Competitive Analysis of On-Line Disk Scheduling

In this paper we study three popular on-line disk scheduling algorithms, FCFS, SSTF, and LOOK, using competitive analysis. Our results show that, in a competitive sense, the performance of LOOK is better than those of SSTF and FCFS. As a by-product, our analysis also reveals quantitatively the role played by the size of the window, which in our model is a waiting buffer that holds a fixed number of requests waiting to be serviced next. The window, in some sense, offers the lookahead ability which is mentioned in several on-line problems. Received February 1997, and in revised form November 1997, and in final form February 1998.     

A novel scheme of lensed fiber employing a quadrangular-pyramid-shaped fiber endface for coupling between high-power laser diodes and single-mode fibers

This paper proposes a new scheme for the lensed fiber employing a quadrangular-pyramid-shaped fiber endface (QPSFE) for coupling between the high-power 980-nm laser diodes and the single-mode fibers (SMFs). The QPSFE was fabricated by grinding and polishing techniques and then heating in a fusing splicer to form an elliptical microlens endface. A coupling efficiency of 83% has been demonstrated. Based on the far-field profile measurements, the higher coupling efficiency of the QPSFE lensed fiber was attributed to the better matching of both the elliptical Gaussian field distribution and the aspect ratio between the laser source and the fiber lens, The advantage of the QPSFE structure was to be able to control two axial curvatures, and, therefore, this novel QPSFE can form any different aspect ratios of elliptical microlenses to match the far field of the high-power diode lasers as well as the commercial diode lasers used in lightwave communications.     

A novel approach for multistage inference fuzzy control

This paper presents a methodology to the design of a multistage inference fuzzy controller in which the consequence in an inference stage is passed to the next stage as fact, and so forth. A new general method which is based on a performance index of the control system is used to generate fuzzy rule bases for the multistage inference. This proposed method can reduce the design cycle time. In order to reduce the computation time, a method for precomputing the match-degrees of fuzzy values is adopted. Thus, the number of operations that must be carried out at execution time can be significantly reduced. The new method has been applied to two applications, a two-trailer-and-truck system and a three-trailer-and-truck system. The simulation studies showed that the proposed method is feasible.     

SEPARATION OF m-XYLENE FROM o-XYLENE BY EXTRACTIVE DISTILLATION

m-Xylene is difficult to separate from o-xylene by rectification because the relative volatility is only 1.12. m-Xylene can be separated from o-xylene using extractive distillation in which the extractive agent is composed of the proper higher boiling organic compounds. Typical effective agents are benzoates, DMSO, DMFA, adiponitrile, maleic anhydride, phthalic anhydride, polychloroaromatics and sulfolane.     

On dual algebraic Riccati equations

A method is presented to solve dual algebraic Riccati equations. It is shown that only one Schur decomposition of the Hamiltonian matrix is necessary to solve the dual equations     

Color difference measurement and color removal from dye wastewaters using different adsorbents

Pollution from textile mills is a problem of formidable dimensions and color removal is the most perplexing problem facing environmental engineers designing appropriate treatment facilities for textile wastewaters. The CIE colorimetric system has been used in this study to measure the color in the treatment of disperse-red-60 dye wastewater using different adsorbents. The color removal is determined by using the CIE 1976 L*a*b* (CIELAB) color difference equation. The effect of contact time and dosage on color and color removal has been investigated for various adsorbents, namely, powdered activated carbon, granular activated carbon, activated alumina, molecular sieves and diatomite.     

An efficient algorithm on optimal Hankel-norm approximation formultivariable systems

This note provides a novel methodology for Hankel approximation and H^∞-optimization problems, based on a new formulation of the one-step extension problem, which is solved by the Sarason interpolation theorem. The present method does not require an initial balanced realization, and the parameterization of all optimal solutions is given in terms of the eigenvalue decomposition of a Hermitian matrix composed directly from the coefficients of the given transfer function matrix     

Spatial judgments with monoscopic and stereoscopic presentation of perspective displays.

Spatial judgments with monoscopic and stereoscopic presentation of perspective displays were investigated in the present study. The stimulus configuration emulated a visual scene consisting of a volume of airspace above a ground reference plane. Two target symbols were situated at various positions in the space, and observers were instructed to identify the relative depth or altitude of the two symbols. Three viewing orientations (15, 45, or 90 deg elevation angle) were implemented in the perspective projection. In the monoscopic view, depth cues in size, brightness, occlusion, and linear perspective were provided in the format. In the stereoscopic view, binocular disparity was added along the line of sight from the center of projection to reinforce the relative depth in the visual scene. Results revealed that spatial judgments were affected by manipulation of the relative spatial positions of the two target symbols and by the interaction between relative position and viewing orientation. The addition of binocular disparity improved judgments of three-dimensional spatial relationships, and the enhancement was greater when monocular depth cues were less effective and/or ambiguous in recovering the three-dimensional spatial characteristics.     

THE OPTIMUM PLATE-SPACING FOR THE BEST PERFORMANCE IN A FLAT-PLATE THERMAL DIFFUSION COLUMN WITH TRANSVERSE SAMPLING STREAMS

The equations for estimating optimum plate-spacing for maximum separation and for maximum production rate in a flat-plate thermal diffusion column with transverse sampling stream and with fixed operating expense, have been derived. Considerable improvement in performance is obtainable if the optimum plate-spacing is selected so that the convective strength can be properly reduced and controlled, resulting in suppressing the undesirable remixing effect while still preserving the desirable cascading effect and thereby leading to improved performance.     

Hot-carrier-induced degradation for partially depleted SOI 0.25-0.1 /spl mu/m CMOSFET with 2-nm thin gate oxide

Hot-carrier-induced degradation of partially depleted SOI CMOSFETs was investigated with respect to body-contact (BC-SOI) and floating-body (FB-SOI) for channel lengths ranging from 0.25 down to 0.1 /spl mu/m with 2 nm gate oxide. It is found that the valence-band electron tunneling is the main factor of device degradation for the SOI CMOSFET. In the FB-SOI nMOSFET, both the floating body effect (FBE) and the parasitic bipolar transistor effect (PBT) affect the hot-carrier-induced degradation of device characteristics. Without apparent FBE on pMOSFET, the worst hot-carrier stress condition of the 0.1 /spl mu/m FB-SOI pMOSFET is similar to that of the 0.1 /spl mu/m BC-SOI pMOSFET.