. There are multiple ways to acquire packets for deep packet inspection. Using port mirroring (sometimes called Span Port) is a very common way, as well physically inserting a network tap which duplicates and sends the data stream to an analyzer tool for inspection. Deep Packet Inspection (and filtering) enables advanced network management, user service, and security functions as well as internet data mining, eavesdropping, and internet censorship. Although DPI has been used for Internet management for many years, some advocates of net neutrality fear that the technique may be used anticompetitively or to reduce the openness of the Internet. DPI is used in a wide range of applications, at the so-called "enterprise" level (corporations and larger institutions), in telecommunications service providers, and in governments.
  • 2.7K
  • 09 Nov 2022
Topic Review
Yakuza Kenzan
Ryū ga Gotoku Kenzan! (Japanese: 龍が如く 見参!, "Like a Dragon Arrives!"), unofficially known as Yakuza Kenzan, is a jidaigeki-themed spin-off game in the Yakuza series. The game was developed and published by Sega for PlayStation 3. It was unveiled at the Tokyo Game Show 2007 and released in 2008. A second Yakuza series spin-off set in samurai era, Ryū ga Gotoku Ishin!, was released in 2014 on both the PlayStation 3 and the PlayStation 4 systems. Ishin! is set two centuries later than Kenzan!, hence the plots are not related to each other since both games focus on different characters, the historical figures of Sakamoto Ryōma (1836-1867) and Miyamoto Musashi (1584-1645) respectively.
  • 2.7K
  • 20 Oct 2022
Topic Review
Bluetooth Low Energy Mesh Networks
Bluetooth Low Energy (BLE) is an increasingly prevalent Wireless Ad-Hoc Network (WAHN) technology for battery-powered Internet of Things (IoT) devices [1]. The BLE standard was introduced by the Bluetooth Special Interest Group (SIG) in Bluetooth version 4.0, and subsequently enhanced in versions 4.2 and 5. Initially, BLE 4.x adopted the legacy Bluetooth Personal Area Network (PAN) model for multi-hop communications and the interconnection of networks. BLE 5 intends to address these inadequacies via the implementation of pure mesh topology to provide enhanced network coverage, inter-network connectivity, and improved security [2].
  • 2.7K
  • 28 Oct 2020
Topic Review
Iperius Backup
Iperius Backup is a backup software for Windows PCs and Servers, databases and virtual machines. It allows to make automatic backups of files and folders on many devices: external USB hard drives, RDX drives, NAS, LTO tape drives, networked computers, Cloud storage, Amazon S3, Google Drive and FTP servers. Iperius Backup includes drive imaging capabilities, backup of SQL Server, MySQL, PostgreSQL, Oracle databases, backup of Microsoft Exchange servers, backup and replication of VMware ESXi, vCenter, ESXi Free and Hyper-V virtual machines.
  • 2.7K
  • 30 Oct 2022
Topic Review
Multiply-with-carry
In computer science, multiply-with-carry (MWC) is a method invented by George Marsaglia for generating sequences of random integers based on an initial set from two to many thousands of randomly chosen seed values. The main advantages of the MWC method are that it invokes simple computer integer arithmetic and leads to very fast generation of sequences of random numbers with immense periods, ranging from around 260 to 22000000. As with all pseudorandom number generators, the resulting sequences are functions of the supplied seed values.
  • 2.6K
  • 29 Sep 2022
Topic Review
Disk Defragmenter (Windows)
Disk Defragmenter is a utility in Microsoft Windows designed to increase access speed by rearranging files stored on a disk to occupy contiguous storage locations, a technique called defragmentation. Defragmenting a disk minimizes head travel, which reduces the time it takes to read files from and write files to the disk. Beginning with Windows XP, Disk Defragmenter also reduces system startup times. From Windows 8, the program was renamed to Defragment and Optimize Drives.
  • 2.6K
  • 31 Oct 2022
Topic Review
Nehru Memorial Museum & Library
The Nehru Memorial Museum & Library (NMML) is a museum and library in New Delhi, India , which aims to preserve and reconstruct the history of the Indian independence movement. Housed within the Teen Murti House complex, it is an autonomous institution under the Indian Ministry of Culture, and was founded in 1964 after the death of India's first prime minister, Jawaharlal Nehru. It aims to foster academic research on modern and contemporary history. Today, the Nehru Memorial Library is the world’s leading resource centre on India’s first prime minister. Its archives contain the bulk of Mahatma Gandhi's writings, as well as private papers of C. Rajagopalachari, B. C. Roy, Jayaprakash Narayan, Charan Singh, Sarojini Naidu and Rajkumari Amrit Kaur. In March 2010 it launched a digitization project of its archives, and by June 2011, 867,000 pages of manuscripts and 29,807 photographs had been scanned and 500,000 pages had been uploaded on the digital library website. Amongst noted publications of the NMML are Selected Works of Jawaharlal Nehru, Man of Destiny by Ruskin Bond, Nehru Anthology (1980) and Nehru Anthology. Nehru Memorial Museum & Library has over the years supported scholars and historians across India. Through its fellowship programme, the Nehru Memorial Fellowship, it has funded some of India’s best academics such as Chief Information Commissioner OP Kejriwal. It is also one of the best libraries in Delhi for the social sciences as it has a huge collection on labour related issues in the form of PhD dissertations, reports, books, journals and news papers. On 26 April 2016 a dagger gifted to former prime minister Jawaharlal Nehru by Saudi Arabia was stolen from the Nehru Memorial Museum and Library.
  • 2.6K
  • 11 Nov 2022
Topic Review
Inti
Inti is the ancient Incan sun god. He is revered as the national patron of the Inca state. Although most consider Inti the sun god, he is more appropriately viewed as a cluster of solar aspects, since the Inca divided his identity according to the stages of the sun. Worshiped as a patron deity of the Inca Empire, Pachacuti is often linked to the origin and expansion of the Inca Sun Cult. The most common story says that he is the son of Viracocha, the god of civilization.
  • 2.6K
  • 23 Nov 2022
Topic Review
Internationalized Country Code Top-Level Domain
An internationalized country code top-level domain is a top-level domain in the Domain Name System (DNS) of the Internet. IDN ccTLDs are specially encoded domain names that are displayed in an end user application, such as a web browser, in their language-native script or alphabet, such as the Arabic alphabet, or a non-alphabetic writing system, such as Chinese characters. IDN ccTLDs are an application of the internationalized domain name system to top-level Internet domains assigned to countries, or independent geographic regions. Although the domain class uses the term code, some of these ccTLDs are not codes but full words. For example, السعودية (as-Suʻūdiyya) is not an abbreviation of "Saudi Arabia", but the common short-form name of the country in Arabic. Countries with internationalized ccTLDs also retain their traditional ASCII-based ccTLDs. As of August 2018 there are 59 approved internationalized country code top-level domains, of them at least 47 used. The most used are .рф (Russia) with over 900,000 domains names, .台灣 (Taiwan) with around 500,000 and .中国 (China) with over 200,000 domains. Still as of 2018 around 20 countries using non-Latin script do not have an internationalized country code top-level domain, including Japan .
  • 2.6K
  • 10 Nov 2022
Topic Review
Public Interest Registry
Public Interest Registry is a Reston, Virginia-based not-for-profit created by the Internet Society in 2002 to manage the .ORG top-level domain. It took over operation of .ORG in January 2003 and launched the .NGO and .ONG top-level domains in March 2015. In November 2019, it was announced the Public Interest Registry would be sold by the Internet Society to private equity investment firm Ethos Capital for 1.135 billion USD, but in April 2020, ICANN decided to reject the sale.
  • 2.6K
  • 05 Dec 2022
Topic Review
Born–Oppenheimer Approximation
In quantum chemistry and molecular physics, the Born–Oppenheimer (BO) approximation is the best-known mathematical approximation in molecular dynamics. Specifically, it is the assumption that the wave functions of atomic nuclei and electrons in a molecule can be treated separately, based on the fact that the nuclei are much heavier than the electrons. Due to the larger relative mass of a nucleus compared to an electron, the coordinates of the nuclei in a system are approximated as fixed, while the coordinates of the electrons are dynamic. The approach is named after Max Born and J. Robert Oppenheimer who proposed it in 1927, in the early period of quantum mechanics. The approximation is widely used in quantum chemistry to speed up the computation of molecular wavefunctions and other properties for large molecules. There are cases where the assumption of separable motion no longer holds, which make the approximation lose validity (it is said to "break down"), but even then the approximation is usually used as a starting point for more refined methods. In molecular infrared spectroscopy, using the BO approximation means considering molecular energy as a sum of independent terms, e.g.: [math]\displaystyle{ E_\text{total} = E_\text{electronic} + E_\text{vibrational} + E_\text{rotational} + E_\text{nuclear spin}. }[/math] These terms are of different orders of magnitude and the nuclear spin energy is so small that it is often omitted. The electronic energies [math]\displaystyle{ E_\text{electronic} }[/math] consist of kinetic energies, interelectronic repulsions, internuclear repulsions, and electron–nuclear attractions, which are the terms typically included when computing the electronic structure of molecules.
  • 2.6K
  • 16 Nov 2022
Topic Review
Java Persistence API
The Java Persistence API (JPA), in 2019 renamed to Jakarta Persistence, is a Java application programming interface specification that describes the management of relational data in applications using Java Platform, Standard Edition and Java Platform, Enterprise Edition/Jakarta EE. Persistence in this context covers three areas: The reference implementation for JPA is EclipseLink.
  • 2.6K
  • 14 Oct 2022
Topic Review
Windows 2.0
Windows 2.0 is an obsoleted 16-bit Microsoft Windows GUI-based operating environment that was released on December 9, 1987, and the successor to Windows 1.0. This product's family includes Windows 2.0, a base edition for 8086 real mode, and Windows/386 2.0, an enhanced edition for i386 protected mode.
  • 2.6K
  • 08 Oct 2022
  • Page
  • of
  • 48
Academic Video Service