• Title/Summary/Keyword: Pohang Korea

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Result of CO2 Geological Storage Site Survey for Small-scale Demonstration in Pohang Basin, Yeongil Bay, SE Korea (영일만 해상 포항분지 소규모 CO2 지중저장 실증을 위한 부지 탐사 결과)

  • Shinn, Young Jae;Kwon, Yi Kyun;Yoon, Jong-Ryeol;Kim, Byoung-Yeop;Cheong, Snons
    • The Journal of Engineering Geology
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    • v.28 no.2
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    • pp.161-174
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    • 2018
  • $CO_2$ storage site for small-scale demonstration has been investigated in Yeongil Bay, Pohang, SE Korea, using seismic survey and exploration well data. We found a potential storage formation consisting mainly of conglomerate and sandstone. The storage formation unconformably overlies volcanic basement rocks that are located in a depth from 650 to 950 m (below sea level). The depth of the storage formation is suitable for injecting supercritical $CO_2$ in the Pohang Basin. The average thickness of the storage formation is about 123 m, which possibly provides sufficient capacity at the level of small-scale storage demonstration. The overlying fine-grained deposits consist mainly of marine hemipelagic muds and interlayered turbidite sands. The overlying formation is considered as a good seal rock that is over 600 m thick and widely distributed in the onshore and offshore portions of the basin. NNE-trending faults found in the study area likely formed at basement level, probably not continue to seafloor. Such faults are interpreted as syndepositional faults involved to the basin initiation. This study reveals that the offshore area of the Pohang Basin contains deep geological formations suitable for small-scale $CO_2$ storage demonstration.

A Framework for Illustration of Buffer Overflow Vulnerability (버퍼 오버플로우 취약점 증명을 위한 프레임워크)

  • Kwon, O-Hoon;Min, Byung-Gil;Kim, Jong;Kim, Soo-Yong;Han, Kwang-Taek
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 2002.11a
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    • pp.334-337
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    • 2002
  • 특정 프로그램의 취약점 여부를 판단하기 위해 프로그램의 버전이나 작동여부를 점검하여 검증하는 방식이 많이 사용되었다. 하지만, 이 방식은 취약점 증명에 영향을 미치는 많은 요소들을 모두 고려할 수 없기 때문에 점검 결과가 부정확하다는 단점이 있다. 최근에는 이를 보완하기 위해 해당 프로그램에 실제로 공격을 수행하고 그 성공 여부를 통해 취약점 여부를 검증하는 방식이 사용되고 있다. 이렇게 실제 공격코드를 이용하는 방법은 정확한 결과를 얻을 수 있다는 장점이 있지만, 공격코드를 구현하기 어렵다는 단점이 있다. 본 논문에서는 공격코드들의 구조를 분석하여 공통된 부분들을 모듈화하고 이를 재사용함으로써 다양한 취약점을 정확하게 점검할 수 있고, 새로운 취약점에 대해서도 쉽게 확장할 수 있는 취약점 증명을 위한 프레임워크를 제시한다.

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Hyperpolarized 129 NMR Study of TiO2 Nanotubes

  • Lee, Sang-Man;Lee, Soon-Chang;Mehrotra, Vandana;Kim, Hae-Jin;Lee, Hee-Cheon
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.511-514
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    • 2012
  • A continuous flow hyperpolarized (HP) $^{129}Xe$ NMR spectroscopy was employed for the first time to investigate $TiO_2$ nanotubes (Ti-NTs) synthesized from commercial nanoparticles with different reaction times. A single peak attributing to channels for Ti-NTs was observed for variable temperature HP $^{129}Xe$ NMR spectra. It was also noted that there is alteration in value for heat of adsorption, ${\Delta}H$ from $12.6{\pm}1.3$ to $16.4{\pm}0.4kJ/mol$ and variation in chemical shift of the xenon adsorbed in channels, ${\delta}_s$ from $120{\pm}2\sim135{\pm}9ppm$ which were closely correlated to channel length and it was shown that P25-24 Ti-NTs with longest channel is most favorite Ti-NTs for Xe adsorption.

Hysteresis-free organic field-effect transistors with ahigh dielectric strength cross-linked polyacrylate copolymer gate insulator

  • Xu, Wentao;Lim, Sang-Hoon;Rhee, Shi-Woo
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.11a
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    • pp.48.1-48.1
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    • 2009
  • Performance of organic field-effect transistors (OFETs) with various temperature-cured polyacrylate(PA) copolymer as a gate insulator was studied. The PA thin film, which was cured at an optimized temperature, showed high dielectric strength (>7 MV/cm), low leakage current density ($5{\times}10^{-9}\;A/cm^2$ at 1 MV/cm) and enabled negligible hysteresis in MIS capacitor and OFET. A field-effect mobility of ${\sim}0.6\;cm^2/V\;s$, on/off current ratio (Ion/Ioff) of ${\sim}10^5$ and inverse subthreshold slope (SS) as low as 1.22 V/decwere achieved. The high dielectric strength made it possible to scale down the thickness of dielectric, and low-voltage operation of -5 V was successfully realized. The chemical changes were monitored by FT-IR. The morphology and microstructure of the pentacene layer grown on PA dielectrics were also investigated and correlated with OFET device performance.

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Development of deep-seated geothermal energy in the Pohang area, Korea (경북 포항지역에서의 심부 지열수자원 개발 사례)

  • Song, Yoonho;Lee, Tae-Jong;Kim, Hyoung-Chan
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.693-696
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    • 2005
  • KIGAM (Korea Institute of Geoscience and Mineral Resources) launched a new project to develop the low-temperature geothermal water in the area showing high geothermal anomaly, north of Pohang city, for large-scale space heating. Surface geologic and geophysical surveys including Landsat 1M image analysis, gravity, magnetic, Magnetotelluric (MT) and controlled-source audio-frequency MT (CSAMT), and self-potential (SP) methods have been conducted and the possible fracture zone was found that would serve as deeply connected geothermal water conduit. In 2004, two test wells of 1.1km and 1.5km depths have been drilled and various kinds of borehole survey including geophysical logging, pumping test, SP monitoring, core logging and sample analysis have followed. Temperature of geothermal water at the bottom of 1.5km borehole reached over $70^{\circ}C$ and the pumping test showed that the reservoir contained huge amount of geothermal water. Drilling for the production well of 2 km depth is on going. After test utilization and the feasibility study, geothermal water developed from the production well is going to be provided to nearby apartments.

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Effect of Oscillatory Shear on the Interfacial Morphology of a Reactive Bilayer Polymer System

  • Kim, Hwang-Yong;Lee, Dong-Hyun;Kim, Jin-Kon
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.350-350
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    • 2006
  • We investigated, via atomic force microscopy and transmission electron microscopy, the effect of shear force on the interfacial morphology of a reactive bilayer polymer system composed of PS-mCOOH and PMMAGMA. It has been observed that in the absence of oscillatory shearing the roughness of the interface increased with reaction period, while at large values of ${\gamma}_{0}\;and\;{\omega}$ it became less than that observed in the absence of oscillatory shearing. This observation may be attributable to the possibility that oscillatory shearing might have hindered the diffusion of polymer chains, which are located away from the interface, to the interface of the layers. However, the effect of ${\gamma}_{0}\;and\;{\omega}$ on the roughness of the interface of (PS-mCOOH)/(PMMA-GMA) bilayer is found to be quite different.

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Investigation of Forming Stabilities Criteria in Hot Backward Extrusion of Ti-6Al-4V (Ti-6Al-4V합금의 열간 후방압출에 대한 성형 안정성 평가모델의 고찰)

  • Yeom Jong-Taek;Park Nho-Kwang;Lee You-Hwan;Shin Tae-Jin;Hwang Sang-Mu;Hong Sung-Suk;Shim In-Ok;Lee Chong-Soo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.7 no.3 s.18
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    • pp.84-92
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    • 2004
  • The metal forming behavior of Ti-6Al-4V tube during hot backward extrusion was investigated with various forming stabilities or instabilities criteria. that is, Ziegler's instability criterion, dynamic materials model(DMM) stability criteria and Rao's instability criterion. These approaches also were coupled to the internal variables generated from FE simulation. In order to validate the reliabilities of three criteria, hot backward extrusions for Ti-6Al-4V tube making were carried out with different backward extrusion designs. The useful model for predicting the forming defects was suggested through the comparison between experimental observations and simulation results.

Hydrogen Production in Biological Way as Alternative Energy (생물학적인 방법을 통한 대체 에너지로서의 수소생산)

  • Jo, Younghwa;Jo, ByungHoon;Cha, Hyung Joon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.19 no.1
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    • pp.57-63
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    • 2011
  • Development of alternative energy is needed as the fossil is started to be exhausted. This alternative energy should be environmental friendly and renewable. Currently, the alternative energy which gets the most attraction is hydrogen. Hydrogen can be produced by a number of different processes. Among those methods, hydrogen production in biological way is considered as the most environmental friendly method. However, productivity of biological hydrogen production is not good enough to be commercialized yet. Thus, many researchers are trying to improve productivity and yield of biohydrogen production. Here, progress in the diverse developmental approaches on biological hydrogen production, is reviewed.