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Primary mirror active control system simulation of Prototype Segmented Mirror Telescope
The upcoming large astronomical telescopes are trending towards the Segmented Mirror Telescope (SMT) technology, initially developed at the W M Keck Observatory in Hawaii, where two largest SMTs in the world are in use. SMT uses large number of smaller hexagonal mirror segments aligned and positioned by the use of three position/force actuators and six intersegment edge sensors. This positioning needs to be done within nanometer range to make them act like a monolithic primary mirror in the presence of different disturbances like wind, vibration & thermal effects. The primary mirror active control system of SMT does this important task at two levels. First at a global scale, by measuring edge sensor information continuously and commanding actuators to correct for any departure from the reference surface. And second at local actuator level, where all the actuators maintain their position to the reference control inputs. The paper describes our novel approach of primary mirror active control simulation of Prototype Segmented Mirror Telescope (PSMT) under design and development at Indian Institute of Astrophysics (IIA), Bangalore. The PSMT is a 1.5m segmented mirror telescope with seven hexagonal segments, 24 inductive edge sensors, and 21 soft actuators. The state space model of the soft actuator with Multiple-Input Multiple-Output (MIMO) capability is developed to incorporate dynamic wind disturbances. Further, a segment model was developed using three such actuators which accept actuator position commands from the global controller and telescope control system and yields tip-tilt-piston (TTP) of a single segment. A dynamic wind disturbance model is developed and used to disturb the mirror in a more realistic way. A feed forward PID controller is implemented, and gains are appropriately tuned to get the good wind rejection. In the last phase, a global controller is implemented based on SVD algorithm to command all the actuators of seven segments combined to act as a single monolithic mirror telescope. In this paper, we present the progress of PSMT active control system simulation along with the simulation results. 2017 IEEE. -
The Influence of Alloying Constituent Fe on Mechanical Properties of NiTi Based Shape Memory Alloys
The influences of Fe-addition on phase transformation behavior, mechanical properties and microstructure of Ti50Ni50-xFex alloys were investigated by means of optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results indicate that, as a substitute for Ni, Fe added to TiNi alloys can dramatically decrease the martensite transformation temperature and R phase transformation and martensite transformation are accordingly separated. The results show that TiNiFe alloys exhibit two-step martensitic transformation. The start temperature of martensitic transformation increases sharply from 212 K to 267 K when 2% Fe is added in, and then decreases gradually if Fe content further increases. The hardness of TiNiFe ternary alloys before heat treatment is constant for up to 6% of the composition and suddenly increases for 9% composition and also it behaves same for heat treated specimens because of formation of equilibrium precipitates Ni3Ti formation. 2017 Elsevier Ltd. -
Android security issues and solutions
Android operating system uses the permission-based model which allows Android applications to access user information, system information, device information and external resources of Smartphone. The developer needs to declare the permissions for the Android application. The user needs to accept these permissions for successful installation of an Android application. These permissions are declarations. At the time of installation, if the permissions are allowed by the user, the app can access resources and information anytime. It need not re-request for permissions again. Android OS is susceptible to various security attacks due to its weakness in security. This paper tells about the misuse of app permissions using Shared User ID, how two-factor authentications fail due to inappropriate and improper usage of app permissions using spyware, data theft in Android applications, security breaches or attacks in Android and analysis of Android, iOS and Windows operating system regarding its security. 2017 IEEE. -
Performance analysis of optimized corporate-fed microstrip array for ISM band applications
This paper presents a low cost high gain corporate feed rectangular microstrip patch antenna array of two elements having cuttings at the corners, with detailed steps of design process, operates in Industrial Scientific Medical (ISM) band (2.4 GHz). The proposed antenna structures are designed using FR4 dielectric substrate having permittivity ?r= 44 and substrate thickness of 1.6 mm. The gain of these simulated antennas are obtained as 2.4819 dB with return loss of -17.779 dB for a single element patch and 6.3128 dB with return loss of -15.8320 dB for an array of two elements. The simulations have been carried out by using Antenna simulator HFSS version 15.0.0 to obtain the VSWR, return loss and radiation pattern. 2017 IEEE. -
Optimal locations for PMUs maintaining observability in power systems
Population of Phasor Measurement Units (PMUs) in power systems are increasing day by day as PMUs measure the electrical quantities more accurately with time-stamping. The measurements done by PMU can be used for monitoring, controlling and for state estimation of the power system. Since the installation of PMUs demand high capital cost, their number and location to be chosen optimally is by minimizing investment without losing observability of the system. In this paper Integer Programming techniques used to solve Optimal Placement of PMU (OPP) problem. The OPP problem is solved for normal power system as well as for a few contingency conditions like one PMU outage, considering zero injection bus, outage of single line on various standard IEEE Bus Systems. The work is also trying to place PMUs under planned islanding in certain standard networks. 2016 IEEE. -
Impact of demand response contracts on short-term load forecasting in smart grid using SVR optimized by GA
In a Smart Grid environment the performance measure of the grid is calculated by considering the fact that how accurately and precisely a load forecasting (LF) is done. A true Load Forecasting is vital to make a current grid smarter and more reliable when it comes to its performance. Demand Response (DR) contracts is a type of program in smart grid where the customer is free to select a type of contract which is given by the utility and is one of the growing factor which affects the load forecasting results in the Smart Grid, therefore in order to do a complete evaluation of smart grid performance and to accomplish an accurate load forecasting results the different types of contracts should also be studied. The purpose of this study is to accomplish two goals. The first one is to develop a suitable model which can incorporate various factors that can affect the load forecasting results. The subsequent goal is to identify the impact of the demand response contracts on the load forecasting results. In the proposed study, Support Vector Machine-Regression (SVR) is selected as the base methodology to perform a Short - Term Load Forecasting (STLF) under smart grid environment. 2017 IEEE. -
Electrically small S-band antenna for cubesat applications
This research paper deals with the design and development of a circularly polarized S-band rectangular patch antenna providing performance suitable for application in CubeSat. A CubeSat is a type of miniaturized satellite used primarily by university research groups for demonstration of technology. They are low earth orbiting sun-synchronous (LEOSS) type of satellites. The design protocol specifies maximum outer dimensions equal to 100 mm00 mm00 mm and weighing a mass between 1.3-6 kg. However, being small in size, they pose some challenges such as low profile antenna, possibility for cross-link communication with other similar satellites and high reliability of communication in a swarm without the prior knowledge of their positions. Additionally CubeSats dictate the space limitation for placing the antenna within it. With all these, it also requires small antenna with high gain and wide directivity. The most suitable antennas that address most of the aforementioned challenges are planar antennas. The design and simulation of the proposed design of electrically small sband antenna for CubeSat achieves gain of 5.01 dBi with a narrow bandwidth of 100 MHz. The analysis is performed using MATLAB and HFSS (High Frequency Structural Simulator). 2017 IEEE. -
Variable initial energy and unequal clustering (VEUC) based multicasting in WSN
Multicast Communication plays an important role in most of the resource constrained networking environments such as Wireless Sensor Networks (WSN), Internet of Things (IOT). Communication in WSN is restricted by energy, computation and memory capabilities of sensor nodes. Designing an efficient routing algorithm to achieve communication between Stationary Base station (BS) and a cluster of sensor nodes in a specific region requires the base station to send individual messages to all sensor nodes. This approach consumes a large amount of energy and bandwidth. A variety of algorithms exist to address this issue by dividing the sensor nodes into clusters. Each cluster is monitored by a Cluster Head (CH), responsible for gathering and aggregating data to send the same to the BS. In this paper, we reviewed existing clustering techniques and propose an unequal clustering based scheme. This allows the BS to communicate a multicast message to cluster members as well as a cluster head to communicate with other cluster members. The results show that our approach improves network lifetime. 2017 IEEE. -
Cumulative istributionfunction: Stock price forecasting
In this paper, an attempt has been made to predict the movement of the stock price for the next day using Cumulative Distribution Function (CDF). For the purpose of the research, three companies from the Bearings Industry, namely - ABC Bearings Ltd, SNL Bearings Ltd and Austin Engineering Company Ltd, and two companies from the chemical industry, namely-Nocil ltd and Manali Petrochemicals Ltd were chosen. Historical prices of these companies were analyzed and by using Cumulative Distribution Function (CDF) the movement of the stock price for the next day is predicted. 2017 IEEE. -
An analysis on direct authentication of data
Authentication is the procedure which permits a sender and receiver of data to validate each other. On the off chance that the sender and receiver of data can't legitimately confirm each other, there is no trust in the activity or data gave by either party. This paper talks about where and when can the service providers use the various authentication models adopted and the comparison between two authentication models. 2017 IEEE. -
Enhancement of substitution voices using F1 formant deviation analysis and DTW based template matching
Speech is the best way to express the thoughts and feelings among the human beings. But for many reasons the sound produced by human beings becomes disordered voice and termed with many names based on the cause as stammering, dys-theria, apraxia and so on. In the above mentioned few examples, the voice becomes disordered because of the underperformance of body's organ. The larynx is removed in some human beings because of cancer. For them an artificial larynx transducer (ALT) is used to produce the sounds. The above all sounds are categorized as disordered voice and the sound produced by ALT is also called as Substitution voice. In this paper, a method is used to improve the quality of substitution voice produced by ALT. Algorithm is developed to estimate undesired audio components from the device output and remove the same using Non Linear Spectral Subtraction (NLSS) technique. Further, Fundamental (F0) contour and novel parameter F1 formant deviation of healthy speech (HE) and ALT speech are determined. The above two parameters are estimated and stored during the training phase of the system. In the test phase, the above mentioned parameters are estimated and they are used to scale down the database to reduce overall enhancement time. Next step is template matching done by mapping test data with training data using Dynamic Time Warping (DTW) Technique. The data base with least distance estimation is recognized as the utterance and the same is played back. 2017 IEEE. -
Physical layer impairment-aware routing and wavelength assignment (PLI-RWA) strategy for mixed line rate (MLR) wavelength division multiplexed (WDM) optical networks
The ever increasing global Internet traffic is resulting in a serious upgrade of the current optical networks' capacity. The legacy infrastructure can be enhanced not only by increasing the capacity, but also by adopting advance modulation formats, having increased spectral efficiency at higher data rate. In a mixed-line-rate (MLR) optical network, different line rates, on different wavelengths, can coexist on the same fiber. Further, studies have shown that migration to data rates higher than 10Gbps requires implementation of phase modulation schemes. However, the co-existing On-Off Keying (OOK) channels cause critical physical layer impairments (PLIs) to the phase modulated channels, mainly due to cross-phase modulation (XPM), which in turn limits the network's performance. In order to mitigate this effect, a more sophisticated PLI-Routing and Wavelength Assignment (PLI-RWA) scheme needs to be adopted. In this work, we investigate the critical impairment for each data rate and the way it affects the quality of transmission (QoT). We propose a novel PLI-RWA algorithm for MLR optical networks. The proposed algorithm is compared through simulations with the existing shortest path and minimum hop routing schemes. 2015 IEEE -
Polynomial time learner for inferring subclasses of internal contextual grammars with local maximum selectors
Natural languages contain regular, context-free, and context-sensitive syntactic constructions, yet none of these classes of formal languages can be identified in the limit from positive examples. Mildly context-sensitive languages are capable to represent some context-sensitive constructions such as multiple agreement, crossed agreement, and duplication. These languages are important for natural language applications due to their expressiveness, and the fact that they are not fully context-sensitive. In this paper, we present a polynomial-time algorithm for inferring subclasses of internal contextual languages using positive examples only, namely strictly and k-uniform internal contextual languages with local maximum selectors which can contain mildly context-sensitive languages. 2017, Springer International Publishing AG. -
Analysis on emotion-aware healthcare and Google cloud messaging
Cloud computing has the potential to get integrated with the healthcare sector. It provides functionality for managing data in a distributed environment. The concept of Healthcare services is becoming popular in the Healthcare sector as it helps the patients to get immediate access regarding his/her health related information whenever needed and wherever needed using cloud computing technology. The Big Data Application in Emotion-aware Healthcare system [BDAEH], gives attention to both the emotion factor and logical reasoning of the user. The basic functions of this system are collecting health-related data, transmitting the collected data, analyzing the received data, storing them and making it available to a user in order to perform diagnosis and predict medications. Mobile devices are becoming an essential tool in our day to day lives. By integrating the concept of Google Cloud messaging alongside BDAEH system, numerous tasks can be done efficiently. 2017 IEEE. -
Performance inquisition of web services using soap UI and JMeter
Web Service is a managed code through which the user can expose the existing functionality over the network. Web Service allows multiple applications to communicate with each other. The communication involves passing the data or interaction of two services for a specified action. There are commercial and open source tools available for testing web services. This paper describes about two popular open source tools to test the performance of the web services in terms of response time. The performance is tested based on the time acquired by each service. The comparison study will help in understanding the usage of web service testing tools and adoption of these tools for testing purpose. 2017 IEEE. -
Performance analysis of antenna with different substrate materials at 60 GHz
With a tremendous demand on data rate and bandwidth utilization in RF communication systems, current research studies leads to explore the millimeter-wave unlicensed 57-64 GHz bandwidth of electromagnetic spectrum. This high frequency band is not channelized for long distance communication. However, it could be efficiently utilized for indoor and short range digital communication transmission systems for enhanced data rate and bandwidth utilization. This paper focused on designing antenna that utilizes 60 GHz frequency which falls under this spectrum by using different substrate materials such as like RT Duroid, FR4 Epoxy, Rogers RO3010 and GaAs for Rectangular Microstrip Antenna (RMSA). This research paper presents a detailed analysis on performance parameters comparison like gain, VSWR, return loss & radiation pattern analysis for the 60 GHz antenna designed with substrate materials having different properties. 2017 IEEE. -
Crown shaped broadband monopole fractal antenna for 4G wireless applications
This paper proposes a novel crown shaped fractal antenna design suitable for 4G wireless applications. One of the promising approaches in miniaturizing the antenna size is to use the fractal geometries. Several efforts have been made by various investigators around the globe to amalgamate benefits of fractal structures with electromagnetic concepts and applications. This paper outlines a new approach in designing broadband monopole 2.1 GHz fractal antenna. The design starts with square patch antenna and goes up to third iteration for obtaining better performance and impedance matching. The proposed antenna was designed and simulated using the HFSS EM simulator. Performance analysis of the antenna was done with characteristics such as return loss, VSWR, efficiency and radiation pattern found to be good at 2.1 GHz. Wireless application demands miniaturization in system as well as antenna size with better performance, hence attempts have been made to reduce the size and improve the gain, efficiency and bandwidth of the proposed antenna. 2017 IEEE. -
An approach for efficient capacity management in a cloud
Cloud computing is an emerging technology where computing resources such as software and hardware are accessed over the internet as a service to customers. In the past, due to less demand, cloud capacity management was not critical. However, with the increase in demand, capacity management has become critical. Cloud customers can frequently use web-based portals to provision and de-provision virtual machines on demand. Due to dynamic changes as per the demand, managing capacity becomes a challenging task. In this paper, we discuss the emergence of cloud computing, traditional versus cloud computing, and how capacity management can be efficiently handled in a cloud. A detail on high availability of virtual machines in a cloud using the N+1 model is discussed in this paper. With templates, many repetitive installation and configuration tasks can be avoided. We discuss the sizing of templates and the overheads of using virtual machines. We suggest ideal combinations of sizing templates to create virtual machines with optimum utilization of blades. Finally we discuss a few benefits of efficient capacity management in cloud computing. 2017 IEEE. -
Phonon limited diffusion thermopower in phosphorene
A theoretical investigation of diffusion thermopower, Sd, of phosphorene employing Boltzmann transport formalism is presented. We assume carriers in phosphorene to be scattered by in-plane single and flexural two-phonon processes via deformation potential coupling. Our calculations of Sd in phosphorene show that, at low temperatures (T?< 20 K) Sd increases linearly with temperature and for the range of temperatures considered single phonon contribution to Sd dominates. As function of carrier concentration, ns, considered (1016?1018 m-2), at T = 300K, Sd decreases from 189?V/K to 9.9 ?V/K. 2017 Author(s). -
A comparitive study on traditonal healthcare system and present healthcare system using cloud computing and big data
Cloud computing is one the emerging technology which provides all the necessary resources required for day to day operations of an organization in a virtual environment. It is also known as green computing as it reduces the physical existence of the hardware resources. Health is being considered as a basic right for an individual. Even though there are advancements in the healthcare sector of India when compared to earlier stages, there is still a need for betterment in this sector. In order to make progress in this field, constant learning and better economic standards are needed. This paper provides a comparative view of the progress made by India in the healthcare sector after the introduction of two major technologies such as cloud computing and big data. 2017 IEEE.