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1.
M. K. Karthikeyan R. K. Gupta V. Rajesh B. R. Ghosh P. P. Sinha 《Journal of Failure Analysis and Prevention》2007,7(6):429-433
17-4 PH stainless steel is used as internal drive shaft material in liquid engine pumps. One of the drive shafts failed during
operation. The shaft pieces were in contact for short duration after failure, which has resulted in abrasion of fractured
surfaces. Samples from the location of failure were taken, and investigation of the failure was carried out using optical
and scanning electron microscopy. The microstructural analysis of the material and fractographic analysis of the fractured
surface show that the failure was caused by excessive torsion. 相似文献
2.
N. Satyanarayana A. Karthikeyan M. Venkateswarlu 《Journal of Materials Science》1996,31(20):5471-5477
A new quaternary fast-ion conducting silver molybdo-arsenate [Agl-Ag2O-(MoO3 + As2O5)] (SMA) glassy system has been prepared using the melt-quenching technique for various dopant salt (Agl) concentrations by fixing the formers (MoO3 + As2O5) composition and the modifier (Ag2O) to formers (M/F) ratio. The prepared compounds were characterized by X-ray diffraction. The impedance measurements were made on different Agl compositions of the SMA glasses as a function of frequency (6.5 Hz–65 kHz) and temperature (303–343 K), using the Solatron frequency-response analyser (model 1250). The bulk conductivity and the appropriate physical model (equivalent circuit) of the SMA glass were obtained from the impedance analysis. The a.c. conductivity was calculated for different Agl compositions of SMA glasses at various temperatures and the obtained a.c. conductivity results were analysed using Jonscher's Universal Law. The conduction mechanism for the highest conducting SMA glassy compound has been explained using the diffusion path model. 相似文献
3.
Software is the key technology in applications as diverse as accounting, hospital management, aviation, and nuclear power. Application advances in different domains such as these-each with different requirements-have propelled software development from small batch programs to large, real-time programs with multimedia capabilities. To cope, software's enabling technologies have undergone tremendous improvement in hardware, communications, operating systems, compilers, databases, programming languages, and user interfaces, among others. In turn, those improvements have fueled even more advanced applications. Improvements in VLSI technology and multimedia, for example, have resulted in faster, more compact computers that significantly widened the range of software applications. Database and user interface enhancements, on the other hand, have spawned more interactive and collaborative development environments. Such changes have a ripple effect on software development processes as well as on software techniques and tools. In this article, we highlight software development's crucial methods and techniques of the past 30 years 相似文献
4.
Lakshmi Ramachandran Nanjangud C. Narendra Karthikeyan Ponnalagu 《Service Oriented Computing and Applications》2012,6(4):283-302
Cloud-based systems promise an on-demand service provisioning system along with a ??pay-as-you-use?? policy. In the case of multi-tenant systems this would mean dynamic creation of a tenant by integrating existing cloud-based services on the fly. Presently, dynamic creation of a tenant is handled by building the required components from scratch. Although multi-tenant systems help providers save cost by allocating multiple tenants to the same instance of an application, they incur huge reconfiguration costs. Cost and time spent on these reconfiguration activities can be reduced by re-constructing tenants from existing tenant configurations supported by service providers. Multi-tenant cloud-based systems also lack the facility of allowing clients to specify their requirements. Giving clients the flexibility to specify requirements helps them avoid spending an excessive amount of time and effort looking through a list of services, many of which might not be relevant to them. Moreover, dynamic provisioning in the cloud requires an integrated solution across the technology stack (software, platform and infrastructure) combining functional, non-functional and resource allocation requirements. Existing research works in the area of web service matching, although numerous, still fall short, since they usually consider each requirement type in isolation and cannot provide an integrated solution. To that end, in this paper we investigate the features needed for dynamic service provisioning on the cloud. We propose a novel User Interface-Tenant Selector-Customizer (UTC) model and approach, which enables cloud-based services to be systematically modeled and provisioned as variants of existing service tenants in the cloud. Our approach considers functional, non-functional and resource allocation requirements, which are explicitly specified by the client via the user interface component of the model. To the best of our knowledge, ours is the first such integrated approach. We illustrate our ideas using a realistic running example, and also present a proof-of-concept prototype built using IBM??s Rational Software Architect modeling tool. We also present experimental results demonstrating the applicability of our matching algorithm. Our results show significant reduction in matching time with the help of an elimination process that reduces the search space needed for performing matching. 相似文献
5.
Jayaraman J. Thiagarajan Karthikeyan Natesan Ramamurthy Andreas Spanias 《Digital Signal Processing》2013,23(1):9-18
Mixing matrix estimation in instantaneous blind source separation (BSS) can be performed by exploiting the sparsity and disjoint orthogonality of source signals. As a result, approaches for estimating the unknown mixing process typically employ clustering algorithms on the mixtures in a parametric domain, where the signals can be sparsely represented. In this paper, we propose two algorithms to perform discriminative clustering of the mixture signals for estimating the mixing matrix. For the case of overdetermined BSS, we develop an algorithm to perform linear discriminant analysis based on similarity measures and combine it with K-hyperline clustering. Furthermore, we propose to perform discriminative clustering in a high-dimensional feature space obtained by an implicit mapping, using the kernel trick, for the case of underdetermined source separation. Using simulations on synthetic data, we demonstrate the improvements in mixing matrix estimation performance obtained using the proposed algorithms in comparison to other clustering methods. Finally we perform mixing matrix estimation from speech mixtures, by clustering single source points in the time-frequency domain, and show that the proposed algorithms achieve higher signal to interference ratio when compared to other baseline algorithms. 相似文献
6.
Ferroelectrically Gated Atomically Thin Transition‐Metal Dichalcogenides as Nonvolatile Memory 下载免费PDF全文
7.
Harminder Singh Henna Khosla T. S. Sidhu S. B. S. Kalsi J. Karthikeyan 《Materials and Manufacturing Processes》2018,33(2):140-148
For better performance in erosive–corrosive, wear and other extreme environmental conditions surface properties of metals and alloys are usually altered by different techniques. Amongst the various surface coating techniques cold spraying is a relatively new and less reported method. Coating formation at energy lower than the melting stage of materials brings novelty to this process. In this study surface of UNS No. - N07718 alloy is altered by cold spraying chromium-carbide (nickel-chromium) layer. The microstructure properties of this cold sprayed surface are observed by various characterization techniques and the results are used to study mechanism of coating layer formation by cold spray process. This newly developed cold sprayed surface is found to be eligible for further testing in wear and erosive-corrosive environmental conditions. 相似文献
8.
In this article, free space capacitance of dielectric‐coated conducting curvilinear surfaces is obtained using method of moments (MOM). The surfaces are discretized using triangular subsections. The curvilinear surfaces are represented by quadratic parametric elements. The MOM based on the pulse basis function and point matching is used. The integrand is divided into a regular and a singular part. The regular part of the integral is numerically evaluated by using the Gaussian quadrature algorithm for triangles. The Duffy transformation is used to evaluate the singular part of the integrals. Computed results are given for the capacitance of the dielectric‐coated conducting cylinder of finite axial length and truncated cone, and compared with the previously published results. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. 相似文献
9.
Currently, standards for web services are being developed via three different initiatives (W3C, Semantic web services and
ebXML). To the best of our knowledge, no theoretical perspectives underlie these standardization efforts. Without the benefit
of a strong theoretical basis, the results, within and across these initiatives, have remained piecemeal. We suggest ‘Language–Action
Theories’ as a plausible perspective that can effectively define, assess and refine web services standards. In this paper,
we first investigate the existing initiatives to identify commonalities that point to theories of ‘Language–Action’ as an
appropriate theoretical basis for web services standards. Next, we adapt work from these theories to develop a comprehensive
reference framework for understanding web services standards. Finally, we use this reference framework to assess the three
initiatives, and analyze the findings to provide insights for future development and refinement of web services standards.
相似文献
Sandeep PuraoEmail: |
10.
Karthikeyan Duraisamy James D. Baeder Jian-Guo Liu 《Journal of scientific computing》2003,19(1-3):139-162
A new class of implicit high-order non-oscillatory time integration schemes is introduced in a method-of-lines framework. These schemes can be used in conjunction with an appropriate spatial discretization scheme for the numerical solution of time dependent conservation equations. The main concept behind these schemes is that the order of accuracy in time is dropped locally in regions where the time evolution of the solution is not smooth. By doing this, an attempt is made at locally satisfying monotonicity conditions, while maintaining a high order of accuracy in most of the solution domain. When a linear high order time integration scheme is used along with a high order spatial discretization, enforcement of monotonicity imposes severe time-step restrictions. We propose to apply limiters to these time-integration schemes, thus making them non-linear. When these new schemes are used with high order spatial discretizations, solutions remain non-oscillatory for much larger time-steps as compared to linear time integration schemes. Numerical results obtained on scalar conservation equations and systems of conservation equations are highly promising. 相似文献