• Title/Summary/Keyword: S-parameters

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Modeling for Efficient QoS support in wireless Networks (무선 네트웍에서의 효율적인 QoS제공을 위한 모델링)

  • 이성협;염익준
    • Proceedings of the IEEK Conference
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    • 2001.06a
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    • pp.249-252
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    • 2001
  • This paper focuses on the consideration of not only QoS parameters in wired network, but also QoS parameters in wireless network that supported for the Efficient QoS in the Al1 Service Levels. So, We supposed the "Efficient QoS Model" that guaranteed the QoS parameters "Loss Profile" , "Service Degradation" , "Latency and Jittering" , "Mobility of Mobile User" , "Probability of seamless communication" in wired-wireless networks. And the Method of Efficient QoS support that we supposed consists of "Multicast Routing-RSVP Protocol architecture based on Mobile IP" and "Protocols internetworking model ".

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Host Plant-Antheraea mylitta Interactions and Its Effect on Reproductive and Commercial Parameters

  • Rath, S.S.;Singh, G.S.;Singh, S.S.;Singh, M.K.;Suryanarayana, N.;Vijayaprakash, N.B.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.17 no.2
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    • pp.205-209
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    • 2008
  • Impact of food plant on reproductive and commercial parameters in Antheraea mylitta, a polyphagous insect of economic importance was studied upon feeding the insect larvae on the same host plants for six continuous generations. A. mylitta larvae were fed upon Terminalia tomentosa, Terminalia arjuna and Zizyphus jujuba and restricted them to the same host plant for six generations to document the quantitative improvement in reproductive and commercial parameters. The parameters showed significant improvement in all the host plants studied over their respective controls. Fecundity among the reproductive parameters was highly improved than others (85.9% in T. tomentosa; 58% in T. arjuna and 49.7% in Z. jujuba). Likewise in commercial parameters, the shell weight in male showed the highest improvement (by 52.9%, 45.8% and 42.1% in T. tomentosa; T. arjuna and Z. jujuba respectively). On the other hand, the shell ratio percentage in female recorded the lowest improvement. The values for all characters were recorded a decline in T. arjuna and Z. jujuba fed ones over T. tomentosa, except that of shell ratio percentage in female has registered an increase in Z jujuba fed. The study thus revealed the comparative superiority of T. tomentosa over T. arjuna and Z. jujuba.

Extraction of Extrinsic Parameters for GaAs MESFET by S-parameters (S-파라미터를 이용한 GaAs MESFET의 외부 파라미터 추출)

  • 조영송;나극환;박광호;신철재
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.2 no.2
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    • pp.30-37
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    • 1991
  • The modified method which determines the extrinsic parameters at the small signal equivalent model for GaAs MESFET is presented. It is important that extrinsic parameters are completely eliminated, in order to calculate exact intrinsic parameters. Extrinsic circuit is established by transmission lines, parasitic inductors and capacitors. After these are extracted by S-parameters, intrinsic parameters are calculated. Especially, frequency dependence of parastic inductance and capacitance is considerally constant.

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A Study on Tire Radial Force Variation and Modal Testing (타이어 상하 힘변동과 모드 시험에 관한 연구)

  • Park, S.K.;Kim, J.K.;Song, S.K.
    • Journal of Power System Engineering
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    • v.2 no.3
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    • pp.55-59
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    • 1998
  • This paper probes into the influence of tire uniformity on tire's modal parameters with the method of experimental modal analysis. Two radial tires of the same kind with different uniformity level are taken to be tested at different exciting points and real modal parameters are abstracted. The differences of their modal parameters are presented. Then tire transfer functions are constructed with experimental modal parameters and ideal modal parameters respectively. It is found that the measured transfer functions of tire of good uniformity are closer to ideal transfer function than that of tire of bad uniformity. The study shows evident interrelation of experimental modal parameters and tire uniformity, and further study should be of great value.

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Frequency-Variant Power and Ground Plane Model for Electronic Package (패키지의 주파수 의존형 파워 및 그라운드 평판 모델)

  • 이동훈;어영선
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.385-388
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    • 1999
  • A new frequency-variant equivalent circuit model of power/ground plane is presented. The equivalent circuit is modeled with grid cells. The circuit parameters of each cell were extracted by using Fasthenry. To verify the developed circuit model, its s-parameters are compared with the measured s-parameters 〔2〕 and the full-wave simulation-based s-parameters. Consequently, it is shown that our frequency-variant equivalent circuit model can accurately predict imperfect ground effects under the high frequency operation of electronic package.

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Association between metabolic syndrome components and cardiac autonomic modulation in southern Indian adults with pre-metabolic syndrome: hyperglycemia is the major contributing factor

  • Endukuru Chiranjeevi Kumar;Girwar Singh Gaur;Dhanalakshmi Yerrabelli;Jayaprakash Sahoo;Balasubramaniyan Vairappan;Alladi Charanraj Goud
    • The Korean Journal of Physiology and Pharmacology
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    • v.27 no.1
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    • pp.49-59
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    • 2023
  • Metabolic syndrome (MetS) involves multi-factorial conditions linked to an elevated risk of type 2 diabetes mellitus and cardiovascular disease. Pre-metabolic syndrome (pre-MetS) possesses two MetS components but does not meet the MetS diagnostic criteria. Although cardiac autonomic derangements are evident in MetS, there is little information on their status in pre-MetS subjects. In this study, we sought to examine cardiac autonomic functions in pre-MetS and to determine which MetS component is more responsible for impaired cardiac autonomic functions. A total of 182 subjects were recruited and divided into healthy controls (n=89) and pre-MetS subjects (n=93) based on inclusion and exclusion criteria. We performed biochemical profiles on fasting blood samples to detect pre-MetS. Using standardized protocols, we evaluated anthropometric data, body composition, baroreflex sensitivity (BRS), heart rate variability (HRV), and autonomic function tests (AFTs). We further examined these parameters in pre-MetS subjects for each MetS component. Compared to healthy controls, we observed a significant cardiac autonomic dysfunction (CAD) through reduced BRS, lower overall HRV, and altered AFT parameters in pre-MetS subjects, accompanied by markedly varied anthropometric, clinical and biochemical parameters. Furthermore, all examined BRS, HRV, and AFT parameters exhibited an abnormal trend and significant correlation toward hyperglycemia. This study demonstrates CAD in pre-MetS subjects with reduced BRS, lower overall HRV, and altered AFT parameters. Hyperglycemia was considered an independent determinant of alterations in all the examined BRS, HRV, and AFT parameters. Thus, hyperglycemia may contribute to CAD in pre-MetS subjects before progressing to MetS.

A New Extraction Method of GaAs/InGaP HBT Small-signal Equivalent Circuit Model Parameters (GaAs/InGaP HBT 소신호 등가회로 모델 파라미터의 새로운 추출방법)

  • 이명규;윤경식
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.357-360
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    • 2000
  • This paper describes a parameter extraction method for HBT(Heterojunction Bipolar Transistor) equivalent circuit model without measurements of special test structures or numerical optimizations. Instead, all equivalent circuit parameters are calculated analytically from small-signal S-parameters measured under different bias conditions. These values being extracted from the cutoff mode can be used to extract intrinsic parameters at the active mode. This method yields a deviation of about 1.3 % between the measured and modeled S-parameters.

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The Potential of Sentinel-1 SAR Parameters in Monitoring Rice Paddy Phenological Stages in Gimhae, South Korea

  • Umutoniwase, Nawally;Lee, Seung-Kuk
    • Korean Journal of Remote Sensing
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    • v.37 no.4
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    • pp.789-802
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    • 2021
  • Synthetic Aperture Radar (SAR) at C-band is an ideal remote sensing system for crop monitoring owing to its short wavelength, which interacts with the upper parts of the crop canopy. This study evaluated the potential of dual polarimetric Sentinel-1 at C-band for monitoring rice phenology. Rice phenological variations occur in a short period. Hence, the short revisit time of Sentinel-1 SAR system can facilitate the tracking of short-term temporal morphological variations in rice crop growth. The sensitivity of SAR backscattering coefficients, backscattering ratio, and polarimetric decomposition parameters on rice phenological stages were investigated through a time-series analysis of 33 Sentinel-1 Single Look Complex images collected from 10th April to 25th October 2020 in Gimhae, South Korea. Based on the observed temporal variations in SAR parameters, we could identify and distinguish the phenological stages of the Gimhae rice growth cycle. The backscattering coefficient in VH polarisation and polarimetric decomposition parameters showed high sensitivity to rice growth. However, amongst SAR parameters estimated in this study, the VH backscattering coefficient realistically identifies all phenological stages, and its temporal variation patterns are preserved in both Sentinel-1A (S1A) and Sentinel-1B (S1B). Polarimetric decomposition parameters exhibited some offsets in successive acquisitions from S1A and S1B. Further studies with data collected from various incidence angles are crucial to determine the impact of different incidence angles on polarimetric decomposition parameters in rice paddy fields.

The Tuning Method on Consequence Membership Function of T-S Type FLC (T-S형 퍼지제어기의 후건부 멤버십함수 동조방법)

  • Choi, Han-Soo;Lee, Kyoung-Woong
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.3
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    • pp.264-268
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    • 2011
  • This paper presents a Takagi-Sugeno (T-S) type Fuzzy Logic Controller (FLC) with only 3 rules. The choice of parameters of FLC is very difficult job on design FLC. Therefore, the choice of appropriate linguistic variable is an important part of the design of fuzzy controller. However, since fuzzy controller is nonlinear, it is difficult to analyze mathematically the affection of the linguistic variable. So this choice is depend on the expert's experience and trial and error method. In this paper, we propose the method to choose the consequence linear equation's parameter of T-S type FLC. The parameters of consequence linear equations of FLC are tuned according to the system error that is the input of FLC. The full equation of T-S type FLC is presented and using this equation, the relation between output and parameters can represented. The parameters are tuned with gradient algorithm. The parameters are changed depending on output. The simulation results demonstrate the usefulness of this T-S type 3 rule fuzzy controller.

An improved Robust and Adaptive Controller Design for a Robot Manipulator (로보트 매니퓰레이터의 개선된 견실 및 적응제어기의 설계)

  • Park, H.S.;Kim, D.H.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.6
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    • pp.20-27
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    • 1994
  • This paper presents a controller design to coordinate a robot manipulator under unknown system parameters and bounded disturbance inputs. To control the motion of the manipulator, an inverse dynamics control scheme is applied. Since parameters of the robot manipulators such as mass and inertia are not perfectly known, the difference between the actual and estimated parameters works as a disturbance force. To identify the unknown parameters, an improved adaptive control algorithm is directly derived from a chosen Lyapunov's function candidate based on the Lyapunov's Second Method. A robust control algorithm is devised to counteract the bounded disturbance inputs such as contact forces and disturbing forces coming from the difference between the actual and the estimated system parameters. Numerical examples are shown using three degree-of-freedom planar arm.

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