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Low-Sampling Rate UWB Channel Characterization and Synchronization
Maravic, Irena,Kusuma, Julius,Vetterli, Martin The Korea Institute of Information and Commucation 2003 Journal of communications and networks Vol.5 No.4
We consider the problem of low-sampling rate high-resolution channel estimation and timing for digital ultrawideband (UWB) receivers. We extend some of our recent results in sampling of certain classes of parametric non-bandlimited signals and develop a frequency domain method for channel estimation and synchronization in ultra-wideband systems, which uses sub-Nyquist uniform sampling and well-studied computational procedures. In particular, the proposed method can be used for identification of more realistic channel models, where different propagation paths undergo different frequency-selective fading. Moreover, we show that it is possible to obtain high-resolution estimates of all relevant channel parameters by sampling a received signal below the traditional Nyquist rate. Our approach leads to faster acquisition compared to current digital solutions, allows for slower A/D converters, and potentially reduces power consumption of digital UWB receivers significantly.
Martina Stefanini,Edoardo Ceraolo,Claudia Mazzitelli,Tatjana Maravic,Matteo Sangiorgi,Giovanni Zucchelli,Lorenzo Breschi,Annalisa Mazzoni 대한치주과학회 2022 Journal of Periodontal & Implant Science Vol.52 No.1
Purpose: This in vitro study was conducted to evaluate the effects of different debridement techniques and conditioning procedures on root surface morphology and blood clot stabilization. Methods: Two debridement techniques (curette [CU] vs. high-speed ultrasound [US]) and 2 conditioning procedures (ethylenediaminetetraacetic acid [EDTA] and phosphoric acid [PA]) were used for the study. Seven experimental groups were tested on root surfaces: 1) no treatment (C); 2) CU; 3) US; 4) CU+EDTA; 5) US+EDTA; 6) CU+PA; and 7) US+PA. Three specimens per group were observed under scanning electron microscopy (SEM) for surface characterization. Additional root slices received a blood drop, and clot formation was graded according to the blood element adhesion index by a single operator. Data were statistically analyzed, using a threshold of P<0.05 for statistical significance. Results: The C group displayed the most irregular surface among the tested groups with the complete absence of blood traces. The highest frequency of blood component adhesion was shown in the CU+EDTA group (P<0.05), while no differences were detected between the CU, US+EDTA, and CU+PA groups (P<0.05), which performed better than the US and US+PA groups (P<0.05). Conclusions: In this SEM analysis, EDTA and conventional manual scaling were the most efficient procedures for enhancing smear layer removal, collagen fiber exposure, and clot stabilization on the root surface. This technique is imperative in periodontal healing and regenerative procedures.
Stefanini, Martina,Ceraolo, Edoardo,Mazzitelli, Claudia,Maravic, Tatjana,Sangiorgi, Matteo,Zucchelli, Giovanni,Breschi, Lorenzo,Mazzoni, Annalisa Korean Academy of Periodontology 2021 Journal of Periodontal & Implant Science Vol.51 No.-
Purpose: This in vitro study was conducted to evaluate the effects of different debridement techniques and conditioning procedures on root surface morphology and blood clot stabilization. Methods: Two debridement techniques (curette [CU] vs. high-speed ultrasound [US]) and 2 conditioning procedures (ethylenediaminetetraacetic acid [EDTA] and phosphoric acid [PA]) were used for the study. Seven experimental groups were tested on root surfaces: 1) no treatment (C); 2) CU; 3) US; 4) CU+EDTA; 5) US+EDTA; 6) CU+PA; and 7) US+PA. Three specimens per group were observed under scanning electron microscopy (SEM) for surface characterization. Additional root slices received a blood drop, and clot formation was graded according to the blood element adhesion index by a single operator. Data were statistically analyzed, using a threshold of P<0.05 for statistical significance. Results: The C group displayed the most irregular surface among the tested groups with the complete absence of blood traces. The highest frequency of blood component adhesion was shown in the CU+EDTA group (P<0.05), while no differences were detected between the CU, US+EDTA, and CU+PA groups (P<0.05), which performed better than the US and US+PA groups (P<0.05). Conclusions: In this SEM analysis, EDTA and conventional manual scaling were the most efficient procedures for enhancing smear layer removal, collagen fiber exposure, and clot stabilization on the root surface. This technique is imperative in periodontal healing and regenerative procedures.
Layer-by-Layer Self-Assembly of Bisdendrons: An Unprecedented Route to Multilayer Thin Films
이옥주,Valérie Maraval,Anne-Marie Caminade,정경화,King Hang Aaron Lau,신관우,Jean-Pierre Majoral,Wolfgang Knoll,김동하 한국고분자학회 2016 Macromolecular Research Vol.24 No.10
We present an unprecedented route to fabricate multilayer thin films by single component layer-by-layer molecular self-assembly. Tailored water-soluble phosphorus bisdendrons were obtained via core to core assembling of two dendrons bearing anionic groups at one end and quaternizable amino groups at the other end. Adsorption of a 1st bisdendron monolayer on a charged substrate followed by sequential quaternization/deposition of a 2nd layer leads to a stepwise growth of multilayers. By this way, homogeneous multilayer thin films were successfully constructed as confirmed by spectroscopic and microscopic analysis.