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HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

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Common Factors Theory
Common factors theory, a theory guiding some research in clinical psychology and counseling psychology, proposes that different approaches and evidence-based practices in psychotherapy and counseling share common factors that account for much of the effectiveness of a psychological treatment. This is in contrast to the view that the effectiveness of psychotherapy and counseling is best explained by specific or unique factors (notably, particular methods or procedures) that are suited to treatment of particular problems. According to one review, "it is widely recognized that the debate between common and unique factors in psychotherapy represents a false dichotomy, and these factors must be integrated to maximize effectiveness". In other words, "therapists must engage in specific forms of therapy for common factors to have a medium through which to operate". Common factors is one route by which psychotherapy researchers have attempted to integrate psychotherapies.
  • 7.1K
  • 08 Nov 2022
Topic Review
Tracking and Data Relay Satellite
File:TDRS Heart of Communication.ogv File:Tracking Data Relay Satellite (TDRS) Orbital Fleet Communicating with User Spacecraft.ogg File:Tracking Data Relay Satellite (TDRS) Orbital Fleet Communicating with User Spacecraft 2017 - 360 video.webm A tracking and data relay satellite (TDRS) is a type of communications satellite that forms part of the Tracking and Data Relay Satellite System (TDRSS) used by NASA and other United States government agencies for communications to and from independent "User Platforms" such as satellites, balloons, aircraft, the International Space Station, and remote bases like the Amundsen-Scott South Pole Station. This system was designed to replace an existing worldwide network of ground stations that had supported all of NASA's crewed flight missions and uncrewed satellites in low-Earth orbits. The primary system design goal was to increase the amount of time that these spacecraft were in communication with the ground and improve the amount of data that could be transferred. These TDRSS satellites are all designed and built to be launched to and function in geosynchronous orbit, 35,786 km (22,236 mi) above the surface of the Earth. The first seven TDRSS satellites were built by the TRW corporation. The three later versions have been manufactured by the Boeing corporation's Satellite Systems division. Thirteen satellites have been launched; however, one was destroyed in the Challenger disaster. TDRS-1 was decommissioned in October 2009. TDRS-4 was decommissioned in December 2011. Ten TDRSS satellites are currently in service. All of the TDRSS satellites have been managed by NASA's Goddard Space Flight Center. The contract for TDRS versions L & K was awarded to Boeing on December 20, 2007. On November 30, 2011, NASA announced the decision to order an additional third-generation TDRS satellite, TDRS M.
  • 1.7K
  • 04 Nov 2022
Topic Review
Halt and Catch Fire
In computer engineering, Halt and Catch Fire, known by the assembly mnemonic HCF, is an idiom referring to a computer machine code instruction that causes the computer's central processing unit (CPU) to cease meaningful operation, typically requiring a restart of the computer. It originally referred to a fictitious instruction in IBM System/360 computers, making a joke about its numerous non-obvious instruction mnemonics. With the advent of the MC6800, a design flaw was discovered by the programmers. Due to incomplete opcode decoding, two illegal opcodes, 0x9D and 0xDD, will cause the program counter on the processor to increment endlessly, which renders the processor useless. Those codes have been unofficially named HCF. During the design process of MC6802, engineers originally planned to remove this instruction, but kept it as-is for testing purposes. As a result, HCF was officially recognized as a real instruction. Later, HCF became a humorous catch-all term for instructions that may freeze a processor, including intentional instructions for testing purposes, and unintentional illegal instructions. Some are considered hardware defects, and if the system is shared, a malicious user can execute it to launch a denial-of-service attack. In the case of real instructions, the implication of this expression is that, whereas in most cases in which a CPU executes an unintended instruction (a bug in the code) the computer may still be able to recover, in the case of an HCF instruction there is, by definition, no way for the system to recover without a restart. The expression "catch fire" is a facetious exaggeration of the speed with which the CPU chip would be switching some bus circuits, causing them to overheat and burn.
  • 4.5K
  • 04 Nov 2022
Topic Review
Design Thinking
Design thinking is a term used to represent a set of cognitive, strategic and practical processes by which design concepts (proposals for products, buildings, machines, communications, etc.) are developed. Many of the key concepts and aspects of design thinking have been identified through studies, across different design domains, of design cognition and design activity in both laboratory and natural contexts. Design thinking is also associated with prescriptions for the innovation of products and services within business and social contexts. Some of these prescriptions have been criticized for oversimplifying the design process and trivializing the role of technical knowledge and skills.
  • 2.4K
  • 04 Nov 2022
Topic Review
Abstract Syntax Notation One
Abstract Syntax Notation One (ASN.1) is a standard interface description language for defining data structures that can be serialized and deserialized in a cross-platform way. It is broadly used in telecommunications and computer networking, and especially in cryptography. Protocol developers define data structures in ASN.1 modules, which are generally a section of a broader standards document written in the ASN.1 language. The advantage is that the ASN.1 description of the data encoding is independent of a particular computer or programming language (other than ASN.1.) Because ASN.1 is both human-readable and machine-readable, an ASN.1 compiler can compile modules into libraries of code, CODECs, that decode or encode the data structures. Some ASN.1 compilers can produce code to encode or decode several encodings, e.g. packed, BER or XML. ASN.1 is a joint standard of the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) and ISO/IEC, originally defined in 1984 as part of CCITT X.409:1984. In 1988, ASN.1 moved to its own standard, X.208, due to wide applicability. The substantially revised 1995 version is covered by the X.680 series. The latest revision of the X.680 series of recommendations is the 5.0 Edition, published in 2015.
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  • 04 Nov 2022
Topic Review
SSC Aero
The SSC Ultimate Aero is a mid-engined sports car that was produced by SSC North America (formerly known as Shelby SuperCars) from 2004 until 2013. The SSC Ultimate Aero held the world production car speed record title, according to the Guinness World Records, from 2007 (when it was officially timed at 410 km/h) until the introduction of the Bugatti Veyron Super Sport in 2010. In April 2013, the Guinness World Records temporarily disqualified the Veyron's record time for a period of five days due to concerns about electronic speed limiting changing the function of the car, but after investigation reinstated the Veyron as the record holder. The SSC Ultimate Aero was not sold with electronic driver aids such as an anti-lock braking system or traction control system, as according to Jerod Shelby (no relations to Carroll Shelby), "Early design philosophy on the car was to make it a driver's car. I wanted a car that you not only throttled with your right foot but at times you could steer with your right foot and a sensor."
  • 8.0K
  • 04 Nov 2022
Topic Review
Philo
Philo of Alexandria (/ˈfaɪloʊ/; Ancient Greek:; Hebrew: יְדִידְיָה הַכֹּהֵן‎, romanized: Yedidia (Jedediah) HaCohen; c. 20 BCE – c. 50 CE), also called Philo Judaeus, was a Hellenistic Jewish philosopher who lived in Alexandria, in the Roman province of Egypt. Philo used philosophical allegory to harmonize Jewish scripture, mainly the Torah, with Greek philosophy. His method followed the practices of both Jewish exegesis and Stoic philosophy. His allegorical exegesis was important for some Christian Church Fathers, but he had very little reception history within the Rabbinic Judaism. He adopted allegorical instead of literal interpretations of the Hebrew Bible. Some scholars hold that his concept of the Logos as God's creative principle influenced early Christology. Other scholars deny direct influence but say that Philo and Early Christianity borrow from a common source. The only event in Philo's life that can be decisively dated is his participation in the embassy to Rome in 40 CE. He represented the Alexandrian Jews in a delegation to the Roman Emperor Gaius (Caligula) following civil strife between the Alexandrian Jewish and Greek communities. The story of this event, and a few other biographical details, are found in Josephus and in Philo's own works, especially in Legatio ad Gaium (Embassy to Gaius) of which only two of the original five volumes survive. The thought of Philo was largely inspired by Aristobulus of Paneas and the Alexandrian School, concerning his work "Wisdom of Solomon" and the occupations of the Therapeutæ and the Essenes.
  • 3.1K
  • 04 Nov 2022
Topic Review
Peace Be Upon Him
The Arabic phrase ʿalayhi s-salām (عَلَيْهِ ٱلسَّلَامُ), which translates as "peace be upon him" is a conventionally complimentary phrase or durood attached to the names of the prophets in Islam. The English phrase is also given the abbreviation PBUH in English-language writing. An extended variant of the phrase reads ṣallā -llāhu ʿalayhī wa-ʾālihī wa-sallama (Arabic: صَلَّىٰ ٱللَّٰهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ), and it is often abbreviated SAW or SAWS in writing, even in English. The Arabic phrase is given the name Salawat. The phrase is encoded as a ligature at Unicode code point U+FDFA ﷺ ARABIC LIGATURE SALLALLAHOU ALAYHE WASALLAM Some Islamic scholars have voiced disagreement with the practice of abbreviating these phrases, arguing that it demonstrates laziness and a lack of respect.
  • 118.8K
  • 04 Nov 2022
Topic Review
Country Code Top-Level Domain
A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country, sovereign state, or dependent territory identified with a country code. All ASCII ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs. In 2018, the Internet Assigned Numbers Authority (IANA) began implementing internationalized country code top-level domains, consisting of language-native characters when displayed in an end-user application. Creation and delegation of ccTLDs is described in RFC 1591, corresponding to ISO 3166-1 alpha-2 country codes. While gTLD have to obey international regulations, ccTLD are subjected to requirements that are determined by each country’s domain name regulation corporation. With over 150 million domain name registrations today, ccTLDs make up 40% of the total domain name industry. Country code extension applications began in 1985. The registered first extensions that year were .us (United States), .uk (United Kingdom), and .il (Israel). There are 312 ccTLDs in active use totally. .cn, .tk, .de and .uk contain the highest number of domains.
  • 7.2K
  • 08 Nov 2022
Topic Review
Cartan Formalism
The vierbein or tetrad theory much used in theoretical physics is a special case of the application of Cartan connection in four-dimensional manifolds. It applies to metrics of any signature. (See metric tensor.) This section is an approach to tetrads, but written in general terms. In dimensions other than 4, words like triad, pentad, zweibein, fünfbein, elfbein etc. have been used. Vielbein covers all dimensions. (In German, vier means four, zwei means two, fünf means five, elf means eleven and, in general, viel means many.) For a basis-dependent index notation, see tetrad (index notation).
  • 1.1K
  • 04 Nov 2022
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