Comparison Result Research Articles

Flight experimental analysis of largemulti-propeller airtanker dropping capability

Abstract In the absence of a dropping capability experiment of domestic airtankers, it is necessary to know the actual dropping capability of fixed-wing airtankers for data support to wildfire-fighting, improving fire-fighting efficiency, and reducing the loss of forest and grassland resources. According to the design characteristics of large multi-launch propeller airtankers in China, this experiment shall collect retardant samplesof the filled flame retardant with collection equipment on the flat ground after being dropped by the airtanker in the air. Then, the sample coverage was counted and contour maps of the ground patterns were plotted to compare the dropping coefficients, dropping heights, and dropping speeds of the different dropping modes. At the last, according to the comparison result, the best dropping strategy shall be shown in different requirements. The result shows that when the coverage level is required to be GPC-6, the maximum coverage shall be obtained by all compartments released simultaneously, with a maximum coverage coefficient of 0.16. When the coverage level is required to be GPC-1, it is better to release the retardant from the tank independently with a suitable interval for larger coverage, and the maximum coverage coefficient is 4.49.

Redefinition for Fundamental Characteristics of Waterway Traffic Stream Considering Vessel Displacement

As the basis for characterizing traffic conditions in waterways, fundamental characteristics of waterway traffic streams are of great practical significance in ensuring traffic safety and improving navigation efficiency. In the study of the fundamental characteristics of waterway traffic flow, although some scholars consider the length or area of the vessel, few scholars take the displacement of the vessel into account and make light of the influence of the three-dimensional size of the vessel. This paper proposes a method for defining the fundamental characteristics of a waterway traffic stream considering vessel size. This method defines fundamental characteristics in terms of vessel displacement and quantifies flow, density, and speed based on vessel trajectories in time–space regions. This study selects a unidirectional channel in the south trough waters of Shanghai Harbor for a case study and draws the fundamental diagram of the waterway traffic stream while considering vessel number and displacement. The comparison result shows that the definition considering vessel displacement can more accurately reflect the actual traffic condition of the selected channel. Finally, based on the flow–density subgraph of the waterway traffic stream (measured by vessel displacement), this paper constructs a traffic stream model and derives critical parameters. The definition proposed in this study effectively characterizes how vessels occupy the time–space resources of waterways, revealing the inherent mechanisms governing waterway traffic stream and, thus, enhancing accuracy in describing fundamental relationships among waterway stream characteristics. The outcome of this research underlies how the waterway traffic stream is measured, operated, and managed to ensure safety and productivity.

Heat rejection effect study on large-scale sodium test facility STELLA-2

The STELLA-2 facility is a large-scale sodium test facility to support the development of PGSFR and is accumulating extensive experiment data. The experiment campaigns of STELLA-2 are mostly planned to be transient and therefore it is very challenging to analyze and quantify the amount of heat loss. In this study, a deliberate heat rejection at arbitrary points to consider the heat loss is discussed and the comparison result between the experiment and code calculation is described. The code calculation with heat loss indicates improvement in prediction and it was verified that the behavior of heat transfer in IHTS loops was mostly influenced by the heat loss. For further study, the heat loss effect on other experiments will be evaluated in the coming years.

考虑作业工况特性的纯电动园艺作业机械动力传动系统参数匹配方法研究

To meet the economy requirement of the horticultural machinery, a two-speed transmission system was proposed based on the characteristics of the driving cycle of the horticultural machinery. Firstly, the test cycle of the horticultural machinery was established based on the data collector that fixed on the machinery. Secondly, the two-speed driveline system was designed. To reduce the energy consumption in the horticultural machinery working cycle, the gear ratio of the two-speed gear box was optimized with the goal of minimum energy consumption by the Genetic Algorithm. The optimized gear ratio were 11.6 and 9.62. The comparison of energy consumption between single gear ratio and two-speed gear ratio was made. The comparison result showed that the energy consumption can reduce 0.25% under one transportation test condition, the energy consumption can reduce 0.41% under one ploughing test condition, and the energy consumption can reduce 0.41% under one rotary test condition.

Research on Conduction Delay Time Characteristics of Double-Gap Surface Flashover Triggered Multistage Vacuum Switch

Due to the insulation saturation effect of a vacuum gap, the series connection is the main method to improve the capability of the triggered vacuum switch (STVS) to withstand voltage. In this paper, a double-gap surface flashover triggered multistage vacuum switch (DMVS) is constructed based on a removable vacuum chamber. The DMVS consists of a surface flashover triggered vacuum gap (STG) and a self-breakdown vacuum gap (SBG) in series. The trend in DMVS conduction delay time under different operating parameters and gap distances is firstly measured through experiments, and then the conduction delay time characteristics of DMVS and single-gap STVS compared. The test results show that increasing the trigger current and operating voltage and decreasing the gap distance of each vacuum gap can optimize the conduction delay time of the DMVS, but the voltage division ratio between the STG and the SBG has no obvious influence on the conduction delay time. The comparison result between the DMVS and the STVS shows that increasing the number of series gaps increases the conduction delay time but, for a certain vacuum gap distance, DMVS exhibits superior conduction delay time characteristics compared to STVS.

On Various Soil Moisture Measurement Techniques Available in the Literature

The sustainability and health of soil associated with its productivity and health are closely related to soil moisture. The amount of water or moisture in the soil is an important parameter in the mobility of nutrients in the soil, in soil reclamation studies, and in the washing-transportation and mixing of fertilizers and other chemicals applied to the soil into the ground water. On the other hand, it has become important today not only to minimize water consumption but also to accurately measure the amount of moisture in the soil so that proper amount of water that the plant needs can be circulated to the root zone of the plant. In this context, information was given about various measurement methods for determining soil moisture (direct and indirect - thanks to correlations) existing in the literature, and among these studies, especially the studies on microwave methods were examined. Comparison results of the dielectric constant values obtained for three different soil samples with different gravimetric volumetric moisture rates by one of the calibration-independent non-resonant microwave measurement methods, which has a high application potential and is different from the existing calibration-requiring microwave measurement methods, and the dielectric constant values predicted by the Mironov model in the literature are presented. The comparison result showed that this new type of microwave measurement method has a high potential for measuring the moisture value of soil samples

Effectiveness Of Moringa Oleifera And Ginger Extract On The Intensity Of Dysmenorrhea In Adolescent Girls

Dysmenorrhea is one of the most common gynecological problems experienced by adolescence girls. Introduction to non-pharmacological treatment of dysmenorrhea in adolescence girls is required to reduce the risks arising from dysmenorrhea with pharmacology that has side effects on the body. Moringa Oleifera and Ginger Extracts are non-pharmacological therapies that have analgesic and anti-inflammatory benefits. To find out the comparison of the effectiveness of Moringa Oleifera and Ginger Extracts against the intensity of dysmenorrhea in adolescent girls. The research methodology was a Study Case Literature Review of dysmenorrhea with the Numeric Rating Scale (NRS) before and after the intervention. There was a decrease in the intensity of dysmenorrhea in the two respondents. The comparison result was that Ginger Extract was more effective (83.3%) than Moringa Oleifera Extract (50%) in reducing the intensity of dysmenorrhea. We expected that Moringa Oleifera and Ginger Extracts could be an alternative in handling both prevention and non-pharmacological treatment of dysmenorrhea.

Effects of structure parameter and material property on thermal performance of on-board hydrogen storage tanks during fast refueling

As a power generation fuel, high-pressure hydrogen gas is widely used in transportation, and significantly contributed to development of hydrogen fuel cell electric vehicles. However, obvious temperature rise generated during fast refueling causes serious safety risk to reliable operation of fuel cell stacks. Therefore, it is necessary to conduct in-depth research on fast filling process. Based on safety reasons, the SAE J2601/ISO 15869 strictly regulates the maximum temperature limit of 85 °C in specifications for refueling hydrogen gas tanks. In this study, a 70 MPa, Type IV on-board hydrogen storage tank is adopted as the research object, and a 2-dimensional axisymmetric numerical model is established to study the temperature rise of the vapor within storage tanks during fast refueling. The Realizable k-ε turbulence model is employed to simulate high intensity turbulent fluctuation during fast filling. Considering the compressibility of vapor, the state of equation for real hydrogen gas is used by obtaining fluid thermodynamic properties from the National Institute of Standards and Technology database. Three groups of fast filling experiments are selected to validate the developed numerical model. The comparison result shows that the numerical model has good prediction ability on hydrogen fast refueling. The final mass average temperature differences between numerical results and experimental data are 2.6 K, 4.3 K, and 0.03 K, respectively. Based on the developed numerical model, the influences of structure parameters and material properties on the temperature rise of hydrogen storage tanks are investigated. The results indicate that the inlet diameter and wall thickness of the inner and outer layers of the storage tank have weaken impacts on the temperature rise during rapid charging, with the maximum temperature differences of 1.8 K, 0.74 K, and 0.54 K, respectively. Due to the influence of heat capacity, the material properties of different layers exhibit a similar variation trend. This work can deepen researchers' understanding of the temperature rise of on-board hydrogen storage tanks during fast filling, and provide technical references for the structural optimal design of tanks and rapid refueling at hydrogen stations.

Cops and robbers game and applications of its variant

Pursuit-evasion game is a game with a pursuer player and an evader player, it has numerous applications including artificial intelligence, robot motion planning and so on. The cops and robbers game is a type of pursuit-evasion game played on graphs, and its variant is a very fruitful research area in graph theory. The purpose of this paper is to find the specific relations between pursuit-evasion game applications and different types of variants of the cops and robbers game. The research method is to find variants with different game rules and winning strategies and classify them. Then compare these rules and strategies with the applications of pursuit-evasion games to find their relationships. The comparison result shows that there are many differences between the variants and the applications, which lead to their inability to be directly related. The application of the pursuit-evasion game is mainly based on route planning and object distance, and generally contains multiple variant types, which is different from the current research direction of variant.

Study on internal load distribution of deep groove ball bearings considering raceway surface waviness

Abstract A full circumferential contact mechanics modeling study considering the effect of waviness mesoscopic profile and rolling element contact relationship on bearing load distribution is carried out. In the model, a sinusoidal function is adopted to simulate the profile of the waviness section. According to the contact tangency condition, a model of the contact deformation relationship between a single rolling element and the raceways is established. On this basis, a full circumferential rolling elements contact load distribution model of the bearing is established by introducing the contact deformation of all rolling elements with the raceway surfaces. Focusing on contact deformation of a full circumferential rolling elements with the raceways, this model can conduct more accurate modeling and reflect the load distribution state inside the bearing more realistically. The correctness of the mechanical analysis model proposed in this paper is proved by an average error of 3.38%, which is the comparison result between the mechanical analysis model and the finite element model. Meanwhile, computational efficiency is improved. Further, based on the model, the influence of the waviness parameters on the load distribution inside the bearing under the action of different types of loads is analyzed.

An Accurate Calculation Method on Blasingame Production Decline Model of Horizontal Well with Dumbbell-like Hydraulic Fracture in Tight Gas Reservoirs

Blasingame production decline is an effective method to obtain permeability and single-well controlled reserves. The accurate Blasingame production decline curve needs an accurate wellbore pressure approximate solution of the real-time domain. Therefore, the aim of this study is to present a simple and accurate wellbore pressure approximate solution and Blasingame production decline curves calculation method of a multi-stage fractured horizontal well (MFHW) with complex fractures. A semi-analytical model of MFHWs in circle-closed reservoirs is presented. The wellbore pressure and dimensionless pseudo-steady productivity index JDpss (1/bDpss) are verified with a numerical solution. The comparison result reaches a good match. Wellbore pressure and Blasingame production decline curves are used to analyze parameter sensitivity. Results show that when the crossflow from matrix to natural fracture appears after the pseudo-state flow regime, the value of the inter-porosity coefficient has an obvious influence on the pressure approximate solution of the pseudo-steady flow regime in naturally fractured gas reservoirs. The effects of relevant parameters on wellbore pressure and the Blasingame decline curve are also analyzed. The method of pseudo-steady productivity index JDpss can applied to all well and reservoir models.

Application of the Inflection Point in the Evaluation of the Halley and Newton-Raphson Techniques for Finding the Root of Non-Linear Equations

Numeric Method is one of the methods used to solve nonlinear equation roots. Many methods can be used, both open methods and closed methods. In this case, the method used is closed, namely the Newton-Raphson Method and Halley Method. The research aims to find out the comparison result between the Newton-Raphson Method and the Halley Method. The research used a literature method from a book, journal, and any other literature, where it connected with the topic. The steps used are formulation problem, finding and collecting information, describing and explaining the information, analysis, and conclusion of the result. The conclusion can be explained with a table of data and explanations Based on data analysis, it can be stated that the Halley Method is faster toward convergence compared to the Newton-Raphson Method based on the first case or second case.

A comparison of two models for detecting inconsistency in network meta-analysis.

The application of network meta-analysis is becoming increasingly widespread, and for a successful implementation, it requires that the direct comparison result and the indirect comparison result should be consistent. Because of this, a proper detection of inconsistency is often a key issue in network meta-analysis as whether the results can be reliably used as a clinical guidance. Among the existing methods for detecting inconsistency, two commonly used models are the design-by-treatment interaction model and the side-splitting models. While the original side-splitting model was initially estimated using a Bayesian approach, in this context, we employ the frequentist approach. In this paper, we review these two types of models comprehensively as well as explore their relationship by treating the data structure of network meta-analysis as missing data and parameterizing the potential complete data for each model. Through both analytical and numerical studies, we verify that the side-splitting models are specific instances of the design-by-treatment interaction model, incorporating additional assumptions or under certain data structure. Moreover, the design-by-treatment interaction model exhibits robust performance across different data structures on inconsistency detection compared to the side-splitting models. Finally, as a practical guidance for inconsistency detection, we recommend utilizing the design-by-treatment interaction model when there is a lack of information about the potential location of inconsistency. By contrast, the side-splitting models can serve as a supplementary method especially when the number of studies in each design is small, enabling a comprehensive assessment of inconsistency from both global and local perspectives.

Event-Triggered Interval Observer Fault Detection and Isolation for Multiagent Systems.

This article investigates an event-triggered interval observer (ETIO) fault detection and isolation method for multiagent systems. First, an event-triggered mechanism is developed to reduce unnecessary communication transmission. Then, a distributed ETIO is designed by combining an interval observer and the proposed event-triggered mechanism. Furthermore, for achieving the desired tradeoff between the robustness to disturbances and the sensitivity to faults, the ETIO is formulated as a multiobjective optimization with l1 / H∞ performance. Second, a bank of ETIOs are interpreted to isolate the faulty agent on a local agent using only the output information from itself and its neighbors. Comparison result with the existing method is given to highlight the superiority of our methodology. Finally, the multiunmanned aerial vehicles system is utilized as the case research, and specific simulation results are presented.

Continuous casting process based on an optimized submerged entry nozzle

Continuous casting process is an important part in the steel manufacturing process. The slab production quality is commonly influenced by mould and flow pattern of submerged entry nozzles (SEN). Hence, the present work aimed to attain a more liquid flow rate to increase the slab production quantity within a certain period. Moreover, a novel African Buffalo Algorithm (ABA) is presented in this work to optimise the SEN parameters and the SEN was designed in the MATLAB environment. The developed ABA model optimises the design parameters of SEN such as the size of the nozzle, the shape of the port, length, submergence depth, etc. The fitness of buffalo effectively optimises the SEN parameters and by utilising the optimised design parameters, the SEN was resigned in the MATLAB to identify the proposed framework's effectiveness. The results demonstrated that the liquid flow rate is increased and surface tension gets minimised. When the flow rate of liquid grows, the wave amplitude also upturns. The effect of liquid and air flow rate, port shape and size, maximum wave amplitude, surface tension, etc., were calculated with 0° parallel port. In addition, the presented SEN's results were compared with other existing SEN to determine the optimised SEN's effectiveness. The comparison result demonstrated that the designed optimised SEN has a high liquid flow rate, casting speed, density and viscosity.

Should Bank Provide Insurance for Horticultural Crop Damage? (A Stackelberg Game Approach)

Abstract This study provides insight for a bank to insure farmers with the possibility of having horticultural crops damaged. Specifically, a Stackelberg leadership game is formulated with the bank as the leader and the farmer as the follower. The bank declares its insurance fee first to anticipate the horticulture prices and maximize its profit. Then, the farmer decides the horticulture price sequentially given the insurance fee and the crop condition. The game is solved under the with and without insurance scenarios. The farmer decides its horticulture price with no banking insurance fee in without insurance scenario. The bank decision-making is only included in with insurance scenario. From the analytical comparison result, it is better for the farmer to have insurance from the bank when the probability of damage to a horticultural crop exists. However, the bank should give an insurance fee to the farmer with a high probability of having good horticultural crops and less customer sensitivity to damaged crops.

Étale cohomology of algebraizable rigid analytic varieties via nearby cycles over general bases

We prove a finiteness theorem and a comparison theorem in the theory of étale cohomology of rigid analytic varieties. By a result of Huber, for a quasi-compact separated morphism of rigid analytic varieties with target being of dimension ≤1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\le 1$$\\end{document}, the compactly supported higher direct image preserves quasi-constructibility. Though the analogous statement for morphisms with higher dimensional target fails in general, we prove that, in the algebraizable case, it holds after replacing the target with a modification. We deduce it from a known finiteness result in the theory of nearby cycles over general bases and a new comparison result, which gives an identification of the compactly supported higher direct image sheaves, up to modification of the target, in terms of nearby cycles over general bases.

A Short-Term Forecasting Method for High-Frequency Broadcast MUF Based on LSTM

This paper proposes a short-term forecasting method for high-frequency broadcast Maximum Usable Frequency (MUF) based on Long Short-Term Memory (LSTM) to meet the demand for refined and precise high-frequency broadcast coverage. Based on the existing infrastructure of broadcast and television stations, we established an experimental verification system to collect data for approximately three years. Two links were selected based on data quality: Urumqi to Lhasa and Lanzhou to Lhasa. A short-term forecast of MUF was conducted using the data from these two links. Comparison and analysis were conducted between the forecasting results of our model and those of the REC533 model. Our proposed method outperforms the REC533 forecasting results overall, with a reduction in root mean square error (RMSE) of 0.66 MHz and an improvement in forecast accuracy of 14.77%. The comparison result demonstrates the feasibility and accuracy of our model.

Characterization of olive (Olea europaea L.) cultivars; colour properties, biochemical contents, antioxidant activity and nutrient contents

AbstractThe olive tree, scientifically known as Olea europaea L., is an evergreen xerophytic tree that defines the natural flora, historical background, and cultural essence of the Mediterranean Basin. This study aimed to establish relationships using multivariate analysis methods between the nutrient content of soil conditions in which olive cultivars grown in Türkiye are cultivated and the nutrient element content, phytochemical contents, antioxidant activity, total chlorophyll amount, and leaf colors of these cultivars. All data sets used in the study were analyzed in 2022 and 2023, and average values were used in the research. According to Tukey's comparison result, it was determined that the soil structure of the garden was homogeneous in terms of nutrients it contained. In nutrient analysis conducted on leaves, in the ‘Çelebi’ cultivar, Al (59.25 mg kg−1), B (6.53 mg kg−1), Cu (48.36 mg kg−1), Fe (69.34 mg kg−1), K (1438.11 mg kg−1), Na (197.12 mg kg−1) nutrients are the highest; in the ‘Gemlik-21’ cultivar, Ca (5485.03 mg kg−1) nutrient is the highest; in the ‘Sarı Haşebi’ cultivar, Mg (928.11 mg kg−1), Mn (19.71 mg kg−1), S (632.77 mg kg−1) nutrients are the highest; and in the ‘Tavşan Yüreği’ cultivar, Ni (1.71 mg kg−1), Zn (9.76 mg kg−1) nutrients are the highest. The L* (49.19), b* (29.43) color values are highest in the ‘Sarı Yaprak’ cultivar, while the a* (28.84) value is highest in the ‘Girit Zeytini’ cultivar. The highest leaf chlorophyll content was determined in the ‘Girit Zeytini’ cultivar (95.57). Total phenolics, total flavonoids, antioxidant capacity were determined to be highest in the ‘Manzanilla’ (151.49 mg GAE/100 g), ‘Edincik Su’ (39.01 mg QE/100 g), ‘Nizip Yağlık’ (91.18%) cultivars, respectively. According to the principal component analysis, the first three principal components accounted for 82% of the total variation. The correlation matrix analysis revealed that high levels of certain minerals in the soil led to an increase in the leaves, resulting in positive correlation, while the opposite was true for negative correlation. According to heat map analysis, mineral elements in the leaf were in the same group, while other data sets were in different groups. The data obtained will shed light on future research on similar topics.

Study on Pile Bearing Capacity Improvement in Soft Soil After Vacuum Consolidation

The main problem in developing property over soft soil is significant settlement due to the consolidation process. The soil settlement, which will occur gradually throughout the years, will disrupt existing infrastructures, in this case bridges. To mitigate this issue, the common method is by speeding up the consolidation. The consolidation process must be sped up to avoid the differential settlement problem at the bridge abutments. Due to the limited supply of fill material, a vacuum consolidation method is adopted. In this method, a Prefabricated Vertical Drain (PVD) is installed, and a vacuum is applied to impose pressure as preloading. Because of the consolidation process, theoretically, the effective stress of the consolidated soil increases, and the soil shear strength does as well. Increasing the shear strength of the soils will increases the pile capacity. However, the interesting question is how much the shear strength of the soil can increase and impacts the pile capacity. In this paper, the shear strength improvement of the consolidated soil and the effect on pile bearing capacity is evaluated. This study used a series of in-situ tests that were carried out before and after the vacuum consolidation. A pile loading test using the Pile Dynamic Analyzer (PDA) method was carried out to verify the pile bearing capacity improvements. From the comparison result, it is shown that the theoretical capacity of the piles after consolidation were close to the pile test results.