Search

The article discusses the study which develops a dynamic modular paper machine simulator package. It has been noted that computer simulation can be a valuable tool for the optimization of paper production processes, designing wastewater closure strategies and the visualization of a complicated process. It shows that by structuring the simulator as a set of modular blocks, a variety of configurations can be modeled by assembling the blocks in different ways. In addition, researchers have recommended that the simulator package can help in developing simple models for the simulation of complex dynamic systems.

The article discusses the application of the Purdue model, a mathematical model, to simulate an industrial Lo-Solids pulp digester for Pinus radiata cultivated in Chile. It states that simulation results for pulp yield, free liquor temperature profile, and pulp production rate is validated by pulp mill data from the Arauco plant of Celulosa Arauco y Constitucion SA. Accordingly, researchers applied the mathematical model to simulate an increase in filtrate flow to the continuous cooking zone to save white liquor consumption. It mentions that results of the simulation shows a 9.1% savings of white liquor and a decrease in dissolved solids content, which proves that the pulping process of Lo-Solids improved.

Copyright of Ciencia e Ingenieria Neogranadina is the property of Ciencia e Ingenieria Neogranadina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Biotechnologie, Agronomie, Societe et Environnement is the property of Les Presses Agronomiques de Gembloux and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper attempts to apply both global and local sensitivity analyses (SA) to fully test the integrated activity-based model (ABM) within several experiments based on a Chinese medium-sized city, Baoding. MATSim (Multi-agent Transport Simulation) that is a typical integrated ABM is used as an example for the SA. The global SA, which is based on the elementary effect method, is firstly applied to identify the influential parameters. Then the once-at-a-time (OAT)-based Local SA is employed to further reveal the relationship between the influential parameters and the outputs of interest, such as traffic flow. The SA results show the extent to which and how three influential MATSim parameters (population scaling factor, the number of iterations and time step size) influence the outputs of interest. In addition, the SA results of MATSim suggest that the parameters of time mutation rate and performing utility can heavily influence the outputs of interest and properly setting them can optimize the daily plans of agents. Finally, this paper concludes with suggestions on how to wisely use the SA findings for both MATSim and other ABM users. [ABSTRACT FROM AUTHOR]

The article cites studies on the evaluation of mathematical models that are capable of predicting the outlet kappa number of the delignification reactor of one of the paper mills in Brazil. The author insists that the applications of these models to process simulation, optimization, and control are a useful tool for cellulose mills. The study suggests three kinetic models and has identified nonlinear models for the delignification plant. It reveals that the models can be applied to simulate daily processes and can be used as a performance indicator of the process.

Currently known fire models are capable to describe fire dynamics in complex environments incorporating a wide variety of fire-related physical and chemical phenomena and utilizing large computational power of contemporary computers. In this paper, some issues related to realization of the simulation of fire in a cinema hall with sloping floor and curved ceiling furnished by upholstered seats modelled by FDS (Fire Dynamics Simulator) are discussed. The paper concentrates particularly on the impact of a computational meshes choice on resolving flow field and turbulence in the simulation and indicates problems related to parallelization of the calculation illustrated comparing sequential and parallel MPI calculation using 6 CPU cores. Results of the simulation described and their discussion demonstrate the ability of FDS simulation to capture main tendencies of smoke spread and to forecast the related safety risks realistically. [ABSTRACT FROM AUTHOR]

In this paper, mathematical modelling and simulation of microgrid (MG) system comprised solar photovoltaic system, wind turbine generator and fuel cell as its main components. Battery energy storage systemisalsopresented in the system to account for those periods when renewable energy sources are not available to fulfil the load demand because of the unavailability of resources or environmental condition. The proposed model is considered in p.u. system under normal operating conditions. First, the mathematical model of each subsystem has discussed in detail in this paper, then the system is approximated to its transfer function for simplicity. The power distribution among subsystems of MG according to the demand power has been done efficiently with power management scheme. Then the simulation and analysis of system has been carried out in time domain for 24 h with real-time data. Data is given into small time slots of 15-15 min to increase understanding of results. The system is designed and simulated on MATLAB/Simulink. [ABSTRACT FROM AUTHOR]

• The rock failure volume model under particle jet impact is put forward and established. • Damage evolution and failure volume under particle jet impact are dynamically simulated and analyzed. • The correctness and applicability of mathematical model were verified by comparative analysis with experiment and simulation. There are some difficult problems in deep and ultra-deep oil and natural gas drilling process due to the complex stress environment and hard formation, such as slow drilling speed, well deviation and high cost. As one of the important parameters to measure rock-breaking efficiency, mathematical model of failure volume is proposed in this paper, which is suitable for deep-well rock-breaking technology. First, the particle jet impact rock-breaking laboratory experiment was conducted based on the self-developed experimental platform, and the strength of rock specimen was tested. Then, the failure volume model of particle jet impact rock-breaking which varied with particle size, and water-jet velocity was established based on contact mechanics. Meanwhile, the simulation model and method of particle jet impact rock was carried out and introduced, and damage evolution was dynamical simulated. Comparative analysis of experiment results, model calculation and dynamic simulation was used to analyze the failure volume, and it showed, failure volume would increase linearly with increase of water-jet velocity, while particle size has little effect on failure volume under the condition of constant nozzle diameter. The comparison results of theoretical modeling and rock-breaking experiment are basically consistent, which proves the correctness and applicability of failure volume model. [ABSTRACT FROM AUTHOR]

The paper presents the modeling and simulation of heat transfer in ANSYS in a room of a house. The house is a three-room apartment located in Resita, Caras-Severin. The room where the heat transfer was studied is the coolest room in the apartment. The mathematical model of heat transfer was developed and then based on this mathematical model the numerical model with finite elements was elaborated, thus making possible the simulation of the thermal transfer in ANSYS. The results obtained can help the homeowner in the correct sizing of the heating system. [ABSTRACT FROM AUTHOR]

This paper is the part of research aimed at creating robotic manipulator controlled by means of Brain-Computer Interface for improving household self-reliance of persons with disabilities and expanding the scope of their activity. The robotic manipulator gives possibility of self-fulfillment in basic household functions, s.a. drinking, eating, facial hygiene. The paper presents a mathematical model of the kinematics of the robotic manipulator. The solution of the forward and inverse kinematics problems based on the geometric method are given and obtained in MATLAB for the 5DOF manipulator. [ABSTRACT FROM AUTHOR]

A fully dynamic model of a microchannel evaporator is presented. The aim of the model is to study the highly dynamic parallel channel instabilities that occur in these evaporators in more detail. The numerical solver for the model is custom-built and the majority of the paper is focused on detailing the various aspects of this solver. The one-dimensional homogeneous two-phase flow conservation equations are solved to simulate the flow. The full three-dimensional (3D) conduction domain of the evaporator is also dynamically resolved. This allows for the correct simulation of the complex hydraulic and thermal interactions between the microchannels that give rise to the parallel channel instabilities. The model uses state-of-the-art correlations to calculate the frictional pressure losses and heat transfer in the microchannels. In addition, a model for inlet restrictions is also included to simulate the stabilizing effect of these components. In the final part of the paper, validation results of the model are presented, in which the stability results of the model are compared with the existing experimental data from the literature. Next, a parametric study is performed focusing on the stabilizing effects of the solid substrate properties. It is found that increasing the thermal conductivity and thickness of the solid substrate has a strong stabilizing effect, while increasing the number of microchannels has a small destabilizing effect. Finally, representative dynamic results are also given to demonstrate some of the unique capabilities of the model. [ABSTRACT FROM AUTHOR]

This paper describes simulation model of real network with various neutral earthing methods when a single pole earth fault occurs. Model was made using Matlab. The aim of the paper is to analyse values of the currents and of the temporary overvoltages with power frequency in case of a single pole earth fault. The currents of single phase to ground faults depend (along with the neutral earthing method) mostly on the earth capacitances of the overhead lines or cables connected to the network. A comparison of the network with a large number of long cables and network with mostly overhead lines was made with the purpose to determine their influence. With the intention to control results given by simulation models the mathematical model was created as well. The comparison of the simulation model results and calculated values show match. Simulation models are powerfull analysis tools used to validate different solutions of neutral point earthing. [ABSTRACT FROM AUTHOR]

Abstract: Multiagent-based simulations enable us to validate different use-case scenarios in a lot of application domains. The idea is to develop a realistic virtual environment to test particular domain-specific procedures. This paper presents a multilevel model of a physic environment for the simulation of crowd in a virtual 3D building. The major contributions of this paper is the agentification of the model to support multilevel simulation of the environment. Finally, the application of the model inside an airport terminal is presented. [Copyright &y& Elsevier]

A number of effective methods for multiple-attribute group decision making (MAGDM) with interval-valued intuitionistic fuzzy numbers (IVIFNs) have been proposed in recent years. However, the different methods frequently yield different, even sometimes contradictory, results for the same problem. In this paper a novel criterion to determine the advantages and disadvantages of different methods is proposed. First, the decision-making process is divided into three parts: translation of experts' preferences, aggregation of experts' opinions, and comparison of the alternatives. Experts' preferences aggregation is considered the core step, and the quality of the collective matrix is considered the most important evaluation index for the aggregation methods. Then, methods to calculate the similarity measure, correlation, correlation coefficient, and energy of the intuitionistic fuzzy matrices are proposed, which are employed to evaluate the collective matrix. Thus, the optimal method can be selected by comparing the collective matrices when all the methods yield different results. Finally, a novel approach for aggregating experts' preferences with IVIFN is presented. In this approach, experts' preferences are mapped as points into two-dimensional planes, with the plant growth simulation algorithm (PGSA) being employed to calculate the optimal rally points, which are inversely mapped to IVIFNs to establish the collective matrix. In the study, four different methods are used to address one example problem to illustrate the feasibility and effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Software defect prediction (SDP) models facilitate software practitioners to find out defect-prone software modules in software. Software practitioners can then test these defect-prone software modules with limited testing resources to minimize software defects. Among various SDP models, Naive Bayes (NB) has been widely used in SDP because of its simplicity, effectiveness and robustness. The NB classifier is an effective classification approach, especially for data sets with discrete attributes. In NB, the attributes are assumed to be independent and thus equally important. However, in common practice, the attributes of software defect data sets are usually continuous or numeric, and because they are designed for different purposes, their contributions to prediction are different. Therefore, this paper proposes a new NB method called TSWNB, which contains two stages: feature (i.e. attribute) discretization and feature weighting. More specifically, for the stage of feature discretization, we make the comparison between two discretization methods i.e. equal-width discretization method and equal-frequency discretization method, and identify the most appropriate one. For the stage of feature weighting, we use the feature weighting technique to alleviate the equal importance assumption, which combines the obtained feature weights into the NB formula and its likelihood estimations. To evaluate the proposed method, we carry out experiments on 5 software defect data sets of NASA MDP provided by PROMISE repository. Three well-known classification algorithms and two feature weighting techniques are included for comparison. The experimental results reveal the effectiveness and practicability of the two-stage feature weighting method TSWNB. [ABSTRACT FROM AUTHOR]

This paper presents the statistical analysis of vortex particle swarm optimization (VPSO) which is a boost algorithm based on self-propelled particle swarms. In order to avoid local minima, the optimization algorithm uses two separated behaviors: translational and dispersion. This idea mimics living organism strategies such as foraging and predator avoidance. The dispersion is given by vortex behavior (circular movements) to scape from local minima. Via suitable parameter configuration is possible to switch between translational (convergence) and circular movements (dispersion). Performance of the algorithm is studied via statistical analysis results using well-known test functions. [ABSTRACT FROM AUTHOR]

Abstract: In designing complex engineered systems, various experiments and simulations are needed for the verification of design hypotheses. Because the conducted verification is multidisciplinary, synthesis of these verification results should be based on a neutral model regarding the domains and disciplines. This paper introduces a metamodel, to which the roles and designers’ intentions (i.e., design situation) of various verification models are referred, and uses it for analyzing the synthesis process. The design of a paper-handling device is used for an analysis example, which clarifies advantages and drawbacks in modeling the synthesis process with such a metamodel. [Copyright &y& Elsevier]

This paper presents mathematical modeling of dynamic phenomena in large pressurized water reactors to study load-follow capability. One of the main reactor types in China's national nuclear development, CPR1000, uses a mode G control method, with G banks, N banks, R banks, and soluble boron to adjust reactor power changes and the axial power shape. In this paper, a new control mode is adopted that can follow the daily variation of power demand without changing the boron concentration. The control banks are regrouped to realize reactivity/temperature control by M banks and axial offset control by an AO bank. A two-node dynamic core model is constructed, taking into account the coupling coefficient and the mutual influence. The transient parameters are obtained by steady-state calculation of a single channel using the original design and operation parameters of CPR1000. Then, to adopt a control mode without soluble boron adjustment, the optimal control implementation is connected to the core simulation platform. Simulation results show that this optimal control policy can provide the capability for the CPR1000 to follow a daily load curve. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a model of semantic ontologies integration into workflow co mposition design process via Virtual Simu lation Objects (VSO) concept and technology. Doma in knowledge distributed over open linked data sources may be usefully applied for new VSO-images design and used for organization co mputational-intensive simulation e xpe riments. In this paper we describe the VSO- architecture e xtended with novel functionality regarding integration with lin ked open data sources. We also provide a computational-scientific e xa mp le of do ma in-specific use-case offering a solution for some public-transportation domain problem. [Copyright &y& Elsevier]

Ropes and woven webbing used in personal equipment protecting against falls from a height determine the course of forces acting on the human body during fall arrest, as well as the fall arrest distance. This paper presents a model of a system made up of a textile connecting and shock-absorbing component and the mass constituting its load. The model is based on non-linear rheological models ofvisco-elasto-plastic objects developed by Maxwell and Kelvin-Voigt. The definite structure of the model is described with a nonlinear differential equation, enabling numerical analysis of its performance. Identification of the model parameters was carried out utilising a software package allowing to analyse the static load-elongation characteristics and the time courses of a dynamic force acting during fall arrest. The paper presents the results of identification of selected connecting and shock-absorbing components used in equipment protecting against falls from a height. The models identified were subjected to verification involving comparison of their numerically simulated response with the results of laboratory tests. The comparison demonstrated the correctness of the model structure and identification of its parameters. The paper also presents an example of application of the model for simulation of the performance of a connecting and shock-absorbing component during fall arrest. [ABSTRACT FROM AUTHOR]

This is the second part of the paper for modeling and validation of the rotational vibra-tion responses for an accessory drive system. The unified formulas for modeling the rota-tional vibration of an accessory drive system are presented. In the modeling of an accessory drive system, the damping and stiffness of a belt are regarded as the function of the excitation frequency of an engine and the amplitude of belt stretching. Additionally, the creeping effect of a belt on the pulley wrap arc is included in the model. A general purpose software for calculating the rotational vibration of an accessory drive system is developed, based on the presented unified formulas. One accessory drive system with seven pulleys, a tensioner, and a serpentine belt is used as a studying example to demon-strate the unified formulas and the procedure for obtaining the rotational vibration. In the simulation of the accessory drive system, the stiffness and damping of the belt, the friction coefficient between the belt and pulley, and the excitation torques with multifre-quency components from the crankshaft torsional vibration are obtained from the experi-ment in the first part of this paper. The static tension and steady-state tension of each belt span, along with the natural frequency of the accessory drive system, rotational vibra-tions of the driven pulley and tensioner arm, and the dynamic tension of the belt span are calculated and compared well with the experimental data, which validate the presented unified formulas and the developed general purpose software. The modeling method and the procedure described in this paper are instructive for designing an accessory drive system. [ABSTRACT FROM AUTHOR]

Military tracked vehicle and crew are modelled together in this paper as integrated man-machine lumped parameter model, by integrating the simplified 5 degrees of freedom (DoF) tracked vehicle model, including seat and 4 DoF human bio-dynamic model, thus resulting in a 9 DoF simplified vehicle-occupant model. Then the natural frequency of major mass segment namely the chassis mass is obtained through simulation study, for a known road input. The value obtained is compared with that of an earlier research work, for validation of said man-machine model. Then focusing our study locally at crew seat location, parameters of crew seat suspension for ride comfort are optimised using the optimal digital state space controller designed for this purpose by implementing it in a 2 DoF occupant - seat suspension model and its Simulink model constructed. Simulation results illustrate the attainment of the goal by meeting the controller design requirements. [ABSTRACT FROM AUTHOR]

Multi-node and multi-feature fusion is an important approach for digital modulations signal recognition in modern communication field. Information obtained from multi-node and multi-feature needs to be fused because of incompleteness of single feature and uncertainty of single node. As a powerful method for data fusion and conclusion reasoning in uncertain environments, evidence theory is widely used. Establishing reliable BPA is the prerequisite for evidence fusion. In this paper, in order to improve the coincidence of basic probability assignment (BPA) with real probability, the notion of bell function (Bell-F) based similarity evaluation model (SEM) is introduced. Through comparative experiments, it is proved that the new method based on Bell-F is effective for BPA acquisition. Furthermore, a new information fused based digital signal modulation recognition scheme is described. Finally, a case study is given to illustrate the performance of the proposed model. Through test and calculations under the digital modulation signal data set, under 0 ~ 10dB, the recognition rate based on the Bell-F fusion method is above 90%, which is 20% higher than methods without fusion. Under 0dB or less, the integrated recognition rate of the Bell-F is 40% higher than the Gray relation method. [ABSTRACT FROM AUTHOR]

Allocation of channel resources in a cognitive radio system for achieving minimized transmission energy at an increased transmission rate is a challenging research. This paper proposes a resource allocation algorithm based on the meta-heuristic search principle. The proposed algorithm is an improved version of the Group Search Optimizer (GSO), which is a currently developed optimization algorithm that works through imitating the searching behaviour of the animals. The improvement is accomplished through introducing dynamics in the maximum pursuit angle of the GSO members. A cognitive radio system, relying on Orthogonal Frequency Division Multiplexing (OFDM) for its operation, is simulated and the experimentations are carried out for sub-channel allocation. The proposed algorithm is experimentally compared with five renowned optimization algorithms, namely, conventional GSO, Particle Swarm Optimization, Genetic Algorithm, Firefly Algorithm and Artificial Bee Colony algorithm. The obtained results assert the competing performance of the proposed algorithm over the other algorithms. [ABSTRACT FROM AUTHOR]

Emotion contagion is an indispensable behavior in a dynamic crowd, especially in an evacuation situation. As a consequence, generating emotion contagion results is very useful in the crowd simulation field. However, because the topology of the crowd usually keeps changing dynamically, computing the contagion process is a challenge. In this paper, we represented our research about the emotion contagion effects on the virtual pedestrian dynamic aggregation process. First of all, we calculated individuals' moving parameters based on their prefixed expectations according to the social force theory. After this, we made an adjacent test for each individual to generate nearer neighbors for further emotional contagions computing between neighbors. We then treated the emotional contagions between individuals and their neighbors as the information spreading process so that we can adopt the emotional information spreading model SIR (Susceptible Infective Removal) to calculate emotional influences, which are represented as their changing moving velocities during aggregation. Social force for computing low level moving parameters and SIR model for generating emotional influences were integrated by our method to simulate the dynamic pedestrian aggregation. Experimental results showed that the SIR model can effectively improve the fidelity of the emotional interaction process and crowd aggregation. [ABSTRACT FROM AUTHOR]

In this paper, a series of experiments was conducted by using a gas burner to characterize the flame geometry under the inclined surface condition and trench configuration. The inclination angle was systematically varied from 0° to 26°. The centerline temperature distribution of the inclined surface was measured and the flame geometry parameters were obtained by the post-processing of the side-view images. Results show that the flame tilt angle appears a linear decrease with the increase of the inclination angle for both the inclined surface and trench configuration experiments, and decreases faster for the trench configuration. The flame length shows a non-monotonic variation with the inclination angle and a transformation process of flame from the plume-type to attachment type is observed. There is no significant effect of the aspect ratio on the flame geometry parameters. The flame attachment length fluctuated with time was obtained. A variable-interval time-average (VITA) method was used to determine the level-crossing rate and the peak frequency location. The peak frequency location has a linear relationship with the horizontal flame length. The flame attachment length and the centerline temperature increase sharply from 15° to 20° under the inclined surface condition, indicating the occurrence of flame attachment. [ABSTRACT FROM AUTHOR]

In this paper, a stability analysis is suggested for adaptive fuzzy logic systems (FLSs) without the requirement of states measurement or estimation. Fuzzy logic is viewed as a powerful tool in providing accurate approximation of systems with uncertainties. The proposed methodology exploits the power of adaptive control theory to find a Lyapunov-based adaptation law for FLSs. As such, both stability and tracking problems are addressed for a class of nonlinear dynamic systems. The proposed method yields reduced complexity with respect to many adaptive FLSs available in the literature. In addition, the use of an observer to estimate immeasurable states is not required as in other methods. First, a stability analysis is presented for adaptive control. Then, results are extended to adaptive FLSs with unknown dynamics. A numeric illustrative example highlights the implementation details and the performance of the suggested scheme. [ABSTRACT FROM AUTHOR]

The paper presents the simulation results of the executive body of the mechanism parameters of the mine loading machine of continuous action. The requirements to the trajectory, described by the leading edge of the working body and the possibility of their realization, are formulated. Based on the analysis of the shortcomings of the kinematic scheme of the working mechanism, a mathematical model of a rectilinear crank-and-link mechanism has been developed. The trajectories of motion are analyzed depending on the parameters of the kinematic scheme. The influence of each of the parameters on the flexibility of the trajectory in the dimensions of the bedplate and on the area enclosed within the trajectory is established. A rational combination of the parameters of the crank-rocking mechanism with a rectilinear wedge is suggested. This provides an increase in the area of capture of bulk cargo in relation to the existing situation. [ABSTRACT FROM AUTHOR]

The paper presents the results of a mathematical simulation on a gas-liquid flow at cooling a cylindrical metal workpiece from constructional steel. The two-dimensional mathematical model of the nonstationary flow takes into account the axial symmetry of the cooling medium flow relative to the cylinder longitudinal axis. To solve the system of equation, the control volume approach is used. The flow field parameters for the gas-liquid medium are calculated with the help of the SIMPLE algorithm. For the iterative solution of the system of linear algebraic equations, Gauss-Seidel method with under-relaxation is used. The results of the numerical calculation are given for the parameters of convective heat exchange at the cylinder-heating initial temperature characteristic of high-temperature bodies, on the surface of which the cooling with the boiling of liquid takes place. During cooling by the gas-liquid medium flow with the velocities characteristic of the turbulent flow regime, the values of the heated cylinder temperatures are determined in the longitudinal and radial directions. The intensity of the variation of the metal-cylinder surface temperature is analyzed depending on the medium flow velocity and the time of the cooling process. [ABSTRACT FROM AUTHOR]

Recently researchers have proposed innovative solutions aiming to improve the energy performance of building envelope components such as Trombe walls, ventilated storage walls. The principle of all the innovative systems can be simplified as heat/cold sources in walls. However, the thermal performance and energy savings potential of the innovative heating walls comparing to the traditional heating pattern with heat sources in room air are still lack of clarification. In this paper, the thermal response of an ideal building model under two ideal heating patterns, are analyzed by using a simple thermal and airflow macroscopic model. The analytical formulas for indoor air temperature and thermal mass temperature are also derived to identify the critical parameters that affect the levels and fluctuations of them. By numerical calculation, it can be observed that the indoor air temperature under HP1 quickly falls down as the heat source removed and has big variation, while the results of HP2 look favourable with less variation, and the mean air temperature during the non-heating period is higher than that of HP1. This implies that the heating pattern HP2 has the potentials to create a stable indoor thermal environment. [ABSTRACT FROM AUTHOR]

Based on a public building in China, this paper built a benchmark model and analyzed the influence of main thermal performance of building envelopes on energy consumption in different climatic regions by EnergyPlus. The results showed that in the order of hot summer and warm winter region, hot summer and cold winter region, cold region, severe cold region, the energy-saving effect was getting better and better with the increase of roof insulation, exterior wall insulation and exterior window insulation. If SHGC of exterior window was reduced, building energy consumption decreased in hot summer and warm winter region, hot summer and cold winter region, but it increased in cold region and severe cold region. For hot summer and warm winter region, hot summer and cold winter region, the factors that affected energy consumption was as follows: SHGC > K win > K wal > K ro, for cold region and severe cold region, it was as follows: K win > K wal > SHGC > K ro . [ABSTRACT FROM AUTHOR]

In recent years, Beijing rural “coal to electricity” is more and more attention. Among them, the air source heat pump as a clean energy is vigorously promoted, but due to of its low water supply temperature. So, for what kind of terminal equipment need to be researched. In this paper, the two terminal equipment of PE-X pipe are adopted as the low-temperature floor radiant heating and four-post 760 cast iron radiator in the bedroom of a Beijing farmhouse are simulated. The performance of two kinds of terminal equipment is analyzed from four aspects: indoor temperature field distribution, indoor air cleanliness, indoor air velocity distribution and energy consumption. The commercial CFD software was used to simulate the characteristics of two heating terminal equipment. The simulation results show that PE-X pipes as the low-temperature floor radiant heating is better than that the four-post 760 cast iron radiator heating, it has good heating effect. [ABSTRACT FROM AUTHOR]

To improve cooling and energy utilization efficiency, under-floor flexible baffles (UFBs) was applied to transform the under-floor airflow pattern in this paper. The application of UFBs impacted the airflow pattern within the Cold aisle containment (CAC). As a result, the exhaust air temperatures of racks were reduced and the exhaust air temperature distribution of the racks was better distributed. The results indicated that, although the use of CAC reduced the exhaust air temperature of racks and the maximum temperature of local hotspot, the air temperature distribution of the racks presented as a non-uniform distribution and the temperature of local hotspot was still high. However, not only could UFBs further reduce exhaust air temperature, but also it made the exhaust airflow more uniform. When the angle between the baffle and CRACs outlet air orientation was at 45, the maximum temperature of local hotspots dropped most, which was from 30.5℃ to 28.4℃ and achieved a 2.1℃ temperature drop. Under the circumstance, the exhaust air temperature distribution was more uniform compared to the data center with CAC but without UFBs. [ABSTRACT FROM AUTHOR]

Taking a two-story building in Shenyang as an example, this paper uses DeST-C and TRNSYS software to simulate the heat pump system and the solar coupled heat pump system. It is modeled by DeST-C software.And the results show that the construction area of 288㎡and the annual cumulative heat load of 14906KW•h, the annual cumulative cooling load of 8103.49 KW•h. The COP value of the solar coupled heat pump system is 11.62%, which is higher than that of the simple heat pump system, and the energy saving effect is remarkable. Through the PVT collector system and vacuum tube solar collectors coupled the heat pump found that, these two solar-related components to the heat pump system COP value changes brought about by the same, are increased by more than 10%. However, due to the PVT collector system collector efficiency is low. It is not recommended. [ABSTRACT FROM AUTHOR]

Uncertainty analysis has become an active research area in the field of building energy analysis because most of parameters are inherently uncertain in buildings. Most of previous studies implement probabilistic-based uncertainty analysis, which requires detailed information to define probability for input factors. However, it is hard to obtain detailed information for these inputs, especially at the initial design stage of a building project. Therefore, this paper applies the non-probabilistic Dempster-Shafer theory of evidence approach for uncertainty analysis in an office building using the EnergyPlus program. The results indicate that the Dempster-Shafer theory can be very useful to provide pertinent and reliable results by taking into account the level of available information in the design stage of building projects for sustainable buildings. The reliable machine learning models can be constructed in order to reduce high computational cost of this non-probabilistic uncertainty analysis method. [ABSTRACT FROM AUTHOR]

In this paper, two sets of design schemes of air source heat pump heating and gas boiler heating are given, and the economical performance of the two heating modes is compared. Through the simulation and calculation of the two kinds of heating system economy, it can be concluded that the operating cost of the gas-fired boiler is about 21.39 RMB•m -2 in the normal operation of the whole year. The operating cost of the air-source heat pump system in the regular operation is about 17.81 RMB•m -2 , and it is about 10.82 RMB•m -2 in the valley operation. [ABSTRACT FROM AUTHOR]

The coaxial parallel-type hybrid power gas engine-driven heat pump (HPGHP) system combines hybrid power technology with gas engine-driven heat pump, which can be divided into three parts: the power-driven system, the heat pump system and the heat reclaim system. In this paper, on the basis of HPGHP system experiments, the mode of the heat reclaim system is established, then the engine waste heat reclaim coefficient of flue gas waste heat, cylinder liner waste heat and total heat is researched. The results show that the waste heat reclaim coefficient of cylinder liner waste heat is significantly higher than the flue gas waste heat. In addition, to evaluate the thermal performance and fuel economy of flue gas heat exchanger, the annual net income of unit flue gas heat reclaim model is established. Finally, the heat transfer area of flue gas heat exchanger is optimized. The results show that when NTU is approximately 0.6, the annual net income of per unit flue gas heat reclaim reaches a maximum value, this moment, the economic optimum heat transfer area is 1.79 m 2 approximately. [ABSTRACT FROM AUTHOR]

In this paper, The utility model relates to a heating system which is composed of a traditional solar air collector, a floor air supply and a phase change heat storage air duct, which is used for heating the room in winter. Using Fluent software to simulate the whole system in winter. The results show that this system conforms to the standard of winter heating. The system needs to add an electric heating auxiliary heat source, which is used to heat the room in the night or rainy day. [ABSTRACT FROM AUTHOR]

Subway transfer station is the intersection of the lines in the subway network structure. In this paper, the simulation model of fire simulation is established with Liuliqiao station of cross type subway station. The influence of the piston wind effect on the spread control of fire smoke at the bottom platform was studied. Through analysis, the piston wind effect strengthens the airflow disturbance in the station, and accelerates the deposition of the smoke layer, which is not conducive to the evacuation of personnel. [ABSTRACT FROM AUTHOR]

The internal structure of solar energy storage water tank partition design was carried out in this paper. The energy storage tank with different internal structure had been simulated to analysis convective heat transfer mechanism in the water tank by using CFD method. The temperature stratification mechanism of water tank had been deeply analysed to improve the availability of storage tank as the goal based on the heat transfer and flow field synergy theory. The calculation results showed that the partition plate in the water tank could obviously improve the effect of hot and cold stratification of the water tank, so that a good effect of cold and hot stratification from left to right could be achieved; The influence of flow field on temperature field had been studied by analyzing the degree of synergy between velocity vector and temperature gradient vector, The flow resistance, drag reduction mechanism and influencing factors in the water tank were studied by analyzing the synergy between the velocity vector and the pressure gradient vector; Through the adjustment of internal structure and the change of water flow and heat transfer and pressure gradient direction, that was to change the angle between the velocity and the temperature gradient and the velocity and pressure gradient, and It could effectively improve the energy storage and delamination effect of the water tank; and provided a theoretical basis for the future design of efficient solar energy storage tank with low flow resistance. [ABSTRACT FROM AUTHOR]

An air cycle heat pump has large potentials than the PTC (positive temperature coefficient thermistor) in heating applications for full electric vehicles. A key challenge faced nowadays is the matching problem between the expander and compressor of a conventional air cycle heat pump. This paper designed an air cycle heat pump system using a turbocharger (ACHPT) to replace the expander and compressor. The heating power consumptions of PTC and ACHPT were numerically compared, the results showed the ACHPT could save more energy with the outside temperature lower for the full electric vehicles. The simulation results also showed the ACHPT could work below the outside temperature of -10℃ and the optimal pressure ratio is more sensitive to the environment temperature. In order to validate its operation effect, a test bench of the ACHPT was worked out. [ABSTRACT FROM AUTHOR]

A different modelling approach for modelling of hydraulic systems is presented in this paper. The modelling approach deals with how to obtain adequate mathematical models of the most common hydraulic elements, which are often used in process industries. Partial models should be suitable for behaviour simulation of the complete hydraulic system, for simulation of hydraulic process control applications, for supervision of hydraulic processes, and for educational purposes. All partial models, model of the pump, model of the pipeline, model of the tank, and model of the control valve, are connected logically and properly connected in a M ATLAB/Simulink environment and form the mathematical model of the desired hydraulic system. The difference between the classical and presented approach is explained where non-linear and linearized models of all hydraulic elements tanks are derived. T wo hydraulic processes are simulated and results show the potential of the presented modelling approach. The proposed hydraulic modelling approach was used in Bachelor and Master Study Programmes in the scope of students' individual work as seminar or project work. The model and real process measurements gave students a proper insight of modelling problems, design and selection issues of equipment and examples of good engineering practice. Positive students' feedback was towards understanding the underlying physics of the developed theoretic models in connection to real process behaviour and measurements, which is mostly missing when dealing with classic modelling and simulation courses. [ABSTRACT FROM AUTHOR]

With the goal of reducing the investment in monitoring equipment and simultaneously keep an adequate accuracy in structural condition assessment, this paper studies the results that can be obtained with different strategies of instrumentation of a 2.0 MW onshore wind turbine. The data processing strategy is based on the continuous tracking of the wind turbine main vibration modes using Operational Modal Analysis techniques combined with algorithms that deal with the particularities of operation of the wind turbines and that permit an online automated identification. A database of continuously collected acceleration time series during one year is used to evaluate the efficiency on the monitoring system on the detection of simulated damage scenarios, considering variations on the number of sensors, on their distribution in the wind turbine tower and on their noise level. [ABSTRACT FROM AUTHOR]

3D city models are widely used in many applications such as electricity simulation, urban planning, navigation, transportation, city management and so on. One of the key issues in the 3D city study fields is how to reduce the complexity of 3D city models. In this paper, we present a novel method to simply the 3D city object using PCA (Principal component analysis). Different from the ordinary 3D objects in computer graphics, polygons in 3D city objects are usually correlated e.g. parallel to each other or nearly located in the same plane. Therefore, PCA can reduce the data volume efficiently. According to the experimental results, the proposed method can compress the 3D city models by 95% while preserving the overall similarity between the simplified and original models. [ABSTRACT FROM AUTHOR]

In this research paper, the numerical simulation of a Susceptible-Exposed-Infected- Recovered- Susceptible (SEIRS) epidemic model with saturated incidence rate with the saturated terms for the susceptible individuals was analyzed. We established the disease-free equilibrium and endemic equilibrium states of the model. We also investigated the local and global stabilities of the disease free equilibrium using matrix and Lyapunov function methods when the basis reproduction number, 10<1. The work is an extension Kolawole and Olayiwola [KO16a] to investigate the effect of saturation term on the susceptible individual. We used maple for the simulation of the analysis and the result we obtained are in good agreement with other results in the literature. [ABSTRACT FROM AUTHOR]