An Effective Cache Algorithm for Heterogeneous Storage Systems

Modern storage environment is commonly composed of heterogeneous storage devices. However, traditional cache algorithms exhibit performance degradation in heterogeneous storage systems because they were not designed to work with the diverse performance characteristics. In this paper, we present a new cache algorithm called HCM for heterogeneous storage systems. The HCM algorithm partitions the cache among the disks and adopts an effective scheme to balance the work across the disks. Furthermore, it applies benefit-cost analysis to choose the best allocation of cache block to improve the performance. Conducting simulations with a variety of traces and a wide range of cache size, our experiments show that HCM significantly outperforms the existing state-of-the-art storage-aware cache algorithms.

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Probabilistic Benefit-Cost Analysis for Earthquake Damage Mitigation: Evaluating Measures for Apartment Houses in Turkey

Earthquake Spectra ◽

10.1193/1.1649937 ◽

2004 ◽

Vol 20 (1) ◽

pp. 171-203 ◽

Cited By ~ 73

Author(s):

Andrew W. Smyth ◽

Gülay Altay ◽

George Deodatis ◽

Mustafa Erdik ◽

Guillermo Franco ◽

...

Keyword(s):

Cost Analysis ◽

Seismic Hazard ◽

Fragility Curves ◽

Earthquake Damage ◽

Mitigation Measures ◽

Benefit Cost Analysis ◽

Damage Mitigation ◽

Time Horizons ◽

Wide Range ◽

Benefit Cost

In the wake of the 1999 earthquake destruction in Turkey, the urgent need has arisen to evaluate the benefits of loss mitigation measures that could be undertaken to strengthen the existing housing stock. In this study, a benefit-cost analysis methodology is introduced for the comparative evaluation of several seismic retrofitting measures applied to a representative apartment building located in Istanbul. The analysis is performed probabilistically through the development of fragility curves of the structure in its different retrofitted configurations. By incorporating the probabilistic seismic hazard for the region, expected direct losses can be estimated for arbitrary time horizons. By establishing realistic cost estimates of the retrofitting schemes and costs of direct losses, one can then estimate the net present value of the various retrofitting measures. The analysis in this work implies that, even when considering only direct losses, all of the retrofitting measures considered are desirable for all but the very shortest time horizons. This conclusion is valid for a wide range of estimates regarding costs of mitigation, discount rates, number of fatalities, and cost of human life. The general methodology developed here for a single building can be extended to an entire region by incorporating additional structural types, soil types, retrofitting measures, more precise space- and time-dependent seismic hazard estimates, etc. It is hoped that this work can serve as a benchmark for more realistic and systematic benefit-cost analyses for earthquake damage mitigation.

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Using STEAM for Benefit-Cost Analysis of Transportation Alternatives

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1649-08 ◽

1998 ◽

Vol 1649 (1) ◽

pp. 63-71 ◽

Cited By ~ 7

Author(s):

Patrick Decorla-Souza ◽

Harry Cohen ◽

Dan Haling ◽

James Hunt

Keyword(s):

Cost Analysis ◽

Travel Demand ◽

Demand Management ◽

Decision Makers ◽

Pollutant Emissions ◽

Travel Demand Management ◽

Benefit Cost Analysis ◽

Wide Range ◽

Surface Transportation ◽

Benefit Cost

The Intermodal Surface Transportation Efficiency Act emphasizes assessment of multimodal alternatives and demand management strategies. This emphasis has increased the need for planners to provide good comparative information to decision makers with regard to proposed alternative transportation solutions. Benefit-cost analysis is a useful tool to compare the economic worth of alternatives and evaluate tradeoffs between economic benefits and nonmonetizable social and environmental impacts. FHWA has developed a new tool for benefit-cost analysis called the Surface Transportation Efficiency Analysis Model (STEAM). The software is based on the principles of economic analysis and allows development of monetized impact estimates for a wide range of transportation investments and policies, including major capital projects, pricing, and travel demand management. Impact measures are monetized to the extent feasible, and quantitative estimates of natural resource usage (e.g., energy consumption) and environmental impact (e.g., pollutant emissions) are also provided. Decision makers can then use net monetary benefits (or costs) of alternatives as computed by STEAM to evaluate tradeoffs against nonmonetizable impacts. The software was applied in evaluation of corridor alternatives for the Central Freeway corridor in the hypothetical urban area of Any City, U.S.A.

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Measuring Nontraditional Benefits and Costs of Inland Navigation

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105190900107 ◽

2005 ◽

Vol 1909 (1) ◽

pp. 47-53

Author(s):

Anne Sudar

Keyword(s):

Cost Analysis ◽

Standard Procedure ◽

Air Emissions ◽

Development Projects ◽

Water Resource Development ◽

Benefit Cost Analysis ◽

Inland Navigation ◽

Wide Range ◽

Benefit Cost ◽

Benefits And Costs

The evaluation of navigation projects has evolved from a standard procedure done strictly by engineers and economists to a process that involves a wide range of stakeholders. Not surprisingly, these diverse stakeholders have different views regarding what should count in the benefit–cost analysis of water resource development projects and how the effects are to be economically valued. The methodologies that are described have been used to measure and monetize some of the externalities of inland navigation, the benefits and costs of which have not traditionally been included in benefit–cost ratios. The emphasis is the benefits (lower air emissions) associated with freight transport via water compared with those of other modes, particularly truck.

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