• Computers and Concrete
• /
• 제25권5호
• /
• pp.433-445
• /
• 2020

A method is proposed in this paper to estimate the workability of self-compacting concrete (SCC) in different mixing conditions with different mixers and mixing volumes by recording the mixing process based on deep learning (DL). The SCC mixing videos were transformed into a series of image sequences to fit the DL model to predict the SF and VF values of SCC, with four groups in total and approximately thirty thousand image sequence samples. The workability of three groups SCC whose mixing conditions were learned by the DL model, was estimated. One additionally collected group of the SCC whose mixing condition was not learned, was also predicted. The results indicate that whether the SCC mixing condition is included in the training set and learned by the model, the trained model can estimate SCC with different workability effectively at the same time. Our goal to estimate SCC workability in different mixing conditions is achieved.

• 한국멀티미디어학회논문지
• /
• 제18권6호
• /
• pp.734-741
• /
• 2015

Coating is a type of paint. It protects a product forming a film layer on the product and assigns various properties to the product. Coating is one of the fields which is being studied actively in the polymer industry. Importance of coating in various industries is more increased. However, mixing process has been performing in dependence on operator's experience. In this paper, we found the relationship between each data from coating formulation process. We propose a framework to analyze the coating formulation process as well. It can improve the coating formulation process. In particular, the suggested framework may reduce degradation and loss costs due to absence of standard data which is accurate formulation criteria. Also it suggests responses to errors which can be occurred in the future through the analysis of the error data generated in mixing step.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2000년도 제20회 KOSCO SYMPOSIUM 논문집
• /
• pp.76-84
• /
• 2000

A numerical study was conducted for the investigation of thermal choking process in a model scramjet engine based on the experimental results at the Australian National University. The results of numerical simulation showed that thermal choking process could be related to the interaction between hypersonic flow and fuel-air mixing process. Especially, we could make sure that turbulent mixing was most important parameter to the thermal choking process.

• Journal of the Korean Statistical Society
• /
• 제30권3호
• /
• pp.407-418
• /
• 2001

Buhlmann(1944) established the validity of the block bootstrap proposed by Kunsch when it is applied to p-dimensional $\alpha$-mixing dependent sequence. But his result requires a rather restrictive condition on p in the sense that p is entangled with dependence structure. We address that such restriction on p(or complication of dependence structure with p) could be removed completely when the underlying dependence structure is replace by more weakly dependent structure such as ø-mixing.

• Journal of the Korean Data and Information Science Society
• /
• 제22권2호
• /
• pp.353-360
• /
• 2011

We consider an asymmetric power transformed threshold GARCH(1.1) process and find sufficient conditions for the existence of a strictly stationary solution, geometric ergodicity and ${\beta}$-mixing property. Moments conditions are given. Box-Cox transformed threshold GARCH(1.1) is also considered as a special case.

• 대한기계학회논문집B
• /
• 제33권3호
• /
• pp.149-155
• /
• 2009

In this work a numerical study to find the characteristics of the internal flow and mixing process has been conducted in a static mixer used in the system of catalytic combustor of the fuel cell power plant. After introducing the model description and final governing equations the present numerical approach is applied to the analysis of static mixer, which may have one or more helical elements inside the circular tube by changing such various parameters as incoming mass flow rates and the number of helical elements. The results show that although the static mixer is efficient in mixing fuel and air, more optimization processes are required to achieve the appropriate mixing characteristics in front of the honeycomb type catalytic combustor used in the MCFC power plant

• 상하수도학회지
• /
• 제18권4호
• /
• pp.508-514
• /
• 2004

Industrial and municipal wastewater treatment plants produce large amounts of sludge cakes for final disposal. This problem is an inevitable drawback inherent to the activated sludge process. Both the reduction of the amount of sludge produced and improvement of its dewaterability are presently very important issue also in Korea. So many pre-treatment processes have been developed in order to improve sludge dewatering efficiency. In this study the effects of hydrogen peroxide and paper sludge mixing processes were considered as reasonable alternatives to enhance sludge dewaterability. The CST of sludge was significantly decreased, and dewaterability improved by hydrogen peroxide oxidation treatment. The optimum dosage of hydrogen peroxide was proved to be 10mg/g-TS (when TS of sludge was 2%) with the conditions of pH 4 and only 1~2 minutes of reaction time. The mixing of paper sludge with sewage sludge was turned out to be very effective in reduction of sludge cake; 30% of sludge cake reduction was accomplished. Optimum mixing ratio of paper sludge was about 30%(v/v). This process also could save 25% of polymer to be required. These two alternatives are somewhat realistic, but it was concluded that paper sludge mixing process will be the best choice.

• 대한금속재료학회지
• /
• 제46권6호
• /
• pp.382-389
• /
• 2008

To manufacture Al MMCs, in-situ melt mixing process is used because it is free from contamination, and it makes reinforcements homogeneously dispersed. Large eddy simulation method is used to find the optimum melt mixing condition. At the Re 3000, the most suitable mixing is occurred between Al-Ti and Al- B melts. The in-situ formed $TiB_2$ particles has the size varying from 40 nm to 130 nm, due to the increase of cooling rate, and exhibits a homogeneous dispersion. And the interface between reinforcement and matrix is clean. Both hardness and Young's modulus of this composite are improved with increasing the cooling rate.

• Journal of the Korean Statistical Society
• /
• 제22권2호
• /
• pp.259-269
• /
• 1993

A moving average model, LMA(q) and an autoregressive-moving average model, NLARMA(p, q), with Laplacian marginal distribution are constructed and their properties are discussed; Their autocorrelation structures are completely analogus to those of Gaussian process and they are partially time reversible in the third order moments. Finally, we study the mixing property of NLARMA process.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2011년도 추계학술대회 초록집
• /
• pp.99.1-99.1
• /
• 2011

Reactant mixing has a critical role in ensuring reformate quality and an important design objective is to achieve sufficiently complete mixture of reactants. For that purpose it is required to understand the coupled transport-kinetics phenomena in the mixing region. Three-dimensional computational fluid dynamics model was developed and validated in previous works. The mixing characteristics in various alternatives of a prototype mixing chamber were compared, and then a reduced reaction kinetics was applied to two extreme designs for investigating the impact of gas-phase reactions. Both designs did not reach threshold ethylene mole fraction of 0.001, but surprisingly more ethylene was generated in the design having better mixing characteristics. The presentation will deliver the development process of coupled transport and kinetics model briefly and the detailed information about the mixing characteristics and gas-phase reactions in two mixer designs.