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En produkthistoria! : AB Hägglund & Söner 1922-1981Anderson, Helén January 1994 (has links)
Kring en kärna av kompetens inom mekanisk verkstadsindustri har det ständigt tillverkats nya produkter vid AB Hägglund & Söner med säte i Örnsköldsvik. Möbler, busskarosserier, flygplan, gruvlok, elektriska motorer, svetsmaskiner, fartygskranar och hydrauliska motorer är bara några exempel. Utvecklingen av nya produkter har skett i nära samarbete med kunder med vilka man haft långvariga affärsutbyten. Inom företaget har intresset och entusiasmen för nya produkter och konstruktioner varit en ständig drivkraft till ökad kunskap. Redan tidigt utvecklades en kultur och tradition av att gärna och med stor arbetsinsats ge sig in på svåra men utmanande och spännande projekt kring nya produkter. I denna empiriska del behandlas företagets omvandling under en period av sextio år. Med utgångspunkt från produkterna söker författaren beskriva förändring såväl i intern resursomvandling som externt i interaktion med kunder och leverantörer. Boken utgör den empiriska delen av "Ett industriföretags omvandling". / <p>Utgör jämte förf:s: "Ett industriföretags omvandling" diss. Stockholm : Handelshögsk</p>
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Investigation of RAPDs and microsatellites for use in South African cranes.King, Heather Anne. 29 November 2013 (has links)
The three South African crane species, namely, the Wattled Crane (Bugeranus
carunculatus), the Blue Crane (Anthropoides paradisea) and the Grey Crowned Crane
(Balearica regulorum regulorum) are all threatened. South African legislation protects the
cranes, however eggs and/or fledglings are sometimes illegally collected from the wild. These
are then sold, often by registered breeders, who falsely claim them as the offspring of their
captive breeding pair. DNA fingerprinting is one method to detect this crime.
Fifteen RAPD primers were screened for polymorphism in the three species. Seven
primers produced polymorphic profiles in the Blue Crane and eight each in the Grey Crowned
Crane and Wattled Crane, with an average of 14.57, 12.38 and 5.88 scorable loci per primer,
respectively. The Band Sharing Coefficient for unrelated individuals was found to be 0.665,
0.745 and 0.736 for the Blue, Grey Crowned and Wattled Crane respectively.
Five microsatellite primers, originally developed for use in Whooping Cranes (Grus
american), had previously been shown to be polymorphic in the Wattled Crane. This was also
the case in this study with an average of 3.6 alleles per primer. Although all primers cross
amplified, only a single primer each showed polymorphism in the Blue Crane (showing 6
alleles) and the Grey Crowned Crane (showing 5 alleles).
The RAPDs were found to be irreproducible, show high numbers of novel bands and
had parent: offspring BSC values that were not significantly higher than those of unrelated
individuals. Statistics showed that, in the Blue Crane, the probability that misassigned parents
would be detected was low whilst there was an almost certainty that true parents would be
incorrectly excluded.
The five microsatellite primers examined gave exclusionary powers of 0.869 and 0.641
where one or two parents were unknown in the Wattled Crane. The exclusionary powers for
the Blue Crane and Grey Crowned Crane calculated at only one locus were much lower. It was concluded that RAPDs were totally inappropriate for parentage analyses,
however, microsatellites are a suitable technique and recommendations are made that other microsatellites, developed for other species of crane, should be examined for their potential in
this respect. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.
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En produkthistoria! : AB Hägglund & Söner 1922-1981Anderson, Helén January 1994 (has links)
Kring en kärna av kompetens inom mekanisk verkstadsindustri har det ständigt tillverkats nya produkter vid AB Hägglund & Söner med säte i Örnsköldsvik. Möbler, busskarosserier, flygplan, gruvlok, elektriska motorer, svetsmaskiner, fartygskranar och hydrauliska motorer är bara några exempel. Utvecklingen av nya produkter har skett i nära samarbete med kunder med vilka man haft långvariga affärsutbyten. Inom företaget har intresset och entusiasmen för nya produkter och konstruktioner varit en ständig drivkraft till ökad kunskap. Redan tidigt utvecklades en kultur och tradition av att gärna och med stor arbetsinsats ge sig in på svåra men utmanande och spännande projekt kring nya produkter. I denna empiriska del behandlas företagets omvandling under en period av sextio år. Med utgångspunkt från produkterna söker författaren beskriva förändring såväl i intern resursomvandling som externt i interaktion med kunder och leverantörer. Boken utgör den empiriska delen av "Ett industriföretags omvandling".
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Robust Control For Gantry CranesCosta, Giuseppe, Electrical Engineering & Telecommunications, Faculty of Engineering, UNSW January 1999 (has links)
In this thesis a class of robust non-linear controllers for a gantry crane system are discussed. The gantry crane has three degrees of freedom, all of which are interrelated. These are the horizontal traverse of the cart, the vertical motion of the goods (i.e. rope length) and the swing angle made by the goods during the movement of the cart. The objective is to control all three degrees of freedom. This means achieving setpoint control for the cart and the rope length and cancellation of the swing oscillations. A mathematical model of the gantry crane system is developed using Lagrangian dynamics. In this thesis it is shown that a model of the gantry crane system can be represented as two sub models which are coupled by a term which includes the rope length as a parameter. The first system will consist of the cart and swing dynamics and the other system is the hoist dynamics. The mathematical model of these two systems will be derived independent of the other system. The model that is comprised of the two sub models is verified as an accurate model of a gantry crane system and it will be used to simulate the performance of the controllers using Matlab. For completeness a fully coupled mathematical model of the gantry crane system is also developed. A detailed design of a gain scheduled sliding mode controller is presented. This will guarantee the controller's robustness in the presence of uncertainties and bounded matched disturbances. This controller is developed to achieve cart setpoint and swing control while achieving rope length setpoint control. A non gain scheduled sliding mode controller is also developed to determine if the more complex gain scheduled sliding mode controller gives any significant improvement in performance. In the implementation of both sliding mode controllers, all system states must be available. In the real-time gantry crane system used in this thesis, the cart velocity and the swing angle velocity are not directly available from the system. They will be estimated using an alpha-beta state estimator. To overcome this limitation and provide a more practical solution an optimal output feedback model following controller is designed. It is demonstrated that by expressing the system and the model for which the system is to follow in a non-minimal state space representation, LQR techniques can be used to design the controller. This produces a dynamic controller that has a proper transfer function, and negates the need for the availability of all system states. This thesis presents an alternative method of solving the LQR problem by using a generic eigenvalue solution to solve the Riccati equation and thus determine the optimal feedback gains. In this thesis it is shown that by using a combination of sliding mode and H??? control techniques, a non-linear controller is achieved which is robust in the presence of a wide variety of uncertainties and disturbances. A supervisory controller is also described in this thesis. The supervisory control is made up of a feedforward and a feedback component. It is shown that the feedforward component is the crane operator's action, and the feedback component is a sliding mode controller which compensates as the system's output deviates from the desired trajectory because of the operator's inappropriate actions or external disturbances such as wind gusts and noise. All controllers are simulated using Matlab and implemented in real-time on a scale model of the gantry crane system using the program RTShell. The real-time results are compared against simulated results to determine the controller's performance in a real-time environment.
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Science, Practice, and Policy: The Committee on Rare and Endangered Wildlife Species and the Development of U.S. Federal Endangered Species Policy, 1956-1973January 2011 (has links)
abstract: The Committee on Rare and Endangered Wildlife Species (CREWS) of the U.S. Fish and Wildlife Service (FWS) made important and lasting contributions to one of the most significant pieces of environmental legislation in U.S. history: the Endangered Species Act of 1973 (ESA). CREWS was a prominent science-advisory body within the U.S. Department of the Interior (DOI) in the 1960s and 1970s, responsible for advising on the development of federal endangered-wildlife policy. The Committee took full advantage of its scientific and political authority by identifying a particular object of conservation--used in the development of the first U.S. list of endangered species--and establishing captive breeding as a primary conservation practice, both of which were written into the ESA and are employed in endangered-species listing and recovery to this day. Despite these important contributions to federal endangered-species practice and policy, CREWS has received little attention from historians of science or policy scholars. This dissertation is an empirical history of CREWS that draws on primary sources from the Smithsonian Institution (SI) Archives and a detailed analysis of the U.S. congressional record. The SI sources (including the records of the Bird and Mammal Laboratory, an FWS staffed research group stationed at the Smithsonian Institution) reveal the technical and political details of CREWS's advisory work. The congressional record provides evidence showing significant contributions of CREWS and its advisors and supervisors to the legislative process that resulted in the inclusion of key CREWS-inspired concepts and practices in the ESA. The foundational concepts and practices of the CREWS's research program drew from a number of areas currently of interest to several sub-disciplines that investigate the complex relationship between science and society. Among them are migratory bird conservation, systematics inspired by the Evolutionary Synthesis, species-focused ecology, captive breeding, reintroduction, and species transplantation. The following pages describe the role played by CREWS in drawing these various threads together and codifying them as endangered-species policy in the ESA. / Dissertation/Thesis / Ph.D. Biology 2011
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Modelagem paramétrica de pórticos rolantes: estabilidade estrutural e otimização. / Gantry cranes parametric modeling: structural stability and optimization.Gustavo Sobue 29 July 2005 (has links)
O objetivo deste trabalho é desenvolver uma ferramenta de automatização de cálculo para projeto estrutural de pórticos rolantes. Com o apoio da geração automática de um modelo de elementos finitos e um memorial de cálculo, o projeto estrutural desses equipamentos pode ser rapidamente verificado quanto ao limite de escoamento do material e resistência à flambagem. Optou-se pela utilização do método dos elementos finitos para o cálculo estrutural, pois se trata de uma ferramenta de cálculo moderna, que permite avaliar soluções para as quais não há ferramentas analíticas disponíveis. Porém, o tempo para geração de modelos de cálculo pode ser longo em relação ao cronograma do projeto, principalmente se houver a necessidade de se alterar a geometria inicial ou se existirem várias condições de carregamento a serem analisadas. A utilização de um pré-processador permite que várias alternativas sejam analisadas para escolha da que melhor atenda aos requisitos de projeto e de custo. Assim como ocorre com outras estruturas de engenharia, não existe uma equação de dimensionamento, mas sim de verificação; as estruturas ótimas são procuradas por tentativa e erro com base na experiência do projetista. Para facilitar a busca de uma estrutura ótima, implementou-se também uma rotina para otimizar as estruturas metálicas do pórtico. Adotou-se como função objetivo nesta implementação a minimização da massa, o que no caso dos pórticos implica em redução da área da seção transversal das vigas. Como restrições a esta redução adotaram-se o limite de escoamento do material e limite de estabilidade da estrutura (flambagem). Foram utilizados os aplicativos Excel (Microsoft), Ansys (Ansys Inc.) e Mathcad (Mathsoft) de maneira integrada a fim de se obter uma interface amigável, uma análise estrutural confiável e a elaboração automática de um memorial de cálculo. / The objective of this work is to develop a tool to generate an automatic structural design of gantry cranes. With an automatic generation of finite element models and also a design report, this routine allows a fast verification against yield of material and structural instability. The use of the finite element method was chosen for the structural design because it is a modern analysis tool that permits the evaluation of geometric configurations for which there are no analytical formulations available. However, the time necessary to build these models may be high, especially if there are changes in the initial geometry and many load cases. The use of a pre-processor allows the evaluation of a series of geometric alternatives, within which would be chosen the one with the lowest cost that attends the clients specifications. Like many other engineering problems, there are no direct equations to find an adequate structure; there are only verification procedures available; the optimum structures are searched by trial and error, based on the designers experience. To accelerate this search process, an optimization routine was developed. Mass reduction was adopted as the objective function, which leads to reduction of the cross section area of the beams. Yield strength and buckling were adopted as restrictions to this optimization. Excel (Microsoft), Ansys (Ansys Inc) and Mathcad (Mathsoft) software were integrated to provide an user-friendly interface, reliable structural analysis and an automatic report generation.
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Jeřáb pro manipulaci s leteckými agregáty / Aviation maintenace craneBureš, Martin January 2013 (has links)
This master´s thesis solves design of a mobile crane for handling air aggregates and ejection seats. Handling crane provides lifting a maximum weight of 300 kg to a height of 4600 mm. Subject of the work is the choice of appropriate technical solutions, design of lifting mechanisms, supporting structures and accessories. The suitability of the solution is checked by strength analysis of individual units. Another task is to provide mobility equipment and control stability against overturning. The appendix includes protocols static analysis of the program Nexis32, drawing overall crane assembly and manufacturing drawings selected parts.
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Seismic performance evaluation of port container cranes allowed to upliftKosbab, Benjamin David 31 March 2010 (has links)
The seismic behavior of port container cranes has been largely ignored-by owners, operators, engineers, and code officials alike. This is despite their importance to daily port operations, where historical evidence suggests that port operational downtime following a seismic event can have a crippling effect on the affected local, regional, and national economies. Because the replacement time in the event of crane collapse can be a year or more, crane collapse has the potential to be the "critical path" for post-disaster port recovery. Since the 1960's, crane designers allowed and encouraged an uplift response from container cranes, assuming that this uplift would provide a "safety valve" for seismic loading; i.e. the structural response at the onset of uplift was assumed to be the maximum structural response. However, cranes have grown much larger and more stable such that the port industry is now beginning to question the seismic performance of their modern jumbo container cranes.
This research takes a step back, and reconsiders the effect that uplift response has on the seismic demand of portal-frame structures such as container cranes. A theoretical estimation is derived which accounts for the uplift behavior, and finds that the "safety valve" design assumption can be unconservative. The resulting portal uplift theory is verified with complex finite element models and experimental shake-table testing of a scaled example container crane. Using the verified models, fragility curves and downtime estimates are developed which characterize the risk of crane damage and operational downtime for three representative container cranes subjected to a range of earthquakes. This research demonstrates that container cranes designed using previous and current standards can significantly contribute to port seismic vulnerability. Lastly, performance-based design recommendations are provided which encourage the comparison of demand and capacity in terms of the critical portal deformation, using the derived portal uplift theory to estimate seismic deformation demand.
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Investigation of the utilization of microsatellites for fingerprinting in three endangered southern African crane species.Moodley, Eshia Stephany. January 2006 (has links)
Cranes are large elegant birds that occur on all continents of the world except for
South America and Antarctica. Of the fifteen species of crane worldwide, three
predominantly occur in southern Africa; the Wattled crane (Bugeranus carunculatus),
the Blue crane (Anthropoides paradisea) and the Crowned crane (Balearica
regulorum). Crane numbers throughout the world are diminishing, mostly because of
the destruction of their habitat and illegal bird trading. Efforts are underway to
prevent species extinction, legally and through the compilation of a studbook that
contains descriptions of physical attributes, ownership, location and possible
kinships of birds in captivity . This investigation, first of its kind, WdS undertaken to
assess whether twelve published and unpublished microsatellite primers developed
for the related Whooping crane and Red-Crowned crane could be used to fingerprint
the southern African crane species using cost effective polyacrylamide gel
electrophoresis. The results obtained were then used to determine the extent of
genetic variation within species and distance between species.
All primer sets amplified heterologous microsatellite loci in the three crane species,
however, the unpublished primers produced poorly defined fingerprints even after
extensive optimization. Of the twelve microsatellite loci investigated, the Blue crane
and the Wattled crane revealed a high level of polymorphism. The Blue crane
displayed 76% polymorphism and the Wattled crane 92%. In contrast, for the
Crowned crane, that belongs to a different subfamily, Balearicinae, only 50% of the
loci were polymorphic. The alleles displayed sizes similar to that of the species for
which the primers were developed. Little variation in size, less than 10 bp, was noted
for the different alleles of the polymorphic loci. The number of alleles, on the other
hand, at each of the polymorphic loci was found to be low. The frequency of the
most prevalent allele at most of the loci was generally reasonably high. These
results therefore suggest that these primer sets are not suitable for individual
identification and differentiation using polyacrylamide gel electrophoresis.
Xll
The observed heterozygosity of the three crane species was low; 12% in Blue crane;
7% in Crowned crane; and 13% in Wattled crane. Nei's identity further confirmed the
high similarity between individuals; 66-100% for Blue crane; 55-100% for Crowned
crane and 41-95% for Wattled crane. This low genetic variation is attributed to
possible relatedness between birds supplied by aviculturists whom have a limited
number of birds in captivity. A Hardy-Weinberg test for equilibrium revealed that
most of the microsatellite loci displayed a deficiency of heterozygotes, while a few
loci displayed an excess of heterozygotes. In general, the Hardy Weinberg test of
equilibrium supported the notion that the individuals within each of the species might
have been related.
Differentiation between the three crane species ranged from 3-5%, with Blue and
Wattled crane displaying a higher degree of genetic similarity when compared to the
Crowned crane, known to be the oldest extant crane species.
The limited allelic variation within the microsatellite loci tested, as well as the
extensive genetic similarity between individuals suggests that a wide-ranging search
for additional microsatellite loci that are more polymorphic and contain a larger
number of alleles should be undertaken for the southern African crane species. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
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Operational Performance Enhancement of Human Operated Flexible SystemsSorensen, Khalid Lief 08 July 2008 (has links)
Recent decades have been witness to explosive leaps in manufacturing productivity. Advances in communication technology, computing speed, control theory, and sensing technology have been significant contributors toward the increased productivity and efficiency that industry has exhibited. The continued growth of technological equipment and engineering knowledge challenges engineers to fully utilize these advancements in more sophisticated and useful automation systems.
One such application involves enhancing bridge and gantry crane operation. These systems are used throughout the globe, and are critical aspects of industrial productivity. Consequently, improving the operational effectiveness of cranes can be extremely valuable.
Effective control of cranes can be largely attributed to two distinct, but related aspects crane manipulation: 1) the expertise of operators, which are responsible for issuing commands to the structures, and 2) the dynamic properties of cranes, which influence how the structures respond to issued commands. Accordingly, the operational efficiency of cranes can be influenced by changing both the way that operators issue commands to cranes, and also how the crane responds to issued commands.
This thesis is concerned with dynamic control theory of flexible machines, and human/machine interaction, especially as these areas relate to industrial crane control. In the area of dynamic control, this thesis investigates control strategies that are specifically suited for use on systems that possess common actuator nonlinearities, like saturation, rate limiting, dead-zone, backlash, and finite-state actuation. In the area of human/machine interaction, this thesis investigates the effects of different crane interface devices on the operational efficiency of cranes.
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