2,708 research outputs found
Can Strategic Uncertainty Help Deter Tax Evasion? – An Experiment on Auditing Rules
This paper adds to the economic-psychological research on tax compliance by experimentally testing a simple auditing rule that induces strategic uncertainty among taxpayers. Under this rule, termed the bounded rule, taxpayers are informed of the maximum number of audits by a tax authority, so that the audit probability depends on the joint decisions among the taxpayers. We compare the bounded rule to the widely studied flat-rate rule, where taxpayers are informed that they will be audited with a constant probability. The experimental evidence shows that, as theoretically predicted, the bounded rule induces the same level of compliance as the flat-rate rule when strategic uncertainty is low, and a higher level of compliance when strategic uncertainty is high. The bounded rule also suppresses the "bomb crater" effect often observed in prior studies. The results suggest that strategic uncertainty due to interactions among taxpayers could be an effective device to deter tax evasion
Void Formation Study of Flip Chip in Package Using No-Flow Underfill
©2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.DOI: 10.1109/TEPM.2008.2002951The advanced flip chip in package (FCIP) process using no-flow underfill material for high I/O density and fine-pitch interconnect applications presents challenges for an assembly process that must achieve high electrical interconnect yield and high reliability performance. With respect to high reliability, the voids formed in the underfill between solder bumps or inside the solder bumps during the no-flow underfill assembly process of FCIP devices have been typically considered one of the critical concerns affecting assembly yield and reliability performance. In this paper, the plausible causes of underfill void formation in FCIP using no-flow underfill were investigated through systematic experimentation with different types of test vehicles. For instance, the effects of process conditions, material properties, and chemical reaction between the solder bumps and no-flow underfill materials on the void formation behaviors were investigated in advanced FCIP assemblies. In this investigation, the chemical reaction between solder and underfill during the solder wetting and underfill cure process has been found to be one of the most significant factors for void formation in high I/O and fine-pitch FCIP assembly using no-flow underfill materials
A New Soil Testing Apparatus
Green (1967) has effectively stated the case regarding certain serious deficiencies of the Authors' new soil test box. Ko and Scott mention that small volumes of the sample at the corners and along the edges of the box may not be in a homogeneous stress state but did not consider this to be important. This would appear to represent simply an error in judgement. The Writer agrees with Green (1967) that the soil cube was appreciably restrained by the relatively
stiff stainless steel spacing frame. The Authors offer insufficient evidence to support the conclusion that the stress state generated in the sample contained within the new soil test box was found to be uniform or the opinion that the present equipment measures the true deformational behaviour of the soil tested. The opinions of Green (1967) and those of the Writer can easily be verified analytically or through the performance of simple experiments. The following brief and approximate analysis based on the theory of elasticity analytically demonstrates the possible importance of edge restraint for a particular stress path and a cylindrical specimen. Fig. 1 (a) represents a free cylinder with homogeneous triaxial compression while Fig. l (b) represents the same cylinder subjected to identical vertical loads but laterally fixed at four vertical edges
Deconvolution techniques for linear systems
Superposition for linear systems is the process in which the input is convolved with the transfer function of the system, whereby the output is obtained. Deconvolution is, therefore, the reverse process in which an unknown input (or the transfer function) is calculated from the measured output and a known transfer function (or input). Several methods of deconvolution are developed and the advantages and disadvantages of each are discussed. Examples are given to demonstrate the applicability of the methods
Bilateral acute angle closure glaucoma precipitated by over the counter oral decongestant
Letter to the edito
Temporal Stability and Precision of Ventricular Defibrillation Threshold Data
Over two-hundred measurements of the minimum damped sinusoidal current and energy for transchest electrical ventricular defibrillation (ventricular defibrillation threshold) were made to determine the stability and precision of threshold data in 15 pentobarbital-anesthetized dogs. Threshold was determined by repeated trials of fibrillation and defibrillation with successive shocks of diminishing current, each 19% less than that of the preceeding shock. The lowest shock intensity that defibrillated was defined as threshold. In three groups of five dogs each, threshold was measured at intervals of 60, 15, and 5 min. over periods of 8, 5, and 1 hr. respectively. Similar results were obtained for all groups. There was no significant change in mean threshold current with time. Due to a decrease in transchest impedance, threshold delivered energy decreased by 10% during the first hour of testing. The standard deviations for threshold peak current and delivered energy in a given animal were 11 and 22 percent of their respective mean values. Arterial blood pH, pc02, and p02 averaged 7.38, 34 mmHg, and 72 mmHg respectively. The rates of change of pH, pCO2 and p02 were not significantly different from zero. The data demonstrate that ventricular defibrillation threshold is a stable physiologic parameter which may be measured with reasonable precision
Pathological Changes in Microvascular Morphology, Density, Size and Responses Following Comorbid Cerebral Injury
Aberrations in brain microcirculation and the associated increase in blood-brain-barrier (BBB) permeability in addition to neuroinflammation and Aβ deposition observed in Alzheimer’s disease (AD) and ischemia have gained considerable attention recently. However, the role of microvascular homeostasis as a pathogenic substrate to disturbed microperfusion as well as an overlapping etiologic mechanism between AD and ischemia has not been thoroughly explored. In this study, we employ temporal histopathology of cerebral vasculature in a rat model of β-amyloid (Aβ) toxicity and endothelin-1 induced-ischemia (ET1) to investigate the panorama of cerebral pathology and the protein expression on d1, d7, and d28 post-injury. The combination of Aβ and ET1 pathological states leads to an alteration in microvascular anatomy, texture, diameter, density, and protein expression, in addition to disturbed vessel-matrix-connections, inter-compartmental water exchange and basement membrane profile within the lesion epicenter localized in the striatum of Aβ+ET1 brains compared to Aβ and ET1 rats. We conclude that the neural microvascular network, in addition to the neural tissue, is not only sensitive to structural deterioration but also serves as an underlying vascular etiology between ischemia and AD pathologies. Such investigation can provide prospects to appreciate the interrelationships between structure and responses of cerebral microvasculature and to provide a venue for vascular remodeling as a new treatment strategy
GPS Position and Heading Circuitry for Ships
Circuit boards that contain radio-frequency (RF) and digital circuitry have been developed by NASA to satisfy a requirement of the Port of Houston Authority for relatively inexpensive Global Positioning System (GPS) receivers that indicate the azimuthal headings as well as the positions of ships. The receiver design utilizes the unique architecture of the Mitel commercial chip-set, which provides for an accurate GPS-based heading-determination device. The major components include two RF front ends (each connected to a separate antenna), a surface-acoustic-wave intermediate-frequency filter between second- and third-stage mixers, a correlator, and a reduced-instruction- set computer. One of the RF front ends operates as a master, the other as a slave. Both RF front ends share a 10-MHz sinusoidal clock oscillator, which provides for more accurate carrier phase measurements between the two antennas. The outputs of the RF front ends are subjected to conventional GPS processing. The commercial-based chip-set design approach provides an inexpensive open architecture GPS platform, which can be used in developing and implementing unique GPS-heading and attitude-determination algorithms for specific applications. The heading is estimated from the GPS position solutions of the two antennas by an algorithm developed specifically for this application. If a third (and preferably a fourth) antenna were added, it would be possible to estimate the attitude of the GPS receiver in three dimensions instead of only its heading in a horizontal plane
Reconfiguration for Modular Robots Using Kinodynamic Motion Planning
This paper presents computational and experimental evi-dence that it is possible to plan and execute dynamic motions that involve chain reconfiguration for modular reconfigurable robots in the presence of obstacles. At the heart of the approach is the use of a sampling-based motion planner that is tightly integrated with a physics-based dynamic simulator. To evaluate the method, the planner is used to compute motions for a chain robot con-structed from CKbot modules to perform a reconfiguration, at-taching more modules and continuing a dynamic motion while avoiding obstacles. These motions are then executed on hard-ware and compared with the ones predicted by the planner
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