• 제목/요약/키워드: Pohang Formation

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An Ad hoc Scatternet Formation Algorithm on Bluetooth

  • Kim, Dong-Kyoo;Choi, Yun-Jong;Park, Poo-Gyeon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.2418-2423
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    • 2003
  • Bluetooth is a low cost, license-free, and short-range radio communication technology. This gradually gaining de facto standard for applications of a personal area network over the world. To make it further popular, it should provide faster and more flexible connectivity than that supported by the existing bluetooth specification. This paper proposes a new Ad hoc scatternet formation algorithm that supports those connectivity under circumstances such that devices can not get in direct touch with one another; say out-of-bounded case. It also maintains the character that those connectivity minimizes the number of piconets when all devices are in the communication range with one another, say in-bounded case, as pervious works.

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Inhomogeneous Growth of PtSi Studied by Spatially Resolved Photoelectron Spectroscopy

  • Kumar, Yogesh;Lee, Kyoung-Jae;Yang, Mihyun;Ihm, Kyuwook;Hwang, C.C.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.149.1-149.1
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    • 2013
  • Noble metal silicides are widely used in silicon based microelectronic and optoelectronic devices. Among them, as compared to other silicides, structural and electronic properties of platinum silicide (PtSi) are found to be less sensitive to change in its dimensions. PtSi is known to overcome the junction spiking problems of Al-Si contacts. Present study is regarding the spatial evolution of platinum silicide in Pt/SiOx/Si. Scanning photoelectron emission microscopy (SPEM) was used for this purpose. SPEM images were obtained for pristine samples and after an annealing at $500^{\circ}C$ for 1 hr. Core-level spectra were recorded at different points in SPEM images contrasted by the intensity of Pt 4f7/2. Both Pt 4f and Si 2p spectra reveal the formation of PtSi after annealing. However, in contrast to earlier reports, PtSi formation is found to be non-uniform confirmed by the SPEM images and from the core level spectra taken at different intensity points.

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한반도의 제3기 분지와 포항분지내 지질구조 연구 (Tertiary basin in Korean peninsula and the study of geologic structure at Pohang basin)

  • 이병주
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 암반역학위원회 학술세미나 논문집
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    • pp.3-17
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    • 2002
  • Tertiary Pohang basin distributed in south weatern part of the korean peninsula, is composed of Chunbuk formation as the basal conglomerate, Hakjon formation, Duho formation and intrusive basalt which is 15 Ma by absolute age data. The basement of the basin is represented by Cretaceous sedimentary rocks, Hakjon welded tuff and Chilpo welded tuff and rhyolite. The fault systems at the basement of the Pohang basin are consist of NNE direction fault, WNW to EW trend fault. NNE fault is not only strike-slip fault but also normal fault. n fault has sinistral strike-slip sene and the EW fault is strike-slip and normal fault. In the Tertiary basin, the fault system is represented by nm strike-slip fault, EW normal fault and NNE thrust fault. By these fault relationships and geometries, it is interpreted that NNE sinistral strike-slip fault and nomal fault have acted at Creceous times. At Tertiary tines, NNE dextralstrike-slip fault and EW normal fault has created. Progressively Tertiary Pohang basin was influenced by the trenspression to make thrust fault and fold, namely as inversion tectonics.

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Influence of Selective Oxidation Phenomena in CGLs on Galvanized Coating Defects Formation

  • Gong, Y.F.;Birosca, S.;Kim, Han S.;De Cooman, B.C.
    • Corrosion Science and Technology
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    • 제7권1호
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    • pp.1-5
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    • 2008
  • The gas atmosphere in continuous annealing and galvanizing lines alters both composition and microstructure of the surface and sub-surface of sheet steel. The formation and morphology of the oxides of alloying elements in High Strength Interstitial Free (HS-IF), Dual Phase (DP) and Transformation-Induced Plasticity (TRIP) steels are strongly influenced by the furnace dew point, and the presence of specific oxide may result in surface defects and bare areas on galvanized sheet products. The present contribution reviews the progress made recently in understanding the selective formation of surface and subsurface oxides during annealing in hot dip galvanizing and conventional continuous annealing lines. It is believed that the surface and sub-surface composition and microstructure have a pronounced influence on galvanized sheet product surface quality. In the present study, it is shown that the understanding of the relevant phenomena requires a combination of precise laboratory-scale simulations of the relevant technological processes and the use of advanced surface analytical tools.

DESIGN AND TEST RESULTS ON A 45-KV PULSED POWER MODULATOR FOR A 1.5-MW MAGNETRON APPLICATION OF KSTAR LHCD

  • Jang, Sung-Duck;Son, Yoon-Gyu;Oh, Jong-Seok;Bae, Young-Soon;Cho, Moo-Hyun;NamKung, Won
    • Nuclear Engineering and Technology
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    • 제38권8호
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    • pp.785-792
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    • 2006
  • The microwave heating system of KSTAR consists of ECH and LHCD. ECH and LHCD offer the benefits ofa reliable operation at the start of plasma formation and a non-inductive current drive durable steady state operation, respectively. LHCD uses a C-band microwave system with a frequency of 5 GHz. A pulsed power modulator with a power of 3.6 MW, $4{\mu}S$, 200 pps is required to drive the high-powered magnetron. The development of a pulse modulator with 1:4 pulse transformers is the focus of the research in this study. The peak power handling capability is 3.6 MW (45 kV, 90 A at load side with a pulse width of $4{\mu}S$). This paper describes the system overview and test results of the pulsed modulator. In particular, a simulated waveform is compared with the tested waveform.

Fabrication of Metal Nanohoneycomb Structures and Their Tribological Behavior

  • Kim, Sung-Han;Lee, Sang-Min;Choi, Duk-Hyun;Lee, Kun-Hong;Park, Hyun-Chul;Hwang, Woon-Bong
    • Advanced Composite Materials
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    • 제17권2호
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    • pp.101-110
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    • 2008
  • Metal nanohoneycomb structures were fabricated by E-beam evaporation and a two-step anodization process in phosphoric acid. Their tribological properties of adhesion and friction were investigated by AFM in relation to the pore size of the nanohoneycomb structures. Variations of the adhesive force are not found with pore size, but formation of the pore greatly reduces the adhesive force compared to the absence of pore structure. The coefficient of friction increased nonlinearly with pore size, due to surface undulation around the pore. Tribological properties do not differ greatly between the original nanohoneycomb structure and the metal nanohoneycomb structure.

Synthesis of Monodispersed Barium Titanate Nanopowders by Alkoxide-Hydroxide Sol-Precipitation Method

  • Yoon, Song-Hak;Kim, Min-Gyu;Shin, Nam-Soo;Kim, In-Sung;Baik, Sung-Gi
    • 한국세라믹학회지
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    • 제43권11호
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    • pp.710-714
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    • 2006
  • Barium titanate nanoparticles were synthesized under N$_2$ atmosphere by the hydrolysis and condensation of barium hydroxide octahydrate and titanium (IV) isopropoxide. The synthesized particles were aggregates of nanosized primary particles. The primary particles of about 20-50 nm in diameter became building blocks of larger secondary particles, which are in most cases spherical in shape. The size and morphological evolution of secondary particles are strongly related to the precursor concentration. The observations suggest that formation and control of secondary particles is an essential step in the alkoxidehydroxide sol-precipitation process to obtain monodispersed barium titanate nanopowders.

Fossil Albizia Legume (Mimosaceae) from the Miocene Duho Formation of the Yeonil Group in the Pohang Area, Korea

  • Kim Jong-Heon
    • 한국지구과학회지
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    • 제26권2호
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    • pp.166-171
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    • 2005
  • Fossil legumes of Albizia miokalkora Hu et Chaney (Mimosoideae) were found in the Miocene Duho Formation of the Yeonil Group distributed along the coast of Yeonil Bay in the Pohang area. The legume is flat and long and has 5-7 rounded seeds. The legumes of Albizia miokalkora are rare in the Cenozoic floras of the world and only known to Middle Miocene of East Asia. The fossil Albizia may use one of the important taxa to construct the biogeographic history of East Asia. This discovery is the first record of Albizia from the Neogene strata of Korea.