This study was conducted to determine whether novel experimental low-shrinkage dimethacrylate co-monomers could provide low polymerization shrinkage composites without sacrifice to degree of conversion, and mechanical properties of the composites. Experimental composites were prepared by mixing 28.6 wt% of bisphenol-A-glycidyl dimethacrylate based resin matrix (bis-GMA) with various weight-frac...

In this dissertation we studied asymptotic properties of shrinkage estimators, and compared their performance with absolute penalty estimators (APE) in linear and partially linear models (PLM). A robust shrinkage M-estimator is proposed for PLM, and asymptotic properties are investigated, both analytically and through simulation studies. In Chapter 2, we compared the performance of shrinkage an...

Purpose. This study tested the null hypothesis that different classes of direct restorative dental materials: silorane-based resin, low-shrinkage and conventional (non-flowable and flowable) resin-based composite (RBC) do not differ from each other with regard to polymerization shrinkage, depth of cure or microhardness. Methods. 140 RBC samples were fabricated and tested by one calibrated opera...

Penalized regression methods, such as L1 regularization, are routinely used in high-dimensional applications, and there is a rich literature on optimality properties under sparsity assumptions. In the Bayesian paradigm, sparsity is routinely induced through two-component mixture priors having a probability mass at zero, but such priors encounter daunting computational problems in high dimension...

recent tendencies in concrete technology have been towards to high- performance concrete with a low water-cement ratio. however, high performance concretes have some problems. one of the problems is early-age cracking due to autogenous shrinkage. this study presents the results of an experimental investigation carried out to evaluate the autogenous shrinkage of high-strength concrete. accordin...

Donoho and Johnstone’s (1994) WaveShrink procedure has proven valuable for signal de-noising and non-parametric regression. WaveShrink has very broad asymptotic near-optimality properties. In this paper, we introduce a new shrinkage scheme, firm, which generalizes the hard and soft shrinkage proposed by Donoho and Johnstone (1994). We derive minimax thresholds and provide formulas for computing...

This paper contains the research on a hybrid algorithm combining the Matching Pursuit (MP) and the wavelet shrinkage. In this algorithm, we propose to shrink the scalar product of the element which best correlates with the residue before modifying. The study concerns a broad family of shrinkage functions. Using weak properties of these shrinkage functions, we show that the algorithm converges t...

Polymer networks that can serve as model systems for dental applications were prepared by photopolymerizations of 1,1,1-trimethylolpropane triacrylate, 1,1,1-trimethylolpropane trimethacrylate, 1,1,1-trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, Photomer 2028 and Photomer 3015. The UV polymerizations were initiated by 2,2-dimethoxy-2-pheny...

The film shrinkage effect of photopolymeric phase media failed to provide the desired volume holograms for point-to-point optical interconnects. In this paper, we report a new compensation method to physically correct the shrinkage effect resulted from the holographic recording and the post baking. Dupont photopolymer HRF-600X001 is studied. The correction of the Bragg diffraction angle shift o...