Search results for: characteristic landscape

Authors: Yihao Kuang, Bowen Ding

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With the increasing scale and complexity of knowledge graph, modern knowledge graph contains more and more types of entity, relationship, and attribute information. Therefore, in recent years, it has been a trend for knowledge graph inference to use reinforcement learning to deal with large-scale, incomplete, and noisy knowledge graphs and improve the inference effect and interpretability. The Proximal Policy Optimization (PPO) algorithm utilizes a near-end strategy optimization approach. This allows for more extensive updates of policy parameters while constraining the update extent to maintain training stability. This characteristic enables PPOs to converge to improved strategies more rapidly, often demonstrating enhanced performance early in the training process. Furthermore, PPO has the advantage of offline learning, effectively utilizing historical experience data for training and enhancing sample utilization. This means that even with limited resources, PPOs can efficiently train for reinforcement learning tasks. Based on these characteristics, this paper aims to obtain a better and more efficient inference effect by introducing PPO into knowledge inference technology.

Keywords: reinforcement learning, PPO, knowledge inference

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Authors: Hala O. El-Mesallamy, Salwa M. Suwailem, Mae M. Seleem

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Visfatin and apelin are two new adipokines that recently gained a special interest in diabetes research. This study was conducted to study the interplay between these two adipokines and their correlation with other inflammatory and biochemical parameters in type 2 diabetic (T2D) postmenopausal women with CAD. Visfatin and apelin were measured by enzyme-linked immunoassay (ELISA). Visfatin was found to be significantly higher in the following groups: T2D patients without CAD, non-obese and obese T2D patients with CAD when compared to control group. Apelin was found to be significantly lower in non-obese and obese T2D patients with CAD when compared to control group. Visfatin and apelin were found to be significantly associated with each other and with other biochemical parameters. The current study provides evidence for the interplay between visfatin and apelin through the inflammatory milieu characteristic of T2D and their possible role in the pathogenesis of CAD complication of T2D.

Keywords: apelin, coronary artery disease, inflammation, type 2 diabetes, visfatin

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Authors: Aleksandra Majewska

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The article analyses the impact of Western sanctions on Russian rhythmic gymnastics since the outbreak of war in Ukraine. The chronological presentation of events shows how international political tensions and economic sanctions have affected the organisation of competitions, training and the careers of athletes. The article outlines the key moments and decisions that have changed the landscape of Russian sport, including the decision to change the citizenship made by some gymnasts in order to continue competing in international competitions. Russia strongly opposes participation in competitions without its flag and anthem while maintaining the view that Russian gymnasts are crucial to the prestige of rhythmic gymnastics in the world. In response to the sanctions, Russia created its own rules for rhythmic gymnastics, according to which they now compete domestically. Furthermore, this sport in Russia is strongly linked to politics, which further emphasises its importance in the national and international context. The information collected derives from numerous interviews with Russian athletes, coaches and other people, which are available only in the Russian language. The findings highlight the significant difficulties Russian athletes have faced due to their isolation in the international arena and the adaptive strategies adopted by Russia in the face of these challenges. The article makes an important contribution to understanding the consequences of global politics on the world of sport and the fate of individual athletes.

Keywords: sport, gymnastics, war in Ukraine, sanctions

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Authors: Heather E. Ewart, Keith Jensen, Rebecca N. Cliffe

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Fragmentation and changes in the structural composition of tropical forests – as a result of intensifying anthropogenic disturbance – are increasing pressures on local biodiversity. Species with low dispersal abilities have some of the highest extinction risks in response to environmental change, as even small-scale environmental variation can substantially impact their space use and energetic balance. Understanding the implications of forest disturbance is therefore essential, ultimately allowing for more effective and targeted conservation initiatives. Here, the impact of different levels of forest disturbance on the space use, energetics, movement and behavior of 18 brown-throated sloths (Bradypus variegatus) were assessed in the South Caribbean of Costa Rica. A multi-scale framework was used to measure forest disturbance, including large-scale (landscape-level classifications) and fine-scale (within and surrounding individual home ranges) forest composition. Three landscape-level classifications were identified: primary forests (undisturbed), secondary forests (some disturbance, regenerating) and urban forests (high levels of disturbance and fragmentation). Finer-scale forest composition was determined using measurements of habitat structure and quality within and surrounding individual home ranges for each sloth (home range estimates were calculated using autocorrelated kernel density estimation [AKDE]). Measurements of forest quality included tree connectivity, density, diameter and height, species richness, and percentage of canopy cover. To determine space use, energetics, movement and behavior, six sloths in urban forests, seven sloths in secondary forests and five sloths in primary forests were tracked using a combination of Very High Frequency (VHF) radio transmitters and Global Positioning System (GPS) technology over an average period of 120 days. All sloths were also fitted with micro data-loggers (containing tri-axial accelerometers and pressure loggers) for an average of 30 days to allow for behavior-specific movement analyses (data analysis ongoing for data-loggers and primary forest sloths). Data-loggers included determination of activity budgets, circadian rhythms of activity and energy expenditure (using the vector of the dynamic body acceleration [VeDBA] as a proxy). Analyses to date indicate that home range size significantly increased with the level of forest disturbance. Female sloths inhabiting secondary forests averaged 0.67-hectare home ranges, while female sloths inhabiting urban forests averaged 1.93-hectare home ranges (estimates are represented by median values to account for the individual variation in home range size in sloths). Likewise, home range estimates for male sloths were 2.35 hectares in secondary forests and 4.83 in urban forests. Sloths in urban forests also used nearly double (median = 22.5) the number of trees as sloths in the secondary forest (median = 12). These preliminary data indicate that forest disturbance likely heightens the energetic requirements of sloths, a species already critically limited by low dispersal ability and rates of energy acquisition. Energetic and behavioral analyses from the data-loggers will be considered in the context of fine-scale forest composition measurements (i.e., habitat quality and structure) and are expected to reflect the observed home range and movement constraints. The implications of these results are far-reaching, presenting an opportunity to define a critical index of habitat connectivity for low dispersal species such as sloths.

Keywords: biodiversity conservation, forest disturbance, movement ecology, sloths

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Authors: Ghusen al-Kafri, Mohammed Ali Abdallah Elsageer, Ahmed Mohamed Hadya Alsdaai, Abdeimanam Salhien Salih Khalifa

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In this paper, external reinforcement to enhance a reinforced concrete structure performance has been done using externally bonded steel plate. This technique has been reported effective in enhancing the strength of reinforced concrete beam, a study to determine the effectiveness of steel plate as an external reinforcement was carried out. A total of two groups of beams and one group content five beams, each 750 mm long, 150 mm wide, and 150 mm deep were cast, strengthened and tested till failure under two point loads. One beam was act as a control beam without strengthening and other four beams were strengthened with steel plate at a different arrangement. Other group beams were strengthened with steel plate in shear zone and also strengthened at bottom as first group. The behaviours of the strengthened beams were studied through their load-deflection characteristic upon bending, cracking and mode of failure. The results confirmed that all steel plate arrangements enhanced the strength of the reinforced concrete beam, the positioning of the steel plate affect the moment carrying capacity of the beam.

Keywords: beams, bending, beflection, steel plates

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Authors: Vincent King Soon Wong, Hong Seng Ng, Florinna Sim

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Negative Bias Temperature Instability (NBTI) is one of the critical degradation mechanisms in semiconductor device reliability that causes shift in the threshold voltage (Vth). However, thorough understanding of this reliability failure mechanism is still unachievable due to a recovery characteristic known as NBTI recovery. This paper will demonstrate the severity of NBTI recovery as well as one of the effective methods used to mitigate, which is the minimization of measurement system delays. Comparison was done in between two measurement systems that have significant differences in measurement delays to show how NBTI recovery causes result deviations and how fast measurement systems can mitigate NBTI recovery. Another method to minimize NBTI recovery without the influence of measurement system known as Fast Wafer Level Reliability (FWLR) NBTI was also done to be used as reference.

Keywords: fast vs slow BTI, fast wafer level reliability (FWLR), negative bias temperature instability (NBTI), NBTI measurement system, metal-oxide-semiconductor field-effect transistor (MOSFET), NBTI recovery, reliability

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Authors: A. Hemmati, H. Mirsaeedghazi, M. Aboonajmi

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Carrot juice is one of the most nutritious foods that are consumed around the world. Large particles in carrot juice causing turbid appearance make some problems in the concentration process such as off-flavor due to the large particles burnt on the walls of evaporators. Microfiltration (MF) is a pressure driven membrane separation method that can clarify fruit juices without enzymatic treatment. Fouling is the main problem in the membrane process causing reduction of permeate flux. Ultrasound as a cleaning technique was applied at 20 kHz to reduce fouling in membrane clarification of carrot juice using dead-end MF system with polyvinylidene fluoride (PVDF) membrane. Results showed that application of ultrasound waves reduce diphasic characteristic of carrot juice and permeate flux increased. Evaluation of different membrane fouling mechanisms showed that application of ultrasound waves changed creation time of each fouling mechanism. Also, its behavior was changed with varying transmembrane pressure.

Keywords: Carrot juice, Dead end, Microfiltration, Ultrasound

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Authors: Elmahdi Elgharbaoui, Tamou Nasser, Ahmed Essadki

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In the era of sustainable development, photovoltaic (PV) technology has shown significant potential as a renewable energy source. Photovoltaic generators (GPV) have a non-linear current-voltage characteristic, with a maximum power point (MPP) characterized by an optimal voltage, and depends on environmental factors such as temperature and irradiation. To extract each time the maximum power available at the terminals of the GPV and transfer it to the load, an adaptation stage is used, consisting of a boost chopper controlled by a maximum power point tracking technique (MPPT) through a stage of pulse width modulation (PWM). Our choice has focused on three techniques which are: the perturbation and observation method (P&O), the incremental conductance method (InCond) and the last is that of control using the fuzzy logic. The implementation and simulation of the system (photovoltaic generator, chopper boost, PWM and MPPT techniques) are then performed in the Matlab/Simulink environment.

Keywords: photovoltaic generator, technique MPPT, boost chopper, PWM, fuzzy logic, P&O, InCond

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Authors: Ich Long Ngo, Dinh Tai Dang, Ngoc Tu Nguyen, Minh Duc Nguyen

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This paper describes an investigation on designing and enhancing the performance of H-Darrieus wind turbine (HDWT) of 10kW at the medium wind speed. The aerodynamic characteristics of this turbine were investigated by both theoretical and numerical approaches. The optimal design procedure was first proposed to enhance the power coefficient under various effects, such as airfoil type, number of blades, solidity, aspect ratio, and tip speed ratio. As a result, the overall design of the 10kW HDWT was well achieved, and the power characteristic of this turbine was found by numerical approach. Additionally, the maximum power coefficient predicted is up to 0.41 at the tip speed ratio of 3.7 and wind speed of 8 m/s. Particularly, a generalized correlation of power coefficient with tip speed ratio and wind speed is first proposed. These results obtained are very useful for enhancing the performance of the HDWTs placed in a country with high wind power potential like Vietnam.

Keywords: computational fluid dynamics, double multiple stream tube, h-darrieus wind turbine, renewable energy

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Authors: Sam J. Cooley, Mary L. Quinton, Benjamin J. Parry, Mark J. G. Holland, Richard J. Whiting, Jennifer Cumming

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Practitioners draw attention to people’s character strengths to promote empowerment and well-being. This paper explores the possibility that existing approaches for assessing character strengths (e.g., the Values in Action survey; VIA-IS) could be even more autonomy supportive and empowering when combined with strengths profiling, an ideographic tool informed by personal construct theory (PCT). A PCT approach ensures that: (1) knowledge is co-created (i.e., the practitioner is not seen as the ‘expert’ who leads the process); (2) individuals are not required to ‘fit’ within a prescribed list of characteristics; and (3) individuals are free to use their own terminology and interpretations. A combined Strengths Profiling and VIA approach was used in a sample of homeless youth (aged 16-25) who are commonly perceived as ‘hard-to-engage’ through traditional forms of assessment. Strengths Profiling was completed face-to-face in small groups. Participants (N = 116) began by listing a variety of personally meaningful characteristics. Participants gave each characteristic a score out of ten for how important it was to them (1 = not so important; 10 = very important), their ideal competency, and their current competency (1 = poor; 10 = excellent). A discrepancy score was calculated for each characteristic (discrepancy score = ideal score - current score x importance), whereby a lower discrepancy score indicated greater satisfaction. Strengths Profiling was used at the beginning and end of a 10-week positive youth development programme. Experiences were captured through video diary room entries made by participants and through reflective notes taken by the facilitators. Participants were also asked to complete a pre-and post-programme questionnaire, measuring perceptions of well-being, self-worth, and resilience. All of the young people who attended the strengths profiling session agreed to complete a profile, and the majority became highly engaged in the process. Strengths profiling was found to be an autonomy supportive and empowering experience, with each participant identifying an average of 10 character strengths (M = 10.27, SD = 3.23). In total, 215 different character strengths were identified, each with varying terms and definitions used, which differed greatly between participants and demonstrated the value in soliciting personal constructs. Using the participants’ definitions, 98% of characteristics were categorized deductively into the VIA framework. Bravery, perseverance, and hope were the character strengths that featured most, whilst temperance and courage received the highest discrepancy scores. Discrepancy scores were negatively correlated with well-being, self-worth, and resilience, and meaningful improvements were recorded following the intervention. These findings support the use of strengths profiling as a theoretically-driven and novel way to engage disadvantaged youth in identifying and monitoring character strengths. When young people are given the freedom to express their own characteristics, the resulting terminologies extend beyond the language used in existing frameworks. This added freedom and control over the process of strengths identification encouraged youth to take ownership over their profiles and apply their strengths. In addition, the ability to transform characteristics post hoc into the VIA framework means that strengths profiling can be used to explore aggregated/nomothetic hypotheses, whilst still benefiting from its ideographic roots.

Keywords: ideographic, nomothetic, positive youth development, VIA-IS, assessment, homeless youth

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Authors: Gastão Soares Ximenes de Oliveira, Richar Nicolás Durán, Romeo Micah Szmoski, Eloiza Aparecida Avila de Matos, Elano Gustavo Rein

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This article aims to present an experimental method to determine Planck's constant by calculating the cutting potential V₀ from LEDs with different wavelengths. The experiment is designed using Arduino as a central tool in order to make the experimental activity more engaging and attractive for students with the use of digital technologies. From the characteristic curves of each LED, graphical analysis was used to obtain the cutting potential, and knowing the corresponding wavelength, it was possible to calculate Planck's constant. This constant was also obtained from the linear adjustment of the cutting potential graph by the frequency of each LED. Given the relevance of Planck's constant in physics, it is believed that this experiment can offer teachers the opportunity to approach concepts from modern physics, such as the quantization of energy, in a more accessible and applied way in the classroom. This will not only enrich students' understanding of the fundamental nature of matter but also encourage deeper engagement with the principles of quantum physics.

Keywords: physics teaching, educational technology, modern physics, Planck constant, Arduino

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Authors: Revai Boterere

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The study explores the decolonial theory in the context of engaging with living heritages in the formally colonised through the case of the Great Zimbabwe World Heritage Site. It followed a qualitative research paradigm in the form of a situational analysis, with both primary and secondary data sources examined to enable an analysis focusing on the decolonial discourse and practice at Great Zimbabwe. Unlike the dominant model (in terms of interpretation) used at Great Zimbabwe, that of Thomas Huffman, which views the site as ruins, new literature (Ashton Sinamai, 2017, 2020; Webber Ndoro, 1994, 2005; ShadreckChirikure 2008, etal 2016; Njabulo Chipanguraetal 2019) on zimbabwe culture, Great Zimbabwe World Heritage Site is a living site, a shrine, and a cultural landscape. it argue that the new literature, perhaps decolonial, remain in the hands of academics and not synthesised down to the interpreters. This is a problem, and it needs to be addressed. There is need of a pragmatic thrust to decolonisation at the Great Zimbabwe World Heritage Site. Though there are efforts to involve local communities at Great Zimbabwe as a decolonial approach, there is need to reorder the current system of producing knowledge in place. This paper will unpack these debates of decoloniality between what Huffman’s propositions of the interpretation of Great Zimbabwe vis-a-vis the new decolonial school of thought by local researchers.

Keywords: cultural tourism, decoloniality, living heritage, local community

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Authors: Geon Bae, Cheol Hee Moon

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Organic Light Emitting Diodes (OLEDs) are being developed rapidly as next-generation displays due to their self-luminous and flexible characteristics. OLEDs are highly susceptible to moisture and oxygen due to their structural properties. Thus, requiring a high level of encapsulation technology. Recently, encapsulation technology such as Thin Film Encapsulation (TFE) has been developed for OLED, but it is not perfect to prevent moisture permeation on the side. In this study, we propose OLED encapsulation method using Low melting Point Alloy (LMPA). The LMPA line was designed in square box shape on the outer edge of the device and was formed by screen printing method. To determine if LMPA has an effect on OLED, we fabricated solution processed OLEDs with a square-shaped LMPA line and evaluate the I-V-L characteristics of the OLEDs. Also, the resistance characteristic of the LMPA line was observed by repeatedly bending the LMPA line. It is expected that LMPA encapsulation will have a great advantage in shortening the process time and cost reduction.

Keywords: OLED, encapsulation, LMPA, solution process

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Authors: Nur Syarafina Binti Othman, Tsubasa Jindo, Makato Yamada, Miho Tsuyama, Hitoshi Nakano

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A novel method to produce a fast high voltage solid states switch using Insulated Gate Bipolar Transistors (IGBTs) is presented for discharge-pumped gas lasers. The IGBTs are connected in series to achieve a high voltage rating. An avalanche transistor is used as the gate driver. The fast pulse generated by the avalanche transistor quickly charges the large input capacitance of the IGBT, resulting in a switch out of a fast high-voltage pulse. The switching characteristic of fast-high voltage solid state switch has been estimated in the multi-stage series-connected IGBT with the applied voltage of several tens of kV. Electrical circuit diagram and the mythology of fast-high voltage solid state switch as well as experimental results obtained are presented.

Keywords: high voltage, IGBT, solid state switch, bipolar transistor

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Authors: Joseph Thomas Eghwerido, Julian I. Mbegbu

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In modelling environment processes, we apply multidisciplinary knowledge to explain, explore and predict the Earth's response to natural human-induced environmental changes. Thus, the analysis of spatial-time ecological and environmental studies, the spatial parameters of interest are always heterogeneous. This often negates the assumption of stationarity. Hence, the dispersion of the transportation of atmospheric pollutants, landscape or topographic effect, weather patterns depends on a good estimate of spatial covariance. The generalized linear mixed model, although linear in the expected value parameters, its likelihood varies nonlinearly as a function of the covariance parameters. As a consequence, computing estimates for a linear mixed model requires the iterative solution of a system of simultaneous nonlinear equations. In other to predict the variables at unsampled locations, we need to know the estimate of the present sampled variables. The geostatistical methods for solving this spatial problem assume covariance stationarity (locally defined covariance) and uniform in space; which is not apparently valid because spatial processes often exhibit nonstationary covariance. Hence, they have globally defined covariance. We shall consider different existing methods of solutions of spatial covariance of a space-time processes at unsampled locations. This stationary covariance changes with locations for multiple time set with some asymptotic properties.

Keywords: parametric, nonstationary, Kernel, Kriging

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Authors: Nur Aisyah Jalalludin, Arwindra Rizqiawan, Goro Fujita

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In this study, we aim to demonstrate a microgrid system experimental simulation for an easy understanding of a large-scale microgrid system. This model is required for industrial training and learning environments. However, in order to create an exact representation of a microgrid system, the laboratory-scale system must fulfill the requirements of a grid-connected inverter, in which power values are assigned to the system to cope with the intermittent output from renewable energy sources. Aside from that, during changes in load capacity, the grid-connected system must be able to supply power from the utility grid side and microgrid side in a balanced manner. Therefore, droop control is installed in the inverter’s control board to maintain equal power sharing in both sides. This power control in a stand-alone condition and droop control in a grid-connected condition must be implemented in order to maintain a stabilized system. Based on the experimental results, power control and droop control can both be applied in the system by comparing the experimental and reference values.

Keywords: droop control, droop characteristic, grid-connected inverter, microgrid, power control

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Authors: Zeinab Zaremohzzabieh, Syasya Firzana Azmi, Haslinda Abdullah, Soh Kim Geok, Aini Azeqa Ma'rof, Hayrol Azril Mohammed Shaffril

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The escalating prevalence of doping in sports, casting a shadow over both high-performance and recreational settings, has emerged as a formidable concern, particularly within the realm of young athletes. Doping, characterized by the surreptitious use of prohibited substances to gain a competitive edge, underscores the pressing need for comprehensive and efficacious preventive measures. This study aims to address a crucial void in current research by unraveling the motivations that drive clean adolescent athletes to steadfastly abstain from performance-enhancing substances. In navigating this intricate landscape, the study adopts a positive psychology perspective, investigating into the conditions and processes that contribute to the holistic well-being of individuals and communities. At the heart of this exploration lies the application of the PERMA model, a comprehensive positive psychology framework encapsulating positive emotion, engagement, relationships, meaning, and accomplishments. This model functions as a distinctive lens, dissecting intervention results to offer nuanced insights into the complex dynamics of clean sport behavior. The research is poised to usher in a paradigm shift from conventional anti-doping strategies, predominantly fixated on identifying deficits, towards an innovative approach firmly rooted in positive psychology. The objective of this study is to evaluate the efficacy of a positive education intervention program tailored to promote clean sport behavior among Malaysian adolescent athletes. Representing unexplored terrain within the landscape of anti-doping efforts, this initiative endeavors to reshape the focus from deficiencies to strengths. The meticulously crafted pilot study engages thirty adolescent athletes, divided into a control group of 15 and an experimental group of 15. The pilot study serves as the crucible to assess the effectiveness of the prepared intervention package, providing indispensable insights that will meticulously guide the finalization of an all-encompassing intervention program for the main study. The main study adopts a pioneering two-arm randomized control trial methodology, actively involving adolescent athletes from diverse Malaysian high schools. This approach aims to address critical lacunae in anti-doping strategies, specifically calibrated to resonate with the unique context of Malaysian schools. The study, cognizant of the imperative to develop preventive measures harmonizing with the cultural and educational milieu of Malaysian adolescent athletes, aspires to cultivate a culture of clean sport. In conclusion, this research aspires to contribute unprecedented insights into the efficacy of positive education interventions firmly rooted in the PERMA model. By unraveling the intricacies of clean sport behavior, particularly within the context of Malaysian adolescent athletes, the study seeks to introduce transformative preventive methods. The adoption of positive psychology as an avant-garde anti-doping tool represents an innovative and promising approach, bridging a conspicuous gap in scholarly research and offering potential panaceas for the sporting community. As this study unfurls its chapters, it carries the promise not only to enrich our understanding of clean sport behavior but also to pave the way for positive metamorphosis within the realm of adolescent sports in Malaysia.

Keywords: positive education interventions, a pilot study, clean sport behavior, adolescent athletes, Malaysia

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Authors: Mehrji Khosravan, Mostafa Fathali-Sianib, Davood Soudbar, Sasan Talebnezhad, Mohammad-Reza Ebrahimi

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The late transition metal catalyst of the end group of transition metals in the periodic table as Ni, Fe, Co, and Pd was grown up rapidly in polyolefin industries recently. These metals with suitable ligands exhibited special characteristic properties and appropriate activities in the production of polyolefins. The ligand 1,4-bis (2,6-diisopropyl phenyl) acenaphthene was synthesized by reaction of 2,6-diisopropyl aniline and acenaphthenequinone. The ligand was added to nickel (II) dibromide salt for synthesis the 1,4-bis (2,6 diisopropylphenyl) acenaphthene nickel (II) dibromide catalyst. The structure of the ligand characterized by IR technique. The catalyst then deposited on graphene and graphene oxide by vander walss-attachment for use in Ethylene slurry polymerization process in the presence of catalyst activator such as methylaluminoxane (MAO) in hexane solvent. The structure of the catalyst characterized by IR and TEM techniques and some of the polymers were characterized by DSC. The highest activity was achieved at 600 C for catalyst.

Keywords: α-diimine nickel (II) complex, graphene as supported catalyst, late transition metal, ethylene polymerization

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Authors: M. Kagan Keler, Sibel Daglilar, Isil Kerti, Oguzhan Gunduz

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Electrospinning is a versatile way to occur fibers at nano-scale and polycaprolactone is a biomedical material which has a wide usage in cartilage defects and tissue regeneration. PCL is biocompatible and durable material which can be used in bio-implants. Therefore, electrospinning process was chosen as a fabrication method to get PCL fibers in an effective way because of its significant adjustments. In this research study, electrospinning parameters was evaluated during the producing of polymer tissue scaffolds. Polycaprolactone’s molecular weight was 80.000 Da and was employed as a tissue material in the electrospinning process. PCL was decomposed in dimethylformamid(DMF) and chloroform(CF) with the weight ratio of 1:1. Different compositions (1%, 3%, 5%, 10% and 20 %) of PCL was prepared in the laboratory conditions. All solvents with different percentages of PCL have been taken into the syringe and loaded into the electrospinning system. In electrospinning dozens of trial were applied to get homogeneously uniform scaffold samples. Taylor cone which is crucial point for electrospinning characteristic was occurred and changed in different voltages up to the material compositions’ conductivity. While the PCL percentages were increasing in the electrospinning, structure started to arise with droplets, which was an expressive problem for tissue scaffold. The vertical and horizontal layouts were applied to produce non-woven structures at all.

Keywords: tissue engineering, artificial scaffold, electrospinning, biocomposites

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Authors: Suha I. Al-Nassar, K. M. Adel, F. Zainab

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This work was devoted for producing ZnO nanoparticles by pulsed laser ablation (PLA) of Zn metal plate in the aqueous environment of cetyl trimethyl ammonium bromide (CTAB) using Q-Switched Nd:YAG pulsed laser with wavelength= 1064 nm, Rep. rate= 10 Hz, Pulse duration= 6 ns and laser energy 50 mJ. Solution of nanoparticles is found stable in the colloidal form for a long time. The effect of ablation time on the optical and structure of ZnO was studied is characterized by UV-visible absorption. UV-visible absorption spectrum has four peaks at 256, 259, 265, 322 nm for ablation time (5, 10, 15, and 20 sec) respectively, our results show that UV–vis spectra show a blue shift in the presence of CTAB with decrease the ablation time and blue shift indicated to get smaller size of nanoparticles. The blue shift in the absorption edge indicates the quantum confinement property of nanoparticles. Also, FTIR transmittance spectra of ZnO2 nanoparticles prepared in these states show a characteristic ZnO absorption at 435–445cm^−1.

Keywords: zinc oxide nanoparticles, CTAB solution, pulsed laser ablation technique, spectroscopic characterization

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Authors: K. Berhanu

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Improper land use results in land degradation and decline in agricultural productivity. Hence, in order to get maximum benefits out of land, proper utilization of its resources is inevitable. The present study was aimed at identifying the landcover changes in the study area in the last 25 years and determines the extent and direction of change that has occurred. The study made use of Landsat TM 1986 and 2011 Remote Sensing Satellite Image for analysis to determine the extent and pattern of rangeland change. The results of the landuse/landcover change detection showed that in the last 25 years, 3 major changes were observed, grassland and open shrub-land resource significantly decreased at a rate of 17.1km2/year and 12 km2/year/, respectively. On the other hand in 25 years dense bushland, open bush land, dense shrubland and cultivated land has shown increment in size at a rate of 0.23km2/year,13.5 km2/year, 6.3 km2/year and 0.2 km2/year, respectively within 25 years. The expansion of unpalatable woody species significantly reduced the rangeland size and availability of grasses. The consequence of the decrease in herbaceous biomass production might result in high risk of food insecurity in the area unless proper interventions are made in time.

Keywords: GIS and remote sensing, Dire District, land use/land cover, land sat TM

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Authors: Reini S. Ilmiaty, Muhammad B. Al Amin, Sarino, Muzamil Jariski

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Kedukan River is an artificial river which serves as a Watershed Boang drainage channel in Palembang. The river has upstream and downstream connected to Musi River, that often overflowing and flooding caused by the huge runoff discharge and high tide water level of Musi River. This study aimed to analyze the flood water surface profile on Kedukan River continued with flood inundation simulation to determine flooding prone areas in research area. The analysis starts from the peak runoff discharge calculations using rational method followed by water surface profile analysis using HEC-RAS program controlled by manual calculations using standard stages. The analysis followed by running flood inundation simulation using ArcGIS program that has been integrated with HEC-GeoRAS. Flood inundation simulation on Kedukan River creates inundation characteristic maps with depth, area, and circumference of inundation as the parameters. The inundation maps are very useful in providing an overview of flood prone areas in Kedukan River.

Keywords: flood modelling, HEC-GeoRAS, HEC-RAS, inundation map

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Authors: Yihao Kuang, Bowen Ding

Abstract:

With the increasing scale and complexity of knowledge graph, modern knowledge graph contains more and more types of entity, relationship, and attribute information. Therefore, in recent years, it has been a trend for knowledge graph inference to use reinforcement learning to deal with large-scale, incomplete, and noisy knowledge graph and improve the inference effect and interpretability. The Proximal Policy Optimization (PPO) algorithm utilizes a near-end strategy optimization approach. This allows for more extensive updates of policy parameters while constraining the update extent to maintain training stability. This characteristic enables PPOs to converge to improve strategies more rapidly, often demonstrating enhanced performance early in the training process. Furthermore, PPO has the advantage of offline learning, effectively utilizing historical experience data for training and enhancing sample utilization. This means that even with limited resources, PPOs can efficiently train for reinforcement learning tasks. Based on these characteristics, this paper aims to obtain better and more efficient inference effect by introducing PPO into knowledge inference technology.

Keywords: reinforcement learning, PPO, knowledge inference, supervised learning

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Authors: Amira M. Attia, Karim H. Youssef, Nabil H. Abbasi

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Demand Side Management (DSM) is an essential characteristic of current and future smart grid systems. As one of DSM functions, load management aims to control customers’ total electric consumption and utility’s load factor by using various load shaping techniques. However, applying load shaping techniques such as load shifting, peak clipping, or strategic conservation individually does not provide the desired level of improvement for load factor increment and/or customer’s bill reduction. In this paper, two load shaping techniques will be simulated as constrained optimization problems. The purpose is to reflect the application of combined load shifting and strategic conservation model together at the same time, and the application of combined load shifting and peak clipping model as well. The problem will be formulated and solved by using disciplined convex programming (CVX) based MATLAB® R2013b. Simulation results will be evaluated and compared for studying the most impactful multi-techniques model in improving load curve.

Keywords: convex programing, demand side management, load shaping, multiple, building energy optimization

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Authors: Fuling Deng

Abstract:

Today’s children are frequently exposed to multimodal texts that adopt diverse modes to communicate myriad meanings within different cultural contexts. To respond to the new textual landscape, scholars have considered new literacy theories which propose picturebooks as important educational resources. Picturebooks are multimodal, with their meaning conveyed through the synchronisation of multiple modes, including linguistic, visual, spatial, and gestural acting as access to multimodal literacy. Picturebooks have been popular reading materials in primary educational settings in China. However, often viewed as “easy” texts directed at the youngest readers, picturebooks remain on the margins of Chinese upper primary classrooms, where they are predominantly used for linguistic tasks, with little value placed on their multimodal affordances. Practices with picturebooks in the upper grades in Chinese primary schools also encounter many challenges associated with the curation of texts for use, designing curriculum, and assessment. To respond to these issues, a qualitative study was conducted with a community of Chinese primary teachers using multi-methods such as interviews, focus groups, and documents. The findings showed the impact of the teachers’ increased awareness of picturebooks' multimodal affordances on their pedagogical decisions in using picturebooks as educational resources in upper primary classrooms.

Keywords: picturebook education, multimodal literacy, teachers' response to contemporary picturebooks, community of practice

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Authors: Orose Rugchati, Sarawut Wattanawongpitak

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The Chainat 1 variety (CN1) of rice, which generally has high amylose starch, is distributed in the lower part of Northern Thailand. CN1 rice starch can be used in both food and non-food products. In this research, the CN1 rice starch from the wet-milling process was prepared by Pre-Gelatinization (Heat-Moisture Treatments, HMT) under different conditions: percentage of moisture contents (20% and 30%) and duration time in minutes (0, 30, 60, and 90) at a specific temperature 110°C. The physicochemical characteristics of CN1 rice starch modification, such as amylose content, viscosity, swelling, and solubility property, were evaluated and compared with native CN1 rice starch. The results showed that modification CN1 rice starch tends to have some characteristics better than native starch. The appearance color and starch granule of modified CN1 by HMT have more effective characteristics than native starch when increased duration time. The duration time and moisture content are significant factors to the CN1 starch characteristic by HMT. Moreover, physical modification of CN1 starch by HMT can be described as a modified rice starch providing in many applications and the advantage of biodegradability development.

Keywords: physicochemical characteristics, physical modification, pre-gelatinization, Heat-Moisture Treatments, rice starch, Chainat 1 variety (CN1)

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Authors: E. T. Svahn

Abstract:

This article documents how open science policy is perceived in the scientific literature globally throughout the history. It also presents what policy needs are persistent to enable safe and effective dissemination of scientific knowledge. This information may be of interest to open science and science policy makers globally, especially in the view of recent adoption of supranational open science policies such as Plan S. Evaluation of open science policy landscape is in pressing need of assessment regarding its impact on the research community and society at wide as no previous literature review has been conducted on the topic. This study is a rigorous literature review based on constructivist grounded theory method on the full body of scientific open science policy publications. Selection of these articles has been conducted in 2019 and 2020 in major global knowledge databases. Through the analysis of these articles, two key themes emerged that are seen to shape the relationship between science and society. 1st is that of the policy enabling open science in a safe and effective way, and 2nd is that of the outcome of the science policy may have on the research community and the wider society. These findings accentuate that open science policies can have a major impact on not only research process and availability of knowledge but also on society itself. As an outcome of this study, a theoretical framework is constructed, and the need for further study on open science policy itself on a higher level becomes apparent.

Keywords: constructivist grounded theory, open science policy, rigorous literature review, science policy

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Authors: Venkata Reddy Kota

Abstract:

These days, the industrial trend is moving away from heavy and bulky passive components to power converter systems that use more and more semiconductor elements. Also, it is difficult to connect the traditional converters to the high and medium voltage. For these reasons, a new family of multilevel inverters has appeared as a solution for working with higher voltage levels. Different modulation topologies like Sinusoidal Pulse Width Modulation (SPWM), Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) are available for multilevel inverters. In this work, different hybrid modulation techniques which are combination of fundamental frequency modulation and multilevel sinusoidal-modulation are compared. The main characteristic of these modulations are reduction of switching losses with good harmonic performance and balanced power loss dissipation among the device. The proposed hybrid modulation schemes are developed and simulated in Matlab/Simulink for cascaded H-bridge inverter. The results validate the applicability of the proposed schemes for cascaded multilevel inverter.

Keywords: hybrid PWM techniques, cascaded multilevel inverters, switching loss minimization

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Authors: V. Pérez-Herranz, C. González-Buch, E. M. Ortega, S. Mestre

Abstract:

In this work new macroporous Ni electrodes modified with Au nanoparticles for hydrogen production have been developed. The supporting macroporous Ni electrodes have been obtained by means of the electrodeposition at high current densities. Then, the Au nanoparticles were synthesized and added to the electrode surface. The electrocatalytic behaviour of the developed electrocatalysts was studied by means of pseudo-steady-state polarization curves, electrochemical impedance spectroscopy (EIS) and hydrogen discharge curves. The size of the Au synthetized nanoparticles shows a monomodal distribution, with a very sharp band between 10 and 50 nm. The characteristic parameters d10, d50 and d90 were 14, 20 and 31 nm respectively. From Tafel polarization data has been concluded that the Au nanoparticles improve the catalytic activity of the developed electrodes towards the HER respect to the macroporous Ni electrodes. EIS permits to obtain the electrochemically active area by means of the roughness factor value. All the developed electrodes show roughness factor values in the same order of magnitude. From the activation energy results it can be concluded that the Au nanoparticles improve the intrinsic catalytic activity of the macroporous Ni electrodes.

Keywords: Au nano particles, hydrogen evolution reaction, porous Ni electrodes, electrochemical impedance spectroscopy

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Authors: Azita Ramezani, Atousa Ramezani

Abstract:

In the ever-escalating landscape of windows malware the necessity for pioneering defense strategies turns into undeniable this study introduces an avant-garde approach fusing the capabilities of clustering random forests and support vector machines SVM to combat the intricate web of cyber threats our fusion model triumphs with a staggering accuracy of 98.67 and an equally formidable f1 score of 98.68 a testament to its effectiveness in the realm of windows malware defense by deciphering the intricate patterns within malicious code our model not only raises the bar for detection precision but also redefines the paradigm of cybersecurity preparedness this breakthrough underscores the potential embedded in the fusion of diverse analytical methodologies and signals a paradigm shift in fortifying against the relentless evolution of windows malicious threats as we traverse through the dynamic cybersecurity terrain this research serves as a beacon illuminating the path toward a resilient future where innovative fusion models stand at the forefront of cyber threat defense.

Keywords: fusion models, cyber threat defense, windows malware, clustering, random forests, support vector machines (SVM), accuracy, f1-score, cybersecurity, malicious code detection

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