The proposed study addresses a supplier-retailer inventory problem by considering the detrimental impacts of deterioration. The inventory produced by the supplier undergo a machine-shift and hence, produces non-conforming items. The retailer uses the preservation technology to deal with deteriorating items ingeniously where the demand is price-sensitive at the buyers end. Two models are developed through different means viz. Integrated and Bi-level approach and compared so to impart some constructive organizational insights. Sensitivity analysis was done over a numerical example to validate strength of the developed models.

This work considers cooperative advertising decisions in a manufacturer-distributor-retailer supply chain, where the manufacturer is taken as the Stackelberg leader, using differential game theory. The distributor and retailer are the first and the second followers, respectively. We introduce the distributor into the traditional manufacturer-retailer channel through his direct involvement in advertising as being incorporated into the non-stochastic Sethi's sales-advertising dynamics. This is used to model the awareness share dynamics in which the distributor and the retailer directly engage in advertising, while the manufacturer bypasses the distributor to subsidise only the retail advertising effort. We consider a subsidised and unsubsidised channel structures, where each structure results in a system of three nonlinear equations, which cannot be solved analytically, but only numerically. However, we show that the unique solution to each of the systems exists, provided certain conditions are satisfied. The distributor and the retailer's advertising strategies are developed for both when subsidy is provided and when it is not provided. We also obtain the manufacturer's subsidy rate and the market awareness share for both when retail advertising is subsidised and when it is not subsidised. We observe that with the provision of subsidy, the distributor reduces his advertising effort. However, the resulting increase in the retail advertising effort is larger than the reduction in the distributor's advertising commitment, thus making the channel advertising effort larger with subsidy. It further shows that to avoid being shortchanged, each player should adopt only his optimal strategy or strategies as the case may be.

Nowadays, environment is an important concern of industries parallel to the economy. In this direction, a joint vendor-buyer model is exhibited where the system reliability and inspection errors are discussed along with the carbon emission issue. The main goal of this model is to obtain the optimum investment, shipment size, reliability and lead time even the inspection errors present in the system. A reliability dependent unit production cost is utilized to raise the machinery system reliability. Transportation of products use the single-setup-multi-unequal-delivery (SSMUD) policy to reduce carbon emission. Mathematical problem is solved analytically and a quasi-closed-form solution is found. Total cost is minimized with the optimum level of decision variables. Globality of the decisions is proved by Hessian matrix. Results demonstrate that the total cost is minimized even though the optimum solutions are obtained in quasi-closed- form. Numerical example is elaborated to test the validity of the model and to clarify the comparison among SSSD, SSMD, and SSMUD policies.

The present work frames a pair of symmetric dual problems for second order nondifferentiable fractional variational problems over cone constraints with the help of support functions. Weak, strong and converse duality theorems are derived under second order F-convexity assumptions. By removing time dependency, static case of the problem is obtained. Suitable numerical example is constructed.

In this paper, models on concepts of radio frequency identification adoption (RFID), imperfect products reworking system, and trade credit for deteriorating inventory with / without utilizing the preservation investment technology are derived, which makes this article, a unique one. Estimation of optimal values of RIFD levels of investment for ordering, operating, just in time efficiencies along with production cycle time, and preservation investment are carried out. The rate of market demand is quadratic in nature based on time and is suitable for the items for which demand rises primarily, and then after it begins to decline. This form of demand is applicable to a vast range of items like garments, fashion accessories, electronics, etc.. The model is further divided into two cases based on demand rate and products reworking of imperfect quality items. Further, in each case, four subcases based on credit period and time of production cycle are analysed. The main objective of the inventory problem is to calculate total manufacturing cost in each subcase. The classical optimization technique is utilized for calculating the optimal values of decision variables. For the validation of developed models in each case, numerical examples are demonstrated, then using the concept of eigen-values of a Hessian matrix, we have proved the convex nature of the systems total cost for the case which has the minimum total cost. Also the decision variable sensitivity analysis is done by altering the inventory parameters for generating fruitful managerial insights. The model derived in this article can be applied in supply chain management of packaged food products/seasonal food products/milk products like butter, cheese, etc., where the tags for RFID are applied to track eatable/milk items of during delivery and storing. Also, if the model deals with a product of improper production, then it undergoes the reworking process.

The ranked set sampling (RSS) is a cost-effective method of sampling that can be used in a wide range of statistical problems. In this paper, the shape and the scale parameters of Nadarajah-Haghighi extension of the exponential distribution are estimated based on a simple random sample (SRS) and RSS. Three cases are considered: 1) the scale parameter is known; 2) the shape parameter is known; 3) both shape and scale parameters are unknown. Observations are done when the ranking mechanism in the ranked set sample is perfect and when it is not. Method of moments, the maximum likelihood method, and a modification of the maximum likelihood method are used. The obtained estimators are compared in terms of their biases and mean square errors (MSE). The results revealed that estimators based on RSS tend to show better properties (smaller bias and MSE) relative to their SRS counterparts, regardless of the quality of the ranking.

To compare the geometry of two or more geometric structures consisting of N ordered points, and which can be considered as solids in three-dimensional space, we developed a method based on the minimization of a certain comparison function. This function is the sum of squared distances between pairs of elements of the two structures under comparison with the same indices. Distances change when changing the mutual orientation of the structures with all possible shifts and rotations of the structures as rigid bodies. The comparison function is minimized with respect to Euler angles, provided that centers of mass of two compared structures are superposed. The minimization of the comparison function with respect to Euler angles is carried out numerically by the Rosenbrock method. The developed method for comparison of geometric structures is used to solve problems in structural chemistry, that is to compare molecules with the same structural formula in one crystal.

In this work, we introduce a pair of multiobjective second-order symmetric dual variational problems. Weak, strong, and converse duality theorems for this pair are established under the assumption of ?-bonvexity/?-pseudobonvexity. At the end, the static case of our problems has also been discussed.

We consider a resource-constrained project scheduling problem with respect to the makespan minimization criterion. The problem accounts for technological constraints of activities precedence together with resource constraints. Activities pre- emptions are not allowed. The problem with renewable resources is NP-hard in the strong sense. We propose an exact branch and bound algorithm for solving the problem with renewable resources. It uses our new branching scheme based on the representation of a schedule in form of the activity list. We use two approaches of constructing the lower bound. We present results of numerical experiments, illustrating the quality of the proposed lower bounds. The test instances are taken from the library of test instances PSPLIB.

In this paper, we propose a simulation model for mapping Quality of Service (QoS) parameters to Quality of Business (QoBiz) in IP networks. We assume that Internet Service Provider (ISP) offers tariff packages based on the proposed QoS to QoBiz mapping and users? requirements. Available bit rate and security are chosen as the key QoS parameters, and price is selected as a main QoBiz parameter from users? perspective, while revenue singles out as the main QoBiz parameter from ISP?s perspective. We also assume that ISP applies hybrid pricing so that price reduction is performed depending on QoS violation, defined through network load. The simulation model is conducted using agent-based simulation methodology. Agents can be seen as autonomous units that mutually interact in the environment. In this research, users and ISP are observed as simulation agents and IP market is seen as the environment. Output parameters in the simulation analysis are ISP?s revenue and service price. The proposed model enables direct reflection of QoS violation on service prices and consequently on ISP?s revenue. Simulation results show prices decrease for most of the tariff packages.