• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1039-1046
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• 2017

Campus microgrid is designed and built by considering not only power generation but also power consumption management as connected microgrid type because the main goal of the campus microgrid is to save power consumption costs. There are many functions to achieve the goal and they are mainly to use generation-based functions such as islanding operation for peak management and for emergency events. In power distribution operation, Conservation Voltage Reduction (CVR) is applied in order to reduce power consumption. The CVR is defined as a function for load consumption reduction by voltage reduction in order to reduce peak demands and energy consumption. However, application of CVR to microgrid is difficult because the microgrid cannot control a tap of transformer in a substation and the microgrid normally is not designed with phase modifying equipment like a step-voltage-regulator which can control voltage in power distribution system operation. In addition, an impact of the CVR is depended on load characteristics such as a normal load, a rated power, and synchronous motors. Therefore, this paper proposes an application of CVR using linear voltage control based AVR in campus microgrid with power consumption reduction considering characteristics of load and component in the microgrid. The proposed system can be applied to each buildings by a configuration of power distribution cables; and the application results and CVR factor are presented in this paper.

• The Research Journal of the Costume Culture
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• v.15 no.5
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• pp.875-887
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• 2007

The purpose of this study is to provide the fashion industry in Korea with materials that could enhance its international competitiveness by suggesting marketing strategies for fast fashion brands after taking product, price, place, and promotion into consideration. The product strategy should focus on developing products that accurately reflect the general market trend and consumer demand, selecting optimal materials, and pursuing internal production. This, coupled with strategic cooperation with designers, will ensure reliable quality and enhance the brand image. The pricing strategy should place greater emphasis on reducing production costs. Diverse task outsourcing and design competition, for instance, can lower the cost of design development. The place strategy should be set according to the operation of a systematic and efficient distribution system based on SPA, an automatic delivery system, sales or return system, speed control system, and a value chain that consists of horizontal business alliances. The promotion strategy should be run under the central control of the headquarters using various unique VMDs. Furthermore, online marketing campaigns, spectacular fashion shows, design competitions, catalogue marketing campaigns, and other new sales promotion schemes could all be introduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.1
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• pp.43-51
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• 2001

Metacomputing system is the environment, which helps the users easily and promptly deal with their jobs. with integration of the distributed computing resources and visualization device. In this research, we have developed a prototype of a special-purpose metacomputing system for simulation in CFD(Computational Fluid Dynamics) field. This system supports the automatic remote compilation, transparent data distribution, the selection of appropriate computing resource, and the realtime visualization. This research can be summarized as following: a study on selecting resource and the integration of component systems. In the research of selecting computing resource, we use the property of CFD algorithm. In the research of realtime visualization. we modify a popular visualizer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.6
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• pp.819-828
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• 2001

The operating point of a small-sized axial fan is strongly dependent upon the system resistance. Therefore, the turbulent flow characteristics around a small-sized axial fan may change significantly according to the operating point. This study represents three-dimensional turbulent flow characteristics around a small-sized axial fan measured at the ideal design point $\phi$=0.25, which is equivalent to the maximum total efficiency point, by using three dimensional fiber-optic type LDA system. This LDA system is composed of a 5 W Argon-ion laser, two optics in back-scatter mode, three BSAs, a PC, and a three-dimensional automatic traversing system. A kind of paraffin fluid is used to supply particles by means of fog generator. Mean velocity profiles downstream of a small-sized axial fan along the radial distance show that the streamwise and the tangential components exist in a predominant manner, while the radial component has a small scale distribution and shows the inflection which its flow direction is inward or outward. Moreover, the turbulent intensity profiles show that the radial component exists the most greatly among turbulent energies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.735-739
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• 2010

This study investigated a method for monitoring fishes immigrating to upper streams from the sea in relation to water level with elapsed time, and measured fish behavior patterns and swimming speed in a fishing boat gateway using an acoustic camera system. This method was employed due to difficulties, linked to high turbidity, of using only underwater optical systems for monitoring fish migrating to brackish water. Results showed that fish length distribution showed high correlation between haul sampling and an automatic counting algorithm supported by the DIDSON software program. These results will help to maximize the effects of fish run management by increasing understanding of the amount of major fish species migrating in relation to durable water levels.

• Korean Journal of Remote Sensing
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• v.25 no.6
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• pp.465-474
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• 2009

Convective/stratiform radar echo classification schemes by Steiner et al. (1995) and Biggerstaff and Listemaa (2000) are examined on a monsoonal front during the summer monsoon-Changma period, which is organized as a cloud cluster with mesoscale convective complex. Target radar is S-band with wavelength of 10cm, spatial resolution of 1km, elevation angle interval of 0.5-1.0 degree, and minimum elevation angle of 0.19 degree at Jindo over the Korean Peninsula. For verification of rainfall amount retrieved from the echo classification, ground-based rain gauge observations (Automatic Weather Stations) are examined, converting the radar echo grid data to the station values using the inverse distance weighted method. Improvement from the echo classification is evaluated based on the correlation coefficient and the scattered diagram. Additionally, an optimal use method was designed to produce combined rainfalls from the radar echo and Tropical Rainfall Measuring Mission Precipitation Radar (TRMM/PR) data. Optimal values for the radar rain and TRMM/PR rain are inversely weighted according to the error variance statistics for each single station. It is noted how the rainfall distribution during the summer monsoon frontal system is improved from the classification of convective/stratiform echo and the use of the optimal use technique.

• Journal of Information Technology Services
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• v.22 no.4
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• pp.97-110
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• 2023

In this study, we propose a technique to automatically generate transfer documents using sensor data from livestock manure transfer systems. The research involves analyzing sensor data and applying machine learning techniques to derive optimized outcomes for livestock manure transfer documents. By comparing and contrasting with existing documents, we present a method for automatic document generation. Specifically, we propose the utilization of Gradient Boosting, a machine learning algorithm. The objective of this research is to enhance the efficiency of livestock manure and liquid byproduct management. Currently, stakeholders including producers, transporters, and processors manually input data into the livestock manure transfer management system during the disposal of manure and liquid byproducts. This manual process consumes additional labor, leads to data inconsistency, and complicates the management of distribution and treatment. Therefore, the aim of this study is to leverage data to automatically generate transfer documents, thereby increasing the efficiency of livestock manure and liquid byproduct management. By utilizing sensor data from livestock manure and liquid byproduct transport vehicles and employing machine learning algorithms, we establish a system that automates the validation of transfer documents, reducing the burden on producers, transporters, and processors. This efficient management system is anticipated to create a transparent environment for the distribution and treatment of livestock manure and liquid byproducts.

• Journal of Environmental Science International
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• v.4 no.2
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• pp.181-194
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• 1995

Flocculation kinetics using ferric nitrate as a coagulant to coagulate kaolin clay in water was examined as a tool to investigate the effect of low temperature under tightly controlled treatment conditions. Both the particle size distribution data obtained from Automatic Image Analysis (AIA) system and the on-line measurement of the degree of turbidity fluctuation in a flowing suspension by Photometric Dispersion Analyzer (PDA) were used to measure flocculation kinetics. Results show that cold water temperature had a pronounced detrimental effect on flocculation kinetics. For improving flocculation kinetics at low water temperature, maintaining constant pOH to adjust water chemistry for temperature changes was found to be partially effective only in the more acidic pH range studied.

• Journal of Wind Energy
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• v.9 no.4
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• pp.65-71
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• 2018

To establish an offshore wind turbine test site, a wind resource assessment of the candidate site is required as a preliminary procedure. The wind resource assessment must be performed with at least one year of wind data. If the assessment is performed with short-term wind data, the results cannot validate the wind conditions of the candidate site. This study performs wind resource assessment of Kokunsangun-do to investigate the wind conditions of the candidate site. The wind data is measured by the Automatic Weather System (AWS) of the Korea Meteorological Administration, located at Maldo. The data is for five years, measured from 2013 to 2017. Measured wind data is statistically processed with a 10-minute average scheme to find out the dominant wind direction and wind power density, with yearly wind speed distribution (Weibull-based). This study contributes to build a database of wind energy resources around Maldo. Also, the results of this study could be used for the establishment of an offshore wind turbine test site.

• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.113-121
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• 2013

In this paper, simulations were carried out to determine the efficiency of the rotation efficiency according to the draft of waterwheel in open rectangular channel. In the small hydroelectric generators to get the highest efficiency of waterwheel is very important. But the presence of various elements(free water surface flow, non-uniform velocity distribution because of the waterways wall friction etc) makes it difficult to create a mathematical formula. In this paper, we made a scale model and perform a physical simulation where the draft, gradient and flux is variable. Scale modelling with 10-step draft, 3-step gradients and 2-step flux, as well were constructed then computerized automatic experimental system were configured to acquire the rotational efficiency vs. draft of itself. Rotational efficiency is analyzed as for the draft of waterwheel using the acquired data by varying the gradient and flux of canal. Reviewing the analyzed data, it is confirmed that phenomena of efficiency shown at previous and present experiment is similar and revealed that computerized system shows more sophisticated numerical figures.