System Model Research Articles

Precession of a rotor with a different number of discrete radial elastic damping supports

A design model of a rotary system in the form of a cantilevered flexible shaft with a massive unbalanced disk at the free end is considered. In the plane of rotation of the disk, point elastically damped supports are discretely located with a clearance, stabilizing the vibrations of the rotor in the supercritical zone. With the help of the introduced precession indicator, the type and direction of the precession of the rotor during interaction with the supports is analyzed. The influence of a different number of supports on the evolution of the rotor precession in the supercritical zone after the Poincare-Andronov-Hopf bifurcation is investigated. The effect of the clearance and eccentricity of the disk mass at the contact of the disk with the supports on the precession of the rotor is analyzed.

THE RESULTS OF THE COURSE ON MASTERING THE ANALYSIS OF INDICATORS OF FUTURE SPECIALISTS IN THE FORMATION OF A HEALTHY LIFESTYLE ((WHOQOL-BREF) KAZ)

It is stated that the relevance of the problem studied in this article depends on the result of the course designed to master the analysis of the indicators of future specialists in the formation of QOL ((WHOQOL-BREF) KAZ). According to the WHO, the countries of the world that followed a healthy lifestyle reached 86.9 years of life, 81.5 years for men, and 84.3 years on average. On the contrary, the death rate in the Republic of Kazakhstan in recent years was 29%, 6.77 per 1000 inhabitants. Mortality from diseases of the circulatory system was -32.7%, from cancer -7.9%, from injuries -5.3%.Due to these conditions, as a result of recent measures taken in the country, by 2025, the share of citizens living a healthy lifestyle will increase to 40%, life expectancy will increase to 75 years, non-infectious diseases will decrease to 7%, and medical rehabilitation services will increase to 75%. coverage is expected.It can be noted that the average life expectancy of people in our country is behind that of many countries in the world, and this situation needs to be studied fundamentally and applied in the economic, social and humanitarian direction in the Republic of Kazakhstan. It is necessary to find a solution to the problems of understanding the tasks of protecting the health, strengthening the body, and increasing the responsibility for improving and strengthening the health of the population. During the analysis of the results of the training program of the course, its goals and objectives are to improve the introduction and use of the KAZZ scale (WHOQOL-BREF) in the field of sports for students of higher educational institutions of the country and to form a model of the education system and the formation of a healthy lifestyle. to increase the competitiveness of teachers; to provide teachers with the necessary knowledge and methodological skills for effective formation of a healthy lifestyle among students; aimed at forming a model of healthy lifestyle formation among teachers and students of higher educational institutions of the country.

A Target Tracking Method Based on the Self-organizing Fuzzy Extended Kalman Filter for UAV

T his paper proposed a novel approach based on integrated tracking and positioning for Unmanned Aerial Vehicle (UAV) systems. In the proposed scheme, a self-organizing fuzzy Extended Kalman Filter (EKF) system was studied to track the flight trajectory of an UAV. With this goal, the control model of the UAV system with the disturbances was established based on the dynamic equation firstly. Secondly, the self-organizing Fuzzy EKF system was designed to identify and estimate the errors of the UAV position adaptively. And then, the trajectory tracking control was determined for the UAV according to the obtained errors. Finally, the proposed strategy was applied to a UAV to demonstrate the effectiveness.

Analysis of Influence of Grid-Following and Grid-Forming Static Var Generators on High-Frequency Resonance in Doubly Fed Induction Generator-Based Wind Farms

In Doubly Fed Induction Generator (DFIG)-based wind farms with Static Var Generators (SVGs), high-frequency resonance will be more like to occur when an unloaded cable is put into operation, which will threaten the stable operation of the wind farm. To address this issue, the influence of power outer loops on the impedance of grid-connected inverters is considered. Based on harmonic linearization, theoretical models for the sequence impedances of DFIGs, Grid-following (GFL) SVGs, and Grid-forming (GFM) SVGs are established. The correctness of the three models is verified by impedance scanning using the frequency sweep method. Through a comparative analysis of these sequence impedances, it is found that unlike the GFM SVG (which exhibits inductive impedance), the GFL SVG exhibits capacitive impedance in the high-frequency band, which leads to negative damping characteristics in the high-frequency band for the wind farm system with the grid-following SVG; thereby, the risk of high-frequency resonance also increases accordingly. On the contrary, GFM control adopted by SVGs can effectively eliminate the negative damping region in the high-frequency band for wind farms to suppress high-frequency resonance. Meanwhile, for grid-forming SVGs, the parameter variations in power synchronous loops have no significant impact on the suppressing effect of high-frequency resonance for wind farms. Finally, an electromagnetic simulation model for a DFIG-based wind farm system with an SVG is established using the StarSim-HIL (hardware-in-the-loop) experiment platform, and the simulation results validate the correctness of the theoretical analysis.

QUALITY MANAGEMENT SYSTEM ACCORDING WITH STANDARD ISO 9001:2015

The paper presents a review of standard ISO 9001:2015 used in quality management systems. It indicates a process approach, as recommended for thinking based on the risk, which is a basic model of the quality management system. It identifies the quality management system as an organisational tool for fulfilment of assumed objectives. Keywords:

Posisi Pasar Karet Indonesia Di Pasar Internasional

Indonesia's position as the largest rubber producing country in the world allows them to become the main exporter of natural rubber. Indonesia exports the majority of its natural rubber production to countries like Japan, India, Brazil, the United States, South Korea, China, Turkey, and others. The competition between Indonesia and other producing countries in exporting rubbers to international markets is relatively tight. The aim of this research is to analyze the position of Indonesia’s technically specified natural rubbers (TSNR) in the international market compared to other exporting countries. The analytical method used is the Almost Ideal Demand System (AIDS) Model. The data used in this research is secondary data from Indonesia, Thailand, Malaysia, Ivory Coast, Vietnam, Belgium, and Nigeria over the last 10 years (2012 – 2022). The results show that there is a tight competition between Indonesia and Thailand, Ivory Coast, Belgium, Nigeria and the Rest of the World in competing for market share of natural rubber in the international market because the relationship between Indonesia's natural rubber and these countries are substitutional. Meanwhile, Indonesia's natural rubber relationship with Malaysia is complementary. Indonesian natural rubber is a normal good, so if there is an increase in prices it will cause a decrease in demand. If there is an increase in demand for rubber exports in the international market, then the country that will benefit the most is Vietnam. Meanwhile, Indonesia is the fourth ranked country that will benefit the most if it happens.

Mesoscale eddies inhibit intensification of the Subantarctic Front under global warming

Abstract Oceanic mesoscale eddies are important dynamical processes in the Southern Ocean. Using high-resolution (~0.1○ for the ocean) Community Earth System Model (CESM-HR) simulations under a high-carbon emission scenario, we investigate the role of mesoscale eddies in regulating the response of the Subantarctic Front (SAF) to global warming. The CESM-HR simulates more realistic oceanic fronts and mesoscale eddies in the Southern Ocean than a coarse-resolution (~1○ for the ocean) CESM. Under global warming, the SAF is projected to intensify. The mean flow temperature advection intensifies the front, whereas the mesoscale-eddy-induced temperature advection and atmospheric dampening play primary (~67%) and secondary (~28%) roles in counteracting the effect of mean flow temperature advection. Our study suggests the importance of mesoscale eddies on inhibiting the SAF intensification under global warming and necessity of mesoscale-eddy-resolving simulations for faithful projection of future climate changes in the Southern Ocean.

A microvascularizedin vitroliver model for disease modeling and drug discovery.

Drug discovery for complex liver diseases faces alarming attrition rates. The lack of non-clinical models that recapitulate key aspects of liver (patho)-physiology is likely contributing to the inefficiency of developing effective treatments. Of particular notice is the common omission of an organized microvascular component despite its importance in maintaining liver function and its involvement in the development of several pathologies. Increasing the complexity of in vitro models is usually associated with a lack of scalability and robustness which hinders their implementation in drug development pipelines. Here, we describe a comprehensive liver microphysiological system model comprising stellates, liver-derived endothelial cells and hepatocytes conceived within a scalable and automated platform. We show that endothelial cells self-organize in a microvascular network when co-cultured with stellates in a hydrogel. In a tri-culture, hepatocytes polarize accordingly, with a basolateral side facing blood vessels and an apical side facing bile-canaliculi-like structures. Stellates interact and surround the hollow microvessels. Steatosis was induced by exogenous administration of fatty acids which could be prevented by co-administration of firsocostat. Administration of TGF-β resulted in an activated stellate cells phenotype which could be prevented by the co-administration of SB-431542. The model was implemented on a microtiter plate format comprising 64 chips which enabled the development of a fully automated, multiplexed fibrosis assay with a robust Z' factor suitable for high-throughput applications.

Decision Support System Model for College Kartu Indonesia Pintar (KIP) Scholarship Recipients Using the C4.5 Decision Tree Method and Simple Additive Weighting (SAW)

The KIP-Kuliah Scholarship is an Indonesian government program that is used to help high school students (SMA) or equivalent who are less capable but have academic potential in financing education in college. In this study, the problem limitation or scope of research is at Prof. DR. HAMKA Muhammadiyah University College in the Management Study Program. In each year the selection of scholarship acceptance often changes criteria, because of the frequent changes in scholarship criteria each year users often experience problems in selecting KIP-Kuliah scholarship recipients. Decision Support System (SPK) is a solution to assist in decision making. The purpose of this research is to assist in decision making in determining scholarship recipients in accordance with existing criteria. The method used in this research is using Decision Tree C4.5 to determine the weight of the KIP-Kuliah scholarship criteria and the Simple Additive Weighting (SAW) method is used to determine the ranking of scholarship recipients. In this study, researchers used 3 criteria, namely the amount of parents' income, the number of dependents, and the interview test scores. The results of the analysis of the calculations using the Decision Tree C4.5 and Simple Additive Weighting (SAW) methods and the results of the selection of college KIP scholarships consisting of the criteria for the amount of parents' income, the number of dependents and the interview test, the 12 students who deserve college KIP scholarships are students who get the highest preference scores, namely M11, M3, M6, M4, M14, M1, M5, M12, M10, M2, M7, and M9. In conclusion, the use of a Decision Support System with the Decision Tree C4.5 and Simple Additive Weighting (SAW) methods is effective in helping determine the recipients of the KIP-Kuliah scholarship in accordance with predetermined criteria.

Towards SDG Digital Quality Learning: a Conceptual DLR based Model for Online Language Encoding-Skill Enhancement

Objectives: This present research has objectives to encourage digital quality learning as part of SDG quality education through proposing a DLR-based model on Zoom and WhatsApp as the main digital learning platforms for enhancing language encoding skills, i.e. the speaking and writing skills, within online learning activities. DLR refers to digital learning resources. Method: This qualitative research model is interpretatively descriptive and digitally creative. The research design consists of a system model which consists of Input, Throughput or Process, and Output, with Zoom and WhatsApp as the main platforms, and other digital platforms as digital learning resources to support the endeavor. The Zoom main platform is mainly used for observing the spoken activities, while the other WhatsApp main platform is used for observing the written interactions or communication. Results and Discussion: The novelty or the strengths of this presently proposed DLR-based model for enhancing the learners’ speaking and writing skills are on the comprehensive surveys to include the speaking and writing tests, on the learners’ online learning independence or their flexible ways or styles of online learning, on the equally sufficient opportunities for the learners’ speaking and writing activities, and on the inclusive and encouraging roles of the digitally-literate teachers. Research Implications: The presently proposed DLR-based model is aimed at enhancing the speaking and writing skills within online learning platforms for any language learners or research subjects, not necessarily high-school teachers as the previous model suggested. Originality/Value: This conceptual DLR-based model for learning language encoding skills is, therefore, promoting the world endeavor for digital quality learning, thus encouraging the quality education within the United Nations’ 17 Goals of Sustainable Development.

Enhanced “Wind‐Evaporation Effect” Drove the “Deep‐Tropical Contraction” in the Early Eocene

AbstractThe equatorward contraction of tropical precipitation, commonly referred to as the “deep‐tropical contraction”, is witnessed in the paleoclimate simulations of the early Eocene. However, the mechanism driving this contraction is still unclear. Based on the energetics framework of the Intertropical Convergence Zone (ITCZ) and the decomposition method of the latent heat flux along with the simulations of a climate system model, CESM1.2, we proposed a novel mechanism responsible for the “deep‐tropical contraction” in the early Eocene. The greenhouse gases‐induced sea surface warming amplifies the sensitivity of evaporation to surface wind speed changes through Clausius‐Clapeyron scaling, leading to an interhemispheric asymmetric enhancement of the latent heat flux. To maintain hemispheric energy balance, the cross‐equatorial atmospheric energy transport must be reduced during the solstice seasons. As a result, the solstitial location of the ITCZ shifts equatorward, causing the “deep‐tropical contraction” in the early Eocene.

Effect of laughing therapy on level of depression among elderly

The early recognition and management of depression in the elderly in old age homes using the healthcare resources help to return them to a happier and more fulfilling life. This study investigated the effect of laughing therapy on level of depression among the elderly in selected old age homes in Thiruvananthapuram. The objectives of the study were to assess the level of depression among elderly and to find out the effect of laughing therapy on level of depression among elderly. The third objective was to find out the association of pre-test level of depression among elderly and selected demographic variables. The study was based on J.W.Kenny’s Open System Model. The research design of this study is Quasi experimental two group pre-test-post-test design. The sample consisted of 60 elderly residing in old age homes Thiruvananthapuram district. Purposive sampling was used. The instruments used in this study were the Modified Yesavage Geriatric Depression Scale and demographic proforma. The participants in the treatment group involved in laughing therapy for 30 minutes each day for 7 consecutive days and those in the control group were monitored for depression. A pre-test was given before administering the laughing therapy and a post-test was performed after 1 week. The findings revealed that in experimental group 60% had mild depression and 40% had moderate depression and in control group 46.7% had mild depression and 53.3% had moderate depression. The laughing therapy given to elderly residing in old age homes had significantly reduced their level of depression (p < 0.01) and also there was significant association between level of depression and gender and educational status. Laughing therapy is an innovative option to promote a healthy environment for elderly.

Mechanism of introduction of quality management system at the enterprises of the construction industry: case of the Republic of Kazakhstan

Purpose – The aim of the research was to apply the principles of the quality management system in order to establish a framework for implementing quality management practices within the construction industry. Research methodology – The study involved analysing the global experience of certifying enterprises according to ISO 9001 standards. The research used a qualitative approach, analysing QMS documentation, case studies, and literature to gain a comprehensive understanding of QMS implementation in established companies. Findings – It resulted in the development of a system model for introducing and implementing the quality management system in construction industry enterprises, following the ISO 9001 standard. Practical implications – The enterprises of the Republic of Kazakhstan are not exceptions from world practice, including the enterprises of the construction industry. However, there are few construction industry enterprises that would be certified according to quality management standards, including the ISO 9001 standard. Some do not have the financial and human resources to implement a quality management system, others lack understanding of where to start. Originality/Value – The study also focused on generalising and providing detailed insights into the processes involved in implementing the quality management system at construction industry enterprises.

The relative contributions of internal variability and external forcing to Pacific Walker Circulation over the last millennium

Abstract Pacific Walker Circulation (PWC) is an important component of tropical atmospheric circulation. Current studies have mainly focused on PWC changes over recent decades and the near future, while less effort has been devoted to long-term PWC variations. In this study, we investigate PWC changes over the last millennium (LM) based on the Community Earth System Model Last Millennium Ensemble (CESM-LME). The simulated PWC variations show no significant trend but do reveal decadal fluctuations during the LM, which underestimate the strengthened LIA-MCA PWC differences indicated by proxy-based reconstructions. A quantitative estimation of the contributions made to PWC variability from internal variability and external forcing is conducted by using multiple linear regression (MLR) analysis. The internal variabilities contribute approximately 80% to the changes of PWC during the LM, among which the Interdecadal Pacific Oscillation (IPO) has the largest contribution. In the positive phase of the IPO, the Indo-Pacific sea-level pressure (SLP) gradient decreases, and anomalous westerlies occur in the tropical western Pacific, corresponding to a weakened PWC. The relationships between the IPO and PWC show multidecadal to centennial fluctuations, suggesting that other internal modes or external forcings may have modulated the IPO-PWC relationship. Volcanic forcing is also an important contributor to PWC variability during the LM. The simulated PWC significantly weakens and lasts for 1-2 years after large volcanic eruptions. The El Niño-like SST pattern and the corresponding zonal SLP gradient lead to the PWC weakening following large volcanic eruptions.

Development of a Non-Linear Battery Management System Model for Lithium-Ion Batteries Using MATLAB Simulation

Abstract: This research focuses on developing a comprehensive battery model tailored for Battery Management Systems (BMS) using lithium-ion batteries. Given the increasing reliance on lithium-ion batteries in electric vehicles and portable electronic devices, this study aims to construct a non-linear battery model that accurately reflects the charging and discharging characteristics under various load conditions. The research identifies suitable characteristics of lithium-ion batteries essential for effective battery model construction. A MATLAB-Simulink approach is employed to build the model, which integrates both charging and discharging processes into a single simulation framework. This merged model enhances the existing non-linear models by offering improved accuracy in simulating battery behavior under fixed parameters. The outcome is expected to provide a reference model for future studies and applications in power management systems. Additionally, this research underscores the critical role of BMS in extending battery life and ensuring safety, making it a significant contribution to the field of energy management. The study's findings highlight the potential of the proposed model to serve as a foundation for further research and development in battery technologies.

Marine carbon sink dominated by biological pump after temperature overshoot

AbstractIn the event of insufficient mitigation efforts, net-negative CO2 emissions may be required to return climate warming to acceptable limits as defined by the Paris Agreement. The ocean acts as an important carbon sink under increasing atmospheric CO2 levels when the physico-chemical uptake of carbon dominates. However, the processes that govern the marine carbon sink under net-negative CO2 emission regimes are unclear. Here we assessed changes in marine CO2 uptake and storage mechanisms under a range of idealized temperature-overshoot scenarios using an Earth system model of intermediate complexity over centennial timescales. We show that while the fate of CO2 from physico-chemical uptake is very sensitive to future atmospheric boundary conditions and CO2 is partly lost from the ocean at times of net-negative CO2 emissions, storage associated with the biological carbon pump continues to increase and may even dominate marine excess CO2 storage on multi-centennial timescales. Our findings imply that excess carbon that is attributable to the biological carbon pump needs to be considered carefully when quantifying and projecting changes in the marine carbon sink.

Heat pump and thermal energy storage: Influences of photovoltaic, the control strategy, and price assumptions on the optimal design

Combining heat pump, thermal energy storage, and photovoltaic is a common option to increase renewable energy usage in building energy systems. While research finds that optimal system design depends on the control, design guidelines neglect an influence of (1) photovoltaic, (2) the supervisory control, and (3) prices assumptions on the design of heat pump and thermal energy storage. We analyze how these influences may impact the optimal design. To analyze possible impacts, a pre-screening approach is used to identify relevant model input combinations with a potentially high influence on the optimal design. Applying a simulation-based design optimization with a detailed building energy system model, we optimize three cases: no photovoltaic, no supervisory control, and a state-of-the-art supervisory control. Results indicate that cost optimal design does not change with photovoltaic or the supervisory control, but heat pump size increases with higher electricity prices. For the storage, maximizing the size achieves high self-sufficiency degrees, but cost optimal design changes only for selected price assumptions. Overall, we find that neglecting photovoltaic and surplus control in the system design is a valid assumption. However, price assumptions should be included to allow simple but optimal design rules in current guidelines.

Measurement of pulse current during high voltage tests using Rogowski coil with non-inverting integrator

The work is devoted to the development and modelling of the system of pulse current measurement during high-voltage tests and experiments. The proposed measurement system is based on the application of Rogowski coil with non-inverting integrator. The results of numerical modelling of the developed current measurement system are compared with the results of application of a low-inductance shunt resistor, Rogowski coil with passive RC-integrator and Rogowski coil with inverting active integrator in similar measurement systems. Various standard pulse currents including steep edge pulse (1/20 µs), large amplitude current pulse (4/10 µs), lightning pulse current (8/20 µs), switching pulse current (30/80 µs), and 1-3 ms pulse currents are modelled for the comparative test. From the simulation results, it follows that the developed Rogowski coil with the proposed non-inverting integrator has sufficiently high accuracy in a wide frequency band overlapping the frequency band of standard pulse currents in high-voltage tests.

A Multi-Sensor Fusion Underwater Localization Method Based on Unscented Kalman Filter on Manifolds

In recent years, the simplified computation of position and velocity changes in nonlinear systems using Lie groups and Lie algebra has been widely used in the study of robot localization systems. The unscented Kalman filter (UKF) can effectively deal with nonlinear systems through the unscented transformation, and in order to more accurately describe the robot localization system, the UKF method based on Lie groups has been studied successively. The computational complexity of the UKF on Lie groups is high, and in order to simplify its computation, the Lie groups are applied to the manifold, which efficiently handles the state and uncertainty and ensures that the system maintains the geometric constraints and computational simplicity during the updating process. In this paper, a multi-sensor fusion localization method based on an unscented Kalman filter on manifolds (UKF-M) is investigated. Firstly, a system model and a multi-sensor model are established based on an Autonomous Underwater Vehicle (AUV), and a corresponding UKF-M is designed for the system. Secondly, the multi-sensor fusion method is designed, and the fusion method is applied to the UKF-M. Finally, the proposed method is validated using an underwater cave dataset. The experiments demonstrate that the proposed method is suitable for underwater environments and can significantly correct the cumulative error in the trajectory estimation to achieve accurate underwater localization.

Design and Experimental Research of a Non-Destructive Detection Device for High-Precision Cylindrical Roller Dynamic Unbalance

Due to their small size and light mass, small precision cylindrical rollers present challenges in dynamic unbalance detection, including difficulties in measurement and the risk of surface damage. This paper proposes a non-destructive detection device for assessing the dynamic unbalance of small precision cylindrical rollers. The device utilizes an air flotation support method combined with resonance amplification to indirectly measure the dynamic unbalance. A dynamic model of the air flotation tooling-cylindrical roller vibration system was developed to explore the relationship between the vibration parameters of the air flotation tooling and the dynamic unbalance of the cylindrical roller. Modal analysis and harmonic response analysis were performed, revealing that the amplitude of the vibration system at resonance could be detected using the sensor. Additionally, modal testing was conducted to determine the natural frequency of the system. A non-destructive detection platform was constructed for testing the dynamic unbalance of cylindrical rollers. Microscopic observation of the roller surface before and after testing confirmed that the device successfully performs non-destructive detection of dynamic unbalance.