Location Of Centers Research Articles

Multi-objective location-distribution optimization in blood supply chain: an application in Turkiye.

Blood donors are crucial in maintaining the blood supply chain. This study aims to improve the location and distribution of blood donation centers by focusing on two main objectives: minimizing costs and maximizing quality. Minimizing costs includes setting up and transporting blood efficiently while maximizing quality to ensure that blood products are delivered to hospitals promptly and in the right quantities. A multi-objective mathematical model is proposed to address the placement of both fixed and mobile blood donation centers. The first objective focuses on minimizing the costs of setting up centers and transporting blood. The second objective aims to maximize quality by ensuring timely deliveries and meeting hospitals' blood demand. The model utilizes real-world traffic and blood donation data from urban settings to simulate its effectiveness and applicability in practice. The model uses the constraint method to optimize both objectives simultaneously. The model was tested in various scenarios, optimizing cost and quality separately. The algorithm determined the ideal locations for blood donation centers to meet demand by exploring different options. It also accounted for factors that reduce quality, such as delayed deliveries and product returns, and showed that these issues could be minimized. This study highlights the need to balance cost and quality when determining the locations of blood donation centers. Using the constraint method, the model successfully optimized both objectives, offering valuable insights for improving the efficiency and effectiveness of blood donation operations.

On the relation between urban road network and distribution centre location strategy of Franchise retail firms

AbstractFranchise retailers such as supermarkets and convenience stores have achieved greater efficiency in delivering products to their chain stores by locating distribution centres (DCs) within or near cities. In this study, we propose that the reduction of product transportation time due to the construction of intra-urban roads facilitates the location of distribution centres. To this end, we model the inventory management behaviour of franchise retailers and show that distribution centres have two functions: (1) consolidating the inventory holding risk faced by individual chain stores and (2) achieving larger lot sizes when purchasing goods from outside the city. We then analyse the effects of facilitating logistics by improving intra-city roads on reorganizing the location patterns of chain stores and distribution centres in the city and on improving the convenience of shopping for consumers.

Abstract 4135127: Traveling more than a 20-mile radius to a Heart Failure Center can affect the quality of Heart Failure Care.

Introduction: We recognized the profound importance of access to care among patients with heart failure (HF). The geographical location of HF centers may significantly impact health outcomes, especially for those with limited transportation. This social determinant of health (SDOH) aspect is critical in bridging the gap in achieving HF care. Hypothesis/Methods: This was a single-center observational study conducted at a tertiary heart failure center in central Pennsylvania. We assessed the impact of travel distance by comparing patients who travel within a 20-mile radius to those who travel beyond a 20-mile radius. A total of 322 patients were referred to the HF clinic and enrolled in a guideline-directed medical therapy (GDMT) optimization program. Data collected included distance to Hershey Medical Center (HMC), health insurance coverage, HF etiology, onset, and echocardiogram. The distance was calculated based on the patient’s zip code. Results: Among patients enrolled in the HF-GDMT program, 194 travel within 20 miles, and 128 travel beyond a 20-mile radius to HMC. The mean travel distance to HMC was 9.1 miles (within) and 40.9 miles beyond 20 miles. The majority of patients were 81.3% white, 67% male, and the average age was 64. Most patients had heart failure with reduced ejection fraction (HFrEF) at 92.9%, 63% nonischemic, and 57.5% new onset. The comorbidities in both groups were similar, including hypertension, hyperlipidemia, and coronary artery disease (CAD). When comparing both groups, those who traveled beyond the 20-mile radius to HMC had more chronic HF at 55.5% vs. 34% in patients who traveled within the 20-mile radius. Upon enrollment, most patients were on suboptimal doses of either 1 or 2 of the four pillars of GDMT for HFrEF. Conclusions: The findings of this study revealed that patients with HF who travel beyond a 20-mile radius to HMC are more likely to have chronic HF, suggesting a delay in seeking care. A delay in referral may affect the timely initiation of appropriate GDMT and will likely lead to worse health outcomes. This underscores the urgent need for interventions to address barriers like transportation to improve HF care, offering a potential avenue for better patient outcomes.

Towards greener freight transport networks: An integrated model for location planning and carbon regulation policy evaluation

This paper proposes a mathematical model to assist governmental planning in the transport sector by suggesting optimal locations for logistics integration centers considering intermodality, logistics costs, and carbon costs. Seven scenarios were evaluated considering the assessment of carbon-tax and carbon-cap policies. The findings showed that logistic costs are more significant than carbon costs across the network investigated. Only non-competitive conditions such as considering carbon costs alone or adopting outrageous values for the carbon tax could change this situation. If no facility were opened, the total cost would be 2.8 times higher than the baseline scenario, while intermodality would reduce the baseline emissions by up to 3.753%. Therefore, the government should prioritize greener strategies and modal shifts in addition to implementing carbon policies to ensure a more sustainable and cost-effective transportation sector.

Designing and improving the efficiency of placement of logistics infrastructure for storage, distribution and trade of agri-food products

Purpose: The article considers a methodological approach to the formation and determination of potential locations of logistics infrastructure: warehouse storage facilities, wholesale distribution centers for storage, marketing and trade of agro-food products.Design/methodology/approach: A study of 204 objects - administrative districts and cities of Kazakhstan, where the production, storage, distribution and trade of agri-food products is carried out. The standardization of indicators, cluster, correlation-regression, factor analysis was carried out, the method of ranking and center of gravity.Findings: At the first stage of the study, potential locations of distribution centers of agricultural products were identified based on the proposed criteria. Based on factor analysis, new factors have been formed in order to determine the criteria for choosing the location of the logistics infrastructure. Cluster analysis made it possible to differentiate territories and determine the characteristics of the logistics infrastructure for their placement, depending on their specialization. At the second stage, the potential locations of logistics infrastructure and the geographical location of objects on the territory of administrative-territorial units were clarified. At the third stage, with the help of weighting coefficients and an integral indicator of the attractiveness of the location of logistics infrastructures, the service area of the logistics infrastructure of storage, sales and trade is determined in accordance with potential locations on the territory. The proposed approach, in contrast to the existing ones, takes into account the peculiarities of the functioning of the storage, marketing and trade infrastructure and links these facilities with transport and warehouse availability in the regions.Research limitations/implications: The study is aimed at complementing existing approaches and methods for determining the location of logistics infrastructure facilities with a more detailed account of the specialization of districts and the economic potential of regions.Practical implications: The conclusions allow us to use different criteria when determining the location of logistics infrastructures depending on their purpose. They also provide important information in the process of designing logistics infrastructure, conducting a differentiated investment policy during their construction and operation.Originality: In this article, a new point of view is given on the choice of criteria for the placement and determination of the number of logistics infrastructure, based on their functional purpose, specialization of districts and the potential of regions, which increase their efficiency.

Application of Geographic Information System (GIS), for Crisis Management

Natural disasters have always existed as a natural phenomenon throughout the life of the earth. The occurrence of natural disasters such as floods, earthquakes, storms, etc. in most cases have destructive effects on human settlements and heavy casualties on their residents. It has destroyed the buildings and infrastructures of such areas and imposed unfortunate economic and social consequences on cities and countries. Despite many scientific advances, mankind is still not able to prevent and resist these natural events. Natural disaster management and sustainable development are considered an integrated issue today. Due to limited resources, real development will not be possible without integration with disaster reduction programs. Earthquakes as a natural phenomenon do not have adverse results by themselves. What makes this phenomenon a disaster is the lack of prevention and lack of preparation to deal with its consequences. Therefore, one of the most necessary measures is to apply "principles of crisis management". Crisis management measures can be summarized in three parts: 1. Prevention, 2. Response, and 3. Reconstruction. Therefore, the title is the most important discussion in the strategy of reducing the effects of earthquakes. In this research, we seek to find the best location for crisis management support bases in Malair City, which first identified the effective factors and criteria in the location of relief centers during a crisis. Then, the AHP model was used to determine the importance and value of each criterion and effective elements in the decision, and a questionnaire was designed and distributed among experts and specialists. In the next step, the weight of each of the decision criteria and elements was determined using the hierarchical analysis process method and Expert Choice software. Then, using the field method, figures of the studied area were updated and prepared. In the next step, all information layers were converted to raster in the geographic information system (GIS). Finally, using the Index overlay method, the layers were combined. Three locations were suggested as the best locations for crisis management support bases in Malayer City. Among them, two options, one in the eastern part of the city on Molvi Street, and the other in the southern part of the city on Motahari Street, have been proposed as the best options. In terms of accessibility, they are in a good position. An option, that has a lower score, is located in the southeastern part of the city on Sheikh Kilini Street.

Solving the Problem of Fuzzy Partition-Distribution with Determination of the Location of Subset Centers

A large number of real-world problems from various fields of human activity can be reduced to optimal partitioning-allocation problems with the purpose of minimizing the partitioning quality criterion. A typical representative of such problem is an infinite-dimensional transportation problem and more generalized problems—infinite-dimensional problems of production centers placement along with the partitioning of the area of continuously distributed consumers with the purpose of minimizing transportation and production costs. The relevant problems are characterized by some kind of uncertainty level of a not-probabilistic nature. A method is proposed to solve an optimal fuzzy partitioning-allocation problem with the subsets centers placement for sets of n-dimensional Euclidean space. The method is based on the synthesis of the methods of fuzzy theory and optimal partitioning-allocation theory, which is a new science field in infinite-dimensional mathematical programming with Boolean variables. A theorem was proved that determines the form of the optimal solution of the corresponding optimal fuzzy partitioning-allocation problem with the subsets centers placement for sets of n-dimensional Euclidean space. An algorithm for solving fuzzy partitioning-allocation problems is proposed, which is based on the proved theorem and on a variant of Shor’s r-algorithm—a non-differential optimization method. The application of the proposed method is demonstrated on model tasks, where the coefficient of mistrust is integrated to interpret the obtained result—the minimum value of the membership function, which allows each point of the set partition to be assigned to a specific fuzzy subset.

ENGINEERING-GEODESIC EQUIPMENT OF THE TERRITORY USED BY USING GEOINFORMATION SYSTEMS

The purpose of the scientific article is the implementation of an important part of the agricultural spatial data infrastructure, planning of the domestic economy using geographic information systems (GIS). Taking this direction into account, the work examines the following main elements of designing the domestic economy: location of settlements and economic centers; design of internal roads; placement of external engineering networks; use of types of land reclamation for agricultural purposes; allocation of land for the construction of roads of various categories of local importance; placement of agricultural machinery in land use; conduct a technical and economic analysis of the effective use of road junctions and reclamation works as an engineering structure, as well as systematize the engineering and geodetic process necessary to implement these studies based on GIS technologies. With the help of geographic information systems technologies, it will be necessary to determine the following directions of engineering and geodetic equipment of the territory: Information about road transport and roads, Roads in plan, longitudinal and horizontal profiles, Driving through bodies of water and bodies of water on the road, Road surfaces, Road surveys and design of agricultural roads, The basic principle of organizing the construction, maintenance and repair of agricultural roads.

The influence of the bounding surface on the structural ordering of short chains of oligoetherimides.

In this study, we have conducted a comparative analysis of the structural ordering of short oligoetherimide chains (dimers) near the bounding surface, depending on the structure of that surface. In order to clarify the possibility of oligoetherimide ordering along the symmetry axes of graphene, two types of bounding surfaces were considered: graphene, with a regular discrete position of interaction centers (carbon atoms), and a smooth, structureless impermeable wall. The chemical structures of the considered dimers consist of two repeating units of BPDA-P3, ODPA-P3, or aBPDA-P3 thermoplastic polyetherimides. Using all-atom molecular dynamics simulations, the process of structural ordering of the dimers near the surface of the graphene or wall was established. The ODPA-P3 and BPDA-P3 dimers form an ordered state near the graphene surface, while the aBPDA-P3 dimers do not demonstrate structural ordering. The simulation results confirmed that the ordering direction of the BPDA-P3 and ODPA-P3 dimers near the graphene surface is chosen randomly. Comparison of the oligoetherimide structure formed near the attracting wall without a symmetrical location of the interaction centers shows the similarity of the ordering of dimers near the graphene surface and the wall. As in the case of the graphene surface, the ordering of oligoetherimide molecules near the structureless wall demonstrates one direction of ordering. Therefore, we confirmed that the key factor for the onset of ordering is the presence of a confining surface, rather than the symmetrical arrangement of interaction centers in the substrate structure.

Location of the Anatomic Footprint Centers of the Anterior Cruciate Ligament Determined by Quadrant Method on Three-Dimensional Magnetic Resonance Imaging.

The quadrant method is widely used to determine the femoral footprint center (FFC) on radiographs or computed tomography (CT) and can also describe the tibial footprint center (TFC). However, its application on three-dimensional (3D) magnetic resonance imaging (MRI) has been limited. This study aims to describe the ACL footprint center position on 3D MRI of healthy knees using the quadrant method. Proton density (PD) sequence 3D MRI was conducted on 45 intact knees, aged 18 to 45years. The centers of the ACL footprints were determined, and 2D simulated radiographic images were generated from the 3D MRI data. The quadrant method was then applied to calculate the positions of the footprint centers. The FFC was located at 31.6% in the deep-shallow (DS) direction and 31.3% in the high-low (HL) direction. The TFC was positioned at 45.1% in the mediolateral (ML) direction and 39.9% in the anteroposterior (AP) direction. The ACL footprint centers identified in this study were positioned similarly to previous studies, with the exception of the TFC in the ML direction, which was found to be more medial. This approach has the potential to enhance preoperative planning and intra-operative navigation in ACL reconstruction surgeries.

A multi-level multi-product supply chain network design of vegetables products considering costs of quality: A case study.

Effective logistics management is crucial for the distribution of perishable agricultural products to ensure they reach customers in high-quality condition. This research examines an integrated, multi-echelon supply chain for perishable agricultural goods. The supply chain consists of four stages: supply, processing, storage, and customers. This study investigates the quality-related costs associated with product perishability to maximize supply chain profitability. Key factors considered include the network design, location of processing and distribution centers, the ability to process raw products to minimize post-harvest quality degradation, the option to sell the excess produce to a secondary market due to unpredictable yields, and the decision not to fulfill demand from distant customers where significant quality loss and price drops would be involved, instead diverting those products to the aforementioned secondary market. Quantitative methods and linear mathematical programming are employed to model and validate the proposed supply chain using actual data from a real-world case study on vegetable supply chains. The main contribution of this research is the incorporation of quality costs into the objective function, which allows the supply chain to prioritize meeting nearby customers' demands with minimal quality loss over serving distant customers where high quality loss is unavoidable. Additionally, deploying a faster transportation fleet can significantly improve the overall profitability of the perishable product supply chain.

Renewable energy-powered water desalination and treatment network under wind power and water demand uncertainty: A possibilistic chance-constrained programming

Given the scarcity of freshwater resources, the growing significance of desalination is undeniable. It holds immense potential, particularly in regions grappling with severe water shortages. However, desalination's Achilles heel lies in its voracious energy appetite, requiring roughly ten times more energy than wastewater treatment. Moreover, the prevalent use of fossil fuels in desalination plants poses concerning issues like environmental pollution, fossil fuel depletion, and rising costs. The present study has designed an integrated Water desalination and treatment Network that includes a number of desalination facilities, storage centers, wind farms, and wastewater treatment facilities. The water desalination and treatment network has been structured using a Mixed-Integer Linear Programming (MILP) model, considering uncertainties in wind power and water demand. Employing a chance constraint probabilistic programming approach, this model ensures robustness and balances conservatism with investment attractiveness. It aims to enhance resilience against fluctuations in wind energy and water demand within the water and energy supply chain network. The study applied this model to optimize the locations of desalination plants, treatment centers, and storage facilities. This integrated model ensures autonomy, eliminating the need for external water and energy sources while reliably meeting regional demands. In the context of the Makran coasts case study, our comprehensive mathematical model demonstrates an optimal allocation with 96.67 % attributed to fixed costs and only 3.33 % to variable costs. Moreover, this model precisely optimizes the locations of two desalination centers, two storage facilities, and ten water treatment centers, effectively managing the need for external water resources. Ultimately, through a rigorous sensitivity analysis, we unveiled that the chance constraint parameters have a significant impact on the variable costs.

ASSESSMENT OF PORT CITY SERVICE CENTER ALIGNMENT IN THE TERRAIN

Medan, in North Sumatra, is growing rapidly, especially in the sub-districts of Medan Marelan and Medan Belawan, where urban activities and population movement are increasing. As a result, North Medan has been designated as the City Service Centre (CSC) of Medan City, with CSC Labuhan in Medan Labuhan sub-district playing a major role. This highlights the importance of Medan Labuhan in providing essential services and infrastructure to support the growth of the area. In order to effectively serve the community, it is important to ensure that CSC Labuhan meets the area's needs and standards for a city service center. Aims: The objective of this research is twofold: first, to determine the status of the service center system in North Medan; and second, to evaluate the suitability of CSC Labuhan's functions in serving the North Medan region. Methodology and results: The research method is descriptive analysis using both quantitative data and qualitative information. This is achieved through the use of scalogram analysis, centrality index analysis and rank-size rule analysis. Conclusion, significance and implication: The results indicate that the optimal locations for urban service centers are in Sub-District Besar (Medan Labuhan subdistrict), Subdistrict Rengas Pulau (Medan Marelan subdistrict), and Subdistrict Belawan I (Medan Belawan subdistrict). Conversely, Medan City RTRW 2022-2042 designates Labuhan CSC as Subdistrict Pekan Labuhan.

Technical efficiency and its determinants in health service delivery of public health centers in East Wollega Zone, Oromia Regional State, Ethiopia: Two-stage data envelope analysis

BackgroundPriority-setting becomes more difficult for decision-makers when the demand for health services and health care resources rises. Despite the fact that the Ethiopian healthcare system places a strong focus on the efficient utilization and allocation of health care resources, studies of efficiency in healthcare facilities have been very limited. Hence, the study aimed to evaluate efficiency and its determinants in public health centers.MethodsA cross-sectional study was conducted in the East Wollega zone, Oromia Regional State, Ethiopia. Ethiopian fiscal year of 2021–2022 data was collected from August 01–30, 2022 and 34 health centers (decision-making units) were included in the analysis. Data envelope analysis was used to analyze the technical efficiency. A Tobit regression model was used to identify determinants of efficiency, declaring the statistical significance level at P < 0.05, using 95% confidence interval.ResultsThe overall efficiency score was estimated to be 0.47 (95% CI = 0.36–0.57). Out of 34 health centers, only 3 (8.82%) of them were technically efficient, with an efficiency score of 1 and 31 (91.2%) were scale-inefficient, with an average score of 0.54. A majority, 30 (88.2%) of inefficient health centers exhibited increasing return scales. The technical efficiency of urban health centers was (β = -0.35, 95% CI: -0.54, -0.07) and affected health centers’ catchment areas by armed conflicts declined (β = -0.21, 95% CI: -0.39, -0.03) by 35% and 21%, respectively. Providing in-service training for healthcare providers increased the efficiency by 27%; 95% CI, β = 0.27(0.05–0.49).ConclusionsOnly one out of ten health centers was technically efficient, indicating that nine out of ten were scale-inefficient and utilized nearly half of the healthcare resources inefficiently, despite the fact that they could potentially reduce their inputs nearly by half while still maintaining the same level of outputs. The location of health centers and armed conflict incidents significantly declined the efficiency scores, whereas in-service training improved the efficiency. Therefore, the government and health sector should work on the efficient utilization of healthcare resources, resolving armed conflicts, organizing training opportunities, and taking into account the locations of the healthcare facilities during resource allocation.

Assessing the potential of Eddy detection in MIZ using SAR and Lagrangian modeling: A test case on Fram Strait

The analysis of ocean eddies in the marginal ice zone via remote sensing and modeling data is a challenging task. However, it is of crucial importance for various scientific applications and anthropogenic activities in the Arctic. Models often struggle to accurately represent eddies near the MIZ due to the intricate nature of sea ice-ocean interactions, unresolved small-scale processes, and coarse resolution. Nevertheless, combining the information provided from both SAR and model data offers promising results that can potentially improve eddy detection accuracy near the MIZ. Furthermore, accurate characterization of the spatial and temporal variability of eddies near the MIZ demands a holistic approach that incorporates multi-platform observations, including numerical models and remote sensing data. This study demonstrates a specific test case on the intercomparison of the eddy signatures located in the MIZ in the Fram Strait based on remote sensing SAR scenes and Lagrangian modeling data from the two global oceanographic reanalysis GOFS 3.1 and GLORYS 12 V1. The study specifically displays the strong agreement in the eddy polarity and synchronism with reality, as well as differences in spatial scales and location of eddy centers. Overall, the obtained results support the further use of the presented approach for studying the eddies in the MIZ regions in the Arctic.

Review on Location of Fresh Cold Chain Logistics Distribution Center

This paper reviews the research status, existing problems and challenges, and future research directions of the location of fresh cold chain logistics distribution centers. The research background is based on factors such as the development of the fresh product market, the technological progress of cold chain logistics, the requirements of environmental protection and sustainable development, and the intensification of market competition. The significance of site selection includes improving transportation efficiency, reducing costs, improving customer satisfaction, optimizing supply chain networks, and achieving environmental sustainability.The former focuses on low-carbon, demand uncertainty, and competitive distribution center location, while the latter focuses on the new retail environment and cold chain distribution. The review of relevant literature points out that some progress has been made in the research, but there are challenges such as market demand uncertainty, incomplete data and limited model applicability.Future research directions include the location model of cold chain logistics distribution center based on big data, the location model considering sustainable development factors, and the location method of cold chain logistics distribution center integrating multi-index evaluation.In the conclusion, it is pointed out that in the past, the time window and the overall logistics network were rarely used as research evaluation indicators in the site selection problems, and the cost of reverse logistics and closed-loop supply chain was rarely considered. In the prospect part, it is proposed that in the future, we should pay attention to the problems of reverse logistics and closed-loop supply chain in the distribution of fresh agricultural products, consider the multi-objective optimization of low-carbon cold chain logistics network in different policies and fields, and combine full simulation technology and optimization technology to realize the system optimization research.

A dimensionality reduction optimization method for thin-walled parts to realize mass center control and lightweight design

Structural lightweight design has attracted growing attention. However, most studies have ignored the impact of lightweight design on the location of mass centres, which is an important factor affecting the dynamic performance of structures. This article proposes a structural optimization method for thin-walled parts to achieve both mass centre control and lightweight design. First, mass centre and volume are taken as the constraints for structural optimization, and a mathematical model for multi-constrained topology optimization is developed. Secondly, a dimensionality reduction method based on a 3D spatial filter is introduced for the optimization of thin-walled parts. The maximum error between the mass centre of the optimized structure and the target mass centre is only 1.03%, which indicates that the method has high accuracy in mass centre control. Numerical analysis shows that adjusting the mass centre can achieve regulation of the moment of inertia and can also suppress flutter.

Global supply chain network design for shelf-life products under uncertainty: a case study of pistachios

PurposeSupply chain management has become critical in today’s globalized environment, with growingly intense competition on the international level. The particular characteristics of modern trade have led companies to globalize and devise increasingly sophisticated supply chains to meet customer demand worldwide. Motivated by the need to address these challenges, we have developed a new model for a global supply chain that incorporates uncertainties in exchange rates, demand fluctuations, and the quantity of produce.Design/methodology/approachThe objective of the proposed model is to maximize supply chain profitability. Our model optimizes several critical decisions in the proposed global supply chain, including the location of domestic and foreign distribution centers, allocating the centers to customers, transportation mode selection, storage temperature, optimal farm purchase quantities, product flows across the network, and the shelf-life of products. Scenario-based stochastic programming approach is employed to account for the inherent uncertainties within the model. A pistachio supply chain is examined as a case study in this article, and the efficiency of the proposed model is demonstrated through computational results.FindingsThe model was solved using the CPLEX solver in GAMS and the results, the Sirjan DDC and Turkey FDC have been selected. In general, 40% of demand for customers from FDC (turkey) and 60% of demand from DDC (sirjan) is provided. Changes in the demand of foreign customers make the net profit more effective than changes in the demand for domestic customers. The decrease in exchange rate decreases the network profit with a higher slope and the increase in exchange rate will increase network profit with a relatively stable slope.Originality/valueWhile research on GSCs for perishable products has been ongoing for several years, the importance of the subject necessitates continued investigation in this area. This paper aimed to address this gap by presenting an optimization model for designing GSCs for perishable products under uncertainty and with various transportation modes. The proposed model was designed with the aim of improving supply chain performance and real-world applicability.

Typical Development of the Secondary Ossification Centers of the Acetabulum and Their Effects on Acetabular Coverage of the Femoral Head.

We investigated the normal development of the secondary ossification centers of the acetabulum, focusing on their location and the amount of acetabular coverage increased by them. We enrolled 132 patients who were 7 to 16 years of age and had no pelvic deformity but did have ≥1 os ischium, os ilium, and/or os pubis on abdominal or pelvic computed tomographic (CT) scans. The locations of the ossification centers were evaluated by adopting an orientation using 0° for the superior acetabulum, 90° for the anterior acetabulum, 180° for the inferior acetabulum, and 270° for the posterior acetabulum, on a reconstructed 3-dimensional (3D) CT image. The acetabular coverage increase by the os ischium, os ilium, or os pubis was defined as the difference in the posterior acetabular sector angle (ΔPASA), posterosuperior acetabular sector angle (ΔPSASA), superior acetabular sector angle (ΔSASA), anterosuperior acetabular sector angle (ΔASASA), or anterior acetabular sector angle (ΔAASA) measured with and without each secondary ossification center. Patients were grouped into 3 age ranges: late childhood, preadolescence, and early adolescence. The location of each ossification center and the increase in acetabular coverage were compared between these groups. In the late-childhood group, the median start-to-end positions in right hips were 269° to 316° for the os ischium, 345° to 356° for the os ilium, and 81° to 99° for the os pubis. These positions tended to be wider in the early-adolescence group at 252° to 328° for the os ischium (p < 0.001), 338° to 39° for the os ilium (p = 0.005), and 73° to 107° for the os pubis (p = 0.049) in right hips. In right hips in the late-childhood group, the median values were 8.1° for ΔPASA, 14.0° for ΔPSASA, 9.9° for ΔSASA, 11.1° for ΔASASA, and 3.9° for ΔAASA; and in the early-adolescence group, the median values in right hips were 10.7° for ΔPASA, 12.9° for ΔPSASA, 8.4° for ΔSASA, 7.4° for ΔASASA, and 5.6° for ΔAASA. Only the median ΔPASA was larger in the early-adolescence group than in the late-childhood group (p = 0.026). Similar results were observed in left hips. In early adolescence, the secondary ossification centers appeared at more extended areas along the acetabular rim, and the increase in acetabular coverage by the secondary ossification centers tended to be larger in the posterior area but not in the anterior or superior area. Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Impact of mistriages in on-scene injury assessment on trauma network and patient safety

An accurate on-scene assessment of a trauma patient’s injury by emergency medical service providers is critical to determining the right hospital for prompt care delivery. However, literature and anecdotal evidence from trauma professionals in the Midwestern U.S. suggest that mistriages (i.e., an error in assessing a severely injured patient as having non-severe injuries, and vice versa) often occur in practice. Due to a lack of approaches that consider such mistriages while designing the trauma network, we propose a stochastic nested multi-level, multi-transportation capacitated facility location model, which explicitly considers mistriages in injury assessment, to maximize patient safety by determining the number and locations of major trauma centers (MTCs). Assessment-related mistriages are modeled using a Bernoulli random variable for each of the two injury groups, moderate (ISS 9–15) and severe (ISS>15). We propose a Simheuristic approach that integrates Monte Carlo Simulation with a genetic algorithm. We convert infeasible solutions into feasible ones during offspring generation and maintain a superior population pool to balance quality against computational time. Our findings based on a realistic data set suggest that assessment-related mistriages in the ISS>15 group can substantially decrease patient safety and may lead to a clustering of MTCs, while mistriages in the ISS 9–15 group tend to have a dispersed distribution of MTCs in the resulting network. Our case study using actual 2019 data from a midwestern state of the U.S. resulted in an over 20% reduction in the mistriages, further providing evidence for incorporating injury assessment-related mistriages in trauma network design.