A Comparative Study of Reservoir Computing for Temporal Signal Processing

Reservoir computing (RC) is a novel approach to time series prediction using recurrent neural networks. In RC, an input signal perturbs the intrinsic dynamics of a medium called a reservoir. A readout layer is then trained to reconstruct a target output from the reservoir's state. The multitude of RC architectures and evaluation metrics poses a challenge to both practitioners and theorists who study the task-solving performance and computational power of RC. In addition, in contrast to traditional computation models, the reservoir is a dynamical system in which computation and memory are inseparable, and therefore hard to analyze. Here, we compare echo state networks (ESN), a popular RC architecture, with tapped-delay lines (DL) and nonlinear autoregressive exogenous (NARX) networks, which we use to model systems with limited computation and limited memory respectively. We compare the performance of the three systems while computing three common benchmark time series: H{\'e}non Map, NARMA10, and NARMA20. We find that the role of the reservoir in the reservoir computing paradigm goes beyond providing a memory of the past inputs. The DL and the NARX network have higher memorization capability, but fall short of the generalization power of the ESN

Time of Flight Analysis Using Cosmic Ray Muons in the ATLAS Tile Calorimeter

Using cosmic ray muon data recorded during the summer of 2007, we have studied the time-of-flight distributions between back-to-back modules of the ATLAS Tile Calorimeter. The results are in good agreement with the distributions expected from calorimeter geometry, and allow for cross-checks of timing corrections obtained in laser runs. Calorimeter timing is a useful tool to remove non-physics backgrounds, and we introduce new cuts at the cell level which improve the signal-to-noise ratio

Nature-Inspired Interconnects for Self-Assembled Large-Scale Network-on-Chip Designs

Future nano-scale electronics built up from an Avogadro number of components needs efficient, highly scalable, and robust means of communication in order to be competitive with traditional silicon approaches. In recent years, the Networks-on-Chip (NoC) paradigm emerged as a promising solution to interconnect challenges in silicon-based electronics. Current NoC architectures are either highly regular or fully customized, both of which represent implausible assumptions for emerging bottom-up self-assembled molecular electronics that are generally assumed to have a high degree of irregularity and imperfection. Here, we pragmatically and experimentally investigate important design trade-offs and properties of an irregular, abstract, yet physically plausible 3D small-world interconnect fabric that is inspired by modern network-on-chip paradigms. We vary the framework's key parameters, such as the connectivity, the number of switch nodes, the distribution of long- versus short-range connections, and measure the network's relevant communication characteristics. We further explore the robustness against link failures and the ability and efficiency to solve a simple toy problem, the synchronization task. The results confirm that (1) computation in irregular assemblies is a promising and disruptive computing paradigm for self-assembled nano-scale electronics and (2) that 3D small-world interconnect fabrics with a power-law decaying distribution of shortcut lengths are physically plausible and have major advantages over local 2D and 3D regular topologies

Effects of alcohol consumption on mortality in patients with Type 2 diabetes mellitus

Aims/hypothesis: Moderate alcohol intake has been associated with increased life expectancy due to reduced mortality from cardiovascular disease. We prospectively examined the effects of alcohol consumption on mortality in Type 2 diabetic patients in Switzerland. Methods: A total of 287 patients with Type 2 diabetes mellitus (125 women, 162 men), recruited in Switzerland for the WHO Multinational Study of Vascular Disease in Diabetes, were included in this study. After a follow-up period of 12.6±0.6 years (means ± SD), mortality from CHD and from all causes was assessed. Results: During the follow-up, 70 deaths occurred (21 from CHD, 49 from other causes). Compared with non-drinkers, alcohol consumers who drank alcohol 1 to 15g, 16 to 30g and 30g or more per day had the following risk rates of death from CHD: 0.87 (95% CI: 0.25 to 2.51, NS), 0.00 (95% CI: 0.00 to 0.92, p less than 0.05) and 0.37 (95% CI, 0.01 to 2.42, NS), respectively. The corresponding risk rates of death from all causes were 1.27 (95% CI: 0.68 to 2.28, NS), 0.36 (95% CI: 0.09 to 0.99, p less than 0.05) and 1.66 (95% CI: 0.76 to 3.33, NS). Conclusions/interpretation: In Swiss Type 2 diabetic patients moderate alcohol consumption of 16 to 30g per day was associated with reduced mortality from CHD and from all causes. Alcohol intake above 30g per day was associated with a tendency towards increased all-cause mortalit

Anti-Diabetic Drugs In The Private And Public Sector In Dar Es Salaam, Tanzania

Objectives: To compare availability, cost, affordability and sources of anti-diabeticdrugs between private and public health facilities in Dar es Salaam, Tanzania.Design: Cross sectional descriptive study.Setting: Diabetic clinics in private and public health facilities in Dar es Salaam,Tanzania.Subjects: Eighty patients randomly selected and 45 health facility personnel staffworking in the diabetic clinics. Semi-structured questionnaires and a checklist wereused to collect the information.Results: Oral hypoglycaemic agents were available in all seven private and three publicfacilities that were studied. Private facilities stocked more types of oral hypoglycaemicagents than public facilities, which stocked only chlorpropamide and tolbutamide,based on the National Essential Drugs List. The cost of chlorpropamide was five timeshigher in private facilities compared to public facilities. Insulin was also available inall the facilities. The price of animal insulin in private health facilities was ten timesthat in public health facilities. Human insulin, which is generally more expensive thananimal insulin, was only available in private facilities. Although prices were muchlower in public facilities, affordability emerged as a common issue in both privateand public facilities.Conclusions: Urban private health facilities offer a wider choice for the needs ofdiabetic patients but this advantage is compromised by higher prices as compared topublic facilities as well as inconsistent supply across facilities. Public health facilitiesoffer only a limited selection of essential oral hypoglycaemics and insulin but at alower price and across all facilities. Twenty six per cent and 10% of patients in publicand private facilities respectively are unable to afford anti-diabetic drugs. The needfor intervention to increase affordability of anti-diabetic drugs is evident. Financingand cost of drugs needs to be addressed, either by means of health insurance orother mechanisms, in this era of increasing prevalence of diabetes mellitus amongdeveloping countries

A mobile data acquisition system

A mobile data aquisition (MobiDAQ) was developed for the ATLAS central hadronic calorimeter (TileCal). MobiDAQ has been designed in order to test the functionalities of the TileCal front-end electronics and to acquire calibration data before the final back-end electronics were built and tested. MobiDAQ was also used to record the first cosmic ray events acquired by an ATLAS subdetector in the underground experimental area

Energy-Efficient Neuromorphic Architectures for Nuclear Radiation Detection Applications

A comprehensive analysis and simulation of two memristor-based neuromorphic architectures for nuclear radiation detection is presented. Both scalable architectures retrofit a locally competitive algorithm to solve overcomplete sparse approximation problems by harnessing memristor crossbar execution of vector–matrix multiplications. The proposed systems demonstrate excellent accuracy and throughput while consuming minimal energy for radionuclide detection. To ensure that the simulation results of our proposed hardware are realistic, the memristor parameters are chosen from our own fabricated memristor devices. Based on these results, we conclude that memristor-based computing is the preeminent technology for a radiation detection platform