• Journal of Korean Elementary Science Education
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• v.36 no.4
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• pp.316-330
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• 2017

The purpose of this study was to develop the ESD program related to creative-experience activity, and to examine the effect of its application. The program was composed of 13 sessions for fifth-grade class in elementary school, including all of the environmental, economic, and social aspects of ESD. This program was connected to the domains of creative hands-on activities, that is, career activities, club activities, self-regulated activities and voluntary service activities. The results was as follows. First, the experimental group to undergo the ESD program related to creative-experience activity did not show significant differences in environmental literacy compared to the control group, but it is proven that this program contributed to the improvement of learners' environmental emotion, skill, and participation. Second, the experimental group did not show significant differences in scientific attitude compared to the control group, but it was considered to affect the elementary students' criticism, self-esteem, and patience in positive and effective manner. In conclusion, more ESD program that cultivate elementary school students' environmental literacy need to be developed continuously, and more intensive research should be conducted to earn better understanding of ESD.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.284-299
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• 2015

The purpose of this study is to look at the elementary school teachers' practical experiences of change and knowledges in promotion of Education for Sustainable Development(ESD) process with Community of Practice(CoP) of teachers and Biographical Approach. ESD project of 'S' elementary school was started by Principal's recognition of further and that was practiced with a common theme over the course through various experiences in educational field with teachers' involvement and finally came to the changes in teachers' personal life and lifelong cognition. Through Community of Practice teachers could look the concept of ESD to a wide field of view and tried various activities in the classroom with students and also, as a further, were able to equip new professional competency with skills. Through the process of learning and experience teachers accepted the ESD philosophy as the engine of life and experienced that their long-term recognition was extended to the whole personal life and the global community.

• ETRI Journal
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• v.38 no.2
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• pp.272-279
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• 2016

In this paper, a new structure for an advanced high holding voltage silicon controlled rectifier (AHHVSCR) is proposed. The proposed new structure specifically for an AHHVSCR-based electrostatic discharge (ESD) protection circuit can protect integrated circuits from ESD stress. The new structure involves the insertion of a PMOS into an AHHVSCR so as to prevent a state of latch-up from occurring due to a low holding voltage. We use a TACD simulation to conduct a comparative analysis of three types of circuit - (i) an AHHVSCR-based ESD protection circuit having the proposed new structure (that is, a PMOS inserted into the AHHVSCR), (ii) a standard AHHVSCR-based ESD protection circuit, and (iii) a standard HHVSCR-based ESD protection circuit. A circuit having the proposed new structure is fabricated using $0.18{\mu}m$ Bipolar-CMOS-DMOS technology. The fabricated circuit is also evaluated using Transmission-Line Pulse measurements to confirm its electrical characteristics, and human-body model and machine model tests are used to confirm its robustness. The fabricated circuit has a holding voltage of 18.78 V and a second breakdown current of more than 8 A.

• Hwankyungkyoyuk
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• v.22 no.3
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• pp.1-14
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• 2009

The UNESCO World Conference on "Education for Sustainable Development - Moving into the Second Half of the United Nations Decade" was held in Bonn, Germany, from 31 March to 2 April 2009, as the DESD approaches it's mid-point. It brought 900 participants including 47 ministers and deputy-ministers of education from 147 countries. The objectives of the conference were to: (1) highlight the essential contribution of Education for Sustainable Development (ESD) to all of education and to achieving quality education ("Why is ESD relevant?"); (2) promote international exchange on ESD ("What can we learn from each other?"); (3) carry out a stock-taking of DESD implementation ("What have we achieved so far, what are the lessons learnt?"); (4) develop strategies for the way ahead ("Where do we want to go from here ?"). The conference provided opportunities for all participants to recognize the importance of ESD as the way to meet challenges of the present unsustainable world and discuss outcomes of first-half of DESD and action plans for second-half of DESD. In particular, one plenary session was focused on the DESD Monitoring and Evaluation process, with a presentation of the key findings of the draft global report on the context and structures of ESD, as well as regional perspectives. As a result of the conference, participants adopted the Bonn Declaration which would serve as the backbone for the further development of the post-Bonn process within the framework of the DESD.

• Journal of Applied Reliability
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• v.11 no.3
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• pp.251-265
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• 2011

Low-noise amplifier(LNA) is a component that amplifies the signal while lowering the noise figure of high-frequency signal. LNA holds a very important position in RF system so that it is widely used for telecommunication. Electro static discharge(ESD) is the most common cause of malfunction for low-powered components, such as Large Scale Integration and IC type LNA is weak in ESD. This thesis studies static effect of communication LNA. It analyzes ESD effect, which occurs within LNA circuit, and describes testing standard and methods. In order to find out LNA's susceptiblity to electro static, two well-recognized communication IC type LNA models were selected to be tested. Then static-induced malfunction was carefully analyzed and it suggests architectural problem and improvement from the LNA's ESD point of view.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.57-62
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• 2001

In order to analyze the mechanism of semiconductor device damages by ESD, this paper adopts a new charged-device model(CDM), field-induced charged nudel(FCDM), simulator that is suitable for rapid routine testing of semiconductor devices and provides a fast and inexpensive test that faithfully represents ESD hazards in plants. The high voltage applied to the device under test is raised by the fie]d of non-contacting electrodes in the FCDM simulator. which avoids premature device stressing and permits a faster test cycle. Discharge current md time are measured and calculated The FCDM simulator places the device at a huh voltage without transferring charge to it, by using a non-contacting electrode. The only charge transfer in the FCMD simulator happens during the discharge. This paper examine the field charging mechanism, measure device thresholds, and analyze failure modes. The FCDM simulator provides a Int and inexpensive test that faithfully represents factory ESD hazards. The damaged devices obtained in the simulator are analyzed and evaluated by SEM Also the results in this paper can be used for to prevent semiconductor devices from ESD hazards.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.178-179
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• 2005

ESD(Electrostatic Discharge) 보호에 응용되는 소자는 ESD가 발생했을 때, 빠르게 턴-온되어 외부로부터 EOS(Electric OverStress)를 차단함으로서 집적회로 내부의 코어를 보호해 주어야 한다. 이러한 기능에 충실한 LVTSCR(Low-Voltage Silicon Controlled Rectifier)은 트리거링 전압을 기존의 SCR보다 낮추어 ESD에 대해 민감한 반응을 할 수 있도록 개선한 소자이다. 그러나 트리거링 전압을 낮추면서 래치업 전압 또한 낮아지는 특성이 trade-off 관계로 맞물려 있어, LVTSCR의 단점인 낮은 래치업 전압을 효과적으로 다루는 것이 큰 이슈가 되고 있다. 본 논문에서는 LVTSCR의 ESD 보호에 대한 응용시 발생 가능한 래치업을 차폐하는 회로적 방법을 제시하였다. 제시된 새로운 구조의 차폐회로는 LVTSCR에서 래치업이 발생했을 때, 천이 전류를 감지하여 래치업이 발생되는 소자에 대한 전원을 스스로 차폐시켜 래치업에 대한 안정성을 시뮬레이션으로 검증하였다.

• Journal of IKEEE
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• v.25 no.2
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• pp.280-284
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• 2021

In this paper, a new ESD protection circuit is proposed to improve the snapback characteristics. The proposed a new structure ESD protection circuit applying the conventional SCR structural change and stack structure. The electrical characteristics of the structure using penta-well and double trigger were analyzed, and the trigger voltage and holding voltage were improved by applying the stack structure. The electron current and total current flow were analyzed through the TCAD simulation. The characteristics of the latch-up immunity and excellent snapback characteristics were confirmed. The electrical characteristics of the proposed ESD protection circuit were analyzed through HBM modeling after forming a structure through TCAD simulator.

• Korean Journal of Childcare and Education
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• v.17 no.6
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• pp.53-72
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• 2021

Objective: This study aimed to reveal early childhood teachers' perceptions of teacher competency for ESD using concept mapping and demonstrating its importance. Methods: 16 early childhood teachers in charge of 3-5 year olds conducted statement writing, and then the importance of selected statements were rated by 160 early childhood teachers in charge of 3-5 year olds. Selected statements were analyzed through multidimensional scaling and hierarchical cluster analysis. Results: Early childhood teachers perceived teacher competency for ESD in early childhood as concept mapping with two-dimensions and six clusters. The following six clusters were established (1) ethics for sustainable development, (2) willingness to participate in ESD, (3) development and operation of a sustainable development curriculum, (4) recognition and practice of environmental issues, (5) realization of value for sustainable development, and (6) practical thinking for ESD. And then among the six clusters, the most important cluster was recognized as 'ethics for sustainable development', and among the statements 'having an open mind to understand multiculturalism and the disabled' was considered relatively important Conclusion/Implications: Based on these results, we discussed the importance of teacher competency for ESD in early childhood, development of teacher competency scale, and preparation of a teacher education plans for each competency.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.573-579
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• 2019

The purpose of this study is predicted easily the entrance surface dose (ESD) in chest digital radiography. We used two detector type such as flat-panel detector (FP) and IP (Imaging plate detector). ESD was measured at each exposure condition combined tube voltage with tube current using dosimeter, after attaching on human phantom, it was repeated 3 times. Phantom images were evaluated independently by three chest radiologists after blinding image. Dose-area product (DAP) or exposure index (EI) was checked by Digital Imaging and Communications in Medicine (DICOM) header on phantom images. Statistical analysis was performed by the linear regression using SPSS ver. 19.0. ESD was significant difference between FP and IP($85.7{\mu}Gy$ vs. $124.6{\mu}Gy$, p=0.017). ESD was positively correlated with image quality in FP as well as IP. In FP, adjusted R square was 0.978 (97.8%) and linear regression model was $ESD=0.407+68.810{\times}DAP$. DAP was 4.781 by calculating the $DAP=0.021+0.014{\times}340{\mu}Gy$. In IP, adjusted R square was 0.645 (64.5%) and linear regression model was $ESD=-63.339+0.188{\times}EI$. EI was 1748.97 by calculating the $EI=565.431+3.481{\times}340{\mu}Gy$. In chest digital radiography, the ESD can be easily predicted by the DICOM header information.