Nonlinear wave dispersion in monoatomic chains with lumped and distributed masses:discrete and continuum models

The main objective of this paper is to investigate the influence of inertia of nonlinear springs on the dispersion behavior of discrete monoatomic chains with lumped and distributed masses.The developed model can represent the wave propagation problem in a non-homogeneous material consisting of heavy inclusions embedded in a matrix.The inclusions are idealized by lumped masses,and the matrix between adjacent inclusions is modeled by a nonlinear spring with distributed masses.Additionally,the model is capable of depicting the wave propagation in bi-material bars,wherein the first material is represented by a rigid particle and the second one is represented by a nonlinear spring with distributed masses.The discrete model of the nonlinear monoatomic chain with lumped and distributed masses is first considered,and a closed-form expression of the dispersion relation is obtained by the second-order Lindstedt-Poincare method(LPM).Next,a continuum model for the nonlinear monoatomic chain is derived directly from its discrete lattice model by a suitable continualization technique.The subsequent use of the second-order method of multiple scales(MMS)facilitates the derivation of the corresponding nonlinear dispersion relation in a closed form.The novelties of the present study consist of(i)considering the inertia of nonlinear springs on the dispersion behavior of the discrete mass-spring chains;(ii)developing the second-order LPM for the wave propagation in the discrete chains;and(iii)deriving a continuum model for the nonlinear monoatomic chains with lumped and distributed masses.Finally,a parametric study is conducted to examine the effects of the design parameters and the distributed spring mass on the nonlinear dispersion relations and phase velocities obtained from both the discrete and continuum models.These parameters include the ratio of the spring mass to the lumped mass,the nonlinear stiffness coefficient of the spring,and the wave amplitude.

Modeling urban land use dynamics using Markov-chain and cellular automata in Gondar City,Northwest Ethiopia

Modeling urban land-use dynamics is critical for urban experts’and infrastructure managers’planning.This study attempts to explore the land-use/land-cover(LULC)dynamics of Gondar using satellite images from 1984 to 2020.Markov-Chain and Cellular Automata(MC-CA)models have been recognized as performing well in predicting urban land-use change.However,only a few models work in Ethiopia in general,and no study in Gondar has applied this approach to study urban land-use patterns.Therefore,Gondar land-use/land cover changes of Gondar were predicted using the MC-CA model in IDRISI.The built-up area in Gondar city covered 1413 ha(3%of the total area)in 1984 and increased to 2380 ha(5%)in 1994;21153 ha(45.5%)in 2004;22622 ha(48.7%)in 2014;and 23427 ha(50.5%)in 2020.The area has been predicted to reach 57.5%in the 2050s,showing a faster increase that will cause a very vast loss of farmland.This will increase urban sprawl challenges as well as overall environmental disequilibrium in the preceding decade.Thus,innovative and careful structures and systems in urban planning are required to secure a sustainable urban future and to make our cities livable and competitive in the paradigm of sustainable cities.

A Study on the Factors Influencing Value-Added in the Cruise Ship Value Chain Based on the DEMATEL-ISM Model

Cruise value chain is to take the exchange of cruise products and services as the core in a certain spatial scope,and enterprises with core advantages within or between different industries establish associations in accordance with certain technical and economic conditions,so as to realise the multi-dimensional extension and value appreciation of the cruise value chain in the vertical and horizontal links,and ultimately establish a chain-network type of enterprise strategic alliance.This paper tries to analyse the value-added factors of the cruise industry chain by constructing a multi-level hierarchical structural model with reference to the influencing factor analysis methods of relevant literature-DEMATEL(Decision Making Experiment and Evaluation Experiment)and ISM(Interpretative Structural Model).The study shows that the innovation and scale value-added module in the upstream of the cruise industry chain is the core module of value-added of the whole cruise industry chain,and the value-added mainly originates from the design and manufacturing of cruise ships.The middle reaches of the cruise industry chain are mainly cruise operation enterprises,and the specificity of cruise operation determines that its brand value-added is mainly accomplished through the global layout of multinational corporations,and the cruise brand is able to drive the consumption demand and has value-added ability.The downstream value-added of the cruise industry chain is mainly realised through the increase in profits of cruise tourism service products.

A dynamic food-chain model and program for predicting the consequences of nuclear accident

ＡｄｙｎａｍｉｃｆｏｏｄｃｈａｉｎｍｏｄｅｌａｎｄｐｒｏｇｒａｍｆｏｒｐｒｅｄｉｃｔｉｎｇｔｈｅｃｏｎｓｅｑｕｅｎｃｅｓｏｆｎｕｃｌｅａｒａｃｉｄｅｎｔＨｕＥｒｂａｎｇ，ＧａｏＺｈａｎｒｏｎｇ，ＺｈａｎｇＨｅｙｕａｎ，ＷｅｉＷｅｉｑｉａｎｇ...

Analysis of Supply Chain Model of Agricultural Products and Quality Safety——A Case Study of Heilongjiang Province

This paper analyses the supply chain models of four types of agricultural products,namely fruits and vegetables,poultry,aquatic products and dairy,and the food safety problems arising from the links of supply chain.In view of different models,corresponding suggestions are put forward to ensure the quality safety of agricultural products in Heilongjiang Province.

电子商务网站的关键信息要素分析——基于消费者购买决策过程理论和Means-End Chain理论

本文以消费者购买决策过程理论和手段目的理论为基础,对电子商务网站的关键要素进行界定和分析,并希望基于此能为实现一个网站的全面信息化、便捷化、安全高效化提供重要的理论依据,从而更好地为广大消费者服务。

Green Investment Cost Optimization Model in the Supply Chain

The objective of this study is to develop a model that determines the optimal points for investment in green management by defining a mathematical relationship between carbon trading profits and investments in green management using a company’s supply chain information. To formulate this model, we first define and analyze a green supply chain in a multi-dimensional and quantitative manner. The green investment alternatives considering in our model are as follows: 1) purchasing eco-friendly raw materials that cost more than conventional raw materials but whose use in production results in lower CO2 emissions;2) replacing current facilities with new eco-friendly facilities that have the capability to reduce CO2 emissions;and 3) changing modes of transport from less eco-friendly to more eco-friendly modes. We propose a green investment cost optimization (GICO) model that enables us to determine the optimal investment points. The proposed GICO model can support decision-making processes in green supply chain management environments.

Correctness and accuracy of template-based modeled single chain fragment variable (scFv) protein anti-breast cancer cell line (MCF-7)

Multiple sequence alignments can be used in the template-based modelling of protein structures to build fragment-based assembly models. Therefore, useful functional information on the 3D structure of the anti-MCF-7 scFv protein can be obtained using available bioinformatics tools. This paper utilises several commonly-used bioinformatics tools and databases, including BLAST (Basic Local Alignment Search Tool), GenBank, PDB (Protein Data Bank), KABAT numbering and SWISS-MODEL, to gain specific functional insights into the anti-MCF-7 scFv protein and the assembly of single-chain fragment variable (scFv) antibodies, which consist of a variable heavy chain (VH) and a variable light chain (VL) connected by the linker (Gly4-Ser)3. The linker has been built as a loop structure using the Insight II software. The accuracy of the loop structure has been evaluated using Root Mean Square Deviation (RMSD). The accuracies of the VL and VH template-based structures are enhanced by using the evaluation methods Verify3D, ERRAT and Ramchandran plotting, which measure the error in the residues. In the results, 100% of the light-chain residues scored above 0.2, whereas 88.5% of the heavy-chain residues’ scored above 0.15 in the Verify3D evaluation method. Meanwhile, using ERRAT, the alignments of both chains scored more than 70% in space. Additionally, the Ramchandran plot evaluation method showed large numbers of residues in the favoured areas in both chains;these findings demonstrated that all of the chosen templates were the best candidates.

Transverse relaxation characteristic and stress relaxation model considering molecular chains of HTPB coating based on pre-strained thermal aging

In order to accurately describe the transverse relaxation characteristic and stress relaxation modulus of HTPB coating during pre-strain thermal aging process,a one month thermal aging test was carried out at70C with pre-strain of 0%,3%,6%and 9%,respectively.The low-field1 H NMR and stress relaxation modulus tests were carried out for HTPB coating at different aging stages.The stress relaxation model considering the molecular chains was proposed according to the changes of crosslinking chain and dangling chain of HTPB coating during pre-strain aging.The results showed that with the increase of aging time,the decay rate of transverse relaxation curve became faster,the transverse relaxation time decreased,the value of combined parameter q Mrl increased,the proportion of crosslinking chain decreased,while the proportion of dangling chain increased.Moreover,the stress relaxation modulus increased,the crosslinking network structure of HTPB coating became denser and the degree of crosslinking increased.At the initial aging stage,the pre-strain will destroy the crosslinking network structure of HTPB coating to a certain extent.With the increase of aging time,the effect of pre-strain will gradually weaken and the influence of aging on materials will gradually increase.The correlations between the stress relaxation model considering the molecular chains and the test results were more than 0.9950,which can accurately describe the stress relaxation modulus of HTPB coating during the pre-strain thermal aging process.

A joint inventory–finance model for coordinating a capital‑constrained supply chain with financing limitations

Faced with economic recession,firms struggle to find ways to stay competitive and maintain market share.Effective coordination of the supply chain can solve this problem,but this may fail if existing capital constraints and financial flows are ignored.This study addresses the challenge by exploiting coordination through joint decision-making on the physical and financial flows of a capital-constrained supply chain.We also consider the capital-constrained member’s financing limitations that lead to lost sales.Two scenarios based on non-coordinated and coordinated structures are modeled in the form of bi-objective optimization problems that simultaneously optimize system costs and service levels.The models are solved using the -constraint method.The results indicate that the non-coordinated model cannot satisfy more than about 50%of the demand due to capital shortage and financing limitations,while the coordinated model can satisfy all of the demand via internal financing.Furthermore,the proposed coordination scheme leads to cost reduction for the members and the total system.To motivate all members to accept the proposed coordination scheme,a cost-sharing mechanism is applied to the coordination procedure.Finally,a sensitivity analysis concerning financial parameters is provided for validating the coordination model.

Dynamic Modeling of a Roller Chain Drive System Considering the Flexibility of Input Shaft

Roller chain drives are widely used in various high-speed, high-load and power transmission applications, but their complex dynamic behavior is not well researched. Most studies were only focused on the analysis of the vibration of chain tight span, and in these models, many factors are neglected. In this paper, a mathematical model is developed to calculate the dynamic response of a roller chain drive working at constant or variable speed condition. In the model, the complete chain transmission with two sprockets and the necessary tight and slack spans is used. The effect of the flexibility of input shaft on dynamic response of the chain system is taken into account, as well as the elastic deformation in the chain, the inertial forces, the gravity and the torque on driven shaft. The nonlinear equations of movement are derived from using Lagrange equations and solved numerically. Given the center distance and the two initial position angles of teeth on driving and driven sprockets corresponding to the first seating roller on each side of the tight span, dynamics of any roller chain drive with two sprockets and two spans can be analyzed by the procedure. Finally, a numerical example is given and the validity of the procedure developed is demonstrated by analyzing the dynamic behavior of a typical roller chain drive. The model can well simulate the transverse and longitudinal vibration of the chain spans and the torsional vibration of the sprockets. This study can provide an effective method for the analysis of the dynamic characteristics of all the chain drive systems.

Grey Markov chain and its application in drift prediction model of FOGs

A novel grey Markov chain predictive model is discussed to reduce drift influence on the output of fiber optical gyroscopes (FOGs) and to improve FOGs’ measurement precision. The proposed method possesses advantages of grey model and Markov chain. It makes good use of dynamic modeling idea of the grey model to predict general trend of original data. Then according to the trend, states are divided so that it can overcome the disadvantage of high computational cost of state transition probability matrix in Markov chain. Moreover, the presented approach expands the applied scope of the grey model and makes it be fit for prediction of random data with bigger fluctuation. The numerical results of real drift data from a certain type FOG verify the effectiveness of the proposed grey Markov chain model powerfully. The Markov chain is also investigated to provide a comparison with the grey Markov chain model. It is shown that the hybrid grey Markov chain prediction model has higher modeling precision than Markov chain itself, which prove this proposed method is very applicable and effective.

Rheological Behaviour for Polymer Melts and Concentrated Solutions Part Ⅰ:A New Multiple Reptation Model to Predict the Nonlinear Visco-elasticity with Nagai Chain Constraints in Entangled Polymer Melts

An approach of stochastically statistical mechanics and a unified molecular theory of nonlinear viscoelasticity with constraints of Nagai chain entanglement for polymer melts have been proposed. A multimode model structure for a single polymer chain with n tail segments and N reversible entanglement sites on the test polymer chain is developed. Based on the above model structure and the mechanism of molecular flow by the dynamical reorganization of entanglement sites, the probability distribution function of the end-to-end vectr for a single polymer chain at entangled state and the viscoelastic free energy of deformation for polymer melts are calculated by using the method of the stochastically statistical mechanics. The four types of stress-strain relation and the memory function are derived from this thery. The above theoretical relations are verified by the experimentaf data for various polymer melts. These relations are found to be in good agreement with the experimental

A dynamic optimization model of an integrated coal supply chain system and its application

Various nodes,logistics,capital flows,and information flows are required to make systematic decisions concerning the operation of an integrated coal supply system. We describe a quantitative analysis of such a system. A dynamic optimization model of the supply chain is developed. It has achieved optimal system profit under conditions guaranteeing a certain level of customer satisfaction. Applying this model to coal production of the Xuzhou coal mines allows recommendations for a more systematic use of washing and processing,transportation and sale resources for commercial coal production to be made. The results show that this model,which is scientific and effective,has an important value for making reasonable decisions related to complex coal enterprises.

A new grey forecasting model based on BP neural network and Markov chain

A new grey forecasting model based on BP neural network and Markov chain was proposed. In order to combine the grey forecasting model with neural network, an important theorem that the grey differential equation is equivalent to the time response model, was proved by analyzing the features of grey forecasting model(GM(1,1)). Based on this, the differential equation parameters were included in the network when the BP neural network was constructed, and the neural network was trained by extracting samples from grey system’s known data. When BP network was converged, the whitened grey differential equation parameters were extracted and then the grey neural network forecasting model (GNNM(1,1)) was built. In order to reduce stochastic phenomenon in GNNM(1,1), the state transition probability between two states was defined and the Markov transition matrix was established by building the residual sequences between grey forecasting and actual value. Thus, the new grey forecasting model(MNNGM(1,1)) was proposed by combining Markov chain with GNNM(1,1). Based on the above discussion, three different approaches were put forward for forecasting China electricity demands. By comparing GM(1, 1) and GNNM(1,1) with the proposed model, the results indicate that the absolute mean error of MNNGM(1,1) is about 0.4 times of GNNM(1,1) and 0.2 times of GM(1,1), and the mean square error of MNNGM(1,1) is about 0.25 times of GNNM(1,1) and 0.1 times of GM(1,1).

CONSIDER SAINT-VENANT'S PRINCIPLE BY MEANS OF CHAIN MODEL

A precise background theory of computational mechanics is formed. Saint_Venant’s principle is discussed in chain model by means of this precise theory. The classical continued fraction is developed into operator continued fraction to be the constrictive formulation of the chain model. The decay of effect of a self_equilibrated system of forces in chain model is decided by the convergence of operator continued fraction, so the reasonable part of Saint_Venant’s principle is described as the convergence of operator continued fraction. In case of divergence the effect of a self_equilibrated system of forces may be non_zero at even infinite distant sections, so Saint_Venant’s principle is not a common principle.

The Analysis of B2B Business Model from the Viewpoint of Value Chain

Electronic business impacts differently the busines s process in or between the corporations in variant degree. In view of the new fea tures of the internet, critical questions to be answered inclued: what are t he emerging business models and related to this, which strategic marketing appro aches are applied,or emerging. In the paper, the business models in B2B are clas sified into four types as e-procurement, e-marketplace, e-trade exchange, and collaborative trading community from the value viewpoint.And then the paper giv es the measure among the four business models by providing a framework that has been developed on the basis of current commercial Internet business and experime ntal work. The difference between the value chain in traditional commerce and th e one in e-business is compared. And we give the success factors by a case stud y and the barriers to electronic business in the developing B2B business model.

Reseach of Supply Chain Modeling Technology

The supply chain modeling technology is research. Firstly, the concept of supply chain and supply chain management is introduced. Secondly, enterprise modeling methods, such as CIM OSA, GIM GRAI, PERA and ARIS, are analyzed and compared. The supply chain modeling technology is studied. Then the ARIS based supply chain modeling method is proposed and the supply chain operation reference model is set up. Finally, the applications of ARIS based supply chain modeling method in Shanghai Turbine Generator Co. Ltd. (STGC) is described in detail.

Reengineering Model of Supply Chain of Tea Industry in Yunnan

Yunnan University of finance and Trade recording to t he statistics of chain’s output of tea, Yunnan province has entered the ranks of the larger ones of the production in China. Yunnan’s tea industry has the natur al resources and the economic effects envied, on the orther hand, Yunnan’s tea m arket has gradually become less and the economic effects have been poor. Through our comprehensive investigation and study, we consider that because the supply chain has seriously been disjointed among production, supply and sale of tea ind ustry in Yunnan, the supply chain of Yunnan’s tea industry need to be reorganize d for the promoting the development of Yunnan’s tea industry. The essence of reengineering of Yunnan’s tea industrial supply chain is to set u p the model of the trailed operation,to strengthen the strategic partnership man agement between the supply chain, to optimize the design of the supply chain and build up and improve the working mechanism for management of the tea industrial supply chain. The structure of Yunnan’s model of tea industrial supply chain: the model of com mercial flow; the model of logistics flow; the model of information flow and the model of cash flow. The solutions and policies for the reorganization of Yunnan’s tea industrial sup ply chain: planning, logistics and distribution and sales. Set up the supporting system of information technology. Build up the control system of production and planning.Improve the working mechanism of Yunnan’s tea industrial supply chain. Implement the engineering of exporting Yunnan’s tea into the markets of other p rovinces and foreign markets. Have many the channels that raise the funds of dev elopment for Yunnan’s tea industry.