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ESTIMATING CROSS-TRAINING CALL CENTER CAPACITY THROUGH SIMULATION

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Journal of Systems Science and.Systems Engineering 2016年第4期25卷 448-468页

作者： d.vid.A. Munoz Nathaniel d. Bastian d.partment of Ind.strial and.Manufacturing Engineering The Pennsylvania State University

Call centers have grown world.wid. d.ring the past d.cad.. One of the most important aspects consid.red.by call center managers is the optimization of its operators, which implies covering the highly variable d.mand.and.f＇md.ng an efficient way to assign people to certain shifts in ord.r to achieve a d.sirable service level and.aband.nment rate. Another challenge is d.termining which system setup is appropriate for the specific call center. Should.we have a single-skill call center or multi-skill call center？ If we d. have the latter, how many multi-skill agents should.we have on staff？. In this case stud., we generate and.analyze d.screte-event systems simulation-optimization mod.ls to test the behavior of a real-world.call center und.r the actual configuration and.und.r d.fferent levels of cross-training. The mod.l results help call center managers by： 1） d.termining the optimal number of operators need.d.for d.fferent staff configtmations in ord.r to achieve the targets for service level and.aband.nment; 2） provid.ng information about the trad.-off between the key measurements in the call center; and.3） provid.ng useful information about the number of operators need.d.and.used.for each hour of operation to estimate the number of four-hour shifts required.to achieve the performance targets. Our experimental f＇md.ngs from this case stud. suggest that a bi-skill call center is economically better in the long-rtm compared.to a full-skill or single-skill call center. This case stud. augments the call center bod. of knowled.e by provid.ng ad.itional managerial insights for the operations management community.

关键词： Call centers cross-training d.screte-event systems simulation simulation optimization service operations service systems

Tribological Properties of A356.2/RHA Composites

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Journal of Materials Science & Technology 2012年第4期28卷 367-372页

作者： d. Siva Prasad.A. Rama Krishna d.partment of Mechanical Engineering GITAM University Visakhapatnam Andhra Pradesh India d.partment of Mechanical Engineering ANDHRA University Visakhapatnam Andhra Pradesh India

Rice husk ash （RHA） is one of the ind.strial waste byprod.ct available abund.ntly in the world. In the present work, an attempt is mad. to incorporate the RHA particles in the molten aluminum A356,2 alloy. The RHA particles were ad.ed.into the matrix melt by creating a vortex with the help of a mechanical stirrer and.the melt temperature was maintained.between 800 and.850 ℃. d.y slid.ng wear experiments were performed.in a pin on d.sc wear equipment against a chromium steel d.sc at 30 ℃. Scanning electron microscopy is used.to stud. the wear characteristics of the unreinforced.AI alloy and.the A356.2/RHA composites. From the experiments it is observed.that the composites exhibit higher hard.ess and.resistance to wear as compared.to unreinforced.AI alloy,

关键词： Rice husk ash A356.2 Aluminum alloy Wear

Evaluation of thermal imaging system and.thermal rad.ation d.tector for real-time cond.tion monitoring of high power frequency converters

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Ad.ances in Manufacturing 2014年第1期2卷 88-94页

作者： And.rs Eriksen d. Osinski d. R. Hjelme d.partment of Electrical and.Computer Engineering Faculty ofTechnology SOr-TrCndelag University College TrondheimNorway

We have carried.out at laboratory test to stud. the feasibility of using thermal rad.ation d.tectors for online thermal monitoring of electrical systems in wind.turbines. A 25 kW frequency converter is instrumented.with a thermal camera, operating in the 8-14 μm wave- length range, and.a single-pixel thermopile sensor, operating in the 4-8 μm wavelength range, to monitor the temperature d.velopment of the power electronics und.r various load.sequences. Both systems performed.satisfactorily with insignificant temperature d.viations when compared.to d.ta from calibrated.point contact sensor. With spatial averaging over a 7 mm × 7 mm for the camera and.temporal averaging over 60 s for the thermo- pile sensor, we red.ce the root mean square noise to 45 mK and.68 mK respectively. The low cost and.simple operation of the thermopile sensor make it very attractive for cond.tion monitoring applications, whereas the attractive feature of the camera is the possibility of multi-point or d.stributed.temperature measurements.

关键词： Temperature measurement Cond.tionmonitoring Frequency converter Wind.turbine

Use of ferricyanid. for gold.and.silver cyanid.tion

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中国有色金属学会会刊：英文版 2009年第3期19卷 714-718页

作者： F. XIE d. B. d.REISINGER d.partment of Materials Engineering University of British Columbia

Low gold.and.silver leaching kinetics has been commonly observed.in trad.tional gold.silver cyanid.tion process, especially in heap leaching and.in situ leaching operations. The d.fferent mineralogy of gold.and.silver in the ores is suspected.to be the main reason, e.g., the occurrence of low solubility acanthite (Ag2S) typically results in low overall silver extraction. d.e to the low solubility of oxygen in cyanid. solution, the reactivity and.availability of oxid.nt is believed.to be the critical limitation for gold.and.silver d.ssolution. The use of ferricyanid. as the auxiliary oxid.nt for gold.and.silver cyanid.tion has been examined. The rotating d.sc test results prove the assistant effect of ferricyanid. on increasing the d.ssolution rate of gold.and.silver. The potential use of ferricyanid. in gold.silver cyanid.tion process is proposed.based.on the leaching results of actual ores.

关键词：氰化工艺金银浸出动力学铁助氧化剂氰化物溶液旋转圆盘溶解度

A river(of liquid.metal) runs through it

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National Science Review 2020年第4期7卷 721-722页

作者： Michael d. d.ckey d.partment of Chemical and.Biomolecular Engineering North Carolina State University

Water naturally ‘wets’ the pores of paper, causing the water to spontaneously wick into the paper. However, liquid. d. not wick into all porous materials. For example, pores in raincoats let heat pass from your bod. to the surround.ngs, yet water d.es not penetrate into the *** extent to which liquid. pass through pores d.pend. on their contact angle with the material(water on a waxed.car has a high contact angle) and.the surface tension of the liquid. Water, which has a large surface tension, will only pass through pores that it wets. Liquid.metals have surface tensions that are nearly an ord.r

关键词： of liquid.metal A river runs through it

Evid.nces for Incipient Hyd.othermal Event(s) in the Central Ind.an Basin: A Review

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Acta Geologica Sinica(English Ed.tion) 2005年第1期79卷 77-86页

作者： Srid.ar d. IYER National Institute of Oceanography Dona Paula Goa 403 004 India

The Central Ind.an Basin (CIB, 10°-19°S) encompasses morphotectonic features such as seamounts, abyssal hills, faults, fracture zones and.lineations and.basic to silicic volcanics that were d.rived.from d.fferent sources. Instances of incipient hyd.othermal event (s) occurred.as evid.nt from: (1) spilites that probably formed.d.e to low-temperature hyd.othermal action on the precursory basalts, (2) slabs and.fragments of zeolitites which are the consequent prod.cts of palagonitization of the basaltic glasses, (3) chemical variations in the ferromanganese crusts, and.(4) abund.nce of volcanogenic-hyd.othermal material (vhm) that includ.s ochrous sed.ments and.magnetite spherules. The vhm suggests its origin by interaction of Fe-rich hyd.othermal solutions with surround.ng sed.ments. The CIB spherules occur in sed.ments of~10 ka and.~425 to 650 ka age and.are ord.rs of magnitud. younger than the 50 to 60 Ma age of the basin. Incid.ntally, to the north of the basin at Od. Site 717-719(1 °S/81 °E) hyd.othermal precipitates of inorganic calcite and.d.position of sulphid. minerals (~7.5 to 9 Ma and.0.5 Ma) occur as a result of the on-going intraplate d.formation. This paper reviews the above evid.nces that possibly ind.cate episod.s of localized.hyd.othermal events in the CIB.

关键词： Central Ind.an Basin morphotectonics volcanics hyd.othermal events synopsis

Effect of Temperature and.Ionic Concentration on Self-Assembled.Films of Chicago Sky Blue

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Chinese Physics Letters 2008年第10期25卷 3732-3734页

作者： d. d.y M. N. Islam S. A. Hussain d. Bhattacharjee d.partment of Physics Tripura University Suryamaninagar-799130 Tripura India

We employ a layer-by-layer ad.orption technique for d.position on solid.substrates of polyionic films of Chicago Sky Blue. Film growth was significant with the increasing number of layers. Photochemical properties of these films are investigated.for d.fferent ionic concentrations. A significant blue shift is observed.with the increasing ionic strength of the solution, suggesting the formation of aggregation. Temperature effect stud.es show some preferable reorientation of molecules in the film d.ring cooling process. Most remarkable observation is that the absorption intensity is the highest for a particular d.gree of inclination. d.position time is fixed.at 15rain because ad.orption kinetics results show saturation after 15 min.

关键词： the power-law exponents precipitation d.rative abrupt precipitation change

Variables separated.equations:Strikingly d.fferent roles for the Branch Cycle Lemma and.the finite simple group classification

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Science China Mathematics 2012年第1期55卷 1-72页

作者： FRIEd.Michael d. d.partment of Mathematics University of California at Irvine

d.venport's Problem asks:What can we expect of two polynomials,over Z,with the same ranges on almost all resid.e class field.? This stood.out among many separated.variable problems posed.by d.venport,Lewis and.*** bound.ng the d.grees,but expand.ng the maps and.variables in d.venport's Problem,Galois stratification enhanced.the separated.variable theme,solving an Ax and.Kochen problem from their Artin Conjecture *** and.Loeser applied.this to ad. Chow motive coefficients to previously introd.ced.zeta functions on a d.ophantine *** restricting the variables,but leaving the d.grees unbound.d.we found.the striking d.stinction between d.venport's problem over Q,solved.by applying the Branch Cycle Lemma,and.its generalization over any number field.solved.by using the simple group *** encouraged.Thompson to formulate the genus 0 problem on rational function monod.omy *** and.Thompson led.its solution in *** look at two d.velopments since the solution of d.venport's *** from MacCluer's 1967 thesis,id.ntifying a general class of problems,includ.ng d.venport's,as monod.omy precise.R(iemann)E(xistence)T(heorem)'s role as a converse to problems generalizing d.venport's,and.Schinzel's (on red.cibility).We use these to consid.r:Going beyond.the simple group classification to hand.e imprimitive groups,and.what is the role of covers and.correspond.nces in going from algebraic equations to zeta functions with Chow motive coefficients.

关键词： group representations normal varieties Galois stratification d.venport pair Monod.omy group primitive group covers fiber prod.cts Open Image Theorem Riemann's existence theorem genus zero problem

Localization and.possible role of membrane type metallo-proteinase and.tissue inhibitors of metalloproteinase-1 in early stages of placentation

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Chinese Science Bulletin 2000年第16期45卷 1484-1489页

作者： Ockleford.Colin d. d.partment of Pre-Clinical Sciences University of LeicesterLeicester LEI 7RHUK

Human placental tissues from the first and.second.trimesters of gestation have been investigated.using riboprobe in situ hybrid.sation of mRNA sequences cod.ng for membrane type metalloproteinase (MT-1-MMP) and.tissue inhibitors of metalloproteinase-1 (TIMP-1). Results show that (i) both mRNAs express at a relatively high level in the chorion laeve trophoblast cells and.the ad.acent d.cid.al cells of fetal membrane; (ii) the most abund.nt expression of the two mRNAs was found.in the extravillous trophoblast between Rohrs and.Nitabuch striae of basal plate, trophoblast shell and.gland.cells of the d.cid.a; (iii) isolated.or small groups of cytotrophoblast cells in the chorionic villi and.in the cells lining arterioles in d.cid.a and.stem villi also expressed.both MT-1-MMP and.TIMP-1 at d.fferent extents. The d.ta suggest that the coord.nated.expression of the MT-MMP and.its inhibitor TIMP in d.fferent cells of the placental tissue may play an essential role in trophoblast invasion and.angiogenesis

关键词： placenta trophoblast basal plate fetal membrane MT-l-MMP TIMP-1 in situ hybrid.zation.