Forward-backward Method Research Articles

Need for recovery scale in the firefighting context: Examination of the Persian culture-adapted version.

Work-related fatigue can cause disruption in mental and physical activities of the workers. Considering the importance of recovery from fatigue in emergency services, as seen in firefighting duties, the preparation and validation of the Need For Recovery Scale (NFRS) questionnaire can be useful and effective. This study assessed the reliability and validity of the Persian version of Need For Recovery Scale among industrial firefighters. Need for recovery scale contains 11 questions. First, a questionnaire was translated using backward-forward method. Then, for measuring validity of the questionnaire, the opinions of 10 experts in related fields were obtained. Content Validity Index (CVI) and Content Validity Ratio (CVR) were calculated. The reliability was determined through 107 questionnaires completed by the industrial firefighters. The average age of the firefighters in this study was 37.5 years and they had an average of 10 years of work experience. The mean Need For Recovery Index from fatigue was 33.03 for the study population. Of the first 11 questions, 9 questions in the original NFRS showed a satisfactory level of CVR. The Content Validity Index and Cronbach's α were 0.89 and 0.77 respectively. Based on the results, the Need For Recovery Scale is a reliable tool for assessing fatigue and revealed an acceptable level of validity and reliability that makes it usable for fatigue assessment in the industrial firefighters.

Quality of life after hemifacial spasm surgery: French versions of the HFS-8 and HFS-30 questionnaires

ObjectivesThe aim of the present study was to assess quality of life before and after surgery for hemifacial spasm, in order to validate two specific quality of life scales translated in French. Surgical results and complications were reported. Material and methodsTwenty-three patients with hemifacial spasm treated by microvascular decompression were retrospectively included. The HFS-8 and HFS-30 quality of life scales were translated from English into French using a forward-backward method and implemented on patients at least one year after surgery. ResultsMedian HFS-8 and HFS-30 values were respectively 16±12.5 (range: 8–20.5) and 38±38.5 (range: 23–61.5) before surgery and 0.5±4.5 (range: 0–4.5) and 5±17.5 (range: 1–18.5) after surgery, showing significant improvement in quality of life (P<0.001). The internal consistency of both scales was excellent (Cronbach's alpha>0.9), and they were significantly correlated (Pearson coefficient=0.95; 95% CI [0.91; 0.98]; P<0.0001). Success rates were 83% and 91%, respectively, after primary and revision surgeries. Complications were transient with minor consequences in 80% of cases, but could impact quality of life when lasting. ConclusionsThese results support the validity of the French versions of HFS-8 and HFS-30. Microvascular decompression is a safe and effective treatment for hemifacial spasm, and these scales are reliable tools to assess postoperative quality of life.

Psychometric Evaluation of the Chinese Version of the Modified Online Compulsive Buying Scale among Chinese Young Consumers

ABSTRACT This study aimed to examine the psychometric properties of the Chinese translation of the modified online compulsive buying scale. A convenience sample of 539 Chinese university students were recruited in four major cities in China. The scale was translated from English to Chinese using forward-backward method. Performing a maximum likelihood exploratory factor analysis revealed one factor consisting of 10 items, which was confirmed by conducting a confirmatory factor analysis. Reliability, face validity, content validity, and construct validity of the scale were assessed. The Chinese version of the modified online compulsive buying scale showed good internal consistency (Cronbach’s alpha = .909), and good construct reliability (composite reliability = .911, maximal reliability = .919, McDonald’s omega = .910). Moreover, convergent validity of the scale was established (average variance extracted = .510). The validated instrument can be used in future studies to measure young consumers’ online compulsive buying behavior in China.

Translation and cross language validation of human immunodeficiency virus stigma scale in a Pakistani context

Objectives: To evaluate the translation and validation of human immunodeficiency virus stigma scale in Urdu language. Methods: The evaluation study was conducted in Lahore, Kasur, Gujranwala and Faisalabad from January 2019 to June 2019. Forward-backward translation method was used to translate the human immunodeficiency virus stigma scale from English to Urdu. Additionally, inter-correlation among variables was assessed by using correlation to determine the psychometric properties. Exploratory factor analysis of the scale was done followed by confirmatory factor analysis for establishing a good model fit. Results: Cronbach’s alpha coefficient was 0.95. There was high correlation among the sub-components of the the scale, ranging from 0.38 to 0.80 (p&lt;0.001). Confirmatory factor analysis depicted good model fit. Conclusion: The Urdu version of the human immunodeficiency virus stigma scale was found to be a valid and reliable tool to measure personal stigma, disclosure concern, concerns about public attitude and negative self-image. Key Words: HIV/AIDS stigma, Translation, Cross-validation. Continuous...

Mittag–Leffler synchronization for impulsive fractional-order bidirectional associative memory neural networks via optimal linear feedback control

In this paper, we are concerned with the synchronization scheme for fractional-order bidirectional associative memory (BAM) neural networks, where both synaptic transmission delay and impulsive effect are considered. By constructing Lyapunov functional, sufficient conditions are established to ensure the Mittag–Leffler synchronization. Based on Pontryagin’s maximum principle with delay, time-dependent control gains are obtained, which minimize the accumulative errors within the limitation of actuator saturation during the Mittag–Leffler synchronization. Numerical simulations are carried out to illustrate the feasibility and effectiveness of theoretical results with the help of the modified predictor-corrector algorithm and the forward-backward sweep method.

Translation, Cultural Adaptation, and Psychometric Features of the Persian Version of the Copenhagen Multi-Centre Psychological Infertility-Fertility Problem Stress Scales (COMPI-FPSS)

Aims: This study was conducted for translation, cultural adaptation, and validation of the Persian version of the Copenhagen multi-centre psychological infertility-fertility problem stress scales (COMPI-FPSS).&#x0D; Study Design: This study was a methodological study.&#x0D; Place and Duration of Study: This research was done in an infertility clinic of an educational hospital in Rasht (north of Iran), from November 2019 to January 2020.&#x0D; Methodology: This study was performed in two phases including tool translation and psychometric testing. Totally, 200 infertile people selected through convenience sampling among subjects met inclusion criteria were included in the study. After obtaining permission from the original tool designer, the COMPI-FPSS (14 items) was translated into Persian using the forward-backward method. Face, content, and construct validity, as well as internal consistency (Cronbach's alpha coefficient and McDonald's coefficient omega) were evaluated, and test-retest was conducted. The data were analyzed using exploratory factor analysis (EFA) by SPSS software Ver. 16.&#x0D; Results: EFA led to retaining of 11 items with 3 factors of “personal domain”, “marital domain”, and “social domain”, which explained 54.42% of the total variance. Cronbach's alpha coefficient for the whole questionnaire was calculated as 0.89; also the overall McDonald's coefficient omega of the questionnaire was equal to 0.82. The correlation between the two test administrations with a 14-day interval was estimated as 0.93.&#x0D; Conclusion: The Persian version of the COMPI-FPSS with 11 items and 3 factors had the desired cultural adaptation, validity, and reliability and it is recommended to use it in the future studies and infertility treatment centers.

Health insurance satisfaction, financial burden, locus of control and quality of life of cancer patients: a moderated mediation model

PurposeThe purpose of this paper is to examine the relationship between consumers' satisfaction with their health insurance and quality of life (QoL), the mediating role of perceived financial burden in this relationship, as well as the moderating effect of external locus of control (LoC) on the relationship between perceived financial burden and QoL among cancer patients.Design/methodology/approachA cross-sectional design was employed in order to collect quantitative data by means of a self-administrated questionnaire. Participants consisted of 387 conveniently selected consumers diagnosed with cancer in Iran. Furthermore, the questionnaire was translated into Persian using a forward–backward method. The model was tested using partial least squares structural equation modeling (PLS-SEM).FindingsThe results indicate that the more satisfied patients are with their health insurance, the higher QoL they experience, and this relationship is explained through reducing perceived financial burden in terms of direct and indirect costs of the disease. Although external LoC belief is negatively related to QoL, it buffers the negative association between financial burden and QoL.Practical implicationsReducing the disparity between consumers' expectation and perception of the comprehensiveness of health insurance policies may relieve consumers' anxiety stemming from financial worries.Originality/valueThis paper fills a gap in the literature where consumers' perception about quality of insurance and its relationship with their QoL has received little attention so far.

Psychometric Properties of the Persian Version of Children's Sleep Comic

Background: Insomnia is one of the most common sleep problems among children and is associated with a wide variety of impairments such as aggression, decreased attention and concentration, daytime sleepiness, hyperactivity, and irritability. A child with insomnia can affect the whole family. It is important to assess insomnia and sleep behaviors of children because insomnia is not a common diagnosis in them. Children’s Sleep Comic is a questionnaire to diagnose insomnia in children aged 5-11 years, which can be completed within 20 minutes. Objectives: The aim of the present study was to translate and investigate the Persian form of Children’s Sleep Comic's content validity and reliability. Methods: This cross-sectional study was carried out on 209 children aged 5-11 years in primary schools and preschools of Tehran who were selected by random cluster sampling in 2019. The translation was done with the forward-backward method. The content validity was evaluated by 10 occupational therapists, and quantitative content validity was determined by calculating the Content Validity Index (CVI) and Content Validity Ratio (CVR). Internal consistency was assessed through Cronbach’s alpha and test-retest reliability via Intraclass Correlation Coefficient (ICC) among 30 children after one week as well as Standard Error of Measurement (SEM). Results: Overall, 220 children were entered into the study; however, 11 children were excluded because of missing data. The translation of Children's Sleep Comic was considered easy and acceptable. The content validity, which was assessed by CVR and CVI were desirable (0.8 and 0.8, respectively), and the internal consistency was 0.76. ICC and SEM were 0.97 and 0.02, respectively. Conclusions: The findings of this study showed that the Persian version of the Children's Sleep Comic questionnaire is a reliable and valid instrument that can be used for screening insomnia in Iranian children aged 5-11 years.

Online Learning of Any-to-Any Path Loss Maps

Learning any-to-any (A2A) path loss maps might be a key enabler for many applications that rely on a device-to-device (D2D) communication, such as vehicle-to-vehicle (V2V) communications. Current approaches for learning A2A maps have a number of important limitations, including i) a high complexity that increases rapidly with the number of samples, making the problems quickly intractable, and ii) the inability of coping with a time-varying environment, among others. In this letter, we propose a novel approach that reconstruct A2A path loss maps in an online fashion. To that end, we leverage on the framework of stochastic learning to deal with the sequential arrival of samples, and propose an online algorithm based on the forward-backward splitting method. Preliminary simulation results show a significant decrease in complexity, while its performance is comparable to that of a batch approach.

Validating the Persian version of the amyotrophic lateral sclerosis-specific quality of life-revised instrument

Background: Amyotrophic Lateral Sclerosis-Specific Quality of Life-Revised (ALSSQOL-R) encompasses 50 items which assess quality of life (QOL) in patients with amyotrophic lateral sclerosis (ALS) in six major domains. This study aims to translate the ALSSQOL-R into Persian and evaluate its reliability and validity among Iranian patients. Methods: ALSSQOL-R was translated by the standard multi-step forward-backward method. Content validity was calculated using item content validity index (I-CVI). Three items in the “intimacy” domain were deleted considering Iranian culture. Cronbach’s alpha was used for all 6 dimensions to calculate the internal consistency reliability. Test-retest reliability was evaluated using intraclass correlation coefficient (ICC) with one-month interval. Concurrent validity was measured by the validated version of 36-Item Short Form Health Survey (SF-36) questionnaire. Results: Sixty-three patients with ALS were enrolled in the study. I-CVI was 70%, promoted to 85% after modifications (acceptable). Regarding internal consistency reliability, Cronbach’s alpha in all six domains was 0.70 and total Cronbach’s alpha was 0.89 which is assumed as good. In terms of test-retest reliability, ICC [95% confidence interval (CI)] was 0.91 (91%) and Pearson correlation coefficient (r) was 0.90 (P < 0.001), all indicating an excellent reliability. The concurrent validity was established based on a strong correlation with SF-36 (r = 0.744, P < 0.001). Conclusion: The findings show that the modified Persian version of ALSSQOL-R is a valid and reliable QOL questionnaire which can be used for Iranian patients with ALS in both clinical and research settings.

Dyspnea Index: An upper airway obstruction instrument; translation and validation in Swedish.

ObjectiveUpper airway dyspnoea is a challenging condition in which assessing the discomfort experienced by the patient is essential. There are three patient‐reported outcome (PRO) instruments developed particularly for this patient group, none of which is available in Swedish. The aim of this study was to translate the Dyspnea Index (DI) into Swedish and validate the instrument for use in the Swedish‐speaking population by investigating its basic psychometric properties.DesignA prospective instrument validation study.SettingTertiary referral centre.ParticipantsFifty‐three (n = 53) patients with upper airway dyspnoea and 19 healthy controls.Main outcome measuresThe questionnaire was translated into Swedish (swDI) with a forward‐backward method. Reliability, repeatability, responsiveness and construct validity were assessed by asking the subjects to complete the swDI, a visual analog scale (VAS) at exertion and at rest and the Voice Handicap Index (VHI).ResultsThe swDI showed excellent internal consistency (Cronbach's α: 0.85) and repeatability (interclass correlation coefficient: 0.87 and Pearson's r: .89) in the patient group. No ceiling effect was observed (maximum score achieved was 39; 85% of the patients scored ≤ 36). SwDI scores moderately correlated with VAS at exertion (r: .59) and at rest (r: .42), yet poorly with the VHI (r: .36). The effect size (ES) was 3.8.ConclusionsThe swDI is a valid, robust and reliable questionnaire for self‐assessment in Swedish‐speaking patients with upper airway obstruction. A future anchor‐based longitudinal study is needed to assess the smallest detectable change (SDC) and minimal important change (MIC) that were not estimated in our study.

Optimal control problem for a tuberculosis model with multiple infectious compartments and time delays

In this paper, we formulate an optimal control problem based on a tuberculosis model with multiple infectious compartments and time delays. In order to have a more realistic model that allows highlighting the role of detection, loss to follow-up and treatment in TB transmission, we propose an extension of the classical SEIR model by dividing infectious patients in the compartment (I) into three categories: undiagnosed infected (I), diagnosed patients who are under treatment (T) and diagnosed patients who are lost to follow-up (L). We incorporate in our model delays representing the incubation period and the time needed for treatment. We also introduce three control variables in our delayed system which represent prevention, detection and the efforts that prevent the failure of treatment. The purpose of our control strategies is to minimize the number of infected individuals and the cost of intervention. The existence of the optimal controls is investigated, and a characterization of the three controls is given using the Pontryagin's maximum principle with delays. To solve numerically the optimality system with delays, we present an adapted iterative method based on the iterative Forward-Backward Sweep Method (FBSM). Numerical simulations performed using Matlab are also provided. They indicate that the prevention control is the most effective one. To the best of our knowledge, it is the first work to apply optimal control theory to a TB model which considers infectious patients diagnosis, loss to follow-up phenomenon and multiple time delays.

Translation and Validation of Fear of Pain-9 Items into Simplified Chinese Version for Mainland China.

PurposeThis study aimed to obtain a translation and validation of the Fear of Pain Questionnaire 9 Items (FOP-9) into simplified Chinese.MethodsThe questionnaire was translated following the forward-backward method. The final version was filled out by (n = 300) patients. Cronbach’s coefficient was calculated to test the internal consistency of simplified Chinese version of FOP-9 (sc-FOP-9), and 50 painless patients completed the sc-FOP-9 questionnaire within a 2-weeks interval to evaluate test–retest reliability. To verify the construct validity, exploratory factor analysis was used to explore the factor structure, and confirmatory factor analysis was conducted to evaluate the goodness fit of models.ResultsSatisfactory psychometric qualities were obtained (Cronbach’s α of the total score was 0.873 and intraclass correlation coefficient was 0.975). Three first-order models were tested and all show a good model fit and the 3-factor structure may be better due to its higher factor loading.ConclusionThe sc-FOP-9 is a reliable and valid instrument to evaluate the fear of pain among Chinese patients with or without pain. Fear of pain may have an important effect on perioperative pain and chronic pain, and this tool is a good complement to the measurement in mainland China.

Translation of the Fear of COVID-19 Scale into French-Canadian and English-Canadian and Validation in the Nursing Staff of Quebec

Introduction: During the COVID-19 pandemic, Quebec has been one of the most affected provinces in Canada. Rising fear of COVID-19 is inevitable among healthcare workers, and a new scale was developed to measure this type of fear, the Fear of COVID-19 Scale (FCV-19S). Aims: To translate the FCV-19S into French-Canadian and English-Canadian, and to validate both versions in the nursing staff from Quebec. Methods: A cross-sectional online survey was sent to approximately 15 000 nursing staff including nurses and licensed practical nurses among those who had consented to their respective Order to be contacted for research. The forward-backward method was used to translate the FCV-19S into French-Canadian and English-Canadian. Both versions along with stress and work-related questionnaires, were used to establish validity. Results: A total of 1708 nursing staff, with a majority of women, completed the survey (1517 and 191 completed the French-Canadian and English-Canadian versions). A unidimensional scale was confirmed for both versions with Cronbach alphas of 0.90 and 0.88. Discriminative values showed higher fear levels in women, and in generation X (40-56 years old). Higher fear levels were also found in nursing staff working in long-term care facilities, provided care to COVID-19 patients who died, and those who felt less prepared to provide safe care. Convergent associations were found between fear levels, stress, work satisfaction, and turnover intention. Discussion and conclusion: A rigorous approach was used to translate the fear of COVID-19 scale into French-Canadian and English-Canadian. Both Canadian versions of the FCV-19S supported a valid unidimensional scale in Quebec nursing staff.

Nonlinear dynamics of COVID-19 SEIR infection model with optimal control analysis

In this study, we have presented a data-driven SEIR compartmental model for the 2019 coronavirus infections in Ghana. Using the fminsearch optimization routine in Matlab, and the reported cumulative infected cases of COVID-19 in Ghana from 13th March 2020 to 6th October 2020, we have estimated the basic reproduction number, R0 ≈ 1.0413. We have further developed a controlled SEIR dynamical model for COVID-19 disease with a personal protection control strategy. We have derived an optimality system from our proposed optimal control problem. Using the fourth Runge-Kutta iterative scheme with the forward-backward method, we have performed numerical simulations for the model problem. From the numerical results, we can argue that proper personal protection practices can help reduce the disease transmission in the susceptible human population.

A Bregman Forward-Backward Linesearch Algorithm for Nonconvex Composite Optimization: Superlinear Convergence to Nonisolated Local Minima

We introduce Bella, a locally superlinearly convergent Bregman forward backward splitting method for minimizing the sum of two nonconvex functions, one of which satisfying a relative smoothness condition and the other one possibly nonsmooth. A key tool of our methodology is the Bregman forward-backward envelope (BFBE), an exact and continuous penalty function with favorable first- and second-order properties, and enjoying a nonlinear error bound when the objective function satisfies a Lojasiewicz-type property. The proposed algorithm is of linesearch type over the BFBE along candidate update directions, and converges subsequentially to stationary points, globally under a KL condition, and owing to the given nonlinear error bound can attain superlinear convergence rates even when the limit point is a nonisolated minimum, provided the directions are suitably selected.

Formant Tracking Using Quasi-Closed Phase Forward-Backward Linear Prediction Analysis and Deep Neural Networks

Formant tracking is investigated in this study by using trackers based on dynamic programming (DP) and deep neural nets (DNNs). Using the DP approach, six formant estimation methods were first compared. The six methods include linear prediction (LP) algorithms, weighted LP algorithms and the recently developed quasi-closed phase forward-backward (QCP-FB) method. QCP-FB gave the best performance in the comparison. Therefore, a novel formant tracking approach, which combines benefits of deep learning and signal processing based on QCP-FB, was proposed. In this approach, the formants predicted by a DNN-based tracker from a speech frame are refined using the peaks of the all-pole spectrum computed by QCP-FB from the same frame. Results show that the proposed DNN-based tracker performed better both in detection rate and estimation error for the lowest three formants compared to reference formant trackers. Compared to the popular Wavesurfer, for example, the proposed tracker gave a reduction of 29%, 48% and 35% in the estimation error for the lowest three formants, respectively.

Accelerated modified inertial Mann and viscosity algorithms to find a fixed point of $ \alpha - $inverse strongly monotone operators

<abstract> In this paper, strong convergence results for $ \alpha - $inverse strongly monotone operators under new algorithms in the framework of Hilbert spaces are discussed. Our algorithms are the combination of the inertial Mann forward-backward method with the CQ-shrinking projection method and viscosity algorithm. Our methods lead to an acceleration of modified inertial Mann Halpern and viscosity algorithms. Later on, numerical examples to illustrate the applications, performance, and effectiveness of our algorithms are presented. </abstract>

Validation of diabetes knowledge questionnaire in Croatian with assessment of diabetes knowledge and quality of life in patients with type 2 diabetes mellitus

Background. Diabetes mellitus (DM) is one of the biggest challenges in global healthcare and society in general. Assessment of the patient’s level of knowledge regarding diabetes is an important step in adapting group education programs to achieve better treatment outcomes. The aim of this study was to validate Diabetes Knowledge Questionnaire (DKQ) in Croatian language, to evaluate knowledge about diabetes and examine the relationship between knowledge and quality of life among type 2 DM patient’s in Croatia. Methods. The study was conducted as a cross-sectional study on 500 subjects. Validation of DKQ questionnaire in Croatian language was done using forward-backward method and internal consistency was examined using Cronbach’s Alpha. Quality of life was assessed using WHOQOL-BREF Questionnaire. Results. Good reliability and internal consistency of DKQ was confirmed (a = 0,740). Overall knowledge about diabetes was satisfactory (average DKQ score was 12,13). Longer duration of disease and previous education about diabetes were observed as predictive factors of better knowledge. No association was found between diabetes knowledge and quality of life. Conclusions. Our study confirms that DKQ is a good tool for assessing diabetes knowledge in Croatian language. Patients with DM demonstrated good diabetes knowledge but education in areas of self-care and nutrition needs to be improved which may increase quality of life.

A Study of Composite Scattering Characteristics of Movable/Rotatable Targets and a Rough Sea Surface Using an Efficient Numerical Algorithm

The composite electromagnetic scattering characteristics of movable/rotatable targets coexisting with a randomly rough sea surface are studied by the extended propagation-inside-layer expansion (EPILE) combined with the generalized forward-backward method (GFBM). The composite scattering formulation is given. The multiple scattering characteristics related to the self- and mutual coupling of the targets and sea surface under different parameters are numerically implemented and analyzed.