scholarly journals On the Lateral Instability Analysis of MEMS Comb-Drive Electrostatic Transducers

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3770
Author(s):  
Binh Duc Truong ◽  
Cuong Phu Le ◽  
Einar Halvorsen
Keyword(s):  
Virtual Work ◽  
Operation Mode ◽  
Optimization Techniques ◽  
Critical Voltage ◽  
Rotational Stiffness ◽  
Lateral Instability ◽  
Equilibrium Conditions ◽  
Mechanical Spring ◽  
Electrostatic Transducers ◽  
First Time

This paper investigates the lateral pull-in effect of an in-plane overlap-varying transducer. The instability is induced by the translational and rotational displacements. Based on the principle of virtual work, the equilibrium conditions of force and moment in lateral directions are derived. The analytical solutions of the critical voltage, at which the pull-in phenomenon occurs, are developed when considering only the translational stiffness or only the rotational stiffness of the mechanical spring. The critical voltage in a general case is numerically determined by using nonlinear optimization techniques, taking into account the combined effect of translation and rotation. The influences of possible translational offsets and angular deviations to the critical voltage are modeled and numerically analyzed. The investigation is then expanded for the first time to anti-phase operation mode and Bennet’s doubler configuration of the two transducers.

Diffusion and Phase Transformations in Steels: a Tool for Experimentation and a Method for Modelling

2006 ◽  
Vol 249 ◽  
pp. 239-246
Author(s):  
Yves Bréchet ◽  
Christopher R. Hutchinson ◽  
Gary R. Purdy ◽  
Hatem S. Zurob
Keyword(s):  
Grain Boundary ◽  
Phase Transformations ◽  
Annealing Time ◽  
Experimental Temperature ◽  
Equilibrium Conditions ◽  
First Time

The kinetics and morphology of the grain boundary grooving of Zn bicrystals with 16° <1010> tilt GB by Sn(Zn) melt has been studied at 325°C in equilibrium conditions in vacuum. It is shown that grooving process is interface controlled at least on the first stage. Groove walls mobility is evaluated. Changing of GB grove shape from “faceted walls” corner for annealing time < 78 h to concave “Mullins type” groove for annealing time > 78 h at the same experimental temperature was observed for the first time.

On the Equilibrium Conditions of Nonstationary Mechanical Systems

1999 ◽  
Vol 66 (4) ◽  
pp. 937-939
Author(s):  
M. Kazic ◽  
R. Bulatovic
Keyword(s):  
Equilibrium Problem ◽  
Virtual Work ◽  
Mechanical Systems ◽  
Principle Of Virtual Work ◽  
Equilibrium Conditions ◽  
New Approach ◽  
Starting Point ◽  
Stationary Problems ◽  
Nonstationary Systems

The equilibrium problem of nonstationary systems is studied. The starting point is the principle of virtual work (PVW). Contrary to stationary problems, some additional conditions (along with PVW) should be satisfied. Proof of Gantmacher’s postulate is derived. A new approach is given, and some results of other authors are discussed.

Voltage Sag Frequency Assessment Considering Uncertain Influencing Factors in the Power System

2014 ◽  
Vol 997 ◽  
pp. 814-820
Author(s):  
Xi Mu Yu
Keyword(s):  
Fault Location ◽  
Operation Mode ◽  
Maximum Entropy Principle ◽  
Voltage Sag ◽  
Testing System ◽  
System Operation ◽  
Operation Modes ◽  
Entropy Principle ◽  
Assessing Method ◽  
First Time

Many uncertain factors influence the assessment of voltage sag frequency (VSF), such as system operation modes, the fault rates of components and fault locations. In existing methods these factors are considered constant resulting in reasonless results. In this study, the uncertain property of fault location, system operation mode and failure rate of component are integrated to assess the VSF for the first time. The maximum entropy principle, typical operation modes and time-varying rate are used for characterizing the uncertainty of these factors. The assessing method and approaches are presented. Three cases considered different conditions are simulated on IEEE-30 standard testing system. The proposed method compared with Monte Carlo Simulation has been shown that it is reasonable and accurate and with good academic value and practical foreground.

A Novel Iterative Method of Determining the Pose Error of Planar Clearance-Affected Flexible Parallel Mechanisms Under Loaded Mode

2020 ◽  
Author(s):  
Qiangqiang Zhao ◽  
Junkang Guo ◽  
Jun Hong
Keyword(s):  
Iterative Method ◽  
Iterative Scheme ◽  
Virtual Work ◽  
Parallel Mechanisms ◽  
Single Chain ◽  
Linear Superposition ◽  
Equilibrium Conditions ◽  
Virtual Work Principle ◽  
Taylor Series Approximation ◽  
Flexible Model

Abstract Clearance and flexibility play an essential role in determining the accuracy of a planar parallel mechanism. However, previous accuracy prediction methods either considered only one of them or combined them in linear superposition. Therefore, this study proposes a novel iterative method for determining the pose error by considering clearance and flexibility simultaneously. First, the rigid-flexible model of the mechanism with clearances is developed based on the virtual joint method, in which the equilibrium conditions under the external load are established via the virtual work principle and differential forward kinematics. Then, using a Taylor series approximation, the “instant” stiffness matrix corresponding to a specific load is deduced. On this basis, an iterative scheme is explored to search for the final equilibrium pose, in which a child iterative scheme is constructed to determine the joint variables and suffered wrench of the single chain given a pose. Finally, the developed method is demonstrated by calculating the comparative pose errors of the planar five-bar mechanism and 3-RPR robot.

Computer Assisted Design of Rubber Shear Springs

1993 ◽  
Author(s):  
T. E. Shoup ◽  
G. R. Fegan
Keyword(s):  
Numerical Methods ◽  
Numerical Optimization ◽  
Numerical Procedure ◽  
Design Procedure ◽  
Nonlinear Behavior ◽  
Optimization Techniques ◽  
Computer Assisted ◽  
Design Procedures ◽  
Computer Assisted Design ◽  
First Time

Abstract While analysis procedures for the design of rubber mountings have existed for a number of years, the nonlinearity of these useful devices has limited the number of robust design procedures that are available. This paper presents a design procedure for the static deflections of rubber shear springs that accommodates the nonlinear behavior of these devices. It is believed that this is the first time such numerical procedures have been described in the design literature. The procedures are made possible by a combination of numerical approximations of nonlinear data in the engineering literature and numerical methods for handling transcendental relationships. Such design procedures would clearly not be possible without the use of digital computers and numerical optimization techniques. Design examples are presented to illustrate the use of the numerical procedure.

scholarly journals Parallel Implementations of ARX-Based Block Ciphers on Graphic Processing Units

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1894
Author(s):  
SangWoo An ◽  
YoungBeom Kim ◽  
Hyeokdong Kwon ◽  
Hwajeong Seo ◽  
Seog Chung Seo
Keyword(s):  
Graphics Processing Units ◽  
Block Cipher ◽  
Personal Information ◽  
Operation Mode ◽  
Optimization Methods ◽  
Block Ciphers ◽  
Optimization Techniques ◽  
Parallel Optimization ◽  
Graphic Processing Units ◽  
Iot Devices

With the development of information and communication technology, various types of Internet of Things (IoT) devices have widely been used for convenient services. Many users with their IoT devices request various services to servers. Thus, the amount of users’ personal information that servers need to protect has dramatically increased. To quickly and safely protect users’ personal information, it is necessary to optimize the speed of the encryption process. Since it is difficult to provide the basic services of the server while encrypting a large amount of data in the existing CPU, several parallel optimization methods using Graphics Processing Units (GPUs) have been considered. In this paper, we propose several optimization techniques using GPU for efficient implementation of lightweight block cipher algorithms on the server-side. As the target algorithm, we select high security and light weight (HIGHT), Lightweight Encryption Algorithm (LEA), and revised CHAM, which are Add-Rotate-Xor (ARX)-based block ciphers, because they are used widely on IoT devices. We utilize the features of the counter (CTR) operation mode to reduce unnecessary memory copying and operations in the GPU environment. Besides, we optimize the memory usage by making full use of GPU’s on-chip memory such as registers and shared memory and implement the core function of each target algorithm with inline PTX assembly codes for maximizing the performance. With the application of our optimization methods and handcrafted PTX codes, we achieve excellent encryption throughput of 468, 2593, and 3063 Gbps for HIGHT, LEA, and revised CHAM on RTX 2070 NVIDIA GPU, respectively. In addition, we present optimized implementations of Counter Mode Based Deterministic Random Bit Generator (CTR_DRBG), which is one of the widely used deterministic random bit generators to provide a large amount of random data to the connected IoT devices. We apply several optimization techniques for maximizing the performance of CTR_DRBG, and we achieve 52.2, 24.8, and 34.2 times of performance improvement compared with CTR_DRBG implementation on CPU-side when HIGHT-64/128, LEA-128/128, and CHAM-128/128 are used as underlying block cipher algorithm of CTR_DRBG, respectively.

scholarly journals Ion-Selective Optical Sensors: A New Look at Well-Established Techniques of Signal Acquisition

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 825 ◽  
Author(s):  
Andrey Kalinichev ◽  
Maria Peshkova ◽  
Nadezhda Pokhvishcheva ◽  
Konstantin Mikhelson
Keyword(s):  
Optical Sensors ◽  
Sensor Arrays ◽  
Analysis Time ◽  
Signal Acquisition ◽  
Color Analysis ◽  
Equilibrium Conditions ◽  
Color Scale ◽  
Calibration Free ◽  
And Shifts ◽  
First Time

It is demonstrated for the first time that the registration of the optode signal under non-equilibrium conditions reduces analysis time and shifts the sensor working range. The fabrication of optode-like color standards for digital color analysis (DCA) is described, and a multi-parameter color scale for calibration-free sensor arrays is proposed. Advantages and limitations of monochrome and color camera for DCA with colorimetric optodes are discussed.

New Compositionally-Ordered GeSi Nano Dots Fabricated with 1250 keV Electrons

2007 ◽  
Vol 26-28 ◽  
pp. 1195-1198 ◽  
Author(s):  
Se Ahn Song ◽  
Liudmila I. Fedina ◽  
Hion Suck Baik ◽  
Youn Joong Kim ◽  
Young Min Kim ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Crystal Thickness ◽  
Hrtem Image ◽  
Image Simulation ◽  
Equilibrium Conditions ◽  
Chemical Ordering ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
Point To Point ◽  
First Time

Transformation of uniformly strained GexSi1-x layers into GeSi dots of 3 ~ 7 nm which are compositionally ordered by one or concurrently two sets of {111} planes was carried out for the first time under non-equilibrium conditions induced by 1.25 MeV electron irradiation at Tc ≥ 200 oC in the high voltage electron microscope (JEM-ARM1300S). This microscope installed in the KBSI is characterized by an excellent point-to-point resolution of 0.12 nm allowing obtaining detailed information on chemical ordering at specific parameters of defocus (-800 Å) and crystal thickness (200~250 Å) determined by extensive HRTEM image simulation for the ordered dots.

scholarly journals Grain Boundary Wetting in Zn Bicrystals by a Sn-Based Melt

2006 ◽  
Vol 249 ◽  
pp. 235-238 ◽  
Author(s):  
Vladimir Murashov ◽  
Boris B. Straumal ◽  
Pavel Protsenko
Keyword(s):  
Grain Boundary ◽  
Annealing Time ◽  
Experimental Temperature ◽  
Equilibrium Conditions ◽  
Grain Boundary Wetting ◽  
First Time

The kinetics and morphology of the grain boundary grooving of Zn bicrystals with 16° <1010> tilt GB by Sn(Zn) melt has been studied at 325°C in equilibrium conditions in vacuum. It is shown that grooving process is interface controlled at least on the first stage. Groove walls mobility is evaluated. Changing of GB grove shape from “faceted walls” corner for annealing time < 78 h to concave “Mullins type” groove for annealing time > 78 h at the same experimental temperature was observed for the first time.

Global storm surges during a past warm climate, the Last Interglacial

2020 ◽  
Author(s):  
Pepijn Bakker ◽  
Paolo Scussolini ◽  
Sanne Muis ◽  
Job Dullaart ◽  
Alessio Rovere ◽  
...  
Keyword(s):  
Climate Model ◽  
State Of The Art ◽  
Storm Surges ◽  
Horizontal Resolution ◽  
Climate Variables ◽  
Last Interglacial ◽  
Warm Climate ◽  
Equilibrium Conditions ◽  
Temperature And Precipitation ◽  
First Time

&lt;p&gt;We present here a novel application of state-of-the-art surge modeling on a past climate of special interest. The Last Interglacial (LIG; 125,000 years ago) was the latest instance of a climate (slightly) warmer than present: for this reason its study can inform on the response of several climate components to a climate state with partial resemblance to possible futures. Climate variables like temperature and precipitation have been extensively studied for the LIG. Here, we calculate for the first time the implications of the altered LIG atmospheric circulation (both in mean state and extremes) for storm surges along the global coastline. This presents particular interest since it is often claimed that a warmer climate may imply enhanced storminess in some ocean basins. We use sub-daily results from simulations of the LIG and of the pre-industrial periods with the climate model CESM1.2 (equipped with atmosphere module CAM5, with ca. 1 degree horizontal resolution) to force the Global Tide and Surge Model (GTSM) for 30-years at climate equilibrium conditions. We analyze patterns of storminess and of storm surges, and report on the anomalies in those metrics between the LIG and the pre-industrial climate. These results can help contextualize proxy-based reconstructions of storms of the LIG, as well as projections of storm surges in a future warmer climate. Finally, we also reconstruct tides of the LIG, aiming to provide useful constrains to paleo sea-level reconstructions.&lt;/p&gt;

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