It is generally accepted that populations which experience severe bottlenecks have a reduction in fitness. One of the most frequently reported fitness costs is increased hatching failure in bottlenecked populations of birds. The mechanism responsible for increased hatching failure is unknown. Research on other animals suggest that reduced population numbers cause unavoidable inbreeding that in turn leads to abnormalities in the gametes. In this thesis I examine some of the possible causes for increased hatching failure in severely bottlenecked populations of introduced birds in New Zealand. I look at three traits identified as a cause for infertility or hatching failure previously and determine whether there is a link with the size of a population s bottleneck. It is possible that reduced numbers of sperm reaching the site of fertilisation is a primary cause of hatching failure. I examined the perivitelline membrane of various species of introduced birds and counted the total number of sperm present to compare to how many would be expected in non-bottlenecked species. Although there was no relationship between the size of the bottleneck and the number of sperm present, all species had lower than expected sperm counts. In many species of mammals, a reduction in the quality of sperm is attributed to inbreeding depression bought about by genetic bottlenecks. I next compared the level of sperm abnormalities, variation in midpiece size sperm, and sperm motility with the size of the bottleneck each species passed through when introduced to New Zealand. There was no significant correlation between either the variation in midpiece size or sperm motility with bottleneck size. However, there was a trend for species that passed through more severe bottlenecks to have a slightly higher level of midpiece size and lower motility. Finally, I examined whether there was a link between abnormalities in the eggshell and the size of the respective bottleneck. There was no significant change in eggshell thickness or any change in the number of pores associated bottleneck size. However, there was a decreased number of round pores in severely bottlenecked species, although the consequences of this are unknown. My findings do not directly link a single cause for increased hatching failure in bottlenecked species of birds, but they do highlight the need for monitoring of reproductive traits in endangered species that have experienced a population bottleneck.

Eidgenössische Techn. Hochsch., Diss.--Zürich, 2007. / Zsfassung in dt. Sprache.

O propósito deste trabalho é estruturar uma sequência de aplicação de uma série de técnicas de aumento da capacidade de produção em um equipamento gargalo citadas na literatura. Esta sequência deverá ser colocada em prática para aumentar a capacidade de produção de linhas de fabricação em ambientes de manufatura enxuta. O trabalho foi desenvolvido através da análise das técnicas encontradas para aumento de capacidade de produção de equipamentos (Pesquisa Aplicada) e da estruturação de uma aplicação seqüencial das técnicas (Pesquisa-Ação). Esta sequência de aplicação é seguida até que a melhoria de capacidade de produção necessária seja atingida. A seqüência de aplicação desenvolvida foi aplicada em uma linha de arranjo celular numa empresa de autopeças. As metodologias de pesquisa utilizadas foram a pesquisa aplicada e pesquisa-ação. Foi possível observar que os assuntos que mais contribuíram para as bases deste trabalho foram a Teoria das Restrições e a Produção Enxuta, em particular o processo de focalização em cinco etapas da Teoria das Restrições. Foi possível identificar a necessidade de aumento da capacidade de produção tanto quando a capacidade é insuficiente para atendimento do cliente como quando uma estratégia de redução de custo impõe uma impossibilidade de atendimento à demanda do cliente. Futuros trabalhos podem explorar as diferentes incidências de aplicação de cada uma das técnicas apresentadas para cada tipo de equipamento. Tipos estes ligados à indústria, complexidade, porte, custo, etc. Novas técnicas podem surgir e ser anexadas à seqüência apresentada. Esta forma estruturada de elevação da restrição, neste caso o gargalo de fabricação, poderá ser utilizada em diferentes ambientes fabris pelos profissionais responsáveis por estas ações de melhoria. / The purpose of this work is structuring a sequence of application of a series of production capacity increase techniques mentioned in literature on an equipment bottleneck. This sequence must be placed into practice to increase production capacity of manufacturing lines in lean manufacturing environments. The work was developed through the analysis of the techniques have been found to increase equipment production capacity (applied research) and a sequential procedure to techniques application (action research). This sequential procedure is followed up until the improvement required production capacity is reached. The sequential procedure developed was applied in one line of cellular arrangement in an auto parts company. Research methodologies used were the applied research and research-action. It was possible to observe that matters most contributed to the foundations of this work were the theory of constraints and lean production, in particular the process of focus on five stages of the theory of constraints. It was possible to identify the need of using this sequential procedure when production capacity is insufficient to support the customer demand as when a cost reduction strategy imposes an inability to support the customer demand. Future work can explore the different number of using of each of the techniques presented for each type of equipment. These equipment types are related to complexity, cost, etc. New techniques may arise and be attached to the sequential procedure. This structured way of elevating the restriction in this case the bottleneck manufacturing could be used in different environments works by professionals responsible for these actions for improvement.

This thesis focuses on the enhancement of the IEEE 802.15.4 beaconless-enabled MAC protocol as a solution to overcome the network bottleneck, less flexible nodes, and more energy waste at the centralised wireless sensor networks (WSN). These problems are triggered by mechanism of choosing a centralised WSN coordinator to start communication and manage the resources. Unlike IEEE 802.11 standard, the IEEE 802.15.4 MAC protocol does not include method to overcome hidden nodes problem. Moreover, understanding the behaviour and performance of a large-scale WSN is a very challenging task. A comparative study is conducted to investigate the performance of the proposed ad hoc WSN both over the low data rate IEEE 802.15.4 and the high data rate IEEE 802.11 standards. Simulation results show that, in small-scale networks, ad hoc WSN over 802.15.4 outperforms the WSN where it improves 4-key performance indicators such as throughput, PDR, packet loss, and energy consumption by up to 22.4%, 17.1%, 34.1%, and 43.2%, respectively. Nevertheless, WSN achieves less end-to-end delay; in this study, it introduces by up to 2.0 ms less delay than that of ad hoc WSN. Furthermore, the ad hoc wireless sensor networks work well both over IEEE 802.15.4 and IEEE 802.11 protocols in small-scale networks with low traffic loads. The performance of IEEE 802.15.4 declines for the higher payload size since this standard is dedicated to low rate wireless personal access networks. A deep performance investigation of the IEEE 802.15.4 beaconless-enabled wireless sensor network (BeWSN) in hidden nodes environment has been conducted and followed by an investigation of network overhead on ad hoc networks over IEEE 802.11 protocol. The result of investigation evinces that the performance of beaconless-enabled ad hoc wireless sensor networks deteriorates as indicated by the degradation of throughput and packet reception by up to 72.66 kbps and 35.2%, respectively. In relation to end-to-end delay, however, there is no significant performance deviation caused by hidden nodes appearance. On the other hand, preventing hidden node effect by implementing RTS/CTS mechanism introduces significant overhead on the network that applies low packet size. Therefore, this handshaking method is not suitable for low rate communications protocol such as IEEE 802.15.4 standard. An evaluation study of a 101-node large-scale beaconless-enabled wireless sensor networks over IEEE 802.15.4 protocol has been carried out after the nodes deployment model was arranged. From the experiment, when the number of connection densely increases, then the probability of packet delivery decreases by up to 40.5% for the low payload size and not less than of 44.5% for the upper payload size. Meanwhile, for all sizes of payload applied to the large-scale ad hoc wireless sensor network, it points out an increasing throughput whilst the network handles more connections among sensor nodes. In term of dropped packet, it confirms that a fewer data drops at smaller number of connecting nodes on the network where the protocol outperforms not less than of 34% for low payload size of 30 Bytes. The similar trend obviously happens on packet loss. In addition, the simulation results show that the smaller payload size performs better than the bigger one in term of network latency, where the payload size of 30 Bytes contributes by up to 41.7% less delay compared with the contribution of the payload size of 90 Bytes.

Moelven är en av Skandinaviens största trämekaniska koncerner med 52 operativa enheter i Norge, Sverige och Danmark. Denna studie har utförts i hyvlerianläggningen hos Moelven Valåsen Wood AB som är ett hyvleri och vidareförädling av byggvirke beläget i Karlskoga. Problemet grundar sig i att Moelven vill öka utnyttjandegraden i hyvlerianläggningen. Denna ligger idag på ca 65% och hyvleriet begränsar därför en stor del av materialflödet. Syftet med denna fallstudie var att undersöka vilka orsaker som ligger bakom den låga utnyttjandegraden för att ge förslag på åtgärder till dessa. Studien inleddes med ett brett perspektiv för att kunna undersöka de verkliga orsakerna till problemet. En analys gjordes av de olika stopporsakerna för att klargöra vilka olika stopp som uppstår samt hur stor del av den totala stopptiden de utgör. Vidare gjordes avgränsningar som innebar en fördjupning inom omställningsprocessen då omställningar av hyveln utgjorde 30% av den totala stopptiden under tidsperioden. För att kunna analysera denna process gjordes videoinspelningar där de olika arbetsmomenten definierades och tidsattes. Då fräsbyten var de omställningar som observerades flest antal gånger utformades konkreta förbättringsförslag främst för dessa. Moelven får även underlag för att kunna gå vidare med de övriga omställningarna. Fallstudien resulterade i olika förbättringsförslag som främst syftade till att effektivisera omställningarna. Dessa förslag innebar: • Separera externa och interna aktiviteter, såsom att förbereda verktyg inför omställningen. • Använda verktygsvagnar för att eliminera rörelser i så stor utsträckning som möjligt. • Skapa bättre ordning på verktyg genom att utforma en check table. • Standardisering av arbetsmoment genom att skapa en rutinbeskrivning samt dela upp  operatörerna i olika arbetsroller. • Involvera alla i organisationen för att kunna arbeta med ständiga förbättringar. En simulering gjordes genom att implementera delar av förbättringsförslaget vilken medförde en ställtidsreducering om 32.5% för fräsbyte. Då en stor gemensam faktor för alla typer av omställningar är rörelser, vilket förbättringsförslaget syftar till att reducera kan det antas vara generaliserbart för övriga omställningar. / Moelven is an industrial group that produces building materials and systems for the construction industry; with its 52 productions units in Norway, Sweden and Denmark, it is one of the biggest in Scandinavia. This study has been carried out in the planing mill at Moelven Valåsen Wood AB in Karlskoga. Because of the low utilization rate in the planing mill (65%), it constitutes a bottleneck, meaning it limits the capacity and flow of material, for most of the products. The purpose of the study was to analyze the stoppage in the planing mill in order to make recommendations on how the utilization rate can be increased. The study began with a wide perspective to identify the reasons behind this problem. A summary of all stops in the planing mill concluded that set ups of the planer made up for 30% of total stoppage. Because of this, the study was narrowed down to mainly analyze the different types of set ups, which was done through extensive observations and videotaping. The solutions and recommendations that were given are therefore almost entirely regarding set up-time reduction, and more specifically, milling set ups. The recommendations, based on the results of the study, includes: • Suggestions on how to separate internal and external set up. • Better order of tools through designing a check table. • Standardizing the procedure by creating a routine and dividing the operators into different work roles. • Involving everyone in the organization in order to work with continuous improvement. A simulation of milling set ups was done by implementing parts of the recommendations – this resulted in a setup up-time reduction of 13 minutes, which corresponds to 32.5%. Because of common denominators, such as movements, the recommendations given are likely generalizable for all set ups.

The aim of thesis is implemention the chosen techniques of lean management in the company named European Trailer Systems Ltd. based on the identification of bottlenecks. The theoretical part provides basic definitions of bottleneck, Theory of Constraints, Lean management and selected methods of lean management. The practical part begins with the company's European Trailer Systems s.r.o characteristic while describe the current situation. Furthermore, the practical part will focus on the identification of bottlenecks that occur in company European Trailer Systems Ltd. in the production process of sliding roofs, will be followed by a proposal to eliminate found bottlenecks with using methods of lean management and possibly their implementation.

Orientadora: Profa. Dra. Cibele Biondo / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Evolução e Diversidade, São Bernardo do Campo, 2018. / A queixada (Tayassu pecari) é uma espécie considerada vulnerável globalmente e criticamente ameaçada em áreas de Mata Atlântica, devido à pressão de caça e fragmentação de habitat. A fragmentação de habitat devido a atividades antrópicas pode acarretar em estruturação genética das populações, além perda de diversidade genética e aumento de endogamia, o que pode contribuir para o processo de extinção local. O presente estudo teve como objetivo estimar o status genético da população de queixadas da região do Pontal do Paranapanema, na Mata Atlântica de SP. Essa região foi altamente fragmentada por atividades antrópicas e, no momento da realização da amostragem para este trabalho, a espécie se encontrava em apenas três dos fragmentos remanescentes (Parque Estadual do Morro do Diabo ¿ PEMD, Fazenda Ponte Branca ¿ FPB e Fazenda Santa Mônica ¿ FSM). Atualmente, é considerada extinta na região. Foram analisadas 47 amostras de sangue, coletadas entre os anos de 1999 e 2005, que foram genotipadas para 11 locos de microssatélites. Observou-se uma estruturação genética das três localidades amostradas em duas subpopulações. Duas das três localidades foram agrupadas em uma única subpopulação (PEMD e FPB) e houve diferenciação genética significativa apenas entre duas delas (PEMD e FSM). Os índices de diversidade genética foram similares para as três localidades e não foram encontradas evidências significativas de endogamia. Esses resultados podem ser explicados de duas formas: 1) existência de fluxo gênico, mesmo que baixo, entre as localidades amostradas (principalmente entre PEMD e FPB); 2) diferenciação recente das subpopulações. Conforme esperado para populações fragmentadas, houve evidências de gargalo populacional recente nas três localidades. Os resultados aqui obtidos podem ser indicativos do papel da paisagem antropizada na estruturação de populações de queixadas mesmo em pequena escala, já que o mesmo não tem sido registrado para regiões mais conservadas. Desta forma, estas evidências podem servir de direcionamento para planos de manejos e ações conservacionistas para outras populações de queixadas que se encontram em condições semelhantes a esta, visando diminuir as chances de extinção local em outras regiões. / The white-lipped peccary (Tayassu pecari) is considered vulnerable throughout its distribution and it is critically endangered in the Atlantic Forest, due to hunting pressure and habitat fragmentation. Habitat fragmentation caused by anthropic activities usually lead to population genetic structure, loss of genetic diversity and higher levels of inbreeding, which contributes to local extinctions. In this study, we addressed the genetic status of a white-lipped peccary population from Pontal do Paranapanema region, located in the Atlantic Forest of São Paulo State in Brazil. This area was highly fragmented by anthropic activities and white-lipped peccaries were found only in three remnant fragments (Parque Estadual do Morro do Diabo ¿ PEMD, Fazenda Ponte Branca ¿ FPB e Fazenda Santa Mônica ¿ FSM) when they were sampled for this work. Currently, they are considered extinct in the region. A total of 47 blood samples were collected between 1999 and 2005 and were genotyped for 11 microsatellite loci. We found that the three fragments sampled were structured in two subpopulations, with two of them being grouped into a single subpopulation (PEMD and FPB). We observed significant genetic differentiation only between two fragments (PEMD and FSM). The genetic diversity indices were similar for the three fragments and no indicators of inbreeding were found. These results can be explained in two ways: 1) existence of gene flow, even if low, between fragments (mainly between PEMD and FPB); 2) recent differentiation of the subpopulations. As expected for fragmentated populations, we found evidence of a population bottleneck for all the fragments sampled. These results can be indicative of the role of anthropized landscape in the structuration of white-lipped peccary populations even on a small scale, since it has not been recorded for well conserved regions. These finds can serve to delineate management plans and conservation actions for other white-lipped peccary populations that are in similar conditions, aiming to reduce the chances of local extinction in other regions.

We propose a model that generates a family network based on real-world family network data. We use this model to study the extent to which distances to union and the number of children characterize family networks. To determine how accurate our model is we use persistent homology to identify and compare the structure of our modeled family networks to real-world family networks. To accomplish this, we introduce the notion of a network's persistence curve, which encodes the network's set of persistence intervals. Using the bottleneck distance allows us to measure the difference in the homological structure between any pair of networks. We also study how the distribution of distance to union and the distribution of children build family networks. What we find is that these two features of distance to union and number of children allow us to fairly accurately recreate family networks at least at the level of their persistent homology.

This diploma project deals with the production line in the selected company. The theoretical part is dealing with lean production, followed by the company description and description of the production line itself. The diploma project looks at the production line from a variety of perspectives and looks for the most appropriate points to optimize. The most important aspects are the efficiency of production and ergonomics. After finding critical points, different solutions are proposed and they are further elaborated, evaluated and the most appropriate one is recommended.

This masters thesis optimises production of the step plates (which are parts of the sliding steps systems used in tramways, subways, hi-speed trains etc.) to increase the production rate to meet customers demand. The purpose of the work was reached by detailed analysis of the production process followed by evaluation of the results which led to the list of the possible solutions. The solution with the greatest time improvement was chosen and explained in detail.