Effectiveness Evaluation of Replacement Policies for On-Chip Caches in Multiprocessors

A Cache plays a vital role in improving performance in the multicore environment, especially the Last Level Cache (LLC). The improvements in performance are based on the block size, associativity, and replacement policies. Most of the papers concentrate on traditional Least Recently Used (LRU) based replacement policies for their replacement decisions. Unfortunately, the replacement decisions do not enhance performance of the cache as expected. An enhanced modified Pseudo LRU policy is proposed, which is an approximation of LRU. The proposed methodology uses counters to enhance the confidence of replacement decisions based on the history of the replaceable blocks in cache. It is very clear from the Simulation results that the replacement scheme proposed exhibits better performance improvement in terms of miss ratio of about 3% and energy efficiency of about 2% on an average.

Monitoring the health status of water mains using a scorecard modelling approach

There has been considerable research into prediction of water mains failure, however, those models are very complex and fail to convey the message of the health status of an asset to the relevant stakeholders. The study developed a ‘pipe health scorecard’ based on historical failure data which could be used for operation, maintenance, refurbishment, or replacement decisions by a water utility. This scorecard model was developed by using 160,413 pipe-condition datasets from the South Australian Water Corporation over 10 years. Measures such as the Kolmogorov–Smirnov (KS) statistic, Area Under the ROC Curve (AUC), and Population Stability Index (PSI) showed the model is strong enough to predict the health status of water mains. The study found that the factors influencing water mains failure to be in the order of importance: length, material, age, location (road vs verge), diameter, and operating parameters. The development of a simple but reliable model for the assessment of the health status of water mains will have major benefits to the water utility with the ability to identify and potentially replace water pipes prior to failure. Additional benefits of flexible scheduling of the maintenance and replacement programs would contribute to cost savings.

Examination of Electrolyte Replacements in the ICU Utilizing MIMIC-III Dataset Demonstrates Redundant Replacement Patterns

Electrolyte repletion in the ICU is one of the most ubiquitous tasks in critical care, involving significant resources while having an unclear risk/benefit ratio. Prior data indicate most replacements are administered while electrolytes are within or above reference ranges with little effect on serum post-replacement levels and potential harm. ICU electrolyte replacement patterns were analyzed using the MIMIC-III database to determine the threshold governing replacement decisions and their efficiency. The data of serum values for potassium, magnesium, and phosphate before and after repletion events were evaluated. Thresholds for when repletion was administered and temporal patterns in the repletion behaviors of ICU healthcare providers were identified. Most electrolyte replacements happened when levels were below or within reference ranges. Of the lab orders placed, a minuscule number of them were followed by repletion. Electrolyte repletion resulted in negligible (phosphate), small (potassium), and modest (magnesium) post-replacement changes in electrolyte serum levels. The repletion pattern followed hospital routine work and was anchored around shift changes. A subset of providers conducting over-repletion in the absence of clinical indication was also identified. This pattern of behavior found in this study supports previous studies and may allude to a universal pattern of over-repletion in the ICU setting.

Managing replacement and culling in dairy herds

Approximately one third of dairy cows are replaced every year. Replacement of dairy cattle is an important part of the cost of dairy production and an environmental sustainability concern. Primary culling reasons are reduced health and fertility. Reduced welfare often proceeds culling. This chapter focuses on factors that affect replacement and culling in dairy herds with a focus on cows. The act of culling is simple, but the risk factors and economic considerations are complex. The chapter first presents some data on culling risks and reasons, explores more in depth the effects of poor health on culling, and presents aspects of economic decision making regarding culling and replacement decisions.

Development of a remaining useful life (RUL) model for reinforced concrete beams subjected to high-cycle fatigue

PurposeFailure of a critical reinforced concrete beam due to fatigue can have severe safety and production consequences, and preventative repair/replacement of such a beam is expensive. It would therefore be beneficial if repair/replacement can be done based on an accurately and conservatively predicted remaining useful life (RUL). The purpose of this paper is to develop such a model.Design/methodology/approachCondition-based maintenance is a maintenance approach that uses empirical/analytical models and a measurable condition to predict remaining useful life. The P-F curve (condition-life) is a useful tool that can aid in making these decisions. A model to create a P-F curve is developed using rebar fatigue test results (in the form of an S–N curve) and the Palmgren-Miner law of damage accumulation. A Monte Carlo simulation with statistical distributions is employed to provide confidence levels of RUL outputs.FindingsAn example of how the model can successfully be used in practice is shown in this paper, and a sensitivity study is performed leading to conclusions being drawn with regard to damage tolerant design considerations.Originality/valueIf a critical reinforced concrete beam fails due to fatigue can have serious consequences. This paper develops a model to help base repair/replacement decisions based on accurately and conservatively predicted RUL. Financial and safety benefits would be gained if this model would be used in practice.

An analytical model of the replacement costs of aircraft engine life-limited parts

Purpose The purpose of this paper is to present novel recursive expressions for modelling the replacement costs of aircraft engine life-limited parts during shop visits to assist engine operators in both evaluating their decisions regarding the applied life-limited parts management strategies and tracking the replacement costs consistently throughout the life of the engine. Design/methodology/approach The replacement costs of aircraft engine life-limited parts are modelled analytically in this research, which strives to quantify the costs of used and unused lives of the replaced parts, incurred during engine shop visit events. Inputs for this model include the list price of life-limited parts, the replacement decisions made on all previous shop visits and the number of cycles the engine has operated at different thrust ratings on all previous operating intervals. Findings The average annual escalation rate of life-limited parts list prices was shown to range from 5% to 7%. The presented model is not only suitable for calculating the costs of used and unused lives of life-limited parts during past engine shop visit events but also for application in the life-limited parts replacement cost forecasting and optimisation models. Originality/value Uniquely derived recursive expressions represent the final result of the developed model which, to the authors’ knowledge, had not been studied elsewhere in the academic literature. The analysis of aircraft engine life-limited part list prices carried out to account for the average annual escalation rate enables the prediction of replacement costs during subsequent shop visits.

Financial Reporting Material Misstatements, Earnings Conservatism and Managerial Replacement Decisions

Purpose: Based on signal theory and legitimacy theory, this paper examines whether firms with financial reporting misstatements (restatements) would prefer conservative financial reporting to send signals regarding their determinants of improving financial reporting credibility and legitimate organizational image in Taiwan. This paper further examines whether these firms reduce the demand for conservative financial reporting after replacing managers in the reveal of restatements.

Cluster-based Cache Replacement in 5G Network

In this thesis, we proposed a Cluster-Based Cache Replacement (CBR) scheme for 5G Networks to reduce the backhaul traffic. We developed our scheme based on the understanding of the degradation of the performance of the cache placement algorithm. We expect that whenever file request pattern differs from the file popularity distribution, such as unpopular files become more popular or vice versa, the caching system should experience performance degradation. We address this problem by presenting a cache replacement scheme based on the idea of Least Frequency Used (LFU) replacement policy, but we consider only the recent request to avoid cache pollution. We evaluated the performance of CBR through simulation and compared its performance with LRU that is widely used as a cache replacement technique in practice. We simulated three different configurations of LRU scheme in a cluster-based mobile network model. Our simulation results show that the CBR outperforms LRU, where it reduces the miss ratio from 86% to 76% and the backhaul traffic from 3.67×105 to 3.47×105 MB with 10% of cache size. This superior performance it achieves by fewer replacement decisions and storing more files in the cache.