Iasir Journals - Academia.edu (original) (raw)

Papers by Iasir Journals

Mobile Ad-hoc networks (MANETs) are self organizing, infrastructureless and multi-hop packet forw... more Mobile Ad-hoc networks (MANETs) are self organizing, infrastructureless and multi-hop packet
forwarding networks. There is no concept of fixed base station. So, each node in the network acts as a router to
forward the packets to the next node. Ad-hoc networks are capable of handling of topology changes and
malfunctions in nodes. Routing is one of the most important aspect of ad hoc networks. All operations and
applications built around as hoc networks, utilize the routing services of ad hoc networks in some way or the
other. Considering the importance of routing techniques and their efficiency, in this paper we have taken a
literature survey of different routing methods, their strengths and weaknesses. For this study we have classified
different routing methods into some heads based on the characteristics they display. All methods under a given
head display some common behavior and similarities in their functionalities. This paper helps to identify and
understand different research areas in mobile ad hoc networks.

: Today, wireless networks are widely used in our day to day operations. A few years back, wirele... more : Today, wireless networks are widely used in our day to day operations. A few years back, wireless
networks existed only in labs, as they were typically expensive. However recently, there has been mass
proliferation of inexpensive wireless devices. This has made wireless networks immensely popular and
attractive. One such wireless network, where a lot of interest has generated, over last few years, is ad hoc
networks. Ad hoc networks are self configuring, infrastructureless mobile networks, which are established on
the fly. They are multi-hop in nature. This paper is an attempt to document major aspects concerning ad hoc
networks and their suitability to become the preferred networks of the future. We bring to focus, potential
applications of ad hoc networks and the benefits accrued from them. Implementation details of ad hoc networks,
alongwith the underlying technology and various concerns of ad hoc networks, such as routing and security, are
also discussed. There are several challenges concerning successful implementation of these networks
commercially, which are highlighted. Despite these challenges, the importance of ad hoc networks in pervasive,
ubiquitous computing is imminent and supported in this paper.

An ad-hoc network is a collection of wireless mobile nodes dynamically forming a temporary networ... more An ad-hoc network is a collection of wireless mobile nodes dynamically forming a temporary
network without the use of any existing infrastructure or centralized administration. Routing is the process
of communication established for exchange of messages. The process of routing is central to any
application for ad hoc networks. This paper brings about a performance comparison between three existing
reactive routing protocols: AODV, DSR and LAR1. These three protocols exhibit different levels of
processing requirements and overheads. Our study is different from existing studies as we are concentrating
only on reactive routing methods, while most other studies compare reactive with proactive methods. Also,
we are comparing the behavior of protocols vis-à-vis different mobility patterns, which we define as a
combination of varying three parameters: pause time, minimum speed and maximum speed of movement.
High mobility is marked by rapid movement and constantly changing topology, which has its own
challenges. The goal of this study is to bring out adaptability of existing routing solutions with respect to
varying network characteristics and see their suitability.

, ultrasonic velocity (U) and viscosity (η) of potassium thiocyanate (KSCN) at different mole fra... more , ultrasonic velocity (U) and viscosity (η) of potassium thiocyanate (KSCN) at different mole fractions of 2-ethoxyethanol has been measured at 288.15, 298.15, 308.15 and 318.15K. An ultrasonic interferometer working at 2 MHz was used to measure the sound velocity. Using the experimental data, adiabatic compressibility (βad), inter molecular free length , acoustic impedance (Z), Relative association (RA), apparent molar compressibility (ɸk), apparent molar volume (ɸv), limiting apparent molar compressibility (ɸ 0 k), limiting apparent molar volume (ɸ 0 v), association constant (Sk and Sv) and solvation number were computed. The observed variation of these parameters with respect to electrolyte concentration and temperature signifies the presence of ion-solvent and solvent-solvent interactions. Masson's and Gucker's equation has been verified. The maxima in ultrasonic velocity and minima in adiabatic compressibility are observed at X2EE= 0.0136 elucidating complex formation in this composition. The positive Sk values suggests structure breaking property of KSCN.

Solar energy, made from sunlight by solar cells, is naturally clean, carbon-free and renewable. I... more Solar energy, made from sunlight by solar cells, is naturally clean, carbon-free and renewable. It has the promising possibility to fulfill the terawatt energy demand of the world, provided it is available at par with grid electricity. The established solar cells made from silicon (Si) or cadmium telluride (CdTe) or copper indium gallium selenide (CIGS) generate electricity that is still too costly. Hence, there is a frantic inquiry for new materials for solar cells which will generate cost-effective electricity [1]. One such promising candidate is earth-abundant, low-cost and non-toxic kesterite copper zinc tin sulfide. CZTS is a mineral which has been found in nature . However, CZTS material usually appears in kesterite phase because of its thermodynamical stability compared to the stannite-type . Recently considerable work has been done on the quaternary compound semiconductor, Cu2ZnSnS4 (CZTS) to make it a good absorber layer for thin film solar cells and thermoelectric power generators . Copper zinc tin sulfide (CZTS) is a classic example of p-type semiconductor bearing a direct band gap of 1.5 eV as well as absorption coefficient greater than 10 4 cm -1 in the chromatic spectrum . These factors together led to a quick development in the CZTS based thin film PV research in last few years, which is evident from the rise of record power conversion efficiency to 12.6 % [8] in a very short span. Although, this is quite impressive, the value is still far below the Schockley-Quessier limit for a single junction cell based on CZTS (~30%) [9].

A large number of extensions of Banach Contraction Mapping Principle are attempted by many author... more A large number of extensions of Banach Contraction Mapping Principle are attempted by many authors in many research papers. Rakotch used a decreasing function on ℝ + to [0, 1) for a contraction type condition and obtained a fixed point theorem. A slight variation of the Rakotch theorem is presented by Geraghty. In the theorem of Geraghty, the function of Rakotch satisfies the condition that ( ) → 1 ⇒ → 0 whereas in Rakotch it is a decreasing function : ℝ + → [0, 1). Boyd and Wong obtained more general fixed point theorem by replacing the decreasing function in the theorem of Rakotch by an upper semi-continuous function. Matkowski in his fixed point theorem further modified the condition on the function : ℝ + → [0, 1) of Rakotch by defining : (0, ∞) → (0, ∞) to be monotone non-decreasing and satisfying the condition →∞ ( ) = 0 for all > 0. Browder, Meer and Keeler, Kirk, Suzuki, Alber and Rhoades extended the results further. Three fixed point theorems are proved in this article by taking to be an upper semi-continuous function from right. The function is from the set of all positive real numbers to itself and appears out of the metric function as ( ( ). Examples are provided to support the theorems. Finally the celebrated fixed point theorem by Kannan is generalized. In the next theorem an attempt has been made to take the function inside the metric. Precisely, is defined to be function from a general metric space to itself. Thus in the next theorem it appears like ( ( ), ( )). This theorem is also illustrated by an example.

Ramanujan sum is a sum of powers of primitive roots of unity defined by Srinivasa Ramanujan. Afte... more Ramanujan sum is a sum of powers of primitive roots of unity defined by Srinivasa Ramanujan. After this, there have been many generalizations of the Ramanujan sum one of which was given by E. Cohen. In a series of articles, he proved that several interesting properties of the classical Ramanujan sum extends to his generalization as well. Many other authors followed the footsteps of Cohen to give various such generalized results. In this survey article, we list some of the most important properties of the original sum and the generalization and also give some expected results using the generalized sum

In 1962 ,Ore used the name " dominating set" and "domination number". In 1977 , Cockayne and Hede... more In 1962 ,Ore used the name " dominating set" and "domination number". In 1977 , Cockayne and Hedetniemi made an interesting and extensive survey of the results known at that time about dominating sets in graphs. The survey paper of cockayne and Hedetniemi has generated a lot of interest in the study of domination in graphs. Domination has a wide range of applications in Radio station, modeling social networks, coding theory, nuclear power plants problems. A non-empty subset D of vertices in a graph G=(V,E) is a "Dominating set", if every vertex in V-D is adjacent to some vertex in D. The domination numberγ(G) of G is the minimum cardinality of a minimal dominating set. A total dominating set Dt of G is a dominating set such that the induced subgraph has no isolated vertices. The total domination number γt(G) of G is the minimum cardinality of a minimal total dominating set of G. Let D be the minimum dominating set of G. If V-D contains a dominating set say ′,then ′ is called an inverse dominating set with respect to D. The invese domination number ′( )of G is the order of the smallest inverse dominating set of G. "Kulli and Sigarkandi" introduced the concept of inverse domination in Graphs. Let G = (V,E) be a simple graph. Let Dt be the minimum total dominating set of G. If V-Dt contains a total dominating set ′ of G, then ′ is called an inverse total dominating set with respect to D. The inverse total domination number ′( ) of G is the minimum number of vertices in an inverse total dominating set of G. The concept of total domination is first introduced by Cockayne, Dawes and Hedetniemi in 1980. V.R. Kulli and RadhaRajamaniIyer introduced the concept of inverse total domination in graphs. In this paper, we found the total domination number and inverse total domination number of some special classes of graphs.