• 제목/요약/키워드: Reversal method

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A Cross-sectional Study of Pattern Identification in Adolescents - School doctor Program of Seongnam - city in 2017 (청소년들의 변증에 대한 단면조사 연구 - 2017 성남시 교의사업을 중심으로 -)

  • Lee, Dong-Nyung;Shin, Seon Mi;Park, Jeong-Su;Sung, Hyun Kyung;Go, Jae-Eon;Go, Ho-Yeon
    • Journal of Society of Preventive Korean Medicine
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    • v.23 no.2
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    • pp.101-115
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    • 2019
  • Objective : This study is aimed to application possibility and status of pattern identification in middle and high school students. Method : This study was cross-sectional study. We recruited 277 students through school doctor program of Seongnam city in 2017. Male students are 66 in middle school, 32 in high school. Female students are 117 in middle school, 62 in high school. For pattern identification, we used the tool of Qui Xui Shui pattern identification in students. Students fill questionnaires in inquiry of pattern identification and Korean medicine doctor diagnosis inspection and palpation of students. Results : Among 277 students, no pattern identification were 114(41.2%). It appeared in the order of phlegm, blood deficinecy, qi deficiency, qi stagnation and qi reversal. Qi deficiency, qi stagnation, qi reversal, blood deficiency and phlegm pattern are statistically significant by gender except blood stagnation. of 277 students, 105 (37.9%) had one more pattern identification. Conclusions : This study showed possibility of Qui Xui Shui pattern for student health management. In the future, large scale follow up study will be needed to clarify the relationship of pattern identification and student's health.

Parabiosis and Blood Exchange Techniques in Aging Research (개체병렬결합(parabiosis)실험모델과 혈액교환을 이용한 노화(aging)연구 분석)

  • Kyung Tae Chung
    • Journal of Life Science
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    • v.33 no.2
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    • pp.208-215
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    • 2023
  • In recent decades, the field of aging research has progressed from the genetic and cellular levels to in vivo models of blood exchange. Since genes capable of extending the lifespan in C. elegance have been reported, various potential target molecules have been discovered through genomics, proteomics, metabolomics, and transcriptomics. Accordingly, research on the interactions between target molecules has also been increasing. The parabiosis method, in which two experimental animals are surgically combined, was introduced, and a factor that could reverse the aging phenomenon was discovered using this method. The parabiosis method is used to find more accurate and effective aging-reversal factors that could exist in young blood. As more new evidence has been revealed, the parabiosis method has established a new paradigm for aging research. Moreover, a device capable of exchanging blood elaborately in laboratory animals was published in 2022 and presented new results necessary for aging reversal. Since GDF11, was reported, many other anti-aging candidates that are soluble factors in blood, such as β2m, TIMP2, VCAM1, Gpld1, and clusterin, have been discovered. In addition, mcicroglia cells and neuroinflammation have been directly proven to be aging factors. These latest research results were obtained by parabiosis, the newly designed device for plasmapheresis, and injecting young blood or conditioned blood methods. In this review, we discuss the latest research results using the device and young blood administration in old mice.

A channel parameter-based weighting method for performance improvement of underwater acoustic communication system using single vector sensor (단일 벡터센서의 수중음향 통신 시스템 성능 향상을 위한 채널 파라미터 기반 가중 방법)

  • Kang-Hoon, Choi;Jee Woong, Choi
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.6
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    • pp.610-620
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    • 2022
  • An acoustic vector sensor can simultaneously receive vector quantities, such as particle velocity and acceleration, as well as acoustic pressure at one location, and thus it can be used as a single input multiple output receiver in underwater acoustic communication systems. On the other hand, vector signals received by a single vector sensor have different channel characteristics due to the azimuth angle between the source and receiver and the difference in propagation angle of multipath in each component, producing different communication performances. In this paper, we propose a channel parameter-based weighting method to improve the performance of an acoustic communication system using a single vector sensor. To verify the proposed method, we used communication data collected from the experiment conducted during the KOREX-17 (Korea Reverberation Experiment). For communication demodulation, block-based time reversal technique which is robust against time-varying channels were utilized. Finally, the communication results showed that the effectiveness of the channel parameter-based weighting method for the underwater communication system using a single vector sensor was verified.

Evaluation of polarization and mobile charge in ferroelectric films using TVS(Triangular Voltage Sweep) method (삼각전압소인법을 이용한 강유전체 박막내에서의 분극 및 유동이온에 대한 평가)

  • 김용성;이남열;정순원;김진규;정상현;김광호;유병곤;이원재;유인구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.86-89
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    • 2000
  • The detection technique both the polarization and the mobile charge density at the same time in ferroelectric films on Si using TVS method have been proposed. This method yields a polarizable and an ionic displacement current peaks whose areas are proportional to the total polarization reversal charge and the total moble ionic space charge, respectively. The calculated polarization and the mobile charge density were 0.42 [$\mu$C/$\textrm{cm}^2$] and 5.5$\times$10$^{11}$ (ions/$\textrm{cm}^2$) in the SBT film of MFIS structure measured at 25$0^{\circ}C$, and 1.4 [$\mu$C/$\textrm{cm}^2$] in the LiNbO$_3$ film of MFS structure measured at 30$0^{\circ}C$, respectively.

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Ultimate Analysis of Prestressed Concrete Cable-Stayed Bridges (프리스트레스트 콘크리트 사장교의 극한해석)

  • Lee, Jae Seok;Kang, Young Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.5
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    • pp.85-98
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    • 1993
  • A method of analysis for the material and geometric nonlinear analysis of planar prestressed concrete cable-stayed bridges including the time-dependent effects due to load history, creep, shrinkage, aging of concrete and relaxation of prestress is described. The analysis procedure, based on the finite element method, is capable of predicting the response of these structures through elastic, cracking, inelastic and ultimate ranges. The nonlinear formulation for the description of motion is based on the updated Lagrangian approach. To account for the material nonlinearity, nonlinear stress-strain relationship and cracking of concrete, nonlinear stress-strain relationships of reinforcing steel, prestressing steel, and cable, including load reversal are given. Results from a numerical examples on ultimate analyses of cable-stayed bridges are presented to illustrate the analysis method.

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Practical Silicon-Surface-Protection Method using Metal Layer

  • Yi, Kyungsuk;Park, Minsu;Kim, Seungjoo
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.4
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    • pp.470-480
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    • 2016
  • The reversal of a silicon chip to find out its security structure is common and possible at the present time. Thanks to reversing, it is possible to use a probing attack to obtain useful information such as personal information or a cryptographic key. For this reason, security-related blocks such as DES (Data Encryption Standard), AES (Advanced Encryption Standard), and RSA (Rivest Shamir Adleman) engines should be located in the lower layer of the chip to guard against a probing attack; in this regard, the addition of a silicon-surface-protection layer onto the chip surface is a crucial protective measure. But, for manufacturers, the implementation of an additional silicon layer is burdensome, because the addition of just one layer to a chip significantly increases the overall production cost; furthermore, the chip size is increased due to the bulk of the secure logic part and routing area of the silicon protection layer. To resolve this issue, this paper proposes a practical silicon-surface-protection method using a metal layer that increases the security level of the chip while minimizing its size and cost. The proposed method uses a shift register for the alternation and variation of the metal-layer data, and the inter-connection area is removed to minimize the size and cost of the chip in a more extensive manner than related methods.

Trends of Underwater Communications and Channel Environment Characteristics (수중통신의 국내외 동향 및 채널환경특성)

  • Kim, Nam-Ri;Chung, Jea-Hak
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.5
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    • pp.243-247
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    • 2009
  • For obtaining high speed data rate, underwater acoustic communication has several problems by the different environmental problem compared to wireless communication. To overcome this problem, the research is going steadily. In this paper, the property of underwater acoustic channel is considered, and the explanation of recently various method of transmitting and receiving and the domestic and foreign trend of underwater acoustic communication are taken into account.

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Performance prediction of mixed-flow pumps (혼류 펌프의 성능 해석)

  • O, Hyeong-U;Yun, Ui-Su;Jeong, Myeong-Gyun;Ha, Jin-Su
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.1
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    • pp.70-78
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    • 1998
  • The present study has tested semi-empirical loss models for a reliable performance prediction of mixed-flow pumps with four different specific speeds. In order to improve the predictive capabilities, this paper recommends a new internal loss model and a modified parasitic loss model. The prediction method presented here is also compared with that based on two-dimensional cascade theory. Predicted performance curves by the proposed set of loss models agree fairly well with experimental data for a variety of mixed-flow pumps in the normal operating range, but further studies considering 'droop-like' head performance characteristic due to flow reversal in mixed-flow impellers at low flow range near shut-off head are needed.

Characterization of step-edge dc SQUID magnetometer fabricated on sapphire substrate (사파이어 기판 위에 제작된 step-edge dc SQUID magnetometer의 특성)

  • 임해용;박종혁;정구락;한택상;김인선;박용기
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.127-130
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    • 2002
  • Step-edge dc SQUID magnetometers have been fabricated on sapphire substrate. Ce$O_{2}$ buffer layer and $YBa_{2}$$Cu_{3}$ $O_{7}$(YBCO) films were deposited in-situ on the low angle (~$35^{\circ}$)steps formed on the substrates. Typical 5-$\mu$m-wide junction has $R_{N}$ of 4 $\Omega$ and $I_{c}$ of 60 $\mu$A with $I_{c}$$R_{N}$ product of 240 $\mu$V at 77 K. According to applied bias current, depth of voltage modulation was changed and maximum voltage was measured 100~300 fT/$\checkmark$ Hz at 100 Hz, and about 1.5 pT/$\checkmark$ Hz at 1 Hz. For ac bias reversal method, field noise was decreased in the 1/f region. The QRS peak of magneto-cardiogram was measured 50 pT in the magnetically shielded room.

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Study on the effects of space charge and conduction current by reversal of polarity (극성반전에 따른 공간전하 분포와 전도전류의 변화)

  • Gwak, Min-Woo;HwangBo, Seung;Chun, You-Jun;Shin, Hyun-June
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1578-1579
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    • 2011
  • 본 논문에서는 고분자 절연체가 인가된 전압의 시간에 따라 변화하는 공간전하와 전도 전류의 영향에 대하여 조사를 하였다. 또한 극성반전에 따른 공간전하의 분포와 전도 전류에 변화에 대한 연구를 실시하였다. 기존의 공간전하 분포 측정법들은 주로 고분자 절연재료 내에서 공간전하분포의 측정만을 목표로 한 반면에 공간전하 측정법 중의 하나인 PEA(Pulsed Electro-Acoustic method)을 개선시켜 공간전하와 전도전류의 동시 측정을 가능하게 하였다. 개선된 PEA법은 시간변화에 따른 공간전하와 전기전도의 직접적인 상관관계와 미리 형성 되어 있는 공간전하가 전기전도 및 절연특성에 미치는 영향을 직접적으로 분석할 수 있는 장점을 가지고 있다. 이러한 공간전하와 전류의 동시 측정법을 이용하여 연구하였다.

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