• Title/Summary/Keyword: $Z_2$ distribution

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Soil microarthropods fauna in plantations of the Korean pine(Pinus koraiensis S. et Z.). 3. Population densities of soil microarthropods (잣나무 조림지내 토양미소절지동물상에 관한 연구. 3. 토양미소절지동물의 종류와 분포)

  • 권영립
    • Korean journal of applied entomology
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    • v.32 no.2
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    • pp.168-175
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    • 1993
  • This study investigated the composition and distribution of the soil microarthropods community in plantations of the Korean pine(Pinus Koraiensis SIEB. et ZUCC, the sudong area, Namyangju-gun, Korea) , which had been planted in different years. The soil samples intended to collect soil animals were taken monthly from June 1988 to July 1989. The composition of soil microarthropods community included Arachnida, Chilopoda, Insecta, Collembola, Diplopoda, Crustacea, and Symphyla. The Acarina were composed of 82.4% of Cryptostigmata, 8.0% of Mesostigmata, 7.9% of nymphs, and 1.7% of others. The Insecta included six orders including Hymenoptera(65.8%) and Diptera(13.9%). Population densities increased from when the plantations were first established until the planting were 25 years old, after which they declined. Population densities of the soil microarthropods were highest in July and lowest in January. The Collembola/Acarina ratio is 0.16 overall, and was highest in January and lowest in August.

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The Security Method for GIS Data (GIS 정보유통을 위한 보안방안)

  • Kim, Ji-Hong;Lee, Sang-Moo
    • Journal of Korea Spatial Information System Society
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    • v.2 no.1 s.3
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    • pp.83-90
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    • 2000
  • According to the development of Internet system recently, we focused in GIS data distribution and applications via internet rather than GIS data construction. Therefore in this paper, we present the necessity of security policy on GTS data. So we analyze the actual condition of GIS data through expert poll. We classify all of data used in GIS with the three security level : high level, middle level, low level. Finally we propose the proper security method on GIS data transfer and on GIS database access in accordance with progree of PKI project.

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A study on the stress Distributions and magnetic properties during Hot-pressing according to Strain Rate of Nd-Fe-B-Cu Alloys (Nd-Fe-B-Cu합금의 변형속도에 따른 열간압축시 응력분포와 자기적 특성에 관한 연구)

  • Park, J.D.;Jeung, W.Y.;Kwak, C.S.
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.2
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    • pp.146-153
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    • 1993
  • Thd specimens were melited in high frequency induction furnace. The samples for measurements were prepared by machining cylinder of 9.5mm diameter and 15mm height. These samples were then hot-pressed according to strain rate ( .epsilon. ). These samples were decanned and cut out, and subsequently heat treated at 1000 .deg. C for 4hours. These were investigated for the change of microstructure, domain pattern, X-ray diffraction and magnetic properties. The stress distributions in the specimens during compressing process were calculated by a finite element method program(SPID). The calculated stresses were effective stress( .sigma. $_{eff}$), compressive direction stress( .sigma. $_{z}$), and shear stress( .tau. $_{rz}$ ). These stresses were compared with the experimental data.a.a.

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Study of Morphology and Physical Properties of Indian Mallow(Abutilon avicennae Gaertner) Fibers by CLSM( I ) (CLSM을 이용한 어저귀 섬유의 형태학적 특성과 물성 연구(제1보) -인피 및 목질부 섬유를 이용한 한지제조-)

  • 정선화;조남석
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.34 no.2
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    • pp.61-66
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    • 2002
  • This study was carried out to investigate sheet properties of Indian mallow hanji, made by different pulping methods such as alkali and sulfomethylated pulpings, and different stock compositions, various mixing ratios of bast fiber and woody core fibers. Effect of morphological properties of pulp stocks on the sheet formation and their optical properties were also evaluated using an image analyzer and confocal laser scanning microscope(CLSM). In addition, the effect of fiber distribution index(FDI), which was calculated based on the image in a z-direction of a sheet from CLSM, on the sheet properties of Indian mallow hanji was discussed. The proposed FDI had a good correlation with various properties of paper, such as apparent density, opacity, tear index, breaking length and zero-span tensile strength. Especially, sulfomethylated pulp sheets'FDI was higher than alkali pulp sheets.

Hydrodynamics Simulation of the Off-Axis Cluster Merger Abell 115

  • Lee, Wonki;Kim, Mincheol;Jee, M. James
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.60.3-61
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    • 2018
  • Abell 115 is a renowned cluster merger at z=0.197. It exhibits an asymmetric X-ray distribution with cometary tails and a megaparsec-sized radio relic stretching in the northeastern direction from the core of the northern cluster. Many observations have concluded that this cluster merger has a large impact parameter, but there has been no numerical analysis on the structure of Abell 115. In this study, we simulate Abell 115 with Gadget2 N-body/SPH code to reproduce the X-ray and weak lensing features of Abell 115. We find a new plausible merger scenario of Abell 115, wherein the northern cluster is currently in an outgoing phase. The predicted X-ray emission has a similar morphology to the observed tail of the northern cluster. However, in order to reproduce the observed line-of-sight velocity and projected distance while maintaining the two systems gravitationally bound, the system should possess a large projection angle, which makes the shock look considerably more diffused than the observed radio relic.

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COSMIC RAY ACCELERATION AT BLAST WAVES FROM TYPE Ia SUPERNOVAE

  • Kang, Hye-Sung
    • Journal of The Korean Astronomical Society
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    • v.39 no.4
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    • pp.95-105
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    • 2006
  • We have calculated the cosmic ray(CR) acceleration at young remnants from Type Ia supernovae expanding into a uniform interstellar medium(ISM). Adopting quasi-parallel magnetic fields, gasdynamic equations and the diffusion convection equation for the particle distribution function are solved in a comoving spherical grid which expands with the shock. Bohm-type diffusion due to self-excited $Alfv\acute{e}n$ waves, drift and dissipation of these waves in the precursor and thermal leakage injection were included. With magnetic fields amplified by the CR streaming instability, the particle energy can reach up to $10^{16}Z$ eV at young supernova remnants(SNRs) of several thousand years old. The fraction of the explosion energy transferred to the CR component asymptotes to 40-50 % by that time. For a typical SNR in a warm ISM, the accelerated CR energy spectrum should exhibit a concave curvature with the power-law slope flattening from 2 to 1.6 at $E{\gtrsim}0.1$ TeV.

Sound Radiation From Infinite Beams Under the Action of Harmonic Point Forces (조화집중하중을 받는 무한보에서의 음향방사)

  • 김병삼;홍동표
    • Journal of KSNVE
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    • v.2 no.1
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    • pp.33-39
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    • 1992
  • The problem of sound radiation from infinite elastic beams under the action of harmonic point forces is studied. The reaction due to fluid loading on the vibratory response of the beam is taken into account. The beam is assumed to occupy the plane z = 0 and to be axially infinite. The beam material and the elastic foundation re assumed to be lossless and Bernoulli-Euler beam theory including a tension force (T), damping coefficient (C) and stiffness of foundation $(\kappa_s)$ will be employed. The non-dimensional sound power is derived through integration of the surface intensity distribution over the entire beam. The expression for sound power is integrated numerically and the results are examined as a function of wavenumber ratio$(\gamma)$ and stiffness factor$(\Psi)$. Here, our purpose is to explain the response of sound power over a number of non-dimensional parameters describing tension, stiffness, damping and foundation stiffness.

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WALLABY - the ASKAP HI All-Sky Survey

  • Oh, Se-Heon
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.235-235
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    • 2012
  • The "Widefield ASKAP L-band Legacy All-sky Blind surveY" (WALLABY) is an extragalactic HI survey which aims to examine HI properties and large-scale distribution of ~500,000 galaxies out to z ~ 0.27, covering a wide range of science goals associated with galaxy formation and evolution (P.I.: B. Koribalski & L. Staveley-Smith). The combination of ASKAP's exquisite column density sensitivity and a large primary beam will make it possible to systematically investigate the rarely explored low column-density HI in the universe. Ultimately, the largest and most homogeneous data set from WALLABY will drastically improve and broaden our knowledge on galaxy formation and evolution. ASKAP will be on-line in 2013, so to ensure timely and efficient reduction and analysis of the large WALLABY data set, we have been developing and testing reliable source finding tools and data analysis pipelines. In this talk I present recent progress of WALLABY, especially on the kinematic parameterisation pipeline for the spatially resolved galaxies detected by WALLABY.

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Pharmacokinetics of SD-0542, a Novel Histone Deacetylase Inhibitor, in Rats

  • Shin, Beom-Soo;Yoo, Sun-Dong
    • Journal of Pharmaceutical Investigation
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    • v.35 no.5
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    • pp.349-353
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    • 2005
  • This study reports the pharmacokinetics of a novel histone deacetylase inhibitor, SD-0542, in rats after i..v. and oral administration. SD-0542 was injected intravenously at doses of 10, 20, and 40 mg/kg. The terminal elimination half-life $(t_{1/2})$, systemic clearance (Cl), and steady-state volume of distribution $(V_{ss})$ remained unaltered as a function of dose, with their values ranging from 2.0-2.5 hr, 157.2-214.1 ml/min/kg, and 11.1-17.5 L/kg, respectively, whereas, the initial serum concentration $(C_0)$ and AUC increased linearly as the dose was increased. Renal excretion of SD-0542 was minimal. Oral pharmacokinetic studies were conducted in rats at a dose of 20 mg/kg. The $T_{max}$, Cl/F, $V_{z}/F$, and $t_{1/2}$ were 2.0 hr, 92864 ml/min/kg, 16331 L/kg, and 2.0 hr, respectively. Taken together, SD-0542 showed linear pharmacokinetics over the i.v. bolus dose range studied. SD-0542 was poorly absorbed, with the absolute oral bioavailability of 0.9%.

The Distribution Characteristics of Fish Community by Habitat Type in the Nonsan Stream (논산천의 서식처 유형별 어류군집의 분포특성)

  • Lee, Hwang-Goo;Choi, Jun-Kil
    • Journal of Wetlands Research
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    • v.16 no.3
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    • pp.303-313
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    • 2014
  • The spatial distribution characteristic of fish community were investigated at the 10 habitat types in the Nonsan stream from August, 2008 to June, 2009. The collected species during the surveyed period were 26 species belong to 6 families. Korean endemic species were Sarcocheilichthys nigripinnis morii, Squalidus japonicus coreanus, Hemiculter eigenmanni, Pseudobagrus koreanus, and Odontobutis interrupta which showed 19.2% ratio of total species. Dominant species was Zacco platypus, and subdominant species was Tridentiger brevispinis. Dominant species according to habitat types were Micropterus salmoides(substrate type pool and rock type pool), Lepomis macrochirus(channel connected pool and channel unconnected pool/abandoned type pool), T. brevispinis(channel unconnected pool/overflow type and run) and Z. platypus(riffle, meander type pool, side channel, and dam type pool). As a results of community analysis in side channel, diversity index showed relatively high values, indicating that habitat types in the Nonsan stream have relatively stable community structure. Bray-curtis cluster analysis indicated that the meander type pool and riffle showed the most similar values(80.8%). Moreover, cluster and principal component analysis were classified as 2 groups(lotic and lentic habitats).