Proper Position Research Articles

A new efficient algorithm for short path planning of the vertical take-off and landing air-ground integrated vehicle

With excellent air-ground multi-mode movements, the vertical take-off and landing (VTOL) air-ground integrated vehicle can easily traverse complex terrains and maintain high energy efficiency. During movement, path planning plays an important role in achieving the autonomous operation of the vehicle, which faces the following difficulty. A short air-ground multi-mode path requires efficient planning, with proper judgment of the timing and position for mode switching. To address this difficulty, we propose a new path planning algorithm, named Dynamically Directed Graph Algorithm (DDGA). It can realize short path search in limited search nodes via dynamically extracting key search nodes in maps and forming a dynamically directed graph. To be specific, adjacent nodes of the first obstacle traversed by the connection line from the current search node to the destination are defined as key search nodes. As the current node changes, key search nodes are dynamically updated. The above key search nodes and the directed paths between them form a dynamically directed graph. Considering the air-ground movement capability, obstacle areas below maximum flight altitudes in maps are defined as pending flight areas. The directed paths traversing these areas are considered in the above graph. Besides the two-dimensional distance cost, flight altitude cost is added to the cost values of different directed paths. This cost contributes to judging the proper switching timing and position. Compared to other algorithms, DDGA can find short paths with fewer search nodes in multiple obstacle maps. It efficiently plans a short air-ground multi-mode path for the VTOL air-ground integrated vehicle.

Intriguing type-II g-GeC/AlN bilayer heterostructure for photocatalytic water decomposition and hydrogen production

Adapting two-dimensional (2D) van der Walls bilayer heterostructure is an efficient technique for realizing fascinating properties and playing a key role in solar energy-driven water decomposition schemes. By means of first-principles calculations, this study reveals the intriguing potential of a novel 2D van der Walls hetero-bilayer consisting of GeC and AlN layer in the photocatalytic water splitting method to generate hydrogen. The GeC/AlN heterostructure has an appropriate band gap of 2.05 eV, wherein the band edges are in proper energetic positions to provoke the water redox reaction to generate hydrogen and oxygen. The type-II band alignment of the bilayer facilitates the real-space spontaneous separation of the photogenerated electrons and holes in the different layers, improving the photocatalytic activity significantly. Analysis of the electrostatic potential and the charge density difference unravels the build-up of an inherent electric field at the interface, preventing electron–hole recombination. The ample absorption spectrum of the bilayer from the ultra-violet to the near-infrared region, reaching up to 8.71 × 105/cm, combined with the resiliency to the biaxial strain, points out the excellent photocatalytic performance of the bilayer heterostructure. On top of rendering useful information on the key features of the GeC/AlN hetero-bilayer, the study offers informative details on the experimental design of the van der Walls bilayer heterostructure for solar-to-hydrogen conversion applications.

Smart double glazing integrated polymer dispersed liquid crystal for enhancing building's thermal performance in hot-arid climate

Polymer-dispersed liquid crystal glazing is an electrically activated smart switchable glazing that requires an AC power supply to become transparent and remains opaque without power. This dynamic feature, with multiple transparency states, is suitable for building in hot and arid climates. It can effectively reject unwanted solar energy, allowing visible light while contributing to building energy efficiency by reducing the carbon footprint. In this work, the PDLC glazing system was included with a low-e coated glass and this coupled system was investigated with two control approaches for residential buildings in hot arid climates. The first control is a standard On-Off operation based on the tenant preferences, while the second is able to set glazing transparencies according to the solar radiation intensity, in order to minimize the penetration of direct solar radiation and to provide daylighting and indoor privacy protection. The system is reversed to examine the proper positions and layer order in the glazing system. The proposed system demonstrates remarkable enhancements in indoor thermal performance, surpassing clear glass by 21 % in the south orientation and 25.5 % in the west orientation. Furthermore, when the PDLC is oriented towards the outdoor environment, the system achieves an impressive 53.9 % improvement in heat gain control compared to clear glass. Additionally, the system not only enables dynamic control over direct solar radiation but also offers efficient daylighting and indoor privacy protection.

Surgical correction of chronic penile retroversion through a castration incision in a horse

SummaryThis is a clinical case report describing the surgical correction of a penis retroverted through a scrotal castration site fistula of at least 4 months duration. The penile retroversion was not observed in the immediate post‐operative period or for the first 2 months of ownership by the owner. Surgical correction involved breaking down adhesions, replacing the penis into its proper anatomic position and debriding and closing the scrotal fistula. The gelding was discharged 1 day post‐operatively without any complications. Follow‐up communication with the owner revealed no apparent concerns with surgical site healing or abnormalities in ability to urinate long‐term.

Relocation incentives for ride-sourcing drivers with path-oriented revenue forecasting based on a Markov Chain model

Proper positioning of ride-sourcing drivers may improve vacant travel times, waiting times, and matching opportunities. Herein, we evaluate the potential repositioning response of drivers when provided guidance based on estimates of their earnings in a system offering ride-hailing (solo) and ridesplitting (shared) rides. Therefore, we develop a strategy that enumerates the best regional repositioning destination based on the expected number of requests a driver will encounter during the forecast horizon. A mixed continuous-discrete time Markov Chain (MDCTMC) is developed to predict a driver’s activities and the associated revenues. In summary, the developed strategy provides a group of drivers with individualized near-future revenue estimates guiding drivers toward repositioning decisions that are more likely to maximize their earnings. Our main findings indicate that if the operator selects only a fraction of active drivers to provide guidance, these are likely to expect higher earnings than those without guidance. We also show that it manages to decrease the number of unserved requests compared to several state-of-art benchmarks while increasing vehicle occupancy and decreasing the deadheading.

Impact of priority assignment on schedule-based attacks in real-time embedded systems

In this paper, we investigate the impact of priority assignment on schedule-based attacks in fixed-priority real-time systems. Through the schedule-based attacks, attackers may manipulate the input and output buffers of victim tasks, cause instability, and/or steal hidden information. The success of those attacks highly depends on the proper positioning of the malicious task with respect to the victim tasks in the actual schedule. Firstly, we develop an optimal priority assignment algorithm that incorporates the user specified priority preferences that reflect task types (anterior task, posterior task, or victim task), while still meeting all the deadlines. Secondly, we propose a dynamic delaying algorithm to further reduce posterior schedule-based attacks at run-time. Finally, we derive and compare the performance of six attack-aware priority-assignment policies as well as their dynamic extensions through comprehensive simulations. Our results suggest that the well-known RMS algorithm can be easily outperformed in terms of reducing schedule-based attacks, by properly specifying the relative priorities of malicious, anterior, and posterior tasks through our optimal algorithm. In particular, the AMP assignment, which assigns the anterior, malicious, and posterior tasks execution priorities in decreasing order, is shown to offer rather robust and consistent performance even at high system utilizations. Our framework explicitly incorporates the logical execution time and attack effective window constraints to model schedule-based attacks in realistic manner.

Activation of the DNA damage checkpoint perturbs asymmetric localization of Kar9 to spindle pole bodies in Saccharomyces cerevisiae

During cell cycle progression in Saccharomyces cerevisiae, spindle pole bodies (SPBs) are duplicated during the G1/S-phase transition. SPBs are crucial for the organization of both the spindle and astral microtubules, and their orientation defines the direction of nuclear division. In this process, an old SPB, which serves as the template SPB during the duplication process, is oriented toward the bud side. The patterning microtubule plus-end tracking protein, Kar9, plays an important role in the orientation of SPBs by asymmetrically localizing to the old SPB. Here, methylglyoxal (MG), a metabolite derived from glycolysis, was found to perturb asymmetric Kar9 localization and influence proper positioning of the old SPB. MG activated the DNA damage checkpoint pathway, and MG-induced perturbation of asymmetric Kar9 localization was abolished by the deletion of MEC1, a sensor for the DNA damage checkpoint pathway. Methyl methanesulfonate, a DNA-alkylating agent, also perturbed asymmetric Kar9 localization. Our results suggest that activation of the DNA damage checkpoint pathway perturbs the asymmetric Kar9 localization required for proper positioning of SPBs.

Musculoskeletal disorders among dental students: a survey from Saudi Arabia

BackgroundWork-related musculoskeletal disorders (WMSD) are injuries affecting bones, joints, muscles, and tendons due to improper working conditions with serious consequences on health and career. Dentists were found to be at greater risk of developing WMSD compared to other healthcare providers. This study aimed to investigate the prevalence and risk factors of WMSD among dental students in Saudi Arabia.MethodsThis cross-sectional survey-based study recruited dental students across the kingdom using respondent-driven sampling technique. Data was collected using the Nordic Musculoskeletal scale and a validated, self- administered, close-ended questionnaire which assessed WMSDs predisposing factors, enabling factors and musculoskeletal disorders consequences and management. The questionnaire was administered in both Arabic and English languages and was distributed online using google forms. Data analysis was performed using SPSS, Chi-square test or Fisher Exact test was used where appropriate and Multivariate Logistic regression analysis was performed to identify predictors of developing WMSDs.ResultsThe prevalence of WMSD was 87% (95% CL; 83.9% to 90.3%) among the 462 respondents. Gender, study year, type of practice, having clinics for left-handed, hours of clinical practice, sitting in the proper position while working, use of coping strategies were significantly associated with WMSD prevalence (P < 0.05). Males were OR = 10 times at higher risk of WMSD compared to females (P = 0.0001). Those with daily clinical practice were OR = 5 times at higher risk of WMSD than those who have weekly practice. Those practicing walking, workout, and yoga showed lower prevalence of WMSD (OR = 0.377 & 0.323, p = 0.015, 0.010 respectively).ConclusionsThe prevalence of WMSD among dental students in KSA was high. Males and those with prolonged clinical sessions were at greater risk of WMSD. There is a need for awareness campaigns to educate dental students about risk factors of WMSD. Collegesy, dental colleges should adopt policies in reducing WMSD among their students.

Patient-Specific Instrumentation with Laser-Guide-Navigated THA: Clinical and CT Evaluation of the First 100 Cases

Obtaining a proper position for total hip arthroplasty components is a crucial aspect of implant performance and consequently of patient outcomes. Restoring the original hip center and maintaining the limb length are key factors in reaching the optimal implant positioning. The aim of this study was to assess the accuracy and safety of a computed dynamic analysis system that, through patient-specific guides, tries to improve implant positioning and functional orientation according to patients’ spinopelvic mobility and anatomy. A total of 100 consecutive patients were prospectively enrolled. All patients received an Optimized Positioning System dynamic hip preoperative planning schedule. A CT scan protocol follow-up analysis was performed 6 months after surgery. The mean deviations from the planned acetabular inclination and anteversion were 4.3° and 3.8°, respectively. In total, 98% of cases were within ± 10° of the Lewinnek safe zone, both for inclination and anteversion. The height of osteotomy deviated, on average, 1.6 mm. In total, 100% of cases were included within 4 mm of osteotomy. Patient-specific and laser-guided instrumentation was found to be safe and accurately reproduced dynamic planning in terms of the component orientation, osteotomy level, leg length and offset.

Economic Viability of NaS Batteries for Optimal Microgrid Operation and Hosting Capacity Enhancement under Uncertain Conditions

Recent developments have increased the availability and prevalence of renewable energy sources (RESs) in grid-connected microgrids (MGs). As a result, the operation of an MG with numerous RESs has received considerable attention during the past few years. However, the variability and unpredictability of RESs have a substantial adverse effect on the accuracy of MG energy management. In order to obtain accurate outcomes, the analysis of the MG operation must consider the uncertainty parameters of RESs, market pricing, and electrical loads. As a result, our study has focused on load demand variations, intermittent RESs, and market price volatility. In this regard, energy storage is the most crucial facility to strengthen the MG’s reliability, especially in light of the rising generation of RESs. This work provides a two-stage optimization method for creating grid-connected MG operations. The optimal size and location of the energy storage are first provided to support the hosting capacity (HC) and the self-consumption rate (SCR) of the RESs. Second, an optimal constrained operating strategy for the grid-connected MG is proposed to minimize the MG operating cost while taking into account the optimal size and location of the energy storage that was formerly determined. The charge–discharge balance is the primary criterion in determining the most effective operating plan, which also considers the RES and MG limitations on operation. The well-known Harris hawks optimizer (HHO) is used to solve the optimization problem. The results showed that the proper positioning of the battery energy storage enhances the MG’s performance, supports the RESs’ SCR (reached 100% throughout the day), and increases the HC of RESs (rising from 8.863 MW to 10.213 MW). Additionally, when a battery energy storage system is connected to the MG, the operating costs are significantly reduced, with a savings percentage rate of 23.8%.

A RETROSPECTIVE ANALYSIS OF SURGICAL POSITIONING INJURY USING INCIDENT REPORTING SYSTEM

(Purpose) Surgical positioning injury (SPI) is a cutaneous, musculoskeletal, neurological, or vascular injury resulting from the position of the patient during surgery. We performed a retrospective study using incident reporting system to examine the incidence of SPI at our hospital. (Materials and methods) Among anesthesiology managed surgical cases, SPI cases reported in the incident reporting system between 2012 and 2017 were examined. The primary endpoint was the incidence of SPI. (Results) Of 35,400 anesthesiology managed cases, 59 (0.2%) had SPI reported in the incident reporting system. Forty-four (75%) were male patients. Median age and BMI were 60 and 23.6 years, respectively. Forty-four (75%) were not supine position. Median operative time and blood loss were 419 minutes and 220 ml, respectively. Nurses reported incident reports in 52 (88%) cases, and only 7 (12%) by physicians. Skin injuries were reported in 42 cases (71%) and neurovascular injuries in 17 cases (29%). Of the neurovascular injuries, 4 (7%) were lower extremity compartment syndrome. Three cases of the 4 received the fasciotomy. (Conclusions) The incidence of SPI reported in the incident report system was 0.2%. Four cases had compartment syndrome. This result suggested the importance of intraoperative and postoperative observation in addition to proper correct positioning.

Surgical and Orthodontic Management of Multiple Supernumerary Teeth Associated with Impacted Permanent Teeth: A Case Report

Background: Clinical problems are frequently detected when there are various irregularities in the number, structure, quantity, size, and eruption of the teeth. Supernumerary teeth can be found in almost any part of the dental arch, and because they are typically asymptomatic, they are frequently found by radiographic screening. Case report: The existence of the supernumerary teeth is the most frequent reason for impacted permanent teeth. This article describes the surgical and orthodontic treatment of a 20-year-old female with many supernumerary teeth and an impacted permanent tooth. All supernumerary teeth in the maxillary arch were extracted as part of the patient's treatment, and then the maxillary teeth were aligned using fixed appliances. The mandibular arch is left untreated, as the surgical removal of mandibular supernumerary teeth could damage the inferior alveolar nerve and result in numbness in the lower lip. Conclusion: In this case, we removed the extra teeth and used orthodontic traction to bring the remaining teeth into the proper position. After the procedure, the cosmetic outcome was greatly improved, and the patient's confidence increased.

Pelvis radiographs in children with cerebral palsy: effects of patient positioning on calculating migration percentages.

Hip displacement in children with cerebral palsy (CP) is monitored by measuring migration percentage on anteroposterior pelvis radiographs. However, proper positioning for radiography in children with spasticity is difficult. The reliability and accuracy of migration percentage as a function of patient positioning is unknown. To determine the effects of patient positioning on migration percentage measurements in children with CP. We identified children with CP (≤18-year-old) with pelvis CT and anteroposterior pelvis radiograph obtained <6 months apart (10/2018-11/2021). Digitally reconstructed radiographs were generated from each pelvis CT, to simulate nine different patient positions: neutral; 10° and 20° lordosis and kyphosis; and 10° and 20° right rotation and left rotation. Two radiologists measured migration percentages from the simulated and real pelvis radiographs. We used Spearman's rho to assess inter-rater reliability, and Wilcoxon signed rank test to determine statistical significance. We studied sixty-three children (male=41; median age=8 years; range=4-18 years). The two radiologists' migration percentage measurements were highly correlated with each other across all simulated and real radiographs (Spearman's rho=0.86-0.99, P<0.01). For both readers and hips, migration percentages measured from real radiographs were significantly different from those measured from neutral simulated radiographs (P<0.01), with median absolute difference=5-6 percentage points (PP) and interquartile range (IQR)=9-12 PP. When comparing migration percentage measurements from neutral simulated radiographs to those in kyphosis/lordosis and right/left rotations, median absolute differences were 2-4 PP (IQR=3-8 PP) and 4-15 PP (IQR=6-17 PP), respectively. Inter-rater reliability of measured migration percentages is high, but accuracy decreases with patient positional changes.

Proper position of single and large (≥5 cm) hepatocellular carcinoma in Barcelona Clinic Liver Cancer classification.

The purpose of this study was to evaluate the proper position of single large hepatocellular carcinoma (HCC) in the Barcelona Clinic Liver Cancer (BCLC) staging system. The data were collected from the nationwide multicentre database of the Korean Liver Cancer Association. Patients with single large (≥5 cm) HCC were separated from BCLC stage A patients and designated as Group X. The remaining BCLC stage A and stage B patients were classified as Group A and Group B, respectively. The survival outcomes of propensity score-matched groups were compared. Among the 3965 randomly selected patients, the number of patients in Group X, Group A, and Group B was 414, 2787, and 760, respectively. TriMatch analysis allowed us to obtain 116 well-balanced triplets. The 1-, 3-, and 5-year overall survival rates in Group X were worse than in Group A (91%, 71%, and 48% vs 90%, 78%, and 64%, respectively; P < .000). However, the rates were not different compared with those in Group B (91%, 71%, and 48% vs 90%, 69%, and 48%, respectively; P < .09). In multivariate analysis, Group X, Group B, age over 60 years, prothrombin time-international normalized ratio, and creatinine level were independent predictors of worse overall survival. Our findings suggest that Group X should be relocated to BCLC stage B rather than BCLC stage A.

Piezoelectric polarization accelerated charge separation in Zinc stannate based Schottky barrier for high-efficiency hydrogen evolution

Piezoelectric polarization can effectively improve the separation and transfer of the carriers in photocatalyst. Herein, a dimension-matched piezo-photocatalyst was designed based on plate-like orthorhombic perovskite Zinc stannate (ZnSnO3)@reduced graphene oxide (rGO), which verified the prominent hydrogen (H2) evolution performance. Driven by the mechanical vibration induced piezoelectric field, the limitation of photocatalytic H2 evolution on the proper band edge position had been breached. The band of ZnSnO3 could be tilted more negative than H2O/H2 redox potential under the piezoelectric field, making it possible to achieve H2 evolution which was originally unsatisfactory. Moreover, on the basis of piezoelectric field, the Schottky barriers established in the catalyst further accelerated the electron separation. The electron paramagnetic resonance results demonstrated that the strongest ·O2− and ·OH radical intensities could only be observed when under the synergistic of light and ultrasonic. The effect of contents, size, surface chemistry of rGO and the ultrasonic power on piezo-photocatalytic performance were also optimized. Satisfactory, the ZnSnO3@rGO exhibited superior piezo-photocatalytic H2 evolution (5.66 mmol g−1), which was four times more than that of ZnSnO3 (1.37 mmol g−1). This work sheds light on the essentially synergistic effect of the mechanical and luminous energy in H2 evolution through piezo-phototronic process.

Can Computer Virtual Influencers Replace Human Influencers in the Future? An Empirical Investigation in the Age of Digital Transformation

Marketers often face challenges when pursuing and working with social-media influencers. However, these challenges can be bypassed when choosing virtual influencers. This paper investigates computer-generated virtual influencers’ impact on a new fashion brand associations and buying intentions. Drawing on virtual humans’ literature and human influencer marketing literature, this study utilizes a fictional fashion brand and manipulates this brand using a popular Instagram virtual influencer.&#x0D; To understand the effect of virtual influencers’ characteristics on brand associations and buying intentions, 225 survey forms were distributed using a random-sampling method. Structural equation modeling was used to examine the virtual influencer attributes’ effects on brand attitudes and buying intentions. The study concluded that replacing human influencers in the fashion context, especially for new brands to establish a proper brand positioning, is integral to success. The study contributes to influencers’ marketing literature by integrating the virtual influencer concept into a celebrity endorsement discourse. Furthermore, the study offers a blueprint for marketing managers who are keen to understand virtual influencers’ attributes required to have an effective endorsement.

Ectopic Lingual Thyroid: A Case Presentation

Lingual thyroid is by far the most common manifestation of ectopic thyroid. Although often asymptomatic, it is associated with congenital hypothyroidism and, most importantly, the absence of the thyroid in its usual position, making it the only functional thyroid tissue the patient has in many cases. It appears indistinguishable from thyroid tissue that located in the proper anatomical position on imaging, with strong homogeneous enhancement on contrast CT. Here we report the clinical and imaging presentation of lingual thyroid in a 33-year-old female.

An experimental and numerical study on optimization of number and position of the clamps in sheet metals fixture

The accuracy of the machining process is highly dependent on how well a workpiece is constrained in a fixture. A well-constrained workpiece has high stiffness and shows minimum deformation under the application of load. Workpiece can be constrained by the proper positioning of fixture elements. This research introduces a finite element-based numerical methodology to automatically select optimum number and position of clamps in the sheet metal, necessary for good quality of manufacturing process. The objective function is to minimize the total deformation normal to the plane of sheet metal while keeping maximum deformation of individual nodes upto 2 mm. The N-3-2-1 fixturing principle is used to place clamps on primary plane of the workpiece. The proposed method consists of two stages; in first stage, the initial number of clamps are determined. In second stage, initial number of clamps and their positions are optimized using genetic algorithm. The proposed method implemented on the case studies successfully reduced the total deformation with optimized number of clamps. The maximum deformation in individual nodes was kept upto 2 mm. An experimental setup was developed to verify the numerical results. The numerical and experimental results fully justify the proposed method.

Evolution of Medical Modeling and 3D Printing in Microvascular Midface Reconstruction: Literature Review and Experience at MD Anderson Cancer Center.

Reconstruction of the midface represents a challenge for reconstructive microsurgeons given the formidable task of restoring both aesthetics and functionality. In particular, preservation of proper globe positioning and maintaining normal vision are as important as restoring the proper projection of the midface and enabling a patient to speak and eat as normally as possible. The introduction of virtual surgical planning (VSP) and medical modeling has revolutionized bony reconstruction of the craniofacial skeleton; however, the overwhelming majority of studies have focused on mandibular reconstruction. Here, we introduce some novel advances in utilizing VSP for bony reconstruction of the midface. The present review aims (1) to provide a review of the literature on the use of VSP in midface reconstruction and (2) to provide some insights from the authors' early experience.

Improved Confidence and Clinical Application: The Effects of a Longitudinal Suture Curriculum for Medical Students.

The ability to competently suture is an expected skill for graduating medical students, but many graduates report feeling unprepared to perform this skill. This study aimed to improve student confidence and clinical readiness for third-year clerkships by implementing a novel, mandatory 7.5-hour longitudinal suturing skills curriculum across the first 3 years of medical school. The required suturing skills curriculum was implemented for all medical students throughout the first 3 years of medical school at a large academic health center in the mid-South United States. Precurriculum (n = 167) and postcourse (n = 148) surveys were administered to first-year students in the first year of the curriculum (2017-2018), and a parallel follow-up survey was administered to this cohort in 2020 after students completed their clinical clerkship year (n = 82). Aggregate changes in students' survey responses were analyzed for proper instrument position, simple interrupted sutures, and instrument ties using independent groups Mann-Whitney U tests and Rosenthal correlation coefficients for effect sizes. Statistically significant improvement from pre to post was observed in student comfort in performing three basic skills: proper instrument position (P < 0.001), simple interrupted suture (P < 0.001), and instrument ties (P < 0.001). These pre-post gains were sustained at 2-year follow-up (P < 0.001). Also, the majority of students (66%) reported they were very or completely prepared to suture wounds during their clerkships. Most (83%) also reported they had successfully sutured patient wounds during third-year clerkships without needing significant direction or guidance. We found that a longitudinal suture curriculum with dedicated faculty involvement can improve student confidence in suturing and overall preparedness for third-year clerkships. Although the study is limited to ratings of student comfort and self-reported performance as well as some attrition of responses at postcourse survey and postclerkship survey, the findings highlight the importance of a focused curriculum dedicated to teaching basic suturing skills. Our findings also contribute to the limited body of work examining longitudinal surgical skills development for medical students.