Numerical Schemes for Variational Inequalities Arising in International Asset Pricing

This paper introduces a valuation model of international pricing in the presence of political risk. Shipments between countries are charged with shipping costs and the country specific production processes are modelled as diffusion processes. The political risk is modelled as a continous time jump process that affects the drift of the returns in the politically unstable countries. The valuation model gives rise to a singular stochastic control problem that is analyzed numerically. The fundamental tools come from the theory of viscosity solutions of the associated Hamilton–Jacobi–Bellman equation which turns out to be a system of integral-differential Variational Inequalities with gradient constraints.     

Equilibrium and kinetic measurements of muscarinic receptor antagonism on living cells using bead injection spectroscopy

Bead injection spectroscopy (BIS) techniques are introduced for automated measurement of pharmacological antagonism by functional assay. Chinese hamster ovary cells that express the rat type 1 muscarinic receptor are cultured on microbeads and used as a renewable biological target for muscarinic receptor antagonist ligands. A flow injection instrument is used to reproducibly sample and capture the cells in a jet ring chamber. The effect of the antagonist pirenzepine on the carbachol-induced intracellular calcium response of the cells is measured with a fluorescence microscope photometry system. The BIS functional assay is used to quantify both equilibrium and kinetic pharmacological values for pirenzepine. In addition, two muscarinic receptor antagonists (pirenzepine and atropine) are assayed to compare their relative efficacy at diminishing the calcium response. Due to the precision of the automated fluid/bead handling protocols, and reproducibility of the measured calcium response, the quantification of useful pharmacological information from living cells by BIS techniques is demonstrated.     

Practical arc-flash reduction

This article will discuss various methods that have been used to reduce the incident energy levels in an existing electrical system is to review and modify the overcurrent protection settings. Specific solutions implemented at a large chemical manufacturing facility are presented. The solutions include equipment upgrades, overcurrent protection modifications, changes to work methods, and worker training which increase the effectiveness of an already robust safety program.     

Arc flash hazard calculations

This article discusses a method for generalizing the arc flash calculations for select areas of a power distribution system. The method presented here helps to reduce the number of equipment locations and also calculations which are analyzed using a commercial software package. In an industrial example, this method reduced the number of small feeder locations that required a detailed analysis by 94%. This resulted in a large reduction of onsite data collection, detailed modeling, and arc flash warning labels     

A flow injection renewable surface technique for cell-based drug discovery functional assays

A novel flow injection-renewable surface (FI-RS) technique is introduced for the execution of automated pharmacology-based assays on living cells. Cells are attached to microcarrier beads, which serve as the disposable and renewable surface with which the assay is performed. The feasibility of this FI-RS technique is demonstrated by performing a functional assay using Chinese hamster ovary cells transfected with the rat muscarinic receptor (M1). The intracellular calcium elevation resulting from the agonist-receptor interaction is measured via a calcium-sensitive fluorescent probe (fura-2) and a fluorescence microscope photometry system. The FI apparatus allows reproducible and precise control of the concentration gradient of chosen muscarinic receptor agonists (carbachol, acetylcholine, pilocarpine) delivered to cells attached to microcarrier beads. The RS methodology eliminates problems associated with diminishing biological response vis-à-vis traditional functional assays that are performed repetitively on the same group of cells. Using this technique, reproducible responses are measured and pharmacologic parameters quantified that compare favorably to literature values. In addition, the use of the FI-RS functional assay as an analytical method for discrimination of agonists based on kinetic parameters is proposed.     

Monitoring of HTS compound library quality via a high-resolution image acquisition and processing instrument

This report presents the high-resolution image acquisition and processing instrument for compound management applications (HIAPI-CM). The HIAPI-CM combines imaging spectroscopy and machine-vision analysis to perform rapid assessment of high-throughput screening (HTS) compound library quality. It has been customized to detect and classify typical artifacts found in HTS compound library microtiter plates (MTPs). These artifacts include (1) insufficient volume of liquid compound sample, (2) compound precipitation, and (3) colored compounds that interfere with HTS assay detection format readout. The HIAPI-CM is also configured to automatically query and compare its analysis results to data stored in a LIMS or corporate database, aiding in the detection of compound registration errors. To demonstrate its capabilities, several compound plates (n=5760 wells total) containing different artifacts were measured via automated HIAPI-CM analysis, and results compared with those obtained by manual (visual) inspection. In all cases, the instrument demonstrated high fidelity (99.8% empty wells; 100.1% filled wells; 94.4% for partially filled wells; 94.0% for wells containing colored compounds), and in the case of precipitate detection, the HIAPI-CM results significantly exceeded the fidelity of visual observations (220.0%). As described, the HIAPI-CM allows for noninvasive, nondestructive MTP assessment with a diagnostic throughput of about 1min per plate, reducing analytical expenses and improving the quality and stewardship of HTS compound libraries.     

A practical approach to arc flash hazard analysis and reduction

Recent efforts to quantify the dangers associated with potential arc flash hazards rely on overcurrent protection to remove a given fault condition. The effectiveness of various devices is determined by a clearing time related to the maximum available fault current for each system location. As industrial and commercial facilities begin to embrace arc flash labeling procedures and begin to recognize arc flash prevention as a part of a complete safety program, the current method of calculation will allow them to quantify the incident energy (cal/cm/sup 2/) associated with a maximum three-phase fault condition. Most faults produce current magnitudes less than the three-phase maximum. This paper will consider fault current magnitudes less than that of the maximum three-phase condition, and discuss the resulting calculations for incident energy across the range of current magnitudes. Under these additional scenarios, the performance of various overcurrent protection devices will be demonstrated. Associated considerations for design, modeling, and maintenance will be presented.     

Beam-selection performance analysis of a switched multibeam antennasystem in mobile communications environments

The probability of incorrect beam selection (PIBS) with a switched multibeam antenna system is theoretically analyzed under power-limited and interference-limited mobile communication environments. Periodic transmission of a unique word sequence followed by the information symbol sequence is assumed. The model of beam selection used is based upon a simple three-stage mechanism: (1) signal validation; (2) averaging; and (3) selection of the largest output. Complex correlation peaks corresponding to the unique words, detected by the matched filter for the signal validation are averaged over several consecutive unique words, and a beam having the largest output is selected. Equally weighted noncoherent integration is assumed for the averaging process. The beam selection takes place frame-by-frame. The paper discusses the PIBS derivation for a simple switched two-beam antenna system. Numerical calculation results are then presented. It also investigates the impact of the incorrect beam selection on the overall average signal-to-noise (SNR) power ratio and signal-to-interference (SIR) power ratio. The amount of the overall SNR (or SIR) improvement over the omnidirectional antenna depends on the propagation conditions. In general, larger improvements can be achieved by smaller values of the PIBS