46 research outputs found
Program and Proceedings: The Nebraska Academy of Sciences 1880-2023. 142th Anniversary Year. One Hundred-Thirty-Third Annual Meeting April 21, 2023. Hybrid Meeting: Nebraska Wesleyan University & Online, Lincoln, Nebraska
AERONAUTICS & SPACE SCIENCE Chairperson(s): Dr. Scott Tarry & Michaela Lucas
HUMANS PAST AND PRESENT Chairperson(s): Phil R. Geib & Allegra Ward
APPLIED SCIENCE & TECHNOLOGY SECTION Chairperson(s): Mary Ettel
BIOLOGY Chairpersons: Lauren Gillespie, Steve Heinisch, and Paul Davis
BIOMEDICAL SCIENCES Chairperson(s): Annemarie Shibata, Kimberly Carlson, Joseph Dolence, Alexis Hobbs, James Fletcher, Paul Denton
CHEM Section Chairperson(s): Nathanael Fackler
EARTH SCIENCES Chairpersons: Irina Filina, Jon Schueth, Ross Dixon, Michael Leite
ENVIRONMENTAL SCIENCE Chairperson: Mark Hammer
PHYSICS Chairperson(s): Dr. Adam Davis
SCIENCE EDUCATION Chairperson: Christine Gustafson
2023 Maiben Lecturer: Jason Bartz
2023 FRIEND OF SCIENCE AWARD TO: Ray Ward and Jim Lewi
Virginia Commonwealth University Courses
Listing of courses for the 2022-2023 year
Advanced Trends in Wireless Communications
Physical limitations on wireless communication channels impose huge challenges to reliable communication. Bandwidth limitations, propagation loss, noise and interference make the wireless channel a narrow pipe that does not readily accommodate rapid flow of data. Thus, researches aim to design systems that are suitable to operate in such channels, in order to have high performance quality of service. Also, the mobility of the communication systems requires further investigations to reduce the complexity and the power consumption of the receiver. This book aims to provide highlights of the current research in the field of wireless communications. The subjects discussed are very valuable to communication researchers rather than researchers in the wireless related areas. The book chapters cover a wide range of wireless communication topics
Virginia Commonwealth University Courses
Listing of courses for the 2021-2022 year
Best available techniques (BAT) reference document on surface treatment using organic solvents including preservation of wood and wood products with chemicals: Industrial Emissions Directive 2010/75/EU (Integrated Pollution Prevention and Control)
The Best Available Techniques (BAT) Reference Document (BREF) on Surface Treatment using Organic Solvents including Preservation of Wood and Wood Products with Chemicals is part of a series of documents presenting the results of an exchange of information between EU Member States, the industries concerned, non-governmental organisations promoting environmental protection, and the Commission, to draw up, review and – where necessary – update BAT reference documents as required by Article 13(1) of Directive 2010/75/EU on Industrial Emissions (the Directive). This document is published by the European Commission pursuant to Article 13(6) of the Directive.
The BREF on Surface Treatment Using Organic Solvents including Preservation of Wood and Wood Products with Chemicals covers the surface treatment of substances, objects or products using organic solvents as well as the preservation of wood and wood products using chemicals as specified in Sections 6.7 and 6.10 of Annex I to Directive 2010/75/EU respectively.
Important issues for the implementation of Directive 2010/75/EU in the surface treatment using organic solvents (STS) and the wood preservation with chemicals (WPC) sectors are emissions to air and water as well as energy and water consumption. Chapter 1 provides general information on the STS sector and on the main environmental issues associated with their use. Chapters 2 to 14 give the applied processes, current emission and consumption levels, techniques to consider in the determination of BAT for the STS sectors that are covered by these chapters. Chapter 15 provides general information, applied processes, current emission and consumption levels, techniques to consider in the determination of BAT for the wood preservation sector. Chapter 16 provides thumbnail descriptions of additional STS sectors, for which a data collection via questionnaires has not been carried out. General techniques to consider in the determination of BAT (i.e. those techniques to consider that are widely applied in the STS sector) are reported in Chapter 17. Chapter 18 presents the BAT conclusions as defined in Article 3(12) of the Directive, both general and sector-specific. Chapter 19 provides the emerging techniques for the STS and WPC sectors. Concluding remarks and recommendations for future work are presented in Chapter 20.JRC.B.5-Circular Economy and Industrial Leadershi
Algorithms for DFM in electronic design automation
As the dimension of features in integrated circuits (IC) keeps shrinking to fulfill Moore’s law, the manufacturing process has no choice but confronting the limit of physics at the expense of design flexibility. On the other hand, IC designs inevitably becomes more complex to meet the increasing demand of computational power. To close this gap, design for manufacturing (DFM) becomes the key to enable an easy and low-cost IC fabrication. Therefore, efficient electronic design automation (EDA) algorithms must be developed for DFM to address the design constraints and help the designers to better facilitate the manufacture process. As the core of manufacturing ICs, conventional lithography systems (193i) reach their limit for the 22 nm technology node and beyond. Consequently, several advanced lithography techniques are proposed, such as multiple patterning lithography (MPL), extreme ultra-violet lithography (EUV), electron beam (E-beam), and block copolymer directed self-assembly (DSA); however, DFM algorithms are essential for them to achieve better printability of a design. In this dissertation, we focus on analyzing the compatibility of designs and various advanced lithography techniques, and develop efficient algorithms to enable the manufacturing.
We first explore E-Beam, one of the promising candidates for IC fabrication beyond the 10 nm technology node. To address its low throughput issue, the character projection technique has been proposed, and its stencil planning can be optimized with an awareness of overlapping characters. 2D stencil planning is proved NP-Hard. With the assumption of standard cells, the 2D problem can be partitioned into 1D row ordering subproblems; however, it is also considered hard, and no efficient optimal solution has been provided so far. We propose a polynomial time optimal algorithm to solve the 1D row ordering problem, which serves as the major subroutine for the entire stencil planning problem. Technical proofs and experimental results verify that our algorithm is efficient and indeed optimal.
As the most popular and practical lithography technique, MPL utilizes multiple exposures to print a single layout and thus allows placement of features within the minimum distance. Therefore, a feasible decomposition of the layout is a must to adopt MPL, and it is usually formulated as a graph k-coloring problem, which is computationally difficult for k > 2. We study the k-colorability of rectangular and diagonal grid graphs as induced subgraphs of a rectangular or diagonal grid respectively, since it has direct applications in printing contact/via layouts. It remains an open question on how hard it is to color grid graphs due to their regularity and sparsity. In this dissertation, we conduct a complete analysis of the k-coloring problems on rectangular and diagonal grid graphs, and particularly the NP-completeness of 3-coloring on a diagonal grid graph is proved. In practice, we propose an exact 3-coloring algorithm for those graphs and conduct experiments to verify its performance and effectiveness. Besides, we also develop an efficient algorithm for model based MPL, because it is more expensive but accurate than the rule based decomposition.
As one of the alternative lithography techniques, block copolymer directed self-assembly (DSA) is studied. It has emerged as a low-cost, high- throughput option in the pursuit of alternatives to traditional optical lithography. However, issues of defectivity have hampered DSA’s viability for large-scale patterning. Recent studies have shown the copolymer fill level to be a crucial factor in defectivity, as template overfill can result in malformed DSA structures and poor LCDU after etching. For this reason, the use of sub-DSA resolution assist features (SDRAFs) as a method of evening out template density has been demonstrated. In this dissertation, we propose an algorithm to place SDRAFs in random logic contact/via layouts. By adopting this SDRAF placement scheme, we can significantly improve the density unevenness and the resources used are also optimized. We also apply our knowledge in coloring grid graphs to the problem of group-and-coloring in DSA-MPL hybrid lithography. We derive a solution to group-3-coloring and prove the NP-completeness of grouping-2-coloring
Virginia Commonwealth University Courses
Listing of courses for the 2019-2020 year
Generalized averaged Gaussian quadrature and applications
A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal