Neste projeto estudamos algoritmos de aproximação para o problema da árvore de Steiner com coleta de prêmios. Trata-se de uma generalização do problema da árvore de Steiner, onde é dado um grafo com custos positivos nas arestas e penalidades positivas nos vértices. O objetivo é encontrar uma subárvore do grafo que minimize a soma dos custos das arestas mais a soma das penalidades dos vértices que não pertencem à subárvore. Em 2009, os autores Archer, Bateni, Hajiaghayi e Karloff obtiveram pela primeira vez um algoritmo com fator de aproximação estritamente menor do que 2. Além de analisarmos este algoritmo, estudamos também a implementação de algoritmos 2-aproximação para o problema da árvore de Steiner e da árvore de Steiner com coleta de prêmios. / In this project we analyze approximation algorithms for the prize-collecting Steiner tree problem. This is a generalization of the Steiner tree problem, in which it is given a graph with positive costs in edges and positive penalties in vertices. The goal is to find a subtree of the graph that minimizes the sum of costs of edges plus the sum of the penalties of the vertices that don\'t belong to the subtree. In 2009, the authors Archer, Bateni, Hajiaghayi e Karloff described, for the first time an algorithm with approximation factor strictly less than 2. Besides analyzing this algorithm, we also study the implementation of 2-approximation algorithms to the Steiner tree problem and prize-collecting Steiner tree problem.

Recommender systems are used on many different websites today and are mechanisms that are supposed to accurately give personalized recommendations of items to a set of different users. An item can for example be movies on Netflix. The purpose of this paper is to implement an algorithm that fulfills five stated goals of the implementation. The goals are as followed: the algorithm should be easy to implement, be effective on query time, accurate on recommendations, put little expectations on users and alternations of algorithm should not have to be changed comprehensively. Slope One is a simplified version of linear regression and can be used to recommend items. By using the Netflix Prize data set from 2009 and the Root-Mean-Square-Error (RMSE) as an evaluator, Slope One generates an accuracy of 1.007 units. The Weighted Slope One, which takes the relevancy of items into the calculation, generates an accuracy of 0.990 units.  Adding Weighted Slope One to the Slope One implementation can be done without changing the fundamentals of the Slope One algorithm. It is nearly instantaneous to generate a recommendation of a movie with regular Slope One and Weighted Slope One. However, a precomputing stage is needed for the mechanism. In order to receive a recommendation of the implementation in this paper, the user must at least have rated two items. / Rekommendationssystem används idag på många olika hemsidor, och är en mekanism som har syftet att, med noggrannhet, ge en personlig rekommendation av objekt till en mängd olika användare. Ett objekt kan exempelvis vara en film från Netflix. Syftet med denna rapport är att implementera en algoritm som uppfyller fem olika implementationsmål. Målen är enligt följande: algoritmen ska vara enkel att implementera, ha en effektiv tid på dataförfrågan, ge noggranna rekommendationer, sätta låga förväntningar hos användaren samt ska algoritmen inte behöva omfattande förändring vid alternering.  Slope One är en förenklad version av linjär regression, och kan även användas till att rekommendera objekt. Genom att använda datamängden från Netflix Prize från 2009 och måttet Root-Mean-Square-Error (RMSE) som en utvärderare, kan Slope One generera en precision på 1.007 enheter. Den viktade Slope One, som tar hänsyn till varje föremåls relevans, genererar en precision på 0.990 enheter. När dessa två algoritmer kombineras, behövs inte större fundamentala ändringar i implementationen av Slope One. En rekommendation av något objekt kan genereras omedelbart med någon av de två algoritmerna, dock krävs det en förberäkningsfas i mekanismen. För att få en rekommendation av implementationen i denna rapport, måste användaren åtminstone ha värderat två objekt.

AFRIKAANS: Die Suid-Afrikaanse Akademie vir Wetenskap en Kuns vier vanjaar sy eeufees. Hierdie instansie is die kurator van die Hertzogprys, ’n gesogte letterkundeprys en die oudste en bekendste prestigetoekenning wat deur hierdie instansie gemaak word. Die terrein wat deur hierdie proefskrif gedek word, is die Akademie se houding teenoor en bevordering van Afrikaanse drama, met ’n geslypter fokus op die Hertzogprystoekennings vanaf 1915 tot net voor 1972. Etlike gegewens met betrekking tot die prys soos aangebied in reeds gepubliseerde werk, is verwarrend of nie feitelik korrek nie. Ten einde klarigheid daaroor te kry, is ’n grondige studie gemaak van die toekenningsprosedures en die invloed daarvan op die dramabekronings tot voor 1972. Dit was veral verhelderend met betrekking tot die dramaturg Uys Krige. Aanvanklik het die drie literêre kategorieë prosa, poësie en drama gelyktydig in aanmerking gekom vir die prys. Vanaf 1928 roteer dit en kom Afrikaanse dramas elke derde jaar aan die beurt. In vergelyking met die literêre kategorieë prosa en poësie, is daar relatief min dramabekronings gemaak – veral aan die beginjare van die prys. Deur noukeurige studie is gepoog om die gebrek aan dramatoekennings in perspektief te stel. Klem word gelê op die rol wat prosedures gespeel het, byvoorbeeld minder goeie prosedures wat veroorsaak het dat die verkeerde of geen toekennings gemaak is nie en sodoende bygedra het tot ’n skewe beeld wat bestaan oor Hertzogprystoekennings vir Drama. Sekere toekennings (of gebrek daaraan) kan direk gekoppel word aan foutiewe uitsprake van administratiewe amptenare, onbevredigende prosedures of aan die invloed van persone wat seggenskap oor die prys gehad het. Bepalende bakens en beslissings word aangetoon. Die sestigerjare was in die geskiedenis van die land en van die Akademie vol beroeringe. Met betrekking tot die Akademie se beleid oor die handhawing en bevordering van die Afrikaanse kultuur, het Akademielede van mekaar verskil oor die vertolking en uitlewing daarvan. Dit het gelei tot uiteenlopende menings oor die rigting wat die Akademie moes inslaan, maar ook oor sekere literêre werke. Verskillende menings het geheers oor wie die finale seggenskap oor die Hertzogprys moes hê: die Akademieraad as kurator van die prys volgens die skenkingsakte, of die Letterkundige Kommissie wat die kundiges op letterkundegebied was. Hierdie meningsverskille is op die spits gedryf in 1966 – die jaar waarin Uys Krige vir ’n dramatoekenning aanbeveel is. Die Akademieraadsbesluit om nie daardie jaar ’n prys toe te ken nie, het hewige kritiek ontlok – selfs van Kommissielede, en sou nog vir jare daarna ’n rimpeleffek hê. Die eerste staande Letterkundige Kommissie is aangewys vir die periode April 1968 tot April 1971 en die eerste toekenning waaroor hulle moes besluit, was die Dramatoekenning van 1969. In teenstelling met die stormagtige sestigerjare, het dramabekronings in die jare daarna verloop sonder onmin tussen die Akademieraad, die Fakulteitsraad en die Letterkundige Kommissie. Die jare waartydens ’n Hertzogprys vir Drama toegeken kon word vanaf 1972 tot 2009, word slegs kortliks en skematies gedek om die bespreking af te rond met betrekking tot dié dramaturge wat reeds voor 1972 gedebuteer het, maar eers daarna met die prys bekroon is. ENGLISH: The year 2009 marks the centenary celebrations of the Suid-Afrikaanse Akademie vir Wetenskap en Kuns. This institution is the curator of the Hertzog Prize, a sought-after literary prize and the oldest and most prestigious award made by this institution. This dissertation focuses on the Academy’s attitude towards and advancement of Afrikaans drama, with the focus on the Hertzog Prize awards from 1915 until 1971. Certain information relating to the prize as recorded in previously published works on the subject, are confusing and factually incorrect. In an effort to clarify these, an in depth study was undertaken of the award procedures and their influence on the awards for drama up to 1972. It was especially enlightening with regard to the dramatist Uys Krige. Initially the three literary categories prose, poetry and drama were considered simultaneously, but as from 1928 they rotate and Afrikaans dramas are considered every third year. In comparison with the literary categories prose and poetry, there is a paucity of drama awards – especially during the early years of the prize. An effort was made to place the paucity in perspective. Emphasis is placed on procedures with specific reference to those less than perfect ones which lead to incorrect, or the lack of, awards, resulting in a warped image of drama awards. Certain awards or lack thereof, can be attributed to incorrect statements by administrators, unsatisfactory procedures or the influence of people with authority. Defining beacons and decisions are indicated. In the nineteen sixties the country and the Academy experienced years of turbulence. With regards to the Academy’s policy on the protection and advancement of Afrikaans culture, members of the Academy differed on the interpretation and implementation thereof. This lead to differing views on the Academy’s course and on certain literary works. There were different views on who should have the final say on the Hertzog Prize: the Board as curator of the prize according to the deed of gift, or the Commission for Literature as literary experts. These differences lead to a boiling point in 1966 when Uys Krige was nominated for the prize. The Board’s decision not to award the prize lead to severe criticism – even from members of the Committee, and had a ripple effect for years thereafter. The first standing Commission for Literature was appointed for the period April 1968 to April 1971 and the first award they had to adjudicate was the Drama award for 1969. As opposed to the stormy sixties, the awards for drama in the following years were made without discord between the board of the Academy, the Faculty and the Commission for Literature. The years during which the Drama Prize could be awarded during the period 1972 to 2009 are dealt with briefly and schematically in order to conclude the discussion with reference to those dramatists who made their drama debut before 1972, but were only awarded the Hertzog Prize after 1972. / Thesis (DLitt)--University of Pretoria, 2009. / Afrikaans / unrestricted

This paper extends Beviá and Corchón (2013) to a model with both endogenous contestable prize and endogenous relative strength. Such a setting is ideal for the study of intra-organizational rivalries, commonly observed in family, sports, promotion, and duopoly. We find that when the game starts with asymmetric players, the weaker player exerts more effort than the stronger player. As a result, the weaker player partially overcomes the disadvantage of being weak. In this setting, neither domino nor avalanche effect exists.

During the past 50 years, air pollution has become a growing problem throughout the Intermountain West because of increases in personal vehicle ownership and usage. Scientists continue to design interventions to improve air quality by encouraging people to reduce their personal vehicle miles of travel (VMT). However, results of these interventions have only seen modest reductions in VMT because of some methodological and measurement issues. To address these limitations, a 14-week driving reduction intervention was conducted in Cache County, Utah. This intervention employed a prizebased contingency management system within a single-subject, A-B-A withdrawal research design that rewarded participants with prizes if they were able to reduce their VMT below their baseline mean. The VMT was measured each day with an in-car GPS electronic tracking device. Results of this intervention indicate both short- and long-term reductions in VMT as a result of the treatment. Specifically, 6 of the 10 participants showed a statistically significant reduction from the baseline to the intervention stage and maintenance of this reduction during the return-to-baseline stage. The other four participants exhibited a similar pattern but their change in vehicle miles of travel was not statistically significant. Interaction effects were not found between the quo;Choose Clean Airquo; social marketing campaign, gas prices, temperature, and PM 2.5 levels. Despite some problems with the transmission and recording of VMT data, this intervention provides further evidence for the application of prize-based contingency management systems to the reduction of a problematic behavior or encouragement of proenvironmental or pro-social behaviors. The in-car GPS devices improved VMT data collection and quality of the data but hardware and software improvements are still needed to prevent data loss. Further replication is necessary to determine the efficacy of driving reduction intervention that employs prize-based contingency management systems at the community or group level. Future research should also test the possible demographic differences between those that respond favorably to this type of intervention and those that do not, and the differences between prize delivery systems (immediate versus delayed) and prize magnitude (low- versus high-dollar amounts) on driving behaviors.

The diploma thesis deals with preparing the production process of the winning prize, which contains a selection in the form of a hyperbolic paraboloid in its upper part. The work is divided into four main chapters. First of all, the introduction part of the diploma thesis presents the possibilities of programming in the Sinumerik control system. Next, the mathematical requirements of the selected surface - hyperbolic paraboloid - are explained. The practical part consists of creating an NC program where all the theoretical knowledge from the introduction is applied. Finally, the diploma thesis ends with an economic evaluation of the selected element.

Hazel Brannon Smith, a prominent white newspaper owner in Mississippi before, during, and after the civil rights era was an avowed supporter of Jim Crow segregation for the first half of her career, until pressure from the white establishment and the changing political and social milieu of the 1950s and 1960s pushed her to become an ally of the black struggle for social justice. Smith's biography reveals how many historians have miscast white liberals of this period. Smith was considered a liberal by her peers, but her actions reveal the firm limits of white liberalism in the rural South during the Civil Rights era. While this dissertation undergirds scholarly research over the last twenty years which viewed the fight for civil rights from a grounds root level, it shows how Smith was unique. She never fully escaped her white paternalistic sentiments, yet she spoke out consistently against racial extremism in Mississippi in the 1960s. Based upon newspaper accounts, personal collections, oral histories and recent scholarly treatments, this work argues that the white response to the civil rights movement in Mississippi was far from uniform.

Yes / In the pharmaceutical industry, enhanced process understanding resulting in superior control of product attributes, has the potential to save up to 20% of process engineering and product development costs during drug development. With the aim of achieving enhanced process understating, a novel approach for granulation of fine powders is presented. First, a mould with the desired particle shape and size is created using 3D printing followed by casting using elastomeric material. The formulation is prepared through wet massing and tested as a thin film on flat elastomeric membranes. The thin film itself can be a product but it also gives a good indication of coating performance before coating the patterned elastic membrane with the formulation i.e., 3D printed elastic mould granulation. Results show that following granulation and drying, granules of controlled size and shape (e.g. cubic and 500 μm), strength, friability and flowability can be formed. The method presented may allow for more robust process development in particle engineering. / Research Development Fund Publication Prize Award winner, December 2018.

Yes / Industry 4.0 promotes highly automated mechanisms for setting up and operating flexible manufacturing systems, using distributed control and data-driven machine intelligence. This paper presents an approach to reconfiguring distributed production systems based on complex product requirements, combining the capabilities of the available production resources. A method for both checking the “realisability” of a product by matching required operations and capabilities, and adapting resources is introduced. The reconfiguration is handled by a multi-agent system, which reflects the distributed nature of the production system and provides an intelligent interface to the user. This is all integrated with a self-adaptation technique for learning how to improve the performance of the production system as part of a reconfiguration. This technique is based on a machine learning algorithm that generalises from past experience on adjustments. The mechanisms of the proposed approach have been evaluated on a distributed robotic manufacturing system, demonstrating their efficacy. Nevertheless, the approach is general and it can be applied to other scenarios. / This work was supported by the SURE Research Projects Fund of the University of Bradford and the European Commission (grant agreement no. 314762). / Research Development Fund Publication Prize Award winner, Nov 2022

Yes / A set of shallow-water equations (SWEs) based on a k-epsilon Reynold stress model is established to simulate the turbulent flows over a complex roughness bed. The fundamental equations are discretized by the second-order finite-difference method (FDM), in which spatial and temporal discretization are conducted by staggered-grid and leap-frog schemes, respectively. The turbulent model in this study stems from the standard k-epsilon model, but is enhanced by replacing the conventional vertical production with a more rigorous and precise generation derived from the energy spectrum and turbulence scales. To verify its effectiveness, the model is applied to compute the turbulence in complex flow surroundings (including a rough bed) in an abrupt bend and in a natural waterway. The comparison of the model results against experimental data and other numerical results shows the robustness and accuracy of the present model in describing hydrodynamic characteristics, especially turbulence features on the complex roughness bottom. / National Key Research and Development Program of China (Grant No: 2016YFE0122500, 2013CB036401 and 2013CB036402), China Postdoctoral Science Foundation (Grant No: 2016M591184) and Programme of Introducing Talents of Discipline to Universities (Grant No: BC2018038) / Research Development Fund Publication Prize Award winner, June 2019.