Number Of Slots Research Articles

Design and optimization of slot number in supercooled vapor suction in steam turbine blades for reducing the wetness

An enormous amount of the world's electricity is produced by steam power plants. The existence of a liquid phase in the steam turbine results in an efficiency drop and mechanical losses, which are very expensive due to its high price. Creating a suction slot in the stationary blade of the steam turbine for sucking the supercooled vapor and wetness fraction in the low-pressure stages of the turbine is one of the most effective methods of preserving the rotor blades against corrosion and erosion. The Eulerian-Eulerian method is employed for modeling the condensing flow. In the current research, the impact of the suction slot location and number on the surfaces of the turbine blades is investigated on condensation, total suction ratio, liquid suction ratio, average droplet radius, and condensation losses. Optimization is performed by the TOPSIS algorithm. Based on the results, the location and number of the suction slots affect the flow pattern in the turbine blade. Creating a suction slot in the optimal case has a total suction ratio of 4.1 %, which decreases the liquid suction ratio, condensation losses, and average droplet radius, respectively, by 5.28 %, 6 %, and 25 % compared to the original case.

Optimizing modular equipment in the design of multi-product reconfigurable production lines

This work addresses the problem of the design and balancing of a modular multi-product line in a reconfigurable environment. The study emphasizes the importance of modularity in the reconfigurable manufacturing systems (RMS), which allows fast, efficient, and cost-effective adaptation to changes by rearranging, moving, or removing modules. The line consists of a fixed number of modular machines arranged linearly and connected by a material handling system. Each machine has a limited number of slots for modules. The line can handle several product types per batch, and each batch requires a specific line configuration to be produced. The objective consists in identifying the minimum number of modules needed and their arrangement in different configurations to produce each product type. To solve this problem, a compact integer linear programming (ILP) formulation is initially investigated. Then an ILP reformulation, based on a decomposition approach, as well as a heuristic that uses this ILP reformulation are developed. The results demonstrate the effectiveness of the proposed methods.

Numerical Analysis of Outer-Rotor Synchronous Motors for In-Wheel E-Bikes: Impact of Number of Windings, Slot, and Permanent Magnet Shapes

This study investigates the design an electric motor propelling hubless wheel mounted on an electric bicycle (e-bike) by numerical analysis. The motor is part of an in-wheel system that uses a permanent magnet synchronous motor (PMSM) to drive the hubless wheel. This paper presents an optimized PMSM design and compares various torque-related parameters, such as cogging torque, cogging torque total harmonic distortion (THD), and ripple torque. The comparison is based on a motor design that examines the effect of different factors, including the number of windings, slot openings, permanent magnet span, and magnet thickness. The motor was modeled and analyzed with variations in the number of windings (21, 23, 25), slot openings (2.4 mm, 3.0 mm, 3.6 mm), permanent magnet span (23 mm, 25 mm, 27 mm), and permanent magnet thickness (3.5 mm, 4.0 mm, 4.5 mm). Our findings suggest that increasing the permanent magnet’s thickness leads to a higher magnetic flux density. Additionally, when the permanent magnet span exceeds 25 mm, there is a sharp increase in cogging torque THD. Based on these results, a slot opening of 3.0 mm and the use of 25 windings are considered suitable for a hubless e-bike.

Deep Reinforcement Learning for Optimizing Restricted Access Window in IEEE 802.11ah MAC Layer.

The IEEE 802.11ah standard is introduced to address the growing scale of internet of things (IoT) applications. To reduce contention and enhance energy efficiency in the system, the restricted access window (RAW) mechanism is introduced in the medium access control (MAC) layer to manage the significant number of stations accessing the network. However, to achieve optimized network performance, it is necessary to appropriately determine the RAW parameters, including the number of RAW groups, the number of slots in each RAW, and the duration of each slot. In this paper, we optimize the configuration of RAW parameters in the uplink IEEE 802.11ah-based IoT network. To improve network throughput, we analyze and establish a RAW parameters optimization problem. To effectively cope with the complex and dynamic network conditions, we propose a deep reinforcement learning (DRL) approach to determine the preferable RAW parameters to optimize network throughput. To enhance learning efficiency and stability, we employ the proximal policy optimization (PPO) algorithm. We construct network environments with periodic and random traffic in an NS-3 simulator to validate the performance of the proposed PPO-based RAW parameters optimization algorithm. The simulation results reveal that using the PPO-based DRL algorithm, optimized RAW parameters can be obtained under different network conditions, and network throughput can be improved significantly.

Influence of Slot and Pole Number Combinations on Cogging Torque in PM Machines With Interaction of Tooth Bulge and Rotor Eccentricity

Influence of Slot and Pole Number Combinations on Cogging Torque in PM Machines With Interaction of Tooth Bulge and Rotor Eccentricity

Effect of Waiting Time and Number of Slots on Vehicular Networking Employing Slotted ALOHA Protocol

Effect of Waiting Time and Number of Slots on Vehicular Networking Employing Slotted ALOHA Protocol

Heterogeneous Forgetting Rates and Greedy Allocation in Slot-Based Memory Networks Promotes Signal Retention.

A key question in the neuroscience of memory encoding pertains to the mechanisms by which afferent stimuli are allocated within memory networks. This issue is especially pronounced in the domain of working memory, where capacity is finite. Presumably the brain must embed some "policy" by which to allocate these mnemonic resources in an online manner in order to maximally represent and store afferent information for as long as possible and without interference from subsequent stimuli. Here, we engage this question through a top-down theoretical modeling framework. We formally optimize a gating mechanism that projects afferent stimuli onto a finite number of memory slots within a recurrent network architecture. In the absence of external input, the activity in each slot attenuates over time (i.e., a process of gradual forgetting). It turns out that the optimal gating policy consists of a direct projection from sensory activity to memory slots, alongside an activity-dependent lateral inhibition. Interestingly, allocating resources myopically (greedily with respect to the current stimulus) leads to efficient utilization of slots over time. In other words, later-arriving stimuli are distributed across slots in such a way that the network state is minimally shifted and so prior signals are minimally "overwritten." Further, networks with heterogeneity in the timescales of their forgetting rates retain stimuli better than those that are more homogeneous. Our results suggest how online, recurrent networks working on temporally localized objectives without high-level supervision can nonetheless implement efficient allocation of memory resources over time.

Design and heat transfer numerical analysis of high-speed continuous casting mold water slot system

The water slot structure can reduce the temperature of the mold and increase the heat transfer between the mold and cooling water. It has significant impacts on high-speed continuous casting. Therefore, a three-dimensional model of heat transfer from mold to cooling water was used to analyze the influence of water slot size on the cooling capacity of a single water slot. Then, the fluid flow, heat transfer, and solidification three-dimensional models were used to analyze the temperature distribution and cooling effect of three kinds of water slot molds and non-water slot molds. Finally, the water slot mold was designed to achieve high-speed continuous casting. The results show that to make full use of the cooling water in the water slot, the width and height of a single water slot should be less than 8 mm. Compared with the conventional mold without the water slot structure, the temperature of the mold with the water slot structure significantly decreases. The final design of the mold water slot system is as follows: the water slot width and depth are 8 mm, and the number of water slots on one side of the mold is 9. The water slots have a symmetrical distribution, and the symmetrical plane is the middle plane of the mold. The high-speed continuous casting experiment was carried out, and the casting speed can reach 4–4.5 m/min. The water slot mold in this study can be applied in the high-speed continuous casting process.

CAR PARKING SLOT DETECTION USING YOLO ALGORITHM

Finding free slots in the parking area has become a major problem that the modern society is facing nowadays, which also leads to traffic overcrowding at the parking area. As the number of vehicles are increasing at a quick pace find parking slots has become difficult. The proposed paper helps to solve the parking problem. In traditional parking system a person has to find vacant slot or a gate keeper needs to inform about the available parking slot at parking area. To address the issue, a system where the user will be able to know the number of vacant slots in a particular parking area along with total number of slots at the entrance of the parking area. As a critical component of this project, by built a car parking slot detection system which collects data from a camera at parking area. Today's most popular object detection model YOLO, is trained to achieve desired results with good precision scores at real-time speed. The model will be getting all the parking slots that are present in the parking area, to which marking boxes are drawn around for training. Real time processing is performed on the obtained data by the model to find whether the slot is vacant or occupied. Thus, it gives the information of available vacant slots to park the car at parking area. Key Words: YOLO, Object detection, Computer vision, Machine learning.

A compact and narrow-band bandpass filter based on substrate integrated waveguide and spoof surface plasmon polaritons for millimeter-wave applications

This paper presents bandpass filter (BPF) comprising substrate integrated waveguide (SIW) and spoof surface plasmon polaritons (SSPPs), achieving miniaturized size, low insertion loss in the millimeter-wave band. SIW with single-slotted SSPP structure is employing to obtain the transmission zero (TZ) at the low-frequency part, and by introducing the SIW with rhombic periodic walls to enhance the low-frequency rejection. The target passband and TZ of the high-frequency part are realized by increasing the number of etching slots. Furthermore, we innovatively incorporate nonradiative (NR) slots etched below the SSPP structure to gain high out-of-band rejection level. SIW with rhombic periodic walls and slotted SSPP structure as one unit cell is analyzed and demonstrated. Ultimately, the two SIW unit cells are cascaded together to get better out-of-band rejection characteristics and serve as our final design. To validate the proposed design, the BPF prototype is fabricated and measured, showing good electrical performance in terms of high selectivity, low loss, and compact size.

Parametric Finite Element Study on FREEDAM Beam to Column Joints with Different Details of the Haunch Slotted Holes

Parametric Finite Element (FE) simulations were performed to investigate the ultimate flexural of different configurations of friction steel beam-to-column joints equipped with FREEDAM (free from damage) dampers. The main aim of this study was to compare the effectiveness of friction dampers featuring either single or multiple slotted holes, examining how these variations influence the behavior of the joint and the devices under seismic loads. In particular, the ultimate behavior of the connection (i.e., when the device reaches its maximum stroke) was investigated to characterize the involvement of the bolts in shear, the bearing of the plates, and the yielding of the supporting components. The analysis of bolt stress states revealed significant differences influenced by the number of bolts and slots. The FE models were calibrated against the experimental results obtained within the FREEDAM RFCS Project. These insights contribute to the design and performance evaluation of steel beam-to-column joints with FREEDAM connections, in particular the detailing of the haunch slots, laying the groundwork for future research and applications.

Surface engineering and selection of materials for lunar regolith adherence characterization

As the quest for long-term lunar exploration and habitation comes closer to reality, widespread efforts are ongoing to effectively mitigate lunar dust surface contamination and infiltration. This dust is hazardous to humans and tends to adhere tenaciously to all exposed surfaces, causing performance issues and ultimately failure. While several active and passive technologies have been developed to address this challenge, assessing the performance of these technologies in the lunar environment is required. The Regolith Adherence Characterization experiment payload scheduled to be flown to the lunar surface in 2024 provides an important opportunity for this evaluation. A limited number of material testing slots were available to the NASA Langley Research Center for this mission, so it was critical to make an informed selection. Two polymers, Kapton® HN and Teflon™ FEP, a carbon fiber reinforced bismaleimide composite, and a titanium alloy, Ti–6Al–4V, were chosen to be a diverse selection of structural materials from the NASA Langley Research Center. Each material was topographically modified using laser ablation patterning. This article describes the selection, surface modification, terrestrial characterization, and performance evaluation for these passive dust mitigating materials.

Investigation of Key Parameters on Cogging Torque in Permanent Magnet Machines Based on Dominant Harmonic Contents

The investigation of design parameters on the cogging torque has been a classical and common research subject over the last few decades. Nevertheless, an accurate analysis of major contributors to the cogging component is still difficult to find in past published works. This paper aims to address this knowledge gap by identifying the dominant harmonic contents responsible for the amplitude of cogging torque. As a result, a new factor is introduced to denote the level of cogging torque, rectifying the defect of the well-known existing factor called the goodness factor. The correlations between the key parameters (i.e., pole and slot numbers, pole arc to pole pitch ratio, and slot opening to slot pitch ratio) and the cogging torque are clarified by the proposed methodology. Finally, finite element (FE) and statistical results demonstrate the validity of the proposed results. It is expected that the key findings reported in this paper will serve as a valuable reference in the field of electric machines.

A method to synthesise groove cam Geneva mechanisms with increased dwell period

The present study develops a method to synthesise the groove cam Geneva mechanism with increased dwell period. The main condition of the synthesis is to provide the desired law of motion of the wheel. Additional synthesis conditions are the limitation of the maximum pressure angle and the limitation of the minimum curvature radius of the cam profile. Unlike the conventional Geneva mechanisms, the synthesised groove cam Geneva mechanisms enable motion of the wheel due to an arbitrarily specified law, double locking of the wheel at its dwell-to-motion and motion-to-dwell transitions, absence of soft impacts in the extreme positions. The analysis shows that for the cycloidal law of motion, number of slots in range 3–15 and additional dwell coefficient in range 0–0.7, the operating time coefficient can be provided in wide range from 0.053 to 0.765. The effectiveness of the method is illustrated by numerical examples.

Design and harmonic analysis of single winding bearingless PM synchronous motor with high winding coefficient

Compared with double-winding bearingless permanent magnet synchronous motor, single-winding bearingless permanent magnet synchronous motor (SBPMSM) has the advantages of low copper loss and low failure rate. However, if the slot-pole combination of SBPMSM is not reasonably selected, the winding coefficient will be reduced, and even many advantages of the single-winding structure will be offset. In this paper, a single-winding design method based on magnetomotive force (MMF) star diagram is proposed, which can ensure high winding coefficient. The design process of the proposed single winding structure is introduced. This method can match the appropriate number of stator slots according to the number of rotor poles, and the winding phase separation design can be realized by reversing the slot number transposition. The mathematical models of the suspension force and torque of the bearingless permanent magnet synchronous motor are derived considering the magnetic field harmonics, and the 6-slot/2-pole SBPMSM and 18-slot/8-pole SBPMSM are taken as examples to analyze the magnetic field. The finite element simulation models of 6-slot/2-pole SBPMSM and 18-slot/8-pole SBPMSM are built and analyzed. Through the analysis of electromagnetic torque, suspension force and air-gap magnetic field under different magnetic fields, the general rules of main torque fluctuation and suspension force fluctuation are summarized.

Analysis of -ary tree algorithms with successive interference cancellation

AbstractWe calculate the mean throughput, number of collisions, successes, and idle slots for random tree algorithms with successive interference cancellation. Except for the case of the throughput for the binary tree, all the results are new. We furthermore disprove the claim that only the binary tree maximizes throughput. Our method works with many observables and can be used as a blueprint for further analysis.

RFID tag recognition model for Internet of Things for training room management

With the rapid development of the Internet of Things and intelligent technology, the application of Radio Frequency Identification (RFID) technology in training room management is becoming increasingly widespread. An efficient and accurate RFID system can significantly improve the management efficiency and resource utilization of the training room, thereby improving teaching quality and reducing management costs. Although RFID technology has many advantages, there are still some problems in practical applications, such as label collision and recognition of unknown labels. These issues not only affect the performance of the system but may also cause interference with actual teaching and management. This study proposes a grouping-based bit arbitration query tree algorithm and anti-collision technology to solve label collisions and reduce label recognition time in the technology. A new unknown label recognition algorithm is also proposed to improve the recognition efficiency and accuracy of identifying new unknown labels. Related experiments have shown that the recognition accuracy of the algorithm designed this time is 95.86%. Compared with other algorithms, the number of idle time slots is the smallest. When the number of queries is 1000, the algorithm has 1842 queries, and the communication complexity is the best. When the number of unknown tags is 10,000, the actual accuracy rate is 95.642%. Compared with traditional recognition algorithms, the new unknown label recognition algorithm has a smaller frame length in the same label proportion and good recognition performance. On a theoretical level, the research content on RFID technology helps to improve and develop the basic theories of the Internet of Things and intelligent recognition technology and provides solutions and application technologies for equipment management and IoT applications in training rooms. On a practical level, the research results can provide specific guidance for the management of training rooms, help solve equipment management and safety maintenance problems in practical applications, and improve the management efficiency of training rooms.

Analysis The Effect Of Magnet Structure On The Unbalance Magnetic Pull Of Fractional Slot Number Type In Permanent Magnet Machine

Within this study, the effect of magnet structure on the unbalanced magnetic draw (UMP) of fractional slot number permanent magnet machines (PMMs) was methodically investigated. The literature revealed that fractional slot number PMMs use a variety of magnet structure configurations, including radial, parallel, and hybrid arrangements. Different magnet configurations were discovered to affect the distribution of magnetic flux density, thereby impacting UMP concentrations. The effect of various magnet geometries, including arc, rectangular, and trapezoidal, on UMP was examined. Moreover, the selection of magnet materials, such as ferrite, neodymium-iron-boron, and samarium-cobalt, influenced the magnetic field distribution and UMP characteristics. Due to their particular slot and pole combinations, fractional slot number PMMs were found to be more susceptible to UMP than other PMM varieties. Unbalanced forces caused by UMP resulted in unwanted vibrations, increased noise levels, and possible machine durability issues. Numerous factors influence UMP in fractional slot number PMMs, including the number of slots and poles, the length of the stator-rotor air gap, the magnet pole breadth, and the magnet thickness. The level of UMP was affected by the interaction of these factors with magnet structure configurations.

A Novel Framed Slotted Aloha Medium Access Control Protocol Based on Capture Effect in Vehicular Ad Hoc Networks

The capture effect is a frequently observed phenomenon in vehicular ad hoc networks (VANETs) communication. When conflicts arise during time slot access, failure to access does not necessarily occur; instead, successful access may still be achieved. The capture effect can enhance the likelihood of multiple access and improve communication efficiency. The security of VANETs communication is undoubtedly the primary concern. One crucial approach to enhance security involves the design of an efficient and reliable medium access control (MAC) protocol. Taking into account both aspects, we propose a novel framed slotted Aloha (FSA) MAC protocol model. Firstly, we derive the closed-form expression for the capture probability in the Rician fading channel in this paper. Subsequently, we analyze how the number of vehicles and time slots influence the success probability of vehicle access channels as well as examine the impact of the capture effect on this success probability. Then, under constraints regarding vehicle access channel success probability, we derive optimal values for slot numbers, access times, and transmission power while proposing a comprehensive implementation method to ensure high access channel success probabilities. We verify both theoretical derivations and proposed methods through simulation experiments.

Analisis Transformasi Gender Pada Tokoh Utama Dalam Film Imperfect Sutradara Ernest Prakarsa.

Gender transformation is an effort to achieve liberation from all forms of oppression, whether structural, personal, class, skin color or international economic. The transformation discussed by the author is gender transformation which is seen based on the appearance of the female main character in the imperfect film which is caused by the work environment, family, and so on, causing the female main character to undergo a gender transformation in appearance. This research aims to ensure that development benefits and resources are directed effectively and fairly to men and women. The method used by the author in this research is a quantitative method. Quantitative method is a research method that uses a lot of numbers. Starting from the data collection process to its interpretation. Meanwhile, the research method is an in-depth and careful study of all the facts.