The Mechanism of Additive Composition

Additive composition (Foltz et al, 1998; Landauer and Dumais, 1997; Mitchell and Lapata, 2010) is a widely used method for computing meanings of phrases, which takes the average of vector representations of the constituent words. In this article, we prove an upper bound for the bias of additive composition, which is the first theoretical analysis on compositional frameworks from a machine learning point of view. The bound is written in terms of collocation strength; we prove that the more exclusively two successive words tend to occur together, the more accurate one can guarantee their additive composition as an approximation to the natural phrase vector. Our proof relies on properties of natural language data that are empirically verified, and can be theoretically derived from an assumption that the data is generated from a Hierarchical Pitman-Yor Process. The theory endorses additive composition as a reasonable operation for calculating meanings of phrases, and suggests ways to improve additive compositionality, including: transforming entries of distributional word vectors by a function that meets a specific condition, constructing a novel type of vector representations to make additive composition sensitive to word order, and utilizing singular value decomposition to train word vectors.Comment: More explanations on theory and additional experiments added. Accepted by Machine Learning Journa

Improved toughness of refractory compounds

The concept of grain-boundary-engineering through elimination of the grain-boundary silicate phase in silicon nitride was developed. The process involved removal of the silica from the nitride powder via a thermal treatment coupled with the use of nitride additives to compensate the remaining oxygen. Magnesium and aluminum nitrides are found to be the most effective additive for use as oxygen compensators. Strength decreases at elevated temperatures are not observed in the alumina containing material. The creep rate of a dual additive sialon composition was two orders of magnitude lower at 1400 C than commercial silicon nitride. A cursory analysis of the creep mechanism indicate that grain-boundary sliding is avoided through elimination of the grain-boundary silicate phase

Sharing Variable Returns of Cooperation

A finite set of agents jointly undertake a project. Depending on the aggregate of individual agent characteristics the project runs losses or profits, which have to be shared. This paper adopts the mechanistic view and concentrates on devices that a contingent planner may use in order to share the net profits. The Moulin and Shenker (1994) representation theorem is used to show that additive mechanisms with the constant returns property relate 1 to 1 to rationing methods. Refinements are discussed dealing with monotonicity and equity properties that relate to the dispersion of shares. The second part introduces the notion of a consistent solution. Each rationing method induced by a consistent mechanism is consistent. If such mechanism is continuous as well, then the corresponding rationing method is parametric in the terminology of Young (1998) and Moulin (2000). Most prevalent mechanisms (average, serial, Shapley-Shubik) are consistent as member of the class of incremental mechanisms. Each interval consistent incremental mechanism is shown to be a composition of marginal mechanisms and the average mechanism. Immediately the average mechanism is the unique strongly consistent solution. Finally a characterization of mechanisms within the general class is discussed using super-additivity.

The spatial distribution patterns of condensed phase post-blast explosive residues formed during detonation

The continued usage of explosive devices, as well as the ever growing threat of ‘dirty’ bombs necessitates a comprehensive understanding of particle dispersal during detonation events in order to develop effectual methods for targeting explosive and/or additive remediation efforts. Herein, the distribution of explosive analytes from controlled detonations of aluminised ammonium nitrate and an RDX-based explosive composition were established by systematically sampling sites positioned around each firing. This is the first experimental study to produce evidence that the post-blast residue mass can distribute according to an approximate inverse-square law model, while also demonstrating for the first time that distribution trends can vary depending on individual analytes. Furthermore, by incorporating blast-wave overpressure measurements, high-speed imaging for fireball volume recordings, and monitoring of environmental conditions, it was determined that the principle factor affecting all analyte dispersals was the wind direction, with other factors affecting specific analytes to varying degrees. The dispersal mechanism for explosive residue is primarily the smoke cloud, a finding which in itself has wider impacts on the environment and fundamental detonation theory

Microstructures in phase inversion membranes. Part II. The role of a polymeric additive

Membranes were prepared from a casting solution of a water-soluble polymer, poly (vinyl pyrrolidone) (PVP), and a membrane forming polymer, poly (ether sulfone), in 1-methyl-2-pyrrolidone (NMP) as solvent by immersing them in mixtures of water and NMP. It was found that the addition of PVP to the ternary system suppresses the formation of macrovoids in the sub-layer, while the ultrafiltration-type top-layer consists of a closely packed layer of nodules. Using a model for pass transfer in this quaternary system, it is possible to explain the effects of the additive on macrovoid formation. Strong indications are found that the appearance of a nodular structure in the top-layer follows a mechanism of spinodal decomposition during the very early stages of the immersion step

A-STATE-OF-ART REVIEW ON ADDITIVES FUNCTION ON POLYMERIC MEMBRANE PERFORMANCE FOR WASTEWATER TREATMENT

In this article, the recent development of polymeric membrane fabrication using additive for wastewater treatment is presented. The application of this substance has been recognized reliable to increase membrane performance against fouling phenomenon, especially for purifying industrial wastewaters that mostly have high loading of hazardous pollutants. The effects of modification techniques through additives addition on membrane casting solution are considerably included. This paper also discusses membrane fouling mechanism and other existing technologies available for treating contaminated water. Despite the existence of review paper discussing membrane fouling mitigation on literature, there is still the need of comprehensive review related to the novel technology regarding additive blending on membrane, especially on polymer-based membrane for water pollution control. Eventually, clear conclusion can be drawn that the suitability of additive substances and its composition as well as suitable operating conditions have great leverage on polymeric membrane performance regarding its anti-fouling and hydrophilic level

Microstructural Barrier-locking Formation Mechanism of Dispersed Current-forming Components of Current Power Supply

The influences of carbon additive on the structure and phase composition of the positive electrode ma-terial as well as technical and operational characteristics of starter lead-acid batteries have been studied. The mechanism of interaction of carbon additives with lead powder is proposed. It is established that the presence of carbon in the positive electrode material increases the lifetime of lead-acid starter batteries, as confirmed by tests. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3626

Mass transfer and thermodynamics during immersion precipitation for a two-polymer system: Evaluation with the system PES-PVP-NMP-water

An extended version of the mass transfer model by Reuvers et al. for a four-component system is evaluated, which is shown to be generally valid for short times. The thermodynamics under these circumstances are evaluated, together with the kinetics. Initial composition paths (concentration profiles) are calculated. It appears that delay of demixing is not possible when a polymeric additive is used, which is soluble in the nonsolvent, while the velocity of demixing decreases. The calculations are evaluated for the system poly(ether sulfone)-poly(vinylpyrrolidone)-N-methylpyrrolidone-water by means of light transmission measurements during immersion precipitation, for a wide range of compositions of the polymer solution and coagulation bath

Composable and Efficient Mechanisms

We initiate the study of efficient mechanism design with guaranteed good properties even when players participate in multiple different mechanisms simultaneously or sequentially. We define the class of smooth mechanisms, related to smooth games defined by Roughgarden, that can be thought of as mechanisms that generate approximately market clearing prices. We show that smooth mechanisms result in high quality outcome in equilibrium both in the full information setting and in the Bayesian setting with uncertainty about participants, as well as in learning outcomes. Our main result is to show that such mechanisms compose well: smoothness locally at each mechanism implies efficiency globally. For mechanisms where good performance requires that bidders do not bid above their value, we identify the notion of a weakly smooth mechanism. Weakly smooth mechanisms, such as the Vickrey auction, are approximately efficient under the no-overbidding assumption. Similar to smooth mechanisms, weakly smooth mechanisms behave well in composition, and have high quality outcome in equilibrium (assuming no overbidding) both in the full information setting and in the Bayesian setting, as well as in learning outcomes. In most of the paper we assume participants have quasi-linear valuations. We also extend some of our results to settings where participants have budget constraints

Recent advances in the formation of phase inversion membranes made from amorphous or semi-crystalline polymers

Structural characteristics in membranes formed by diffusion induced phase separation processes are discussed. Established theories on membrane formation from ternary systems can be extended to describe the effects of high or low molecular weight additives. A mechanism for the formation of nodular structures in the top layer of ultrafiltration membranes is presented. In the last part structures arising from polymer crystallization during immersion precipitation are discussed