• Title/Summary/Keyword: RET Model

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RET Modelling through the Phase Function Measurement at 12.5 GHz (12.5 GHz 대역 위상 함수 특성 측정을 통한 RET 모델링)

  • Han, Il-Tak;Bae, Seok-Hee;Jung, Myoung-Won;Pack, Jung-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.3 s.118
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    • pp.334-340
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    • 2007
  • The prediction for vegetation attenuation using the RET model recommended in the ITU-R requires six RET input parameters. Among these, 4 parameters are related to the scattering characteristics of vegetation. To extract these parameters, two methods can be used. One is to extract the parameters by curve fitting of the measured vegetation-attenuation curve with the RET prediction model, and the other is to use the additional phase function measurement data. In the former method, fitting is quite complex and it does not result in the unique results in some cases. In addition, the extracted parameters lack the physical meaning as well. Thus, in this paper, the measurement method of phase function, and the method of extracting the RET model parameters which lead to more accurate and physically more meaningful results are presented. The extracted RET model parameters are also presented. The RET modeling method, measurement data, and the extracted RET model parameters presented in this paper were submitted to the ITU-R meeting in 2006, and adapted for ITU-R report and recommendation P.833.

Evaluation of Meteorological Elements Used for Reference Evapotranspiration Calculation of FAO Penman-Monteith Model (FAO Penman-Monteith 모형의 증발산량 산정에 이용되는 기상요소의 평가)

  • Hur, Seung-Oh;Jung, Kang-Ho;Ha, Sang-Keun;Kim, Jeong-Gyu
    • Korean Journal of Soil Science and Fertilizer
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    • v.39 no.5
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    • pp.274-279
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    • 2006
  • The exact estimation of crop evapotranspiration containing reference or potential evapotranspiration is necessary for decision of crop water requirements. This study was carried out for the evaluation and application of various meteorological elements used for the calculation of reference evapotranspiration (RET) by FAO Penman-Monteith (PM) model. Meteorological elements including temperature, net radiation, soil heat flux, albedo, relative humidity, wind speed measured by meteorological instruments are required for RET calculation by FAO PM model. The average of albedo measured for crop growing period was 0.20, ranging from 0.12 to 0.23, and was slightly lower than 0.23. Determinant coefficients by measured albedo and green grass albedo were 0.97, 0.95 and standard errors were 0.74, 0.80 respectively. Usefulness of deductive regression models was admitted. To assess an influence of soil heat flux (G) on FAO PM, RET with G=0 was compared with RETs using G at 5cm soil depth ($G_{5cm}$) and G at surface ($G_{0cm}$). As the results, RET estimated by G=0 was well agreed with RET calculated by measured G. Therefore, estimated net radiation, G=0 and albedo of green grass could be used for RET calculation by FAO PM.

Measurement and Modeling of Vegetation Loss in the Frequency Range of 1~6 GHz (1~6 GHz 대역 수풀 손실 특성 측정 및 모델링)

  • Han, Il-Tak;Jung, Myoung-Won;Back, Jung-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.1 s.116
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    • pp.96-104
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    • 2007
  • Currently, there is a lack of suitable prediction model and measurement data for vegetation loss. So in this paper, vegetation loss measurement has been performed for seven different tree-species, including dawn-redwood tree, plane tree, pine tree and hymalaya cedar in the frequency range of $1.0{\sim}6.0\;GHz$, for the two years, from 2005 to 2006 years. And then, extraction and revision for the proposed RET model input parameters in ITU-R P.833 has been performed. The key results of measurement and RET modeling has been presented in this paper. The results of this study have been adapted for ITU-R recommendation at the ITU-R meeting in 2005 and 2006.

Characterization of Wild-Type and Mutated RET Proto-Oncogene Associated with Familial Medullary Thyroid Cancer

  • Masbi, Mohammad Hosein;Mohammadiasl, Javad;Galehdari, Hamid;Ahmadzadeh, Ahmad;Tabatabaiefar, Mohammad Amin;Golchin, Neda;Haghpanah, Vahid;Rahim, Fakher
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2027-2033
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    • 2014
  • Background: We aimed to assess RET proto-oncogene polymorphisms in three different Iranian families with medullary thyroid cancer (MTC), and performed molecular dynamics simulations and free energy stability analysis of these mutations. Materials and Methods: This study consisted of 48 patients and their first-degree relatives with MTC confirmed by pathologic diagnosis and surgery. We performed molecular dynamics simulations and free energy stability analysis of mutations, and docking evaluation of known RET proto-oncogene inhibitors, including ZD-6474 and ponatinib, with wild-type and mutant forms. Results: The first family consisted of 27 people from four generations, in which nine had the C.G2901A (P.C634Y) mutation; the second family consisted of six people, of whom three had the C.G2901T (P.C634F) mutation, and the third family, who included 12 individuals from three generations, three having the C.G2251A (P.G691S) mutation. The automated 3D structure of RET protein was predicted using I-TASSER, and validated by various protein model verification programs that showed more than 96.3% of the residues in favored and allowed regions. The predicted instability indices of the mutated structures were greater than 40, which reveals that mutated RET protein is less thermo-stable compared to the wild-type form (35.4). Conclusions: Simultaneous study of the cancer mutations using both in silico and medical genetic procedures, as well as onco-protein inhibitor binding considering mutation-induced drug resistance, may help in better overcoming chemotherapy resistance and designing innovative drugs.

Measurement and Modeling of Vegetation Loss in the Frequency Range of 1 $\sim$ 6 (1 $\sim$ 6 GHz대역 수풀손실 특성 측정 및 모델링)

  • Park, Yong-Ho;Jung, Myoung-Won;Han, Il-Tak;Pack, Jeong-Ki
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2005.11a
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    • pp.163-168
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    • 2005
  • Attenuation in vegetation is important, for both terrestrial and earth-space systems. However, the wide range of conditions and types of foliage makes it difficult to develop a generalized prediction procedure. Currently, there is also a lack of suitably prediction model and measured experimental data for vegetation loss. So in this paper, vegetation loss data for four different tree-species, including Dawn-redwood tree, Plane tree, Pine tree and Fir tree are obtained by measurement in the frequency range of 1.0 $\sim$ 6.0 GHz. The through or scattered component is calculated using a model based upon the theory of RET(Radiative Energy Transfer) and RET modeling parameters are extracted from the measured data.

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The Effectiveness of 448-kHz Capacitive Resistive Monopolar Radiofrequency for Subcutaneous Fat Reduction in a Porcine Model

  • Kwon, Tae-Rin;Lee, Sung-Eun;Kim, Jong Hwan;Jeon, Yong Jae;Jang, You Na;Yoo, Kwang Ho;Kim, Beom Joon
    • Medical Lasers
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    • v.8 no.2
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    • pp.64-73
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    • 2019
  • Background and Objectives The effectiveness of many physiotherapy modalities in reducing subcutaneous fat has been investigated in numerous previous studies. However, to the best of our knowledge, there have been no attempts to determine the effectiveness of physiotherapy modalities in body contouring. The present report determined the effect of 448-kHz capacitive resistive monopolar radiofrequency (CRMRF) in a porcine model. Materials and Methods This study investigated the effect of selective destruction of the subcutaneous fat layer in abdominal fat tissue using CRMRF. The effects of two types of CRMRF (capacitive electric transfer (CET) and resistive electric transfer (RET)) treatment were evaluated using regular digital photography in addition to thermal imaging evaluation, ultrasound measurement, hematological evaluation, and histologic analyses (H&E (hematoxylin and eosin), Oil red O, and immunohistochemistry staining). Results Preclinical evaluation was performed to obtain the data for comparison of the safety and efficacy of the subcutaneous fat reduction after applying CRMRF using CET and RET. After treatment, the thermal transmission was effective, and a 42-47℃ temperature change was observed in the fat layer while an approximately temperature of 42℃ was confirmed on the skin surface. Moreover, after the application of both types of CRMRF treatment, fibrotic septa were observed in the adipose tissue induced by heat at the treatment sites. TUNEL staining was also performed to confirm the process of apoptosis in the adipocytes. Conclusion These results suggest that both CET and RET for CRMRF treatment are safe and effective for subcutaneous fat reduction in a porcine model.

Estimation of Actual Evapotranspiration over Paddy Rice Field (수도 포장의 실증발산량 추정에 관한 연구)

  • 이변우;김병찬
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.6
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    • pp.518-524
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    • 1990
  • Actual evapotranspiration was measured over rice paddy field by Bowen ratio heat balance method and based on this, investigated was the reliability of actual evapotranpiration estimation from Class-A Pan and small pan evaporation and reference evapotranspiration calculated by modified Penman-Monteith model. Crop coefficients based on Class-A Pan and small pan evaporation and reference evapotranspiration by modified Penman-Monteith model were averaged to be 1.57. 1.10 and 1.49 over the whole rice growing season, respectively. Their respective coefficients of variation were 28.7. 22.7 and 12.8 percent, respectively. Crop coefficient based on modified Penman-Monteith model varied in good agreement with the trend of leaf area development, being greatest around heading stage.

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Critical Review of Current Trends in ASIC Writing and Layout Analysis

  • Vikram, Abhishek;Agarwal, Vineeta
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.2
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    • pp.236-250
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    • 2016
  • Electrical Designs for Application Specific Integrated Circuits (ASIC) has undergone a change recently with the advent of the sub-wavelength lithography. The optical projection with 193 nm wavelength has been further extended with the use of immersion and other techniques. The competing trends for printing smaller design features have been discussed in this paper with the discussion of the electrical layout analysis to find unfriendly design features. The early knowledge of the unfriendly design features allows remedial actions in time for better yield on the wafer. There are existing standard design qualification criteria being used in the design and fabrication community, but they seem to be insufficient to guarantee defect free designs. This paper proposes an integrated approach for screening the layout with multiple aspects: layout geometry based, graphical analysis and process model based verification. The results have been discussed with few example design features from the 28nm design layout.

A Study on the Effect of Inclusions on the Fatigue Life of Titanium Investment Castings (티타늄 정밀주조품의 피로수명에 미치는 개재물의 영향에 관한 연구)

  • Park, Yong-Kuk;Ret, P.L.;Kim, Jin-Gon
    • Journal of Korea Foundry Society
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    • v.26 no.2
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    • pp.85-91
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    • 2006
  • Inclusions in Ti investment castings are generally known to have detrimental effects on the performance of the castings. However, actual inclusions are infrequent and hard to be located. As a result, it is extremely difficult to obtain sufficient amount of fatigue test specimens of titanium investment castings having inclusions in the gage section. Thus, in-depth research of the adverse influence of inclusions is also hindered. To address this problem, a new casting methodology of specimens containing hard alpha inclusions was developed in this study. To guarantee successful introduction of an inclusion and casting, a carefully designed mold with 8 legs and a special tool were employed. After solidification, castings were cut, and X-ray radiography determined that the inclusions were successfully incorporated into the castings. The castings were further prepared to obtain multiple test specimens and they were fatigue-tested consecutively. Fractography analysis confirmed that fatigue cracks initiated at the hard alpha inclusion. In a nonlinear regression model, the fatigue life can be modeled as an exponential function with a negative exponent of the cross-sectional area of an inclusion. The fatigue life of Ti specimens containing inclusions is inversely proportional to the cross-sectional area of an inclusion.

A Study on the Variation of Suspended Sediment Concentration in the Reservoir due to a Rainstorm (호우발생시 저수지 유입 부유사농도의 변화특성 연구)

  • Jang, Su-Hyung;Park, Moo-Jong;Yoon, Yong-Nam
    • Journal of Korea Water Resources Association
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    • v.37 no.1
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    • pp.43-54
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    • 2004
  • The objective of this study is to propose reservoir operation method in relation to the suspended sediment concentration due to rainstorms. Present analysis is made for the Tamjin reservoir which is under construction. For the hydrologic computations the Huff rainfall distribution, Clark unit hydrograph method and Puls reservoir routing method are used. The variation of suspended sediment concentration is calculated by 2-dimensional RMA-4 model. As a result of this study, the possible intake time from the reservoir under low frequency flood is estimated and the rainfall-ret urn period - possible intake time relationship is established, which is very important in maintaining the water quality standard when supplying water from the reservoir for different utilizationurn period- possible intake time relationship is established, which is very important in maintaining the water quality standard when supplying water from the reservoir for different utilizations.