Natural frequency

Recently, machine learning (ML) algorithms have proven to be highly effective tools for predicting structural damage. However, the data used in structural health monitoring often consists primarily of normal operational conditions or slight deviations from the original state, with a scarcity of data representing potentially dangerous conditions.

21p viyamanaka 06-02-2025 1 1   Download

Located in the northwest of Laocai province, Batxat district has been frequently affected by natural disasters, including landslides and debris flows. Therefore, landslide hazard assessment (LHA) has been a significant task for planning, economic development, and minimizing human and property damage.

12p viyamanaka 06-02-2025 5 2   Download

An experiment was conducted to study the effectiveness and efficiency of one physical mutagen i.e. gamma rays and two chemical mutagens i.e. ethyl methanesulfonate (EMS) and nitrosoguanidine (NG) in greengram. To study the nature and effect of mutagens in greengram, the percentage of lethality, pollen sterility, frequency of chlorophyll mutations, mutagenic effectiveness, mutagenic efficiency and mutation rates of each mutagen were estimated.

9p angicungduoc6 22-07-2020 16 3   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 12 4   Download

This paper presents a numerical analysis of free vibration of thin circular and annular plate using finite element method. The first five natural frequencies are presented for uniform annular plates of various inner-to-outer radius ratios, with nine possible combinations of free, clamped and simply supported boundary conditions at the inner and outer edges of plates.

8p tohitohi 19-05-2020 30 2   Download

In this paper, an analytical solution for whirling analysis of axial-loaded Timoshenko rotor is presented and corresponding basic functions are derived. The set of governing equations for whirling analysis of the rotor consists of four coupled partial differential equations; using complex displacements, these equations can be reduced to two coupled partial differential equations.

12p tohitohi 19-05-2020 17 1   Download

In this research, the influences of modal properties of a micro cubic satellite on equivalent static loads (due to combination of quasi-static and dynamic loads during launch time) have been studied. The study shows that the magnitude of equivalent static loads can be affected by satellite effective modes and effective mass distribution along natural frequencies.

10p tohitohi 19-05-2020 13 1   Download

In this paper, an analytical method is proposed for calculation of natural frequencies of a delaminated composite beam from both free and constrained mode frequencies. In previous studies, the frequencies of a delaminated composite beam were computed with assumption of occurring open or close delamination during the vibration.

8p tohitohi 19-05-2020 19 1   Download

The research objectives of the thesis are to study the nature of operational efficiency, criteria for identifying and measuring the performance of enterprises; survey the importance and frequency of using performance analysis criteria; complete a system of criteria for analyzing operational efficiency to meet the use needs of Vietnamese paper enterprises.

0p gaunguyen6789 17-09-2019 52 2   Download

The aim of this thesis is to study crack-induced change in natural frequencies and to develop a procedure for detecting cracks in stepped beams by measurement of natural frequencies.

27p xacxuoc4321 11-07-2019 33 3   Download

In both industrial fermenters and in their natural habitats, microorganisms often experience an inhomogeneous and fluctuating environment. In this paper we mimicked one aspect of this nonideal behaviour by imposing a low and oscillating extracellular glucose concentration on nonoscillating suspensions of yeast cells. The extracellular dynamics changed the intracel-lular dynamics – which was monitored through NADH fluorescence – from steady to equally dynamic; the latter followed the extracellular dynamics at the frequency of glucose pulsing....

9p awards 06-04-2013 48 4   Download

In this paper, we study the growth of sX(L), the number of simple closed geodesics of length ≤ L on a complete hyperbolic surface X of finite area. We also study the frequencies of different types of simple closed geodesics on X and their relationship with the Weil-Petersson volumes of moduli spaces of bordered Riemann surfaces.

30p dontetvui 17-01-2013 49 7   Download

We study the ac-conductivity in linear response theory in the general framework of ergodic magnetic Schr¨dinger operators. For the Anderson model, o if the Fermi energy lies in the localization regime, we prove that the ac1 conductivity is bounded from above by Cν 2 (log ν )d+2 at small frequencies ν. This is to be compared to Mott’s formula, which predicts the leading term to 1 be Cν 2 (log ν )d+1 .

30p noel_noel 17-01-2013 61 8   Download

We characterize precisely the possible rate of decay of the anti-analytic half of a trigonometric series converging to zero almost everywhere. 1. Introduction 1.1. In 1916, D. E. Menshov constructed an example of a nontrivial trigonometric series on the circle T ∞ (1) n=−∞ c(n)eint which converges to zero almost everywhere (a.e.). Such series are called nullseries. This result was the origin of the modern theory of uniqueness in Fourier analysis, see [Z59], [B64], [KL87], [KS94]. Clearly for such a series |c(n)|2 = ∞.

33p noel_noel 17-01-2013 39 6   Download

We show that for almost every frequency α ∈ R\Q, for every C ω potential v : R/Z → R, and for almost every energy E the corresponding quasiperiodic Schr¨dinger cocycle is either reducible or nonuniformly hyperbolic. This result o gives very good control on the absolutely continuous part of the spectrum of the corresponding quasiperiodic Schr¨dinger operator, and allows us to complete o the proof of the Aubry-Andr´ conjecture on the measure of the spectrum of e the Almost Mathieu Operator. ...

31p noel_noel 17-01-2013 36 6   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Speech Enhancement with Natural Sounding Residual Noise Based on Connected Time-Frequency Speech Presence Regions

11p dauphong20 11-03-2012 51 4   Download

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Seasonal fluctuations of cosmopolitan inversion frequencies in a natural population of Drosophila melanogaster

0p toshiba20 12-11-2011 68 2   Download

1. Các khái niệm cần lưu ý: 1.1. Khối lượng, m: Theo định luật Newton, lực F = m x a. Khối lượng m º F Û gia tốc a = 1 m/s2. 1.2. Bậc tự do, DOF: Có hai loại sau: MDOF, hệ nhiều bậc tự do; SDOF, hệ một bậc tự do. 1.3. Tần số dao động tự nhiên và mode dao động tự nhiên (Natural Frequency, dao động mà công trình có được do trọng lượng bản thân của nó, không có sự tác động của tải trọng ngoài)

14p hoangduyngoc 26-05-2011 334 143   Download