The flight efficiency analysis on the Multi-Arrival Route Point Merge System

This study proposes a new operational concept of the Point Merge System, called Multi-Arrival Route Point Merge System (MAR-PMS), which is an air traffic control method used to sequence aircraft arrivals in a given terminal control area. The proposed concept enables the additional arrival routes that have an angular difference to each sequencing leg. Furthermore, a time-indexed 0-1 linear programming model is formulated. The obtained results are validated in a real time simulation. The comparison results of PMS and MAR-PMS show that the average reduction of 19% of total flight time, 23% of total flight distance, and 19% in total fuel burned and reduction in CO2 emissions in favor of a proposed concept.

Three-Dimensional Cephalometric Landmarking and Frankfort Horizontal Plane Construction: Reproducibility of Conventional and Novel Landmarks

In some dentofacial deformity patients, especially patients undergoing surgical orthodontic treatments, Computed Tomography (CT) scans are useful to assess complex asymmetry or to plan orthognathic surgery. This assessment would be made easier for orthodontists and surgeons with a three-dimensional (3D) cephalometric analysis, which would require the localization of landmarks and the construction of reference planes. The objectives of this study were to assess manual landmarking repeatability and reproducibility (R&R) of a set of 3D landmarks and to evaluate R&R of vertical cephalometric measurements using two Frankfort Horizontal (FH) planes as references for horizontal 3D imaging reorientation. Thirty-three landmarks, divided into “conventional”, “foraminal” and “dental”, were manually located twice by three experienced operators on 20 randomly-selected CT scans of orthognathic surgery patients. R&R confidence intervals (CI) of each landmark in the -x, -y and -z directions were computed according to the ISO 5725 standard. These landmarks were then used to construct 2 FH planes: a conventional FH plane (orbitale left, porion right and left) and a newly proposed FH plane (midinternal acoustic foramen, orbitale right and left). R&R of vertical cephalometric measurements were computed using these 2 FH planes as horizontal references for CT reorientation. Landmarks showing a 95% CI of repeatability and/or reproducibility > 2 mm were found exclusively in the “conventional” landmarks group. Vertical measurements showed excellent R&R (95% CI < 1 mm) with either FH plane as horizontal reference. However, the 2 FH planes were not found to be parallel (absolute angular difference of 2.41°, SD 1.27°). Overall, “dental” and “foraminal” landmarks were more reliable than the “conventional” landmarks. Despite the poor reliability of the landmarks orbitale and porion, the construction of the conventional FH plane provided a reliable horizontal reference for 3D craniofacial CT scan reorientation.

Weight-bearing knee flexion angle better correlates with patient-reported outcome measures than non-weight-bearing condition in total knee arthroplasty: a three-dimensional analysis study

Background This study aims to elucidate and compare the relationship between the knee flexion angle and patient-reported outcome measures (PROM) in both non-weight-bearing (NWB) and weight-bearing (WB) conditions. Methods This retrospective cohort study included 61 knees (47 patients) who underwent total knee arthroplasty. The knee flexion angle was measured by three conditions: NWB in manual goniometer, NWB in fluoroscopic three-dimensional (3D) analysis and WB in the fluoroscopic 3D analysis. The PROM was evaluated by postoperative 2011 Knee Society Score (2011 KSS) and Knee injury and Osteoarthritis Outcome Score (KOOS). Correlations between the knee flexion angle and PROM was analyzed using Spearman’s correlation coefficient. Additionally, whether the angular difference between NWB and WB correlated with the PROM or not was evaluated. Results The NWB knee flexion angle in a goniometer, NWB in 3D analysis, and WB in 3D analysis were 124.6° ± 8.4°, 118.0° ± 10.5°, and 109.5° ± 13.3°, respectively. The angular difference was 8.5° ± 12.8°. No PROM correlation existed in NWB using a goniometer. Moreover, significant positive correlations in 2011 KSS symptoms (r = 0.35) and 2011 KSS functional activities (r = 0.27) were noted in NWB using 3D analysis. Significant positive correlations existed in 2011 KSS symptoms (r = 0.32), 2011 KSS functional activities (r = 0.57), KOOS pain (r = 0.37), KOOS activity of daily living (ADL; r = 0.45), KOOS sports (r = 0.42), and KOOS quality of life (r = 0.36) in WB using 3D analysis. Significant negative correlations were noted in 2011 KSS functional activities (r = − 0.45), KOOS ADL (r = − 0.30), and KOOS sports (r = − 0.38) in angular difference. Conclusions The WB knee flexion angle better correlated with PROM compared with NWB by evaluation of 3D analysis. The larger the angular difference existed between NWB and WB, the lower the PROM score.

Both Intraoperative Medial and Lateral Soft Tissue Balances Influence Intraoperative Rotational Knee Kinematics in Bi-Cruciate Stabilized Total Knee Arthroplasty: A Retrospective Investigation.

BackgroundTibial internal rotation following total knee arthroplasty (TKA) is important in achieving favorable postoperative clinical outcomes. Studies have reported the effect of intraoperative soft tissue balance on tibial internal rotation in conventional TKA, however, its effect on bi-cruciate stabilized (BCS) TKA has not reported enough. Furthermore, although studies have shown that both medial and lateral soft tissue balances are important for a good tibial internal rotation, no studies have evaluated the effects of soft tissue balance at medial or lateral compartments separately on tibial internal rotation in BCS TKA. The purpose of this study was to clarify the relationship between medial or lateral component gaps and rotational knee kinematics in BCS TKA.MethodsOne hundred fifty-eight knees that underwent BCS TKA were included in this study. They were divided into two groups according to the medial or lateral joint laxities, which was defined as the value of component gap minus the selected thickness of the tibial component at 30°, 60°, and 90° flexion, respectively: Group M-stable (medial joint laxity, ≤2 mm) or Group M-loose (medial joint laxity, ≥3 mm) and Group L-stable (lateral joint laxity, ≤3 mm) or Group L-loose (lateral joint laxity, ≥4 mm). The intraoperative rotational knee kinematics was compared between Group M-stable and Group M-loose or between Group L-stable and Group L-loose at each angle, respectively.ResultsThe rotational angular difference between 30° flexion and maximum flexion was significantly larger in Group M-stable at 30° flexion than that in Group M-loose at 30° flexion. The rotational angular difference between 60° flexion and maximum flexion was significantly larger in Group L-loose at 60° flexion than that in Group L-stable at 60° flexion. The rotational angular difference between 60° flexion and maximum flexion was significantly larger in Group L-loose at 90° flexion than that in Group L-stable at 90° flexion.ConclusionSurgeons should pay attention to the importance of medial joint stability at midflexion and lateral joint laxities at midflexion and 90° flexion on a good tibial internal rotation from midflexion to deep flexion in BCS TKA.

Weight-Bearing Knee Flexion Angle Better Correlates with Patient-Reported Outcome Measures Than Non-Weight-Bearing Condition in Total Knee Arthroplasty: A Three-Dimensional Analysis Study

Background: This study aims to elucidate and compare the relationship between the knee flexion angle and patient-reported outcome measures (PROM) in both non-weight-bearing (NWB) and weight-bearing (WB) conditions. Methods: This retrospective cohort study included 61 knees (47 patients) who underwent total knee arthroplasty. The knee flexion angle was measured by three conditions: NWB in manual goniometer, NWB in fluoroscopic three-dimensional (3D) analysis and WB in the fluoroscopic 3D analysis. The PROM was evaluated by postoperative 2011 Knee Society Score (2011 KSS) and Knee injury and Osteoarthritis Outcome Score (KOOS). Correlations between the knee flexion angle and PROM was analyzed using Spearman’s correlation coefficient. Additionally, whether the angular difference between NWB and WB correlated with the PROM or not was evaluated. Results: The NWB knee flexion angle in a goniometer, NWB in 3D analysis, and WB in 3D analysis were 124.6° ± 8.4°, 118.0° ± 10.5°, and 109.5° ± 13.3°, respectively. The angular difference was 8.5° ± 12.8°. No PROM correlation existed in NWB using a goniometer. Moreover, significant positive correlations in 2011 KSS symptoms (r = 0.35) and 2011 KSS functional activities (r = 0.27) were noted in NWB using 3D analysis. Significant positive correlations existed in 2011 KSS symptoms (r = 0.32), 2011 KSS functional activities (r = 0.57), KOOS pain (r = 0.37), KOOS activity of daily living (ADL; r = 0.45), KOOS sports (r = 0.42), and KOOS quality of life (r = 0.36) in WB using 3D analysis. Significant negative correlations were noted in 2011 KSS functional activities (r = −0.45), KOOS ADL (r = −0.30), and KOOS sports (r = −0.38) in angular difference. Conclusions: The WB knee flexion angle better correlated with PROM compared with NWB by evaluation of 3D analysis. The larger the angular difference existed between NWB and WB, the lower the PROM score.

SVD-based angular difference estimation

In this paper, the estimation of angular difference between adjacent sources is investigated in the uniform linear array. In the presence of additive Gaussian noise, we use singular value decomposition to obtain the eigenvalues of the spatial covariance matrix. Thus, the expressions of eigenvalues related to the signal are obtained. The smaller one between the eigenvalues is related to the degree of difference between the two sources and we derive the expression of the angular difference estimation through it. In practice, the more samples observed, the more accurate the estimate is. Numerical results confirm our theoretical analysis and demonstrate the effectiveness of the proposed estimation method. The result in this paper has important guiding significance for array signal processing in the actual environment.

Online Calibration Method for Current Sensors Based on GPS

At present, most sensor calibration methods are off-line calibration, which not only makes them time-consuming and laborious, but also causes considerable economic losses. Therefore, in this study, an online calibration method of current sensors is proposed to address the abovementioned issues. The principle and framework of online calibration are introduced. One of the calibration indexes is angular difference. In order to accurately verify it, data acquisition must be precisely synchronized. Therefore, a precise synchronous acquisition system based on GPS timing is proposed. The influence of ionosphere on the accuracy of GPS signal is analyzed and a new method for measuring the inherent delay of GPS receiver is proposed. The synchronous acquisition performance of the system is verified by inter-channel synchronization experiment, and the results show that the synchronization of the system is accurate. Lastly, we apply our online calibration method to the current sensor; the experimental results show that the angular difference and ratio difference meet the requirements of the national standard and the accuracy of the online calibration system can be achieved to 0.2 class, demonstrating the effectiveness of the proposed online calibration method.

Spatial constraints in saccadic inhibition of return

Despite being one of the most prominent and well-known biases in visual orienting, inhibition of return (IOR), a tendency to avoid recently viewed locations, remains a controversial and poorly understood phenomenon. To investigate the characteristics of IOR, participants made rapid alternating saccades between two targets, return saccades, or produced eye movements that followed an “hourglass” pattern in which the same location was only revisited every fourth eye movement. Saccade dwell times and secondary saccade frequency increased when the eye returned immediately to a previously viewed location. Surprisingly, the higher rate of secondary saccades did not contribute directly to the longer dwell times in the return condition. Saccade precision was equivalent between conditions, but saccade gain was smaller for hourglass saccades. Varying the height and width of the hourglass revealed that the magnitude of inhibition of return depended on the angular separation between subsequent saccades and was not characterized by a constant zone around the targets. Even when the angular difference of hourglass saccades, relative to return saccades, was made as small as 3 degrees, significant differences in dwell times and secondary saccade characteristics were observed. The results further explicate constraints on inhibition of return, reveal novel factors guiding secondary saccade programming, and provide insight into motor and attentional constraints governing the rate of sequential eye movements.