Rural off-grid electrification systems powered by renewable energy have become popular in the Global South. Unfortunately, many microgrids have experienced trouble during their first years of ...operation, leading to premature system deterioration. In this paper we trace these problems to institutional issues associated with goal displacement in implementing organizations and, relatedly, ineffective programme upscaling, which have remained under-researched in the rural renewable energy literature thus far. Using literature about implementation of large infrastructure projects, political economy of policy making, and replication of innovations as our conceptual lens, we examine a government-initiated microgrid programme in Indonesia. Early project failure was found to be linked to a one-sided policy focus on expanding the number of installed systems, instead of ensuring service quality. This focus is driven by political campaign strategies in which microgrid technologies are used as instruments for political legitimation, and pressure from aid donors to achieve early quantifiable results. It leads higher governmental echelons to care about reaching pre-set installation targets rather than ensuring that lower-level governments face incentives to focus on maintenance and repair. The focus on quantitative expansion also explains a lack of incentives or pressures to address a persistent lack of clarity about responsibilities of each government level, local communities, consultants, and contractors. Similar patterns can be noted in other countries, suggesting the findings have broader relevance for understanding key determinants of microgrid unsustainability in the Global South. To improve governance, pressure needs to be brought on the government by the general public, academia, NGOs and the press through increased public exposure of early system deterioration. These actions should be grounded in research that seeks to understand the complex causes of the problem, considering the whole scope of interlinked incentives and policies, before trying to tackle it.
•Failure of government initiated microgrids is due to focus on system numbers, not service quality.•Focus on quantitative expansion explains a lack of incentives to address lack of responsibilities.•Similar patterns are seen in the Global South on key determinants of microgrid unsustainability.•To improve, the government needs to be pressured by the general public, academia, NGOs and press.
Biological activity is a critical quality attribute for biopharmaceuticals, which is accurately measured using an appropriate relative potency bioassay. Developing a bioassay is a complex, rigorous ...undertaking that needs to address several challenges including modelling all of the mechanisms of action associated with the biotherapeutic. Bioassay development is also an exciting and fast evolving field, not only from a scientific, medical and technological point of view, but also in terms of statistical approaches and regulatory expectations. This has led to an industry-wide discussion on the most appropriate ways to develop, validate and control the bioassays throughout the drug lifecycle.
Three-dimensional (3D) digital images are helpful in studying the physical properties of a medium. Moreover, reconstructing a 3D image from a two-dimensional (2D) image via computer-mathematical ...modeling is an important process. Based on the relationship between cascaded grids, an ingenious cascaded polymorphic method is proposed in this work to reconstruct a 3D image from a 2D image. By using the cascaded polymorphic method, a patch can be copied directly into a reconstruction grid by matching the patterns between cascaded grids; the polymorphism of the templates correspond to the grid size. To improve the reconstruction performance further, the non-edge region expansion strategy for a layer and the non-edge region replication strategy for adjacent layers were also proposed. A core sample and building material were selected as the test materials, and several effective measurements were used as quantitative means. To display the reconstruction effect intuitively, 2D reconstruction experiments were also performed along with the 3D experiment. The results show that the reconstruction speed is significantly improved using the cascaded polymorphic method, and the morphological features of the 3D reconstruction are clearly promoted.
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•Novel cascaded polymorphic method for reconstructing 3D porous medium from 2D image•It uses polymorphic templates to promote the morphological features of images•Reconstruction speed improved by copying multi-grid system-based matching patterns•This method outperformed the original pattern density function simulation method
This paper examines the effects of the nondiscretionary trading demands of volatility index (VIX) exchange‐traded products (ETPs) issuers on the prices and volumes in the VIX futures. We find that ...the ETPs' informationless, mechanical rebalancing of futures positions to maintain the constant maturity of the index and the promised leverage ratios of the VIX ETPs have significantly positive predictive power for end‐of‐day futures returns. We also show that the impact on price has diminished through time from increased liquidity provided by hedge funds, and the “natural” hedging of the issuers' inverse products.
The relation between cigarette smoking and metabolic syndrome (MetS) remains unclear, and previous studies focusing on MetS are limited in sample size. We investigated the association between ...life-course smoking and MetS with independent discovery and replication samples.
Preliminary analysis utilized data from an annual cross-sectional survey of 15,222 participants aged ≥ 60 years in Tianjin, China. Suggestive associations were followed-up in 8565 adults from the China Health and Nutrition Survey. MetS was identified according to the criteria of the Chinese Diabetes Society in 2013. Life-course smoking was assessed by a comprehensive smoking index (CSI), based on information on smoking intensity, duration, and time since cessation across life-course, collected through standard questionnaires. Participants were divided into four groups: non-smokers; and the tertiles of CSI in ever smokers. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between life-course smoking and MetS.
In the discovery sample, ORs of MetS were 2.01 (95%CI: 1.64-2.47) and 1.76 (95%CI: 1.44-2.16) for smokers in the highest and second tertile of CSI compared with never smokers. Potential interaction was shown for age, with increased ORs for MetS associated with smoking limited to individuals who aged < 70 years (P
= 0.015). We were able to replicate the association between cigarette smoking and MetS in an independent adult sample (second tertile vs. never: OR = 1.30, 95%CI: 1.04-1.63). The interaction of smoking with age was also replicated.
Life-course cigarette smoking is associated with an increased odds of MetS, especially among individuals who aged < 70 years.
Generally, bacteria have a circular genome with a single replication origin for each replicon, whereas archaea and eukaryotes can have multiple replication origins in a single chromosome. In ...Escherichia coli, bidirectional DNA replication is initiated at the origin of replication (oriC) and arrested by the 10 termination sites (terA-J). We constructed E. coli derivatives with additional or ectopic replication origins, which demonstrate the relationship between DNA replication and cell physiology. The cultures of E. coli derivatives with multiple replication origins contained an increased fraction of replicating chromosomes and the cells varied in size. Without the original oriC, E. coli derivatives with double ectopic replication origins manifested impaired growth irrespective of growth conditions and enhanced cell size, and exhibited excessive and asynchronous replication initiation. The generation time of an E. coli strain with three replication origins decreased in a minimal medium supplemented with glucose as the sole carbon source. As well as cell growth, the introduction of additional replication origins promoted increased biomass production. Balanced cell growth and physiological stability of E. coli under rapid growth condition are affected by changes in the position and number of replication origins. Additionally, we show that, for the first time to our knowledge, the introduction of replication initiation sites to the chromosome promotes cell growth and increases protein production.
Data replication is widely used in cloud storage and data grid to improve the parallel service efficiency and the performance of system, which can promote the file availability and system load ...balancing, reducing the response time with multiple copies. But high volume of big data gives a new, enormous and rigorous challenge to data storage and business access of cloud storage, specially to the quality of cloud services. In this paper, a novel dynamic predicted replication strategy (DPRS) combining with the access frequency of files and prediction method is proposed to predict the future access of each file and calculating the optional number of replicas based on the real access and future access periodically. The experiment results show that DPRS can availably decrease the response time of a file request and reduce the additional cost of the cloud storage system simultaneously.
Peer-to-Peer Video-on-Demand (VoD) is a favorable solution which compromises thousands of videos to millions of users with completeinteractive video watching stream. Most of the profitable P2P ...streaming groupsPPLive, PPStream and UUSee have announced a multi-channel P2P VoD system that approvals user to view extra one channel at a time. The present multiple channel P2P VoD system resonant a video at a low streaming rate due to the channel resource inequity and channel churn. In order to growth the streaming capacity, this paper highlights completely different effective helpers created resource balancing scheme that actively recognizes the supply-and-demand inequity in multiple channels. Moreover, peers in an extra channel help its unused bandwidth resources to peers in a shortage channel that minimizes the server bandwidth consumption. To provide a desired replication ratio for optimal caching, it develops a dynamic replication strategy that optimally tunes the number of replicas based on dynamic popularity in a distributed and dynamic routine. This work accurately forecasts the varying popularity over time using Auto-Regressive Integrated Moving Average (ARIMA) model, an effective time-series forecasting technique that supports dynamic environment. Experimental assessment displays that the offered dynamic replication strategy which should achieves high streaming capacity under reduced server workload when associated to existing replication algorithms.
A Round-based Data Replication Strategy Bsoul, Mohammad; Abdallah, Alaa E.; Almakadmeh, Khaled ...
IEEE transactions on parallel and distributed systems,
2016-Jan.-1, 2016-1-1, Volume:
27, Issue:
1
Journal Article
Peer reviewed
Data Grid allows many organizations to share data across large geographical area. The idea behind data replication is to store copies of the same file at different locations. Therefore, if a copy at ...a location is lost or not available, it can be brought from another location. Additionally, data replication results in a reduced time and bandwidth because of bringing the file from a closer location. However, the files that need to be replicated have to be selected wisely. In this paper, a round-based data replication strategy is proposed to select the most appropriate files for replication at the end of each round based on a number of factors. The proposed strategy is based on Popular File Replicate First (PFRF) strategy, and it overcomes the drawbacks of PFRF. The simulation results show that the proposed strategy yields better performance in terms of average file delay per request, average file bandwidth consumption per request, and percentage of files found.
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