Approximate string matching Fuzzy Mediawiki search for "angry emoticon": "Did you mean: andré emotions" Overview[edit] The closeness of a match is measured in terms of the number of primitive operations necessary to convert the string into an exact match. This number is called the edit distance between the string and the pattern. The usual primitive operations are:[1] insertion: cot → coatdeletion: coat → cotsubstitution: coat → cost These three operations may be generalized as forms of substitution by adding a NULL character (here symbolized by *) wherever a character has been deleted or inserted: insertion: co*t → coatdeletion: coat → co*tsubstitution: coat → cost Some approximate matchers also treat transposition, in which the positions of two letters in the string are swapped, to be a primitive operation. Different approximate matchers impose different constraints. Problem formulation and algorithms[edit] One possible definition of the approximate string matching problem is the following: Given a pattern string
Wireless mesh network Diagram showing a possible configuration for a wireless mesh network, connected upstream via a VSAT link (click to enlarge) History[edit] Network structures[edit] Architecture[edit] Wireless mesh architecture is a first step towards providing cost effective and dynamic high-bandwidth networks over a specific coverage area. Wireless mesh networks have a relatively stable topology except for the occasional failure of nodes or addition of new nodes. Management[edit] Applications[edit] Mesh networks may involve either fixed or mobile devices. Some current applications: Operation[edit] Multi-radio mesh[edit] Multi-radio mesh refers to a unique pair of dedicated radios on each end of the link. Research topics[edit] One of the more often cited papers on Wireless Mesh Networks identified the following areas as open research problems in 2005 Protocols[edit] Routing protocols[edit] There are more than 70 competing schemes for routing packets across mesh networks. Autoconfiguration protocols[edit]
Battery room Battery room Telecommunications[edit] Telephone system central offices contain large battery systems to provide power for customer telephones, telephone switches, and related apparatus.[2] Terrestrial microwave links, cellular telephone sites, fibre optic apparatus and satellite communications facilities also have standby battery systems, which may be large enough to occupy a separate room in the building. Batteries often used in battery rooms are the flooded lead-acid battery, the valve regulated lead-acid battery or the nickel–cadmium battery. Electrical utilities[edit] Battery rooms are also found in electric power plants and substations where reliable power is required for operation of switchgear, critical standby systems, and possibly black start of the station. The world's largest battery is in Fairbanks, Alaska, composed of Ni-Cd cells.[3] Sodium-sulfur batteries are being used to store wind power.[4] Submarines and ocean going vessels[edit] Design issues[edit] References[edit]
Key Enabling Technologies to spur Europe's technological leadership European Commission - Press release Key Enabling Technologies to spur Europe's technological leadership Brussels 28 June 2011. A key expert group set up by the Commission today set out guidelines on giving European industry a competitive edge in deploying the industrial technologies of the future (Key Enabling Technologies). The main conclusions call on decision-makers to adopt radical policy objectives to retain critical capability and capacity in Europe through a single and comprehensive approach to KETs. In particular, the group recommends that the vital importance of KETs should be reflected in the structure and funding balance in the upcoming framework for research and innovation and in the priorities of the EU's future regional policy. Technological research and product demonstration projects should be given a high priority. The Commission will report back on the policy recommendations in a communication at the beginning of 2012. Background More information
Mel scale Plots of pitch mel scale versus Hertz scale Play . 440 Hz = 549.64 mels A popular formula to convert hertz into mel is:[2] History and other formulas[edit] There is no single mel-scale formula.[3] The popular formula from O'Shaugnessy's book can be expressed with different log bases: The corresponding inverse expressions are: There were published curves and tables on psychophysical pitch scales since Steinberg's 1937[4] curves based on just-noticeable differences of pitch. In 1949 Koenig published an approximation based on separate linear and logarithmic segments, with a break at 1000 Hz.[8] Gunnar Fant proposed the current popular linear/log formula in 1949, but with the 1000 Hz corner frequency.[9] An alternate expression of the formula, not depending on choice of log base, is noted in Fant (1968):[10][11] Data by which some of these formulas are motivated are tabulated in Beranek (1949), as measured from the curves of Stevens and Volkman:[14] References[edit] External links[edit] See also[edit]
FreedomBox/ExampleProjects See also: ?FreedomBox/DesignAndToDos#Relevantprotocols and : FreedomBox/LeavingTheCloud Proposed Decentralized IANA DIANNA Project (BitDNS based) ??? Decentralised DNS Unmanaged Internet Architecture CoDNS Not opensource , but worth to have a look at Storage Filesystems Tahoe-LAFS (Least Authority File System) - is a Free Software/Open Source decentralized data store. Network Attached Storage OpenMediaVault is the next generation network attached storage (NAS) solution based on Debian Linux. Synchronisation ownCloud, data storage project from the wider KDE community SparkleShare - opensource dropbox replacement - doesn't really need a server side setup (ssh access+git) but could be included by installation instructions to user iFolder - "Sync and Share Files." sucsynct - "Instant and efficient distributed backup and syncing, triggered whenever a file in a watched replica changes."
Healy Clean Coal Project Healy Clean Coal Project is a clean coal technology demonstration program consisting of a coal fired electrical power station located in Healy, Alaska in Denali Borough. The project was a demonstration of the TRW Clean Coal Combustion System and the Babcock and Wilcox/Joy Spray Dryer Absorber (SDA) System designed to reduce oxides of nitrogen (NOX) and sulfur dioxide (SO2) emissions while burning a variety of coal types, including waste coal. The project constructed a plant adjacent to Golden Valley Electric Association (GVEA) 25 MW coal plant Healy Unit 1. Costs[edit] According to Golden Valley Electric Association (GVEA) the facility cost around $300 million, with the United States Department of Energy contributing $120 million, the Alaska Legislature contributing $25 million, the Alaska Industrial Development and Export Authority (AIDEA) contributing $150 million and both GVEA & Usibelli Coal Mine contributing $10 million in addition to in-kind contributions.[2] See also[edit]
NFC (Near Field Communication) : définition, actualité, solutions... La technologie de communication de données sans contact fait office de mini-révolution dans le monde des terminaux mobiles. Elle pourrait notamment faciliter les achats via téléphone portable. Qu'est ce que la technologie NFC ?Technologie de communication de proximité (quelques centimètres) lancée par Sony et Philips, le NFC (pour Near Field Communication ou communications en champ proche), permet d'échanger des données entre un lecteur et n'importe quel terminal mobile ou entre les terminaux eux-mêmes et ce, à un débit maximum de 424 Kbits/s. Les utilisations sont multiples : un smartphone peut se connecter à un ordinateur pour télécharger un fichier, un téléviseur échangera des données avec un smartphone...
Mel-frequency cepstrum In sound processing, the mel-frequency cepstrum (MFC) is a representation of the short-term power spectrum of a sound, based on a linear cosine transform of a log power spectrum on a nonlinear mel scale of frequency. Mel-frequency cepstral coefficients (MFCCs) are coefficients that collectively make up an MFC. They are derived from a type of cepstral representation of the audio clip (a nonlinear "spectrum-of-a-spectrum"). The difference between the cepstrum and the mel-frequency cepstrum is that in the MFC, the frequency bands are equally spaced on the mel scale, which approximates the human auditory system's response more closely than the linearly-spaced frequency bands used in the normal cepstrum. This frequency warping can allow for better representation of sound, for example, in audio compression. MFCCs are commonly derived as follows:[1][2] The European Telecommunications Standards Institute in the early 2000s defined a standardised MFCC algorithm to be used in mobile phones.[5]
Hackerspace Global Grid [shackspace wiki] This work by hackerspace global grid is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License . As proposed on CCCamp11 we need our own infrastructure and space program. HGG's aim is to develop a modular antenna grid for satellite communication. The hacker community needs a fallback infrastructure in case of natural and economic disaster to stay connected. Design and build a modular terrestrial base-station for satellite communication. Based on open-source hard- and software as well as open standards. Gain insight into the nature, protocols and security features of satellite <> earth communication. There's a HGG Hackathon at shackspace every Saturday and Sunday afternoon. Research existing systems to receive satellite communications (off-the-shelf dishes, etc) Research existing software to decode satellite communications Setup infrastructure to record and store received signals for later analysis General Timing & Position GPS most current sollution