• Title/Summary/Keyword: ${\pi}$ value

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A Study on the Physicochemical Properties of a Sweet Flavor for Oriental Herbal Medicines (감미 한약재의 이화학적 특성에 관한 연구)

  • Deog-Bin, Lim;Ho-Young, Choi;Jae-Seong, Rhee
    • The Journal of Korean Medicine
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    • v.23 no.1
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    • pp.61-66
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    • 2002
  • 목적: 본 연구는 감미의 작용에 관한 "감보" 등의 이론적 바탕과 약물의 이화학적인 특성을 통해 약효를 어느 정도 예측하고자 하였다. 방법: 한약재의 오미별 이화학적 특성을 구명하기 위하여 수소이온농도(pH), $200^{\circ}C$$550^{\circ}C$에서의 질량감소량, 전기전도도, 가시부 및 자외부 흡수 spectrum의 전자전이에 따른 비율, TLC에 의한 주요 성분의 이동율($R_{f}{\;}value$)과 낮은 성분의 이동율($R_{f}{\;}value$)을 측정하였다. 결과: 전탕에 따른 수소이온농도(pH)의 평균은 $5.24{\pm}0.56$이었으며. 약재의 휘발 성분 및 수분 함유량은 $288{\pm}125mg$이었고, 유기물함량의 평균은 $867{\pm}116g$이었으며, 전기전도도의 평균은 $5.46{\pm}0.93S/cm$이었으며, 가시부 및 자외부 흡수 spectrum의 전자전이에 따른 흡광도 비율($\pi{\\rightarrow}\pi^{*}/n{\rightarrow}\pi^{*}$)의 평균은 $3.043{\pm}0.679$이었으며, TLC에 의한 주요 성분의 이동율($R_{f}{\;}value$)의 평균은 $0.553{\pm}0.317$이었고, TLC에 의한 낮은 성분의 이동율($R_{f}{\;}value$)의 평균은 $0.136{\pm}0.122$ 이었다. 결론:약재의 pH는 모두 7보다 낮은 약산성 이었으며, 약재의 휘발 성분 및 수분 함유량은 대략 10~50%정도를 나타내었다. 유기물함량은 대략 80~95%정도를 나타내었다. 전기전도도를 통하여 산약이나 감초는 이온성 물질을 많이 포함하고 있으리라 추정된다.

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Performance Analysis of the prioritized MAC protocol under the CATV/LAN network (CATV/LAN 전송망에서 우선권 문제를 추가한 MAC프로토콜의 성능해석에 관한 연구)

  • 우상철;윤종호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.1A
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    • pp.81-89
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    • 2000
  • In this paper, we analyzed the performance for CATV/LAN added priority problem. Upstrea nm channel which analyzed very deeply for CATV/LAN network have the preferential access property depending upon that positionand unidirectional property. To solve that fairness problem and priority, we propose the CSMA-CD/U/P-P protocolthat transmit as P1 probability if data packets happen. We assumed 2-Class priority(high, low). As the analyticresult and simulation, we obtained P1, value and its average delay time under priority problem assumed twoscenarios. Also, we get its variance value and queue length. Especially, the mean delay time increases nearer thanposition from H/E

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A Multipath Delay Time Detection Method For $\frac{\pi}{4}$ Shift QPSK Modulation Under The Frequency Selective Fading Environment (주파수 선택성 페이딩 환경하에서 $\frac{\pi}{4}$ shift QPSK 변조방식에 대한 다중파의 시간지역 검출법 제안)

  • 조병진;김대영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.10
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    • pp.941-950
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    • 1991
  • channel is severely degraded by multipath delay time spread. In this paper. We propose a simple multipath delay time detection method, which has a merit of in serviceable, yet simple H/W realizability for $\pi/4$ shift QPSK by detecting cross channel interference. A $\pi/4$ shift QPSK signal originally has quadrature channel(Q-ch) component. Thus in order to measure CCI between in-phase channel(I-ch) and quadrature channel(Q-ch), which closely related to multipath delay time, Frequency doubling scheme(frequency doubler) and differential detector is proposed, which makes $\pi/4$ shift QPSK signal look like BPSK and also makes it possible for CCI to be detected at I-ch detector output. To get an information from time varying I-ch output signal under the multipath lading environment, a method for obtaining the mean of the absolute value$(V_{MABS}(t))$ and another one for obtaining the root mean square value$(V_{RMS}(t))$ of CCI are proposed. Furthermore, a relationship between delay spread and CCI is also analyzed. In order to confirm theoretical results, computer simulation has been carried out under the quasi-static and Reyleigh distributed two ray multipath fading environments. A fairly good result was obtained. However it was also shown that this method is sensitive to bandwidth restriction to some extent. In addition, some idea for a simple hardware realization for the frequency doubler are given.

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Investigating the Use of Energy Performance Indicators in Korean Industry Sector (한국 산업부문의 에너지성과 지표 이용에 관한 연구)

  • Shim, Hong-Souk;Lee, Sung-Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.707-725
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    • 2021
  • Energy management systems (EnMS) contribute to sustainable energy saving and greenhouse gas reduction by emphasizing the role of energy management in production-oriented economies. Although understanding the methods used to measure energy performance is a key factor in constructing successful EnMS, few attempts have been made to examine these methods, their applicability, and their utility in practice. To fill this research gap, this study aimed to deepen the understanding of energy performance measures by focusing on four energy performance indicators (EnPIs) proposed by ISO 50006, namely the measured energy value, ratio between measured values, linear regression model, and nonlinear regression model. This paper presents policy and managerial implications to facilitate the effective use of these measures. An analytic hierarchy process (AHP) analysis was conducted with 41 experts to analyze the preference for EnPIs and their key selection criteria by the industry sector, and organization and user type. The findings suggest that the most preferred EnPI is the ratio between the measured values followed by the measured energy value. The ease of use was considered to be most important while choosing EnPIs.

Detection of Incidental Prostate Cancer or Urothelial Carcinoma Extension in Urinary Bladder Cancer Patients by Using Multiparametric MRI: A Retrospective Study Using Prostate Imaging Reporting and Data System Version 2.0 (방광암 환자의 다중 매개 자기공명영상에서 우연히 발견된 전립선암 또는 요로상피세포암종의 전립선 침범의 검출: 전립선 이미징 보고 및 데이터 시스템 버전 2.0을 사용한 후향적 연구)

  • Sang Eun Yoon;Byung Chul Kang;Hyun-Hae Cho;Sanghui Park
    • Journal of the Korean Society of Radiology
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    • v.81 no.3
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    • pp.610-619
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    • 2020
  • Purpose The study aimed to investigate the role of Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) in predicting incidental prostate cancer (PCa) or urothelial carcinoma (UCa) extension in urinary bladder (UB) cancer patients. Materials and Methods A total of 72 UB cancer patients who underwent radical cystoprostatectomy and 3 Tesla multiparametric MRI before surgery were enrolled. PI-RADS v2 ratings were assigned by two independent radiologists. All prostate specimens were examined by a single pathologist. We compared the multiparametric MRI findings rated using PI-RADS v2 with the pathologic data. Results Of the 72 UB cancer patients, 29 had incidental PCa (40.3%) and 20 showed UCa extension (27.8%), with an overlap for 3 patients. With a score of 4 as the cut-off value for predicting incidental PCa, the diagnostic accuracy was 65.3%, specificity was 90.7%, and positive predictive value (PPV) was 66.7%. The diagnostic accuracy for incidental UCa extension was 47.2%, specificity was 92.3%, and PPV was 83.3%. Conclusion Despite the low diagnostic accuracy, the PPV and specificity were relatively high. Therefore, PI-RADS v2 scores of 1, 2, or 3 may help exclude the probability of incidental PCa or UCa extension.

A Study on the Inverse Calibration of Industrial Robot Using Neural Networks (신경회로망을 이용한 산업용 로봇의 역보정에 관한연구)

  • 서운학
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.2
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    • pp.108-115
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    • 1999
  • This paper proposes the robot inverse calibration method using a neural networks. A highorder networks called Pi-Sigma networks has been used. The Pi-Sigma networks uses linear summing units in the hidden layer and product unit in output layer. The inverse calibration model which compensates the difference of joint variables only between measuring value and analytic value about the desired pose(position orientation) of a robot is proposed. The compensated values are determined by using the weights obtained from the learning process of the neural networks previously. To prove the reasonableness the SCARA type direct drive robot(4-DOF) and anthropomorphic robot(6-DOF) are simulated. It shows that the proposed calibration method can reduce the errors of the joint variables from $\pm$3 to $\pm$0.1.

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A Study on the Inverse Calibration of Industrial Robot(AM1) Using Neural Networks (신경회로망을 이용한 산업용 로봇(AM1)의 역보정에 관한 연구)

  • 안인모
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.131-136
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    • 1999
  • This paper proposes the robot inverse calibration method using a neural networks. A highorder networks called Pi-Sigma networks has been used. The Pi-Sigma networks uses linear summing units in the hidden layer and product unit in output layer. The inverse calibration model which compensates the difference of joint variables only between measuring value and analytic value about the desired pose(position, orientation) of a robot is proposed. The compensated values are determined by using the weights obtained from the learning process of the neural networks previously. To prove the reasonableness, the SCARA type direct drive robot(4-DOF) and anthropomorphic robot(6-DOF) are simulated. It shows that the proposed calibration method can reduce the errors of the joint variables from $\pm$2$^{\circ}$to $\pm$ 0.1$^{\circ}$.

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A Comparative Study of Controllers for CSI Fed Induction Motor

  • Kumar, Piush;Agarwal, Vineeta
    • Journal of Power Electronics
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    • v.10 no.2
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    • pp.165-170
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    • 2010
  • This paper presents a comparative study of P and PI controllers for a current source inverter (CSI) fed induction motor drive system. A dq model has been used which incorporates the induction motor and the inverter power supply with current feedback. The model is used first to generate the steady state curves to determine the operating point through computer simulations using the software package MATLAB. Then a transient analysis has been carried out for different values of the speed and current controller parameters. The controller value is adjusted by the Ziegler-Nichols method. It has been observed that the transient time to reach the steady state value is larger with the PI controller than with the P controller.

Fucoidan Stimulates Glucose Uptake via the PI3K/AMPK Pathway and Increases Insulin Sensitivity in 3T3-L1 Adipocytes (후코이단의 3T3-L1 지방세포에서 PI3K/AMPK 경로를 통한 포도당 흡수 촉진 및 인슐린 민감성 증진 효과)

  • Lee, Ji Hee;Park, Jae Eun;Han, Ji Sook
    • Journal of Life Science
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    • v.31 no.1
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    • pp.1-9
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    • 2021
  • Brown seaweeds have been shown to decrease blood glucose levels and improve insulin sensitivity previously. In this study, we investigated the effect of fucoidan, a complex polysaccharide derived from brown seaweeds, on glucose uptake to improve insulin resistance, and examined its mechanism of action in 3T3-L1 adipocytes. We observed that fucoidan significantly increased glucose uptake and it was related to an increased expression of plasma membrane-glucose transporter 4 (PM-GLUT4) in 3T3-L1 adipocytes. Fucoidan treatment increased the activation of phosphatidylinositol-3-kinase (PI3K) and the phosphorylation of insulin receptor substrate 1 (IRS1tyr) compared with that of the control cells. Fucoidan also promoted the phosphorylation of Akt and protein kinase C (PKC)-λ/ζ compared to that of the control cells. Moreover, fucoidan significantly upregulated acetyl-CoA-carboxylase (ACC) and adenosine monophosphate - activated protein kinase (AMPK) phosphorylation. As a result, translocation of GLUT4 was significantly enhanced in 3T3-L1 adipocytes, which significantly promoted glucose uptake via the PI3K/AMPK pathways. The elevation of glucose uptake by fucoidan was blocked by inhibitor of PI3K and inhibitor of AMPK in 3T3-L1 adipocytes. These findings indicate that fucoidan might ameliorate glucose uptake through GLUT4 translocation to the plasma membrane by activating the PI3K/Akt and AMPK pathways in 3T3-L1 adipocytes. Fucoidan is thought to be of high material value to diabetes treatments and functional foods.

Angle Difference Based State Transition Modeling Technique for the Classification of Signal Pattern from the Sensor Array (센서 어레이의 신호패턴 분류를 위한 각도 변이 기반 상태 천이 모델링 기법)

  • Kim, A-Ram;Lee, Seung-Jae;Kim, Sung-Kyung;Park, Soo-Hyun;Kim, Chang-Hwa
    • Journal of the Korea Society for Simulation
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    • v.15 no.3
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    • pp.49-60
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    • 2006
  • We propose a method to use a state transition model so that the sensing object can be distinguished through classification of signal patterns sensed by a sensor array. Focusing on the design of the model that is able to distinguish the sensed object more exactly, we present an idea in which the modeling elements, 'states' and 'transitions' are defined as each same-sized angle intervals into which the angle interval $(-\frac{\pi}{2},\frac{\pi}{2})$ is divided and the angle differences between adjacent signal values on sampling signal value sequence value sequence sensed from the sensor array in the uniform time interval, respectively. In addition we show the usefulness of our model through experiments.

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