A simulation model of the optimal maintenance strategy: conceptual agent-based approach

In this Master’s thesis agent-based modeling has been used to analyze maintenance strategy related phenomena. The main research question that has been answered was: what does the agent-based model made for this study tell us about how different maintenance strategy decisions affect profitability of equipment owners and maintenance service providers? Thus, the main outcome of this study is an analysis of how profitability can be increased in industrial maintenance context. To answer that question, first, a literature review of maintenance strategy, agent-based modeling and maintenance modeling and optimization was conducted. This review provided the basis for making the agent-based model. Making the model followed a standard simulation modeling procedure. With the simulation results from the agent-based model the research question was answered. Specifically, the results of the modeling and this study are: (1) optimizing the point in which a machine is maintained increases profitability for the owner of the machine and also the maintainer with certain conditions; (2) time-based pricing of maintenance services leads to a zero-sum game between the parties; (3) value-based pricing of maintenance services leads to a win-win game between the parties, if the owners of the machines share a substantial amount of their value to the maintainers; and (4) error in machine condition measurement is a critical parameter to optimizing maintenance strategy, and there is real systemic value in having more accurate machine condition measurement systems.

Spontaneous Focusing on Quantitative Relations and the Development of Rational Number Conceptual Knowledge

The aim of the present set of studies was to explore primary school children’s Spontaneous Focusing On quantitative Relations (SFOR) and its role in the development of rational number conceptual knowledge. The specific goals were to determine if it was possible to identify a spontaneous quantitative focusing tendency that indexes children’s tendency to recognize and utilize quantitative relations in non-explicitly mathematical situations and to determine if this tendency has an impact on the development of rational number conceptual knowledge in late primary school. To this end, we report on six original empirical studies that measure SFOR in children ages five to thirteen years and the development of rational number conceptual knowledge in ten- to thirteen-year-olds. SFOR measures were developed to determine if there are substantial differences in SFOR that are not explained by the ability to use quantitative relations. A measure of children’s conceptual knowledge of the magnitude representations of rational numbers and the density of rational numbers is utilized to capture the process of conceptual change with rational numbers in late primary school students. Finally, SFOR tendency was examined in relation to the development of rational number conceptual knowledge in these students. Study I concerned the first attempts to measure individual differences in children’s spontaneous recognition and use of quantitative relations in 86 Finnish children from the ages of five to seven years. Results revealed that there were substantial inter-individual differences in the spontaneous recognition and use of quantitative relations in these tasks. This was particularly true for the oldest group of participants, who were in grade one (roughly seven years old). However, the study did not control for ability to solve the tasks using quantitative relations, so it was not clear if these differences were due to ability or SFOR. Study II more deeply investigated the nature of the two tasks reported in Study I, through the use of a stimulated-recall procedure examining children’s verbalizations of how they interpreted the tasks. Results reveal that participants were able to verbalize reasoning about their quantitative relational responses, but not their responses based on exact number. Furthermore, participants’ non-mathematical responses revealed a variety of other aspects, beyond quantitative relations and exact number, which participants focused on in completing the tasks. These results suggest that exact number may be more easily perceived than quantitative relations. As well, these tasks were revealed to contain both mathematical and non-mathematical aspects which were interpreted by the participants as relevant. Study III investigated individual differences in SFOR 84 children, ages five to nine, from the US and is the first to report on the connection between SFOR and other mathematical abilities. The cross-sectional data revealed that there were individual differences in SFOR. Importantly, these differences were not entirely explained by the ability to solve the tasks using quantitative relations, suggesting that SFOR is partially independent from the ability to use quantitative relations. In other words, the lack of use of quantitative relations on the SFOR tasks was not solely due to participants being unable to solve the tasks using quantitative relations, but due to a lack of the spontaneous attention to the quantitative relations in the tasks. Furthermore, SFOR tendency was found to be related to arithmetic fluency among these participants. This is the first evidence to suggest that SFOR may be a partially distinct aspect of children’s existing mathematical competences. Study IV presented a follow-up study of the first graders who participated in Studies I and II, examining SFOR tendency as a predictor of their conceptual knowledge of fraction magnitudes in fourth grade. Results revealed that first graders’ SFOR tendency was a unique predictor of fraction conceptual knowledge in fourth grade, even after controlling for general mathematical skills. These results are the first to suggest that SFOR tendency may play a role in the development of rational number conceptual knowledge. Study V presents a longitudinal study of the development of 263 Finnish students’ rational number conceptual knowledge over a one year period. During this time participants completed a measure of conceptual knowledge of the magnitude representations and the density of rational numbers at three time points. First, a Latent Profile Analysis indicated that a four-class model, differentiating between those participants with high magnitude comparison and density knowledge, was the most appropriate. A Latent Transition Analysis reveal that few students display sustained conceptual change with density concepts, though conceptual change with magnitude representations is present in this group. Overall, this study indicated that there were severe deficiencies in conceptual knowledge of rational numbers, especially concepts of density. The longitudinal Study VI presented a synthesis of the previous studies in order to specifically detail the role of SFOR tendency in the development of rational number conceptual knowledge. Thus, the same participants from Study V completed a measure of SFOR, along with the rational number test, including a fourth time point. Results reveal that SFOR tendency was a predictor of rational number conceptual knowledge after two school years, even after taking into consideration prior rational number knowledge (through the use of residualized SFOR scores), arithmetic fluency, and non-verbal intelligence. Furthermore, those participants with higher-than-expected SFOR scores improved significantly more on magnitude representation and density concepts over the four time points. These results indicate that SFOR tendency is a strong predictor of rational number conceptual development in late primary school children. The results of the six studies reveal that within children’s existing mathematical competences there can be identified a spontaneous quantitative focusing tendency named spontaneous focusing on quantitative relations. Furthermore, this tendency is found to play a role in the development of rational number conceptual knowledge in primary school children. Results suggest that conceptual change with the magnitude representations and density of rational numbers is rare among this group of students. However, those children who are more likely to notice and use quantitative relations in situations that are not explicitly mathematical seem to have an advantage in the development of rational number conceptual knowledge. It may be that these students gain quantitative more and qualitatively better self-initiated deliberate practice with quantitative relations in everyday situations due to an increased SFOR tendency. This suggests that it may be important to promote this type of mathematical activity in teaching rational numbers. Furthermore, these results suggest that there may be a series of spontaneous quantitative focusing tendencies that have an impact on mathematical development throughout the learning trajectory.

El Marco Común Europeo de Referencia: su utilidad en la planificación y evaluación de un test de comprensión de lectura de ELE

Eurooppalainen viitekehys ja sen hyödyllisyys espanjan luetun ymmärtämisen testin suunnittelussa ja arvioinnissa Tämän pro gradu -tutkielman tavoitteena oli tutkia Eurooppalaista viitekehystä espanjan luetun ymmärtämisen testin suunnittelun ja arvioinnin pohjana. Työn teoriaosa koostuu kahdesta pääaiheesta: Eurooppalaisesta viitekehyksestä ja vieraalla kielellä lukemisesta. Viitekehys on 2000-luvun alussa julkaistu Euroopan neuvoston projekti, jonka tarkoituksena on näyttää suunta modernille kielten opetukselle Euroopassa. Teoksen ehkä kuuluisin osa ovat kielitaitoa mittaavat taitotasot, perinteisen asteikon mukaisesti A1 – C2. Muun muassa juuri taitotasojen avulla eurooppalaista kielten opiskelua ja opetusta on voitu yhtenäistää – esimerkiksi eri maiden oppilaitosten tutkintoja, kielikursseja ja kielitestejä pystytään nykyään vertailemaan helposti. Vieraalla kielellä lukeminen on ollut erittäin suosittu tutkimuksen kohde jo pitkään. Tässä tutkielmassa esitellään muutamia vieraan kielen lukemisen teorioita (kuten skeemateoria), malleja (kuten Rumelhartin malli) ja strategioita (Mendoza Fillolan strategiat). Lisäksi käsitellään vieraalla kielellä lukemisen ongelmia ja sitä, miten vieraalla kielellä lukemista voidaan opettaa. Empiirisessä osassa kuvaillaan tutkimusta, johon osallistui 35 tutkimushenkilöä jotka jaettiin kolmeen vertailuryhmään. Keskeisessä osassa empiiristä osiota on, testitulosten lisäksi, kuvaus Eurooppalaisen viitekehyksen toimivuudesta espanjan luetun ymmärtämisen testin suunnittelussa ja arvioinnissa. Testin tuloksista päätellen ryhmistä selvästi parhaiten suoriutui ryhmä A, joka koostui kielikeskuksen opiskelijoista. Huomattiin myös, että B- ja C-ryhmien sisäisissä kokonaistuloksissa oli enemmän hajontaa kuin A:n tuloksissa. Tutkimuksesta saatujen kokemusten perusteella todettiin, että Eurooppalainen viitekehys sisältää melko hyödyllisiä yleisen tason ohjeita ja muita lähtökohtia tällaisen testin suunnittelua ja arviointia varten. Teosta tulisi kuitenkin kehittää – konkreettiset ja selkeät esimerkit ja ohjeet tekisivät siitä huomattavasti käyttökelpoisemman. Eurooppalainen viitekehys näkyy varmasti yhä enemmän tulevaisuuden kielten oppimisessa ja opetuksessa. Myös meillä Suomessa viitekehystä arvostetaan: lähivuosina muun muassa ylioppilaskokeiden arvosanat saavat rinnalleen viitekehyksessä määritellyt taitotasot.

A map of Marco Polo's voyages & travels in the 13th century through a great part of Asia, all Tartary, the East India islands & part of Africa

Nimeketiedot nimiönkehyksissä

Al molto magnifico signor Marco del Sole ... essendomi questi di addietro occorso di fare intagliare, una carta da navigare et sapendo quanto

Nimeke- ja tekijätiedot nimiönkehyksissä

Maalta ja mereltä: eli kokous matkakertomuksia kaikkien aikojen kuuluimmista löytöretkeilijöistä Marco Polosta meidän aikoihin asti - 1, Marco Polo ; Columbo ; Vasco di Gama

Suomennoksia

A conceptual and practical overview of cDNA microarray technology: implications for basic and clinical sciences

cDNA microarray is an innovative technology that facilitates the analysis of the expression of thousands of genes simultaneously. The utilization of this methodology, which is rapidly evolving, requires a combination of expertise from the biological, mathematical and statistical sciences. In this review, we attempt to provide an overview of the principles of cDNA microarray technology, the practical concerns of the analytical processing of the data obtained, the correlation of this methodology with other data analysis methods such as immunohistochemistry in tissue microarrays, and the cDNA microarray application in distinct areas of the basic and clinical sciences.

De Marco Attilio Regulo

Invokaatio: I.N.J.

WALTER BENJAMIN Y GEORGES SOREL: ENTRE EL MITO DE LA HUELGA GENERAL Y UNA POLÍTICA DE MEDIOS PUROS

En su ensayo Para una crítica de la violencia, Walter Benjamin reivindica el fenómeno social de la huelga general revolucionaria teorizada por Georges Sorel en su obra Reflexiones sobre la violencia, como una figura ejemplar de lo que sería un “medio puro de la política”, al margen de cualquier forma legitimada de poder. En este marco, pocos comentadores contemporáneos advierten una discordancia conceptual entre ambos filósofos: para Sorel, la huelga revolucionaria es un mito social, mientras que el mito, categoría esencialmente negativa en Benjamin, describe la violencia que aprisiona la vida y que se traduce en una forma de poder político superior. En este artículo quisiéramos demostrar esta discordancia conceptual para examinar en seguida cómo ha sido comentada por otros pensadores contemporáneos. La filosofía de la historia, la posibilidad de una acción política ética y la temporalidad mesiánica aparecen en el horizonte teórico que emparenta a estos filósofos y por el cual podría descifrarse su impasse conceptual. Esto se confirma si se despliega la idea de un “medio puro de la política”, pista que Benjamin ofrece sin profundizar y sobre la cual reenvía al pensamiento de un filósofo poco explorado, Erich Unger. En la última parte de este artículo desarrollaremos las claves dadas por Unger, que entran justamente en sintonía con la mención de la huelga general como medio puro de la política.