• Horticultural Science & Technology
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• v.19 no.1
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• pp.71-77
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• 2001

Experiments were conducted to evaluate quality and vase life of cut rose 'Rote Rose' cultivated in soil or hydroponically in rockwool. Rose flower stems harvested in commercial greenhouses in Kimhae on May 27 and June 14, 1998 were transported for about two hours to a laboratory and recut in water to an uniform stem length of 45cm. The rose flowers harvested on the same day were displayed at a density of $10cm{\times}10cm$ and were subjected to the same environmental conditions in a growth chamber. The stems were put in four different preservative solutions, 0.5% Chrysal RVB, BS (2% sucrose+200ppm 8HQS+0.3% Chrysal RVB), Sonk1 (BS+0.1mM ethionine), and double distilled $H_2O$. Flower stems harvested on May 27 were displayed at $18{\pm}1^{\circ}C$, RH 60-70%, and light intensity of 220lux provided by fluorescent lamps for $16h{\cdot}d^{-1}$. Flower stems harvested on June 14 were displayed at $25{\pm}1^{\circ}C$, RH 70-80%, and light intensity of 220lux provided by fluorescent lamps for $16h{\cdot}d^{-1}$. Fresh weight and flower diameter were affected by cultivation method, and were greater in hydroponically-grown roses than in soil-grown roses. Among the preservative solutions, BS and Sonk1 were superior to Chrysal RVB in terms of prolonging vase life. Vase life extension in Chrysal RVB, BS and Sonk1 over the control was about one day in both display temperatures. At $18^{\circ}C$ vase life was maintained for three to four additional days as compared to that at $25^{\circ}C$.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.127-138
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• 2021

The aim of this study is to demonstrate interaction as a describable field and tries to understand interaction from the perspective of attributes, thus building a theoretical to help interactive designer understand this field by common rule, rather than waste huge time and labor cost on iteration. Since the concept of interaction language has been brought out in 2000, there are varies of related academical studies, but all with defect such as proposed theoretical models are built on a non-uniform scale, or the analyzing perspective are mainly based on researcher's personal experience and being too unobjective. The value of this study is the clustered resource of research which mainly based on academical review. It collected 21 papers researched on interaction paradigm or interaction attributes published since 2000, extracting 19 interaction attribute models which contains 174 interaction attributes. Furthermore, these 174 attributes were re-clustered based on a more unified standard scale, and the two theoretical models summarized from it are respectively focuses on interaction control and interaction experience, both of which covered 6 independent attributes. The propose of this theoretical models and the analyzation of the cluster static will contribute on further revealing of the importance of interaction attribute, or the attention interaction attribute has been paid on. Also, in this regard, the interactive designer could reasonably allocate their energy during design process, and the future potential on various direction of interaction design could be discussed.

• Journal of the Korean Electrochemical Society
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• v.21 no.4
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• pp.80-87
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• 2018

Safety issues in Li-ion battery system have been prime concerns, as demands for power supply device applicable to wearable device, electrical vehicles and energy storage system have increased. To solve safety problems, promising strategy is to replace organic liquid electrolyte with non-flammable solid electrolyte, leading to the development of all-solid-state battery. However, relative low conductivity and high resistance from rigid solid-solid interface hinder a wide application of solid electrolyte. Composite electrolytes composed of organic and inorganic parts could be alternative solution, which in turn bring about the increase of conductivity and conformal contact at physically rough interfaces. In our study, composite electrolytes were prepared by combining poly(ethylene oxide)(PEO) and $Li_7La_3Zr_2O_{12}$ (LLZO). The crystallinity, morphology and electrochemical performances were investigated with the control of LLZO contents from 0 wt% to 50 wt%. From the results, it is concluded that optimum content and uniform dispersion of LLZO in polymer matrix are significant to improve overall conductivity of composite electrolyte.

• Journal of Adhesion and Interface
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• v.20 no.1
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• pp.1-8
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• 2019

Fabrication of monolayer is important method for enhancing physical and chemical characteristics such as light shielding and antireflection while maintaining thin film properties. In previous studies, monolayers were fabricated by various methods on small substrates, but processes were complicated and difficult to form monolayers with large area. We used rod coating equipment with a small amount of coating liquid to form a HCP (hexagonal closed packing) coating of PMMA beads on PET(poly(ethylene terephthalate)) substrate with $20cm{\times}20cm$ size. We observed that changes in morphologies of monolayers by using the solvents with different boiling points and vapor pressures, by adapting surfactants on particles and by applying plasma treatment on substrates. The coverage was increased by 20% by optimizing the coating conditions including meniscus of beads, control of the attraction - repulsion forces and surface energy. This result can potentially be applied to optical films and sensors because it is possible to make a uniform and large-scale monolayer in a simple and rapid manner when it is compared to the methods in previous studies.

• The Korean Journal of Archival Studies
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• no.70
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• pp.85-117
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• 2021

The purpose of this study is to investigate and analyze the current status of unit tasks, unit task operation, and record management problems used by local governments, and to present improvement measures using text-based big data technology based on the implications derived from the process. Local governments are in a serious state of record management operation due to errors in preservation period due to misclassification of unit tasks, inability to identify types of overcommon and institutional affairs, errors in unit tasks, errors in name, referenceable standards, and tools. However, the number of unit tasks is about 720,000, which cannot be effectively controlled due to excessive quantities, and thus strict and controllable tools and standards are needed. In order to solve these problems, this study developed a system that applies text-based analysis tools such as corpus and tokenization technology during big data analysis, and applied them to the names and construction terms constituting the record management standard. These unit task operation support tools are expected to contribute significantly to record management tasks as they can support standard operability such as uniform preservation period, identification of delegated office records, control of duplicate and similar unit task creation, and common tasks. Therefore, if the big data analysis methodology can be linked to BRM and RMS in the future, it is expected that the quality of the record management standard work will increase.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.1
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• pp.59-69
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• 2021

Recently, large-scale offshore and coastal structures have been constructed owing to the increasing interest in eco-friendly energy development. To achieve this, precise simulations of waves are necessary to ensure the safe operations of marine structures. Several experiments are required in the field to understand the offshore wave; however, in terms of scale, it is difficult to control variables, and the cost is significant. In this study, numerical waves under various wave conditions are produced using a piston-type wavemaker, and the produced wave profiles are verified by comparing with the results from a numerical wave tank (NWT) modeled using the smoothed particle hydrodynamics (SPH) method and theoretical equations. To minimize the effect by the reflected wave, a mass-weighted damping zone is set at the right end of the NWT, and therefore, stable and uniform waves are simulated. The waves are generated using the linear and Stokes wave theories, and it is observed that the numerical wave profiles calculated by the Stokes wave theory yield high accuracy. When the relative depth is smaller than two, the results show good agreement irrespective of the wave steepness. However, when the relative depth and wave steepness are larger than 2 and 0.04, respectively, the errors are negligible if the measurement position is close to the excitation plate. However, the error is 10% or larger if the measurement position is away from the excitation location. Applicable target wave ranges are confirmed through various case studies.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.25-33
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• 2020

To investigate the relationship between strain distribution and tensile properties of brittle material, five types of tensile coupon of carbon fiber reinforced polymer (CFRP) modified the tab portion in order to have a strain distribution including S0, SD1, SD2, SV1, SV2 were tested. The ultimate stress and strain of SD2 and SV2 which was intended to have larger strain distribution were smaller than those of SD1 and SV1, that was more clearly shown in the test results of the symmetric coupons (SV series) than the asymmetric coupons (SD series). In addition, the ultimate stress and strain of most coupons with strain distribution in this study were decreased when compared to the control group with uniform strain. These results were analyzed in various ways through 1) the average of the strain values directly measured by the strain gages, 2) the converted strain calculated by dividing the total deformation by the effective length, and 3) the ultimate effective strain derived from both the elastic modulus and the ultimate load. The values measured by strain gage indicates response of the local region precisely, but it does not represent the response from whole section. However, the converted strain and effective strain can supplement disadvantage of gage because they represent the average response of whole section. In particular, the effective strain can provide rupture strain conservatively, which can be utilized in practice, when the value obtained by strain gage was not effective due to gage damage or abnormal gage readings near ultimate load. This value provides a value that can be used even when partial rupture has occurred and is reasonably useful for specimens with strain distribution.

• Clean Technology
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• v.27 no.1
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• pp.61-68
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• 2021

Selective catalytic reduction (SCR) is widely used as a method of removing nitrogen oxide in large-capacity thermal power generation systems. Uniform mixing of the injected ammonia and the inlet flue gas is very important to the performance of the denitrification reduction process in the catalyst bed. In the present study, a computational analysis technique was applied to the ammonia injection system design process of a denitrification facility. The applied model is the denitrification facility of an 800 MW class coal-fired power plant currently in operation. The flow field to be solved ranges from the inlet of the ammonia injection system to the end of the catalyst bed. The flow was analyzed in the two-dimensional domain assuming incompressible. The steady-state turbulent flow was solved with the commercial software named ANSYS-Fluent. The nozzle arrangement gap and injection flow rate in the ammonia injection system were chosen as the design parameters. A total of four (4) cases were simulated and compared. The root mean square of the NH3/NO molar ratio at the inlet of the catalyst layer was chosen as the optimization parameter and the design of the experiment was used as the base of the optimization algorithm. The case where the nozzle pitch and flow rate were adjusted at the same time was the best in terms of flow uniformity.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.11-18
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• 2022

An electromagnetic generator with variable stimulation parameters is required to conduct basic research on magnetic flux density and frequency for pulsed electromagnetic fields (PEMFs). In this study, we design an electromagnetic generator that can conduct basic research by providing parameters optimized for cell and animal experimental conditions through adjustable stimulation parameters. The magnetic core was selected as a solenoid capable of uniform and stable electromagnetic stimulation. The solenoid was designed in consideration of the experimental mouse and cell culture dish insertion. A voltage and current adjustable power supply for variable magnetic flux density was designed. The system was designed to be adjustable in frequency and pulse width and to enable 3-channel output. The reliability of the system and solenoid was evaluated through magnetic flux density, frequency, and pulse width measurements. The measured magnetic flux density was expressed as an image and qualitatively observed. Based on the acquired image, the stimulation area according to the magnetic flux density decrease rate was extracted. The PEMF frequency and pulse width error rates were presented as mean ± SD, and were confirmed to be 0.0928 ± 0.0934% and 0.529 ± 0.527%, respectively. The magnetic flux density decreased as the distance from the center of the solenoid increased, and decreased sharply from 60 mm or more. The length of the magnetic stimulation area according to the degree of magnetic flux density decrease was obtained through the magnetic flux density image. A PEMF generator and stimulation parameter control system suitable for cell and animal models were designed, and system reliability was evaluated.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.3
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• pp.89-95
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• 2022

In this study, glassy carbon coating was performed on the graphite using a phenolic resin and a curing agent was mixed with ethylene glycol as an additive to form the uniform surface. The phenolic resin was dried and cured under the environments of hot air, then converted into a glassy carbon layer by pyrolysis at 500~1,500℃. FTIR, XRD, SEM analysis, and density/porosity/contact angle measurement were performed for characterization of glassy carbon. The pyrolysis temperature for high-quality glassy carbon was optimized to be about 1,000℃. As the content of the additive increased, the effect of reducing surface defects on the coated surface, reduction of porosity, increase of contact angle, and increase of density were investigated in this study. The method of forming a glassy carbon coating layer through an additive is expected to be applicable to graphite coating and other fields.