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Interrupt latency

In computing, interrupt latency is the time that elapses from when an interrupt is generated to when the source of the interrupt is serviced. For many operating systems, devices are serviced as soon as the device's interrupt handler is executed. Interrupt latency may be affected by microprocessor design, interrupt controllers, interrupt masking, the operating system's interrupt handling methods. There is a trade-off between interrupt latency and processor utilization. Many of the techniques of CPU and OS design that improve interrupt latency will decrease throughput and increase processor utilization. Techniques that increase throughput may increase interrupt latency and increase processor utilization. Lastly, trying to reduce processor utilization may increase interrupt latency and decrease throughput. Minimum interrupt latency is determined by the interrupt controller circuit and its configuration, they can affect the jitter in the interrupt latency, which can drastically affect the real-time schedulability of the system.

The Intel APIC architecture is well known for producing a huge amount of interrupt latency jitter. Maximum interrupt latency is determined by the methods an OS uses for interrupt handling. For example, most processors allow programs to disable interrupts, putting off the execution of interrupt handlers, in order to protect critical sections of code. During the execution of such a critical section, all interrupt handlers that cannot execute safely within a critical section are blocked. So the interrupt latency for a blocked interrupt is extended to the end of the critical section, plus any interrupts with equal and higher priority that arrived while the block was in place. Many computer systems require low interrupt latencies embedded systems that need to control machinery in real-time. Sometimes these systems use a real-time operating system. An RTOS makes the promise that no more than a specified maximum amount of time will pass between executions of subroutines. In order to do this, the RTOS must guarantee that interrupt latency will never exceed a predefined maximum.

Advanced interrupt controllers implement a multitude of hardware features in order to minimize the overhead during context switches and the effective interrupt latency. These include features like: Minimum jitter through non-interruptible instructions Zero wait states for the memory system Switchable register banks Tail chaining Lazy stacking Late arrival Pop preemption Sleep-on-exit featureAlso, there are many other methods hardware may use to help lower the requirements for shorter interrupt latency in order to make a given interrupt latency tolerable in a situation; these include buffers, flow control. For example, most network cards implement transmit and receive ring buffers, interrupt rate limiting, hardware flow control. Buffers allow data to be stored until it can be transferred, flow control allows the network card to pause communications without having to discard data if the buffer is full. Modern hardware implements interrupt rate limiting; this helps prevent interrupt storms or live-locks by having the hardware wait a programmable minimum amount of time between each interrupt it generates.

Interrupt rate limiting reduces the amount of time spent servicing interrupts, allowing the processor to spend more time doing useful work. Exceeding this time results in a soft or hard error. Advanced Programmable Interrupt Controller Ethernet flow control IEEE 802.3 Inter-processor interrupt Interrupt Interrupt handler Non-maskable interrupt Programmable Interrupt Controller Response time Latency Computer hardware and operating system latency

Nepal Academy

The Nepal Academy Royal Nepal Academy is a national institution of Nepal for promotion of the languages, culture and social sciences of Nepal. The academy commissions research and aims to promote the development of cultural and intellectual endeavour by coordinating national and international activities. At present Mr. Ganga Prasad uprety is the chancellor of the Nepal Academy & Mr. Vishwas Ghimire is handling his secretariat. A movement for a national cultural academy of Nepal began during the 20th century, with national figures calling for its establishment, including the Nepali poet Laxmi Prasad Devkota; the Academy was established in 1957 as the Nepal Academy of Art. It was named as the Royal Nepal Academy following the passage of the Royal Nepal Academy Act 1974. After the transition of Nepal into a Democratic Federal Republic in 2008, it was renamed to the Nepal Academy, by provision of the Nepal Academy Act 2007 enacted by the Parliament of Nepal; the academy annually organises the National Folk Music and Dance Festival, the National Cultural Festival, a Bhanu Jayanti celebration to commemorate the poet Bhanubhakta Acharya, stage performances and a national poetry competition.

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The Black Widow (1951 film)

The Black Widow is a 1951 British thriller film directed by Vernon Sewell and starring Christine Norden and Robert Ayres. The film was a B-movie production by Hammer Film Productions and was based on a radio serial entitled Return from Darkness. Mark Sherwin is driving in the country. Assuming the man is the victim of a hit-and-run, he stops to offer assistance, only to be coshed and left stunned while his wallet and car are stolen. On recovering his senses, he staggers towards a nearby farmhouse, he is found by the farm owner. Meanwhile, the car thief comes to grief while speeding round a corner on a clifftop road, the car plunges over the edge and explodes in flames. Sherwin regains consciousness, but is suffering from complete amnesia with no idea of his own identity or how he came to be found in such a remote location; the farm owner and his daughter agree to look after Sherwin. The police investigate missing persons reports but find no case to match Sherwin's age and physical description; some days Sherwin is on the mend, happens to find in his overcoat pocket a ticket stub from a theatre in a town some 50 miles away.

Hoping to find some clue as to his identity, he takes a train to the town and walks the streets to see whether anything will jog his memory. He comes across a house which he walks in through the unlocked door. Inside he finds a flower-covered coffin in the front room. A woman enters and on seeing Sherwin and faints; this jolts Sherwin's memory back into gear and he recognises the woman as his wife Christine, who has believed him dead since there was no reason for anybody to consider that the body found in the burned-out car was not his. Sherwin is bothered by his wife's odd demeanour her excessive concern about whether or not anybody could have seen him in the street or arriving at the house, his suspicions aroused, he decides to continue to play the amnesiac. Saying he is going upstairs to rest, he eavesdrops on her telephone calls and soon realises that she is speaking to a lover of some time standing, the gist of the conversation being the need to dispose of Sherwin before anyone else finds out that he was not the crash victim.

He finds out that Christine and her lover had been intending to sell the house and cash all his assets, his inconvenient reappearance has derailed their plans. Aware now of Christine's true colours, he decides to play along with her schemes until he can engineer a suitable come-uppance for the pair. Christine Norden as Christine Sherwin Robert Ayres as Mark Sherwin Jennifer Jayne as Sheila Kemp Anthony Forwood as Paul Kenton John Longden as Mr. Kemp John Harvey as Dr. Wallace Reginald Dyson as Police Sergeant Joan Carol as Hotel Desk Clerk Madoline Thomas as Housekeeper Jill Hulbert as Helen TV Guide noted the film as having "some exciting moments." The Black Widow on IMDb The Black Widow at AllMovie The Black Widow at BritMovie

Oscar Ghiglia

Oscar Alberto Ghiglia is an Italian classical guitarist. Born in Livorno to an artistic family – his father and grandfather were both famed painters, his mother an accomplished pianistOscar Ghiglia had to choose between a path strewn with brushes and colours and a world cut into harmony and melody. Though his early choice produced a few hundred water colours and a number of oil paintings, he soon realized music was his way. For this decision he thanks his father, who one day made him pose for a painting showing a guitarist. For this he had to hold his father's guitar, a companion to his artistic musings in front of his forming works; this painting was the start to a lifetime of disciplined dedication to music. Oscar Ghiglia graduated from the Santa Cecilia Conservatory in Rome and soon began study with Andrés Segovia, his major influence and inspiration during his formative years. Oscar Ghiglia "inherited" Segovia's class in Siena's Accademia Chigiana and spread his own teaching around the five continents in a sister vocation to his concertizing.

Oscar Ghiglia founded the Guitar Department at the Aspen Music Festival, as well as the Festival de Musique des Arcs and the "Incontri Chitarristici di Gargnano", of having been artist in residence, or visiting professor in such centers as the Cincinnati and San Francisco conservatories, the Juilliard School, the Hartt School and the Northwestern University of Evanston, Illinois. In all these centers and elsewhere Ghiglia has been nurturing talents and forming or perfecting young artists' musical outlook and interpretation, he has been teaching at the Accademia Musicale Chigiana since 1976. Besides touring as a solo performer, Oscar Ghiglia has played and recorded with such names as singers Victoria de Los Angeles, Jan de Gaetani, Gerald English, John McCollum. Giuranna, P. Zuckerman. Oscar Ghiglia was a founding member of the International Classic Guitar Quartet. Presently, after his newest CD Manuel Ponce Guitar music, a new set of recording projects is under way and his teaching continues, year long, in Basel Switzerland, where he has held the professorship in guitar at the Musik-Akademie der Stadt Basel from 1983 to 2004.

Founder of the International Guitar Competition of Gargnano, Ghiglia boasts a high number of first prize winners among his students, in competitions around the world. In 2006, after retiring from the Basel Musik-Akademie in Switzerland, where he had held the professorship in guitar from 1983 to 2004, he moved to Greece, following his marriage to colleague and former pupil Elena Papandreou, now guitar professor in the University of Makedonia in Thessaloniki. Following his CDs Manuel Ponce Guitar music, J. S. Bach Lute Works, a DVD of his favourite repertoire, he continues his concertizing across the oceans, his residencies in the universities of Cincinnati, Evanston, Illinois, as well as his summer teaching in the Accademia Chigiana of Siena and his "Incontri Chitarristici di Gargnano", on the shores of Lake Garda. Oscar Ghiglia- Accademia Musicale Chigiana Interview with Oscar Ghiglia, April 15, 1998 Some photos of LP covers

Yohanan Moyal

Yohanan Moyal is an Israeli former Olympic gymnast. He was born in Israel, is Jewish, his mother, a ballerina, was a Holocaust survivor. He attended the University of Oregon where he competed in gymnastics, Louisiana State University, where he was an All American in gymnastics, he competed for Israel at the 1984 Summer Olympics in Los Angeles, when he was 18 years old. In the Men's Individual All-Around he came in 67th, in the Men's Floor Exercise he came in tied for 70th, in the Men's Horse Vault he came in tied for 68th, in the Men's Parallel Bars he came in 63rd, in the Men's Horizontal Bar he came in 65th, in the Men's Rings he came in 62nd, in the Men's Pommel Horse he came in 64th; when he competed in the Olympics he weighed 132 lbs. Moyal founded Elite Gymnastics Academy in Baton Rouge, Louisiana, in 1987 where he is the owner and coach. Among those whom he had coached is Carly Patterson, the 2004 Olympic all-around champion and a member of the USA Gymnastics Hall of Fame

Dominique Gauzin-Müller

Dominique Gauzin-Müller is a French architect and architectural critic, focusing on wood and sustainability in architecture and urbanism. She is the author of several books on these subjects, which have been translated into several languages, she wrote Construire avec le Bois, L'architecture écologique, 25 maisons en bois and 25 maisons écologique. Dominique Gauzin-Müller grew up in Saint-Céré, Lot, she studied architecture at the École d'architecture Paris-Tolbiac, under Roland Schweizer, the French specialist in wooden buildings, Marion Tournon-Branly. 1984 she received a "Diplôme" and in 1985 a "Certificat d'études approfondies" in wooden building from the same university. In 1983 she attended a seminar called "Energy planning and the environment" at the Summer University of Oslo. Since her marriage to a German engineer, she lives in Germany. Dominique Gauzin-Müller worked as an architect for a few years, before devoting herself to writing and teaching, she lectured at the University of Stuttgart between 1988 and 1989.

She published Le Bois dans la Construction in 1990. Between 1998 and 2004, Gauzin-Müller was the editor of the book Jean Prouvé - Complete Works, in three volumes, by Peter Sulzer. Since 1994 she has organized over 40 study tours for French architects and engineers in Germany and in the Vorarlberg, including the French National Order of Architects and the National Committee for Development the promotion of Wood. In 1995, she received the Prix Henri Courbot for her book Le Bois dans la construction. In 1997 she published, in German, Behnisch & Partner 50 Jahre Architektur on the German architect Günter Behnisch, a book which received the prize awarded to the "50 most beautiful books of Germany". In 1999, Gauzin-Müller published Construire avec le Bois, a work for which she received the Prix Henri Le Même awarded by the French Académie d'architecture; the same year, she participated in the competition for the Mirecourt High School, with the architectural firm Jockers. Her most successful book, L'Architecture Écologique, was published in 2001 and has since been translated into six languages, including Chinese.

Gauzin-Müller participated as co-designer in the project of the Waste-Recovery Center of the "Parc d'activités" in Mayenne, led by Joel Gimbert. In 2003 she published 25 Maisons en Bois, translated into three languages, in 2005 25 Maisons Écologiques translated into five languages. In 2007, the French Académie d'architecture awarded her the Prix Dejean "for studies and research on the implementation of the principles of sustainable development to architecture and urbanism". In addition to her personal works, Gauzin-Müller has published essays in numerous books, including "Une Terre humaine" in L'Architecte et l'autre, "Développement durable dans l’architecture et l’urbanisme" and "Les énergies renouvelables dans le bâtiment" in the Neufert, "L’exemple du Vorarlberg" in La maison individuelle, "L’architecture éco-responsable" in La science au présent 2008, une année d’actualité scientifique et technique of the Encyclopædia Universalis, she works with several publishers, has published essays in community works such as "Les éléments des projets de construction" or the "Encyclopedia Universalis".

Since the early 1980s, Gauzin-Müller has written for many European architectural magazines: D'Architectures, Techniques et architecture, Maisons à vivre, Séquence bois, Architecture intérieure créé, Le Moniteur des travaux publics et du bâtiment, L'Architettura naturale, Deutsche Bauzeitung, etc. Gauzin-Müller, who gives talks all over Europe, was invited to several architectural universities, for example in Vienna, La Coruña. From 2004 to 2007, she taught at the École Nationale Supérieure d'Architecture in Nancy, she is a professor at the Ecole Nationale Supérieure d'Architecture in Strasbourg. Since its foundation in 2007, she is the chief editor of the French architecture magazine écologiK, which deals with issues of sustainability in architecture and urban planning