Astronomy Research Paper Example | Topics and Well Written Essays - 1000 words

Astronomy - Research Paper Example The gravity would decrease since as you come closer to the center of the earth there is the decrease in gravitational pull. Therefore, the gravitational force would be weak almost the same as the moon’s centrifugal force. The moon would move away from the earth’s atmosphere since there would be less gravitational strength to keep it within the earth’s atmosphere. Furthermore, the weight of everything will be less by half since the gravity will decrease by half. Because of the reduced gravity the fish and other sea creature will float on water easily and would have problem sinking because of the in density of the earth’s matter. When the astronaut floats out of the international space station for him, to get back to the arm of the space station, he should throw away the set of tools he has. This concept applies the Newton third law of motion which states that for every action force there is the reaction force. So by throwing the tools away, the center of gravity of the set of tools and the astronaut will react against each other and, therefore, move in the opposite direction. This because the astronaut and the tools have the common center of gravity hence, they must remain the same. The tool set will move to the other direction as the body moves toward the space station. Hence, the astronaut will be able to rescue himself. The Newton third law is what works in aerospace engineering. It explains the generation of thrust by the rocket engine. James Webb space telescope is the next big thing in the field of astrophysics. I support it because Webb’s telescope has a combination of large apertures, diffracted image quality and infrared sensitivity over an extensive wavelength range that is not available from the ground or spaced-based facilities. In addition, Webb’s telescope has broad collecting than Hubble’s, and it is capable of extending to longer wavelengths in the infrared. Moreover, it

Theme, Charractor Development, and Symbolism in The Fall of The House Research Paper

Theme, Charractor Development, and Symbolism in The Fall of The House of Usher - Edgar Allen Poe - Research Paper Example The personification of the mansion implies a lot of things which is discussed in this paper along with the theme and character development in the story. Edgar Allan Poe is considered as one of the unhappiest nineteenth century American poets, who wrote great horror tales and detective stories. His works can be included the gothic genre, and dealt mainly with deaths, unknown diseases and madness. The peculiarity of his themes arises from the mishaps in the life of Poe. He lost his parents at a very early age, his brother died when he was young and his only sister became insane later. â€Å"In his supernatural fiction Poe usually dealt with paranoia rooted in personal psychology, physical or mental enfeeblement, obsessions, the damnation of death, feverish fantasies, the cosmos as source of horror and inspiration†¦Ã¢â‚¬  (Edgar Allen Poe (1809-1849)). ‘The Fall of the House of Usher’ is one of his best short stories, in which he narrates the story of an insane man, Roderick, who buries his twin sister alive out of mere superstition only to find her returning after a few days. Roderick dies out of terror as the sist er dies and falls onto him. In this paper, the theme, character development and symbolism in the story, is going to be discussed. The main theme in the story is the decline of an ancient incestuous family and the psychological effects it has on its members and probably the physical effect on the mansion. There are various interpretations about the theme in the story. The story narrates the theme of duality with the characterization of Roderick and his sister. It means that Roderick and Madeline, his sister are not two people, but one. The old mansion gets destroyed with the death of Roderick and his sister, giving a direct relation between the members of the family and the mansion. â€Å"An interpretation of the story is that the Usher House represents the main character’s psyche or personality. The fissures

Evolution of the Ipod Essay Example for Free

Evolution of the Ipod Essay Personalized music took a big leap towards what we call the Ipod generation today , way back in 1979 when Sony introduced its audio cassette player Walkman. When we see the original Walkman today it does seem outdated and for many a piece of junk. But 30 years back it was a breakthrough in terms of technological advancement and an instant sensation worldwide which continued for decades. WALKMAN: Walkman is a portable audio cassette player which introduced a change in listening habits and providing people an opportunity to listen to the music of their own choice, which seemed a distant dream before its inception when transistor radios were the only option for the masses. Origin and History: The first original Walkman was launched by Sony that went on sale on 1st July 1979, in Japan. It was launched subsequently under different names in many countries for instance, In US it was launched under the name Soundabout . In Sweden it was launched under the name Freestyle.. In UK it was launched under the name Stowaway. The device was built in 1978, by an audio division engineer Nobotushi Kihara who worked for Sony. Sony’s co-chairman Morita who wanted to listen operas during his frequent plane trips requested for such a device and therefore Nobotushi came up with the Walkman. Although Morita hated the name Walkman and insisted on changing it , but accepted later on when junior executives told him that a campaign had been started and changing the name now would cost the company dearly. (Sony History) Cassette-based Walkman: The first and original Walkman was a blue and silver cassette-based model TPS-L2. It came with one set of headphones and had limited features of play, stop and forward with no record function. In 1984, Sony presented its memorable model Walkman Professional WM-D6C. It was comparable in audio quality with most non-portable audio cassette decks.. Among the standard play,stop functions it also introduced the record function which made it famous. Later on, Toshiba’s Walky , Aiwa’s Cassette Boy and Panasonic’s Stereo-To-Go were giving stiff competition to the Walkman. Therefore in 1989, Sony launched its famous and unique playback only model WM-DD9, this model attracted a niche following with hardcore Walkman fans making it a must in their collection. It featured auto-reverse and had improved power consumption requiring only 1 AA battery with optional AC adapter input. Moreover it had superior sound quality as compared to its predecessors. Although the cassette based walkman had started losing its appeal probably due to increasing competition from Sanyo and emergence of CDs as a better storage medium in all respects, Sony still kept launching new models every 5 years uptill 2000, these models not only continued to represent features of previous models but also had some new ones of their own for intance, WM-701S which also came out in 1989 was more user-friendly as it came with a remote control and slim silver plated body. After which cassettes had reached technological obsolence and any future production of cassette-based models had to be stopped. (Sony Design- 1980s) PORTABLE CD PLAYERS: Portable CD players took personalized music to a further new level from portable cassette players. These players used audio CDs instead of cassettes , not only CDs were lighter than cassettes but they could store considerably more than multiple cassettes could or could record in a much better audio format which would give a superior sound quality than cassettes. History: CDs as a storage medium were introduced in the early 1980s. Once again Sony created history in 1984 when it launched its CD-based Walkman (which was a first of its kind portable CD player) D-50. Although it was also known as D-5 in some markets but its official name was Discman. Discman was considered a marvel , its size was just a little more than that of a CD case which made it very handy. Moreover it had additional features and better sound quality as compared cassette-based walkman but still they managed to gain momentum till the late 1980s because CDs were quite expensive prior to that and CD players didn’t had anti-shake protection feature which caused CDs to damage since they were delicate. (Discman) Evolution of CD Players: Portable CD players had the basic features of a cassette player besides that it also had some new features for instance hold, toggle in later versions and portable CD players in the present age are capable of supporting numerous audio formats as well . In the mid-nineties these players also featured a LCD display also. Since Sony was continuing to face increasing competition from Panasonic in the late 1980s, it improved its own design of Discman and came up with a new model D121 which had additional features from its predecessors. The competition is still ongoing with Sony, Panasonic, JVC, Bose, Coby etc. coming up with new portable cd players after every few months. Although Ipods are the in thing these days but still portable cd players continue to survive probably because CDs haven’t gone into obsolence like cassettes did. However they don’t enjoy the same popularity they did in late 1980s and mid 90s. MINI-DISC PLAYERS: Mini disc was a magneto-optical disc. It could store upto 80 minutes of digitized audio almost that of CD quality. Mini-disc players were capable of playing these storage media. The reason MD was launched was because they had the anti-skip feature which prevented disc-skipping even under the most extreme conditions and was unlike CDs which used to skip on the slightest of vibration and shocks and used to annoy users. History: Sony launched its first MD Player in 1992 named MZ1 along with the Mini-disc itself. However many other companies for instance JVC, Sharp, Pioneer and Panasonic launched their respective mini-disc players as well. MD Players were initially launched as an alternative to Philips analogue cassette system which was quite popular at that time. Moreover till the mid-nineties MD players were popular in Japan and Asia but largely unknown elsewhere. (Music on the move: Minidisc) Evolution of the Mini-disc and the Mini-disc player: nitially when Sony introduced the Mini-disc it was based on ATRAC audio data compression but later it was based on linear PCM inorder to give CD quality audio. Although MD Walkmans when launched by Sony were multi-featured i. e. they could play and record on MDs from both digital and analogue sources for example, live audio from their microphone inputs ; but were somewhat large and couldn’t be placed in a pocket. Therefore, Sony released a new model MZ-R2 which was quite compact. MD Walkmans gradually improved over the years for instance, when MDLP(Mini-disc Long Play) was introduced in MDs in 2000 which allowed MDs to record 4 times of what they initially could MD Players were enabled with this feature and many in the following years for example, Net MD, Hi MD. (Sony MZ RH1) MP3 PLAYERS: MP3 players are also technically known as Digital Audio Players. It is a device that stores, organizes and plays audio files. MP3 players were a breakthrough in their own right since they didn’t require CDs or cassettes to be inserted into them , common features of an MP3 player were a flash memory drive or a miniature hard drive, an embedded processor and an audio codec microchip which would convert digitally compressed sound into analogue form which was then played through the speaker jack. The user can store hundreds of songs on the flash memory drive/mini hard drive. History: The first MP3 player came from a Korean company SaeHan Information Systems which in collaboration with Eiger Labs US launched in 1998 the first solid state digital audio player named MPMan . It featured 32 Mb of RAM which could hold 8 average length of tracks( i. e. 32 minutes of music). (World’s 1st MP3 Player) The same year Diamond Multimedia lauched its version of MPMan named Rio PMP300. However its sales were better than expected initially but later had a fall from grace probably due to lawsuits. (Collecting MP3 Portables) In 1999, Compaq developed the first hard-drive based mp3 player in collaboration with HanGo Electronics and named it PJB-100(Personal Jukebox). The player had a capacity of 4. 8 GB and it was extensively advertised that it could hold 1200 songs! (Net Audio) Evolution Of MP3 Players: Initially MP3 players supported only the . mp3 format but in the following years MP3 players started supporting multiple formats for example , AAC, WMA, WAV, Ogg Vorbis. Flash-based MP3 players: These are solid state devices that store audio files on internal flash memory. Initially internal memory of these players was in a few MBs and users couldn’t store any more than on a CD but soon makers got notice of this and today we see internal memory in GBs which is capable of holding hundreds of songs. (World ‘s 1st 32 GB Flash based PMP) Similarly, internal memory couldn’t be extended by users however in a couple of years removable flash memory was made available better known as memory cards. Moreover with the passage of time , these players became more resilient and required less power consumption as compared to portable CD player or a hard-drive based mp3 player. Hard-drive based Players: These devices are also known as Digital Jukeboxes. Initially their capacity was 4-5 GB but these days players are available with capacity upto 250 GB. This loosely means that thousands of songa could be stored on a single player. (Wolverine ESP 250 GB) MP3 CD Players: With the growth in popularity of MP3 players and mp3 format itself . Many portable CD players started supporting playback for CDs which had MP3 files stored on them. iPOD REVOLUTION: iPod is a popular brand of portable media players which are designed by Apple Inc. Apple has produced a number of models over years iPod Classic, iPod Nano to name a few. iPods have become a sensation for this generation and seems to be for the following ones too just like Walkman was in the 1980s. As per stats upto September 2008, 173 million iPods have been sold worldwide which has made it the best selling portable music player ever. History: In early 2000, Apple had started making software for the growing market of digital audio players. The company found that the MP3 players were either too big (those that were hard-drive based) or too small (those that were flash-drive based) and had mediocre user-interfaces. Apple’s CEO Steve Jobs took the initiative, he decided that Apple would make their own PMPs(personal music players). Therefore Apple’s hardware engineering head Jon Rubinstein assembled a team including hardware engineers Tony Fadell and Michael Dhuey and a design engineer Jon Ive, however Apple didn’t make the product completely on in-house instead they used Portal Player( a semi-conductor company) platform based on 2 ARM cores. Nevertheless the product within an year and was unveiled on 23rd October 2001, it was a Mac-compatible product with 5 Gb hard-drive and could hold upto 1000 songs. The name iPod was suggested by Vinnie Chieco a freelance copy-writer. iPod Models: iPod Classic: It was the iPod that was launched originally. Uptill now six generations have been produced of this model and is the only model that is hard-drive based. iPod Mini: Its first generation was launched in 2004. However it was discontinued after its 2nd generation. Its storage medium was based on mini hard-drive. iPod Shuffle: iPod Shuffle was first introduced in January 2005. Due to it smaller size and sleeker look it became an instant hit. Its flash-drive based PMP. Uptill now 2 generations have been produced of this model. iPod Nano: iPod Nano was also a flash-drive based model. It was also launched the same year Shuffle was launched . What separated Nano from Shuffle was its greater storage capacity and coloured display. iPod Touch: It is the latest in the iPod family and was launched in 2007. It was also a flash drive based model similar to Nano and Shuffle . But Touch is way ahead of all of its predecessors. It was the first iPod with Wi-Fii and Multitouch interface. Moreover it featured the Safari browser and wireless access to iTunes Stores and YouTube. (Identifying Ipods) Software: Initially when Apple introduced its iTunes software it was only compatible with Mac OS but later on Apple a Windows version of it as well. iPod first generation models although various audio formats, image formats and video formats but only worked with Mac-OS. However when Apple launched its second generation models the software within those models was compatible with MS Windows. Apple developed alternatives for various formats which were previously not supported by it for example, Microsoft’s WMA audio format was not supported earlier so they provided a converter along with their Windows version of iTunes. Adding further open source formats like Ogg Vorbis, FLAC were previously not supported however these formats can be played now on installing a firmware onto the iPod for example, Rockbox User-Interface: All iPods have colour displays which incorporates anti-aliased graphics and text with sliding animations. Moreover except iPod shuffle and iPod Touch all other iPods have 5 buttons and second generation onwards buttons have been integrated on the click wheel. Click-wheel is an innovation that brings refineness and clarity to the interface. The buttons given perform the basic play,stop etc. functions as for scrolling the click-wheel is used in a rotational manner. In its later models Apple made some changes for instance, iPod Touch doesn’t have a click wheel instead it has a 3. 5 inch touchscreen and in addition to it a home button , a sleep/wake button and volume up/down button. Hardware: A typical iPod comprises of the following chipset and electronics: Microcontroller Audio Chip Storage Medium Batteries Different iPods have used different microcontrollers along their different generations for example, iPod Nano used a variable-speed ARM in its first generation model however it has continued to use Samsung System-On Chip second generation onwards. iPod Classic has a hard-drive based storage medium and has been since first generation however the capacity has increased considerably i. e. from 10 GB in its first generation model to 160 GB in its sixth generation model. Similarly, iPod Mini was based on the Mini Hard-drive however Apple discontinued it after its 2nd generation model. Moving on iPod Nano, Shuffle and Touch are flash-drive based and there capacity has also increased considerably with newer models. Connectivity: Originally Apple used a Firewire connection was used to the host computer and for charging battery. Third generation onwards, Apple allowed both Firewire and USB connectivity. This allowed for better compatibility with PCs. Therefore 5th generation onwards Apple dropped Firewire for data transfer and made complete transition to USB 2. 0 in an attempt to reduce cost . CONCLUSION: From Walkman to iPod people have seen a great advancements in personal music players. Walkman ruled 1980s which continued till the mid-nineties. However , after that advancements were made very speedily and we saw MD players, MP3 players and finally the iPod in 2001. iPod completely redefined infact revolutionised portable entertainment. Infact in these 8 years since its inception it has made record breaking sales and won several awards for engineering excellence , it has acheived much more than what the Walkman in a decade and a half. But then again, Walkman has its own place in history and iPod is making its own. ? REFERENCES: Sony Global, n. d. , â€Å"Sony History† retrived from : http://www. sony. net/Fun/design/history/ Sony Gobal, n. d. â€Å"Sony Design- History 1980s† retrieved from: http://www. sony. net/Fun/design/history/product/1980/wm-2. html Walkman Central, n. d, â€Å"Discman† retrieved from: http://www. walkmancentral. com/list/discman Minidisc Org, n. d. â€Å"Sony MZ RH1† retrieved from : http://www. minidisc. org/manuals/sony/Sony_MZ-RH1_user_manual. pdf Van Buskrik, Eliot, n. d. â€Å"Introducing the World’s first MP3 Player† retrived from: http://reviews. cnet. com/4520-6450_7-5622055-1. html Menta, Richard, n. d. â€Å" Collecting MP3 Portables-Part 1† retrieved from: http://www. antiqueradio. com/Dec04_Menta_mp3pt1. html Yoshido Junko, n. d. â€Å"OEMS ready to roll on jukeboxes for Net audio† retrieved from: http://www. eetimes. com/story/OEG20000818S0035 Creative, (2007-12-03), â€Å"Creative inroduces World’s 1st 32 GB Flash based PMP† retrieved from: http://asia. creative. com/corporate/pressroom/releases/welcome. asp? pid=12867 Wolverine Data, (2008-01-02), â€Å"Wolverine ESP 250 GB† retrieved from: http://secure. serverlab. net/shop/merchant. mvc? Screen=PRODProduct_Code=5250Category_Code=ESPStore_Code=T00107 â€Å"Identifying Ipod Models† retrieved from: http://docs. info. apple. com/article. html? artnum=61688

Information Systems On Delta Airlines

Information Systems On Delta Airlines Headquartered in Atlanta, USA, Delta Airlines is by far the worlds largest airline by fleet size, destinations as well as passenger revenue. Delta airlines, founder and included in the SkyTeam airline alliance, encompasses a broad domestic and international travel network, with it unsurpassed global network. The largest operational hub of Delta airlines is the Hartsfield-Jackson Atlanta Internal Airport and the Detroit Metropolitan Wayne County Airport. Serving more than 170 million passengers every year, and counting, Delta together with its Northwest subsidiary as well as the Delta Connection carriers fly to as many as 355 destinations covering 66 countries, across 6 continents (Delta 2009) (StealingShare). Delta accomplished its merger with the Northwest Airlines on October 29, 2008, with the main aim of forming the globes largest commercial carrier. Then, in February 2009, it started merging ticket counters and gates at airports at which both Delta and Northwest operated, and received permission from the Federal Aviation Administration to commence its operations under a single certificate. This consolidation was finished in February 2010. With the successful incorporation of the Northwest acquisition, investments of Delta Airlines, in newer products and network backed by continued efforts for strengthening its balance sheet, the company is favourably positioned to gain full benefit of the economic recovery. Northwest acquisition is estimated to generate about $2billion as annual revenue and price synergies by 2012(Delta 2009) (Travel Video News 2010). Evaluation: Ever-increasing competition throughout the airline industry is causing the development of new applications of information systems and technology. This includes a new strategic focus on electronic commerce or e-commerce at Delta Airlines. Deltas mid-tier operation information systems has been presented as a scheme for leveraging its operational online transaction processing system (OLTP) infrastructure, in order to be an active part of the emerging world of e-commerce and enable new applications. The basic approach is to insert minimally intrusive taps within the OLTP systems to track transactions as they occur for reproducible reply in the mid-tier operational information system (OIS). For the existing environment, a hybrid approach can be developed and evaluated, Conventionally, large enterprise computing at organizations like Delta is based on the usage of clusters of mainframes that run patent information systems software. A goof evidence of this statement is that Delta works depending on the cluster of IBM S/390 mainframe machines that run system TPF or Transaction Processing Facility. Such traditional OLTPs often support applications which automate most of the airlines operational services. Further, the TPS systems architecture has shown high degree of scalability and availability, with the system operating successfully since the last 30 years and withstanding the Y2K bug scare (Delta 2009). Technically, it is difficult to change the functionalities of these existing OLTP applications in order to accommodate a varying business. Several applications were deployed in assembly language and have evolved since then. The applications were originally designed for executing specific business models and providing little flexibility to support newer business models as well as processes. Particularly, these applications sustain ownership of fixed data sets, and their legacy data formats do not allow creation of new relationships to application data. Also, new business models and processes lead to new applications, many of which leverage the Internet, thereby resulting in exposure of legacy systems to unanticipated transaction volumes (Vasilecas et al 2006). As a response to these drawbacks, Delta pursued a novel strategy of adding mid-tier enterprise information systems known as operation information systems, (OIS). In essence, the pool of information in the current OLTP systems is gathered by grabbing strategic transactions when they occur in soft real-time. The transactions are then duplicated and consistently reproduced in the newly formed OIS. This new environment sees the mapping of data stemming from the transactions into alternative acquirable formats, which bears a correlation with initial unrelated information, together with information from sources apart from the OLTP systems. Furthermore, the immediate mutual-relation triggers events that are extracted from the transaction records. This susceptibility allows for a totally new category of real-time event based applications, which aim at radically improving the effectiveness of airline operations. Moreover, the new mid-tier OIS, considered along with the legacy OLTP system, is said to be the foundation on which Delta generates new applications and enhances its existing business operations, such as improvement of the Customer Experience. The primary factor to their ever-growing success is the development of new mission-driven software and hardware infrastructures supporting these efforts (Vasilecas et al 2006). The architecture of the operation information systems has evolved on a whole, since the scalability and availability requisites have changed. Earlier, the system represented a concept that gained instant success and was implemented far-ahead of its designed capability. The currently executed system has been technically refined to fulfil the scalability and availability requirements (HubPages 2008). From a perspective, relative to data warehouses that generally store enormous bulk of historical information, an operational information system contains only the basic subset of information needed for day-to-day operations. While the size of the operational working set is relatively smaller, the collection of operation flows from internal as well as external sources may lead to operational data stores of terabytes in value. Maintaining such databases and the analytical processing of the data are two primary and basic tasks of the mid-tier OIS. Additional tasks are acquisition, derivation, broadcasting events having low latencies and in soft real time. Taking into account the demands of these tasks, a crucial observation indicates that the order of magnitude of the information from where applications events are obtained is possible to be reduced, mainly by emphasizing on the data required for operational decisions and actions. Hence, event latencies and throughput are improved by spec ifying a derivation subset termed as the Derivation Working Set. The DWS comprises of minimal amount of data required to derive the events needed for the OIS applications. Moreover, performance of data storage as well as data access for derivation of events is significantly enhanced as this working set can be executed as a main-memory database which is organized for accommodating event derivation and initial state queries (Oleson et al) (Mendelson Brynjolfsson 1993). A window scheme is used for operating the DWS, in which the content appears and disappears from the DWS based on relevance of information. Particularly, this set holds all state of current interest to be able to be rapidly accessed by relevant business process. For example, information regarding a flights arrival is stored in the DWS until the flight has departed, immediately after which business logic is added to the DWS indicating that the data in regards to a certain flight section has been finished. Further, the lifetime or window of the data in the DWS depends on the business operations for a certain business domain. Such as years of experience in using flight information results in identification of a window of flight data coupled with behaviour for a number of days in the past and days in the future. Furthermore, lifetimes are different across business domains, and are not dynamic like the lifetimes of event arrivals. For example, a flight exits from a gate and starts taxiing, so the boarding process for that flight is not relevant anymore and may be discarded into the operational data store (ODS), and also to the data warehouse (Oleson et al). Since an existing deployment crosses 10,000 machines, displaying flight status information, the greatest profile service of the OIS infrastructure is the soft real time delivery support of event information to numerous subscribing passengers. Further, real-time applications for event trigger the re-thinking of business processes and motivate to revolutionize the operations of the airlines. For example, when gate agents are supplied with alert displays which give the current view of relevant flight information, such as seat maps inside the flights they work for. The conventional request/reply approach is restricted as agents spend maximum time operating at the computer terminal, generally sending answers to customer questions. These heads up displays inform both the customers as well as the agents freeing the agents to spend their time in responding to more crucial issues, such as facilitating the boarding procedure (Travel Video News 2010) (Vasilecas et al 2006). For achieving high scalability and lower latencies, the liberalization of the reliance of every event transmission is dependent on the application characteristics. Although some applications need tight assurances, others may run successfully under relaxed rules, known as the reliability spectrum. For exploiting this spectrum, the usage of a mixed sender and receiver-driven multicast protocol is capable of providing dramatic enhancements in the latency as well as communication scalability of an EDE. The Event Driven Engine (EDE) is the major data provider and consumer for extra services related to the operational subsystem, like the Internet-based reservation and flight schedule and information services, which is the reservation system employed by external systems of a business to business model. Eventually, the EDE can directly distribute events to display points like the flight displays at airports, leading to the need for greater scalability in terms of amount of displays for certain event output streams emitting from the EDE. The earlier EDE design employed a commercial relational database for internalizing the transaction records and depicting the operation working set. The initial purpose was to enable quick, flexible queries coupled with distribution of low latency event. Nonetheless, as the operational working sets are growing to Terabyte magnitudes, experts and the management of Delta instantly realized the competition among sustaining massive databases and rapid event derivation from this database. After using this deployed architecture, disk-resident relational data provided inadequate performance only to handle all of the work needed for the OIS infrastructure. Furthermore, not only the OIS should process the variable peaks of 12 million source message per day, but also must the OIS additionally derive a minimum of that many application friendly events to a deployment of approximately 10,000 workstations (Oleson et al). This desired amount of workstations is anticipated to increase dramatically in the future. The explosion of initial state queries take place as computers dynamically subscribe, which in turn require initial states. This initial state, for FIDS (Flight Information Display Systems) applications, resulting in XML result set of 5 MB exerts a massive load on the system. Worst case scenario will be all current 10,000 machines might come on-line at the same time requiring 10,000 queries. Further, this situation is worsened by the presence of additional external systems, such as passenger-booking traffic through the Internet, thereby resulting into the addition of much more information flows as well as resulting analysis tasks such as small flows like automatic passenger paging services, multimedia flows, etc (Mendelson Brynjolfsson 1993). Therefore, Delta discontinued offering further support to the feature of analytical queries of the OIS and started to maintain a lower in-memory depiction of the working set. Again, the relational database representation was used to recover this evaluated state during failures. However, frequent failures in the system could result into businesses facing substantial downtime. For this, the time to substitute the running cache from the many terabyte RDMS is approximately 45 minutes. Furthermore, the client connectivity for the existing system depends on a hierarchical fan out on the basis of TCP socket concentrators. Delta was able to identify that this scheme adds unnecessary moving parts and inserts latency while events traverse the hops. Additionally, Deltas requirements along with experiences in constructing a commercially embraced OIS infrastructure have greatly prompted the existing academic research. The present scalability challenges and future scalability projections demand clean slate scheme for researching more desirable and favourable architectures for an operational information system (Oleson et al). Several applications operate successfully during incidents of message loss and take advantage of relaxed reliability protocols. This feature does not entail that the applications will have inconsistent views of information. This feature also proves that natural alternative means exist to guarantee the application information integrity. Furthermore, the most fundamental characteristic needed here is the ability to identify event loss and the capability of re-synchronizing a client application on detection of message loss. And this functionality is offered by the FIDS application of the OIS, where if a message loss takes place, the FIDS client re-synchronizes by asking for an initial state and starts receiving events that can update that state. In essence, the reliability/performance tradeoffs of sender- vs. receiver-initiated multicast protocols are widespread, which offer stronger vs. weaker throughput vs. reliability, wherein attributes of both kinds of protocols are utilized for gaining a compromise for demanded reliability coupled with greater throughput. The receiver, in this protocol, controls and detects lost messages via sequence number analysis, while the sender is responsible for buffering the messages to accommodate retransmission requests (Mendelson Brynjolfsson 1993). Toward that end, the research as well as commercial opportunities have been presented by operational information systems (OIS) along with their strategic importance to Delta Airlines. Tapping the legacy operational systems is an interesting approach used by the research study to developing new systems employed by Delta. Further, desired representations of operational information can be reproduced for new, mid-tier OIS. The basic idea is to build additional systems across which new business applications are developed, without threatening the existing systems and their normal operations. The evaluation of OIS then focuses on efficient, scalable and low latency processing together with the distribution of events, by evolving the existing communication/ event infrastructures and OIS event processing as well as storage engines (StealingShare).

Sir Gawain and the Green Knight:The First Swing :: Arthurian Legends English Literature Essays

Sir Gawain and the Green Knight:The First Swing In Sir Gawain and the Green Knight, a stranger rides into King Arthur's court with a challenge. This stranger, green in color from head to toe, proposes to play a game with a member of King Arthur's court. This game will be played by each participant taking a blow from a weapon at the hands of the opponent. The person that dies from the hit is obviously the loser. On top of this, the Green Knight offers to let his opponent take the first swing. This sets up the action in the passage beginning with line 366 and ending with line 443. Sir Gawain steps in to take the challenge after King Arthur first agrees to participate himself. Sir Gawain wants to bring honor to Arthur and asks permission to take his place. Gawain knows that he is not the strongest, smartest knight but the loss of his life would not be as bad as if King Arthur loses his life. King Arthur agrees to let him enter this game and gives him a weapon to use against this Green Knight. King Arthur says to Sir Gawain, "Keep, cousin what you cut with this day, and if you rule it aright, then readily, I know you shall stand the stroke it will strike after." (372-374) Gawain, with his weapon in his hand, is now ready to take part in the game. Before the contest starts, the Green Knight goes over the rules of the game again. He says that if he survives the hit from Gawain's ax, Gawain must search out where he lives so that he can take his hit from the Green Knight. When the Green Knight tells Gawain he must find the place where he lives, Gawain quickly asks, "What is the way there? Where do you dwell?" (398) The Green Knight refuses to tell, as this is part of the game. If the stranger survives Sir Gawain's blow from the ax, he will tell Gawain his name and the name of his dwelling.

The Symbolic Pearl in Hawthornes The Scarlet Letter :: Scarlet Letter essays

Pearls have always held a great price to mankind, but no pearl had ever been earned at as high a cost to a person as in Hester Prynne, a powerful Heroine in Nathaniel Hawthorne’s novel The Scarlet Letter. Her daughter Pearl, born into a Puritan prison in more ways than one, is an enigmatic character serving entirely as a vehicle for symbolism. From her introduction as an infant on her mother’s scaffold of shame to the stormy peak of the story, Pearl is an empathetic and intelligent child. Throughout the story she absorbs the hidden emotions of her mother and magnifies them for all to see. Pearl is the essence of literary symbolism. She is, at times, a vehicle for Hawthorne to express the inconsistent and translucent qualities of Hester and Dimmesdale’s unlawful bond, and at other times, a forceful reminder of her mother’s sin. Pearl Prynne is her mother’s most precious possession and her only reason to live, but Pearl also serves as a priceless trea sure purchased with Hester’s life. Pearl’s strange beauty and deeply enigmatic qualities make her the most powerful symbol Hawthorne has ever created. The product of Hester’s sin and agony, Pearl, was a painfully constant reminder of her mother’s violation of the Seventh Commandment: Thou shalt not commit adultery. Hester herself felt that Pearl was given to her not only as a blessing but a punishment worse than death or ignominy. She is tormented by her daughter’s childish teasing and endless questioning about the scarlet letter and its relation to Minister Dimmesdale. After Pearl has created a letter â€Å"A† on her own breast out of seaweed, she asks her mother: But in good earnest, now, mother dear, what does this scarlet letter mean? -- and why dost thou wear it on thy bosom? -- and why does the minister keep his hand over his heart? In saying this Pearl implies that she knows much, much more about the scarlet letter than she lets on. T hroughout the conversation Pearl is impish and teasing, saying one thing and contradicting it soon after. She refuses to say just what she means, which makes it hard for Hester to give a straight answer. Hester is shocked that her playful daughter has lead their conversation to the topic of the scarlet letter, and even more disturbed that she has assumed Hester’s letter and Dimmesdale’s habit of pressing his hand to his heart a branch from the same issue. The Symbolic Pearl in Hawthorne's The Scarlet Letter :: Scarlet Letter essays Pearls have always held a great price to mankind, but no pearl had ever been earned at as high a cost to a person as in Hester Prynne, a powerful Heroine in Nathaniel Hawthorne’s novel The Scarlet Letter. Her daughter Pearl, born into a Puritan prison in more ways than one, is an enigmatic character serving entirely as a vehicle for symbolism. From her introduction as an infant on her mother’s scaffold of shame to the stormy peak of the story, Pearl is an empathetic and intelligent child. Throughout the story she absorbs the hidden emotions of her mother and magnifies them for all to see. Pearl is the essence of literary symbolism. She is, at times, a vehicle for Hawthorne to express the inconsistent and translucent qualities of Hester and Dimmesdale’s unlawful bond, and at other times, a forceful reminder of her mother’s sin. Pearl Prynne is her mother’s most precious possession and her only reason to live, but Pearl also serves as a priceless trea sure purchased with Hester’s life. Pearl’s strange beauty and deeply enigmatic qualities make her the most powerful symbol Hawthorne has ever created. The product of Hester’s sin and agony, Pearl, was a painfully constant reminder of her mother’s violation of the Seventh Commandment: Thou shalt not commit adultery. Hester herself felt that Pearl was given to her not only as a blessing but a punishment worse than death or ignominy. She is tormented by her daughter’s childish teasing and endless questioning about the scarlet letter and its relation to Minister Dimmesdale. After Pearl has created a letter â€Å"A† on her own breast out of seaweed, she asks her mother: But in good earnest, now, mother dear, what does this scarlet letter mean? -- and why dost thou wear it on thy bosom? -- and why does the minister keep his hand over his heart? In saying this Pearl implies that she knows much, much more about the scarlet letter than she lets on. T hroughout the conversation Pearl is impish and teasing, saying one thing and contradicting it soon after. She refuses to say just what she means, which makes it hard for Hester to give a straight answer. Hester is shocked that her playful daughter has lead their conversation to the topic of the scarlet letter, and even more disturbed that she has assumed Hester’s letter and Dimmesdale’s habit of pressing his hand to his heart a branch from the same issue.

Ketamine Pain Mechanism

Pain is communicated from the brain to other parts of the body by the CNS (Central Nervous System) and nerve endings. (Mayer, Mao, Holt, Price, 7731-7736) The ligand-gated ion channels, also referred to as LGICs, or ionotropic receptors, are a group of intrinsic transmembrane ion channels that are opened in response to binding of a chemical messenger. (Collingridge, Singer, 290-296) (Dickenson, 307-309) (Dickenson, Chapman, Green, 633-638)The ion channel is regulated by a neurotransmitter ligand that is very selective to one or more ions like potassium, sodium, calcium, and chloride. (Kandel, Schwartz, Jessell, 178-180)   Such receptors located at synapses converting the chemical signal to an electric signal in the post-synaptic cell. (Connolly, Wafford, 529-534)   The NMDA receptor (N-methyl-D-aspartate) is such an ionotropic receptor for glutamate. (Dingledine, Borges, Bowie, Traynelis, 7-61) (Lodge, Johnson, 81-86) (Meller, 435-436)   By X-ray crystallography, the NMDA recep tors have an heterodimer subunits, which are involved in the binding of agonists and antagonists like Ketamine. (Hirota, Lambert, 441-444)This channel complex contributes to excitatory synaptic transmission at sites throughout the brain and the spinal cord, and is modulated by a number of endogenous and exogenous compounds. (Rabben, Skljelbred, Oye, 1060-1066)   NMDA receptors play a key role in a wide range of physiologic and pathologic processes. (Hoffman, Coppejans, Vercauteren, Adriemsen, 240-242) (Klepstadt, Maurset, Moberg, Oye, 513-518) (Coderre, Katz, Vaccarino, Melzack, 259-285) Ketamine is primarily a non-competitive antagonist, which opens in response to binding of glutamate. This NMDA receptor mediates the reduction of pain effects of ketamine at low doses. (Lofwall, Griffiths, Mintzer, 439-449)Evidence for this is reinforced by the fact that naxolone, an opioid antagonist, does not reverse the analgesia. Studies also seem to indicate that ketamine is ‘use depend ent' meaning it only initiates its blocking action once a glutamate binds to the NMDA receptor. (Sorensen, Bengtsson, Ahlner, Henriksson, Ekselius et al., 1615-1621)   At high level doses, ketamine has also been found to bind to opioid mu receptors and sigma receptors. Thus, loss of consciousness that occurs may be partially due to binding at the opioid mu and sigma receptors. (Lonnqvist, Norton, 617-621)(Menigaux, Fletcher, Dupont, Guignard, Guirimand, et al. 129-135) (Koppert, Sittl, Scheuber, Alsheimer, Schmelz, 152-159) (Bushell, Endoh, Simen, Ren, Bindokas, 55-64)Works CitedMayer DJ, Mao J, Holt J, Price DD. Cellular Mechanisms of Neuropathic Pain, Morphin Tolerance, and their Interactions. Proc. Natl Acac. Sci. USA. 1999, 96(14): 7731-7736.Collingridge G, Singer W. Excitatory Amino Acid Receptors and Synaptic Plasticity. Trends Pharmacol Sci. 1990 11: 290-296.Dickenson AH. A cure for wind-up: NMDA receptor antagonists as potential analgesics. Trends Pharmacol Sci 1990 11: 30 7-309Dickenson AH, Chapman V and Green GM. The pharmacology of excitatory and inhibitory amino acid-mediated events in the transmission and modulation of pain in the spinal cord. Gen Pharmacol 1997 28: 633-638Kandel ER, Schwartz JH, Jessell TM. Principles of Neural Science, 4th ed. McGraw-Hill: New York, (2000), pp.178-180Connolly CN, Wafford KA. The Cys-Loop Superfamily of Ligand-Gated Ion Channels – the Impact of Receptor Structure on Function. Biochemical Society Transactions (2004) Vol. 32: 529-534.Dingledine R, Borges K, Bowie D, Taynelis SF. The Glutamate Receptors Ion Channels. Pharmacology Reviews, 1999 51(1): 7-61Lodge D and Johnson KM. Non-Competitive Excitatory Amino Acid Antagonists. Trends Pharmacol Sci 1990 11: 81-86Meller ST. Ketamine: Relief from Chronic Pain through Actions at the NMDA Receptor? Pain   1996 68: 435-436Hirota K, Lambert DG. Ketamine: Its Mechanism (s) of Action and its Unusual Clinical Uses. Br. J. Anesth. 1996, 77(4):441-444.Rabben T, Skjel bred P, Oye I. Prolonged Analgesic Effects of Ketamine, an N-Methyl-D-Aspartate Receptor Inhibitor, in Patients with Chronic Pain. The Journal of Pharmacology and Experimental Pharmaceutics. 1999, 289(2):1060-1066.Hoffmann V, Coppejans H, Vercauteren M and Adriaemsen H Successful Treatment of Postherpetic Neuralgia with Oral Ketamine. 1994 Clin J Pain 10: 240-242Klepstad P, Maurset A, Moberg ER and Oye I Evidence for a Role for NMDA Receptors in Pain Perception. Eur J Pharmacol   1990 187: 513-518Coderre TJ, Katz J, Vaccarino AL and Melzack R.   Contribution of Central Neuroplasticity to Pathological Pain: A Review of Clinical and Experimental Evidence. 1993 Pain 52: 259-285.Lofwall MR, Griffiths RR, Mintzer MZ. Cognitive and Subjective Acute Dose Effects of Intramuscular Ketamine in Healthy Adults. Ex. Clin. Psychopharmacol. (2006), 14(4):439-449Sorensen J, Bengtsson A, Ahlner J, Henriksson KG, Ekselius L and Bengtsson M.   Fibromyalgia. Are there different mechanisms in the processing of pain? A double Blind Crossover Comparison of analgesic Drugs. 1997 J Rheumatol 24: 1615-1621Lonnqvist PA, Norton NS. Pediatric Day-Case Anesthesia and Pain Control.   Curr. Opin. Anaest. (2006), 19(6): 617-621.Menigaux C, Fletcher D, Dupont X, Guignard B, Guirimand F, Chauvin M. The Benefits of Intraoperative Small-Dose Ketamine on Postoperative Pain after Anterior Cruciate Ligament Repair. Anesth. Analg. 2000 90(1): 129-135Koppert W, Sittl R, Scheuber K,Alsheimer M, Schmeltz M, Schuttler J. Differential Modulation of Remifentanil-Induced Analgesia and Post-Infusion Hyperalgesia by S-Ketamine and Clonidine in Humans. Anesthesiology. 2003, 99(1): 152-159.Bushell T, Endoh T, Simen AA, Ren D, Bindokas VP, Miller RJ. Molecular Components of Tolerance to Opiates In Single Hippocampal Neurons. Mol. Pharmacol. 2002, 61(1): 55-64.