To see the other types of publications on this topic, follow the link: Single and dual component systems.
Journal articles on the topic 'Single and dual component systems'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Single and dual component systems.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Nijboer, Menno, Jelmer Borst, Hedderik van Rijn, and Niels Taatgen. "Contrasting single and multi-component working-memory systems in dual tasking." Cognitive Psychology 86 (May 2016): 1–26. http://dx.doi.org/10.1016/j.cogpsych.2016.01.003.
Full text
2
Yuan, Shibo, Peng Li, and Bin Wu. "Towards Single-Component and Dual-Component Radar Emitter Signal Intra-Pulse Modulation Classification Based on Convolutional Neural Network and Transformer." Remote Sensing 14, no. 15 (August 1, 2022): 3690. http://dx.doi.org/10.3390/rs14153690.
Full textAbstract:
In the modern electromagnetic environment, the intra-pulse modulations of radar emitter signals have become more complex. Except for the single-component radar signals, dual-component radar signals have been widely used in the current radar systems. In order to make the radar system have the ability to classify single-component and dual-component intra-pulse modulation at the same period of time accurately, in this paper, we propose a multi-label learning method based on a convolutional neural network and transformer. Firstly, the original single channel sampled sequences are padded with zeros to the same length. Then the padded sequences are converted to frequency-domain sequences that only contain the amplitude information. After that, data normalization is employed to decrease the influence of amplitude. After radar signals preprocessing, a designed model which combines a convolutional neural network and transformer is used to accomplish multi-label classification. The extensive experiments indicate that the proposed method consumes lower computation resources and has higher accuracy than other baseline methods in classifying eight types of single and thirty-six types of dual-component intra-pulse modulation, where the overall accuracy and weighted accuracy are beyond 90%.
3
FELDMAN, JOEL, HORST KNÖRRER, and EUGENE TRUBOWITZ. "SINGLE SCALE ANALYSIS OF MANY FERMION SYSTEMS PART 2: THE FIRST SCALE." Reviews in Mathematical Physics 15, no. 09 (November 2003): 995–1037. http://dx.doi.org/10.1142/s0129055x03001783.
Full textAbstract:
The first renormalization group map arising from the momentum space decomposition of a weakly coupled system of fermions at temperature zero differs from all subsequent maps. Namely, the component of momentum dual to temperature may be arbitrarily large — there is no ultraviolet cutoff. The methods of Part 1 are supplemented to control this special case.
4
Pektezel and Acar. "Energy and Exergy Analysis of Combined Organic Rankine Cycle-Single and Dual Evaporator Vapor Compression Refrigeration Cycle." Applied Sciences 9, no. 23 (November 21, 2019): 5028. http://dx.doi.org/10.3390/app9235028.
Full textAbstract:
This paper presents energy and exergy analysis of two vapor compression refrigeration cycles powered by organic Rankine cycle. Refrigeration cycle of combined system was designed with single and dual evaporators. R134a, R1234ze(E), R227ea, and R600a fluids were used as working fluids in combined systems. Influences of different parameters such as evaporator, condenser, boiler temperatures, and turbine and compressor isentropic efficiencies on COPsys and ƞex,sys were analyzed. Second law efficiency, degree of thermodynamic perfection, exergy destruction rate, and exergy destruction ratio were detected for each component in systems. R600a was determined as the most efficient working fluid for proposed systems. Both COPsys and ƞex,sys of combined ORC-single evaporator VCR cycle was detected to be higher than the system with dual evaporator.
5
Rao, A. D., and G. S. Samuelsen. "A Thermodynamic Analysis of Tubular Solid Oxide Fuel Cell Based Hybrid Systems." Journal of Engineering for Gas Turbines and Power 125, no. 1 (December 27, 2002): 59–66. http://dx.doi.org/10.1115/1.1499728.
Full textAbstract:
The goals of a research program recently completed at the University of California, Irvine were to develop analysis strategy for solid oxide fuel cell (SOFC) based systems, to apply the analysis strategy to tubular SOFC hybrid systems and to identify promising hybrid configurations. A pressurized tubular SOFC combined with an intercooled-reheat gas turbine (SureCell™ cycle) is chosen as the base cycle over which improvements are sought. The humid air turbine (HAT) cycle features are incorporated to the base cycle resulting in the SOFC-HAT hybrid cycle which shows an efficiency of 69.05 percent while the base cycle has an efficiency of 66.23 percent. Exergy analysis identified the superior efficiency performance of the SOFC component. Therefore, an additional cycle variation added a second SOFC component followed by a low pressure combustor in place of the reheat combustor of the gas turbine of the SOFC-HAT hybrid. The resulting dual SOFC-HAT hybrid has a thermal efficiency of 75.98 percent. The single SOFC-HAT hybrid gives the lowest cost of electricity (3.54¢/kW-hr) while the dual SOFC-HAT hybrid has the highest cost of electricity (4.02¢/kW-hr) among the three cycles with natural gas priced at $3/GJ. The dual SOFC-HAT hybrid plant cost is calculated to be significantly higher because the fraction of power produced by the SOFC(s) is significantly higher than that in the other cases on the basis of $1100/kw initial cost for the SOFC. The dual SOFC-HAT hybrid can only be justified in favor of the single SOFC-HAT hybrid when the price of natural gas is greater than $14/GJ or if a severe carbon tax on the order of $180/ton of CO2 is imposed while natural gas price remains at $3/GJ.
6
Wang, Yunheng, Jidong Gao, Patrick S. Skinner, Kent Knopfmeier, Thomas Jones, Gerry Creager, Pamela L. Heiselman, and Louis J. Wicker. "Test of a Weather-Adaptive Dual-Resolution Hybrid Warn-on-Forecast Analysis and Forecast System for Several Severe Weather Events." Weather and Forecasting 34, no. 6 (November 12, 2019): 1807–27. http://dx.doi.org/10.1175/waf-d-19-0071.1.
Full textAbstract:
Abstract A real-time, weather adaptive, dual-resolution, hybrid Warn-on-Forecast (WoF) analysis and forecast system using the WRF-ARW forecast model has been developed and implemented. The system includes two components, an ensemble analysis and forecast component, and a deterministic hybrid three-dimensional ensemble–variational (3DEnVAR) analysis and forecast component. The goal of the system is to provide on-demand, ensemble-based, and physically consistent gridded analysis and forecast products to forecasters for making warning decisions. Both components, the WRF-DART system with 36 ensemble members and the hybrid 3DEnVAR system, assimilate radar data, satellite-retrieved cloud water path, and surface observations at 15-min intervals with dual-resolution capability. In the current hybrid configuration, one-way coupling of the two analysis systems is performed: ensemble covariances derived from the WRF-DART system are incorporated into the hybrid 3DEnVAR system with each data assimilation (DA) cycle. This study examines deterministic, 3-h forecasts launched from the hybrid 3DEnVAR analyses every 30 min for three severe weather events in 2017. The performance of the deterministic component is evaluated for four configurations: dual-resolution coupling, single-resolution coupling, forecasts initialized using a cloud analysis for reflectivity assimilation, and forecasts initialized from the WRF-DART ensemble mean. Quantitative and subjective evaluation of composite reflectivity and updraft helicity (UH) swath forecasts for the three events indicate that the dual-resolution strategy without the cloud analysis performs best among the four configurations and provides the most realistic prediction of reflectivity patterns and UH tracks.
7
Hwang, Seon-Ik, Seong-Hyeon Cho, Jun-Hyung Jung, and Jang-Mok Kim. "Phase Current Measurement Method of Dual Inverter-Motor Drive System Using a Single DC Link Current Sensor." Energies 14, no. 18 (September 7, 2021): 5626. http://dx.doi.org/10.3390/en14185626.
Full textAbstract:
In recent years, electric propulsion systems have become widely, used and these systems have strict limits in volume and weight. Therefore, it is necessary to reduce the weight of the inverter-motor drive system. In a typical n inverter-motor drive system, at least 2n phase current sensors are required. In order to reduce the number of phase current sensors, this paper proposes a method for measuring phase current using n DC link current sensors in a 2n inverter-motor drive system. Two phase currents per inverter-motor system are measured during one period of the switching frequency using the pulse width modulation (PWM) shift method. However, since the measured phase current contains an error component in the average current, the error component was compensated for in order to obtain a current similar to the actual phase current by using the slope and dwell time of the phase current. The effectiveness of the proposed method is verified through experiments.
8
Davis, R. N., M. E. Polites, and L. C. Trevino. "Autonomous Component Health Management with Failed Component Detection, Identification, and Avoidance." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 219, no. 6 (June 1, 2005): 483–95. http://dx.doi.org/10.1243/095441005x30270.
Full textAbstract:
This article describes a novel scheme for autonomous component health management (ACHM) with failed actuator detection and identification and failed sensor detection, identification, and avoidance. This new scheme has features that are very superior to those with triple redundant sensing and voting, yet requires fewer sensors; it can be applied to any system with redundant sensing. Relevant background to the ACHM scheme is provided in this article. Simulation results for its application to a single-axis spacecraft attitude control system with a third-order plant and dual-redundant measurements of the system states are presented. The ACHM scheme fulfills key functions needed by an integrated vehicle health monitoring (IVHM) system. It is autonomous; is adaptive; works in real time; provides optimal state estimation; identifies failed components; avoids failed components; reconfigures for multiple failures, reconfigures for intermittent failures; works for hard-over, soft, and zero-output failures; and works for both open- and closed-loop systems. The ACHM scheme combines a prefilter that generates preliminary estimates of the system states, detects and identifies failed sensors and actuators, and avoids failed sensors in generating preliminary estimates of the system states with a fixed-gain Kalman filter that provides model-based state estimates, which are utilized in the failure detection logic, and generates optimal estimates for the system states. The simulation results show that ACHM can successfully detect, identify, and avoid sensor failures that are single or multiple; persistent and intermittent; and hard-over, soft, and zero-output types. It is now ready to be tested on a computer model of an actual system.
9
Röhner, Luisa, and Katja Träumner. "Aspects of Convective Boundary Layer Turbulence Measured by a Dual-Doppler Lidar System." Journal of Atmospheric and Oceanic Technology 30, no. 9 (September 1, 2013): 2132–42. http://dx.doi.org/10.1175/jtech-d-12-00193.1.
Full textAbstract:
Abstract Special designed dual-Doppler setups can be used to retrieve simultaneous measurements of two wind components with high temporal resolution in several heights throughout the atmospheric boundary layer. During a field campaign in summer 2011, different scan strategies were performed to demonstrate the opportunities of obtaining variance profiles of the vertical and horizontal wind components in complex terrain. A simplified error analysis reveals the effects of the error propagation of the uncorrelated noise of the single lidar systems. A comparison shows that the course of the derived horizontal wind component is in accordance to in situ measurements. The dual-Doppler vertical wind velocity reflects the up- and downdrafts in a convective boundary layer and is even able to reflect a light rain event. The normalized profiles of the vertical velocity variances reproduce the well-known decrease from about one-third of the boundary layer height to its top. The horizontal velocity variance did not reveal a systematic behavior on the considered days.
10
Javan Nikkhah, Sousa, Elsi Turunen, Anneli Lepo, Tapio Ala-Nissila, and Maria Sammalkorpi. "Multicore Assemblies from Three-Component Linear Homo-Copolymer Systems: A Coarse-Grained Modeling Study." Polymers 13, no. 13 (June 30, 2021): 2193. http://dx.doi.org/10.3390/polym13132193.
Full textAbstract:
Multicore polymer micelles and aggregates are assemblies that contain several cores. The dual-length-scale compartmentalized solvophobic–solvophilic molecular environment makes them useful for, e.g., advanced drug delivery, high-precision synthesis platforms, confined catalysis, and sensor device applications. However, designing and regulating polymer systems that self-assemble to such morphologies remains a challenge. Using dissipative particle dynamics (DPD) simulations, we demonstrate how simple, three-component linear polymer systems consisting of free solvophilic and solvophobic homopolymers, and di-block copolymers, can self-assemble in solution to form well-defined multicore assemblies. We examine the polymer property range over which multicore assemblies can be expected and how the assemblies can be tuned both in terms of their morphology and structure. For a fixed degree of polymerization, a certain level of hydrophobicity is required for the solvophobic component to lead to formation of multicore assemblies. Additionally, the transition from single-core to multicore requires a relatively high solvophobicity difference between the solvophilic and solvophobic polymer components. Furthermore, if the solvophilic polymer is replaced by a solvophobic species, well-defined multicore–multicompartment aggregates can be obtained. The findings provide guidelines for multicore assemblies’ formation from simple three-component systems and how to control polymer particle morphology and structure.
11
Zhang, Manying, Lei Wang, Weimin Zheng, Hongqiao Peng, Yue Zhu, and Jie Gu. "Short Term Probabilistic Load Forecasting With Integrated Methods." E3S Web of Conferences 118 (2019): 01040. http://dx.doi.org/10.1051/e3sconf/201911801040.
Full textAbstract:
In smart grid era, electric load is becoming more stochastic and less predictable in short horizons with more intermittent energy and competitive electricity market transactions. As a result, short-term probabilistic load forecasting (STPLF) is becoming essential for energy utilities because it helps quantify the risks of decision-making for power systems operation. Currently, probabilistic load forecasts (PLF) are commonly produced from three single components, namely input, model and output. Nevertheless, whether integrating two components to represent dual uncertainties of electric load is practical and able to improve STPLF attracts little regards. To address this issue, this paper proposes three integrated methods by pairwise combination of single representative component, i.e. uniform-biased temperature scenarios (UBTS), quantile regression (QR) and logarithmic residual empirical simulation (LRES). Case study on real utility data demonstrates the superiority of the integrated methods and excavates the relationship between predictive model class and specific integrated method.
12
Fu, Wenju, Guanwen Huang, Yuanxi Zhang, Qin Zhang, Bobin Cui, Maorong Ge, and Harald Schuh. "Multi-GNSS Combined Precise Point Positioning Using Additional Observations with Opposite Weight for Real-Time Quality Control." Remote Sensing 11, no. 3 (February 4, 2019): 311. http://dx.doi.org/10.3390/rs11030311.
Full textAbstract:
The emergence of multiple global navigation satellite systems (multi-GNSS), including global positioning system (GPS), global navigation satellite system (GLONASS), Beidou navigation satellite system (BDS), and Galileo, brings not only great opportunities for real-time precise point positioning (PPP), but also challenges in quality control because of inevitable data anomalies. This research aims at achieving the real-time quality control of the multi-GNSS combined PPP using additional observations with opposite weight. A robust multiple-system combined PPP estimation is developed to simultaneously process observations from all the four GNSS systems as well as single, dual, or triple systems. The experiment indicates that the proposed quality control can effectively eliminate the influence of outliers on the single GPS and the multiple-system combined PPP. The analysis on the positioning accuracy and the convergence time of the proposed robust PPP is conducted based on one week’s data from 32 globally distributed stations. The positioning root mean square (RMS) error of the quad-system combined PPP is 1.2 cm, 1.0 cm, and 3.0 cm in the east, north, and upward components, respectively, with the improvements of 62.5%, 63.0%, and 55.2% compared to those of single GPS. The average convergence time of the quad-system combined PPP in the horizontal and vertical components is 12.8 min and 12.2 min, respectively, while it is 26.5 min and 23.7 min when only using single-GPS PPP. The positioning performance of the GPS, GLONASS, and BDS (GRC) combination and the GPS, GLONASS, and Galileo (GRE) combination is comparable to the GPS, GLONASS, BDS and Galileo (GRCE) combination and it is better than that of the GPS, BDS, and Galileo (GCE) combination. Compared to GPS, the improvements of the positioning accuracy of the GPS and GLONASS (GR) combination, the GPS and Galileo (GE) combination, the GPS and BDS (GC) combination in the east component are 53.1%, 43.8%, and 40.6%, respectively, while they are 55.6%, 48.1%, and 40.7% in the north component, and 47.8%, 40.3%, and 34.3% in the upward component.
13
Zhou, Jing, Pengzhi Yao, Rui He, Kan Guo, Yao Zhang, and Hao Ma. "Dual Resonant Frequency Inductive Power Transfer in an Underwater Tight Coupling System." Energies 14, no. 1 (January 5, 2021): 242. http://dx.doi.org/10.3390/en14010242.
Full textAbstract:
The application of wireless power transfer technology in the underwater environment proposes both opportunities and challenges to undersea power feeding. Due to the attenuation of electromagnetic waves in seawater, the distance between transmitter and receiver is always maintained at a minimum value, which results in tight coupling between the transmitter and receiver. The tight coupling condition provides a low impedance loop for high-order harmonic, so the component of the harmonic wave is thus significantly increased and cannot be ignored in the power transmission system. In order to fully utilize the harmonic energy, a fundamental-harmonic dual-channel system was proposed and studied in this paper. Compared with single-channel systems transmitting fundamental wave only, the dual-channel system has higher power transmission capability, while the loss in dual channel system can be less than that of a single-channel system after proper optimization. A 3 kW experiment platform is established to verify the effectiveness of theoretical analysis.
14
Capriotti, Margherita, and Francesco Lanza di Scalea. "Robust non-destructive inspection of composite aerospace structures by extraction of ultrasonic guided-wave transfer function in single-input dual-output scanning systems." Journal of Intelligent Material Systems and Structures 31, no. 5 (January 9, 2020): 651–64. http://dx.doi.org/10.1177/1045389x19898266.
Full textAbstract:
Ultrasonic guided-wave testing is widely utilized for damage detection in plate-like structural components, including composite aircraft fuselage and wing panels. Many guided-wave tests involve transducer scanning to cover finite areas, a task that is most effectively performed by non-contact wave transduction means. The most common guided-wave test implementation consists of a “single-input single-output” scheme. The single-input single-output scheme leads to a transfer function that is convolved with the particular frequency response of the transducers and that of the transducer-to-structure paths (in both excitation and detection). These responses can be unknown or generally variable, especially in non-contact scanning systems and impact excitations. This article proposes a “single-input dual-output” scheme for ultrasonic guided-wave testing in scanning systems that is based on a deconvolution operation. The single-input dual-output scheme better isolates the structural transfer function that is the only property affected by the presence of possible damage. The single-input dual-output scheme was applied to two guided-wave scanning systems under development to detect impact-type damage in stiffened skin-to-stringer panels representative of modern composite aircraft construction. The results demonstrate the dual-output technique and also shed some light on the role of the different frequency bands for the detection of damage at different locations of the skin-to-stringer assembly.
15
Yang, In-Hwan, Joon-Hyung Jin, and Nam Ki Min. "A Micromachined Metal Oxide Composite Dual Gas Sensor System for Principal Component Analysis-Based Multi-Monitoring of Noxious Gas Mixtures." Micromachines 11, no. 1 (December 24, 2019): 24. http://dx.doi.org/10.3390/mi11010024.
Full textAbstract:
Microelectronic gas-sensor devices were developed for the detection of carbon monoxide (CO), nitrogen dioxides (NO2), ammonia (NH3) and formaldehyde (HCHO), and their gas-sensing characteristics in six different binary gas systems were examined using pattern-recognition methods. Four nanosized gas-sensing materials for these target gases, i.e., Pd-SnO2 for CO, In2O3 for NOX, Ru-WO3 for NH3, and SnO2-ZnO for HCHO, were synthesized using a sol-gel method, and sensor devices were fabricated using a microsensor platform. Principal component analysis of the experimental data from the microelectromechanical systems gas-sensor arrays under exposure to single gases and their mixtures indicated that identification of each individual gas in the mixture was successful. Additionally, the gas-sensing behavior toward the mixed gas indicated that the traditional adsorption and desorption mechanism of the n-type metal oxide semiconductor (MOS) governs the sensing mechanism of the mixed gas systems.
16
Song, Ruixia, and Kuang-Pang Li. "Fluorometry of Carcinogenic Polycyclic Aromatic Hydrocarbons in Biological Systems." Applied Spectroscopy 47, no. 10 (October 1993): 1604–8. http://dx.doi.org/10.1366/0003702934334813.
Full textAbstract:
Benzo(a)pyrene (BP) in liposomes and microsomes exhibits overlapping excimer bands peaked at 495 and 520 nm, respectively, in contrast to the single band of pyrene at 480 nm. Since BP is asymmetrical and pyrene is symmetrical, the dual maxima imply that the BP molecules in the excimer must be oriented either parallel or anti-parallel to each other. Time-resolved studies of BP oxidation by cytochrome P-450 show that the 520-nm component dissipates much faster than the 495-nm component during the first 30 min of metabolism, indicating that the initial P-450-BP interaction may be BP orientation sensitive. The binding of BP to the porphyrin group of a heme protein (e.g., hemoglobin or myoglobin) appears to be stronger under oxygen saturation than under CO2 saturation conditions. The transfer of BP between the membrane and the porphyrin group, as measured by means of excimer/monomer ratios, appears to be significantly different from that of pyrene. As the liposome-to-protein ratio increases, the excimer/monomer of BP steadily decreases, whereas that of pyrene increases and reaches a plateau. The significance of this phenomenon in their mechanisms of metabolism will have to be investigated further.
17
Fang, Hongbin, Suyi Li, and K. W. Wang. "Self-locking degree-4 vertex origami structures." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, no. 2195 (November 2016): 20160682. http://dx.doi.org/10.1098/rspa.2016.0682.
Full textAbstract:
A generic degree-4 vertex (4-vertex) origami possesses one continuous degree-of-freedom for rigid folding, and this folding process can be stopped when two of its facets bind together. Such facet-binding will induce self-locking so that the overall structure stays at a pre-specified configuration without additional locking elements or actuators. Self-locking offers many promising properties, such as programmable deformation ranges and piecewise stiffness jumps, that could significantly advance many adaptive structural systems. However, despite its excellent potential, the origami self-locking features have not been well studied, understood, and used. To advance the state of the art, this research conducts a comprehensive investigation on the principles of achieving and harnessing self-locking in 4-vertex origami structures. Especially, for the first time, this study expands the 4-vertex structure construction from single-component to dual-component designs and investigates their self-locking behaviours. By exploiting various tessellation designs, this research discovers that the dual-component designs offer the origami structures with extraordinary attributes that the single-component structures do not have, which include the existence of flat-folded locking planes, programmable locking points and deformability. Finally, proof-of-concept experiments investigate how self-locking can effectively induce piecewise stiffness jumps. The results of this research provide new scientific knowledge and a systematic framework for the design, analysis and utilization of self-locking origami structures for many potential engineering applications.
18
Jing, Zhaokun, Yuchao Yang, and Ru Huang. "Dual-mode dendritic devices enhanced neural network based on electrolyte gated transistors." Semiconductor Science and Technology 37, no. 2 (December 23, 2021): 024002. http://dx.doi.org/10.1088/1361-6641/ac3f21.
Full textAbstract:
Abstract As a fundamental component of biological neurons, dendrites have been proven to have crucial effects in neuronal activities. Single neurons with dendrite structures show high signal processing capability that is analogous to a multilayer perceptron (MLP), whereas oversimplified point neuron models are still prevalent in artificial intelligence algorithms and neuromorphic systems and fundamentally limit their efficiency and functionality of the systems constructed. In this study, we propose a dual-mode dendritic device based on electrolyte gated transistor, which can be operated to generate both supralinear and sublinear current–voltage responses when receiving input voltage pulses. We propose and demonstrate that the dual-mode dendritic devices can be used as a dendritic processing block between weight matrices and output neurons so as to dramatically enhance the expression ability of the neural networks. A dual-mode dendrites-enhanced neural network is therefore constructed with only two trainable parameters in the second layer, thus achieving 1000× reduction in the amount of second layer parameter compared to MLP. After training by back propagation, the network reaches 90.1% accuracy in MNIST handwritten digits classification, showing advantage of the present dual-mode dendritic devices in building highly efficient neuromorphic computing.
19
Ozden, Vahit E., Goksel Dikmen, Burak Beksac, and Remzi Tozun. "Dual-mobility bearings for patients with abductor-trochanteric complex insufficiency." HIP International 28, no. 5 (May 20, 2018): 491–97. http://dx.doi.org/10.1177/1120700018757788.
Full textAbstract:
Introduction: The purpose of this study was to summarise the performance of dual-mobility cup systems for revision total hip arthroplasty in patients with abductor-trochanteric complex deficiency. Methods: We prospectively followed 17 patients (20 hips) with a mean age of 64.5 years (range 33-89 years) who underwent acetabular reconstruction with dual-mobility cups for aseptic loosening in 12 hips, infection treatment as second or single stage in 6 hips, and instability in 2 hips. All of the patients had abductor insufficiency. We evaluated the clinical Harris Hip scores (HHS) and radiographs for migration, loosening, and osteolysis. The survival of the components was calculated according to Kaplan-Meier survivorship analysis, and failure was defined as any dislocation, acetabular component or total hip revision for any reason. Results: The mean duration of follow-up was 38.1 months (range 24-98 months). There were 2 (12.5%) revisions for cemented cup migration after 11 months and 19 months respectively. There were no dislocations. At the last follow-up, the mean HHS increased from 42 points preoperatively to 86 points. The cumulative survival rate of the dual-mobility cup system was 93% (95% confidence interval 88-98.7%) at 5 years, with any revision as the end point. Conclusion: Dual-mobility cups may provide excellent stability in patients with abductor-trochanteric complex insufficiency.
20
Lavanya, A., K. Vijaya Kumar, and J. Divya Navamani. "Topological Comparison of Dual-Input DC-DC Converters." International Journal of Power Electronics and Drive Systems (IJPEDS) 8, no. 2 (June 1, 2017): 804. http://dx.doi.org/10.11591/ijpeds.v8.i2.pp804-811.
Full textAbstract:
Dual input dc-dc converters have two input voltage sources or one input source and an energy storage system like ultra capacitor, PV, battery, super capacitors and a single output load. In order to process the power in hybrid energy systems using reduced part count, researchers have proposed several multi-input dc-dc power converter topologies to transfer power from different input voltage sources to the output. This paper compares non-isolated dual-input converter topologies topologically ,based on the components count, various fields of application and different modes of operation for hybrid systems mainly used in electric vehicles and renewable energy systems composed of energy storage systems (ESSs) with different voltage-current characteristics. Dual input dc-dc converter topologies considered in this paper are investigated using MATLAB and PSIM software and output voltage and inductor current waveforms are shown.
21
Wu, Sen-Tung, and Yu-Ting Cheng. "Design and Implementation of a Single-Stage PFC Active-Clamp Flyback Converter with Dual Transformers." Electronics 10, no. 21 (October 22, 2021): 2588. http://dx.doi.org/10.3390/electronics10212588.
Full textAbstract:
This paper proposes an AC/DC single-stage structure by integrating a boost topology and an active clamp flyback (ACF) circuit with power-factor-correction (PFC) function. The PFC function can be achieved by controlling a boost PFC topology operated in the discontinuous conduction mode. With the coordination of active clamping components, a resonant technique is obtained and zero-voltage-switching (ZVS) can be achieved. The proposed converter is combined with the advantages of: (1) compared with two-stage circuit, a single stage circuit decreases the component of the main circuit and reduces the complexity of the control circuit; (2) a boost topology with PFC function operated in discontinuous conduction mode can be accomplished without adding any current detecting technique or detecting input signal; (3) by using the inductor from the PFC stage, ZVS function can be achieved without any additional inductor; (4) the increment of switching frequency facilitates the optimization of power density; (5) the conducting loss at the secondary side can be reduced by adding the synchronous rectification; (6) in this proposed scheme, the dual transformers with series-parallel connection are utilized, the current at the secondary side can be shared for lowering the conduction loss of the synchronous transistors. Finally, a prototype converter with AC 110 V input and DC 19 V/6.32 A (120 W) output under 300 kHz switching frequency is implemented. The efficiency of the proposed converter reaches 88.20% and 0.984 power factor in full load condition.
22
Hagelberg, J., N. Engler, C. Fontanive, S. Daemgen, S. P. Quanz, J. Kühn, M. Reggiani, M. Meyer, R. Jayawardhana, and V. Kostov. "VIBES: Visual Binary Exoplanet survey with SPHERE." Astronomy & Astrophysics 643 (November 2020): A98. http://dx.doi.org/10.1051/0004-6361/202039173.
Full textAbstract:
Context. Recent surveys indicate that planets in binary systems are more abundant than previously thought, which is in agreement with theoretical work on disc dynamics and planet formation in binaries. So far, most observational surveys, however, have focused on short-period planets in binaries, thus little is known about the occurrence rates of planets on longer periods (≥10 au). Aims. In order to measure the abundance and physical characteristics of wide-orbit giant exoplanets in binary systems, we have designed the “VIsual Binary Exoplanet survey with Sphere” (VIBES) to search for planets in visual binaries. It uses the SPHERE instrument at VLT to search for planets in 23 visual binary and four visual triple systems with ages of <145 Myr and distances of <150 pc. Methods. We used the IRDIS dual-band imager on SPHERE to acquire high-contrast images of the sample targets. For each binary, the two components were observed at the same time with a coronagraph masking only the primary star. For the triple star, the tight components were treated as a single star for data reduction. This enabled us to effectively search for companions around 50 individual stars in binaries and four binaries in triples. Results. We derived upper limits of <13.7% for the frequency of sub-stellar companions around primaries in visual binaries, <26.5% for the fraction of sub-stellar companions around secondaries in visual binaries, and an occurrence rate of <9.0% for giant planets and brown dwarfs around either component of visual binaries. We have combined our observations with literature measurements to astrometrically confirm, for the first time, that 20 binaries and two triple systems, which were previously known, are indeed physically bound. Finally, we discovered a third component of the binary HD 121336. Conclusions. The upper limits we derived are compatible with planet formation through the core accretion and the gravitational instability processes in binaries. These limits are also in line with limits found for single star and circumbinary planet search surveys.
23
Al-Durgham, Kaleel, Derek Lichti, Gregor Kuntze, Gulshan Sharma, and Janet Ronsky. "Toward an Automatic Calibration of Dual Fluoroscopy Imaging Systems." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5 (June 16, 2016): 757–64. http://dx.doi.org/10.5194/isprsarchives-xli-b5-757-2016.
Full textAbstract:
High-speed dual fluoroscopy (DF) imaging provides a novel, in-vivo solution to quantify the six-degree-of-freedom skeletal kinematics of humans and animals with sub-millimetre accuracy and high temporal resolution. A rigorous geometric calibration of DF system parameters is essential to ensure precise bony rotation and translation measurements. One way to achieve the system calibration is by performing a bundle adjustment with self-calibration. A first-time bundle adjustment-based system calibration was recently achieved. The system calibration through the bundle adjustment has been shown to be robust, precise, and straightforward. Nevertheless, due to the inherent absence of colour/semantic information in DF images, a significant amount of user input is needed to prepare the image observations for the bundle adjustment. This paper introduces a semi-automated methodology to minimise the amount of user input required to process calibration images and henceforth to facilitate the calibration task. The methodology is optimized for processing images acquired over a custom-made calibration frame with radio-opaque spherical targets. Canny edge detection is used to find distinct structural components of the calibration images. Edge-linking is applied to cluster the edge pixels into unique groups. Principal components analysis is utilized to automatically detect the calibration targets from the groups and to filter out possible outliers. Ellipse fitting is utilized to achieve the spatial measurements as well as to perform quality analysis over the detected targets. Single photo resection is used together with a template matching procedure to establish the image-to-object point correspondence and to simplify target identification. The proposed methodology provided 56,254 identified-targets from 411 images that were used to run a second-time bundle adjustment-based DF system calibration. Compared to a previous fully manual procedure, the proposed methodology has significantly reduced the amount of user input needed for processing the calibration images. In addition, the bundle adjustment calibration has reported a 50% improvement in terms of image observation residuals.
24
Al-Durgham, Kaleel, Derek Lichti, Gregor Kuntze, Gulshan Sharma, and Janet Ronsky. "Toward an Automatic Calibration of Dual Fluoroscopy Imaging Systems." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5 (June 16, 2016): 757–64. http://dx.doi.org/10.5194/isprs-archives-xli-b5-757-2016.
Full textAbstract:
High-speed dual fluoroscopy (DF) imaging provides a novel, in-vivo solution to quantify the six-degree-of-freedom skeletal kinematics of humans and animals with sub-millimetre accuracy and high temporal resolution. A rigorous geometric calibration of DF system parameters is essential to ensure precise bony rotation and translation measurements. One way to achieve the system calibration is by performing a bundle adjustment with self-calibration. A first-time bundle adjustment-based system calibration was recently achieved. The system calibration through the bundle adjustment has been shown to be robust, precise, and straightforward. Nevertheless, due to the inherent absence of colour/semantic information in DF images, a significant amount of user input is needed to prepare the image observations for the bundle adjustment. This paper introduces a semi-automated methodology to minimise the amount of user input required to process calibration images and henceforth to facilitate the calibration task. The methodology is optimized for processing images acquired over a custom-made calibration frame with radio-opaque spherical targets. Canny edge detection is used to find distinct structural components of the calibration images. Edge-linking is applied to cluster the edge pixels into unique groups. Principal components analysis is utilized to automatically detect the calibration targets from the groups and to filter out possible outliers. Ellipse fitting is utilized to achieve the spatial measurements as well as to perform quality analysis over the detected targets. Single photo resection is used together with a template matching procedure to establish the image-to-object point correspondence and to simplify target identification. The proposed methodology provided 56,254 identified-targets from 411 images that were used to run a second-time bundle adjustment-based DF system calibration. Compared to a previous fully manual procedure, the proposed methodology has significantly reduced the amount of user input needed for processing the calibration images. In addition, the bundle adjustment calibration has reported a 50% improvement in terms of image observation residuals.
25
Mabrok, Mussa, Zahriladha Zakaria, Yully Erwanti Masrukin, Tole Sutikno, and Hussein Alsariera. "Effect of the defected microstrip structure shapes on the performance of dual-band bandpass filter for wireless communications." Bulletin of Electrical Engineering and Informatics 10, no. 1 (February 1, 2021): 232–40. http://dx.doi.org/10.11591/eei.v10i1.2662.
Full textAbstract:
Due to the progression growth of multiservice wireless communication systems in a single device, multiband bandpass filter has attract a great attention to the end user. Therefore, multiband bandpass filter is a crucial component in the multiband transceivers systems which can support multiple services in one device. This paper presents a design of dual-band bandpass filter at 2.4 GHz and 3.5 GHz for WLAN and WiMAX applications. Firstly, the wideband bandpass filter is designed at a center frequency of 3 GHz based on quarter-wavelength short circuited stub. Three types of defected microstrip structure (DMS) are implemented to produce a wide notch band, which are T-inversed shape, C-shape, and U- Shape. Based on the performance comparisons, U-shaped DMS is selected to be integrated with the bandpass filter. The designed filter achieved two passbands centered at 2.51 GHz and 3.59 GHz with 3 dB bandwidth of 15.94 % and 15.86 %. The proposed design is very useful for wireless communication systems and its applications such as WLAN and WiMAX
26
Gomez, Carlos A., Malaya K. Sahoo, Ghazala Yasmeen Kahn, Lina Zhong, José G. Montoya, Benjamin A. Pinsky, and Thuy Doan. "Dual-target, real-time PCR for the diagnosis of intraocular Toxoplasma gondii infections." British Journal of Ophthalmology 103, no. 4 (January 12, 2019): 569–72. http://dx.doi.org/10.1136/bjophthalmol-2018-313064.
Full textAbstract:
BackgroundToxoplasma gondii is the most common infectious cause of posterior uveitis worldwide. Two multicopy targets (B1 and Rep529) are commonly used in T. gondii PCR assays, but studies evaluating these targets in ocular fluid samples are limited. Herein, we determine the analytical characteristics of a single-reaction, internally controlled, dual-target, real-time T. gondii PCR and evaluate the clinical performance of this assay in intraocular fluid samples obtained at a reference ophthalmologic centre in the USA.MethodsLower limits of detection for the B1 and Rep529 components of the dual-target assay were determined using serial dilutions of cultured T. gondii strain Z185. The dual-target assay was then used to test 148 archived intraocular samples (132 vitreous,16 aqueous humour) collected at the Francis I. Proctor Foundation between January 2010 and December 2015 for testing by a nested, conventional PCR targeting the B1 gene.ResultsThe 95% lower limits of detection for the dual-target assay was determined to be 1.05 tachyzoites/mL for B1 and 0.83 tachyzoites/mL for Rep529. Using archived clinical intraocular specimens, the dual-target assay demonstrated 97.2% positive per cent agreement (n=35/36; 95% CI 83.7% to 99.9%) and 99.1% negative per cent agreement (n=111/112; 95% CI 94.4% to 100%) compared with the nested, conventional B1 PCR.ConclusionThis single-reaction, internally controlled, dual-target (B1, Rep529) real-time PCR for the detection of T. gondii DNA in intraocular specimens demonstrated excellent agreement with nested, conventional, B1 PCR. The dual-target design may ensure T. gondii detection when variation is present in one of two target regions.
27
Twum, Stephen Boakye, and Elaine Aspinwall. "Multicriteria reliability modeling and optimisation of a complex system with dual failure modes and high initial reliability." International Journal of Quality & Reliability Management 35, no. 7 (August 6, 2018): 1477–88. http://dx.doi.org/10.1108/ijqrm-02-2017-0032.
Full textAbstract:
Purpose System reliability optimisation in today’s world is critical to ensuring customer satisfaction, businesses competitiveness, secure and uninterrupted delivery of services and safety of operations. Among many systems configurations, complex systems are the most difficult to model for reliability optimisation. The purpose of this paper is to assess the performance of a novel optimisation methodology of the authors, developed to address the difficulties in the context of a gas carrying system (GCS) exhibiting dual failure modes and high initial reliability. Design/methodology/approach The minimum cut sets involving components of the system were obtained using the fault tree approach, and their reliability constituted into criteria which were maximised and the associated cost of improving their reliabilities minimised. Pareto optimal generic components and system reliabilities were subsequently obtained. Findings The results indicate that the optimisation methodology could improve the system’s reliability even from an initially high one, granted that the feasibility factor for improving a component’s reliability was very high. The results obtained, in spite of the size (41 objective functions and 18 decision variables), the complexity (dual failure modes) and the high initial reliability values provide confidence in the optimisation model and methodology and demonstrate their applicability to systems exhibiting multiple failure modes. Research limitations/implications The GCS was assumed either failed or operational, its parameters precisely determined, and non-repairable. The components failure rates were exponentially distributed and failure modes independent. A single weight vector representing expression of preference in which components reliabilities were weighted higher than cost was used due to the stability of the optimisation model to weight variations. Practical implications The high initial reliability values imply that reliability improvement interventions may not be a critical requirement for the GCS. The high levels could be sustained through planned and systematic inspection and maintenance activities. Even so, purely from an analytical stand point, the results nevertheless show that there was some room for reliability improvement however marginal that is. The improvement may be secured by: use of components with comparable levels of reliability to those achieved; use of redundancy techniques to achieve the desired levels of improvement in reliability; or redesigning of the components. Originality/value The novelty of this work is in the use of a reliability optimisation model and methodology that focuses on a system’s minimum cut sets as criteria to be optimised in order to optimise the system’s reliability, and the specific application to a complex system exhibiting dual failure modes and high component reliabilities.
28
Yuce, Erkan, Leila Safari, Shahram Minaei, Giuseppe Ferri, Gianluca Barile, and Vincenzo Stornelli. "A New Simulated Inductor with Reduced Series Resistor Using a Single VCII±." Electronics 10, no. 14 (July 15, 2021): 1693. http://dx.doi.org/10.3390/electronics10141693.
Full textAbstract:
This paper presents a new realization of a grounded simulated inductor using a single dual output second-generation voltage conveyor (VCII±) as an active building block, two resistors and one grounded capacitor. The main characteristic of the proposed circuit is that the value of the series resistor can be significantly reduced. Thus, it has the property of improved low-frequency performance. Another feature is the use of a grounded capacitor that makes the proposed circuit attractive for integrated circuit (IC) realization. A simple CMOS implementation of the required VCII± is used. However, a single passive component-matching condition is required for the proposed structure. As an application example, a standard fifth-order high-pass ladder filter is also given. SPICE simulations using 0.18 μm CMOS technology parameters and a supply voltage of ±0.9 V as well as experimental verifications, are carried out to support the theory.
29
Orscheschek, Franziska, Tilo Strobach, Torsten Schubert, and Timothy Rickard. "Two retrievals from a single cue: A bottleneck persists across episodic and semantic memory." Quarterly Journal of Experimental Psychology 72, no. 5 (May 28, 2018): 1005–28. http://dx.doi.org/10.1177/1747021818776818.
Full textAbstract:
There is evidence in the literature that two retrievals from long-term memory cannot occur in parallel. To date, however, that work has explored only the case of two retrievals from newly acquired episodic memory. These studies demonstrated a retrieval bottleneck even after dual-retrieval practice. That retrieval bottleneck may be a global property of long-term memory retrieval, or it may apply only to the case of two retrievals from episodic memory. In the current experiments, we explored whether that apparent dual-retrieval bottleneck applies to the case of one retrieval from episodic memory and one retrieval from highly overlearned semantic memory. Across three experiments, subjects learned to retrieve a left or right keypress response form a set of 14 unique word cues (e.g., black—right keypress). In addition, they learned a verbal response which involved retrieving the antonym of the presented cue (e.g., black—“white”). In the dual-retrieval condition, subjects had to retrieve both the keypress response and the antonym word. The results suggest that the retrieval bottleneck is superordinate to specific long-term memory systems and holds across different memory components. In addition, the results support the assumption of a cue-level response chunking account of learned retrieval parallelism.
30
Shramkova, Oksana, Valter Drazic, Guillaume Bourcin, Bobin Varghese, Laurent Blondé, and Valérie Allié. "Metagrating solutions for full color single-plate waveguide combiner." EPJ Applied Metamaterials 9 (2022): 5. http://dx.doi.org/10.1051/epjam/2022003.
Full textAbstract:
In this work we propose several full-color metagrating solutions for single waveguide-based Augmented and Virtual Reality near-eye display systems. The presented solutions are based on a combination of reflective and/or transmissive diffraction gratings inside or outside a waveguide. The proposed in-coupler designs have high diffraction efficiency across a wide angular range. Applying our new grating combination solution, we can provide good gathering of diffracted rays for the different colors. We demonstrate that by using a dual-mode symmetrical in-coupling system and angular pupil tiling, we can extend the overall horizontal FoV for three RGB colors. The new characteristics of the full single waveguide system including Eye Pupil Expander and out-coupling components compatible with the proposed in-coupling solutions are discussed. We show that a new nonsymmetrical design of metagratings can be used to change its diffraction properties improving the diffraction efficiency and diffraction uniformity of the optical components.
31
WALL, RICHARD W., and HERBERT L. HESS. "DESIGN AND MICROCONTROLLER IMPLEMENTATION OF A THREE PHASE SCR POWER CONVERTER." Journal of Circuits, Systems and Computers 06, no. 06 (December 1996): 619–33. http://dx.doi.org/10.1142/s0218126696000431.
Full textAbstract:
A single processor controls a three phase silicon controlled rectifier (SCR) power converter. An inexpensive, dual optoisolator interface to the power line provides noise rejection and an improved measure of the zero crossing. A dynamic digital phase-locked loop (PLL) algorithm implemented in an Intel 87C196KD-20 processor achieves frequency tracking, dynamically changing characteristics for improved performance. Dynamically modifying the PLL characteristics permits independent capture and locked dynamics. A feedforward method provides command tracking for improved response without loss of performance. This three-component design (processor, optoisolator, and SCR gate drivers) represents a minimal implementation with potential for closed loop voltage and current control. High speed input and output resources included on the 87C196KD processor make an efficient single-device implementation possible. The processor is less than 1% utilized allowing for additional functions to be added in the future. This system operates on both 50 Hz and 60 Hz power systems without modification or loss of performance.
32
Spingola, C., J. P. McKean, D. Massari, and L. V. E. Koopmans. "Proper motion in lensed radio jets at redshift 3: A possible dual super-massive black hole system in the early Universe." Astronomy & Astrophysics 630 (September 30, 2019): A108. http://dx.doi.org/10.1051/0004-6361/201935427.
Full textAbstract:
In this paper, we exploit the gravitational lensing effect to detect proper motion in the highly magnified gravitationally lensed source MG B2016+112. We find positional shifts up to 6 mas in the lensed images by comparing two Very Long Baseline Interferometric (VLBI) radio observations at 1.7 GHz that are separated by 14.359 years, and provide an astrometric accuracy of the order of tens of μas. From lens modelling, we exclude a shift in the lensing galaxy as the cause of the positional change of the lensed images, and we assign it to the background source. The source consists of four sub-components separated by ∼175 pc, with proper motion of the order of tens μas yr−1 for the two components at highest magnification (μ ∼ 350) and of the order of a few mas yr−1 for the two components at lower magnification (μ ∼ 2). We propose single active galactic nuclei (AGN) and dual AGN scenarios to explain the source plane. Although, the latter interpretation is supported by the archival multi-wavelength properties of the object. In this case, MG B2016+112 would represent the highest redshift dual radio-loud AGN system discovered thus far, and would support the merger interpretation for such systems. Also, given the low probability (∼10−5) of detecting a dual AGN system that is also gravitationally lensed, if confirmed, this would suggest that such dual AGN systems must be more abundant in the early Universe than currently thought.
33
TODINOV, M. T. "RELIABILITY ANALYSIS OF COMPLEX SYSTEMS BASED ON THE LOSSES FROM FAILURES." International Journal of Reliability, Quality and Safety Engineering 13, no. 02 (April 2006): 127–48. http://dx.doi.org/10.1142/s0218539306002161.
Full textAbstract:
The conventional reliability analysis is based on the premise that increasing the reliability of a system will decrease the losses from failures. In this paper it is demonstrated that increasing the reliability of the system does not always mean decreasing the losses from failures. An inappropriate increase of the reliability of the system may lead to a simultaneous increase of the losses from failure. In other words, a system reliability improvement, which is disconnected from the losses from failure does not necessarily reduce the losses from failures. An efficient discrete-event simulation model and algorithm have been proposed for reliability analysis based on the losses from failure for production systems with complex topology. The model links reliability with losses from failures. A new algorithm has also been developed for system reliability analysis related to productions systems based on multiple production units where the absence of critical failure means that at least m out n production units are working. The parametric study conducted on the basis of the developed models revealed that a dual-control production system is characterized by enhanced production availability, which increases with increasing the number of production units in the system. A production unit from a dual-control production system including multiple production units is characterized by a larger availability compared to a production unit from a dual-control production system including a single production unit. The proposed approach has been demonstrated by comparing the losses from failures and the net present values of two competing design topologies: one based on a single-channel control and the other based on a dual-channel control. The proposed models have been successfully applied and tested for reliability value analysis of productions systems in deepwater oil and gas production. It is also argued that the reliability allocation in a production system should be done to maximize the net profit/value obtained from the system. Consequently, a method for setting reliability requirements and reliability allocation maximizing the net profit by minimizing the sum of the capital costs and the expected losses from failures has been proposed. Reliability allocation which maximizes the net profit in case of a system consisting of blocks arranged in series is achieved by determining for each block individually, the reliabilities of the components which minimize the sum of the capital costs and the expected losses from failures.
34
Nguyen, Nhan Duc, Anh-Tu Le, Munyaradzi Munochiveyi, Fatemeh Afghah, and Evangelos Pallis. "Intelligent Reflecting Surface Aided Wireless Systems with Imperfect Hardware." Electronics 11, no. 6 (March 14, 2022): 900. http://dx.doi.org/10.3390/electronics11060900.
Full textAbstract:
In this article, we investigate the design of reconfigurable intelligent surface (RIS)-aided transmission as a smart method to reflect signals received from access points to users and, hence, improving users’ performance. To implement smart Internet of Things (IoT) networks, massive connectivity and low-cost deployment are essential in designing such systems. In particular, we consider two practical scenarios (dual-hop and single-hop transmissions). These scenarios highlight the potential of RIS in enhancing the system’s outage probability performance. Furthermore, to characterize channel conditions in practice, we pay particular attention to two-channel distributions that are non-central chi-square (NCCS) distributions that approximate the channel distribution of the RIS-aided wireless system and the squared KG distribution. In addition, the RIS-aided system may face imperfect hardware-related issues in practice. Therefore, we need to consider the degraded performance of practical RIS-aided systems by considering the detrimental impact of in-phase and quadrature-phase imbalance (IQI). To characterize the main system performance metric, we provide closed-form formulas of outage probability and ergodic capacity. We then evaluate system performance under the impacts of signal-to-noise ratio (SNR), the number of meta-surfaces, and channel parameters. All closed-form outage expressions are validated via Monte Carlo simulations. Simulation results indicate that the considered RIS scheme at dual-hop and single hop under the impact of IQI and RIS hardware impairment achieves significant improvements in terms of outage probability at high SNR and high meta-surface number N. Additionally, the simulation results demonstrate that the impact of IQI on the proposed system is limited. It is worth noting that, in terms of ergodic capacity, ergodic capacity faces an upper limit. Despite this limitation, the proposed system can still work well once some parameters are controlled well, such as the transmit SNR, levels of IQI, and the number of RIS components.
35
Lisienko, Svetlana. "MODELING “FISHERY” SYSTEM USING PRINCIPLES OF BIOTECHNOLOGICAL DUALISM." Vestnik of Astrakhan State Technical University. Series: Fishing industry 2021, no. 3 (September 30, 2021): 94–101. http://dx.doi.org/10.24143/2073-5529-2021-3-94-101.
Full textAbstract:
The article considers the essential feature of the system modeling of high-level fishery systems, e.g. the ‘Fishery’ system, the use of the principle of their internal self-organization, taking into account the influence of external factors - limitations. The internal structure of the ‘Fishery’ system is formed by a combination of biological, technical and technological components. Objects and sets of technical and technological components are interdependent, have a technical and technological nature and are combined into a single technological component. In this sense, the ‘Fishery’ system has a dual natural structure - biotechnological dualism, which is determined by the two components which simultaneously present and function in the system. In addition, the fishing process is greatly influenced by a set of restrictions and certain uncontrollable factors. By their simultaneous action they impart stochasticism and uncertainty to the fishing production process. Modeling of the ‘Fishery’ system was carried out using the decomposition method with consideration of the model of the composition of the system according to the signs (components) of duality - biological and technological components, which are its interrelated subsystems with the choice of an appropriate decomposition strategy - decomposition by subsystems (structural decomposition) with simultaneous embedding restrictive probabilistic component. Modeling of the blocks and the entire system was carried out taking into account the definition of component and restrictive relationships and relationships that determine both the static and dynamic nature of the ‘Fishery’ system in their initial state, i.e. without taking into account possible transient states in time intervals determined by the fishing situation. The generalized ‘Fishery’ system modeled on the basis of biotechnological dualism makes it possible to obtain a holistic view of its compositional composition, taking into account the impact of restrictions of a different nature, uncontrollable factors accompanying the production process of extraction of aquatic biological resources in the fishing areas. The resulting model in its initial static state is the initial biotechnological model for carrying out subsequent optimization control actions during its transition to a dynamic state in the time intervals indicated by the fishery
36
Vanchurin, Vitaly. "Differential equation for partition functions and a duality pseudo-forest." Journal of Mathematical Physics 63, no. 7 (July 1, 2022): 073501. http://dx.doi.org/10.1063/5.0004357.
Full textAbstract:
We consider finite quantum systems defined by a mixed set of commutation and anti-commutation relations between components of the Hamiltonian operator. These relations are represented by an anti-commutativity graph that contains necessary and sufficient information for computing the full quantum partition function. We derive a second-order differential equation for an extended partition function z[ β, β′, J] that describes a transformation from a “parent” partition function z[0, β′, J] (or anti-commutativity graph) to a “child” partition function z[ β, 0, J] (or anti-commutativity graph). The procedure can be iterated, and then one forms a pseudo-forest of duality transformations between quantum systems, i.e., a directed graph in which every vertex (or quantum system) has at most one incoming edge (from its parent system). The pseudo-forest has a single tree connected to a constant partition function, many pseudo-trees connected to self-dual systems, and all other pseudo-trees connected to closed cycles of transformations between mutually dual systems. We also show how the differential equation for the extended partition function can be used to study disordered systems.
37
Parent, L. E., and M. Dafir. "A Theoretical Concept of Compositional Nutrient Diagnosis." Journal of the American Society for Horticultural Science 117, no. 2 (March 1992): 239–42. http://dx.doi.org/10.21273/jashs.117.2.239.
Full textAbstract:
The premises underlying univariate (CVA = critical value approach) and bivariate (DRIS = diagnosis and recommendation integrated system) diagnostic systems were reexamined with regard to compositional data analysis (CDA). CDA recognizes a structure of dependence among plant nutrients, the bounded sum constraint to one (the whole composition equals 100% or 1), and removes the curvature problem carried by crude components and by dual ratios or logratios when treated in isolation. Linearization by “rowcentered logrationing” of nutrient fractions shows great potential for carrying multivariate diagnosis and principal component analysis on nutrient data. Compositional nutrient diagnosis (CND) is supported by the theory of CDA. CND is the multivariate expansion of CVA and DRIS and is fully compatible with PCA. CND takes all possible nutrient interactions into account. CND nutrient indices are composed of two separate functions, one considering differences between nutrient levels, another examining differences between nutrient balances (as defined by nutrient geometric means), of individual and target specimens. These functions indicate that nutrient insufficiency can be corrected by either adding a single nutrient or taking advantage of multiple nutrient interactions to improve nutrient balance as a whole. A theoretical interpretative table is presented for CND.
38
Hill, Ginel C., Daniel R. Soto, Anne M. Peattie, Robert J. Full, and T. W. Kenny. "Orientation angle and the adhesion of single gecko setae." Journal of The Royal Society Interface 8, no. 60 (February 2, 2011): 926–33. http://dx.doi.org/10.1098/rsif.2010.0720.
Full textAbstract:
We investigated the effects of orientation angle on the adhesion of single gecko setae using dual-axis microelectromechanical systems force sensors to simultaneously detect normal and shear force components. Adhesion was highly sensitive to the pitch angle between the substrate and the seta's stalk. Maximum lateral adhesive force was observed with the stalk parallel to the substrate, and adhesion decreased smoothly with increasing pitch. The roll orientation angle only needed to be roughly correct with the spatular tuft of the seta oriented grossly towards the substrate for high adhesion. Also, detailed measurements were made to control for the effect of normal preload forces. Higher normal preload forces caused modest enhancement of the observed lateral adhesive force, provided that adequate contact was made between the seta and the substrate. These results should be useful in the design and manufacture of gecko-inspired synthetic adhesives with anisotropic properties, an area of substantial recent research efforts.
39
Banash, Mark A., and Warren S. Warren. "State-to-State Collisional Dynamics by Coherent Laser Pulse Phase, Shape, and Frequency Modification." Laser Chemistry 6, no. 1 (January 1, 1986): 47–60. http://dx.doi.org/10.1155/lc.6.47.
Full textAbstract:
Conventional coherent pulse sequences such as photon echoes measure only highly averaged relaxation rates in complex multilevel systems, such as molecules undergoing state-changing collisions. Pulse frequency, phase, and shape control lets us generate sequences which give a more detailed understanding of the dynamics. Results of dual frequency, crafted shape sequences on I2 are presented which show that the "coherence dephasing" time T2 is primarily due to population redistribution (energy changing collisions) in the electronically excited state, and that the electronic ground state has a much smaller cross section for such collisions. Quantitative analysis is only possible with modified laser pulse shapes which excite a single velocity component, and requires pulse sequences which correct for the hyperfine dependence of predissociation. Since this correction is rarely made in previously reported coherent transient measurements, literature values of T2 and T1 may not be reliable in the zero pressure limit.
40
Shi, Zhigang, Yuting Bai, Xuebo Jin, Xiaoyi Wang, Tingli Su, and Jianlei Kong. "Deep Prediction Model Based on Dual Decomposition with Entropy and Frequency Statistics for Nonstationary Time Series." Entropy 24, no. 3 (March 2, 2022): 360. http://dx.doi.org/10.3390/e24030360.
Full textAbstract:
The prediction of time series is of great significance for rational planning and risk prevention. However, time series data in various natural and artificial systems are nonstationary and complex, which makes them difficult to predict. An improved deep prediction method is proposed herein based on the dual variational mode decomposition of a nonstationary time series. First, criteria were determined based on information entropy and frequency statistics to determine the quantity of components in the variational mode decomposition, including the number of subsequences and the conditions for dual decomposition. Second, a deep prediction model was built for the subsequences obtained after the dual decomposition. Third, a general framework was proposed to integrate the data decomposition and deep prediction models. The method was verified on practical time series data with some contrast methods. The results show that it performed better than single deep network and traditional decomposition methods. The proposed method can effectively extract the characteristics of a nonstationary time series and obtain reliable prediction results.
41
Villa, Jesus M., Tejbir S. Pannu, Preetesh D. Patel, Wael K. Barsoum, Carlos A. Higuera, and Aldo M. Riesgo. "What Factors Reduce the Incidence of Early Dislocations in Aseptic Total Hip Revisions with Stem Retention?" Journal of Hip Surgery 05, no. 03 (June 15, 2021): 101–5. http://dx.doi.org/10.1055/s-0041-1729873.
Full textAbstract:
AbstractIt is unclear which factors are the most important protectors for early postoperative dislocation in aseptic total hip arthroplasty (THA) revisions with stem retention. Therefore, we sought to determine what factors reduce the incidence of dislocations among these patients. Single institution retrospective review was made of 83 consecutive aseptic THA revisions of the head/liner and/or cup performed by five surgeons between 2017 and 2020. Periprosthetic infections and femoral component revisions were excluded. Demographics, preoperative diagnosis, revision type, surgical approach, use of dual mobility systems, length of stay, skin-to-skin time, transfusions, complications, and dislocations were assessed. Pearson correlation/logistic regression analyses were used to determine association/independent predictors of dislocation; α was set at 0.05. The overall dislocation rate was 12%. In Pearson correlation, only preoperative diagnosis (instability vs. other, −0.241, p = 0.028) and revision type (only liner vs. cup, −0.304, p = 0.005) were significantly associated with dislocations. In logistic regression, only preoperative diagnosis other than instability (odds ratio [OR] = 0.235, p = 0.038) and cup revision (OR = 0.130, p = 0.014) were found significant protectors against dislocation. Surgical approach and dual mobility systems were not independent predictors of dislocations (p = 0.184 and p = 0.083, respectively). Dislocation rates were significantly different between those cases that had the cup revised (4.0%) and those that did not (24.2%; p = 0.012). Preoperative diagnosis other than instability and cup revision seemed to be protective against early dislocation. Revision of the cup, in particular, seemed to be the most important factor to avoid dislocations while use of dual mobility liners per se did not significantly reduce that risk. The role of isolated liner exchanges in revision THA continues to evolve and should be reserved for appropriately selected patients.
42
Vasylkivsky, K., V. Gidzhelitsky, and A. Lapin. "Dynamics and energy provision of cargo transportation systems in food packing lines." Technological Complexes 16 (December 5, 2019): 31–43. http://dx.doi.org/10.36910/2312-0584-16-2019-003.
Full textAbstract:
The work is related to the search for the possibilities of using internal energy resources in transport and technological systems by the example of food packaging lines packed in glass containers. Trends in switching to high-performance lines have led to the need for their equipment with dual-purpose transport systems. Obviously, the first task is to ensure the movement of artificial products in the respective sections between units of technological machines, and the second component of their task - to fulfill the role of storage devices in combination with the need for restructuring mass flows. This combination of tasks has led to the exclusive use of closed circuit circuits with two friction planes in transport systems. Meanwhile, it is known that energy costs in mechanical systems are associated with the need to achieve the specified levels of kinetic energy of the moving masses in order to overcome the forces of harmful and useful resistance. The peculiarity of such transport systems is the constant presence of transients and dynamic components of loads. The study complements the known dynamic manifestations with new ratios of indicators for the possibility of energy recovery. In the transportation systems for glass production of foodstuffs, the driving factors in most cases are represented by friction forces. Simultaneously, the closure of kinematic pairs between the products and the supporting moving planes is due to gravity forces, which, in cases where their velocities do not coincide, leads to the formation of an additional friction plane with a corresponding increase in energy costs and dynamic components of the loads. The uneven velocity of the closed circuit circuits is accompanied by additional relative displacements at certain ratios of kinematic and geometric parameters. An appropriate set of parameters is achievable by eliminating these additional displacements of the product arrays relative to the reference planes and limiting energy costs. The use of rigid kinematic bonds in parallel systems allows for changes in velocities in counter-phases and provides energy recovery. With stabilized kinematic parameters, compared to single-stream systems, higher loads of drive motors with improved performance are achieved.
43
SHAO, Y. Z., W. R. ZHONG, T. LAN, and R. H. LEE. "EXCHANGE COUPLING AND DECOUPLING IN A NANOCOMPOSITE SPIN SYSTEM." International Journal of Modern Physics B 20, no. 01 (January 10, 2006): 61–72. http://dx.doi.org/10.1142/s0217979206033103.
Full textAbstract:
We studied the exchange coupling and decoupling process in a nanocomposite spin system based on a 3D Heisenberg model by means of Monte Carlo numerical computation simulation. Different from the conventional micromagnetism approach in which finite elements method (FEM) is usually adopted to compute, in a top-down way, the magnetic property of micromagnetic ensemble in micron even nanometer scale our current paper presents a new approach in computing the magnetic property of above nanomagnetic ensemble. Our approach addressed a composite spin lattice structure consisting of both single spin and cluster spin built up from single spin in a bottom-up way. Two species of distinctive spins were taken into account further in order to imitate the magnetic behavior of heterogeneous ensemble. The simulation revealed the influence of exchange coupling constant Jab, the size of cluster spins d and system reduced temperature t upon the exchange coupling and decoupling between component spin phases, respectively. Smaller value of Jab, larger d and lower temperature t usually lead to the decoupling of originally exchange-coupled component phases and the occurrence of a characteristic two-stage shoulder with an inflexion on the demagnetization curve. The results reported here are, to some extent, of universality and applicable to other dual-phase magnetic systems since our simulation simply focus on a pure duplex spin system rather than a specific material, and all physical variables were treated in a reduced form.
44
Czernel, Grzegorz, Arkadiusz Matwijczuk, Dariusz Karcz, Andrzej Górecki, Agnieszka Niemczynowicz, Aleksandra Szcześ, Grzegorz Gładyszewski, Alicja Matwijczuk, Bożena Gładyszewska, and Andrzej Niewiadomy. "Spectroscopic Studies of Dual Fluorescence in 2-(4-Fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thiadiazole: Effect of Molecular Aggregation in a Micellar System." Molecules 23, no. 11 (November 2, 2018): 2861. http://dx.doi.org/10.3390/molecules23112861.
Full textAbstract:
The article presents the results of spectroscopic studies focused on a selected compound from the 1,3,4-thiadiazole group—2-(4-fluorophenylamino)-5-(2,4-dihydroxybenzeno)-1,3,4-thia-diazole (FABT)—in a micellar system formed by Triton X-100, a non-ionic detergent. Fluorescence measurements revealed the phenomenon of dual fluorescence whose emergence is related to the particular molecular organisation of the compound, which depends both on the concentration of the detergent and, most of all, the concentration of the compound itself. Dual fluorescence of FABT in a micellar system was observed for the compound dissolved in a methanol aqueous system, i.e., an environment wherein the dual fluorescence of the compound had never been reported before. Based on the interpretation of UV-Vis electronic absorption, resonance light scattering (RLS), emission and excitation fluorescence spectra, as well as measurements of dynamic light scattering (DLS) and Principal Component Analysis (PCA), we were able to relate the occurrence of this effect to the process of molecular aggregation taking place between FABT molecules in the micellar system in question. Results of fluorescence spectra measurements and time-correlated single photon counting (TCSPC) indicate that dual fluorescence occurs at detergent concentrations necessary to form micellar systems, which in turn facilitate the process of aggregation of FABT molecules. The correlation between the observed fluorescence effects and the previous measurements performed for analogues from this group suggests the possibility of charge transfer (CT) within the range of detergent concentrations wherein the aforementioned fluorescence effects are observed. It ought to be emphasised that this type of fluorescence effects are relatively easy to induce, which predisposes this groups of fluorophores as ideal fluorescence probes in the context of biological samples.
45
Ramos, Leonardo A., Rafael F. Van Kan, Marcello Mezaroba, and Alessandro L. Batschauer. "A Control Strategy to Smooth Power Ripple of a Single-Stage Bidirectional and Isolated AC-DC Converter for Electric Vehicles Chargers." Electronics 11, no. 4 (February 19, 2022): 650. http://dx.doi.org/10.3390/electronics11040650.
Full textAbstract:
This paper proposes a single-stage AC-DC rectifier with power factor correction (PFC), high-frequency isolation and bidirectional power conversion capability for on-board battery charger (OBC) applications. The proposed converter is based on the interleaving technique and the Dual Active Bridge (DAB) operation, applying the phase-shift control to regulate the power flow. In addition to topology, this article presents a control strategy for reducing low-frequency power ripples transferred to the secondary side without any additional component and hence maintaining overall size and cost. The single-phase OBC can interchange active power with the grid to charge batteries while performing grid-to-vehicle (G2V) functionality or transferring energy back to the grid via vehicle-to-grid (V2G) mode. The theoretical analysis of the converter including modulation strategy and feedback control scheme are presented. The proposed topology and control strategy have been verified by experimental results of a 650 W SiC-based prototype.
46
Sello, Lehlohonolo, Akhona Maqhubela, and Gaathier Mahed. "Remote sensing-based evapotranspiration determination: A review of single-source energy balance models." South African Journal of Geomatics 11, no. 2 (September 1, 2022): 262–73. http://dx.doi.org/10.4314/sajg.v11i2.7.
Full textAbstract:
Remote Sensing evapotranspiration models are critical in order to understand the cycling of water in the environment. Initially, an outline of the concepts related to evapotranspiration, as well as the shortcomings of land-based methods, is presented. The aim of the study was based on reviewing remote sensing evapotranspiration models which provide an alternative data source. These models have proved to be a cheaper alternative to mapping and estimating spatiotemporal evapotranspiration measurements across local and regional scales. This paper reviews the single-source energy balance model, which differs from the two-source model, for estimating spatiotemporal measurements of evapotranspiration. The single-source energy balance model is underpinned by mathematical equations which differentiate the various single-source evapotranspiration models (Surface Energy Balance Systems, Simplified Surface Energy Systems, Surface Energy Balance Algorithm, and Mapping Evapotranspiration at high Resolution and with Internalised Calibration). The soil surface and forest canopy components were observed to be the major difference between the single and dual-source models. Further advice was discussed on the implementation of the OpenET tool, which provides an open and accessible satellite-based estimation of evapotranspiration for improved water management.
47
Pati, Shyam Sundar, and Swaroop Sahoo. "Single/Dual/Triple Broadband Metasurface Based Polarisation Converter with High Angular Stability for Terahertz Applications." Micromachines 13, no. 9 (September 18, 2022): 1547. http://dx.doi.org/10.3390/mi13091547.
Full textAbstract:
This paper presents design and characterisation of a new compact metasurface based linear polarisation converter for terahertz applications. The metasurface unit cell with periodicity of 0.292λ0 consists of an asymmetrically oriented planar double semicircular goblet-shaped resonators. It is printed on a polydimethylsiloxane (PDMS) dielectric substrate backed by a gold layer that acts as a ground plane. This metasurface structure exhibits a broadband cross-polarisation conversion in the frequency range of 0.72–0.99 THz with a polarisation conversion ratio (PCR) > 95% and angular stability > 40∘ for both TE and TM modes. However, the PCR for the single band is >99% at resonant frequencies of 0.755 and 0.94 THz, while the optimised design shows 100% PCR over a BW of 95 GHz. Furthermore, slight modification and optimisation of the broadband design results in quad-ring and slotted DSGRs that produce dual and triple broadband polarisation conversion, respectively. The quad-ring DSGR performs polarisation conversion for frequency range of 0.70–1.08 and 1.61–1.76 THz while the slotted DSGR shows the triple broadband cross-conversion for frequency range of 0.67–0.85, 1.04–1.11, and 1.62–1.76 THz with PCR > 95%. This design is simple, easy to modify to implement single and multi broadband polarisation conversion with high PCR at terahertz regime. In addition to that, it is easy to fabricate and integrate with other components like multiple-input multiple-output terahertz antennas for mutual coupling reduction.
48
Snow, David. "A Prominence Account of Syllable Reduction in Early Speech Development." Journal of Speech, Language, and Hearing Research 41, no. 5 (October 1998): 1171–84. http://dx.doi.org/10.1044/jslhr.4105.1171.
Full textAbstract:
When young children produce multiword utterances and words that are polysyllabic in adult speech, they are most likely to omit unstressed syllables. Because unstressed syllables are omitted more often in weak-strong (iambic) than in strong-weak (trochaic) environments, a trochaic metrical theory has been proposed to account for the asymmetrical omission pattern. This paper presents an alternative explanation based on the notion of relative prosodic prominence. I propose that syllable prominence is a product of two orthogonal suprasegmental systems: one that marks stress/accent peaks and one that marks phrase boundaries. A two-component scale of prominence values reflecting the contributions of both systems was used to analyze single- and multi-word speech samples of 11 children 19 to 26 months of age. The results show that the prominence scale parsimoniously accounts not only for the bias toward syllable omissions in nontrochaic environments but also explains other types of syllable reduction not captured by metrical theories. Implications of the dual-system prosodic model are discussed in terms of possible contributions to a perceptually based theory of early polysyllabic and multiword patterns in child speech.
49
Sin, Anthony, Hugo Cuellar, and Benjamin Brown. "Carotid-cavernous fistula caused by laceration of persistent fetal trigeminal artery treated with single catheter coil embolization." Indian Journal of Neurosurgery 01, no. 01 (January 2012): 072–74. http://dx.doi.org/10.4103/2277-9167.94375.
Full textAbstract:
Abstract We present the endovascular treatment of traumatic carotid-cavernous fistula from persistent fetal trigeminal artery (PFTA) laceration. To date, there are six such cases of traumatic PFTA-cavernous fistulas reported in the literature. These injuries can pose a unique challenge in that rupture of a PFTA in its course through the cavernous sinus may produce a fistula feeding from both anterior and posterior circulations. Previously, these have been treated with dual catheter coil embolization from the carotid and basilar systems. We utilize a single catheter technique accessing the cavernous sinus through the origin of the PFTA on the internal carotid. Both anterior and posterior fistula components may be embolized through this single access. This represents a simple yet safe treatment option.
50
Fawcett, Angela J., and Roderick I. Nicolson. "Automatisation Deficits in Balance for Dyslexic Children." Perceptual and Motor Skills 75, no. 2 (October 1992): 507–29. http://dx.doi.org/10.2466/pms.1992.75.2.507.
Full textAbstract:
Traditional theories of dyslexia have focused on components of the reading process. The Dyslexic Automatisation Deficit hypothesis takes a broader view, attributing deficits to an inability to become completely fluent in cognitive and motor skills. A series of experiments compared the balance of 15-yr.-old and 11-yr.-old groups of dyslexic children and normal children matched for age and IQ under single-task and dual-task conditions. There were no group differences in the single-task conditions. However, introduction of a concurrent secondary task led to a dissociation in that, whereas the balance of normal children was unaffected, the dyslexic children's balance was significantly impaired. It was concluded that the normal children balanced automatically whereas the dyslexic children did not. These results directly support the proposed framework.