The calculation results of marine environmental design parameters obtained from different data sampling methods,model distributions,and parameter estimation methods often vary greatly.To better analyze the uncertainti...The calculation results of marine environmental design parameters obtained from different data sampling methods,model distributions,and parameter estimation methods often vary greatly.To better analyze the uncertainties in the calculation of marine environmental design parameters,a general model uncertainty assessment method is necessary.We proposed a new multivariate model uncertainty assessment method for the calculation of marine environmental design parameters.The method divides the overall model uncertainty into two categories:aleatory uncertainty and epistemic uncertainty.The aleatory uncertainty of the model is obtained by analyzing the influence of the number and the dispersion degree of samples on the information entropy of the model.The epistemic uncertainty of the model is calculated using the information entropy of the model itself and the prediction error.The advantages of this method are that it does not require many-year-observation data for the marine environmental elements,and the method can be used to analyze any specific factors that cause model uncertainty.Results show that by applying the method to the South China Sea,the aleatory uncertainty of the model increases with the number of samples and then stabilizes.A positive correlation was revealed between the dispersion of the samples and the aleatory uncertainty of the model.Both the distribution of the model and the parameter estimation results of the model have significant effects on the epistemic uncertainty of the model.When the goodness-of-fit of the model is relatively close,the best model can be selected according to the criterion of the lowest overall uncertainty of the models,which can both ensure a better model fit and avoid too much uncertainty in the model calculation results.The presented multivariate model uncertainty assessment method provides a criterion to measure the advantages and disadvantages of the marine environmental design parameter calculation model from the aspect of uncertainty,which is of great significance to analyze the uncertainties in the calculation of marine environmental design parameters and improve the accuracy of the calculation results.展开更多
A controlled rocking concentrically steel braced frame(CR-CSBF)is introduced as an alternative to conventional methods to prevent major structural damage during large earthquakes.It is equipped with elastic post-tensi...A controlled rocking concentrically steel braced frame(CR-CSBF)is introduced as an alternative to conventional methods to prevent major structural damage during large earthquakes.It is equipped with elastic post-tensioned(PT)cables and replaceable devices or fuses to provide overturning resistance and dissipate energy,respectively.Although CR-CSBFs are not officially legalized in globally valid codes for new buildings,it is expected to be presented in them in the near future.The main goal of this study is to determine the optimal design parameters consist of the yield strength and modulus of elasticity of the fuse,the initial force of the PT cable,and the gravity load on the rocking column,considering different heights of the frame,spanning ratios and ground motion types for dual-configuration CR-CSBF.Nonlinear time-history analyses are performed in OpenSees.This study aims to define the optimal input variables as effective design parameters of CR-CSBFs by comparing four seismic responses consisting of story drift,roof displacement,roof acceleration and base shear,and also using the Euclidean metric optimization method.Despite the previous research,this study is innovative and first of its kind.The results demonstrate that the optimal design parameters are variable for various conditions.展开更多
There are many design parameters in precision planters to be considered such as cell diameter, peripheral speed of roller, number of cells, manner of feeding seeds into cell and travel speed. In precision planters eac...There are many design parameters in precision planters to be considered such as cell diameter, peripheral speed of roller, number of cells, manner of feeding seeds into cell and travel speed. In precision planters each cell must contain only one seed. Therefore, sliding the seed to the cell is important and depends on several parameters such as seed repose angle, seed dimensions and physics of cell. To help the seed to repose in the cell, making a groove on the roller would be very useful. Dimensions of this groove are very important and are considered as basic design parameters. This research was performed to determine some design parameters such as roller speed, travel speed, length and depth of groove for tomato seeds precision planting. In this regard, seeds with a diameter of 4 mm were used. The range of variation was based on calculations obtained. A roller with 42 mm width, 118 mm diameter and 15 cells on the surface was used in the experiment. For each cell, a triangular groove was created on the roller. The groove depth varied from zero at the beginning to the maximum value where the groove connected to the cell. The test unit had a continued and wide belt with 1 l m length. In each replication, planter worked for 20 s to reach a stable state. Thereafter, seeds were allowed to drop on the grease belt. Number of seeds and their spacing were measured on the 4.5 m of the belt. Results showed that the roller speed of 41.5 rpm, the planter travel speed of approximately 1 km/h, groove length of 6-8 mm and groove depth of 1.5 mm can improve planter performance for tomato pelleted seed.展开更多
Non-dimensional design concept for FOD tolerant fan blades is introduced based on the analyses of simplified impact models. The fan blades arc idealized as either beams or plates of elastic or rigid-plastic materials....Non-dimensional design concept for FOD tolerant fan blades is introduced based on the analyses of simplified impact models. The fan blades arc idealized as either beams or plates of elastic or rigid-plastic materials. The case of constant force impact as well as that of mass impact is analyzed. The centrifugal force effects are also considered in the beam models. The critical fracture conditions arc shown in simple npn-dimensional formulae or diagrams for each case.展开更多
Studies show that the photovoltaic-thermal(PVT)heat pump soil cross-seasonal energy storage system can effectively harness solar energy to supply heating,electricity,and cooling for buildings.The present study investi...Studies show that the photovoltaic-thermal(PVT)heat pump soil cross-seasonal energy storage system can effectively harness solar energy to supply heating,electricity,and cooling for buildings.The present study investigates a real-world application of this system in Dalian,China,outlining its design framework and optimizing key parameters using orthogonal methods.The factors examined include the area,slope angle,and azimuth angle of the PVT collectors,the flow rate through the PVT collectors,and the depth,spacing,count,and flow rate of the borehole.Through variance analysis,the influence of these parameters is evaluated on heat pump efficiency,soil temperature dynamics,and the system’s investment payback period.Findings indicate that borehole depth and PVT area are the dominant factors affecting the heating efficiency of the heat pump,contributing 66.86%and 16.25%,respectively.In the cooling efficiency of the heat pump,the most significant factors include borehole spacing(31.30%),borehole depth(26.36%),PVT area(16.98%),and borehole flow rate(16.67%).The investment payback period is primarily influenced by borehole depth(41.25%)and borehole quantity(25.24%),with PVT area and borehole spacing contributing 15.34%and 15.18%,respectively.Variations in soil temperature are largely governed by PVT area(40.85%)and borehole spacing(32.75%),followed by PVT slope angle(11.41%)and borehole depth(10.31%).The results of this research provide valuable insights for optimizing the design and implementation of PVT heat pump soil cross-seasonal energy storage systems scientifically and efficiently.展开更多
Design parameters at different scales in the pre-design phase could significantly impact both building energy consumption and photovoltaic(PV)power generation potential.However,existing studies often overlook the syne...Design parameters at different scales in the pre-design phase could significantly impact both building energy consumption and photovoltaic(PV)power generation potential.However,existing studies often overlook the synergistic effects of design parameters across multiple scales(block-building-facade scales)when evaluating these aspects.This paper aims to propose a workflow for the assessing building energy consumption and PV power generation potential of office blocks applicable in the pre-schematic design phase considering the synergistic influence of multi-scale design parameters,using building typology and parametric modelling approach.The study proposed a multi-scale design parameter classification system combined with parametric modelling.The study investigated 80 office blocks in Wuhan as the study case,which were classified into array type and enclosed type.Correlation analysis and multiple regression equations were used to quantify the single versus synergistic effects of different scale design parameters.Results suggest that focusing solely on a single scale during the pre-design stage is typically inadequate for understanding building energy potential.In contrast,multi-scale synergistic analysis boosts energy use intensity(EUI)by 7.56%and net energy use intensity(NEUI)by 33.96%.Under multi-scale synergistic conditions,the EUI of array type is more influenced by the building design parameters,while the NEUI is effected by the balance of multi-scales design parameters.While the EUI of enclosed types exhibit balanced effects across multi-scale design parameters,with NEUI results aligning closely with PV power generation potential.Multiple regression equations highlight building density and shape factor as key influencers for both array and enclosure layouts.This study offers designers a flexible and scalable workflow for evaluating building energy consumption and PV power generation potential in the pre-design phase.The findings can guide nearly-zero energy urban block planning to achieve a balance between energy supply and demand.展开更多
Seismic design of RC structures requires estimation of structural member behavioral measures as functions of design parameters. In this study, the relations among cyclic behavioral measures and design parameters have ...Seismic design of RC structures requires estimation of structural member behavioral measures as functions of design parameters. In this study, the relations among cyclic behavioral measures and design parameters have been investigated for rectangular RC shear walls using numerical simulations calibrated based on the published laboratory tests. The OpenSEES numerical simulations modeling of plastic hinge hysteretic behavior of RC shear walls and estimation of empirical relations among wall hysteretic indices and design parameters are presented. The principal design parameters considered were wall dimensions, axial force, reinforcement ratios, and end-element design parameters. The estimated hysteretic response measures are wall effective stiffness, yield and ultimate curvatures, plastic moment capacity, yield and ultimate displacements, flexural shear capacity, and dissipated energy. Using results of numerous analyses, the empirical relations among wall cyclic behavioral measures and design parameters are developed and their accuracy is investigated.展开更多
In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still rel...In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still relies mainly on experience and is incapable of quantifying the balance between the photovoltaic(PV)generation and the light requirements for agricultural production.As a result,actual PVGs are primarily PV-based,without carefully considering the needs of agricultural daylighting.To quantify the influence of the design parameters of PVGs and the layout of PV panels on the internal daylighting of serrated PVGs,and to optimize the daylighting design of the roof,this paper utilizes the Design Builder software to establish gradient models for a multi-span serrated-type PVG in tropical regions.Gradient models were established in terms of aspects,namely span,width of longitudinal/transverse daylighting strip,height,roof angle,and photovoltaic panel coverage rate(PCR).Daylighting in the greenhouse of each gradient model was simulated,and with the annual average daily light integral(A_(DLI))and distribution uniformity(DU)as evaluation indicators,the influence of various design parameters on the daylighting inside the greenhouse was quantified.The result reveals that:(1)PCR is the decisive indicator for daylighting in the PVG,and a function between PCR and the A_(DLI) is derived as A_(DLI)=-15.5 PCR+16.841;(2)Increasing the width of longitudinal daylighting strip significantly improves the A_(DLI) and enhances DU while increasing the span has a noticeable effect on improving A_(DLI) but does not significantly enhance DU;(3)Increasing the eave height without changing PCR does not enhance A_(DLI) but effectively improves DU;increasing the transverse daylighting strip and adjusting the roof angle hardly improves A_(DLI).In summary,it is recommended that the optimal span for PVGs in tropical regions be set within the range of 6.5-8.0m,and the eave height be set within the range of 2.5-3.5m.Preferably,the longitudinal daylighting strip with a width ranging from 0.5-0.8m should be installed.Based on the above relationship function,the PCR can be calculated according to the appropriate light demand for the cultivated crops.The daylighting design theory proposed in this paper can provide a theoretical basis and reference for the healthy development of the PV industry in tropical regions.展开更多
To reveal nonlinear dynamic rules of low viscosity fluid-lubricated tilting-pad journal bearings(TPJBs),the effects of design parameters on journal center orbits and dynamic minimum film thicknesses of water-lubricate...To reveal nonlinear dynamic rules of low viscosity fluid-lubricated tilting-pad journal bearings(TPJBs),the effects of design parameters on journal center orbits and dynamic minimum film thicknesses of water-lubricated TPJBs with and without static loads are investigated.The hydrodynamic bearing force used in the nonlinear dynamic analysis is an approximate analytical solution including the turbulence effect.The results reveal the methods for vibration suppression and load capacity improvement and give an optimal pivot offset and clearance ratio that can maximize the minimum film thickness.The results also show that four-pad TPJBs with loads between pads are preferred due to good dynamic performance and load capacity.This study would provide some guidance for nonlinear design of low viscosity fluid-lubricated TPJBs under dynamic loads.展开更多
Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self...Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self-developed. Fuel injection characteristics experiment is performed on the GD-1 system. And double-factor variance analysis is applied to investigate the influence of the rail pressure and injection pulse width on the consistency of fuel injection quantity, thus to test whether the design of structure parameters is sound accordingly. The results of experiment and test show that rail pressure and injection pulse width as well as their mutual-effect have no influence on the injection quantity consistency, which proves that the structure parameters design is successful and performance of GD-1 system is sound.展开更多
Squeeze casting(SC)is an advanced net manufacturing process with many advantages for which the quality and properties of the manufactured parts depend strongly on the process parameters.Unfortunately,a universal effic...Squeeze casting(SC)is an advanced net manufacturing process with many advantages for which the quality and properties of the manufactured parts depend strongly on the process parameters.Unfortunately,a universal efficient method for the determination of optimal process parameters is still unavailable.In view of the shortcomings and development needs of the current research methods for the setting of SC process parameters,by consulting and analyzing the recent research literature on SC process parameters and using the CiteSpace literature analysis software,manual reading and statistical analysis,the current state and characteristics of the research methods used for the determination of SC process parameters are summarized.The literature data show that the number of pub-lications in the literature related to the design of SC process parameters generally trends upward albeit with signifi-cant fluctuations.Analysis of the research focus shows that both“mechanical properties”and“microstructure”are the two main subjects in the studies of SC process parameters.With regard to materials,aluminum alloys have been extensively studied.Five methods have been used to obtain SC process parameters:Physical experiments,numeri-cal simulation,modeling optimization,formula calculation,and the use of empirical values.Physical experiments are the main research methods.The main methods for designing SC process parameters are divided into three categories:Fully experimental methods,optimization methods that involve modeling based on experimental data,and theoreti-cal calculation methods that involve establishing an analytical formula.The research characteristics and shortcomings of each method were analyzed.Numerical simulations and model-based optimization have become the new required methods.Considering the development needs and data-driven trends of the SC process,suggestions for the develop-ment of SC process parameter research have been proposed.展开更多
Domestic nuclear power plants are basically located in the seaside, plant site according to the planning requirements, through the site level to meet the nuclear power unit and supporting engineering layout requiremen...Domestic nuclear power plants are basically located in the seaside, plant site according to the planning requirements, through the site level to meet the nuclear power unit and supporting engineering layout requirements, different regions of the site and the gay love situation is different. There are a variety of buildings in the plant, different buildings, according to their importance, their seismic requirements are different. Therefore, although the buildings in the factory are located in the same area, the seismic requirements of different buildings and the ground foundation conditions of the site are different. The designed ground motion parameters cannot be determined directly according to the Chinese ground motion parameter zoning map of GB18306-2015 and the provisions of the building seismic design code of GB50011-2010, but need to be re-calculated.展开更多
Children, who are the most weak people about sensibility and telling their desires clearly, act differently at every age phases. Because of this, child oriented designs must appeal to children about whole ages and fea...Children, who are the most weak people about sensibility and telling their desires clearly, act differently at every age phases. Because of this, child oriented designs must appeal to children about whole ages and features. Playgrounds are places where children of all ages and features spend their times commonly. But when these playgrounds were observed, that can be seen, playgrounds can not meet children＇s need and, because of this, they become quitted places. Within this article, child, play and playground concepts have been examined and the parameters of playground design have been classified. The aim of article is revealing the parameters for playgrounds design and offering a guide so that it can give an idea for the new- designs.展开更多
This analysis investigates the widespread use of solar drying methods and designs in developing countries,particularly for agricultural products like fruits,vegetables,and bee pollen.Traditional techniques like hot ai...This analysis investigates the widespread use of solar drying methods and designs in developing countries,particularly for agricultural products like fruits,vegetables,and bee pollen.Traditional techniques like hot air oven drying and open sun drying have drawbacks,including nutrient loss and exposure to harmful particles.Solar and thermal drying are viewed as sustainable solutions because they rely on renewable resources.The article highlights the advantages of solar drying,including waste reduction,increased productivity,and improved pricing.It is also cost-effective and energy-efficient.The review study provides an overview of different solar drying systems and technologies used in poor nations,aiming to identify the most effective and efficient designs.The focus is on comparing current models of solar dryers for optimal performance.The review underscores the importance of solar drying as a long-term,eco-friendly approach to drying food in developing countries.This review aims to evaluate how using solar-powered drying techniques can enhance food preservation,minimize waste,and enhance the quality and marketability of agricultural goods.The paper will specifically focus on examining the efficacy of these methods for drying bee pollen and pinpointing where enhancements can be made in their advancement.展开更多
S<span>everal challenges are associated </span></span><span style="font-family:"">with</span><span style="font-family:""> the development, adoption and...S<span>everal challenges are associated </span></span><span style="font-family:"">with</span><span style="font-family:""> the development, adoption and de</span><span style="font-family:"">ployment of biogas digesters in developing countries. Amongst these challenges is a comprehensive and systematic procedure for the design of digesters suitable for rural communities. This paper proposes the Flexible Biogas Digester System (FBDS) as a viable option for rural communities in developing countries and provide</span><span style="font-family:"">s</span><span style="font-family:""> a detailed step-by-step procedure for it</span><span style="font-family:"">s</span><span style="font-family:""> design. The biogas production process is a function of the digester operating factors which may be grouped into physical, process and performance parameters. The physical design parameters include</span><span style="font-family:""> </span><span style="font-family:"">the digester volume, the volume of the biogas storage tank, and the volume of the installation pit. The process parameters include total solid content of the slurry (TS), organic loading rate (OLR), digester operating temperatures, pH of the slurry inside the digester. The performance parameters include</span><span style="font-family:""> </span><span style="font-family:"">biogas production rate, biogas productivity and biogas quality. The Net Present Value and the Levelised Cost of Energy are presented for simple economic evaluation of the FBDS.展开更多
Based on two modified Rosslor hyperchaotic systems, which are derived from the chaotic Rosslor system by introducing a state feedback controller, this paper proposes a new switched Rosslor hyperchaotic system. The swi...Based on two modified Rosslor hyperchaotic systems, which are derived from the chaotic Rosslor system by introducing a state feedback controller, this paper proposes a new switched Rosslor hyperchaotic system. The switched system contains two different hyperchaotic systems and can change its behaviour continuously from one to another via a switching function. On the other hand, it presents a systematic method for designing the circuit of realizing the proposed hyperchaotic system. In this design, circuit state equations are written in normalized dimensionless form by rescaling the time variable. Furthermore, an analogous circuit is designed by using the proposed method and built for verifying the new hyperchaos and the design method. Experimental results show a good agreement between numerical simulations and experimental results.展开更多
Orthogonal frequency division multiplexing (OFDM) waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output ...Orthogonal frequency division multiplexing (OFDM) waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output (SISO) systems. To solve these problems, an integrated radar and communication system (IRCS) with multiple input multiple output (MIMO) OFDM waveform is proposed. The different limitations of radar and communication in designing such a system are investigated. Then, an optimization problem is devised to obtain suitable system parameters, including the number of subcarriers, subcarrier spacing, number of symbols, pulse repetition frequency (PRF) and length of cyclic prefix (CP). Finally, to satisfy the requirements of both radar and communication, the IRCS parameters are derived in three typical cases. Several numerical results are presented to illustrate the demands of radar and communication, inconsistent or consistent, for the IRCS parameters and the superiority of the proposed system.展开更多
The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing paramet...The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing parameter design method, this paper proposes an optimization design scheme based on orthogonal testing and support vector machines （SVMs）. Orthogonal testing design is used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iterations and improve the identification accuracy and efficiency. Orthogonal tests consisting of three factors and three levels are designed to analyze the parameters of pressure, uniform applied load and the number of chambers that affect the bending response of inflatable wings. An SVM intelligent model is established and limited orthogonal test swatches are studied. Thus, the precise relationships between each parameter and product quality features, as well the signal-to-noise ratio （SNR）, can be obtained. This can guide general technological design optimization.展开更多
The hadal zone(ocean depths of 6 – 11 km) is one of the least-understood habitats on Earth because of its extreme conditions such as high pressure, darkness, and low temperature. With the development of deep-sea vehi...The hadal zone(ocean depths of 6 – 11 km) is one of the least-understood habitats on Earth because of its extreme conditions such as high pressure, darkness, and low temperature. With the development of deep-sea vehicles such as China's 7000 m manned submersible Jiaolong, abyssal science has received greater attention. For decades, gravity-piston corers have been widely used to collect loose subsea-sediment long-core samples. However, the weight and length of the gravity sampler cables and the operating environment limit sampling capacity at full ocean depths. Therefore, a new self-floating sediment sampler with a spring-loaded auto-trigger release and that incorporates characteristics from traditional gravity-driven samplers is designed. This study analyzes the process by which a gravity-piston corer penetrates the sediment and the factors that affect it. A formula for obtaining the penetration depth is deduced. A method of optimizing the sampling depth is then developed based on structure design and parametric factor modeling. The parameters considered in the modeling include the sampling depth, balance weight, ultimate stress friction coefficient, dimensions of the sampler, and material properties. Thus, a new deep-sea floating parametric sampler designed based on virtual prototyping is proposed. Accurate values for all the design factors are derived from calculations based on the conservation of energy with penetration depth, analyses of the factors affecting the penetration depth, and analyses of the pressure bar stability. Finally, experimental data are used to verify the penetration-depth function and to provide theoretical guidance for the design of sediment samplers.展开更多
基金Supported by the National Natural Science Foundation of China(No.52071306)the Natural Science Foundation of Shandong Province(No.ZR2019MEE050)。
文摘The calculation results of marine environmental design parameters obtained from different data sampling methods,model distributions,and parameter estimation methods often vary greatly.To better analyze the uncertainties in the calculation of marine environmental design parameters,a general model uncertainty assessment method is necessary.We proposed a new multivariate model uncertainty assessment method for the calculation of marine environmental design parameters.The method divides the overall model uncertainty into two categories:aleatory uncertainty and epistemic uncertainty.The aleatory uncertainty of the model is obtained by analyzing the influence of the number and the dispersion degree of samples on the information entropy of the model.The epistemic uncertainty of the model is calculated using the information entropy of the model itself and the prediction error.The advantages of this method are that it does not require many-year-observation data for the marine environmental elements,and the method can be used to analyze any specific factors that cause model uncertainty.Results show that by applying the method to the South China Sea,the aleatory uncertainty of the model increases with the number of samples and then stabilizes.A positive correlation was revealed between the dispersion of the samples and the aleatory uncertainty of the model.Both the distribution of the model and the parameter estimation results of the model have significant effects on the epistemic uncertainty of the model.When the goodness-of-fit of the model is relatively close,the best model can be selected according to the criterion of the lowest overall uncertainty of the models,which can both ensure a better model fit and avoid too much uncertainty in the model calculation results.The presented multivariate model uncertainty assessment method provides a criterion to measure the advantages and disadvantages of the marine environmental design parameter calculation model from the aspect of uncertainty,which is of great significance to analyze the uncertainties in the calculation of marine environmental design parameters and improve the accuracy of the calculation results.
文摘A controlled rocking concentrically steel braced frame(CR-CSBF)is introduced as an alternative to conventional methods to prevent major structural damage during large earthquakes.It is equipped with elastic post-tensioned(PT)cables and replaceable devices or fuses to provide overturning resistance and dissipate energy,respectively.Although CR-CSBFs are not officially legalized in globally valid codes for new buildings,it is expected to be presented in them in the near future.The main goal of this study is to determine the optimal design parameters consist of the yield strength and modulus of elasticity of the fuse,the initial force of the PT cable,and the gravity load on the rocking column,considering different heights of the frame,spanning ratios and ground motion types for dual-configuration CR-CSBF.Nonlinear time-history analyses are performed in OpenSees.This study aims to define the optimal input variables as effective design parameters of CR-CSBFs by comparing four seismic responses consisting of story drift,roof displacement,roof acceleration and base shear,and also using the Euclidean metric optimization method.Despite the previous research,this study is innovative and first of its kind.The results demonstrate that the optimal design parameters are variable for various conditions.
文摘There are many design parameters in precision planters to be considered such as cell diameter, peripheral speed of roller, number of cells, manner of feeding seeds into cell and travel speed. In precision planters each cell must contain only one seed. Therefore, sliding the seed to the cell is important and depends on several parameters such as seed repose angle, seed dimensions and physics of cell. To help the seed to repose in the cell, making a groove on the roller would be very useful. Dimensions of this groove are very important and are considered as basic design parameters. This research was performed to determine some design parameters such as roller speed, travel speed, length and depth of groove for tomato seeds precision planting. In this regard, seeds with a diameter of 4 mm were used. The range of variation was based on calculations obtained. A roller with 42 mm width, 118 mm diameter and 15 cells on the surface was used in the experiment. For each cell, a triangular groove was created on the roller. The groove depth varied from zero at the beginning to the maximum value where the groove connected to the cell. The test unit had a continued and wide belt with 1 l m length. In each replication, planter worked for 20 s to reach a stable state. Thereafter, seeds were allowed to drop on the grease belt. Number of seeds and their spacing were measured on the 4.5 m of the belt. Results showed that the roller speed of 41.5 rpm, the planter travel speed of approximately 1 km/h, groove length of 6-8 mm and groove depth of 1.5 mm can improve planter performance for tomato pelleted seed.
文摘Non-dimensional design concept for FOD tolerant fan blades is introduced based on the analyses of simplified impact models. The fan blades arc idealized as either beams or plates of elastic or rigid-plastic materials. The case of constant force impact as well as that of mass impact is analyzed. The centrifugal force effects are also considered in the beam models. The critical fracture conditions arc shown in simple npn-dimensional formulae or diagrams for each case.
基金supported by Liao Ning Revitalization Talents Program(Grant No.XLYC1902068)the Science and Technology Partnership Program,Ministry of Science and Technology of China(Grant No.KY20202012)the Dalian University of Technology Basic Research Business Expense Project,Green Building Evaluation and BIM Intelligent Operation and Maintenance Control Platform Technology Development Service for Dalian Metro Line 5 Project Control Center of China Railway Dalian Metro Line No.5 Co.,LTD.,Xiajin County Public Medical Center Solar PVT Heat Pump Soil Cross-seasonal Energy Storage Low Carbon Energy Technology Service Project(Grant No.SDLS-2024012).
文摘Studies show that the photovoltaic-thermal(PVT)heat pump soil cross-seasonal energy storage system can effectively harness solar energy to supply heating,electricity,and cooling for buildings.The present study investigates a real-world application of this system in Dalian,China,outlining its design framework and optimizing key parameters using orthogonal methods.The factors examined include the area,slope angle,and azimuth angle of the PVT collectors,the flow rate through the PVT collectors,and the depth,spacing,count,and flow rate of the borehole.Through variance analysis,the influence of these parameters is evaluated on heat pump efficiency,soil temperature dynamics,and the system’s investment payback period.Findings indicate that borehole depth and PVT area are the dominant factors affecting the heating efficiency of the heat pump,contributing 66.86%and 16.25%,respectively.In the cooling efficiency of the heat pump,the most significant factors include borehole spacing(31.30%),borehole depth(26.36%),PVT area(16.98%),and borehole flow rate(16.67%).The investment payback period is primarily influenced by borehole depth(41.25%)and borehole quantity(25.24%),with PVT area and borehole spacing contributing 15.34%and 15.18%,respectively.Variations in soil temperature are largely governed by PVT area(40.85%)and borehole spacing(32.75%),followed by PVT slope angle(11.41%)and borehole depth(10.31%).The results of this research provide valuable insights for optimizing the design and implementation of PVT heat pump soil cross-seasonal energy storage systems scientifically and efficiently.
基金supported by the National Natural Science Foundation(No.52378020)Open Foundation of the State Key Laboratory of Subtropical Building and Urban Science(No.2023KA02)+1 种基金Fundamental Research Funds for the Central Universities(YCJJ20230576)Program for HUST Academic Frontier Youth Team(No.2019QYTD10).
文摘Design parameters at different scales in the pre-design phase could significantly impact both building energy consumption and photovoltaic(PV)power generation potential.However,existing studies often overlook the synergistic effects of design parameters across multiple scales(block-building-facade scales)when evaluating these aspects.This paper aims to propose a workflow for the assessing building energy consumption and PV power generation potential of office blocks applicable in the pre-schematic design phase considering the synergistic influence of multi-scale design parameters,using building typology and parametric modelling approach.The study proposed a multi-scale design parameter classification system combined with parametric modelling.The study investigated 80 office blocks in Wuhan as the study case,which were classified into array type and enclosed type.Correlation analysis and multiple regression equations were used to quantify the single versus synergistic effects of different scale design parameters.Results suggest that focusing solely on a single scale during the pre-design stage is typically inadequate for understanding building energy potential.In contrast,multi-scale synergistic analysis boosts energy use intensity(EUI)by 7.56%and net energy use intensity(NEUI)by 33.96%.Under multi-scale synergistic conditions,the EUI of array type is more influenced by the building design parameters,while the NEUI is effected by the balance of multi-scales design parameters.While the EUI of enclosed types exhibit balanced effects across multi-scale design parameters,with NEUI results aligning closely with PV power generation potential.Multiple regression equations highlight building density and shape factor as key influencers for both array and enclosure layouts.This study offers designers a flexible and scalable workflow for evaluating building energy consumption and PV power generation potential in the pre-design phase.The findings can guide nearly-zero energy urban block planning to achieve a balance between energy supply and demand.
文摘Seismic design of RC structures requires estimation of structural member behavioral measures as functions of design parameters. In this study, the relations among cyclic behavioral measures and design parameters have been investigated for rectangular RC shear walls using numerical simulations calibrated based on the published laboratory tests. The OpenSEES numerical simulations modeling of plastic hinge hysteretic behavior of RC shear walls and estimation of empirical relations among wall hysteretic indices and design parameters are presented. The principal design parameters considered were wall dimensions, axial force, reinforcement ratios, and end-element design parameters. The estimated hysteretic response measures are wall effective stiffness, yield and ultimate curvatures, plastic moment capacity, yield and ultimate displacements, flexural shear capacity, and dissipated energy. Using results of numerous analyses, the empirical relations among wall cyclic behavioral measures and design parameters are developed and their accuracy is investigated.
基金2024 Science and Technology Commissioner Service Group's Emergency Science and Technology Research Project for Wind Disaster Relief in Hainan Province(ZDYF2024YJGG002-8)China Huaneng Group Co.,Ltd.Headquarters Technology Project,Optimization of Photovoltaic Vegetable Greenhouse Structure and Research on Planting Agronomy in Tropical Regions(HNKJ22-HF77)。
文摘In the tropical regions represented by Hainan,there are abundant solar and thermal resources,and it is relatively suitable for the construction of photovoltaic greenhouse(PVG).However,the construction of PVG still relies mainly on experience and is incapable of quantifying the balance between the photovoltaic(PV)generation and the light requirements for agricultural production.As a result,actual PVGs are primarily PV-based,without carefully considering the needs of agricultural daylighting.To quantify the influence of the design parameters of PVGs and the layout of PV panels on the internal daylighting of serrated PVGs,and to optimize the daylighting design of the roof,this paper utilizes the Design Builder software to establish gradient models for a multi-span serrated-type PVG in tropical regions.Gradient models were established in terms of aspects,namely span,width of longitudinal/transverse daylighting strip,height,roof angle,and photovoltaic panel coverage rate(PCR).Daylighting in the greenhouse of each gradient model was simulated,and with the annual average daily light integral(A_(DLI))and distribution uniformity(DU)as evaluation indicators,the influence of various design parameters on the daylighting inside the greenhouse was quantified.The result reveals that:(1)PCR is the decisive indicator for daylighting in the PVG,and a function between PCR and the A_(DLI) is derived as A_(DLI)=-15.5 PCR+16.841;(2)Increasing the width of longitudinal daylighting strip significantly improves the A_(DLI) and enhances DU while increasing the span has a noticeable effect on improving A_(DLI) but does not significantly enhance DU;(3)Increasing the eave height without changing PCR does not enhance A_(DLI) but effectively improves DU;increasing the transverse daylighting strip and adjusting the roof angle hardly improves A_(DLI).In summary,it is recommended that the optimal span for PVGs in tropical regions be set within the range of 6.5-8.0m,and the eave height be set within the range of 2.5-3.5m.Preferably,the longitudinal daylighting strip with a width ranging from 0.5-0.8m should be installed.Based on the above relationship function,the PCR can be calculated according to the appropriate light demand for the cultivated crops.The daylighting design theory proposed in this paper can provide a theoretical basis and reference for the healthy development of the PV industry in tropical regions.
基金This work is supported by National Basic Research Program of China(Grant No.2015CB057303)National Natural Science Foundation of China(Grant No.51775412).
文摘To reveal nonlinear dynamic rules of low viscosity fluid-lubricated tilting-pad journal bearings(TPJBs),the effects of design parameters on journal center orbits and dynamic minimum film thicknesses of water-lubricated TPJBs with and without static loads are investigated.The hydrodynamic bearing force used in the nonlinear dynamic analysis is an approximate analytical solution including the turbulence effect.The results reveal the methods for vibration suppression and load capacity improvement and give an optimal pivot offset and clearance ratio that can maximize the minimum film thickness.The results also show that four-pad TPJBs with loads between pads are preferred due to good dynamic performance and load capacity.This study would provide some guidance for nonlinear design of low viscosity fluid-lubricated TPJBs under dynamic loads.
文摘Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self-developed. Fuel injection characteristics experiment is performed on the GD-1 system. And double-factor variance analysis is applied to investigate the influence of the rail pressure and injection pulse width on the consistency of fuel injection quantity, thus to test whether the design of structure parameters is sound accordingly. The results of experiment and test show that rail pressure and injection pulse width as well as their mutual-effect have no influence on the injection quantity consistency, which proves that the structure parameters design is successful and performance of GD-1 system is sound.
基金Supported by National Natural Science Foundation of China(Grant Nos.51965006 and 51875209)Guangxi Natural Science Foundation of China(Grant No.2018GXNSFAA050111)+1 种基金Innovation Project of Guangxi Graduate Education of China(Grant No.YCSW2019035)Open Fund of National Engineering Research Center of Near-Shape Forming for Metallic Materials of China(Grant No.2019001).
文摘Squeeze casting(SC)is an advanced net manufacturing process with many advantages for which the quality and properties of the manufactured parts depend strongly on the process parameters.Unfortunately,a universal efficient method for the determination of optimal process parameters is still unavailable.In view of the shortcomings and development needs of the current research methods for the setting of SC process parameters,by consulting and analyzing the recent research literature on SC process parameters and using the CiteSpace literature analysis software,manual reading and statistical analysis,the current state and characteristics of the research methods used for the determination of SC process parameters are summarized.The literature data show that the number of pub-lications in the literature related to the design of SC process parameters generally trends upward albeit with signifi-cant fluctuations.Analysis of the research focus shows that both“mechanical properties”and“microstructure”are the two main subjects in the studies of SC process parameters.With regard to materials,aluminum alloys have been extensively studied.Five methods have been used to obtain SC process parameters:Physical experiments,numeri-cal simulation,modeling optimization,formula calculation,and the use of empirical values.Physical experiments are the main research methods.The main methods for designing SC process parameters are divided into three categories:Fully experimental methods,optimization methods that involve modeling based on experimental data,and theoreti-cal calculation methods that involve establishing an analytical formula.The research characteristics and shortcomings of each method were analyzed.Numerical simulations and model-based optimization have become the new required methods.Considering the development needs and data-driven trends of the SC process,suggestions for the develop-ment of SC process parameter research have been proposed.
文摘Domestic nuclear power plants are basically located in the seaside, plant site according to the planning requirements, through the site level to meet the nuclear power unit and supporting engineering layout requirements, different regions of the site and the gay love situation is different. There are a variety of buildings in the plant, different buildings, according to their importance, their seismic requirements are different. Therefore, although the buildings in the factory are located in the same area, the seismic requirements of different buildings and the ground foundation conditions of the site are different. The designed ground motion parameters cannot be determined directly according to the Chinese ground motion parameter zoning map of GB18306-2015 and the provisions of the building seismic design code of GB50011-2010, but need to be re-calculated.
文摘Children, who are the most weak people about sensibility and telling their desires clearly, act differently at every age phases. Because of this, child oriented designs must appeal to children about whole ages and features. Playgrounds are places where children of all ages and features spend their times commonly. But when these playgrounds were observed, that can be seen, playgrounds can not meet children＇s need and, because of this, they become quitted places. Within this article, child, play and playground concepts have been examined and the parameters of playground design have been classified. The aim of article is revealing the parameters for playgrounds design and offering a guide so that it can give an idea for the new- designs.
文摘This analysis investigates the widespread use of solar drying methods and designs in developing countries,particularly for agricultural products like fruits,vegetables,and bee pollen.Traditional techniques like hot air oven drying and open sun drying have drawbacks,including nutrient loss and exposure to harmful particles.Solar and thermal drying are viewed as sustainable solutions because they rely on renewable resources.The article highlights the advantages of solar drying,including waste reduction,increased productivity,and improved pricing.It is also cost-effective and energy-efficient.The review study provides an overview of different solar drying systems and technologies used in poor nations,aiming to identify the most effective and efficient designs.The focus is on comparing current models of solar dryers for optimal performance.The review underscores the importance of solar drying as a long-term,eco-friendly approach to drying food in developing countries.This review aims to evaluate how using solar-powered drying techniques can enhance food preservation,minimize waste,and enhance the quality and marketability of agricultural goods.The paper will specifically focus on examining the efficacy of these methods for drying bee pollen and pinpointing where enhancements can be made in their advancement.
文摘S<span>everal challenges are associated </span></span><span style="font-family:"">with</span><span style="font-family:""> the development, adoption and de</span><span style="font-family:"">ployment of biogas digesters in developing countries. Amongst these challenges is a comprehensive and systematic procedure for the design of digesters suitable for rural communities. This paper proposes the Flexible Biogas Digester System (FBDS) as a viable option for rural communities in developing countries and provide</span><span style="font-family:"">s</span><span style="font-family:""> a detailed step-by-step procedure for it</span><span style="font-family:"">s</span><span style="font-family:""> design. The biogas production process is a function of the digester operating factors which may be grouped into physical, process and performance parameters. The physical design parameters include</span><span style="font-family:""> </span><span style="font-family:"">the digester volume, the volume of the biogas storage tank, and the volume of the installation pit. The process parameters include total solid content of the slurry (TS), organic loading rate (OLR), digester operating temperatures, pH of the slurry inside the digester. The performance parameters include</span><span style="font-family:""> </span><span style="font-family:"">biogas production rate, biogas productivity and biogas quality. The Net Present Value and the Levelised Cost of Energy are presented for simple economic evaluation of the FBDS.
基金Project supported by the Natural Science Foundation of Zhejiang Province, China (Grant No Y105175)the Science Investigation Foundation of Hangzhou Dianzi University, China (Grant No KYS051505010)
文摘Based on two modified Rosslor hyperchaotic systems, which are derived from the chaotic Rosslor system by introducing a state feedback controller, this paper proposes a new switched Rosslor hyperchaotic system. The switched system contains two different hyperchaotic systems and can change its behaviour continuously from one to another via a switching function. On the other hand, it presents a systematic method for designing the circuit of realizing the proposed hyperchaotic system. In this design, circuit state equations are written in normalized dimensionless form by rescaling the time variable. Furthermore, an analogous circuit is designed by using the proposed method and built for verifying the new hyperchaos and the design method. Experimental results show a good agreement between numerical simulations and experimental results.
基金supported by the National Natural Science Foundation of China(6123101761671352)
文摘Orthogonal frequency division multiplexing (OFDM) waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output (SISO) systems. To solve these problems, an integrated radar and communication system (IRCS) with multiple input multiple output (MIMO) OFDM waveform is proposed. The different limitations of radar and communication in designing such a system are investigated. Then, an optimization problem is devised to obtain suitable system parameters, including the number of subcarriers, subcarrier spacing, number of symbols, pulse repetition frequency (PRF) and length of cyclic prefix (CP). Finally, to satisfy the requirements of both radar and communication, the IRCS parameters are derived in three typical cases. Several numerical results are presented to illustrate the demands of radar and communication, inconsistent or consistent, for the IRCS parameters and the superiority of the proposed system.
文摘The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing parameter design method, this paper proposes an optimization design scheme based on orthogonal testing and support vector machines （SVMs）. Orthogonal testing design is used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iterations and improve the identification accuracy and efficiency. Orthogonal tests consisting of three factors and three levels are designed to analyze the parameters of pressure, uniform applied load and the number of chambers that affect the bending response of inflatable wings. An SVM intelligent model is established and limited orthogonal test swatches are studied. Thus, the precise relationships between each parameter and product quality features, as well the signal-to-noise ratio （SNR）, can be obtained. This can guide general technological design optimization.
基金jointly supported by the Stable Supporting Fund of Science and Technology on Underwater Vehicle Technology (No. JCKYS2019604SXJQR-06)the National Natural Science Foundation of China-Marine Science Research Center of Shandong Provincial Government Joint Funding Project (No. U1606401)+3 种基金the National Natural Science Foundation of China (No. 61603108)the Taishan Scholar Project Funding (No. tspd20161007)the National Key Research and Development Plan (Nos. 2016YFC03007042017YFC030660)。
文摘The hadal zone(ocean depths of 6 – 11 km) is one of the least-understood habitats on Earth because of its extreme conditions such as high pressure, darkness, and low temperature. With the development of deep-sea vehicles such as China's 7000 m manned submersible Jiaolong, abyssal science has received greater attention. For decades, gravity-piston corers have been widely used to collect loose subsea-sediment long-core samples. However, the weight and length of the gravity sampler cables and the operating environment limit sampling capacity at full ocean depths. Therefore, a new self-floating sediment sampler with a spring-loaded auto-trigger release and that incorporates characteristics from traditional gravity-driven samplers is designed. This study analyzes the process by which a gravity-piston corer penetrates the sediment and the factors that affect it. A formula for obtaining the penetration depth is deduced. A method of optimizing the sampling depth is then developed based on structure design and parametric factor modeling. The parameters considered in the modeling include the sampling depth, balance weight, ultimate stress friction coefficient, dimensions of the sampler, and material properties. Thus, a new deep-sea floating parametric sampler designed based on virtual prototyping is proposed. Accurate values for all the design factors are derived from calculations based on the conservation of energy with penetration depth, analyses of the factors affecting the penetration depth, and analyses of the pressure bar stability. Finally, experimental data are used to verify the penetration-depth function and to provide theoretical guidance for the design of sediment samplers.
