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This paper aims to apply He's homotopy perturbation method (HPM) to obtain solitary solutions for the nonlinear dispersive equations with fractional time derivatives.

The authors choose as an example the nonlinear dispersive and equations with fractional time derivatives to illustrate the validity and the advantages of the proposed method.

The paper extends the application of the HPM to obtain analytic and approximate solutions to the nonlinear dispersive equations with fractional time derivatives.

This paper extends the HPM to the equation with fractional time derivative.

The study aims to examine the effect of knowledge management strategy (KMS) on knowledge-sharing behavior (KSB) and its subsequent effect on knowledge performance (KP). It also throws light on the mediating role of KM enablers (KMEs) and KSB.

In purview of previous literature, several hypotheses were framed. Structural equation modeling (SEM) using SPSS 20, PROCESS macro and AMOS 20 was used to examine the research hypotheses in a sample of empirical data collected from 350 employees of information technology (IT) service provider firms.

This paper empirically proves the existence of mediation effect of the proposed mediators (KME, KSB) between predictors (KMS, KSB) and outcomes (KSB, KP) in different hypothesized relationships. Result provides empirical evidence toward the positive influence of KMS dimensions (internal-oriented KMS, external-oriented KMS) on KSB and also confirms the influence of KSB on KP.

This study examines the effect of KMS and KSB on KP with reference to the IT sector, thereby limiting generalization to other sectors. Practical and managerial implications have been discussed in the later sections of the study.

This study adds value to the existing KM literature by adjoining the links among knowledge strategy, sharing behavior and performance.

WHEN the temperature of the gas reaches the high level, the molecules begin to break up into atoms or groups of atoms, which after recombination form new and smaller molecules of a simpler structure. For instance, tri‐atomic molecules after having been split form diatomic ones. This process is called the dissociation of gases. The newly‐formed molecules, when colliding, again form molecules of the original gas, so two processes are occurring simultaneously. However, the higher the temperature, the larger the percentage of dissociated molecules.

This study aims to examine the value of the call option contract in hedging the risks in the supply chain. The decentralized supply chain without call option contract is first studied as the criterion model for evaluations. This paper addresses several questions: What will be the optimal manufacturer’s production quantity, retailer’s ordering and pricing policies in the presence of random demand and random yield by applying the downconversion approach? How will the call option contract influence the optimal decisions for the members of the supply chain? Can the risk from randomness be divided among the members in the supply chain through the call option contract?

This paper considers a two-level decentralized supply chain under random yield and random demand in which the manufacturer takes advantage of the downconversion approach with two scenarios, with and without option contract. To the best of the authors’ knowledge, no article or study uses the downconversion approach in a supply chain regarding random yield and random demand. Furthermore, the paper considers pricing with option contract in the supply chain, which makes this article stands out significantly from other articles in the literature.

This study shows that the downconversion approach would reduce the risk caused by the random yield, which appears to be the appropriate method for the environmental goal of the supply chains. Moreover, adopting a call option contract can increase flexibility and mitigate risks, resulting in more expected members’ profits.

To simplify the model, the authors assume one manufacturer and one retailer, so extending the model to consider multiple retailers instead of one retailer and inventory sharing between them would be interesting. Considering the option and exercise prices as decision variables would be important future research topics. Put option and bidirectional option contracts could be investigated in the future. Another extension is modeling asymmetry of information in supply chain.

This paper provides managerial insights on dealing with both demand and yield risks in a manufacturer–retailer supply chain. The manufacturer has a random yield production and produces two types of vertical products: low-end and high-end. To reduce waste caused by the random yield, the manufacturer uses a downconversion approach in which low-end products are made by converting the defective high-end products. The manufacturer purchased a shortage of high-end products from the secondary market (i.e. emergency sourcing). High-end products are sold through the retailer, and low-end products are sold directly by the manufacturer. The customer demand for high-end products in the end market is random and depends on the selling price, and the customer demand for the low-end products in the secondary market is independent and random. The retailer contracts the manufacturer with the call option to obtain high-end products to meet a random demand; in fact, by using the call option contract, the authors try to balance the risks between two members. Two scenarios of with and without call option contract are proposed. After the high-end product demand is observed, the retailer would exercise the option order quantity in the call option contract scenario and then place an instant order with the manufacturer if necessary. In each scenario, the manufacturer and the retailer make their decisions simultaneously (static game) to determine the retailer’s optimal ordering and pricing policies and the optimal production quantity of the manufacturer (Nash equilibrium) by maximizing their expected profits. Finally, the impact of the model parameters on the supply chain is expressed through numerical examples. The numerical analysis shows that the call option contract provides greater profit than the wholesale price contract.

The aim of this paper is to develop a detailed descriptive model for kitting operations, allowing resources sizing and computation of systems’ economic performances.

A mathematical model allows to size resources, given product characteristics and production mix, and determines total system costs by assessing relevant cost items including investment costs (vehicles, containers, storage racks), direct operating costs (transport and kitting workforce, vehicles energy consumption and maintenance, quality costs), indirect operating costs (space requirements, work in process (WIP) and safety stock holding costs, administration and control).

The choice of parts delivery supply to assembly lines requires a thorough economic comparison of alternatives. However, existing models are often simplistic and neglect many critical factors which affect the systems’ performances. As a consequence, industries are unsure about which system is best for their environment. This model allows assessment of the cost and suitability of kitting in any specific industrial setting. Results of the model application are case-specific and cannot be generalized, but the major impact of labour and error correction cost has been highlighted.

The model at present focusses on the in-house kitting systems based on travelling kits concept only. Although all quantitative cost drivers are included, some context-related qualitative decision factors are not yet included. The model assumes that the information about product structure and part requirements is known and that a preliminary design of the assembly system (i.e. line balancing) has been carried out.

Production managers are given a quantitative decision tool to properly assess the implementation of kitting policies at an early decision stage. This allows exploring the trade-offs between the alternatives and properly planning the adoption of kitting systems, as well as comparing kitting with alternative material supply methods.

With respect to previous simplified literature models, this new approach allows quantification of a number of additional factors which are critical for successful implementation of cost-effective kitting systems, including kitting errors. An exhaustive cost estimation of kitting systems in multiple, mixed-model assembly lines is thus permitted.

Based on the Jones (1971) model, we construct two dynamic models of international trade in which the rate of time preference is either constant or time-varying. The main purpose is to study whether and under what conditions the results derived in the Jones model still hold in the dynamic framework. It is shown that the results of dynamic models may be similar or different to those obtained in the static model. For example, it is possible that, in both static and dynamic models, an increase in the commodity price raises this commodity's output and the return to the specific factor in this sector. However, the effects on the wage rate may be different due to the factor accumulation impact in the dynamic framework.

The purpose of this paper is to propose a two-degrees-of-freedom wire-driven 4SPS/U rigid‒flexible parallel trunk joint mechanism based on spring, in order to improve the robot’s athletic ability, load capacity and rigidity, and to ensure the coordination of multi-modal motion.

First, based on the rotation transformation matrix and closed-loop constraint equation of the parallel trunk joint mechanism, the mathematical model of its inverse position solution is constructed. Then, the Jacobian matrix of velocity and acceleration is derived by time derivative method. On this basis, the stiffness matrix of the parallel trunk joint mechanism is derived on the basis of the principle of virtual work and combined with the deformation effect of the rope driving pair and the spring elastic restraint pair. Then, the eigenvalue distribution of the stiffness matrix and the global stiffness performance index are used as the stiffness evaluation index of the mechanism. In addition, the performance index of athletic dexterity is analyzed. Finally, the distribution map of kinematic dexterity and stiffness is drawn in the workspace by numerical simulation, and the influence of the introduced spring on the stiffness distribution of the parallel trunk joint mechanism is compared and analyzed. It is concluded that the stiffness in the specific direction of the parallel trunk joint mechanism can be improved, and the stiffness distribution can be improved by adjusting the spring elastic structure parameters of the rope-driven branch chain.

Studies have shown that the wire-driven 4SPS/U rigid‒flexible parallel trunk joint mechanism based on spring has a great kinematic dexterity, load-carrying capacity and stiffness performance.

The soft-mixed structure is not mature, and there are few new materials for the soft-mixed mixture; the rope and the rigid structure are driven together with a large amount of friction and hindrance factors, etc.

It ensures that the multi-motion mode hexapod mobile robot can meet the requirement of sufficient different stiffness for different motion postures through the parallel trunk joint mechanism, and it ensures that the multi-motion mode hexapod mobile robot in multi-motion mode can meet the performance requirement of global stiffness change at different pose points of different motion postures through the parallel trunk joint mechanism.

The trunk structure is a very critical mechanism for animals. Animals in the movement to achieve smooth climbing, overturning and other different postures, such as centipede, starfish, giant salamander and other multi-legged animals, not only rely on the unique leg mechanism, but also must have a unique trunk joint mechanism. Based on the cooperation of these two mechanisms, the animal can achieve a stable, flexible and flexible variety of motion characteristics. Therefore, the trunk joint mechanism has an important significance for the coordinated movement of the whole body of the multi-sport mode mobile robot (Huang Hu-lin, 2016).

In this paper, based on the idea of combining rigid parallel mechanism with wire-driven mechanism, a trunk mechanism is designed, which is composed of four spring-based wire-driven 4SPS/U rigid‒flexible parallel trunk joint mechanism in series. Its spring-based wire-driven 4SPS/U rigid‒flexible parallel trunk joint mechanism can make the multi-motion mode mobile robot have better load capacity, mobility and stiffness performance (Qi-zhi et al., 2018; Cong-hao et al., 2018), thus improving the environmental adaptability and reliability of the multi-motion mode mobile robot.