• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.159-165
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• 2020

The purpose of this study is to consider the home environment and awareness of elementary school students in the first grade of elementary school, and to find ways to support them. Participants were 31 1st graders in elementary schools nationwide. Data collection was conducted from June 6, 2017 to July 7, 2017. The focus group interview was used as a data collection method for this study. Results were analyzed as 'The Changing family environment that first graders think' and 'First graders' awareness of elementary school'. 'The Changing family environment that first graders think' include 'Changes in language used by parents', 'Changes in how parents and families live', and 'What to do after school'. 'First graders' awareness of elementary school' was analyzed as 'Awareness of Elementary school life', 'Awareness of peers', 'Awareness of homeroom teacher', and 'Awareness of learning'. As the conclusion of this study, we suggest that because the children have more free time than attending kindergarten, they need quality programs and support plans to support their first grade primary adjustment. Also, we propose a common problem facing first-year students: the difficulty of adjusting to study and support for how to study in an easier way.

• 한국디지털정책학회:학술대회논문집
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• 2007.06a
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• pp.33-40
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• 2007

The Customs Administration, unlike other administrative service, should respond to constantly changing external environment. The Customs has to actively adapt itself to government policy changes, economic changes and international environment changes to facilitate the flow of trade logistics and maintain trading relations wi th other countries. The purpose of this paper is to explain policy directions of the Korea Customs Service which enforces various policies related to tariff and non-tariff barrier elimination for the trade liberalization while the Korean government is pursuing FTAs on a multi-track basis. This paper aims to seek ways to apply FTA policies to the Korean society and economy in a smooth manner. First of all, this paper examines changes in Customs administration brought by the proliferation of FTAs to such areas as FTA negotiations, import/export management, duties and taxes collection, drawback reduction/exempt ion of duty application area of preferential tariff rate and country of origin management. Then, the paper sets FTA missions of "supporting Customs Administration to lead the new trend of free trade environment" after analyzing the environment changes. To achieve the FTA mission mentioned above, the KCS designated 4 strategies and 40 implementation tasks. The 4 strategies are named "4C Strategies" taking initial letters from Client-oriented, Customized procedures, Cooperation and Constitution. "4C" also refers to Foresee(strategies to foresee the successful establishment of FTA policies) or For C(Customer or Customs). The KCS will continue to create new tasks through various channels and monitor their implementation process, and to help FTA regime successfully take root in Korea.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.159-164
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• 2021

Heavy metals exist in soils in various chemical forms including free metal ions and organo-metal complexes. The ratio of free metal ions has been known to be highly associated with the plant absorption of heavy metals. This study aims to understand the effect of free ions and organo-metal complexes on the absorption of lead (Pb) and cadmium (Cd) by plants. For this, lettuce grown in a hydroponic system for 28 days was consequently grown another 48 hours using Pb and Cd solutions. The ratios of free ion to organo-metal complexes in the solutions were adjusted at 100:0, 90:10, 70:30, 60:40 by four different organic acids (citric, oxalic, acetic, and humic acid). After that, the concentration of Pb and Cd in lettuce were analyzed. The Pb and Cd absorption by lettuce was more relied on the types of organic acids treated and the type of metals rather than the ratio of free metal ions. For example, citric acid increased the Pb absorption while it decreased the Cd absorption by lettuce. There was no significant relationship between free metal ion ratios and both Pb and Cd uptake by lettuce. It could be explained that citric acid, a relatively higher molecular weight organic acid, has higher ion binding capacity, so it forms organo-Pb complex easily due to the higher affinity of Pb on the binding site in comparison with Cd. Consequently, this complexation would assist Pb uptake by lettuce.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1697-1702
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• 2011

A facile, green, efficient and environment-friendly protocol for the synthesis of 14-aryl- or alkyl-14Hdibenzo[a,j]xanthene, 1,8-dioxooctahydroxanthene and 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one have been developed by one-pot condensation of various aldehydes with (i) ${\beta}$-naphthol (ii) cyclic 1,3-dicarbonyl compounds and (iii) ${\beta}$-naphthol and cyclic 1,3-dicarbonyl compounds, in the presence of 1,3,5-trichloro-2,4,6-triazinetrion (trichloroisocyanuric acid, TCCA) as catalyst under solvent-free conditions. The present approach offers the advantages of clean reaction, simple methodology, short reaction time, easy purification, and economic availability of the catalyst.

• Advances in aircraft and spacecraft science
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• v.5 no.1
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• pp.107-128
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• 2018

Thermo-mechanical vibration of sandwich beams with a stiff core and face sheets made of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) is investigated within the framework of Timoshenko beam theory. The material properties of FG-CNTRC are supposed to vary continuously in the thickness direction and are estimated through the rule of mixture and are considered to be temperature dependent. The governing equations and boundary conditions are derived by using Hamilton's principle and are solved using an efficient semi-analytical technique of the differential transform method (DTM). Comparison between the results of the present work and those available in literature shows the accuracy of this method. A parametric study is conducted to study the effects of carbon nanotube volume fraction, slenderness ratio, core-to-face sheet thickness ratio, and various boundary conditions on free vibration behavior of sandwich beams with FG-CNTRC face sheets. It is explicitly shown that the vibration characteristics of the curved nanosize beams are significantly influenced by the surface density effects.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.417-422
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• 1993

In order to minimize turnaround of machining in FMS lines, CAD/CAM/CAT integrated system called MascCAM was developed. Developing enhanced CAM and inspection modules in the MascCAM environment, 2D came, 2 $^{1}$2/ D prismatic parts and 3D free-formed surfaces were able to be automatically designed, manufactured and inspected on the machine tools by using AutoCAM and Z-map. Introducing Z-map technique, the MascCAM was able to be interfaceed with and CAD system. Developed QPPGT module generates a quick and fool-proof inspection work to users. A vertical and a horizontal machining center equipped with FANUC OMC were used for experiments. Performance of the system was confirmed by a large amount of experiments.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.9 s.174
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• pp.123-129
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• 2005

As the robot industry changes from industrial robot into personal robot used in home, the concept also changes from the existing fixed manipulator into Mobile Manipulator of free move in the aspect of appliance. For personal robot with such features, the role of mobile system is very important technology that rules the roost of robot functions. Especially, it is necessary to develop moving mechanism for free move in a narrow environment with obstacles such as home. This study introduces 3-axis structure in order to develop synchronous method that has turret capable of endless revolution for practical use as well as semi-omnidirectional function, and suggests applicable method to solve the problem of mechanical coupling.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.331-335
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• 2011

Digital images are often corrupted by impulse noise, and it is very important to remove random-valued impulse noise. Cleaning such noise is far more difficult than cleaning salt and pepper impulse noise. In this paper, we proposed an efficient way to remove random-valued impulse noise from digital images. This novel method comprises two stages. The first stage is to detect the random-valued impulse noise in the image and the pixels are roughly divided into two classes, which are "noise-free pixel" and "noise pixel". Then, the second stage is to eliminate the random-valued impulse noise from the image. In this stage, only the "noise pixels" are processed. The "noise-free pixels" are copied directly to the output image. Simulation results indicated that our method provides a significant improvement over many other existing algorithms.

• Journal of the Korean Magnetic Resonance Society
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• v.11 no.1
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• pp.56-63
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• 2007

A series of bromophenols and corresponding debrominated phenolic compounds was prepared by isolation from red alga Tichocarpus crinitus and by structural modification of natural bromophenols. Their structures were determined by extensive NMR analysis and the antioxidant activities were established through the determination of their abilities to inhibit free radicals using DPPH as the stable radical. The most active free radical scavengers were the debrominated phenolic derivatives 3,4-dihydroxybenzyl alcohol and 3,3',4,4'-tetrahydroxydiphenylmethane.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.85-86
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• 2009

The sloshing phenomenon can be defined as the nonlinear movement of the free-surface of liquids inside tanks. It generates dynamic loads on the tank structure and thus becomes a problem of relative importance in the design of marine structures. The present study describes a experiment of the sloshing of flows with free-surface which contained in a rectangular tank moving in pitching motion.