Algorithm For Repair Research Articles

A hierarchical combination algorithm for real-time cycle slip detection and repair in low satellite elevation and high ionospheric activity conditions

To enhance the accuracy and robustness of cycle slip detection and repair for triple-frequency data while minimizing the adverse effects of low satellite elevation and high ionospheric activity, a hierarchical combination algorithm for real-time cycle slip detection and repair is proposed. This algorithm begins by prioritizing the reduction of noise and ionospheric delay coefficients. It determines the optimal coefficients for the combination of observations from the BeiDou Navigation Satellite System’s (BDS) Extra-Wide Lane (EWL), Wide Lane (WL), and Narrow Lane (NL). Leveraging the longer wavelength characteristics of the EWL combination, it simultaneously conducts cycle slip detection on the EWL combination alongside the pseudorange combination. Following this, based on the detection outcomes from the EWL combination, cycle slip detection is carried out on the WL combination. Finally, using the detection findings from the WL combination, cycle slip detection is executed on the NL combination. Given the NL combination’s shorter wavelength and higher susceptibility to ionospheric delay, a dynamic ionospheric prediction model is applied to the NL combination to further mitigate the impact of ionospheric disturbances. After completing the cycle slip detection process, the results from the EWL, WL, and NL combinations are integrated and solved. Experimental results clearly demonstrate that, even in scenarios characterized by low satellite elevation and active ionospheric conditions, this algorithm consistently delivers outstanding detection performance for cycle slip instances, particularly for small cycle slip (less then two cycles). Remarkably, this performance is achieved without the need for intricate searches during cycle slip repair.

A New Algorithm for Secondary Repair of Unilateral Cleft Lip Nasal Deformity.

Following primary surgery for unilateral cleft lip palate (UCLP), cleft lip nasal deformities (CLNDs) (nasal asymmetry, collapsed nasal alae, and a widened alar base) are generally inevitable and often require secondary rhinoplasty. However, reconstructing a cleft nose with an alar tissue deficiency remains challenging for rhinoplasty surgeons. The manifestations of common deformities are described herein, and a secondary rhinoplasty technique for unilateral CLNDs using a nasolabial flap (NLF) has been proposed for patients with alar tissue deficiency. Secondary rhinoplasties were performed in 12 patients with unilateral CLNDs between 2020 and 2021 using a NLF. Photogrammetric measurements were performed preoperatively and postoperatively. A total of 12 flaps were successfully transferred. Ten patients were followed up for >1 year. Significant postoperative decreases in nasal alar width were measured in both the base view (p < 0.050) and the frontal view (p < 0.050). Despite the additional facial scars that occurred in some cases, all patients were satisfied with the aesthetic effects. The NLF achieved satisfactory results in secondary rhinoplasty of unilateral CLND for patients with nasal tissue deficiencies in whom the surgeon weighed the potential benefits over postoperative scarring. 4 Laryngoscope, 134:1648-1655, 2024.

Open Retromuscular Lateral Abdominal Wall Hernia Repair: Algorithmic Approach and Long-Term Outcomes at a Single Center.

Lateral abdominal wall hernias are relatively rare and present unique challenges to repair. Our group has developed an algorithm for repair based on several anatomic characteristics identified on preoperative imaging. Herein, we report our algorithm and outcomes of a large series of open retromuscular lateral abdominal wall hernia repairs. Open retromuscular lateral abdominal wall hernia repairs performed at our institution from August 2014 through April 2021 were identified in the Abdominal Core Health Quality Collaborative. Hernia characteristics, etiology, operative techniques, postoperative outcomes, and long-term patient-reported outcomes were extracted from the Abdominal Core Health Quality Collaborative database, chart review, and telephone follow-up. Of 464 patients who underwent hernia repair, 121 with isolated lateral abdominal wall hernias (L1-4) and mean follow-up of 34 ± 24 months had a clinical recurrence rate of 0.9% (n = 1) and bulge rate of 37% (n = 42). The median Hernia-Related Quality of Life Survey and PROMIS pain intensity scores improved 37 and 9 points, respectively. Another 343 patients with lateral (L1-4) and midline (M1-5) abdominal wall hernias and mean follow-up of 29 ± 21 months had a clinical recurrence rate of 6% (n = 20) and bulge rate of 35% (n = 117). The median Hernia-Related Quality of Life Survey and PROMIS pain intensity scores improved by 43 and 16 points, respectively. We present an algorithm for open retromuscular lateral abdominal wall hernia repair with relatively low anatomic recurrence rates and substantial improvement in patient-reported quality of life and pain. Notably, postoperative bulging is commonly reported by patients, likely due to underlying denervation injuries from the original incision.

A treatment algorithm for secondary cleft palate repair based on age and preoperative velopharyngeal closure ratio

This study aimed to find a surgical treatment algorithm for secondary velopharyngeal insufficiency (VPI), with Furlow palatoplasty or posterior pharyngeal flap (PPF), balancing speaking and breathing. Non-syndromic cleft palate patients with secondary VPI who underwent Furlow palatoplasty or PPF were reviewed. A multinomial logistic regression model was employed to estimate the association between preoperative variables and surgical outcomes. A series of multinomial logistic regression models was utilized to determine the cut-off value of the significant predictors for subgroup comparison. In total, 203 patients were enrolled, with 73 receiving Furlow palatoplasty and 130 receiving PPF. The surgical outcomes of the two techniques were significantly different (p = 0.005). Age was a significant predictor in all intragroup comparative analyses. Preoperative VCR was associated with postoperative velopharyngeal function in patients undergoing Furlow palatoplasty (p = 0.042). The best cut-off values were an age of 13 years and a VCR of 70%. Surgical outcomes in both group B (age <13, VCR <70%; p = 0.017) and group C (age ≥13, VCR ≥70%; p = 0.003) differed significantly between the two surgical techniques. Within the limitations of the study, it is seems that in patients aging <13 years and with a VCR of ≥70%, Furlow palatoplasty should be preferred whenever appropriate to receive adequate velopharyngeal function.

Factors Associated With an Abnormal Blood Pressure Response During Exercise After Coarctation Repair.

Although resting blood pressures following aortic arch repair or the extended end-to-end anastomosis (EEA) repair for coarctation can be physiologic, factors associated with an abnormal blood pressure response after exercise are unknown. We measured blood pressure gradients following exercise in children who had undergone previous repair in accordance with a surgical selection algorithm and sought to identify factors associated with an abnormal blood pressure response. In accordance with our practice's surgical algorithm for repair of coarctation, infants were stratified to aortic arch repair when the distal transverse arch-to-left carotid artery ratio (DTA:LCA) ≤ 1.0, or when a brachiocephalic trunk or intra-cardiac lesion requiring repair was present. A thoracotomy and EEA were otherwise used. A follow-up exercise stress test (EST) measured the arm:leg blood pressure gradient after exercise, and a gradient ≥ 20 mm Hg was defined as an abnormal blood pressure response. Thirty-seven infants who had previously undergone coarctation repair (aortic arch repair-19, EEA-18) completed an EST at 12.3 ± 2.2 years of age. Thirteen (35%) children (aortic arch repair-5, EEA-8; p = .3) exhibited an abnormal blood pressure response. Factors associated with an abnormal blood pressure response included: smaller DTA:LCA ratios prior to repair (1.0 ± .2 vs. 1.2 ± .3; p = .04) and greater body weight at the time of EST (57.5 ± 19.1 vs. 40.9 ± 15.6 kg; p = .03). An abnormal blood pressure response following exercise is associated with smaller DTA:LCA ratios at the time of repair and increased weight during follow-up suggesting that patients with these factors warrant close observation.

Algorithm for Real-Time Cycle Slip Detection and Repair for Low Elevation GPS Undifferenced Data in Different Environments

Real-time cycle slip detection and repair is one of the key issues in global positioning system (GPS) high precision data processing and application. In particular, when GPS stations are in special environments, such as strong ionospheric disturbance, sea, and high-voltage transmission line interference, cycle slip detection and repair in low elevation GPS observation data are more complicated than those in normal environments. For low elevation GPS undifferenced carrier phase data in different environments, a combined cycle slip detection algorithm is proposed. This method uses the first-order Gauss–Markov stochastic process to model the pseudorange multipath in the wide-lane phase minus narrow-lane pseudorange observation equation, and establishes the state equation of the wide-lane ambiguity with the pseudorange multipath as a parameter, and it uses the Kalman filter for real-time estimation and detects cycle slips based on statistical hypothesis testing with a predicted residual sequence. Meanwhile, considering there are certain correlations among low elevation, observation epoch interval, and ionospheric delay error, a second-order difference geometry-free combination cycle slip test is constructed that takes into account the elevation. By combining the two methods, real-time cycle slip detection for GPS low elevation satellite undifferenced data is achieved. A cycle slip repair method based on spatial search and objective function minimization criterion is further proposed to determine the correct solution of the cycle slips after they are detected. The whole algorithm is experimentally verified using the static and kinematic measured data of low elevation satellites under four different environments: normal condition, high-voltage transmission lines, dynamic condition in the sea, and ionospheric disturbances. The experimental results show that the algorithm can detect and repair cycle slips accurately for low elevation GPS undifferenced data, the difference between the float solution and the true value for the cycle slip does not exceed 0.5 cycle, and the differences obey the normal distribution overall. At the same time, the wide-lane ambiguity and second-order difference GF combination sequence calculated by the algorithm is smoother, which give further evidence that the algorithm for cycle slip detection and repair is feasible and effective, and has the advantage of being immune to the special observation environments.

Lexicographic Repair Under Querying Prioritised DL-Lite Knowledge Bases

This article discusses the issue of inconsistency in responses from various DL-Lite knowledge bases. This inconsistency problem is at the origin of several sources of assertions with different levels of reliability. The various solutions proposed in the literature that have to do with retrieving an exhaustive and coherent list of responses are not satisfactory from the point of view of reliability and performance. The solution that we present to solve this problem is articulated around two phases: the first phase consists of interrogating the different knowledge bases to retrieve all of the possible answers, which may be inconsistent and/or contradictory, and the second phase consists in repairing these inconsistencies and/or contradictions. To do this, we propose an approach based on three algorithms that we developed in this framework: a first algorithm for non-defeat repair, a second algorithm for lexicographic repair and a third algorithm for non-defeat repair based on lexicography of possible inconsistent responses. The experimental study carried out on the different data collections, as well as the analysis of the results obtained, confirm the performance of our approach as well as its efficiency in regards to productivity and complexity in terms of execution time.

Efficacy Evaluation of a Case-Specific Approach for Surgical Treatment of Inicisional Ventral Hernia.

Background:The research aims to improve the surgical treatment results of incisional ventral hernia by applying a case-specific approach and a new method of anterior abdominal wall surgery.Materials and Methods:The paper reports the results of the prospective dynamic cohort study on 219 patients under 60 years of age, with small and medium hernias and up to 10 cm defects in the anterior abdominal wall (W1–W2), who underwent incisional ventral hernia treatment with mesh endoprostheses.Results:The paper offers a selection algorithm for anterior abdominal wall repair surgery and an original proprietary technique. We have developed and described in detail a new ‘extra-sublay’ technique of surgical intervention. The paper displays the frequency and pattern of complications, as well as the quality of life of patients after different prosthetic surgeries. In the main group, 65.0% of patients showed improvement, 88.4% showed long-term surgical success, 13.6% faced complications, and 4.5% experienced recurrence.Conclusion:After receiving the “on lay” treatment, 59.4% of patients showed positive results, 74.7% showed long-term surgical success, 40% had complications, and 3.1% experienced recurrence. After the “sub lay” intervention, 40.0% of patients demonstrated excellent results, 81.9% reached long-term success, 12% had complications, and 1.4% encountered recurrence.Highlights:The article shows a selection algorithm for anterior abdominal wall plastic repair method.One of the factors that cause relapses and ventral hernias themselves is obesity.The authors’ method of the VH surgical treatment has shown good results.Excellent indicators showed 65.0% of patients of the main group.

A multiparameter algorithm to guide repair of degenerative mitral regurgitation

PurposeDegenerative mitral regurgitation repair using a measured algorithm could increase the precision and reproducibility of repair outcomes. MethodsDirect and echocardiographic measurements guide the repair to achieve a coaptation length of 5 to 10 mm and minimize the risk of systolic anterior motion. Leaflet reconstruction restored the normal 2 to 1 ratio of anterior to posterior leaflet length without residual prolapse or restriction. The choice of ring size was based on anterior leaflet length, the distance from the leaflet coaptation point to the septum, and the anterior-posterior ring dimension. Freedom from reoperation and mitral regurgitation recurrence were based on multistate models. ResultsOne thousand fifty-one patients had mitral surgery and 1026 (97.6%) were repaired. A2 length was 27.2 ± 4.5 mm; and the reconstructed posterior leaflet was 13.9 ± 2.3 mm. Median ring size was 34 mm and strongly correlated to A2 length (R = 0.76; P < .001). The coaptation length at P2 after repair was 6.4 ± 1.7 mm and 87% of measurements were between 5 and 10 mm. Results at predischarge and 10 years, respectively, included mild regurgitation (7.5% and 26.1%), moderate (0.7% and 15.6%), moderate to severe (0% and 1.4%), and severe (0% and 0%), with mean mitral gradient values 3.5 ± 1.5 and 2.9 ± 1.2 mm Hg, respectively. Systolic anterior motion at discharge and last follow-up were 0.2% and 1.1%, respectively. Ten-year freedom from mitral valve reoperation was 99.7%. ConclusionsA simple, reproducible, measured algorithm for degenerative mitral valve repair provides excellent early and late results and is a useful adjunct to established surgical techniques.

Hybrid Fixation Restores Tibiofibular Kinematics for Early Weightbearing After Syndesmotic Injury.

Background:Disruption of the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), and interosseous membrane (IOM) is a predictive measure of residual symptoms after an ankle injury. Controversy remains regarding the ideal fixation technique for early return to sport, which requires restoration of tibiofibular kinematics with early weightbearing.Purpose:To quantify tibiofibular kinematics after syndesmotic fixation with different tricortical screw and suture button constructs during simulated weightbearing.Study Design:Controlled laboratory study.Methods:A 6 degrees of freedom robotic testing system was used to test 9 fresh-frozen human cadaveric specimens (mean age, 65.1 ± 17.3 years). A 200-N compressive load was applied to the ankle, while a 5-N·m external rotation and a 5-N·m inversion moment were applied independently to the ankle at 0° of flexion, 15° and 30° of plantarflexion, and 10° of dorsiflexion. Fibular medial-lateral translation, anterior-posterior translation, and internal-external rotation relative to the tibia were tracked by use of an optical tracking system in the following states: (1) intact ankle; (2) AITFL, PITFL, and IOM transected ankle; (3) single-screw fixation; (4) double-screw fixation; (5) hybrid fixation; (6) single suture button fixation; and (7) divergent suture button fixation. Repeated-measures analysis of variance with Bonferroni correction was performed for statistical analysis.Results:In response to the external rotation moment and axial compression, single tricortical screw fixation resulted in significantly higher lateral translation of the fibula compared with that of the intact ankle at 10° of dorsiflexion (P < .05). Suture button fixation resulted in significantly higher posterior translation of the fibula at 0° of flexion and 10° of dorsiflexion, whereas divergent suture button fixation resulted in higher posterior translation at only 0° of flexion (P < .05). In response to the inversion moment and axial compression, single tricortical screw and hybrid fixation significantly decreased lateral translation in plantarflexion, whereas double tricortical screw fixation and hybrid fixation significantly decreased external rotation of the fibula compared with that of the intact ankle at 15° of plantarflexion (P < .05).Conclusion:Based on the data in this study, hybrid fixation with 1 suture button and 1 tricortical screw may most appropriately restore tibiofibular kinematics for early weightbearing. However, overconstraint of motion during inversion may occur, which has unknown clinical significance.Clinical Relevance:Surgeons may consider this data when deciding on the best algorithm for syndesmosis repair and postoperative rehabilitation.

Refining Approaches to Surgical Repair of Rectovaginal Fistulas.

Rectovaginal fistulas are notorious for both their morbidity and their difficulty to treat effectively. A variety of methods for repair has been described; however, there is no consensus on the ideal repair. A better understanding of the anatomical relationship of fistulas to the anal sphincter and detrusor muscles is one of the components necessary to develop an effective treatment plan for repair and preservation of sphincter mechanics. A review of the literature was conducted to determine the types of methods typically used by reconstructive surgeons for repair of rectovaginal fistulas. A critical clinical analysis of our series of 10 patients was performed to determine optimal strategies for and pitfalls of repair in the context of recent reports in hopes of refining surgical techniques. Detailed anatomical understanding of the relationship of fistulas to the surrounding sphincter muscles is described. Etiology of the fistula and its anatomical relationship to the surrounding sphincter complex is used to help develop an algorithm for repair. Suprasphincteric fistulas will necessitate a laparotomy for repair, intersphincteric fistulas will often require muscle interposition with recreation of the vaginal and rectal walls, and low/transphincteric fistulas will require local flaps mostly for coverage and repair of the sphincter muscles. Complex rectovaginal fistulas are both debilitating for the patient and extremely difficult to manage. Plastic surgeons are often involved in such cases only after previous attempts at repair have failed. The success of surgery in treating these patients with rectovaginal fistulas depends on a variety of factors. Unfortunately, the available literature describing these repairs lacks uniform guidance regarding approach to repair. Herein, we attempt to detail the possible anatomical variations of fistulas in relationship to the sphincter muscles to begin the discussion necessary for the development of an algorithm for repair that considers preservation of sphincter mechanism function.

Ant Colony Optimization Algorithm for Maintenance, Repair and Overhaul Scheduling Optimization in the Context of Industrie 4.0

Maintenance, Repair, and Overhaul (MRO) is a crucial sector in the remanufacturing industry and scheduling of MRO processes is significantly different from conventional manufacturing processes. In this study, we adopted a swarm intelligent algorithm, Ant Colony Optimization (ACO), to solve the scheduling optimization of MRO processes with two business objectives: minimizing the total scheduling time (make-span) and total tardiness of all jobs. The algorithm also has the dynamic scheduling capability which can help the scheduler to cope with the changes in the shop floor which frequently occur in the MRO processes. Results from the developed algorithm have shown its better solution in comparison to commercial scheduling software. The dependency of the algorithm’s performance on tuning parameters has been investigated and an approach to shorten the convergence time of the algorithm is emerging.

Fenestrated endovascular aneurysm repair and open surgical repair for the treatment of juxtarenal aortic aneurysms

ObjectiveThe objective of this study was to compare surgical risk and early and late mortality of patients treated for anatomically classified juxtarenal aortic aneurysms (JRAs) by fenestrated endovascular aneurysm repair (F-EVAR) or open surgical repair (OSR) during a period when the two treatments were available and to validate an institutional algorithm for JRA repair. MethodsWe retrospectively included all patients treated electively in our center between January 2005 and December 2015 for JRAs classified into three anatomic categories, excluding suprarenal aneurysms. Lee score and American Society of Anesthesiologists (ASA) class evaluated preoperative surgical risk. We compared clinical and radiologic parameters between the patients treated by F-EVAR and those treated by OSR. The primary study end point was 30-day mortality. We also compared 5-year survival. ResultsFrom 2005 to 2015, there were 191 patients separated into two groups, one treated by OSR (n = 134; mean age, 69 years) and the other treated by F-EVAR (n = 57; mean age, 74 years). Patients of the F-EVAR group were significantly older (P = .001). Intensive care unit length of stay was significantly higher in the OSR group (3.4 days vs 1.5 days; P = .01). Surgical risk was significantly higher in the F-EVAR group as measured by Lee score ≥2 (OSR, 8.9 %; F-EVAR, 21%; P = .02) and ASA class 3 and class 4 (OSR, 32.8%; F-EVAR, 73.6%; P = .001), whereas 30-day postoperative mortality was not significantly different (OSR, 1.5%; F-EVAR, 0%; P = .394). The 5-year survival was not significantly different in the two groups (OSR, 82.1%; F-EVAR, 69.2%). ConclusionsIn this study, despite a higher surgical risk by Lee score and higher ASA class in the group of patients treated by F-EVAR, postoperative mortality was not significantly different between these groups. In our opinion, F-EVAR and OSR of JRA are complementary.

An enhanced cycle slip repair algorithm for real-time multi-GNSS, multi-frequency data processing

Cycle slip detection and repair are crucial quality control steps in high-precision global navigation satellite system (GNSS) positioning using carrier phase measurements. Correct detection and repair of cycle slips can avoid repeated integer ambiguity resolution in real-time kinematic (RTK) or long convergence time in precise point positioning (PPP), especially in the context of multi-GNSS and multi-frequency cases. We introduce a generalized procedure for cycle slip detection and repair. The cycle slip detection is carried out using quality control theory on a single satellite–receiver pair. Upon successful detection, integer least-squares estimation is applied to repair the cycle slip vectors. Then if the cycle slips are detected but not repaired, and no cycle slip exists in the coming epochs, an enhanced repair algorithm, which uses measurements over multiple epochs, is developed. The mathematical model for cycle slip repair is strengthened to allow for higher success rate and its implementation is efficiently accomplished using Kalman filter to suit real-time applications. The generalized procedure and the enhanced algorithm for repair are theoretically analyzed for the dual- and triple-frequency cases under different elevations and ionospheric disturbances. Both high- and low-sampling rate MGEX data with artificial cycle slips are processed, and results indicate that the generalized procedure performs well in benign situations and a higher repair success rate is obtained by implementing the enhanced algorithm in extreme conditions.

Reconstruction of Complex Full-Thickness Scalp Defects After Dog-Bite Injuries Using Dermal Regeneration Template (Integra): Case Report and Literature Review

The purpose of this article is to review the current applications of dermal regeneration templates in reconstruction of full-thickness scalp defects, most commonly resulting from oncologic surgery, and show its success in reconstruction of a complex full-thickness scalp defect resulting from a dog-bite injury. A systematic review conforming to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines was completed. A PubMed search was completed using key terms including Integra, dermal regeneration template, full-thickness scalp defects, dog-bite injuries, and scalp. Eligible articles were selected based on the characteristics of defect size, procedural protocol, and reconstruction modality. Outcomes reported were based on reports of follow-up, complications, and percentage graft take. The case report presents reconstruction of a complex full-thickness scalp defect due to a dog-bite injury with a dermal regeneration template. Fifteen articles were included. Reported ages ranged from 2 to 93years. The mean defect size ranged from 6 to 610cm2, with 67% of defects averaging more than 50cm2. All articles reported the 2-stage approach to Integra (Integra LifeSciences, Plainsboro, NJ)-based reconstruction with follow-up ranging from 5 to 23months, with only 2 articles reporting less than 90% graft take. Acellular dermal matrix provides an alternative reconstructive mechanism to free tissue transfer and flap reconstruction and offers a unique advantage in the medically complex patient, as well as in pediatric and geriatric populations. Successful Integra-based reconstruction of full-thickness complex scalp defects is well reported in the literature in relation to reconstruction of Mohs surgical defects, as well as burns of the trunk and extremities; however, reports of reconstruction of post-traumatic soft tissue defects of the head and neck are limited. On the basis of the reported successes from the reviewed literature, as well as the clinical outcome of the reported case, we believe Integra to be a valuable reconstructive tool in the algorithm for repair of post-traumatic, full-thickness, complex scalp defects when used appropriately.

A Competition-based Algorithm for Routing Discovery and Repair in Large-scale VANET

A Competition-based Algorithm for Routing Discovery and Repair in Large-scale VANET

Multifeature-Fitting and Shape-Adaption Algorithm for Component Repair

In recent years, the usage of additive manufacturing (AM) provides new capabilities for component repair, which includes low heat input, small heat-affected zone, and freeform near-net-shape fabrication. Because the geometry of each worn component is unique, the automated repair process is a challenging and important task. The focus of this paper is to investigate and develop a general best-fit and shape-adaption algorithm for automating alignment and defect reconstruction for component repair. The basic principle of using features for rigid-body best-fitting is analyzed and a multifeature-fitting method is proposed to best fit the 3D mesh model of a worn component and its nominal component. The multifeature-fitting algorithm in this paper couples the least-squares method and a density-based outlier detection method. These two methods run alternately to approach the best-fit result gradually and eliminate the disturbance caused from the defect geometry. The shape-adaption algorithm is used to do cross section comparison and defect reconstruction based on the best-fitted 3D model. A “point-line-surface” fracture surface detection method is proposed to construct fracture surface and the fracture surface boundary is dilated to trim the nominal 3D model to obtain defect geometry. Illustrative examples with typical components and different kinds of defects are used to demonstrate the flexibility and capability of using multifeature-fitting and shape-adaption algorithm developed in this paper.

Damage detection and reconstruction algorithm in repairing compressor blade by direct metal deposition

Aero-engine blade repair is challenging due to its complicated geometry and unique defects after serving in a harsh environment. Traditional manual-based remanufacturing processes are not capable of yielding consistently repaired part quality, significantly limiting the application of repair technologies. For building up materials on damaged blades, it is required to detect and extract the repair volume and generate corresponding tool path for additive manufacturing. Therefore, the objective of this paper is to propose an automated damage detection and reconstruction algorithm for jet engine blade repair. Reverse engineering was utilized to reconstruct models of nominal and damaged blades. The reconstructed damaged model was best fitted with the nominal model by transformation matrix and using overlapping area comparison method. Through area comparison method, the damaged blade was separated into intact section and damaged section. A set of parallel and equidistant casting rays were used to intersect with damaged layers to extract the repair volume. Laser scanning tracks were generated according to the extracted geometry. The laser-assisted direct metal deposition process was performed to deposit Ti-6Al-4V particles on the damaged region. Finally, microstructure analysis was carried out to evaluate the repaired part quality. The repair experiment validated that the proposed algorithm is suitable and efficient for automated repair of curved blades.

Autoreject: Automated artifact rejection for MEG and EEG data

We present an automated algorithm for unified rejection and repair of bad trials in magnetoencephalography (MEG) and electroencephalography (EEG) signals. Our method capitalizes on cross-validation in conjunction with a robust evaluation metric to estimate the optimal peak-to-peak threshold – a quantity commonly used for identifying bad trials in M/EEG. This approach is then extended to a more sophisticated algorithm which estimates this threshold for each sensor yielding trial-wise bad sensors. Depending on the number of bad sensors, the trial is then repaired by interpolation or by excluding it from subsequent analysis. All steps of the algorithm are fully automated thus lending itself to the name Autoreject.In order to assess the practical significance of the algorithm, we conducted extensive validation and comparisons with state-of-the-art methods on four public datasets containing MEG and EEG recordings from more than 200 subjects. The comparisons include purely qualitative efforts as well as quantitatively benchmarking against human supervised and semi-automated preprocessing pipelines. The algorithm allowed us to automate the preprocessing of MEG data from the Human Connectome Project (HCP) going up to the computation of the evoked responses. The automated nature of our method minimizes the burden of human inspection, hence supporting scalability and reliability demanded by data analysis in modern neuroscience.

Hypospadias: an algorithm for repair with the aid of the microscope in 102 patients

Hypospadias: an algorithm for repair with the aid of the microscope in 102 patients