Simulation Evaluation of Outdoor Noise Environment in Buildings

Green campus design has become an essential strategy to enhance campus life and learning.However,noise pol-lution remains a troubling aspect that impacts teaching and learning processes,even causing harm to the health of students and teachers.Therefore,acoustic environment quality design is crucial.This article focuses on the expansion project of a school campus in Shenzhen.We simulated and analyzed the outdoor noise environment separately for the proposed teach-ing building,as well as the existing buildings like the dining hall,teaching building,and laboratory building.The results showed that the proposed teaching building was mainly affected by surrounding noise,with the worst outdoor noise being in classrooms adjacent to the teaching building in the south and the basketball court at the west of the classroom,with maximum noise values reaching 73 dB and 66 dB,respectively.In the future,these rooms should be renovated to achieve an excellent indoor soundproof environment.

Simulation of Seabed Erosion Produced by an Inclined Jet

Water jets are widely used in seabed scouring and desilting applications.In the present work,dedicated tests have been conducted using a jet scour model test platform and sand beds containing grains with different sizes.The FLOW-3D simulation software has also been used to tackle the problem form a numerical point of view.The boundary conditions of the simulation have been optimized to reduce the gap between the numerical results and the outcomes of the experimental tests.Scour area calculation has been based on a RNG k-εTurbulence model.Moreover,the FAVOR(Fractional Area Volume Obstacle Representation)technology has been selected for grid division to make the simulation results more accurate.Jet scours with inclination angles of 10–20°have been simulated.It has been found that jet scouring is greatly affected by the environmental water flow,that is,water flow can weaken the scouring capacity of the jets.

Selection and thermal physical characteristics analysis of in-situ condition preserved coring lunar rock simulant in extreme environment

With the increasing scarcity of Earth’s resources and the development of space science and technology,the exploration, development, and utilization of deep space-specific material resources(minerals, water ice, volatile compounds, etc.) are not only important to supplement the resources and reserves on Earth but also provide a material foundation for establishing extraterrestrial research bases. To achieve large depth in-situ condition-preserved coring(ICP-Coring) in the extreme lunar environment, first, lunar rock simulant was selected(SZU-1), which has a material composition, element distribution, and physical and mechanical properties that are approximately equivalent to those of lunar mare basalt. Second, the influence of the lunar-based in-situ environment on the phase, microstructure, and thermal physical properties(specific heat capacity, thermal conductivity, thermal diffusivity, and thermal expansion coefficient)of SZU-1 was explored and compared with the measured lunar rock data. It was found that in an air atmosphere, low temperature has a more pronounced effect on the relative content of olivine than other temperatures, while in a vacuum atmosphere, the relative contents of olivine and anorthite are significantly affected only at temperatures of approximately-20 and 200 ℃. When the vacuum level is less than100 Pa, the contribution of air conduction can be almost neglected, whereas it becomes dominant above this threshold. Additionally, as the testing temperature increases, the surface of SZU-1 exhibits increased microcracking, fracture opening, and unevenness, while the specific heat capacity, thermal conductivity,and thermal expansion coefficient show nonlinear increases. Conversely, the thermal diffusivity exhibits a nonlinear decreasing trend. The relationship between thermal conductivity, thermal diffusivity, and temperature can be effectively described by an exponential function(R^(2)>0.98). The research results are consistent with previous studies on real lunar rocks. These research findings are expected to be applied in the development of the test and analysis systems of ICP-Coring in a lunar environment and the exploration of the mechanism of machine-rock interaction in the in-situ drilling and coring process.

Numerical analysis on mechanical difference of sandstone under in-situ stress,pore pressure preserved environment at depth

Deep in-situ rock mechanics considers the influence of the in-situ environment on mechanical properties,differentiating it from traditional rock mechanics.To investigate the effect of in-situ stress,pore pressure preserved environment on the mechanical difference of sandstone,four tests are numerically modeled by COMSOL:conventional triaxial test,conventional pore pressure test,in-situ stress restoration and reconstruction test,and in-situ pore pressure-preserved test(not yet realized in the laboratory).The in-situ stress restoration parameter is introduced to characterize the recovery effect of in-situ stress on elastic modulus and heterogeneous distribution of sandstone at different depths.A random function and nonuniform pore pressure coefficient are employed to describe the non-uniform distribution of pore pressure in the in-situ environment.Numerical results are compared with existing experimental data to validate the models and calibrate the numerical parameters.By extracting mechanical parameters from numerical cores,the stress-strain curves of the four tests under different depths,in-situ stress and pore pressure are compared.The influence of non-uniform pore pressure coefficient and depth on the peak strength of sandstone is analyzed.The results show a strong linear relationship between the in-situ stress restoration parameter and depth,effectively characterizing the enhanced effect of stress restoration and reconstruction methods on the elastic modulus of conventional cores at different depths.The in-situ pore pressurepreserved test exhibits lower peak stress and peak strain compared to the other three tests,and sandstone subjected to non-uniform pore pressure is more prone to plastic damage and failure.Moreover,the influence of non-uniform pore pressure on peak strength gradually diminished with increasing depth.

Study on the Outdoor Wind Environment Simulation and Design Strategies of Rural Settlements in Cold Areas

To improve the outdoor environment of rural settlement and reduce the energy consumption of rural houses in winterin cold areas,the seriously bad wind environment should been controlled and considered. This paper applies the method of numerical simulation to simulate the wind environment of some typical arrangement of building and courtyard in winter,and concludes the optimal building and courtyard arrangement types and strategies. It aims to provide some technical supports for improving the wind environment of rural settlements in cold regions.

Numerical Simulation Analysis and Ecological Evaluation on Wind Environment of Dwelling Groups in Severe Cold Regions

The wind environment around residential building groups is increasingly concerned,while the dwelling groups as the elementary unit of planning design,its quality of surrounding wind environment will directly affect people's life. This study based on the climatic conditions of severe cold regions,selects four dwellings groups with different openings scale and position as the research objects,and then simulates and analyzes the wind speed distribution characteristics of each pattern. Meanwhile,it extracts the wind speed values of one hundred points of each pattern and applies the coefficient of uniformity method to the ecological evaluation. It has been found that grouping pattern of buildings has a dramatic effect on the resulting airflow behavior. Configurations that contain a T-shaped central space with small opened side can effectively prevent and contain airflow in the site offer. The interactive influence between layout of dwelling groups and wind environment are explored,so as to provide basis for the planning design of dwelling groups.

Numerical Simulation of Contamination Accumulation Characteristics of Composite Insulators in Salt Fog Environment

To investigate the fouling characteristics of the composite insulator surface under the salt fog environment,the FXBW-110/120-2 composite insulator was taken as the research object.Based on the field-induced charge mechanism,the multi-physical field coupling software COMSOL was used to numerically simulate the fouling characteristics,explored the calculation method of ESDD,and demonstrated its rationality.Based on this method,the pollution characteristics of the composite insulator under the pollution fog environment were studied,and the influence of wind speed,droplet size,and voltage type on the pollution characteristics of the composite insulator was analyzed.The results showed that:with the increase in wind speed,the amount of accumulated pollution of insulator increases in the range of droplet size,and the relationship between wind speed and accumulated pollution is approximately linear;at the same wind speed,the amount of accumulated pollution increases with the increase of droplet size under the action of DC voltage;when there is no voltage,the amount of dirt on the upper surface of the insulator is more than that on the lower surface,while it is the opposite under DC voltage.

Wind and Snow Impacts on Urban Space Planning:A Multiphase Numerical Simulation

The wind and snow environment outside the planned space plays a key role in the comfort and safety of the human habitat in severe cold regions. Traditional studies of the external environment of human settlements, however, frequently overlook the combined impacts of wind and snow environments. Furthermore, in urban meteorological studies, it is impossible to accurately assess the wind and snow environment in specific areas or locations. In this study, a refined Computational Fluid Dynamics(CFD) multiphase flow numerical method was used to simulate a planning space's wind and snow environment. The study classified the Snowstorm Weather Grade(SWG) by incorporating the Snowstorm Weather Index(SWI) to generate calculation results of the wind environment and snow environment. In particular, 150 measurement points in the planning space were chosen for analysis and evaluation of their wind and snow environments. The results demonstrated that the SWI index can effectively correlate to the wind and snow environment calculation results. In addition, the graph of SWI showed that 55% of the measurement points had a moderate wind and snow grade SWI, which exceeds the average grade for the entire region. The practical application shows that the wind and snow environment assessment indexes and technical methods developed in this paper can be successfully applied to wind and snow environment studies in other cold cities.

Mixed Model, AMMI and Eberhart-Russel Comparison via Simulation on Genotype ×Environment Interaction Study in Sugarcane

Brazil is the world leader in sugarcane production and the largest sugar exporter. Developing new varieties is one of the main factors that contribute to yield increase. In order to select the best genotypes, during the final selection stage, varieties are tested in different environments (locations and years), and breeders need to estimate the phenotypic performance for main traits such as tons of cane yield per hectare (TCH) considering the genotype × environment interaction (GEI) effect. Geneticists and biometricians have used different methods and there is no clear consensus of the best method. In this study, we present a comparison of three methods, viz. Eberhart-Russel (ER), additive main effects and multiplicative interaction (AMMI) and mixed model (REML/BLUP), in a simulation study performed in the R computing environment to verify the effectiveness of each method in detecting GEI, and assess the particularities of each method from a statistical standpoint. In total, 63 cases representing different conditions were simulated, generating more than 34 million data points for analysis by each of the three methods. The results show that each method detects GEI differently in a different way, and each has some limitations. All three methods detected GEI effectively, but the mixed model showed higher sensitivity. When applying the GEI analysis, firstly it is important to verify the assumptions inherent in each method and these limitations should be taken into account when choosing the method to be used.

SCENARIOS SIMULATION OF COUPLING SYSTEM BETWEEN URBANIZATION AND ECO-ENVIRONMENT IN JIANGSU PROVINCE BASED ON SYSTEM DYNAMICS MODEL

By means of ISM (Interpretative Structural Modeling) and SD (System Dynamics) methods, this paper made a system dynamics model of urbanization and eco-environment coupling in Jiangsu Province according to the implication and PSR (Pressure State Response) framework of urbanization and eco-environment coupling. Moreover, five typical scenarios during 2000-2015 have been simulated and analyzed based on the time serial statistical data during 1990-2003 in Jiangsu, which indicates: firstly, there are significant differences between the results and the scenarios, and the five coupling models all have comparative advantages and drawbacks; secondly, in terms of the characteristics and regional development disparities of Jiangsu and the general rule of world urbanization process, this paper reveals that only when either population urbanization model or social urbanization model to be correspondingly adopted, the sustainable development among population, economy, urbanization and eco-environment can be realized.

Object-oriented Battlefield Environment Simulation Process Object Model Based on Task-driven

Battlefield environment simulation process is an important part of battlefield environment information support, which needs to be built around the task process. At present, the interoperability between battlefield environment simulation system and command and control system is still imperfect, and the traditional simulation data model cannot meet war fighters’ high-efficient and accurate understanding and analysis on battlefield environment’s information. Therefore, a kind of task-orientated battlefield environment simulation process model needs to be construed to effectively analyze the key information demands of the command and control system. The structured characteristics of tasks and simulation process are analyzed, and the simulation process concept model is constructed with the method of object-orientated. The data model and formal syntax of GeoBML are analyzed, and the logical model of simulation process is constructed with formal language. The object data structure of simulation process is defined and the object model of simulation process which maps tasks is constructed. In the end, the battlefield environment simulation platform modules are designed and applied based on this model, verifying that the model can effectively express the real-time dynamic correlation between battlefield environment simulation data and operational tasks.

High-efficiency sodium storage of Co_(0.85)Se/WSe_(2) encapsulated in N-doped carbon polyhedron via vacancy and heterojunction engineering

With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption ability and provide extra active sites for Na+adsorption.However,their synchronous engineering is rarely reported.Herein,a hybrid of Co_(0.85)Se/WSe_(2) heterostructure with Se vacancies and N-doped carbon polyhedron(CoWSe/NCP)has been fabricated for the first time via a hydrothermal and subsequent selenization strategy.Spherical aberration-corrected transmission electron microscopy confirms the phase interface of the Co_(0.85)Se/WSe_(2) heterostructure and the existence of Se vacancies.Density functional theory simulations reveal the accelerated charge transfer and enhanced Na+adsorption ability,which are contributed by the Co_(0.85)Se/WSe_(2) heterostructure and Se vacancies,respectively.As expected,the CoWSe/NCP anode in sodium-ion battery achieves outstanding rate capability(339.6 mAh g^(−1) at 20 A g^(−1)),outperforming almost all Co/W-based selenides.

Novel Sum-of-Sinusoids Simulation Channel Modeling for 6G Multiple-Input Multiple-Output Vehicle-to-Everything Communications

In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environments.In the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless channels.The statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and discussed.Simulation results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and analysis.The proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems.

Simulation on Single Server &Distributed Environment (It’s Comparison &Issues)

Simulation has become the evaluation method of choice for many areas of distributing computing research. Simulation has been applied successfully for modeling small and large complex systems and understanding their behavior, especially in the area of distributed systems or parallel environment. The aim of my research is to study and qualitative analysis of simulation on a single server & on distributed environment and finding the related issues & its comparison.

Factor analysis and countermeasure simulation on the socio-ecological environment risks during the development of coalbed methane:based on the DEMATEL and FCM models

The socio-ecological environmental problem caused by the development of coalbed methane(CBM)is becoming more serious,so it is very significant for accelerating the development of CBM industrialization to identify the main influential factors of socioecological environmental risks and take effective risk prevention measures.Based on the triangular fuzzy number method,this paper firstly establishes a comprehensive correlation matrix.Then,the affected factors of socio-ecological environmental risks are analyzed by the DEMATEL method during the development of CBM.Then according to the aspects of centrality and causality,the key indicators are determined.Furthermore,the scenario simulation based on the FCM,the steady-state value and the comprehensive importance of key indicators,and the core indicators are selected.Finally,the scenario simulation of risk management countermeasure is done.The results show that:①The index weights are calculated by the triangular fuzzy numbers,and the correlation matrix in DEMATEL is obtained by the weight ratio,which reduces the shortcomings and the subjectivity of traditional DEMATEL method.②The correlation matrix in FCM is established based on the comprehensive correlation matrix in the above improved DEMATEL,which not only makes the FCM model more comprehensive and reduces the difficulty that the FCM correlation matrix is obtained considering the indirect influence relationship between indicators,but also makes up for the disadvantages that DEMATEL excludes during the selection of the core indexes,which are the considerations of the dynamic change of the importance of the indicators.③The rate of forestry and grass coverage,the ratio of investment in prevention and construction,the pollution index of soil Merlot,the reliability of machinery and equipment,the standard evaluation index of major pollution factors of underground water,and the ability of personal risk prevention are the key indicators,in which the rate of forestry and grass coverage,the ratio of investment in prevention and construction,and the reliability of machinery and equipment are the core indicators and are extremely important for the management of socio-ecological environmental risks during the development of coalbed methane.④The results of the scenario simulation of risk management countermeasure show that the core variables affect the socio-ecological environmental risks through such indicators as the degree of production mechanization,the degree of demolition and resettlement,and the ratio of economic loss by the influenced mechanism analysis;the ratio of investment in prevention and construction has the greatest impact on the socio-ecological environment risks in the early stage of CMB development,while the rate of forestry and grass coverage is the most important in the middle and late stages by the influenced result analysis.Therefore,this paper puts forward some corresponding stage suggestions on the prevention and control of socio-ecological environmental risks during the CMB development.In the early stage of CMB development,the ratio of investment in prevention and construction should be increased.In the middle stage,it is very important to reduce the damage of vegetation regions and to improve the reliability of machinery and equipment;in the late stage,the investment in prevention and construction should be increased steadily and the recovery of damaged vegetation areas should be focused on.

The Design of a Graphical User Environment for Numerical Simulation of Powder Forming Processes

As computer simulation increasingly supports engine er ing design and manufacture, the requirement for a computer software environment providing an integration platform for computational engineering software increas es. A key component of an integrated environment is the use of computational eng ineering to assist and support solutions for complex design. Computer methods fo r structural, flow and thermal analysis are well developed and have been used in design for many years. Many software packages are now available which provi de an advanced capability. However, they are not designed for modelling of powde r forming processes. This paper describes the powder compaction software (PCS_SU T), which is designed for pre- and post-processing for computational simulatio n of the process compaction of powder. In the PCS_SUT software, the adaptive analysis of transient metal powder forming process is simulated by the finite element method based on deformation theories . The error estimates and adaptive remeshing schemes are applied for updated co -ordinate analysis. A generalized Newmark scheme is used for the time domain di scretization and the final nonlinear equations are solved by a Newton-Raphson p rocedure. An incremental elasto-plastic material model is used to simulate the compaction process. To describe the constitutive model of nonlinear behaviour of powder materials, a combination of Mohr-Coulomb and elliptical yield cap model is applied. This model reflects the yielding, frictional and densification char acteristics of powder along with strain and geometrical hardening which occurs d uring the compaction process. A hardening rule is used to define the dependence of the yield surface on the degree of plastic straining. A plasticity theory for friction is employed in the treatment of the powder-tooling interface. The inv olvement of two different materials, which have contact and relative movement in relation to each other, must be considered. A special formulation for friction modelling is coupled with a material formulation. The interface behaviour betwee n the die and the powder is modelled by using an interface element mesh. In the present paper, we have demonstrated pre- and post-processor finite elem ent software, written in Visual Basic, to generate the graphical model and visua lly display the computed results. The software consist of three main part: · Pre-processor: It is used to create the model, generate an app ropriate finite element grid, apply the appropriate boundary conditions, and vie w the total model. The geometric model can be used to associate the mesh with th e physical attributes such as element properties, material properties, or loads and boundary conditions. · Analysis: It can deal with two-dimensional and axi-symmetric applications for linear and non-linear behaviour of material in static and dyna mic analyses. Both triangular and quadrilateral elements are available in the e lement library, including 3-noded, 6-noded and 7-noded (T6B1) triangles and 4 -noded, 8-noded and 9-noded quadrilaterals. The direct implicit algorithm bas ed on the generalized Newmark scheme is used for the time integration and an aut omatic time step control facility is provided. For non-linear iteration, choice s among fully or modified Newton-Raphson method and quasi-Newton method, using the initial stiffness method, Davidon inverse method or BFGS inverse method, ar e possible. · Post-processor: It provides visualization of the computed resu lts, when the finite element model and analysis have been completed. Post-proce ssing is vital to allow the appropriate interpretation of the completed results of the finite element analysis. It provides the visual means to interpret the va st amounts of computed results generated. Finally, the powder behaviour during the compaction of a multi-level component is numerically simulated by the PCS_SUT software, as shown in Fig.1. The predict ive compaction forces at different displacements are computed and compared with the available experimental

Analysis of Commuting Modal Shift in Consideration of Social Interaction of Consciousness for Environment

It is the matter for achievement of the low carbon transport system that the excessive use of private vehicles can be controlled appropriately.Not only improvement of service level of modes except private vehicle,but also consciousness for environmental problem of individual trip maker is important for eco-commuting promotion.On the other hand,consciousness for environment would be changed by influence of other person.Accordingly,it is aimed in the study that the structure of decision-making process for modal shift to the eco-commuting mode in the local city is described considering environmental consciousness and social interaction.For the purpose,the consciousness for the environment problem and the travel behavior of the commuter at the suburban area in the local city are investigated by the questionnaire survey.The covariance structure about the eco-consciousness is analyzed with the database of the questionnaire survey by structural equation modeling.As the result,it can be confirmed with the structural equation model that the individual environmental consciousness is strongly related with the intention of self-sacrifice and is influenced with the local interaction of the individual connections.On the other hand,the intention of modal shift for the commuting mode is analyzed with the database of the questionnaire survey.It can be found out that the environmental consciousness is not statistically significant for commuting mode choice with the present poor level of service of public transport.However,the intention of self-sacrifice for the prevention of the global warming is statistically confirmed as the factor of modal shift with the operation of eco-commuting bus service with the RP/SP integrated estimation method.As the result,the multi-agent simulation system with social interaction model for eco consciousness is developed to measure the effect of the eco-commuting promotion.For the purpose,the carbon dioxide emission is estimated based on traffic demand and road network condition in the traffic environment model.On the other hand,the relation between agents is defined based on the small world network.The proposed multi-agent simulation is applied to measure the effect of the eco-commuting promotion such as improvement of level of service on the public transport or education of eco-consciousness.The effect of the promotion plan can be observed with the proposed multi-agent system.Finally,it can be concluded that the proposed multi-agent simulation with social interaction for eco-consciousness is useful for planning of eco-commuting promotion.

城市低空出行工具的MBSE开发框架研究

城市低空出行工具(UAM)开发目前处于早期阶段,作为一种复杂的新系统,UAM开发需要一套完整、科学的开发框架。提出了一种MBSE开发框架,对UAM的开发流程进行详细的分析和设计。该MBSE开发框架基于MBSE方法论从人—机—环的视角进行UAM的利益相关方识别、使用场景的识别定义,并采用建模的方法完成UAM的能力开发,最后按照体系架构设计的思想使用模型在环仿真和人在环仿真试验对UAM概念阶段的设计进行测试与验证。该MBSE开发框架在数字域闭环UAM的需求、设计、验证,大部分设计缺陷在数字方案阶段被发现解决,能够提高产品开发效率、降低开发风险、提高产品质量,对新型复杂产品开发具备一定的指导价值。