Simple and effective neural coreference resolution for Korean language

We propose an end-to-end neural coreference resolution for the Korean language that uses an attention mechanism to point to the same entity. Because Korean is a head-final language, we focused on a method that uses a pointer network based on the head. The key idea is to consider all nouns in the document as candidates based on the head-final characteristics of the Korean language and learn distributions over the referenced entity positions for each noun. Given the recent success of applications using bidirectional encoder representation from transformer (BERT) in natural language-processing tasks, we employed BERT in the proposed model to create word representations based on contextual information. The experimental results indicated that the proposed model achieved state-of-the-art performance in Korean language coreference resolution.     

Kinetics of the reactions of carbon containing zinc oxide composites under microwave irradiation

As a fundamental study for the recycling of EAF dust using microwave heating, the reduction rate of a zinc oxide composite by solid carbon under microwave irradiation was investigated. It was found that the reduction of zinc oxide by solid carbon under microwave irradiation was much faster than the conventional method, and the activation energy for the reaction under microwave irradiation was estimated to be 335 kJ/mol.     

Reduction of electrical arc furnace oxidizing slag by coke under microwave irradiation

The reduction of iron from electrical arc furnace oxidizing slag by coke was investigated under microwave irradiation (1.7 kW, 2.45 GHz). The heating behavior of cokes of different sizes were examined and a maximum heating rate of 550 K/min and a maximum temperature of 1783 K were obtained with coke particles smaller than 75 m. In the reduction of the oxidizing slag (15 g) by coke (1.45～1.65 g) under microwave irradiation for 25 min, the maximum recovery ratio of iron was 0.87, obtained when the amount of coke addition was 1.55 g. In addition, the reduced slag composition was modified by adding 5.9 g of CaO. With the addition of 1.55 g coke or more, free CaO in the slag was effectively reduced.     

Kinetics of SiC Formation on Graphite Using N2-CO-SiO and N2-CO-H2-SiO Gas Mixtures

Metallurgical and Materials Transactions B - The formation of SiC on a graphite surface through the reaction between SiO gas and C was investigated. Experiments were conducted at 1843 K,...     

Experimental study on synthetic jet array for aerodynamic drag reduction of a simplified car

This paper describes an experimental parametric study of synthetic jet array actuation to reduce the aerodynamic drag of a threedimensional simplified car. By using two configurations of an Ahmed body with 25° and 35° slant angles, we performed wind tunnel tests under different conditions of synthetic jet array. Several parameters, namely, jet location, jet direction, jet momentum coefficient, jet driving frequency, and number and position of activated jets within the actuator array, were considered. The total aerodynamic drag coefficients were compared, and the rear wake flows were studied by using the data obtained from rear surface pressure distribution and flow visualization tests. Results of the parametric study show that the aerodynamic drag exhibits different behavior depending on the location of the jet for each slanted model. Jet direction, jet momentum coefficient, and jet driving frequency affect only the amount of change in the aerodynamic drag. The distribution of the activated jets also affects jet efficiency.     

Nonlinear static composition estimator for distillation columns using open equation-based nonlinear programming

In distillation column control, secondary measurements such as temperatures and flows are widely used to infer product composition. This paper addresses the development of nonlinear static estimators using secondary measurements for estimating product compositions of distillation columns. An open equationbased optimization problem, which minimizes the differences between the measured outputs and the estimated outputs, has been formulated and solved by using the nonlinear program (NLP) solver, MINOS5. It is shown that the proposed nonlinear estimator is robust and more powerful than the conventional PLS (Partial-Least-Squares) estimator.     

Kinetics of Carbon Dissolution of Coke in Molten Iron

The effect of temperature on the dissolution rate of carbon from coke in molten iron was investigated using a sampling technique in the temperature range of 1723?K to 1923?K (1450?°C to 1650?°C). The dissolution rate of carbon from coke in molten iron increased as the temperature increased. At 1923?K (1650?°C), the rate-determining step was the mass transfer of carbon in the boundary layer adjacent to the metal-carbon interface. At 1723?K (1450?°C), the rate-determining step changed from the mass transfer to the interfacial chemical reaction as the reaction proceeded. At 1823?K (1550?°C), both reaction steps affected the apparent reaction rates. Sulfur dissolution did not affect the carbon dissolution rates in molten iron, so it was considered that the sulfur adsorption at the metal/coke interface was not so significant. The apparent activation energy of the carbon dissolution of coke in molten iron was estimated to be 442?kJ/mol.     

Surface tension of liquid Fe-Cr-O alloys at 1823 K

The surface tension of liquid Fe-Cr-O alloys has been determined by using the sessile drop method at 1823 K. It was found that the surface tension of liquid Fe-Cr-O alloy markedly decreases with oxygen content at constant chromium content, and the surface tension at a given oxygen content remains almost constant, regardless of the chromium content. When the surface tension of liquid Fe-Cr-O alloys is plotted as a function of oxygen activity, with an increase in the chromium content, the surface tension shows a much steeper decrease with respect to oxygen activity. The surface tension of liquid Fe-Cr-O alloys at 1823 K is given as follows: σ=1842-279 ln (1+K _O a _O). Here, assuming a Langmuir-type adsorption isotherm, the adsorption coefficient of oxygen, K _O(Fe-Cr), as a function of chromium content, was shown to be K _O=140+4.2 × [wt pct Cr]+1.14 × [wt pct Cr]².