• Title/Summary/Keyword: I/O

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Synthesis of $Ni_2Y$ magnetic particles by coprecipitation method (공침법에 의한 $Ni_2Y$ 자성 분말의 합성)

  • 김한근;사공건
    • Electrical & Electronic Materials
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    • v.9 no.9
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    • pp.906-910
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    • 1996
  • Ferroxplana N $i_{2}$Y(B $a_{2}$N $i_{2}$F $e_{12}$ $O_{22}$ ) magnetic particles, which is one of the hexagonal ferrite were synthesized by a coprecipitation method. The coprecipitates were prepared by adding aqueous solution of BaC $I_{2}$ - 2 $H_{2}$O, NiC $I_{2}$ - 6 $H_{2}$O and FeC $I_{3}$ - 6 $H_{2}$O(of which the mole ratio is $Ba^{+2}$ : N $i^{+2}$ : F $e^{3+}$= 1 : 1 : 6) to a mixture of NaOH and N $a_{2}$C $O_{3}$. The shape of Ferroxplana N $i_{2}$Y magnetic particles obtained at 1, 100(.deg. C) was hexagonal plate-like, average particle size and aspect ratio were 2(.mu.m) and 7, respectively.y.

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TDX-1 시스팀의 I/O Device 처리방식에 관한 소고

  • Hwang, Seung-Hoe;Kim, Hak-Seong;O, Chang-Hwan
    • ETRI Journal
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    • v.7 no.2
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    • pp.26-33
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    • 1985
  • 본고는 교환기에 사용되는 각종 I/O device를 분류한 후 일반적인 I/O device의 처리방식을 서술하였으며, ANSI에서 개발한 이들 방식의 implementation technique를 TDX-1 시스팀의 storage architecture에 적용시키는 방안을 제시하였다.

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Power Loss and Electro-Magnetic Characteristics of Ni-Cu-Zn Ferrites (Ni-Cu-Zn페라이트의 損失과 磁性 特性)

  • Otsuki, E.;Kim, Jeong-Su
    • Resources Recycling
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    • v.13 no.6
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    • pp.37-42
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    • 2004
  • The power loss analysis was carried out for Ni-Cu-Zn ferrite sample with different content of NiO and ZnO. The power loss, Pcv decreases monotonically with increasing temperature and attains to a certain value at around 100~120 degrees Celsius. The frequency dependence of Pcv can be explained by Pcv~f$^n$, and n is independent of the frequency, f up to 1 MHz. The Pcv decreases with an increase in ZnO/NiO. The Pcv was separated to hysteresis loss(Ph) and residual loss(Pcv-Ph). The temperature characteristics and compositional dependence of Pcv can be attributed to the Ph, while Pcv-Ph is not affected by both temperature and ZnO/NiO. By analyzing temperature and composition dependence of Ph and initial permeability, ${\mu}_i$ like following equations could be formularized. ${\mu}_i{\mu}_0=I_s^2/(K_I+b{\sigma}_0{\lambda}_s)$ Wh=13.5(I$_s^2/{\mu}_i{\mu}_0)$ Where ${\mu}_0$ is permeability of vacuum, I$_s$ is saturation magnetization, K$_I$ is anisotropy constant, $s_0$ is internal heterogeneous stress, ${\lambda}_s$ is magnetostriction constant, b is unknown constant, and Wh is hysteresis loss per one cycle of excitation (Ph=Wh${\times}$f). Steinmetz constant of Ni-Cu-Zn ferrite, m=1.64~2.2 is smaller than that of Mn-Zn ferrites, which suggests the difference of loss mechanisms between these materials.

Petrology of the Cretaceous Volcanic Rocks in Eastern Part of the Kyeongsan Caldera (경산칼데라 동부지역에 분포하는 백악기 화산암류의 암석학적 특징)

  • Park Sung-Ok;Jang Yun-Deuk;Hwang Sang-Koo;Kim Jeong-Jin
    • The Journal of the Petrological Society of Korea
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    • v.15 no.2 s.44
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    • pp.90-105
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    • 2006
  • The Cretaceous volcanic rocks in the study area represented by andesitic rocks occupy eastern part of the Kyeongsan Caldera. The volcanic rocks comprise andesite I, andesitic tuff, andesite II, and andesitic tuff breccia in their stratigraphic succession, and andesitic porphyry. Andesite I is distinguished from andesite II in their color, texture, phenocryst mineralogy and petrochemisty. In outcrops, andesite I is compact and dark-green, and andesite II is brick red in color and porphyritic in texture. In their phenocryst mineralogy, andesite I contains olivine phenocryst in addition to plagioclase and pyroxene which occur in both of andesites. Compared to andesite II, andesite I is higher in $SiO_2$ and $K_2O$ contents and lower in CaO, MgO, MnO, $TiO_2,\;Fe_2O_3$, and $P_2O_5$. Major elements petrochemistry shows that magma series of the volcanic rocks spread widely from calc-alkaline to alkaline series. On the other hand, immobile trace elements petrochemistry shows that the magma series is calc-alkaline without exception, suggesting that the volcanics has experienced more or less alkali enrichment after their eruption. Trace element diagrams for discrimination of tectonic setting show that the volcanics of the study area might be originated from calc-alkaline continental volcanic arc.

Performance Evaluation and Analysis of NVM Storage for Ultra-Light Internet of Things (초경량 사물인터넷을 위한 비휘발성램 스토리지 성능평가 및 분석)

  • Lee, Eunji;Yoo, Seunghoon;Bahn, Hyokyung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.6
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    • pp.181-186
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    • 2015
  • With the rapid growth of semiconductor technologies, small-sized devices with powerful computing abilities are becoming a reality. As this environment has a limit on power supply, NVM storage that has a high density and low power consumption is preferred to HDD or SSD. However, legacy software layers optimized for HDDs should be revisited. Specifically, as storage performance approaches DRAM performance, existing I/O mechanisms and software configurations should be reassessed. This paper explores the challenges and implications of using NVM storage with a broad range of experiments. We measure the performance of a system with NVM storage emulated by DRAM with proper timing parameters and compare it with that of HDD storage environments under various configurations. Our experimental results show that even with storage as fast as DRAM, the performance gain is not large for read operations as current I/O mechanisms do a good job hiding the slow performance of HDD. To assess the potential benefit of fast storage media, we change various I/O configurations and perform experiments to quantify the effects of existing I/O mechanisms such as buffer caching, read-ahead, synchronous I/O, direct I/O, block I/O, and byte-addressable I/O on systems with NVM storage.

KIM YŎNG AND NEW POCH'ŎN'GA PUBLISHED IN 1792 (김영(金泳)과 1792년에 출간된 새로운 『보천가(步天歌)』)

  • Ahn, Sang-Hyeon
    • Publications of The Korean Astronomical Society
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    • v.26 no.4
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    • pp.147-157
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    • 2011
  • I found evidence that Kim Y$\breve{o}$ng (金泳, 1749-1817) is the author of the Korean Poch'$\breve{o}$n'ga with New Charts published in 1792 by the Astronomical Bureau of the Chos$\breve{o}$n dynasty. I reconstructed a history of Kim Y$\breve{o}$ng from various literature remained in other persons' anthologies and governmental records. My findings on the author and publication year can help to solve the problem on the origin of star charts in the Poch'$\breve{o}$n'ga with New Charts. I also considered the changes of Chinese Bu-Tian-Ge and their star charts after Chongzhenglishu (崇禎曆書). I found that the new charts in the book of Huantiantushuo published by Li Mingche (李明徹, 1751-1832) in 1819 are approximately the same to those in the Poch'$\breve{o}$n'ga with New Charts by Kim Y$\breve{o}$ng in 1792.

Adaptable I/O System based I/O Reduction for Improving the Performance of HDFS

  • Park, Jung Kyu;Kim, Jaeho;Koo, Sungmin;Baek, Seungjae
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.6
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    • pp.880-888
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    • 2016
  • In this paper, we propose a new HDFS-AIO framework to enhance HDFS with Adaptive I/O System (ADIOS), which supports many different I/O methods and enables applications to select optimal I/O routines for a particular platform without source-code modification and re-compilation. First, we customize ADIOS into a chunk-based storage system so its API semantics can fit the requirement of HDFS easily; then, we utilize Java Native Interface (JNI) to bridge HDFS and the tailored ADIOS. We use different I/O patterns to compare HDFS-AIO and the original HDFS, and the experimental results show the design feasibility and benefits. We also examine the performance of HDFS-AIO using various I/O techniques. There have been many studies that use ADIOS, however our research is expected to help in expanding the function of HDFS.

High Conductive Transparent Electrode of ITO/Ag/i-ZnO by In-Line Magnetron Sputtering Method (인-라인 마그네트론 스퍼터링 방법에 의한 고전도성 ITO/Ag/i-ZnO 투명전극)

  • Kim, Sungyong;Kwon, Sangjik
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.3
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    • pp.33-36
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    • 2015
  • It has increased several decades in the field of Indium Tin Oxide (ITO) transparent thin film, However, a major problem with this ITO thin film application is high cost compared with other transparent thin film materials[1]. So far, in order to overcome this disadvantage, we show that a transparent ITO/Ag/i-ZnO multilayer thin film electrode would be more cost-effective and it has not only highly transparent but also conductive properties. The aim of this research has therefore been to try and establish how ITO/Ag/i-ZnO multilayer thin film would be more effective than ITO thin film. Herein, we report the properties of ITO/Ag/i-ZnO multilayer thin film by using optical spectroscopic method and measuring sheet resistance. At a certain total thickness of thin film, sheet resistance of ITO/Ag/i-ZnO multilayer was drastically decreased than ITO layer approximately $40{\Omega}/{\Box}$ at same visible light transmittance. (minimal point $5.2{\Omega}/{\Box}$). Tendency, which shows lowly sheet resistive in a certain transmittance, has been observed, hence, it should be suitable for transparent electrode device.

The Accessibility Improvement of Grid Data I/O based on GASS (GASS 기반 그리드 데이터 I/O의 접근성 개선에 관한 연구)

  • Kwon, Oh-Kyoung;Park, Hyoung-Woo;Lee, Sang-San
    • Proceedings of the Korea Information Processing Society Conference
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    • 2002.11a
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    • pp.147-150
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    • 2002
  • 인터넷 기반의 컴퓨팅 환경이 발전함에 따라 자원과 정보의 공유를 위한 그리드 컴퓨팅이 나타나게 되었다. 그리드 컴퓨팅에서는 그리드 응용 수행시 프로그램과 데이터간의 위치가 다르고 분산되어 있는 경우가 많다. 현재 그리드 미들웨어 시장 표준인 글로버스 툴킷(Globus Toolkit$^{TM}$)에서 사용하는 GASS와 같은 그리드 I/O 시스템들이 원격에 있는 관련 데이터들을 로컬 시스템의 데이터에 접근하는 것처럼 처리하는 것을 지원한다. 그러나 GASS(Global Access to Secondary Storage)에서는 원격지의 파일 시스템의 접근시 URL을 이용하는데, 그리드 환경에서의 I/O을 위한 파일 시스템은 복수의 파일 형태로 분산되어있기 때문에 하나의 그리드 응용을 수행할 때 URL 을 동적으로 바꿔저야 하는 문제점을 갖고 있다. 본 논문에서는 URL 보다 상위 개념의 주소 체계인 URI 을 도입하고 이를 RSL과 연계하여 분산 환경의 그리드 I/O에서도 간을 주소 형태로 I/O 처리가 가능하는 등 효율적인 그리드 I/O를 위한 GASS 개선 방안을 제시 한다.

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Spectroscopic Analyses of Rose Bengal Sensitized and NaI Supersensitized Photocurrent (Rose Bengal 감응 및 NaI 초감응 광전류의 분광학적 분석)

  • Yoon Kil-Joong;Min Hyun-Jin;Kim Kang-Jin
    • Journal of the Korean Chemical Society
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    • v.36 no.1
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    • pp.107-112
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    • 1992
  • Electron injection from excited rose bengal into the conduction band of a thin film of $SnO_2$ semiconductor in acetonitrile was investigated in an electrochemical cell, ITO/$SnO_2$/rose bengal, NaI or $I_2$, $NaClO_4$/Pt. It was observed that NaI enhanced the supersensitized photocurrent, followed by the slow reduction, whereas $I_2$ yielded a fast decaying photocurrent. Spectroscopic analyses of the dye solution containing NaI revealed that electron is transferred to the $SnO_2$ electrode from the reduced rose bengal and iodide is responsible for the reduction of the dye in triplet state. However $I_2$ appears to possess neither the reducing ability of the oxidized dye nor the retardation of the dehalogenation of RB.

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