• Title, Summary, Keyword: K Bank

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HLA-restricted and Antigen-specific CD8+ T Cell Responses by K562 Cells Expressing HLA-A*0201

  • Yun, Sun-Ok;Sohn, Hyun-Jung;Yoon, Sung-Hee;Choi, Hee-Baeg;Kim, Tai-Gyu
    • IMMUNE NETWORK
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    • v.6 no.4
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    • pp.179-184
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    • 2006
  • Background: Identification of antigen-specific T cells has yielded valuable information on pathologic process and the disease state. Assays for quantification of inflammatory cytokines or lytic-granule molecules have been generally used to evaluate antigen specific T cell response, however their applicability have been hampered due to the limited source of autologous antigen-presenting target cells (APC). Methods: K562, a leukemic cell line deficient of human leukocyte antigen (HLA), was transfected with a gene encoding HLA-A*02 (K562/ A*02) and its function as stimulator cells in inducing activation of HLA-matched T cells was evaluated by IFN-${\gamma}$ enzyme linked immunospot (ELISPOT) assay. Results: The stable transfectant K562/ A*02 pulsed with HLA- A*02 restricted peptide could specifically induce IFN-${\gamma}$ secretion by CD8+ T cells compared to no detectable secretion by CD4+ T cells. However, CD56+ NK cells secreted IFN-${\gamma}$ in both K562/ A*02 with peptide and without peptide. The number of IFN-${\gamma}$ secreted CD8+ T cells was increased according to the ratio of T cells to K562 and peptide concentration. Formalin-fixed K562/ A*02 showed similar antigen presenting function to live K562/ A*02. Moreover, K562/ A*02 could present antigenicpeptide to not only A*0201 restricted CD8+ T cells but also CD8+ T cells from A*0206 donor. Conclusion: These results suggest that K562/ A*02 could be generally used as target having specificity and negligible background for measuring CD8+ T cell responses and selective use of K562 with responsder matched HLA molecules on its surface as APC may circumvent the limitation of providing HLA-matched autologous target cells.

Cloning of hnRNP E1 cDNA via yeast two-hybrid system and a study on protein-protein interaction between hnRNP E1 and hnRNP K (이스트 two-hybrid 시스템을 이용한 hnRNP E1 cDNA의 클로닝과 hnRNP E1-hnRNP K 상호결합에 대한 연구)

  • Choi, Mie-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.6
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    • pp.1795-1799
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    • 2008
  • The heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a component of hnRNP complexes. This protein binds strongly to cytidine-rich RNA/DNA sequences. It is a nucleocytoplasmic shuttling protein. To investigate the functions of hnRNP K, I searched for hnRNP K-interacting proteins in HeLa cDNA library using a yeast two-hybrid screening system. One of the cDNA clones is identical to human hnRNP E1 (poly(rC) binding protein 1) cDNA (GenBank accession number XM_031585). In this study, hnRNP K is shown to specifically interact with hnRNP E1 in yeast two-hybrid system and in vitro biochemical assay.

150 kJ Compact Capacitive Pulsed Power System for an Electrothermal Chemical Gun

  • Lee, Byung-Ha;Kim, Jin-Sung;Kim, Seong-Ho;Lee, Young-Hyun;Yang, Kyung-Seung
    • Journal of Electrical Engineering and Technology
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    • v.7 no.6
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    • pp.971-976
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    • 2012
  • A 150 kJ compact capacitive pulsed power system (CCPPS) capable of delivering electrical energy into an electrothermal chemical (ETC) gun on a vehicle has been studied. The CCPPS provides pulsed electrical energy into a capillary plasma injector which generates plasma of tens of thousands $^{\circ}K$ in temperature and has a nonlinear resistance depending on the current. The design requirements of the CCPPS are as follows: the maximum power of 250 MW, the pulse width of about 0.6 ms, the volume of no more than 0.5 cubic meter, the efficiency of energy transfer over 80 % and the repetition rate of 4~5 times per minute. The constructed CCPPS is composed of four 37.5 kJ capacitor bank modules in parallel to make a trapezoid pulse shape and to satisfy the design requirements. Each module is designed to achieve high reliability, safety, efficiency and energy density to endure severe operating conditions. The results of the performance test on the CCPPS using a 120 mm ETC gun are described.

Low-cost crowbar system and protection scheme in capacitor bank module (커패시터 뱅크 모듈 구성에 있어서 경제적인 크로바 시스템과 보호회로)

  • Rim, Geun-Hie;Cho, Chu-Hyun;Lee, Hong-Sik;Pavlov, E.P.
    • Proceedings of the KIEE Conference
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    • pp.2089-2091
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    • 2000
  • Pulsed power systems consist of a capacitor bank, an isolated high-voltage charging power-supply, high-current bus-work for charging and discharging and a control system. In such pulsed power systems, the operating-lifetime of the capacitors is closely dependent on the voltage reversal. Hence, most capacitor-discharging systems includes crowbar circuits. The crowbar circuit prevents the capacitor recharging with reverse voltage. Usually it consists of crowbar resistors and high pulse-current diode-stacks connected in series. The requirements for the diode-stacks are fast-recovery time and high-voltage and large-current ratings, which results in the high cost of the pulsed-power system. This paper presents a protection scheme of a charging and discharging system of a 500kJ capacitor bank using a low-cost crowbar circuit and safety-fuses.

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Measurement of Short Reverberation Times of an Acoustic Room at Low Frequencies Using Wavelet Transform (웨이브렛 변환을 이용한 저주파에서 짧은 잔향 시간을 갖는 실음향에서의 잔향시간 측정에 관한 연구)

  • 이상권
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.1077-1080
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    • 2002
  • In building acoustics, reverberation time is an important acoustic parameter. However, it is often difficult to measure short reverberation times at low frequencies using the traditional band pass filter bank if the product of bandwidth (B) and reverberation time (T) is small. It is well known that the minimum permissible product of bandwidth and reverberation time of the traditional band pass filter is at least 16 [F. Jacobsen, J. Sound Vib. 115, 163-170 (1987)]. This strict requirement makes it difficult to measure short reverberation times of an acoustic room at low frequencies exactly. In order to reduce this strict requirement, recently, the wavelet filter bank is developed and the minimum permissible product of bandwidth and reverberation time is replaced with 4 [S. K. Lee, J, Sound Vib. 252, 141-153 (2002)]. In the present paper, it is demonstrated how the short reverberation times at low frequencies are successfully measured by using the wavelet filter bank. In order to present this job, two synthetic signals and one measured signal are used for impulse responses of an acoustic room.

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Optimal Location and Design of RC-Bank on Korean Electric Railway System (한국 전기철도 시스템의 RC-Bank의 최적 위치 및 설계)

  • Lee Han-Min;Kim Gil-Dong;Oh Seh-Chan;Park Sung-Hyuk
    • Proceedings of the KSR Conference
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    • pp.754-764
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    • 2005
  • This paper presents the RC-Bank installation by its optimal location and design to reduce harmonics on the Korean high-speed railway system. The system model of the Korean high-speed railway system is based on 8-port representation, which is an extension of 2-port network theory. A new proposed model is for harmonic analysis in $2\times27.5kV$ traction power supply system including feeders, contact lines, rails and autotransformers. The proposed model is developed by combining fundamental element models of the Korean high-speed railway system, and it is verified by comparing simulation results with measurement data regarding the amplification rate of harmonic currents.

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Audio Event Classification Using Deep Neural Networks (깊은 신경망을 이용한 오디오 이벤트 분류)

  • Lim, Minkyu;Lee, Donghyun;Kim, Kwang-Ho;Kim, Ji-Hwan
    • Phonetics and Speech Sciences
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    • v.7 no.4
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    • pp.27-33
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    • 2015
  • This paper proposes an audio event classification method using Deep Neural Networks (DNN). The proposed method applies Feed Forward Neural Network (FFNN) to generate event probabilities of ten audio events (dog barks, engine idling, and so on) for each frame. For each frame, mel scale filter bank features of its consecutive frames are used as the input vector of the FFNN. These event probabilities are accumulated for the events and the classification result is determined as the event with the highest accumulated probability. For the same dataset, the best accuracy of previous studies was reported as about 70% when the Support Vector Machine (SVM) was applied. The best accuracy of the proposed method achieves as 79.23% for the UrbanSound8K dataset when 80 mel scale filter bank features each from 7 consecutive frames (in total 560) were implemented as the input vector for the FFNN with two hidden layers and 2,000 neurons per hidden layer. In this configuration, the rectified linear unit was suggested as its activation function.

A Study on the Development of the Korean Internet Banks (한국 인터넷은행의 발전 방안에 관한 연구)

  • Ok, S.H.;Hwang, K.T.
    • Journal of Digital Convergence
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    • v.15 no.12
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    • pp.111-126
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    • 2017
  • Korea came to see its first internet bank as 'K bank' obtained the digital-only banking license in December 2016. This paper suggests ways to foster internet banks of Korea in their early stage by analyzing the successful cases of overseas internet banks. The followings are the key success factors identified from those cases across Europe, Japan, China, and USA: Support from the related government authorities; Stable governance structure; Distinct business capabilities based on information & communications technology(ICT). These points lead to the following implications for Korean internet banks. Regulatory restrictions on owning and running internet banks should be lifted to facilitate innovation. Policies to support internet bank industry should be introduced as it is a vital part of the 4th industrial revolution. Finally, internet banks should strive to differentiate themselves by utilizing their ICT capabilities. Subjects of the further research hereafter should include the following: Analyzing the ongoing performance and developments of digital banks in Korea; Deriving success factors from the analysis; Assessing the influence and effects on financial market and economic environment.

Isolation and Purification of Methyl Mercaptan Oxidase from Rhodococcus rhodochrous for Mercaptan Detection

  • Kim, Sang-Joon;Shin, Hyun-Jae;Kim, Yeu-Chun;Lee, Dae-Sil;Yang, Ji-Won
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.6
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    • pp.465-468
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    • 2000
  • Methyl mercaptan oxidase was successfully induced from Rhodococcus rhodochrous IGTS8 using methyl mercaptan gas and purified to homogeneity for the detection of mercaptans. The purification procedure involved DEAE-Sephacel and Superose 12 column chromatography with recovery yields of 85.8 and 83.3%, and a specific activity of 92.7 and 303.4 units/mg-protein, respectively. The molecular weight of purified methyl mercaptan oxidase was determined to be 64.5 kDa by SDS-PAGE. The extract from gel filtration chromatography oxidizes methyl mercaptan to produce formaldehyde, which can be easily detected by the purpald-coloring method. Optimum temperature for activity was achieved at 60$^{\circ}C$. This enzyme was inhibited by both K$_2$SO$_4$and NaCl at concentration of less than 100mM and recovered to original activity at concentration of 200mM. In the presence of methanol, the activity decreased by 33%.

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