Search results for "parametric"

SM identification of approximating models forH∞ robust control

1999

Set Membership (SM) W, identification of mixed parametric and nonparametric models is investigated, aimed to estimate a low order approximating model and an identification error, giving a measure of the unmodeled dynamics in a form well suited for H, control methodologies. In particular, the problem of estimating the parameters of the parametric part and the H, bound on the modeling error is solved using frequency domain data, supposing lbo bounded measurement errors and exponentially stable unmodeled dynamics. The effectiveness of the proposed procedure is tested on some numerical examples, showing the advantages of the proposed methods over the existing nonparametric H, identification app…

2014

This paper proposes an observer-based robust guaranteed cost control method for thrust-limited rendezvous in near-circular orbits. Treating the noncircularity of the target orbit as a parametric uncertainty, a linearized motion model derived from the two-body problem is adopted as the controlled plant. Based on this model, a robust guaranteed cost observer-controller is synthesized with a less conservative saturation control law, and sufficient condition for the existence of this observer-based rendezvous controller is derived. Finally, an illustrative example with immeasurable velocity states is presented to demonstrate the advantages and effectiveness of the control scheme.

Landmark identification on direct digital versus film-based cephalometric radiographs: A human skull study

2002

The purpose of this study was to investigate differences in landmark identification on vertically scanned, direct digital and conventional (18 x 24 cm) cephalometric radiographs. Eight observers, all orthodontists or postgraduate orthodontic students, recorded 6 landmarks twice on 3 digital and 3 conventional cephalograms obtained from 3 human skulls in a standardized fashion. Digital images were displayed on a 15.1-in TFT monitor in 3:1 mode (20 x 26 cm). Recordings were transferred into standardized coordinate systems and evaluated separately for each coordinate. After correcting for magnification, precision was assessed with Maloney-Rastogi tests, and intraobserver and interobserver repr…

Evaluation of a digital radiography to estimate working length

1997

The working lengths obtained with different methods in single-rooted teeth were compared. An endodontic rule in millimeters and calipers was used as a direct method of measurement (on endodontic files). As indirect methods, measurements were taken from conventional x-rays with calipers and with a digital radiological measurement system. No statistically significant differences were obtained between the direct and indirect methods. Three vertical angulations were taken for the indirect methods (0 degree, 15 degrees, and 30 degrees). No significant differences were found between results for the two indirect methods versus the standard method except for the 30 degrees angulation, which resulte…

Acute effects of 1,1,1-trichloroethane on human olfactory functioning.

2004

Background Animal experiments indicate that 1,1,1-trichloroethane can cause degeneration of the olfactory epithelium. The effects of 1,1,1-trichloroethane on human odor perception still have not been investigated. The goal of this study was to learn more about acute effects of 1,1,1-trichloroethane. Methods Twelve healthy, nonsmoking students were exposed to 200 and 20 ppm (control) 1,1,1-trichloroethane in an exposure chamber for 4 hours according to a crossover design. Olfactory functioning was investigated with the Sniffin’ Sticks. The test includes the determination of the detection threshold for n-butanol and an odor identification test. Results After 1 hour of exposure to 200 ppm 1,1,…

Is first-line single-agent mitoxantrone in the treatment of high-risk metastatic breast cancer patients as effective as combination chemotherapy? No …

2002

BACKGROUND: To determine whether patients with high-risk metastatic breast cancer draw benefit from combination chemotherapy as first-line treatment. PATIENTS AND METHODS: A total of 260 women with measurable metastatic breast cancer fulfilling high-risk criteria, previously untreated with chemotherapy for their metastatic disease, were randomized to receive either mitoxantrone 12 mg/m(2) or the combination of fluorouracil 500 mg/m(2), epirubicin 50 mg/m(2) and cyclophosphamide 500 mg/m(2) (FEC) every 3 weeks. Treatment was continued until complete remission plus two cycles, or until disease progression. In the case of partial remission or stable disease, treatment was stopped after 12 cycl…

Apolipoprotein E genotype does not influence the progression of multiple sclerosis

2003

OBJECTIVE: To investigate the association between apolipoprotein E (APOE) polymorphisms and the progression of MS. METHODS: We investigated 428 subjects affected by clinically defined MS, with a disease duration of at least three years. We collected data concerning the age at onset of MS, clinical type, disease duration and disability according to the expanded disability status scale (EDSS). We also calculated the progression index (PI) to evaluate disease progression. APOE genotyping and the -491 A/T polymorphism of the APOE promoter were determined. RESULTS: No association was observed between the APOE epsilon4 allele and clinical characteristics of our study population. We also investiga…

No evidence of beneficial effects of plasmapheresis in natalizumab-associated PML

2017

Objective:To examine retrospectively the effects of plasmapheresis (PLEX) on the survival and clinical outcomes of patients with multiple sclerosis (MS) and natalizumab (NTZ)–associated progressive multifocal leukoencephalopathy (PML).Methods:The medical literature was searched for the terms natalizumab and progressive multifocal leukoencephalopathy. A total of 193 international and 34 Italian NTZ-PML cases were included. Clinical outcome was determined by comparing the patients' clinical status at PML diagnosis with status after PML resolution. The effects on survival and clinical outcome of PLEX, sex, age, country, pre-PML Expanded Disability Status Scale score, NTZ infusion number, prior…

A randomized trial comparing tamoxifen therapy vs. tamoxifen prophylaxis in bicalutamide-induced gynecomastia.

2012

BACKGROUND: Tamoxifen (TAM) has been shown to be active against the bicalutamide-induced breast events (BEs) gynecomastia, and breast pain in patients with prostate cancer (PC). Optimal doses and schedules are not yet established. Debate still exists about whether prophylaxis with TAM is more effective than treatment of BEs when diagnosed. The results of a randomized study comparing TAM prophylaxis vs. TAM therapy are presented. METHODS: One hundred seventy-six patients with prostate cancer (PC) who were candidates for bicalutamide monotherapy were randomized to receive TAM 20 mg daily orally within 1 month from the onset of BEs (arm A) vs. TAM 10 mg daily starting simultaneously with bical…

Quantitative modeling of clinical, cellular, and extracellular matrix variables suggest prognostic indicators in cancer: a model in neuroblastoma

2014

BACKGROUND: Risk classification and treatment stratification for cancer patients is restricted by our incomplete picture of the complex and unknown interactions between the patient's organism and tumor tissues (transformed cells supported by tumor stroma). Moreover, all clinical factors and laboratory studies used to indicate treatment effectiveness and outcomes are by their nature a simplification of the biological system of cancer, and cannot yet incorporate all possible prognostic indicators. METHODS: A multiparametric analysis on 184 tumor cylinders was performed. To highlight the benefit of integrating digitized medical imaging into this field, we present the results of computational s…