Software Aging Analysis of Web Server Using Neural Networks

Software aging is a phenomenon that refers to progressive performance degradation or transient failures or even crashes in long running software systems such as web servers. It mainly occurs due to the deterioration of operating system resource, fragmentation and numerical error accumulation. A primitive method to fight against software aging is software rejuvenation. Software rejuvenation is a proactive fault management technique aimed at cleaning up the system internal state to prevent the occurrence of more severe crash failures in the future. It involves occasionally stopping the running software, cleaning its internal state and restarting it. An optimized schedule for performing the software rejuvenation has to be derived in advance because a long running application could not be put down now and then as it may lead to waste of cost. This paper proposes a method to derive an accurate and optimized schedule for rejuvenation of a web server (Apache) by using Radial Basis Function (RBF) based Feed Forward Neural Network, a variant of Artificial Neural Networks (ANN). Aging indicators are obtained through experimental setup involving Apache web server and clients, which acts as input to the neural network model. This method is better than existing ones because usage of RBF leads to better accuracy and speed in convergence.Comment: 11 pages, 8 figures, 1 table; International Journal of Artificial Intelligence & Applications (IJAIA), Vol.3, No.3, May 201

A modified fifth-order WENO scheme for hyperbolic conservation laws

This paper deals with a new fifth-order weighted essentially non-oscillatory (WENO) scheme improving the WENO-NS and WENO-P methods which are introduced in Ha et al. J. Comput. Phys. (2013) and Kim et al., J. Sci. Comput. (2016) respectively. These two schemes provide the fifth-order accuracy at the critical points where the first derivatives vanish but the second derivatives are non-zero. In this paper, we have presented a scheme by defining a new global-smoothness indicator which shows an improved behavior over the solution to the WENO-NS and WENO-P schemes and the proposed scheme attains optimal approximation order, even at the critical points where the first and second derivatives vanish but the third derivatives are non-zero.Comment: 23 pages, 14 figure

A case of hermaphroditism and some other gonadal abnormalities in the skipjack Katsuwonus pelamis (Linnaeus).

IN the course of the examination of more than 2300 gonads of Katsuwonus pelamis (Linnaeus) for the study of the spawning habits of this fish, from the Laccadive Sea at Minicoy, I came across three abnormal gonads including a hermaphrodite one. As this is the first record of abnormal gonads of tuna from Indian waters it has been described in this present note. The normal gonads of the skipjack (Fig. 1) are paired and elongate organs with the left lobe usually being shghtly larger than the right and both are suspended from the dorsal wall of the body cavity by a fold of the peritoneum. They are free distally but proximally they unite to form a common duct opening into the cloaca. In the female the posterior part of the ovary itself functions as the duct whereas in the male there is a slender duct running along the entire length of the mid-ventral side of each testis

Spawning of the oceanic skipjack Katsuwonus pelamis (Linnaeus) in the Laccadive Sea

Preliminary observations on the spawning of K. pelamis in the Laccadive Sea have been made and comparisons drawn with observations from different parts of the Pacific. The peak spawning of K. pelamis in Laccadive Sea around Minicoy island appears to be mainly February through June . Fractional or multiple spawning is indicated

On structuring the rules of a fuzzy controller

Since the pioneering work of Zadeh and Mamdani and Assilian, fuzzy logic control has emerged as one of the most active and fruitful research areas. The applications of fuzzy logic control can be found in many fields such as control of stream generators, automatic train operation systems, elevator control, nuclear reactor control, automobile transmission control, etc. In this paper, two new structures of hierarchical fuzzy rule-based controller are proposed to reduce the number of rules in a complete rule set of a controller. In one approach, the overall system is split into sub-systems which are treated independently in parallel. A coordinator is then used to take into account the interactions. This is done via an iterating information exchange between the lower level and the coordinator level. From the point of view of information used, this structure is very similar to central structure in that the coordinator can have at least in principle, all the information that the local controllers have

Recent developments in flotation for the beneficiation of lowgrade finely disseminated ores

Rapid increase in consumption rate of metals and minerals over the last few decades and consequent depletion of mineral resources have necessitated the effective utilization oflow-grade finely disseminated ores. The utilization of such reserves and recycling of metallic waste can help to maintain an adequate supply of minerals to meet economic and strategic needs of our nation. Since the yield of low-grade ores is generally very low, the technoiQgy/ process should be efficient to make it cost effictive. Recent equipments like flotation column and Jameson ceil which are basically designed to float fine particles are energy efficient. Selective reagents are being designed for the separation of individual minerals from complex assemblage. The necessity of biodegradable and eco-friendly reagents is highlighted. In the present paper; recent developments in flotation celis and beneficiation of low-grade ores was presented and discussed. Beneficiation of low-grade barite sample from Mangampet deposit was conducted both by direct flotation using oleic acid and reverse flotation by cationic collector. Production of barite concentrate assaying Less than 1% silica by reverseflotation was demonstrated. Similarly, limestone concentrate assaying 97% of CaC03 and Less than 1% Si02 was achieved by reverseflotation process. The viability offlotation processfor up-graddtion of siliceous iron ores waS also studied and discussed

Beneficiation of low-grade iron ores

The Government of India highlighted, processing and utilization of iron ore fines as pre-requisite to meet the domestic raw material requirements for the projected 110 million tonnes of domestic steel production by the year 2019-20 in the National Steel Policy announced in November 2005. This would require 190 million tonnes of iron ore. The depletion of high grade iron ore and increased generation of fines during mining and handling and demand for high grade iron orefines for export has necessitated the processing of low to medium grade fines. The R&D efforts undertaken at NML-Madras Centre, India in this direction have been highlighted. Beneficiation of iron ores in general and column flotation in particular are highlighted in this paper. This would also mitigate the environmental problem created by the dumping of huge quantities of low and medium grade iron orefines. Three case studies involving iron ore fines of varying silica and alumina content from Goa and Kudremukh regions of India have been discussed. The results clearly indicate the feasibility and significance of flotation process in treating the fines to obtain marketable concentrates