• Journal of Environmental Science International
• /
• v.29 no.1
• /
• pp.15-23
• /
• 2020

The determination of soil characteristics is important in the simulation of rainfall runoff using a distributed FLO-2D model in catchment analysis. Digital maps acquired using remote sensing techniques have been widely used in modern hydrology. However, the determination of a representative parameter with spatial scaling mismatch is difficult. In this investigation, the FLO-2D rainfall-runoff model is utilized in the Yongdam catchment to test sensitivity based on three different methods (mosaic, arithmetic, and predominant) that describe soil surface characteristics in real systems. The results show that the mosaic method is costly, but provides a reasonably realistic description and exhibits superior performance compared to other methods in terms of both the amount and time to peak flow.

• Journal of Environmental Science International
• /
• v.29 no.1
• /
• pp.25-32
• /
• 2020

The determination of soil parameters is important in predicting the simulated surface runoff using either a distributed or a lumped rainfall-runoff model. Soil characteristics can be collected using remote sensing techniques and represented as a digital map. There is no universal agreement with respect to the determination of a representative parameter from a gridded digital map. Two representative methods, i.e., arithmetic and predominant, are introduced and applied to both FLO-2D and HEC-HMS to improve the model's accuracy. Both methods are implemented in the Yongdam catchment, and the results show that the former seems to be more accurate than the latter in the test site. This is attributed to the high conductivity of the dominant soil class, which is A type.

• Korean Journal of Environmental Biology
• /
• v.35 no.3
• /
• pp.265-272
• /
• 2017

The order Prorocentales currently includes two genera Prorocentrum Ehrenberg and Mesoporos Lillick. The Prorocentrum genus is a predominant group throughout the year found in Korean waters. To date, the Prorocentrum genus includes 31 species and the Mesoporos genus has only one species in Korean waters. In this study, we identified one Mesoporos species and three Prorocentrum species around a coast of Jeju Island, and described them as newly recorded species in Korean waters.

• Geomechanics and Engineering
• /
• v.7 no.5
• /
• pp.539-552
• /
• 2014

A simplified probability-based design charts for stone column-improved ground have been presented based on the unit cell approach. The undrained cohesion ($c_u$) and coefficient of radial consolidation ($c_r$) of the soft soil are taken as the most predominant random variables. The design charts are developed to estimate the diameter of the stone column or the spacing between the stone columns by employing a factored design value of $c_r$ and $c_u$ so as to satisfy a specific probability level of the target degree of consolidation and/or a target safe load that needs to be achieved in a specified timeframe. The design charts can be used by the practicing engineers to design the stone column-improved ground by considering consolidation and /or bearing capacity of the improved ground.

• Transactions of Materials Processing
• /
• v.7 no.3
• /
• pp.274-281
• /
• 1998

The service life of tools in metal forming process is to a large extent limited by wear, fatigue fracture and plastic deformation. In elevated temperature forming processes wear is the predominant factor for tool operating life. To predict tool life by wear Achard's model is generally applied. Usually hardness of die is considered to be a function of temperature. But hardness of die is a function of not only tem-perature but also operating time of die. To consider softening of die by repeated operation it is necessary to express hardness of die by a function of a function of temperature and time. By experiment of reheating of die softening curve was obtained and applied to suggest modified Archard's Model in which hardness is a function of main tempering curve.

• Journal of Korean Society for Atmospheric Environment
• /
• v.20 no.1
• /
• pp.129-138
• /
• 2004

Determination of some PAHs in ambient air at Ulsan have been carried out by collection of the components into n-hexane followed by synchronous spectrofluorimetric technique. 10 PAHs, such as acenaphthene (Ace), anthracene (Anth), benz[a]anthracene (BaA), benzo[b]fluoranthene (BbFt), benzo[k]fluoranthene (BkFt) benzo[a]pyrene (BaP), chrysene (Chry), phenanthrene (Phen), fluoranthene (Ft), perlyrene (Per), and pyrene (Pyr) in air samples were able to determine separately by synchronous spectrofluorimetry. Calibration curves for those components were linear for the concentration range of 0.2∼166ppb PAHs with the correlation factor of 0.9985∼0.9999. The predominant contribution was phenanthrene which was included 36.9∼85.1% to the overall level of the 10 PAHs in some areas. Also benzo[a]pyrene which was known to carcinogenicity was detected from 6.4 to 55.8ng/㎥, benzo[a]anthracene of some areas was contained from 21.9∼153ng/㎥.

• Proceedings of the KSME Conference
• /
• 2001.06e
• /
• pp.783-788
• /
• 2001

Choosing the most suitable mathematical model and relating this to turbulent tangential tensions model are very important in the investigations of turbulent two-phase flow. This paper considers two-fluid scheme. According to it, two phases have their own densities, velocities, and temperatures at any spatial point and at any moment. The equations of motion and heat transfer for each phase are linked with the forces of interaction between two phases. These forces are considered as predominant for the flow. As a closure in the system of motion equations, one modification of $K - {\epsilon}$ turbulent model is worked out. The modification uses two equations for turbulent kinetic energy of the phases and one - for the turbulent energy loss of main phase. This model can be set as a $K_g - K_p -{\epsilon}$ model. The modified model has been tested for both a two-phase non-isothermal flat jet and axially symmetrical jet. The numerical results are compared with the reference data revealing a good agreement between them.

• Proceedings of the KIPE Conference
• /
• 1997.07a
• /
• pp.166-170
• /
• 1997

A Single phase induction motor is the predominant fractional horsepower power rated, extensively used in domestic and industrial application. For example, these motors provide the motive power to washing machines, fans, refrigerators, etc. In this paper, single phase induction motor input current was detected by a small current transformer and determined TRIAC gate signal by using op-amp analog circuit. The soft-start strategy is based on limited auxiliary current angle during starting period in the closed-loop control. The Simulation and experimental result show the motor's starting characteristics of the proposal starting system and are compared with centrifugal switch starting motor.

• Food Science and Preservation
• /
• v.8 no.2
• /
• pp.199-205
• /
• 2001

Red mold was isolated from meju prepared by traditional mtehod and characterized. The isolated red mold grew well on potato dextrose agar medium, In microscopic observation, it had a septum in mycelium and ellipsoidal spore. Optimal temperature and pH for growth were 30$\^{C}$ and 6.0, respectively. Enzyme activities such as protease, a-amylase and glucoamulase in ted mold were lower than those in Aspergillus oryzae. A competitive growth between red mold and Asp. oryzae was greatly affecten by cultivation temperature. The growth of isolated red mold on meju was predominant at below 30$\^{C}$ as compared with Asp. oryzae.

• Korean Journal of Child Studies
• /
• v.30 no.6
• /
• pp.267-279
• /
• 2009

Child care in Korea has been officially institutionalized due to the legislation of the Child Care Act in 1991. Since then, the predominant social phenomena such as growing female workforce, more intensified female education, and the low birth rates have led the stronger demand for child care at the national level. Accordingly, the supply of child care services and the demand of families using the services have increased dramatically, producing enhancement of the quality of child care via improved and extended laws and regulations. Such movements have arisen academic interests and policy issues to specific sectors with details including child care policies, curriculum and professionals working with young children at child care centers, needs of children and their families attending child care centers, and program evaluations.