Models of statistical self-similarity for signal and image synthesis

Statistical self-similarity of random processes in continuous-domains is defined through invariance of their statistics to time or spatial scaling. In discrete-time, scaling by an arbitrary factor of signals can be accomplished through frequency warping, and statistical self-similarity is defined by the discrete-time continuous-dilation scaling operation. Unlike other self-similarity models mostly relying on characteristics of continuous self-similarity other than scaling, this model provides a way to express discrete-time statistical self-similarity using scaling of discrete-time signals. This dissertation studies the discrete-time self-similarity model based on the new scaling operation, and develops its properties, which reveals relations with other models. Furthermore, it also presents a new self-similarity definition for discrete-time vector processes, and demonstrates synthesis examples for multi-channel network traffic. In two-dimensional spaces, self-similar random fields are of interest in various areas of image processing, since they fit certain types of natural patterns and textures very well. Current treatments of self-similarity in continuous two-dimensional space use a definition that is a direct extension of the 1-D definition. However, most of current discrete-space two-dimensional approaches do not consider scaling but instead are based on ad hoc formulations, for example, digitizing continuous random fields such as fractional Brownian motion. The dissertation demonstrates that the current statistical self-similarity definition in continuous-space is restrictive, and provides an alternative, more general definition. It also provides a formalism for discrete-space statistical self-similarity that depends on a new scaling operator for discrete images. Within the new framework, it is possible to synthesize a wider class of discrete-space self-similar random fields

Use of Engineering Controls and Personal Protective Equipment by Certified Pesticide Applicators

A convenience survey of 702 certified pesticide applicators was conducted in three states to assess the use of 16 types of engineering controls and 13 types of personal protective equipment (PPE). Results showed that 8 out of 16 engineering devices were adopted by more than 50% of the respondents. The type of crop, size of agricultural operation, and the type of pesticide application equipment were found to influence the adoption of engineering controls. Applicators working on large farms, users of boom and hydraulic sprayers, and growers of field crops were more likely to use engineering devices. Respondents reported a high level of PPE use, with chemical-resistant gloves showing the highest level of compliance. An increase in pesticide applicators wearing appropriate headgear was reported. The majority of respondents did not wear less PPE simply because they used engineering controls. Those who did modify their PPE choices when employing engineering controls used tractors with enclosed cabs and/or were vegetable growers

Core/Sheath-Structured Composite Nanofibers Containing Cinnamon Oil: Their Antibacterial and Antifungal Properties and Acaricidal Effect against House Dust Mites

This study aimed to fabricate core/sheath-structured composite nanofibers containing cinnamon oil by emulsion electrospinning and to investigate their acaricidal effect on house dust mites as well as their antibacterial and antifungal properties in relation to cinnamon oil concentration in the nanofibers. An oil-in-water emulsion, which comprised cinnamon oil and poly(vinyl alcohol) solution as oil and water phases, respectively, was used to prepare core/sheath-structured nanofibers. The morphology and the inner structure of the electrospun nanofibers were observed by scanning electron microscopy and confocal laser scanning microscopy. Core/sheath-structured nanofibers containing cinnamon oil were successfully prepared by emulsion electrospinning. The composite nanofibers prepared from an emulsion containing 20 wt% of cinnamon oil exhibited a strong acaricidal effect against house dust mites (Dermatophagoides farinae). The composite nanofibers fabricated from an emulsion containing 4.29 wt% of cinnamon oil showed excellent antimicrobial effects against Staphylococcus aureus and a series of fungi that can trigger respiratory- and skin-related diseases. The release profile of cinnamon oil from the core/sheath-structured nanofibers showed a continuous release of functional ingredients over 28 days. Our findings demonstrate that the use of such fibrous structures could be a promising approach for delivering naturally derived bioactive agents in a controlled way

Use of Engineering Controls and Personal Protective Equipment by Certified Pesticide Applicators

A convenience survey of 702 certified pesticide applicators was conducted in three states to assess the use of 16 types of engineering controls and 13 types of personal protective equipment (PPE). Results showed that 8 out of 16 engineering devices were adopted by more than 50% of the respondents. The type of crop, size of agricultural operation, and the type of pesticide application equipment were found to influence the adoption of engineering controls. Applicators working on large farms, users of boom and hydraulic sprayers, and growers of field crops were more likely to use engineering devices. Respondents reported a high level of PPE use, with chemical-resistant gloves showing the highest level of compliance. An increase in pesticide applicators wearing appropriate headgear was reported. The majority of respondents did not wear less PPE simply because they used engineering controls. Those who did modify their PPE choices when employing engineering controls used tractors with enclosed cabs and/or were vegetable growers.This article is from Journal of Agricultural Safety and Health 15, no. 4 (2009): 311–326.</p

Impedance Spectroscopic Study of p-i-n Type a-Si Solar Cell by Doping Variation of p-Type Layer

We investigated p-i-n type amorphous silicon (a-Si) solar cell where the diborane flow rate of the p-type layer was varied and the solar cell was measured static/dynamic characteristics. The p/i interface of the thin film amorphous silicon solar cells was studied in terms of the coordination number of boron atoms in the p layer. p-type layer and p/i interface properties were obtained from the X-ray photoelectron spectroscopy (XPS) and impedance spectroscopy. One of the solar cells shows open circuit voltage (oc)=880 mV, short circuit current density (sc)=14.21 mA/cm2, fill factor (FF)=72.03%, and efficiency ()=8.8% while the p-type layer was doped with 0.1%. The impedance spectroscopic measurement showed that the diode ideality factor and built-in potential changed with change in diborane flow rate