• Structural Engineering and Mechanics
• /
• 제30권6호
• /
• pp.699-712
• /
• 2008

The effectiveness of wavelet transform in detecting delamination damages in multilayered composite beams and plates is studied here. The damaged composite beams and plates are modeled in finite element software ABAQUS and the first few mode shapes are obtained. The mode shapes of the damaged structures are then wavelet transformed. It is observed that the distribution of wavelet coefficients can identify the damage location of beams and plates by showing higher values of wavelet coefficients at the position of damage. The effectiveness of the method is studied for different boundary conditions, damage location and size for single as well as multiple delaminations in composite beams and plates. It is observed that both discrete wavelet transform (DWT) and continuous wavelet transform (CWT) can detect the presence and location of the damaged region from the mode shapes of the structures. DWT may be used to approximately evaluate the size of the delamination area, whereas, CWT is efficient to detect smaller delamination areas in composites.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제12권4호
• /
• pp.377-387
• /
• 2012

An intrinsic small signal equivalent circuit model of Cylindrical/Surrounded gate MOSFET is proposed. Admittance parameters of the device are extracted from circuit analysis and intrinsic circuit elements are presented in terms of real and imaginary parts of the admittance parameters. S parameters are then evaluated and justified with the simulated data extracted from 3D device simulation.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제12권4호
• /
• pp.482-491
• /
• 2012

In the present work, comprehensive investigation of the ambipolar characteristics of two silicon (Si) tunnel field-effect transistor (TFET) architectures (i.e. p-i-n and p-n-p-n) has been carried out. The impact of architectural modifications such as heterogeneous gate (HG) dielectric, gate drain underlap (GDU) and asymmetric source/drain doping on the ambipolar behavior is quantified in terms of physical parameters proposed for ambipolarity characterization. Moreover, the impact on the miller capacitance is also taken into consideration since ambipolarity is directly related to reliable logic circuit operation and miller capacitance is related to circuit performance.

• 호남수학학술지
• /
• 제39권4호
• /
• pp.575-590
• /
• 2017

A new class of functions called $R_{\theta}$-supercontinuous functions is introduced. Their basic properties are studied and their place in the hierarchy of strong variants of continuity, which already exist in the literature, is elaborated. The class of $R_{\theta}$-supercontinuous functions properly contains the class of $R_z$-supercontinuous functions [39] which in turn properly contains the class of $R_{cl}$-supercontinuous functions [43] and so includes all cl-supercontinuous (clopen continuous) functions ([38], [34]) and is properly contained in the class of $R_{\delta}$-supercontinuous functions [24].

• Journal of Plant Biotechnology
• /
• 제44권4호
• /
• pp.364-371
• /
• 2017

The key to development of barnase-barstar transgene based hybrid seed technology is the availability of tightly regulated tapetum specific promoter, as any leaky expression of the barnase gene leads to several unintended effects. In the present study, we used two different tapetum specific promoters i.e. promoter of the RTS gene isolated from rice cultivar IR64 and the OsG6b promoter from japonica rice cultivar Hayayuki to express the barnase gene in rice transgenic lines. While viable male sterile transgenic lines could not be obtained with RTS promoter we could develop single copy male sterile lines when the barnase gene was expressed under the OsG6b promoter.

• Journal of Electrical Engineering and Technology
• /
• 제12권4호
• /
• pp.1386-1396
• /
• 2017

In this paper, a new approach is proposed to select the optimal sitting and sizing of distributed solar photovoltaic generation (SPVG) in a radial electrical distribution systems (EDS) considering load/generation uncertainties. Here, distributed generations (DGs) allocation problem is modeled as optimization problem with network loss based objective function under various equality and inequality constrains in an uncertain environment. A boundary power flow is utilized to address the uncertainties in load/generation forecasts. This approach facilitates the consideration of random uncertainties in forecast having no statistical history. Uncertain solar irradiance is modeled by beta distribution function (BDF). The resulted optimization problem is solved by a new Dynamic Harmony Search Algorithm (DHSA). Dynamic band width (DBW) based DHSA is proposed to enhance the search space and dynamically adjust the exploitation near the optimal solution. Proposed approach is demonstrated for two standard IEEE radial distribution systems under different scenarios.

• International Journal of Reliability and Applications
• /
• 제17권1호
• /
• pp.21-49
• /
• 2016

Many mechanical, electrical and electronic products have more than one performance characteristics (PCs). For example the performance degradation of rubidium discharge lamps can be characterized by the rubidium consumption or the decreasing intensity the lamp. The product may degrade due to all the PCs which may be independent or dependent. This paper deals with the design of optimal bivariate step-stress partially accelerated degradation test (PADT) with degradation paths modelled by gamma process. The dependency between PCs has been modelled through Frank copula function. In partial step-stress loading, the unit is tested at usual stress for some time, and then the stress is accelerated. This helps in preventing over-stressing of the test specimens. Failure occurs when the performance characteristic crosses the critical value the first time. Under the constraint of total experimental cost, the optimal test duration and the optimal number of inspections at each intermediate stress level are obtained using variance optimality criterion.

• Journal of applied mathematics & informatics
• /
• 제33권3_4호
• /
• pp.235-246
• /
• 2015

In this paper, a vector optimization problem over cones is considered, where the functions involved are $\eta$-semidifferentiable. Necessary and sufficient optimality conditions are obtained. A dual is formulated and duality results are proved using the concepts of cone $\rho$-semilocally preinvex, cone $\rho$-semilocally quasi-preinvex and cone $\rho$-semilocally pseudo-preinvex functions.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제13권5호
• /
• pp.500-510
• /
• 2013

In this paper, a high-sensitivity low power photodetector using double gate (DG) MOSFET is proposed for the first time using change in subthreshold current under illumination as the sensitivity parameter. An analytical model for optically controlled double gate (DG) MOSFET under illumination is developed to demonstrate that it can be used as high sensitivity photodetector and simulation results are used to validate the analytical results. Sensitivity of the device is compared with conventional bulk MOSFET and results show that DG MOSFET has higher sensitivity over bulk MOSFET due to much lower dark current obtained in DG MOSFET because of its effective gate control. Impact of the silicon film thickness and gate stack engineering is also studied on sensitivity.

• Journal of Information Science Theory and Practice
• /
• 제1권4호
• /
• pp.48-66
• /
• 2013

The aim of this study is to examine the user's online searching behavior in IR interfaces of e-journal database systems. The study is purely based on survey methods and tries to analyse the online searching behavior of respondents of social science disciplines who were doing research in three target central universities of Delhi (i.e. DU, JMI, and JNU). For measuring the responses of the respondents in IR interfaces of e-journal database systems, a total of 396 questionnaires were distributed among the students and out of all, 305 responses were used for the study. The findings of the study reveal that most of the students were not using all the facilities offered in IR interfaces of e-journal database systems for their retrieval process and also encourages menu based searches rather than command based searching.