Physical Sciences and Mathematics Commons^™

Modules And Dialects As Objects In Grace, Michael Homer, James Noble, Kim B. Bruce, Andrew P. Black

Computer Science Faculty Publications and Presentations

Grace is a gradually typed, object-oriented language for use in education; consonant with that use, we have tried to keep Grace as simple and straightforward as possible. Grace needs a module system for several reasons: to teach students about modular program design, to organise large programs, especially its self-hosted implementation, to provide access to resources defined in other languages, and to support different “dialects”—language subsets, or domain specific languages, for particular parts of the curriculum. Grace already has several organising constructs; this paper describes how Grace uses two of them, objects and lexical scope, to provide modules and dialects.

Interactive Ambient Visualizations For Soft Advice, Emerson Murphy-Hill, Titus Barik, Andrew P. Black

Computer Science Faculty Publications and Presentations

Some software packages offer the user soft advice: recommendations that are intended to help the user create high quality artifacts, but which may turn out to be bad advice. It is left to the user to determine whether the soft advice really will improve quality, and to decide whether or not to adopt it. Visualizations can help the user in making this decision, but we believe that conventional visualizations are less than ideal. In this paper, we describe an interactive ambient visualization to help users identify, understand and interpret soft advice.

Our visualization was developed to help programmers interpret code …

The Grace Programming Language Draft Specification Version 0.3.1261, Andrew P. Black, Kim B. Bruce, James Noble

Computer Science Faculty Publications and Presentations

This is a specification of the Grace Programming Language. This specification is notably incomplete, and everything is subject to change.

On The Role Of Shape Prototypes In Hierarchical Models Of Vision, Michael David Thomure, Melanie Mitchell, Garrett T. Kenyon

Computer Science Faculty Publications and Presentations

We investigate the role of learned shape-prototypes in an influential family of hierarchical neural-network models of vision. Central to these networks’ design is a dictionary of learned shapes, which are meant to respond to discriminative visual patterns in the input. While higher-level features based on such learned prototypes have been cited as key for viewpointinvariant object-recognition in these models [1], [2], we show that high performance on invariant object-recognition tasks can be obtained by using a simple set of unlearned, “shape-free” features. This behavior is robust to the size of the network. These results call into question the roles of …

The Problem Of Semantics In The Metadata Mess, Veronika Margaret Megler, David Maier

Computer Science Faculty Publications and Presentations

This presentation addresses problems related to the volume of available scientific data, and its accessibility or inaccessibility to researchers who seek it. Topics addressed include metadata and reducing semantic diversity, especially as they refer to geospatial and other architectures

Two Methodologies: How Well Can Universities Predict Retention, Tiffany Lynette Gregory

Electronic Theses and Dissertations

Student retention has been a long standing focus in higher education research with one of the earliest work dating back to 1937. Many researchers have proposed factors that affect a student's decision to depart from the university without successfully completing a degree. It is important to not only research different attributes and characteristics that affect student departure but it is also important to study different statistical methodologies. With the advancement in technology, new methodologies such as the Classification and Regression Tree (CART) have proven to yield significant results in a variety of research fields. As these new statistical methodologies emerge, …

Large Eddy Simulation Of Surface Pressure Fluctuations Generated By Elevated Gusts, Jericho Erin Cain

Electronic Theses and Dissertations

Wind gusts cause substantial damage to wind turbines. If these damaging winds could be detected prior to their interaction with the turbine, the turbine rotor can be decoupled from the generator and gearing system to prevent damage during the gust event. This would significantly reduce wind turbine repair costs. Wind gusts can also create unsafe conditions for aircraft landing. A ground based detection system that monitored elevated wind gusts can provide new information for pilots to use when determining whether or not it is safe to land. In addition, the ability to monitor elevated gust events would provide a new …

Well-Covered Graphs, Unique Colorability, And Covering Range, Wanda Renea Payne

Electronic Theses and Dissertations

A graph is called well-covered if all of its maximal independent sets have the same cardinality. We give a characterization of well-covered k-trees. A graph is said to be uniquely χ-colorable if, modulo permutations of colors, it has exactly one proper χ-coloring. The k-trees with at least k+1 vertices are minimal uniquely (k +1)-colorable, i.e., they have the minimal number of edges necessary for uniquely (k+1)-colorable graphs. We introduce the k-frames, a new class of minimal uniquely (k+1)-colorable graphs that generalizes the k-trees.

The covering range of a graph is the difference between the cardinality of a largest maximal independent …

Synthesis, Characterization And Application Of Pt Complexes With Pincer Ccc-Bis(Nhc) Ligands, Xiaofei Zhang

Electronic Theses and Dissertations

The unique metallation/transmetallation route for the synthesis of CCC-bis(NHC) pincer ligand supported transition metal complexes was extended to Pt. Several platinum complexes were synthesized. The identity of these complexes was confirmed through multiple technologies, including nuclear magnetic resonance spectroscopy, mass spectroscopy, elemental analysis, thermal analysis, and X-ray crystallography. The intriguing photophysical and thermal properties of these complexes are reported. These complexes were believed to be congeners of materials for organic light emitting diodes (OLEDs).

Studies Of Mercury In Water, Sediment, And Fish In Mississippi: Concentrations, Speciation, Cycling, And Isotopic Composition, Garry Brown

Electronic Theses and Dissertations

The goal of this project is to better understand the biogeochemical cycle of mercury (Hg) in Mississippi to aid those managing the resources and developing related policy. To that end, Hg levels were determined in a total of 202 fish from Enid, Sardis and Grenada Lakes; Enid and Grenada have fish consumption advisories due to Hg. In addition, total-Hg and methylmercury (MeHg) levels were determined in the inflow and outflows from Enid and Sardis Lakes and in bottom sediment and suspended solids in Enid Lake. Potential sources of Hg to Enid Lake were investigated, including precipitation and runoff from urban, …

Taming The Metadata Mess, Veronika Margaret Megler

Computer Science Faculty Publications and Presentations

The rapid growth of scientific data shows no sign of abating. This growth has led to a new problem: with so much scientific data at hand, stored in thousands of datasets, how can scientists find the datasets most relevant to their research interests? We have addressed this problem by adapting Information Retrieval techniques, developed for searching text documents, into the world of (primarily numeric) scientific data. We propose an approach that uses a blend of automated and “semi-curated” methods to extract metadata from large archives of scientific data, then evaluates ranked searches over this metadata. We describe a challenge identified …

On Binary And Regular Matroids Without Small Minors, Kayla Davis Harville

Electronic Theses and Dissertations

The results of this dissertation consist of excluded-minor results for Binary Matroids and excluded-minor results for Regular Matroids. Structural theorems on the relationship between minors and k-sums of matroids are developed here in order to provide some of these characterizations. Chapter 2 of the dissertation contains excluded-minor results for Binary Matroids. The first main result of this dissertation is a characterization of the internally 4-connected binary matroids with no minor that is isomorphic to the cycle matroid of the prism+e graph. This characterization generalizes results of Mayhew and Royle [18] for binary matroids and results of Dirac [8] and Lovász …

Early Transition Metal Ccc-Nhc Pincer Complexes: Synthesis, Characterization, And Catalysis, Theodore Rudy Helgert

Electronic Theses and Dissertations

The previously reported amine elimination methodology for the metalation of CCC-NHC pincer ligand precursors has been extended to other early-transition metals and ligands. Specifically, synthetic results for the preparation of imidazole based CCC-NHC pincer Ti (IV), CCC-NHC pincer Ta (V) will be discussed. In addition, the synthesis of a new triazole based CCC-NHC pincer ligand precursor and its metalation with Ta (V) will be presented. Coordination sphere manipulation of the new pincer complexes using TMSCl for the Ti complex and lithium t-butylamide for the Ta complexes is also discussed. The reaction of the initial Ta CCC-NHC complex with lithium t-butylamide …

Backscatter And Attenuation Properties Of Mammalian Brain Tissues, Pushpani Vihara Wijekularatne

Electronic Theses and Dissertations

Traumatic Brain Injury (TBI) is a comcategory of brain injuries, which contributes to a substantial number of deaths and permanent disability all over the world. Ultrasound technology plays a major role in tissue characterization due to its low cost and portability that could be used to bridge a wide gap in the TBI diagnostic process. This research addresses the ultrasonic properties of mammalian brain tissues focusing on backscatter and attenuation. Orientation dependence and spatial averaging of data were analyzed using the same method resulting from insertion of tissue sample between a transducer and a reference reflector. Apparent Backscatter Transfer Function …

Online Learning In A Chemical Perceptron, Peter Banda, Christof Teuscher, Matthew R. Lakin

Computer Science Faculty Publications and Presentations

Autonomous learning implemented purely by means of a synthetic chemical system has not been previously realized. Learning promotes reusability and minimizes the system design to simple input-output specification. In this article we introduce a chemical perceptron, the first full-featured implementation of a perceptron in an artificial (simulated) chemistry. A perceptron is the simplest system capable of learning, inspired by the functioning of a biological neuron. Our artificial chemistry is deterministic and discrete-time, and follows Michaelis-Menten kinetics. We present two models, the weight-loop perceptron and the weight-race perceptron, which represent two possible strategies for a chemical implementation of linear integration and …

City Of Poquoson, Virginia Shoreline Inventory Report Methods And Guidelines, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Carl Hershner, David Stanhope, David Weiss, Julie Bradshaw, Christine Tombleson

Reports

The data inventory developed for the Shoreline Inventory is based on a three tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions:

• the immediate riparian zone, evaluated for land use

• the bank, evaluated for height, stability, cover and natural protection

• the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes.

The 2001 Inventory for the City of Poquoson was updated using on-screen, digitizing techniques in ArcMap® v10.0 while viewing conditions …

Summary Tables: City Of Poquoson, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Tamia Rudnicky, Carl Hershner, David Stanhope, David Weiss, Julie Bradshaw, Christine Tombleson

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).

Summary Tables: City Of Suffolk, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Kory Angstadt, David Weiss, Carl Hershner

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).

Comprehensive Coastal Resource Management Guidance : Planning Information And Guidance For The Living Shoreline Preference, Center For Coastal Resources Management

Reports

Guidance to promote Comprehensive Resource Management is being prepared pursuant to recent amendments to the Code of Virginia. Effective July 1, 2011, The “Living Shorelines Bill” SB 964 (2011) amended §28.2-1100 of the Code of Virginia and added §15.2-2223.2 and §28.2- 104.1 to the Code. Beginning in 2013, Section 15.2-2223.2 requires local governments to include a Comprehensive Coastal Resource Management Plan prepared by the Virginia Institute of Marine Science in the next revision of their comprehensive plan. The guidance cultivates long-term sustainability for shoreline resources with consideration of current resource condition, priority planning, and forecasting of projected sea level rise …

Summary Tables: Charles City County, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Sharon A. Killeen, Tamia Rudnicky, Kory Angstadt, Julie G. Bradshaw, David Weiss, Carl Hershner

Reports

The Shoreline Inventory Summary Tables quantify observed conditions based on river systems, such as the combined length of linear features (e.g. shoreline miles surveyed, miles of bulkhead and revetment), the total number of point features (e.g. docks, boathouses, boat ramps) & total acres of polygon features (tidal marshes).

State Space Reduction For Sensor Networks Using Two-Level Partial Order Reduction, Manchun Zheng, David Sanán, Jun Sun, Yang Liu, Jin Song Dong, Yu Gu

Research Collection School Of Computing and Information Systems

Wireless sensor networks may be used to conduct critical tasks like fire detection or surveillance monitoring. It is thus important to guarantee the correctness of such systems by systematically analyzing their behaviors. Formal verification of wireless sensor networks is an extremely challenging task as the state space of sensor networks is huge, e.g., due to interleaving of sensors and intra-sensor interrupts. In this work, we develop a method to reduce the state space significantly so that state space exploration methods can be applied to a much smaller state space without missing a counterexample. Our method explores the nature of networked …

Artificial Immunity-Based Induction Motor Bearing Fault Diagnosis, Hakan Çaliş, Abdülkadi̇r Çakir, Emre Dandil

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the artificial immunity of the negative selection algorithm is used for bearing fault detection. It is implemented in MATLAB-based graphical user interface software. The developed software uses amplitudes of the vibration signal in the time and frequency domains. Outer, inner, and ball defects in the bearings of the induction motor are detected by anomaly monitoring. The time instants of the fault occurrence and fault level are determined according to the number of activated detectors. Anomaly detection in the frequency domain is implemented by monitoring the fault indicator bearing frequencies and harmonics, calculated using the bearing dimensions and …

The Vortex Effect Of Francis Turbine In Electric Power Generation, Veli̇ Türkmenoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the vibration effects of a vortex that occurred in high-head Francis turbines and an alternator are examined. The vortex effect, which directly affects the efficiency and the quality of the energy, was tested at the DarÔøΩca-1 hydroelectric power plant (HPP) located in Ordu Province, Turkey. Formed by undissolved oxygen in the water, the vortex effect, which is parallel to the alternator load, causes tremendous vibration within the alternator and Francis turbine bearings. This problem, which has a direct negative effect on the alternator capacity, was solved by adding an air-admission system. In doing so, power production was …

A Practical Disturbance Generator To Test Performances Of Various Power Quality Mitigation Devices, Ahmet Teke, Mehmet Emi̇n Meral, Mehmet Tümay, Mehmet Uğraş Cuma

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a practical thyristor-based 3-phase sag/swell/outage generator (disturbance generator) is designed to test various power quality mitigation devices (PQMDs), such as solid state transfer switch (SSTS), static voltage compensator (SVC), and uninterruptible power supply. The latest technological disturbance generators (DGs) and the proposed DG are comprehensively discussed and compared with focus on usefulness, economic aspects, and simplicity. The proposed DG is used for experimentally generating different fault conditions and testing a SSTS. The comparisons and analyses show that the proposed DG is an optimum and simple solution to generate sag, swell, unbalance, overvoltage, undervoltage, and outage to test …

Circulating Current Analysis Between Strands In Armature Winding Of A Turbo-Generator Using Analytical Model, Karim Abbaszadeh, Farhad Rezaee Alam

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the circulating current analysis between strands is studied while considering the different transpositions in the active part and without considering the transposition in the end winding region. First, this analysis is done while only considering the slot region, and then the end winding region is added to the model. The model used for this analysis is a circuit model, including the resistance and inductance of the strands and their induced back-electromotive force (EMF). The back-EMF sources and inductances are calculated through a 2D finite element analysis (FEA) of the active part and a 3D FEA for the …

Composite Power System Adequacy Assessment Based On Postoptimal Analysis, Amir Safdarian, Mahmood Fotuhi-Firuzabad, Farrokh Aminifar

Turkish Journal of Electrical Engineering and Computer Sciences

The modeling and evaluation of enormous numbers of contingencies are the most challenging impediments associated with composite power system adequacy assessment, particularly for large-scale power systems. Optimal power flow (OPF) solution, as a widely common approach, is normally employed to model and analyze each individual contingency as an independent problem. However, mathematical representations associated with diverse states are slightly different in one or a few generating units, line outages, or trivial load variations. This inherent attribute brings a promising idea to speed up the contingency evaluation procedure. In this paper, postoptimal analysis (POA), as a well-recognized technique to attack a …

A Novel Multirobot Map Fusion Strategy For Occupancy Grid Maps, Sebahatti̇n Topal, İsmet Erkmen, Aydan Müşerref Erkmen

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we consider the problem of merging partial occupancy grid environment maps, which are extracted independently by individual robot units during search and rescue (SAR) operations in icomplex disaster environments. Moreover, these maps are combined using intensity-based and area-based features without knowing the initial position and orientation of the robots. Our proposed approach handles the limitation of existing studies in the literature; for example, the limited overlapped area between partial maps of robots is enough for good merging performance and unstructured and complex partial environment maps can be merged efficiently. These abilities allow multirobot teams to efficiently generate …

Solution To The Unit Commitment Problem Using An Artificial Neural Network, Mehdi Zareian Jahromi, Mohammad Mehdi Hosseini Bioki, Masoud Rashidi Nejad, Roohollah Fadaeinedjad

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a real-time solution to the unit commitment problem by considering different constraints like ramp-up rate, unit operation emissions, next hours load, and minimum down time. In this method, an optimized trade-off between cost and emission has been taken into consideration. The effectiveness of the proposed method was verified by the significant outcomes demonstrated.

A Comparative Study In Power Oscillation Damping By Statcom And Sssc Based On The Multiobjective Pso Algorithm, Ali Ajami, Mehdi Armaghan

Turkish Journal of Electrical Engineering and Computer Sciences

To improve the damping of power system oscillations by supplementary controller design for the static synchronous series compensator (SSSC) and static synchronous compensator (STATCOM), a multiobjective function based on the particle swarm optimization (PSO) algorithm for solving this optimization problem is introduced. The presented objective function includes the damping factor and the damping ratio of the lightly damped and undamped electromechanical modes. These controllers are adjusted to concurrently transfer the lightly damped and undamped electromechanical modes to a recommended region in the s-plane. For this purpose, the reduced linearized Phillips-Heffron model of the power system with a single machine and …

Control In Networked Systems With Fuzzy Logic, Akhan Akbulut, Oğuzhan Öztaş

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, the development of control systems based on network-based architecture is getting very high attention. Because of its fast data communication, network-based control is in high demand. However, there are some disadvantages, such as delays, data packet dropouts, and communication constraints. Network-based control systems are getting attention in the development of this architecture because of these disadvantages. Optimization of the system is supplied to improve the existing structure. The optimization is categorized into 2 main structures: software optimization and hardware optimization. The structure of the overall system is designed with these optimization strategies. A hierarchical and communicational structure has emerged …