automatic calibration of control parameters based on merit function spectral analysis

Abstract The number of actuations influencing the combustion is increasing, and, as a consequence, the calibration of control parameters is becoming challenging. One of the most effective factors influencing performance and efficiency is the combustion phasing: for gasoline engines control variables such as Spark Advance (SA), Air-to-Fuel Ratio (AFR), Variable Valve Timing (VVT), Exhaust Gas Recirculation (EGR) are mostly used to set the combustion phasing. The optimal control setting can be chosen according to a cost function, taking into account performance indicators, such as Indicated Mean Effective Pressure (IMEP), Brake Specific Fuel Consumption (BSFC), pollutant emissions, or other indexes inherent to reliability issues, such as exhaust gas temperature, or knock intensity. The paper proposes the use of the extremum seeking approach during the calibration process. The main idea consists in changing the values of each control parameter at the same time, identifying its effect on the monitored cost function, allowing to shift automatically the control setting towards the optimum solution throughout the calibration procedure. Obviously, the nodal point is to establish how the various control parameters affect the monitored cost function and to determine the direction of the required variation, in order to approach the optimum. This task is carried out by means of a spectral analysis of the cost function: each control variable is varied according to a sine wave, thus its effect on the cost function can be determined by evaluating the amplitude of the Fast Fourier Transform (FFT) of the cost function, for the given excitation frequency. The FFT amplitude is representative of the cost function sensitivity to the control variable variations, while the phase can be used to assess the direction of the variation that must be applied to the control settings in order to approach the optimum configuration. Each control parameter is excited with a different frequency, thus it is possible to recognize the effect of a single parameter by analyzing the spectrum of the cost function for the given excitation frequency. The methodology has been applied to data referring to a PFI engine, trying to maximize IMEP, while limiting the knock intensity and exhaust gas temperature, using SA and AFR as control variables. The approach proved to be efficient in reaching the optimum control setting, showing that the optimal setting can be achieved rapidly and consistently

A Structurally Simple Vaccine Candidate Reduces Progression and Dissemination of Triple-Negative Breast Cancer

The Tn antigen is a well-known tumor-associated carbohydrate determinant, often incorporated in glycopeptides to develop cancer vaccines. Herein, four copies of a conformationally constrained mimetic of the antigen TnThr (GalNAc-Thr) were conjugated to the adjuvant CRM197, a protein licensed for human use. The resulting vaccine candidate, mime[4]CRM elicited a robust immune response in a triple-negative breast cancer mouse model, correlated with high frequency of CD4+ T cells and low frequency of M2-type macrophages, which reduces tumor progression and lung metastasis growth. Mime[4]CRM-mediated activation of human dendritic cells is reported, and the proliferation of mime[4]CRM-specific T cells, in cancer tissue and peripheral blood of patients with breast cancer, is demonstrated. The locked conformation of the TnThr mimetic and a proper presentation on the surface of CRM197 may explain the binding of the conjugate to the anti-Tn antibody Tn218 and its efficacy to fight cancer cells in mice

Critical Review of Theoretical Models for Anomalous Effects (Cold Fusion) in Deuterated Metals

We briefly summarize the reported anomalous effects in deuterated metals at ambient temperature, commonly known as "Cold Fusion" (CF), with an emphasis on important experiments as well as the theoretical basis for the opposition to interpreting them as cold fusion. Then we critically examine more than 25 theoretical models for CF, including unusual nuclear and exotic chemical hypotheses. We conclude that they do not explain the data.Comment: 51 pages, 4 Figure

Mixing Aβ(1-40) and Aβ(1-42) peptides generates unique amyloid fibrils

Recent structural studies show distinct morphologies for the fibrilsof Ab(1-42) and Ab(1-40), which are believed not to co-fibrillize.We describe here a novel, structurally-uniform 1 : 1 mixed fibrillarspecies, which differs from bothpure fibrils. It forms preferen-tially even when Ab(1-42) : Ab(1-40) peptides are mixed in a non-stoichiometric ratio

Reliable Circuit Design with Nanowire Arrays

The emergence of different fabrication techniques of silicon nanowires (SiNWs) raises the question of finding a suitable architectural organization of circuits based on them. Despite the possibility of building conventional CMOS circuits with SiNWs, the ability to arrange them into regular arrays, called crossbars, offers the opportunity to achieve higher integration densities. In such arrays, molecular switches or phase-change materials are grafted at the crosspoints, i.e., the crossing nanowires, in order to perform computation or storage. Given the fact that the technology is not mature, a hybridization of CMOS circuits with nanowire arrays seems to be the most promising approach. This chapter addresses the impact of variability on the nanowires in circuit designs based on the hybrid CMOS-SiNW crossbar approach