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Dry Stone Walling Group

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Owen Watson
Owen Watson

One Second


Once I figured out what was going on, the reasons for why this film was unceremoniously taken down and disappeared into the ether became pretty apparent. It's a love letter to the movies, about how film is able to preserve the people who lived if only for one second, how going to the theater is this communal bonding experience that brings everyone together.




One Second



Overcoming these limitations required major changes to our ingestion pipeline and our indexing system, but we believe the results were worth the effort. Tweets are now available for searching within one second of creation, which allows us to power product features with strict real-time requirements, such as real-time conversations or the profile pages. Let's take a closer look at how we've achieved this.


In the new document ID assignment scheme, each Tweet is assigned a document ID based on the time that it was created. We needed to fit our document IDs into a 31-bit space, because Lucene uses positive Java integers as document IDs. Each document ID is unique within a segment, and our segments are usually writable for about 12 hours. We decided to allocate 27 bits to store timestamps with millisecond granularity, which is enough for a segment to last for a bit more than 37 hours. We use the last four bits as a counter for the number of Tweets with the same timestamp. This means that if we get more than 24 (16) Tweets with the same millisecond timestamp, then some of them will be assigned a document ID that is in a slightly incorrect order. In practice, this is extremely rare, and we decided that this downside was acceptable because we often ran into a similar situation in the old system when a Tweet was delayed for more than 15 seconds, which also resulted in the assignment of an unordered document ID.


Second, when we search for an element in a skip list, we track our descent down the levels of the skip list, and save that as a search finger. Then, if we later need to find the next posting with a document ID greater than or equal to a given value (assuming the value we are seeking is higher than the original value we found), we can start our search at the pointers given by the finger. This changes our lookup time from O(log n), where n is the number of elements in the posting list, to O(log d), where d is the number of elements in the posting list between the first value and the second value. This is critical because one of the most common and expensive queries in a search engine are conjunctions, which rely heavily on this operation.


Fourth, we only allocate one pointer for every level of the skip list. In a typical skip list, a node will have a value, a pointer to the next largest element in the list and a pointer to the lower level of the skip list. This means that a new value allocated into the second level will require the space for two values and four pointers. We avoid this by always allocating skip list towers contiguously. Each level K pointer will only point to other level K pointers, so to extract the value associated with a level K pointer P, you read the value at P - K. Once you reach a node with a value greater than the one you are searching for, you go back to the previous node, and descend a level by simply subtracting one from the pointer. This lets us allocate a value into the second level by just consuming the space for the value and two pointers. It also reduces the amount of time we need to spend chasing pointers, because a pointer into a tower is likely to be on the same cache line as the lower pointers in that tower.


Making changes to a data storage and retrieval system introduces unique challenges, especially when those systems serve hundreds of thousands of queries per second. To get low search indexing latency at Twitter, we needed to make significant changes to our ingestion pipeline and the core data structure used in our indexes, extensively test these changes, and carefully deploy them. We believe the effort was worth it: indexing a Tweet now takes one second, which allows us to satisfy the requirements of even the most real-time features in our product.


Single electron spins coupled to multiple nuclear spins provide promising multi-qubit registers for quantum sensing and quantum networks. The obtainable level of control is determined by how well the electron spin can be selectively coupled to, and decoupled from, the surrounding nuclear spins. Here we realize a coherence time exceeding a second for a single nitrogen-vacancy electron spin through decoupling sequences tailored to its microscopic nuclear-spin environment. First, we use the electron spin to probe the environment, which is accurately described by seven individual and six pairs of coupled carbon-13 spins. We develop initialization, control and readout of the carbon-13 pairs in order to directly reveal their atomic structure. We then exploit this knowledge to store quantum states in the electron spin for over a second by carefully avoiding unwanted interactions. These results provide a proof-of-principle for quantum sensing of complex multi-spin systems and an opportunity for multi-qubit quantum registers with long coherence times.


This is the way the world ends: with a nanosecond of computer error in a Defense Department laboratory and a million casual contacts that form the links in a chain letter of death. And here is the bleak new world of the day after: a world stripped of its institutions and emptied of 99 percent of its people. A world in which a handful of panicky survivors choose sides - or are chosen.


In cases where the computer cannot provide fairly immediate response, continuous feedback should be provided to the user in form of a percent-done indicator [Myers 1985]. As a rule of thumb, percent-done progress indicators should be used for operations taking more than about 10 seconds. Progress indicators have three main advantages: They reassure the user that the system has not crashed but is working on his or her problem; they indicate approximately how long the user can be expected to wait, thus allowing the user to do other activities during long waits; and they finally provide something for the user to look at, thus making the wait less painful. This latter advantage should not be underestimated and is one reason for recommending a graphic progress bar instead of just stating the expected remaining time in numbers.


For reasonably fast operations, taking between 2 and 10 seconds, a true percent-done indicator may be overkill and, in fact, putting one up would violate the principle of display inertia (flashing changes on the screen so rapidly that the user cannot keep pace or feels stressed). One could still give less conspicuous progress feedback. A common solution is to combine a "busy" cursor with a rapidly changing number in small field in the bottom of the screen to indicate how much has been done.


10 seconds: Limit for users keeping their attention on the task. Anything slower than 10 seconds needs a percent-done indicator as well as a clearly signposted way for the user to interrupt the operation. Assume that users will need to reorient themselves when they return to the UI after a delay of more than 10 seconds. Delays of longer than 10 seconds are only acceptable during natural breaks in the user's work, for example when switching tasks.


That's right, but why would you bother to extract the seconds out of a DATETIME and add 1 if if all you really want is to add 1 second to the current time? But we can guess and guess over this requirement, the only one who can shed a light on this is the original questioner, who hasn't responded since his question.


Since the poster extracted only the seconds 'counter' from the time, then you won't know the minutes. And since 59 + 1 seconds resets seconds to 0 and increments the minute by 1, this is the way it works as long as we're talking about seconds and not about primitive numbers


But Miller High Life's one-second-ad gimmick did turn all the peculiarities of the game -- the massive interest, the incredible expense, Anheuser-Busch InBev's exclusive rights to beer advertising -- into an earned-media bonanza.


The ploy was a big escalation of the prior year's online video starring actor Windell Middlebrooks, in his High Life deliveryman character created by Crispin, Porter & Bogusky in 2007, critiquing Super Bowl advertising. For the follow-up, Miller bought in-game airtime for one-second ads on local TV stations around the country, built a website and publicized its plan in a feature in USA Today.


"Anheuser-Busch will have the only beer ads in the Feb. 1 Super Bowl," Theresa Howard wrote in the article, "but rival MillerCoors plans a counterattack of TV and Web ads that make fun of such free spending, as well as a one-second stunt ad airing on local stations during the game. The pregame TV ads for Miller High Life start Jan. 26 and will tweak advertisers paying NBC $3 million -- $100,000 a second -- for a 30-second ad in the game."


This figure is sometimes rounded to 3 x 108 m, or 300,000 kilometers (3 x 105 km). One second is equal to 1/86,400 of a mean solar day. This is easy to derive from the fact that there are 60 seconds in a minute, 60 minutes in an hour and 24 hours in a mean solar day.


Engineers and scientists often use smaller units of measurement than the second by attaching power-of-10 prefix multipliers. One millisecond is 10-3 seconds; 1 microsecond is 10-6 seconds; 1 nanosecond is 10-9 seconds; and 1 picosecond is 10-12 seconds.


Objectives: To characterize the rate of decline of forced expiratory volume in 1 second (FEV(1)) in children and adolescents with cystic fibrosis and to identify and compare risk factors associated with FEV(1) decline.


One second is all it takes to completely turn a life upside down - ONE SECOND FOREVER explores excessive speeding by telling the stories of five motorists who have caused serious and deadly car accidents. A feeling that one cannot even begin to imagine, yet many drivers casually admit to speeding on a regular basis. By recreating the accidents, director Vít Klusák takes the drivers on a journey to confront their guilt and turn it into a message of prevention. 041b061a72


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