Multistage Method Research Articles

From Viewpoint of Reserve Provider: A Day-ahead Multi-stage Robust Optimization Reserve Provision Method for Microgrid with Energy Storage

From Viewpoint of Reserve Provider: A Day-ahead Multi-stage Robust Optimization Reserve Provision Method for Microgrid with Energy Storage

Risk analysis of construction safety level of prefabricated buildings based on multi-level fuzzy comprehensive evaluation

In order to accurately and quantitatively evaluate the safety risks caused by a series of uncertain factors in the construction process of prefabricated buildings, and analyze the factors affecting the construction of prefabricated buildings, a multi-factor and multi-index evaluation system with 5 evaluation criteria and 18 indexes of operators, construction organization, management system, prefabricated components and machinery and equipment was established. Multistage fuzzy comprehensive evaluation method is used to determine the weight of each index, define the index grade, and construct the membership function combined with fuzzy mathematics to construct the fuzzy comprehensive evaluation model. Based on this method, the construction safety level of prefabricated buildings in a community is analyzed and evaluated. The evaluation results are reasonable and effective, and the feasibility of multistage fuzzy comprehensive evaluation is verified.

Multi-Stage Multidisciplinary Design Optimization Method for Enhancing Complete Artillery Internal Ballistic Firing Performance

Multi-Stage Multidisciplinary Design Optimization Method for Enhancing Complete Artillery Internal Ballistic Firing Performance

Tritrophic fractional model with Holling III functional response

<abstract><p>In this paper, we analyzed the local stability of three species in two fractional tritrophic systems, with Caputo's fractional derivative and Holling type Ⅱ and Ⅲ functional responses, when the prey density has a linear growth. To begin, we obtained the equilibria in the first octant under certain conditions for the parameters. Subsequently, through linearization and applying the Routh-Hurwitz Criterion, we concluded that only the system with Holling type Ⅲ exhibits an asymptotically stable equilibrium point, where the fractional derivative order belongs to the interval $ (0, 1] $. Finally, we obtained the solution of the system with the Holling type Ⅲ functional response, using the multistage homotopic perturbation method, and presented an example that shows the dynamics of the solutions around the stable equilibrium point.</p></abstract>

Attitude of the health team to the infant home care plan during the COVID-19 pandemic: A cross-sectional study.

Maintaining and improving infant health and continuing care at home are very important for the health system. According to the coronavirus disease 2019 (COVID-19) pandemic and its effects on the health system capacity and medical staff's physical-mental health, this study investigated the health staff's attitude on the implementation of an infant home care plan. This descriptive-analytical cross-sectional study was conducted on 130 nurses, midwives, and doctors working in the newborn care department in Isfahan health-therapeutic centers, with at least 6 months of work experience. The samples were selected by random multistage method and completed the researcher-made 5-point Likert questionnaire with 25 items and two areas of education support and security safety. The total score of this questionnaire varied from 25 to 125, and obtaining a score equal to or greater than 91 meant that people had a favorable opinion about home care for babies. The reliability of the questionnaire was reported by Cronbach's α of 0.79, and content validity ratio (CVR) and content validity index (CVI) scores of 0.88-0.99 and 0.79-0.1, respectively. Data analysis was performed using the Statistical Package for the Social Sciences version 18.0 (SPSS) (Chicago, USA) and analysis of descriptive statistics, Chi-square, and Pearson correlation tests at a 0.05 significance level. The mean score of medical staff's attitude was obtained at 77.59 ± 11.71 and the security-safety and education-support domains scores were 41.3 ± 6.34 and 36.29 ± 6.11, respectively. In addition, a significant inverted relationship was observed between the mean score of medical staffs"attitude with age and the number of shifts. According to the results, the medical staff's attitude about the infant home care program is neutral, and designing a professional educational period, considering economic preparations and responsibility assurance is essential for creating confidence and acceptance of the infant home care program by the medical staff.

Modelling of a six-case hardware object for control of potassium ore flotation based on systems thinking

This article discusses computer modelling of the flotation process taking into account the hydrodynamic structure of interacting flows. Modern technologies and processes ensure the effective separation of potash ores into individual components, allowing you to obtain the desired product in its pure form. An important aspect is to minimize the loss of useful substances in order to maximize its use in the production of fertilizers. This is achieved through strict control over each stage of raw material processing, optimization of chemical reagents and improvement of separation systems. Various options have been studied and the possibility of using differential equations of material balances has been shown. This made it possible to justify a multi-stage method for identifying a flotation object. The results obtained made it possible to develop acceptable computer models of the dynamics of the flotation process. Methods for modelling the facility and control systems for flotation complexes have been developed based on computer models of the process occurring in the gas and liquid phases.

Parental and Teacher Factors Associated with Cognitive Development of Preschool Children

Early years are the foundational stages for children's cognitive development. This study aimed at analyzing the parental and teacher characteristics associated with preschool children's cognitive development. A cross-sectional design based on quantitative data was adopted in the study. A standard checklist was used to test the cognitive skills of 280 preschool children sampled through multi-stage cum stratified method equally from community and institutional schools in Birendranagar Municipality of Surkhet district in Nepal. The 280 parents and 32 teachers of these children were interviewed for their background characteristics. Many parental and teacher characteristics had significant association with children's cognitive development. The mothers with secondary level and higher education and employing non-labour occupation were associated with their children's higher cognitive outcomes. Similarly, teachers with secondary level and higher degree, preschool experiences below ten years, and high-paid salaries had significant positive association with children's cognitive development. Additionally, parental interaction and engagement with children and their teachers were beneficial for better cognitive skills of the children. So, the educational plans, policies, and programmes should give equal priority to the parental programmes to sensitize and empower the parents, especially the mothers, for their active roles in caring their children and interacting with the teachers. At the same time, the government and all the educational institutions should minimize the gap on teacher's pay between preschool and higher levels.

Potencial of Rice Bran Extract as a Basic Ingridient in Candida albicans Culture Media

Rice bran is a natural material that contains nutrients that serves as a fungal growth factor, can be used as an alternative media base for fungal growth. The aim of this research is to determine the potential of rice bran as an alternative medium for the growth of Candida albicans. The research design employed an experiment that compared the growth of Candida albicans on rice bran extract media and Sabouraud Dextrose Agar (SDA) media. The sample is rice bran powder obtained from rice mills and rice bran extract was made using a multi-stage pretreatment method. The rice bran extract was used to create Rice bran Agar (RBA) and Rice bran Liquid (RBC) media, while SDA dan (SDB) media were also prepared. The media were inoculated with Candida albicans, incubated, and observed for 5 days. Data analysis included the measurement of fungal colony diameter using One Way Anova and Candida albicans biomass using an independent t-test. The research findings indicate that the average diameter of fungal colonies on RBA extract media was 10.4 mm, whereas it was 12.3 mm on SDA media. The Anova and Post Hoc Tukey HSD results demonstrated significant daily differences in colony diameter on RBA media, indicating notable Candida albicans growth. Conversely, there was no significant difference in colony diameter on SDA media. The biomass average of Candida albicans on RBC media was 0.82 g, compared to 0.45 g on SDB media. The Mann-Whitney test (p < 0.05) indicated a significant contrast in the average dry weight of Candida albicans biomass, with RBC media being heavier than SDB media. The conclusion is RBA and RBC media have the ability to grow Candida albicans which can be used as an alternative to SDA and SDB media.

Enhancing Material Analysis with Statistical and Computer Vision Techniques: A Comprehensive Approach for Evaluating Electrode Quality

The optimization of electrodes for electrocatalysis is critical to the efficient operation of energy conversion applications, i.e., performance and efficiency can be improved by optimizing their fabrication process [1]. In the surface microstructure of anodes has been recognized as a fundamental aspect influencing their functionality [2]. Consequently, it is vital to precisely characterize the microstructure of electrodes. Atomic force microscopy (AFM) has demonstrated to be a potent technique for scrutinizing the nanoscale microstructure of anodes. Nevertheless, AFM has limitations in investigating vast areas, thereby posing a challenge when evaluating the surface microstructure of large-scale electrodes.In this study, we developed a multi-stage data quantification method to overcome the limitations of AFM to measure large electrode areas. The efficacy of the developed approach that combines statistical analysis and computer vision techniques was validated by scrutinizing anodes made under various spray coating process conditions. The results demonstrated that the proposed method facilitated the in-depth evaluation of the degree of homogeneity, surface smoothness, and the presence of cracks or defects, thereby enabling a comprehensive assessment of electrode quality. It was possible to establish structure-performance relationships and delineate the interdependence between surface morphology and anode performance, activity, and cycling stability by combining surface analysis measurements with electrochemical analysis.In conclusion, this link between surface and electrochemical analysis will provide critical insights into anode performance and, in turn, drive the development of advanced materials for energy conversion technologies. Therefore, we believe our method has a high potential to expand the material scientist's toolkit and extend its application to analyze the micro/nanostructure of diverse materials in a wide range of applications, providing novel insights for their optimization. References Siegmund, D., et al., Crossing the valley of death: from fundamental to applied research in electrolysis. Jacs Au, 2021. 1(5): p. 527-535.Chatenet, Marian, et al. "Water electrolysis: from textbook knowledge to the latest scientific strategies and industrial developments." Chemical Society Reviews (2022).

Optimization of construction parameters for salt cavern underground energy storage using horizontal multi-stage leaching method under different geological conditions

In the thinly bedded rock salt in China, the horizontal multi-stage leaching method can solve the problem of constructing an enormous salt cavern in a limited-thickness salt layer. This study aims to investigate how the final morphology of the salt cavern is affected by critical parameters of the horizontal multi-stage leaching method in different geological conditions, such as the injection rate of freshwater, tubing withdrawal distance, and the presence of an air cushion. These parameters will directly affect the shape of the salt cavern and thus influence the stability of the underground energy storage during operation. We developed an experimental device to simulate salt cavern construction using the horizontal multi-stage leaching method. By varying the parameters in the physical simulation experiments, horizontal salt cavern models with different morphologies and sizes were obtained. The experiments showed that the injection rate of freshwater significantly affects the salt cavern height, length, and maximum width. The tubing withdrawal distance mainly affects the shape of the roof of the salt cavern. Introducing an air cushion to protect the salt cavern roof during the construction of a salt cavern results in a “flat-top” morphology. According to these salt cavern models, three-dimensional geomechanical models for different geological conditions are established by using reverse engineering technology. After analyzing the stability of the salt cavern using these models and combining them with economic factors to recommend values for the critical parameters of horizontal multi-stage leaching method in different geological conditions are provided. This study provides reference value and a theoretical basis for the construction of horizontal salt cavern storage in China.

Quantitative Strategic Planning Matrix as a Superior Strategic Management Tools and Techniques in Evaluating Decision Alternatives

Evaluation of alternatives to making decisions still remains as the most difficult field for every manager. Considering that uncertainty, stress, emotions and many other factors still remain insurmountable during decision-making in the work of managers. The research will bring a contemporary approach to the evaluation of alternatives through the multi-stage method by conducting a series of exhibitions for an effective decision. Model will create a logical structure derivation of exhibitions by revealing options and paths toward strategic leadership. The research used mixed methods of data collection to create a more meaningful and integrative research design. The sample was elongated over a survey of 250 organizations. The research brings to the surface a clear analysis of the following path as a guide and practically used to gain differentiating advantages towards the long-term through Strategic Attractiveness Position in Industry (ST-API). From this analysis structure, a clearness leadership orientation is created for managers, a recommendation for strategic leadership, revealing a group of strategies to undertake depending on the ST-API dimension IFE (Internal Factor Evaluation) or ST-API dimension EFE (External Factor Evaluation) through crafting "Option's" since the organizations are concentrated in the vicinity of the corner (nook) in quad IV, conclusively in "growth and build". Occurrated in this axle, organizations are advised to orient their actions towards the "develop products" in order to go towards longevity and leaderism in the industry.

Resource Mobilisation, Utilisation and Wellbeing of Social and Solidarity Groups In The Assin Fosu Municipality, Ghana.

Purpose: The study focused on farm-based cooperatives in the Assin Fosu municipality and examined resource mobilisation as well as the factors that determine resource utilisation and the wellbeing of social and solidarity organisations.
 Design/Methodology/Approach: 180 respondents from six registered farm-based cooperatives in the Assin Fosu Municipality were chosen for the study using a mixed research design and a multi-stage sample method that included purposive, proportional, and simple random sampling procedures. The Focus Group comprised cooperative chairpersons and was further expanded to include the Municipal Co-operative Officer, who was specifically chosen as a key informant. In addition to narratives drawn from qualitative data, descriptive statistics and logistic regression were used to examine the data.
 Research Implications/Limitations: The limitation of this study is the measurement of farm size and income which were based on the mental construct of farmers because most of the cooperative members did not keep records. This tended to distort the reality related to farm size and income which were included in the construct of wellbeing and collective resource mobilisation.
 Findings: We discovered that, except for cooperatives based on cocoa, resource mobilisation was low across all the cooperatives. The study found that the mobilisation of resources and the collective purchase of agricultural equipment and supplies, which reduced production costs, were the driving forces behind resource utilisation. The main wellbeing indicators were longer membership durations and group resource mobilisation and utilisation.
 Practical Implications: The findings of the study will help contribute to the management of social and solidarity groups in Ghana and broaden the understanding of how this development approach affects livelihoods. It is also hoped that the findings will contribute to the mitigation of the cost of neoliberal policies by providing a path to wellbeing at the micro and informal levels through group resource mobilisation and utilisation.
 Social Implications: Social and Solidarity organisations serve as an alternative to economic organisations that are based on neoliberal principles. This is because the latter favours the dominant few in developing economies culminating in widespread poverty, inequalities, and a decline in wellbeing. To maximise wellbeing, cooperatives should intensify resource mobilisation, and utilisation whilst maintaining their membership.
 Originality/Value: The novelty of this paper lies in its contribution to the literature on social and solidarity economies. It provides information on the missing link on how farm-based cooperatives mobilise and utilise resources for the wellbeing of their members.

Investigation on hydrate exploitation in submarine slope: Insights from discontinuous pillar exploitation

The decomposition of natural gas hydrate (NGH) will cause a decrease in reservoir strength, which can easily induce submarine landslides when hydrate reservoirs are located on a submarine slope. Although there have been several studies on the stability of hydrate-bearing submarine slopes (HBSS), little attention has been paid to minimizing the risk of landslides due to NGH exploitation. The “multistage reduction method” based on strength reduction was described in this paper. Subsequently, “discontinuous pillar exploitation” was proposed to achieve safe extraction of NGH and avoid submarine landslides. Finally, the “discontinuous pillar exploitation” was analyzed using the “multistage reduction method”. The results show that NGH decomposition has a far-reaching impact on the HBSS; it reduces the stability of HBSS and can trigger submarine landslides. The “discontinuous pillar exploitation” can divide the continuous plastic failure zone into short discontinuous plastic zones through the setting up of pillars, which significantly improves the stability of HBSS. With the decrease in the exploitation ratio, the safety factor of the submarine slope increases continuously. When the “discontinuous pillar exploitation” is adopted for NGH production on a submarine slope, there are two positions that require special attention: the junctions between the pillars and the exploitation area (peak area of shear stress); the side of exploitation area near the top of the slope (peak area of tensile stress).

Ultrasound tomography based on the coefficient inverse problem as a way to combat structural noise

The paper proposes to use the ultrasound tomography method based on the solution of the inverse coefficient problem to reduce the level of structural noise. Mathematical models used in ultrasonic tomogra-phy well describe such physical effects as refraction, diffraction and redispersion effects. It is logical to ex-pect that reconstruction of the internal structure of metallic samples using ultrasound tomography will be more efficient compared to digital antenna focusing (DAF) techniques. Due to the nonlinearity of the inverse problem of ultrasound tomography, an iterative MultiStage method is used to ensure convergence to the glob-al minima of the non-convexity functional. The paper presents the results of numerical experiments to restore the image of the internal structure of the welded joint, which may contain lateral cylindrical holes and crack models. The region of the welded metal is represented in the form of sections constructed according to the principle of Voronoi diagrams. In each section the velocity is constant and its value is randomly distributed. In the model adopted in the paper, the structural noise is formed due to multiple scattering at the boundaries of sections with different sound velocity. It was assumed that the antenna array is located on the outer surface of the control object of known thickness. The results obtained show that the tomographic method allows us to determine the shape and speed of sound in low-contrast reflectors, for which the CFA method is ineffective.

A multi-stage approach for high-precision measurement of cervical curvature in X-ray images

As people’s lifestyles change, cervical spondylosis affects people more often. Early diagnosis is thus crucial in the management of cervical spondylosis. Cervical curvature abnormalities may serve as an objective diagnostic standard in radiographs, commonly assessed by the Cobb angle measurement in clinical practice. The method involves the clinician marking four corners of each vertebra and then drawing lines to calculate the Cobb angle using specific rules. The whole process takes a long time and mainly relies on subjective experience. In this paper, we propose an automatic multi-stage method for measuring cervical spine Cobb angle, which is referred to as MSM-CSCA that can perform the precise measurement of cervical curvature. In Stage 1, the region of interest (ROI) of the cervical spine is carefully cropped automatically. In Stage 2, an improved CA-UNet is used to achieve detailed segmentation of the cervical spine region for the ROI region, which extracts features from the edges of the vertebrae and integrates them with the original ROI to highlight the vertebrae edges more distinctly. At Stage 3, the integrated features are input into a dual-branch landmark detection network, with segmentation and detection branches. Within this stage, the segmentation branch convolutional results are fed back into the detection branch after feature augmentation to provide a more accurate detection area. Finally, the accurately identified cervical landmarks from this network are used to calculate the Cobb angle. Experimental results show that the proposed method achieves SMAPE 15.05% and MAE 3.19 on X-ray images of the cervical spine, significantly better than the other benchmark methods. The proposed method can provide clinicians with an efficient, accurate, and reliable way for the estimation of cervical curvature.

Accurate Segmentation and Tracking of Chorda Tympani in Endoscopic Middle Ear Surgery with Artificial Intelligence.

Objective: We introduce a novel endoscopic middle ear surgery dataset specifically designed for evaluating deep learning (DL)-based semantic segmentation of chorda tympani. Methods: We curated a dataset comprising 8240 images from 25 patients, divided into a training set (20%, 1648 images), validation set (5%, 412 images), and test set (75%, 6180 images). We employed data enhancement techniques to expand the picture size of the training and validation sets by 5 times (training set: 8240 images, verification set: 2060 images). Subsequently, we employed a multistage transfer learning training method to establish, train, and validate various convolutional neural networks. Results: On the validation set of 2060 labeled images, our proposed network achieved good results, with the U-net exhibiting the highest effectiveness (mIOU = 0.8737, mPA = 0.9263). Furthermore, when applied to the test dataset of 6180 raw images and contrasted with the prediction of otologists, the overall performance of the U-net was excellent (accuracy = 0.911, precision = 0.9823, sensitivity = 0.8777, specificity = 0.9714). Conclusions: Our findings demonstrate that DL can be successfully employed for automatic segmentation of chorda tympani in endoscopic middle ear surgery, yielding high-performance results. This study validates the potential feasibility of future intelligent navigation technologies to assist in endoscopic middle ear surgery.

Effect of ore quality on non‐aqueous oil sand extraction performance

AbstractCurrent commercial aqueous based extraction processes are energy and greenhouse gas (GHG) intensive and require large tailings ponds. Non‐aqueous extraction (NAE) of bitumen from mineable oil sands is an alternative that eliminates tailings ponds with potentially lower energy requirements and GHG emissions. The economics of the NAE process depend partly on the impact of ore quality on bitumen recovery and product quality (low water and solids content). It has been claimed that NAE performance is insensitive to the quality (bitumen content) of the oil sand ores. However, the available data are ambiguous because different extraction methods and solvents were used in different studies and, in many cases, a limited range of ore qualities was examined. In this study, bitumen was extracted from eight ores of different quality with cyclohexane using a multistage method equivalent to a countercurrent process with a solvent/ore ratio of 0.67 w/w. The bitumen recovery and the water and solids content of the product bitumen were determined for each ore. It was found that bitumen recovery correlated negatively to clay content of the ore. The loss of recovery was attributed to bitumen adsorption on clays. The product quality was insensitive to the ore quality and instead depended on the density of the fluid medium, as expected with a centrifuge‐based separation method. The recovery and product quality from the NAE method were similar to those from aqueous extractions.

Sustained production of gas hydrate through hybrid depressurization scheme with enhanced energy efficiency and mitigated ice blockage

Several trial productions have been conducted on marine natural gas hydrate reservoirs, demonstrating its enormous potential as an alternative energy source. Nonetheless, sustained and efficient production still remains challenging, with crucial issues on low gas production efficiency and blockages. The large amount of hydrate decomposition and resulting heat absorption can lead to prolonged subzero conditions close to the well; this can readily induce ice formation and blockage. This study aims to investigate the issue of ice blockages caused by insufficient energy supply during the recovery process. A systematic analysis of the energy consumption and ice blockage quantification at each stage of the traditional multi-stage direct depressurization and constant speed depressurization methods is conducted. A hybrid optimized scheme is proposed, which enhances energy utilization efficiency by appropriately utilizing reservoir sensible heat during the initial stage of production. Additionally, a multi-stage constant speed depressurization method is introduced in the later stages to mitigate production fluctuations and reduce blockage duration. Results showed a 69.5 % increase in energy efficiency and an average 67.1 % decline in gas blockage duration with comparable gas productivity. The proposed method could be a viable solution to mitigate challenges of icing blockages and fluctuating production during trial tests of marine hydrate reservoirs, achieving improved energy efficiency and sustainable production.

Microstructural and mechanical properties of additive manufactured 2319 aluminum alloy annular-shaped components: As-built and multistage heat treatment

A novel multistage aging heat-treatment method was applied to investigate the microstructural evolution and properties of an additive-manufactured 2319 aluminum alloy. The microstructure and mechanical properties were analyzed, and the results revealed that the as-built annular-shaped components were characterized by an alternating distribution of thin equiaxed crystals, dendrites, and coarse columnar crystals. The microstructure occurs recrystallization and the average grain size decreased after the two-stage aging treatment. The maximum texture strength in the selected area increased after the two-stage aging treatment, and the angle grain boundaries were evenly distributed. Solid solution plus aging could significantly improve ultimate tensile strength and hardness. The tensile fracture morphology was typical of ductile fracture. Two-stage aging exhibited a higher corrosion resistance.

Method of information protection based on the integration of probabilistic encryption and noise immune coding

The subject matter of this article is the processes of increasing information security in communication systems to solve applied problems that are critical in the transmission of confidential data. The goal is to develop a multi-stage method for protecting information from unauthorized access, based on probabilistic encryption integration, error-correcting code, and error decorrelation. The tasks to be solved are as follows: to develop a probabilistic encryption algorithm that considers the entropy of the characters’ appearance in a message; to implement iterative coding with variable parameters of the information bits matrix; and to implement error decorrelation based on the generated matrix by interleaving information and check bits according to a given algorithm. Methodology: theory of signal communication and signal processing, theory of cryptography, theory of noise-resistant codes, probability theory, statistical analysis. The following results were obtained: a multi-stage method for protecting information from unauthorized access was proposed, in which at each step of data conversion, information secrecy is increased; probabilistic encryption was implemented, which considers the entropy of a discrete source of information when forming a space of random combinations; based on an iterative code with specified matrix parameters, an additional increase in the space of random combinations was implemented; error decorrelation reduces the multiplicity of errors in codewords and ensures mixing of bits according to a predetermined law. Conclusions. The scientific novelty of the results obtained is as follows: 1) an improved method of information protection from unauthorized access is proposed, based on probabilistic encryption integration, interference-resistant coding, and error decorrelation; 2) increasing information concealment is realized by eliminating the main shortcomings of probabilistic encryption, which did not take into account the entropy of the symbols of the open message; 3) it is proposed to form the space of random combinations taking into account the average probability of the appearance of a symbol in open texts, which will allow the output of a probabilistic cipher to form a stream of random combinations, which, according to its statistical properties, is close to the uniform distribution law; 4) further development of information protection methods based on interference-resistant coding and error decorrelation with encryption functions is received; 5) a further development of the statistical encryption method is the use of all redundant elements for both probabilistic encryption and interference-resistant coding.