James Wen Jun Xue

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It is common that Internet service hosting centres use several logical pools to assign server resources to different applications, and that they try to achieve the highest total revenue by making efficient use of these resources. In this paper, multi-tiered enterprise systems are modelled as multi-class closed queueing networks, with each network station(More)
The Ashkenazi Jewish (AJ) population is a genetic isolate close to European and Middle Eastern groups, with genetic diversity patterns conducive to disease mapping. Here we report high-depth sequencing of 128 complete genomes of AJ controls. Compared with European samples, our AJ panel has 47% more novel variants per genome and is eightfold more effective(More)
Application server clusters are often used to service high-throughput web applications. In order to host more than a single application, an organisation will usually procure a separate cluster for each application. Over time the utilisation of the clusters will vary, leading to variation in the response times experienced by users of the applications.(More)
The Ashkenazi Jewish (AJ) population is important in genetics due to its high rate of Mendelian disorders. AJ appeared in Europe in the 10th century, and their ancestry is thought to comprise European (EU) and Middle-Eastern (ME) components. However, both the time and place of admixture are subject to debate. Here, we attempt to characterize the AJ(More)
This paper investigates profit optimisation by the partitioning of server pools. Different types of web requests are considered in this paper: best-effort requests and multi-class QoS-demanding requests. Each request is associated with a certain amount of revenue. The system earns associated revenue when completing a best effort request, while the revenue(More)
This paper proposes a new priority scheduling algorithm to maximise site revenue of session-based multi-tier Internet services in a multicluster environment. This research is part of a larger study in support of large-scale online trading systems and, as a result, this case study is chosen as a demonstrator for the techniques presented in this paper. The(More)
Container-managed persistence is an essential technology as it dramatically simplifies the implementation of enterprise data access. However it can also impose a significant overhead on the performance of the application at runtime. This paper presents a layered queuing performance model for predicting the effect of adding or removing container-managed(More)
Broadcasting is a fundamental communication task in mobile ad hoc networks, and minimizing broadcasting time (or latency) is crucial to the performance ofmany applications. Extensive studies have been conducted on the minimization of broadcasting time in the context of radio networks, which are usually modeled as general graphs. In this paper, we consider(More)
Distributed enterprise applications store client-specific data in application server memory, in a data structure commonly referred to as the session. The backing up of this session data (in a process known as session persistence) is essential for load balancing between application servers and for managing server failures, and hence is critical for the(More)
Admixed populations are formed by the merging of two or more ancestral populations, and the ancestry of each locus in an admixed genome derives from either source. Consider a simple “pulse” admixture model, where populations A and B merged t generations ago without subsequent gene flow. We derive the distribution of the proportion of an admixed chromosome(More)