Robust design of slow-light tapers in periodic waveguides

This article concerns the design of tapers for coupling power between uniform and slow-light periodic waveguides. New optimization methods are described for designing robust tapers, which not only perform well under nominal conditions, but also over a given set of parameter variations. When the set of parameter variations models the inevitable variations typical in the manufacture or operation of the coupler, a robust design is one that will have a high yield, despite these parameter variations. The ideas of successive refinement, and robust optimization based on multi-scenario optimization with iterative sampling of uncertain parameters, using a fast method for approximately evaluating the reflection coefficient, are introduced. Robust design results are compared to a linear taper, and to optimized tapers that do not take parameter variation into account. Finally, robust performance of the resulting designs is verified using an accurate, but much more expensive, method for evaluating the reflection coefficient.

Assessment and Evaluation of GIScience Curriculum using the Geographic Information Science and Technology Body of Knowledge

Effects of nitrocompounds on uric acid-utilizing microorganisms, nitrogen retention, and microbial community in laying hen manure

A study was conducted to evaluate effects of nitrocompounds on growth of uric acid-utilizing microorganisms, nitrogen retention, and microbial community in laying hen manure. There were three treatments: control, 100 mM nitropropanol (NPL), and 100 mM nitropropionic acid (NPC). The mixed laying hen manure was divided into 3 groups and incubated at 23 degrees C for 7 days. On Days 0, 3, and 7, samples were collected to measure the quantity of uric acid-utilizing microorganisms, total nitrogen retention, and microbial community changes. Both nitrocompounds significantly reduced growth of the uric acid-utilizing microorganisms on Day 3 (P < 0.05). Inhibitory effects of both nitrocompounds remained until Day 7 when the experiment was terminated. NPL treatment retained significantly more manure nitrogen compared to the control on both Days 3 and 7. Manure nitrogen levels of NPC treatment were also significantly higher than the control on Day 7. We further investigated the effects of NPL and NPC on microbial community changes during a 7-day incubation. NPC treatment and control on Day 7 exhibited 94% community similarity. NPC on Day 3 and NPL on Day 7 also showed high community similarity (approximately 94%). Control on Day 0 and Day 7 yielded less than 80% community similarity. Control and NPL treatment groups on Day 3 gave the lowest community similarity (approximately 64%) compared to the other groups. This result indicated that incubation time and treatment moderately influenced microbial community changes. In summary, these results indicate that both nitrocompounds increased manure nitrogen retention by inhibiting the growth of uric acid-utilizing microorganisms, and that NPL and NPC could be used as manure treatments in order to reduce ammonia volatilization and nitrogen retention in poultry manure. Moreover, nitrocompounds may have potential as feed additives to reduce ammonia volatilization.

Zonal Polynomials and Hypergeometric Functions of Quaternion Matrix Argument

We define zonal polynomials of quaternion matrix argument and deduce someimportant formulae of zonal polynomials and hypergeometric functions ofquaternion matrix argument. As an application, we give the distributions of thelargest and smallest eigenvalues of a quaternion central Wishart matrix$W\sim\mathbb{Q}W(n,\Sigma)$, respectively.

Journal Title Display and Citation Practices

Reviews of Books

Phytoplankton dynamics in a chain of subtropical blackwater lakes: the Upper St. Johns River, Florida, USA

Flagship Regeneration in a Global City: The Re-making of Paddington Basin

Enhancing Governmentally Sponsored Export Promotions Through Better Segmentation of the Market of a State's Manufacturing Concerns

This article presents methodology for identifying product categories that, if they were made the subjects of a specified state's export promotions, would hold promise for satisfying relevant needs of members of three key “stakeholder” groups regarding the outcomes of the governmentally sponsored export promotions: the World Trade Organization (WTO), managements of non-exporting, small- and- medium-sized (SME) manufacturing concerns, and governmental entities who are responsible for raising funds to support such promotions. Methodology is applied in the context of a state in the United States (North Carolina). The methodology is then applied in the context of a state in the United States (North Carolina). The presentations of the results of the application of the methodology at each of the 2-, 4- and 6-digit HS-coded product category levels are in each case followed by discussions of implications of the results.

Children's attitudes toward their peers with Down Syndrome in schools in rural Ireland: an exploratory study

Increasingly, children with Down Syndrome are attending mainstream schools, but evidence suggests that these children are more prone to peer rejection and other problems when compared with their non‐disabled counterparts. However, relatively little is known about children's attitudes toward their peers with moderate to serious learning disabilities, including Down Syndrome. This study assessed the attitudes of non‐disabled primary school children (n = 118) in mainstream education toward their peers with Down Syndrome. A secondary aim was to assess whether exposure to audiovisual material promoting inclusion had any immediate effects on overall attitudes. A cross‐sectional, questionnaire‐based survey was administered in four rural‐based schools. The results showed that female participants over 10 were the most sociable. Overall attitudes toward inclusion were consistently and statistically significantly more negative than those toward sociability. Other factors, such as contact with peers with Down Syndrome, were not related to attitudes. Neither was there any change in overall attitudes following exposure to the promotional material. Further work is needed to identify factors underpinning the attitudes of non‐disabled children to their peers with Down Syndrome and how best to promote inclusion in mainstream schools.