Emerging heterogeneities in Italian customs and comparison with nearby countries

In this work we apply techniques and modus operandi typical of Statistical Mechanics to a large dataset about key social quantifiers and compare the resulting behaviours of five European nations, namely France, Germany, Italy, Spain and Switzerland. The social quantifiers considered are $i.$ the evolution of the number of autochthonous marriages (i.e. between two natives) within a given territorial district and $ii.$ the evolution of the number of mixed marriages (i.e. between a native and an immigrant) within a given territorial district. Our investigations are twofold. From a theoretical perspective, we develop novel techniques, complementary to classical methods (e.g. historical series and logistic regression), in order to detect possible collective features underlying the empirical behaviours; from an experimental perspective, we evidence a clear outline for the evolution of the social quantifiers considered. The comparison between experimental results and theoretical predictions is excellent and allows speculating that France, Italy and Spain display a certain degree of {\em internal heterogeneity}, that is not found in Germany and Switzerland; such heterogeneity, quite mild in France and in Spain, is not negligible in Italy and highlights quantitative differences in the customs of Northern and Southern regions. These findings may suggest the persistence of two culturally distinct communities, long-term lasting heritages of different and well-established cultures.Comment: in PLoS One (2015

Multitasking network with fast noise

We consider the multitasking associative network in the low-storage limit and we study its phase diagram with respect to the noise level $T$ and the degree $d$ of dilution in pattern entries. We find that the system is characterized by a rich variety of stable states, among which pure states, parallel retrieval states, hierarchically organized states and symmetric mixtures (remarkably, both even and odd), whose complexity increases as the number of patterns $P$ grows. The analysis is performed both analytically and numerically: Exploiting techniques based on partial differential equations, allows us to get the self-consistencies for the order parameters. Such self-consistence equations are then solved and the solutions are further checked through stability theory to catalog their organizations into the phase diagram, which is completely outlined at the end. This is a further step toward the understanding of spontaneous parallel processing in associative networks

Dimensional reduction in networks of non- Markovian spiking neurons: Equivalence of synaptic filtering and heterogeneous propagation delays

Understanding the collective behavior of the intricate web of neurons composing a brain is one of the most challenging and complex tasks of modern neuroscience. Part of this complexity resides in the distributed nature of the interactions between the network components: for instance, the neurons transmit their messages (through spikes) with delays, which are due to different axonal lengths (i.e., communication distances) and/or noninstantaneous synaptic transmission. In developing effective network models, both of these aspects have to be taken into account. In addition, a satisfactory description level must be chosen as a compromise between simplicity and faithfulness in reproducing the system behavior. Here we propose a method to derive an effective theoretical description - validated through network simulations at microscopic level - of the neuron population dynamics in many different working conditions and parameter settings, valid for any synaptic time scale. In doing this we assume relatively small instantaneous fluctuations of the input synaptic current. As a by-product of this theoretical derivation, we prove analytically that a network with non-instantaneous synaptic transmission with fixed spike delivery delay is equivalent to a network characterized by a suited distribution of spike delays and instantaneous synaptic transmission, the latter being easier to treat

Kilo-instruction processors: overcoming the memory wall

Historically, advances in integrated circuit technology have driven improvements in processor microarchitecture and led to todays microprocessors with sophisticated pipelines operating at very high clock frequencies. However, performance improvements achievable by high-frequency microprocessors have become seriously limited by main-memory access latencies because main-memory speeds have improved at a much slower pace than microprocessor speeds. Its crucial to deal with this performance disparity, commonly known as the memory wall, to enable future high-frequency microprocessors to achieve their performance potential. To overcome the memory wall, we propose kilo-instruction processors-superscalar processors that can maintain a thousand or more simultaneous in-flight instructions. Doing so means designing key hardware structures so that the processor can satisfy the high resource requirements without significantly decreasing processor efficiency or increasing energy consumption.Peer ReviewedPostprint (published version

A novel architecture for large windows processors

Several processor architectures with large instruction windows have been proposed. They improve performance by maintaining hundreds of instructions in flight to increase the level of instruction parallelism (ILP). Such architectures replace a re-order buffer (ROB) with a check-pointing mechanism and an out-of-order release of the processor resources. Check-pointing, however, leads to an imprecise state recovery on mispredicted branches and exceptions and frequent re-execution of current-path instructions during the state recovery. It also requires large register files complicating renaming, allocation and release of physical registers. This technical report proposes a new processor architecture that does not use either a traditional ROB or check-pointing, avoids the above-mentioned problems, and has a fast, distributed state recovery mechanism. Its novel register management architecture allows implementation of large register files with simpler and more scalable, register renaming and commit. It is also key to the precise recovery mechanism.Postprint (published version

A distributed processor state management architecture for large-window processors

Processor architectures with large instruction windows have been proposed to expose more instruction-level parallelism (ILP) and increase performance. Some of the proposed architectures replace a re-order buffer (ROB) with a check-pointing mechanism and an out-of-order release of processor resources. Check-pointing, however, leads to an imprecise processor state recovery on mis-predicted branches and exceptions and re-execution of correct-path instructions after state recovery. It also requires large register files complicating renaming, allocation and release of physical registers. This paper proposes a new processor architecture called a Multi-State Processor (MSP). The MSP does not use check-pointing, avoids the above-mentioned problems, and has a fast, distributed state recovery mechanism. The MSP uses a novel register management architecture allowing implementation of large register files with simpler and more scalable register allocation, renaming, and release. It is also key to precise processor state recovery mechanism. The MSP is shown to improve IPC by 14%, on average, for integer SPEC CPU2000 benchmarks compared to a check-pointing based mechanism ([2]) when a fast and simple branch predictor is used. With a very aggressive branch predictor the IPC improvement is 1%, on average, and 3% if some of the programs are optimized for the MSP. The MSP also reduces the average number of executed instructions by 16.5% (12% for the aggressive branch predictor), mostly due to precise state recovery. This improves the MSP processor energy efficiency even though it uses a larger register file.Peer ReviewedPostprint (published version

Design and Optimization of an Active Leveling System Actuator for Lunar Lander Application

This work proposes a systematic methodology for designing an active leveling system (ALS) actuator for lunar landing application. The ALS actuator is integrated into an inverted tripod leg layout, exploiting a honeycomb crushable damper as a shock absorber. The proposed ALS actuator is fitted within the leg’s primary strut and features a custom permanent-magnet synchronous machine rigidly coupled with a lead screw. The actuator aims to both provide proper leg deployment functioning and compensate for the different shock absorber deformations during landing. The leg dynamic behavior is simulated through a parameterized multi-body model to investigate different landing scenarios. First, a parametric sensitivity approach is used to optimize the transmission system and the electric machine characteristics. Then, the electric motor model is numerically validated and optimized through electromagnetic finite element analysis. To validate the proposed ALS design methodology, a virtual test bench is used to assess the ALS performances under different load scenarios. It is found that the proposed methodology is able to yield a compact, well-sized actuator which is numerically validated with the EL3 platform as a case study

A Modular Lunar Hotel

The aim of this paper is to propose an innovative modular lunar hotel/outpost that can be assembled using the load capacity of future rockets Space X is at present developing and presumably will be opera- tional by 2025. In particular, the design is based on the Space X' Starship, that will have the capability to land large and heavy payloads on the Moon. The lunar building is essentially made of four cylindrical modules assembled around one central distribution and service hub. These four modules, intended for housing, have a geodesic dome with large windows to observe the lunar environment surrounding the outpost. The entry point to the base is in the lower part of the central module, which is the only part of the building touching the ground and rests on four adjustable legs. The central module will be used for vertical connections and services as well as for hydroponic laboratories and greenhouses in which to grow the food the settlers will eat. The whole structure will be about 15m high and will be protected from cosmic radiation by a magnetic eld generated by a number of electric cables laid on a spherical structure made of in atable high pressure tubes. The modules can be made of light material since the protection form radiation is supplied by the magnetic eld, and need only a thermal insulating layer, which can be fairly light. The whole structure can thus be carried from Earth without the need of manufacturing it on site. As an added advantage, large windows can be present, mainly in the a top domes/observatories, which will be the characteristic elements of the installation. The cylindrical modules have a diameter of 6m, suitable to be transported in the cargo hold of the Starship. To reach an height of 15m, they are made in sections and then assembled on site. The modules will be lowered from the hold of the Starship by means of the crane with which each spaceship is equipped. Before starting the assembly of the modules, self-propelled cranes and vehicles will be carried to the Moon so that the construction site of the hotel/outpost can be relatively distant from the landing area. These construction machines will then remain available for other construction projects on the Moon. A total of about 10 launches are expected to be required to carry to the Moon all parts needed to build the facility

Modular Lunar Hotel

The aim of this paper is to propose an innovative modular lunar hotel or outpost that can be assembled using the load capacity of future rockets Space X is at present developing and presumably will be opera- tional by 2025. In particular, the design is based on the Space X Starship, that will have the capability to land large and heavy payloads on the Moon. The lunar building is essentially made of four cylindrical modules assembled around one central distribution and service hub. These four modules, intended for housing, have a geodesic dome with large windows to observe the lunar environment surrounding the outpost. The entry point to the base is in the lower part of the central module, which is the only part of the building touching the ground and rests on four adjustable legs. The central module will be used for vertical connections and services as well as for hydroponic laboratories and greenhouses in which to grow the food the settlers will eat. The whole structure will be about 15m high and will be protected from cosmic radiation by a magnetic eld generated by a number of electric cables laid on a spherical structure made of in a table high pressure tubes. The modules can be made of light materials since the protection from radiation is supplied by the magnetic eld, and need only a thermal insulating layer, which can be fairly light. The whole structure can thus be carried from Earth without the need of manufacturing it on site. As an added advantage, large windows can be present, mainly in the a top domes/observatories, which will be the characteristic elements of the installation. The cylindrical modules have a diameter of 6m, suitable to be transported in the cargo hold of the Starship. To reach an height of 15m, they are made in sections and then assembled on site. The modules will be lowered from the hold of the Starship by means of the crane with which each spaceship is equipped. Before starting the assembly of the modules, self-propelled cranes and vehicles will be carried to the Moon so that the construction site of the hotel/outpost can be relatively distant from the landing area. These construction machines will then remain available for other construction projects on the Moon. A total of about 10 launches are expected to be required to carry to the Moon all parts needed to build the facility