High-throughput and low-latency sorting is a key requirement in many applications that deal with large amounts of data. This paper presents efficient techniques for designing high-throughput, ...low-latency sorting units. Our sorting architectures utilize modular design techniques that hierarchically construct large sorting units from smaller building blocks. The sorting units are optimized for situations in which only the M largest numbers from N inputs are needed, because this situation commonly occurs in many applications for scientific computing, data mining, network processing, digital signal processing, and high-energy physics. We utilize our proposed techniques to design parameterized, pipelined, and modular sorting units. A detailed analysis of these sorting units indicates that as the number of inputs increases their resource requirements scale linearly, their latencies scale logarithmically, and their frequencies remain almost constant. When synthesized to a 65-nm TSMC technology, a pipelined 256-to-4 sorting unit with 19 stages can perform more than 2.7 billion sorts per second with a latency of about 7 ns per sort. We also propose iterative sorting techniques, in which a small sorting unit is used several times to find the largest values.
This study elaborates upon a new modular split‐tooth permanent magnet‐assisted switched reluctance motor (MSTPM‐SRM). In the proposed topology, the stator comprises six modular E‐cores in which the ...middle poles are split into two teeth. Two permanent magnets (PMs) are placed between each module's middle and side poles. Primarily, the proposed topology is introduced. Next, the principle of operation of the proposed topology are elucidated, and the magnetic equivalent circuit analysis is adopted in order to validate the operational basics. It is proved that the embedded PMs significantly increase the air‐gap's flux density and adjusts the poles' flux density. The flux density distributions, static, and steady‐state characteristics of the proposed MSTPM‐SRM motor and its PMless counterpart are extracted by utilising 2‐D finite element analysis. It is illustrated that the average torque of the proposed MSTPM‐SRM is dramatically increased compared to its PMless counterpart, especially at high excitation currents. Furthermore, the cogging torque analysis is done and it is shown that the proposed structure has approximately zero cogging torque. Finally, a prototyping version of the proposed motor is fabricated, and the experimental results are elicited. It is shown that the experimental results endorse the simulation results.
This paper elaborates upon a new modular split‐tooth permanent magnet‐assisted switched reluctance motor. In the proposed topology, the stator comprises six modular E‐cores in which the middle poles are split into two teeth. The results show that the proposed structure dramatically increases the average torque of the motor.
Permanent magnets (PMs) have been widely used in different types of electrical machines to improve their performance. This article introduces a novel multi-tooth hybrid-excited switched reluctance ...motor (MT-HESRM) with PMs placed between the end teeth of the adjacent modules. Thanks to the innovative method of embedding PMs, a unique design is developed. First, the operating principle of the motor is explained, and the magnetic circuit model of the motor is analyzed. The magnetic characteristics in terms of flux density, flux linkage, inductance, and torque are obtained and compared with those of its PM-less counterpart. The mathematical model of the reluctance and PM torques is presented. The reluctance and PM torques are decoupled using the finite-element analysis, and the torque contribution of the PMs is discussed. The steady-state operations of both motors with both current chopping and single-pulse controls are analyzed and compared under different speeds. Finally, both motors are manufactured, the laboratory tests are done, and the experimental results are extracted. Both the simulation and test results elucidate that the MT-HESRM, which has only three small PMs as auxiliary flux sources, has unique features in terms of high output power and torque with a negligible cogging torque.
In this article, a novel exterior-rotor multiple teeth enhanced-torque switched reluctance motor (SRM) is proposed, which exploits permanent magnets (PMs) inside the end teeth of the neighboring ...stator poles. First, the topology of the proposed motor, namely PM-SRM, is introduced and its working principle is illustrated. Then, based on the magnetic equivalent circuit (MEC) of the motor, it is proven that the PMs contribute to increase the air-gap flux density and regulate the stator poles flux density. As a result, the output torque of the motor is increased as well. The electromagnetic analyses of the proposed PM-SRM are performed using 3-D finite-element analysis. To validate the improved performance of the proposed PM-SRM, it is compared with its PMless counterpart and a classical 12/10-pole SRM in terms of the output torque and power, losses, and efficiency. It is shown that the proposed motor outperforms the two compared motors in terms of the output power and torque, and efficiency. Finally, a prototype of the motor is fabricated and tested to evaluate the predicted results. Both simulation and experimental results demonstrate the high torque and power production capability of the proposed PM-SRM.
A comprehensive study on divided-teeth permanent-magnet assisted outer-rotor switched reluctance motors (SRMs) is carried out. Foremost, it looks into the impact of the number of teeth per stator ...pole. The average and maximum torque profiles of the compared structures are obtained using finite-element simulations. It is shown that as the number of teeth increases, higher torque is obtained. Then, six small PMs are inserted inside the teeth of neighbouring modules to form new hybrid reluctance motors (HRMs). The four permanent-magnet assisted SRMs are compared in terms of the average and maximum torques using finite-element simulations. Based on the comparison results, the 48/50 HRM is selected as the best candidate among all compared SRMs and HRMs. The magnetic flux density distributions, static torque, and flux linkage characteristics of the proposed HRM are obtained. Moreover, the cogging torque profile of the motor is obtained, which approximates to zero. Next, the steady-state performances of the proposed HRM are obtained under low- and high-operating speeds. Finally, a prototype of the machine is constructed and the test results are obtained and compared with those of the simulations, which show that there is a good agreement between these results.
This article proposes an enhanced-torque switched reluctance motor with two sets of permanent magnets (PM-SRM) embedded inside the stator yoke and the end teeth of the neighboring modules. The PMs ...contribute to intensify the air-gap flux density and reduce the magnetic saturation in the stator poles. As a result, the output torque can be enhanced to a significant extent. The working principle of the proposed PM-SRM is clarified using its magnetic circuit model (MCM). The characteristics of the PM-SRM are obtained and compared with classical 12/8 and 6/5 SRMs and hybrid reluctance motors (HRMs) in terms of static and average torque and average torque per PMs volume. The steady-state performance of the PM-SRM in terms of current and torque waveforms is carried out, and the PM-SRM is compared with considered SRMs and HRMs in terms of output torque, power, and efficiency. All the comparisons demonstrate the out-performance of the proposed PM-SRM over other SRMs and HRMs. To validate the simulation results, a prototype of the PM-SRM is manufactured and the experimental results are obtained. Both the simulation and experimental results are indicative of the fact that the proposed PM-SRM can gain high torque and high PM utilization factor, simultaneously.
An experimental study was conducted to investigate the effect of conical bluff bodies on the flame dynamics and emissions from a natural gas/air swirl burner. Three bluff bodies (a disc, a 130° cone, ...and an 80° cone) were positioned above burner’s outlet to influence the flame dynamics and optimize emissions. The swirl burner performance in lean premixed combustion condition was evaluated at a constant swirl number of 0.87 at 0.65–0.90 equivalence ratios. The flame height and width were increased in the experiments with conical bluff bodies compared to the disc shape. Also, 130° and 80° bluff bodies enhanced the chemiluminescence of all species, as well as the uniformity of the thermal field by distributing the reaction zone. In particular, the bluff bodies impacted the flame dynamics and resulted in decreased
NO
x
formation by a minimum of 12.79% and 19.13% and increased
CO
emissions by 22.71% and 14.18% for 130° and 80° cone bluff bodies, respectively. The equivalence ratios of blow-off and lift-off reduced and increased with conical bluff bodies compared to the disc shape, respectively. The results suggest that the conical shapes diminish the central recirculation zone (CRZ) that is responsible for a concentrated reaction zone above the burner outlet. A weaker CRZ reduces the temperature of the burner bluff body and resolves the concentrated reaction zone to reduce
NO
x
formation. The cone angle of the bluff body can be utilized as an optimization tool to adjust emissions and increase operational lifetime of swirl burners in industrial combustion systems.
Purpose. This study aimed to (1) assess the levels and associations of workplace spirituality (WPS), compassion satisfaction (CS), burnout (BO), and secondary traumatic stress (STS) among Iranian ...nurses; and (2) identify the impact of WPS components on CS, BO, and STS while controlling for demographic variables. Design and Methods. In this descriptive, cross‐sectional, and correlational study, 295 nurses were selected via proportionate stratified sampling from five hospitals affiliated with the Arak University of Medical Sciences in Iran from June 2022 to December 2022. The scale of workplace spirituality and Professional Quality of Life version 5 (ProQOL-5) were used for data collection. Data were analyzed using SPSS24 and descriptive and inferential statistics (Pearson correlation coefficient and multiple regression). Findings. The mean scores of WPS, CS, BO, and STS were 63.27, 36.55, 27.31, and 29.58, respectively. The highest percentages of nurses reported moderate CS, BO, and STS levels, reaching rates of 76.3%, 80%, and 86.1%, respectively. The Pearson correlation coefficient showed that CS had a negative relationship with BO and STS. There was a direct correlation between BO and STS. Participants who reported higher levels of WPS had higher CS and lower BO scores. Results of multiple regression analyses indicate that the model of WPS components and control variables explains 42.7, 34, and 8.6 percent of the variance of CS, BO, and STS, respectively. Higher “meaningful work” is associated with higher CS and lower BO and STS among nurses. Participants higher in “sense of community” had higher CS scores. Higher “alignment with organizational values” is associated with higher STS. Practice Implications. According to the study results, it is possible to provide a suitable platform for improving nurses’ professional quality of life by strengthening workplace spirituality.
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