Measurement of single charged pion production in the charged-current interactions of neutrinos in a 1.3 GeV wide band beam

Single charged pion production in charged-current muon neutrino interactions with carbon is studied using data collected in the K2K long-baseline neutrino experiment. The mean energy of the incident muon neutrinos is 1.3 GeV. The data used in this analysis are mainly from a fully active scintillator detector, SciBar. The cross section for single $\pi^{+}$ production in the resonance region ($W<2$ GeV/$c^2$) relative to the charged-current quasi-elastic cross section is found to be 0.734 $^{+0.140}_{-0.153}$. The energy-dependent cross section ratio is also measured. The results are consistent with a previous experiment and the prediction of our model.Comment: 15 pages, 12 figures, 7 tables. Uses revtex4. Minor revisions to match version accepted for publication in Physical Review

Reach-To-Grasp Movements: A Multimodal Techniques Study

The aim of the present study was to investigate the correlation between corticospinal activity, kinematics, and electromyography (EMG) associated with the execution of precision and whole-hand grasps (WHGs). To this end, motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS), EMG, and 3-D motion capture data have been simultaneously recorded during the planning and the execution of prehensile actions toward either a small or a large object. Differences in the considered measures were expected to distinguish between the two types of grasping actions both in terms of action preparation and execution. The results indicate that the index finger (FDI) and the little finger (ADM) muscles showed different activation patterns during grasping execution, but only the FDI appeared to distinguish between the two types of actions during motor preparation. Kinematics analysis showed that precision grips differed from WHGs in terms of displayed fingers distance when shaping before object\u2019s contact, and in terms of timing and velocity patterns. Moreover, significant correlations suggest a relationship between the muscular activation and the temporal aspects concerned with the index finger\u2019s extension during whole-hand actions. Overall, the present data seem to suggest a crucial role played by index finger as an early \u201cmarker\u201d of differential motor preparation for different types of grasps and as a \u201cnavigator\u201d in guiding whole-hand prehensile actions. Aside from the novelty of the methodological approach characterizing the present study, the data provide new insights regarding the level of crosstalk among different levels concerned with the neuro-behavioral organization of reach-to-grasp movements

An Approach to Assess Solder Interconnect Degradation Using Digital Signal

Department of Human and Systems EngineeringDigital signals used in electronic systems require reliable data communication. It is necessary to monitor the system health continuously to prevent system failure in advance. Solder joints in electronic assemblies are one of the major failure sites under thermal, mechanical and chemical stress conditions during their operation. Solder joint degradation usually starts from the surface where high speed signals are concentrated due to the phenomenon referred to as the skin effect. Due to the skin effect, high speed signals are sensitive when detecting the early stages of solder joint degradation. The objective of the thesis is to assess solder joint degradation in a non-destructive way based on digital signal characterization. For accelerated life testing the stress conditions were designed in order to generate gradual degradation of solder joints. The signal generated by a digital signal transceiver was travelling through the solder joints to continuously monitor the signal integrity under the stress conditions. The signal properities were obtained by eye parameters and jitter, which represented the characteristics of the digital signal in terms of noise and timing error. The eye parameters and jitter exhibited significant increase after the exposure of the solder joints to the stress conditions. The test results indicated the deterioration of the signal integrity resulted from the solder joint degradation, and proved that high speed digital signals could serve as a non-destructive tool for sensing physical degradation. Since this approach is based on the digital signals used in electronic systems, it can be implemented without requiring additional sensing devices. Furthermore, this approach can serve as a proactive prognostic tool, which provides real-time health monitoring of electronic systems and triggers early warning for impending failure.ope

Design and modelling of variability tolerant on-chip communication structures for future high performance system on chip designs

The incessant technology scaling has enabled the integration of functionally complex System-on-Chip (SoC) designs with a large number of heterogeneous systems on a single chip. The processing elements on these chips are integrated through on-chip communication structures which provide the infrastructure necessary for the exchange of data and control signals, while meeting the strenuous physical and design constraints. The use of vast amounts of on chip communications will be central to future designs where variability is an inherent characteristic. For this reason, in this thesis we investigate the performance and variability tolerance of typical on-chip communication structures. Understanding of the relationship between variability and communication is paramount for the designers; i.e. to devise new methods and techniques for designing performance and power efficient communication circuits in the forefront of challenges presented by deep sub-micron (DSM) technologies. The initial part of this work investigates the impact of device variability due to Random Dopant Fluctuations (RDF) on the timing characteristics of basic communication elements. The characterization data so obtained can be used to estimate the performance and failure probability of simple links through the methodology proposed in this work. For the Statistical Static Timing Analysis (SSTA) of larger circuits, a method for accurate estimation of the probability density functions of different circuit parameters is proposed. Moreover, its significance on pipelined circuits is highlighted. Power and area are one of the most important design metrics for any integrated circuit (IC) design. This thesis emphasises the consideration of communication reliability while optimizing for power and area. A methodology has been proposed for the simultaneous optimization of performance, area, power and delay variability for a repeater inserted interconnect. Similarly for multi-bit parallel links, bandwidth driven optimizations have also been performed. Power and area efficient semi-serial links, less vulnerable to delay variations than the corresponding fully parallel links are introduced. Furthermore, due to technology scaling, the coupling noise between the link lines has become an important issue. With ever decreasing supply voltages, and the corresponding reduction in noise margins, severe challenges are introduced for performing timing verification in the presence of variability. For this reason an accurate model for crosstalk noise in an interconnection as a function of time and skew is introduced in this work. This model can be used for the identification of skew condition that gives maximum delay noise, and also for efficient design verification

Empirical timing analysis of CPUs and delay fault tolerant design using partial redundancy

The operating clock frequency is determined by the longest signal propagation delay, setup/hold time, and timing margin. These are becoming less predictable with the increasing design complexity and process miniaturization. The difficult challenge is then to ensure that a device operating at its clock frequency is error-free with quantifiable assurance. Effort at device-level engineering will not suffice for these circuits exhibiting wide process variation and heightened sensitivities to operating condition stress. Logic-level redress of this issue is a necessity and we propose a design-level remedy for this timing-uncertainty problem. The aim of the design and analysis approaches presented in this dissertation is to provide framework, SABRE, wherein an increased operating clock frequency can be achieved. The approach is a combination of analytical modeling, experimental analy- sis, hardware /time-redundancy design, exception handling and recovery techniques. Our proposed design replicates only a necessary part of the original circuit to avoid high hardware overhead as in triple-modular-redundancy (TMR). The timing-critical combinational circuit is path-wise partitioned into two sections. The combinational circuits associated with long paths are laid out without any intrusion except for the fan-out connections from the first section of the circuit to a replicated second section of the combinational circuit. Thus only the second section of the circuit is replicated. The signals fanning out from the first section are latches, and thus are far shorter than the paths spanning the entire combinational circuit. The replicated circuit is timed at a subsequent clock cycle to ascertain relaxed timing paths. This insures that the likelihood of mistiming due to stress or process variation is eliminated. During the subsequent clock cycle, the outcome of the two logically identical, yet time-interleaved, circuit outputs are compared to detect faults. When a fault is detected, the retry sig- nal is triggered and the dynamic frequency-step-down takes place before a pipe flush, and retry is issued. The significant timing overhead associated with the retry is offset by the rarity of the timing violation events. Simulation results on ISCAS Benchmark circuits show that 10% of clock frequency gain is possible with 10 to 20 % of hardware overhead of replicated timing-critical circuit

In-Orbit Instrument Performance Study and Calibration for POLAR Polarization Measurements

POLAR is a compact space-borne detector designed to perform reliable measurements of the polarization for transient sources like Gamma-Ray Bursts in the energy range 50-500keV. The instrument works based on the Compton Scattering principle with the plastic scintillators as the main detection material along with the multi-anode photomultiplier tube. POLAR has been launched successfully onboard the Chinese space laboratory TG-2 on 15th September, 2016. In order to reliably reconstruct the polarization information a highly detailed understanding of the instrument is required for both data analysis and Monte Carlo studies. For this purpose a full study of the in-orbit performance was performed in order to obtain the instrument calibration parameters such as noise, pedestal, gain nonlinearity of the electronics, threshold, crosstalk and gain, as well as the effect of temperature on the above parameters. Furthermore the relationship between gain and high voltage of the multi-anode photomultiplier tube has been studied and the errors on all measurement values are presented. Finally the typical systematic error on polarization measurements of Gamma-Ray Bursts due to the measurement error of the calibration parameters are estimated using Monte Carlo simulations.Comment: 43 pages, 30 figures, 1 table; Preprint accepted by NIM

BER performance analysis of 100 and 200 Gbit/s all-optical OTDM node using symmetric Mach-Zehnder switches

New insight to the feasibility of all-optical ultra speed switching up to 200 Gb/s. The technique will reduce the dependency and bottleneck on the electronic-to-optical-to-electronic conversion. Current conversion speed is up to 40 Gb/s in laboratories. The novel clock extraction technique proposed shows the potential of an all-optical switch. The research results are directly relevant to the access technology where optical fibre and RF is competing to be the solution. The growing demands of bandwidth will exceed RF capability while the optical fibre will be the optimum solution. A PhD project (Le-Minh) funded by the University Studentship, completed in 2007

Influence of a Concurrent Exercise Training Intervention during Pregnancy on Maternal and Arterial and Venous Cord Serum Cytokines: The GESTAFIT Project

The aim of the present study was to analyze the influence of a supervised concurrent exercise-training program, from the 17th gestational week until delivery, on cytokines in maternal (at 17th and 35th gestational week, and at delivery) and arterial and venous cord serum. Fifty-eight Caucasian pregnant women (age: 33.5 +/- 4.7 years old, body mass index: 23.6 +/- 4.1kg/m(2)) from the GESTAFIT Project (exercise (n = 37) and control (n = 21) groups) participated in this quasi-experimental study (per-protocol basis). The exercise group followed a 60-min 3 days/week concurrent (aerobic-resistance) exercise-training from the 17th gestational week to delivery. Maternal and arterial and venous cord serum cytokines (fractalkine, interleukin (IL)-1 beta, IL-6, IL-8, IL-10, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha) were assessed using Luminex xMAP technology. In maternal serum (after adjusting for the baseline values of cytokines), the exercise group decreased TNF-alpha (from baseline to 35th week, p = 0.02), and increased less IL-1 beta (from baseline to delivery, p = 0.03) concentrations than controls. When adjusting for other potential confounders, these differences became non-significant. In cord blood, the exercise group showed reduced arterial IL-6 and venous TNF-alpha (p = 0.03 and p = 0.001, respectively) and higher concentrations of arterial IL-1 beta (p = 0.03) compared to controls. The application of concurrent exercise-training programs could be a strategy to modulate immune responses in pregnant women and their fetuses. However, future research is needed to better understand the origin and clearance of these cytokines, their role in the maternal-placental-fetus crosstalk, and the influence of exercise interventions on them