• Smart Structures and Systems
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• v.24 no.4
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• pp.435-446
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• 2019

The existing piezoelectric spherical transducers with fixed prescribed dynamic characteristics limit their application in scenarios with multi-frequency or frequency variation requirement. To address this issue, this work proposes an improved design of piezoelectric spherical transducers using the resistance tuning method. Two piezoceramic shells are the functional elements with one for actuation and the other for tuning through the variation of load resistance. The theoretical model of the proposed design is given based on our previous work. The effects of the resistance, the middle surface radius and the thickness of the epoxy adhesive layer on the dynamic characteristics of the transducer are explored by numerical analysis. The numerical results show that the multi-frequency characteristics of the transducer can be obtained by tuning the resistance, and its electromechanical coupling coefficient can be optimized by a matching resistance. The proposed design and derived theoretical solution are validated by comparing with the literature given special examples as well as an experimental study. The present study demonstrates the feasibility of using the proposed design to realize the multi-frequency characteristics, which is helpful to improve the performance of piezoelectric spherical transducers used in underwater acoustic detection, hydrophones, and the spherical smart aggregate (SSA) used in civil structural health monitoring, enhancing their operation at the multiple working frequencies to meet different application requirements.

• Journal of IKEEE
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• v.25 no.1
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• pp.168-173
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• 2021

In this paper, we propose a new structure of ESD protection device that achieves improved electrical characteristics through structural change of LVTSCR, which is a general ESD protection device. In addition, it applies N-Stack technology for optimized design in the ESD Design Window according to the required voltage application. The N-Well area additionally inserted in the existing LVTSCR structure provides an additional ESD discharge path by electrically connecting to the anode, which improves on-resistance and temperature characteristics. In addition, the short trigger path has a lower trigger voltage than the existing LVTSCR, so it has excellent snapback characteristics. In addition, Synopsys' T-CAD Simulator was used to verify the electrical characteristics of the proposed ESD protection device.

• Progress in Superconductivity and Cryogenics
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• v.11 no.1
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• pp.25-29
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• 2009

To reduce the power loss in normal state, non-inductively wound high temperature superconducting (HTS) coils are used for fault current limiter (FCL) application. Non-inductively wound coils can be classified into two types: solenoid type and pancake type. These two types have different electrical and thermal and mechanical characteristics due to their winding structure difference. This paper deals with the current limiting characteristics, magnetic field analysis of the two coils. Simulation using finite element method (FEM) was used to analyze the magnetic field distribution and inductance of the coils. Short circuit test using stabilizer-free coated conductor (CC) was also carried out. We can compare the characteristics of the two types of coil by using the data obtained from simulation and short circuit test. We confirmed the feasibility of FCL application by the analysis about the characteristics of non-inductively wound coil using CC.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.42-47
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• 1977

Experiment was conducted to find out the influence of nitrogen and potassium split application on the yield and physiology of rice plants in a sandy-gravel soil. Nitrogen and potassium mixed application, nitrogen split application, and potassium split application increased yield of rice by 22, 20, and 18%, respectively, compared to conventional fertilizer application. Nitrogen split application increased chlorophyll content and potassium split application increased root activity. Concentration of silica, magnesium, and calcium was increased by the mixed split application of nitrogen and potassium.

• Journal of Radiation Industry
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• v.9 no.3
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• pp.161-166
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• 2015

RI-Biomics is the new radiation fusion technology of which, such as the characteristics of radioisotope, is applied to the biomics. In order to sharing and overall analysis of data between the institutions through total management of information in the field of RI-Biomics, RI-Biomics Information portal 'RIBio-Info' was constructed by KARA (Korean Association for Radiation Application) in February 2015. For systematic operation of this 'RIBio-Info' system, it is required to develop system of collection-analysis-application of information. So, in this paper, we summarized development of document forms at each processes of collection-analysis-application of information and systematization of collection methods of information, establishment of characteristically analysis methods of reports such as issue paper, policy report, global market report and watch report. Therefore, these are expected to improving the practical applicability in this field through the vitalization of technology development of users by achieving the circular structure of collectionanalysis-application of information.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.12
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• pp.77-84
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• 2018

Biomimicry architecture has been highlighted in recent years for the innovative ideas from the nature have provided main developments in many areas. The related studies in Korean architecture is entering the first step and are needed close attentions for its vitalizations. This study starts with the acknowledgement of necessity to establish the architectural application process. First of all, it is named as a 'Passive Cycle' if a problem-solving or a project has been through the analysis of process complexity and biomimicry application process in other areas. Then, the basic frame is structured as a 'Process-Cooperation,' which integrates process complexation with process circulation. The cooperative relationship starts from the beginning of the design with not only professionalists related with architecture but also ones in various areas when it is issued a difficult problem or high environmental performance not found in common architectural design processes. To make the architectural application good progress, the characteristics of bio-mimetic architectural applications are categorized as three areas; the expected effect, the application level, and application method. As a result, the organic complexity should be prioritized to have bio-mimetic application effectively while accessing the principles. Therefore, the process for the architectural application of biomimicry is suggested as 'Organic Cycle-Cooperation.'

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.53-58
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• 2007

This study was carried out to determine the effect of continuous application of animal liquid slurry on the growth and yield of rice in 2005. Field experiment was conducted under variable continuous application years of animal liquid slurry; 1, 3, 5 application years of slurry and chemical fertilizer as control plot. The effects of different application years of slurry on the growth characteristics and yield of rice were determined. The plant height and tiller's number of 1 year application of liquid slurry were lower than those of the chemical fertilizer plot. But in the plot of 5 years continuous application of animal slurry, the height and tillers of rice were higher than those of 1 year application. And the color of leaf 5 years application years plot was darker than that of the chemical fertilizer. Yield of the 5 years continuous application of slurry was 4% higher than that chemical fertilizer, but that of 1 year application was decreased 6% compared with chemical fertilizer. The long time application of animal slurry was increased content of organic matter, $P_2O_5$ and exchangeable caution(K) in soil.

• The Korean Journal of Franchise Management
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• v.12 no.4
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• pp.41-54
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• 2021

Purpose: Delivery food orders are on the rise due to the COVID 19 pandemic. Many customers are ordering food through delivery apps rather than visiting restaurants to eat out. Delivery application platforms are growing due to the development of O2O. Most of the people who provide gig worker for delivery applications are rider. Rider provides labor on their own terms and have more work flexibility and autonomy than ordinary workers. Trust can be transferred from a well-known entity to an unknown entity. From the customer's point of view of using the delivery application, trust can be seen through the third-party trust of the delivery application platform-rider-customer. Therefore, this study intends to investigate the effect on delivery application trust and rider trust through the well-known characteristics of delivery applications. Research design, data, and methodology: This study was conducted on Korean consumers over 20 years of age who have ordered food through a delivery application for the past month. After educating 5 investigators about the purpose of this study, 60 copies of the survey were conducted per person. During the investigation period, from September 2 to September 26, 2021, 322 copies were collected over 25 days. Among the collected questionnaires, 37 were excluded from insincere or partially unanswered, and 285 were used for analysis. In addition, the collected data were analyzed using SPSS 25.0 and AMOS 25.0. Result: As a result of the study, convenience, price, and variety of restaurants were found to have a significant positive (+) effect on app trust, but design did not have a significant effect on app trust. Also, it was found that convenience had a significant positive (+) effect on trust in rider, but design, price, and variety of restaurants did not have a significant effect. App trust was found to have a significant positive (+) effect on rider trust and intention to use, and it was found to have a significant positive (+) effect on rider trust and intention to use. Conclusions: First, this study established a structural framework between delivery application characteristics-delivery-app trust-rider trust-intention to use. Second, in this study, it was found that customer trust in well-known delivery applications was transferred to less-known rider trust. Third, the delivery application should increase the convenience of use. Fourth, delivery application should set the delivery fee appropriately. Fifth, delivery application must continuously train the rider.

• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1305-1309
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• 2013

The application of the superconducting fault current limiter (SFCL) in a power distribution system is expected to contribute the voltage-sag suppression of the bus line as well as the fault-current reduction of the fault line. However, the application effects of the SFCL on the voltage sag of the bus line including the fault current are dependent on its application location in a power distribution system. In this paper, we investigated the fault current limiting and the voltage sag suppressing characteristics of the SFCL due to its application location such as the outgoing point of the feeder, the bus line, the neutral line and the 2nd side of the main transformer in a power distribution system, and analyzed the trace variations of the bus-voltage and fault-feeder current. The simulated power distribution system, which was composed of the universal power source, two transformers with the parallel connection and the impedance load banks connected with the 2nd side of the transformer through the power transmission lines, was constructed and the short-circuit tests for the constructed system were carried out. Through the analysis on the short-circuit tests for the simulated power distribution system with the SFCLs applied into its representative locations, the effects from the SFCL's application on the power distribution system were discussed from the viewpoints of both the suppression of the bus-voltage sag and the reduction of the fault current.

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.185-190
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• 2022

BACKGROUND: Most of the bottom ash(BA) from wood pellet-based thermal power plants that is not recycled is placed into landfill. BA has a function and structure similar to biochar. Hence, BA is classified as waste, but, it is predicted that BA can be used agricultural utilization. METHODS AND RESULTS: To investigate the effect of BA application on lettuce, growth characteristics and Pb contents were examined with BA application levels(0, 1, 2, 3 and 4 g/L), respectively, in hydroponic cultivation with Pb solution. Irrespective with BA application levels, the length, leaf number and fresh weight of lettuce in BA treatments were increased by 84.3~120, 36.2~39.0, and 215~322%, respectively, compared to the BA-0 treatment. The groups with BA treatments, Pb in the nutrient solution was adsorbed to the BA due to the surface area and functional groups of the BA, and the lettuce growth was maintained more smoothly than in the BA-0 treatment. BA application is considered to have created a favorable environment for lettuce growth in hydroponic cultivation with Pb solution. CONCLUSION(S): Although direct comparing the removal effect of heavy metal between BA and biochar is not present, the BA application in contaminated area suggested a significant meaning on the recycling waste, and increasing potential crop productivity by immobilizing heavy metal.