• Textile Coloration and Finishing
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• v.15 no.6
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• pp.39-46
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• 2003

The experiments about dyeing concentration, temperature and time were done using yellow, red and purple loess as natural inorganic dyes in order to verify a degree of dyeing, characteristics of color and fastness. The results were as following; 1. As a result of analyzing components of loess, purple loess was much than other loess in quartz component and coarse particles contained. This affected to the degree of dyeing. 2. The stronger dyeing concentration was, the more the degree of dyeing was improved, and yellow loess containing fine particles was the best in the degree of dyeing. 3. When it was dyed with raising up to $100^\circ{C}$ for 10 minutes after stirring for 20 minutes at $60^\circ{C}$, was better than on starting at $40^\circ{C}$ or $80^\circ{C}$ in the degree of dyeing. Also yellow loess was the best in these experiments. 4. Washing fastness of loess was low such as other natural dyes, but dyeing wasn't transferred to other textiles. On the other hand, light fastness of it was very excellent and rubbing fastness was relatively good as 3~3.5.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.551-554
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• 2005

This study uses a characteristic function to explain correlations between the objective function and design variables. Analysis of means and table of orthogonal array were carried out. The change of shape of diaphragm, thickness of diaphragm and voice coil weight based on the table of orthogonal array is made. Therefore this study carried to decide shape of diaphragm, voice coil weight and thickness of diaphragm for minimizing 1st natural frequency and maximizing 2nd natural frequency of diaphragm using design of experiments and characteristic function with constraints. we showed improved design factors that minimized 1st natural frequency and maximized 2nd natural frequency of diaphragm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.555-558
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• 2005

The precision positioning system requires robust design to obtain enough bandwidth. Therefore, The sub-resonance occurred by the disaccord of force center and mass center should be oppressed. And it is necessary to move the flexible mode to a higher frequency. In this paper, the 3-axis nano stage was proposed and dynamic characteristics was improved by design of experiments (DOE).

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.63-69
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• 2007

The surface roughness in centerless grinding is mainly affected by the many process parameters. For improving the surface roughness, the control of grinding parameters is very important. This paper deals with the analysis of the process parameters such as height of renters, tilting angle of the regulating wheel with respect to grinding wheel, rotation speed of regulating wheel, which are developed based on design of experiments such as factorial design. The investigation can enhance the surface roughness of ferrule. Finally, we have verified improved results of the optimized conditions.

• MALSORI
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• no.57
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• pp.139-152
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• 2006

In this paper, we present a phrase break prediction method using CRF(Conditional Random Fields), which has good performance at classification problems. The phrase break prediction problem was mapped into a classification problem in our research. We trained the CRF using the various linguistic features which was extracted from POS(Part Of Speech) tag, lexicon, length of word, and location of word in the sentences. Combined linguistic features were used in the experiments, and we could collect some linguistic features which generate good performance in the phrase break prediction. From the results of experiments, we can see that the proposed method shows improved performance on previous methods. Additionally, because the linguistic features are independent of each other in our research, the proposed method has higher flexibility than other methods.

• Computers and Concrete
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• v.17 no.4
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• pp.541-551
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• 2016

Asphalt pavements are exposed to complex weather conditions and vehicle traffic loads leading to crack initiation and crack propagation in asphalt pavements. This paper presents the impact of weather conditions on fracture toughness of an asphalt concrete, prevalently employed in Ardabil road networks, under tensile (mode I) and shear (mode II) loading. An improved semi-circular bend (SCB) specimen was employed to carry out the fracture experiments. These experiments were performed in two different weather conditions namely fixed and cyclic temperatures. The results showed that consideration of the impact of temperature cycling resulted in decreasing the fracture toughness of asphalt concrete significantly. Furthermore, the fracture toughness was highly affected by loading mode for the both fixed and cyclic temperature conditions studied in this paper. In addition, it was found that the MTS criterion correctly predicts the onset of fracture initiation although this prediction was slightly conservative.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.7
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• pp.16-21
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• 2008

For Preisach model, Everett function from the transient curves is needed to simulate the hysteresis phenomena. However it becomes very difficult to get the function if the it would be made only from experiments. In this paper, a simple and stable procedure using least square method and logarithm function to determine the Everett function which follows the Gauss distribution for interaction field axis is proposed. The characteristics of the parameters used in this procedure are also presented. The proposed method is applied to implement hysteresis loops. The simulation for hysteresis loop is compared with experiments and good agreements could be shown.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.211-217
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• 2010

This paper introduces the Hull Mounted Sonar Vertical Scanning(HMS Verscan) technique to overcome the limitation of target detection in short range shadow zone. Numerical experiments were done with the HMS Verscan taking advantage of the vertical beamforming technique for two-dimension hydrospace(range-depth). For numerical experiments, ray model and high-frequency monostatic reverberation model were used. HMS Verscan increased a sound pressure level at the short range shadow zone through reflections at the sea surface and seafloor. Inclusion of the boundary scattering improved target detection due to the sound reflected into the shadow zone.

• KSBB Journal
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• v.13 no.1
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• pp.38-43
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• 1998

Application of pervaporative extraction of ethanol to simultaneous saccharification and fermentation(SSF) of cellulose was investigated. From batch experiments, optimum cellulose substrate and enzyme loadings were found to be 10% and 15 IFPU/g cellulose, respectively. The cellulose conversion was lowered in fed-batch system due to the ethanol accumulation. The activity of the yeast Saccharomyces uvarum used in this study was significantly reduced at ethanol concentrations above around 40 g/L. From pervaporation experiments using PDMS membrane, ethanol was efficiently separated at 38$^\circ C$ and 10 mmHg of a down stream pressure. The pervaporation unit with 240 cm$^2$ of surface area was combined into the SSF reactor. The continuous removal of ethanol by pervaporation during SSF resulted in an improved cellulose conversion. Within the scope of this experiment, ethanol yields in the pervaporative SSF and simple SSF were 68.3% and 56.6%, respectively. The permeate flux for SSF broth pervaporation was about one-half that for the pervaporation of aqueous ethanol solution. Accordingly, the development of a membrane with higher ethanol selectivity and flux will increase the feasibility of this technology.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.283-286
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• 2006

This paper presents a numerical study on the overall performance and local flow characteristics of the sirocco fan. The effects of impeller and volute shape distribution on the performance of the sirocco fan were numerically studied using a commercial CFD code and a DOE (design of experiments) software. At present, our attention was focused on the relation of the results of DOE and the performance of the sirocco fan. As a main result of the optimization, the performance of the sirocco fan was successfully improved. Also, detailed effects of geometric parameter of impeller and volute in the sirocco fan were discussed.