• 제목/요약/키워드: S-N approach

검색결과 843건 처리시간 0.03초

AN LMI APPROACH TO AUTOMATIC LOOP-SHAPING OF QFT CONTROLLERS

  • Bokharaie, Vaheed S.;Khaki-Sedigh, Ali
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.433-437
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    • 2003
  • Quantitative Feedback Theory (QFT) is one of effective methods of robust controller design. In QFT design we can considers the phase information of the perturbed plant so it is less conservative than $H_{\infty}$ and ${\mu}$-synthesis methods and as be shown, it is more transparent than the sensitivity reduction methods mentioned . In this paper we want to overcome the major drawback of QFT method which is lack of an automatic method for loop-shaping step of the method so we focus on the following problem: Given a nominal plant and QFT bounds, synthesize a controller that achieves closed-loop stability and satisfies the QFT boundaries. The usual approach to this problem involves loop-shaping in the frequency domain by manipulating the poles and zeros of the nominal loop transfer function. This process now aided by recently developed computer aided design tools proceeds by trial and error and its success often depends heavily on the experience of the loop-shaper. Thus for the novice and First time QFT user, there is a genuine need for an automatic loop-shaping tool to generate a first-cut solution. Clearly such an automatic process must involve some sort of optimization, and while recent results on convex optimization have found fruitful applications in other areas of control theory we have tried to use LMI theory for automating the loop-shaping step of QFT design.

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Frequency-Dependent Line Capacitance and Conductance Calculations of On-Chip Interconnects on Silicon Substrate Using Fourier cosine Series Approach

  • Ymeri, H.;Nauwelaers, B.;Vandenberghe, S.;Maex, K.;De Roest, D.;Stucchi, M.
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제1권4호
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    • pp.209-215
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    • 2001
  • In this paper a method for analysis and modelling of coplanar transmission interconnect lines that are placed on top of silicon-silicon oxide substrates is presented. The potential function is expressed by series expansions in terms of solutions of the Laplace equation for each homogeneous region of layered structure. The expansion coefficients of different series are related to each other and to potentials applied to the conductors via boundary conditions. In the plane of conductors, boundary conditions are satisfied at $N_d$ discrete points with $N_d$ being equal to the number of terms in the series expansions. The resulting system of inhomogeneous linear equations is solved by matrix inversion. No iterations are required. A discussion of the calculated line admittance parameters as functions of width of conductors, thickness of the layers, and frequency is given. The interconnect capacitance and conductance per unit length results are given and compared with those obtained using full wave solutions, and good agreement have been obtained in all the cases treated

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완전방실중격결손증 수술후 심에코도의 역할 (The Role of Intraoperative Echocardiograpby after Repair of Complete Atrioventricular Septal Defect)

  • 홍유선
    • Journal of Chest Surgery
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    • 제27권11호
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    • pp.902-906
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    • 1994
  • Between May 1991 and August 1993, 16 patients underwent repair of complete atrioventricular septal defect without another major anomaly at Cardiovascular Center,Yonsei University College of Medicine. Ages of the patients ranged from 3 months to 38 years with a mean of 42 months. Among 16, 10 patients[63%] are associated with Down`s syndrome. All patients underwent primary repair except and one who received had been repaire of coactation of aorta and patent ductus arteriosus 2 month before. Preoperative mitral valve regurgitation [MR] was evaluated with Doppler echocardiography and angiography which revealed absent or grade I in 1, grade II in 8, grade III in 4, and grade IV in 3. Operative technique was performed under the moderate hypothermic cardiopulmonary bypass with crystalloid cardioplegia. Intraoperative echocardiography was performed epicardial approach [n=7] in the operative table or transthoracic approach [n=9] at intensive care unit. In all patients except 3, MR were improved. But in 3 patients, was not improved or exagerated comparing preoperative one. All of them were died.One patient was showed MR grade IV in intraoperative echocardiography, we re-repaired atriventricular valve with cardiopulmonary bypass. During follow-up period [at a mean of 11 months after repair], doppler echocardiography was performed in all patients. The follow up echocardiography revealed that the degree of MR in immediate postoperative period was not changed except in two patients in whom it was aggravated. Thus it seems that intraoperative and early postoperative echocardiography was employed important role of survival and can be predictable for long term results.

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Antibiotic resistance in Neisseria gonorrhoeae: broad-spectrum drug target identification using subtractive genomics

  • Umairah Natasya Mohd Omeershffudin;Suresh Kumar
    • Genomics & Informatics
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    • 제21권1호
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    • pp.5.1-5.13
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    • 2023
  • Neisseria gonorrhoeae is a Gram-negative aerobic diplococcus bacterium that primarily causes sexually transmitted infections through direct human sexual contact. It is a major public health threat due to its impact on reproductive health, the widespread presence of antimicrobial resistance, and the lack of a vaccine. In this study, we used a bioinformatics approach and performed subtractive genomic methods to identify potential drug targets against the core proteome of N. gonorrhoeae (12 strains). In total, 12,300 protein sequences were retrieved, and paralogous proteins were removed using CD-HIT. The remaining sequences were analyzed for non-homology against the human proteome and gut microbiota, and screened for broad-spectrum analysis, druggability, and anti-target analysis. The proteins were also characterized for unique interactions between the host and pathogen through metabolic pathway analysis. Based on the subtractive genomic approach and subcellular localization, we identified one cytoplasmic protein, 2Fe-2S iron-sulfur cluster binding domain-containing protein (NGFG RS03485), as a potential drug target. This protein could be further exploited for drug development to create new medications and therapeutic agents for the treatment of N. gonorrhoeae infections.

고해상도 X-ray CT 를 이용한 토양표면 피막의 공극율 및 포화수리전도도 측정 (Saturated Hydraulic Conductivity of Surface Seals Estimated from Computed Tomography-Measured Porosity)

  • 이상수;;;;;옥용식
    • 한국환경농학회:학술대회논문집
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    • 한국환경농학회 2011년도 30주년 정기총회 및 국제심포지엄
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    • pp.207-222
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    • 2011
  • Relationships between soil saturated hydraulic conductivity ($K_s$) and porosity (${\phi}$) have been developed over many years; however, use of these relationships for evaluating rain-induced seals is limited mainly because of difficulties in estimating seal pore-size characteristics. The objectives of this study were to evaluate the $K_s$ of soil surface seals over a range of thicknesses, where seal thickness was determined using a High-Resolution-Computed-Tomography (HRCT) scanner, and to investigate relationships between $K_s$ and ${\phi}$ of developing seals in samples with equivalent diameters (e.d.) ${\geq}15\;{\mu}m$. A Mexico silt loam soil was packed to a bulk density (${\rho}_b$) of $1.1\;Mg\;m^{-3}$ in cylinders 160-mm i.d. by 160-mm long and subjected to $61-mm\;h^{-1}$ simulated rainfall having a kinetic energy (KE) of $25\;J\;m^{-2}\;min^{-1}$ for 7.5, 15, 30, and 60 min to create a range in seal development. Thicknesses of the seal layers were determined by analysis of HRCT images of seals. The $K_s$ values of the seals were estimated using an effective $K_s$ value ($K_{s-eff}$). The $K_s-{\phi}$ relationship was described by a Kozeny and Carmen equation, $K_s=B{\phi}^n$; where B and n are empirical constants and n = 31. This approach explained 86% of the variation between $K_s$ and ${\phi}$ within the soil seals. Knowledge of surface seal information and hydraulic conductivity can provide useful information to use in management of sites prone to sealing formation.

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항로표지 시설의 LED 감성조명을 위한 RGB 원격 콘트롤러의 구현 (An Implementation of the RGB Remote Controller for LED Emotion Lighting of AtoN Facilities)

  • 정영철;최조천;조대환
    • 해양환경안전학회지
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    • 제18권5호
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    • pp.475-480
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    • 2012
  • 해안 및 항만에 설치되는 항로표지 시설에 3색 LED를 적용하여 야간에 식별을 용이하게 하는 감성적 시각의 조명과 항만 진입등의 점멸제어 방식에 대하여 연구하였다. 항만 양측에 홍등, 백등의 항로표지를 주변의 조명과 차별화하여 식별을 쉽게 하였고, GPS에 의한 시각동기와 타이머를 통하여 항만 진입등을 좌우 및 일렬순차 점등으로 동기시키는 통합형 콘트롤러를 설계하였다. LED에 의한 AtoN(Aids to Navigation) 시설을 높이에 따른 층별 색상으로 조화시키고 감성조명으로 표현하여 항해사의 표지식별에 대한 혼란을 방지하며 야간항만의 경관을 미화시키는 효과를 얻었다. 또한 선박의 항만진입을 인도하는 메시지를 전달하는 모르스 부호 발광의 기능을 부가적으로 구현하였다. 등명기는 반영구적인 고휘도 LED로 대체되므로써 수명과 소비전력에 대한 효율성을 증대하였다.

디지털 서명을 위한 고속 RSA 암호 시스템의 설계 및 FPGA 구현 (Design and FPGA Implementation of a High-Speed RSA Algorithm for Digital Signature)

  • 강민섭;김동욱
    • 정보처리학회논문지C
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    • 제8C권1호
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    • pp.32-40
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    • 2001
  • 본 논문에서는 기존의 Montgomery 알고리듬을 개선한 고속 모듈러 곱셈 알고리듬을 제안하고, 이를 기본으로 하여 디지털 서명에 적용 가능한 1024비트 RSA 암호 시스템의 설계 및 구현에 관하여 기술한다. 제안된 방법은 부분합 계산시 단지 1번지의 덧셈 연산이 필요하지만, 기존 Montgomery 알고리듬에서는 2번의 덧셈연산이 요구되므로 기존 방법에 비해 계산 속도가 빠르며, 하드웨어 면적도 매우 감소된다. 제안된 RSA 암호 시스템은 VHDL(VHSIC Hardware Description Language)을 이용하여 모델링하였고, $Synopsys^{TM}$사의 Design Analyzer를 이용하여 논리합성(Altera 10K lib. 이용)을 수행하였다. 또한, FPGA 구현을 위하여 Altera MAX+PLUS II상에서 타이밍 시뮬레이션을 수행하였다. 실험을 통하여 제안된 방법은 계산 속도가 매우 빠르며, 하드웨어 면적도 매우 감소함을 확인하였다.

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Early hypopharyngeal cancer treated with different therapeutic approaches: a single-institution cohort analysis

  • Kim, Nalee;Lee, Jeongshim;Kim, Kyung Hwan;Park, Jong Won;Lee, Chang Geol;Keum, Ki Chang
    • Radiation Oncology Journal
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    • 제34권4호
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    • pp.280-289
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    • 2016
  • Purpose: Early hypopharyngeal squamous cell carcinoma (HPSCC) is a rarely diagnosed disease, for which the optimal treatment has not been defined yet. We assessed patterns of failure and outcomes in early HPSCC treated with various therapeutic approaches to identify its optimal treatment. Materials and Methods: Thirty-six patients with stage I (n = 10) and II (n = 26) treated between January 1992 and March 2014 were reviewed. Patients received definitive radiotherapy (RT) (R group, n = 10), surgery only (S group, n = 19), or postoperative RT (PORT group, n = 7). All patients in both the R and PORT groups received elective bilateral neck irradiation. In the S group, 7 patients had ipsilateral and 8 had bilateral dissection, while 4 patients had no elective dissection. Results: At a median follow-up of 48 months, the 5-year locoregional control (LRC) rate was 65%. Six patients had local failure, 1 regional failure (RF), 3 combined locoregional failures, and 2 distant failures. There was no difference in 5-year LRC among the R, S, and PORT groups (p = 0.17). The presence with a pyriform sinus apex extension was a prognosticator related to LRC (p = 0.01) in the multivariate analysis. Patients with a bilaterally treated neck showed a trend toward a lower RF rate (p = 0.08). Conclusion: This study shows that patients with early stage HPSCC involving the pyriform sinus apex might need a tailored approach to improve LRC. Additionally, our study confirms elective neck treatment might have an efficacious role in regional control.

Stable Carbon Isotope Signature of Dissolved Inorganic Carbon (DIC) in Two Streams with Contrasting Watershed Environments: A Potential Indicator for Assessing Stream Ecosystem Health

  • Kim, Chulgoo;Choi, Jong-Yun;Choi, Byungwoong;Lee, JunSeok;Jeon, Yonglak;Yi, Taewoo
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제2권4호
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    • pp.259-273
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    • 2021
  • We conducted a study to investigate the characteristics of the carbon cycle of two streams (located in Shig a Prefecture, Japan), having similar size, namely, the Adokawa stream (length: 52 km, area: 305 km2, watershed population: 8,000) and the Yasukawa stream (length: 62 km, area: 380 km2, watershed population: 120,000), but with different degree of human activity. Samples were collected from these two streams at 14 (Adokawa stream) and 23 (Yasukawa stream) stations in the flowing direction. The dissolved inorganic carbon (DIC) concentration and the stable carbon isotope ratio of DIC (δ13C-DIC) were measured in addition to the watershed features and the chemical variables of the stream water. The δ13C-DIC (-9.50 ± 2.54‰), DIC concentration (249 ± 76 µM), and electric conductivity (52 ± 13 µS/cm) in Adokawa stream showed small variations from upstream to downstream. However, the δ13C-DIC (-8.68 ± 2.3‰) upstream of Yasukawa stream was similar to that of Adokawa stream and decreased downstream (-12.13 ± 0.43‰). DIC concentration (upstream: 272 ± 89 µM, downstream: 690 ± 37 µM) and electric conductivity (upstream: 69 ± 17 µS/cm, downstream: 193 ± 37 µS/cm) were higher downstream than upstream of Yasukawa stream. The DIC concentration of Yasukawa stream was significantly correlated with watershed environmental variables, such as, watershed population density (r = 0.8581, p<0.0001, n = 23), and forest area percentage of the watershed (r = -0.9188, p<0.0001, n = 23). δ13C-DIC showed significant negative correlation with the DIC concentration (r = -0.7734, p<0.0001, n = 23), electric conductivity (r = -0.5396, p = 0.0079, n = 23), and watershed population density (r = -0.6836, p = 0.0003, n = 23). Our approach using a stable carbon isotope ratio suggests that DIC concentration and δ13C-DIC could be used as indicators for monitoring the health of stream ecosystems with different watershed characteristics.

A Straightforward Estimation Approach for Determining Parasitic Capacitance of Inductors during High Frequency Operation

  • Kanzi, Khalil;Nafissi, Hanidreza R.;Kanzi, Majid
    • Journal of international Conference on Electrical Machines and Systems
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    • 제3권3호
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    • pp.339-353
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    • 2014
  • A straightforward method for optimal determining of a high frequency inductor's parasitic capacitance is presented. The proposed estimation method is based on measuring the inductor's impedance samples over a limited frequency range bordering on the resonance point considering k-dB deviation from the maximum impedance. An optimized solution to k could be obtained by minimizing the root mean squared error between the measured and the estimated impedance values. The model used to provide the estimations is a parallel RLC circuit valid at resonance frequency which will be transferred to the real model considering the mentioned interval of frequencies. A straightforward algorithm is suggested and programmed using MATLAB which does not require a wide knowledge of design parameters and could be implemented using a spectrum analyzer. The inputs are the measured impedance samples as a function of frequency along with the diameter of the conductors. The suggested algorithm practically provides the estimated parameters of a real inductance model at different frequencies, with or without design information. The suggested work is different from designing a high frequency inductor; it is rather concentration of determining the parameters of an available real inductor that could be easily done by a recipe provided to a technician.