This paper deals with divergent logistic networks where the inventory at each node is controlled using a periodic review strategy with order-up-to level. An approximate method is presented to analyse the network performance (service levels, mean physical stock). The method is tested on a range of Z-echelon and 3-echelon networks by comparison to results from Monte Carlo simulation. We conclude ...

We consider the optimal strategy of R&D expenditure adopted by a firm that engages in R&D to develop an innovative product to be launched in the market. The firm faces with technological uncertainty associated with the success of the R&D effort and market uncertainty of the stochastic revenue flow generated by the new product. Our model departs from most R&D models by assuming that the firm’s k...

Purpose The purpose of the paper is to analyse how the organizational control mechanisms adopted within project teams in R&D settings influence the effectiveness of knowledge integration processes. In our research we analysed the functioning of project teams within an organization operating in the industry of turn-key devices for power plants. Our unit of analysis is the project team, a setting...

Frequent inlet flow changes typically cause problems for averaging level controllers. For a frequently changing inlet flow the upsets do not occur when the system is in steady state and the tank level at its set-point. For this reason the tuning of the level controller gets quite complicated, since not only the size of the upsets but also the time in between them relative to the hold up of the ...

An important component of quality control for statistical graphics software is the ability not only to test that code runs without errors, but also to test that code produces the right result. The simple way to test for the correct result in graphical output is to test whether a test file differs from a control file; this is effective in determining whether a difference exists. However, the tes...

Neural Network Based Optimal Control of HVAC&R Systems Min Ning, Ph.D Concordia University, 2008 Heating, Ventilation, Air-Conditioning and Refrigeration (HVAC&R) systems have wide applications in providing a desired indoor environment for different types of buildings. It is well acknowledged that 30% 40% of the total energy generated is consumed by buildings and HVAC&R systems alone account fo...

A set of techniques is described which permits the design of computers particularly well suited for outer space and other airborne control applications. These techniques are unified by reference to a representative computer. Some of the properties of the computer are: variable speed, power consumption proportional to speed, relatively few transistors, relatively large storage for program and co...

Objective(s): This study was conducted to evaluate the cerebroprotective effect of methanolic leaf extract of Punica granatum (MePG) in Wistar rats.Materials and Methods: The MePG was initially assessed for in vitro antioxidant activity, and later evaluated on LPS-induced RAW 264.7 cell line assay. Finally, the MePG was evaluated against ischemia-reperfusion (I/R) induced brain injury in Wistar...

We present a system for efficient indexed querying of XML documents, enhanced with sibling operations. R-tree index proposed in [5] has a very high cost for the following-sibling and precedingsibling axes. We develop a family of index structures, which we refer to as transformed split-tree indexes, to address this problem, in which (i) XML data is horizontally split by a simple, yet efficient c...