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Found 6327 publications

Modeling the Correlation of Human Vertebral Body Volumes

B. Benyo Péter Somogyi Bálint Szabó K. Kovacs Sándor Bazsó Ákos Szlávecz Árpád Viola

Publication Name: IFAC Papersonline

Publication Date: 2023-07-01

Volume: 56

Issue: 2

Page Range: 9030-9035

Description:

Anatomical parameters of the human body strongly correlate with each other. Modelling these dependencies enables the creation of a realistic anatomical human body model that can be parameterized. Such a model can be used for several diagnostic processes to identify abnormalities or even give guidance in surgical interventions. This paper proposes a probabilistic model describing the dependencies between the vertebral body volumes of humans from the Caucasian human race. As demonstrated, the proposed model can accurately describe the relationship between the vertebral body volumes and is used for the prediction of an unknown vertebral volume based on a known one. The probabilistic model is created by using the CT segmentation of 37 patients.

Open Access: Yes

DOI: 10.1016/j.ifacol.2023.10.133

Determinants of Rural Households’ Intensity of Flood Adaptation in the Fogera Rice Plain, Ethiopia: Evidence from Generalised Poisson Regression

Kennedy Ndue Melese Mulu Baylie Goda Pál

Publication Name: Sustainability Switzerland

Publication Date: 2023-07-01

Volume: 15

Issue: 14

Page Range: Unknown

Description:

Effective adaptation to flooding risk depends on careful identification and combinations of strategies which, in turn, depends on knowledge of the determinants of flood adaptation. The main objective of this study was to examine the determinants of rural households’ intensity of flood adaptation in the Fogera rice plain, Ethiopia. A three-stage stratified sampling technique was employed to select 337 sample household heads. Primary data was collected through a structured household survey. Data analysis was accompanied by a descriptive and generalised Poisson regression (GP) model. The descriptive analysis showed that households adopted an average of three (3) flood adaptation strategies. The generalised Poisson regression further revealed that family size, availability of off-farm income, previous flood experience, access to credit, access to extension services, and an early warning information system statistically significantly increase flood adaptation strategies’ average number (intensity). However, the age of the household head negatively and significantly influences the intensity of flood adaptation. More specifically, households with off-farm income, previous flood experience, access to credit, access to extension, and an early warning information system were 20%, 94%, 13%, 30%, and 29% more likely to adopt more flood adaptation strategies, respectively. The findings call for immediate response and coordination among stakeholders to design strategies that enhance households’ livelihood, access to credit, access to extension services, and early warning information systems for effective flood adaptation in the study area.

Open Access: Yes

DOI: 10.3390/su151411025

Damping of Dry Sand in Resonant Column-Torsional Simple Shear Device

Majd Ahmad R. P. Ray

Publication Name: Sustainability Switzerland

Publication Date: 2023-07-01

Volume: 15

Issue: 14

Page Range: Unknown

Description:

The damping ratio values of three different Danube sands were measured in the Resonant Column-Torsional Simple Shear device (RC-TOSS). The distinctive configuration of the RC-TOSS device employed in this investigation enabled the performance of both tests using a single sample. This research estimates and compares the damping ratio values measured with three distinct methods (two of which are in the RC test): The Free Vibration Decay (FVD), the Steady-State Vibration (SSV) methods, and the method of calculating the damping ratio from the hysteretic loops generated in the TOSS test. Both dense and loose samples were tested up to a peak-to-peak amplitude shear strain of 1%. The device provides measurements over a wide range of shear strain amplitudes. The results support the employment of the SSV methods at low strains (below 0.005%), while the FVD method gives a better estimate at higher strains (above 0.03%). The two methods and the TOSS results are in agreement with each other between 0.005% and 0.03%. The effect of the number of cycles on the damping ratio was investigated where a significant decrease was observed in the damping ratio with an increasing number of cycles. A parameter is introduced to describe the rate of this decrease, which should be considered during the structural design to reduce maintenance and life-cycle costs and enhance sustainability.

Open Access: Yes

DOI: 10.3390/su151411060

Mechanical and morphological properties of PP/XNBR blends produced with rubber latex

László Lendvai

Publication Name: Journal of Polymer Research

Publication Date: 2023-07-01

Volume: 30

Issue: 7

Page Range: Unknown

Description:

In this work, polypropylene (PP)/carboxylated acrylonitrile butadiene rubber (XNBR) binary blends were prepared with the elastomer component dosed in its suspension (latex) form into the polymer matrix during melt compounding. For this purpose, samples containing 0-20 wt.% rubber were prepared using two different PP grades as matrices with lower and higher viscosity. Analogous reference samples with the same composition were also fabricated using traditional melt mixing by introducing the rubber in its dry, bulk form in order to analyze the efficiency of the latex route. Mechanical, thermomechanical and morphological analyses were used to investigate the structure-property relationships of the blends. Based on the SEM images the average domain size of the dispersed XNBR domains became markedly smaller when the rubber was introduced in its suspension form into the PP. Based on the Charpy impact tests and the tensile test results, the decreased rubber domain size led to improved ductility and toughness. The improvement was more prominent when the difference between the viscosity of the PP matrix and the XNBR rubber was higher.

Open Access: Yes

DOI: 10.1007/s10965-023-03660-3

Stability focused evaluation and tuning of special ground vehicle tracking algorithms

Antal Hiba Ádám Kisari Mihály Nagy Istvan Drotar Erno Simonyi Péter Bauer Gergely Istvan Kuna

Publication Name: IFAC Papersonline

Publication Date: 2023-07-01

Volume: 56

Issue: 2

Page Range: 9282-9287

Description:

This paper deals with a special tracking problem when a ground vehicle should be tracked by a multicopter flying ahead of the vehicle. Pre-designed vehicle route is assumed and the UAV stops or slows down at every intersection to react to route changes. After introducing the problem, the methods applied in a real flight demonstration in the Smart City module of ZalaZONE proving ground are presented. Then new methods are introduced to possibly improve performance. The main focus of the article is the evaluation of the stability of the methods and the provision of tuning guidelines. All of the introduced methods is tuned based-on the guidelines considering real ground vehicle test data and the high fidelity simulation of the applied multicopter. The two best methods are compared in detail and guidelines of their applicability are provided.

Open Access: Yes

DOI: 10.1016/j.ifacol.2023.10.212

Optimal Shape Design of Concrete Sleepers under Lateral Loading Using DEM

Majid Movahedi Rad Jafar Chalabii Seyedsaber Hosseini

Publication Name: Buildings

Publication Date: 2023-07-01

Volume: 13

Issue: 7

Page Range: Unknown

Description:

Despite the significant contribution of sleepers to the lateral resistance of ballasted tracks, limited research has focused on improving the shape of sleepers in this aspect. This study aims to evaluate proposed sleeper shapes based on the B70 form, utilizing a linear optimization algorithm. First, a DEM model was verified for this purpose using the outcomes of the experiments. Then, using this model, the effect of the weight of the B70 sleeper was carried out on lateral resistance. Next, suggested shapes contacted with ballast materials were applied to lateral force while maintaining the mechanical ballast’s properties until a displacement of 3.5 mm was achieved. The current study’s results showed that the rate of lateral resistance increasing becomes lower for weights higher than 400 kg. Additionally, it was demonstrated that the sleeper’s weight will not always increase lateral resistance. The findings also indicated that although some proposal shapes had higher lateral resistance in comparison to other forms, these designs are not practical from an economic standpoint. Furthermore, despite the lower weight of some other suggested shapes in comparison with B70, the lateral resistances are 31.2% greater. As a result, it is possible to recommend employing a proposed sleeper rather than a B70 sleeper.

Open Access: Yes

DOI: 10.3390/buildings13071574

Comparison of Three Artificial Intelligence Methods for Predicting 90% Quantile Interval of Future Insulin Sensitivity of Intensive Care Patients

B. Benyo J. Geoffrey Chase Bálint Szabó K. Kovacs Ákos Szlávecz Béla Paláncz

Publication Name: IFAC Papersonline

Publication Date: 2023-07-01

Volume: 56

Issue: 2

Page Range: 2091-2095

Description:

Three alternative artificial intelligence-based insulin sensitivity prediction methods are compared in this study. Insulin sensitivity prediction is an essential step in calculating the optimal treatment options in model-based glycemic control protocol of insulin-dependent intensive care patients. The prediction methods must predict not only the expected value of the insulin sensitivity for a given time horizon but also the 90% confidence interval making the prediction problem more specific compared to the common prediction problems. All of the proposed prediction methods - proposed in our previous publications - use different neural network models: a classification deep neural network model, a Mixture Density Network based model, and a Quantile regression based model. The patent data set used for the development and accuracy assessment is from 3 clinical ICU cohorts, including 820 treatment episodes of 606 patients and 68,631 hours of treatment. To evaluate the efficacy of the prediction in the context of clinical requirements, three metrics are used Success rate, Interval ratio, and I-Score are applied.

Open Access: Yes

DOI: 10.1016/j.ifacol.2023.10.1110

Case Study: Optimizing Grading Ring Design for High Voltage Polymeric Insulators in Power Transmission Systems for Enhanced Electric Field and Voltage Distribution by Using a Finite Element Method

Fatiha Aouabed Adrienn Dineva Esraa Aziz Hossam Abdellah

Publication Name: Energies

Publication Date: 2023-07-01

Volume: 16

Issue: 13

Page Range: Unknown

Description:

This research paper aims to investigate the optimal design of grading rings for high-voltage polymeric insulators in an actual power transmission system, with a focus on improving the electrical representation of the insulator strings. One such subsidiary accessory commonly used with porcelain and polymer insulator strings is the grading ring, which is employed to improve the electric field and voltage distribution surrounding the insulator string. The efficiency of insulator strings can be enhanced by grading rings, as they facilitate a more linear potential division along the strings. The design parameters of grading rings significantly influence their performance on insulator strings. In this study, we examine the optimal design of the grading rings of high-voltage polymer insulators, since no uniform design methodology has been developed for high-voltage polymer insulators, and their optimization is currently the subject of many research studies. The electric field on an outdoor polymeric insulator is examined using finite element method (FEM) software and COMSOL Multi-Physics program. A 2D model is utilized to simulate a 220 kV polymeric insulator. The effectiveness of high-voltage polymeric insulators greatly depends on the dimensions and locations of the grading rings. Therefore, the impacts of the radius of the grading ring and that of its tube and the tube’s vertical position are thoroughly investigated, under dry and humid conditions. To achieve this objective, a search algorithm is employed to adjust the dimensions and locations of the grading ring. The optimization approach in this study is based on determining the maximum electric field across the insulator surface, while ensuring that it remains below the corona initiation level.

Open Access: Yes

DOI: 10.3390/en16135235

Synthesis of multiperiod heat exchanger networks: n-best networks with variable approach temperature

Ákos Orosz Rozália Lakner Bing Shen How Ferenc Friedler

Publication Name: Thermal Science and Engineering Progress

Publication Date: 2023-07-01

Volume: 42

Issue: Unknown

Page Range: Unknown

Description:

In industrial processes, the stream parameters of the heat exchanger network (HEN) synthesis problem can vary during different periods. As a result of the change in inlet and outlet temperatures and the flow rates of the streams, the optimal HEN and the optimal heat transfer areas of the heat exchangers can be different in each period. In our previous work, the standard HEN synthesis for minimum utility consumption was extended to consider varying stream parameters, where bypasses at the heat exchangers are used to ensure the exit streams meet the expected outlet temperatures. This requires optimization of the total annualized cost based on the maximal heat transfer areas of the heat exchangers for each period. Minimum approach temperature is applied to ensure that the areas of the heat exchangers stay within reasonable limits in the solution network. Since minimum approach temperature affects both the structure of the HEN and the total annualized cost, its value needs to be determined during the optimization procedure. The current work proposes a procedure for HEN synthesis which determines the best, n-best, or all feasible HENs for all periods considering variable approach temperature. The proposed method extends the P-graph-based HEN synthesis method for determining all feasible networks in all periods. Three case studies are used to demonstrate the application of the proposed method. The case studies show that while the commonly applied minimum approach temperature of 10 °C does indeed gives near-optimal results, some problems need different values, such as 25 °C or 30 °C.

Open Access: Yes

DOI: 10.1016/j.tsep.2023.101912