Splitting Procedure Research Articles

The bike routeing problem with energy constraints

As climate change becomes more crucial, transporting products in urban areas by bicycle gains popularity. More companies start using bicycles as an alternative transportation mode and face challenges to efficiently satisfy the needs of their customers and employees. While designing the bike routes for pick up and delivery, it is required to take into account the energy needed by cyclists to move. The energy consumed in a bike route has to be kept under a certain threshold for cyclists to be able to pedal during the whole work shift. This leads to a new variant of the vehicle routeing problem called the bike routeing problem which aims at tackling constraints arising for bicycle deliveries. We propose a novel Mixed Integer Linear Programming model to determine the bike routes for delivering goods in urban areas. An Evolutionary Local Search algorithm is developed to efficiently solve the problem using new split and local search procedures. Experimental results obtained on random and real instances show the accuracy and stability of the proposed algorithms, as well as the relevance of the new problem.

Effects of vibrations during boar semen transport: Low-temperature transport as a new management tool

Transport-related vibrations (TV) compromise the quality of conventionally stored (17 °C) boar semen, but knowledge about TV effects after 5 °C transport is insufficient. This study evaluates the effects of TV after novel 5 °C transport compared to a 17 °C control. Ejaculates of 18 fertile Piétrain boars, diluted in a split sample procedure using Androstar Premium® (AP, 5 °C storage) or Beltsville Thawing Solution (BTS, 17 °C storage), were subjected to transport simulation using a laboratory shaker IKA MTS 4. The timing was set according to the respective processing protocols: for 17 °C BTS samples, TV simulation was performed the day of collection, 5 °C AP samples were subjected to TV the day after collection following completion of the established cooling curve to 5 °C. Six samples per ejaculate were exposed to different TV durations (0 h, 3 h, or 6 h) to evaluate the effect on sperm quality (progressive motility (PM), thermo-resistance test (30 and 300 min incubation at 38 °C (TRT30/TRT300)), mitochondrial activity (MITO), plasma membrane and acrosome integrity (PMAI)). Generalized linear mixed models revealed TV (P = 0.021) and storage time (P < 0.001) dependent declines in PM. Direct, pairwise comparisons revealed that 5 °C samples are not affected by TV (P(3 h vs. 6 h transport) = 1.0; P(0 h vs. 6 h transport) = 1.0). They therefore showed superior quality maintenance after TV compared to 17 °C samples (P(3 h vs. 6 h transport) = 0.025; P(0 h vs. 6 h transport) < 0.001). Concluding, low-temperature transport is possible without significant semen quality loss and with better quality maintenance than standard transport.

Ridge split assisted molar protraction

Protraction of a second molar into the gap left by a missing first molar is an option, although it is challenging to maintain root parallelism during mesial migration due to the thick and dense cortical bone. This study was carried out to make an attempt to evaluate whether molar protraction in subjects with missing mandibular first molar and knife edge ridges is possible or not using ridge split procedure (expansion).The sample consisted of 12 subjects with missing mandibular first molar and knife edge ridges. All pre-treatment records were taken, after initial leveling and alignment ridge split procedure was performed and molar protraction was carried out using mini implants. Data was collected at a fixed interval of every six weeks. Statistical analysis using Repeated-measures ANOVA and Paired t test were done for evaluation of the rate of molar protraction and mesial molar tipping 0.12mm per week and 0.9 mm per six weeks was the rate of molar protraction that was accomplished. The mean edentulous space decreased from pre protraction to third visit significantly with a p value of ≤ 0.001.There is mesial tipping of molar post protraction with a P value of 0.148 which is statistically non-significant. On an average duration for molar protraction was 8.4 months.Ridge split made molar protraction possible in subjects with missing mandibular molar and knife edge ridges and enhanced the rate of tooth movement. The absolute anterior dental anchorage for the desired orthodontic movement was achieved by utilisation of mini implants.

CEA graft take after combining with a modified MEEK procedure

Resourceful surgical planning for coverage of large burns has led to refinement of early innovative procedures including meshed split thickness skin grafts (STSG), MEEK procedure, and use of cultured epidermal autografts (CEAs). The use of STSG remains standard of care for burn wound coverage; however, manual expansion of STSG is limited due to shortcomings with expansion rates greater than 4:1. The MEEK micrografting method is a method of preparing skin grafts with a device instead of manually with an autograft mesher, allowing reliable expansion rates of autografts up to 9:1. Although the CEA indication for use includes both with and without STSG, use of meshed STSG placed under CEA has been reported to minimize shear forces and hasten graft take. The purpose of this study was to evaluate success of graft take in patients receiving MEEK and CEA for wound coverage in extensive burns at a single burn center experienced in the use of both MEEK and CEA. Data in 15 patients who received both MEEK and CEA for the treatment of large burns (mean total body surface area [TBSA] of 66%) demonstrated a high rate of successful engraftment (87%), and an overall 73% survival rate.

Scale‐Awareness in an Eddy Energy Constrained Mesoscale Eddy Parameterization

AbstractThere is an increasing interest in mesoscale eddy parameterizations that are scale‐aware, normally interpreted to mean that a parameterization does not require parameter recalibration as the model resolution changes. Here we examine whether Gent–McWilliams (GM) based version of GEOMETRIC, a mesoscale eddy parameterization that is constrained by a parameterized eddy energy budget, is scale‐aware in its energetics. It is generally known that GM‐based schemes severely damp out explicit eddies, so the parameterized component would be expected to dominate across resolutions, and we might expect a negative answer to the question of energetic scale‐awareness. A consideration of why GM‐based schemes damp out explicit eddies leads a suggestion for what we term a splitting procedure: a definition of a “large‐scale” field is sought, and the eddy‐induced velocity from the GM‐scheme is computed from and acts only on the large‐scale field, allowing explicit and parameterized components to co‐exist. Within the context of an idealized re‐entrant channel model of the Southern Ocean, evidence is provided that the GM‐based version of GEOMETRIC is scale‐aware in the energetics as long as we employ a splitting procedure. The splitting procedure also leads to an improved representation of mean states without detrimental effects on the explicit eddy motions.

Learning heuristics for arc routing problems

Solid waste collection and street sweeping can each be formulated as a capacitated arc routing problem (CARP) in which the streets of a city require service by a fleet of vehicles at minimum total cost. Heuristic and meta-heuristic methods have been used to solve CARP because the problem is known to be NP-Hard. In this paper we introduce Splice, a novel machine learning framework that learns heuristics to solve routing problems, such as CARP, defined on the edges (rather than vertices) of a non-euclidean graph representation of the problem. Splice uses a message passing graph neural network to generate a graph embedding, and deep Q-learning feed-forward layers to learn heuristics to construct a giant tour that results in minimum total cost after applying the splitting procedure, iterating until all tasks are serviced. Compared to the two AI-driven approaches to CARP, Splice has a simpler network architecture and does not require a supervised learning method for training. The total costs of the solutions found by Splice are from 11-30% lower than those found by a path scanning heuristic and a memetic meta-heuristic algorithm. When trained on small instances, the heuristics learned by Splice generalize well, i.e., can be used to solve larger instances without retraining. Due to the route-first split-second form of heuristic learned, the Splice framework may be applied to solve other variants of routing problems by adapting the splitting procedure.

Comparison of temperature changes in different irrigation methods used in guided piezosurgery: in vitro study.

The study aimed to investigate the cooling performance of three different surgical methods for bone splitting during implant dentistry procedures. An in vitro study was conducted on bovine ribs to test the cooling performance of three osteotomy methods: conventional osteotomy with standard cooling irrigation, template-assisted osteotomy with standard cooling irrigation, and modified template-assisted osteotomy with additional cooling fluid through internal irrigation channels in the surgical guide. A negative control group without cooling was also included. Temperature measurements were taken during the procedures using a contactless infrared thermometer. The results showed that the conventional osteotomy without cooling resulted in the highest mean of the peak temperatures (114.7°C ± 45.4), while the modified template-assisted osteotomy with additional cooling achieved the lowest mean of the peak temperatures (29.4°C ± 7). Statistically significant differences in temperature were observed among the groups (p < 0.001). The study rejected the null hypothesis and demonstrated that the cooling method used during bone splitting procedures significantly affected the temperature development at the surgical site. The modified template-assisted osteotomy with additional cooling provided the best cooling performance. However, caution should be exercised in interpreting the results due to the limitations of the in vitro study. Further research with stronger external validity is needed to confirm these findings and explore their applicability in clinical settings to benefit patients.

Lateral augmentation of the jaw by the split expansion ridge technique. A critical review.

Bone augmentation has become a routine procedure to enhance and/or repair a deficient or resorbed alveolar ridge for predictable and successful implant placement. The split expansion ridge i.e., the alveolar ridge splitting (ARS) procedure, is one of the less invasive procedures, and is characterized by minor morbidity. This would allow to widen narrow ridges in order to allow implant reconstruction in a sufficient bone volume. Its efficacy and long-term stability rely upon clinical opinions and long-term retrospective studies, while prospective comparative studies and randomized controlled trials are rare. This critical review presents the development of this technique, describes the surgical procedure, and provides technical notes and modifications. The learning curve and in-depth knowledge of the oral anatomy, as well as the recognition of incidence and management of complications are of utmost importance in the clinical application of the ARS procedure.

An accurate, robust and efficient convection-pressure flux splitting scheme for compressible Euler flows

The popular Roe's flux difference splitting scheme has high resolution for various types of discontinuities but it fails to satisfy the entropy condition and will encounter different forms of instability while calculating shock waves, such as the post-shock oscillation of the slowly moving shock waves and the carbuncle phenomenon of the multidimensional strong shock waves. In the present work, a simple flux difference splitting scheme based on the idea of convection-pressure splitting is proposed. With application of the Toro-Vázquez splitting procedure, the flux of the 3D Euler equations is split into the convection part and the pressure part. Due to having a complete set of linearly independent eigenvectors, the pressure subsystem can be solved by the conventional flux difference splitting method. The weakly hyperbolic convection subsystem, however, does not have a complete set of linearly independent eigenvectors and thus is solved by the flux difference splitting scheme based on the generalized eigenvectors [1]. In addition, a strategy that combines the THINC reconstruction with the BVD algorithm is employed on the numerical dissipation term of the convection flux to further improve the resolution for contact discontinuities. A comprehensive range of numerical simulations for classical 1D, 2D and 3D benchmark test problems demonstrate the good performance of the proposed scheme.

Ultraviolet-complete quantum field theories with fractional operators

We explore quantum field theories with fractional d'Alembertian □ γ . Both a scalar field theory with a derivative-dependent potential and gauge theory are super-renormalizable for a fractional power 1 < γ ≤ 2, one-loop super-renormalizable for γ > 2 and finite if one introduces killer operators. Unitarity is achieved by splitting the kinetic term into the product of massive fractional operators, eventually sending the masses to zero if so desired. Fractional quantum gravity is also discussed and found to be super-renormalizable for 2 < γ ≤ 4 and one-loop super-renormalizable for γ > 4. To make it unitary, we combine the splitting procedure with a fractional generalization of the Anselmi-Piva procedure for fakeons. Among new technical results with wider applications, we highlight the Leibniz rule for arbitrary powers of the d'Alembertian and the Källén-Lehmann representation for a propagator with an arbitrary number of branch cuts.

Time-explicit hybrid high-order method for the nonlinear acoustic wave equation

We devise a fully explicit scheme for the nonlinear acoustic wave equation in its second-order formulation in time, using the HHO method for space discretization and the leapfrog scheme for time integration. The key idea for the explicitation is an iterative procedure to approximate at each time step the static nonlinear coupling between the cell and face unknowns. This procedure is based on a splitting of the HHO stabilization operator and, in the linear case, is proved to converge for a large enough weight of the stabilization uniformly in the mesh size. Increasing the stabilization weight turns out to have a moderate impact on the CFL condition. The numerical experiments demonstrate the computational efficiency of the splitting procedure compared to a semi-implicit scheme for the static coupling between cell and face unknowns.

An improved semi-implicit material point method for simulating large deformation problems in saturated geomaterials

This study presents an improved semi-implicit MPM formulation for coupled large deformation problems in geotechnics based on the fractional step method. The main objective of this study is to make the choice of the time step size independent of the permeability and to reduce the pressure oscillations by applying the special splitting procedure and the stabilized technique. The proposed coupled MPM is validated by comparing numerical results with analytical solutions of the one-dimensional consolidation problem in both small and large deformation regimes. Three numerical tests are performed to further evaluate the performance of the proposed method, including a self-weight slumping block, 2D consolidation test, and the stability of a saturated elasto-plastic slope. The numerical results indicate that the proposed method is suitable for simulating fluid-saturated porous media involving large deformation.

#4203 PREDICTION OF BLEEDING AND THROMBOSIS IN PATIENTS ON CHRONIC HEMODIALYSIS WITH THE TOTAL THROMBUS-FORMATION ANALYSIS SYSTEM

Abstract Background End-stage renal disease patients receiving hemodialysis (HD) are at increased risk of both bleeding and thrombotic complications. There are, however, few tools to help clinicians with risk stratification of the individual patient. Aims and Method To study if the Total Thrombus-formation Analysis System (T-TAS01), which measures thrombus formation in flowing whole blood inside a microchip [1], can be used to predict bleeding and thrombotic complications in patients on HD. Odds-ratios were calculated using the median split procedure. ROC curve analyses were performed to calculate the ability of T-TAS measurements performed at baseline to distinguish between patients with and without future bleeding or thrombotic complications. Results 176 patients on chronic HD were included and followed for one year; 11.4% were on antiplatelet drugs and 8.0% on continuous anticoagulation. Venous blood samples were taken at inclusion before dialysis procedure, and platelet-thrombus formation (PL-AUC; higher value reflects increased thrombogenicity) and platelet-fibrin thrombus formation (AR-OT; higher value reflects reduced thrombogenicity) were registered. Fifty-seven patients (32%) developed a bleeding complication, whereof 12 (6.8%) were ISTH major bleedings. The Odds-Ratio (OR; 95% CI) to develop any bleeding for patients with T-TAS01 measurements below (PL-AUC) or above (AR-OT) median were 7.67 (3.59-16.36) and 8.94 (4.10-19.51), respectively. ROC analyses to predict bleeding with T-TAS01 showed AUCs of 0.85 for all bleeding and 0.83 for ISTH major bleed (PL-AUC and AR-OT data combined). Furthermore, thirty-one patients (17.6%) developed a thrombotic complication, whereof 13 (7.4%) were acute coronary syndrome (ACS) or ischemic stroke (IS). The Odds-Ratio (OR; 95% CI) to develop any thrombosis for patients with T-TAS01 measurements below (PL-AUC) or above (AR-OT) median were 0.14 (0.05-0.40) and 0.28 (0.12-0.67), respectively. ROC analyses to predict thrombosis with T-TAS01 showed AUCs of 0.78 for all thrombosis and 0.62 for ACS/IS (PL-AUC and AR-OT data combined). Conclusion T-TAS01 is a promising tool to aid in the prediction of bleeding and thrombosis in HD patients.

Success rates of lateral canthotomy and cantholysis for treatment of orbital compartment syndrome

PurposeVision loss after facial trauma can occur from orbital compartment syndrome (OCS). Orbital compartment syndrome is commonly treated surgically with a lateral canthotomy and cantholysis (C&C). Our study investigates success rates of lateral C&C for the treatment of OCS amongst emergency medicine (EM) and ophthalmology providers. MethodsA retrospective cohort study was performed. Cases were identified and the electronic medical record of patients was interrogated for clinical and procedural information. Success of a lateral C&C was defined as a decrease in intraocular pressure (IOP) to <30 mmHg after the first attempt at the procedure. Inclusion criteria included documentation of a procedural attempt, a pre-procedure IOP >30 mmHg and a post-procedure IOP measurement; or alternatively if no pre-procedure IOP was documented but the IOP was >30 on arrival to the level 1 trauma center. Exclusion criteria included periprocedural use of ocular hypotensive medications and comorbid hyphema. ResultsThe final analysis included 74 eyes from 64 patients. Emergency medicine providers performed the initial lateral C&C in 68% of cases compared to 32% by ophthalmologists, and success rates were comparable – 68% vs 79.2%, respectively (p = 0.413). Poorer visual outcomes were associated with the initial failure of a lateral C&C and head trauma without an orbital fracture. All patients treated with a vertical lid split procedure met the criteria for ‘success’ as defined by this study. ConclusionsThe success rate of a lateral C&C is comparable amongst EM and ophthalmology providers. Improved training of physicians on the lateral C&C or other simpler procedures, such as the vertical lid split, could improve outcomes in OCS.

An Approximation Algorithm for k-Depot Split Delivery Vehicle Routing Problem

A multidepot capacitated vehicle routing problem aims to serve customers’ demands using a fleet of capacitated vehicles located in multiple depots, such that the total travel cost of the vehicles is minimized. We study a variant of this problem, the k-depot split delivery vehicle routing problem (or k-DSDVRP in short), for the situation where each customer’s demand can be served by more than one vehicle, and the total number of depots, denoted by [Formula: see text], is a fixed constant. This is a challenging problem with broad applications in the logistics industry, for which no constant ratio approximation algorithm is known. We develop a new approximation algorithm for the k-DSDVRP, ensuring an approximation ratio of [Formula: see text] and a polynomial running time for any fixed constant [Formula: see text]. To achieve this, we propose a novel solution framework based on a new relaxation of the problem, a cycle splitting procedure, and a vehicle assignment procedure. To further enhance its efficiency for practical usage, we adapt the newly developed approximation algorithm to a heuristic, which runs in polynomial time even when k is arbitrarily large. Experimental results show that this heuristic outperforms a commercial optimization solver and a standard vehicle routing heuristic. Moreover, our newly proposed solution framework can be applied to developing new constant ratio approximation algorithms for several other variants of the k-DSDVRP with [Formula: see text] being a fixed constant. History: Accepted by Erwin Pesch, Area Editor for Heuristic Search &amp; Approximation Algorithms. Funding: This work was supported in part by the National Natural Science Foundation of China [Grants 71971177, 71725001, U1811462], Research Grants Council of Hong Kong SAR, China [Grant 15221619], and Guangdong Basic and Applied Basic Research Foundation [Grant 2023A1515030260]. Supplemental Material: The e-companion is available at https://doi.org/10.1287/ijoc.2021.0193 . The software that supports the findings of this study is available within the paper and its Supplemental Information ( https://pubsonline.informs.org/doi/suppl/10.1287/ijoc.2021.0193 ) as well as from the IJOC GitHub software repository ( https://github.com/INFORMSJoC/2021.0193 ). The complete IJOC Software and Data Repository is available at https://informsjoc.github.io/ .

Cognitive representations of handball tactic actions in athletes-The function of expertise and age.

The tactical cooperation for the optimal interaction of team members is an essential performance-determining variable in sports games. The underlying cognitive memory structures of cooperative tactical actions have so far been little researched. Therefore, this study investigated the cognitive memory structure of tactical knowledge of handball actions in teams of different expertise and age groups. In the first experiment, tactical mental representation structures (TMRS) of 30 adult handball players of two different level of expertise were investigated. In the second experiment, TMRS of 57 youth handball players from three age levels were investigated. In both experiments the TMRS was measured with the structure dimensional analysis of mental representation (SDA-M) method. The SDA-M commences with a splitting procedure of a given set of concepts and reveals with a cluster analysis the relational structures of the concepts on an individual and a group level. Experiment one revealed that the TMRS differed significantly between skilled either/or less experienced handball players. Skilled handball players showed a hierarchical organized representation that shared more features with the basic tactical structure of the handball game than less experienced players. The second experiment revealed age-related differences of the TMRS between the age groups of the U15, U17 and U19 teams. Further data analysis revealed significant differences of the TMRS between experienced and less experienced handball players and between local and regional competition level players. We conclude that our current findings suggest that tactical expertise is mediated by elaborate cognitive tactical knowledge in memory. Furthermore, our results indicate that tactical knowledge plays a substantial role during tactical skill learning as it differs as function of age, experience, and competition level. From this point of view, team representations of game situations can be seen as a crucial factor for efficient and common interaction in fast-paced team sports.

A truly-explicit time-marching formulation for elastodynamic analyses considering locally-adaptive time-integration parameters and time-step values

In this paper, a novel explicit time-marching procedure, which adapts to the properties of the spatially discretized model, is discussed for the time-domain solution of elastodynamic problems. The proposed technique is entirely automated and highly effective, providing a very attractive formulation to analyse complex wave propagation models. The novel approach is second-order accurate, truly explicit, truly self-starting, and it enables adaptive algorithmic dissipation and extended stability limits. In addition, automated subdomain/sub-cycling splitting procedures may also be carried out in the analyses, enhancing the performance of the proposed formulation. In this context, the technique automatically divides the domain of the model into multiple subdomains (according to the properties of the discretized problem), in which different time-step values are applied, still guaranteeing stability and enabling more accurate and efficient analyses. Adaptive values for the time-integration parameters of the method, which are established following the elements of the adopted spatial discretization, are also considered, providing a locally-defined self-adjustable formulation. This approach allows creating a link between the applied spatial and temporal solution procedures, enabling their errors to be better counterbalanced. Expressions for the adaptive time-integration parameters of the method and for the limiting time-step values of the elements of the discretized domain are presented and discussed. At the end of the paper, benchmark analyses are performed to demonstrate the effectiveness of the proposed technique, considering illustrative theoretical problems and applied intricate models, which are equivalent to those of real applications in the OIL & GAS industry.

SAR time series despeckling via nonlocal matrix decomposition in logarithm domain

Advanced satellite and signal processing techniques have made Synthetic Aperture Radar (SAR) capable of monitoring the dynamic processes of the earth with high temporal frequency through co-registered time series. There are several challenges in interpreting these three-dimensional data cubes, including the inherent speckle effect and outliers caused by abrupt changes or sporadically appearing objects. In this paper, we propose a novel despeckling method, LogSAR-NLMD, based on nonlocal matrix decomposition in the logarithm domain to despeckle SAR time series without producing the artifacts caused by outliers. A maximum a posteriori (MAP) problem is developed by taking into account smoothness and low-rank prior knowledge in addition to the likelihood of SAR reflectivities following the Fisher-Tippett distribution. Additionally, nonlocal self-similarity is exploited to construct time series matrices that satisfy the prior better than the original data. In order to solve the MAP problem, the variable splitting procedure and the alternating direction method of multipliers (ADMM) framework are used. The proposed method has been validated by multiple experiments on synthetic and real data by comparing it with other state-of-the-art methods for despeckling SAR time series.

SETAR-Tree: a novel and accurate tree algorithm for global time series forecasting

Threshold Autoregressive (TAR) models have been widely used by statisticians for non-linear time series forecasting during the past few decades, due to their simplicity and mathematical properties. On the other hand, in the forecasting community, general-purpose tree-based regression algorithms (forests, gradient-boosting) have become popular recently due to their ease of use and accuracy. In this paper, we explore the close connections between TAR models and regression trees. These enable us to use the rich methodology from the literature on TAR models to define a hierarchical TAR model as a regression tree that trains globally across series, which we call SETAR-Tree. In contrast to the general-purpose tree-based models that do not primarily focus on forecasting, and calculate averages at the leaf nodes, we introduce a new forecasting-specific tree algorithm that trains global Pooled Regression (PR) models in the leaves allowing the models to learn cross-series information and also uses some time-series-specific splitting and stopping procedures. The depth of the tree is controlled by conducting a statistical linearity test commonly employed in TAR models, as well as measuring the error reduction percentage at each node split. Thus, the proposed tree model requires minimal external hyperparameter tuning and provides competitive results under its default configuration. We also use this tree algorithm to develop a forest where the forecasts provided by a collection of diverse SETAR-Trees are combined during the forecasting process. In our evaluation on eight publicly available datasets, the proposed tree and forest models are able to achieve significantly higher accuracy than a set of state-of-the-art tree-based algorithms and forecasting benchmarks across four evaluation metrics.

Virtually Coupled Train Sets: Requirements Specification for ETCS application case

This paper presents the Virtually Coupled Train Set (VCTS) requirements specification work addressed within X2Rail-3 project, as part of Shift2Rail Innovation Programme 2. The project objective consists in exploring a new concept in railways signalling aimed at reducing distance between trains, from absolute to relative braking distance, and automating the train joining and splitting procedures. This approach ensures higher line capacity, faster train composition phase and higher robustness of the timetable.