Data Imputation through the Identification of Local Anomalies

We introduce a comprehensive and statistical framework in a model free setting for a complete treatment of localized data corruptions due to severe noise sources, e.g., an occluder in the case of a visual recording. Within this framework, we propose i) a novel algorithm to efficiently separate, i.e., detect and localize, possible corruptions from a given suspicious data instance and ii) a Maximum A Posteriori (MAP) estimator to impute the corrupted data. As a generalization to Euclidean distance, we also propose a novel distance measure, which is based on the ranked deviations among the data attributes and empirically shown to be superior in separating the corruptions. Our algorithm first splits the suspicious instance into parts through a binary partitioning tree in the space of data attributes and iteratively tests those parts to detect local anomalies using the nominal statistics extracted from an uncorrupted (clean) reference data set. Once each part is labeled as anomalous vs normal, the corresponding binary patterns over this tree that characterize corruptions are identified and the affected attributes are imputed. Under a certain conditional independency structure assumed for the binary patterns, we analytically show that the false alarm rate of the introduced algorithm in detecting the corruptions is independent of the data and can be directly set without any parameter tuning. The proposed framework is tested over several well-known machine learning data sets with synthetically generated corruptions; and experimentally shown to produce remarkable improvements in terms of classification purposes with strong corruption separation capabilities. Our experiments also indicate that the proposed algorithms outperform the typical approaches and are robust to varying training phase conditions

Scalable Multifunctional Ultra-thin Graphite Sponge: Free-standing, Superporous, Superhydrophobic, Oleophilic Architecture with Ferromagnetic Properties for Environmental Cleaning.

Water decontamination and oil/water separation are principal motives in the surge to develop novel means for sustainability. In this prospect, supplying clean water for the ecosystems is as important as the recovery of the oil spills since the supplies are scarce. Inspired to design an engineering material which not only serves this purpose, but can also be altered for other applications to preserve natural resources, a facile template-free process is suggested to fabricate a superporous, superhydrophobic ultra-thin graphite sponge. Moreover, the process is designed to be inexpensive and scalable. The fabricated sponge can be used to clean up different types of oil, organic solvents, toxic and corrosive contaminants. This versatile microstructure can retain its functionality even when pulverized. The sponge is applicable for targeted sorption and collection due to its ferromagnetic properties. We hope that such a cost-effective process can be embraced and implemented widely

Factors impacting knowledge transfer success in information systems outsourcing

Despite increased research interest on knowledge transfer in information systems (IS) outsourcing, the field still lacks sound and holistic understanding of the key factors influencing knowledge transfer success. The present paper attempts to provide a synthesis of existing theoretical perspectives and empirical findings related to the factors that facilitate or hamper knowledge transfer success in IS outsourcing. The data collection method is discussed and the key findings are presented. Conclusion is drawn and further research is suggested

T-government for benefit realisation

This paper proposes a model for t-Government and highlights the research agenda needed to increase understanding of transformational government and the processes involved in furthering the agenda of the t-Government. In particular, both an operational and a conceptual model for the effective involvement of citizens and businesses in government functioning have been proposed. This will help to define an agenda for t-Government research that emerges from national UK strategy and policy for e-Government. The main threads of t- Government encompass: (1) A citizen-centric delivery of public services or e-inclusion, (2) A shared services culture to maximize value added to clients, (3) The effective delivery and management of resources and skills within government or professionalism. All three threads should be addressed principally from the perspectives of delivery, evaluation and participation in view of benefit realisation as envisioned by Government strategic planning and policy directives (CabinetOffice, 2005). The management of change dimension of these phenomena have been included in the research agenda. In particular, research is needed to reshape the discourse towards emphasising a citizen centric approach that defines, develops, and benefits from public service. Decision makers in Government will need models of Governance that fulfil transformational objectives. They will also need models of benefits realisation within a strategic Governance framework. It has been argued that t-Government research should be addressing these relative voids

Silicon Derived from Glass Bottles as Anode Materials for Lithium Ion Full Cell Batteries.

Every year many tons of waste glass end up in landfills without proper recycling, which aggravates the burden of waste disposal in landfill. The conversion from un-recycled glass to favorable materials is of great significance for sustainable strategies. Recently, silicon has been an exceptional anode material towards large-scale energy storage applications, due to its extraordinary lithiation capacity of 3579 mAh g-1 at ambient temperature. Compared with other quartz sources obtained from pre-leaching processes which apply toxic acids and high energy-consuming annealing, an interconnected silicon network is directly derived from glass bottles via magnesiothermic reduction. Carbon-coated glass derived-silicon (gSi@C) electrodes demonstrate excellent electrochemical performance with a capacity of ~1420 mAh g-1 at C/2 after 400 cycles. Full cells consisting of gSi@C anodes and LiCoO2 cathodes are assembled and achieve good initial cycling stability with high energy density

Polymer-Metal Hybrid Structures Based on Polydiphenylamine and Co Nanoparticles

AbstractPolymer-metal hybrid structures based on polydiphenylamine (PDPhA) with Co nanoparticles homogeneously distributed in polymer matrix have been prepared for the first time. In situ synthesis of Co/PDPhA hybrid structure is carried out during condensation of diphenylamine crystalline oligomers in the presence of Co acetate (Co(CH3COO)2 4H2O) under the conditions of IR-irradiation. As a result, polymer chain growth occurs and hydrogen molecules are eliminated. Reduction of Co2+ up to Coo takes place under IR-irradiation with participation of hydrogen. The structure, content and morphology of obtained hybrid materials were characterized by Fourier-transform IR-spectroscopy, X-ray powder diffraction patterns, atomic-absorptive spectroscopy and transmission electron microscopy (TEM). Co nanoparticles appeared to exist in -Co and -Co modifications. Their relationship depends on IR-light intensity and time treatment. Co nanoparticles dimensions fall inside the limits of 2 < d < 8nm as it is indicated from TEM microphotographs. Magnetic properties of Co/PDPhA were investigated and superparamagnetic behavior was proved. Thermal properties of nanocomposites were evaluated by thermogravimetric analysis and excellent thermal stability was shown

Reduction of spindle vibrations in milling machine by active magnetic bearing

In this study, a three-dimensional dynamic model of a milling machine is proposed. The cutting forces of the face milling process were obtained according to the cutting parameters by means of computer simulations and experiment. The cutting forces excited the dynamic model of the system. Relative displacements of the contact point of the cutting tool and the workpiece were obtained by using forced vibration analysis. These displacements affected machining accuracy of the milling machine. Therefore, radial and axial electromagnetic bearings were designed for the active control of the system and they were adapted on the spindle of the milling machine. Thereby the electromagnetic force produced around the rotating spindle reduced vibration amplitude of the cutting tool. The system was operated with and without active control and both these cases were compared. It was revealed that active control diminished cutting tool vibrations and improved machining performanc