LSTM-Based Forecasting Model for GRACE Accelerometer Data

The Gravity Recovery and Climate Experiment (GRACE) satellite mission, spanning from 2002 to 2017, has provided a valuable dataset for monitoring variations in Earth's gravity field, enabling diverse applications in geophysics and hydrology. The mission was followed by GRACE Follow-On in 2018, continuing data collection efforts. The monthly Earth gravity field, derived from the integration different instruments onboard satellites, has shown inconsistencies due to various factors, including gaps in observations for certain instruments since the beginning of the GRACE mission. With over two decades of GRACE and GRACE Follow-On data now available, this paper proposes an approach to fill the data gaps and forecast GRACE accelerometer data. Specifically, we focus on accelerometer data and employ Long Short-Term Memory (LSTM) networks to train a model capable of predicting accelerometer data for all three axes. In this study, we describe the methodology used to preprocess the accelerometer data, prepare it for LSTM training, and evaluate the model's performance. Through experimentation and validation, we assess the model's accuracy and its ability to predict accelerometer data for the three axes. Our results demonstrate the effectiveness of the LSTM forecasting model in filling gaps and forecasting GRACE accelerometer data

Strategic management of organizational resources using predicting the organization's bankruptcy level: New approach using Monte Carlo Simulation

Purpose: There are several methods to predict organization bankruptcy; each of them has different accuracy. Another considerable note in investigating organization bankruptcy is the data considered for the study. The goal of this study is to determine which model is the most accurate in predicting organization bankruptcy. Research methodology: In this study, the initial data were used to compare predicting Monte Carlo processes that simulate bankruptcy models to compare models and results more accurately. Simulated data coefficient modification of Mckee, CA-SCORE, Springate, Zmijewski, Shirata, and Altman methods were implemented in some healthy and bankrupt organizations. After that, the results of each modified model were considered to determine the predicting bankruptcy accuracy. Results: Using the final Mckee's method, predicting organization bankruptcy was done in an organization and the results show that the given organization is on a trend of bankruptcy in 2025. Limitations: This research was only described in knowledge-based organizations. Contribution: The Mckee genetic method is more accurate than other methods. Also, modifying coefficient and by using simulated data shows that CA-SCORE and Shirata methods are not able to predict the organization's bankruptcy by using simulated data

Investigating, identifying and evaluating organizational and infrastructural strategic factors affecting organizational management processes from the perspective of productivity management

Purpose: The purpose of this present study is to investigate the impact of institutional and infrastructural factors on knowledge management processes from the perspective of Nonaka and Takeuchi with a case study of design offices of a product organization. Research methodology: The research is applied and is a descriptive survey in terms of data collection. The statistical population of the design offices of a product organization consisted of 75 people and the statistical sample was estimated 63 people. The research tool was a researcher-made questionnaire with a reliability of 77%. Results: The findings show that seven institutional and infrastructure factors affecting knowledge management processes were identified. Also prioritization by TOPSIS showed that organizational structure, culture and values, above average, can be deployed in the design office, and knowledge management policies and guidance are average, but information technology is below average. Limitation: The results extend the understanding of the role of quality of work-life in organizational effectiveness. The research findings have implications for human resource managers. Contribution: The results of the study help the human resource managers of organizations to identify the elements that affect the quality of work-life and help them in planning to increase organizational effectiveness by increasing employee satisfaction and motivation. Keywords: Knowledge management, Institution, Infrastructure, Nonaka and Takeuch

Control strategy for direct voltage and frequency stabilityenhancement in HVAC/HVDC grids

Direct voltage fluctuations due to the presence of relatively large DC reactors (as an essen-tial part of HVDC breakers), lack of inertia, and unwanted frequency fluctuations in theAC side of HVDC grids, have major consequences on the stability of HVAC/HVDC grids.The use of the DC Power System Stabilizer (DC-PSS) can damp and eliminate voltageoscillations caused by the presence of the DC reactors. However, DC-PSS cannot addressthe issues of inertia and unwanted frequency fluctuations. A method to improve inertiais proposed here that can operate well with the droop controller, and DC-PSS does notinterfere with power-sharing and does not interact with any of these elements. Since thepresence of a droop controller in HVAC/HVDC grids associates with power and directvoltage, the method proposed here can improve direct voltage fluctuations by eliminatingsevere power peaks. Moreover, this method does not change the voltage level of the entiresystem, so there is no need to change the set-points of controllers. In addition, all param-eters of the controllers are tuned by an intelligent algorithm, and the Participation factor(PF) scheme is used to find the proper placement of the proposed controller

The Mediating Role of Loneliness between Fear of Corona and Perceived Social Support with Psychological Well-being of Male High School Students in the Corona Pandemic

The aim of this study was to survey mediating role of loneliness between fear of corona and perceived social support with psychological well-being of junior high school students in the corona pandemic. In this descriptive study, the statistical population of the study included all high school students in Isfahan in the academic year 2021-2022. For this purpose, 225 were selected by cluster sampling method and researched into questionnaires including fear of corona (Weiss et al, 2020), (Russell,1980), perceived social support of (Zimet et al,1988) and psychological well-being (Ryff et al, 2002) responded. Research data were analyzed using statistical software package for social sciences and structural equation modeling using SPSS23 statistical software and PLS3 software. The results showed that psychological well-being had a negative relationship with social support and feelings of loneliness and a significant positive relationship with perceived social support. Feelings of loneliness mediate the relationship between fear of coronation, feelings of loneliness, and perceived social support(P<0/05). The results of the structural equation model had a good fit and the feeling of loneliness mediated the relationship between corona fear and perceived social support with the psychological well-being of junior high school male students

Direct current power system stabilizers for HVDC grids: Current status

A power system stabilizer (PSS) is a control system integrated into the control structure of specific generation units within AC grids. It monitors current, voltage, and machine shaft speed. Analysing these variables, the PSS generates appropriate control signals to the voltage regulator unit, aiming to damp system oscillations. With the advancement of high-voltage direct current (HVDC) overlaid high-voltage alternative current (HVAC) grids, it is anticipated that direct current power system stabilizers (DC-PSS) will be developed to perform a similar role as their AC counterparts. DC-PSS will be responsible for monitoring and controlling DC voltage levels, ensuring stable operations. This paper focuses on DC-PSS in HVDC grids, designed to ensure stable operation and mitigate voltage fluctuations. Unlike conventional AC power systems, HVDC includes only DC voltage and power. The input signal for DC-PSS is the variations in DC voltage, and the output signal is proportional to the power changes at the specific bus where the DC-PSS is installed, aiming to minimize DC voltage oscillations. These characteristics pose significant challenges in DC-PSS. The paper addresses the challenges and highlights issues such as inertia and low-frequency oscillations associated with DC-PSS. Various control methods are presented and a comparison is made among these methods

The Efficacy of Phonological Processing Treatments on Stuttering Severity in Persian Pre-school Children

AbstractObjectives: Correct phonological encoding is crucial to fluent speech production. Phonological working memory and phonological awareness are important phonological processes that affect phonological encoding. Studies have shown weakness in phonological encoding in people who stutter. The purpose of this study was to investigate the effect of phonological processing on stuttering severity of Persian pre-school children.Method: Six children who stutter participated in a 13-session treatment protocol. The treatment protocol of the phonological processing included nonword repetition in the phonological working memory and phonological awareness therapy. Stuttering severity measurement was performed pre- and post-treatment.Results: Stuttering severity score was compared in pre- and post-treatment, and in the follow-up phase; that showed stuttering severity was reduced in children who stutter. Moreover, severity rating, reported by parents during treatment, showed a reduction in stuttering severity. Conclusion: The poor performance of phonological awareness and phonological working memory in phonological processing affect stuttering severity. The outcomes of this study showed that treatment of sub-systems of phonological processing can play a role in reducing stuttering severity.

Evaluation of the Clinical, Laboratory and Imaging Findings of Patients with COVID-19 and Their Associations with Clinical Outcomes in an Iranian Hospital: A Cross-Sectional Study

Background: Coronavirus disease 2019 (COVID-19) is a concern in the medical community as the virus spreads around the world. It has a heavy global burden, particularly in low-income countries. This virus has its specific outcomes in each population. Hence, it is necessary to design studies to find the epidemiological behaviour of this virus. Materials and Methods: This cross-sectional study was conducted in the Labbafinezhad hospital, Tehran, Iran. Demographic features include age, sex, past medical history, drug history, habitual file, influenza vaccination history, recent exposure history, clinical symptoms or signs, and the recorded symptoms. The clinical examination and para-clinical assessment, including chest computed tomography (CT) and laboratory testing on admission, were recorded. Results: It was found that patients with a history of kidney transplantation, high level of LDH, high level of AST, and increased neutrophil to lymphocyte ratio are most at risk of death. Conclusion: Parameters mentioned could help practitioners predict patient outcomes, and necessary interventions could be considered in this regard

The Effect of Sagittal STIR and FLAIR Sequences Compared to Sagittal T2-W for Characterizing MS Lesions in Cervical Spine MRI

Purpose: Multiple Sclerosis (MS) is an acute, autoimmune, and inflammatory disease in the central nervous system. This study investigated the effect of sagittal Short Tau Inversion Recovery (STIR) and T2-W Fluid Attenuated Inversion Recovery (FLAIR) sequences rather than sagittal T2-W as complementary sequences in patients with cervical spinal cord lesions and suspected MS. Materials and Methods: This cross-sectional study was performed on all individuals referred to the Shahid Ghazi MRI center in Sanandaj for six months. Sixty patients with a cervical spine MRI request that were suspected of having MS were examined. The number of MS plaques in the sagittal T2-W FSE, sagittal STIR, and sagittal T2-W FLAIR were recorded separately. A comparison between routine sequences and sequence supplementation has been made for characterizing MS plaque in the spine. Results: Results showed that the greatest agreement was related to sagittal STIR, and sagittal FLAIR (Cohen’s kappa = 0.56). Whereas the least agreement values were from sagittal T2-W and sagittal FLAIR, STIR and FLAIR, T2-W and FLAIR, T2-W and STIR (Cohen’s kappa = 0.20, 0.33, 0.48, 0.55), respectively. Sagittal STIR and sagittal FLAIR were excellent predictors for MS plaques diagnosis due to the area under the ROC curve = 0.56; sensitivity (95% CI) = [0.85 (0.73426 to 0.929044)] and specificity (95% CI) = [0.46 (0.336699 to 0.600035)]. Conclusion: Results show that FLAIR T2-W images in sagittal sequence are appropriate for detecting lesions around spinal cord lesions. Furthermore, using thresholds obtained via statistical analysis, plaques in the cervical spinal cord can be identified in sagittal STIR images

Effect of oral capsule of Peganum harmala seeds on bone density in menopausal women prone to osteoporosis

Background and aims: Osteoporosis is one of the most common metabolic bone diseases with systemic involvement of the body skeleton. The Peganum harmala seed contains high amounts of carboline alkaloids, which have been shown to have positive effects on bone formation in animal studies. In the present study, the effect of an oral capsule of P. harmala seed on bone density was evaluated in menopausal women prone to osteoporosis. Methods: In this randomized controlled clinical trial, 100 women referring to the orthopedic clinic with a diagnosis of osteoporosis were included and divided into the intervention group treated with calcium D (500 mg) twice a day, Osteofos (70 mg) per week, and P. harmala (500 mg) twice‐a‐day, and the control group treated with calcium D and Osteofos. Before and three months after the intervention, patients were evaluated for osteoporosis using bone densitometry. Finally, independent t-test, paired t-test, and repeated measures ANOVA were used for statistical analysis. Results: The mean bone mineral density (BMD) of the femur before and after the intervention showed significant improvements in the intervention and control groups (P<0.001). The mean differences in BMD before and after the intervention were significant in both control and intervention groups with higher improvements in the intervention group (P<0.001). Although the mean BMD of the spine before the intervention was not significantly different between the two groups (P=0.167), it was better in the intervention group after the intervention (P=0.030). Conclusion: The findings of the present study confirmed the beneficial effects of P. harmala on osteoporosis while the lack of any changes in liver enzymes. Keywords: Peganum harmala, Bone mineral density, Osteoporosis, Liver enzyme, Calcium, Vitamin