• Journal of The Korean Association For Science Education
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• v.18 no.3
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• pp.383-398
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• 1998

This study was accomplished to analysis and survey on the experimental and practical science education of high school in korea for the consecutive study of the an analysis and survey on the experimental and practical science education of middle school in korea(Lee, Yoon-Jong et aI., 1997). The status of facilities, management for the experiment, practices, teaching methods in high schools have been investigated. The present status and reasonable management of the high school science education have been grasped from the questionaires. To do this 165 high school science teachers, 1977 students and 80 principals of high schools in Korea are administered questionaires of Science Education Research Institute of Kyungpook National University(I997). The results of this study are as follows : The reasonable management for experiments and practices of science education were scanty in the high school around the urban and rural school owing to the shortage of facilities and equipments, crowded class, excessive class works for teacher, excessive contents of present textbooks and insufficiency of the administrative supports etc. The current teaching method of high school science has emphasized knowledge. This fact does not satisfy the objective of learning due to lack of the teaching method. Desirable directions for the improvement of present status of high school science education were proposed in this paper.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.260-260
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• 2017

High temperature is one of major environmental stress. Heat in flowering season of wheat is able to effect negatively to fertilization and also heat effect to maturity. Therefore, Heat stress effects severely to qualities of wheat and yield productivity. In this study, we evaluated to agronomic characteristics and qualities by high temperature in 13 Korean wheat varieties. Weight of 1,000 grains decreased when wheat got the heat stress. In particular, heat stress during the heading dates were more damaged than after the end of heading dates except two varieties Keumkang and Jokyoung. Plant height of each cultivar under high temperature and normal field averaged 80.5 cm and 83.0cm, respectively. The length of spike and awn in each cultivar were similar to both condition. Flour yield and gluten contents of most heat damaged wheat decreased. Under the temperature, protein contents of six varieties like as Keumkang, Baekjoong, Hojoong, Yeonbaek, Joah and Shinmichal 1 decreased but the others increased. The sedimentation values (SDSF) of four varieties decreased under the high temperature. But SDSF of 7 varieties like as Baekjung, Suan, Hojoong, Jojoong, Uri, Shinmichal and Shinmichal 1 was increased. The lightness (L) of wheat flour derived from high temperature treated wheat was darker than non-treated wheat. As a result of this research, we confirmed that agricultural traits and qualities decreased in heat damaged wheat.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.333-333
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• 2011

We have investigated the breakdown properties in liquids by high voltage pulse system. High voltage pulse power system is consisted of the Marx-generator with two capacitors (0.5 ${\mu}F$, withstanding voltage is 40 kV), to which the charging voltage can be applied to maximum 30 kV DC, spark gap switch and charging resistor of 20 $M{\Omega}$. We have made use of tungsten pin electrodes of anode-cathode (A-K), which are immersed into the liquids. The breakdown voltage and current signals are measured by high voltage probe (Tektronix P6015A) and current monitor (IPC CM-1.S). Especially the high speed breakdown or plasma propagation characteristics in the pulsed A-K gap have been investigated by using the high speed ICCD camera. We have measured the electron temperature through the Boltzmann plot method from the breakdown spectrums. Here the A-K gap has been changed by 1 mm, 2 mm, and 3 mm. The used liquids are distilled water and solution of salt (0.9 %). The output voltage and current signals at breakdown in distilled water are shown to be bigger than those in saline solution. The breakdown voltage and current characteristics in liquids will be discussed in accordance with A-K gap distances. It is also found that the electron temperatures and plasma densities in liquids are decreased in conformity with A-K gap.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.168-168
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• 2008

Dimension of a transistor has rapidly shrunk to increase the speed of device and to reduce the power consumption. However, it is accompanied with several problems like direct tunneling through the gate dioxide layer and low conductivity characteristic of poly-Si gate in nano-region. To cover these faults, study of new materials is urgently needed. Recently, high dielectric materials like $Al_2O_3$, $ZrO_2$, and $HfO_2$ are being studied for equivalent oxide thickness (EOT). However, poly-Si gate is not compatible with high-k materials for gate-insulator. Poly Si gate with high-k material has some problems such as gate depletion and dopant penetration problems. Therefore, new gate structure or materials that are compatible with high-k materials are also needed. TiN for metal/high-k gate stack is conductive enough to allow a good electrical connection and compatible with high-k materials. According to this trend, the study on dry etching of TiN for metal/high-k gate stack is needed. In this study, the investigations of the TiN etching characteristics were carried out using the inductively coupled $BCl_3$-based plasma system and adding $Cl_2$ gas. Dry etching of the TiN was studied by varying the etching parameters including $BCl_3$/Ar gas mixing ratio, RF power, DC-bias voltage to substrate, and $Cl_2$ gas addition. The plasmas were characterized by optical emission spectroscopy analysis. Scanning electron microscopy was used to investigate the etching profile.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.1036-1038
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• 2005

고에너지물리학의 거대강입자충돌실험(LHC)에서 생산되는 데이터양은 연간 $12\~14$PetaByte이므로 이러한 데이터를 분석하기 위해서 기존의 전산개념으로는 자료 처리하기가 불가능하다. 그러므로 새로운 개념의 대용량 자료 처리를 위한 분산 처리 시스템이 필요하며, 이와 관련하여 고에너지 물리 실험분야에서는 계층적 구조의 Tier-0, 1, 2의 지역데이터센터의 개념 및 그리드 개념을 도입하였다. LCG(LHC Computing Grid) 및 OSG(Open Science Grid)등의 그리드 팜을 이용하여 자료를 처리한다.

• ETRI Journal
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• v.42 no.4
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• pp.527-533
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• 2020

High-level synthesis (HLS), which automatically synthesizes a register-transfer level (RTL) circuit from a behavioral description written in a high-level programming language such as C/C++, is becoming a more popular technique for improving design productivity. In general, HLS tools often generate a circuit with a larger area than those of hand-designed ones. One reason for this issue is that HLS tools often generate multiple instances of the same module from a function. To eliminate such a redundancy in circuit area in HLS, HLS tools are capable of sharing modules. Function-level module sharing at a behavioral description written in a high-level programming language may promote function reuse to increase effectiveness and reduce circuit area. In this paper, we present two HLS techniques for module sharing at the function level.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.227-230
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• 1991

This paper discussed with a voltage-fed Type high frequency inverter with simple main circuit and high efficiency. The proposed inverter is proper as a high frequency inverter of home applications applied with induction heating principle of high frequency. and also, this paper proposed an computer analysis for resonant L and C.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.116-118
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• 2006

Recently more attention is paid to the development of high-speed permanent magnet (PM) synchronous generators driven by gas-turbine, since they are conductive to high efficiency, high power density, small size, low weight, simple mechanical construction, easy maintenance and good reliability. In this paper, the performance analysis of a high-speed PM synchronous generator for military power application considering the min-max operating speed is presented. The output current and power versus DC-link voltage loci can obtained by solving the PM machine's steady-state equations for variable resistive load.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.318-320
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• 2003

This paper presents a novel single-stage high frequency resonant DC-DC converter using zero voltage switching with high input power factor. The proposed high frequency resonant converter integrates half-bridge boost rectifier as power factor corrector (PFC) and half-bridge resonant converter into a single stage. The input stage of the half-bridge boost rectifier is working in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. So that a high power factor is achieved naturally. Simulation results through the Pspice have demonstrated the feasibility of the Proposed DC-DC converter. This proposed converter will be able to be practically used as a power supply in various fields as induction heating applications, DC-DC converter etc.

• Korean Journal of Mathematics
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• v.20 no.1
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• pp.33-46
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• 2012

Using the direct method, we prove the Hyers-Ulam stability of the orthogonally additive-quartic functional equation (0.1) $f(2x+y)+f(2x-y)=4f(x+y)+4f(x-y)+10f(x)+14f(-x)-3f(y)-3f(-y)$ for all $x$, $y$ with $x{\perp}y$, in non-Archimedean Banach spaces. Here ${\perp}$ is the orthogonality in the sense of R$\ddot{a}$tz.