• The Korean Journal of Ecology
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• v.24 no.5
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• pp.323-332
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• 2001

A cultural landscape results from a combination of human activities for resource-use and the response of nature to such artificial interference. Nature provides resources necessary for human life on the Earth in terms of his survival as well as living. Humanbeing has developed civilization using the benefits that nature provides. In the past, a harmonious relationship between mankind and nature had ensured sustainability of resource-use for human. We can find such facts from the existence of cultural landscape. However, rapid economic growth and a development-oriented logic caused from such socio-economic change led to the environmental crises and the depletion of various resources at global level. In the perspective of preparation for such problems, we investigated the background for establishment, function, and value of cultural landscapes, in which a dynamic equilibrium exists between a supply of natural resources and human needs. Furthermore, we discussed a new economic model including ecological consideration, a strategy for ecological management of environment, and a framework for transmission of traditional culture to new generations on the basis of a cultural landscape regime.

• Journal of the Korean Geotechnical Society
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• v.30 no.10
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• pp.55-65
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• 2014

Recent researches on debris flow is focused on understanding its movement mechanism and building a numerical simulator to predict its behavior. However, previous simulators emulating fluid-like debris flow have limitations in numerical stability, geometric modeling and application of various boundary conditions. In this study, depth integration is applied to continuity equation and force equilibrium for debris flow. Thickness of sediment, and average velocities in x and y flow direction are chosen for main variables in the analysis, which improve numerical stability in the area with zero thickness. Petrov-Galerkin formulation uses a discontinuous test function of the weighted matrix from DG scheme. Presented mechanical constitutive model combines fluid and granular behaviors for debris flow. Effects on slope angle, inducing debris height, and bottom friction resistance are investigated for a simple slope. Numerical results also show the effect of embankment at the bottom of the slope. Developed numerical simulator can assess various risk factors for the expected area of debris flow, and facilitate embankment design in order to minimize damage.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.210-216
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• 2015

Adsorption of brilliant blue FCF dye using coal based the granular activated carbon from aqueous solution was investigated. Batch experiments were carried out as a function of the adsorbent dose, initial concentration, contact time and temperature. The equilibrium adsorption data were fitted to Langmuir, Freundlich and Temkin models. The results indicate that Freundlich model provides the best correlation of the experimental data. Base on the estimated Freundlich constant (1/n = 0.129~0.212), this process could be employed as an effective treatment method. Adsorption data were modeled using the pseudo-first-order and pseudo-second-order kinetic equations. It was shown that the pseudo-second-order kinetic equation could describe well the adsorption kinetics. The negative Gibbs free energy value (-4.81~-10.33 kJ/mol) and positive enthalpy value (+78.59 kJ/mol) indicated that the adsorption was a spontaneous and endothermic process.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.335-340
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• 1992

The amounts of salt diffused into radish after immersing in various concentrations of salt solution at different temperatures were measured and the changes of radish texture by the salt diffusion were estimated with the viscoelastic constants of a 3 element solid model determined by a stress relaxation test. The amount of salt diffused through radish was increased with increasing the salt concentration and soaking temperature. While the instantaneous stress, equilibrium elastic solid content and viscoelastic constants of radish were decreased as salt concentration and soaking temperature increased, the stress relaxed fast. Viscoelastic constants as well as the diffusivity were influenced by salt concentration more than by soaking temperature. The rheological equations for the predictable stress changes of radish after immersed in the salt solution at various conditions (temperature, salt concentration and impure salt) were suggested as a function of time.

• Journal of KSNVE
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• v.8 no.6
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• pp.1181-1192
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• 1998

This paper describes the performance of a full-authority neural network-based fault tolerant system within a flight control system. This fault tolerant flight control system integrates sensor and actuator failure detection, identification, and accommodation (SFDIA and AFDIA), The first task is achieved by incorporating a main neural network (MNN) and a set of n decentralized neural networks (DNNs) to create a system for achieving fault tolerant capabilities for a system with n sensors assumed to be without physical redundancy The second scheme implements the same main neural network integrated with three neural network controllers (NNCs). The function of NNCs is to regain equilibrium and to compensate for the pitching, rolling. and yawing moments induced by the failure. Particular emphasis is placed in this study toward achieving an efficient integration between SFDIA and AFDIA without degradation of performance in terms of false alarm rates and incorrect failure identification. The results of the simulation with different actuator and sensor failures are presented and discussed.

• Journal of the Korean Institute of Gas
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• v.14 no.5
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• pp.32-37
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• 2010

In this study, vapor-liquid equilibrium (VLE) data at several isothermal temperatures for carbon dioxide and ethane binary systems were estimated using binary interaction parameters (BIP's) in Peng-Robinson (PR) equation of state built-in PRO/II with PROVISION (PRO/II) process simulator. Moreover, BIP's in PR equation of state were newly determined by regressing the experimental VLE data for carbon dioxide and ethane systems for each different isothermal temperatures using the summation of squares of the bubble point deviations as an objective function. Comparative works have been performed for absolute average deviation % (AAD(%)) between experimental and predicted bubble pressures using built-in BIP's in PRO/II and newly regressed one, respectively. Our calculation results gave a better estimation result than the simulation result using an existing parameter built-in PRO/II.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1720-1725
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• 2004

Absorption characteristics of green tea powder were investigated. The monolayer moisture content determined by GAB equation was 0.024~0.052 g $H_2O$/g dry solid. The absorption enthalpy was calculated with different particle size and various water activities. It showed that the absorption energy was decreased with increasing water activity but no difference was found on particle size increasement. Among models applied for predicting equilibrium moisture content, Halsey model was the best fit model for green tea powders, showing the lowest prediction deviation of 2.1~4.0%. The prediction model equations for the water activity was established as function of relative humidity, time and temperature. The model equation will be helpful for future work on drying and storage of green tea powder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.409-416
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• 2003

Marine populations are maintained through the processes of spawning, growth, recruitment, natural death and fishing in a marine ecosystem. Based upon each of these processes, a quantitative population dynamic model was developed to estimate damages in fishery production due to accidents in a fishing ground. This model was applied for the abalone culture grounds in Korean waters. Three components of damages were identified in the ecosystem of the abalone culture grounds, namely, physical damages in the substratum of the fishing ground, biological damages in the structure and function of the ecosystem, and damages in fishery production. Considering these three components the processes and durations of damages in fishery production were determined. Because the abalone population is composed of multiple year classes, damages influence all the year classes in the population, when they occur The model developed in this study is: $$y=(n_{\lambda}+1){\times}Y_E\;-\;\sum\limits^{n_\lambda-n_c}_{l=0}\;y_{n_c/i}$$ where, y is the expected damages in fishery production during the period of restoration of the damaged abalony population, $Y_E$ is the annual equilibrium yield, $n_{\lambda}$ is the maximum age in the population, $t_s$ is the year of damage occurrence, $n_c$ is the age at recruitment, and $\sum\limits^{n_\lambda-n_c}_{l=0}\;y\;_{n_c/i}$ is total expected lifetime catch of year classes which were recruited during the restoration period.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.164-170
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• 1999

Cracking of rice caused by moisture migration during storage under different relative humidity conditions was investigated for the establishment of safe storage condition of rice. Rice was cracked when a large difference in equilibrium relative humidity $({\Delta}ERH)$ between the rice and the environment was present. External and internal cracks were generated as the results of moisture desorption and adsorption, respectively. The external cracks by moisture desorption generated in all directions and shaped irregularly, while the internal cracks by moisture adsorption did in radial direction and showed a typical shape. The cracking trend could be analyzed by the Weibull function, and the cracking constant increased with ${\Delta}ERH$. The frequency of cracked rice increased linearly with In $({\Delta}ERH)$. The critical crack-inducing ${\Delta}ERH$ was $11.3{\sim}16.4%$ during desorption and $10.8{\sim}17.1%$ during adsorption. A diagram for the safe storage of rice was developed with respect to the initial moisture content and the water activity of rice.

• Journal of Biosystems Engineering
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• v.11 no.1
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• pp.52-63
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• 1986

This study was performed to find out drying characteristics and develop drying model for the design of an efficient dryer or drying system of red peper. The basic model which describes drying phenomenon of red pepper was firstly established, and drying tests were conducted at 14-different drying conditions. In this test, the effects of drying air temperature and relative humidity on the rate of drying were undertaken. Finally, a new drying model based on these experimental results was developed to describe the drying characteristics of red pepper. The results from this study may be summarized as follows. 1. Drying constant of the basic model established from Lewis' experimental model and diffusion equation was theoretically deduced as a function of moisture content and inner-temperature of red pepper. 2. From the results of drying tests, drying air temperature was found to have the greatest effect on the rate of drying. However, the effect of temperature was small for the condition of high relative humidity, and for low temperature, the effect of relative humidity was found to be large even though the range of relative humidity was low. 3. Modified Henderson equation was found to be better than Chung equation as the EMC model for the estimation of the equilibrium moisture content of red Pepper. 4. Constant-rate drying period did not exist in the red pepper drying test. And falling-rate drying period was divided into three distinct phases. Drying rate was dependent on the moisture content, the inner-temperature of red pepper and the change of physical property due to drying. 5. Drying constant increased with decrease of free moisture content, but it decreased at the end of the drying period. Also, drying constant was dependent on the drying air temperature and relative humidity. 6. The new drying model developed in this study was found to be most suitable in describing the drying characteristics of red pepper. Therefore, it may be concluded that drying time could be accurately estimated by the new drying model.