32 research outputs found
Fundamental theorem of asset pricing with acceptable risk in markets with frictions
We study the range of prices at which a rational agent should contemplate
transacting a financial contract outside a given securities market. Trading is
subject to nonproportional transaction costs and portfolio constraints and full
replication by way of market instruments is not always possible. Rationality is
defined in terms of consistency with market prices and acceptable risk
thresholds. We obtain a direct and a dual description of market-consistent
prices with acceptable risk. The dual characterization requires an appropriate
extension of the classical Fundamental Theorem of Asset Pricing where the role
of arbitrage opportunities is played by acceptable deals, i.e., costless
investment opportunities with acceptable risk-reward tradeoff. In particular,
we highlight the importance of scalable acceptable deals, i.e., investment
opportunities that are acceptable deals regardless of their volume.Comment: 28 page
Doping of silicon by phosphorus end-terminated polymers: drive-in and activation of dopants
An effective doping technology for precise control of P atom injection and activation into a semiconductor substrate is presented
Dual representations for systemic risk measures based on acceptance sets
We establish dual representations for systemic risk measures based on acceptance sets in a general setting. We deal with systemic risk measures of both "first allocate, then aggregate" and "first aggregate, then allocate" type. In both cases, we provide a detailed analysis of the corresponding systemic acceptance sets and their support functions. The same approach delivers a simple and self-contained proof of the dual representation of utility-based risk measures for univariate positions
A Decision Support System Based on Transport Modeling for Events Management in Public Transport Networks
This paper presents a modeling approach developed within the MOTUS project, designed to provide a standardized and solid intervention proposal to face events and disruption on a public transport network. This modeling approach resulted into a tool capable of identify in a formalized way the nodes and links where to broadcast info-mobility information through ITS systems and to lead the users to the best alternative solutions. The tool is exploited to make the decision process less dependent on the expert judgment (that still plays a vital role) and human factors, to allow the service provider to respond in a faster and clear way to the possible disruptions both through info-mobility and the strengthening of the offer on the involved routes. Therefore, this paper describes how the modeling approach is applied, how the resulting tool can be exploited, and finally provides an example on the city of Milan, simulating the closure of one of the main lines and reporting the results provided by the presented model and the developed tool
Doping of silicon with phosphorus end-terminated polymers: source characterization and dopant diffusion in SiO2
A polystyrene homopolymer with narrow molecular weight distribution (Mn= 2.3 ± 0.3 kg mol−1,Đ= 1.05 ± 0.01) and end-terminated with a phosphorus containing moiety has been used to form P δ-layers embedded into a SiO2matrix. The number of P atoms in the δ-layers has been stepwise increased from ∼5 × 1013to ∼1.6 × 1014atoms per cm2by repeated doping cycles. The P δ-layers have been tested as diffusion sources at temperatures ranging from 1000 to 1200 °C for different annealing times, up to 120 s. Variations of the diffusion coefficients with the annealing time have been observed and a clear dependence of diffusion coefficients on the P concentration has been highlighted. These results suggest the presence of two different P species diffusing through the SiO2matrix; an initially fast diffusing P compound and a slow diffusing P atom incorporated into the oxide in a bound form. Collected data provide information about P diffusion in SiO2that is fundamental to the development of predictive models for nanoscale doping processes based on the use of diffusion dopant sources generated by self-limiting reactions of dopant containing molecules onto deglazed or non-deglazed semiconductor substrates
Doping of silicon by phosphorus end-terminated polymers: Drive-in and activation of dopants
An effective doping technology for the precise control of P atom injection and activation into a semiconductor substrate is presented. Polystyrene polymers with a narrow molecular weight distribution and end-terminated with a P containing moiety are used to build up a phosphorus \u3b4-layer to be used as the dopant source. P atoms are efficiently injected into the Si substrate by high temperature (900-1250 \ub0C) thermal treatments. Temperature dependent (100-300 K) resistivity and Hall measurements in the van der Pauw configuration demonstrate high activation rates (\u3b7a > 80%) of injected P atoms. This bottom-up approach holds promise for the development of a mild technology for efficient doping of semiconductors
Synthesis and characterization of P delta-layer in SiO2 by monolayer doping
none7noAchieving the required control of dopant distribution and selectivity for nanostructured semiconducting building block is a key issue for a large variety of applications. A promising strategy is monolayer doping (MLD), which consists in the creation of a well-ordered monolayer of dopant-containing molecules bonded to the surface of the substrate. In this work, we synthesize a P delta-layer embedded in a SiO2 matrix by MLD. Using a multi-technique approach based on time of flight secondary ion mass spectrometry (ToF-SIMS) and Rutherford backscattering spectrometry (RBS) analyses, we characterize the tuning of P dose as a function of the processing time and temperature. We found the proper conditions for a full grafting of the molecules, reaching a maximal dose of 8.3 x 10(14) atoms/cm(2). Moreover, using 1D rate equation model, we model P diffusion in SiO2 after annealing and we extract a P diffusivity in SiO2 of 1.5 x 10(17) cm(2) s(-1).restrictedArduca, Elisa; Mastromatteo, Massimo; De Salvador, Davide; Seguini, Gabriele; Lenardi, Cristina; Napolitani, Enrico; Perego, MicheleArduca, Elisa; Mastromatteo, Massimo; DE SALVADOR, Davide; Seguini, Gabriele; Lenardi, Cristina; Napolitani, Enrico; Perego, Michel
Engineering of the spin on dopant process on silicon on insulator substrate
We report on a systematic analysis of phosphorus diffusion in silicon on insulator thin film via spin-on-dopant process (SOD). This method is used to provide an impurity source for semiconductor junction fabrication. The dopant is first spread into the substrate via SOD and then diffused by a rapid thermal annealing process. The dopant concentration and electron mobility were characterized at room and low temperature by four-probe and Hall bar electrical measurements. Time-of-flight-secondary ion mass spectroscopy was performed to estimate the diffusion profile of phosphorus for different annealing treatments. We find that a high phosphorous concentration (greater than 1020 atoms cm-3) with a limited diffusion of other chemical species and allowing to tune the electrical properties via annealing at high temperature for short time. The ease of implementation of the process, the low cost of the technique, the possibility to dope selectively and the uniform doping manufactured with statistical process control show that the methodology applied is very promising as an alternative to the conventional doping methods for the implementation of optoelectronic devices