A Matrix Partitioning Interface to PaToH in MATLAB

We present the PaToH MATLAB Matrix Partitioning Interface. The interface provides support for hypergraph-based sparse matrix partitioning methods which are used for efficient parallelization of sparse matrix–vector multiplication operations. The interface also offers tools for visualizing and measuring the quality of a given matrix partition. We propose a novel, multilevel, 2D coarsening-based 2D matrix partitioning method and implement it using the interface. We have performed extensive comparison of the proposed method against our implementation of orthogonal recursive bisection and fine-grain methods on a large set of publicly available test matrices. The conclusion of the experiments is that the new method can compete with the fine-grain method while also suggesting new research directions.     

A comparative assessment of satellite-derived Adriatic Sea surface temperature

In this article, five Advanced Very High Resolution Radiometer (AVHRR) and four Moderate Resolution Imaging Spectrometer (MODIS)-based Adriatic-focused satellite sea surface temperature (SST) products are analysed and compared with two sets of in situ SST measurements: a drifter-based dataset collected in 2003, and a platform-based dataset gathered in 2004; an additional set was used to validate the new SST coefficients. Analysis of satellite minus in situ SST residuals shows similar results for both in situ datasets, with the differences being within 0.2 K. All daytime SST biases exhibited positive values (less than 0.5 K). Night-time biases for short-wave infrared (IR) algorithms exhibited near zero and small negative values with an exceptionally low standard deviation (about 0.3 K) regardless of the sensor used. Analysis of filtered residual time-series allowed direct comparison between different SST products. The seasonal change in the daytime biases was found to covary with similar changes in atmospheric water vapour and the Adriatic specific wind regime.     

Thermal‐deformation characterization on the panel of TFT‐LCD TV. Part I: Mechanism of color distortion

Abstract— In this study we applied both numerical simulation and experimental validation to characterize the thermal deformation of the panel and the direct‐lit backlight unit (BLU) of a thin‐film‐transistor liquid‐crystal‐display television (TFT‐LCD TV). Heat emitted from cold‐cathode fluorescent lamps (CCFLs) causes thermal deformation of the LCD and extrudes the panel from the metal front shield at both upper corners: this finally leads to color distortion. In the numerical simulation based on thermal‐fluidic fields of the TFT‐LCD TV, natural convection of air that surrounded the CCFLs resulted in a high temperature at the upper‐right and upper‐left corners of the LCD panel. Numerical results were verified by temperature measurements with good consistency. Additionally, this study has established a measurement system to characterize the temperature distribution on both the BLU and panel and the thermal deformation of the panel causing the color distortion.     

Mathematical model of IRIS replication mechanism for the simulation of tactical networks

The Multilateral Interoperability Programme (MIP) was established to promote more successful and better harmonized operational functions for international peace-keeping forces. The C2IEDM/JC3IEDM (Command and Control Information Exchange Data Model) ensures the interconnection of Command and Control Information Systems (C2ISs) throughout all levels, from the corps down to the lower ranks. The usability of C2ISs highly correlates with the capacities of data information carriers, and the need is growing for greater capacity and reliability of transmission media and cryptographic message security. Simulation of tactical networks is an important task in planning military missions. Such methodologies assure a higher probability of success during critical tactical operations. This article focuses on a new radio network modeling method for the C2IS, which is verified by the OPNET simulation environment. This modeling method can be used in tactical radio network planning and optimization processes.     

基于MAX4069的电流测量电路设计

本文介绍了基于电流检测芯片MAX4069实现对给定电压下的GPRS模块的耗电电流自动测量电路设计.通过该芯片将微弱电压信号放大,然后经过模数转换电路,即可以测得负载在给定电压下的电流.     

Dynamic programming and convex clustering

In this paper the notion of convexity of clusterings for the given ordering of units is introduced. In the case when at least one (optimal) solution of the clustering problem is convex, dynamic programming leads to a polynomial algorithm with complexityO(kn ³). We prove that, for several criterion functions, convex optimal clusterings exist when dissimilarity is pyramidal for a given ordering of units.This research was supported in part by the Research Council of Slovenia.     

Transparent High-Performance Supramolecular Plastics Operating in All-Weather Environments

Supramolecular plastics (SMPs) can be made mechanically robust, repairable, and recyclable, rendering themselves promising alternatives to their conventional predecessors to address environmental concerns. However, dense accumulations of noncovalent bonds generally lead to mechanical brittleness as well as intolerance toward heat and moisture. To resolve this issue, a simple strategy of preparing high-performance SMP by constructing highly dense, but irregular hydrogen-bond networks with hierarchical structures is proposed. The resultant SMP exhibits an outstanding combination of good comprehensive mechanical properties (high stiffness, strength, and toughness with ductile failure when fracturing), excellent dynamic behaviors (repairability and recyclability), and high tolerances toward moisture and high temperatures (as high as 90 °C). Additionally, the SMP also shows a high dielectric constant, exhibiting great potential for applications such as healable flexible touch screens and energy storage. Last, through structure characterizations and molecular dynamic simulation, this study provides a fundamental insight into the mechanism behind such high-performances from nano- to micro-scales, which is expected to inspire the design of a wide range of other SMPs that use different chemistries.     

Mechanochemistry of sulphides

At present mechanochemistry of sulphides appears to be a science with sound theoretical foundation exhibiting a wide range of opportunities in different area of science and technology. For traditional applicationsmechanochemistry is of exceptional importance in mineral processing and extractive metallurgy. Mineral disordering by high energy milling has a positive influence on the reaction kinetics and further phenomena, such as changing the reaction mechanism to reduce environmental impacts. Metal sulphides can be utilized nowadays, in advanced applications such as precursors for synthesis of high temperature superconductors, luminescent and solar energy materials, high-energy density batteries and further materials for opto-electronic and magnetic applications. Mechanochemistry in this case serves as a tool which can effectively control and regulate the solid state reactions for advanced materials preparation. It is aim of this review paper to illustrate the progress in mechanochemistry of sulphides achieved in recent years in Slovakia.     

Decision trees for hierarchical multi-label classification

Hierarchical multi-label classification (HMC) is a variant of classification where instances may belong to multiple classes at the same time and these classes are organized in a hierarchy. This article presents several approaches to the induction of decision trees for HMC, as well as an empirical study of their use in functional genomics. We compare learning a single HMC tree (which makes predictions for all classes together) to two approaches that learn a set of regular classification trees (one for each class). The first approach defines an independent single-label classification task for each class (SC). Obviously, the hierarchy introduces dependencies between the classes. While they are ignored by the first approach, they are exploited by the second approach, named hierarchical single-label classification (HSC). Depending on the application at hand, the hierarchy of classes can be such that each class has at most one parent (tree structure) or such that classes may have multiple parents (DAG structure). The latter case has not been considered before and we show how the HMC and HSC approaches can be modified to support this setting. We compare the three approaches on 24 yeast data sets using as classification schemes MIPS’s FunCat (tree structure) and the Gene Ontology (DAG structure). We show that HMC trees outperform HSC and SC trees along three dimensions: predictive accuracy, model size, and induction time. We conclude that HMC trees should definitely be considered in HMC tasks where interpretable models are desired.     

Fixed-structure Gaussian process model

This article describes a method for modelling non-linear dynamic systems from measurement data. The method merges the linear local model blending approach in the velocity-based linearisation form with Bayesian Gaussian process (GP) modelling. The new Fixed-Structure GP (FSGP) model has a predetermined linear model structure with varying and probabilistic parameters represented by GP models. These models have several advantages for the modelling of local model parameters as they give us adequate results, even with small data sets. Furthermore, they provide a measure of the confidence in the prediction of the varying parameters and information about the dependence of the parameters on individual inputs. The FSGP model can be applied for the extended local linear equivalence class of non-linear systems. The obtained non-linear system model can be, for example, used for control-system design. The proposed modelling method is illustrated with a simple example of non-linear system modelling for control design.