Digital Commons Network^™

An Hmm-Based Framework For Video Semantic Analysis, Gu Xu, Yu-Fei Ma, Hong-Jiang Zhang, Shiqiang Yang

Chemistry Faculty Research & Creative Works

Video semantic analysis is essential in video indexing and structuring. However, due to the lack of robust and generic algorithms, most of the existing works on semantic analysis are limited to specific domains. In this paper, we present a novel hidden Markove model (HMM)-based framework as a general solution to video semantic analysis. In the proposed framework, semantics in different granularities are mapped to a hierarchical model space, which is composed of detectors and connectors. In this manner, our model decomposes a complex analysis problem into simpler subproblems during the training process and automatically integrates those subproblems for recognition. The …

Deuterium Nmr Studies Of Segmental Dynamics Of Anopore-Adsorbed Poly(Methyl Acrylate), Macduff O. Okuom, Frank D. Blum

Chemistry Faculty Research & Creative Works

Studies of segmental dynamics of polymers at interfaces provide a basis for understanding the properties of composite materials. Interfacial phenomena in multi-phase systems need to be understood as devices made from multi-phase polymeric systems become smaller. Various techniques have been used to investigate interfacial polymers at the air-polymer-solid interface; for example, ellipsometry,1 X-ray,2 and neutron reflectometry.3 These techniques typically characterize the structure (often the thickness) of the polymer layer and are normally used to determine the glass-transition temperature (Tg) through a break in the thicknesstemperature curve. There have been a few reports where the dynamics of polymers at the surface-air …

Effect Of Plasticizer On Pvac-D3 Dynamics Using 2h Solid-State Nmr, Rakesh R. Nambiar, Frank D. Blum

Chemistry Faculty Research & Creative Works

Poly(vinyl acetate) (PVAc) is an important polymer for use in many applications due to its various bulk and surface characteristics. The structure of poly(vinyl acetate) results in a relatively low glass transition temperature (Tg) and makes it important for processing and applications such as paints, adhesives, thin films and surface coatings. Poly(vinyl acetate) can also be easily plasticized, widening its range of applications. The term "plasticizer" refers to a species that will decrease Tg of a polymer.1 Polymer-plasticizer systems have been studied for years and continue to be of current interest. The effects of polymer-plasticizer interactions2 and plasticizer structure3 on …

Estimation Of Bound Carbonyls In Pmma-R-Ps Copolymers Adsorbed On Silica, Pavan K. Challa, Bing Zhang, Frank D. Blum

Chemistry Faculty Research & Creative Works

The adsorption of random copolymers on solid surfaces is essential for developing good properties in composite materials. A good control and understanding of interfaces allows tuning of the properties of the individual components. Interfacial polymers are important in many industrial applications such as photoresists, protective coatings, metal insulator and semi-conductor insulator junctions, metal-filled polymer composites and polymer-lined metal containers for protective food packaging. The effect of the drying process,1 configuration and tacticity,2 molecular mass, density of surface hydroxyls,3 and adsorbed amounts4 have already been studied for interfacial polymers. The thermal characterization for polystyrene,5 PMMA11 and PMMA-r- PS6 copolymers adsorbed on …

Magnetic Properties Of (Γ-Fe₂O₃)₈₀Ag₂₀ Nanocomposites Prepared In Reverse Micelles, Joan A. Wiemann, Jianbiao Dai, Jinke Tang, Gary J. Long, Leonard Spinu

Chemistry Faculty Research & Creative Works

The magnetic properties of nanoparticles of gamma-Fe2O3 prepared by reverse micelles have been studied by dc magnetization, transverse ac susceptibility, and Mössbauer spectroscopy. The nanoparticles of gamma-Fe2O3 in the nanocomposite (gamma-Fe2O3)80Ag20 exhibit superparamagnetic behavior. The blocking temperatures determined by the three methods indicate the superparamagnetic nature of (gamma-Fe2O3)80Ag20 above 70-80 K and show correlation with measuring time. The average particle diameter obtained by transmission electron microscopy of the gamma-Fe2O3 particles is ~10 nm and that of the Ag particles is ~20 nm. The average particle size determined from the magnetic analyses for the gamma-Fe2O3 particles is ~12 nm. Mössbauer spectra …

Nmr And Modulated Differential Scanning Calorimetry Of Adsorbed Poly(Methyl Acrylate) On Silica, Frank D. Blum, Burak Metin

Chemistry Faculty Research & Creative Works

The interaction between polymers and solid substrates can be studied by a variety of techniques. The results from different experiments can be affected by the nature of the polymer, surface, polymer-surface interactions and, also, the experiment. A great deal has been learned about the behavior of polymers at interfaces, but there is also much to be learned about the interactions and how they affect the physical properties of adsorbed polymers. In the present study, we report both deuterium nuclear magnetic resonance (NMR) and modulated differential scanning calorimetry (MDSC) of poly(methyl acrylate) (PMA) adsorbed on Cab-O-Sil silica. The focus of this …

Segmental Dynamics In Poly(Methyl Acrylate)-D3 On Strongly And Weakly Adsorbing Silica Surfaces, Burak Metin, Frank D. Blum

Chemistry Faculty Research & Creative Works

The segmental dynamics of a polymer on a solid surface appears to be significantly different than that in bulk. The strength of the interaction between polymer segments and a solid surface is likely to be an important factor affecting the segmental mobility of the polymers. Studies of polymers on a weakly adsorbing surface would provide additional understanding of their motional characteristics on surfaces. In a recent NMR study by Rivillon et al., chain dynamics was seen to be different for samples, even when there was no specific interaction with the surface. Peanasky et al. have found a restricted segmental dynamics …

Synthesis And Electropolymerization Of 2-(3-Thienylethyl)-3-Thiopheneacetate, Nicholas Leventis, Chariklia Sotiriou-Leventis, Sudhir Mulik, Amala Dass

Chemistry Faculty Research & Creative Works

Conducting polymers offer great promise in the development of electronic devices, displays and sensors. In that regard, biomolecules can be attached to these polymers via functional groups, but the presence of such groups oftentimes hinders polymerization.1-3 One strategy is to polymerize a functionalized monomer precursor of a conducting polymer, followed by reaction of the dangling functional groups of the polymer with appropriately functionalized labels. An attractive functionalized thiophene for that purpose is 3-thienylethanol. Unfortunately, however, this monomer is not polymerizable.1,2 Thus, 3-thienylethanol has been esterified, followed by co-polymerization with 3-methylthiophene (3-MT), and subsequent hydrolysis of the ester to the free …

Fuzzy Pso: A Generalization Of Particle Swarm Optimization, S. Abdelshahid, Donald C. Wunsch, Ashraf M. Abdelbar

Electrical and Computer Engineering Faculty Research & Creative Works

In standard particle swarm optimization (PSO), the best particle in each neighborhood exerts its influence over other particles in the neighborhood. In this paper, we propose fuzzy PSO, a generalization which differs from standard PSO in the following respect: charisma is defined to be a fuzzy variable, and more than one particle in each neighborhood can have a non-zero degree of charisma, and, consequently, is allowed to influence others to a degree that depends on its charisma. We evaluate our model on the weighted maximum satisfiability (maxsat) problem, comparing performance to standard PSO and to Walk-Sat.

Measuring Scalability Of Resource Management Systems, A. Mitra, Muthucumaru Maheswaran, Shoukat Ali

Electrical and Computer Engineering Faculty Research & Creative Works

Scalability refers to the extent of configuration modifications over which a system continues to be economically deployable. Until now, scalability of resource management systems (RMSs) has been examined implicitly by studying different performance measures of the RMS designs for different parameters. However, a framework is yet to be developed for quantitatively evaluating scalability to unambiguously examine the trade-offs among the different RMS designs. In this paper, we present a methodology to study scalability of RMSs based on overhead cost estimation. First, we present a performance model for a managed distributed system (e.g., Grid computing system) that separates the manager and …

Modulation Of Millimeter Waves By Acoustically Controlled Hexagonal Ferrite Resonator, Marina Koledintseva, Alexander A. Kitaytsev

Electrical and Computer Engineering Faculty Research & Creative Works

To develop millimeter-wave modulators, high-anisotropy uniaxial monocrystalline hexagonal ferrite resonators (HFRs) can be used. One of the ways to modulate the hexagonal ferrite resonator's resonance frequency is to periodically vary the angle between the equilibrium magnetic moment and the external magnetization field. This angular control can be exercised by the mechanical (acoustic) oscillations excited in a piezoelectric slab having a good acoustic contact with the HFR. We consider a quasi-static mathematical model of the uniaxial HFR with the angular control of its resonance frequency. We analyze the amplitudes of harmonics of the modulated millimeter-wave signal, and we derive the optimal …

Coupled Electrical And Magnetic Properties In (La,Sr)Feo3-Δ, X.-D. Zhou, Qingsheng Cai, Jinbo Yang, M. S. Kim, William B. Yelon, William Joseph James, Y.-W. Shin, B. J. Scarfino, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

This article is aimed at studying the temperature dependence oxygen nonstoichiometry, magnetic moments, Fe³⁺ fraction, Néel temperature and conductivity of (La,Sr)FeO_3-δ. It is found that the magnetic properties in La_0.60 Sr_0.40 Fe_3-δ is determined by Fe³⁺ and its concentration, and the conductance is resulted from Fe⁴⁺ ions, which act as electron holes. Both of magnetic and electrical properties were directly governed by oxygen nonstoichiometry (δ). when δ=0.2, the compound has maximum Fe³⁺, the saturation magnetic moments and Néel temperature are 3.8 µB and 410 °C, both at the highest level, …

Neural Network-Based Control Of Nonlinear Discrete-Time Systems In Non-Strict Form, Jagannathan Sarangapani, Zheng Chen, Pingan He

Electrical and Computer Engineering Faculty Research & Creative Works

A novel reinforcement learning-based adaptive neural network (NN) controller, also referred as the adaptive-critic NN controller, is developed to deliver a desired tracking performance for a class of non-strict feedback nonlinear discrete-time systems in the presence of bounded and unknown disturbances. The adaptive critic NN controller architecture includes a critic NN and two action NNs. The critic NN approximates certain strategic utility function whereas the action neural networks are used to minimize both the strategic utility function and the unknown dynamics estimation errors. The NN weights are tuned online so as to minimize certain performance index. By using gradient descent-based …

Study Of The Electronic Structure Of Cafeo₃, Jinbo Yang, M. S. Kim, Qingsheng Cai, X.-D. Zhou, Harlan U. Anderson, William Joseph James, William B. Yelon

Materials Science and Engineering Faculty Research & Creative Works

We have studied the charge disproportionation phenomenon in CaFeO3 using the local-spin density approximation with the on-site Coulomb interaction parameter U and exchange parameter J. The calculation reveals that the total number of the 3d electrons is about 5.1 for both Fe(1)(Fe5+) and Fe(2)(Fe3+) atoms, and that there are about 0.25 electron holes in the O-2p band. Therefore, the charge disproportionation can be more accurately described as 2d5L(Fe4+)=d5L2(Fe5+)+d5(Fe3+), where L denotes a hole in the oxygen 2p band, instead of 2d4(Fe4+)=d3(Fe5+)+d5(Fe3+). The hybridization between the Fe-3d and O-2p orbitals is stronger for Fe(1) than for Fe(2) due to the shorter …

Structure, Magnetic, And Transport Properties Of Ti-Substituted La₀.₇Sr₀.₃Mno₃, M. S. Kim, Jinbo Yang, Qingsheng Cai, X.-D. Zhou, William Joseph James, William B. Yelon, D. Buddhikot, Satish K. Malik, Paul Ernest Parris

Materials Science and Engineering Faculty Research & Creative Works

Ti-substituted perovskites La_0.7Sr_0.3Mn_1-xTi_xO₃ with 0 ≤ x ≤ 0.20, were investigated by neutron diffraction, magnetization, electric resistivity, and magnetoresistance (MR) measurements. All samples show a rhombohedral structure (space group R3c) from 10 K to room temperature. At room temperature, the cell parameters a,c and the unit cell volume increase with increasing Ti content. However, at 10 K, the cell parameter a has a maximum value for x = 0.10, and decreases for x > 0.10, while the unit cell volume remains nearly constant for x > 0.10. The average (Mn,Ti)-O bond length increases …

Aggregate Gradation Optimization -- Literature Search, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

No abstract provided.

Engineered Struvite Precipitation: Impacts Of Component-Ion Molar Ratios And Ph, Jun Wang, Joel Gerard Burken, Xiaoqi Zhang, Rao Y. Surampalli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Struvite precipitation has the potential for removing and recovering phosphorus from agricultural wastewater streams, such as concentrated animal feeding operations wastewater. However, impacts of anticipated component-ion molar ratios and potentially interfering ions are unknown as are the compounding pH relationship with respect to all potential complexes. This research experimentally investigates and mathematically models these factors. Emphasis is placed upon the composition of formed deposits and model validation with experimental data. Results show that calcium is a major interfering ion affecting the deposit composition, decreasing struvite purity. X-ray diffraction (XRD) and scanning electron microscopy + energy dispersive spectrometry were used to …

Decentralized Discrete-Time Neural Network Controller For A Class Of Nonlinear Systems With Unknown Interconnections, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel decentralized neural network (NN) controller in discrete-time is designed for a class of uncertain nonlinear discrete-time systems with unknown interconnections. Neural networks are used to approximate both the uncertain dynamics of the nonlinear systems and the unknown interconnections. Only local signals are needed for the decentralized controller design and the stability of the overall system can be guaranteed using the Lyapunov analysis. Further, controller redesign for the original subsystems is not required when additional subsystems are appended. Simulation results demonstrate the effectiveness of the proposed controller. The NN does not require an offline learning phase and the weights …

Using A Neural Network To Distinguish Between The Contributions To Harmonic Pollution Of Non-Linear Loads And The Rest Of The Power System, Joy Mazumdar, Frank C. Lambert, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Combining High Conductivity With Complete Optical Transparency: A Band Structure Approach, Julia E. Medvedeva, Arthur J. Freeman

Physics Faculty Research & Creative Works

A comparison of the structural, optical and electronic properties of the recently discovered transparent conducting oxide (TCO), nanoporous Ca12Al14O33, with those of the conventional TCOs (such as Sc-doped CdO) indicates that this material belongs conceptually to a new class of transparent conductors. For this class of materials, we formulate criteria for the successful combination of high electrical conductivity with complete transparency in the visible range and emphasize the significant correlation between their structural characteristics and electronic and optical properties. Our analysis suggests that this set of requirements can be met for a group of novel materials called electrides which may …

A Qualitative Investigation Of Student Interactions In A Learning Activity Center: Defining Success, At-Risk Factors, And Resiliency For Developmental Programs In Community Colleges, John L. Kalkwarf

Dissertations and Theses @ UNI

This purposive study selected ten students of different background in order to understand how the educational success of adults was affected by Learning Activity Centers (LAC) in a community college. The ten selected students were all non-traditional students who had at least these three at-risk factors: (a) they scored below the college minimums on a diagnostic test in reading, writing, or mathematics, (b) they were below student financial aid guidelines, and (c) they had an interrupted educational history of two or more years. The ten students were paired into five categories: (a) Sudanese males, (b) Mexican females, (c) single parent …

The Efficacy Of Writing Course Placement At An Iowa Community College, Kristine D. Owens

Dissertations and Theses @ UNI

The purpose of this study was to investigate the efficacy of writing course placement at an Iowa community college. The following questions were addressed: What indicators, separately or in combination, resulted in an appropriate or inappropriate student writing placement? (a) To what extent did the COMPASS test result in an appropriate placement? (b) To what extent did the self-directed essay result in an appropriate placement? (c) To what extent did a student's preference result in an appropriate placement?

This study was important to understand how the “directed self-placement” model, adapted from Royer and Gilles (1998, p. 1), impacted the institution's …

The Mind Is The Tabernacle Of The Consciousness Soul: A Journey Visiting The Roles Of Consciousness, Communication, Education, And Technology In Human And Curriculum Development By Integrating Dewey, Gebser, And Steiner: Past, Present, Future, Daniel Joseph Kazim Bardy

Dissertations and Theses @ UNI

This descriptive philosophical study examines 355+ question seeds of thought and discourse on consciousness, communication, education, and technology, much in the contexts of philosophical structures of human beings from 4,000,000 B.C. hominid man to the future of humankind and genetic enhancement. Curriculum and consciousness discussion of American John Dewey (1859–1952), Polish-born Jean Gebser (1905–1975), and Austrian-born Rudolf Steiner (1865–1920) is interwoven, finding commonalities of these philosophers and that of Daniel J. K. Bardy. Language being developed only 50,000 years ago is the defining point for Homo sapiens as the tool of linguistic communication, mutated forward much like the protrusion development …

Inventory Simulation And Optimization Using System Dynamics, Structural Modeling Equations And Genetic Algorithms In The Drivetrain Division Of An Automotive Manufacturer, Marco Sisfontes-Monge

Dissertations and Theses @ UNI

Strategic planning and control are among the most critical activities that modern enterprises require to succeed in the global economy. This research is an original study that investigated the combination of tools and methodologies in order to apply them to a midwestern tractor manufacturer. The current study identified the constraints applicable to a polishing line in the Drivetrain Division of a major tractor manufacturer interested in exploring alternative techniques to improve its worldwide manufacturing operations.

The specific questions that this project tried to respond are stated as follows:

1. What were the most important variables that affected inventory levels of an …

The Impact Of The No Child Left Behind (Nclb) Legislation On School Leadership Of Two School Buildings Designated In Need Of Improvement: An Agency Theory Perspective, Susan Pecinovsky

Dissertations and Theses @ UNI

The purpose of conducting this study was to describe and analyze how NCLB has influenced school leaders in school buildings designated in need of assistance (SINA) and to the sanctions that accompany that label. Included in this study is the examination of the principal-agent interactions proposed in agency theory through the relationship of Iowa school leadership and the Iowa Department of Education.

From the 11 school buildings presently designated schools in need of assistance according to the Reauthorization of the Elementary and Secondary Education Act 2001 or No Child Left Behind, the school leadership of two school buildings participated in …

Monitoring Spatial And Temporal Water Quality Changes In Iowa Lakes Using Airborne Hyperspectral Imagery, Nathan Robert Green

Dissertations and Theses @ UNI

The U.S. Environmental Protection Agency (US EPA) has identified more than 20,000 water bodies across America as polluted mainly due to agricultural non-point source pollution. Current techniques for monitoring and assessing the quality of waters in streams, reservoirs, lakes, and estuaries involve on site measurements and/or the collection of water samples for subsequent laboratory analyses. While this approach yields accurate measurements for a point in time and space, it is expensive, laborious, and cannot provide a temporal or spatial overview of water-quality trends. To overcome this liability, state and local agencies are seeking alternative and more cost effective methods. A …

Sticks, Stones, & Stigmas: A Social-Cognitive Account Of Stereotype Threat Mechanisms, Michael C. Philipp

Dissertations and Theses @ UNI

Stereotype threat effects have been a popular domain of much psychological inquiry over the past decade. A number of psychological dispositions (e.g., high levels of stigma consciousness, high levels of social dominance orientation, and high levels of domain identification), situational factors (e.g., out-group presence and task difficulty), and physiological characteristics ( e.g., levels of circulating testosterone) have been identified as factors that determine one's susceptibility to the performance debilitating effects of negative stereotype activation. Although each of these variables has been found to be important in eliciting underperformance under threat, no attempts have yet investigated the relationships between these variables. …

Investigating The Effectiveness Of Professional Development On High School Physics Teachers’ Conceptual Understanding Of Newtonian Mechanics, Instructional Practices, And The Conceptual Growth Of Their Students, Julia K. Moeller

Dissertations and Theses @ UNI

The purpose of this study was to examine the effectiveness of a physics professional development program on secondary science teachers' conceptual knowledge of Newtonian mechanics, instructional practices and the conceptual growth of their students. The University of Northern Iowa Physics Institute enabled a group of twenty-one Iowa high school and middle school science teachers to complete the physics coursework required to obtain the State of lowa 7-12 Grade Physics Teaching endorsement. The Institute provided experiences to improve physics content knowledge and proficiency of constructivist methodologies for teaching high school physics.

Twelve Institute participants completed a two-year program during the 2002 …

Predictive Congestion Control Mac Protocol For Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Available congestion control schemes, for example transport control protocol (TCP), when applied to wireless networks results in a large number of packet drops, unfairness with a significant amount of wasted energy due to retransmissions. To fully utilize the hop by hop feedback information, a suite of novel, decentralized, predictive congestion control schemes are proposed for wireless sensor networks in concert with distributed power control (DPC). Besides providing energy efficient solution, embedded channel estimator in DPC predicts the channel quality. By using the channel quality and node queue utilizations, the onset of network congestion is predicted and congestion control is initiated. …

Reactive Power And Voltage Control Of The Nigerian Grid System Using Micro-Genetic Algorithm, Ganesh K. Venayagamoorthy, G. A. Bakare, U. O. Aliyu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a micro-genetic based approach to the optimization of reactive power and voltage profiles improvement and real power loss minimization is presented. The reactive power control devices such as generators, tap positions of on-load tap changer of transformers, shunt reactors are used to correct voltage limits violations while simultaneously reducing the system real power losses. Genetic algorithms (GAs) are well-known global search techniques anchored on the mechanisms of natural selection and genetics. Because of the time intensive nature of the conventional GA, the micro-GA is proposed as a more time efficient alternative. The feasibility and effectiveness of the …