The empirical mode decomposition (EMD) algorithm is widely used as an adaptive time-frequency analysis method to decompose nonlinear and non-stationary signals into sets of intrinsic mode functions (IMFs). In the traditional EMD, the lower and upper envelopes should interpolate the minimum and maximum points of the signal, respectively. In this paper, an improved EMD method is proposed based on the new interpolation points, which are special inflection points (SIP _n) of the signal. These points are identified in the signal and its first ( n − 1) derivatives and are considered as auxiliary interpolation points in addition to the extrema. Therefore, the upper and lower envelopes should not only pass through the extrema but also these SIP _n sets of points. By adding each set of SIP _i (i = 1, 2, ..., n) to the interpolation points, the frequency resolution of EMD is improved to a certain extent. The effectiveness of the proposed SIP _n-EMD is validated by the decomposition of synthetic and experimental bearing vibration signals.

Photovoltaic (PV) cells are very costly because of the silicon element which is not cheaply available. Usually, PV cells are preferred to be used at maximum efficiency. Therefore, PV plants are emphasized to extract maximum power from PVcells. When inertia free PV plants are integrated into the grid in large numbers, the problem of maintaining system stability subjected to load perturbation is quite difficult. In response to this, a control topology is being an approach to make available the PV cells in maintaining system stability by utilizing the system frequency deviation as feedback to the controller. To implement this, the PVs are operated at Maximum Power Point Tracking (MPPT). This allows the PV to operate at Pseudo Maximum Power Point tracking (PMPPT) which makes it possible to run the PV with reserve power capacity without employing a battery for storage. The control strategy has been implemented over a two-stage power conversion model of the PV system. The simulation results showed that the proposed control PMPPT topology is effective in frequency regulation capability as compared to the MPPT technique.

This article is built on the premise that the topos has become a potent unit of cultural memory, an image that stores a wealth of often vague, buried or forgotten ideas. Its contents, like those of literature, tend to become extraordinarily condensed and confl ated; in consequence, some topoi (in particular the Holocaust topos) defy conventional tools of understanding and analysis. A solution to this problem can be found in an approach which broadens the scope of the sources of the Holocaust to include pop culture; gives up the rigid classifi cation of topoi, based on ‘hard’, documentary evidence; and, draws on a conceptual frame that connects the topos with the mechanisms of remembrance. A practical application of this approach is offered here in a series of readings of selected passages from Marcin Pilis’s novel The Meadow of the Dead (Łąka umarłych), Zygmunt Miłoszewski’s crime story A Grain of Truth (Ziarno prawdy), Marcin Wolski’s alternate history novel Wallenrod, Justyna Wydra’s war romance The SS-man and a Jewess (Esesman i Żydówka), Krzysztof Zajas’s thriller Oszpicyn [local Yiddish: Auschwitz] as well as some poems by Jacek Podsiadło from his volume The Breguet Overcoil (Włos Bregueta).