Physical Sciences and Mathematics Commons^™

Foundations Of Wave Phenomena, Charles G. Torre

Charles G. Torre

This is an undergraduate text on the mathematical foundations of wave phenomena. Version 8.2.

Why Most Bright Stars Are Binary But Most Dim Stars Are Single: A Simple Qualitative Explanation, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

It is known that most visible stars are binary: they have a nearby companion star, and these two stars orbit around each other. Based on this fact, until recently, astronomers believed that, in general, most stars are binary. A few years ago, a surprising paper showed that while most bright stars are indeed binary, most dim stars are single. In this paper, we provide a simple qualitative explanation for this empirical fact.

When Invading, Cancer Cells Do Not Divide: A Geometric (Symmetry-Based) Explanation Of An Empirical Observation, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In general, malignant tumors are known to grow fast, cancer cells that form these tumors divide and spread around. Tumors also experience the process of metastasis, when cancer cells invade neighboring organs. A recent experiment has shown that, contrary to the previous assumptions, when cancer cells are invading, they stop dividing. In this paper, we provide a geometric explanation for this empirical phenomenon.

Structure Of Filled Functions: Why Gaussian And Cauchy Templates Are Most Efficient, Vyacheslav Kalashnikov, Vladik Kreinovich, José Guadalupe Flores Muñiz, Nataliya Kalashnykova

Departmental Technical Reports (CS)

One of the main problems of optimization algorithms is that they often end up in a local optimum. It is, therefore, necessary to make sure that the algorithm gets out of the local optimum and eventually reaches the global optimum. One of the promising ways guiding one from the local optimum is prompted by the filled function method. It turns out that empirically, the best smoothing functions to use in this method are the Gaussian and Cauchy functions. In this paper, we provide a possible theoretical explanation of this empirical effect.

Fuzzy Pareto Solution In Multi-Criteria Group Decision Making With Intuitionistic Linguistic Preference Relation, Bui Cong Cuong, Vladik Kreinovich, Le Hoang Son, Nilanjan Dey

Departmental Technical Reports (CS)

In this paper, we investigate the multi criteria group decision making with intuitionistic linguistic preference relation. The concept of Fuzzy Collective Solution (FCS) is used to evaluate and rank the candidate solution sets for modeling under linguistic assessments. Intuitionistic linguistic preference relation and associated aggregation procedures are then defined in a new concept of Fuzzy Pareto Solution. Numerical examples are presented to demonstrate computing procedures. The results affirm efficiency of the proposed method.

Towards An Algebraic Description Of Set Arithmetic, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

To describe the state of the world, we need to describe the values of all physical quantities. In practice, due to inevitable measurement inaccuracy, we do not know the exact values of these quantities, we only know the sets of possible values for these quantities. On the class of such uncertainty-related sets, we can naturally define arithmetic operations that transform, e.g., uncertainty in a and b into uncertainty with which we know the sum a + b.

In many applications, it has been useful to reformulate the problem in purely algebraic terms, i.e., in terms of axioms that the basic …

A Heuristic Solution Of The Toll Optimal Problem With Congestion Affected Costs, Vyacheslav Kalashnikov, José Guadalupe Flores Muñiz, Nataliya Kalashnykova

Departmental Technical Reports (CS)

An important problem concerning the toll roads is the setting of appropriate costs for driving along paid arcs of a transportation network. Our paper treats this problem as a bilevel programming model. At the upper level, decisions are made by a public regulator/private company that administers the toll roads endeavoring to elevate their benefits. At the lower level, several transportation companies/individual users appease the existing demand for transportation of goods or passengers while selecting the routes that would minimize their total travel costs. In contrast to the previous models, here the lower level problem assumes quadratic costs implied by the …

Yes- And No-Gestures Explained By Symmetry, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In most cultures, "yes" is indicate by a vertical head movement (nod), while "no" is indicated by a left-right movement (shake). In this paper, we show that basic symmetries can explain this cultural phenomenon.

What Is The Best Way To Add Large Number Of Integers: Number-By-Number As Computers Do Or Lowest-Digits-Than-Next-Digits-Etc As We Humans Do?, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

When we need to add several integers, computers add them one by one, while we usually add them digit by digit: first, we add all the lowest digits, then we add all next lowest digits, etc. Which way is faster? Should we learn from computers or should we teach computers to add several integers our way?

In this paper, we show that the computer way is faster. This adds one more example to the list of cases when computer-based arithmetic algorithms are much more efficient than the algorithms that we humans normally use.

Why Product "And"-Operation Is Often Efficient: One More Argument, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

It is an empirical fact that the algebraic product is one the most efficient "and"-operations in fuzzy logic. In this paper, we provide one of the possible explanations of this empirical phenomenon.

Towards Decision Making Under Interval Uncertainty, Andrzej Pownuk, Vladik Kreinovich

Departmental Technical Reports (CS)

In many practical situations, we know the exact form of the objective function, and we know the optimal decision corresponding to each values of the corresponding parameters x_i. What should we do if we do not know the exact values of x_i, and instead, we only know each x_i with uncertainty -- e.g., with interval uncertainty? In this case, one of the most widely used approaches is to select, for each i, one value from the corresponding interval -- usually, a midpoint -- and to use the exact-case optimal decision corresponding to the selected values. …

For Fuzzy Logic, Occam's Principle Explains The Ubiquity Of The Golden Ratio And Of The 80-20 Rule, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In this paper, we show that for fuzzy logic, the Occam's principle -- that we should always select the simplest possible explanation -- explains the ubiquity of the golden ratio and of the 80-20 rule.

How To Make Machine Learning Robust Against Adversarial Inputs, Gerardo Muela, Christian Servin, Vladik Kreinovich

Departmental Technical Reports (CS)

It has been recently shown that it is possible to "cheat" many machine learning algorithms -- i.e., to perform minor modifications of the inputs that would lead to a wrong classification. This feature can be used by adversaries to avoid spam detection, to create a wrong identification allowing access to classified information, etc. In this paper, we propose a solution to this problem: namely, instead of applying the original machine learning algorithm to the original inputs, we should first perform a random modification of these inputs. Since machine learning algorithms perform well on random data, such a random modification ensures …

Why Rsa? A Pedagogical Comment, Pedro Barragan Olague, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

One of the most widely used cryptographic algorithms is the RSA algorithm in which a message m encoded as the remainder c of m^e modulo n, where n and e are given numbers -- forming a public code. A similar transformation c^d mod n$, for an appropriate secret code d, enables us to reconstruct the original message. In this paper, we provide a pedagogical explanation for this algorithm.

A Simple Geometric Explanation Of Occam's Razor, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Occam's razor states that out of possible explanations, plans, and designs, we should select the simplest one. It turns out that in many practical situations, the simplest explanation indeed turns out to be the correct one, the simplest plan is often the most successful, etc. But why this happens is not very clear. In this paper, we provide a simple geometric explanation of Occam's razor.

Fuzzy Data Processing Beyond Min T-Norm, Andrzej Pownuk, Vladik Kreinovich, Songsak Sriboonchitta

Departmental Technical Reports (CS)

Usual algorithms for fuzzy data processing -- based on the usual form of Zadeh's extension principle -- implicitly assume that we use the min "and"-operation (t-norm). It is known, however, that in many practical situations, other t-norms more adequately describe human reasoning. It is therefore desirable to extend the usual algorithms to situations when we use t-norms different from min. Such an extension is provided in this paper.

Specifying A Global Optimization Solver In Z, Angel F. Garcia Contreras, Yoonsik Cheon

Departmental Technical Reports (CS)

NumConSol is an interval-based numerical constraint and optimization solver to find a global optimum of a function. It is written in Python. In this document, we specify the NumConSol solver in Z, a formal specification language based on sets and predicates. The aim is to provide a solid foundation for restructuring and refactoring the current implementation of the NumConSol solver as well as facilitating its future improvements. The formal specification also allows us to design more effective testing for the solver, e.g., generating test cases from the specification.

A Modification Of Backpropagation Enables Neural Networks To Learn Preferences, Martine Ceberio, Vladik Kreinovich

Departmental Technical Reports (CS)

To help a person make proper decisions, we must first understand the person's preferences. A natural way to determine these preferences is to learn them from the person's choices. In principle, we can use the traditional machine learning techniques: we start with all the pairs (x,y) of options for which we know the person's choices, and we train, e.g., the neural network to recognize these choices. However, this process does not take into account that a rational person's choices are consistent: e.g., if a person prefers a to b and b to c, this person should also prefer a and …

Why Growth Of Cancerous Tumors Is Gompertzian: A Symmetry-Based Explanation, Pedro Barragan Olague, Vladik Kreinovich

Departmental Technical Reports (CS)

It is known that the growth of a cancerous tumor is well described by the Gompertz's equation. The existing explanations for this equation rely on specifics of cell dynamics. However, the fact that for many different types of tumors, with different cell dynamics, we observe the same growth pattern, make us believe that there should be a more fundamental explanation for this equation. In this paper, we show that a symmetry-based approach indeed leads to such an explanation: indeed, out of all scale-invariant growth dynamics, the Gompertzian growth is the closest to the linear-approximation exponential growth model.

Grading That Takes Into Account The Need To Learn From Mistakes, Francisco Zapata, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

It is well known that the best way to learn the new material is to try it, to make mistakes, and to learn from these mistakes. However, the current grading scheme, in which the overall grade is a weighted average of the grades for all the assignments, exams, etc., does not encourage mistakes: any mistake decreases the grade on the corresponding assignment and thus, decreases the overall grade for the class. It is therefore desirable to modify the usual grading scheme, so that it will take into account -- and encourage -- learning by mistakes. Such a modification is proposed …

Optimal Group Decision Making Criterion And How It Can Help To Decrease Poverty, Inequality, And Discrimination, Vladik Kreinovich, Thongchai Dumrongpokaphan

Departmental Technical Reports (CS)

Traditional approach to group decision making in economics is to maximize the GDP, i.e., the overall gain. The hope behind this approach is that the increased wealth will trickle down to everyone. Sometimes, this happens, but often, in spite of an increase in overall GDP, inequality remains: some people remain poor, some groups continue to face economic discrimination, etc. This shows that maximizing the overall gain is probably not always the best criterion in group decision making. In this chapter, we find a group decision making criterion which is optimal (in some reasonable sense), and we show that using this …

Impact Of Spatial Averaging On Radar Reflectivity At Internal Snowpack Layer Boundaries, N. Rutter, H.P. Marshall, K. Tape, R. Essery, J. King

CGISS Publications and Presentations

Microwave radar amplitude within a snowpack can be strongly influenced by spatial variability of internal layer boundaries. We quantify the impact of spatial averaging of snow stratigraphy and physical snowpack properties on surface scattering from near-nadir frequency-modulated continuous- wave radar at 12–18 GHz. Relative permittivity, density, grain size and stratigraphic boundaries were measured in-situ at high resolution along the length of a 9 m snow trench. An optimal range of horizontal averaging (4–6 m) was identified to attribute variations in surface scattering at layer boundaries to dielectric contrasts estimated from centimetre-scale measurements of snowpack stratigraphy and bulk layer properties. Single …

Improving Our Understanding Of Ocean Circulation: A Modeling Study, Nicole M. Flecchia

Senior Honors Projects

The Gulf Stream is not a rigidly contained ocean current; it curves and meanders in a manner that causes portions of it to go unstable, breaking off to form warm core rings. These rings travel west – due to the earth’s rotation - through the Slope Sea and onto the southern New England shelfbreak, affecting various physical parameters of our coastal waters as well as the biogeochemical and ecological properties (i.e. the ‘health’) of the those waters. Where a warm core ring lands along the east coast and the time of year it appears varies with each ring, causing each …

Vulnerability Analysis And Security Framework For Zigbee Communication In Iot, Charbel Azzi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Securing IoT (Internet of Things) systems in general, regardless of the communication technology used, has been the concern of many researchers and private companies. As for ZigBee security concerns, much research and many experiments have been conducted to better predict the nature of potential security threats. In this research we are addressing several ZigBee vulnerabilities by performing first hand experiments and attack simulations on ZigBee protocol. This will allow us to better understand the security issues surveyed and find ways to mitigate them. Based on the attack simulations performed and the survey conducted, we have developed a ZigBee IoT framework …

Improvement Of Security In Uas Communication And Navigation Using Ads-B, Vedadatta Gouripeddi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we congregate the security threats on UAS and suggest solutions using ADS-B device. UAS ground and intercommunication is prone to availability, confidentiality and integrity attacks. UAS communication has three layered wireless Ad-Hock network which comprises of Complex group key exchange. Loss of one layer in the Ad-hock network leads to a complete loss of communication in the network. Current UAS navigation methods include complete reliance on on-board sensors, radars and GPS. This research proposes solutions for UAS communication, navigation and collision avoidance using ADS-B. ADS-B acts as a back-up when there is a loss in any one …

A Case Study On Enterprise Content Management Using Agile Methodology, Rohit Raj

UNLV Theses, Dissertations, Professional Papers, and Capstones

Every organization has the need to create, classify, manage and archive information so that it is accessible when they need it. The amount of data or information needed for an organization to build their business and for them to be more positive in today’s business world is increasing exponentially, which also includes unstructured data or unstructured content. It is not appropriate only to “manage” content, but whether the correct version of the data or document or record can be accessed. Enterprise Content Management is an efficient collection and planning of information that is to be used by a very particular …

Analyses Of Streamflow Change Patterns And Correlation Of These Changes With Sea-Surface Temperature Fluctuations, Kazi Ali Tamaddun

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents a comprehensive statistical analysis that determines the direction, rate, and interval of significant streamflow change patterns in the continental U.S. and correlates these changes with sea-surface temperature fluctuations. First, by using two non-parametric tests, namely, the Mann-Kendall trend test and the Pettitt’s test, the presence of long-term trends and abrupt shifts were determined at 10% significance level over continuously adjustable periods that stretched from 1903 to 2012. Modified versions of the tests were applied to account for the presence of persistence (autocorrelation) in data. Theil-Sen slope was determined to evaluate the rate of change across multiple temporal …

Fluorine Atom Influence On Intramolecular Hydrogen Bonding, Isomerization And Methyl Group Rotation In Fluorinated Acetylacetones, Brett De Vries, Mark Muyskens

University Faculty Publications and Creative Works

1-Fluoro-pentane-2,4-dione (monofluoroacetylacetone, MFAA) is an asymmetric β-diketone with a strong intramolecular hydrogen bond similar to acetylacetone (AA) and its fluorinated analogs 1,1,1-trifluoro-(TFAA), and 1,1,1,5,5,5-hexafluoroacetylacetone (HFAA). The presence of a fluorine atom in MFAA has the potential to open an HF elimination channel in its gas-phase photochemistry motivating this study of MFAA hydrogen bonding by computer modeling using Density Functional Theory (DFT). As a context, we also report DFT modeling of AA and selected fluorinated acetylacetones: 1,1-difluoro-pentane-2,4-dione (difluoroacetylacetone, DFAA), TFAA, and HFAA. The most stable molecular structure for all three asymmetric β-diketones (MFAA, DFAA and TFAA) is the isomer with the …

A Non-Traditional Approach To Synthesizing Aryl Vinyl Sulfides Is Described. 2,2-Diphenyl-1,3-Oxathiolane Slowly Liberates Vinyl Sulfide Anion Under Basic Conditions. Using A Pd/Xantphos Catalyst System To Activate A Wide Range Of Aryl Bromides, This Transient Sulfide Species Can Be Effectively Trapped And Fed Into A Traditional Pd0/Pdii Catalytic Cycle. Scope And Limitations Of The Methodology Are Presented Along With Significant Discussion Of A Competitive C–S Bond Activation By This Catalyst System., Jason R. Schmink, Summer A. Baker Dockrey, Tianyi Zhang, Naomi Chebet, Alexis Van Venrooy, Mary Sexton, Sarah I. Lew, Steffany Chou, Ami Okazaki

Chemistry Faculty Research and Scholarship

A non-traditional approach to synthesizing aryl vinyl sulfides is described. 2,2-diphenyl-1,3-oxathiolane slowly liberates vinyl sulfide anion under basic conditions. Using a Pd/Xantphos catalyst system to activate a wide range of aryl bromides, this transient sulfide species can be effectively trapped and fed into a traditional Pd⁰/Pd^II catalytic cycle. Scope and limitations of the methodology are presented along with significant discussion of a competitive C–S bond activation by this catalyst system.

Cucurbit[7]Uril-Tetramethylrhodamine Conjugate For Direct Sensing And Cellular Imaging, Andrew T. Bockus, Lauren C. Smith, Amy G. Grice, Omar A. Ali, Carolyn C. Young, William Mobley, Ashley Leek, James Lewis Roberts, Brittany Vinciguerra, Lyle D. Isaacs, Adam R. Urbach

Chemistry Faculty Research

This paper describes the design and synthesis of a conjugate (Q7R) comprising the synthetic host cucurbit[7]uril (Q7) linked to the fluorescent dye tetramethylrhodamine (TMR), and the characterization of its optical and guest-binding properties as well as its cellular uptake. Q7R was synthesized in two steps from monofunctionalized azidobutyl-Q7 and NHS-activated TMR. The fluorescence of Q7R is quenched upon guest binding, and this observable was used to determine equilibrium dissociation constant (K_d) values. Unexpectedly, the K_d values for guests binding to Q7R and to unmodified Q7 were essentially identical. Therefore, Q7R can directly report binding to Q7 without …