• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.4
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• pp.57-64
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• 1985

An optimization model is presented that can be used in the determination of a loss rate function and conceptual runoff models using observed rainfall and runoff data. In order to estimate the lumped parameters and to control inputs of the model, the differential equations, linear for underground flow and non-linear for overland flow, are transformed into state equations. Parameters of a loss rate function and runoff model under stationary assumption can be determined by the following procedures: optimization technique, linear control and non-linear curve fitting theory using several multiperiod storms simultaneously or using individual multiperiod storms. An infiltration equation that includes rainful intensity is used to dtermine the effective rainfall for a given rain of varying. The optimization model is applied to storms in Hyong Song watershed of Wonju area. The results of the new model are compared with earlier one.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.36-46
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• 2011

It is thought traffic flow management under the ubiquitous transportation system has great potential in view of individual vehicle data availability and V2V, V2I two-way communication environments. However, it is expected that deployment of the ubiquitous transportation system takes some time. Therefore it is necessary to evaluate the feasibility of the algorithm under the ITS environment. The speed management algorithm proposed in the previous research is revised to fit for the ITS data collection and information provision environment. And the feasibility of the algorithm is evaluated through simulation experiments.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.355-363
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• 2022

This paper presents the modeling for islanded hybrid AC/DC microgrid and the verification of the proposed supervisory controller for energy management for this microgrid. The supervisory controller allows the microgrid system to operate in different power flows through the proposed control algorithm, it has several roles in the management of the energy flow between the different components of the microgrid for reliable operation. The proposed microgrid has both essential objectives such as the maximum use of renewable energies resources and the reduction of multiple conversion processes in an individual AC or DC microgrids. The microgrid system considered for this study has a solar photovoltaic (PV), a wind turbine (WT), a battery (BT), and a AC/DC loads. A small islanded hybrid AC/DC microgrid has been modeled and simulated using the MATLAB-Simulink. The simulation results show that the system can maintain stable operation under the proposed supervisory controller when the microgrid is switched from one operating mode of energy flow to another.

• The Journal of the Korean dental association
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• v.15 no.2
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• pp.145-151
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• 1977

The author performed Snyder test, estimation of salivary flow rate, salivary viscosity test, salivary buffering capacity test, M-R test, oral hygiene ability test, estimation of oral glucose clearance time and plaque reformation test in the 107 male Koreans aged form the age of 20 to 29, in order to detect and control the active cariogenic factors contributing to caries development on the individual basis. Thereafter, the data from 8 kinds of caries activity test were analysed and evaluated. The obtained results were as follows: 1. Snyder test was positive in 86.0% of total tested persons, and among those showing positive Snyder test reaction, slight caries activity was appeared in 39.1%, moderate caries activity in 23.9%, and marked caries activity in 37.0%. 2. Salivary flow rate was under the average flow amount in 53.3%. 3. Salivary buffering capacity was low in 22.4%. 5. Buffering capacity of dental plaque was high in 12.5%. 6. Oral hygiene ability was insufficient in all persons tested. 7. Oral glucose clearance time was long in 42.1%. 8. Plaque reformation rate was high in 8.4% of the 107 persons tested.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.10
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• pp.545-552
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• 2009

It is common to design the duct branches where to supply the required air flow for individual room in residential apartment house. And TAB process is applied to control the designed air volume with adjusting volume dampers and/or supply diffusers after fully installing the ventilation system. This process has been resulted increasing the initial cost for the residential ventilation system because of man-hour and accessories such as volume control damper or diffuser. However it is difficult to adjust the air volume adequately in small air duct branches in residential ventilation system. The purpose of this study is to figure out the performance of Multidrop chamber coupling system for the residential ventilation system.

• Membrane Journal
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• v.33 no.3
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• pp.127-136
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• 2023

In this study, the electrochemical performance of a 5-layer fuel cell stack using silica composite membranes as polymer electrolyte membranes was evaluated. It was observed that the flow rate of the fuel gases plays a crucial role in stack performance, particularly being mainly dependent on the flow rate of hydrogen. Increasing the flow rate of oxygen resulted in negligible changes in performance, whereas an increase in the flow rate of hydrogen demonstrated performance improvements. However, this led to an imbalance in the ratio of hydrogen to oxygen flow rates, causing significant degradation in stack performance and durability. A decline in stack performance was also observed over time due to the degradation of stack components. This phenomenon was consistently observed in individual unit cells. Based on these findings, it was emphasized that, in addition to optimizing the performance of each component during stack operation, it is important to optimize design and operating conditions for uniform flow rate control. Lastly, the developed silica composite membrane was assessed to have sufficient performance for application in actual fuel cell systems, exhibiting a performance of over 25 W based on maximum power.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2457-2460
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• 2003

There is a great demand to manipulate biological cell autonomously since biologist should spend much time to obtain skillful manipulation techniques. For this purpose, we propose a cell chip to control, carry, fix and locate the cell. In this paper, we focus on the cell rotator to rotate individual biological cell based on a micro fluidics technology. The cell rotator consists of injection hole and rotation well to rotate a biological cell properly. Under the variation of flow rate in injection hole, the angular velocity of a biological cell is evaluated to find the feasibility of the proposed rotation method. As a practical experiment, Zebrafish egg is employed. Based on this research, we find the possibility of non-contact rotation way that can highly reduce the damage of the biological cell during manipulation. To realize an autonomous biological cell manipulation, a cell chip with manipulation well and micro channel in this research will be utilized effectively in near future.

• Korean Journal of Adult Nursing
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• v.18 no.1
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• pp.41-49
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• 2006

Purpose: This study was conducted to understand the meaning of mind control as it is understood by elderly persons in Korea. Method: This study was conducted by engaging three elderly persons who are over the age of sixty five and presently residing in Seoul. Several in depth interviews were conducted with these individuals from March 2003 until November 2003. The contents of the interviews were analyzed using the Giorgi Method (1985), which places the emphasis on discovering meaning within the phenomenological context of an individual's experience. Results: The analysis of the contents revealed the following four components with regard to the meaning of mind control for elderly persons (1) Settling the mind (2) Gradual lowering of expectations and hope for the success of offspring, (3) Having good thoughts and acting accordingly, and (4) Making up one's mind to follow the 'natural flow of life'. Conclusion: By allowing a wider and deeper understanding of the meaning of mind control for elderly persons the results of this study provide a basis for improving the care of elderly with a holistic perspective.

• Proceedings of the Safety Management and Science Conference
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• 2001.11a
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• pp.193-202
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• 2001

The individual rotten water purification tank recently discharges wastewater and sewage through the outlet without purification ability. The outlet water and affiliated water purification tank with microorganism cultivator tank cultivates microorganism and then drops the value BOD, COD of sewage and discharges the quality of water into the outlet. The blower and water pump operating continuously prompts the waste of energy and deterioration of equipment. Each room of deposition tank, foaming tank, microorganism cultivator tank is equipment with the sludge detection senses so it can detect the density of each room. The power-drive plant of the blower and water pump which ate the system cultivating the microorganism must be made as fuzzy controlization (If the sludge amount of each room become higher, the rate of operation of blower and water pump must heighten, on the contrary, in case of row sludge amount, the total handling amount and microorganism handling amount of each room of control. Tank reducing the rate of operation must be DB. At present, the blower amount in proportion to the sludge and oxygen demanding amount has to control. Each mom must be checked outlet level of the outlet, also each room must flow backward discharge materials, and must operate feed-back control until we want to be come as a below value of BOD/COD(10PPM ; KS).

• Journal of the Korea Safety Management & Science
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• v.3 no.4
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• pp.53-63
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• 2001

The individual rotten water purification tank recently discharges wastewater and sewage through the outlet without purification ability. The outlet water and affiliated water purification tank with microorganism cultivator tank cultivates microorganism and then drops the value BOD, COD of sewage and discharges the quality of water into the outlet. The blower and water pump operating continuously prompts the waste of energy and deterioration of equipment. Each room of deposition tank, foaming tank, microorganism cultivator tank is equipment with the sludge detection senses so it can detect the density of each room. The power-drive plant of the blower and water pump which are the system cultivating the microorganism must be made as fuzzy controlization (If the sludge amount of each room become higher, the rate of operation of blower and water pump must heighten, on the contrary, in case of row sludge amount, the total handling amount and microorganism handling amount of each room of control. Tank reducing the rate of operation must be DB. At present, the blower amount in proportion to the sludge and oxyzen demanding amount has to control. Each room mus be checked outlet level of the outlet, also each room must flow backward discharge materials, and must operate feed-back control until we want to be come as a below value of BOD/COD(10PPM ; KS).