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41.
K.?A.?AriyawansaEmail author C.?Cacho A.?J.?Felt 《Journal of Mathematical Modelling and Algorithms》2005,4(4):369-390
Ariyawansa and Felt (2001, 2004) have recently created a test problem collection for testing software for stochastic linear
programs. This freely-available, web-based collection was originally created with 35 problem instances from 11 problem families
representing a variety of application areas. The collection was created with plans for enriching it with problem instances
based on different application areas from the research community. The work of Martel and Al-Nuaimi (1973) on manpower planning
under uncertain demand represents an application area suitable for creating new problem instances to be added to the collection.
The purpose of this paper is to describe the construction of a new family of stochastic programming test problems based on
the work of Martel and Al-Nuaimi (1973). As part of our construction, we review the work of Martel and Al-Nuaimi (1973) leading
to an extension of their models for which their solution procedure does not apply. The new test problems are based on this
extension. We also present solutions to the test problems obtained using the software package CPA (2002) for stochastic programming
developed by Ariyawansa, Felt and Sarich.
Mathematics Subject Classifications (2000) 90C15, 90C90, 65K05.
K. A. Ariyawansa: The work of this author was supported in part by the U.S. Army Research Office under Grant DAAD 19-00-1-0465. 相似文献
42.
Trischuk W de Troconiz JF Tseng J Turini N Ukegawa F Vaiciulis T Valls J Vejcik S Velev G Vidal R Vilar R Volobouev I Vucinic D Wagner RG Wagner RL Wahl J Wallace NB Walsh AM Wang C Wang CH Wang MJ Watanabe T Waters D Watts T Webb R Wenzel H 《Physical review letters》2000,85(10):2062-2067
We use 106 pb (-1) of data collected with the Collider Detector at Fermilab to search for narrow-width, vector particles decaying to a top and an antitop quark. Model independent upper limits on the cross section for narrow, vector resonances decaying to t&tmacr; are presented. At the 95% confidence level, we exclude the existence of a leptophobic Z' boson in a model of top-color-assisted technicolor with mass M(Z')<480 GeV/c(2) for natural width gamma = 0.012M(Z'), and M(Z')<780 GeV/c(2) for gamma = 0.04M(Z'). 相似文献
43.
Tipton P Tkaczyk S Tollefson K Tollestrup A Toyoda H Trischuk W de Troconiz JF Tseng J Turini N Ukegawa F Vaiciulis T Valls J Vejcik III Velev G Vidal R Vilar R Volobouev I Vucinic D Wagner RG Wagner RL Wahl J Wallace NB Walsh AM Wang C Wang CH Wang MJ 《Physical review letters》2000,85(10):2056-2061
We report the results of a search for second and third generation leptoquarks using 88 pb(-1) of data recorded by the Collider Detector at Fermilab. Color triplet technipions, which play the role of scalar leptoquarks, are investigated due to their potential production in decays of strongly coupled color octet technirhos. Events with a signature of two heavy flavor jets and missing energy may indicate the decay of a second (third) generation leptoquark to a charm (bottom) quark and a neutrino. As the data are found to be consistent with standard model expectations, mass limits are determined. 相似文献
44.
A. Colin P. Morin F. Cacho H. Bono R. Beneyton D. Mathiot E. Fogarassy 《Applied Physics A: Materials Science & Processing》2011,104(2):517-527
We present a study of the temperature non-homogeneities induced by millisecond laser annealing in advanced CMOS technologies
at die level. Because of the design, the device layout at the wafer surface introduces during this anneal significant spatial
variations of optical absorption and heat transfer that can induce temperature non-uniformities over the die, often called
‘pattern effects’. These temperature variations are becoming a major issue, since they are the origin of significant device
properties dispersion. A complete optical and thermal simulation set has been developed to estimate the temperature variations
induced by the topologies at the wafer surface during the laser anneal process. The modelling has been validated by either
a comparison with another software or reflectometry and electrical measurements on real structures. This work demonstrates
that the temperature variations are caused either by optical coupling or by thermal properties dispersion present at the wafer
surface at the anneal step. Finally, we demonstrate that the impact of the thin-film interferences and diffraction phenomena
is the critical issue for these pattern effects. 相似文献
45.
A micromechanically based constitutive model for fibrous tissues is presented. The model considers the randomly crimped morphology of individual collagen fibers, a morphology typically seen in photomicrographs of tissue samples. It describes the relationship between the fiber endpoints and its arc-length in terms of a measurable quantity, which can be estimated from image data. The collective mechanical behavior of collagen fibers is presented in terms of an explicit expression for the strain-energy function, where a fiber-specific random variable is approximated by a Beta distribution. The model-related stress and elasticity tensors are provided. Two representative numerical examples are analyzed with the aim of demonstrating the peculiar mechanism of the constitutive model and quantifying the effect of parameter changes on the mechanical response. In particular, a fibrous tissue, assumed to be (nearly) incompressible, is subject to a uniaxial extension along the fiber direction, and, separately, to pure shear. It is shown that the fiber crimp model can reproduce several of the expected characteristics of fibrous tissues. 相似文献
46.
A fast method for the determination of aroma-powerful polyfunctional thiols at ng L(-1) level has been developed. Mercaptans are selectively retained in a 50mg solid-phase extraction cartridge and derivatization takes place in the same cartridge at room temperature (25 degrees C) in 20 min by adding small amounts of pentafluorobenzyl bromide (PFBBr) and a strong alkali: 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The corresponding derivatives are further eluted and determined by gas chromatography-negative ion mass spectrometry (GC-NCI-MS). Isolation, derivatization, clean-up, elution and calibration conditions were examined. Carrying the reaction in the cartridge makes it possible to use water and non-polar reagents simultaneously, to avoid large volumes of toxic solvent, and to eliminate the excess of reagent. This was last accomplished by the reaction with mercaptoglycerol and further rinsing with a hydromethanolic solution. The method makes it possible to simultaneously determine 2-methyl-3-furanthiol (MF), 2-furfurylthiol (2-furanmethanethiol) (FFT), 4-mercapto-4-methyl-2-pentanone (MP) (as its methoxime), 3-mercaptohexylacetate (MHA) and 3-mercaptohexanol (MH). Absolute limits of detection were 0.2 (MF), 0.1 (FFT), 0.1 (MP), 0.3 (MHA) and 2 (MH) ng L(-1). Repeatability (1%相似文献
47.
A method for the quantitative determination of four powerful aromatic ethyl esters recently identified in some wines has been developed, validated and applied to the determination of these compounds in different samples of wine, whisky and brandy. Ethyl 2-, 3-, and 4-methylpentanoate and ethyl cyclohexanoate are extracted from 100ml of sample by solid phase extraction (SPE) on a 200mg LiChrolut EN bed. Major compounds are eliminated by rinsing with a water-methanol (50:50) solution containing 1% sodium bicarbonate, and analytes are eluted with 1.5ml of dichloromethane. Fifty microlitres of this extract are then injected in a multidimensional gas chromatography-mass spectromety (GC-GC-MS) system. Recoveries in the SPE are quantitative. Method repeatability is satisfactory (5-12% for a 5-10ngl(-1) level, and less than 7% for 25-50ngl(-1) level), the method linearity holds along the whole range of occurrence of analytes (2-2700ngl(-1)), and the signal is independent on the matrix. Method detection limits are below 1ngl(-1) in all cases. Results suggest that these compounds are formed by the slow esterification with ethanol of the corresponding acids formed by different microorganisms. The levels of these compounds are above the corresponding thresholds in most samples of aged wines or distillates, but are particularly high in some sweet wines, whiskeys and brandies where they may constitute the most important contributors to the sweet-fruity notes reaching concentrations up to 85-350 times higher than the corresponding odor thresholds. 相似文献
48.
Determination of Nitrates in Water Samples by In‐Electrode Coulometric Titration in Copper Coated Porous Vitreous Carbon Electrode 下载免费PDF全文
Lukas Lauko Frantisek Cacho Katarina Lenghartova Jana Sadecka Ernest Beinrohr 《Electroanalysis》2015,27(6):1473-1478
Nitrate in water samples was determined by in‐electrode coulometric titration in porous electrode made of vitreous carbon particles coated with copper. The sample was mixed with diluted sulfuric acid containing 1 mmol/L hydrochloric acid, the solution was filled into the cell and electrode and the nitrate ions were directly reduced by constant current to ammonium ions. The stoichiometry of the electrode reaction was found by coulometric and photometric measurements. The detection limit and precision were found to be 0.2 mg/L and 1.7 %, respectively. The interfering effect of high chloride contents was eliminated by precipitating chlorides with silver sulfate. The method was applied for the analysis of various water samples and beverages. The results were in good agreement with data from isotachophoretic and photometric measurements. 相似文献
49.
Calvert CR Belshaw L Duffy MJ Kelly O King RB Smyth AG Kelly TJ Costello JT Timson DJ Bryan WA Kierspel T Rice P Turcu IC Cacho CM Springate E Williams ID Greenwood JB 《Physical chemistry chemical physics : PCCP》2012,14(18):6289-6297
Laser induced acoustic desorption (LIAD) has been used for the first time to study the parent ion production and fragmentation mechanisms of a biological molecule in an intense femtosecond (fs) laser field. The photoacoustic shock wave generated in the analyte substrate (thin Ta foil) has been simulated using the hydrodynamic HYADES code, and the full LIAD process has been experimentally characterised as a function of the desorption UV-laser pulse parameters. Observed neutral plumes of densities >10(9) cm(-3) which are free from solvent or matrix contamination demonstrate the suitability and potential of the source for studying ultrafast dynamics in the gas phase using fs laser pulses. Results obtained with phenylalanine show that through manipulation of fundamental femtosecond laser parameters (such as pulse length, intensity and wavelength), energy deposition within the molecule can be controlled to allow enhancement of parent ion production or generation of characteristic fragmentation patterns. In particular by reducing the pulse length to a timescale equivalent to the fastest vibrational periods in the molecule, we demonstrate how fragmentation of the molecule can be minimised whilst maintaining a high ionisation efficiency. 相似文献
50.