Establishing parameters for problem difficulty in permutation-based genetic algorithms

This thesis examines the performance of genetic algorithm (GA) crossover techniques within two problems: n-queens with poison (NQWP) and processor scheduling (PS). Each problem was analyzed at sizes of 32, 64, and 128, referring to number of queens to be placed and number of single-time-unit processes to be scheduled, respectively. The specific crossover techniques studied were cycle crossover, order crossover, partially mapped crossover, merging crossover, and one-point, two-point, and uniform signature representation crossover, in addition to various greedy approaches. In conjunction with tests that vary crossover techniques, experimentation was performed to determine what percentage of problem constraints (poisoned squares for NQWP or precedence relationships between tasks for PS) makes the problems most difficult to solve, that is, the constraint densities at which optimal solutions require the highest number of GA fitness evaluations. While minor fluctuations in difficulty occur upon variations in fitness function and problem size, the NQWP problem is most difficult around a constraint density of 0.8 and the PS problem is most difficult around constraint densities of 0.2 to 0.3. Even within an individual problem, one crossover technique does not irreproachably outperform others. However, cycle crossover stands out in its performance in the PS problem while merging crossover and uniform signature crossovers most often perform well for NQWP

Sensitivity Analyses of Flexible Pavement Performance in VT, NY and MA using the Mechanistic-Empirical Pavement Design Guide

Many state highway agencies are in the process of transitioning pavement design procedures from the empirical AASHTO design to the new M-E PDG. The New England states and New York initiated NETC Project 06-1 to gather more information about the new design and to make the implementation process smoother. The objective of this project was to evaluate which of the Level 2 and 3 input variables require state specific information, which of the national default values are acceptable for the M-E PDG in New England and New York states, what variables are available and collected by the state agencies, and for which regional or local calibration will be necessary. This study identified critical state specific factors affecting predicted flexible pavement distresses and roughness and to what level. This thesis presents data, analysis, state specific recommendations, and general conclusions for the states of Vermont, Massachusetts and New York

Mathematical Modeling of Carbon Removal in the A-Stage Activated Sludge System

This research developed a dynamic activated sludge model (ASM) to better describe the overall removal of organic substrate, quantified as chemical oxygen demand (COD), from A-stage high rate activated sludge (HRAS) systems. This dynamic computer model is based on a modified ASM1 (Henze et al., 2000) model. It was determined early in the project that influent soluble COD, which is normally represented by a single state variable in ASM1, had to be subdivided into two state variables (SBs and SBf, or slow and fast fractions) to simulate the performance of A-stage systems. Also, the addition of state variables differentiating colloidal COD from suspended COD was necessary due to short hydraulic residence times in A-stage systems which do not allow for complete enmeshment and bioflocculation of these particles as occurs in conventional activated sludge systems (which have longer solid retention times and hydraulic retention times). It was necessary to add several processes (both stoichiometry and kinetic equations) to the original ASM1 model including heterotrophic growth on both soluble substrate fractions and bioflocculation of colloidal solids. How to properly quantify heterotrophic growth on SBs and SBf resulted in two separate approaches with respect to process kinetic equations. In one approach the SBf was metabolized preferentially over SBs which was only utilized when SBf was not available. This is referred to as the Diauxic Model. In the other approach SBf and SBs were metabolized simultaneously, and this is referred to as the Dual Substrate Model. The Dual Substrate Model calibrated slightly better than the Diauxic Model for one of the two available pilot studies data sets (the other set was used for model verification). The Dual Substrate A-stage model was used to describe the effects of varying specific operating parameters including solids retention time (SRT), dissolved oxygen (DO), influent COD and temperature on the effluent COD:N ratio. The effluent COD:N ratio target was based on its suitability for a downstream nitrite shunt (i.e. nitritation/denitritation) process. In the downstream process the goal is to eliminate nitrite oxidizing bacteria (NOB) from the reactor while selecting for ammonia oxidizing bacteria (AOB). The results showed that a low SRT (\u3c 0.25 d) can produce high effluent substrates (SB and CB), and elevated COD:N ratios consistent with NOB out-selection downstream, the HRAS model was able to predict the measured higher fraction of CB in the A-stage effluent at lower SRTs and DO concentrations, and to achieve the benefits of operating an A-stage process, while maintaining an effluent COD:N ratio suitable for a downstream nitritation/denitritation process, an A-stage SRT in the range of 0.1 to 0.25 d should be maintained. This research also included an analysis of A-stage pilot data using stoichiometry to determine the bio-products formed from soluble substrate removed in an A-stage reactor. The results were used to further refine the process components and stoichiometric parameters to be used in the A-stage dynamic computer model, which includes process mechanisms for flocculation and enmeshment of particulate and colloidal substrate, hydrolysis, production of extracellular polymeric substances (EPS) and storage of soluble biodegradable substrate. Analysis of pilot data and simulations with the dynamic computer model implied (indirectly) that storage products were probably significant in A-stage COD removal

Non-stationary extreme models and a climatic application

In this paper, we study extreme values of non-stationary climatic phenomena. In the usually considered stationary case, the modelling of extremes is only based on the behaviour of the tails of the distribution of the remainder of the data set. In the non-stationary case though, it seems reasonable to assume that the temporal dynamics of the entire data set and that of extremes are closely related and thus all the available information about this link should be used in statistical studies of these events. We try to study how centered and normalized data which are closer to stationary data than the observation allows easier statistical analysis and to understand if we are very far from a hypothesis stating that the extreme events of centered and normed data follow a stationary distribution. The location and scale parameters used for this transformation (the central field), as well as extreme parameters obtained for the transformed data enable us to retrieve the trends in extreme events of the initial data set. Through non-parametric statistical methods, we thus compare a model directly built on the extreme events and a model reconstructed from estimations of the trends of the location and scale parameters of the entire data set and stationary extremes obtained from the centered and normed data set. In case of a correct reconstruction, we can clearly state that variations of the characteristics of extremes are well explained by the central field. Through these analyses we bring arguments to choose constant shape parameters of extreme distributions. We show that for the frequency of the moments of high threshold excesses (or for the mean of annual extremes), the general dynamics explains a large part of the trends on frequency of extreme events. The conclusion is less obvious for the amplitudes of threshold exceedances (or the variance of annual extremes) – especially for cold temperatures, partly justified by the statistical tools used, which require further analyses on the variability definition

The Funnel Beaker Culture in the Lublin Region in the Light of the Excavations and Publications of Jan Kowalczyk

The article discusses the contribution of Jan Kowalczyk to the study of the Funnel Beaker culture. The paper presents his achievements in field research on settlements and funerary sites in Central and Eastern Poland (cemeteries and settlements on the Nałęczów Plateau, settlement in Gródek in the Hrubieszów Basin) and thoughts on the methodology of searching and exploration of the Neolithic graves. The most important publications of this author were also recalled. The results of his work are placed in the context of the present state of research

Recognition of the loess covers by using a resistivity imaging method

A main aim of research work was to recognize loess covers by geoelectrical method for three tipped areas, to define loess thickness and show their variability. Resistivity imaging method was used. To research chose Kańczuga Plateau, Nałęczów Plateau and Prydniestrov’ja region (Ukraine). There were used resistivity imaging methods, and the work results were corelated with geological documentation of the research area. The research showed variability in loess covers related to their stratigraphy and allow determine thickness loesses deposit

Preferencje polityczne a gust muzyczny młodych Polaków – raport z badań

W niniejszym artykule autorzy prezentują sprawozdanie z ilościowych badań empirycznych poświęconych relacjom zachodzącym pomiędzy gustem muzycznym a preferencjami politycznymi. Proces gromadzenia danych miał miejsce w roku 2019 na próbie 831 studentów w wieku od 18. do 30. roku życia. Respondenci objęci pomiarami pochodzili z blisko 50 ośrodków akademickich z całej Polski. Głównym celem procesu badawczego było udzielenie odpowiedzi na pytania o to: 1. Czy istnieje związek między preferowanymi gatunkami muzycznymi a poziomem akceptacji przekonań charakterystycznych dla osobowości autorytarnej? 2. Czy istnieje związek między preferowanymi gatunkami muzycznymi a przejawianą orientacją polityczną mierzoną na skali przekonań liberalno-socjalnych vs konserwatywno-libertariańskich? 3. Czy określony poziom akceptacji przekonań charakterystycznych dla osobowości autorytarnej determinuje preferencje polityczne mierzone na skali przekonań liberalno-socjalnych vs konserwatywno-libertariańskich i z jakim prawdopodobieństwem wartości obu zmiennych można przewidywać, opierając się na guście muzycznym? Na podstawie przeprowadzonych analiz na wszystkie trzy zadane pytania uzyskano odpowiedzi twierdzące. W artykule omówiono także szczegółowy zakres otrzymanych zależności

Selection for Non-Amyloidogenic Mutants of Islet Amyloid Polypeptide (IAPP) Identifies an Extended Region for Amyloidogenicity

The aggregation of the 37-residue polypeptide IAPP, as either insoluble amyloid or as small oligomers, appears to play a direct role in the death of pancreatic β-islet cells in type II diabetes. While IAPP has been known to be the primary component of type II diabetes amyloid, the molecular interactions responsible for this aggregation have not been identified. To identify the aggregation-prone region(s), we constructed a library of randomly generated point mutants of IAPP. This mutant IAPP library was expressed in E. coli as genetic fusions to the reporter protein enhanced green fluorescent protein (EGFP). Because IAPP aggregates rapidly, both independently and when fused to EGFP, the fusion protein does not yield a functional, fluorescent EGFP. However, mutations of IAPP that result in non-amyloidogenic sequences remain soluble and allow EGFP to fold and fluoresce. Using this screen, we identified 22 single mutations, 4 double mutations and 2 triple mutations of IAPP that appear to be less amyloidogenic than wild type human IAPP. A comparison of these sequences suggests residues 13 and 15–17 comprise an additional aggregation-prone region outside of the main amyloidogenic region of IAPP