Application of a Standard Power Meter for Detection Source of Harmonic Pollution and Reducing Economic Losses at Power Grid

Abstract—

The modern utility system is faced with two main problems: how to minimize losses in a power system and how to locate the source of harmonic pollution. Namely, the utility has losses whenever the power it delivers is greater than the power it registers at the point of common coupling (PCC). In this paper we will show that these losses occur because the measurement equipment and billing policy are not adequate, and we will stress the reasons why this happens. The main reason is the distortion power generated by nonlinear loads. The number of these loads at power grid is greater every day, thus enlarging the problem. Ordinary power meters are not able to measure distortion power, so in this paper we will also show which small modifications to existing ordinary meters needed, which could lead to the successful detection of sources of harmonic pollution, thus further reducing power losses. The suggested idea will be verified by numerous simulations and measurements on different household/office and industry loads that are commonly used. The proposed method is suitable either for software or hardware upgrade of existing smart meters, or it can be implemented on ordinary measurement systems.     

Analysis of a hybrid micro/macro-optical method for distortion removal in free-space optical interconnections

Eikonal analyses are applied to a hybrid micro/macro-optical shuffle interconnection approach that minimizes distortion in a multichip smart-pixel shuffle interconnection system. The optical system uses off-axis imaging elements to link clusters of dense arrays of vertical-cavity surface-emitting laser (VCSEL) sources to matching clusters within arrays of detectors. A critical requirement for such a system is that the images of the two-dimensional arrays of the VCSELs must be registered on their associated detector arrays with a precision of the order of 10 microm across the entire multichip array. The hybrid approach exploits the typical narrow-beam cone angles of VCSELs by use of beam-deflecting micro-optics to create a distortion-canceling symmetry about a central aperture in the optical system for each VCSEL-detector link. The second- and third-order aberrations of the plane-symmetric system created by the global off-axis imaging system are analyzed. The results prove that the hybrid concept cancels distortion and minimizes the spot size at the detector array plane.     

Learning faces with the BIAS model: On the importance of the sizes and locations of fixation regions

During perception of complex objects, the highest density of fixations occurs on the regions that are most salient. For example, when looking at a face, the regions that receive the largest density of fixations are the eyes, the nose, and the mouth. The fact that some regions within an object are more informative than other regions means that a learning system that can acquire this information from a teacher rather than from random fixations can learn faster and likewise recognize faster. An important question, from both the theoretical and practical points of view is: How important are the properties of the fixation regions for the learning system? In this work we consider one such system, the Bayesian integrate and shift (BIAS) model for learning object categories, and investigate its sensitivity to changes in the sizes and locations of fixation regions. We test the model using a face category and show that the learning algorithm is robust to large variations of the regions’ sizes and locations. Specifically, we show that the performance is inversely proportional to the sizes of the fixation regions and that the preferred locations are those that are closer to the center of the object.     

JuNoLo - Jülich nonlocal code for parallel post-processing evaluation of vdW-DF correlation energy

Nowadays the state of the art Density Functional Theory (DFT) codes are based on local (LDA) or semilocal (GGA) energy functionals. Recently the theory of a truly nonlocal energy functional has been developed. It has been used mostly as a post-DFT calculation approach, i.e. by applying the functional to the charge density calculated using any standard DFT code, thus obtaining a new improved value for the total energy of the system. Nonlocal calculation is computationally quite expensive and scales as N² where N is the number of points in which the density is defined, and a massively parallel calculation is welcome for a wider applicability of the new approach. In this article we present a code which accomplishes this goal.

Program summary

Program title: JuNoLoCatalogue identifier: AEFM_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFM_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 176 980No. of bytes in distributed program, including test data, etc.: 2 126 072Distribution format: tar.gzProgramming language: Fortran 90Computer: any architecture with a Fortran 90 compilerOperating system: Linux, AIXHas the code been vectorised or parallelized?: Yes, from 1 to 65536 processors may be used.RAM: depends strongly on the problem's size.Classification: 7.3External routines:• FFTW (http://www.tw.org/)• MPI (http://www.mcs.anl.gov/research/projects/mpich2/ or http://www.lam-mpi.org/)Nature of problem: Obtaining the value of the nonlocal vdW-DF energy based on the charge density distribution obtained from some Density Functional Theory code.Solution method: Numerical calculation of the double sum is implemented in a parallel F90 code. Calculation of this sum yields the required nonlocal vdW-DF energy.Unusual features: Binds to virtually any DFT program.Additional comments: Excellent parallelization features.Running time: Depends strongly on the size of the problem and the number of CPUs used.     

A new approach for kinetic modeling and optimization of rubber molding

Although extensive research has been carried out on the understanding of the complex vulcanization process, the influence of reversion through exposure time and temperature on the vulcanization degree remains unclear. Therefore, the main aim of this study was a novel optimization approach that can help the industrial practitioners to select the optimal operating parameters, exposure time, and molding temperature, to achieve desired vulcanization degree of selected product. Spheres of four different diameters (2.5, 5, 10, and 20 cm) were selected as test geometry for simulation and optimization of rubber molding. Obtained vulcanization rheometer data for commercially available rubber blend (NR/SBR) were fitted by a new modeling approach, dividing vulcanization curve into two fitting sets: curing and reversion. The heat transfer equations for chosen geometry were coupled with proposed kinetic model. A new temperature-dependent kinetic parameter x, as the maximal reversion degree, was introduced, enabling determination of the lowest operating molding temperature (T_min = 132.36 °C), preventing high reversion and overheating of the rubber product. The final optimization goal was assessment of the optimal temperature and vulcanization time dependence on the rubber products dimensions. Proposed models have precise prediction with R² values greater than 0.8328 and MAPE less than 2.3099%.     

An Integrated Approach to Mandarin Processing: Food Safety and Nutritional Quality,Consumer Preference,and Nutrient Bioaccessibility

Mandarins are a member of the Citrus genus and are the focus of growing commercial interest, with satsuma mandarins (Citrus unshiu) and the common mandarin (Citrus reticulata Blanco) being the most important mandarin varieties. The possible health benefits and functional properties of those fruits are often associated with the antioxidative function of vitamin C, carotenoids, and phenolic compounds. While most mandarins are consumed fresh, many are processed into juices (mostly cloudy), usually via thermal processing which can lead to the creation of off‐flavors and may diminish nutritional quality. The aim of this review is to summarize the most significant and recent information on the safety, sensorial properties, and nutritional benefits of mandarins and their processing into juice. The article also discusses recent information regarding the bioaccessibility of valuable, mandarin specific, compounds.     

Sequential decoding of low-density parity-check codes by adaptivereordering of parity checks

Decoding algorithms in which unpruned codeword trees are generated from an ordered list of parity checks are investigated. The order is computed from the received message, and low-density parity-check codes are used to help control the growth of the tree. Simulation results are given for the binary erasure channel. They suggest that for the small erasure probability, the method is computationally feasible at rates above the computational cutoff rate