Frequency Analysis

This paper applies the homotopy analysis method to study nonlinear free vibrations. The paper has used the homotopy analysis method to find analytical solutions of a nonlinear two-degree-of-freedom system. Analytical results have found the natural oscillation frequencies, the displacement formula of the system are approximately calculated at the 10th order.

9p viengfa 28-10-2024 0 0   Download

This paper presents the impacts of Electric Vehicle Charging Stations (EVCSs) on voltage and frequency quality in the Microgrid. It addresses security analysis, voltage and frequency quality, as well as issues related to EVCSs.

13p viling 11-10-2024 0 0   Download

This paper presents the research results of applying method two-dimensional energy filtering method in the "live window" to separate the high-frequency component of aeromagnetic data in order to eliminate residual flight line errors with amplitude ranges from -5÷5 nT and correct the data source before processing and analysis of data, identify potential field residual anomalies at depths h = 470 m, 1100 m, 1700 m, 2300 m.

13p viyoko 01-10-2024 3 0   Download

In this research, a combination of water quality assessment by statistical analysis with historical monitoring data to analyze and propose a sampling frequency. The objectives of this study included: (1) Assessment of seawater quality of coastal zone in the Northeast region of Quang Ninh province from 2016–2019; (2) Calculate and adjust sampling frequency for monitoring points.

9p viyoko 01-10-2024 0 0   Download

In this article, an efficient numerical approach for weight optimisation of functionally graded (FG) beams in the presence of frequency constraints is presented. For the analysis purpose, a finite element (FE) solution based on the first order shear deformation theory (FSDT) is established to analyse the free vibration behaviour of FG beams.

16p viyoko 24-09-2024 2 1   Download

In this paper, the static and dynamic behaviour of sandwich beams with porous core are numerically analyzed and validated by experimental tests. The beam consists of a thick porous core with a uniform porosity distribution over its domain and two outer face layers.

16p vifaye 20-09-2024 1 1   Download

This article presents an improved procedure for detecting single damage in beam-like structures. Many damage detection methods are based on the analysis of beam natural frequency shifts in damaged and intact states and its analytical modal curvatures.

15p vifaye 20-09-2024 4 1   Download

In the present report, a novel concept of frequency response function (FRF) is introduced for piezoelectric beam. First, a model of Timoshenko beam bonded with a piezoelectric layer is established and used for deriving the conventional frequency response function acknowledged as mechanical frequency response function (MERF). Then, the output charge produced in the piezoelectric layer is calculated from the MFRF and therefore obtained frequency-dependent function is called electrical frequency response function (EFRF) for the integrated beam.

16p dianmotminh02 03-05-2024 5 1   Download

In this work, the free vibration analysis of Timoshenko microbeams made of the Functionally Graded Material (FGM) on the Winkler–Paternak elastic foundation based on the Modified Coupled Stress Theory (MCST) is investigated. Material characteristics of the beam vary throughout the thickness according to the power distribution and are estimated though Mori–Tanaka, Hashin–Shtrikman and Voigt homogenization techniques.

13p dianmotminh02 03-05-2024 9 3   Download

This paper considers the single-degree-of-freedom (SDOF) base excited isolation with piezoelectric energy harvesting. The purpose of this paper is to find how the energy harvesting circuit affects the fixed point of the frequency response.

6p vimarillynhewson 02-01-2024 8 4   Download

The dynamic analysis is a necessity in the design, manufacturing and maintenance of structures. The analytic solutions are not available for most practical cases and the Finite Element Method (FEM) is not reliable due to the joint problem, unclear loading, material properties and numerical error. In this paper, we present a way to find modes shape of 3D Frame by FEM program using Matlab.

8p vidoctorstrange 06-05-2023 7 3   Download

In the course of current research the procedure of obtaining of the piecewise linear vibration systems time and frequency responses have been developed. The method is partly analytical and partly numerical and is based on combining of linear solutions of different sections in a cycle of motion. In a row with the method of obtaining of the exact steady state time and frequency response, also it is provided sensitivity analysis of the vibration isolator.

86p runthenight07 01-03-2023 7 3   Download

Bài viết Nâng cao khả năng phân loại tín hiệu thuỷ âm sử dụng nội suy khối nối trục và phân phối xác suất trong không gian ẩn trình bày một mô hình xử lý tín hiệu dưới nước nhằm mục đích phát hiện và phân loại tàu chân vịt thông qua cách cải tiến kỹ thuật LOFAR (Low Frequency Analysis and Recording) bằng nội suy khối nối trục (Cubic Splines Interpolation - CSI), kết hợp với mô hình xác suất phân phối trong miền không gian ẩn.

10p vichristinelagarde 04-07-2022 19 2   Download

Research objective: Establish the genetic variants database of 04 genes CYP2C9, CYP2C19, CYP2D6 and CYP3A5 in Kinh Vietnamese. Identification of genotype and allele frequencies of 04 genes CYP2C9, CYP2C19, CYP2D6 and CYP3A5 in Kinh Vietnamese. Perform in silico functional analysis of novel variants.

27p extraenglish 24-05-2021 25 4   Download

Để giúp người kỹ sư có thể phân tích các phép thí nghiệm chẩn đoán nâng cao như Phân tích đáp ứng tần số (Frequency Response Analysis), Phân tích đáp ứng điện môi (Dielectric Frequency Response) hay Phóng điện cục bộ (Partial Discharge) ... ứng dụng cho đối tượng máy biến áp lực trong các trạm biến áp tăng áp của nhà máy điện, trạm trung gian và phân phối của lưới điện Việt Nam, bài viết giới thiệu tổng quan cấu trúc hình học và đặc tính vật liệu của thiết bị này

7p vijersey2711 03-03-2021 39 3   Download

Establish the genetic variants database of 04 genes CYP2C9, CYP2C19, CYP2D6 and CYP3A5 in Kinh Vietnamese. Identification of genotype and allele frequencies of 04 genes CYP2C9, CYP2C19, CYP2D6 and CYP3A5 in Kinh Vietnamese. Perform in silico functional analysis of novel variants.

27p capheviahe27 23-02-2021 5 3   Download

Analysis of mutation and protein expression of EGFR in patients with lung adenocarcinoma; investigation the hypermethylation frequency of EGFR, BRCA1, MGMT, MLH1, RASSF1A and correlation of the methylation between these genes with mutations and protein expression of EGFR.

27p capheviahe26 25-01-2021 19 4   Download

In this paper, we consider a general case of FFR in which the users are classified into groups and each group is assigned a serving power level. The mathematical model of the general FFR is presented and analysed through a stochastic geometry approach. The derived analytical results in terms of average coverage probability can covered all the related well-known results in the literature.

8p tamynhan6 14-09-2020 17 3   Download

Analysis of mutation and protein expression of EGFR in patients with lung adenocarcinoma. Investigation the hypermethylation frequency of EGFR, BRCA1, MGMT, MLH1, RASSF1A and correlation of the methylation between these genes with mutations and protein expression of EGFR.

27p trinhthamhodang7 31-08-2020 36 2   Download

The results indicated that the majority of employees belong to the age group of 20-25years. The result also showed that about two-third of ITES employees belong to the monthly income group of Rs 10000- 15000 and the majority of ITES employees are single.

8p guineverehuynh 21-06-2020 11 4   Download