We consider the buffer content of a fluid queue or storage process. The buffer content varies in a way that depends on the state of an underlying three-state Markov process. In state 0 the buffer content increases at a rate α(x) that is a function of the current buffer level x; in states 1 and 2 it decreases linearly, with different speeds. We study the steady-state buffer content, by using lev...

In recent years, heterogeneous devices have been employed frequently in mobile storage systems because a combination of such devices can supply a synergistically useful storage solution by taking advantage of each device. One important design constraint in heterogeneous storage systems is to mitigate I/O performance degradation stemming from the difference between access times of different devi...

A combining window is an interval of time in a combining node during which incoming requests are gathered in the node in order to combine them into a single outgoing request. Our thesis is that a combining window is necessary in order to realize the dual forms of concurrency — execution and storage concurrency — that a combining tree is designed to achieve. Execution concurrency among the nodes...

Cell formation problem mainly address how machines should be grouped and parts be processed in cells. In dynamic environments, product mix and demand change in each period of the planning horizon. Incorporating such assumption in the model increases flexibility of the system to meet customer’s requirements. In this model, to ensure the reliability of the system in presence of unreliable machine...

Classical buffer replacement policies, e. g., LRU, are suboptimal for database systems having flash disks for persistence, because they are not aware of the distinguished characteristics of flash-based storage devices. We introduce the basic principles of buffer management for such devices and present two efficient buffer algorithms that apply these principles. These algorithms significantly im...

A buffer cache mechanism is usually employed in modern operating system to enhance the performance that is limited by slow secondary storage. In this paper, we present the implementation of a trace-driven simulator for buffer cache schemes that consider DRAM/PRAM hybrid main memory and flash memory based storages. The goal of simulator is to analyze the legacy buffer cache schemes by measuring ...

Using magnetic disks as a cache for tertiary storage has been shown to be an effective way to address the high storage costs of large-scale multimedia servers. We investigate a technique for managing the bandwidth of such a hierarchical storage design. In existing schemes, all data items are treated equally; and the same I/O rate is used to load data from tertiary storage when they are requeste...

In Delay Tolerant Networks (DTN) disruptions may happen frequently as end to end path is not available all the time. Thus, delays can also be extended due to its environment nature like deep space, underwater, ocean sensor networks. In manage to achieve message delivery probability in such demanding networking situations , researchers have proposed the design of store-carry-and-forward routing ...

BACKGROUND In agricultural regions, streamside forests have been reduced in age and extent, or removed entirely to maximize arable cropland. Restoring and reforesting such riparian zones to mature forest, particularly along headwater streams (which constitute 90% of stream network length) would both increase carbon storage and improve water quality. Age and management-related cover/condition cl...