Placement Method Research Articles

Study on the Reproduction Method of Miniature Ga Fixed Points for Shipborne Thermometer Calibration

Abstract The onsite calibration precision of the ocean thermometer can be efficiently raised by temperature scale transfer technology based on miniature fixed points. A new reproduction method of miniature Ga fixed points was studied for the sub-millikelvin precision measurement requirement. The onsite calibration system consists of a miniature Ga fixed point and a shipborne calibration device. The performance of miniature Ga fixed point is highly dependent on placement methods and the value-taking methods of phase transition temperature. This paper analyzed and compared the melting plateau of a miniature Ga fixed point with two placement methods and three value-taking methods of phase transition temperatures. The experimental results showed that utilizing horizontal placement and the average value method can achieve fixed point reproducibility within 1 mK. The performance of the miniature Ga fixed point was verified using the SBE 3plus thermometer from the SBE 911plus CTD system, with a thermometer accuracy of ±1 mK. The difference between the measured value by SBE 3plus and the Ga melting plateau value was within 0.5 mK. Thus, the study of the miniature Ga fixed point offers effective technical support for the onsite calibration of ocean thermometer.

Optimizing Scheduled Virtual Machine Requests Placement in Cloud Environments: A Tabu Search Approach

This paper introduces a novel model for virtual machine (VM) requests with predefined start and end times, referred to as scheduled virtual machine demands (SVMs). In cloud computing environments, SVMs represent anticipated resource requirements derived from historical data, usage trends, and predictive analytics, allowing cloud providers to optimize resource allocation for maximum efficiency. Unlike traditional VMs, SVMs are not active concurrently. This allows providers to reuse physical resources such as CPU, RAM, and storage for time-disjoint requests, opening new avenues for optimizing resource distribution in data centers. To leverage this opportunity, we propose an advanced VM placement algorithm designed to maximize the number of hosted SVMs in cloud data centers. We formulate the SVM placement problem (SVMPP) as a combinatorial optimization challenge and introduce a tailored Tabu Search (TS) meta-heuristic to provide an effective solution. Our algorithm demonstrates significant improvements over existing placement methods, achieving up to a 15% increase in resource efficiency compared to baseline approaches. This advancement highlights the TS algorithm’s potential to deliver substantial scalability and optimization benefits, particularly for high-demand scenarios, albeit with a necessary consideration for computational cost.

Study on the grid supporting effects for GFM energy storage system in distribution networks under grid faults

The grid-forming energy storage system (GFM-ESS) plays a critical role in enhancing the reliability of power-electronic-based power systems by providing voltage support to the grid. In this paper, the grid-supporting function of GFM-ESS on different buses was studied under the different types of short-circuit faults. First, the mathematic models for control strategies of the grid-following (GFL) converter and grid-forming (GFM) converter as well as their duality relationships were studied and illustrated. Secondly, the response of the GFM inner control loop to different short-circuit fault types is analyzed using symmetrical component decomposition. An optimization algorithm is then proposed to improve the voltage-supporting capabilities of the GFM-ESS and to identify the optimal placement of energy storage systems (ESSs) within the distribution network. The relationship between the support capabilities of the GFM-ESS under different short-circuit faults was derived and represented. Finally, the results of case studies were presented, analyzed, and discussed. The optimal location for the GFM ESS in the distribution network can be determined with the proposed mathematic models and the method for the optimal placement.

Study on the comprehensive influence of Si-Al-based additives on hydrogen production and K deposition during biomass gasification

Green hydrogen production through gasification is a prospective utilization of biomass. Operational issues (slagging, corrosion and catalyst poisoning) due to inherent alkali metal deposition are main factors affecting gasification. The adoption of Si-Al-based additives as alkali metal inhibitors is a promising approach. In this work, the influence of additive types and placement methods on K deposition and gasification characteristics were studied through a decoupled gasification with online analysis. As a result, separative placement (Sep) method could reduce K deposition without decreasing hydrogen yield compared to mechanical mixture (Mix) method. This advantage is particularly prominent in char gasification. SiO2 is recommended to be added by the Mix to react with alkali and alkaline earth metal species individually to inhibit K release. This match could reduce peak of K deposition content by 55.80 % with less impact on hydrogen yield. Meanwhile, Al2O3 is recommended to be added by the Sep due to its unique comprehensive performance, which could increase hydrogen yield by 4.34 % and reduce peak of K deposition content by 52.72 %. Two recommended addition strategies could be used in different scenarios. This study is expected to guide the design of corrosion-resistant reactors and multifunctional catalysts.

Performance of Urea-Based Enhanced Efficiency Fertilizers Under Sidedress Nitrogen Placement Methods

Enhanced efficiency nitrogen fertilizer (EENF) is a viable N management tool that can minimize N loss and maximize crop productivity. Research on the efficiency of EENF under relatively newer N-sidedress placement methods for liquid fertilizers, such as Y-Drop dribble, is limited, hence the necessity to address this knowledge gap. A two-year field trial was conducted to evaluate ammonia volatilization, grain quality, and grain yield from surface-applied EENF forms of urea and EENF forms of urea ammonium nitrate (UAN) applied under four placement methods in a rainfed no-till corn production system. The EENF forms of urea evaluated in this trial included Environmentally Smart Nitrogen, SuperU, and ANVOL-treated urea, while ANVOL-treated UAN was the EENF form of UAN. All the urea fertilizers were surface broadcasted while the UAN fertilizers were broadcasted, dribbled in between rows, Y-Drop dribbled, and injected behind colters. Among the non-EENF, urea volatilized the most ammonia (23.1% of total N applied) compared to UAN. Broadcast UAN was much more susceptible to ammonia volatilization than dribbled UAN in between rows. In this trial, the EENF forms of urea and UAN reduced ammonia loss by 65 to 94 and 50 to 51%, respectively, compared to their corresponding non-EENF forms. In 2021, the grain yield of the non-EENF forms of UAN was similar to the EENF forms of the corresponding placement methods. In contrast, there was an additive yield effect from all the urea forms of EENF. A significant negative relationship was observed between ammonia loss and grain protein, grain N, and grain yield; hence, placement methods with higher ammonia loss potential are prone to yield loss.

Assessing the impact of rice-wheat-maize residue decomposition rate and nutrient dynamics of residue and soil using different placement method in the IGP of India

The rice-wheat cropping system (RWCS) provides the world’s population with staple foods, and it is crucial to maintain global food demand and security. Food systems are a complex ecosystem and sustain many feedback mechanisms. Crop residue management is one of those feedback mechanisms that was assessed under conservation agriculture, and a decomposition study was analyzed for the rice-wheat cropping system using rice, wheat, and maize crop residue for decomposition rate and nutrients release under agricultural practices (zero till, raised beds). Different zero tillage techniques in Samastipur demonstrated an accelerated decomposition trend, which was especially noticeable in the straw from wheat and rice. At the same time, permanent bed systems showed a relatively larger residue mass, especially in the case of wheat and maize straw. Permanent bed systems (wheat-maize system), particularly those using wheat straw, held the largest amounts of residue mass when the total residue mass throughout the sites was taken into account. Samastipur showed higher nutrient release for all the rice residue in wheat, rice residue in maize, and wheat residue in rice except maize residue in rice as compared to the Karnal sites. Decomposition kinetics, modeled via a first-order exponential decay function, showed high correlations (R2: 0.941 to 0.996) across treatment methods. The research underscores the significant effect of agroecological factors on residue decomposition and nutrient release, irrespective of residue type, highlighting the importance of tailored residue management practices for enhanced nutrient cycling and sustainability. These findings contribute to the optimization of residue management strategies in RWCS, promoting sustainable agriculture practices in the face of climate change and increasing food security demands.

Posterior Tibial Nerve Stimulation Effect on Treatment of Overactive Bladder: A Systematic Review and Meta-analysis

Context: Overactive bladder (OAB) is a symptomatic syndrome indicative of lower urinary tract dysfunction. Current treatments for OAB syndrome include behavioral therapy, pharmacotherapy, minimally invasive procedures like sacral nerve stimulation and tibial nerve stimulation, as well as surgical options. Objectives: This systematic review aimed to evaluate the effectiveness of posterior tibial nerve stimulation (PTNS) as a treatment for OAB syndrome and to identify potentially effective stimulation methods. Evidence Acquisition: A systematic search was conducted using PubMed, Scopus, ProQuest, Web of Science, Google Scholar, and The Cochrane Library databases for predefined keywords. Two independent reviewers screened the studies’ titles, abstracts, and full texts. The quality of the studies was assessed using the JBI risk of bias (RoB) checklists. Studies meeting the inclusion criteria were summarized in an extraction table. Meta-analysis was performed using Review Manager Software. Results: Out of 2,282 studies identified, 63 were included in the data extraction table, and 19 of these were included in the meta-analysis to compare the effect of PTNS based on the number of treatment sessions (less than 12 sessions vs. 12 - 24 sessions). Despite heterogeneity among the studies, results showed a significant reduction in voiding frequency post-intervention (95% confidence interval, -4.25 to -1.48, P < 0.0001, Z = 4.06), with a greater reduction in the 12 - 24 sessions group (chi2 = 8.40, df = 1 (P < 0.004); I2 = 88.1%). Additionally, specific electrode placement methods further reduced voiding frequency after PTNS. Conclusions: Posterior tibial nerve stimulation can reduce voiding frequency in patients with OAB and painful bladder syndrome. However, establishing a standard PTNS method remains challenging due to variations among studies and the absence of control groups in many cases. Based on the results, PTNS with a frequency of 20 Hz, pulse duration of 200 µs, and stimulation intensity at the pain threshold appears effective for both transcutaneous and percutaneous techniques over 12 - 24 sessions. The percutaneous method may be more effective than the transcutaneous method.

Accuracy of percutaneous pedicle screw placement using modified single anterior-posterior fluoroscopy with the C-arm for the treatment of traumatic thoracic and lumbar fractures

We aimed to assess percutaneous pedicle screw (PPS) placement accuracy, fluoroscopy shot number, and operation time using a modified single anterior-posterior (AP) fluoroscopy with a C-arm in treating traumatic thoracic and lumbar vertebral fractures. In total, 164 patients with single-level traumatic thoracic or lumbar fracture who underwent six PPS placements between April 2018 and September 2020 were divided into two groups. Conventional AP combined lateral fluoroscopy was used in Group A, whereas modified single AP fluoroscopy was used in Group B. The accuracy of the PPS placement, number of fluoroscopy shots, and operative time were compared. All patients underwent computed tomography (CT) two days after surgery to evaluate screw position. Pedicle breach was divided into four grades based on postoperative CT. Our study included 984 implanted pedicle screws, of which 36 (3.7%) were malpositioned. The breach rate was 3.5% (grade 2, 3.1%; grade 3, 0.4%) in Group A and 3.7% (grade 2, 3.0%; grade 3, 0.8%) in Group B. The median number of fluoroscopy shots during PPS placement was 21.9 in Group A and 8.4 in Group B. The median operation time was 76.07±6.86 min in Group A and 55.78±7.21 min in Group B. The PPS placement method using modified single AP fluoroscopy for treating traumatic thoracic and lumbar spine fractures was fairly accurate and reduced the number of fluoroscopy shots and operation time. This technique requires only a C-arm for assistance and can be easily mastered by spinal surgeons across hospitals of various levels.

Metal Punch vs. Drill for Rotator Cuff Anchor Socket Creation; Cadaveric and Clinical Comparisons

BackgroundArthroscopic rotator cuff repair has been shown to decrease pain and increase function of certain rotator cuff tears. One potential source of pain is the technique used for bone tunnel creation in the humerus prior to suture anchor placement. This study compared the standard metal punch method to a continuous drilling method for tunnel creation prior to subsequent suture anchor placement. Our hypothesis was that the use of a drill would result in less bony trauma and therefore superior resolution of postoperative pain following rotator cuff repair. MethodsTunnels were created for six cadaveric (age: 50.83±3.25; male n=3; female n=3) shoulder humeri using a 4-anchor construct to mimic transosseous equivalent rotator cuff repair. Following suture fixation, μCT scans were performed for evaluation of peri-tunnel bone architecture. A tensile force was applied to the anchor through the suture material at a constant displacement rate of 1mm/s until ultimate failure of the construct. All statistical analyses were performed using SPSS (version 25; IBM, Armonk, NY, USA), and significance was set at p≤0.05. A total of 43 subjects between 18 and 80 years old were randomized into the study, with 22 in the drill group and 21 in the punch group. Following surgery, the first 5 patients in each cohort underwent MRI at the 2-week postoperative visit. Pain and other patient reported measures (PROMs) were assessed at all standard of care postoperative visits. Patient demographics and PROMs were assessed for significance within the groups using repeated ANOVA and unpaired t-test. A P-value of <0.05 was set for significance. ResultsPreclinical - There were no statistically significant differences (p>0.05) between punched and drilled anchors with respect to peri-socket bone architecture and material properties. Clinical – There were no statistically significant differences (p>0.05) between punch and drill cohorts for assessments of pain, function, or bone marrow lesion size. However, the punch cohort reported statistically significant and clinically meaningful reductions in pain scores at 2 weeks, 6 weeks, 3 months, and 6 months compared to preoperative scores (p<0.02), whereas the drill cohort reported statistically significant and clinically meaningful reductions in pain scores at 6 weeks, 3 months, and 6 months after surgery (p <0.05). Similarly, the punch cohort reported statistically significant reductions in PROMIS pain interference scores, which were within 1 standard deviation of the healthy adult control population, at 2 weeks, 6 weeks, 3 months, and 6 months compared to preoperative scores (p <0.05), whereas the drill cohort did not report statistically significant improvements in PROMIS PI scores until 3 months postoperatively and were not within 1 standard deviation of the healthy adult control population until 6 months after surgery. ConclusionPreclinical and clinical data suggest that it is reasonable to utilize either a punch or drill socket-creation method for suture anchor placement in arthroscopic rotator cuff repair, while considering the potential for earlier pain relief associated with the punch method.

A multi-task genetic programming approach for online multi-objective container placement in heterogeneous cluster

Owing to the potential for fast deployment, containerization technology has been widely used in web applications based on microservice architecture. Online container placement aims to improve resource utilization and meet other service quality requirements of cloud data centers. Most current heuristic and hyper-heuristic methods for container placement rely on single allocation rules, which are inefficient in heterogeneous cluster scenarios. Moreover, some container placement tasks often have similar characteristics (e.g., resource request types and physical machine types), but traditional single-task optimization modeling cannot exploit potential common knowledge, resulting in repeated optimization during resource allocation. Therefore, a new multi-task genetic programming method is proposed to solve the online multi-objective container placement problem (MOCP-MTGP). This method considers selecting appropriate allocation rules according to the types of resource requests and cluster status. MOCP-MTGP can automatically generate multiple groups of allocation rules from historical workload patterns and different cluster states, and capture the similarities between all online tasks to guide the transfer of general knowledge during optimization. Comprehensive experiments show that the proposed algorithm can improve the resource utilization of clusters, reduce the number of physical machines, and effectively meet resource constraints and high availability requirements.

Abstract 4135273: Frailty increases the risk of in-hospital mortality and post-procedural complications in patients undergoing Cardiac Implantable Electronic Devices placement

Background: Heart failure with reduced ejection fraction (HFrEF) often necessitates the use of cardiac implantable electronic devices (CIED) such as cardiac resynchronization therapy defibrillators (CRT-D) or implantable cardioverter-defibrillators (ICD). These devices are proven to reduce mortality, prevent hospitalizations, and improve symptoms and quality of life. Frailty, characterized by an age-associated decline in physiological reserve, significantly impacts outcomes in these patients. This study uses the Hospital Frailty Risk Score (HFRS) to assess the effect of frailty on mortality and post-procedural complications in HFrEF patients undergoing CIED implantation. Hypothesis: Frail patients with HFrEF have worse in-hospital outcomes after CIED placement Methods: We conducted a retrospective cohort study using the 2020 National Inpatient Sample database from the Healthcare Utilization Project. Our population included patients aged 18 years or older with HFrEF who underwent CRT-D or ICD placement, identified using ICD-10 procedure codes. The primary risk factor was frailty, classified by an HFRS score of ≥5 (frail) or &lt;5 (not frail). The primary outcome was in-hospital mortality, and the secondary outcome was the composite of post-procedural complications. Multivariate regression analysis was used to estimate the odds ratio. Results: Out of 24,809 patients who underwent ICD or CRT-D placement, 48.8% were frail. Non-Frail patients had lower mean age compared to Frail patients (66.2 vs 67.3 years old, p=0.003). In-hospital mortality was 1.1%, and 7% experienced post-procedural complications. In-hospital mortality was higher in frail patients compared to non-frail patients (2% vs 0.3%, p&lt;0.001). In the multivariate analysis, frail patients had higher odds of in-hospital mortality compared to the non-frail group subset (OR=5.97; 95% CI: 2.77-12.88, p&lt;0.001). Additionally, frailty was associated with higher odds of post-procedural complications (OR=1.28; 95% CI: 1.01-1.63, p&lt;0.001), increased length of stay (5 vs 11.6 days, p&lt;0.001), and total hospital charges (215,668 vs 324,474 , p&lt;0.001). Conclusion: Frailty significantly increases the risk of in-hospital mortality and post-procedural complications in HFrEF patients. This highlights the importance of considering frailty as part of a pre-procedural risk stratification assessment and tailoring management strategies to improve outcomes for these high-risk patients.

Combined static and dynamic computer-guided surgery for prosthetically driven zygomatic implant placement

ObjectivesTo propose and validate a minimally invasive combined static and dynamic computer assisted implant surgery (CAIS) workflow for zygomatic implant (ZI) placement. MethodsA combined approach leveraging static CAIS for initial positioning, complemented by dynamic CAIS for real-time control of the angle, depth and width was proposed. Fourteen consecutive patients (age: 60.3±9.8 years; 8 females) seeking ZI-supported restoration were enrolled. A single anatomically and prosthetically driven ZI on either the unilateral zygoma or bilateral zygomata was planned and placed using the proposed approach. The zygomatic anatomy-guided approach (ZAGA) type and the ZI length were recorded. The angular, coronal global, and apical global deviation between the planned and placed positions were measured by overlapping post- and pre-operative cone beam computer tomography. Comparisons were made between the left and right sides across the ZAGA type and ZI length. Statistical significance was set at P<0.05. Results22 ZIs were placed using the combined approach and 13 immediate loading prostheses were delivered, with one patient restored 6 months after surgery. The angular deviations and coronal global deviations were 1.99±0.17° and 1.21±0.45 mm, respectively. The median apical global deviation was 1.67 mm (interquartile range [IQR]: 1.11-1.93 mm). No significant differences were found between the left and right sides across the ZAGA type or ZI length. All ZIs remained stable over a median follow-up of 14.5 months (IQR: 7-20 months). ConclusionsThe proposed combination of static and dynamic CAIS is safe, reliable, accurate, and robust for ZI placement. Clinical significanceThis pilot study proposed a minimally invasive ZI placement method that combined static and dynamic computer-guided surgery. The implant positioning accuracy achieved using this approach validated its safety, reliability, accuracy, and robustness. The combined approach may reduce the technique sensitivity of ZI placement, facilitating future rehabilitation of severely atrophic or defective maxillae.

A novel 'stop-hole' strategy to extend the fatigue life of orthodontic thermoformed retainers: an in vitro study.

This study aimed to investigate the potential to limit crack propagation in thermoformed retainers (TRs) and extend their fatigue life by placing a 'stop-hole'. Thirty-two TRs, fabricated from 1mm thick, round polyethylene terephthalate glycol (PETG) blanks of ICONIC®, underwent testing within a custom-built fatigue tester. After initial crack growth of 3mm, the TRs were divided into three groups: a control group (C) and two experimental groups based on the stop-hole placement method. In the first experimental group, stop-holes were placed using a 1mm round carbide bur on a slow-speed handpiece (ES), while the second group utilized a heated 1-mm-width ball-ended CPITN probe (EH). Following the placement of a stop-hole at the crack-tip, all 32 TRs resumed testing until the final crack length of 10mm was reached. Stop-hole placement significantly prolonged the delay in crack re-initiation in both experimental groups compared to the control group (P < .001 for both). The mean re-initiation times for the ES and EH groups were 104.50 and 129.50min, respectively, whereas the control group was 28.94min. Consequently, this discrepancy was reflected in the total testing times, with both experimental groups requiring significantly longer time to reach the final crack length (P < .001). There was no significant difference in the testing times between the two experimental groups. This is an in vitro study. The stop-hole methodology significantly extended the fatigue life of a TR in a controlled laboratory environment.

PSSN: a novel cache placement method based on adapted Shannon entropy and simple additive weighting method in named data networking

PSSN: a novel cache placement method based on adapted Shannon entropy and simple additive weighting method in named data networking

An advanced spatial decision model for strategic placement of off-site hydrogen refueling stations in urban areas

The strategic placement of hydrogen refueling stations (HRSs) is crucial for the successful adoption of hydrogen fuel cell vehicles (HFCVs) and the promotion of sustainable urban transportation. However, existing spatial decision models using Geographic Information Systems (GIS) and Multi-Criteria Decision-Making (MCDM) often stop at generating suitability maps and rely on simplistic or arbitrary site placement methods, such as fixed service radii, without optimizing spatial distribution that overlook inherent uncertainties, limiting the effectiveness of the decision-making process. This study develops an advanced spatial decision model to handle uncertainty and optimize HRS placement in Prague, Czechia. The model integrates multiple methodologies: (i) Utilizing 21 criteria across accessibility, environmental, infrastructural, and socioeconomic dimensions, with criteria weights prioritized using the Fuzzy Analytic Hierarchy Process (FAHP) to manage uncertainty in expert judgments. GIS suitability analysis identified optimal areas, with 18.13% of Prague classified as highly suitable for HRS deployment. (ii) Implementing Fuzzy C-Means (FCM) clustering to optimize site distribution and address uncertainty in HRS placement, proposing 10 optimal locations validated by a Silhouette score of 0.68. (iii) Evaluating model performance through sensitivity analysis, revealing responsiveness to criteria variations. To evaluate and rank the proposed HRS locations, we integrated a Genetic Algorithm (GA) with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), optimizing the selection process by exploring a wider solution space. Additionally, accessibility analysis assessed emergency response coverage, ensuring efficient response times. This multi-methodological framework ensures a robust, data-driven approach to site selection, optimizing accessibility, minimizing environmental impact, and promoting sustainable urban transportation. It advances strategic infrastructure planning, sets a precedent for integrating advanced analytic techniques to handle uncertainty and automate site selection in spatial decision-making, and is adaptable to diverse urban contexts.

Data-driven parallel optimization method for sensor placement and state estimation based on generative adversarial principle in unobservable systems

Abstract Data-Driven State Estimation (DDSE) is characterized by low measurement requirements and high estimation accuracy, which provides the possibility of stable and efficient estimation for unobservable distribution systems with low measurement quantities. However, the lack of an efficient and flexible sensor placement method with DDSE at this stage hinders the development and application of DDSE in distribution networks. To address this issue, a data-driven parallel optimization method for sensor placement and state estimation based on the generative adversarial principle in unobservable systems is proposed in this paper. This method transforms sensor placement and state estimation into an adversarial learning model, solvable through gradient descent. The sensor placement optimization strategy generates a cost-effective placement scheme, while DDSE evaluates the sensor scheme, provides improvement suggestions, and enhances its estimation accuracy. Through adversarial training, the proposed scheme yields a significantly reduced number of sensor placement schemes compared to traditional methods, while maintaining high precision of DDSE. Simulation results on the IEEE-33 node system validate the effectiveness of the proposed approach.

Efficient Stochastic Template Bank Using Inner Product Inequalities

Gravitational wave searches are crucial for studying compact sources such as neutron stars and black holes. Many sensitive modeled searches use matched filtering to compare gravitational strain data to a set of waveform models known as template banks. We introduce a new stochastic placement method for constructing template banks, offering efficiency and flexibility to handle arbitrary parameter spaces, including orbital eccentricity, tidal deformability, and other extrinsic parameters. This method can be computationally limited by the ability to compare proposal templates with the accepted templates in the bank. To alleviate this computational load, we introduce the use of inner product inequalities to reduce the number of required comparisons. We also introduce a novel application of Gaussian Kernel Density Estimation to enhance waveform coverage in sparser regions. Our approach has been employed to search for eccentric binary neutron stars, low-mass neutron stars, primordial black holes, and supermassive black hole binaries. We demonstrate that our method produces self-consistent banks that recover the required minimum fraction of signals. For common parameter spaces, our method shows comparable computational performance and similar template bank sizes to geometric placement methods and stochastic methods, while easily extending to higher-dimensional problems. The time to run a search exceeds the time to generate the bank by a factor of O(105) for dedicated template banks, such as geometric, mass-only stochastic, and aligned spin cases, O(104) for eccentric and O(103) for the tidal deformable bank. With the advent of efficient template bank generation, the primary area for improvement is developing more efficient search methodologies.

Information-theoretic sensor placement for large sewer networks

Utility operators face a challenging task in managing wastewater networks to proactively enhance network monitoring. To address this issue, this paper develops a framework for optimized placing of sensors in sewer networks with the aim of maximizing the information obtained about the state of the network. To that end, mutual information is proposed as a measure of the evidence acquired about the state of the network by the placed sensors. The problem formulation leverages a stochastic description of the network states to analytically characterize the mutual information in the system and pose the sensor placement problem. To circumvent the combinatorial problem that arises in the placement configurations, we propose a new algorithm coined the one-step modified greedy algorithm, which employs the greedy heuristic for all possible initial sensor placements. This algorithm enables further exploration of solutions outside the initial greedy solution within a computationally tractable time. The algorithm is applied to two real sewer networks, the first is a sewer network in the South of England with 479 nodes and 567 links, and the second is the sewer network in Bellinge, a village in Denmark that contains 1020 nodes and 1015 links. Sensor placements from the modified greedy algorithm are validated by comparing their performance in estimating unmonitored locations against other heuristic placements using linear and neural network models. Results show the one-step modified greedy placements outperform others in most cases and tend to cluster sensors for efficiently monitoring parts of the network. The proposed framework and modified greedy algorithm provide wastewater utility operators with a sensor placement method that enables them to design the data acquisition and monitoring infrastructure for large networks.

Accuracy of dental implant surgery with freehand, static computer-aided, dynamic computer-aided, and robotic computer-aided implant systems: An in vitro study

The static computer-aided implant system (S-CAIS), dynamic computer-aided implant system (D-CAIS), and robotic computer-aided implant system (R-CAIS) have been used to improve the accuracy of implant placement. However, the accuracy of freehand (FH),S-CAIS, D-CAIS, and R-CAIS implant placement has not been compared and verified under identical conditions. The purpose of this in vitro study was to compare the accuracy of dental implant placement using S-CAIS, D-CAIS, R-CAIS, and FH techniques under identical conditions. A total of 60 standardized polyurethane resin models with missing mandibular teeth were prepared and divided into 4 groups: FH, S-CAIS, D-CAIS, and R-CAIS, each consisting of 15 models. Preoperative implant planning was performed using cone beam computed tomography (CBCT), and 2 implants were placed in each model using the FH, S-CAIS, D-CAIS, and R-CAIS techniques, respectively. Postoperatively, CBCT scans were made for analysis of the entry, apical, and angle deviations. The error results among groups were compared using 1-way analysis of variance or a nonparametric test. The Dunnett test was used for post hoc comparison (α=.05). The mean ±standard deviation values for entry deviation were 1.09 ±0.33 mm for the FH group, 0.72 ±0.33 mm for S-CAIS, 0.69 ±0.29 mm for D-CAIS, and 0.48 ±0.18 mm for R-CAIS (P<.05). The mean (quartiles) apical deviations were 1.01 (0.94 -1.22) for the FH group, and the mean ±standard deviation values were 0.87 ±0.07 mm for the S-CAIS group, 0.64 ±0.05 mm for D-CAIS, and 0.47 ±0.03 mm for R-CAIS (P<.05). The mean ±standard deviation values for angle deviation for the FH group were 2.74 ±0.84 degrees, 1.99 ±0.76 degrees for S-CAIS, 0.85 ±0.46 degrees for D-CAIS, and 0.53 ±0.20 degrees for R-CAIS (P<.05). R-CAIS is a reliable implant placement method, demonstrating better implant accuracy compared with the S-CAIS, D-CAIS, and FH techniques.

Comparison of Patient-Reported Quality of Life Following Direct-to-Implant Prepectoral and Subpectoral Breast Reconstruction Using BREAST-Q: A Randomized Controlled Trial.

Background Direct-to-implant breast reconstruction (DIR) is becoming more and more accepted. There is a lack of high-quality studies assessing differences in patient-reported quality of life (QoL) between different implant placement methods. The aim of this randomized controlled (clinical) trial was to compare QoL between women reconstructed by sub- or prepectoral implant placement. Methods We included women over 18 years eligible for DIR. Patients were randomly assigned to reconstruction by subpectoral or prepectoral implant placement. Assessment of QoL and patient satisfaction was made using the BREAST-Q questionnaire for postmastectomy breast reconstruction and compared between the sub- and prepectoral reconstructed groups preoperatively and after 3 and 12 months of follow-up. Results A total of 42 women were allocated to sub- or prepectoral reconstruction with 21 patients in each group. There were no differences in patient characteristics between groups. Regarding all the selected BREAST-Q scales: (1) satisfaction with the reconstructed breast, (2) satisfaction with the breast implant, (3) satisfaction with the overall outcome, (4) psychosocial well-being, (5) sexual well-being, and (6) physical well-being-we found no significant differences between the two groups. Assessing each group independently we found, that in both groups sexual well-being improved after surgery postoperatively compared to the preoperative scores. Conclusion We found high satisfaction and QoL following both sub- and prepectoral breast reconstruction. We found no significant differences between groups suggesting both methods for DIR can be used. Despite our high-quality data, a larger sample size and longer postoperative follow-up are needed to further investigate the differences in QoL between sub- and prepectoral breast reconstruction.