Theoretical Model Of System Research Articles

Analysis of characteristics of combined beam in spectral beam combining system based on multilayer dielectric grating

Aiming at the application of multilayer dielectric gratings (MDGs) in spectral beam combining (SBC) systems, a theoretical model of rectangular MDGs is built up and a beam propagation model of SBC systems based on the rectangular MDGs is further developed. The phase modulation introduced by the rectangular MDG is composed of the optical path difference on the top surface of reliefs and that of the relief structure itself, and is affected by the MDG parameters such as the grating groove depth, the grating duty cycle, the incidence angle of the central beam, etc. By the diffraction integral method and the principle of incoherent superposition, the intensity distribution of the combined beam of the SBC system based on the rectangular MDGs is numerically calculated and analyzed. Additionally, the beam quality of the combined beam is also obtained by the intensity second-order moments method, and the effects of the MDG parameters such as the groove depth, the duty cycle, the incidence angle of the central beam, and the fabrication errors of the MDG on the characteristics of the combined beam of the SBC systems are simulated and discussed in detail. The simulation results show that the beam quality of the combined beam after passing through the SBC systems is significantly better than that of the laser array. Since the quality of the combined beam is almost the same as that of an individual laser beam, for a SBC system without fabrication error, changing the groove depth, the duty cycle of the rectangular MDG or the incidence angle of the central beam does not affect the beam quality while it has obvious influence on the energy of the combined beam. This is mainly because the diffraction efficiency of the rectangular MDG depends on both the parameters of the MDG and the incidence angle of the central beam. However, fabrication error of MDG is unavoidable, and the fabrication error has a significant effect on both the beam quality and the energy of the combined beam. Compared with the effect generated by the groove depth error on beam quality, the influence introduced by the duty cycle error is more obvious. It is worth mentioning that the theoretical model of the SBC system based on the rectangular MDG can be applied to some other high-power laser systems due to its advantages such as low absorption and high damage threshold.

A quantitative calculation approach research of tooth surface friction characteristic parameters

A new calculation approach of tooth surface friction characteristic parameters is raised in this paper, the caclulation approach is based on gear drive test experience and finite element multi field coupling analysis method and technology.In the process of solution, friction characteristic concept of engineering oriented complex gear drive is raised, “experiment-calculation composite model” is built, tooth surface friction characteristic parameters(friction coefficients) are inversely analyzed by the composite model under different lubrication conditions. The problem of complicated tooth friction coefficients is solved. The calculation method is a new idea on solving friction characteristic parameters under complex lubrication conditions, it unites theoretical research, system modeling, numerical simulation and experimental test, so its solution is more reasonable. Exactly research friction coefficients can help to search gear friction principle and to upgrade the level of decrease noise and vibration of gear.

English

Solar energy is a green and attractive renewable energy source that can be converted for power generation. The objective of this work is to evaluate the potential of dish Stirling systems if they are used in the fourth worldwide largest island of Madagascar. For that purpose, a theoretical model of the dish Stirling system based on the geometrical configuration and heat transfer was developed and coded on Matlab. Simulations were run to investigate the energy efficiency variation of the system for eight main sites in Madagascar. As results, the proposed model enables to represent the system thermal behaviour to assess its efficiency. Among the eight studied sites, those which are on the coastal zones are more propitious to the dish Stirling system. While, in the north and northwest, the sites of Diego Suarez and Majunga present high efficiencies with, respectively, 31.65(%) and 31.07(%), it is in the south in fort-dauphin that thermal efficiency rate is maximal with 32.17(%). Convincing results that suggest that the implementation of this kind of facility will solve a large part of energy supply problems in these regions.

Stability of Distribution of Relative Sizes of Banks as an Argument for the Use of the Representative Agent Concept

We propose a new theoretical model of the large-scale banking system of an open economy. It is shown that distribution of relative sizes of individual banks is stable over time and does not depend on the volume of deposits. Our findings provide an additional argument in favor of use of the representative agent concept in banking sector modeling.Empirical testing shows that using generalized versions of Pareto and Normal distribution, distributions of relative sizes can be approximated with high accuracy and, moreover, distributions are stable over time. Moreover, banks move within this distribution, thus distribution of the general population of banks is stable over time.

Theoretical model and implementation of a real time intelligent bin status monitoring system using rule based decision algorithms

Due to the rising trend of urbanization along with overconsumption of non-recyclable resources, the volume of municipal solid waste is increasing every day. An efficient, cost effective and environment friendly solution for real time bin status monitoring, collection and transportation of municipal solid waste is still a major challenge to the local municipal authorities. This research proposes a novel model, architecture and intelligent sensing algorithm for real time solid waste bin monitoring system that would contribute to the solid waste collection optimization. The monitoring application is based on decision algorithms for sensing solid waste data in a wireless sensor network. The system is built on a three level architecture like smart bin, gateway and control station. The elementary concept is that, smart bins collect their status when any changes occur and transmit the status data to a server via an intermediate coordinator. A set of applications in server presents the updated bin status on real time. The field test performances show that the system can efficiently monitor real time bin status that makes it feasible to decide, which bin should collect and which should not. Thus the proposed system has achieved its goal to provide real time bin status information to the solid waste management operator. Later, this information can be used for collection route optimization to reduce collection costs and carbon emissions which in turn contribute to build green society.

A Justificação Ética da Tese da Separação entre o Direito e a Moral em John Austin

O jurista britânico John Austin está inserido no limiar do desenvolvimento da tradição juspositivista. Sua obra, que data da primeira metade do século XIX, foi especialmente importante para a fixação dos elementos básicos dessa vertente do pensamento jurídico. Entre suas contribuições para a doutrina juspositivista está a sua formulação da tese da separação entre o direito e a moral. No âmbito ético, por seu turno, John Austin foi um fervoroso utilitarista e defendeu a utilização do princípio da utilidade como o único critério racional para o desvelamento das normas morais superiores (as leis divinas). Considerando essas duas dimensões do seu pensamento, há muito se questiona se a sua ética utilitarista teria influenciado, de algum modo, a sua teoria jurídica, especialmente no que tange à tese da separação. Esta última, que está no centro da tradição juspositivista, tem sido interpretada de diferentes modos no debate jurídico contemporâneo. Uma vertente em especial, o chamado positivismo ético, abriu novas perspectivas para o estudo dessa tradição, ao defender a teoria juspositivista como um modelo teórico moralmente satisfatório para os sistemas jurídicos contemporâneos. Desse modo, utilizando a premissa central do positivismo ético (de que existem razões morais para a defesa da tese da separação) como instrumento metodológico- interpretativo, pretende-se retomar a questão da relação entre as convicções éticas e jurídicas de John Austin, a fim de compreender quais foram as razões morais que o levaram a defender a separação entre o que é o direito e aquilo que ele deveria ser.

Construction of the Model of Health Tourism Innovativeness

Innovation in tourism is a response to the growing public demand to live a long life, remain healthy and retain beauty and good form. The main goal of the paper is to create a theoretical model of the health tourism innovativeness system. The paper is novel in character, since to date the innovations occurring in health tourism have not been classified and there is no model of this innovativeness. The article presents the results of an expert poll, which was carried out in two rounds using the Delphi method. The result of research is construction of three different models of health tourism innovativeness. The paper fills the gap in the theory of management science.

Strongly Interacting Few-Fermion Systems in a Trap

Few- and many-fermion systems on the verge of stability, and consisting of strongly interacting particles, appear in many areas of physics. The theoretical modeling of such systems is a very difficult problem. In this work we present a theoretical framework that is based on the rigged Hilbert space formulation. The few-body problem is solved by exact diagonalization using a basis in which bound, resonant, and non-resonant scattering states are included on an equal footing. Current experiments with ultracold atoms offer a fascinating opportunity to study universal properties of few-body systems with a high degree of control over parameters such as the external trap geometry, the number of particles, and even the interaction strength. In particular, particles can be allowed to tunnel out of the trap by applying a magnetic-field gradient that effectively lowers the potential barrier. The result is a tunable open quantum system that allows detailed studies of the tunneling mechanism. In this Contribution we introduce our method and present results for the decay rate of two distinguishable fermions in a one-dimensional trap as a function of the interaction strength. We also study the numerical convergence. Many of these results have been previously published (R. Lundmark, C. Forss\'en, and J. Rotureau, arXiv: 1412.7175). However, in this Contribution we present several technical and numerical details of our approach for the first time.

Cationic gold clusters ligated with differently substituted phosphines: effect of substitution on ligand reactivity and binding.

We present a systematic study of the effect of the number of methyl (Me) and cyclohexyl (Cy) functional groups in monodentate phosphine ligands on the solution-phase synthesis of ligated sub-nanometer gold clusters and their gas-phase fragmentation pathways. Small mixed ligand cationic gold clusters were synthesized using reactions between pre-formed triphenylphosphine ligated (PPh3) gold clusters and monodentate Me- and Cy-substituted phosphine ligands in solution and characterized using electrospray ionization mass spectrometry (ESI-MS) and collision-induced dissociation (CID) experiments. Under the same experimental conditions, larger gold-PPh3 clusters undergo efficient exchange of unsubstituted PPh3 ligands for singly Me- and Cy-substituted PPh2Me and PPh2Cy ligands. The efficiency of reaction decreases with an increasing number of Me or Cy groups in the substituted phosphine ligands. CID experiments performed for a series of mixed-ligand gold clusters indicate that loss of a neutral Me-substituted ligand is preferred over loss of a neutral PPh3 ligand while the opposite trend is observed for Cy-substituted ligands. The branching ratio of the competing ligand loss channels is strongly correlated with the electron donating ability of the phosphorous lone pair as determined by the relative proton affinity of the ligand. The results indicate that the relative ligand binding energies increase in the order PMe3 < PPhMe2 < PPh2Me < PPh3 < PPh2Cy < PPhCy2 < PCy3. Furthermore, the difference in relative ligand binding energies increases with the number of substituted PPh(3-m)Me(m) or PPh(3-m)Cy(m) ligands (L) on each cluster. This study provides the first experimental determination of the relative binding energies of ligated gold clusters containing differently substituted monophosphine ligands, which are important to controlling their synthesis and reactivity in solution. The results also indicate that ligand substitution is an important parameter that must be considered in theoretical modeling of these complex systems.

Governance of payment systems: a theoretical framework and cross-country comparison

We develop and test the effectiveness of a theoretical governance model for general-purpose payment systems (GPPSs), systems that are used by individuals, businesses and merchants, as well as state, local and federal government entities, to make and receive payments. The model has characteristics found in the governance of large technical systems, whose complexity calls for local operational management and direction, and groups of operationally dissimilar organizations that must cooperate closely to form a network. Five reference countries and the single-currency euro area are placed into one of two groups based on the degree to which their GPPS governance aligns with the model. We test for effective governance across the six reference entities using measures that are based on evolving regulatory norms. We find that payment system governance in Australia, the euro area and the United Kingdom aligns with the theoretical model, and that their governance is effective. Payment system governance in Japan, Canada and the United States does not align with the theoretical model and is shown not to be effective according to the measures. Our findings indicate that government authorities are being increasingly called on to set and oversee the accomplishment of public policy objectives, and that their involvement is consistent with effective governance. We conclude that the theoretical governance model, while not necessarily normative, is strongly consistent with the evolving regulatory norms of effective payment system governance.

DESIGN AND TESTING OF AUTOMOBILE EXHAUST SYSTEM

The aim of this paper is to provide deeper understanding of the dynamics of automobile exhaust system to provide a basis for the improved design & development of computationally inexpensive theoretical system model. Modeling, simulation & experimental investigation of a typical exhaust system are performed to gain such an understanding & to evaluate modeling ideas. These models incorporate adjustable flexibility in their connection to the exhaust pipes & a procedure is developed for automatic updating of these parameters to obtain better correlation with experimental results. The agreement between the simulation results of the updated models & experimental results is very good, which confirms the usability of these models. The main objective of this project is to design exhaust system and to compare its performance with an existing system available. The newly designed exhaust system shows lower back pressure which ultimately results better performance of the engine. Low vibration levels are critical to achievee in automobile exhaust system . It is therefore important design engineers to be able to predict, explain & assess the dynamics of various system design proposals during product development.

The Dynamic Modeling and Vibration Analysis of the Large-Scale Thread Whirling System Under High-Speed Hard Cutting

□ This research took the large-scale thread whirling system as the object, to study the effect of supporting and holding way on the dynamic response of the workpiece system. Considering the specialties of large-scale thread whirling system and high-speed hard cutting technology, the theoretical dynamic model of the workpiece system was set up based on the Generalized Polynomial Assumed Mode Method after simulating cutting force by Deform 3D. Then, the natural frequency and the dynamic response characteristic were analyzed through solving the dynamic model with the Runge–Kutta method; the effect of hold devices as well as cutting position on the natural frequency of workpiece system were studied; and the vibration suppression capability of system damping and holding stiffness were also discussed. In the end, the large-scale thread whirling experiment was carried out to study the relationships between holding parameter, vibration amplitude and roughness. The results show that floating rests, holding stiffness and system damping play important roles in the vibration suppression during thread whirling process, and it is appropriate to set the holding ratio between 40% and 50% or between 65% and 70% in this case to improve machining quality.

Performance study on a dye-sensitized solar cell and thermoelectric hybrid power system

A theoretical model of the dye-sensitized solar cell-thermoelectric hybrid power system is established, which is composed of the dye-sensitized solar cell module and thermoelectric generator module. Based on the theory of non-equilibrium thermodynamics, the expressions for the power output and efficiency of the hybrid power generator system are derived. The general performance characteristics of the hybrid system are analyzed. The optimally operating conditions of the hybrid system at the maximum output power and efficiency are determined. The influence of some main performance parameters on the performance characteristics of the hybrid system are discussed in detail. The results show that the low grade waste heat of the dye-sensitized solar cell module can be effectively used by the thermoelectric generator and the power output and efficiency of the hybrid system can be improved. The results obtained in this paper may provide theoretical significances for the design and optimal operation of practical dye-sensitized solar cell-thermoelectric hybrid power generator system.

Characteristics of bottom-simulating reflectors for Hydrate-filled fractured sediments in Krishna–Godavari basin, eastern Indian margin

The bottom-simulating reflector (BSR) is weak and patchy on the seismic section in the Krishna–Godavari basin, eastern Indian margin, where massive gas-hydrates have been recovered at Site 10 of the Indian National Gas-hydrates Program Expedition 01 (NGHP-01). The depth of the BSR near this site is around 160 m below the sea floor (mbsf). The average reflection coefficient from the BSR is −0.06, significantly smaller than the common global values of −0.1 to −0.2. The BSR shows a strong lateral variation in amplitudes along the seismic line due to the presence of faults. The methane solubility is modeled using a theoretical model of the gas-hydrates system, and methane concentrations from the pressure core show that the distribution of free gas below BSR is not uniform. A combination of synthetic seismogram analysis and rock physics modeling leads to the conclusion that weak and patchy BSRs are primarily caused by lateral discontinuities induced by the gas-filled fractures below BSRs. The free gas zone is thin and it shows segmented characteristics on the seismic section and acoustic impedance profile that we inverted. Fault zones increase the permeability and therefore trap gas in associated fractures that can scatter seismic energy and create low velocity zones.

Governance of Payment Systems: A Theoretical Framework and Cross-Country Comparison

We develop and test the effectiveness of a theoretical governance model for general purpose payment systems (GPPS), systems that are used by individuals, businesses and merchants, and state, local and federal government entities to make and receive payments. We test for effective governance across six reference countries using measures that are based on evolving regulatory norms, finding that governance in Australia, the European Union, and the United Kingdom aligns with the theoretical model, and that their governance is effective. Payment system governance in Japan, Canada, and the United States does not align with the theoretical model, and is shown not to be effective according to the measures. Our findings indicate that national government is being called on increasingly to set and oversee the accomplishment of public policy objectives, and that their involvement is consistent with effective governance.

Performance optimization of a solid oxide fuel cell-stirling heat engine hybrid power system

Based on the theory of the electrochemistry, non-equilibrium thermodynamics and finite-time thermodynamics, a new theoretical model of the hybrid power system consisting of an existing solid oxide fuel cell and a Stirling heat engine is established, in which some main irreversible losses existing real hybrid systems are taken into account. Expressions for the power output and efficiency of the hybrid system are derived from this model. The maximum power output and maximum efficiency of the hybrid system and the operating conditions of the maximum power output and maximum efficiency are determined. The optimally working regions of the hybrid system are given. The influences of some cyclic irreversibilities on the optimal performance of the system are discussed in detail. The best matching relationship between an existing solid oxide fuel cell and a Stirling heat engine is discussed. All the results obtained in this paper will provide some theoretical basis for the design and optimal operation of practical fuel cell-Stirling heat engine hybrid system.

Mechanical passive logic module

Nothing from nothing gives simple simile, but something from nothing is an interesting and challenging task. Adolf Lohmann once proposed ‘do nothing machine’ in optics, which only copies input to output. Passive logic module (PALM) is a special type of ‘do nothing machine’ which can converts inputs into one of 16 possible binary outputs. This logic module is not like the conventional irreversible one. It is a simple type of reversible Turing machine. In this manuscript we discussed and demonstrated PALM using mechanical movement of plane mirrors. Also we discussed the theoretical model of micro electro mechanical system (MEMS) based PALM in this manuscript. It may have several valuable properties such as passive operation (no need for nonlinear elements as other logic device require) and modular logic (one device implementing any Boolean logic function with simple internal changes). The result is obtained from the demonstration by only looking up the output. No calculation is required to get the result. Not only that, PALM is a simple type of the famous ‘billiard ball machine’, which also discussed in this manuscript.

Molecular Imaging of the Breast Using a Variable-Angle Slant-Hole Collimator

Purpose: The purpose of this work is to develop an improved method for 3D molecular imaging of the breast using limited angle SPECT. Methods: The proposed method uses a variable-angle slant-hole (VASH) collimator. Rather than rotate the camera around the breast, the VASH collimator allows limited angle, tomographic acquisition while the detector remains stationary and flush against the compression paddle. This design minimizes object-to-detector distance for high spatial resolution. Theoretical analysis is presented of VASH spatial resolution and sensitivity, including depth-of-interaction (DOI) effects and magnification. The theory is compared with Monte Carlo simulation results for a point source and breast phantom including a compression paddle. An iterative reconstruction method for the slant hole data is used. Results: The theoretical model of the VASH system showed good agreement with Monte Carlo simulations based on spatial resolution, including DOI effects, and sensitivity. For 140 keV photons and a NaI(Tl) scintillator, the DOI effect resulted in roughly a 2 mm loss in spatial resolution only in depth dimension; in the other two dimensions the spatial resolution was not affected by DOI. In reconstructed breast phantom images, VASH out-performed a parallel hole SPECT approach in terms of contrast-to-noise ratio. Conclusions: The proposed method for breast imaging using limited angle SPECT and a VASH collimator demonstrated the potential for superior spatial resolution/sensitivity. In addition to high spatial resolution/sensitivity, the system design has advantages of simple detector motion, ability to image close to the chest wall and conducive to on-board biopsy and multi-modal imaging with mammography.

Identification of active magnetic bearing system with a flexible rotor

Active magnetic bearings (AMBs) are widely applied in high-speed rotating machinery, especially in special environments. In designing and adjusting an AMB system, the mathematical model of the system plays an important role. Identification is a useful method to obtain the models of AMB systems. This paper concentrates on identification method for an AMB system with a flexible rotor. Based on the theoretical system model and the measured frequency–response model, the proposed method estimates the unknown parameters and establishes the transfer function matrix model of the AMB system. According to the theoretical model, this paper decomposes the identification procedure into a few steps and the model is sequentially reduced by these steps. In this procedure, the submodels are identified separately and finally combined together. The proposed method is validated by experiments on three AMB systems.

Efficient techniques of key management and quantum cryptography in RFID networks

An efficient way of handling security keys using quantum cryptography QC for increasing security in radio frequency identification RFID networks is being investigated by network security industries. To establish secure RFID network, communication between any two nodes that hold RFID tags and/or readers merged with existing networks should be protected. In order to maximize the data security and secure transmission around RFID network, theoretical model of the quantum key management KM system based on RFID is introduced as a proposed research. This model not only manages the secure keys but also it defends passive eavesdropping attacks and other potential attacks. Novelties in this research are security keys of which QC is being utilized in RFID network with continuous key updates. To establish future security around RFID networks, efficient KM protocol and QC, which deal with quantum mathematical procedures and quantum physics, should be analyzed without affecting the legacy. Computational complexities in KM are increasing with the large key sizes, which are manageable through QC. To maximize the security and minimize the complexity in KM, QC with Grover's algorithm is introduced as a method in RFID network environments. So, we have proved that a number of operations with key sizes obtained in KM are reduced. In this proposal, QC will help to reduce the complexity of algorithms used in KM protocols and maximize the security. Copyright © 2014 John Wiley & Sons, Ltd.