• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.4
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• pp.36-44
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• 1997

This experiment was mainly performed with a mechanical treatment using ultrasound. We got the following conclusions : At seven minutes-ultrasonic treatment using nonionic surfactant, yield, brightness and residual ink contents were superior to other treatment, but several strength properties were decreased. On the other hand anionic surfactant was considerably low ink removal efficiency. For ultrasonic treatment using nonionic surfactant, yield and brightness were dropped when temperature was over 4$0^{\circ}C$, but were observed to be insensitive to the pulp consistency and flotation time. In the case of nonionic surfactant, tensile and burst strength were improved when ultrasonic treatment was used comparing to non-treatment, and nonionic surfactant was generally better than anionic surfactant in terms of tensile and burst strength regardless of ultrasound conditions. Several properties were decreased when anionic surfactant was used in comparison with nonionic surfactant except yield, therefore, anionic surfactant. was not proper to be used in this condition.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.74-76
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• 2008

Autohydrolysis at different temperature levels was applied as industrial hemp pretreatment technique for glucose generation. Main structural components removed by autohydrolysis was xylan, which is more sensitive in acidic hydrolysis condition than cellulose or lignin. Higher temperature reaction conditions promoted more biomass components (xylan) removal than lower temperature, which led to better respond to enzymatic saccharification of residual biomass after autohydrolysis. With $185^{\circ}C$ and 60 min, saccharification degree was 53.0% of cellulose in hemp woody core biomass.

• Journal of the Korean Society for Heat Treatment
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• v.9 no.1
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• pp.62-68
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• 1996

In order to establish making process of water atomized iron powder for powder metallurgy, effect of heat treatment condition on change of powder properties and impurities was investigated at each tempeature of $850{\sim}950^{\circ}C$. The results are as follows. Particle morphology of iron powder changed slightly from sphercial type to irregular type and the amount of fine particle decreased more and more with increasing of heat treatment time at each temperature. The flow rate and apparent desity of iron powder also decreased due to particle coalescence in order of $850^{\circ}C$, $950^{\circ}C$, $900^{\circ}C$. Those powder Properties became to decrease particularly at $900^{\circ}C$ in alpha iron region. On the other hand, residual carbon and oxygen contents in iron powder decreased extremely with increasing of heat treatment temperature and time.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.24-33
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• 1999

This paper investigate the effects of the variations of engine operation condition in the flame kernel formation and developmnet . A model for calculating the initial kernel development in spark ignition engines is formualted. It considered input of electrical energy, combustion energy release and heat transfer to the spark plyg, cylinder head, and unburned mixture. The model also takes into accounts strain rate of initial kernel and residual gas fraction. The breakdown process and the subsequent electrical power input initially control the kernel growth while intermediate growth is mainly dominated by diffusion or conduction. Then, the flame propagates by the chemical energy and turbulent flame expansion. Flame kernel development also influenced by engine operating conditions, for example, EGR rate, air-fuel ration and intake manifold pressure.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.373-385
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• 2004

Irradiation offers an effective and simple means to extend shelf-life of meat and improve processing properties of meat products. Many researches have been conducted to evaluate the effects of irradiation on meats and meat products. There were some interesting reports such as increase of redness and tenderness of meat and decrease of carcinogenic N-nitrosamines and residual nitrite in cured meat products by irradiation. And, the safety of irradiated products have been also studied. Lipid oxidation and off-odor induced by irradiation can be minimized by appropriate controls of irradiation and storage condition such as addition of antioxidants or oxygen exclusion packaging. The objective of this paper is to introduce the effect of gamma irradiation on quality of meats and meat products reported from the previous researches.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.307-310
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• 2003

In this paper, an iterative learning control method is applied to suppress the vibration of a 2-mass system which has a flexible coupling between a load an a motor. More specifically, conditions for the load speed without vibration are derived based on the steady-state condition. And the desired motor position trajectory is synthesized based on the relation between the load and motor speed. Finally, a PD-type learning iterative control law is applied for the desired motor position trajectory. Since the learning law applied for the desired trajectory guarantees the perfect tracking performance, the resulting load speed shows no vibration. In order to handle the initial position error, the PD-type learning law is changed to PID-type and a weight function is added to suppress the residual vibration caused by the initial error. The simulation results show the effectiveness of the proposed learning method.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.118-123
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• 2007

A robust objective function in the frequency domain is applied to the acoustic full waveform inversion. The proposed objective function is defined as $l_1$-norm of residual wavefields in the frequency domain. Generally, the full waveform inversion is extremely sensitive to a number of factors such as parameterization, initial model, noise and so on. The numerical tests were performed for checking the sensitivity to attenuation and several noises. For the comparison with other objective functions, the conventional least-squares method and the logarithmic method were tested under the same condition. The synthetic data examples show that the proposed algorithm is more robust than the well-known methods.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1519-1524
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• 2009

Construction of high-speed concrete track embankments over soft ground needs many of the ground improvement techniques. Drains, surcharge loading, and geosynthetic reinforcement, have all been used to solve the settlement and embankment stability issues associated with construction on soft soils. However, when time constraints are critical to the success of the project, another measures should be considered. Especially, since the design criteria of residual settlement is limited as 30mm for concrete track embankment, it is very difficult to satisfy this allowable settlement by using the former construction method. Pile net method consist of vertical columns that are designed to transfer the load of the embankment through the soft compressible soil layer to a firm foundation and one or more layers of geosynthetic reinforcement placed between the top of the columns and the bottom of the embankment. In this paper, three cases with different embankment height and number of geosynthetic reinforcement, were studied through FEM analysis for efficient use of pile net method.

• Journal of the Korea Society for Simulation
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• v.10 no.4
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• pp.41-50
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• 2001

When optimizing a complex system by determining the optimum condition of the system parameters of interest, we often employ the process of estimating the unknown objective function, which is assumed to be a second order spline function. In doing so, we normally use common random numbers for different set of the controllable factors resulting in more accurate parameter estimation for the objective function. In this paper, we will show some mathematical result for the analysis of variance when using common random numbers in terms of the regression error, the residual error and the pure error terms. In fact, if we can realize the special structure of the covariance matrix of the error terms, we can use the result of analysis of variance for the uncorrelated experiments only by applying minor changes.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.960-966
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• 2011

In this paper, an $\mathfrak{H}$_/$\mathfrak{H}_{\infty}$ fault detection and isolation (FDI) observer design problem is investigated for discrete-time delayed systems. To that end, a bank consisting of the sensor's number of observers is introduced. Each residual should be sensitive to a certain partial group of faults, but robust against the disturbance as far as possible. We formulate this multiobjective FDI problem as $\mathfrak{H}$_/$\mathfrak{H}_{\infty}$ observers design problem. Sufficient design condition is expressed as iterative linear matrix inequalities. The fault is then detected and isolated by evaluating the residuals through an FDI decision logic. A computer simulation is provided for verification of the proposed technique.