Forward Backward Research Articles

Working memory span in Persian-speaking children with speech sound disorders and normal speech development

ObjectivesThe aim of this study was to compare working memory span in Persian-speaking preschool children with speech sound disorder (SSD) and their typically speaking peers. Additionally, the study aimed to examine Non-Word Repetition (NWR), Forward Digit Span (FDS) and Backward Digit Span (BDS) in four groups of children with varying severity levels of SSD. MethodsThe participants in this study comprised 35 children with SSD and 35 typically developing (TD) children -matched for age and sex-as a control group. The participants were between the age range of 48 and 72 months. Two components of working memory including phonological loop and central executive were compared between two groups. We used two tasks (NWR and FDS) to assess phonological loop component, and one task (BDS) to assess central executive component. Percentage of correct consonants (PCC) was used to calculate the severity of SSD. ResultsSignificant differences were observed between the two groups in all tasks that assess working memory (p < 0.001). In addition, the comparison of the phonological loop of working memory between the various severity groups indicated significant differences between different severities of both NWR and FDS tasks among the SSD children (p < 0.001). Nevertheless, comparison of the central executive between various severity groups, which was assessed with the BDS task, did not show any significant differences (p > 0.05). The result showed that PCC scores in TD children were associated with NWR (p < 0.001), FDS (p = 0.001), and BDS (p < 0.001). Furthermore, PCC scores in SSD children were associated with NWR and FDS (p < 0.001), but not with BDS (p > 0.05). ConclusionThe working memory skills were weaker in SSD children, in comparison to TD children. In addition, children with varying levels of severity of SSD differed in terms of NWR and FSD, but not BDS.

Phonological awareness and spatial visual memory among sample of dyslexic children

This study aims to identify the relationship between phonological awareness and spatial visual memory, as well as, to detect the differences between Kuwaiti males and females and non-Kuwaitis with regard to reading learning difficulties in certain variables. The study adopts a comparative descriptive approach and uses sample of 350 primary students (3-5 grades) with reading learning difficulties (200 males and 150 females) Kuwaitis and non-Kuwaitis. Their ages ranged between 8- 10 years. Phonological awareness test and spatial visual memory test are applied. The findings of the study show that there is a statistically significant positive correlation between the components of phonological awareness tests (syllable &amp; phoneme deletion test and non-word reading accuracy test) and between spatial visual memory tests (Forward Spatial Span Test and Backward Spatial Span Test) from males and females sample. There are no significant differences between males and females in phonological awareness skills (phoneme deletion test, and non-word reading accuracy test). Females show better performance than males in spatial visual memory tasks (Forward Spatial Span Test and Backward Spatial Span Test). Non-Kuwaitis show better performance than Kuwaitis in phonological awareness skills (syllable &amp; phoneme deletion, and non-word reading accuracy test) and in spatial visual memory tasks (Forward Spatial Span Test and Backward Spatial Span Test). The results of the regression suggested that the integration of sounds is the only test that can predict reading disabilities. As (syllable &amp; phoneme deletion, and t non-word reading accuracy test) are the most predictable of spatial visual memory.

Phonological awareness and spatial visual memory among sample of dyslexic children

This study aims to identify the relationship between phonological awareness and spatial visual memory, as well as, to detect the differences between Kuwaiti males and females and non-Kuwaitis with regard to reading learning difficulties in certain variables. The study adopts a comparative descriptive approach and uses sample of 350 primary students (3-5 grades) with reading learning difficulties (200 males and 150 females) Kuwaitis and non-Kuwaitis. Their ages ranged between 8- 10 years. Phonological awareness test and spatial visual memory test are applied. The findings of the study show that there is a statistically significant positive correlation between the components of phonological awareness tests (syllable &amp; phoneme deletion test and non-word reading accuracy test) and between spatial visual memory tests (Forward Spatial Span Test and Backward Spatial Span Test) from males and females sample. There are no significant differences between males and females in phonological awareness skills (phoneme deletion test, and non-word reading accuracy test). Females show better performance than males in spatial visual memory tasks (Forward Spatial Span Test and Backward Spatial Span Test). Non-Kuwaitis show better performance than Kuwaitis in phonological awareness skills (syllable &amp; phoneme deletion, and non-word reading accuracy test) and in spatial visual memory tasks (Forward Spatial Span Test and Backward Spatial Span Test). The results of the regression suggested that the integration of sounds is the only test that can predict reading disabilities. As (syllable &amp; phoneme deletion, and t non-word reading accuracy test) are the most predictable of spatial visual memory.

Particle Image Velocimetry measurement of flow around an inclined square cylinder

This study investigated flow around an inclined square cylinder by using Particle Image Velocimetry technique in a wind tunnel. Two types of inclinations, i.e. forward inclination and backward inclination, were tested. Two inclination angles, i.e. α = 15° and 30° were tested for each type of inclinations. It was found that the forward inclination enhances the downwash that originally appears behind the upper part of the vertical cylinder, whereas weakens the upwash that is exhibited behind the base part of the vertical cylinder. When the forward inclination angle is large enough, the downwash is enhanced to a downward axial flow, whereas the upwash is completely suppressed. On the contrary, the backward inclination depresses the downwash, while enlarges the upwash. As the backward inclination angle increases, the upwash evolves into an upward axial flow.

Forward–Backward SDEs Driven by Lévy Process in Stopping Time Duration

As the first part in the present paper, we study a class of backward stochastic differential equation (BSDE, for short) driven by Teugels martingales associated with some Levy processes having moment of all orders and an independent Brownian motion. We obtain an existence and uniqueness result for this type of BSDEs when the final time is allowed to be random. As the second part, we prove, under a monotonicity condition, an existence and uniqueness result for fully coupled forward–backward stochastic differential equation (FBSDE, for short) driven by Teugels martingales in stopping time duration. As an illustration of our theoretical results, we deal with a portfolio selection in Levy-type market.

DOA Finding with Support Vector Regression Based Forward-Backward Linear Prediction.

Direction-of-arrival (DOA) estimation has drawn considerable attention in array signal processing, particularly with coherent signals and a limited number of snapshots. Forward–backward linear prediction (FBLP) is able to directly deal with coherent signals. Support vector regression (SVR) is robust with small samples. This paper proposes the combination of the advantages of FBLP and SVR in the estimation of DOAs of coherent incoming signals with low snapshots. The performance of the proposed method is validated with numerical simulations in coherent scenarios, in terms of different angle separations, numbers of snapshots, and signal-to-noise ratios (SNRs). Simulation results show the effectiveness of the proposed method.

CSF flowmetry: an innovative technique in diagnosing normal pressure hydrocephalus

Background: Normal pressure hydrocephalus is a very gloomy entity. The objective of this study is to analyse aqueductal velocity parameters by phase contrast MRI CSF flowmetry in Idiopathic Normal pressure hydrocephalus patients (NPH).Methods: This study consists of 72 participants which included 36 patients and 36 matched healthy controls. The study stretched over three years in multicentre tertiary research hospitals using 3T MRI scanner. Both normal MRI sequences and phase contrast CSF flowmetry was done for both group of patients and result analysed using SPSS 17 software.Results: Mean age of patients in our study is 61.07 years. The most common clinical symptom was gait unsteadiness in our study. Most common conventional MRI finding was ventriculomegaly with transependymal seepage of CSF. Amongst CSF flowmetry parameters Aqueductal stroke volume, peak systolic velocity, mean systolic velocity, forward flow volume and backward flow volume were statistically significant in differentiating cases from controls.Conclusions: MRI CSF flowmetry using phase contrast method is an advanced imaging parameter which can non-invasively and reliably detect NPH. Also, it can be used to follow the response to treatment following shunting and can act as a prognostic marker.

Dynamic transverse vibration characteristics and vibro-buckling analyses of axially moving and rotating nanobeams based on nonlocal strain gradient theory

Dynamic transverse vibration characteristics and vibro-buckling analyses of axially moving nanobeam and rotating nanobeam based on nonlocal strain gradient theory are investigated. The axially moving model involves axial velocity in kinetic energy, and the effect of rotating is added as Coriolis acceleration to energy relation for rotating model. Governing equations of two dynamical models are derived by Hamilton’s principle. Meanwhile, corresponding classical and high order non-classical boundaries are also given. Numerical results are obtained by employing Galerkin approach for double simply supported boundary. Results for influence of axial velocity on transverse vibration characteristics illustrate that natural frequencies decrease with increasing axial velocity. However, frequencies of rotating nanobeam model are splitted into forward and backward frequencies with increasing rotating velocity. It is found that forward frequencies increase and backward frequencies decrease with elevated rotating velocity. It is revealed that the nonlocal effect weakens the rigidity and the strain gradient effect strengthens the rigidity. Finally, vibro-buckling analyses of two models, referring to fundamental frequencies vanishing for axially moving model and frequencies corresponding to rotating velocity for rotating model, are shown.

Adapted numerical methods for advection–reaction–diffusion problems generating periodic wavefronts

The paper presents an adapted numerical integration for advection–reaction–diffusion problems. The numerical scheme, exploiting the a-priori knowledge of the qualitative behaviour of the solution, gains advantages in terms of efficiency and accuracy with respect to classic schemes already known in literature. The adaptation is here carried out through the so-called trigonometrical fitting technique for the discretization in space, giving rise to a system of ODEs whose vector field contains both stiff and non-stiff terms. Due to this mixed nature of the vector field, an Implicit–Explicit (IMEX) method is here employed for the integration in time, based on the first order forward–backward Euler method. The coefficients of the method here introduced rely on unknown parameters which have to be properly estimated. In this work, such an estimate is performed by minimizing the leading term of the local truncation error. The effectiveness of this problem-oriented approach is shown through a rigorous theoretical analysis and some numerical experiments.

On optimal control of forward–backward stochastic differential equations

We consider a control problem where the system is driven by a decoupled as well as a coupled forward–backward stochastic differential equation. We prove the existence of an optimal control in the class of relaxed controls, which are measure-valued processes, generalizing the usual strict controls. The proof is based on some tightness properties and weak convergence on the space $$\mathcal {D}$$ of cadlag functions, endowed with the Jakubowsky S-topology. Moreover, under some convexity assumptions, we show that the relaxed optimal control is realized by a strict control.

Deferred Correction Methods for Forward Backward Stochastic Differential Equations

AbstractThe deferred correction (DC) method is a classical method for solving ordinary differential equations; one of its key features is to iteratively use lower order numerical methods so that high-order numerical scheme can be obtained. The main advantage of the DC approach is its simplicity and robustness. In this paper, the DC idea will be adopted to solve forward backward stochastic differential equations (FBSDEs) which have practical importance in many applications. Noted that it is difficult to design high-order and relatively “clean” numerical schemes for FBSDEs due to the involvement of randomness and the coupling of the FSDEs and BSDEs. This paper will describe how to use the simplest Euler method in each DC step–leading to simple computational complexity–to achieve high order rate of convergence.

Asymmetric forward–backward–adjoint splitting for solving monotone inclusions involving three operators

In this work we propose a new splitting technique, namely Asymmetric Forward–Backward–Adjoint splitting, for solving monotone inclusions involving three terms, a maximally monotone, a cocoercive and a bounded linear operator. Our scheme can not be recovered from existing operator splitting methods, while classical methods like Douglas–Rachford and Forward–Backward splitting are special cases of the new algorithm. Asymmetric preconditioning is the main feature of Asymmetric Forward–Backward–Adjoint splitting, that allows us to unify, extend and shed light on the connections between many seemingly unrelated primal-dual algorithms for solving structured convex optimization problems proposed in recent years. One important special case leads to a Douglas–Rachford type scheme that includes a third cocoercive operator.

Translation, validation, and cross-cultural adaption of the Western Ontario Meniscal Evaluation Tool (WOMET) into German.

The Western Ontario Meniscal Evaluation Tool (WOMET) was developed in order to investigate the health-related quality of life of patients with meniscal pathologies. The aim of the present study was to translate and validate the WOMET into German. A standardized forward backward translation of the WOMET into German was first performed. One hundred ninety-two patients with isolated meniscal tears completed the German version of the WOMET as well as the Western Ontario McMasters University Arthritis Index, and the Knee Osteoarthritis Outcome Score. Furthermore, reliability, construct validity, feasibility, internal consistency, ceiling, and floor effects were then calculated. Excellent feasibility (85.4% fully complete questionnaire), internal consistency (Cronbach's α=0.92), and test-retest reliability (ICC, r=0.90) were found. The standard error of measurement and the minimal detectable change were ±4.6 and 12.7 points, respectively. All predefined hypothesises were confirmed. No floor or ceiling effects were found. The presented German version of the WOMET is a valid and reliable tool for investigating the health-related quality of life of German-speaking patients with meniscal pathologies. Cross-sectional study, Level II.

Rule-based scheduling of multi-stage multi-product batch plants with parallel units

Abstract A novel rule-based model for multi-stage multi-product scheduling problem (MMSP) in batch plants with parallel units is proposed. The scheduling problem is decomposed into two sub-problems of order assignment and order sequencing. Firstly, hierarchical scheduling strategy is presented for solving the former sub-problem, where the multi-stage multi-product batch process is divided into multiple sequentially connected single process stages, and then the production of orders are arranged in each single stage by using forward order assignment strategy and backward order assignment strategy respectively according to the feature of scheduling objective. Line-up competition algorithm (LCA) is presented to find out optimal order sequence and order assignment rule, which can minimize total flow time or maximize total weighted process time. Computational results show that the proposed approach can obtain better solutions than those of the literature for all scheduling problems with more than 10 orders. Moreover, with the problem size increasing, the solutions obtained by the proposed approach are improved remarkably. The proposed approach has the potential to solve large size MMSP.

6주간의 경사진 트레드밀에서 전ㆍ후방 보행 운동이 하지 및 심부근육 활성도와 기능수행에 미치는 영향

The purpose of this study is to compare the effects of inclined backward and forward walking on electromyographic activity, functional capacity, and pain for patients with patellofemoral pain syndrome. Participants were divided into three groups of 10 people, exercising three times per week for 20 minutes for total six weeks. We measured surface electromyographic activity, functional capacity and pain at week zero and at week six. when climbing up and down stairs, there were significant muscle activity increases regarding the rectus femoris, vastus medialis, vastus lateralis, multifidus, transeverse abdominals and gluteus medius muscles in forward walking and backward walking exercise on treadmillS. econdly, there were significant increases in functional capacity for both forward and backward walking grou.p Finally, there was an increase in the measures taken with the FVAS for forward walking group, The resusl tof this study support the recommendation for patients with Patellofemoral Pain Syndrome and low back pain to participate in exercises of walking forward and walking backward on an inclined treadmill. In addition, there was an evidence that walking backward on an inclined treadmill resulted in greater functional capacity than walking forward according to functional capacity and functional visual analysis scale results.

Fault tolerance in TCAM-limited software defined networks

In Software Defined Networks (SDNs), while a proactive fault tolerance based on the local rerouting approach enables fast failure recovery, it requires to install forwarding rules for the backup paths in the switch Ternary Content Addressable Memory (TCAM) in advance. Since the TCAM size is limited and forwarding rules are long, using large number of forwarding rules for backup paths leads to frequent eviction of flows at the switches. To guarantee the bandwidth requirement for a flow upon a link failure, bandwidth reservation is also required on the backup path. Inefficient backup bandwidth usage will cause rejection of increased number of flows. In this paper, we address the problem of proactive fault tolerance in SDNs, considering the above challenges by adopting the local rerouting approach. We develop an optimization programming formulation that determines the set of backup paths to protect a flow while minimizing the number of additional rules and bandwidth required for the backup paths. Since this problem is computationally prohibitive, we develop two heuristic algorithms, namely Forward Local Rerouting (FLR) and Backward Local Rerouting (BLR) to compute backup paths so as to improve TCAM and bandwidth usage efficiency. We propose a flexible adaptive failure recovery framework that takes the decision of using FLR or BLR based on the network state. We evaluate the proposed algorithms through simulations and compare their performance with the optimal solution. The results show that the proposed algorithms perform very close to the optimal solution and reduce the number of additional rules required to protect a flow by up to 75% compared to the approaches that do not consider the limited size of TCAM. The results also show that the proposed algorithms are effective in terms of backup bandwidth efficiency and meet the carrier-grade requirement with the recovery time below 50 ms.

Activity of Erector Spinae During Trunk Forward Bending and Backward Return: The Effects of Age.

Electromyography (EMG)-based measures of the trunk muscles behavior have been used for objective assessment of biomechanical impairments in patients with low back pain (LBP); yet the literature on normal age-related differences in such measures is scant. A cross-sectional study was designed to assess age-related differences in activity of trunk extensors during forward bending and backward return. Sixty asymptomatic individuals were recruited to form five gender-balanced age groups between 20 and 70years old. Participants completed two sets of trunk forward bending and backward return task using self-selected and fast motion paces. For bending and return phases of each task, the normalized lumbar flexion angles corresponding to different event times of erector spinae activity along with the peak normalized and non-normalized EMG activities of erector spinae were calculated. The mean normalized and non-normalized EMG activities of erector spinae during the entire task also were calculated. There was no age-related difference in normalized lumbar flexion angles corresponding to different event times of erector spinae activity. However, the peak normalized EMG activity during forward bending and backward return as well as the mean normalized EMG activity during the entire task were found to be larger in older vs. younger individuals. Given the suggested unreliability of normalized EMG in elders and considering that we did not find any age-related differences in non-normalized EMG activity of erector spinae, our results do not strongly support the existence of normal age-related differences in EMG profile of erector spinae during forward bending and backward return. Therefore, when interpreting EMG-based measures of trunk muscles behavior for identification of biomechanical impairment in patients with LBP, potential abnormalities in EMG activity of trunk muscles may not be attributed to patient's age.

Fusion Forward–Backward Pursuit Algorithm for Compressed Sensing

The Forward–Backward Pursuit (FBP), which is a recently proposed method, receives wide attention due to the high reconstruction accuracy. In this paper, we use the fusion strategy and propose the Fusion Forward–Backward Pursuit (FFBP) algorithm. This strategy only needs the reconstruction information of two FBP with different parameters. According to the termination conditions of the FBP algorithm, FFBP adopts different operation strategies, during the signal reconstruction. Without other priori information, FFBP effectively improves the exact reconstruction rate, compared with the original algorithm. Moreover, FFBP, which fuses two FBP with non-optimal parameter, can reconstruct a better signal than a single FBP with optimal parameter. We demonstrate the advantage of the proposed method through numerical simulations.

High Order Numerical Schemes for Second-Order FBSDEs with Applications to Stochastic Optimal Control

AbstractThis is one of our series papers on multistep schemes for solving forward backward stochastic differential equations (FBSDEs) and related problems. Here we extend (with non-trivial updates) our multistep schemes in [W. Zhao, Y. Fu and T. Zhou, SIAM J. Sci. Comput., 36 (2014), pp. A1731-A1751] to solve the second-order FBSDEs (2FBSDEs). The key feature of the multistep schemes is that the Euler method is used to discretize the forward SDE, which dramatically reduces the entire computational complexity. Moreover, it is shown that the usual quantities of interest (e.g., the solution tuple (Yt,Zt,At,Γt) of the 2FBSDEs) are still of high order accuracy. Several numerical examples are given to show the effectiveness of the proposed numerical schemes. Applications of our numerical schemes to stochastic optimal control problems are also presented.

Maximum Principle for Markov Regime-Switching Forward–Backward Stochastic Control System with Jumps and Relation to Dynamic Programming

This paper presents a sufficient stochastic maximum principle for a stochastic optimal control problem of Markov regime-switching forward–backward stochastic differential equations with jumps. The relationship between the stochastic maximum principle and the dynamic programming principle in a Markovian case is also established. Finally, applications of the main results to a recursive utility portfolio optimization problem in a financial market are discussed.