We examine the problem of parallel imports: unauthorized flows of products across countries, which compete with authorized distribution channels. The traditional economics model of a discriminating monopolist that has different prices for the same good in different markets requires the markets to be separated in some way, usually geographically. The profits from price discrimination can be threatened by parallel imports that allow consumers in the high-priced region some access to the low-priced marketplace. However, as this article shows, there is a very real possibility that parallel imports may actually increase profits. The basic intuition is that parallel importation becomes another channel for the authentic goods and creates a new product version that allows the manufacturer to price discriminate. We propose a two-country, three-stage model to quantitatively study the effects and strategies. In the third stage, and in the higher priced country where parallel imports have entered, we characterize the resulting market segmentation. One segment of consumers stays with the authorized version as they place more value on the warranty and services that come with the authorized version. Another segment switches to parallel imports because a lower price is offered due to lack of country-specific features or warranties. Parallel imports also generate a third and new segment that would not have bought this product before. Unlike counterfeits that are fabricated by imitators, all parallel imports are genuine and sourced from the manufacturer in the lower-priced country through authorized dealers. Therefore, the manufacturer's global sales quantity should increase, but profit may rise or fall depending on the relative sizes and profitability of the segments. A profit-maximizing parallel importer should set price and quantity in the second stage after observing the manufacturer's prices in both countries. There will be a threshold of across-country price gap above which parallel imports would occur. In the first stage, the manufacturer can anticipate the possible occurrence of a parallel import, its price and quantity, and its effect on authorized sales in each country to make a coordinated pricing decision to maximize the global supply chain profit. Under some circumstances the manufacturer should allow parallel imports and under others should prevent them. Through a Stackelberg game we solve for the optimal pricing strategy in each scenario. We then find in one extension that when the number of parallel importers increases, the optimal authorized price gap should narrow, but the prices and quantities of parallel imports may rise or fall. In another extension, we .nd that when the manufacturer has other means—such as monitoring dealers, differentiating designs, and unbundling warranties—to contain parallel imports, the authorized price gap can widen as a function of the effectiveness of nonpricing controls. In summary, parallel imports may help the manufacturer to extend the global reach of its product and even boost it...

The aim of this study was to evaluate the cytotoxicity and gelation of thermosensitive chitosan-beta-glycerol phosphate (GP) solutions, which undergo sol-gel transition around body temperature. Chitosan 0.5-2% (w/v) mixed with GP 5-20% (w/v) solutions all gel at 37 degrees C and possess pH around the physiological range. High GP and chitosan concentrations result in faster gelation time. Extracts of all chitosan concentrations mixed with or without 5% (w/v) GP and 2% (w/v) chitosan combined with 10% (w/v) GP demonstrated up to 34% increase in proliferation rate of goat bone marrow derived mesenchymal stem cells when compared with control medium. Extracts from all other chitosan-GP combinations resulted in reduced cell proliferation relative to control medium. Increasing GP content in the gel resulted in a linear increase in the osmolality of the extracts in contact with the gels. The results of this study indicate that chitosan-GP is a biocompatible hydrogel, extracts of which can stimulate mesenchymal stem cell proliferation at certain concentrations. This material is therefore a promising vehicle for cell encapsulation and injectable tissue-engineering applications.

We consider a situation in which the manufacturing system is equipped with batch and discrete processors. Each batch processor can process a batch (limited number) of jobs simultaneously. Once the process begins, no job can be released from the batch processor until the entire batch is processed. In this paper, we analyze a class of two-machine batching and scheduling problems in which the batch processor plays an important role. Specifically, we consider two performance measures: the makespan and the sum of job completion times. We analyze the complexity of this class of problems, present polynomial procedures for some problems, propose a heuristic, and establish an upper bound on the worst case performance ratio of the heuristic for the NP-complete problem. In addition, we extend our analysis to the case of multiple families and to the case of three-machine batching.

This paper studies supply chain demand variability in a model with one supplier and Nretailers that face stochastic demand. Retailers implement scheduled ordering policies: Orders occur at fixed intervals and are equal to some multiple of a fixed batch size. A method is presented that exactly evaluates costs. Previous research demonstrates that the supplier's demand variance declines as the retailers' order intervals are balanced, i.e., the same number of retailers order each period. This research shows that the supplier's demand variance will (generally) decline as the retailers' order interval is lengthened or as their batch size is increased. Lower supplier demand variance can certainly lead to lower inventory at the supplier. This paper finds that reducing supplier demand variance with scheduled ordering policies can also lower total supply chain costs.supply chain management, multi-echelon inventory, bullwhip effect

Increasingly shorter product life cycles impel ÿrms to design, develop, and market more products in less time than ever before. Overlapping of design and development stages is commonly regarded as the most promising strategy to reduce product development times. However, overlapping typically requires additional resources and can be costly. Our research addresses the trade-o between product development time and costs and introduces an algorithm to determine an appropriate overlapping strategy under di erent scenarios. The methodology developed was successfully employed at Rocketdyne Division of Rockwell International.