• Journal of the Korean Society of Industry Convergence
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• v.13 no.3
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• pp.183-189
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• 2010

The purpose of this study was to examine the Industrial High Schools Technical Subjects teachers' perceptions and attitudes toward sustainable development(SD). The instrument consisted of totally 12 items. The subjects of this study were 98 Industrial High Schools Technical Subjects teachers. The period of survey is from June 23 to July 15 of 2010. The questionnaire included items asking whether they heard about terms such as sustainability or sustainable development, the source of information on SD, the level of understanding or the urgent task 2 for SD in Korea. Result of survey is following. First, Teacher thought that urgent task for SD is conservation of natural environment. Second, Most of the teacher consider the concept SD as 'pursuing the balance between environmental protection and economic development, and some of the teachers recognized the concept of SD in the paradigm of continuous economic development. Third, half of teachers have not heard terminology of SD .and 80% of them have not conducted ESD. Fourth, a few of teachers replied that obstacle of ESD is shortage of teacher's professionalism.

• Journal of IKEEE
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• v.22 no.4
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• pp.1202-1205
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• 2018

In this paper, we proposed ggNMOS based on 4H-SiC material and analyzed its electrical characteristics. 4H-SiC is a wide band-gap meterial, which is superior in area contrast and high voltage characteristics to Si material, and is attracting attention in the power semiconductor field. The proposed device has high robustness and strong snapback characteristics. The process consisted of SiC process and electrical characteristics were analyzed by TLP measurement equipment.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.2
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• pp.292-300
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• 2015

This paper proposes a high-efficiency, dual-mode PWM / linear buck converter with a wide-input range. The proposed converter was designed with a mode selector that can change the operation between PWM / linear mode by sensing a load current. The proposed converter operates in a linear mode during a light load and in PWM mode during a heavy load condition in order to ensure high efficiency. In addition, the mode selector uses a bit counter and a transmission gate designed to protect from a malfunction due to noise or a time-delay. Also, in conditions between $-40^{\circ}C$ and $140^{\circ}C$, the converter has variations in temperature of $0.5mV/^{\circ}C$ in the PWM mode and of $0.24mV/^{\circ}C$ in the linear mode. Also, to prevent malfunction and breakdown of the IC due to static electricity, the reliability of IC was improved by embedding a self-produced 8 kV-class(Chip level) ESD protection circuit of a P-substrate Triggered SCR type with high robustness characteristics.

• Journal of IKEEE
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• v.11 no.1 s.20
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• pp.69-76
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• 2007

This paper presents the design of LVDS (Low-Voltage-Differential-Signaling) transmitter for Gb/s-per-pin operation. The proposed LVDS transmitter is designed using BiCMOS technology, which can be compatible with CMOS technology. To reduce chip area and enhance the robustness of LVDS transmitter, the MOS switches of transmitter are replaced with lateral bipolar transistor. The common emitter current gain($\beta$) of designed bipolar transistor is 20 and the cell size of LVDS transmitter is $0.01mm^2$. Also the proposed LVDS driver is operated at 1.8V and the maximum data rate is 2.8Gb/s approximately In addition, a novel ESD protection circuit is designed to protect the ESD phenomenon. This structure has low latch-up phenomenon by using turn on/off character of P-channel MOSFET and low triggering voltage by N-channel MOSFET in the SCR structure. The triggering voltage and holding voltage are simulated to 2.2V, 1.1V respectively.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.1
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• pp.77-86
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• 2001

With the growth of the EC(Electronic Commerce), Buying and selling software through the internet are expanded. Among the ESD(Electronic Software Distribution) methods, Buy-first method and TrY-before-bu1 method can not solve the illegal copy problem. Recently developed EL(Electronic License) model solve the illegal copy problem by separating the software and license. But this method also can not support various ways for payment. In this paper we propose the software license management system that is a newly form like ESD model. This system proposes NL(New License) to support various payment methods and SC(Software Charge) to insure that a seller takes the software price. Agent of the proposed system offers scalability to other systems and illegal copy protection function bv managing NL and SC.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.1
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• pp.1-7
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• 2014

A bidirectional transient voltage suppression (TVS) diode consisting of specially designed $p^--n^{{+}+}-p^-$ multi-junctions was developed using low temperature (LT) epitaxy and fabrication processes. Its electrostatic discharge (ESD) performance was investigated using I-V, C-V, and various ESD tests including the human body model (HBM), machine model (MM) and IEC 61000-4-2 (IEC) analysis. The symmetrical structure with very sharp and uniform bidirectional multi-junctions yields good symmetrical I-V behavior over a wide range of operating temperature of 300 K-450 K and low capacitance as 6.9 pF at 1 MHz. In addition, a very thin and heavily doped $n^{{+}+}$ layer enabled I-V curves steep rise after breakdown without snapback phenomenon, then resulted in small dynamic resistance as $0.2{\Omega}$, and leakage current completely suppressed down to pA. Manufactured bidirectional TVS diodes were capable of withstanding ${\pm}4.0$ kV of MM and ${\pm}14$ kV of IEC, and exceeding ${\pm}8$ kV of HBM, while maintaining reliable I-V characteristics. Such an excellent ESD performance of low capacitance and dynamic resistance is attributed to the abruptness and very unique profiles designed very precisely in $p^--n^{{+}+}-p^-$ multi-junctions.

• Journal of Korean Home Economics Education Association
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• v.32 no.3
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• pp.161-177
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• 2020

This research aims to identify the relevance of 'Adolescence consumption' units to ESD(Education for Sustainable Development), and to analyze the unit's inquiry tendency through the Romey analysis method. The assessment criteria in association with ESD developed in the previous literature were summarized and established to set up an analysis framework consisted of 11 key points including environmental perspective (natural resources, climate change/disaster prevention and mitigation, and sustainable rural and urban systems), economic perspective (corporate sustainability, market economy, and poverty gap mitigation), and socio-cultural perspective (human rights/peace/human protection, cultural diversity and understanding, health/safety, civic engagement, and management of nation). With this framework, the learning contents of 'adolescence consumption life' unit in twelve middle school Home Economics textbooks were analyzed including the texts, images/illustrations/tables/graphs, and activities. The analysis revealed that the core elements of the 'market economy' and 'management of nation' from the economic perspective were presented in three different formats: texts, images/illustrations/tables/graphs, and activities. However, relatively insufficient contents were presented in terms of health/safety, civic engagement, sustainable rural and urban systems, and corporate sustainability, and thus, development of textbooks dealing with various ESD contents is neededrecommended. Additionally, most textbooks' texts and images/illustrations/tables/graphs tend to be authoritative, while activities and assignments exhibited an inquiry tendency. It is advisable to incorporate a wider variety of ESD-related content in Home Economics classes and creatively employ inquiry-based learning activities for the development of pro-sustainable-development consumption values and behavioral tendencies among young students.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1236-1251
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• 2015

This study examined understanding and attitude of sustainable development(SD) of 38 college students in a nuclear power plant construction after education for sustainable development(ESD) through panel discussion. The results were as follows: First, after lesson 66% of students were expected that SD is possible if scientific technology is developed and a frugal life for the protection of environment is carried out. However, the remaining students regarded SD as an ideal concept, because they thought it is not possible to pursue environmental sustainability and socio-economic development simultaneously. Second, students' opinions in the evaluation of constructing a nuclear power plant in three aspects(environment, society and economy) before and after panel discussion were changed as follows; 1) After panel discussion, the objectors increased to 21% in economic evaluation, while the supporters increased to 11% in environmental evaluation. 2) Students majoring in engineering or natural sciences changed their opinions to agree in environmental evaluation because they considered a nuclear power plant safe and eco-energy. However students majoring in social science/business or liberal arts/arts changed their opinions to disagree in economic evaluation because they considered a nuclear power plant as high-cost energy when assessing danger-accidents cost, public consensus cost, operation and maintenance cost, and waste disposal cost. 3) This change of decision-making in students majoring in social science/business or liberal arts/arts after panel discussion was statistically significant(p<0.05). Implications of panel discussion as a teaching and learning method in ESD are also discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.1 s.92
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• pp.102-112
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• 2005

In this work, we developed fully integrated broadband MMIC chip set employing CSP(Chip Size Package) for K/Ka band applications. By utilizing an ACF for the RF-CSP, the fabrication process for the packaged amplifier MMIC could be simplified and made cost effective. $STO(SrTi_{3})$ capacitors were employed to integrate the DC biasing components on the MMIC, and LC parallel circuits were employed for DC feed and ESD protection. A pre-matching technique and RC parallel circuit were used to achieve a broadband matching and good stability fer the amplifier MMIC in K/Ka band. The amplifier CSP MMIC exhibited good RF performance over a wide frequency range in K/Ka band. This work is the first report of a fully integrated CSP amplifier MMIC successfully operating in the K/Ka band.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.565-566
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• 2008

The high efficiency power management IC(PMIC) for Moblie application is proposed in this paper. PMIC is controlled with PWM control method in order to have high power efficiency at high current level. The saw-tooth generator is made to have 1.2 MHz oscillation frequency and full range of output swing from ground to supply voltage(VDD:3.3V). The comparator is designed with two stage OP amplifier. And the error amplifier has 70dB DC gain and $64^{\circ}$ phase margin. DC-DC converter, based on Voltage-mode PWM control circuits, achieved the high efficiency near 95% at 100mA output current. DC-DC converter is designed with LDO in stand-by mode which fewer than 1mA for high efficiency.