Linearized dynamic models for trajectory control of robot manipulators

To make an appropriate choice of linear model for the development of real-time control of robot manipulators, four direct linearization schemes have been studied here on the basis of computation and accuracy. Accuracy is assured in the state linearization method, whereas the rate linearization method leads to a satisfactory trade-off between computational effort and accuracy. In the case of high-velocity motions, a combination of state and rate linearization is proposed.     

Frequency Specification Testing of Analog Filters Using Wavelet Transform of Dynamic Supply Current

Wavelet transform has the property of resolving signal in both time and frequency unlike Fourier transform. In this work, we show that time-domain information obtained from wavelet analysis of supply current can be used to test the frequency specification of analog filters efficiently. The pole/zero locations in the frequency response of analog filters shift due to change in component values with process variations. It is essential to test the filters for the shift in frequency response and fix it during production test. Wavelet analysis of supply current can be a promising alternative to test frequency specification of analog filters, since it needs only one AC stimulus and is virtually unaffected by transistor threshold variation. Simulation results on two test circuits demonstrate that we can estimate pole/zero shift with less than 3% error using only one measurement, which requires about 18 measurements in the conventional technique.Swarup Bhunia received the undergraduate degree from Jadavpur University, Calcutta, India, and the Masters degree from the Indian Institute of Technology (IIT), Kharagpur. He is currently working toward the Ph.D. degree in the Department of Electrical Engineering, Purdue University, West Lafayette, IN, USA. He has worked in the EDA industry on RTL synthesis and verification for about three years. His research interest includes design methodologies for high-performance low-power testable VLSI system, defect-based testing, noise analysis, and noise-aware design.Arijit Raychowdhury received the B.E. degree in 2001 in electronics and telecommunication engineering from Jadavpur University, India. He is currently pursuing the Ph.D. degree in electrical and computer engineering in Purdue University, West Lafayette, IN, USA. He has worked as an analog circuit designer in Texas Instruments India. His research interests include device/circuit design for scaled silicon and nonsilicon devices. He has received academic excellence awards in 1997, 2000, and 2001 and Messner Fellowship from Purdue University in 2002. Mr. Raychowdhury has been awarded the Best Student Paper Award in the IEEE Nanotechnology Conference, 2003.Kaushik Roy received the B.Tech. degree in electronics and electrical communications engineering from the Indian Institute of Technology, Kharagpur, India, and the Ph.D. degree from the Electrical and Computer Engineering Department, University of Illinois, Urbana, in 1990. He was with the Semiconductor Process and Design Center of Texas Instruments, Dallas, TX, where he worked on FPGA architecture development and low-power circuit design. He joined the electrical and computer engineering faculty, Purdue University, West Lafayette, IN, in 1993, where he is currently a Professor. His research interests include VLSI design/CAD with particular emphasis in low-power electronics for portable computing and wireless communications, VLSI testing and verification, and reconfigurable computing. He has published more than 250 papers in refereed journals and conferences, holds six patents, and is Co-Author of a book on Low Power CMOS VLSI Design (New York: Wiley). He was Guest Editor for a Special Issue on Low-Power VLSI in IEE Proceedings Computers and Digital Techniques (July 2002). Dr. Roy received the National Science Foundation Career Development Award in 1995, the IBM Faculty Partnership Award, AT&T/Lucent Foundation Award, Best Paper Awards at the 1997 International Test Conference and 2000 International Symposium on Quality of IC Design, 2003 IEEE Latin American Test Workshop, and 2003 IEEE Nano. He is on the Editorial Board of IEEE Design and Test, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS, and IEEE TRANSACTIONS ON VLSI SYSTEMS. He was Guest Editor for a Special Issue on Low-Power VLSI in IEEE DESIGN AND TEST (1994), and for the IEEE TRANSACTIONS ON VLSI SYSTEMS (June 2000).     

Response of calcitonin cells, parathyroid glands and bone to prolonged calcitonin administration in the Indian palm squirrel, Funambulus pennanti (Wroughton)

The administration of calcitonin (4 MRC units injected intraperitoneally daily for 42 days) caused hypocalcaemia, hypophosphataemia and a decrease in the serum acid phosphatase level in adult Indian palm squirrels, Funambulus pennanti. Hypocalcaemia and the decrease in the serum acid phosphatase level persisted up to 21 days but the hypophosphataemic effect continued throughout the experiment. The serum calcium level increased from day 28 up to day 35 and the serum acid phosphatase level reached the control level at 28 days. At the close of the experiment (42 days), both serum calcium and acid phosphatase levels were again decreased. Calcitonin-induced hypocalcaemia resulted in hypertrophy of calcitonin cells which were densely packed with secretory granules up to day 21 of the treatment. Thereafter they displayed both hypertrophy and hyperplasia till the end of the experiment. Some calcitonin cells showed degranulation after 35 and 42 days of treatment. Few lead-haematoxylin-positive calcitonin cells with collapsed membranes and pyknotic nuclei were also seen in the lumina of the thyroid follicles toweards the close of the experiment. Parathyroid chief cells showed hypertrophy from 21 to 35 days of the treatment. From day 28 to the close of the experiment they released their secretory product. After 42 days of experimental treatment a growth-promoting effect of calcitonin was observed (increase in body weight and femur weight.     

Dielectric properties of breast carcinoma and the surroundingtissues

Relative permittivity of infiltrating breast carcinoma and the surrounding tissue was measured. The experiments were performed at frequencies from 20 kHz to 100 MHz at 37°C using an automatic network analyzer and an end-of-the-line capacitive sensor. Cole-Cole dielectric parameters were calculated by curve fitting using a computer program. Three main categories of tissues were considered: the central part of the tumor, the tumor surrounding tissue, and the peripheral tissue. Within each category, the large spread of the dielectric data for different specimens suggests structural and cellular inhomogeneities of the tumor tissue. However, certain consistency has been found in the dielectric relaxation time and the coefficient of the distribution of the relaxation time within each category. The results seem to indicate that RF impedance imaging can potentially be used as a diagnostic modality for the detection of human breast carcinoma     

The case of significant variations in gold–green and black open access: evidence from Indian research output

Scientometrics - Open Access has emerged as an important movement worldwide during the last decade. There are several initiatives now that persuade researchers to publish in open access journals...     

Bandwidth Enhancement of a Wide Slot Antenna Using Fractal Geometry for UWB Application with Multiple Notched Bands

Wireless Personal Communications - In this paper a combination of rectangular and elliptical fractal geometry is applied on a regular hexagonal wide slot antenna fabricated using a FR4 substrate to...     

Preparation of turmeric-derived sulfur-functionalized carbon dots: antibacterial and antioxidant activity

Journal of Materials Science - The work describes the preparation of carbon dots using turmeric as the carbon source and their functionalization with sulfur to enhance the functionality. The...     

Tent-Shaped Surface Morphologies of Silicon: Texturization by Metal Induced Etching

Silicon - Nano-metal/semiconductor junction dependent porosification of silicon has been studied here. The silicon nanostructures (SiNSs) have been textured on n- and p- type silicon wafers using...