• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.8
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• pp.2399-2416
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• 2024

The current automotive industry is transitioning from Internal Combustion Engine (ICE) vehicles to Electric Vehicles (EVs), adopting a mixed assembly production approach to respond to fluctuating demand. While mixed assembly production offers the advantages of lower investment costs and flexibility in responding to changing demands, the supply of EV components requires more extensive provisioning compared to ICE vehicle components, potentially leading to unexpected issues such as congestion of transport vehicles. This study proposes a digital twin system architecture that uses Discrete Event Simulation (DES) and Business Intelligence (BI) tools to specifically address logistics challenges. The proposed architecture facilitates real-time, data-driven decision making across three layers; Data source, Simulation, and BI. It was implemented in factories engaged in the mixed assembly production of ICE and EV vehicles. The simulation challenges involve a tier 1 vendor supplying parts to Korean automobile manufacturers that produce both ICE and EV parts. A total of 240 scenarios were created to run the simulations. The deployment of the proposed architecture demonstrates its capability to quickly respond to diverse experimental situations and promptly identify potential issues.

• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.160-165
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• 2018

BACKGROUND: Mixed cropping of legume and grass was effective system in view point of providing organic matter and nitrogen or reducing the nitrogen starvation of following crop. The relation of the change of N and P constituents depending on the cropping types and those effects on the growth and nutrient uptake of the following crop were observed. METHODS AND RESULTS: Three cropping types, hairy vetch mono cropping, barley mono cropping, and mixed cropping of hairy vetch and barley were applied. Soil properties, growth characteristics, and nitrogen production of green manure crops were observed. In additions, the effect of cropping types on the growth pattern of corn as the following crop was observed. In the mixed cropping system, creeping type hairy vetch climbed to the erect type barely for light utilization resulting in improvement of light interception rate and higher LAI (Leaf Area Index) than in mono cropping. Mixed cropping showed higher biomass production and soil nitrogen availability among the cropping types, indicating relatively much more nutrient supply and higher yield production of following crop. CONCLUSION: Mixed cropping showed relatively higher LAI (dry matter) mainly because of intense competition for light utilization usually after flowering stage. Mixed cropping also showed relatively higher yield of corn, the following crop rather than other types, mainly due to the more biomass production potential and higher N and P production ability. Therefore, mixed cropping was adaptable method to reduce or replace chemical fertilizer application for environmentally-friendly agriculture.

• International Journal of Advanced Culture Technology
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• v.8 no.1
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• pp.182-187
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• 2020

Silver nanoparticles (AgNPs) have been manufactured in recent years and widely used in various fields. Reactive oxygen species (ROS), which occur in AgNPs, destroy cell membranes. It is widely accepted that ROS generated in this manner inhibit microorganisms growth and causes toxic effects, However, it does not affect cell membranes directly but positively affects growth in plants with cell walls. The nanoball used in this experiment is a new material that generates ROS stably and is used in aqueous solution. Results of this study indicate a 30% increase in yield of Ginseng mixed with culture soil. The analysis of soil condition after cultivation showed that the possibility of repetitive cultivation in soil mixed with Nanoball was high. This suggests that Nanoball is an antimicrobial active material due to the microbial / extermination effect of pathogenic microorganisms. Therefore, there may be potential applications in agricultural cultivation sites as a repetitive cultivation technology that reuses soil.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1113-1118
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• 2004

This paper presents the dynamic analysis method for an electromechanical system. The engineer has at his disposal a variety of software simulation tools. However, difficulties arise when the study of the behavior of complex electromechanical systems in combination with coupling element is required. Typical examples of such systems are machines for factory automation, home automation, and office automation. Dynamic systems analysis packages or electronic systems analysis packages offer the restrictive to simulate these mixed systems such electromechanical product. Electronic circuit analysis algorithm is easily incorporated into a multi-body dynamics analysis algorithm. The governing equation of electronic circuit is formulated as a differential algebraic equation form including both electrical and mechanical variables and is simultaneously solved in every time step. This analysis method clearly demonstrates the application potential for mixed electromechanical simulation.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1130-1135
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• 2008

The effect of pH on anaerobic hydrogen production was investigated under various pH conditions ranging from pH 3 to 10. When the modified Gompertz equation was applied to the statistical analysis of the experimental data, the hydrogen production potential and specific hydrogen production rate at pH 5 were 1,182 ml and 112.5 ml/g biomass-h, respectively. In this experiment, the maximum theoretical hydrogen conversion ratio was 22.56%. The Haldane equation model was used to find the optimum pH for hydrogen production and the maximum specific hydrogen production rate. The optimum pH predicted by this model is 5.5 and the maximum specific hydrogen production rate is 119.6 ml/g VSS-h. These data fit well with the experimented data($r^2=0.98$).

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.4
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• pp.462-466
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• 2010

A new buffer cache management scheme that aims at reducing power consumption in mixed HDD and NAND flash memory storage systems is presented. The proposed scheme reduces power consumption by considering different energy-consumption rate of storage devices, I/O operation type (read or write), and reference potential of cached blocks in terms of both recency and frequency. Simulation shows that the proposed scheme reduces power consumption by 18.0% on average and up to 58.9%.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.395-398
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• 2000

Recently, increasement of usage contents of sea sand in constructing concrete structures due to insufficiency of high quality river sand, led to many studies for steel corrosion and control methods on it in concrete. But, domestic studies for threshold chloride contents of steel corrosion are not so many as those of foreign states. In this study, the electrochemical test as half cell potential measurement and linear polarization method to estimate the corrosion of steel in contents mixed with several levels chloride contents was performed, thereby, pre-mixed chloride were compared with results measured quantitatively for steel corrosion. And, based on these data, a trial to determine threshold chloride contents of steel corrosion was made.

• Journal of the Korean housing association
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• v.12 no.2
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• pp.143-150
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• 2001

The purpose of this study is to analyze the preferences for urban residence. Data was collected from the people who are working in the CBD area. The results of this study are as following; 1) The 40.3% of people working in CBD area prefer living in the CBD area. It contains 5.6% of people who are working in the CBD area. It can be interpreted that there are some potential residential preference in the CBA area. 2) People who prefer living in the CBD area are shown that they have been working in the CBD area for a long time with their living status of the middle class and their ages over 50. 3) The favorable area for CBD workers is located within 10 minutes by bus or within working distance. 4) Their favorable housing types are respectively apartments, mixed, and single housing. It means that they prefer the mixed functioning type of housing to the apartment. It tells that it is necessary to develop the new types of housing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.1125-1129
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• 2015

Increasing peak load is one of the major concerns about operation of urban railroad systems. Since ESSs (Energy Storage Systems) have a great potential for shaving the peak load, there has been a growing interest in the use of ESS for peak load reduction. Also, ESS can be optimally scheduled to minimize the electricity purchasing cost under a given ToU (Time-of-Use) tariff by taking advantage of electricity price difference between peak and off-peak time. This paper presents a Mixed Integer Programming (MIP)-based ESS scheduling method to minimize the electricity purchasing cost under a ToU tariff for an urban railroad system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.784-787
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• 1997

Enzymatically hydrolyzed soy sauce(eHSS) was prepared by the treatment of defatted soy flake using two types of proteases, followed by maillard reaction and formulation with some ingredients. The eHSS was mixed with fermented soy sauce(FSS) to make enzymatically hydrolyzed mixed soy sauce(eHMSS). The properties and sensory characteristics were evaluated and compared with commercially available soy sauces. The control of salt and total nitrogen contents in eHSS and eHMSS was easy, and the production of soy sauce of low salt and high protein was possible. However, the free amino acid content of eHSS was lower than FSS. due to lower degree of hydrolysis. In sensory evaluation, the eHSS have no loss taste and overall acceptance than FSS. Consequently, the eHSS and eHMSS have the potential for use with FSS to produce high quality soy sauce of low salt and high protein contents.