• Journal of electromagnetic engineering and science
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• v.16 no.1
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• pp.57-65
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• 2016

In this paper, based on the mode analysis of four-conductor lines, the extended mixed-mode chain-parameters and S-parameters of four-conductor lines are estimated using current division factors. The extended mixed-mode chain-parameters of cascaded four-conductor lines are then obtained with mode conversion. And, the extended mixed-mode S-parameters of cascaded four-conductor lines can be predicted from the transformation of the extended chain-parameters. Compared to the extended mixed-mode S-parameters of four-conductor lines, the cross-mode S-parameters are induced in the extended mixed-mode S-parameters of cascaded four-conductor lines, due to the imbalanced current division factors of cascaded two sections. The generated cross-mode S-parameters make the equivalent different- and common-mode conductors not independent from each other again. In addition, a new mode conversion, which applies the imbalanced current division factors, between the extended mixed-mode S-parameters and standard S-parameters is also proposed in this paper. Finally, the validity of the proposed extended mixed-mode S-parameters and mode conversion is confirmed by a comparison of the simulated and estimated results of shielded cable.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.37 no.1
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• pp.1-11
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• 2000

An accurate technique to retrieve HEMT modeling parameters with measurements of S-parameters and DC characteristics of HEMT is proposed. The extrinsic series resistances among HEMT modeling parameters are determined by the FUKUI method using the measured DC characteristics. And other parameters are determined by the measured S-parameters by HP 8510C Network Analyzer with various values of DC bias. The transconductance retrieved from the measured S-parameters, however, shows only 0.078% error comparing with the measured gm values. Therefore, the S-parameters measured directly for an individual transistor should be used for an accurate determination of the model parameters. The procedure for the retrieval of the circuit modeling parameters redescribed in detail in this thesis.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.205-210
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• 2012

This paper investigated the performance of QoS management using variations of RED parameters in Differentiated Service. Differentiated Service separates packets from a specific traffic by using QoS parameters such as CIR or PIR. A code point is used to mark each packet which is enqueued into each virtual queue. Different RED parameters are configured for virtual queues according to each code point. As the code point value increases, the RED parameters become harsher. To show QoS Management using variations of RED parameters, this paper used the policy model of time sliding window with 2 color marking (TSW2CM). Simulation results using NS-2 showed that the QoS management of a differentiated service can be obtained from using variations of RED parameters.

• Structural Engineering and Mechanics
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• v.69 no.4
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• pp.361-369
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• 2019

The determination of Paris' law parameters based on crack growth experiments is an important procedure of fatigue life assessment. However, it is a challenging task because it involves various sources of uncertainty. This paper proposes a novel probabilistic method, termed the S-N Paris law (SNPL) method, to quantify the uncertainties underlying the Paris' law parameters, by finding the best estimates of their statistical parameters from the S-N curve data using a Bayesian approach. Through a series of steps, the SNPL method determines the statistical parameters (e.g., mean and standard deviation) of the Paris' law parameters that will maximize the likelihood of observing the given S-N data. Because the SNPL method is based on a Bayesian approach, the prior statistical parameters can be updated when additional S-N test data are available. Thus, information on the Paris' law parameters can be obtained with greater reliability. The proposed method is tested by applying it to S-N curves of 40H steel and 20G steel, and the corresponding analysis results are in good agreement with the experimental observations.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1105-1110
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• 2007

This paper describes an equivalent circuit modeling of 4-port connector system. A coupled transmission line was designed and fabricated, mimicking a 4-port connector system, and then S-parameters were measured using 4 port VNA (Vector Network Analyzer). The S-parameters from measurement and from Full-wave simulator coincided quite nice. By using these S parameters, an equivalent circuit parameters for a 4-port system was obtained. The time domain response from the equivalent circuit model matched to the signals, which was measured using TDR(Time Domain Reflectometry) meter. We were also convinced that there should be enough bandwidth to get a meaningful time domain result from Fourier inverse transformation of the S parameters. In addition, we applied the conversion algorithm to the 4-port connector system, which calculates the S-parameters of a 4 port system using the data from a 2-port VNA with the other ports open. Comparison of the two data, one from measurement and the other one from the conversion algorithm, was made in this manuscript.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.6
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• pp.876-885
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• 2000

A new and simple method is presented for determining the parasitic resistances of MESFET and HEMT from the measured S-parameters under normal active bias without depending on additional DC measurements or iteration or optimization process. The presented method is based on the fact that the difference between source resistance(Rs) and drain resistance(Rd) can be obtained from the measured Z-parameters under zero bias condition. It is possible to define the new internal device including intrinsic device and 3 parasitic resistances by elimination the parasitic inductances and capacitances from the measured S-parameters. Three parasitic resistances are calculated easily from the fact that the real parts of Yint,11 and Yint,12 of intrinsic Y-parameters are zero theoretically and the relations between S-,Z-, Y-matrices. The calculated parasitic resistances using the presented method and successively calculated equivalent circuit parameters give modeled S-parameters which are in good agreement with the measured S-parameters up to 400Hz.

• Animal Bioscience
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• v.34 no.6
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• pp.949-956
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• 2021

Objective: This study was focused on the estimation of parameters of Wood's model and description of the lactation curve using the cows which were lactated over 24 months on the first lactation. Methods: The database included 1,333 pure-bred dairy Simmental primiparous cows which lactated for 24 months (732 days). The initial dataset entering the procedure of assessment of parameters of Wood's function included 35,826 milk yield records. Milk yield was recorded throughout lactation, with the earliest record taken on day 6 and the latest on day 1,348 of lactation. This dataset was used for the assessment of parameters a, b, c of Wood's model using the non-linear statistical procedure. These parameters were estimated for different length of lactation. The assessed parameters were used for calculation of some characteristics of lactation curves. Results: The lowest value of a parameter (15.2317) of Wood's model of lactation curve was found out in lactations up to 305 days long, contrary to b and c parameters which were highest in those lactations (0.1029 and 0.0015, respectively). The maximum value of a parameter (17.4329) was found out in lactations up to 640 days long, unlike b and c parameters which were minimal in those lactations (0.0603 and 0.0010, respectively). Conclusion: It can be concluded that the parameters of Wood's model and the shape of lactation curve are changing with the growing number of milk yield records. Also, the assessed parameters revealed a significant milk production potential after 305 days of lactation.

• Journal of Periodontal and Implant Science
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• v.49 no.2
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• pp.105-113
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• 2019

Purpose: An unresolved inflammatory state contributes to the pathogenesis of periodontal disease and metabolic syndrome (MetS). Therefore, the purpose of this study was to evaluate the role of lipoxin A4 (LXA4), a proresolving lipid mediator, in the association between periodontal disease and MetS. Methods: Sixty-seven patients with MetS and 65 patients without MetS were included in the study. Sociodemographic information was obtained via a questionnaire, and detailed medical diagnoses were made. Periodontal parameters (plaque index [PI], gingival index [GI], probing pocket depth [PD], and clinical attachment level [CAL]) and metabolic parameters were measured, and serum LXA4 levels were determined. The associations among MetS, periodontal parameters, and serum LX levels were evaluated by adjusted multivariate linear regression analyses. Results: Patients with MetS were older and had a higher body mass index than patients without MetS. Periodontal parameters (PI, GI, PD, and CAL) were higher in patients with MetS than in those without MetS. Serum LXA4 levels were higher in patients without MetS. Multivariate linear regression analysis indicated a positive association between MetS and periodontal parameters (PD and CAL). Negative associations were established between MetS and LXA4 levels, and between LXA4 and periodontal parameters (PI, PD, and CAL). Conclusions: The presence of higher values of periodontal parameters in patients with MetS and the negative relationship of LXA4 with MetS and periodontal disease may support the protective role of proresolving lipid mediators in the association between periodontal disease and MetS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.8
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• pp.808-820
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• 2014

In this paper, we fabricated two on-wafer type DUT(Device-Under-Test)s; a 10-dB attenuator and an amplifier using commercially available MMIC and we proposed the measurement method of the noise parameters for the two fabricated DUTs. Since the 10-dB attenuator DUT is a passive device, its noise parameters can be accurately determined when its S-parameters are measured. In the case of the amplifier DUT, its noise parameters are available in the datasheet. Hence, the measured noise parameters using the proposed method can be assessed by comparing with the known noise parameters. The noise parameter measurement method having been presented by the authors requires the S-parameters of the 8-port network used in the measurement and limited to coaxial type DUTs. When on-wafer probes are included in the 8-port network, the 8-port S-parameters requires the measurements with different kinds of connectors. In this paper, we obtained the 8-port S-parameters using the Smart-Cal function in the network analyzer. The measured noise parameters shows about ${\pm}0.2dB$ fluctuations for $NF_{min}$. Other noise parameters with the frequency change show good agreement with the expected results.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.344-353
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• 2000

Recent mechatronics technology is the most appropriate high technology in the agricultural application to save repetitious labor. Cow's body parameters were measured by traditional several measurer. Image processing technology was used to measure automatically their parameters to reduce lots of labor and time. The parameters were measured form a small model cow, which is easily measured, instead to a real cow. The image processing system designed and built for this project was composed of a Pentium PC, and TV frame card two cameras which were located on side and top of model cow. 11 parameters of cow's body were measured and the error between real data and the data by image processing was less than 10%. Based on the results of this research the parameters of a real cow could be measured in the future.