Cramer-von Mises Variance Estimators for Simulations

Proceedings of the 1991 Winter Simulation Conference Barry L. Nelson, W. David Kelton, Gordon M. Clark (eds.)We study estimators for the variance parameter u 2 of a stationary process. The estimators are based on weighted Cramer-van Mises statistics formed from the standardized time series of the process. Certain weightings yield estimators which are "first-order unbiased" for u2 and which have low variance. We also show how the Cramer-von Mises estimators are related to the standardized time series area estimator; we use this relationship to establish additional estimators for u2

Verilog-A Device Models for Cryogenic Temperature Operation of Bulk Silicon CMOS Devices

Verilog-A based cryogenic bulk CMOS (complementary metal oxide semiconductor) compact models are built for state-of-the-art silicon CMOS processes. These models accurately predict device operation at cryogenic temperatures down to 4 K. The models are compatible with commercial circuit simulators. The models extend the standard BSIM4 [Berkeley Short-channel IGFET (insulated-gate field-effect transistor ) Model] type compact models by re-parameterizing existing equations, as well as adding new equations that capture the physics of device operation at cryogenic temperatures. These models will allow circuit designers to create optimized, reliable, and robust circuits operating at cryogenic temperatures

Violencia de género expandida: vigilancia y privacidad en red

In this paper, we present a reflection that links gender violence in digital environments, mass surveillance, discussions about privacy and the right to privacy on the internet. We analyze how the Internet can be the scene of two types of violence: one, located at the level of interactions (doxing, harassment, extortion and threats, identity theft, alteration and publication of photos and videos without consent, among others). The other, more invisible, is implicit in the architecture of the network, because, by promoting a systematic and gigantic system of tracking and analysis of personal data to feed the Internet business model, it has established a potential monitoring system that can affect the rights of women, via digital traces. To support this, we will examine the various notions of surveillance and privacy (Bruno, 2013; Siri, 2015; Sparrow, 2014) and current legislation in order to understand how they affect the human rights of women in cyberspace.Keyword: gender violence, surveillance and privacy, Internet.En este trabajo exponemos una reflexión que enlaza la violencia de género en entornos digitales, la vigilancia masiva, las discusiones sobre la privacidad y el derecho a la intimidad en internet. Analizamos cómo internet puede ser escenario de dos tipos de violencias: una, localizada en el plano de las interacciones (doxing, acoso, extorsión y amenazas, robo de identidad, alteración y publicación de fotos y videos sin consentimiento, entre otras). La otra, más invisible, está implícitaen la arquitectura de la red, pues al propiciar un sistemático y gigantesco sistema de rastreo y análisis de datos personales para alimentar el modelo de negocios de internet, se ha instaurado un potencial sistema de vigilancia que puede afectar los derechos de las mujeres, vía rastros digitales. Para sostener esto examinaremos las diversas nociones de vigilancia y privacidad (Bruno, 2013; Siri, 2015; Sparrow, 2014) y la legislación vigente, en función de comprender cómo afectan los derechos humanos de las mujeres en el ciberespacio. Palabras clave: violencia de género, vigilancia y privacidad, internet

Modelling human network behaviour using simulation and optimization tools: the need for hybridization

The inclusion of stakeholder behaviour in Operations Research / Industrial Engineering (OR/IE) models has gained much attention in recent years. Behavioural and cognitive traits of people and groups have been integrated in simulation models (mainly through agent-based approaches) as well as in optimization algorithms. However, especially the influence of relations between different actors in human networks is a broad and interdisciplinary topic that has not yet been fully investigated. This paper analyses, from an OR/IE point of view, the existing literature on behaviour-related factors in human networks. This review covers different application fields, including: supply chain management, public policies in emergency situations, and Internet-based human networks. The review reveals that the methodological approach of choice (either simulation or optimization) is highly dependent on the application area. However, an integrated approach combining simulation and optimization is rarely used. Thus, the paper proposes the hybridization of simulation with optimization as one of the best strategies to incorporate human behaviour in human networks and the resulting uncertainty, randomness, and dynamism in related OR/IE models.Peer Reviewe

Deformation Potential Carrier-Phonon Scattering in Semiconducting Carbon Nanotube Transistors

Theoretical calculations of carrier transport in single-walled carbon nanotubes are compared with recent experiments. Carrier-phonon scattering is accounted for using the deformation potential approximation. Comparing with experiments, a deformation potential coupling constant of 14eV is determined for semiconducting carbon nanotubes. Theory is shown to closely predict the low-field mobility, on conductance, and on resistance of field-effect transistors as a function of induced nanotube charge density, diameter, and temperature. Results indicate that the device conductance is reduced as multiple subband channels conduct due to strong intersubband scattering. Comparison with experiment allows identification of the mean free path (Lm) in semiconducting carbon nanotubes. As the device turns on, Lm is found to increase significantly. When the device is in the on state, the mean free path (Lm-ON) varies linearly with tube diameter and inversely with temperature. Intersubband scattering is found to strongly decrease Lm-ON when a few subbands are occupied. When 3 subband channels are considered at room temperature, Lm-ON decreases from 570nm to 200nm for a 4nm diameter tube when intersubband scattering is included. Since the subband spacing increases with decreasing tube diameter, the effects of intersubband are reduced for smaller diameters.Comment: 11 pages, 6 figure

Hybrid AlGaN-SiC Avalanche Photodiode for Deep-UV Photon Detection

The proposed device is capable of counting ultraviolet (UV) photons, is compatible for inclusion into space instruments, and has applications as deep- UV detectors for calibration systems, curing systems, and crack detection. The device is based on a Separate Absorption and Charge Multiplication (SACM) structure. It is based on aluminum gallium nitride (AlGaN) absorber on a silicon carbide APD (avalanche photodiode). The AlGaN layer absorbs incident UV photons and injects photogenerated carriers into an underlying SiC APD that is operated in Geiger mode and provides current multiplication via avalanche breakdown. The solid-state detector is capable of sensing 100-to-365-nanometer wavelength radiation at a flux level as low as 6 photons/pixel/s. Advantages include, visible-light blindness, operation in harsh environments (e.g., high temperatures), deep-UV detection response, high gain, and Geiger mode operation at low voltage. Furthermore, the device can also be designed in array formats, e.g., linear arrays or 2D arrays (micropixels inside a superpixel)

Reactive strategies for containing developing outbreaks of pandemic influenza

Abstract Background In 2009 and the early part of 2010, the northern hemisphere had to cope with the first waves of the new influenza A (H1N1) pandemic. Despite high-profile vaccination campaigns in many countries, delays in administration of vaccination programs were common, and high vaccination coverage levels were not achieved. This experience suggests the need to explore the epidemiological and economic effectiveness of additional, reactive strategies for combating pandemic influenza. Methods We use a stochastic model of pandemic influenza to investigate realistic strategies that can be used in reaction to developing outbreaks. The model is calibrated to documented illness attack rates and basic reproductive number (R0) estimates, and constructed to represent a typical mid-sized North American city. Results Our model predicts an average illness attack rate of 34.1% in the absence of intervention, with total costs associated with morbidity and mortality of US$81 million for such a city. Attack rates and economic costs can be reduced to 5.4$37 million, respectively, when low-coverage reactive vaccination and limited antiviral use are combined with practical, minimally disruptive social distancing strategies, including short-term, as-needed closure of individual schools, even when vaccine supply-chain-related delays occur. Results improve with increasing vaccination coverage and higher vaccine efficacy. Conclusions Such combination strategies can be substantially more effective than vaccination alone from epidemiological and economic standpoints, and warrant strong consideration by public health authorities when reacting to future outbreaks of pandemic influenza