Recent advances in reversible opticalstorage materials compatible with low-cost semiconductor lasers have led to experiments on high-areal-density high-data-rate opticalstorage of digital data. The results of these ...
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Recent advances in reversible opticalstorage materials compatible with low-cost semiconductor lasers have led to experiments on high-areal-density high-data-rate opticalstorage of digital data. The results of these experiments indicate that areal-densities of 10**8 bits/in**2 (1. 6 multiplied by 10**7 bits/cm**2) and data-rates from 10-25 Mbits/sec appear feasible. This, together with an improved high-track-density beam servo scheme, allows a high-capacity (1G Byte/surface) optical file to be configured using 14 inch diameter disk technology.
Communication to application developers and data users of CD-R characteristics such as data integrity, media reliability and life expectancy should be considered as engineers create opticalstorage media that can stor...
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ISBN:
(纸本)081943292X
Communication to application developers and data users of CD-R characteristics such as data integrity, media reliability and life expectancy should be considered as engineers create opticalstorage media that can store more data. Though the point of view of this paper is primarily based on the views of a few experienced CD-R end-users, optical engineers should consider implementation of the following design recommendations explained in this paper. The authors' extensive experience in using CD-R technology and their substantial interaction with other CD-R users provides a rare perspective on CD-R characteristic information. Although this paper is directed to optical engineers, it is written with the expectation that a broader readership will also benefit from the information presented. The paper presents to the engineering community potential methods of communicating CD-R characteristics with an emphasis on the types of information that would be useful to CD-R users.
Non-volatile memories (NVMs) have revolutionized modern datastorage systems, especially boosting the performance of power-latency-sensitive applications. Recently, they have also emerged as an important technical ave...
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Cloud computing and Cloud datastorage have become the preferred method for delivering services over a network. As the data in today's scenario is proliferative, there is a need to keep it safer which requires org...
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ISBN:
(纸本)9781479963935
Cloud computing and Cloud datastorage have become the preferred method for delivering services over a network. As the data in today's scenario is proliferative, there is a need to keep it safer which requires organizations to integrate their data usage and management patterns. To meet these requirements, No-SQL due to its better scalability, is a vantage over RDBMS. This paper presents a prototype implementation of storage efficiency techniques in No-SQL database (SETiNS) in which deduplication and compression together are used to avoid unnecessary storage purchases and reduce storage space for unraveling large volumes of data handling problems. The improved storage efficiency for No-SQL database is evaluated by using the combination of the MapReduce capabilities of Hadoop with the schema-less database MongoDB. The result shows improved storage efficiency by saving subsequent storage space and network bandwidth in the case of internode data transfer.
An all-optical telecommunications network requires all-optical routers. These routers would be able to process optical signals directly, without the transformation to the electrical domain. Thus, optical routers have ...
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ISBN:
(纸本)9780819493989
An all-optical telecommunications network requires all-optical routers. These routers would be able to process optical signals directly, without the transformation to the electrical domain. Thus, optical routers have the potential to accelerate telecommunications, i.e. to enhance the data rate and to minimize the latency times. Furthermore, since the double transformation at each network node can be omitted, they could be able to reduce the energy consumption of telecommunications. Key elements of optical routers are optical buffers, which are able to store the optical packets prior to processing in order to avoid congestion. Therefore, many different concepts for the realization of optical buffers have been presented so far. Most of these can just store or delay on-off keyed (OOK) signals. However, in optical telecommunications advanced modulation formats will be increasingly used because they are able to improve the transmission properties and to take advantage of the capacity of optical fibers. Thus, advanced modulation formats can drastically increase the transmissible data rates. Most of these advanced formats modulate the carrier's phase or are a combination of amplitude and phase modulation. Here the storage of amplitude and phase modulated data packets with the so called quasi-light-storage (QLS) method will be shown. The QLS relies on the time-bandwidth coherence of each signal. Thus, as long as the sampling theorem in the frequency domain is not violated, a distortion-free storage of opticaldata packets with a delay-bandwidth product (DBP) of several thousand bits is possible. Here we will discuss the applicability of the QLS method to advanced modulation formats and we show experimental results of the tunable all-opticalstorage of OOK modulated signals with a DBP of 160 bit and the storage of phase shift keyed signals with a DBP of 60 bits.
Vertical degree of pick-up and disc is an important factor that influences reading and writing date in DVD drive. Measuring and adjusting vertical degree of pick-up and disc is a key working procedure in DVD drive man...
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ISBN:
(纸本)0819455989
Vertical degree of pick-up and disc is an important factor that influences reading and writing date in DVD drive. Measuring and adjusting vertical degree of pick-up and disc is a key working procedure in DVD drive manufacture. Now, measuring method in actual production is an indirect measuring, which measure parallel between spindle motor and traverse. It's not very accuracy as there are error in pick-up assembles, The paper suggests a new method to measure vertical degree of pick-up and disc, new method measure vertical degree of pick-up and disc directly. The key of new method is measure position of laser from pick-up. A specialty optical circuit and fine CCD camera is need. The CCD camera is responsibility for collection information of laser image of pick-up and sends information to a computer. The specialty software responsibility for calculating position of laser and calculating incline angle between pick-up and disc. Because of characteristic of DVD drive manufacture, the algorithm calculating position of laser image must be design for accuracy and quickness. The paper suggests a specialty algorithm to calculating position of laser image. The algorithm is very accuracy and quickly, it can measure 0.05-degree incline angle error. The new method is helpful to automatic adjusting technique vertical degree of pick-up and disc.
The opticalstorage device has been put into practical use greatly as a ultimate high capacity, low cost per bit, removability and reliability information recording device. But it has a great disadvantage of slow spee...
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ISBN:
(纸本)0780339061
The opticalstorage device has been put into practical use greatly as a ultimate high capacity, low cost per bit, removability and reliability information recording device. But it has a great disadvantage of slow speed compared with magnetic disks. In order to improve the data transfer rate of opticalstorage subsystem, and to enhance the overall data throughput of system, we propose a new opticalstorage system architecture in this paper, which is the combination of array of opticalstorage devices and a plurality of buffers coupled to separate opticalstorage device. In the scheduling of buffer, we use the technique of Ping-Pong buffer and the tagged elevator write back as the destage algorithm. In this manner, the performance of opticalstorage system is dramatically enhanced, especially for the small writes.
Information storage in DASDs is a key part of a computer system. The worldwide revenue opportunity for DASD products is more than $50 billion. In order to meet the ever-increasing demand in capacity, performance, and ...
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ISBN:
(纸本)0819410160
Information storage in DASDs is a key part of a computer system. The worldwide revenue opportunity for DASD products is more than $50 billion. In order to meet the ever-increasing demand in capacity, performance, and cost-savings, rapid technological advances in magnetic recording have been carried out in laboratories around the world. The recent development for laptop and notepad PCs further demands the need for low power and smaller files. The technology trends in magnetic recording in terms of areal density, volumetric efficiency, and material advances based on published data are reviewed. opticalstorage including read-only, write-once, and read/write drives becomes an emerging technology with a removability feature, which may complement magnetic recording DASDs. The recent advances in opticalstorage media and drives and their comparisons with magnetic recording technology are discussed.
Nowadays, cloud storage service has been widely deployed by multiple providers that offer free and large-sized datastorage. Nevertheless, along with the advantages are the risks of data loss, the service providers...
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ISBN:
(纸本)9783319490731;9783319490724
Nowadays, cloud storage service has been widely deployed by multiple providers that offer free and large-sized datastorage. Nevertheless, along with the advantages are the risks of data loss, the service providers' unauthorized access to data, and data loss due to the providers' unsustainability. This paper will investigate how to use cloud storage capability in a safe and low-cost way. The authors will present solutions for secured cloud datastorage based on the RAID redundancy mechanism, partially encrypted data and mathematical models established on the probability theory and the system reliability.
optical inverse multiplexing is a promising technology for high-rate data transmission and rapidly increased demand for capacity. To realize this technology, a key issue is the buffering to alleviate the delay among p...
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optical inverse multiplexing is a promising technology for high-rate data transmission and rapidly increased demand for capacity. To realize this technology, a key issue is the buffering to alleviate the delay among parallel routes. As described in this paper, delay time characteristics and wavelength increase of optical inverse multiplexing using optical parallel routes in WDM mesh networks are evaluated quantitatively for rapid capacity demand, comparison with the case of whether the existing route is still used or not.
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