Information Retrieval Systems: A Perspective on Human Computer Interaction
| Autor: | Panagiotis Petratos |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | Issues in Informing Science and Information Technology, Vol 3, Pp 511-518 (2006) |
| ISSN: | 1547-5867 1547-5840 |
| Popis: | Introduction During the last few decades the amount of digital information has been constantly increasing at an accelerating rate. This condition is often referred to as the information overload problem. The reasons for this information overload problem are of technological as well as of social and economic nature. Technological reasons include the recent advances in high density information storage as well as high speed telecommunications. Currently there are four types of media for the storage of information, magnetic, optical, film and the good old paper. Analogously, at present there are four types of streams for the dissemination of electronic information, the Internet, telephone, television and radio. A more traditional non-electronic but still very powerful source of information is the formal printed press which includes periodic publications such as newspapers and journals and non-periodic publications such as books. It is interesting to note that the majority of new information created during 2002, or more than 98% of the total of all information transmitted in electronic information flows was exchanged between individuals during communication sessions including email, peer to peer file exchanges, and the telephone including both voice and data such as fax on land lines and instant messaging on wireless mobiles (Lyman & Varian, 2003). Currently in the well-developed countries found in the continents of North America and Western Europe there is a digital convergence trend evident. Telecommunications companies such as Vonage are currently attempting to offer a flat fee model by diverting the enormous amount of information from telephone communications through the Internet and routing it as Internet packet traffic primarily due to economic reasons as the per minute charges are eliminated. It is only a matter of time before the Internet becomes the primary backbone for telephone communications and the principal information flow infrastructure for all information transmitted. Information Storage Technologies Furthermore, recent magnetic storage technology advances are offering an alternative to the rapidly approaching physical limit of magnetic disk storage density. During the last fifty years the traditional storing process for magnetic disks has been utilizing longitudinal recording technology. The data bits of hard disks are microscopic magnetic grains that are aligned horizontally on the surface of the disk and are magnetized according to the longitudinal recording; please see Figure 1. [FIGURE 1 OMITTED] Based on this technology there is only one way to increase the data density of hard disks. This approach has been used successfully for the last fifty years steadily increasing data density by continuous miniaturization of the data bits. However, there are practical as well as physical limits to miniaturization, just as it is evident now to the microprocessor industry where the strategy of manufacturing ever smaller transistors, in order to pack as many as possible inside a single chip, is beginning to encounter its physical limits. For the hard disk industry the practical as well as the physical limits are elucidated by a natural phenomenon called superparamagnetism, which occurs when the microscopic magnetic grains on the disk surface become so minute that haphazard thermal vibrations at room temperature are the aetiology for them to lose their ability to hold their magnetic orientations. The corollary is instant damage to data integrity that occurs as the microscopic magnetic grains whose north and south poles suddenly and arbitrarily reverse and experience magnetic anastrophe leading to data corruption and storage device unreliability. A different approach from the existing data storing strategies is the new perpendicular recording technology; please see Figure 2. Perpendicular recording utilizes the depth of the disk, not just the surface of the circular platter, by aligning the microscopic magnetic grains vertically and thus allows for more data bits to be stored in the same space, which under longitudinal recording it was occupied by much fewer horizontal data bits (Mallary, Torabi, & Benakli, 2002). … |
| Databáze: | OpenAIRE |
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