• Title/Summary/Keyword: tKR

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Changes in superconducting properties of Nb films irradiated with Kr ion beam

  • Minju Kim;Joonyoung Choi;Chang-Duk Kim;Younjung Jo
    • Progress in Superconductivity and Cryogenics
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    • v.26 no.1
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    • pp.5-9
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    • 2024
  • This study investigated the effect of Kr ion beam irradiation on the superconducting properties of Nb thin films, which are known for their high superconducting transition temperature (Tc) at ambient pressure among single elements. Using the Stopping and Range of Ions in Matter (SRIM) program, we analyzed the distribution of Kr ions and displacement per atom (DPA) after irradiation, finding a direct correlation between irradiation amount and DPA. In samples with stronger beam energy, deeper ion penetration, fewer ions remained, and higher DPA values were observed. X-ray diffraction (XRD) revealed that the Nb (110) peak at 38.5° weakened and shifted with increasing irradiation. Tc decreased in all samples after irradiation, more significantly in those with higher beam energy. Irradiation raised resistivity of the film and lowered the residual-resistivity ratio (RRR). AC susceptibility measurements were also consistent with these findings. This research could potentially lead to more efficient and powerful superconducting devices and a better understanding of superconducting materials.

Cloning and Sequencing of Coat Protein Gene of the Korean Isolate of Rice stripe virus

  • Hong, Yeon-Kyu;Kwak, Do-Yeon;Park, Sung-Tae;Choi, Jo-Im;Lee, Key-Woon;Lee, Bong-Choon
    • The Plant Pathology Journal
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    • v.20 no.4
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    • pp.313-315
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    • 2004
  • The coat protein gene of Korean isolate of Ricer stripe virus (RSV-Kr) was cloned and its nucleotide sequence was determined. Total RNA was extracted from infected leaves and RSV viral RNA was detected by using RT-PCR with specific primer of coat protein gene. The result of RT-PCR showed a specific band. Purified RT-PCR products of coat protein gene were ligated into the pGEM-T Easy plasmid vector and cloned cDNA was obtained for nucleotide sequence determination. Coat protein gene of RSV-Kr consisted of 969 bp long encoding a protein of 322 amino acids. RSV-Kr showed 94%-99% sequence identities to that of Japanese- and Chinese isolates.

The Effects of Self-Controlled Learning on Balance in Hemiplegics (자기통제 결과지식이 편마비 환자의 균형능력에 미치는 영향)

  • Yoon, Jung-Gyu;Kim, Myung-Hoon;Yook, Dong-Won
    • Physical Therapy Korea
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    • v.12 no.1
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    • pp.36-44
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    • 2005
  • The purpose of this study was to examine the effects of self-controlled learning using the (KR) feedback schedule versus the yoked KR on the acquisition and retention of balance training for individuals with hemiplegics. Sixteen hemiplegics were randomly assigned to either a self-controlled or yoked KR group. All subjects were ambulatory with or without an assistive device. The self-controlled group was provided with feedback whenever they requested it, whereas the yoked group had no influence on the feedback schedule. All subjects performed 10 acquisition trials and 10 retention trials the day after acquisition. The data were analyzed using an independent t-test and a Mann-Whitney U test. Participants in the self-controlled group achieved significantly more effective learning than the yoked group during the acquisition and retention test except anterior/posterior (AP) body sway. These results suggest that a feedback schedule which is controlled by the individuals with hemiplegics may be more effective in balancing training than a yoked KR which is not controlled by the subject.

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ITO Thin Film Ablation Using KrF Excimer Laser and its Characteristics

  • Lee, Kyoung-Chel;Lee, Cheon;Le, Yong-Feng
    • Transactions on Electrical and Electronic Materials
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    • v.1 no.4
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    • pp.20-24
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    • 2000
  • This study aimed to develop ITO(Indium Tim Oxide) tin films ablation with a pulsed type KrF excimer laser required for the electrode patterning application in flat panel display into small geometry on a large substrate are. The threshold fluence for ablating ITO on glass substrate is about 0.1 J/㎠. And its value is much smaller than that using 3 .sup rd/ harmonic Nd:YAG laser. Through the optical microscope measurement the surface color of the ablated ITO is changed into dark brown due to increase of surface roughness and transformation of chemical composition by the laser light. The laser-irradiated regions were all found to be electrically isolating from the original surroundings. The XPS analysis showed that the relative surface concentration of Sn and In was essentially unchanged (In:Sn=5:1)after irradiating the KrF excimer laser. Using Al foil made by 2$\^$nd/ harmonic Na:YAG laser, the various ITO patterning is carried out.

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Pathogenicity of a Korean isolate of Pepper mild mottle virus and development of full-length cDNA clone for infectious in vitro transcripts

  • J.Y. Yoon;Park, J.K.;Y.M. Yu;K.H. Ryu
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.143.3-144
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    • 2003
  • A Korean isolate of Pepper mild mottle virus (PMMoV-Kr) was isolated from a diseased pepper crop in Chunchon, Korea. The isolate was biologically purified on Nicoticaa tabacum cv. Xanthi-nc by successive single local transfer steps, and propagated on N. tabacum cv. Samsun. PMMoV-Kr could systemically infect on N. glauca, N. benthmiana, N. occidentalis and Lycopersicon esculentum, which is typical of known isolates of PMMoV. PMMoV-Kr belongs to the pathotype P1,2 based on pepper-tobamoviral indicator experiments; Capsicn chinone harboring L3 gene revealed resistant (necrotic local lesion on inoculated leaf, HR) whereas L+, L1 and L2 pepper plants expressed susceptible reactions of mosaic systemic symptoms for the isolate. To confirm the pathology and delineate symptom determinant of the isolate, full-length cDNAs of PMMoV-Kr were amplified by RT-PCR with a primer set corresponding to the 5'- and 3'-ends of PMMoV. The RT-PCR molecules amplified from genome RNA of the isolate was cloned into the pUC18 vector. Full-length cDNA clones constructed under the control of the T7 RNA promoter could be successfully transcribed to produce in vitro transcript RNA. Infectivity of the capped transcripts and its progeny virus was verified by Western blot and RT-PCR analyses.

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Theoretical Calculation of Activity Coefficients of Liquid Mixtures (액체혼합물의 활동도계수의 이론적 계산)

  • Moon Dae-Won;Jhon Mu Shik;Lee Taikyue
    • Journal of the Korean Chemical Society
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    • v.21 no.6
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    • pp.395-403
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    • 1977
  • Significant structure theory was applied to some liquid mixture systems ranging from simple monatomic molecule systems to polyatomic molecule systems, and the activity coefficients ${\gamma}$ of the liquid mixture systems were calculated over whole mole fractions using the following thermodynamic relation $RTln_{{\gamma}i} = (\frac{{\partial A}^E}{{\partial N}_i})_{T,V,N_i} $ where $A^E$ represents the excess Helmholtz free energy, and $N_i$ is the number of molecules of component i. The activity coefficients of the solutions such as monatomic molecule systems (Ar-Kr, Kr-Xe) and diatomic molecule systems $(Ar-O_2,\;N_2-CO)$ and $CH_4-Kr$ systems whose components have similar shapes for intermolecular potential curves were calculated successfully only with the ${\delta}E_s$, correction parameter for energy $E_s$, for mixture systems. For other systems such as $Ar-N_2,\;O_2-N_2\;and\;CH_4-C_3H_8$ whose components have dissimilar intermolecular potential curve shapes an additional correction parameters ${\delta}$V and even one more parameter ${\delta}$n were necessary [see Eqs.(10)∼(12)].

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Design and fabrication of dichroic mirror and broadband H/R mirror for color separation (색분리를 위한 Dichroic미러 및 광대역 고반사 미러의 설계와 제작)

  • 박영준;박정호;황영모;김용훈;이진호;이상학
    • Korean Journal of Optics and Photonics
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    • v.8 no.3
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    • pp.183-188
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    • 1997
  • Cut-off filters would reject all the radiation below and transmit all that above a certain wavelength or vice versa. In this paper, we study design and farbrication of dichroic mirror and broadband high reflective mirror for color separation of white laser beam source to R.G.B color beam source. In laser display system, color separation is very important. We fabricated below specific component for finite color separation of the Kr-Ar laser source. At 45$^{\circ}$ incidence s-polarized light , it is required that - H/R in blue region R>99%, H/T in green and red region T>90% - H/R in green and red region R>99%, H/T in blue region T>90% - H/R in green region R>99%, H/T in red region T>90% We composed the optical system and realize the full color image.

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An Energy Efficient Intelligent Method for Sensor Node Selection to Improve the Data Reliability in Internet of Things Networks

  • Remesh Babu, KR;Preetha, KG;Saritha, S;Rinil, KR
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.9
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    • pp.3151-3168
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    • 2021
  • Internet of Things (IoT) connects several objects with embedded sensors and they are capable of exchanging information between devices to create a smart environment. IoT smart devices have limited resources, such as batteries, computing power, and bandwidth, but comprehensive sensing causes severe energy restrictions, lowering data quality. The main objective of the proposal is to build a hybrid protocol which provides high data quality and reduced energy consumption in IoT sensor network. The hybrid protocol gives a flexible and complete solution for sensor selection problem. It selects a subset of active sensor nodes in the network which will increase the data quality and optimize the energy consumption. Since the unused sensor nodes switch off during the sensing phase, the energy consumption is greatly reduced. The hybrid protocol uses Dijkstra's algorithm for determining the shortest path for sensing data and Ant colony inspired variable path selection algorithm for selecting active nodes in the network. The missing data due to inactive sensor nodes is reconstructed using enhanced belief propagation algorithm. The proposed hybrid method is evaluated using real sensor data and the demonstrated results show significant improvement in energy consumption, data utility and data reconstruction rate compared to other existing methods.

The Effect of Feedback on Somesthetic Video Game Training for Improving Balance of Stroke Patients (뇌졸중 환자의 균형 증진을 위한 체감형 전자게임 훈련에 적용되는 되먹임 방식에 따른 효과)

  • Ahn, Myung-Hwan;Park, Ki-Dong;You, Young-Youl
    • Journal of the Korean Society of Physical Medicine
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    • v.7 no.4
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    • pp.401-409
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    • 2012
  • PURPOSE: The purpose of this study is to assess the difference in the effect of provision of feedback on knowledge of performance and knowledge of result in the training using somesthetic video game aimed at enhancement of balance of hemiparalysis patients due to stroke. METHODS: 20 stroke patients participated in the study. The participants were randomly divided into 2 groups, namely, the knowledge of performance feedback group (KP group, n=10) and the knowledge of result feedback group (KR group, n=10). Both groups received somesthetic video game training 5 times (30 minutes each) a week for total of 4 weeks. The KP group received feedback on the patterns of movement in execution of somesthetic video game. The KR group received feedback on the scores acquired following execution of somesthetic video game. Verification of the significance of the data was performed through paired t-test and independent t-test. RESULTS: Both groups displayed significant reduction in the movement of center of pressure (COP) and Timed up and Go (TUG), and significant increase in the Berg Balance Scale (BBS) following the training. Although the movement of COP was reduced for the KP group in comparison to the KR group, it was not statistically significant, and there was significant reduction in TUG and significant increase in BBS. CONCLUSION: The above results illustrate that provision of feedback on knowledge of performance is more effective than feedback on knowledge of result in somesthetic video game training for the purpose of enhancement of balance in stroke patients. Therefore, provision of feedback on knowledge of performance is necessary in somesthetic video game training for stroke patients.

Release Characteristics of Fission Gases with Spent Fuel Burn-up during the Voloxidation and OREOX Processes (사용후핵연료의 연소도 변화에 따른 산화 및 OREOX 공정에서 핵분열기체 방출 특성)

  • Park, Geun-Il;Cho, Kwang-Hun;Lee, Jung-Won;Park, Jang-Jin;Yang, Myung-Seung;Song, Kee-Chan
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.1
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    • pp.39-52
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    • 2007
  • Quantitative analysis on release behavior of the $^{85}Kr\;and\;^{14}C$ fission gases from the spent fuel material during the voloxidation and OREOX process has been performed. This thermal treatment step in a remote fabrication process to fabricate the dry-processed fuel from spent fuel has been used to obtain a fine powder The fractional release percent of fission gases from spent fuel materials with burn-up ranges from 27,000 MWd/tU to 65,000 MWd/tU have been evaluated by comparing the measured data with these initial inventories calculated by ORIGEN code. The release characteristics of $^{85}Kr\;and\;^{14}C$ fission gases during the voloxidation process at $500^{\circ}C$ seem to be closely linked to the degree of conversion efficiency of $UO_2\;to\;U_3O_8$ powder, and it is thus interpreted that the release from grain-boundary would be dominated during this step. The high release fraction of the fission gas from an oxidized powder during the OREOX process would be due to increase both in the gas diffusion at a temperature of $500^{\circ}C$ in a reduction step and in U atom mobility by the reduction. Therefore, it is believed that the fission gases release inventories in the OREOX step come from the inter-grain and inter-grain on $UO_2$ matrix. It is shown that the release fraction of $^{85}Kr\;and\;^{14}C$ fission gases during the voloxidation step would be increased as fuel burn-up increases, ranging from 6 to 12%, and a residual fission gas would completely be removed during the OREOX step. It seems that more effective treatment conditions for a removal of volatile fission gas are of powder formation by the oxidation in advance than the reduction of spent fuel at the higher temperature.

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