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Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Magnetic disks are the most common devices used in online mass-storage systems. Magnetic disks record information in the form of magnetic polarization of particles on its surface. A disk system consists of a number of platters mounted on a common spindle, with coupled read/write heads for each platter. A platter is made up of a number of concentric tracks, divided into smaller units known as sectors. A common sector size is 512 bytes, and is the smallest unit of access. The tracks in different platters line up to form a cylinder. Disk systems have shown remarkable improvements in capacity and performance over the past decade, resulting in dramatically decreasing costs. Innovations in technology have resulted in higher recording densities, smaller form factors, increased spindle speeds, and optimized transfer rates by the use of multizoned disks.
Hardware and systems issues
Published in Francis Rumsey, Desktop Audio Technology, 2003
A sector typically contains 512 bytes. The disk is of the ‘write-many-times’ format which means that old data may be overwritten many times in order to reuse the storage space. Although the disk surfaces of such a drive are not removable, drives exist that may be interchanged in their entirety. Such drives are known as removable drives (not removable disks) and they are usually mounted in a cartridge with a handle so that they can be ‘unplugged’ from a docking frame of some sort. Figure 5.6 shows a photograph of such a system. This is a useful feature, but it is relatively expensive to interchange complete drives in this way. It may be considered worth the advantage of being able to take a complete session’s primary storage from one system and insert it into another.
S
Published in Phillip A. Laplante, Dictionary of Computer Science, Engineering, and Technology, 2017
sector mapping a cache organization in which the cache is divided into sectors where each sector is composed of a number of consecutive lines. A complete sector is not transferred into the cache from the memory, only the line requested. A valid bit is associated with each line to differentiate between lines of the sector that have been transferred and lines from a previous sector. Originally appeared in the IBM System/360 Model 85.
Novel, compact, circular-sectored antenna for Ultra-Wideband (UWB) communications
Published in Electromagnetics, 2020
Arnab De, Bappadittya Roy, Anup Kumar Bhattacharjee
The Geometry of the proposed antenna configuration is demonstrated in Figure 1. To design the proposed one at first, a rectangular shape reference antenna is considered and denoted as Antenna 1 having a dimension of 40 × 40 mm2 as shown in Figure 1(a). In the second step, the patch structure is changed and made as a circular sector shape of radius (a) shown in Figure 1(b), where the ground plane structure is same as Antenna 1. In the next step, the ground structure is modified and another circular sector part of radius (b) is introduced in the ground plane which is shown in Figure 1(c). Now the structure consists of two circular sectored parts, in which one element on the top is the patch, shown in Figure 1(b) and the other sectored part is the ground plane on the back surface, shown in Figure 1(c). In the last step, the final geometry is achieved by embedding two symmetrical circular slots in the patch of radius (r1 = r2) 5.0 mm. The distance (d) is the center-to-center distance of the two circles. The radius of the circles plays an important part in enlarged bandwidth and compactness. A Rogers RT/Duroid 5880 substrate having thickness of 0.787 mm, dielectric constant (Ɛr) of 2.2 and loss tangent (tan δ) = 0.002 is used for the structure. The overall dimension of the antenna as well as width and length of the substrate are 40 mm and 40 mm, respectively. The designed prototype is fed by a co-axial probe of 50 Ω impedance with the help of an SMA connector of radius 0.5 mm. The feed point is optimized to match the input impedance over the entire UWB range. Table 1 shows all the dimensions of the parameters starting from Antenna 1–4.
An impulse response formulation for small-sample learning and control of additive manufacturing quality
Published in IISE Transactions, 2023
We can find a smallest circular sector to approximate each shape primitive Apparently, if is a circular sector. Then (7) can be rewritten as:
Dynamic stability, and absorbed energy measurements in a sandwich structure resting on the novel frictional viscoelastic torsional substrate and horizontal friction force
Published in Mechanics Based Design of Structures and Machines, 2022
Zhao Yan-wen, Yan Zhenwei, Sun Le-min
Figure 5 is presented to investigate the influence associated with the angle of the circular sector plate on the vibrational response of the disk. The higher θ is, the lower the vibrational frequency of the system can be. Also, the effect of l/h and μ/h on the vibrational frequency is higher in the cases with higher θ.