Effect Of Position Research Articles

The Effects of Positive Psychological Capital on Innovative Behavior and Turnover Intention of the Start-ups employees: Focused on the Moderating Effects of Gender and Job Position

The Effects of Positive Psychological Capital on Innovative Behavior and Turnover Intention of the Start-ups employees: Focused on the Moderating Effects of Gender and Job Position

Hybrid algorithm GA-PSO-BP in secure localization technology for wireless sensor networks

ABSTRACT Wireless sensors face problems such as poor positioning accuracy in their applications. A hybrid indoor space safety positioning technology is proposed for this purpose. This technology uses genetic models and particle swarm optimization models to optimize the parameters of neural networks. Considering the vulnerability of wireless sensors to Sybil attacks during the positioning process, communication encryption and location awareness are used for optimization. In the positioning experiment, the proposed method had maximum positioning errors of 0.23 m and 0.43 m on the first and second floors, respectively, which were superior to other methods. In the positioning security experiment, the positioning errors of the first and second floors after being attacked by Sybil were 4 m and 5 m respectively, while the proposed security positioning technology had an error range of 1 m. In terms of security comparison, when there are 31–35 attack samples, the proposed method has a maximum root mean square error and average absolute error of 0.72 m and 0.79 m, respectively, which is superior to other models. It can be seen that the proposed technology has excellent positioning effect and stability. The research content will provide important technical support for the practical deployment and security management of wireless sensor networks.

Numerical simulation study on the effect of ignition position on premixed hydrogen deflagration characteristics in tunnels

To analyze the influence of different ignition positions on the propagation of deflagration characteristics and the disaster mechanism in the hydrogen deflagration process in the tunnel, this study compares and verifies the experimental data of tunnel model deflagration based on the CFD code GASFLOW-MPI. A combustion velocity model based on the accelerated separation effect is used, and the effect of heat transfer on the consequences of deflagration is considered. The propagation laws of pressure waves, fluid velocity and temperature in the tunnel are analyzed, and it is found that the changing trends of shock waves and fluid velocity in the tunnel are consistent, but completely opposite in the tunnel outside. The effects of different ignition positions on the hydrogen deflagration characteristics are compared and analyzed. The results show that when ignition occurs at different heights of the center of the premixed region, the impact on the deflagration characteristics is relatively small, while when ignition occurs at different horizontal distances in the premixed region, the impact on the deflagration characteristics is relatively large; the peak overpressure of side ignition is far lower than the case where ignition occurs in the center of the premixed region, but the maximum flow velocity is much higher than the center ignition. The impact on temperature is the smallest. In general, in areas close to the hydrogen/air premixed zone, side ignition results in more severe consequences, whereas in areas far from the premixed zone and outside the tunnel, central ignition leads to more severe consequences. This study provides theoretical support for understanding the disaster-causing mechanisms of hydrogen/air premixed gas deflagration in tunnels under different ignition positions.

Effect of Stem Design and Positioning on the Leg Axis after Total Hip Arthroplasty: A Secondary Analysis.

Background/Objectives: Various parameters, like femoral offset and leg length, are associated with good patient outcomes after total hip arthroplasty. In this prospective study, the effects of stem design, its placement in the proximal femur and the resulting femoral offset on the total leg axis were investigated. Methods: The 27 patients included in this study received biplanar radiography (EOS®, EOS Imaging) with 3D reconstruction using sterEOS® both preoperatively and postoperatively. For all leg alignment parameters obtained from the 3D reconstruction and from measurements using mediCAD, the deltas between the postoperative and preoperative values were determined. Patients were divided into those who received a short-stem prosthesis and those who received a straight-stem prosthesis. Results: The change in femoral offset with the implantation of a short-stem prosthesis was significantly greater than that with the implantation of a straight-stem prosthesis (11.4 ± 5.9 vs. 4.6 ± 7.4 mm, p = 0.014). Compared with the straight-stem implantation, short-stem implantation caused a significantly greater increase in the varus orientation of the leg (-1.4 ± 0.9 vs. -0.4 ± 1.4°, p = 0.048). There was no significant difference in the positioning of the short-stem prosthesis compared to the straight-stem prosthesis in the proximal femur (3.6 ± 3.1 vs. 2.6 ± 1.9°, p = 0.317). Conclusions: These findings substantiate the impact of prosthesis design on offset and leg alignment. The implantation of short-stems is more variable and requires precise planning. Intraoperative non-physiological offset changes and varus deviation of the leg axis should be avoided. Trial registration: This study was retrospectively registered with the German Clinical Trials Register (DRKS) under the number DRKS00015053 on the 1 August 2018.

Comparison of the Effectiveness Lateral Position 30 Degrees and 90 Degrees on Decubitus Events in Stroke Patients

Aims: Stroke is the second leading cause of death and disability globally, characterized by sudden neurological deficits. Pressure ulcers, caused by prolonged bed rest, can be managed non-pharmacologically through immobilization and routine tilting to prevent decubitus. To compare the effectiveness of the lateral position with an inclination of 30 and 90 degrees on the risk of decubitus in stroke patients, in this study the control group was tilted 90 degrees and the intervention group was tilted 30 degrees. Method: The sampling method is non-probability sampling with purposive sampling, a sample of 22 patients. Results: Data analysis using Reapeted Measurement Anova resulted in a value in the experimental group resulting in a sum of square value of 24.9, f value 14.3, P < 0.001, while in the control group a sum of square value of 76.5, f value 26.8, P < 0.001 was obtained, so it can be concluded that the lateral position with an inclination of 90 degrees and 30 degrees has the same effect, namely providing a significant influence on reducing the risk of decubitus. Conclusions: The study reveals that stroke patients aged 56-65 have a higher risk of pressure ulcers, with low-weight patients at higher risk. Early lateral position intervention and nutrition can significantly reduce the risk of decubitus, highlighting the importance of early wound healing.

Association between operative position and postoperative nausea and vomiting in patients undergoing laparoscopic sleeve gastrectomy.

Bariatric surgery is one of the most effective ways to treat morbid obesity, and postoperative nausea and vomiting (PONV) is one of the common complications after bariatric surgery. At present, the mechanism of the high incidence of PONV after weight-loss surgery has not been clearly explained, and this study aims to investigate the effect of surgical position on PONV in patients undergoing bariatric surgery. To explore the effect of the operative position during bariatric surgery on PONV. Data from obese patients, who underwent laparoscopic sleeve gastrectomy (LSG) in the authors' hospital between June 2020 and February 2022 were divided into 2 groups and retrospectively analyzed. Multivariable logistic regression analysis and the t-test were used to study the influence of operative position on PONV. There were 15 cases of PONV in the supine split-leg group (incidence rate, 50%) and 11 in the supine group (incidence rate, 36.7%) (P = 0.297). The mean operative duration in the supine split-leg group was 168.23 ± 46.24 minutes and 140.60 ± 32.256 minutes in the supine group (P < 0.05). Multivariate analysis revealed that operative position was not an independent risk factor for PONV (odds ratio = 1.192, 95% confidence interval: 0.376-3.778, P = 0.766). Operative position during LSG may affect PONV; however, the difference in the incidence of PONV was not statistically significant. Operative position should be carefully considered for obese patients before surgery.

Nonlinear dynamics of a dual-rotor system with active elastic support/dry friction dampers based on complex nonlinear modes

In this study, the nonlinear dynamics of a dual-rotor system with active elastic support/dry friction dampers (ESDFDs) are investigated based on complex nonlinear modes (CNMs). The finite element method (FEM) combined with a full-3D friction model is introduced to construct the governing equation for the system. Additionally, the Craig–Bampton technique is applied to downscale the finite element model of the system. Based on the reduced order model (ROM), the nonlinear modal damping ratio of the target mode is employed to measure the dry friction damping performance of active ESDFD. The effects of the active ESDFD position, normal force, and tangential contact stiffness on the nonlinear modal damping ratio and modal frequency are analysed. Moreover, the softening characteristics of the active ESDFD are revealed, and the critical speed intervals of the active ESDFD/dual-rotor system are determined. Furthermore, by using the harmonic balance–alternating frequency/time domain (HB–AFT) method, the steady-state response of the system under unbalanced excitation is calculated. The accuracy and effectiveness of nonlinear modal analysis are validated based on the relationships between nonlinear modes and steady-state unbalanced responses. Conversely, the vibration mitigation effects of active ESDFD are determined by the unbalanced response amplitude. Additionally, the controllable region and optimal normal force for effective vibration control in the target mode are defined. Depending on the controllable region, a control strategy for turning on/off the optimal normal force is developed. The findings demonstrate that the developed control strategy enables the active ESDFD to significantly reduce the response amplitude of the dual-rotor system across various excitation levels, showing substantial potential for engineering applications.

Optimized gap positions for improved leakage impedance in dry-type transformer design

The power and distribution transformers must be properly designed to operate in a variety of conditions and manufactured following all applicable international standards to provide a reliable energy supply to consumers. The transformer can fail if it is improperly designed, and it cannot withstand the short-circuit condition if the short-circuit current is not calculated properly. Short-circuit current can be easily calculated by evaluating the leakage impedance. Customers can also demand the transformer companies to increase or decrease the leakage impedance. This paper evaluates the effect of the gap's position in the four different sections of the high voltage winding on the leakage impedance of the two-winding transformer and proposes effective design options for minimizing the leakage impedance. The accuracy of the finite element models was also investigated using an experimental laboratory transformer model specially designed for optimizing the leakage impedance. The experimental and finite element methods results show that the leakage impedance can be changed to the desired value and limits and easily assessed by the finite element analysis technique. The results indicate that even with the same use of the winding and core material, there was a considerable difference in the leakage impedance for each of the conditions.

Assessment of joint position sense in active and passive modes with various elbow flexion angles and movement speeds using an isokinetic dynamometer

BackgroundJoint position sense is the ability to detect body segment position in space and is commonly used to represent proprioceptive performance. The isokinetic dynamometer is frequently used to evaluate elbow joint position sense during active and passive reproduction tasks with various testing protocols. However, few studies have reported the performance of joint position sense under different testing conditions. ObjectiveTo compare elbow joint position sense between active and passive reproduction tasks under different matching speeds and reference targets. DesignA cross-sectional study. MethodsTwenty participants without a history of upper-extremity surgery or neuromuscular diseases that affect the joint position sense of the elbow. Active and passive ipsilateral matching tasks were performed at four movement speeds (0.5°/s, 1°/s, 2°/s, and 4°/s) and three reference targets (elbow flexion at 0°–15°, 45°–60°, and 75°–90°), using an isokinetic dynamometer. The absolute and variable errors of each condition were calculated for comparison. ResultsIn active matching task with elbow flexion of 0°–15°, the absolute error at 0.5°/s was significantly larger than that at 2°/s and 4°/s, while the variable error at 1°/s was significantly larger than that at 2°/s. However, no differences were found at elbow flexion angles of 45°–60° and 75°–90°. Larger absolute errors were found at 4°/s with three testing angles in passive matching task. ConclusionsThis study compared the joint position sense errors under various testing conditions in the active and passive reproduction tasks. The movement speeds and target position effects should be considered during evaluation.

Finite element analysis of the effects of different archwire forms and power arm positions on maxillary incisors in en masse retraction using fixed lingual orthodontic appliances.

This study aimed to investigate the effects of archwire form and power arm positions on maxillary incisors during lingual en masse retraction supported by miniscrew implants, using the finite element analysis method. Sliding mechanics for lingual en masse retraction were simulated using the finite element method. Power arms were placed mesial and distal to the maxillary canine with straight and mushroom-shaped archwires. Miniscrews provided absolute anchorage for retraction force. When power arms were positioned mesial to the canine teeth, an increase in the intercanine distance was observed, while a decrease was noted when the power arms were distal to the canine tooth. Lateral incisors exhibited a greater torque loss, particularly when the power arm was mesial to the canine tooth. In the central incisors, the mushroom archwire resulted in intrusion, while the straight archwire showed an extrusion tendency. Movements in groups using the straight archwire were less controlled compared to those in groups using the mushroom archwire. The archwire form and the position of the power arm affected the torque loss and vertical position of incisors during lingual en masse retraction supported by miniscrew implants. The most controlled movement was achieved with the combination of a power arm positioned distal to the canine tooth and a mushroom archform.

The effects of aperture position and length in side-vented needles on root canal irrigation: A computational fluid dynamics study

IntroductionRoot canal irrigation is crucial for infection control during root canal treatment. Side-vented needles for positive pressure irrigation are commonly used in clinical practice. However, variations in needle design among manufacturers can impact the fluid dynamics of irrigation. This study aims to use computational fluid dynamics to explore the flow characteristics of different needle aperture lengths and positions, and their effects on the effectiveness and safety of irrigation, using a validated passive scalar transport numerical model. MethodsThe validation of the CFD irrigant model was achieved by comparing it with an in vitro irrigation experiment model. The CFD model used scalar concentration, while the in vitro experiment model used red dye tracing. Using a standard 30G side-vented needle as a reference, virtual needle models featuring four aperture lengths and three positions were created. These virtual irrigation needles were then placed in two root canal geometries for CFD simulation to evaluate fluid exchange capabilities and related fluid dynamic parameters. ResultsThe results of the CFD simulation, using a scalar transport model, closely matched the in vitro tracer tests for irrigation experiments across seven root canal geometries. The CFD analysis indicated that positioning the aperture lower increased the irrigant exchange distance. Notably, decreasing the aperture length to 0.25x, and positioning it at the lower end of the needle significantly increased exchange distance and shear stress, while reducing apical pressure. ConclusionsThese results indicate that the position and length of the aperture affect the exchange distance of irrigant flow, wall shear stress, and apical pressure. The CFD validation model for scalar transport, based on a steady state, can function as a valuable tool for optimizing the side-vented needle in research. Further research on the design of side-vented needles will enhance the understanding of flow characteristics beneficial for irrigation efficiency in clinical practice.

Quantum computation with logical gates between hot systems

We consider quantum computer architectures where interactions are mediated between hot qubits that are not in their mechanical ground state. Such situations occur, e.g., when not cooling ideally, or when moving ions or atoms around. We introduce quantum gates between logically encoded systems that consist of multiple physical ones and show how the encoding can be used to make these gates resilient against such imperfections. We demonstrate that, in this way, one can improve gate fidelities by enlarging the logical system, and counteract the effect of unknown positions or position fluctuations of involved particles. We consider both a classical treatment of positions, in terms of probability distributions, and a quantum treatment using mechanical eigenmodes. We analyze different settings including a cool logical system mediating interactions between two hot systems, as well as two logical systems consisting of hot physical systems whose positions fluctuate collectively or individually. In all cases, assuming ideal local control to logical systems, we demonstrate a significant improvement in gate fidelities, which provides a platform-independent tool to mitigate thermal noise in the context of trapped-particle-based architectures. Published by the American Physical Society 2024

On the local scour around a jacket foundation under bidirectional flow loading

Jacket structure is a new type of offshore wind turbine foundations with advantages for its lightweight construction, high stability, and suitability for various water depths. However, jacket foundations are often subjected to scouring caused by tidal flows, which can significantly affect the stability of offshore wind energy systems. Limited research has been conducted on the scour characteristics around the jacket foundation under bidirectional flow actions due to the structural complexity. To address this gap, this study performs physical model tests to investigate the effects of flow properties and foundation position on the scour around the jacket foundation. This study assesses the impact of a complex upper truss structure and finite pile height on scouring, in contrast to monopile and regularly arranged pile group foundations. It also analyzes the differences in scour characteristics between a monopile foundation and a jacket foundation subjected to identical bidirectional flow conditions. The impact of flow direction on the scour evolution is evaluated by comparing the scour characteristics under unidirectional and bidirectional flow actions with the same hydrodynamic conditions. The results indicate that the equilibrium scour depth increases with the flow strength and water depth, and reaching its maximum at a foundation angle of 30°. Findings are of great significance for predicting the scour extent around the jacket foundation.

Effect of patient position on the success rate of placing triple-cuffed double lumen endotracheal tubes: a two-center interventional observational study.

Double-lumen endotracheal tubes (DLT) are essential for one-lung ventilation during thoracic surgery. Bronchoscopy is crucial for correct placement of a DLT to avoid complications such as hypoxemia. This study evaluated the effectiveness of the triple-cuffed DLT (tcDLT) in the supine and lateral positions for correct placement without bronchoscopic guidance. This prospective observational study included 167 patients scheduled for elective thoracic surgery requiring one-lung ventilation. The incidence of successful placement of left-sided tcDLTs was compared between the supine and lateral decubitus positions under bronchoscopic surveillance. Successful tcDLT placement was defined as the placement of the proximal end of the bronchial cuff within 5 mm of the carina. Among 153 patients who completed the study, the successful tcDLT placement rate in the lateral position (70.6%) was significantly higher than that in the supine position (50.3%). The rate of difference was 20.3% (95% confidence interval [CI], 10.6-29.9%). The extended successful placement rate, including slightly deeper placements, showed no significant differences between the positions (88.9%; 95% CI, 83.9‒93.9% in supine, 86.3%; 95% CI, 80.8‒91.7% in lateral). tcDLT facilitates correct tube placement in both the supine and lateral positions, with a higher lateral success rate. This finding supports the idea that tcDLTs offer a reliable alternative for lung separation when bronchoscopy is not feasible.

The development of grain resolved stress fields around notch tips in soft-textured zirconium polycrystals: A three-dimensional synchrotron X-ray diffraction study

Texture, microstructure, and local grain neighbourhood contribute to the development of localized stresses in polycrystals. For hexagonal close-packed materials, crystal's elastic and plastic anisotropy can also be a major contributing factor, yet there is a paucity of experimental studies focusing on the extent of contribution of such parameters on the magnitude of localized stresses at microscales. This study focuses on addressing this knowledge gap by deforming double-edge-notched soft-textured α-zirconium specimens in-situ, while measuring grain scale tensorial stresses using high energy synchrotron X-ray diffraction. The specimens were subjected to cyclic loads to study the evolution of stresses in the vicinity of both shallow and deep notches. The soft-texture of the specimens is such that there are no c-axes of grains aligned along the macroscopic loading direction thereby inhibiting deformation twinning. The “as-measured” microstructures and notch geometries were imported into a crystal plasticity finite element model for further analysis. Results show that despite the absence of c-axes of grains aligned along loading direction, the developed stresses were substantially influenced by crystallographic orientations. Stress drop was observed near the onset of plasticity with further loading and the orientation and position effects were highlighted. A plastic deformation mechanism was revealed where, upon specimen loading, the mechanical constraints enforced during grain-grain interactions led to hardening. Accordingly, a parameter was devised to quantify the grain level hardening arising from this mechanism. It was shown that grain-scale stress concentration factors vary significantly before the onset of plasticity, but they settle in the plastic zone and with the progression of cycles.

Nested compressed co-representations of multiple sequential experiences during sleep.

Animals encounter and remember multiple experiences daily. During sleep, hippocampal neuronal ensembles replay past experiences and preplay future ones. Although most previous studies investigated p/replay of a single experience, it remains unclear how the hippocampus represents many experiences without major interference during sleep. By monitoring hippocampal neuronal ensembles as rats encountered 15 distinct linear track experiences, we uncovered principles for efficient multi-experience compressed p/replay representation. First, we found a serial position effect whereby the earliest and the most recent experiences had the strongest representations. Second, distinct experiences were co-represented in a multiplexed, flickering manner during nested p/replay events, which greatly enhanced the network's representational capacity. Third, spatially contiguous and disjunct track pairs were bound together into contiguous conjunctive representations during sleep. Finally, sequences spanning day-long multi-track experiences were p/replayed at hyper-compressed ratios during sleep. These coding schemes efficiently parallelize, bind and compress multiple sequential representations with reduced interference and enhanced capacity during sleep.

How Surgical Positions Affect Cerebral Oxygenation

How Surgical Positions Affect Cerebral Oxygenation? This study investigates the use of cerebral oximetry in various surgical positions and its impact on cerebral oxygenation. We conducted a literature review through Medline, and Ebscohost, focusing on articles published until October 30, 2023. Our findings indicate that: • Cerebral oxygenation is affected by all surgical positions, with the most significant clinical impact observed in the seated position. • Maintaining cerebral autoregulation is crucial for preventing cerebral hypoxia or desaturation. Upholding a mean arterial pressure above 60 mmHg is essential for this purpose. • Anesthesia can negatively impact cerebral oxygenation by potentially impairing cerebral autoregulation. • Inhalation anesthetics may have a more beneficial effect on cerebral oxygenation compared to intravenous anesthetics. • The risk of cerebral desaturation increases in elderly patients and those with comorbidities. • Standardization of cerebral desaturation definitions is needed to better assess its relationship with postoperative complications. • The position of the blood pressure transducer can affect the accuracy of intraoperative monitoring. In the seated position, placing it at the level of the acoustic meatus provides a more precise assessment. Our study highlights the importance of considering the effects of different surgical positions on cerebral oxygenation. This knowledge can assist anesthesiologists in monitoring patients intraoperatively and potentially preventing postoperative neurological complications. Keywords: Cerebral oximetry, Beach chair, cerebral oxygenation, Prone, Near-infrared spectroscopy

Effect of impact position on the mechanical response and viscoelastic behavior of double‐blade composite stiffened structures

AbstractThis paper focuses on the mechanical response and viscoelastic properties of double‐blade composite stiffened structure (DCSS) under low‐velocity impact (LVI). Firstly, the impact resistance and viscoelastic behavior of the DCSS are revealed by LVI testing at four different locations using the same initial velocity. Next, the damage morphologies at the impact locations are observed with ultrasonic A‐ and C‐scan equipment and optical microscopy. At last, the DCSS containing impact damage is implemented for axial compression and the strain values of the DCSS surface are obtained using a strain testing system to reveal its residual properties and buckling behavior. The results show that there are significant differences in the impact damage modes at the four different locations. The maximum impact resistance is observed at location D, while location A has the opposite. The DCSS has a certain viscoelastic behavior at LVI and conforms to an exponential decay model. Moreover, position B presents interface debonding damage due to stiffness discontinuities at the flange and skin bonding and severely weakens the load carrying performance of the DCSS.Highlights The impact resistance of different positions is analyzed by LVI experimental results. Viscoelastic properties exist at different impact locations and obey the exponential decay model. Impact damage alters the buckling load and residual strength of the DCSS. The damage mechanism of the triangular zone is revealed by damage morphology.

Unravelling the Intricacies of Telomere Replication: A Molecular Conundrum

Telomeres are specialized structures at the ends of linear chromosomes that protect them from degradation and fusion. It’s replication is a complex process that involves both DNA polymerases and a specialized enzyme called telomerase which is a ribonucleoprotein complex that synthesizes telomeric DNA by using an internal RNA template. However, telomerase alone cannot fully replicate the telomeric DNA, and requires the cooperation of other factors, such as shelterin, CST, and DNA repair proteins. Telomere replication is tightly regulated by various mechanisms, such as cell cycle checkpoints, telomere length homeostasis, and telomere position effect and dysregulation of it can lead to genomic instability, cellular senescence, and cancer. Therefore, understanding the molecular details of telomere replication is crucial for elucidating the role of telomeres in aging and disease.

Effects of anther-stigma position on cross-pollination efficiency in a hermaphroditic plant.

Evolution of cross-pollination efficiency depends on the genetic variation of flower traits, the pollen vector, and flower trait matching between pollen donors and recipients. Trait matching has been almost unexplored among nonheterostylous species, and we examined whether the match of anther length in pollen donors and stigma length in pollen recipients influences the efficiency of cross-pollination. To explore potential constraints for evolutionary response, we also quantified genetic variation and covariation among sepal length, petal length and width, stamen length, style length, and herkogamy. We created 58 experimental arrays of Turnera velutina that varied in the extent of mismatch in the position of anthers and stigmas between single-flowered plants. Genetic variation and correlations among flower traits were estimated under greenhouse conditions. Style length, but not herkogamy, influenced the efficiency of cross-pollination. Plants with stamen length that matched the style length of other plants were more efficient pollen donors, whereas those with the style protruding above the stamens of other plants were more efficient pollen recipients. Significant broad-sense heritability (0.22 > hB 2 < 0.42) and moderate genetic correlations (0.33 > r < 0.85) among floral traits were detected. Our results demonstrated that anther-stigma mismatch between flowers contributed to variation in the efficiency of cross-pollination. The genetic correlations between stamen length and other floral traits suggests that any change in cross-pollination efficiency would be driven by changes in style rather than in stamen length.