Scientific African最新文献

{"title":"Unveiling Asymptomatic Transmission: Analytical and Stability Insights of a Fractional-Order COVID-19 Model","authors":"Hatıra Günerhan ,&nbsp;Mohammad Sharif Ullah ,&nbsp;Kottakkaran Sooppy Nisar ,&nbsp;Waleed Adel","doi":"10.1016/j.sciaf.2025.e02929","DOIUrl":"10.1016/j.sciaf.2025.e02929","url":null,"abstract":"<div><div>In this paper, we present a fractional-order SAIP epidemic model that incorporates asymptomatic transmission to jointly examine infection pathways and the influence of long-term memory effects. The Caputo fractional derivative is employed to capture the memory and hereditary characteristics intrinsic to real-world infectious disease dynamics, providing an alternative framework to traditional integer-order approaches. We establish key mathematical properties, including the positivity and boundedness of solutions, and derive the basic reproduction number. <span><math><mrow><msub><mi>R</mi><mn>0</mn></msub><mspace></mspace></mrow></math></span>to determine thresholds for disease extinction or persistence. Both local and global stability analyses of the disease-free and endemic equilibria are conducted to clarify the conditions required for outbreak control. To address the complexities introduced by the fractional structure, we adapt the Laplace Adomian Decomposition Method (LADM) and demonstrate its effectiveness through detailed numerical simulations. The results show that variations in the fractional order affect epidemic trajectories, altering peak infection levels and duration, and thus emphasize the important role of memory effects in disease propagation.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02929"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An advanced sensorless control strategy using PS-EKF-based Integral Backstepping Controller for PMSM : Experimental validation using dSPACE DS1104","authors":"El-Houssine Bekkour ,&nbsp;Zakariae Sakhri ,&nbsp;Said Mahfoud ,&nbsp;Badre Bossoufi ,&nbsp;Safae Merzouk ,&nbsp;Mohamed I. Mosaad ,&nbsp;Shimaa A. Hussien","doi":"10.1016/j.sciaf.2025.e02951","DOIUrl":"10.1016/j.sciaf.2025.e02951","url":null,"abstract":"<div><div>High-performance sensorless (SL) control of Permanent Magnet Synchronous Motors (PMSMs) remains a crucial challenge in modern industrial applications, particularly in harsh environments where mechanical sensors are impractical. In this paper, we propose an advanced SL position and speed (PS) approach combining an extended Kalman filter (EKF) with an Integral Backstepping controller (IBSC). The developed SLPS-IBSC-EKF method eliminates the need for position and speed sensors while maintaining high dynamic performance. To achieve this, the EKF with its optimal statistical formulation and adaptability to non-linear systems ensures precise reconstruction of rotor PS even in the presence of noise. Meanwhile, the IBSC, through its recursive design based on Lyapunov stability criteria, adaptively compensate for PMSM non-linearities, guarantees stability against external disturbances, and addresses parametric uncertainties. Furthermore, incorporating integral action significantly reduces steady-state tracking errors, improves disturbance rejection, and enhances overall control performance. Comparative analysis in Matlab/Simulink shows that the proposed method surpasses the SLPS-PI-EKF technique across several key performance metrics, including Settling time, Rise time, Rejection time, Steady-State Error and Torque ripple (peak-to-peak). These improvements represent enhancements of 91.7 %, 90.9 %, 89.9 %, 85.6 %, and 63.4 % respectively, achieved by the SLPS-IBSC-EKF compared to the SLPS-PI-EKF. Furthermore, a performance comparison table with other recent methods from the literature reinforces the advantages of the proposed method. Finally, the SLPS-IBSC-EKF is implemented and tested on a small-scale physical test bench using the DSPACE DS1104 board. The results from these tests confirm excellent correlation with simulations and demonstrate the practical viability of the proposed method for real-time implementation.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02951"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145060078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quasi-Z Source Inverter based 3-Phase Grid-Tied Photovoltaic System with Dual Loop Shoot-Through Control using Discrete Time Sliding Mode Control","authors":"Piyush B. Miyani ,&nbsp;Amit V. Sant ,&nbsp;Gulshan Sharma ,&nbsp;Pitshou N. Bokoro ,&nbsp;Rajesh Kumar","doi":"10.1016/j.sciaf.2025.e02936","DOIUrl":"10.1016/j.sciaf.2025.e02936","url":null,"abstract":"<div><div>This paper proposes a discrete-time sliding mode (DTSM) controller designed for <em>dc</em>-link voltage control for quasi-Z source inverter (<em>q</em>-ZSI) employed in a 3-phase grid-tied photovoltaic system. The <em>dc</em>-link voltage control of <em>q</em>-ZSI offers non-minimum phase behavior, which complicates the controller design. The proposed DTSM controller is separately employed to regulate <em>dc</em>-link voltage in the outer loop and inductor current control in the inner loop. Thus, the <em>dc</em>-link voltage control of <em>q</em>-ZSI is achieved with the proposed DTSM controller-based dual-loop control. In the outer voltage control loop, the DTSM controller determines the reference inductor current for the inner current control loop and the inner current control loop further determines the shoot-through duty ratio. The discrete-time model of <em>q</em>-ZSI is developed for the derivation of the proposed DTSM based control law. The designed DTSM controller offers advantages in terms of simplified discrete implementation, robustness, and achieves good steady-state and dynamic operating conditions. The effectiveness of the proposed DTSM controller is assessed with twenty-six different operating conditions with ideal and non-ideal grid conditions as well as balanced and unbalanced loading. The results reveal that the <em>q</em>-ZSI-based 3-phase grid-tied photovoltaic(PV) system operation with the proposed DTSM controller results in IEEE-1547 compliant operation with active power injection and sinusoidal currents supplied by the inverter.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02936"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145009966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental and genetic interactions underlying the morphological and genetic variability of the red juniper (Juniperus turbinata Guss.) in northeastern Morocco: implications for conservation","authors":"Mehdi Boumediene ,&nbsp;Chaymae Benkirane ,&nbsp;Saida Lhousni ,&nbsp;Christina M. Müller ,&nbsp;Larbi Rhazi ,&nbsp;Ahmed Marhri ,&nbsp;Alicia Ayerdi-Gotor ,&nbsp;Majida Charif ,&nbsp;Mohammed Bellaoui ,&nbsp;Malika Abid ,&nbsp;Nargis Sahib","doi":"10.1016/j.sciaf.2025.e02949","DOIUrl":"10.1016/j.sciaf.2025.e02949","url":null,"abstract":"<div><div>Plant species often show morphological variations in response to their environments. In this study, we examined the trees, cones, seeds and leaves of three populations of <em>Juniperus turbinata</em> in north-eastern Morocco, located in littoral, semi-continental and continental zones, to evaluate how local conditions influence morphological characters. Additionally, a genetic study using Simple Sequence Repeat (SSR) markers was conducted to assess the genetic diversity and structure within these populations, aiming to determine the genetic contributions to observed morphological differences. The results showed significant morphological variation across zones. Cones from the littoral population were larger and rounder, while those of the semi-continental and continental populations were more elongated and robust. Seeds and leaves characters also varied in patterns linked with elevation and aridity. Genetic analysis revealed moderate differentiation among populations, with higher genetic diversity in the continental site, as confirmed by several calculated indices such as the number of effective and private alleles, Shannon’s information index, and observed and expected heterozygosities. Interestingly, the population structure profile identified two distinct genetic pools, with littoral and continental populations clustering closely together. This <del>l</del>imited genetic differentiation likely due to gene flow or shared ancestry, suggests the formation of a single genetic group despite geographical separation. The results of this study show that the local environmental factors are the primary drivers of morphological variation, particularly in cones and seeds, while also highlighting a notable genetic component. These findings data are essential for defining conservation strategies adapted to local populations of <em>J. turbinata</em> in the context of climate change.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02949"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring forest resources depletion through Markov switching analysis","authors":"Lahcen Boulaasair ,&nbsp;Namana Seshagiri Rao ,&nbsp;Hassane Bouzahir ,&nbsp;Salma Haque ,&nbsp;Nabil Mlaiki","doi":"10.1016/j.sciaf.2025.e02909","DOIUrl":"10.1016/j.sciaf.2025.e02909","url":null,"abstract":"<div><div>This paper develops a mathematical model to explore forest resource depletion, integrating the dynamics of forest growth, rapid industrialization, and demographic expansion. Unlike prior literature, which predominantly relies on deterministic frameworks, our approach employs stochastic mathematical techniques to embed regime switching within differential equations, driven by irreducible Markov chains with an ergodic stationary distribution. Initially, the deterministic core of the stochastic model, excluding Markov chains, is analyzed by identifying equilibrium points and assessing their asymptotic stability analytically. The well-posedness of the stochastic system with Markov switching is then established, proving the existence and uniqueness of a positive solution. The asymptotic dynamics are subsequently investigated to pinpoint critical thresholds governing resource depletion or sustainability. This pioneering use of stochastic calculus unveils complex interactions overlooked by traditional deterministic models, constituting the primary contribution of this work. Numerical simulations substantiate the theoretical findings, offering a precise quantitative depiction of the system’s behavior and confirming the analytical implications. The results provide a basis for sustainable management policies, recommending external regulatory actions and controlled population pressure to maintain ecological equilibrium and prevent resource depletion. The research underscores the importance of integrating such stochastic methods for more realistic ecological forecasting and policy-making.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02909"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting precipitation using dynamic distributed lag models in arid and sub-humid regions of South Africa","authors":"Lyson Chaka ,&nbsp;Mohamed A.M. Abd Elbasit ,&nbsp;Simbarashe Jombo","doi":"10.1016/j.sciaf.2025.e02924","DOIUrl":"10.1016/j.sciaf.2025.e02924","url":null,"abstract":"<div><div>Ocean characteristics have contributed to a series of unusual rainfall patterns and floods, leading to severe land degradation, loss of life and infrastructure in various regions. Modelling and prediction of precipitation using in-situ data and oceanographic variables is possible. There are limited studies to substantiate this approach in less-developed countries. This study aims to model and predict precipitation in the arid, semi-arid and sub-humid regions of South Africa using dynamic linear regression (DLR) models, with sea surface temperature (SST) anomalies, evaporation-precipitation differences, longwave radiation (<em>lwRad</em>), net surface heat flux and relative humidity as input variables. The prediction accuracy of the autoregressive integrated moving average model with extra data (ARIMAX) and dynamic distributed lag (DDL) models was compared on the mean monthly rainfall data for the period 2008 to 2022. The results highlighted that the DDL models predict better than the other ARIMAX models, with SST anomalies and <em>lwRad</em> having a significant contribution (p-values &lt; 0.05). These models had the smallest root mean squared error (RMSE) values for the arid (8.27 mm), semi-arid (19.15 mm) and the sub-humid (26.77 mm) regions, indicating that DDL models are suitable tools for the prediction of precipitation in these regions. However, additional oceanographic predictors such as sea surface salinity, ocean heat content, and upper-ocean current patterns may further enhance precipitation prediction accuracy, particularly in regions with strong ocean-atmosphere coupling, such as coastal or monsoon-influenced areas.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02924"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144925733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How knowledge management systems trap dynamic organisations into outdated practices: a systematic review","authors":"Daniel Kogi Njiru ,&nbsp;David Muchangi Mugo ,&nbsp;Faith Mueni Musyoka ,&nbsp;Wilberforce Murikah","doi":"10.1016/j.sciaf.2025.e02946","DOIUrl":"10.1016/j.sciaf.2025.e02946","url":null,"abstract":"<div><div>Knowledge Management Systems (KMS) are widely used to capture institutional knowledge and support organizational decision-making. Paradoxically, the very systems designed to foster learning, and adaptation can entrench outdated practices, creating <em>competency traps</em>. For example, healthcare organization may continue relying on pre-pandemic protocols because its KMS prioritizes them, or technology firm may repeatedly surface obsolete coding practices from its knowledge base. Understanding how such traps arise and how they can be prevented represents a key gap in the literature. To address this, the present review analysed 65 peer-reviewed studies published between 2019 and 2025 to investigate the paradoxical effects of KMS. The findings integrate mechanisms, contextual factors, and interventions into a unified framework and identify seven recurring mechanisms that reinforce competency traps: codification bias, algorithmic reinforcement, rigid governance, performance-driven adherence, narrow classification, cultural legitimation, and failure to remove outdated knowledge. Environmental dynamism (the speed and unpredictability of change) tends to worsen these problems, while diverse knowledge sources and deliberate unlearning can mitigate them. From this evidence, the study proposes four intervention strategies: introducing time-based review features, increasing diversity in search and recommendation algorithms, adopting flexible governance structures, and implementing regular “challenge” processes to test prevailing knowledge. The framework connects causes, contexts, and solutions, offering clear guidance for designing KMS that remain relevant in dynamic environments. While such systems can enhance learning in stable settings, they must be deliberately managed to stay adaptive. Organizations are therefore advised to complement KMS with mechanisms that encourage questioning, experimentation, and renewal to avoid stagnation.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02946"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing voltage stability index and reducing power loss through optimal sizing and placing of distribution generation types using puma optimization algorithm","authors":"Abeer Mohammed Alazab,&nbsp;Hamdy Kanaan,&nbsp;Mohammed I. Elsayed","doi":"10.1016/j.sciaf.2025.e02920","DOIUrl":"10.1016/j.sciaf.2025.e02920","url":null,"abstract":"<div><div>The incorporation of Distributed Generation (DG) units into radial distribution networks (RDNs) is a proven strategy to mitigate power losses and enhance voltage stability. However, the efficacy of DG integration heavily depends on optimal placement and sizing, which remains a complex optimization challenge. This study introduces the novel Puma Optimization Algorithm (POA) to address the optimal location of three DG types—Type-1 (active power), Type-2 (reactive power), and Type-3 (active and reactive power)—in IEEE 33 and 69-buses RDNs. POA, drawing inspiration from the foraging behavior of pumas, dynamically balances exploration and exploitation to reduce power losses and enhance the Voltage Stability Index (VSI). Results demonstrate POA’s superior performance compared to established algorithms like BSOA, CSFS, GA, and hybrid techniques. For the IEEE 33-bus, POA achieved a 48.77 % loss reduction with Type-1 DG (single unit), 65.83 % with multiple Type-1 units, and 94.45 % with Type-3 units, alongside significant VSI improvements (up to 0.9705 pu). In the IEEE 69-bus, POA reduced losses by 80.11 % (Type-1) and 80.05 % (Type-3), with VSI reaching 0.9772 pu. Type-3 DG consistently outperformed other types, underscoring its dual-power capability for stability enhancement. The study validates POA as a robust tool for DG location, offering utilities a scalable solution to enhance grid efficiency and reliability. Key contributions include a comparative analysis of DG types, a novel metaheuristic approach, and actionable insights for real-world deployment.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02920"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shoreline changes and its impact on coastal communities: A case study of Senya Beraku, Ghana","authors":"Elorm Fiawotoafor ,&nbsp;Solomon S.R. Gidigasu ,&nbsp;Emmanuel Gikunoo ,&nbsp;Jonathan A.Q. Ballard ,&nbsp;Bright Andoh-Baidoo","doi":"10.1016/j.sciaf.2025.e02901","DOIUrl":"10.1016/j.sciaf.2025.e02901","url":null,"abstract":"<div><div>Senya Beraku on the southern coast of Ghana is a heavily populated community and serves as one largest fishing communities. The area is threatened by coastal erosion impacting fishing, tourism, endangered ecosystems, damaged infrastructure and affecting local economic activities. This research sought to determine the pre-dominant drivers of shoreline changes, estimate the rate of change between 1990 and 2024, examine the effects of these changes on the socio-economic development and propose a coastal management policy. Field surveys, questionnaires, and interviews were employed to determine the drivers of shoreline changes, and the rate of change determined using landsat satellite images obtained from the U.S. Geological Survey and analysed using ArcGIS software. Results of the study indicate that the presence of the sea-break, sand mining, discharge of wastewater unto the shore and the growing population were the pre-dominant drivers contributing to the shoreline changes. Significant shoreline changes occurred within the period, with the maximum accretion distance (NSM) and rates (EPR and LRR) being 8.42 m, 1.5 and 1.42 m/year respectively. The maximum erosion distance (NSM) and rates (EPR and LRR) were -153.51 m, -5.9 and -7.34 m/year respectively. LS-TM model predicts further erosion of -16.5 m by 2034 and -18.5 m by 2044 using 2024 as baseline. Impacts identified were reduced income/poverty due to loss of livelihood, destruction of building structures and coconut trees, among others. Caesation of sand mining and restoration of degraded mangroves/grasses along the coast could serve as a cost-effective coastal management plan, which allows beach processes to continue and protect the source of livelihood.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02901"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Truncated power Chris–Jerry distribution: Classical estimation methods and modeling to survival data","authors":"Amal S. Hassan ,&nbsp;Gaber Sallam Salem Abdalla ,&nbsp;Ehab M. Almetwally ,&nbsp;Ahmed W. Shawki ,&nbsp;Ibrahim E. Ragab ,&nbsp;Mohammed Elgarhy","doi":"10.1016/j.sciaf.2025.e02898","DOIUrl":"10.1016/j.sciaf.2025.e02898","url":null,"abstract":"<div><div>In many real-world scenarios, a truncated distribution arises when the domain of the parent distribution is restricted to a smaller region. This paper presents the truncated power Chris-Jerry distribution (TPC-JD), a novel flexible two-parameter truncated distribution with a domain [0, 1]. The introduction of a new distribution opens up a wide range of options and possibilities, making it possible to choose the model that best fits certain data and research goals. The associated probability density function is very adaptable as it may take on unimodal, reversed j-shaped, and various asymmetric patterns. The corresponding hazard rate function indicates that data with U- or j-shaped failure rates may be adapted by the TPC-JD. The mathematical computation of a number of statistical characteristics is given. Several estimation techniques, including twelve traditional approaches, are investigated to evaluate and compare the behavior of parameter estimates for the TPC-JD. To identify the optimal estimation strategy, a simulation study is conducted. The simulation results indicate that the percentile method is the optimal technique to estimate the quality of TPC-JD estimators. In addition, we investigate two real-world survival data sets using the TPC-JD, showing its better performance compared to some competitors.</div></div>","PeriodicalId":21690,"journal":{"name":"Scientific African","volume":"29 ","pages":"Article e02898"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}