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3kpc 내 은하평면의 성간소광법칙

  • Seong, Hwan-Gyeong;Bessell, M.S.
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.57.1-57.1
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    • 2013
  • Non-LTE 항성대기모형인 Tlusty 모형의 합성색지수와 성간소광을 매우 적게 받은 산개성단에 있는 별들의 색지수를 바탕으로 O와 B형 별의 고유색지수 관계를 채택하였다. 태양인근 3kpc 내에 있는 약 190개 젊은 산개성단의 가시광 및 근적외선 2MASS JHKs 관측자료와 위에서 채택한 고유 색지수 관계를 적용하여 색 초과비 E(V-I)/E(B-V), E(V-J)/E(B-V), E(V-H)/E(B-V), 및 E(V-Ks)/E(B-V)를 얻고, 색 초과비와 $R_V$의 관계를 사용하여, 각 성단의 성간소광법칙 $R_V$를 결정하였다. 국부 나선팔의 백조자리 방향과 Per 나선팔에 있는 산개성단들은 약간 작은 $R_V$를 보이며, 큰개자리 방향의 국부 나선팔에 있는 산개성단은 정상적인$R_V$를, 그리고 Sgr-Car 나선팔에 있는 산개성단들은 약간 큰 값을 보였다. 이 결과는 최대 편광도를 보이는 파장과 $R_V$의 관계로 얻을 수 있는 양상과 잘 일치한다.

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A study on thermally stimulatede current in semi-insulating GaAs (반절연성 GaAs에서 열자극 전류에 관한 연구)

  • 배인호;김기홍;김인수;최현태;이철욱;이정열
    • Electrical & Electronic Materials
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    • v.7 no.5
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    • pp.383-388
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    • 1994
  • Deep levels in semi-insulating GaAs were observed by thermally stimulated current(TSC) measurement In the temperature ranges of 100-300K Tl(E$\_$c/-0.18eV), T2(E$\_$c/-0.20eV), T3(E$\_$c/-0.31eV), T4(E$\_$c/-0.40eV), and T5(E$\_$c/-O.43eV) traps have been observed. The TI, T2, and T5 traps seem to be related to the V$\_$As/, V$\_$Ga/-complex, and As$\_$Ga/$\^$++/ respectively. T4 trap is considered with respect to V$\_$Ga/-V$\_$As/ complex.

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HIGH DIMENSION PRUFER DOMAINS OF INTEGER-VALUED POLYNOMIALS

  • Cahen, Paul-Jean;Chabert, Jean-Luc;K.Alan Loper
    • Journal of the Korean Mathematical Society
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    • v.38 no.5
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    • pp.915-935
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    • 2001
  • Let V be any valuation domain and let E be a subset of the quotient field K of V. We study the ring of integer-valued polynomials on E, that is, Int(E, V)={f$\in$K[X]|f(E)⊆V}. We show that, if E is precompact, then Int(E, V) has many properties similar to those of the classical ring Int(Z).In particular, Int(E, V) is dense in the ring of continuous functions C(E, V); each finitely generated ideal of Int(E, V) may be generated by two elements; and finally, Int(E, V) is a Prufer domain.

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Synthesis and Photovoltaic Properties of Low Band Gap π-conjugated Polymers Based on 2-pyran-4-ylidene-malononitrile Derivatives (2-pyran-4-ylidene-malononitrile을 기본으로 하는 작은 Band Gap을 가지는 공중합체의 합성 및 광전변환 특성)

  • You, Hyeri;Shin, Woong;Park, Jeong Bae;Park, Sang Jun;Lim, Jun Heok;Kim, Joo Hyun
    • Applied Chemistry for Engineering
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    • v.20 no.3
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    • pp.273-278
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    • 2009
  • A series of poly[2-(2,6-dimethylpyran-4-ylidene)malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PM-PPV), poly[2-{2,6-Bis-[2-(5-bromothiophen-2-yl)-vinyl]-pyran-4-ylidene}-malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PMT-PPV) and poly[2-[2,6-Bis-(2-{4-[(4-bromophenyl)-phenylamino]-phenyl}-vinyl)-pyran-4-ylidene]-malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PMTPA-PPV) were synthesized by the Heck coupling reaction. The band gap of PM-PPV, PMT-PPV and PMTPA-PPV were 2.18 eV, 1.90 eV and 2.07 eV, respectively. The LUMO energy levels of PM-PPV, PMT-PPV and PMTPA-PPV were 3.65 eV, 3.54 eV and 3.62 eV, respectively and the HOMO energy levels of those were 5.83 eV, 5.61 eV and 5.52 eV, respectively. The photovoltaic devices based on the polymers was fabricated. The efficiency of the solar cells based on PM-PPV, PMT-PPV and PMTPA-PPV were 0.028%, 0.031% and 0.11%, respectively and the open circuit voltage (Voc) was 0.59 V~0.69 V under AM 1.5 G and 1 sun condition ($100mA/cm^2$).

Microsecond molecular dynamics simulations revealed the inhibitory potency of amiloride analogs against SARS-CoV-2 E viroporin

  • Jaber, Abdullah All;Chowdhury, Zeshan Mahmud;Bhattacharjee, Arittra;Mourin, Muntahi;Keya, Chaman Ara;Bhuyan, Zaied Ahmed
    • Genomics & Informatics
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    • v.19 no.4
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    • pp.48.1-48.10
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    • 2021
  • Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encodes small envelope protein (E) that plays a major role in viral assembly, release, pathogenesis, and host inflammation. Previous studies demonstrated that pyrazine ring containing amiloride analogs inhibit this protein in different types of coronavirus including SARS-CoV-1 small envelope protein E (SARS-CoV-1 E). SARS-CoV-1 E has 93.42% sequence identity with SARS-CoV-2 E and shared a conserved domain NS3/small envelope protein (NS3_envE). Amiloride analog hexamethylene amiloride (HMA) can inhibit SARS-CoV-1 E. Therefore, we performed molecular docking and dynamics simulations to explore whether amiloride analogs are effective in inhibiting SARS-CoV-2 E. To do so, SARS-CoV-1 E and SARS-CoV-2 E proteins were taken as receptors while HMA and 3-amino-5-(azepan-1-yl)-N-(diaminomethylidene)-6-pyrimidin-5-ylpyrazine-2-carboxamide (3A5NP2C) were selected as ligands. Molecular docking simulation showed higher binding affinity scores of HMA and 3A5NP2C for SARS-CoV-2 E than SARS-CoV-1 E. Moreover, HMA and 3A5NP2C engaged more amino acids in SARS-CoV-2 E. Molecular dynamics simulation for 1 ㎲ (1,000 ns) revealed that these ligands could alter the native structure of the proteins and their flexibility. Our study suggests that suitable amiloride analogs might yield a prospective drug against coronavirus disease 2019.

Comparison between Old and New Versions of Electron Monte Carlo (eMC) Dose Calculation

  • Seongmoon Jung;Jaeman Son;Hyeongmin Jin;Seonghee Kang;Jong Min Park;Jung-in Kim;Chang Heon Choi
    • Progress in Medical Physics
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    • v.34 no.2
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    • pp.15-22
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    • 2023
  • This study compared the dose calculated using the electron Monte Carlo (eMC) dose calculation algorithm employing the old version (eMC V13.7) of the Varian Eclipse treatment-planning system (TPS) and its newer version (eMC V16.1). The eMC V16.1 was configured using the same beam data as the eMC V13.7. Beam data measured using the VitalBeam linear accelerator were implemented. A box-shaped water phantom (30×30×30 cm3) was generated in the TPS. Consequently, the TPS with eMC V13.7 and eMC V16.1 calculated the dose to the water phantom delivered by electron beams of various energies with a field size of 10×10 cm2. The calculations were repeated while changing the dose-smoothing levels and normalization method. Subsequently, the percentage depth dose and lateral profile of the dose distributions acquired by eMC V13.7 and eMC V16.1 were analyzed. In addition, the dose-volume histogram (DVH) differences between the two versions for the heterogeneous phantom with bone and lung inserted were compared. The doses calculated using eMC V16.1 were similar to those calculated using eMC V13.7 for the homogenous phantoms. However, a DVH difference was observed in the heterogeneous phantom, particularly in the bone material. The dose distribution calculated using eMC V16.1 was comparable to that of eMC V13.7 in the case of homogenous phantoms. The version changes resulted in a different DVH for the heterogeneous phantoms. However, further investigations to assess the DVH differences in patients and experimental validations for eMC V16.1, particularly for heterogeneous geometry, are required.

Polarographic Behaviors of Copper and Cadmium Complexes with 2,2'-Bipyridine and Ethylenediamine in Acetonitrile (아세토니트릴에서 구리와 카드뮴의 2,2'-Bipyridine과 Ethylenediamine 착물에 대한 폴라로그래프적 연구)

  • Park, Du Won;Lee Heung Lark;Bae Zun Ung
    • Journal of the Korean Chemical Society
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    • v.18 no.3
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    • pp.202-209
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    • 1974
  • Polarographic behaviors of copper and cadmium complexes with 2,2'-bipyridine and ethylenediamine in acetonitrile have been investigated by the DC and AC polarography. The reduction processes are estimated as follows; $Cu(II)-bipy. \;complex\;{\longrightarrow^{e^-}_{E_{1/2}\risingdotseq+0.1V}}\;Cu(I)-bipy.\;complex\;{\longrightarrow^{e^-}_{E_{1/2}=-0.43V}}\;Cu(Hg)$$Cu(II)-en.\;complex\;{\longrightarrow^{e^-}}\;Cu(I)-en.\;complex\;{times}\;{\longrightarrow^{e^-}_{E_{1/2}=-0.56V}}\;Cu(Hg)$$Cu(II)-bipy. \;complex\;{\longrightarrow^{e^-}_{E_{1/2}=-0.57V}}\;Cu(I)-bipy.\;complex\;{\longrightarrow^{2e^-}_{E_{1/2}=-0.97V}}\;Cd(I)-bipy\;complex$$Cu(II)-en.\;complex\;{\longrightarrow^{e^-}_{E_{1/2}=+0.05V}\;Cu(I)-en.\;complex{\longrightarrow^{e^-}_{E_{1/2}=-0.92V}}\;Cu(Hg)$ The limiting currents of all steps are controlled by diffusion. The number of ligand and the dissociation constant for Cu(Ⅰ)-bipy. complex were found to be n = 2 and $K_d=(1.5{\pm}0.1){\times}10^{-7}$, respectively.

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Study on The lonzation Potential, Electron Affinity and Electrochemical Property of PBO and PVK using Cyclic Voltammetry and Constant Current Potentiometry (순환전압전류법과 일정전류전위차법을 이용한 PBD와 PVK의 이온화에너지, 전자친화도 및 전기화학적 특성에 관한 연구)

  • 형경우;최돈수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.12S
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    • pp.1273-1277
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    • 2003
  • The effects of molecular structure on the redox properties are explored by the cyclic voltammetry, constant current potentiometry and spectroscopy using the thin films of organic electroluminescence materials of Poly(N-vinylcarbazole); PVK and 2- (4'-tert-butylphenyl) -5-(4"-bisphenyl) -1,3,4-oxadiazole; PBD. The UV/visible absorption maxima and band gap (E$\_$g/) show at 310nm (4.00eV) and 368nm (3.37eV) for FBD, 344nm (3.60eV) and 356nm (3.48eV) for PVK, respectively. The measured electrochemical ionization potential (IP) and electron affinity (EA) of these materials we 5.87 and 2.82eV for PBD, 5.80 and 3.17eV for PVK, respectively. The electrical band gaps are 3.05eV for PBD and 2.78eV for PVK, respectively. The electrical hole gap and electron gap with respect to the first rising potentials and the inflection potentials are obtained to be 0.39V and 0.41V for PBD, 0.25V and 0.28V for FVK, respectively.

Photoconductivity spectra of undoped and co-doped $Cd_4GeSe_6$ single crystals ($Cd_4GeSe_6$$Cd_4GeSe_6:Co^{2+}$ 단결정의 광전도도 특성)

  • 김덕태
    • Electrical & Electronic Materials
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    • v.9 no.2
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    • pp.152-158
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    • 1996
  • Optical absorption and photoconductivity spectra of undoped and Co-doped Cd$_{4}$GeSe$_{6}$ single crystals, grown by the chemical transport reaction using iodine as a transporting agent, were investigated. At 20K, the optical energy gaps of the single crystals are 1.934eV for Cd$_{4}$GeSe$_{6}$ and 1.815eV for Cd$_{4}$GeSe$_{6}$ :Co$^{2+}$. The photoconductivity spectra of these single crystals were closely investigated over the temperature range 20-290K. At 20K, the photoconductivity peaks were located at 1.797eV, 1.347eV for Cd$_{4}$GeSe$_{6}$ and 1.815eV, I,.57eV, 1.46eV and 1.38eV for Cd$_{4}$GeSe$_{6}$ :Co$^{2+}$, respectively.ely.

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A Study on the Improvement of e-Call Services Using V2N(Vehicle to Nomadic Device) Technology (V2N(Vehicle to Nomadic Device) 기술을 이용한 e-Call 서비스 개선에 관한 연구)

  • Choi, Su-min;Shin, Yong-tae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.321-324
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    • 2018
  • Recently, the evolution of V2X (Vehicle to Everything) technology is accelerating. In particular, it can be seen that C-V2X (Cellular V2X) technology and services combined with mobile telecommunication network are developing rapidly. However, in Korea, e-Call and emergency communication services are inferior to the developed communication technologies and the proportion of vehicles arriving at Golden Hour is considerably low. Therefore, this paper designed the communication architecture with C-V2X and Android operating systems, and presented ways to improve existing e-Call services using V2N (Vehicle to Nomadic Device) communication based on it.

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