Speed Adjustment Research Articles

Концепція оцінки ергономічної стійкості транспортного потоку великих міст з урахуванням динамічності зміни впливових факторів

The methodological approach of forecasting the congestion of the streets of large cities, taking into account the fluctuations in the density of traffic flows and the speed of movement of cars in the flow, received further development. The methodical approach takes into account fluctuations in the dynamics of the traffic flow in the form of changes in the acceleration of the movement of cars in the flow and fluctuations in changes in the infrastructure of the road environment, which is associated with the number of traffic lights, pedestrian crossings and the number of lanes for the movement of vehicles. Through modeling, it was found that increasing the acceleration values of cars in the stream significantly increases the range of robustness. At low values of acceleration of cars, the reserve of resistance to the formation of traffic jams decreases, which negatively affects the traffic flow, there is a probability of the formation of traffic jams. The presence of fluctuations in the density of the traffic flow and the speed of movement of cars in the flow, due to changes in the acceleration of cars, allows making adjustments to the value of the robustness criterion. Adjustments can be made for different clusters of the road network, for different times of the day, and take into account the period of fluctuations. The dependences of the change in the robustness range of the traffic flow upon changing the infrastructure of the road network are given. It has been established that increasing the number of lanes and simultaneously reducing the number of traffic lights and pedestrian crossings on the controlled cluster significantly increases the stability of the movement of vehicles in the flow. Conversely, reducing the number of lanes, increasing the number of traffic lights and pedestrian crossings on the controlled cluster significantly reduces the stability of the movement of vehicles in the flow. Adjustment of density and movement speed can be performed taking into account the amplitude of oscillations. The concept of modeling and forecasting the stability of traffic flows of large cities to the formation of traffic jams is formulated. The main components of the concept, according to which such an assessment is performed step by step, taking into account the dynamics of changes in influencing factors, are substantiated. The proposed concept differs from the known ones in that it takes into account fluctuations in traffic flow parameters - the density and speed of movement of vehicles over time. Such changes are characteristic of the city's road network during "peak hours".

Development and application of power head for CBM vehicle mounted drilling rig

In order to meet the construction needs of surface coalbed methane extraction holes, cable holes, and mine surface rescue holes, a multifunctional power head suitable for coalbed methane vehicle mounted drilling rigs has been developed. The power head adopts a dual speed hydraulic motor to drive the spindle rotation through a first gear reduction, with a compact structure, high transmission efficiency, large spindle diameter, wide range of speed and torque adjustment, and spindle braking function. It can be applied to various drilling processes such as air down the hole hammer, air lift reverse circulation, and directional drilling. On site tests have shown that the power head has high capacity, efficiency, comprehensive functions, and is easy to operate, providing equipment support for efficient and safe drilling construction.

Solar and Wind Power Electric Vehicle

This project concerns a vehicle, the “Solar and Wind Power Electrical Vehicle,” whose operation is controlled using IoT. The principal purpose is to use renewable forces for vehicle movement. There is an ESP32 microcontroller that connects to two electric engines and a motor driver enabling precise commands in the structure. Furthermore, the car consists of a solar battery panel and a wind turbine providing sustainable and ecological energy production. Our main objective is to build a car that uses no oil or gas at all since it can run on something more unconventional, such as solar power, wind energy, etc.; thus, the focus of this project is on creating a green car that will not use fuel made from fossil fuels like petrol or diesel while making sure that it works using only sustainable sources of energy available today. The motor driving system integrates the ESP32 module into the motor speed adjustment circuit (MSAC), which acts as an electronic hub for both motor control signals and serial communication codes between the motor and the CPU (central processing unit) on a single chip. Remote car control using just your phone is possible because IoT connects it. When connected, the driver can have control over each motor's direction individually such that they are interconnected with the two motors by default on the driver circuit board (or the relation may occur by default). Consequently, the vehicle gets an increased capacity for navigating various surfaces more effectively this way—The two engines act as an independent supposing of its configuration. If you want it to move off the road or even on hilly ground, this car would do so easily because there is a mechanism that makes it easier for her to move on such surfaces. It is equipped with a solar panel and wind turbine, allowing the car to be powered by renewable energy from its environment. During the day, the sun charging system converts sunlight into electricity, whereas during the night the wind generator creates power from wind when there is some wind. The stored energy can be preserved in accumulators.

Changes in acceleration and deceleration factors associated with active gait speed adjustment.

[Purpose] The ability to actively adjust walking speed is fundamental and the factors enabling it should be assessed. The present study aimed to demonstrate how active gait speed is kinematically adjusted. [Participants and Methods] Walking acceleration and deceleration were evaluated in 16 healthy adults using three-axis accelerometers and surface electromyographs. The root mean square (RMS) of each axis in the center-of-gravity acceleration was calculated as an index of gait stability. Electron myograph data were obtained from images captured of the right lower muscles, and the integral value of total muscle activity per gait cycle was calculated. [Results] The RMS of each axis increased during acceleration and decreased during deceleration. The integral values of total activity of the gastrocnemius, biceps femoris, and tibialis anterior muscles increased in acceleration. In contrast, the values increased in the biceps femoris but decreased in other muscles during deceleration. [Conclusion] These results suggest that the specific kinematic mechanisms of each factor regulate the acceleration and deceleration of walking. In addition, these mechanisms and factors indicate how exercise therapy may be used in rehabilitation to improve the ability to adjust walking speed in daily life.

Efficiency of aerobic biodegradation of sugar beet distillery stillage under dissolved oxygen tension-controlled conditions.

The efficiency of aerobic biodegradation of distillery wastewater using various microbial cultures is intricately linked to process conditions. The study aimed to examine the aerobic biodegradation by a Bacillus bacteria under controlled dissolved oxygen tension (DOT) conditions as a novel approach in the treatment of sugar beet distillery stillage. The processes were conducted in a 2-L Biostat®B stirred-tank reactor (STR), at a temperature of 36°C, with aeration of 1.0 L/(L·min), and uncontrolled pH of the medium (an initial pH of 8.0). Each experiment was performed at a different DOT setpoint: 75%, 65% and 55% saturation, controlled through stirrer rotational speed adjustments. The study showed that the DOT setpoint did not influence the process efficiency, determined by the pollutant load removal expressed as COD, BOD5 and TOC. In all three experiments, the obtained reduction values of these parameters were comparable, falling within the narrow ranges of 78.6-78.7%, 97.3-98.0% and 75.0-76.4%, respectively. However, the DOT setpoint did influence the rate of process biodegradation. The removal rate of the pollutant load expressed as COD, was the lowest when DOT was set at 55% (0.48 g O2/(L•h)), and the highest when DOT was set at 65% (0.55 g O2/(L•h)). For biogenic elements (nitrogen and phosphorus), a beneficial effect was observed at a low setpoint of controlled DOT during biodegradation. The maximum extent of removal of both total nitrogen (54%) and total phosphorus (67.8%) was achieved at the lowest DOT setpoint (55%). The findings suggest that conducting the batch aerobic process biodegradation of sugar beet stillage at a relatively low DOT setpoint in the medium might achieve high efficiency pollutant load removal and potentially lead to a reduction in the process cost.

Reduction of surface defects by optimization of casting speed using genetic programming: An industrial case study

Štore Steel Ltd. produces more than 200 different types of steel with a continuous caster installed in 2016. Several defects, mostly related to thermomechanical behaviour in the mould, originate from the continuous casting process. The same casting speed of 1.6 m/min was used for all steel grades. In May 2023, a project was launched to adjust the casting speed according to the casting temperature. This adjustment included the steel grades with the highest number of surface defects and different carbon content: 16MnCrS5, C22, 30MnVS5, and 46MnVS5. For every 10 °C deviation from the prescribed casting temperature, the speed was changed by 0.02 m/min. During the 2-month period, the ratio of rolled bars with detected surface defects (inspected by an automatic control line) decreased for the mentioned steel grades. The decreases were from 11.27 % to 7.93 %, from 12.73 % to 4.11 %, from 16.28 % to 13.40 %, and from 25.52 % to 16.99 % for 16MnCrS5, C22, 30MnVS5, and 46MnVS5, respectively. Based on the collected chemical composition and casting parameters from these two months, models were obtained using linear regression and genetic programming. These models predict the ratio of rolled bars with detected surface defects and the length of detected surface defects. According to the modelling results, the ratio of rolled bars with detected surface defects and the length of detected surface defects could be minimally reduced by 14 % and 189 %, respectively, using casting speed adjustments. A similar result was achieved from July to November 2023 by adjusting the casting speed for the other 27 types of steel. The same was predicted with the already obtained models. Genetic programming outperformed linear regression.

An Energy-Efficient Adaptive Speed-Regulating Method for Pump-Controlled Motor Hydrostatic Drive Powertrains

In this paper, a closed hydrostatic drive powertrain (HSDP) composed of an engine, a variable pump, a variable motor, and an energy-efficient adaptive speed-regulating controller (ADC) based on power following is proposed and investigated. The controller can more than guarantee accurate regulation of motor speed through online efficiency estimation based on established loss models of the pump and the motor. It also facilitates the optimal efficiency control of the engine and hydrostatic system through two redundant control freedoms of the HSDP system, making an energy-saving adjustment of the motor speed. At the same time, the controller can prevent engine overload stall and high system pressure by limiting the displacement of the pumps and motors in real time based on the system loads to improve the automatic adaptability of the system to varying loads. Field testing experiments performed by means of a heavy transportation vehicle under different conditions were conducted to verify the efficacy of the proposed controller. The results showed that the average errors of motor speed were 3.3% under empty load conditions and 9.6% under heavy load conditions. In terms of energy saving, comparison tests involving a rule-based controller (RBC) and the ADC were carried out, and the results showed that the energy-saving ratio of the ADC was at least 11.5% and up to 25.8% under empty load conditions and at least 2.8% and up to 9% under heavy load conditions. The ADC controller showed good performance in terms of speed control, load adaptability, and energy saving and a superior advantage due to its simple structure and ease of implementation. Therefore, the proposed controller is an excellent choice for the real-time control of machinery with an HSDP system, especially heavy-duty machinery.

Precise Fabrication of Ocular Inserts Using an Innovative Laser-Driven CaliCut Technology: In Vitro and in Vivo Evaluation

Ocular inserts offer distinct advantages, including a preservative-free drug delivery system, the ability to provide tailored drug release, and ease of administration. The present research paper delves into the development of an innovative ocular insert using CaliCut technology. Complementing the hot melt extrusion (HME) process, CaliCut, an advanced technology in ocular insert development, employs precision laser gauging to achieve impeccable cutting of inserts with desired dimensions. Its intelligent control over the stretching process through auto feedback-based belt speed adjustment ensures unparalleled accuracy and consistency in dosage form manufacturing. Dry eye disease (DED) poses a significant challenge to ocular health, necessitating innovative approaches to alleviate its symptoms. In this pursuit, castor oil has emerged as a promising therapeutic agent, offering beneficial effects by increasing the thickness of the lipid layer in the tear film, thus improving tear film stability, and reducing tear evaporation. To harness these advantages, this study focuses on the development and comprehensive characterization of castor oil-based ocular inserts. Additionally, in-vivo irritancy evaluation in rabbits has been undertaken to assess the inserts' safety and biocompatibility. By harnessing the HME and CaliCut techniques in the formulation process, the study demonstrates their instrumental role in facilitating the successful development of ocular inserts.

A High-Precision Planar NURBS Interpolation System Based on Segmentation Method for Industrial Robot

NURBS curve parameter interpolation is extensively employed in precision trajectory tasks for industrial robots due to its smoother performance compared to traditional linear or circular interpolation methods. The trajectory planning systems for industrial robots necessitate four essential functional modules: first, the spline curve discretization technique ensuring chord error compliance; second, the contour scanning technique for determining the maximum feasible feed rate for multi-constraint and multi-segment paths; third, the technique for achieving a smooth feed rate profile; and fourth, the continuous curve parameter interpolation technique. Therefore, this paper proposes a high-precision planar NURBS interpolation system for industrial robots. Firstly, a segmentation method for NURBS curves based on a closed-loop chord error constraint is proposed, which segments the original global NURBS curve into a collection of Bezier curves that strictly meet the chord error constraint. Secondly, a bidirectional scanning technique is presented to meet the joint space constraint, establishing an analytical mapping between the tool tip kinematic constraint and the joint kinematic constraint. Then, based on the traditional S-shaped feed rate profile, an adaptive algorithm with a displacement constraint is introduced, considering the real-time speed adjustment requirements of robots. Finally, a compensation interpolation strategy based on arc length parameterization is adopted to solve the accumulated error problem in parameter interpolation. The effectiveness of and potential for enhancing the quality of planar machining of the proposed planar NURBS interpolation system for industrial robots are validated through simulations and experiments. The results demonstrate the system’s applicability and accuracy, and its ability to improve planar machining quality.

Modified Buck Boost DC-DC Converter with Hyeteresis Band on Ocean Wave Emulator

Indonesia has the potential of sea wave energy with the second largest coastline having a density of up to 20 kW / m2. Currently, the use of sea wave technology is still at the prototype stage, with several weaknesses such as erratic sea waves, tides and ocean currents so that they can affect the power generated in ocean wave energy. The results of ocean wave energy in mechanical arrays cannot be utilized because of erratic waves. The higher the wave, the greater the power generated and vice versa. If this problem is not resolved, it can cause unstable power output and cause damage to electronic equipment. The solution to this problem is to modify the DC-DC buck boost converter circuit using the Hyeteresis band method, which limits voltage surges below or above to produce the desired voltage in order to maintain constant power and as energy for storage in the storage system. The result of this study is that the performance of DC generators in producing voltage is greatly influenced by speed. At low speeds, the voltage produced by the generator is still too low to charge the battery or in other words cannot be in a perfect charging position, while at maximum speed it produces voltage with Achieve a level sufficient for battery charging. Therefore, control and adjustment of generator speed is key in maximizing battery charging efficiency using a buck-boost converter.

Model of Multi-Parameter Optimization of the Characteristics of a Cable Car in a Solid Waste Transportation System

Introduction. Modern scientific and applied literature examines the problems of cable cars functioning quite thoroughly. First of all, it concerns ensuring the reliability and safety of traffic, both during operation and during project development. In addition, the paper considers the relationship of cable cars with the environment and the level of environmental load from this type of transport. A good solution could be the use of mathematical models that can take into account a set of parameters and criteria that characterize the cable car as a system. The same approach would be useful for optimizingtechnical characteristics of the object. However, there is no description of such a solution in the literature. This gap is partially filled by the presented work. The study aims to create a model of multivariable optimization of cable car technical characteristics for the transportation of municipal solid waste (MSW). Material and Methods. To clarify the theoretical basis, the literature describing the problems of cable cars and their solutions in general has been studied. Mathematical calculations were justified by a volume of equations that proved their adequacy in determining the useful transport work, load, adjustment of time and speed of cargo movement and other significant parameters of the system under study. When forming the model, we proceeded from the principles of L. S. Pontryagin (needle variation) and Hamilton — Ostrogradsky (kinematics of a certain road segment). Text data about the features of the system elements and their interaction were summarized in tables. The main calculations results were visualized in the form of graphs. Results. The solution to the problem of optimal control of the cable car on which solid waste was moved was presented. The motion control vector was shown as a vector of optimized technical parameters of the system: speed of movement, rope tension, number and weight of containers. The well-known solution to the optimization problem was reproduced in a general form, which involved determination of a control vector function and its corresponding trajectory with the achievement of a minimum of the target functional. The weak point of the system of differential equations for the realization of the goals of this scientific work was noted. In this regard, it was proposed to consider the investigated section of the cable car as a dynamic system with distributed parameters. The formulation of the multi-criteria optimization problem was described in detail. The advantages of reducing the number of criteria taken into account were listed and the use of the reduction method, which was based on the hierarchical structuring of the system of partial optimality criteria, was justified. Four main elements of the municipal solid waste (MSW) transportation system were considered in interrelation. This was a cable car, a transport and logistics point, a transport and logistics terminal and an environment that generated solid waste. Within the framework of this work, we considered an urbanized environment. The sub-elements of the named elements were listed and 12 directions of their interactions were shown. In detail, within the framework of a three-level hierarchy, four main complex indicators of the complexity of the system under study were described: environment, road, point and terminal. The solution of a multi-criteria optimization problem was shown, calculations were performed for the optimized parameters — the characteristic of the complexity of the road and the characteristic of the terrain. The results of calculations were presented in the form of graphs. Thus, the dependences of the optimized parameters on the weight of the loaded container, the length and speed of the cable car were illustrated. Conclusions. The main result of the study is an idea of the possibility of a mathematical solution of a multivariable and multi-criteria problem of optimizing two characteristics of a cable car (complexity and terrain feature). The proposed approach allows you to change the hierarchy in the complex of indicators. The results of this scientific work can be used, if necessary, to integrate the road project with neural network models, to work with fuzzy linguistic indicators, to solve applied problems.

Comparative research on the speed performance of Axial flux Permanent Magnet Generator (PMG)165 with manufacturing specification and experimental for implementation in the Low-Speed Wind Turbine System

This paper is on working on energy assessment of generator’s voltage, current and power output based on the generator speed. Today, demand of power is increasing because of technology advancement and increasing electrical devices being manufactured and installed. For this reason, the generator applied in renewable energy is recommended. It must be improved because it is an important component inside the energy system in producing enough power. This research is used the DC Motor function as prime mover and direct shaft to the shaft connection of AFPM165. The parameters of the investigational research are generator speed (rpm), DC current value form generator output (Amp), and voltage value (V). The speed of DC Motor has been gradually increases, from 0 ∼ 300 rpm by adjusted speed adjustment knob. The series circuit 15-ohm resistor and 5 Watts lamp to make it total 19-ohm constant as a load. The result is presented that the more speed of generator, the more voltage, and current it can be inducted. The findings of the study are presented that there is a difference between the factory specification and the experiment where the experimental value is more than the factory specification value which is 11.43% variation.

HeartWare Left Ventricular Assist Device Exercise Hemodynamics With Speed Adjustment Based on Left Ventricular Filling Pressures.

Functional capacity remains limited in heart failure patients with left ventricular assist devices (LVADs) due to fixed pump speed and inability to offload the left ventricle adequately. We hypothesized that manually adjusting LVAD speed during exercise based on pulmonary capillary wedge pressures would increase total cardiac output and maximal oxygen consumption. Two participants with a HeartWare LVAD underwent an invasive ramp study at rest followed by an invasive cardiopulmonary stress test exercising in two randomized phases: fixed speed and adjusted speed. In the latter phase, speed was adjusted every 1 minute during exercise at ±20 rpm/1 mm Hg change from baseline pulmonary capillary wedge pressure. There was no difference in maximal oxygen consumption between the two phases, with a modest increase in total cardiac output during speed adjustment. Filling pressures were initially controlled during speed adjustment until speed was capped at 4,000 rpm, at which point filling pressures increased. Blood pressure was variable. The pressure across the head of the pump (ΔP) was higher with speed adjustment. Contrary to our hypothesis, LVAD speed adjustment during exercise did not improve total cardiac output and functional capacity. This variable response may be attributed to the native cardiac reserve and baroreceptor response; however, additional studies are needed.

Optimasi Kenyamanan Suhu Ruangan Melalui Perancangan Otomatisasi Kipas Angin di Masjid Nurhidayatullah Maguwoharjo

This research explores a solution to optimise room temperature comfort in Masjid Nurhidayatullah Maguwoharjo. Mosques are susceptible to temperature and humidity fluctuations, which can affect the worship experience of congregants. To address this challenge, the study developed an automated fan system that dynamically responds to environmental changes, such as temperature and congregation density, using DHT22 temperature and PIR sensors to monitor these parameters. The results indicate that the system effectively maintains temperature and humidity within predefined comfort ranges. Additionally, the study incorporated the TM1637 module and LCD I2C 20x4 display to provide users with temperature, humidity, fan speed, and room capacity information. During testing, temperature and humidity fluctuations throughout the day were recorded, along with changes in congregation density during prayer times. The fan speed adjustment results were reflected in the system's responsiveness to environmental conditions. This research successfully provides an effective solution to enhance comfort in mosques. Therefore, it makes a valuable contribution to the development of automation systems aimed at improving the congregational worship experience and energy efficiency in mosques.

Impact of federated deep learning on vehicle-based speed control in mixed traffic flows

This study investigates the application of Federated Learning (FL) in an environment of mixed traffic flow with Connected and Automated Vehicles (CAVs). The focus of this study is set on the CAV cruise control speed adjustment which is enforced by the Intelligent Speed Adaptation (ISA) system. It is modelled as an Actor-Critic-based learning architecture with the goal of computing the vehicle speed based on the data of the nearby vehicles. Some CAVs achieve poor travel time performance in comparison to others. Thus, the proposed FL framework selects periodically best-performing CAVs which are local clients in the context of FL. The updated global model is computed based on the weighted averaging of the best-performing models of clients. The use case environment is modelled as a simulation of a synthetic motorway with an induced capacity drop in the form of a work-zone under moderate and high traffic demand. It is shown that the FL framework can stabilise the individual client learning convergence and reduce their travel time compared to the local learning approach. The overall motorway throughput is also increased by the proposed FL framework. This indicates that the global model of FL can utilise the optimal ratio between generalisation and bias towards the most effective control policy of individual speed control. Results show that those effects are more prominent under moderate traffic demand.

Scaling strategy for cell and gene therapy bioreactors based on turbulent parameters.

So far, power input has been used as the main parameter for bioreactor scale-up/-down in upstream process development and manufacturing. The rationale is that maintaining a consistent power input per unit volume should result in comparable mixing times at different scales. However, shear generated from turbulent flow may compromise the integrity of non-robust cells such as those used during the production of cell and gene therapies, which may lead to low product quality and yield. Of particular interest is the Kolmogorov length parameter that characterizes the smallest turbulent eddies in a mixture. To understand its impact on scale-up/-down decisions, the distribution of Kolmogorov length along the trajectory flow of individual particles in bioreactors was estimated in silico with the help of computational fluid dynamics simulations. Specifically, in this study the scalability of iPSC-derived lymphocyte production and the impact of shear stress across various differentiation stages were investigated. The study used bioreactors of volumes from 0.1 to 10 L, which correspond to the scales most used for parameter optimization. Our findings, which align with in vitro runs, help determine optimal agitation speed and shear stress adjustments for process transfer between scales and bioreactor types, using vertically-oriented wheel and pitched-blade impellers. In addition, empirical models specific to the bioreactors used in this study were developed. The provided computational analysis in combination with experimental data supports selection of appropriate bioreactors and operating conditions for various cell and gene therapy process steps.

Design and performance of a distributed electric drive system for a series hybrid electric combine harvester

In order to solve the problems of high energy consumption, high pollution and difficult adjustment of operational parameters caused by the coupling of operating components of conventional combine harvester, a novel series hybrid electric combine harvester (SHECH) is proposed. This paper is based on series hybrid power technology and distributed electric drive technology. The balance between SHECH energy consumption and endurance is coordinated by a range-extender and power battery with components decoupled by independent multi-motor driving. The mathematical models of SHECH operating components are established and the power system parameters are designed according to the operational requirements. Furthermore, the dynamic performance, performance of components and fuel economy of SHECH are analysed. Simulation results indicate that SHECH can recover 7.50% of battery state of charge during a single unloading operation, and the maximum operating area in pure electric mode is approximately 10,000 m2. This not only ensures operational performance but also effectively reduces fuel consumption. A hardware in the loop test was carried out to verify the power performance and the function of energy management system of SHECH. In addition, SHECH greatly simplifies the drive system and improves power transmission efficiency compared to conventional combine harvesters. Moreover, the function of independent operation of each component provides the basis for realising the speed adjustment of each key component as required. It provides a new idea for the research of improving harvester operation performance, and further expand space for strengthening the intelligence and adaptability of combine harvesters.

Pumping for Two: Pregnancy in Patients Supported With a Left Ventricular Assist Device.

This review discusses the challenges and outcomes associated with pregnancy during left ventricular assist device (LVAD) support. Women account for a third of the heart failure population in the United States. Left ventricular assist devices have emerged as a safe and effective treatment option for patients with advanced heart failure. Pregnancy during LVAD support can occur, and it presents significant risks to both mother and fetus, including hemodynamic stress, thrombotic events, medication-associated teratogenicity, and uterine impingement. This literature review identified 10 cases of confirmed pregnancy during LVAD support, of which eight resulted in successful births. Maternal and fetal mortality occurred in one case, and there was a spontaneous abortion in one case. The review highlights the importance of a multidisciplinary approach, promotion of shared decision-making, thoughtful anticoagulation, adjustment of LVAD speed, and medication optimization to maintain hemodynamic support during pregnancy. Hemodynamic changes during pregnancy include increased cardiac output, heart rate, and plasma volume, as well as decreased systemic vascular resistance, which can impact LVAD support. Despite reduced pulsatility in LVAD-supported patients, ovulation and reproductive capacity might be preserved, and viable pregnancies may be achieved with appropriate management. The review provides insights into the risks and considerations for a viable pregnancy during LVAD support, including the need for ongoing research to inform joined decision-making.

Study on dynamic control system of tunnel variable air volume ventilation based on first-order delay and predictive compensation control model

Using a variable air volume ventilation system is an efficient way to save energy in the tunnel. To address the issues of low control parameter accuracy and high operating energy consumption, the transient flow field and ventilation resistance characteristics were analyzed using conservation equations, and the first-order delay mathematical model of tunnel ventilation control was established by taking tunnel and jet fan parameters into account. The airflow dynamic control model's related parameters and transfer function were also solved. The overshoot, steady value, and adjustment time of the control system were evaluated using simulation and experiment. In full-scale experiments, the required wind speed was converted into the frequency of the jet fans to achieve variable air volume ventilation control. The results show that the variable air volume ventilation control system has the characteristics of nonlinear, and the first-order delay time transfer function is related to the 1/2-th power of ventilation resistance and pressure. The control system performs well, and the response parameters are all within the error range. Moreover, the discussion results of the comparative tests also illustrated that the purpose of dynamic wind speed adjustment could be achieved through frequency conversion control.

A Catalogue of Deconfliction Actions Extracted from Historical ADS-B Data

A conflict in Air Traffic Management is defined by a potential future risk of loss of separation. To solve a conflict, air traffic controllers take proactive actions to ensure safe separations between aircraft. They issue specific instructions to pilots for corrective measures, such as lateral manoeuvres, changes in altitude or speed adjustments. To alleviate the workload of controllers, the conflict detection and resolution process can be automated, resulting in recommendations for efficient manoeuvres. Traditional conflict resolution algorithms often neglect factors inherent to controllers' decision-making, leading to seemingly impractical manoeuvre suggestions from a human standpoint, causing reluctance in acceptation among controllers. The aim of our research is to obtain a catalogue of prevalent deconfliction practices, incorporating controllers' uncertainty models derived from actual flight data. In the current contribution, we focus on lateral deconfliction manoeuvres in en-route air traffic, and implement a simple heuristic method to extract a catalogue of resolved conflict situations from historical ADS-B data. This catalogue will provide insights into controllers' decision-making processes. In future works, we intend to use this catalogue to identify the best practices for traffic deconfliction, taking into account human factors and operational uncertainties, and to incorporate them into conflict resolution algorithms.