Rolling element bearings find widespread domestic and industrial applications. In the present study some of the conditions monitoring techniques used for the detection of defects in rolling element bearings are reviewed. Various causes of vibration in rolling bearings are discussed. Vibration measurement in both time and frequency domain along with various signal processing techniques such as Envelope detection, HFRT have been covered.
Pipes in the offshore industry normally subjected to combined loadings during installation or in service phase. In this paper limit state equations for pipe are derived analytically. These equations can be used to predict the failure of the pipe which is under combined loadings. Loading conditions considered are axial force, internal pressure, external pressure, bending and torsional loadings.
In the present investigation experimental work has been carried out to analyze the emission and performance characteristics of a single cylinder 3.67 kW, compression ignition engine fuelled with mineral diesel and diesel-biodiesel blends at an injection pressure of 200 bar. The performance parameters evaluated were break thermal efficiency, break specific energy consumption (BSEC) and the emissions measured were carbon monoxide (CO), carbon dioxide (CO2), hydrocarbon (HC), and oxides of nitrogen (NOx). The results of experimental investigation with biodiesel blends were compared with that of baseline diesel. The results indicate that the CO emissions were slightly higher, HC emissions decreased from 12.8 % for B20 and 2.85 % for B40, NOx emissions decreased up to 39 % for B20 and 28 % for B40. The efficiency decreased slightly for blends in comparison with diesel. The BSEC was slightly more for B20 and B40. From the investigation it can be concluded that biodiesel can be used as an alternative to diesel in a compression ignition engine without any engine modifications.
The phasor measurement unit (PMU) is considered to be one of the most important measuring devices in the future of power systems. The distinction comes from its unique ability to provide synchronized phasor measurements of voltages and currents from widely dispersed locations in an electric power grid. global positioning satellite (GPS) with accuracy of timing pulses in the order of 1 microsecond made possible the commercial production of PMU. Simulations and field experiences suggest that PMUs can revolutionize the way power systems are monitored and controlled. However, it is perceived that costs and communication links will affect the number of PMUs to be installed in any power system. A novel method of PMU placement based on incomplete observability using graph theoretic approach is proposed. The objective is to reduce the required number of PMUs by intentionally creating widely dispersed pockets of unobserved buses in the network. Observable buses enveloped such pockets of unobserved regions thus enabling the interpolation of the unknown voltages. The concept of depth of unobservability is introduced. It is a general measure of the physical distance of unobserved buses from those known.
Image similarity is used in image registration, content based image retrieval, medical application etc. Entropy is measure uncertainty of an random variable in information theory. Joint entropy is a measure of the uncertainty associated with a set of variables. For digital image, entropy is A probability distribution of grey values can be estimated by counting the number of times each grey value occurs in the image and dividing those numbers by the total number of occurrences. Similarity of two images is finding based on joint entropy which is applicable through joint histogram.
: In this paper, Computer-Aided Design of PMBLDC Motor is Presented. The design variables such as air-gap flux density and torque per unit rotor volume constant are assumed. The basic output equations are derived and used for the CAD program. The developed CAD program gives dimensions and performance of the motor. Two different motors of rating 10 kW and 5 kW are designed using the developed program and then compared with Motor Solve result to validate the design.
Web accessibility means that people with and without disabilities can use the web. We aim to provide web accessibility through web template that supports speech recognition and can be used for designing static website. The web template will be designed using guidelines of Web Accessibility Initiative (WAI). The websites created using this template will be accessed by normal as well as physically handicapped people and people with low vision. Moreover, we are providing text magnification functionality for low vision people. Through this we aim to provide equal access of information to all users.
Currently, there is demand of efficient & secure network monitoring & management due to incredible growth in heterogeneous computer network & proliferation of network traffic in network communication infrastructure. The centralized approach of network management and monitoring using SNMP (Simple Network Management Protocol) based Client/Server architecture which is inefficient in terms of performance. The mobile agent based network management overcome scalability & flexibility limitations of centralized network management. This approach also reduces processing load and bandwidth usage. The security is main concern with this approach. The protection of both host that execute the agent and agent against malicious hosts and agents are very much important. This paper provides solution to protect mobile agent against malicious hosts.
: It is well-known that cloud computing has many potential advantages and many enterprise applications and data are migrating to public or hybrid cloud. But regarding some business-critical applications, the organizations, especially large enterprises, still wouldn’t move them to cloud. The market size the cloud computing shared is still far behind the one expected. From the consumers’ perspective, cloud computing security concerns, especially data security and privacy protection issues, remain the primary inhibitor for adoption of cloud computing services. This paper provides a concise but all-round analysis on data security and privacy protection issues associated with cloud computing across all stages of data life cycle. Then this paper discusses some current solutions. Finally, this paper describes future research work about data security and privacy protection issues in cloud.