Some Novel Methods of Ordered Dither

Various authors have contributed their original works in the field of digital halftoning during past two to three decades. Still this field has not lost its glory. The goal of the study was to investigate novel methods in digital halftoning specially, in ordered dithering. This paper is concerned with two novel methods of ordered dither. In the first method dithering is done first by pre-embedding a pattern image generated from a matrix pattern with the original image. In the second method dithering is done by thresholding the original image with respect to a threshold matrix pattern constructed using a character writing pattern. The two methods may be applied in digital halftone reproduction and as special effect imaging

A Statistical Approach for Study of Roundness in Commercially Produced Round Metal Bars

Commercially produced ferrous and non-ferrous metal round bars are available at various sizes. These bars have tremendous engineering use in multiple areas like automobile, aerospace, power, manufacturing, paper, printing, packaging and construction industries. Due to its wide range of utility of round bars, it is naturally pertinent to understand and ascertain quality aspect of these bars. Quite often it has been observed that round bars as available are not completely geometrically round at various sections along the length, also straightness is also somewhat compromised. Therefore, it is necessary to check the uniformity of diameters at various sections. In this paper statistical process control has been used to ascertain whether such round bars as commercially available can be utilized for industrial application or not. Control limits in terms of diameter measurement along the length of bars help to evaluate the characteristics of data variation which is needed to take decision about confirmation of utility of commercially produced bar

Quantitative Assessment of Effectiveness and Utilization of Medical Equipment

The problem of operational efficiency assessment of medical equipment is becoming crucial, due to its increasing requirement in hospitals. It has been observed that a significant amount of medical equipment is out of service for several reasons such as lack of training, maintenance and health technology management. The unexpected failures, downtime associated with breakdown and make ready, loss of production and poor maintenance costs of medical equipment are the major drawback in any hospital. Quality of diagnostic and treatment care provided to patients largely depends on the reliability, availability and maintainability of sophisticated medical equipment. Aim of the present study is to determine quantitatively overall effectiveness and utilization of some medical equipment. Overall Equipment Effectiveness (OEE) and utilization coefficient is the metric measurement of Total Productive Maintenance (TPM) which specifies effective functioning of devices.  The results of the effectiveness of the devices are found to be below the standard of 85%. The cause of low effectiveness value was due to poor performance and availability. Equipment utilization is also needed for the evaluation of medical equipment necessity, appropriateness and efficiency of the use in diagnosis and treating a patient. The proposed methodology may be able to increase the amount of working medical equipment by implementing preventive maintenance schedule. The methodology is also validated by failure probability and reliability of the machines

Delay Analysis of a Discrete-Time Non-Preemptive Priority Queue with Priority Jumps

In this paper, we consider a discrete-time non-preemptive priority queueing model with priority jumps. Two classes, real-time (high priority) and non-real time (low priority), of traffic will be considered with providing jumps from lower priority traffic to the queue of high priority traffic. We derive expressions for the joint probability generating function of the system contents of the high and the low priority traffic in the steady state and also for some performance measures such as the mean value of the system contents and the packet delay. The behavior of the priority queues with priority jumps will be illustrated by using these results and is compared to the FIFO scheme

Traumatic bilateral hip dislocation with bilateral sciatic nerve palsy

AbstractBilateral hip dislocation rarely occurs. In this paper, a case of bilateral hip dislocation associated with bilateral sciatic nerve palsy resulted from a road traffic accident is reported. Both hips were emergently reduced under general anaesthesia. Acetabular reconstruction was done bilaterally due to the unstable hips. The patient subsequently developed heterotopic ossification and avascular necrosis on the left hip and underwent total hip arthroplasty. The sciatic nerve on the right side achieved complete recovery but that on the left side only partly recovered and was augmented by tendon transfer. Such injuries are serious and one should be aware of the complications because they can resurface and so patients should be followed up for a long time. To the best of our knowledge, this kind of injury has not been reported in the English language literature

Graphene: Kinks, Superlattices, Landau levels, and Magnetotransport

We review recent work on superlattices in monolayer and bilayer graphene. We highlight the role of the quasiparticle chirality in generating new Dirac fermion modes with tunable anisotropic velocities in one dimensional (1D) superlattices in both monolayer and bilayer graphene. We discuss the structure of the Landau levels and magnetotransport in such superlattices over a wide range of perpendicular (orbital) magnetic fields. In monolayer graphene, we show that an orbital magnetic field can reverse the anisotropy of the transport imposed by the superlattice potential, suggesting possible switching-type device applications. We also consider topological modes localized at a kink in an electric field applied perpendicular to bilayer graphene, and show how interactions convert these modes into a two-band Luttinger liquid with tunable Luttinger parameters. The band structures of electric field superlattices in bilayer graphene (with or without a magnetic field) are shown to arise naturally from a coupled array of such topological modes. We briefly review some bandstructure results for 2D superlattices. We conclude with a discussion of recent tunneling and transport experiments and point out open issues.Comment: Invited Review Article for Special Issue on Graphene, References added, Typos correcte