Oscilation

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 2 0   Download

In this study, we propose a novel approach using the oscillation characteristics of the RMS current as the input to machine learning models, combined with the confident learning technique. Using the oscillation characteristics obtained by taking a discrete Fourier transform (DFT) of the RMS current as model input, we aim to reduce the computational requirements of the machine learning models.

12p viling 11-10-2024 2 1   Download

In this paper, the effects of wind velocity according to height above the ground on the rain-wind induced vibration (RWIV) of stay cables are investigated. RWIV of the cable is modeled using the linear theory of cable vibration and the central difference algorithm.

14p vifilm 24-09-2024 3 1   Download

he study uses Best Track Data in the Western North Pacific region from 1961 to 2020. The wind speed fields of all TCs over the coastal zones are calculated using a semi-empirical model with a square grid of 0.05° resolution. The results show that the frequencies of TCs over the coastal zones decrease during El Niño years, whilethe TC intensities increase significantly compared to those in Neutral years. Meanwhile, TC intensities over all coastal zones during La Niña years, and some coastal zones during El Niño years, decrease significantly compared to those in Neutral years.

15p dianmotminh02 03-05-2024 1 1   Download

The F2B slab model weakens the oscillations and calculations on F2B model quickly converge. However, the F2B model leads to artificial narrowness of band gap. Besides, when the number of layers increases, surface energy obtained from all three slab models approaches similar values. In particular, values of surface energy from DFT calculations converge to the experimental range for all three slab models.

8p dianmotminh02 03-05-2024 11 3   Download

Bài báo "Mạch phát hiện mất khóa cải tiến cho mạch CDR dải rộng trên công nghệ CMOS 28nm" đề xuất mạch LoLD sẽ kiểm tra mối quan hệ giữa tốc độ dữ liệu đầu vào mới và tần số của mạch dao động điều khiển bằng điện áp (Voltage-Controlled Oscillator: VCO) để quyết định trạng thái làm việc tiếp theo cho mạch FD mà không reset ngay mạch FD về trạng thái ban đầu. Mạch LoLD đề xuất cho mạch CDR dải rộng được thiết kế trên công nghệ CMOS 28 nm.

4p phocuuvan0201 02-02-2024 11 2   Download

Để đánh giá vai trò của hệ thống dao động xung lực IOS (Impulse oscillation system) đo sức cản đường thở trong chẩn đoán hen phế quản ở trẻ em. Đối tượng và phương pháp: Nghiên cứu mô tả loạt ca bệnh trên 156 trẻ được chẩn đoán hen phế quản theo GINA (Global Initiative for Asthma) 2016 đã được lựa chọn.

7p visoros 01-11-2023 8 2   Download

Single electron transistor (SET) is a key element in current research area of nanoelectronics which can offer nano-feature size, low power consumption and high operating speed. SET could be promising alternative for MOSFET in the future.

7p vidoctorstrange 06-05-2023 11 3   Download

The limits of current micro-scale technology is approaching rapidly. As the technology is going toward nano-scale devices, physical phenomena involved are fundamentally different from micro-scale ones. Principles in classical physics are no longer powerful enough to explicate the phenomena involved in nano-scale devices. At this stage, quantum mechanic sheds some light on those topics which cannot be described by classical physics. The primary focus of this research work is the development of an analysis technique for understanding the behavior of strongly perturbed harmonic oscillators.

165p runthenight07 01-03-2023 6 3   Download

The objective of this research was to determine the role of neural feedback and muscle mechanics in the generation of physiological tremor oscillation. This research developed a neuromuscular model to simulate the individual and resulting oscillatory mechanisms of tremor. The oscillations found in EMG signal were also analysed empirically from EMG data from 54 subjects using Hilbert Transform and rectification to obtain the envelope of the signal. The time between rhythmical waveform patterns in the EMG signal, TC was found to be 78ms.

117p runthenight07 01-03-2023 6 3   Download

Mạch dao động điều khiển bằng điện áp (VCO) từ 0,1 đến 1,65 GHz trên công nghệ CMOS 180 nm trình bày về thiết kế mạch tạo dao động điều khiển bằng điện áp (Voltage Controlled Oscillator: VCO) ứng dụng cho các mạch khôi phục dữ liệu và xung đồng hồ dải rộng trong các hệ thống thông tin nối tiếp tốc độ cao.

8p vimalfoy 08-02-2023 21 2   Download

The current research is undertaken by performing Computational Fluid Dynamics (CFD) simulations for a 2D aerofoil fitted with a shock control bump at a transonic flow condition. Reynolds-Averaged Navier-Stokes equation coupled with turbulence models is adopted to solve the flowfield. The bump has a conventional geometric feature which consists of a ramp, a crest and a tail, and it has eight variants for which the designed parameters are reasonably specified according to the compressible aerodynamics theory.

84p runthenight04 02-02-2023 7 3   Download

Bài viết Ảnh hưởng của ENSO đến VCI khu vực Nam Trung Bộ, Tây Nguyên và Đông Nam Bộ được nghiên cứu nhằm đánh giá các ảnh hưởng của ENSO (the El Niño Southern Oscillation) đến sự phát triển của thực vật qua chỉ số điều kiện thực vật.

16p viporsche 03-11-2022 24 4   Download

The objectives of the present study are: To design and produce functional samples of woven single-layer, fire-resistant fabrics made from natural, FR man-made cellulosics, and high-performance synthetic blended yarns; to determine the physiological consequences and health risks associated with wearing PPC in hot, humid environments in relation to metabolic heat production and physical work for firefighters trying to maintain the balance between protection and comfort, and its implication on the required Station Wear fabric properties.

184p runordie3 06-07-2022 9 3   Download

Wet periods are evidenced by dark olive green mixed lithology (sandy, clay, and silts) and high values in MS and log(Sr/Ca). On the other hand, dry periods are associated with light olive green clayey mud lithology and high values in log(Ca/K). We relate the wet periods to negative North Atlantic Oscillation (NAO–) and the dry periods to NAO+. Additionally, all wet periods are related with time of low solar activity and dry periods, except Dalton Minimum, are related with periods of high solar activity.

10p tanmocphong 29-01-2022 11 1   Download

Bài viết trình bày thiết kế bộ phát tín hiệu RF hoạt động ở tần số 315 MHz điều chế OOK cho các mạng cảm biến không dây cự ly gần. Trong thiết kế này, một bộ dao động mạch vòng (ring oscillator) được dùng để tạo tín hiệu tần số thấp, sau đó nhân tần lên đến tần số sóng mang 315 MHz bằng bộ nhân tần số tổ hợp sườn xung.

7p vivelvet2711 06-09-2021 28 3   Download

Lecture Physics A2: Oscillations - PhD. Pham Tan Thi present the content what is an Oscillation, simple harmonic oscillation/motion, period and frequency, angular frequency, displacement as function of time in SHM,...

24p xusong 21-07-2021 17 2   Download

Lecture Physics A2: Interference - PhD. Pham Tan Thi present the content a single oscillating wave, multiple waves - superposition, superposing sinusoidal waves, adding sine waves with different phases,...

41p xusong 21-07-2021 22 1   Download

Bài giảng Kỹ thuật nâng & vận chuyển - Chương 13: Máy vận chuyển liên tục không có bộ phận kéo (tractionless - type conveyors). Những nội dung chính trong chương này gồm có: Thiết bị trọng trường (gravity-type conveyor), băng lăn (gravity roller conveyors), máng lắc có áp lực thay đổi của vật lên máng (oscillating conveyor with variable pressure on deck), máng lắc có áp lực không đổi của vật lên máng (oscillating conveyor with constant pressure on deck).

12p lovebychance05 16-06-2021 18 3   Download

The main objective of the thesis is to provide general methods to control oscillation based on measurement of energy flow, namely: Find the optimal solution for passive control systems based on energy flows; propose the semi-active control algorithms to control the energy flow.

27p capheviahe27 23-02-2021 20 3   Download