• Smart Media Journal
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• v.9 no.3
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• pp.98-106
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• 2020

Currently, as Internet users increase, the use of swearword is indiscriminately increasing. As a result, cyber violence among teenagers is increasing very seriously, and among them, cyber-language violence is the most serious. In order to eradicate cyber-language violence, research on detection of swearword has been conducted, but the method of detecting swearword by looking at the meaning of words and the flow of context is insufficient. Therefore,in this paper,we propose a method of detecting swearword using FastText model and LSTM model so that deliberately modified swearword and standard language can be accurately detected by looking at the flow of context.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.4
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• pp.526-533
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• 2011

This research is about the pulsatile pump system utilized in the perfusion bioreactor for the in vitro human tissue culture. A pulsatile pump system which can be applied to the culture of the vascular tissues including blood vessel is developed by using the idea of human heart's blood pumping into organs as followings: culture chamber, a pressurizing device which generates laminar pulsatile flow by controlling the x-sectional area of the culture media delivering tubing, a compliance chamber which supplies the pressuring device with a constant pressure, and a peristaltic pump which circulates the culture media in a circuit ranging from the culture chamber to the compliance chamber. The developed pulsatile pump system shows that a physiology of the human heart's blood pumping including pulsatile pressure waveform of systolic-diastolic pressure is well represented. Not only time domain but also frequency domain characteristics of pulsatile pump system which are necessary for the vascular tissue culture such as pulsatile pressure waveform's shape, the frequency, and the magnitude can be easily generated and manipulated by using the proposed system.

• Smart Media Journal
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• v.2 no.3
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• pp.34-38
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• 2013

Several costs including printing and management are added in commerce by vouchers. In this case that a voucher is digitalized and flown through mobile phones, these costs are diminished considerably. Also, as mobile commerce is on the increase according to the activation of smart phones, NFC technology with near distance communication is gave attention to. Therefore, researches for using NFC-based electronic vouchers to pay electronically on mobile are made. To analyze the flow path of electronic vouchers, which helps marketing strategy, this paper proposes the method to put useful data into them. The proposed method utilizes object memory model. The proposed electronic voucher includes the block for flow history data in addition to its information. In the future, we will implement and test this electronic voucher.

• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.59-62
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• 2012

This test method covers a procedure for measuring particle removal characteristic of equipment fan filter unit(EFFU) installed inside of semiconductor process equipments, FPD manufacturing equipments and so on. Since EFFU is a combination of air filter and the assembly of fan, motor and frame, the integrity of these parts is very important for the performance of EFFU. So a conventional particle removal test method for air filters is not suitable for EFFU particle removal performance. This test method defines an evaluation method for EFFU which is installed inside an enclosed space to remove particles that are generated inside process equipment. The particle removal performance of EFFUs is usually depending on the performance of filter media and air flow rate. To understand a performance of an EFFU, the filter media characteristic, air flow rate and the integrity of EFFU parts should be considered simultaneously. This test method is intended to demonstrate the system performance of an EFFU and successfully evaluated EFFU performance characteristics.

• Nuclear Engineering and Technology
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• v.45 no.2
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• pp.191-202
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• 2013

A numerical analysis of thermal stratification in the upper plenum of the MONJU fast breeder reactor was performed. Calculations were performed for a 1/6 simplified model of the MONJU reactor using the commercial code, CFX-13. To better resolve the geometrically complex upper core structure of the MONJU reactor, the porous media approach was adopted for the simulation. First, a steady state solution was obtained and the transient solutions were then obtained for the turbine trip test conducted in December 1995. The time dependent inlet conditions for the mass flow rate and temperature were provided by JAEA. Good agreement with the experimental data was observed for steady state solution. The numerical solution of the transient analysis shows the formation of thermal stratification within the upper plenum of the reactor vessel during the turbine trip test. The temporal variations of temperature were predicted accurately by the present method in the initial rapid coastdown period (~300 seconds). However, transient numerical solutions show a faster thermal mixing than that observed in the experiment after the initial coastdown period. A nearly homogenization of the temperature field in the upper plenum is predicted after about 900 seconds, which is a much shorter-term thermal stratification than the experimental data indicates. This discrepancy may be due to the shortcoming of the turbulence models available in the CFX-13 code for a natural convection flow with thermal stratification.

• Journal of applied mathematics & informatics
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• v.29 no.5_6
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• pp.1269-1283
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• 2011

Here we consider magneto-convection in a mushy layer which is formed during solidification of binary alloys. The mushy layer is treated as an active porous media with variable permeability. The equations governing the layer are conservation of mass, conservation of heat, conservation of solute, magnetic induction equation, momentum equation governed by the Darcy's law and Maxwell's equations for the magnetic field. To study the second order effects on the flow without solving the second order system, we need to obtain the adjoint system for the flow. This motivates the authors we derive the adjoint system analytically for the mushy layer case. Numerical results of the adjoint system are presented for passive and active mushy layers at the onset of the motion using a set of parameters experimentalists use.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.134-136
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• 2005

Homogenization method is adopted to predict the permeability tenor for glass fiber plain woven fabrics. Calculating the permeability tensor numerically is an encouraging task because the permeability tensor is a key parameter in resin transfer molding (RTM). Based on multi-scale approach of the homogenization method, the permeability for the micro-unit cell within fiber tow is computed and compared with that obtained from flow analysis for the same micro-unit cell. It is found that they are in good agreement. In order to calculate the permeability tensor of macro-unit cell for the plain woven fabrics, the Stokes and Brinkman equations which describe inter-tow and intra-tow flow respectively are employed as governing equations. The effective permeabilities homogenized by considering intra-tow flow are compared with those obtained experimentally. Control volume finite element method (CVFEM) is used as a numerical method. It is shown that the asymptotic expansion homogenization method is an attractive method to predict the effective permeability for heterogeneous media.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.96.2-96.2
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• 2011

Water transport through the microporous membrane was modeled considering capillary condensation as well as capillary flow in porous media as a function of pore diameter and relative humidity at the surface. The present model was adopted by the numerical simulation of non-isothermal, non-homogenous flow in a shell and tube typed gas to gas membrane humidifier for PEMFC (proton exchange membrane fuel cell) and the result shows good agreement with experimental data.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.4
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• pp.542-550
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• 1998

A direct contact heat exchanger using particle-suspended gas as a heat transfer medium is analyzed with an extended emphasis on the radiation, i. e., considering the radiation by both gas and particles. While the Runge-Kutta method is used for a numerical analysis of the momentum and energy equations, the finite volume method is utilized to solve the radiative transfer equation. Present study shows a notable effect by the gas radiation in addition to the particle radiation, especially when changing the chamber length as well as the gas and particle mass flow rate. When the gas and particle mass flow rate is raised, the gas temperature in the particle heater still increases as the gas absorption coefficient increases, which is different from the results for the small scale heat exchanger.

• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.215-220
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• 2004

A mathematical formulation based on two-phase, two-fluid hyperbolic conservation laws is developed to investigate propagation of shock waves in one- and two-dimensions. We used a high resolution upwind scheme called the split-coefficient matrix method. Two extreme cases are computed for validation of the computer code: the states of a pure gas and a pure liquid. Computed results agreed well with the previous experimental and numerical results. It is studied how the shock wave propagation pattern is affected by the void fraction in the two-phase flow. The shock structure in a two-phase flow turned out, in fact, much deviated from the shape well known in the gas only phase.