Analysis on an alternative structure of damping-factor-control frequency compensation

Author(s):  
Ka Nang Leung ◽  
P.K.T. Mok ◽  
Wing-Hung Ki ◽  
J.K.O. Sin
2000 ◽  
Vol 35 (2) ◽  
pp. 221-230 ◽  
Author(s):  
Ka Nang Leung ◽  
P.K.T. Mok ◽  
Wing-Hung Ki ◽  
J.K.O. Sin

Author(s):  
SRIRANGANATHA SAGAR.K.N ◽  
POORNIMA N. ◽  
VIJAYA KUMAR. V

A 1.2-V 40-mA capacitor-free CMOS low-dropout regulator (LDO) for system-on-chip applications to reduce board space and external pins is presented. By utilizing damping-factor control frequency compensation on the advanced LDO structure, the proposed LDO provides high stability, as well as fast line and load transient responses, even in capacitorfree operation. The proposed LDO has been implemented in a tsmc65nm CMOS technology, and the total error of the output voltage due to line and load variations is less. Moreover, the output voltage can recover with ≈2.3μs for full load current changes. The power-supply rejection ratio at 1 MHz is 26 dB.


Author(s):  
Michael F. Smith ◽  
John P. Langmore

The purpose of image reconstruction is to determine the mass densities within molecules by analysis of the intensities within images. Cryo-EM offers this possibility by virtue of the excellent preservation of internal structure without heavy atom staining. Cryo-EM images, however, have low contrast because of the similarity between the density of biological material and the density of vitreous ice. The images also contain a high background of inelastic scattering. To overcome the low signal and high background, cryo-images are typically recorded 1-3 μm underfocus to maximize phase contrast. Under those conditions the image intensities bear little resemblance to the object, due to the dependence of the contrast transfer function (CTF) upon spatial frequency. Compensation (i.e., correction) for the CTF is theoretically possible, but implementation has been rare. Despite numerous studies of molecules in ice, there has never been a quantitative evaluation of compensated images of biological molecules of known structure.


1974 ◽  
Vol 32 (01) ◽  
pp. 057-064 ◽  
Author(s):  
Y Nemerson ◽  
S.A Silverberg ◽  
J Jesty

SummaryTwo reactions of the extrinsic pathway of coagulation, the activations of Factor X and prothrombin, have been studied in purified systems and shown to be self-damping. Factor X was activated by the tissue factor - Factor VII complex, and prothrombin by two systems: the coagulant protein of Taipan venom, and the physiological complex of activated Factor X, Factor V, lipid, and calcium ions. In each case the yield of enzyme, activated Factor X or thrombin, is a function of the concentration of activator. These and other observations are considered as a basis for a control mechanism in coagulation.


2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 173-180
Author(s):  
Giorgia Di Gangi ◽  
Giorgio Monti ◽  
Giuseppe Quaranta ◽  
Marco Vailati ◽  
Cristoforo Demartino

The seismic performance of timber light-frame shear walls is investigated in this paper with a focus on energy dissipation and ductility ensured by sheathing-to-framing connections. An original parametric finite element model has been developed in order to perform sensitivity analyses. The model considers the design variables affecting the racking load-carrying capacity of the wall. These variables include aspect ratio (height-to-width ratio), fastener spacing, number of vertical studs and framing elements cross-section size. A failure criterion has been defined based on the observation of both the global behaviour of the wall and local behaviour of fasteners in order to identify the ultimate displacement of the wall. The equivalent viscous damping has been numerically assessed by estimating the damping factor which is in use in the capacity spectrum method. Finally, an in-depth analysis of the results obtained from the sensitivity analyses led to the development of a simplified analytical procedure which is able to predict the capacity curve of a timber light-frame shear wall.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Zhiyu Wang ◽  
Shun Wang ◽  
Guangyou Fang ◽  
Qunying Zhang

Nonpolarizable electrodes are applied widely in the electric field measurement for geophysical surveys. However, there are two major problems: (1) systematic errors caused by poor electrical contact in the high resistive terrains and (2) environmental damage associated with using nonpolarizable electrodes. A new alternative structure of capacitive electrode, which is capable of sensing surface potential through weak capacitive coupling, is presented to solve the above problems. A technique is introduced to neutralize distributed capacitance and input capacitance of the detection circuit. With the capacitance neutralization technique, the transmission coefficient of capacitive electrode remains stable when environmental conditions change. The simulation and field test results indicate that the new capacitive electrode has an operating bandwidth range from 0.1 Hz to 1 kHz. The capacitive electrodes have a good prospect of the applications in geophysical prospecting, especially in resistive terrains.


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