886 resultados para management optimization in age-structured models
Resumo:
The degree of fusion at the anterior aspect of the sacral vertebrae has been scored in 242 male and female skeletons from the Lisbon documented collection, ranging in age from 16 to 59 years old. Statistical tests indicate a sex difference towards earlier fusion in young females compared with young males, as well as a clear association between degree of fusion and age. Similar results have been found in documented skeletal samples from Coimbra and Sassari, and the recommendations stated by these authors regarding age estimation have been positively tested in the Lisbon collection. Although more research from geographically diverse samples is required, a general picture of the pattern of sacral fusion and its associations with age and sex is emerging. We also provide a practical example of the usefulness of the sacrum in age estimation in a forensic setting, a mass grave from the Spanish Civil War. It is concluded that the scoring of the degree of fusion of the sacral vertebrae, specially of S1-2, can be a simple tool for assigning skeletons to broad age groups, and it should be implemented as another resource for age estimation in the study of human skeletal remains.
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Purchasing and supply management (PSM) has become increasingly important for companies to survive in current highly competitive market. Increased outsourcing has extended the role of PSM, making external resource management and supplier relationships critical success factors in business. However, the recent research has mainly concentrated on large enterprises. Therefore the PSM issues related to medium-sized enterprises represent a significant research area. The thesis aims to explore the status and role of PSM in Finnish medium-sized firms, understand how strategic companies consider PSM to be, clarify what are the competence requirements for PSM professionals, and increase the understanding of PSM capabilities needed from the points view of individual competence and organisational capabilities. The study uses data that was collected in 2007 from purchasing executives at the director/CEO level representing a sample of 94 Finnish firms. 54 % of the respondent enterprises had a supply strategy. The total supply cost was on average 60 % of firms' turnover. Centralisation of PSM and outsourcing of logistics will increase in Finnish medium-sized enterprises. The findings point out that Finnish medium-sized enterprises had strategical features of PSM. However, Finnish firms have not concentrated on making strategies that relate to PSM. The elements that explain the existence of a supply strategy could be found in this study. It can be concluded from this study that there is an advantageous base for the development of strategic PSM, because nearly all the enterprises were of the opinion that PSM capabilities have an effect on business success. When reviewing the organisational capabilities, the five most important development elements were supplier relationships, both operational and strategic processes, time management, and personnel's competence. Training in internationalisation, strategic management, and communication could help to improve competences of PSM personnel.
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In this paper, we obtain sharp asymptotic formulas with error estimates for the Mellin con- volution of functions de ned on (0;1), and use these formulas to characterize the asymptotic behavior of marginal distribution densities of stock price processes in mixed stochastic models. Special examples of mixed models are jump-di usion models and stochastic volatility models with jumps. We apply our general results to the Heston model with double exponential jumps, and make a detailed analysis of the asymptotic behavior of the stock price density, the call option pricing function, and the implied volatility in this model. We also obtain similar results for the Heston model with jumps distributed according to the NIG law.
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More and more companies are interested in implementing knowledge management. However, the majority of knowledge management initiatives will fail to have any significant impact. In this study, theories regarding knowledge management implementation and adoption are investigated further. The objective of this study is to deepen understanding regarding the critical factors that contribute to successful knowledge management adoption in large multinational companies. The study is formulated around the following four research questions: 1. What are the key success and failure factors in knowledge management implementation? 2. How can knowledge management adoption be improved at the individual, group and organizational levels of the company? 3. What are the critical factors that hinder knowledge management adoption in the case company? 4. How can the case company promote the adoption of knowledge management among company personnel? The methodology used in this study is a combination of a literature review and an explanatory, exploratory, qualitative single-case study. The literature review answers the first and second research questions. Based on the literature review, a framework is presented to illustrate the factors contributing to the success of knowledge management implementation. The framework also links together knowledge management implementation and adoption. The third research question is answered by revealing the relevant findings from 21 expert interviews and 2 online questionnaires with 42 respondents in total. By comparing and contrasting the results of the literature review with the findings of the empirical case study, the fourth research question is answered. The concrete outcomes of this study are a framework to elucidate the factors contributing to the success of knowledge management implementation, a case study highlighting the issues that hinder knowledge management adoption within the case company, and recommendations for the case company.
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The purpose of this thesis was to create design a guideline for an LCL-filter. This thesis reviews briefly the relevant harmonics standards, old filter designs and problems faced with the previous filters. This thesis proposes a modified design method based on the “Liserre’s method” presented in the literature. This modified method will take into account network parameters better. As input parameters, the method uses the nominal power, allowed ripple current in converter and network side and desired resonant frequency of the filter. Essential component selection issues for LCL-filter, such as heating, voltage strength, current rating etc. are also discussed. Furthermore, a simulation model used to verify the operation of the designed filter in nominal power use and in transient situations is included in this thesis.
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The aim of this study was to investigate herpes simplex virus type 1 (HSV-1)- and measles virus (MV)-induced cell death. HSV-1 with deletion in genes encoding infected cell protein (ICP)4 and protein kinase Us3 (d120) induced apoptosis and cathepsin activation in epithelial (HEp-2) and monocytic (U937) cells. Inhibition of cathepsin activity decreased the amount of d120-induced apoptosis indicating that d120-induced apoptosis could be cathepsin-mediated. Also, HSV-1 infection increased caspase activation suggesting that d120-induced apoptosis is probably caspase-mediated. Cystatin treatment decreased the activity of cathepsins and the replication of HSV-1 indicating that cathepsins contribute to HSV-1 infection. Interestingly, d120 induced also necroptosis in monocytic cells. This is the first report on necroptosis in HSV-1- infected cells. MV induced apoptosis in uninfected bystander T lymphocytes, probably via interaction of MV-infected monocytes with uninfected lymphocytes. The expression of death receptor Fas was clearly increased on the surface of lymphocytes. The number of apoptotic cells and the activation of cathepsins and caspases were increased in MVinfected U937 cells suggesting that MV-induced apoptosis could be cathepsin- and caspase-mediated. Cystatin treatment inhibited cathepsin activities but not MV-induced apoptosis. Besides HSV-1-induced apoptosis, innate immune responses were studied in HSV-1-infection. HSV-1 viruses with either ICP4 and Us3, or Us3 deletion only, increased the expression of Toll-like receptor (TLR)3 and stimulated its downstream pathways leading to increased expression of type I interferon gene and to functional interferons. These findings suggest that besides controlling apoptosis, HSV-1 ICP4 and Us3 genes are involved in the control of TLR3 response in infected cell.
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In order to produce useful knowledge to the initiatives of protection and management of forest fragments, more specifically for tropical dry forests which suffer with frequent anthropic activities, and due to the lack of specific studies, this article aimed describe the structure and the floristic similarity among three areas of dry forest with different management histories. The study was developed in Capitão Enéas municipality, Northern Minas Gerais, Brazil, where three fragments were evaluated, being one in regeneration for 30 years, another submitted to occasional fire and the third with selective cut in small scale. The sampling was developed through the point quarter method considering all the alive phanerophyte individuals with circumference at breast height (CBH) > 15 cm. In the three fragments, 512 individuals, distributed in 60 species, 47 genera, and 23 families were sampled. The most representative families were Fabaceae (26), Anacardiaceae (4), Bignoniaceae (3) and Combretaceae (3). However, fourteen families were represented by only one species. Only eight species were common to all fragments - Myracrodruon urundeuva standed out with 26.9% of all sampled individuals - while a great number of species were exclusive of each fragment. The floristic and structural differences between the fragments are possibly related to the history and intensity of management in each area besides the topography variations and the presence or absence of limestone outcrops. These results show the importance of each fragment, indicating that the loss of anyone would cause negative impacts on the regional flora and consequently to the associated biodiversity.
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The aim of this study was to characterize the spatial variability of soil bulk density (Bd), soil moisture content (θ) and total porosity (Tp) in two management systems of sugarcane harvesting, with or without burning, in a Haplustox soil, in the 0-0.20 m layer. The study area is located in Rio Brilhante, state of Mato Grosso do Sul, Brazil, in Eldorado Sugar Mill. The plots have presented 180 m length, and 145.6 m width, totaling 90 points distributed in the form of a grid of nine rows by ten columns, with points spaced 20 m from its neighbor. Soil samples were collected at 0-0.20 m layer in 2007/2008 and 2008/2009 crops. The harvest with burning system had a higher density compared to mechanized harvest, in the two study periods. The moisture content as well as the porosity increased proportionally with the decrease of the density of the harvest burning system compared to the mechanized.
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The study of spatial variability of soil and plants attributes, or precision agriculture, a technique that aims the rational use of natural resources, is expanding commercially in Brazil. Nevertheless, there is a lack of mathematical analysis that supports the correlation of these independent variables and their interactions with the productivity, identifying scientific standards technologically applicable. The aim of this study was to identify patterns of soil variability according to the eleven physical and seven chemical indicators in an agricultural area. It was used two multivariate techniques: the hierarchical cluster analysis (HCA) and the principal component analysis (PCA). According to the HCA, the area was divided into five management zones: zone 1 with 2.87ha, zone 2 with 0.8ha, zone 3 with 1.84ha, zone 4 with 1.33ha and zone 5 with 2.76ha. By the PCA, it was identified the most important variables within each zone: V% for the zone 1, CTC in the zone 2, levels of H+Al in the zone 4 and sand content and altitude in the zone 5. The zone 3 was classified as an intermediate zone with characteristics of all others. According to the results it is concluded that it is possible to separate into groups (management zones) samples with the same patterns of variability by the multivariate statistical techniques.
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ABSTRACT The aim of this study was to evaluate the effects of modifying the maintenance programming of equipment used in sugarcane mechanical harvesting, by transferring actions that can be planned to periods when machines are inactive due to meal breaks and other working shift transitions stoppages. A simulation model was developed to represent the maintenance procedures of combines, haulouts, and other vehicles used by a harvest team. Scenarios were tested using alternatives for interventions such as refueling, lubrication and harvester blade replacement, enabling strategies to be focused towards better utilization of cutting, loading, and transport (CLT) system equipment. As a result, it was possible to remove one combine and two haulouts, while maintaining current daily production. The maintenance time for harvesters, which refers to corrective maintenance and the transfer of remaining interventions for periods of inactivity, was reduced from 10.0% to 3.5% over the useful period. This study indicates that maintenance management in the sugarcane sector enables the expanded use of equipment, leading to the greater productivity of the CLT system.
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According to several surveys and observations, the percentage of successfully conducted IT projects without over-budgeting and delays in time schedule are extremely low. Many projects also are evaluated as failures in terms of delivered functionality. Nuldén (1996) compares IT projects with bad movies; after watching for 2 hours, one still tries to finish it even though one understands that it is a complete waste of time. The argument for that is 'I've already invested too much time to terminate it now'. The same happens with IT projects: sometimes the company continues wasting money on these projects for a long time, even though there are no expected benefits from these projects. Eventually these projects are terminated anyway, but until this moment, the company spends a lot. The situation described above is a consequence of “escalation of commitment” - project continuation even after a manager receives negative feedback of the project’s success probability. According to Keil and Mähring (2010), even though escalation can occur in any type of project, it is more common among complex technological projects, such as IT projects. Escalation of commitment very often results in runaway projects. In order to avoid it, managers use de-escalation strategies, which allow the resources to be used in more effective. These strategies lead to project termination or turning around, which stops the flow of wasted investments. Numbers of researches explore escalation of commitment phenomena based on experiments and business cases. Moreover, during the last decade several frameworks were proposed for de-escalation strategy. However, there is no evidence of successful implementation of the de-escalation of commitment strategy in the literature. In addition, despite that fact that IT project management methodologies are widely used in the companies, none of them cover the topic of escalation of commitment risks. At the same time, there are no researches proposing the way to implement de-escalation of commitment strategy into the existing project management methodology The research is focused on a single case of large ERP implementation project by the consulting company. Hence, the main deliverables of the study include suggestions of improvement in de-escalation methods and techniques in the project and in the company. Moreover, the way to implement these methods into existing project management methodology and into the company general policies is found.
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Abstract: From 2012 to 2013 were surveyed gastrointestinal parasites from pig farms located in different municpaliyies in the state of Rio de Janeiro. Fecal samples from 790 pigs were collected from the rectum on 88 family farms and 702 farms with industrial production. The samples were subjected to Faust et al., Sheather, Ritchie, Lutz and direct examination faecal techniques. The estimated parasite prevalence was 93.1% in family farms and 59.1% in industrial farms. Balantidium coli, coccidia and Entamoeba sp. were the parasites with the highest frequencies, and the male and female reproductive categories and fatteners pigs the most infected (p<0.05). Trophozoites of B. coli were most evident in stool samples from semi-solid followed by solid and diarrheal consistencies. Strongyles eggs and Trichuris suis have been detected exclusively in family farms. Ascaris suum eggs and Strongyloides ransomi showed low frequency. The high degree of parasitism, especially protozoa, indicates the need to reassess the management of pigs in both types of production.
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This Master’s Thesis studies performance management system and its benefits, risks and costs. Objective of the thesis is to describe and evaluate currently used supply chain performance management system (SCPMS) in a Finnish paper mill and its interfaces with its business unit’s SCPMS. As a result, the host company has improvement road map for improving its SCPMS. Used SCPMS in the host company and its interfaces to business unit’s SCPMS are described based on interviews held in the host company and the business unit. Evaluation of the host company’s SCPMS is based on literature study. For improvement road map, three areas in need of improvements are chosen. The study shows the need of high level top management commitment in successful performance management system implementation and usage, especially when the system is deployed to lower levels in the organization.
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Two field experiments were conducted in two successive seasons, 2005/2006 and 2006/2007, to determine whether management can improve faba bean competitiveness with weeds, thus helping to achieve its yield potential. The experiment included five treatments, composed of organic and mineral fertilizers, alone and mixed at different rates, along with a control and six weed control treatments, including oxadiargyl, prometryn, hand hoeing treatments alone or mixed with the herbicides, and a nonweeded treatment (control).The herbicide treatments were not superior to the two hand-hoeing treatments. Using compost favored growth and yield of faba bean more than of weeds. Adding fertilizer also improved most yield parameters. Application of compost alone or combined with 50 or 100% of the recommended NPK rate improved faba bean growth in terms of net assimilation rate, specific leaf area, and leaf weight ratio as components of relative growth rate. This improvement in growth resulted in increase of seed yield, yield components and protein of faba bean. Faba bean yield performance improved under interactive fertilizer effects and weed control treatments as growth improved, as a result of nutrient release from fertilizers and weed control.