• Title/Summary/Keyword: 4IR

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Preparation and Characterization of Dinuclear and Trinuclear Metal Complexes, $[(PPh_3)_2(CO)M({\mu}-E)M(CO)(PPh_3)_2]X_2$ (M=Rh, Ir; E=Pyrazine, 4,4'-Bipyridyl, $X=SO_3CF_3$; $E=Pd(CN)_4$, $Pt(CN)_4$, X=none)

  • Ko Jaejung;Lee Myunggab;Kim Moonsik;Kang Sang Ook
    • Bulletin of the Korean Chemical Society
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    • v.13 no.2
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    • pp.158-162
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    • 1992
  • Hydrocarbon solution of $(PPh_3)_2(CO)MOSO_2CF_3(M=Rh$, Ir)reacts rapidly with Pyrazine or 4,4'-bipyridyl to yield dinuclear metal complexes $[(PPh_3)_3(CO)M({\mu}-pyrazine)M(CO)(PPh_3)_2](SO_3CF_3)_2$ (I: M= RhH; III: M=Ir) or [$(PPh_3)_2$(CO)M(${\mu}$-44'-bipyridyl)M(CO)$(PPh_3)_2](SO_3CF_3)_2$, (II: M=Rh; IV: M=Ir), respectively. Compounds, I, II, III, and IV were characterized by $^1H-NMR$, $^{13}C-NMR$, $^{31}P-NMR$, and infrared spectrum. Ethanol solution of $(PPh_3)_2(CO)MOSO_2CF_3$ (M=Rh, Ir) also reacts with $(TBA)_2$M'$(CN)_4$ (M'=Pd, Pt) to yield trinuclear metal complexes [$(PPh_3)_2$(CO)dM-NCM'$(CN)_2$CN-M(CO)$(PPh_3)_2]$ (V : M=Rh, M'=Pd; VI : M=Rh, M'=Pt; VII: M=Ir, M'=Pd; VIII: M=Ir, M'=Pt). The trinuclear metal complexes V, VI, VII, and VIII are bridged by the cyanide groups. The infrared spectrum of V, VI, VII, and VIII supports the presence of the bridged cyanide and terminal cyanide group.

Preparation and Characterization of White Phosphorescence Polymer Light Emitting Diodes Using PFO:Ir(ppy)3:MDMO-PPV Emission Layer

  • Park, Byung-Min;Chang, Ho-Jung
    • Journal of the Microelectronics and Packaging Society
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    • v.18 no.4
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    • pp.79-83
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    • 2011
  • White phosphorescence polymer light emitting diodes (WPhPLEDs) with a glass/ITO/PEDOT:PSS/PFO:$Ir(ppy)_3$:MDMO-PPV/TPBI/LiF/Al structure were fabricated to investigate the effects of $Ir(ppy)_3$ doping concentrations on the optical and electrical properties of the devices. PFO, $Ir(ppy)_3$ and MDMO-PPV conjugated polymers as host and guest materials in the emission layer were spin coated at various concentrations of $Ir(ppy)_3$ ranging from 0.0 to 20.0 vol.%. As the concentration of $Ir(ppy)_3$ increased from 5.0 to 20.0 vol.%, the luminance and current efficiency values of the devices decreased clearly, which are attributable to the quenching effect at a high doping concentration. The maximum luminance and current density were 2850 $cd/m^2$ and 741 $mA/cm^2$, respectively for a WPhPLED with an $Ir(ppy)_3$ concentration of 5.0 vol.%. The CIE color coordinates were about x=0.33 and y=0.34 at 11V, showing a good white color.

Analysis of Impulse Dispersion for IR-UWB Antenna Using Time-Frequency Analysis (시간-주파수 분석을 이용한 IR-UWB 안테나 임펄스 분산 특성 분석)

  • Koh, Young-Mok;Ra, Keuk-Hwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.12
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    • pp.1371-1379
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    • 2010
  • This paper presents an analysis of impulse dispersion for impulse radio ultra-wide band(IR-UWB) antenna. A set of antenna structure configurations are highlighted with verification based on the STFT(Short Time Fourier Transform) in 3.1~5.1 GHz: first, a taper-slotted antenna allowing the optimal impulse transmission, and second, 4 types of the omni-directional IR-UWB antenna using different feed structures(microstrip line, and CPW(Coplanar Waveguide)). The proposed STFT allows the analysis of the IR-UWB antenna's dispersion characteristic.

Synthesis and Characterization of Octamethylenethiafulvalene Compounds with Osmium, Iridium, Platinium and Gold Chloride (Octamethylenethiafulvalene과 염화오스뮴, 이리듐, 백금 및 금 화합물의 합성과 특성에 관한 연구)

  • Jeong, Chan Kyou;Lee, Hong Woo;Kim, Young Jin;Choi, Sung Nak;Kim, Young Inn
    • Journal of the Korean Chemical Society
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    • v.45 no.5
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    • pp.442-447
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    • 2001
  • The charge-transfer compound (OMTTF)AuCl$_4$ was prepared from the direct reaction of octamethylenethiafulvalene (OMTTF) with HAuCl$_4{\cdot}xH_2$O in THF. (OMTTF)$_2PtCl_4$, (OMTTF)_2IrCl_6{\cdot}2H_2$O, and (OMTTF)Os$Cl_5{\cdot}THF$ were also formed using $H_2PtCl_6{\cdot}xH_2O$, $H_2IrCl_6{\cdot}xH_2O$ and $H_2OsCl_6$, respectively. The prepared compounds were characterized by magnetic (EPR, magnetic susceptibility), spectroscopic (IR, UV-Vis), electrochemical (CV) methods, and the powdered electrical conductivity measurement. The powdered electrical conductivities at room temperature were ~$10^{-7}S{\cdot}cm^{-1}$. The experimental results show that $OMTTF^+$ monocation radicals exist in all of the prepared compounds. The redox potential of OMTTF supports that $OMTTF^+$ is relatively stable. The magnetic properties indicate that there are significant magnetic interactions between the localized odd electrons on the central metal (Ir and Os) ions and the odd electrons resided on $OMTTF^+$ cation radicals in both (OMTTF) $_2IrCl_6{\cdot}2H_2O$ and (OMTTF)$OsCl_5{\cdot}THF$.

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A Study on the Collaboration between Government Departments in the Fourth Industrial Revolution Era (4차산업혁명시대의 정부부처 간 협력에 관한 연구)

  • Lee, Sun Young;Cho, Kyung Ho;Park, Kwang Kook
    • Journal of Digital Convergence
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    • v.17 no.6
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    • pp.35-42
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    • 2019
  • This study was conducted to identify the determing factors of the success and constraints based on the perception of public officials preparing for the Fourth Industrial Revolution(4IR) and the collaboration among ministries. The analytic method performed an average value analysis based on the survey of public officials' awareness, and the results of the study are as follows. First, officials from nine ministries who are responsible for the 4IR recognized that they were regarded that the 4IR as a new opportunity, but if it failed to respond properly, there might be a crisis. Second, it recognizes the era of 4IR as the number one priority in big data, second in artificial intelligence and machine learning, and third in cloud computing technology. Third, they recognized that 'flexibility of the institutions' and 'recruitment of experts' were needed to prepare for the 4IR effectively.

Online Searching Behavior of Social Science Researchers' in IR Interfaces of E-journal Database Systems: A Study on JMI, JNU, and DU

  • Kumar, Shailendra;Rai, Namrata
    • Journal of Information Science Theory and Practice
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    • v.1 no.4
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    • pp.48-66
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    • 2013
  • The aim of this study is to examine the user's online searching behavior in IR interfaces of e-journal database systems. The study is purely based on survey methods and tries to analyse the online searching behavior of respondents of social science disciplines who were doing research in three target central universities of Delhi (i.e. DU, JMI, and JNU). For measuring the responses of the respondents in IR interfaces of e-journal database systems, a total of 396 questionnaires were distributed among the students and out of all, 305 responses were used for the study. The findings of the study reveal that most of the students were not using all the facilities offered in IR interfaces of e-journal database systems for their retrieval process and also encourages menu based searches rather than command based searching.

The Exchange Anisotropy and Microstructure of Mn-Ir/Ni-Fe Multilayers with Various Buffer Layer Materials and Stacking Structures (Mn-Ir/Ni-Fe 다층막의 하지층과 적층구조에 따른 교환이방성과 미세구조 연구)

  • 노재철;윤성용;이경섭;김용성;서수성
    • Journal of the Korean Magnetics Society
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    • v.9 no.4
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    • pp.196-202
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    • 1999
  • The magnetic properties and the microstructures of the Mn-Ir/Ni-Fe multilayers with various stacking structures and buffer layer materials have been investigated. The (111) texture of Mn-Ir/Ni-Fe was observed in the top structures with Ta, Zr, or Ti buffer materials. However, all Mn-Ir/Ni-Fe multilayers with top structures exhibit high $H_{ex}$, regardless of the (111) preferred orientation of Mn-Ir film. The samples whose high $H_{ex}$ observed grain-to-grain epitaxial tendency and the large grain of Mn-Ir film at the interface. It can be explained that the $H_{ex}$ does not depend on the (111) texture of the Mn-Ir film and the interface roughness, but depends on the grain size of the Mn-Ir film and the morphology of the interface between the Mn-Ir and the Ni-Fe grains, and the $H_c$ depends on the interface roughness between the Mn-Ir and the Ni-Fe films.

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Prior Literature Investigation of the Human Resource Management (HRM) in the Fourth Industrial Revolution (4IR)

  • Eungoo KANG
    • Fourth Industrial Review
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    • v.3 no.2
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    • pp.27-35
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    • 2023
  • Purpose - In this study, the current author explores how Human Resource Management (HRM) is changing in the context of the Fourth Industrial Revolution (4IR). Understanding the distinctive features of HRM in this day is crucial, given how rapidly industries are changing due to technology. Research design, data, and methodology - This study adopts a thorough literature review methodology to pinpoint and clarify these distinctive characteristics, advancing our understanding of the role of HRM in the modern world. Regarding methodology, this study uses the PRISMA approach to systematically gather pertinent publications from various sources that have undergone peer review. Result - By carefully choosing and examining these studies, the present author was able to identify four crucial HRM traits that are representative of the Fourth Industrial Revolution. The findings emphasizes how common flexible work schedules are. Using data analytics to influence HRM decisions is increasingly important for maximizing hiring, reviewing performance, and fostering organizational growth. Conclusion - By recalibrating their HRM practices in the 4IR, businesses may encourage flexibility, innovation, and employee well-being. This work makes a substantial contribution to both HRM theory and practice and our comprehension of the transformative effects of the 4IR by filling a gap in the existing literature.

THE SHORT-TERM EFFECTS OF LOW-DOSE-RATE RADIATION ON EL4 LYMPHOMA CELL

  • Bong, Jin-Jong;Kang, Yu-Mi;Shin, Suk-Chul;Choi, Moo-Hyun;Choi, Seung-Jin;Lee, Kyung-Mi;Kim, Hee-Sun
    • Journal of Radiation Protection and Research
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    • v.37 no.2
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    • pp.56-62
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    • 2012
  • To determine the biological effects of low-dose-rate radiation ($^{137}Cs$, 2.95 mGy/h) on EL4 lymphoma cells during 24 h, we investigated the expression of genes related to apoptosis, cell cycle arrest, DNA repair, iron transport, and ribonucleotide reductase. EL4 cells were continuously exposed to low-dose-rate radiation (total dose: 70.8 mGy) for 24 h. We analyzed cell proliferation and apoptosis by trypan blue exclusion and flow cytometry, gene expression by real-time PCR, and protein levels with the apoptosis ELISA kit. Apoptosis increased in the Low-dose-rate irradiated cells, but cell number did not differ between non- (Non-IR) and Low-dose-rate irradiated (LDR-IR) cells. In concordance with apoptotic rate, the transcriptional activity of ATM, p53, p21, and Parp was upregulated in the LDR-IR cells. Similarly, Phospho-p53 (Ser15), cleaved caspase 3 (Asp175), and cleaved Parp (Asp214) expression was upregulated in the LDR-IR cells. No difference was observed in the mRNA expression of DNA repair-related genes (Msh2, Msh3, Wrn, Lig4, Neil3, ERCC8, and ERCC6) between Non-IR and LDR-IR cells. Interestingly, the mRNA of Trfc was upregulated in the LDR-IR cells. Therefore, we suggest that short-term Low-dose-rate radiation activates apoptosis in EL4 lymphoma cells.

Performance Evaluation of Antipodal Vivaldi Antenna in the Time- and Frequency-Domains for IR-UWB Systems Application (IR-UWB 시스템 응용을 위한 시간- 및 주파수-영역에서의 앤티포달 비발디 안테나 성능 평가)

  • Koh, Young-Mok;Kim, Keun-Yong;Ra, Keuk-Hwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.2
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    • pp.159-168
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    • 2012
  • In this paper, we designed the antipodal vivaldi antenna for IR-UWB systems application and evaluated IR-UWB antenna performance for the ultra wideband impulse signal transmission in the time- and frequency-domain. The designed antipodal vivaldi antenna was fabricated using FR-4 substrate which thickness 1.6 mm, dielectric constant ${\epsilon}_r=4.7$ and $tan{\delta}=0.002$. We measured the return loss, far filed radiation pattern at the anechoic chamber in the frequency-domain. We also performed the pulse fidelity analysis in the time-domain using nano-second impulse signal transmission and demonstrated the feasibility of ultra wideband signal stable transmission in the UWB band. The designed and fabricated antipodal vivaldi antenna could be emitting and receiving the IR-UWB signal while preserving low pulse distortion and good radiation pattern in time- and frequency-domain.