Due to its superiority such as low access latency, low energy consumption, light weight, and shock resistance, the success of flash memory as a storage alternative for mobile computing devices has been steadily expanded into personal computer and enterprise server markets with ever increasing capacity of its storage. However, since flash memory exhibits poor performance for small-to-moderate sized writes requested in a random order, existing database systems may not be able to take full advantage of flash memory without elaborate flash-aware data structures and algorithms. The objective of this work is to understand the applicability and potential impact that flash memory SSD (Solid State Drive) has for certain type of storage spaces of a database server where sequential writes and random reads are prevalent. We show empirically that up to more than an order of magnitude improvement can be achieved in transaction processing by replacing magnetic disk with flash memory SSD for transaction log, rollback segments, and temporary table spaces.

In this article, a novel FTL (flash translation layer) architecture is proposed for NAND flash-based applications such as MP3 players, DSCs (digital still cameras) and SSDs (solid-state drives). Although the basic function of an FTL is to translate a logical sector address to a physical sector address in flash memory, efficient algorithms of an FTL have a significant impact on performance as well as the lifetime. After the dominant parameters that affect the performance and endurance are categorized, the design space of the FTL architecture is explored based on a diverse workload analysis. With the proposed FTL architectural framework, it is possible to decide which configuration of FTL mapping parameters yields the best performance, depending on the differing characteristics of various NAND flash-based applications.

The past few decades have witnessed a chronic and widening imbalance among processor bandwidth, disk capacity, and access speed of disk. According to Amdhal's law, the performance enhancement possible with a given improvement is limited by the amount that the improved feature is used. This implies that the performance enhancement of an OLTP system would be seriously limited without a considerable improvement in I/O throughput. Since the market debut of flash memory SSD a few years ago, we have made a continued effort to overcome its poor random write performance and to provide stable and sufficient I/O bandwidth. In this paper, we present three different flash memory SSD models prototyped recently by Samsung Electronics. We then show how the flash memory SSD technology has advanced to reverse the widening trend of performance gap between processors and storage devices. We also demonstrate that even a single flash memory drive can outperform a level-0 RAID with eight enterprise class 15k-RPM disk drives with respect to transaction throughput, cost effectiveness and energy consumption.

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The ever-increasing requirement for high-performance and huge-capacity memories of emerging embedded applications has led to the widespread adoption of SDRAM and NAND flash memory as main and secondary memories, respectively. In particular, the use of energy consuming memory, SDRAM, has become burdensome in battery-powered embedded systems. Intuitively, though demand paging can be used to mitigate the increasing requirement of main memory size, its applicability should be deliberately elaborated since NAND flash memory has asymmetric operation characteristics in terms of performance and energy consumption.In this paper, we present energy-aware demand paging technique to lower the energy consumption of embedded systems considering the characteristics of interactive embedded applications with large memory footprints. We also propose a flash memory-aware page replacement policy that can reduce the number of write and erase operations in NAND flash memory. With real-life workloads, we show the systemwide Energy•Delay can be reduced by 15∼30% compared to the traditional shadowing architecture.

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Multimedia applications are an increasingly important workload for general-purpose processors. This paper an-

Ultraviolet (UV) radiation has been reported to induce cutaneous inflammation such as erythema and edema via induction of proinflammatory enzymes and mediators. Sargassum fulvellum is a brown alga of Sargassaceae family which has been demonstrated to exhibit antipyretic, analgesic, antiedema, antioxidant, antitumor, fibrinolytic, and hepatoprotective activities. The purpose of this study is to investigate anti-inflammatory effects of ethylacetate fraction of ethanol extract of Sargassum fulvellum (SFE-EtOAc) in HaCaT keratinocytes and BALB/c mice. In HaCaT cells, SFE-EtOAc effectively inhibited UVB-induced cytotoxicity (60 mJ/cm2) and the expression of proinflammatory proteins such as cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS). Furthermore, SFE-EtOAc significantly reduced UVB-induced production of proinflammatory mediators including prostaglandin E2 (PGE2) and nitric oxide (NO). In BALB/c mice, topical application of SFE-EtOAc prior to UVB irradiation (200 mJ/cm2) effectively suppressed the UVB-induced protein expression of COX-2, iNOS, and TNF-α and subsequently attenuated generation of PGE2 and NO as well. In another experiment, SFE-EtOAc pretreatment suppressed UVB-induced reactive oxygen species production and exhibited an antioxidant potential by upregulation of antioxidant enzymes such as catalase and Cu/Zn-superoxide dismutase in HaCaT cells. These results suggest that SFE-EtOAc could be an effective anti-inflammatory agent protecting against UVB irradiation-induced skin damages.