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The purpose of this paper is to present a unified methodology for the derivation and implementation of the continuous dynamics (equations of motion) and discrete dynamics (transition equations) that comprise the hybrid model of an passive biped robot. A developed general model derivation procedure is presented which generates a complete mathematical model for a selected underactuated bipedal robot. The generated mathematical models are implemented in Simulink using the Stateflow tool. The functionality of the proposed approach has been demonstrated using several case studies. [ABSTRACT FROM AUTHOR]

A process to give teaching assignments for the teachers or lecturers to the available days and times by meeting certain goals is called timetabling. The lecturer's availability, number of courses, type of courses, number of course credits, classroom availability, course start time, and course end time are the factors that affect the learning schedule that makes timetabling complicated especially in university. Therefore, by using a mathematical optimization model, timetabling process becomes easier. Although many mathematical models have been made to do timetabling, there is no general model that can use in every university. In this paper, Binary Integer Programming is used to build the learning schedule in the Mathematics Study Program of Bandung Institute of Technology (ITB). The compulsory courses do not overlap, the courses with the same year are evenly distributed, the lecturer's schedule being unable to teach, the lecturer's schedule shouldn't be teaching, and the lecturer's schedule should be teaching become the consideration in this paper. Then, based on the given data, there are three outputs, that is the schedule of the lecturers, the schedule based on the course year, and the schedule based on the day. The schedule that has been made based on the model is quite good and can be implemented in the daily life. [ABSTRACT FROM AUTHOR]

The paper presents the results of the mathematical model approbation of the cell of a high-voltage traction car battery. A series of experiments was carried out to obtain the characteristics of the storage battery cell. Experimental studies were carried out in laboratory conditions at the constant temperature of 25 C maintained with a thermostat. The work of the battery cell under load is investigated, for which the characteristics of the output voltage are obtained. Experiments were carried out on charging and discharging a battery cell with a pulsed current - charge with a current of 50A, discharge with a current of 50A, cycle of full discharge and charge. Experimental dependences are obtained which are used to assess the reliability of the mathematical model of a cell created in the MATLAB Similink environment. The input parameter of the model is the load current and the output parameter is the voltage of the battery cell. Comparison of experimental dependencies and the results of mathematical simulation modeling was identified. Moreover, the error of the model was determined, which is <1%, relative to field experiments, which makes it possible to use the model when creating software and hardware complexes for mathematical simulation of vehicle electric system. [ABSTRACT FROM AUTHOR]

In this paper the numerical approximation of a fluid-structure interaction problem is described with the main atten-tion paid to the simulation of computational models of human phonation process. The mathematical formulation of the problem is described that allows to treat the numerical simulation of the vocal folds contact resulting in the flow domain closure. The mathematical model is described, numerically approximated and numerical results are shown [ABSTRACT FROM AUTHOR]

This paper presents a design verification for a small Stand-Alone Photovoltaic (SAPV) system under Malaysian tropical climate. The two design methods applied in this study were Mathematical Sizing (MS) model, which claimed to be one of the best sizing methods under Malaysian tropical climate and PVSYST commercial software. The comparison on the design results demonstrated that MS and PVSYST sizing methods have similarities but also differences. The study verified that both methods showed that increasing the system voltage, will reduce the required battery capacity. Significantly, the PVSYST software was found to oversize the battery bank and PV modules capacity required to meet the total energy required from load profile assessment. The differences encountered between the MS and PVSYST software were conceivably due to the different design parameters setting namely the minimum PV module temperature threshold, ambient temperature and battery parameters involved in the design calculation. This study has highlighted several technical understandings on designing SAPV system in both design methods, that can facilitate the PV system designers to evaluate the assumptions and mathematical models applied specifically in each sizing models. [ABSTRACT FROM AUTHOR]

The paper aims at short review for existing approaches for modelling of conditions in tunnel kilns used for production of ceramic bricks. The paper reports common methods used so far and selects the most efficient that can be used for optimization of existing kiln. Based on the survey, appropriate mathematical and physical models are selected and the computational model is recommended for further use within the research project. [ABSTRACT FROM AUTHOR]

The paper describes the development of a digital model of the cooler to calculate in advance the technical characteristics of refrigerating units. The simulation method is used to compare and present the measurement and calculation results through the simulation model. The mathematical model of refrigerating units has been studied and improved. It was concluded that technical characteristics of refrigerating equipment can be specified by means of computational methods. The model developed can be used during the energy audits of enterprises by the experts. [ABSTRACT FROM AUTHOR]

This paper presents the physico-mathematical model of the airflow in the vicinity of the surfaces of the generating sets. Using the developed model, we have carried out the numerical study on the air motion around the generating sets and obtained the distributions of the temperature and air velocity. We have determined the values of the heat fluxes under the natural convective and forced air flow regimes, providing thermostating of the electrical equipment. [ABSTRACT FROM AUTHOR]

This paper describes the development of a mathematical model for the control system of a small-sized crawler felling machine for forest thinning. The substantiation of the choice of the section connection diagram is made, the analysis of the resistance to rotation loads is carried out and the forces arising in the hydraulic cylinders are determined. On the basis of the data obtained, a mathematical model of the control system of a two-link tracked feller was developed. [ABSTRACT FROM AUTHOR]

The paper is dedicated to the building and investigation of mathematical models and numerical methods of human resources management. First, we consider cooperative game theoretic models of reward allocation. An algorithm of solution of the problem basing on different optimality principles is proposed. Then dynamic models of administrative and economic control of the working time are studied. It is assumed that each employee divides his working time between the main work and other kinds of labor activity. A supervisor can bound the share of main work from below (that incurs administrative control cost) or propose the coefficients of reward. These managerial methods are formalized as dynamic Stackelberg games with phase constraints that are solved by means of simulation modeling. At last, the discrete optimization models of staffing are considered. A computational analysis of sensitivity of the solutions to the change of model parameters is made, and an interpretation of the results is proposed. [ABSTRACT FROM AUTHOR]

The excitations caused by the road roughness is the main parameter for the vertical vibrations generated in a vehicle. Their influence in the ride comfort of passengers and vehicle stability is high. It is essential to quantify road excitations so that they could be utilized for vehicle dynamic analysis. In this research paper, an in depth literature survey was carried over regarding the road profile measurement techniques and road roughness representation methods. It was found that the Power Spectral Density(PSD) representation of the road profile has been widely employed by researchers. Based on the ISO standard 8608:2016, the roads were classified and the road profile equation available in the literature survey was studied. A simulink model was created for the road profile equation. The road profiles for different road types and varying vehicle velocities were generated using the simulink model. The road profiles thus created can be utilized for vehicle dynamicanalysis. [ABSTRACT FROM AUTHOR]

The quadrotor type of UAV (QUAV), is arguably the most popular type for civilian purposes, since it does not mandate a complicated remote controlling skill to operate it. This popularity, however, has yet to be balanced with research in mathematical modelling, design, and analysis. This paper describes a mathematical modelling process of a QUAV, by exploiting the usage of MATLAB/Simulink software. The main aim is to provide a proper mathematical model to design and evaluate the control system to maintain QUAV stability. Along with the model, three basic automatic control systems were also designed, i.e., the forward-speed hold, sideward-speed hold, and altitude hold system. Several simulations were conducted afterward, to test both the model and the designed control system, which showed satisfying results in representing a QUAV system. QUAV dynamic characteristics can be observed from the simulation, including the logical commands to alter the rotors thrust, the rotor limitation in handling many commands at once, the vehicle dependency of automatic control systems, and the fact that a motion in one degree of freedom can easily affected others. The developed model evidently has a good potential as a base for QUAV analyses and control design. [ABSTRACT FROM AUTHOR]

Rollovers are complex road accidents causing a big deal of fatalities. FE model for rollover study will costtoo much time due to its long duration. A new multi-body modeling method is proposed in this paper which can save a lot of time and has high-fidelity meanwhile. Following works were carried out to validate this new method. First, a small van was tested following the FMVSS 208 protocol for the validation of the proposed modeling method. Second, a MADYMO model of this small van was reconstructed. The vehicle body was divided into two main parts, the deformable upper body and the rigid lower body, modeled by different waysbased on an FE model. The specific method of modeling is offered in this paper. Finally, the trajectories of the vehicle from test and simulation were compared and the match was very good. Acceleration of left B pillar was taken into consideration, which turned out fitting the test result well in the time of event. The final deformation status of the vehicle in test and simulation showed similar trend. This validated model provides a reliable way for further research in occupant injuries during rollovers. [ABSTRACT FROM AUTHOR]

This paper presents a RELAP/SCDAPSIM MOD3.5 model of the QUENCH 12 experiment. The model uses the new heater rod model and automatic time advancement in the simulation of experiment and it is based on the basis Innovative Systems Software’s input deck with 22 axial nodes. [ABSTRACT FROM AUTHOR]

The article covers new concept of the bus powering - by the liquid air (LABus). The technology is dedicated for the public transport in the big cities. The main aim of the system is to provide power supply for the bus basing on liquid air and pneumatic engine. The system provides cold and heat recovery loops, which increase the cost-effectiveness of the project. The technology can contribute to reduce the air pollution in the cities. In the paper the Aspen Hysys model is described. Article includes LABus calculations and technology assesment.. [ABSTRACT FROM AUTHOR]

This paper gives an overview and comparison of available semi-probabilistic safety formats for non-linear finite element analysis (NLFEA). Methods were applied on shear strength design of prestressed concrete girder and results were compared in terms of computational requirements. Design values determined by stochastic methods are very close, except the ECoV method, which does not meet the safety requirements. The most efficient method for determination of shear strength design value was ECoV modified by Schlune et al. Findings presented herein might be useful for practical design of structures using NLFEA. [ABSTRACT FROM AUTHOR]

Aiming at the question that we rarely consider the impact of target’s attack zone in traditional situation assessment so that the assessment result is not comprehensive enough, a method that takes target’s attack zone into account is presented. This paper has obtained the attack zone and the non-escape zone as the basis for quantitative analysis using the rapid simulation method and the air-to-air missile mathematical model. The situation of air combat is assessed by the ratio of the advantage function values of both sides, and the advantage function is constructed based on some influential factors such as height, speed, distance and angle. The simulation results have shown the effectiveness of this method. [ABSTRACT FROM AUTHOR]

The paper presents aerodynamic calculations of the Sienna Towers high buildings complex in Warsaw using authors mathematical model of the considered issue. Human vibrations comfort criteria were checked according to ISO/6897. Dynamic coefficients used in the calculations were obtained from wind tunnel tests. [ABSTRACT FROM AUTHOR]

This paper discusses the problem of multicriterial adaptive optimization the control of investment projects in the presence of several technologies. On the basis of network modeling proposed a new economic and mathematical model and a method for solving the problem of multicriterial adaptive optimization the control of investment projects in the presence of several technologies. Network economic and mathematical modeling allows you to determine the optimal time and calendar schedule for the implementation of the investment project and serves as an instrument to increase the economic potential and competitiveness of the enterprise. On a meaningful practical example, the processes of forming network models are shown, including the definition of the sequence of actions of a particular investment projecting process, the network-based work schedules are constructed. The calculation of the parameters of network models is carried out. Optimal (critical) paths have been formed and the optimal time for implementing the chosen technologies of the investment project has been calculated. It also shows the selection of the optimal technology from a set of possible technologies for project implementation, taking into account the time and cost of the work.The proposed model and method for solving the problem of managing investment projects can serve as a basis for the development, creation and application of appropriate computer information systems to support the adoption of managerial decisions by business people. [ABSTRACT FROM AUTHOR]

Mathematical modelling and simulation for Hepatitis B discuss in this paper. Population devided by four variables, namely: Susceptible, Exposed, Infected and Recovered (SEIR). Several factors affect the population in this model is vaccination, immigration and emigration that occurred in the population. SEIR Model obtained Ordinary Differential Equation (ODE) non-linear System 4-D which then reduces to 3-D. SEIR model simulation undertaken to predict the number of Hepatitis B cases. The results of the simulation indicates the number of Hepatitis B cases will increase and then decrease for several months.The result of simulation using the number of case in Makassar also found the basic reproduction number less than one, that means, Makassar city is not an endemic area of Hepatitis B. [ABSTRACT FROM AUTHOR]

The purpose of this research is to obtain a mathematical model (Full Vehicle Model) and compare the performance of passive and active suspension systems of a Three-Wheels Reverse Trike vehicle. Vehicle suspension system should able to provide good steering handling and passenger comfort. Vehicle suspension system generally only uses passive suspension components with fix spring and damper coefficients. An active suspension developed from the traditional (passive) suspension design can directly control the actuator force in the suspension system. In this paper, modeling and simulation of passive and active suspension system for a Full Vehicle Model is performed using Simulink-MATLAB software. Ziegler & Nichols tuning method is used to obtain controller parameters of Proportional Integral Derivative (PID) controller. Comparison between passive and active suspension with PID controller is conducted for disturbances input of single bump road surface profile 0.1 meters. The results are the displacement and acceleration of the vehicle body in the vertical direction of active suspension system with PID control is better in providing handling capabilities and comfort for the driver than of passive suspension system. The acceleration of 1,8G with the down time of 2.5 seconds is smaller than the acceleration of 2.5G with down time of 5.5 seconds. [ABSTRACT FROM AUTHOR]

Multiscale coupling techniques are a useful tool needed to simulate complex and huge physical domains. In particular they can be used when a full 3D simulation cannot be performed due to high computational cost or when one is not interested to accurate 3D details of the whole system. In the present paper we focus our attention on the data exchange between different computational domains and present preliminary results obtained from the coupling of 3D and 2D simulations of a power-cooling system. This multidimensional configuration is coupled with a simple 1D closed loop which overlaps the multidimensional domains. The CFD simulations correct the pressure losses and the temperature field of the 1D solution by using the defective method technique. The multiscale coupling is performed with the aid of the numerical platform SALOME and the MED library. The procedure for the coupling can be also used with different codes to perform complex simulations. [ABSTRACT FROM AUTHOR]

This paper focuses on the commissioning process of pipeline on hilly areas (for short, hereinafter referred to as hilly pipeline). Quasi-steady model is established to simulate the hydraulic characteristics of it. Liquid holdup in pipeline with various parameters such as diameter, flow rate, inclination is calculated and analyzed. Variation trend of liquid height of slug and gas pressure of air pocket is emphatically studied and entrainment effect is further considered in the model. According to the calculation result, although entrainment effect can counterbalance the increase of gas pressure of the air pocket to a certain extent, its effect is not significant. The proposed model and research results quantitatively obtained in this paper may provide guidance for the practical commissioning process. [ABSTRACT FROM AUTHOR]

The spiral tunnel arises as a new form of tunnel, with great differences in fire development pattern when compared with traditional straight line tunnel, this paper takes method of numerical simulation, based on computation fluid dynamics theory and fire-turbulence numerical simulation theory, establishing a full-scale spiral tunnel model, and applies CFX simulation software to research full-scale spiral tunnel fire and its ventilation condition. The results indicate that with increasing tunnel slope, high temperature area gradually extends to downstream area, high temperature mainly distributes near fire source area, and symmetrically distributes among the fire center point; With increasing tunnel slope, the highest temperature underneath tunnel arch rises first followed by a downward trend and then rising again, which strengthens chimney effect, and promotes more fresh cold air flow into the tunnel, suppressing fire smoke backflow and simultaneously accelerating fire smoke spread to downstream area; Fire plume presents vertical slender shape with 1% or 3% tunnel slope, and burning flame hits tunnel arch and then extending all around into the ceiling jet flow, when tunnel slope increases to 5% or 7%, fire plume cross section grows bigger and wider with unstable burning flame swaying in all directions, integrally incline to fire downstream. [ABSTRACT FROM AUTHOR]

In this paper, the process of 7T SRAM cell is analyzing and also exploring high level leakage power reduction techniques and cell parameters. The first segment contains the information about process of the 7T SRAM cell like write operation and read operation. Second segment of this paper characterize high level the leakage power reduction techniques, containing the information about how many types of techniques are available for characterizing the high level leakage power reduction techniques and what is the effect on the high level leakage power reduction techniques on 7T SRAM cell design. The third segment of this paper shows the information about cell parameters. This segment of the paper is the most important segment because this segment contains the information about all the parameters of 7T SRAM cell. In the second segment of this paper contains the information about high level leakage power reduction techniques, by using high level leakage power reduction techniques we can make our 7T SRAM cell much better in different area like leakage power reduction, dynamic power consumption. The data of leakage power consumption shows that after voltage scaling technique leakage power consumption and dynamic power consumption is less. [ABSTRACT FROM AUTHOR]

This paper presents the study on deformability analysis of sheet metal forming by using finite element methods (FEM). The paper particularly focuses on application of dynamic explicit and static implicit approaches to simulate metal forming of rectangular cups where different material models and contact conditions with friction are involved. Comparative studies of the results on formability of the forming process using the two approaches are presented. The simulated results are verified using results from experimental study of the deformation on the same material. Further, a comparison between a quadratic Hill anisotropic yield criterion and von Mises yield criterion with isotropic hardening has been presented. The results confirm that the dynamic explicit procedure is more efficient in simulating sheet metal forming processes. The study shows also that the finite element analysis undoubtedly gives good approximate numerical results to real processes when the material and friction anisotropy are considered. [ABSTRACT FROM AUTHOR]

Numerical modeling of machining is an active research field in manufacturing. Despite of the improvement of computers, 3D modeling has still high computational cost. 2D modeling has been extensively used for decades in the prediction of difficult to measure variables in metal cutting. On the other hand long fiber reinforced composites are extensively used in industry; however the numerical modeling of composite cutting is still poorly developed, and mainly focused on 2D approach. Two dimensional approaches imply some simplifying hypotheses those could influence the results obtained from the analysis. In this paper a comparison between 2D and 3D modeling of both metal and composite orthogonal cutting is presented. The aim of the paper is analyzing the validity of the hypothesis involved in 2D modeling comparing with the results obtained from 3D approach. [ABSTRACT FROM AUTHOR]

In present paper, a two-dimensional numerical study on a standing-wave thermoacoustic engine was performed with compressible SIMPLE algorithm based on a pressure-correction method. First, the simulation model was developed, and the time-dependent compressible thermoacoustic engine system was chosen through substantive numerical tests. Appropriate governing equations for mass, momentum and energy were introduced. Then, the computational results of the onset of the self-excited oscillations across the entire evolution process and the acoustical characteristics of the pressure and velocity wave were presented and analyzed. In addition, the standing-wave of the pressure and velocity along the center of the two stacks are investigated. The crucial nonlinear phenomenon that cannot be captured by the existing linear theory, like high harmonic frequencies, is also revealed in present paper. It is concluded that compressible SIMPLE algorithm could be employed in our future work to simulate and optimize thermoacoustic system. The present result is an important step toward development to predict the high-amplitude thermoacoustic systems and optimize thermoacoustic engine performance. [ABSTRACT FROM AUTHOR]

In this paper, two Newtonian fluids, which run through two opposite porous plate channels and exchange their nano-sized solute contents through the porous channel wall, are simulated by adopting numerical “SimpleR (Patankar, 1981)” algorithm. The simulation is developed to predict both flow patterns inside two opposite porous plate channels and ultra-filtration pattern along the porous channel wall. In the simulation, by choosing straight channel style pores located on the porous wall, and by considering only none-charged solute particles, the hydraulic permeability of the porous wall is theoretically determined. The streamlines inside the channel, as well as ultra-filtration velocities are outlined in this simulation. Moreover, in order to avoid pore clogging issue in the process of hemodialysis, a practical suggestion is made in the end of this paper. [ABSTRACT FROM AUTHOR]

This paper presents the analytical solutions and symbolic computations for the temperature distribution of the annular fin under fully-wet surface condition. During the process of dehumidification, the annular fin is separated into two regions. The mathematical models for each region are based on the conservation of energy principle. An assumption used in this paper is the humidity ratio of the saturated air on the wet surface varies linearly with the local fin temperature. The mathematical models are solved by the Cauchy-Euler Equation and modified Bessel Equation to form analytical solutions. Besides, the symbolic computations are shown by the Maple software to visualize the temperature distribution along the fin. [ABSTRACT FROM AUTHOR]

In this paper a Lagrangian formulation of the Natural Element Method (NEM) is proposed to solve shallow water inviscid flows. NEM is a particle-based method which revealed its capabilities in handling large distortion problems. Its main advantage is the interpolant character of its shape function and consequently the easiness of imposing Dirichlet boundary conditions. In this paper we use the NEM method in a collocation form and in a Lagrangian kinematic description. This formulation is found to be a finite volume methodology with flux computation on the Voronoï diagram of the standard triangular or quadrilateral meshes. The Shallow-Water equations are used as the mathematical model. Besides the Lagrangian behavior of the flow which is difficult to capture, these equations have discontinuous solutions. Thus, stabilization issues have been considered. Some inviscid bidimensional flows are used as preliminary benchmark tests. This kind of flows is similar to that of metal casting. Good results were found which promise an interesting future for this method in more complicated applications. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

This paper investigates the population growth of a certain species in which every generation reproduces thrice over a period of predefined time, under certain constraints of resources needed for survival of population. We study the survival period of a species by randomizing the reproduction probabilities within a window at same predefined ages and the resources are being produced by the working force of the population at a variable rate. This randomness in the reproduction rate makes the population growth stochastic in nature and one cannot predict the exact form of evolution. Hence we study the growth by running simulations for such a population and taking an ensemble averaged over 500 to 5000 such simulations as per the need. While the population reproduces in a stochastic manner, we have implemented a constraint on the amount of resources available for the population. This is important to make the simulations more realistic. The rate of resource production then is tuned to find the rate which suits the survival of the species. We also compute the mean life time of the species corresponding to different resource production rate. Study for these outcomes in the parameter space defined by the reproduction probabilities and rate of resource production is carried out. [ABSTRACT FROM AUTHOR]

The paper deals with the applications of modeling and simulation tools in the optimization of business processes, especially in solving an optimization of signal flow in security company. As a modeling tool was selected Simul8 software that is used to process modeling based on discrete event simulation and which enables the creation of a visual model of production and distribution processes. [ABSTRACT FROM AUTHOR]

A Petri net controlled grammar is a Petri net with respect to a context-free grammar where the successful derivations of the grammar can be simulated using the occurrence sequences of the net. In this paper, we introduce a new variant of Petri net controlled grammars, called a place-labeled Petri net controlled grammar, which is a context-free grammar equipped with a Petri net and a function which maps places of the net to productions of the grammar. The language consists of all terminal strings that can be obtained by parallelly applying multisets of the rules which are the images of the sets of the input places of transitions in a successful occurrence sequence of the Petri net. We study the effect of the different labeling strategies to the computational power and establish lower and upper bounds for the generative capacity of placelabeled Petri net controlled grammars. [ABSTRACT FROM AUTHOR]

This paper reports the development and application of a 2D¹ depth-averaged model. The main goal of this contribution is to apply the depth averaged equations to a wind park model in which the treatment of the geometry, introduced on the mathematical model by the mass and momentum source terms. The depth-averaged model will be used in future to find the optimal position of wind turbines in the wind park. Steady-state Navier-Stokes equations were consider in this article. The 2D and 3D² CFD³ simulations for a model task were done to check the depth-averaged model in practise. [ABSTRACT FROM AUTHOR]

In this paper, we concern at situations where we have to compare selected parameters from particular nonlinear models. A motivational examples of previously modelled data are given at the beginning. When comparing parameters from two models, it is possible to combine them into one model. But for three and more models, it is necessary to correct significance level at advance. Two approaches to solving this problem are stated, so-called Šidák correction and Bonferroni method. Results of these methods as well as results coming from the situation where significance level correction is omitted are compared based on simulated data. [ABSTRACT FROM AUTHOR]

In this paper qualitative and quantitative characteristics of particle flows on networks of the rings simulating movement at different scales is considered. In that case each particle means a group of vehicles. Space discretization is naturally agreed with group size, regime and speed. It can be applied to the study of traffic. Computer capacity allows numerical research of qualitative properties of discrete models on networks. KBT-models of flows on chainmail networks are studied,. Estimates of movement characteristics are obtained: average velocity, time interval before synergy or collapse state appearance and its dependance of initial state and rules were considered. [ABSTRACT FROM AUTHOR]

Public transport in crowded cities, in particular bus services play an essential role in the mobility of its citizenry. However, an efficient, reliable and safe bus system is still a distant dream of many cities. This paper uses a simulation approach to provide some insight into the factors that contribute to the service quality of a bus system. SAS Simulation Studio is used to model a city bus route. The simulation model consists of a bus depot, bus stops, terminal station and a bus route. Parameters used in the simulation include the number of buses serving the route, maximum bus capacity, inter departure time of buses, travel time between stops, number of passengers boarding and alighting. The simulation is applied to a real bus route in Kuala Lumpur city center and a sensitivity analysis is performed to evaluate how the different variables affect the service quality of the bus system. [ABSTRACT FROM AUTHOR]

Productivity of the agriculture sector in Iraq has yet to reach an acceptable level. In this paper, we introduce a practical method to help manage Iraqi agriculture sector to control resources and increase production to meet the modern century requirements of good crops. These important resources are identified as water, fertilizer, natural fertilizer, pesticides and labour. The current agricultural patterns in Iraq affect the strategic crops cultivation in the country and lessen agricultural production to some life-threatening limits. Data Envelopment Analysis (DEA), which is a non-parametric tool, is proposed to identify solutions that can maximize farmers' net benefit making an optimal use of the five resources. This model also improves optimal mix of the resources. In reference to the production of each one of the three strategic crops in Iraq, the DEA model is used to find the efficiency of one region among four others in its agriculture sector, with the main problem being the constraint in the number of lands available in the situation. Hence, the simulation technique is used to generate additional regions to the four main regions adopted. This is to resolve the constriction of DEA when the decision making unit is less than the number of variables (outputs and inputs). The result is expected to show the efficiency of each of the evaluated region. [ABSTRACT FROM AUTHOR]

Measuring the combat readiness in military forces involves the measures of tangible and intangible elements of combat power. Though these measures are applicable, the mathematical models and formulae used focus mainly on either the tangible or the intangible elements. In this paper, a review is done to highlight the research gap in the formulation of a mathematical model that incorporates tangible elements with intangible elements to measure the combat readiness of a military force. It highlights the missing link between the tangible and intangible elements of combat power. To bridge the gap and missing link, a mathematical model could be formulated that measures both the tangible and intangible aspects of combat readiness by establishing the relationship between the causal (tangible and intangible) elements and its effects on the measure of combat readiness. The model uses multiple regression analysis as well as mathematical modeling and simulation which digest the capability component reflecting its assets and resources, the morale component reflecting human needs, and the quality of life component reflecting soldiers' state of satisfaction in life. The results of the review provide a mean to bridge the research gap through the formulation of a mathematical model that shows the total measure of a military force's combat readiness. The results also significantly identify parameters for each of the variables and factors in the model. [ABSTRACT FROM AUTHOR]

In the aquaculture production chain, a weaning is a process in larval rearing where the tiny fish larvae are separatedly fed with nutritious food in order to grow well. Live feed, for example feeding Artemia nauplii into angelfish larvae (Pteraphylum Scalare), is generally considered as the most suitable food for first feeding larvae. In practice, the fish farmer could replace the life feed with a formulated feed, which is sold commercially in the store. By experiments conducted by Herath et al (2013), the effect of sudden weaning of angelfish from Artemia sp. to formulated feed is observed with the change in weight of fish during the observation periods. In this paper, we construct a mathematical model describing the growth in weight of fish during this sudden weaning process using logistic model based on data from Herath et al (2013). The resulted model is solved numerically. Furthermore using this model, we consider the production cost of live feed in order to determine the optimal time to wean angelfish larvae. [ABSTRACT FROM AUTHOR]

Eddy current measurements are sensitive to variation in the dimensions of probe. This paper presents the results of a parametric study conducted via simulation to determine the effects of varying dimensions on the split D differential eddy current probe response. Details about the study design, the numerical model and major results are presented. The results provide practical guidance on the sensitivity of certain probe dimensions on eddy current probe response. [ABSTRACT FROM AUTHOR]

In order to measure the mental activity, people measured the subject's oral consultation data, cardiac beats, a pulse wave, brain waves, an electromyogram, action patterns, and so on, together with analyzed data. Regarding the vital signs are the information on a complexity system, we were treating a slight change of vital signs as an error. However, very important information was included in this error. The degree of mental activity which is the information on the complexity system was not able to be solved by the conventional method. In this paper, nonlinear analysis of the pulse wave of a fingertip was conducted, and the fluctuation value was computed. Furthermore, the simulation of a mathematical model and the experiment of anesthesia proved that the value had the information on a central system. The apparatus which can measure the degree of mental activity was developed using this. [ABSTRACT FROM AUTHOR]

In this paper, a simulation study of Bayesian extreme values by using Markov Chain Monte Carlo via slice sampling algorithm is implemented. We compared the accuracy of slice sampling with other methods for a Gumbel model. This study revealed that slice sampling algorithm offers more accurate and closer estimates with less RMSE than other methods. Finally we successfully employed this procedure to estimate the parameters of Malaysia extreme gold price from 2000 to 2011. [ABSTRACT FROM AUTHOR]

Large-eddy simulation (LES) is under its rapid development and is recognized as a possible second generation of CFD methods used in engineering. Spray and coal combustion is widely used in power, transportation, chemical and metallurgical, iron and steel making, aeronautical and astronautical engineering, hence LES of spray and coal two-phase combustion is particularly important for engineering application. LES of two-phase combustion attracts more and more attention; since it can give the detailed instantaneous flow and flame structures and more exact statistical results than those given by the Reynolds averaged modeling (RANS modeling). One of the key problems in LES is to develop sub-grid scale (SGS) models, including SGS stress models and combustion models. Different investigators proposed or adopted various SGS models. In this paper the present author attempts to review the advances in studies on LES of spray and coal combustion, including the studies done by the present author and his colleagues. Different SGS models adopted by different investigators are described, some of their main results are summarized, and finally some research needs are discussed. [ABSTRACT FROM AUTHOR]

The paper presents a set of Monte Carlo algorithms, based on the Kac's stohastic gas model for simulation of the binary collision process in a homogenous rarefied gas. These collision algorithms avoid the repeat collisions and can be used for simualtion of the collsions in grid cells with small average number of particles, when the DSMC method is applied and the simulation requires computational resources of very large proportions. [ABSTRACT FROM AUTHOR]

The paper concerns the design of kinetic models on finite grids for the numerical simulation of flows close to the fluid dynamic limit. Taking into account numerical efficiency, we restrict to small grids. We discuss the limitations of such an approach, derive a suitable mathematical framework and address questions of the design of appropriate grids and corresponding two-particle collision models. [ABSTRACT FROM AUTHOR]

The present study is the logical continuation of a former paper by the first author in which the influence of the chemical models by Gupta and by Park on the computation of heat flux on the Orion and EXPERT capsules was evaluated. Tests were carried out by the direct simulation Monte Carlo code DS2V and by the computational fluiddynamic (CFD) code H3NS. DS2V implements the Gupta model, while H3NS implements the Park model. In order to compare the effects of the chemical models, the Park model was implemented also in DS2V. The results showed that DS2V and H3NS compute a different composition both in the flow field and on the surface, even using the same chemical model (Park). Furthermore DS2V computes, by the two chemical models, different compositions in the flow field but the same composition on the surface, therefore the same heat flux. In the present study, in order to evaluate the influence of these chemical models also in a CFD code, the Gupta and the Park models have been implemented in FLUENT. Tests by DS2V and by FLUENT, have been carried out for the EXPERT capsule at the altitude of 70 km and with velocity of 5000 m/s. The capsule experiences a hypersonic, continuum low density regime. Due to the energy level of the flow, the vibration equation, lacking in the original version of FLUENT, has been implemented. The results of the heat flux computation verify that FLUENT is quite sensitive to the Gupta and to the Park chemical models. In fact, at the stagnation point, the percentage difference between the models is about 13%. On the opposite the DS2V results by the two models are practically equivalent. [ABSTRACT FROM AUTHOR]

In this paper, we applied the Riemann-Liouville approach and the fractional Euler-Lagrange equations in order to obtain the fractional-order nonlinear dynamics equations of a two link robotic manipulator. The aformentioned equations have been simulated for several cases involving: integer and non-integer order analysis, with and without external forcing acting and some different initial conditions. The fractional nonlinear governing equations of motion are coupled and the time evolution of the angular positions and the phase diagrams have been plotted to visualize the effect of fractional order approach. The new contribution of this work arises from the fact that the dynamics equations of a two link robotic manipulator have been modeled with the fractional Euler-Lagrange dynamics approach. The results reveal that the fractional-nonlinear robotic manipulator can exhibit different and curious behavior from those obtained with the standard dynamical system and can be useful for a better understanding and control of such nonlinear systems. [ABSTRACT FROM AUTHOR]

In the present paper, we focus our attention on Altham's multiplicative binomial model under the Bayesian perspective, modeling both the probability of success and the dispersion parameters. We present results based on a simulated data set to access the quality of Bayesian estimates and Bayesian diagnostic for model assessment. [ABSTRACT FROM AUTHOR]