76,010 research outputs found

    Lean six sigma in a call centre : a case study

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    This paper, a case study, aims to illustrate the application of lean six sigma in a call centre of a service industry corporation. The study draws on process information and primary data from a real project. The study describes improvements in the operation of the call centre attributable to lean six sigma: increase in first-call resolution ratio, reduction in operator turnover and streamlining of processes. The introduction of lean six sigma into the call centre daily operations' management may have organizational benefits. Although lean six sigma has been extremely successful in the last two decades in the manufacturing sector, its applicability to the service sector has been a controversial topic. This study illustrates its application to a fast-growing area of the service sector, assisting companies in identifying areas of development for their call centres

    Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV

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    The prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region

    [Memo to J. E. Curry from T. F. Moore]

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    Memorandum to Chief J. E. Curry from T. M. Moore. Moore states that he received a call from Mrs. G. Little. Little told him that a call from J. P. Kavanaugh had originated from a pay telephone in Windsor, Ontario

    Mobile call termination in the UK

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    We discuss policy towards mobile call termination, illustrated by the 2002 Competition Commission enquiry into the UK mobile market. We present a model of the mobile market which includes both fixed-to-mobile and mobile-to-mobile call termination. In broad terms, the former service is likely to involve monopoly pricing if left unchecked, while the latter service–if the termination charge is jointly chosen by networks–may provide the mobile sector with the means by which to relax competition. Competition is often relaxed by choosing a low mobile-to-mobile termination charge. If feasible, then, unregulated networks often wish to set different termination charges depending on whether traffic originates on the fixed or mobile network. By contrast, social optimality often requires that uniform termination charges be imposed

    Modeling and simulation of call centers.

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    In this review, we introduce key notions and describe the decision problems commonly encountered in call center management. Main themes are the central role of uncertainty throughout the decision hierarchy and the many operational complexities and relationships between decisions. We make connections to analytical models in the literature, emphasizing insights gained and model limitations.The high operational complexity and the prevalent uncertainty suggest that simulation modeling and simulation-based decision-making could have a central role in the management of call centers. We formulate some common decision problems and point to recently developed simulation-based solution techniques. We review recent work that supports modeling the primitive inputs to a call center and highlight call center modeling difficulties

    Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′

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    First evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)

    Effective Call Center Management: Evidence from Financial Services

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    Call centers are quickly becoming the major point of contact for serving customers and generating new revenue in a variety of industries. No where is this growth in the importance of call centers more apparent than in the financial services industry. This paper presents the results of a survey of the management of call center operations at major financial service firms. The results clearly indicate the importance of human resource management practices and technology in creating high-performance call center environments.

    Equivalence of call-by-name and call-by-need for lambda-calculi with letrec

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    We develop a proof method to show that in a (deterministic) lambda calculus with letrec and equipped with contextual equivalence the call-by-name and the call-by-need evaluation are equivalent, and also that the unrestricted copy-operation is correct. Given a let-binding x = t, the copy-operation replaces an occurrence of the variable x by the expression t, regardless of the form of t. This gives an answer to unresolved problems in several papers, it adds a strong method to the tool set for reasoning about contextual equivalence in higher-order calculi with letrec, and it enables a class of transformations that can be used as optimizations. The method can be used in different kind of lambda calculi with cyclic sharing. Probably it can also be used in non-deterministic lambda calculi if the variable x is "deterministic", i.e., has no interference with non-deterministic executions. The main technical idea is to use a restricted variant of the infinitary lambda-calculus, whose objects are the expressions that are unrolled w.r.t. let, to define the infinite developments as a reduction calculus on the infinite trees and showing a standardization theorem

    Non-song social call bouts of migrating humpback whales

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    This work was funded by the E&P Sound and Marine Life Joint Industry Programme (JIP), managed by the International Association of Oil and Gas Producers (OGP), the U.S. Bureau of Ocean Energy Management (BOEM), and the U.S. Office of Naval Research (ONR) with additional in-kind support from the Australian Defence Science and Technology Organisation.The use of stereotyped calls within structured bouts has been described for a number of species and may increase the information potential of call repertoires. Humpback whales produce a repertoire of social calls, although little is known about the complexity or function of these calls. In this study, digital acoustic tag recordings were used to investigate social call use within bouts, the use of bouts across different social contexts, and whether particular call type combinations were favored. Call order within bouts was investigated using call transition frequencies and information theory techni- ques. Call bouts were defined through analysis of inter-call intervals, as any calls within 3.9 s of each other. Bouts were produced significantly more when new whales joined a group compared to groups that did not change membership, and in groups containing multiple adults escorting a female and calf compared to adult only groups. Although social calls tended to be produced in bouts, there were few repeated bout types. However, the order in which most call types were produced within bouts was non-random and dependent on the preceding call type. These bouts appear to be at least partially governed by rules for how individual components are combined.Peer reviewe

    Exploiting spatiotemporal locality for fast call stack traversal

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    In the approach to exascale, scalable tools are becoming increasingly necessary to support parallel applications. Evaluating an application’s call stack is a vital technique for a wide variety of profilers and debuggers, and can create a significant performance overhead. In this paper we present a heuristic technique to reduce the overhead of frequent call stack evaluations. We use this technique to estimate the similarity between successive call stacks, removing the need for full call stack traversal and eliminating a significant portion of the performance overhead. We demonstrate this technique applied to a parallel memory tracing toolkit, WMTools, and analyse the performance gains and accuracy
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