Forward Backward Research Articles

Upper and lower adjacent segment range of motion after fixation of different lumbar spine segments in the goat: an in vitro experiment.

ObjectivesThe purpose of this study was to examine the biomechanical effects of fixation on range of motion (ROM) in the upper and lower adjacent segments of different lumbar spine segments in a goat spine model.MethodsFifteen goat spine specimens (vertebrae T12–S1) were randomly divided into three groups: A (single-segment fixation), B (double-segment fixation), and C (triple-segment fixation). Motion in different directions was tested using a spinal motion simulation test system with five external loading forces. Transverse, forward–backward, and vertical displacement of the upper and lower adjacent segments were measured.ResultsAs the external load increased, the upper and lower adjacent segment ROM increased. A significantly greater ROM in group C compared with group A was found when the applied external force was greater than 75 N. The upper adjacent segment showed a significantly greater ROM than the lower adjacent segment ROM within each group.ConclusionsAdjacent segment ROM increased with an increasing number of fixed lumbar segments. The upper adjacent segment ROM was greater than that of the lower adjacent segments. Adjacent segment stability after lumbar internal fixation worsened with an increasing number of fixed segments.

A Multimedia Medical Expert System for Human Diseases Diagnosis

With the great expansion and development of computer science and its systems. Its applications are used in most areas of life, which facilitated the solution of many simple and complex issues, as it was used in multiple fields, including the medical field, where computer applications were designed to help the specialist doctor in his work and reduce the time in diagnosis. In this research, an expert system is built, which is one of the artificial intelligence techniques, using the advanced (forward) sequencing algorithms also called data-directed inference, and the algorithm. Backward (backward) sequence, also called target-directed inference, to diagnose the most common diseases to which a person is exposed. It is supported by multimedia, which includes (text, images, audio, and video) to reach a solution to the problem through dialogue with the user and rely on the stored knowledge as a base on which the inference engine represented by the two algorithms to reach to solutions, instructions and recommendations to diagnose the disease and give the appropriate treatment. These solutions are given to users in several forms using multimedia (text, pictures, audio and video) and this system is used by people who cannot reach a doctor or hospital for any reason. This system consists of major parts, which are the knowledge base that organizes the collection of facts the laws and the inference engine, which in turn include the Forward Chaining and Backward Chaining algorithms. These diseases in order to reach a diagnosis of the disease with high accuracy, and this leads to reducing medical errors. The proposed system can be used as a substitute for the doctor in diagnosing some diseases in general and some diseases in particular. Which is useful in cases where the doctor is absent due to natural conditions or emergency situations, or when it is difficult for the patient to reach hospitals or health centers.

Forward Backward Stochastic Model of Financial Asset Pricing with Idiosyncratic Noise

A new acceptable price approach to stochastic endpoint determination at given horizon accounting for the marginal investor beliefs and behaviour was proposed. Two-sided filtration with FBSDE defined stochastic dynamics was formulated for acceptable asset price under the risk-neutral probability measure, at that the target price distribution is characterized by the averaged over active market agent subset parameters. For the current price at market equilibrium, the acceptable price of risk distribution was found. The implied volatility dependencies for the equilibrium conditions and with predicted utility and liquidity premiums were determined. A generalized solution for the forward-backward stochastic problem and a partial solution for the formulated for options stochastic terminal conditions were found. The deep learning algorithm with simulated idiosyncratic noise was tested.

Computation of low-rank tensor approximation under existence constraint via a forward-backward algorithm

The Canonical Polyadic (CP) tensor decomposition has become an attractive mathematical tool in several fields during the last ten years. This decomposition is very powerful for representing and analyzing multidimensional data. The most attractive feature of the CP decomposition is its uniqueness, contrary to rank-revealing matrix decompositions, where the problem of rotational invariance remains. This paper presents the performance analysis of iterative descent algorithms for calculating the CP decomposition of tensors when columns of factor matrices are almost collinear – i.e. swamp problems arise. We propose in this paper a new and efficient proximal algorithm based on the Forward Backward splitting method. More precisely, the existence of the best low-rank tensor approximation is ensured thanks to a coherence constraint implemented via a logarithmic regularized barrier. Computer experiments demonstrate the efficiency and stability of the proposed algorithm in comparison to other iterative algorithms in the literature for the normal case, and also producing significant results even in difficult situations.

Control of The Spread of TB-HIV/AIDS Coinfection Using Optimal Control

The condition in which an individual is affected by TB and HIV/AIDS in his body is called a TB-HIV/AIDS coinfection. This research aims to minimize the populations of TB-HIV/AIDS coinfection with a minimum expenditure on medical expenses, that means minimizing the objective’s function ( ) or purpose function. In this research, modification of the model was carried out by adding the treatment population for HIV patients with ARV ( ). The population used was 11 classes with the use of three controls including treatment for individuals with latent TB ( ), active TB ( ), and HIV ( ). After performing numerical simulation using the forward backward fourth order Runge-Kutta, the results show that scenario 7 is the best scenario in controlling the spread of TB-HIV/AIDS coinfection because it resulted a minimum value of 1401,44. This means that providing the treatment for individuals with latent TB, active TB, and HIV in tandem can reduce the populations of TB-HIV/AIDS coinfection in the minimum treatment cost.

APPROXIMATION OF ZEROS OF SUM OF MONOTONE MAPPINGS WITH APPLICATIONS TO VARIATIONAL INEQUALITY AND IMAGE RESTORATION PROBLEMS

In this paper, an inertial Halpern-type forward backward iterative algorithm for approximating solution of a monotone inclusion problem whose solution is also a fixed point of some nonlinear mapping is introduced and studied. Strong convergence theorem is established in a real Hilbert space. Furthermore, our theorem is applied to variational inequality problems, convex minimization problems and image restoration problems. Finally, numerical illustrations are presented to support the main theorem and its applications.

Maximum strength levels for pulling and pushing handleless cartons in warehousing tasks

This study examined the variation in individuals’ static maximum forward pushing and backward pulling (FPBP) strength for handleless cartons under different task conditions. Thirty young Taiwanese men were recruited as participants and were requested to perform maximum FPBP exertion tests under four exertion heights (50, 80, 110, and 140 cm), two types of hand contact (bare hands and gloves), and two carton widths (40 and 60 cm). The results of this study indicated that the pushing strength for handleless cartons was almost twice the pulling strength for all exertion heights. This finding is different from those of previous relevant studies. The pulling force generated when gloves were worn was 38% higher than that generated under barehanded pulling. Moreover, the pulling force generated with a 40-cm-wide carton was 13% higher than that generated with a 60-cm-wide carton. Pushing strength was affected by only the exertion height. Practitioner Summary: We examined the effects of exertion height, carton width, and type of contact on the maximum FPBP strengths. Pulling strength should be considered first for the related task design because it is lower than pushing strength. However, pulling strength can be maximised by wearing gloves to pull a 60-cm-wide carton. Abbreviations: FPBP: forward pushing and backward pulling; ANOVA: analysis of variance HIGHLIGHTS Maximum forward pushing and backward pulling (FPBP) forces vary for cartons. FPBP forces for force direction, contact type, carton width, and exertion height were examined. FPBP forces generated for handleless cartons differ from those generated for cartons with handles. Pulling strength can be maximised by wearing gloves and using a 60-cm-wide carton. Gloves are useful tools for pulling handleless cartons.

Verbal and spatial memory spans in mild cognitive impairment.

Working memory (WM) for verbal and visual material may be affected early in individuals with mild cognitive impairment (MCI). Verbal and visuospatial span tasks, that is neuropsychological procedures commonly used for the clinical assessment of WM, have been scarcely investigated in these patients. Therefore, this study was aimed at evaluating whether performance on tests of verbal and visual-spatial span (which rely to different extents on distinct components of the WM system) is differently sensitive to the presence of MCI and, in particular, of a preclinical AD condition in patients with MCI. 99 patients with amnesic MCI were given the Digit Span Forward (DSF) and Digit Span Backward (DSB) tests and the Corsi span task (CS) at baseline and were followed up for two years. 32 MCI patients converted to Alzheimer's disease (MCIc), but 67 patients did not deteriorate to meet the criteria for AD (MCIs). Results showed that although performance on DSF did not differ between groups, performance on DSB and CS and ratio indexes indicative of a performance decline passing from DSF to DSB and from DSF to CS significantly discriminated between a group of matched healthy controls and the overall group of MCI patients. Moreover, the ratio indexes significantly discriminated between MCIc and MCIs individuals. These data are consistent with the hypothesis that individuals with MCI, particularly those destined to convert to AD, are affected by reduced central executive resources even though the phonological loop is still functioning normally.

Linear-quadratic non-zero sum differential game for mean-field stochastic systems with asymmetric information

In this study, we consider a class of asymmetric information linear-quadratic non-zero sum stochastic differential game problems. The system dynamics are governed by a forward linear mean-field stochastic differential equation and the cost functional is quadratic. In order to facilitate some practical applications, the mean-field terms for the state process and control process are considered in both the system dynamics and cost functional. Using the classical calculus of variation and dual methods, the open-loop Nash equilibrium point can be expressed by introducing an auxiliary mean-field forward backward stochastic differential equation, which comprises one forward and two backward components. Due to some Riccati equations and ordinary differential equations that possess unique solutions, the Nash equilibrium point can also be represented in feedback form for several special cases under asymmetric information. The corresponding filtering equations are derived, and the existence and uniqueness of the solutions are proved. An investment problem in finance is discussed to demonstrate the good performance of the theoretical results.

An Efficient of Chimera Grid Scheme with Spline Interpolation in FBTS Inversion Technique for Extremely Dense Breast Cancer Detection

Microwave imaging system is classified as non-invasive, simple to perform and inexpensive compared to MRI and X-Ray machine. Therefore, the novel idea of this research work is to develop a Chimera Grid Scheme (CGS) incorporate with the microwave inverse scattering technique in a low cost, non-ionising and safe short-range. The CGS with spline interpolation in Forward Backward Time-Stepping (FBTS) inversion technique can determined an accurate result especially for the biological anomalies like breast tumours at an early curable stage due to the high electrical properties contrast between malignant cells and normal cells. The findings showed that the proposed method successfully detected and reconstructed the breast structure in relative permittivity profiles. The quantitative information of reconstructed images, such as location, shape, size and internal composition also can be obtained. Furthermore, the normalised functional error for proposed method was also lower than the FDTD method in FBTS. At 150th iteration, the difference of normalised functional error between these two methods was 1.74 × 10−5. The result shows that the CGS method in FBTS inversion technique would reconstruct breast composition more precisely.

High-order Combined Multi-step Scheme for Solving Forward Backward Stochastic Differential Equations

In this work, in order to obtain higher-order schemes for solving forward backward stochastic differential equations, we propose a new multi-step scheme by adopting the high-order multi-step method in Zhao et al. (SIAM J. Sci. Comput., 36(4): A1731-A1751, 2014) with the combination technique. Two reference ordinary differential equations containing the conditional expectations and their derivatives are derived from the backward component. These derivatives are approximated by using the finite difference methods with multi-step combinations. The resulting scheme is a semi-discretization in the temporal direction involving conditional expectations, which are solved by using the Gaussian quadrature rules and polynomial interpolations on the spatial grids. Our new proposed multi-step scheme allows for higher convergence rate up to ninth order, and are more efficient. Finally, we provide a numerical illustration of the convergence of the proposed method.

A regression-based Monte Carlo method to solve two-dimensional forward backward stochastic differential equations

The purpose of this paper is to investigate the numerical solutions to two-dimensional forward backward stochastic differential equations(FBSDEs). Based on the Fourier cos-cos transform, the approximations of conditional expectations and their errors are studied with conditional characteristic functions. A new numerical scheme is proposed by using the least-squares regression-based Monte Carlo method to solve the initial value of FBSDEs. Finally, a numerical experiment in European option pricing is implemented to test the efficiency and stability of this scheme.

Machine learning and automatic selection of attributes for the identification of Chagas disease from clinical and sociodemographic data

Objective: evaluate the potential use of machine learning and the automatic selection of attributes in discrimination of individuals with and without Chagas disease based on clinical and sociodemographic data. Method: After the evaluation of many learning algorithms, they have been chosen and the comparison between neural network Multilayer Perceptron (MLP) and the Linear Regression (LR) was done, seeking which one presents the best performance for prediction of the Chagas disease diagnosis, being used the criteria of sensitivity, specificity, accuracy and area under the ROC curve (AUC). Generated models were also compared, using the methods of automatic selection of attributes: Forward Selection, Backward Elimination and genetic algorithm. Results: The best results were achieved using the genetic algorithm and the MLP presented accuracy of 95.95%, 78.30% sensitivity, and specificity of 75.00% and AUC of 0.861. Conclusion: It was proved to be a very interesting performance, given the nature of the data used for sorting and use in public health, glimpsing its relevance in the medical field, enabling an approximation of prevalence that justifies the actions of active search of individuals Chagas disease patients for treatment and prevention.

Feature of cognitive dysfunction in patients with temporal lobe epilepsy and its clinical influencing factors.

To comprehensively analyze the characteristics of cognitive impairment of temporal lobe epilepsy (TLE), and to explore the effects of different lateral patients' cognitive impairment and different clinical factors on cognitive impairment of TLE. A total of 84 patients, who met the diagnostic criteria for TLE in the Department of Neurology, Xiangya Hospital, were collected as a patient group, with 36 cases of left TLE and 48 cases of right TLE. A total of 79 healthy volunteers with matching gender, age and education level were selected as a control group. The Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and the scores of Arithmetic Test, Information Test, Digit Symbol Substitution Test (DSST), Block Design Test (BDT), Hayling Test and Verbal Fluency Test (VFT) of the revised Chinese Adult Wechsler Intelligence scale were retrospectively analyzed in the 2 groups.Multiple regression analysis was used to analyze the relationship between the clinical factors and the cognitive impairment score. Compared with the control group, the TLE patient group had low scores in all neuropsychological tests, with significant difference (all P<0.05). Compared with the control group, there was significant difference in different neuropsychological tests in the patients with TLE on different sides (all P<0.05). In the left TLE, there were low scores in Information Test, arithmetic, VFT, the completion time of Hayling Test part A, the completion time of Hayling Test part B, the correct number of Hayling Test part A, the correct number of Hayling Test part B, BDT, Forward Digit Span Test (FDST) and Backward Digit Span Test (BDST). While in the right TLE, there were low scores in Information Test, arithmetic, DSST, VFT, the completion time of Hayling Test part A, the correct number of Hayling Test part A, the completion time of Hayling Test part B, the correct number of Hayling Test part B, BDT, FDST and BDST. There are multiple cognitive domain dysfunctions in TLE, including language, short-term memory, long-term memory, attention, working memory, executive function and visual space function. Left TLE has greater impairment of executive function and right TLE has greater damage in working memory. Long pathography of disease, hippocampal sclerosis and a history of febrile convulsions may lead to more severe cognitive impairment. Earlier identification and earlier intervention are needed to improve prognosis of patients.

Looking forward and looking backward: Economic evaluations and regime support in China

It is widely acknowledged that the economic situation is of vital importance for the stability of an authoritarian regime, but it is rarely known how the public’s economic evaluation contributes to such outcomes. This study examines the effects of citizens’ retrospective and prospective evaluations of their household economic situation and the national economy on the level of regime support in China. The findings show that the national economy outweighs household economic conditions in its effects on the public’s support of the regime. However, the gap between evaluations of the national economy and individual economic situations debilitates regime support. The population in different age cohorts has distinct patterns of relationships between retrospective and prospective economic evaluations and regime support. This study elucidates the political-psychological mechanism of the public’s economic evaluation affecting regime support, and the ruling strategy in authoritarian regimes of manipulating this evaluation.

Efficient secret key generation scheme of physical layer security communication in ubiquitous wireless networks

This paper focuses on high efficiency secret key generation mechanism of physical-layer communication over fading channels in ubiquitous wireless networks. The secret key rate via traditional physical-layer approach could be limited when the wireless propagation channels connecting two sensors change slowly. To generate a high-rate secret key and improve the communication efficiency over quasi-static block fading channels, a novel multi-randomness device-to-device secret key generation strategy and a cooperative communication mechanism aided by relay nodes are proposed. In the proposed schemes, the legitimate members to send random signals rotationally in every coherent time T are set; thus, two legitimate ubiquitous wireless network members, Alice and Bob, can obtain the potential correlated information by exploiting the randomness and the reciprocity of the wireless propagation channels. Considering the reciprocity of wireless channels is variable while the forward channel gain and backward channel gain are correlated in coherent time, a modified secret key generation scheme is proposed via layered coding with theoretical secret key rates derived. The simulation results show that the proposed scheme outperforms traditional approaches with favourable application prospects in ubiquitous wireless communications networks and internet of things.

Penerapan Metode Forward-Backward Chaining pada Sistem Pakar Pencegahan dan Pengobatan Penyakit Sapi

Increasing the population of cattle in Aek Nagali village, especially in hamlet V, really helps the economy of the community, the health of the livestock raised by breeders is important for the animals themselves. It is difficult for veterinarians in Aek Nagali village so that it is the custom of people in the village where when their cows are sick and dying they are immediately slaughtered and the meat is traded. Even though this does not mean that the cow is suitable for consumption or not because there is a cow disease that can be transmitted to humans when eating beef. The purpose of this research is to build an expert system-based system that can provide an overview or decision. The method used is Forward Chaining and Backward Chaining in diagnosing cow disease. The discussion is focused on applying Forward Chaining and Backward Chaining rules and applying them to the system. From the results of research, the backward and forward methods provide information on how to prevent and treat cattle disease so that breeders can know what steps to take.

Cognitive Function and Functional Mobility Predict Exercise Adherence in Older Adults Who Fall

Introduction: Strength and balance exercises prevent falls. Yet, exercise adherence is often low. To maximize the benefit of exercise on falls prevention, we aimed to identify baseline cognitive and mobility factors that predict adherence to the Otago Exercise Program (OEP) – a home-based exercise program proven to prevent falls. Methods: We conducted a secondary longitudinal analysis of data from a randomized clinical trial (RCT) (OEP compared with usual care) among 172 participants who were assigned to the OEP intervention of the RCT. Adherence to the OEP was calculated as a percent score (i.e., [frequency of strength and balance retraining session per week/3 strength and balance retraining sessions per week] × 100). Executive function (i.e., mental flexibility) was measured using the Trail Making Tests (Part A and B: TMT B – TMT A) and the Digit Symbol Substitution Test (DSST). Short-term memory and encoding was measured using the Verbal Digits Forward test. Executive function (i.e., inhibition and working memory) was measured using the Stroop Color-Word Test and the Verbal Digits Forward minus Verbal Digits Backward test. Mobility was assessed using the Short Performance Physical Battery and the Timed Up and Go test. We used general estimation equations analysis to determine the predictors of adherence to the OEP. Results: Better set shifting (β = −0.06, z = −2.43, [SE = 0.02] p = 0.018] predicted greater OEP adherence. Greater attention and short-term memory (β = −6.99, z = −2.37 [SE = 2.95]) predicted poorer OEP adherence. Response inhibition, processing speed, working memory, and mobility assessed by the SPPB were not associated with adherence. Poorer baseline Timed Up and Go (β = 1.48 z = 1.94, [SE = 0.76]; p < 0.001), predicted better OEP adherence. Conclusion: Specific cognitive processes (i.e., executive function of set shifting, attention, and short-term memory) and functional mobility predicted exercise adherence. Further research needs to explore the pathways that explain why better attention and short-term memory predicted lower adherence and why poorer functional mobility led to better OEP adherence.

A ‘case-mix’ approach to understand adherence trajectories for a falls prevention exercise intervention: A longitudinal cohort study

ObjectiveWe identified adherence-based case-mixes from participants’ longitudinal adherence to falls prevention exercise interventions over 12 months. Second, we identified modifiable baseline predictors (cognition, mobility and functional status) based on participants' case-mix adherence trajectories. Study design and outcome measuresThis study was a 12-month longitudinal secondary analysis of data from 172 participants who received the Otago Exercise Program (OEP) in a randomized controlled trial. Adherence to the OEP was ascertained monthly via self-report. Case-mixes, groups of individuals who followed similar adherence trajectories, were visually defined using 12-month longitudinal trajectories; we used latent class growth modeling. Baseline predictors of adherence were examined for the following categories: 1) cognition, 2) mobility and 3) functional status. ResultsFour distinct case-mixes were identified. The “non-adherent” case-mix (18 %) was distinguished by a non-adherent and decreasing adherence trajectory over time. The “low adherence” case-mix (45 %) did not have complete adherence or consistent adherence over the 12-month follow-up. The “moderate adherence” case-mix (27 %) was characterized by a stable (i.e., non-variable) adherence trajectory with a slightly increasing pattern at midpoint. The “high adherence” case-mix (10 %) demonstrated consistent and high adherence over the 12-month follow-up. For individuals with “moderate adherence”, the Digit Symbol Substitution Test (DSST) significantly predicted adherence (relative risk ratio (RRR) = 1.12 (0.95 CI: 1.0–1.26); p = 0.049). For individuals with “high adherence”, the Digits Forward minus Digits Backward (RRR = 0.43 (0.95 CI: 0.23−0.79); p = 0.002) and Instrumental Activities of Daily Living (RRR = 0.36 (0.95 CI: 0.16−0.81); p = 0.01) significantly predicted adherence. ConclusionsCognitive profile and activities of daily living at baseline may predict the longitudinal pattern of adherence.

The Persian Translation and validation of the celiac disease quality of life questionnaire (CDQOL)

BackgroundConsidering the importance of having a celiac disease-specific measure of the quality of life (QOL) in Persian, the present study aimed to translate the celiac disease quality of life questionnaire (CDQOL) into Persian and evaluate its psychometric properties.MethodsIn this cross-sectional study, the Forward–Backward translation method was used. The content validation ratio (CVR) and the content validity index (CVI) were used for content validity assessment. The construct validity was assessed by exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) on 220 celiac patients who were selected randomly from the celiac disease (CD) registry database. The correlations between the result of the Persian version of CDQOL (PCDQOL), self-rated QOL, and short form-36 (SF36) were analyzed using the Pearson correlation test. The internal consistency and test–retest reliability were measured through Cronbach’s alpha and intraclass correlation coefficient (ICC).ResultsIn the present study, 220 celiac patients with a mean age of 35.54 ± 10.29 years participated. The mean CVI, CVR, and impact score of PCDQOL were 0.98, 0.96, and 4.82 respectively. Using EFA, four factors have extracted that had a good fit in CFA (Chi-square/DF = 1.74, RMSEA: 0.08, and CFI: 0.90, and NFI: 0.90). The results showed that there was a moderate to high correlation between PCDQOL, SF36 (r: 0.587, p = 0.02), and self-rated QOL (r: 0.64, p < 0.001). The questionnaire had high internal consistency (Cronbach alpha: 0.93) and test–retest reliability (ICC: 0.96 [0.86–0.99]).ConclusionThe PCDQOL questionnaire could be used by physicians and nutritionists to assess HRQOL in celiac patients in Iran.