Benjamin H. Goot, Sonali Patel, Brian Fonseca

Congenital Heart Disease, Vol.12, No.1, pp. 84-90, 2017

Abstract Objective: When imaging the lower airway by MRI, the traditional technique turbo spin echo (TSE) results in high quality 2D images, however planning and acquisition times are lengthy. An alternative, delayed volume interpolated breath-holds examination (VIBE), is a 3D gradient echo technique that produces high spatial resolution imaging of the airway in one breath-hold. The objective of this study is to retrospectively evaluate the accuracy of lower airway measurements obtained by delayed VIBE when compared to TSE.
Design: Patients with congenital heart disease who underwent a cardiac MRI (CMR) that included a delayed VIBE sequence from 5/2008 to 9/2013 were… More >

Wei Zhao^{1, 2}, Shuai Feng¹, Yadan Wang¹, Yuanguo Wang¹, Zhihui Han¹, Hu Peng^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.1, pp. 427-440, 2020, DOI:10.32604/cmes.2020.09387

Abstract Frame rate is an important metric for ultrasound imaging systems, and high frame rates (HFR) benefit moving-target imaging. One common way to obtain HFR imaging is to transmit a plane wave. Delay-and-sum (DAS) beamformer is a conventional beamforming algorithm, which is simple and has been widely implemented in clinical application. Fourier beamforming is an alternative method for HFR imaging and has high levels of imaging efficiency, imaging speed, and good temporal dynamic characteristics. Nevertheless, the resolution and contrast performance of HFR imaging based on DAS or Fourier beamforming are insufficient due to the single plane wave transmission. To address this… More >

Ping Li^*, Huanhuan Ni, Songbei Ying, Jiali Wei, Xiangyang Hu

Phyton-International Journal of Experimental Botany, Vol.89, No.1, pp. 1-12, 2020, DOI:10.32604/phyton.2020.09817

Abstract Primary seed dormancy is a critical trait for sustainable agricultural development, ensuring seed germination under favorable conditions. The induction, maintenance and release of seed dormancy is a complicated physiological process that is strictly controlled by a variety of endogenous signals and environmental factors. In Arabidopsis, DOG1 (DELAY OF GERMINATION 1) is identi- fied as the main quantitative trait locus (QTL) of seed dormancy, which contributes to deep dormancy in the Cvi ecotype. In recent years, considerable progress has been made to elucidate the molecular regulatory mechanism by which DOG1 controls seed dormancy. In this review, we describe a series of… More >

Manlika Ratchagit¹, Benchawan Wiwatanapataphee¹, Nikolai Dokuchaev^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.2, pp. 487-504, 2020, DOI:10.32604/cmes.2020.08865

Abstract The classical autoregressive (AR) model has been widely applied to predict future data using m past observations over five decades. As the classical AR model required m unknown parameters, this paper implements the AR model by reducing m parameters to two parameters to obtain a new model with an optimal delay called as the m-delay AR model. We derive the m-delay AR formula for approximating two unknown parameters based on the least squares method and develop an algorithm to determine optimal delay based on a brute-force technique. The performance of the m-delay AR model was tested by comparing with the… More >

D. Vijeswaran^1,*, V. Manikandan²

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.3, pp. 801-813, 2019, DOI:10.32604/cmes.2019.07793

Abstract In a cyber-physical micro-grid system, wherein the control functions are executed through open communication channel, stability is an important issue owing to the factors related to the time-delay encountered in the data transfer. Transfer of feedback variable as discrete data packets in communication network invariably introduces inevitable time-delays in closed loop control systems. This delay, depending upon the network traffic condition, inherits a time-varying characteristic; nevertheless, it adversely impacts the system performance and stability. The load perturbations in a micro-grid system are considerably influenced by the presence of fluctuating power generators like wind and solar power. Since these non-conventional energy… More >

Bing Hu¹, Feng Xiang², Fan Wu³, Jian Liu⁴, Zhe Sun¹, Zhixin Sun^1,*

CMC-Computers, Materials & Continua, Vol.61, No.3, pp. 1323-1344, 2019, DOI:10.32604/cmc.2019.06414

Abstract To cope with the arbitrariness of the network delays, a novel method, referred to as the composite particle filter approach based on variational Bayesian (VB-CPF), is proposed herein to estimate the clock skew and clock offset in wireless sensor networks. VB-CPF is an improvement of the Gaussian mixture kalman particle filter (GMKPF) algorithm. In GMKPF, Expectation-Maximization (EM) algorithm needs to determine the number of mixture components in advance, and it is easy to generate overfitting and underfitting. Variational Bayesian EM (VB-EM) algorithm is introduced in this paper to determine the number of mixture components adaptively according to the observations. Moreover,… More >

Clyde K Coelho, Cristobal Hiche, Aditi Chattopadhyay

Structural Durability & Health Monitoring, Vol.7, No.1&2, pp. 65-82, 2011, DOI:10.3970/sdhm.2011.007.065

Abstract Low velocity impacts on composite plates often create subsurface damage that is difficult to diagnose. Fiber Bragg grating (FBG) sensors can be used to detect subsurface damage in composite laminates due to low velocity impact. This paper focuses on the prediction of impact loading in composite structures as a function of time using a support vector regression approach. A time delay embedding feature extraction scheme is used since it can characterize the dynamics of the impact using the sensor signals. The novelty of this approach is that it can be applied on complex geometries and does not require a dense… More >

Mahdi Saedshoar Heris¹, Mohammad Javidi¹, Bashir Ahmad^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 249-272, 2019, DOI:10.32604/cmes.2019.08080

Abstract In this paper, we propose numerical methods for the Riesz space fractional advection-dispersion equations with delay (RFADED). We utilize the fractional backward differential formulas method of second order (FBDF2) and weighted shifted Grünwald difference (WSGD) operators to approximate the Riesz fractional derivative and present the finite difference method for the RFADED. Firstly, the FBDF2 and the shifted Grünwald methods are introduced. Secondly, based on the FBDF2 method and the WSGD operators, the finite difference method is applied to the problem. We also show that our numerical schemes are conditionally stable and convergent with the accuracy of O(k+ h²) and O(k²… More >

Yuerong Wang¹, Jianping Jing^1,2,3,*, Changmin Chen¹, Sheng Xiong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 1-22, 2019, DOI:10.32604/cmes.2019.06158

Abstract Fluidelastic instability is destructive in tube bundles subjected to cross flow. Flow channel model proposed by Leaver and Weaver is well used for modeling this problem. However, as the tube motion is supposed to be harmonic, it may not simulate the general dynamic behaviors of tubes. To improve this, a model with arbitrary tube motion is proposed by Hassan and Hayder. While, due to involving in the time delay term, the stability problem cannot be solved by the eigenvalue scheme, and time domain responses of the tube have to be obtained to assess the instability threshold. To overcome this weakness,… More >

Xiaoli Zhong^{1, 2}, Wenying Guo¹, Jie Wang²

Sound & Vibration, Vol.52, No.6, pp. 18-22, 2018, DOI:10.32604/sv.2018.03900

Abstract Early reflection is an important component in an enclosed sound field. Due to the precedence effect, the early reflection may not be the dominant factor in sound source localization; however, it still has obvious influences on spatial position, loudness, timbre, and etc. Till now, there have sparse studies on evaluation of the audible threshold of early reflections with lacking of general and quantitative results. This work investigated the audible threshold of early reflection with a simplified sound field model under various experimental conditions including the combination of eight incidence angles and five time delays. Three-down-one-up adaptive strategy with three-interval three-alternative… More >