A dynamic computation method for fast and accurate performance evaluation of multi-core architectures

A new MVA sensitivity method for fast accurate contingency evaluation

This paper introduces a new method for evaluating dynamic stress caused by rotor-stator interaction (RSI) in Francis turbines and pump turbines. Traditional methods for dynamic stress evaluation using fluid-structure interaction (FSI) analysis are accurate but time-consuming and less practical for iterative design optimization. The proposed method utilizes FSI analysis to quickly assess dynamic stress by replacing transient response analysis with frequency response analysis using single-frequency excitation. The effectiveness of this method is validated through comprehensive analysis and comparison with on-site stress measurements, demonstrating its accuracy and efficiency for practical use. Mapping the unsteady computational fluid dynamics (CFD) result as the excitation force is crucial for obtaining precise analysis results, as it accurately represents the hydraulic load distribution caused by RSI. This ensures the dynamic stress and vibration characteristics of the turbine runner are evaluated with high accuracy and improving the reliability of the design.

Eye-tracking plays a crucial role in the development of virtual reality devices, neuroscience research, and psychology. Despite its significance in numerous applications, achieving an accurate, robust, and fast eye-tracking solution remains a considerable challenge for current state-of-the-art methods. While existing reflection-based techniques (e.g., “glint tracking") are considered to be very accurate, their performance is limited by their reliance on sparse 3D surface data acquired solely from the cornea surface. In this paper, we rethink the way how specular reflections can be used for eye tracking: We propose a method for accurate and fast evaluation of the gaze direction that exploits teachings from single-shot phase-measuring-deflectometry. In contrast to state-of-the-art reflection-based methods, our method acquires dense 3D surface information of both cornea and sclera within only one single camera frame (single-shot). For a typical measurement, we acquire >3000× more surface reflection points ("glints”) than conventional methods. We show the feasibility of our approach with experimentally evaluated gaze errors on a realistic model eye below only 0.13°. Moreover, we demonstrate quantitative measurements on real human eyes in vivo, reaching accuracy values between only 0.46° and 0.97°.

Previous studies of operating performance of listed companies usually adopt static comprehensive evaluation method but not dynamic evaluation method. Besides, the evaluation information is aggregated in a simple weighted method, without integration of management tool. Considering these two deficiencies, this paper puts forward a dynamic incentive evaluation model and applies it in the comprehensive evaluation of the operating performance of listed companies. The paper first introduces dynamic incentive evaluation model, and then carries out an empirical study, using the annual reports data (2005-2009) of 13 refrigeration and air-conditioning industry listed companies. The results indicate that, compared with the evaluation results of traditional static method and dynamic method, the evaluation results of dynamic incentive model can reflect the operating performance of listed companies more objectively and comprehensively. Thus this model achieves good evaluation effect and has practical value.

Carbon nanotube field-effect transistors (CNFETs) show great potential to build digital systems on advanced technology nodes with big benefits in terms of power, performance, and area (PPA). However, CNFET-specific additional features such as the number of tubes, pitch (spacing between tubes), tube position, and diameter in array of tubes play a significant role in accurate PPA evaluation. Furthermore, count and density variations in carbon nanotubes (CNTs) due to manufacturing limitations, like the presence of metallic tubes in the CNFET channel, degrade the anticipated PPA benefits. Moreover, modeling the CNFET parameters, CNT variations and etching techniques for CNTs create additional complexity during performance optimization. Hence, for realistic optimization of CNFET circuit’s performance, it is imperative to incorporate the impact of these parameters and variations. In this paper, we propose delay models [pitch-aware logical effort (PALE) and position-aware pitch factor (PAPF)] for fast and accurate performance evaluation by including the impact due to CNFET-specific parameters and CNT variations. These models are developed based on industry standard logical effort framework. Furthermore, we present an optimization tool using PALE and PAPF to minimize the delay and area of CNFET circuits. We deploy several circuit-level techniques prior to optimizing the tubes (CNTs) in the logic gates to achieve globally optimum solution. For better optimization of the circuits, we also include the impact of wire parasitic in estimating the delay of the individual gates. Our optimization tool results in the maximum and average delay improvement by 27% and 17%, respectively, and $2.5\times $ reduction in area for standard ISCAS and OpenSPARC benchmark circuits. Fast and fairly accurate delay computation in our optimization framework offers great runtime benefits as compared to state-of-the-art simulation and statistical-based methods.

We investigated the feasibility and image quality of dynamic cine-mode imaging of the normal aortic valve using multidetector row computed tomography (MDCT). We acquired contrast-enhanced retrospectively echocardiography (ECG)-gated cardiac MDCT datasets of 35 patients (mean age, 62 years; range, 53-77) who received a transoesophageal echocardiography (TOE) precedent to cardiac bypass graft surgery. Twenty data sets in 5% steps of the R-R interval were reconstructed, and data analysis was performed using a 4D software. Read-out of the MDCT data was performed in parallel and perpendicular planes, similar to TOE standard planes, by 2 independent, blinded readers using a 4-point Likert scale (best score: 4) for the following parameters: image quality of the aortic valve components, contrast media enhancement, contrast media inflow related artifacts, and ECG gating-related artifacts. The aortic valve area (AVA) was measured planimetrically and was compared between TOE and MDCT. The best phase for assessing the open valve using MDCT was at 5% and the closed valve at 65% of the cardiac cycle. The mean image quality scores for cine-mode MDCT ranged between 3.26 and 3.75, with inter-reader agreements ranging between good (kappa = 0.723) and excellent (kappa = 1.00). They did not differ significantly from TOE scores for assessment of the closed and open valve. In transitional phases (close-to-open and open-to-close) TOE performed significantly better when compared with static MDCT images, whereas no significant difference was present between cine-mode presentation of MDCT and TOE. Planimetric AVA measurements correlated significantly between TOE and MDCT (Pearson correlation coefficient, r = 0.96; P < 0.0001). Contrast media inflow-related and ECG gating related artifacts were rated as slightly compromising (scores 3.24 and 3.21). Retrospectively ECG-gated MDCT offers a noninvasive, accurate, and dynamic imaging method for quantitative and qualitative evaluation of the normal aortic valve allowing determination of morphology and function throughout the cardiac cycle. Further studies regarding assessment of diseased valves are necessary.

In this article, a fast and efficient hybrid method that combines the volume-surface integral equation (VSIE) and the modified surface integration (MSI) method is proposed to evaluate the electromagnetic (EM) performance of the large-/medium-sized radome-enclosed antennas (REAs). An approximate equivalence principle is presented to formulate the physical model for the EM radiation of the REA, and then, the full-wave VSIE for the antennas and the high-frequency MSI method for the dielectric radome are coupled with each other in an iterative manner. Since mutual interactions up to the second order among the antennas and the radome are considered, the method shows good accuracy in both the near- and far-field regions of the REA system. In addition, all the computation processes involved in the method, including the method of moments (MoM) solution of the VSIE, surface integrations (SIs) in the MSI, and ray tracing for determining the local transmission matrix for the dielectric radome, are accelerated by the multilevel fast multipole algorithm (MLFMA), which makes the method highly efficient in terms of both computational time and memory requirement. Numerical results show that the proposed hybrid method can predict the EM performance, e.g., the input impedance and radiation pattern, of the REA system with good accuracy compared with the full-wave simulations.

For the planning and optimization of mobile communication networks, a fast and accurate performance evaluation is of essential importance. In this thesis several advanced novel methods for the performance analysis of WCDMA networks are developed and discussed. They significantly out-perform state-of-the-art methods in terms of the flexibility of modeling the air interface, accuracy of results, and computational complexity.KeywordsVariance ReductionOutput QuantityMobile Communication NetworkUser Data RateData Rate ServiceThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Datacenters rapidly evolve by adopting new features such as new hardware deployment and software patches. Adopting a new feature requires an accurate evaluation of its impact to minimize the risk to the multi-million dollar computing infrastructure. However, a comprehensive performance analysis of a datacenter is extremely challenging due to its cost and multitenancy. Evaluating the performance in a live datacenter is accurate but prohibitive to prevent any damage to production services. Using conventional load-testing benchmarks on small-scale testbeds is imprecise as they do not consider the effect of other co-located jobs.

An accurate and non-destructive evaluation method for the hydraulic measure impact range in coal seams is urgently needed. Aiming at the application demands, a theoretical study and field test are presented using the direct current (DC) method to evaluate the impact range of coal seam hydraulic measures. We firstly analyzed the law of the apparent resistivity response of an abnormal conductive zone in a coal seam, and then investigated the principle of non-destructive testing of the coal seam hydraulic measure impact range using the DC method, and used an accurate evaluation method based on the apparent resistivity cloud chart. Finally, taking hydraulic fracturing and hydraulic flushing as examples, field experiments were carried out in coal mines to evaluate the impact ranges. The results showed that: (1) in the process of hydraulic fracturing, coal conductivity was enhanced by high-pressure water in the coal seam, and after hydraulic fracturing, the boundary of the apparent resistivity decrease area was the boundary impact range. (2) In the process of hydraulic flushing, coal conductivity was reduced by holes and cracks in the coal seam, and after hydraulic flushing, the boundary of the apparent resistivity increase area was the boundary impact range. (3) After the implementation of the hydraulic measures, there may be some blind zones in the coal seam; in hydraulic fracturing blind zones, the apparent resistivity increased or stayed constant, while in hydraulic flushing blind zones, the apparent resistivity decreased or stayed constant. The DC method realized a comprehensive and non-destructive evaluation of the impact range of the hydraulic measures, and greatly reduced the time and cost of evaluation.

Closed-form expressions are derived for the error rate performance of coherent M-ary quadrature amplitude modulated (QAM) systems in the presence of an additive combination of Gaussian and highly impulsive noise, using the Fourier-Bessel series expansion method. Analytical as well as computed simulated results are presented for 16, 64, and 256 QAM systems. The analytical results demonstrate a negligible truncation error and an accuracy ranging from approximately 1 dB for the 16 QAM scheme up to 3.5 dB for the 256 QAM scheme. The numerical evaluation of the closed-form expressions has been performed much faster than the corresponding computer simulation procedure. Hence, the validity of Fourier-Bessel analysis as a fast and accurate performance evaluation tool for high-level digital modulation schemes in complex interference environments is verified.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Performance evaluation is an important part of the enterprises' strategic management. The analytic hierarchy process (AHP) can provide an analytical means to determine the importance of the identified factors. The AHP method assumes that the factors presented in the hierarchical structure are independent; however, this assumes that may be inappropriate in light of certain internal and external environment effects. Therefore, it is necessary to employ of analytic network Process (ANP) method. The traditional financial method cannot fully reflect the performance of enterprises, as a result of which the balanced scorecard (BSC) method was developed. However, BSC also some disadvantages. By giving power weights on indicators, ANP method can make up those disadvantages. The objective of this study is to construct an approach based on the ANP and balanced BSC for creating a method of enterprises' performance evaluation.

Dynamic evaluation method of water-sealed gas for ultra-deep buried fractured tight gas reservoir in Kuqa Depression, Tarim Basin, China

Low back pain of caregiver has serious problem in welfare field. Transfer motion is thought as a cause of the low back pain, and it is necessary to reduce the lumbar burden. Also practical quantification method of lumbar burden is required strongly. This study aims to develop a practical and dynamic evaluation method of lumber burden by measuring surface muscle potential of the Erector spine muscle. This study delas with transfer motion and divide it into three motions, "lifting motion", "rotation a motion" and "unloading motion". Experiments have been conducted to show that "lifting motion" and "rotation a motion" can be evaluated by the surface muscle potential of the erector spine muscle by previous studies. This paper focuses on the "unloading motion" and, the relationship between the load and the "surface muscle potential of the erector spine muscle" is confirmed by experiments. It is also shown that the lumbar burden during "unload motion" is possible to be evaluated by using the surface muscle potential. In addition, this study evaluates, whether dynamic evaluation by using the proposed evaluation method is possible. Because caregivers are required to slow down during the "unoad motion", inertial force increass the load during decelerated motion. For an example, a dynamic evaluation in the case of deceleration during the "unloading motion" were confirmed by experiments. Conducting experiments, we found that the value of the potential of the surface of the erector spine was increased during slow down motion. This result indicates that the lumbar burden can be increased by decelerated motion. This study showed the effectiveness of the dynamic evaluation method by surface muscle potential.

In high-frequency applications of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiC}$</tex> MOSFET, crosstalk restricts the switching speed, increases additional switching losses and reduces the system stability. This paper proposes an accurate crosstalk evaluation and prediction method for <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiC}$</tex> MOSFET, which considers nonlinear capacitance and stray parameters. The proposed method is a programmed prediction and evaluation process, including analysis of stray parameters, nonlinear capacitance analysis and measurement of nonlinear transfer capacitance. First, the influence of drain-to-gate stray capacitance <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$C_{\text{dg}^{\prime}}$</tex> caused by PCB layout and probes on crosstalk peak voltage is analyzed in details for the first time. Second, detailed analysis and explanation are made to reveal the disadvantages and inaccuracy of the traditional method which regards the reverse transfer capacitance as a constant. The simulation results show that the error of crosstalk peak voltage under different transfer capacitance values is very large. In addition, the influence of drain-source capacitance is also studied deeply. Third, this paper considers another challenging problem, the accurate measurement of nonlinear reverse transfer capacitance and propose a practical transfer capacitance big-signal measurement method for SiC MOSFETs based on dynamic transient, which can overcome the shortcomings of the frequency measurement method of small signal and shows highperformance and easy-operation. Finally, the performance of this proposed crosstalk evaluation and prediction method is verified and compared experimentally by a double-pulse test (DPT) platform.