• Journal of Biosystems Engineering
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• v.32 no.2 s.121
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• pp.77-83
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• 2007

The purpose of this study is to find optimal conditions for various outlet clearances of prototype garlic clove separator with a rotating cone in the constant inlet clearance and cone height. Optimal outlet clearance from medium to small size garlics was 25 mm at the $200{\sim}400rpm$. For large garlic, optimal outlet clearances of Namdo and Uiseong garlic were 34 mm and 37 mm, respectively, in the range of $300{\sim}400rpm$. The proportion of garlic separation was over 95% for all quality of garlics. The proportions of damaged garlics at 25 mm and 28 mm outlet clearances were below 5% and below 10%, respectively. Therefore, in order to maintain high performance of garlic separation for the various varieties and qualities, the rotating cone type separator should be designed with cone speed ranges of $200{\sim}400rpm$ and the outlet clearance ranges of $25{\sim}37 mm$. The outlet clearance of the separator should be easily controlled within those ranges.

• Journal of Information Technology Services
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• v.9 no.4
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• pp.1-18
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• 2010

Plural governance system in which firms use vertical integration and market governance simultaneously are widely used across various marketing context. Typical examples of plural governance include franchise systems, in which firms own and operate some unit themselves while licensing the operation of some of their units to franchisees. Despite many scholars have attempted to explore the structure of plural governance over decades, there are few insights into its determinants. In this study, we examine the relationship between the proportion of outlets franchised and several franchisor's characteristics based on the perspectives of transaction cost analysis, resource scarcy theory and agency theory. Using franchisor data in Korean Franchise Disclosure Document over the 2006-2009 period, we test the effect of franchisor size, system growth rate, franchise fee, initial investment, and risk sharing on the proportion of outlets franchised. Except for the effect of system growth rate, the results of a series of multiple regression analysis supported the negative effects of franchisor size, franchise fee, initial investment and risk sharing on the proportion of outlets franchised.

• 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).

• 한국가시화정보학회:학술대회논문집
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• 2005.12a
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• pp.111-116
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• 2005

An automobile engine has the Positive Crankcase Ventilation system (PCV system) for preventing air pollution as the environmental problem is important In this system, a PCV valve is the most important component to control the flow rate of Blowby gas which is generated by various engine powers. But, in the working place, the design of a PCV valve is very difficult because of interaction between fluid and solid motions. In this study, we investigated fluid flow characteristics using re-meshing method of a CFD technique to simulate spool behavior. As the results, a spool is periodically oscillated with time and is largely oscillated in proportion to the differential pressure between inlet and outlet. And, although the velocity at the orifice increases with the differential pressure, the flow rate of the outlet decreases. This research may give PCV designers visual flow information to help them

• Journal of Biosystems Engineering
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• v.32 no.2 s.121
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• pp.84-90
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• 2007

This study was conducted to design and manufacture a final prototype of garlic separator and to evaluate its performance. The performance of garlic separation was compared with manual separation. The final prototype for garlic separation consists of bucked-elevator device for automatic feed of garlic, rotating cone typed device, blower, and power transmission device. The optimal condition of outlet clearance was 19 mm and in this clearance, the proportions of fragment garlic separated in the large quality of Namdo garlic and all quality of Uiseong garlic were above 95% and above 85%, respectively. All proportion of damaged garlic was below 5% for all variety and quality. The garlic separation capacities of this developed machine were 310 kg/h for Namdo garlic and 293.6 kg/h for Uiseong garlic in the large quality. Capacities of final prototype compared with human being were $12.9{\sim}19.6$ times for Namdo and $24.2{\sim}31.7$ times Uiseong garlic, respectively.

• Solar Energy
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• v.8 no.2
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• pp.57-65
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• 1988

The coefficients of convective heat transfer were investigated when air is jetted to surface of the heated side-wall. The temperature on the side-wall was measured when the offsets changed from 1.5 to 10.5 as 7 steps at the state of fixed Reynolds numbers that were 35000, 29000 and 23000. The experimental results are as follows: 1. The mean Nusselt number is very high on the surface of reattached flow region. 2. The offset and the recirculation flow region decreased, while the mean Nusselt number increased between the outlet of nozzle and the region of reattachment flow. 3. The local Nusselt number is not concerned with Reynolds number on the recirculation flow and on the reattached flow region when the offset decrease. But the Nusselt number increased only when Reynolds numbers on the wall jet flow region increased. 4. The mean and the maximum Nusselt number decreases linearly, and in particular its values rapidly decrease in accordance with changing of the offset from 1.5 to 3 in inverse proportion.

• Plant Journal
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• v.18 no.3
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• pp.28-40
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• 2022

As the proportion of renewable energy generation is expected to increase, public power generation businesses need to actively consider implementing the expansion of biomass mixing, In this study, the biomass co-firing rate is being changed from 0wt.% to 5.0wt.% at 500MW coal-fired power plant, measuring the major operation characteristics of the pulverizer. First, the composition analysis and grinding characteristics of lignocelluosic biomass were examined, and the effect of volume increase on dirrerential bowl pressure difference, motor current, coal spillage, outlet temperature, and internal fire count was analyzed. As the co-firing rate increased, it was confirmed that the difference in the differential bowl pressure, motor current, and coal spillage treated increased, and the outlet temperature was minimal. The number of internal fires is difficult to find a clear correlation, but it has been confirmed that it is highly likely to occur in combination with other driving factors.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.99-110
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• 2023

Non-point source (NP) pollutants in an agricultural landuse are discharged from a large area compared to those in other land uses, and thus effective source control measures are needed. To develop appropriate control measures, it is necessary to quantify discharge load of each source and evaluate the degree of water quality improvement by implementing different options of the control measures. This study used Hydrological Simulation Program-FORTRAN (HSPF) to quantify pollutant discharge loads from different sources and effects of different control measures on water quality improvements, thereby supporting decision making in developing appropirate pollutant control strategies. The study area is the Gyeseong river watershed in Changnyeong county, Gyeongsangnam-do, with agricultural areas occupying the largest proportion (26.13%) of the total area except for the forest area. The main pollutant sources include chemical and liquid fertilizers for agricultural activities, and manure produced from small scale livestock facilities and applied to agriculture lands or stacked near the facilities. Source loads of chemical fertilizers, liquid fertilizers and livestock manure of small scale livestock facilities, and point sources such as municipal wastewater treatment plants (WWTPs), community WWTPs, private sewage treament plants were considered in the HSPF model setup. Especially, NITR and PHOS modules were used to simulate detailed fate and transport processes including vegitation uptake, nutrient deposition, adsorption/desorption, and loss by deep percolation. The HSPF model was calibrated and validated based on the observed data from 2015 to 2020 at the outlet of the watershed. The calibrated model showed reasonably good performance in simulating the flow and water quality. Five Pollutants control scenarios were established from three sectors: agriculture pollution management (drainge outlet control, and replacement of controlled release fertilizers), livestock pollution management (liquid fertilizer reduction, and 'manure management of small scale livestock facilities) and private STP management. Each pollutant control measure was further divided into short-term, mid-term, and long-term scenarios based on the potential achievement period. The simulation results showed that the most effective control measure is the replacement of controlled release fertilizers followed by the drainge outlet control and the manure management of small scale livestock facilities. Furthermore, the simulation showed that application of all the control measures in the entire watershed can decrease the annual TN and TP loads at the outlet by 40.6% and 41.1%, respectively, and the annual average concentrations of TN and TP at the outlet by 35.1% and 29.2%, respectively. This study supports decision makers in priotizing different pollutant control measures based on their predicted performance on the water quality improvements in an agriculturally dominated watershed.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.230-231
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• 2005

As environmental problems are important, automotive industries are developing various techniques to prevent air pollution. One of these is Positive Crankcase Ventilation (PCV) system. It removes blowby gas which includes about 30% hydrocarbon of total generated quantity. In this system, a PCV valve is attached in a manifold suction tube to control the flow rate of blowby gas which generates differently according to various operating conditions of an automotive engine. As this valve is very important, designers are feeling to design it because of both small size and high velocity. For this reason, we numerically investigated to understand both spool dynamic motion and internal fluid flow characteristics. As the results, spool dynamic characteristics, i.e. displacement, velocity, acting force, increase in direct proportion to the magnitude of differential pressure and indicate periodic oscillating motions. And, the velocity at the orifice region decreases according to the increase of differential pressure because of energy loss which is caused by the sudden decrease of flow area at the orifice region and the increase of flow volume in the front of spool head. Finally, the mass flow rate at the outlet decreases with the increase of spool displacement. We expect that PCV valve designers can easily understand fluid flow inside a PCV valve with our visual information for their help.