• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.161-168
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• 2011

This paper provides the performance measurement and analysis of Wireless LAN IEEE 802.11 in a mobile environment. The performances of IEEE802.11b/g and IEEE802.11p designed for Vehicle-to-Vehicle(V2V) communication are measured and analyzed. Diameter of communication and link access time are compared under variation of speed of the vehicle.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10A
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• pp.816-822
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• 2011

This paper provides the performance measurement and analysis of Wireless LAN IEEE 802.11 in a mobile environment. The performance of IEEE802.11b/g and IEEE802.11p that is designed for Vehicle-to-Vehicle(V2V) communication is measured and analyzed. Diameter of communication, link access time and delay are measured as vehicle's speed varies. Also, the performance is checked in a situation that the load to network varies. In conclusion, the futher research topics are discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.682-684
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• 2003

In this paper, we have designed the p-type SiGe MOSFET and analyzed the electrical characteristics over the temperature range of 300K and 77K. When the gate voltage is biased to -1.5V, the threshold voltage values are -0.97V and -1.15V at room temperature and 77K, respectively. We know that the operating characteristics of SiGe MOSFET is superior to the basic Si MOSFET which the threshold voltage is -1.36V.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.474-477
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• 2003

In this paper, we have designed the p-type SiGe MOSFET and analyzed the electrical characteristics over the temperature range or 300K and 77K. When the gate voltage is biased to -1.5V, the threshold voltage values are -0.97V and -1.15V at room temperature and 77K, respectively. We know that the operating characteristics of SiGe MOSFET is superior to the basic Si MOSFET which the threshold voltage is -1.36V.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.773-776
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• 2003

In this paper, we have designed the p-type SiGe MOSFET and analyzed the electrical characteristics. When the gate voltage is biased to -1.5V, the threshold voltage values are -0.97V and -1.15V at room temperature and 77K, respectively. We know that the operating characteristics of SiGe MOSFET is superior to the basic Si MOSFET which the threshold voltage is -1.36V.

• Journal of IKEEE
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• v.26 no.2
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• pp.329-332
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• 2022

In this paper, retention characteristics of lateral charge migration according to parameters of 3D NAND flash memory to which ferroelectric (HfO₂) structure is applied and ∆V_th were analyzed. The larger the P_s, the greater maximum polarization possible in ferroelectric during Programming. Therefore, the initial V_th increases by about 1.04V difference at P_s 70µC/cm² than at P_s 25µC/cm². Also, electrons trapped after the Program operation causes lateral charge migration over time. Since ferroelectric maintains polarization without applying voltage to the gate after Programming, regardless of P_s value, polarization increases as P_r increases and the ∆V_th due to lateral charge migration becomes smaller by about 1.54V difference at P_r 50µC/cm² than P_r 5µC/cm².

• Journal of Advanced Navigation Technology
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• v.23 no.1
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• pp.36-43
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• 2019

In this paper, a novel channel access scheme for the next-generation vehicle to anything (V2X) system based on IEEE 802.11p standard which is applied to recent connected car technologies is suggested and analyzed. The proposed scheme proposes a channel access method utilizing OFDMA multi-user transmission for IEEE 802.11p based system. In this paper, the authors examine geographical distance and network area performance of IEEE 802.11p system and the proposed scheme. Results of this research show that the proposed scheme is quite suitable for improving conventional V2X standards and systems. This paper also provides mathematical analysis and simulation results of the conventional IEEE 802.11p system and the proposed scheme.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.371-379
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• 2008

In this study, seismic elastic wave and dynamic elastic modulus properties are investigated by down-hole seismic tests that were applied to the 11 gneiss area. The research results show that the realtionship between the two properties are $V_s=0.5589{\times}V_p$ in gneiss. The relationship between the two properties are separated into two groups. Group 1 is influenced mainly by the specific gravity of rock, but group 2 is influenced mainly by the joint aperture. As weathering progresses, group 1 clearly shows a decreasing tendency. In fresh and slightly weathered rock-mass, correlations between $V_p$ and dynamic elastic modulus is expressed in linear line but in moderately-highly weathered rock-mass, correlations between $V_p$ and dynamic elastic modulus is expressed curve as a quadratic function. Correlations between $V_s$ and dynamic elastic modulus are analyzed similar with a $V_p$ case.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.95-95
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• 2008

본 연구에서는 SiGe p-MOSFET을 제작하여 I-V 특성과 게이트 길이, $V_D$, $V_G$의 변화에 따른 저주파 노이즈특성을 측정하였다. Si 기판위에 성장한 $Si_{0.88}Ge_{0.12}$으로 제작된 SiGe p-MOSFET의 채널은 게이트 산화막과 20nm 정도의 Si Spacer 층으로 분리되어 있다. 게이트 산화막은 열산화에 의해 70$\AA$으로 성장되었고, 게이트 폭은 $25{\mu}m$, 게이트와 소스/드레인 사이의 거리는 2.5때로 제작되었다. 제작된 SiGe p-MOSFET은 빠른 동작 특성, 선형성, 저주파 노이즈 특성이 우수하였다. 제작된 SiGe p-MOSFET의 ESD 에 대한 소자의 신뢰성과 내성을 연구하기 위하여 SiGe P-MOSFET에 ESD를 lkV에서 8kV까지 lkV 간격으로 가한 후, SiGe P-MOSFET의 I-V 특성과 게이트 길이, $V_D$, $V_G$의 변화에 따른 저주파 노이즈특성 변화를 분석 비교하였다.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.621-627
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• 2008

In this study, a technique of speciation and determination of the trace inorganic arsenic(As(III) and As(V)) in water sample using HPLC-DRC-ICP-MS has been developed. Isocratic mobile phase of 10 mM ammonium nitrate and 10 mM ammonium phosphate monobasic was used and methanol(5 v/v%) was used as flushing solvent. Selection of the best flow rate of reaction gas, O$_2$, and optimization of the parameters such as pH and flow rate of mobile phase, and injection volume of sample for the separation and detection of arsenic species were carried out. The oxygen flow rate of 0.5 mL/min, pH of 9.4 and flow rate of 1.5 mL/min of mobile phase, and injection volume of sample of 100 $\mu$L were found to be the best parameters for the speciation and determination of arsenic species. The analytical features of the method were detection limit 0.10 and 0.08 $\mu$g/L, precision(RSD) 4.3% and 3.6%, and recovery 95.2% and 96.4% for As(III) and As(V), respectively. Analysis time was 4 minutes per sample. Linear calibration graphs with r$^2$ = 0.998 were obtained for both As(III) and As(V). Speciation analysis of arsenic species in the raw water samples collected from the tributary streams to Han River and main stream of Paldnag were performed by the proposed method. The concentrations of As(III) ranged from 0.10 to 0.22 $\mu$g/L and As(V) concentrations ranged from 0.44 to 1.19 $\mu$g/L, and 93.5% of total arsenic was found to be As(V).