Computer Sciences Commons^™

Optimized Simulation Of Granular Materials, Seth R. Holladay

Theses and Dissertations

Visual effects for film and animation often require simulated granular materials, such as sand, wheat, or dirt, to meet a director's needs. Simulating granular materials can be time consuming, in both computation and labor, as these particulate materials have complex behavior and an enormous amount of small-scale detail. Furthermore, a single cubic meter of granular material, where each grain is a cubic millimeter, would contain a billion granules, and simulating all such interacting granules would take an impractical amount of time for productions. This calls for a simplified model for granular materials that retains high surface detail and granular behavior …

Joint Angle Tracking With Inertial Sensors, Mahmoud Ahmed El-Gohary

Dissertations and Theses

The need to characterize normal and pathological human movement has consistently driven researchers to develop new tracking devices and to improve movement analysis systems. Movement has traditionally been captured by either optical, magnetic, mechanical, structured light, or acoustic systems. All of these systems have inherent limitations. Optical systems are costly, require fixed cameras in a controlled environment, and suffer from problems of occlusion. Similarly, acoustic and structured light systems suffer from the occlusion problem. Magnetic and radio frequency systems suffer from electromagnetic disturbances, noise and multipath problems. Mechanical systems have physical constraints that limit the natural body movement. Recently, the …

Data Mining The Functional Characterizations Of Proteins To Predict Their Cancer-Relatedness, Peter Revesz, Christopher Assi

School of Computing: Faculty Publications

This paper considers two types of protein data. First, data about protein function described in a number of ways, such as, GO terms and PFAM families. Second, data about whether individual proteins are experimentally associated with cancer by an anomalous elevation or lowering of their expressions within cancerous cells. We combine these two types of protein data and test whether the first type of data, that is, the functional descriptors, can predict the second type of data, that is, cancer-relatedness. By using data mining and machine learning, we derive a classifier algorithm that using only GO term and PFAM family …

Just-In-Time Power Gating Of Gasp Circuits, Prachi Gulab Padwal

Dissertations and Theses

In modern integrated circuits, one way to reduce power consumption is to turn off power to parts of the circuit when those are idle. This method is called power gating. This thesis presents a state-preserving technique to achieve power savings in GasP family of asynchronous circuits by turning off the power when the circuit is idle. The power control logic turns on the power in anticipation of the receiving data. The power control logic turns off the power when the stage is idle either because it is empty or because the pipeline is clogged. The low logical effort of GasP …

Online Optimal Control Of Nonaffine Nonlinear Discrete-Time Systems Without Using Value And Policy Iterations, Hassan Zargarzadeh, Qinmin Yang, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Online optimal control of nonlinear discrete-time systems in a forward-in-time manner is a challenging problem due to a lack of closed-form solution to the Hamilton- Bellman-Jacobi (HJB) equation. Traditionally, value and policy iteration-based approximate optimal control schemes are developed in the literature by assuming that a significant number of iterations can be performed within a sampling interval which is not practical. By contrast, this book chapter introduces a novel online time-based optimal framework for nonlinear discrete-time systems by using both: (a) reinforcement learning and (b) online neural network approximation-based forward-in-time dynamic programming without using iterative methodology. The overall stability proof …

An Optimized R5rs Macro Expander, Sean P. Reque

Theses and Dissertations

Macro systems allow programmers abstractions over the syntax of a programming language. This gives the programmer some of the same power posessed by a programming language designer, namely, the ability to extend the programming language to meet the needs of the programmer. The value of such systems has been demonstrated by their continued adoption in more languages and platforms. However, several barriers to widespread adoption of macro systems still exist. The language Racket defines a small core of primitive language constructs, including a powerful macro system, upon which all other features are built. Because of this design, many features of …

Lean Principles:: Can Proven Manufacturing Techniques Benefit An Information Technology Organization?, Erik D. Kim

Regis University Student Publications (comprehensive collection)

The benefits of Lean Principles have been reaped in manufacturing for many years and have been seen recently in other verticals. A comprehensive review of the scientific literature exposed that within the information technology field, Lean Principles remains relatively unknown or used. As corporate senior management seek to save costs, information technology needs to provide clear and concise guidance on how to maximize production efficiencies while minimizing costs. If a company cannot leverage information technology properly, staffing and budget cuts are likely. This paper discusses the potential benefits for information technology organizations to utilize Lean Principles. A case study revealed …

Security Games With Interval Uncertainty, Christopher Kiekintveld, Towhidul Islam, Vladik Kreinovich

Departmental Technical Reports (CS)

Security games provide a framework for allocating limited security resources in adversarial domains, and are currently used in applications including security at the LAX airport, scheduling for the Federal Air Marshals, and patrolling strategies for the U.S. Coast Guard. One of the major challenges in security games is finding solutions that are robust to uncertainty about the game model. Bayesian game models have been developed to model uncertainty, but algorithms for these games do not scale well enough for many applications, and the problem is NP-hard.

We take an alternative approach based on using intervals to model uncertainty in security …

Brans-Dicke Scalar-Tensor Theory Of Gravitation May Explain Time Asymmetry Of Physical Processes, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Most fundamental physical equations remain valid if we reverse the time order. Thus, if we start with a physical process (which satisfies these equations) and reverse time order, the resulting process also satisfies all the equations and thus, should also be physically reasonable. In practice, however, many physical processes are not reversible: e.g., a cup can break into pieces, but the pieces cannot magically get together and become a whole cup. In this paper, we show that the Brans-Dicke Scalar-Tensor Theory of Gravitation, one of the most widely used generalizations of Einstein's General relativity, is, in effect, time-asymmetric. This time-asymmetry …

Comparing Intervals And Moments For The Quantification Of Coarse Information, Michael Beer, Vladik Kreinovich

Departmental Technical Reports (CS)

In this paper the problem of the most appropriate modeling of scarce information for an engineering analysis is investigated. This investigation is focused on a comparison between a rough probabilistic modeling based on the first two moments and interval modeling. In many practical cases, the available information is limited to such an extent that a more thorough modeling cannot be pursued. The engineer has to make a decision regarding the modeling of this limited and coarse information so that the results of the analysis provide the most suitable basis for conclusions. We approach this problem from the angle of information …

Constructing Verifiably Correct Java Programs Using Ocl And Cleanjava, Yoonsik Cheon, Carmen Avila

Departmental Technical Reports (CS)

A recent trend in software development is building a precise model that can be used as a basis for the software development. Such a model may enable an automatic generation of working code, and more importantly it provides a foundation for correctness reasoning of code. In this paper we propose a practical approach for constructing a verifiably correct program from such a model. The key idea of our approach is (a) to systematically translate formally-specified design constraints such as class invariants and operation pre and postconditions to code-level annotations and (b) to use the annotations for the correctness proof of …

Use Of Grothendieck Inequality In Interval Computations: Quadratic Terms Are Estimated Accurately Modulo A Constant Factor, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the main problems of interval computations is to compute the range of a given function f over given intervals. For a linear function, we can feasibly estimate its range, but for quadratic (and for more complex) functions, the problem of computing the exact range is NP-hard. So, if we limit ourselves to feasible algorithms, we have to compute enclosures instead of the actual ranges. It is known that asymptotically the smallest possible excess width of these enclosures is O(Δ²), where Δ is the largest half-width of the input intervals. This asymptotics is attained for the Mean …

Filtering Out High Frequencies In Time Series Using F-Transform, Vilém Novák, Irina Perfilieva, Michal Holčapek, Vladik Kreinovich

Departmental Technical Reports (CS)

In this paper, we will focus on the application of fuzzy transform (F-transform) in the analysis of time series. We assume that the time series can be decomposed into three constituent components: the trend-cycle, seasonal component and random noise. We will demonstrate that by using F-transform, we can approximate the trend-cycle of a given time series with high accuracy.

Research Challenges And Opportunities In Knowledge Representation, Natasha Noy, Deborah Mcguinness, Eyal Amir, Chitta Baral, Michael Beetz, Sean Bechhofer, Craig Boutilier, Anthony Cohn, Johan De Kleer, Michel Dumontier, Tim Finin, Kenneth Forbus, Lise Getoor, Yolanda Gil, Jeff Heflin, Pascal Hitzler, Craig Knoblock, Henry Kautz, Yuliya Lierler, Vladimir Lifschitz, Peter F. Patel-Schneider, Christine Piatko, Doug Riecken, Mark Schildhauer

Computer Science and Engineering Faculty Publications

Modern intelligent systems in every area of science rely critically on knowledge representation and reasoning (KR). The techniques and methods developed by the researchers in knowledge representation and reasoning are key drivers of innovation in computer science; they have led to significant advances in practical applications in a wide range of areas from natural-­‐language processing to robotics to software engineering. Emerging fields such as the semantic web, computational biology, social computing, and many others rely on and contribute to advances in knowledge representation. As the era of “Big Data” evolves, scientists in a broad range of disciplines are increasingly relying …

Checking Monotonicity Is Np-Hard Even For Cubic Polynomials, Andrzej Pownuk, Luc Longpre, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the main problems of interval computations is to compute the range of a given function over given intervals. In general, this problem is computationally intractable (NP-hard) -- that is why we usually compute an enclosure and not the exact range. However, there are cases when it is possible to feasibly compute the exact range; one of these cases is when the function is monotonic with respect to each of its variables. The monotonicity assumption holds when the derivatives at a midpoint are different from 0 and the intervals are sufficiently narrow; because of this, monotonicity-based estimates are often …

Why Complex-Valued Fuzzy? Why Complex Values In General? A Computational Explanation, Olga Kosheleva, Vladik Kreinovich, Thavatchai Ngamsantivong

Departmental Technical Reports (CS)

In the traditional fuzzy logic, as truth values, we take all real numbers from the interval [0,1]. In some situations, this set is not fully adequate for describing expert uncertainty, so a more general set is needed. From the mathematical viewpoint, a natural extension of real numbers is the set of complex numbers. Complex-valued fuzzy sets have indeed been successfully used in applications of fuzzy techniques. This practical success leaves us with a puzzling question: why complex-valued degree of belief, degrees which do not seem to have a direct intuitive meaning, have been so successful? In this paper, we use …

Fault-Tolerant Coverage In Dense Wireless Sensor Networks, Akshaye Dhawan, Magdalena Parks

Mathematics, Computer Science & Statistics Faculty Publications

In this paper, we present methods to detect and recover from sensor failure in dense wireless sensor networks. In order to extend the lifetime of a sensor network while maintaining coverage, a minimal subset of the deployed sensors are kept active while the other sensors can enter a low power sleep state. Several distributed algorithms for coverage have been proposed in the literature. Faults are of particular concern in coverage algorithms since sensors go into a sleep state in order to conserve battery until woken up by active sensors. If these active sensors were to fail, this could lead to …

F-Transform In View Of Aggregation Functions, Irina Perfilieva, Vladik Kreinovich

Departmental Technical Reports (CS)

A relationship between the discrete F-transform and aggregation functions is analyzed. We show that the discrete F-transform (direct or inverse) can be associated with a set of linear aggregation functions that respect a fuzzy partition of a universe. On the other side, we discover conditions that should be added to a set of linear aggregation functions in order to obtain the discrete F-transform. Last but not least, the relationship between two analyzed notions is based on a new (generalized) definition of a fuzzy partition without the Ruspini condition.

Computer Simulation Of Levee Erosion And Overtopping, Mehrad Kamalzare, Tianning Steven Han, Matt Mcmullan, Christopher S. Stuetzle

Computer and Data Science Faculty Publications

Improved computer models of erosion have been developed, considering soil hydraulic conductivity. The models deal with erosion of levees, dams and embankments due to overtopping. The simulations trace the formation of rills and gullies, beginning with initial overtopping and continuing to final breaching. Physical models performed at "1-g" and high "g" using a geotechnical centrifuge have been used to calibrate the models. Previous models did not consider soil hydraulic conductivity, and although results were quite good for the formation of rills and gullies and sediment quantities, breach times were underestimated. Essentially the water flow was treated as if passing over …

Implementing Lan/Wan Network For Small To Medium Size Enterprises - Sme, Armir Kuçi

Theses and Dissertations

Ndërmarrjet e vogla dhe të mesme (SME) për të komunikuar në mes vete, kohë më parë, kanë pasur shumë probleme. Me zhvillimin e rrjeteve kompjuterike, komunikimi në mes tyre është bërë më i lehtë. Mënyra se si komunikojnë në mes vete, më ka bërë kurioz që të përcaktohem për këtë hulumtim që do bëj në vazhdim për rrjetet kompjuterike, zhvillimin dhe implementimin e tyre. Kush i përdorë rrjetet kompjuterike? Institucionet qeveritare dhe joqeveritare, përdoruesit shtëpiakë, industritë e ndryshme, institucionet shëndetësore, ndërmarrjet e ndryshme. Për çka përdoren rrjetet kompjuterike? Transaksione biznesore, e-commerce (shitblerja elektronike), kërkime, lojra online, biseda, posta elektronike (e-mail), …

Game Design And Homemade Powerpoint Games: An Examination Of The Justifications And A Review Of The Research, Jason Paul Siko, Michael Barbour

Education Faculty Publications

Research on educational games often focuses on the benefits that playing games has on student achievement. however, there is a growing body of research examining the benefits of having students design games rather than play them. Problems with game design as an instructional tool include the additional instruction on the programming language itself as well as the potential costs associated with new software. One way to mitigate these problems is to use Microsoft PowerPoint as game design software. While not intended for this purpose, MS PowerPoint is ubiquitous in schools and requires little additional instruction before students can design games. …

Knowledge Representation In The Big Data Age, Pascal Hitzler

Computer Science and Engineering Faculty Publications

No abstract provided.

Research Challenges And Opportunities In Knowledge Representation, Section 2.3.2: Applications Based On Formal Models, Natasha Noy, Deborah Mcguinness, Yuliya Lierler

Computer Science Faculty Proceedings & Presentations

Final report edited by Natasha Noy and Deborah McGuinness.

Report Section 2.3.2, Applications based on formal models, authored by Yuliya Lierer, UNO faculty member.

Research Challenges And Opportunities In Knowledge Representation, Section 4.1.1 Hybrid Kr, Natasha Noy, Deborah Mcguinness, Yuliya Lierler

Computer Science Faculty Proceedings & Presentations

Final report edited by Natasha Noy and Deborah McGuinness.

Report Section 4.1.1 Hybrid KR, co-authored by Yuliya Lierer, UNO faculty member.

Research Challenges And Opportunities In Knowledge Representation, Section 2.4.2 Advances In Satisfiability And Answer Set Programming, Natasha Noy, Deborah Mcguinness, Yuliya Lierler

Computer Science Faculty Proceedings & Presentations

Final report edited by Natasha Noy and Deborah McGuinness.

Report Section 2.4.2, Advances in satisfiability and answer set programming, authored by Yuliya Lierer, UNO faculty member.

3e: Energy-Efficient Elastic Scheduling For Independent Tasks In Heterogeneous Computing Systems, Xiaomin Zhu, Rong Ge, Jinguang Sun, Chuan He

Mathematics, Statistics and Computer Science Faculty Research and Publications

Reducing energy consumption is a major design constraint for modern heterogeneous computing systems to minimize electricity cost, improve system reliability and protect environment. Conventional energy-efficient scheduling strategies developed on these systems do not sufficiently exploit the system elasticity and adaptability for maximum energy savings, and do not simultaneously take account of user expected finish time. In this paper, we develop a novel scheduling strategy named energy-efficient elastic (3E) scheduling for aperiodic, independent and non-real-time tasks with user expected finish times on DVFS-enabled heterogeneous computing systems. The 3E strategy adjusts processors’ supply voltages and frequencies according to the system workload, and …

The Performance Of Mlem For Dynamic Imaging From Simulated Few-View, Multi-Pinhole Spect, Dan Ma, Paul Arthur Wolf, Anne V. Clough, Taly Gilat Schmidt

Mathematics, Statistics and Computer Science Faculty Research and Publications

Stationary small-animal SPECT systems are being developed for rapid dynamic imaging from limited angular views. This work quantified, through simulations, the performance of Maximum Likelihood Expectation Maximization (MLEM) for reconstructing a time-activity curve (TAC) with uptake duration of a few seconds from a stationary, three-camera multi-pinhole SPECT system. The study also quantified the benefits of a heuristic method of initializing the reconstruction with a prior image reconstructed from a conventional number of views, for example from data acquired during the late-study portion of the dynamic TAC. We refer to MLEM reconstruction initialized by a prior-image initial guess (IG) as MLEM …

Combining Crowdsourcing And Google Street View To Identify Street-Level Accessibility Problems, Kotaro Hara, Victoria Le, Jon Froehlich

Research Collection School Of Computing and Information Systems

Jon FroehlichAbstractPoorly maintained sidewalks, missing curb ramps, and other obstacles pose considerable accessibility challenges; however, there are currently few, if any, mechanisms to determine accessible areas of a city a priori. In this paper, we investigate the feasibility of using untrained crowd workers from Amazon Mechanical Turk (turkers) to find, label, and assess sidewalk accessibility problems in Google Street View imagery. We report on two studies: Study 1 examines the feasibility of this labeling task with six dedicated labelers including three wheelchair users; Study 2 investigates the comparative performance of turkers. In all, we collected 13,379 labels and 19,189 verification …

Kinectarms: A Toolkit For Capturing And Displaying Arm Embodiments In Distributed Tabletop Groupware, Aaron Genest, Carl Gutwin, Anthony Tang, Michael Kalyn, Zenja Ivkovic

Research Collection School Of Computing and Information Systems

Gestures are a ubiquitous part of human communication over tables, but when tables are distributed, gestures become difficult to capture and represent. There are several problems: extracting arm images from video, representing the height of the gesture, and making the arm embodiment visible and understandable at the remote table. Current solutions to these problems are often expensive, complex to use, and difficult to set up. We have developed a new toolkit - KinectArms - that quickly and easily captures and displays arm embodiments. KinectArms uses a depth camera to segment the video and determine gesture height, and provides several visual …

Simple Identity-Based Encryption With Mediated Rsa, Xuhua Ding, Gene Tsudik

Research Collection School Of Computing and Information Systems

Identity-based encryption (IBE) [5] and digital signatures are important tools in modern secure communication. In general, identity-based cryptographic methods facilitate easy introduction of public key cryptography by allowing an entity’s public key to be derived from some arbitrary identification value such as an email address or a phone number. Identity-based cryptography greatly reduces the need for, and reliance on, public key certificates. Mediated RSA (mRSA) [4] is a simple and practical method of splitting RSA private keys between the user and the Security Mediator (SEM). Neither the user nor the SEM can cheat one another since each signature or decryption …