Electrical aging behavioral modeling for reliability analyses of ionizing dose effects on an n-MOS simple current mirror

Nowadays, a deterministic approach based on physics of failure is necessary to estimate the lifetime of integrated circuits. Therefore, the reliability analyses via electrical/aging simulations are performed during the design phase. Our previous works consisted in generating an aging behavioral model of a circuit in order to assess its degradation level and to predict its lifetime according to its mission profile. This paper presents obtained experimental results using our developed methodology to evaluate the influence of total ionizing dose effects on an n-MOS simple current mirror taking into account technological dispersions.     

Telecommunications Demand and Pricing Structure: An Econometric Analysis

The main objective of this paper is to analyse residential demand by traffic destination, using a translogarithmic indirect utility function. We focus on five traffic directions, in order to construct a model adapted to evaluate the characteristics of telecommunications demand in a competitive market. The resulting price elasticities express high reactivity to own price changes for the main traffic directions, as well as little interactions between the different types of traffic. Moreover, the high values of income elasticities confirm the importance of income effects when analysing residential telecommunications demand. This model shows useful for welfare analysis. The computation of customers' income equivalent variation shows, on average, a higher willingness to pay for some traffic directions than the bill actually paid. Finally, we show that the optimal prices for the operator, in a cost minimisation point of view, are higher than the observed prices for local and national traffic directions. This emphasises the existence of important cross-subsidies among the different segments of customers.     

Controlling Chiral Spin States of a Triangular‐Lattice Magnet by Cooling in a Magnetic Field

Magnetic materials with a non‐collinear and non‐coplanar arrangement of magnetic moments hosting a nonzero scalar spin‐chirality exhibit unique magnetic and spin‐dependent electronic transport properties. The spin chirality often occurs in materials where competing exchange interactions lead to geometrical frustrations between magnetic moments and to a strong coupling between the crystal lattice and the magnetic structure. These characteristics are particularly strong in Mn‐based antiperovskites where the interactions and chirality can be tuned by substitutional modifications of the crystalline lattice. This study presents evidence for the formation of two unequal chiral spin states in magnetically ordered Mn_3.338Ni_0.651N antiperovskite based on density functional theory calculations and supported by magnetization measurements after cooling in a magnetic field. The existence of two scalar spin‐chiralities of opposite sign and different magnitude is demonstrated by a vertical shift of the magnetic‐field dependent magnetization and Hall effect at low fields and from an asymmetrical magnetoresistivity when the applied magnetic field is oriented parallel or antiparallel to the direction of the cooling field. This opens up the possibility of manipulating the spin chirality for potential use in the emerging field of chiral spintronics.     

Efficient Non-Malleable Commitment Schemes

Non-malleability protects against man-in-the middle attacks on cryptographic protocols. Non-malleable commitment schemes, for example, assure that a commitment of a message does not help to produce a commitment of a related message. Here we present efficient constructions of such commitment schemes in the common reference string model based on standard assumptions such as RSA, factoring, or discrete logarithm. Our protocols require only three rounds and a few modular exponentiations, and provide statistical or even perfect secrecy of committed values.     

Novel Algorithms for Quadratic Programming by Using Hypergraph Representations

In this paper novel algorithms are introduced for solving NP hard discrete quadratic optimization problems commonly referred to as unconstrained binary quadratic programming. The proposed methods are based on hypergraph representation and recursive reduction of the dimension of the search space. In this way, efficient and fast search can be carried out and high quality suboptimal solutions can be obtained in real-time. The new algorithms can directly be applied to the quadratic problems of present day communication technologies, such as multiuser detection and scheduling providing fast optimization and increasing the performance. In the case of multiuser detection, the achieved bit error rate can approximate the Bayesian optimum and in the case of scheduling better Weighted Tardiness can be achieved by running the proposed algorithms. The methods are also tested on large scale quadratic problems selected from ORLIB and the solutions are compared to the ones obtained by traditional algorithms, such as Devour digest tidy-up, Hopfield neural network, local search, Taboo search and semi definite relaxing. As the corresponding performance analysis reveals the proposed methods can perform better than the traditional ones with similar complexity.     

Building an index of activity of inhabitants from their activity on the residential electrical power line

In the framework of context awareness within the home, our team is currently assessing the unobtrusive detection of inhabitants' activity through the monitoring of their use and consumption of electricity. The objective is to develop a system for the remote monitoring of large populations of elderly people living independently at home. To be readily deployable on the field, such a system must be minimally intrusive both for the home environment and for the field professionals (paramedics and social workers) visiting the patients at home. We carried out two successive field experiments to evaluate and to improve our system designed to deliver a single index of daily activity. The first experiment involved 13 elderly persons over a nine-month period (84,240 h data recorded) and the second one 12 elderly over six months (51,840 h). We evaluated both the relevance of the index and the acceptability of the system as a whole. We discovered that electrical activity is a kind of unique "signature" of each person's activity. Moreover, this profile provides unexpected information on the health status of the subject. We confirmed that the system was unobtrusive and well accepted both by the subjects and by the professionals involved. Our unique index of activity, and its trend over time, can provide timely information to the professionals on the patient.     

In Situ Scanning Electron Microscopy Observation of Growth Kinetics and Catalyst Splitting in Vapor–Liquid–Solid Growth of Nanowires

In situ observations during vapor–liquid–solid (VLS) growth of semiconductor nanowires in the chamber of an environmental scanning electron microscope (ESEM) are reported. For nanowire growth, a powder mixture of CdS and ZnS is used as a source material and silver nanoparticles as a metal catalyst. Through tracing growth kinetics of nanowires, it is found that nanowires with a relatively bigger catalyst droplet on the tip grow faster. Intriguingly, it is also found that the growth of nanowires can involve catalyst splitting: while the majority of catalyst remains at the nanowire tip and continues facilitating the growth, a portion of it is removed from the tip due to the splitting. It remains attached to the nanowire at the position where the splitting occurred and subsequently induces the growth of a nanowire branch. As far as it is known, this is the first time that catalyst splitting is revealed experimentally in situ. It is proposed that the instability of catalyst droplet caused by the volume increase is the main reason for the splitting. It is believed that in situ growth inside the ESEM can largely enrich our understanding on the metal‐catalyzed VLS growth kinetics, which may open up more opportunities for morphology‐controlled synthesis of 1D semiconductor nanowires in future study.