• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.28-31
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• 2000

In this paper, the effects of La addition of PLZT(x/30/70) thin films Prepared by sol-gel method are investigated for NVFRAM application. The tetragonality (c/a), the grain size, and the surface roughness of PLZT thin films decrease with an increase of La concentration. As the La concentration increases, the dielectric constants at 10 kHz increase from 450 to 600, while the loss tangent decrease from 0.075 to 0.025. Also, the leakage current density at 100kV/cm decrease from 5.83$\times$10$^{-7}$ to 1.38$\times$10$^{-7}$ 4/$\textrm{cm}^2$. In the results of hysteresis loops measured at $\pm$170kV/cm, the remanent polarization and the coercive field of PLZT thin films with La concentration from 0 to 10㏖％ decrease from 20.8 to 10.5 $\mu$C/cm and from 54.48 to 32.12kV/cm, respectively. After a fatigue measurement by applying 10$^{9}$ square pulses with $\pm$5V, the remanent polarizations of PLZT thin films with 0 and 10㏖％ La concentration decrease about 64 and 42 ％ from initial state. In the results of retention measurement after 10$^{5}$ s, PLZT thin films with 0 to 10mo1％ La concentration show that the remanent polarization is decreased about 43％ and 9％ from initial state, respectively.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.249-256
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• 2011

Tall fescue (Schedonorus phoenix Scop.) is resistant to abiotic and biotic stresses through a symbiotic relationship with Neotyphodium coenophialum. However, this endophyte has been considered detrimental since it produces toxic alkaloids to animals. It is vital to understand mutuality between these two to maximize positive impact of the endophyte on agri-ecosystem. Little research has been conducted on endophyte transmission mechanism in planta. To provide basic information related to endophyte transmission, an experiment was conducted to examine the effect of endophyte genotype and water stress on endophyte transmission by imposing soil moisture deficits at different stages of panicle development. There was water stress effect on endophyte frequency but not on concentration, whereas endophyte genotype significantly influenced endophyte concentration in pseudostem of tall fescue at boot stage. Reproductive tillers showed greater endophyte frequency and concentration. Endophyte frequency in florets or seeds depended on position within panicle. There was no drought effect on endophyte concentration, but showed the effect of endophyte genotype on endophyte concentration in florets and seeds. Overall endophyte concentration in seeds was higher. From this study, we may conclude that although water stress reduced endophyte frequency in vegetative tiller, water stress does not have effect on endophyte transmission, suggesting that drought is not an important factor controlling the endophyte transmission from plant to seed. Endophyte genotype and seed position in a panicle affected endophyte transmission, indicating that these two factors are involved in endophyte transmission and may determine seed transmission of endophyte in tall fescue.

• Journal of Information Technology Services
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• v.12 no.1
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• pp.201-213
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• 2013

The use of online shopping mall has been increasing rapidly, which reflects the convenience and economic benefits associated with its usage. As with traditional offline businesses, internet businesses have to manage customer relations to provide better services in order to ensure their business sustainability. In this regard, identifying the influencing factors to reuse intention of online shopping mall is very important. In this paper, we aim to examine the effects of perceived and individual variables on intention to reuse in the context of online shopping mall. In order to analyze the antecedents, we selected perceived and individual factors such as shopping enjoyment, concentration, perceived variety and maximizing tendency. For empirical analysis, we surveyed real users of online shopping mall. As a result, all antecedents showed significant influence on intention to reuse except perceived variety and among the variables the concentration has top standardized coefficient. In addition, perceived variety has significant effect on shopping enjoyment but not on concentration. Maximizing tendency is related to shopping enjoyment and concentration significantly. The results of this research can be useful guidelines for online shopping mall providers.

• Journal of Information Technology Applications and Management
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• v.9 no.2
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• pp.57-70
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• 2002

In this paper, we propose matrix analysis methods for analyzing national R&D information creation. In order to analyze R&D information creation at national level, it is necessary to analyze whether information is created systematically for each technical category and for each information type. In this paper, ‘uniformity’and ‘concentration’criterions are proposed to check national R&D information creation and we provide formulas to measure the criterions. The criterions are applied to domestic information creation in information and communication domain to show the utilization of the proposed method.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2765-2770
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• 2008

The purpose of tunnel ventilation system for long road tunnels is to keep certain levels of Visibility Index and the concentration of CO. Additional equipments such as jet fans are used in road tunnel to discharge pollutants in the road tunnel. The control algorism of tunnel ventilation system takes the value of sensors as input, and then gives the operation method of jet fans in tunnel as output. Information on the variation of CO concentration in tunnel when jet fans are running is needed to minimize their operation time. Numerical analysis is used in this paper because of the difficulty of conducting experiments under standard condition for ventilation of road tunnel. The concentration of CO has been calculated by using 3-dimensional CFD under transient condition with speed of cars, quantity of air ventilation, and the results for various operation position of jet fans are compared.

• Journal of the Optical Society of Korea
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• v.7 no.2
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• pp.47-52
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• 2003

Effect of soaking temperature on erbium doping of the optical fiber core during solution doping procedure, especially in the modified chemical vapor deposition (MCVD) process, was investigated. The concentration of dopants such as $Er^{3+} and Al^{3+}$ in the preforms and the optical fibers measured by the electron probe microanalysis (EPMA) and the optical spectrum analyzer (OSA) was found to increase with decreasing the soaking temperature. The increase in the concentration of the $Er^{3+}$ is attributed to the precipitation of the erbium due to the decrease in the solubility as well as the increase of capillary force and viscosity of the doping solution by decreasing the temperature.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.155-162
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• 2016

This study attempts to reveal structures of two-dimensional ring polymer solutions in various polymer concentrations ranging from dilute to concentrated regime. Polymer sizes, single molecule structure factors, bond correlation functions and monomer density distribution functions from center of mass are given in order to clarify the polymer structures. Our study shows that a ring in dilute solution maintain pseudo-circular structure with self-avoiding walk (SAW) statistics, and it seems to be composed of two connecting SAW linear chains. In semidilute solutions, ring polymers are not entangled with each other and adopt collapsed configurations. Such assumption of collapsed structures in the semidilute regime gives an overlap concentration of ${\varphi}^*{\sim}N^{-1/2}$ where N is degree of polymerization. By normalizing the polymer concentration by these overlap concentration, we find universal behaviors of polymer sizes and structure factors regardless of N.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.8
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• pp.617-626
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• 2021

During supersonic flight of vehicles, the thermal behavior of structures under high-temperature environment is important for thermal-structural design. In this study, full-field thermal deformation and stress concentration of the notched structure was performed using global-local multi-digital image correlation (multi-DIC) systems. This techniques were developed and implemented by multi-DIC systems consists of 2D DIC system and 3D DIC system. The specimen was heated in a heating chamber to achieve the thermal expansion behavior. Then the images of structure's deformation and stress concentration at various temperature were recorded and analyzed by multi-DIC system. Afterward, full-field thermal deformation of the notched structure was determined with DIC technique and stress concentration at the notched structure was calculated by further processing. Finite element analysis of the notched structure is performed in ABAQUS^TM and the results of the experiments show good agreement with those obtained from simulation. The results achieved in this study show the efficiency of the muilti-DIC method in thermal deformation as well as stress concentration of notched structure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.4
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• pp.553-559
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• 2020

Seaweed(Laver), Korea's largest export product, is currently focused on mass production due to the market situation in Korea. This naturally led to a decrease in the quality of seaweed. Therefore, in this paper, the present method was produced and tested by changing the way of adjusting the ratio of seaweed mixing, which was dependent on the user's sense and experience in the production of seaweed. In addition, I developed an embedded measurement system that can determine the concentration of a mixture of gold in real time based on primary image information obtained through an IR LED lamp that generates a light source and a photo sensor that detects concentration. By collecting and storing precise data in real time, it is easier to cope with the previous year's data in a work environment that is repeated every winter.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.116-124
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• 2020

The advantage of the distance learning universities based on the 4th Industrial Revolution is that anyone can conveniently take lectures anytime, anywhere on the web. In addition, research has been actively conducted on the effect of light color and temperature control upon student performance during online classes. However, research on how the conditions of subjects, lighting colors, and music selection improve the degree of a student's concentration during online lectures has not been completed. To solve these problems in this paper, we have developed automatic analysis system SW for the weak subjects of learners by applying intelligent analysis algorithm, have proposed and simulated music therapy and art therapy. Moreover, It proposed in this paper an algorithm for an automatic analysis system, which shows the weak subjects of learners by adopting intelligence analysis algorithms. We also have presented and simulated a music therapy and art therapy algorithms, based on the blended learning, in order to increase students concentration during lecture.