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Search Results: 1 - 10 of 469668 matches for " Márcio Lopes da;Silva "
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Aplica??o da programa??o dinamica na substitui??o de povoamentos florestais
Silva, Márcio Lopes da;Silva, Rodrigo Firmino da;
Revista árvore , 2007, DOI: 10.1590/S0100-67622007000600011
Abstract: this work aims to develop and apply two models of dynamic programming to decide the best option of management of a forest stand along the planning horizon. the models aimed to maximize profit through a relation of recurrence concerning revenues and costs along the years and it was constructed based on a traditional model of replacement equipment. the results of both the models indicate that the best option for most situations is not to cut the young stands, followed by cutting and remodeling or cutting and lead to shooting for the older stands for all the training periods ( f1 through f7). the advantage of using dp, in this in case, is that this tool offers the planner a wider gamma of decision-making alternatives. it was concluded that for a company to maximize forest stand profits, without being concerned about planning horizon or regulated forest, it would have to opt for the traditionally known economic rotation. however, if the company wants to make decisions for a definite horizon planning and later sell the land and the forest, the alternatives are many. thus, the company can opt for cutting immediately or delaying the cut, perform the shootings or remodel. in this case, the dp model developed can present such alternatives and indicate the best options.
Discuss?o sobre os critérios de avalia??o econ?mica: valor presente líquido (VPL), valor anual equivalente (VAE) e valor esperado da terra
Silva, Márcio Lopes da;Fontes, Alessandro Albino;
Revista árvore , 2005, DOI: 10.1590/S0100-67622005000600012
Abstract: frequently, it has occurred doubts and confusion in the interpretation of criteria of economic evaluation in the forestry sector. the objective of this was to clarify and argue the main issues related to the net present value, equivalent annual value and soil expected value, as well as to compare them and demonstrate that there is a relation among them. therefore, a study of case of a project of investment in eucalyptus reforestation was used in order to compare the criteria. the results indicated that all the criteria were adjusted and could be applied, being enough to know well the difference among them and the correct form of their interpretation.
Estabelecimento de rota??o econ?mica para uma floresta regulada
Silva, Márcio Lopes da;Ribeiro, Carlos Antonio álvares Soares;
Revista árvore , 2006, DOI: 10.1590/S0100-67622006000100009
Abstract: the objective of this work was to determine the economic rotations for a forest stand taking into considereation only one harvest, infinite harvests and a regulated forest using mathematical models, as well as comparing them through the marginal analysis of optimality conditions. to validate the model and to verify the magnitude of the effect a study case of a forest project, with real values of production, costs, revenues and discounting rate, was used. the results indicated that the models were efficient to determine the economic rotation and that the rotation of the stand for one cut, infinite cuts and for the regulated forest were respectively 6.5, 5.5 and 5 years. the soil expectation value (sev) for the regulated forest was smaller than the sev of the stand due toimposed regulations on the forest management.
Estabelecimento de rota o econ mica para uma floresta regulada
Silva Márcio Lopes da,Ribeiro Carlos Antonio álvares Soares
Revista árvore , 2006,
Abstract: O objetivo deste trabalho foi determinar as rota es econ micas para um povoamento florestal, considerando-se um único corte e infinitos cortes, e para uma floresta regulada, por meio de modelos matemáticos, bem como compará-las através da análise marginal das condi es de otimalidade. Para validar o modelo e verificar a magnitude dos efeitos, foi utilizado um estudo de caso de um projeto florestal com valores reais de produ o, custos, receitas e taxa de desconto. Os resultados indicaram que os modelos foram eficientes para determinar a rota o econ mica e que a rota o do povoamento para um único corte e infinitos cortes e para a floresta regulada foi, respectivamente, de 6,5; 5,5; e 5 anos. O Valor Esperado do Solo (VES) para a floresta regulada foi inferior ao VES do povoamento, em virtude de se impor ao manejo a condi o de regula o.
Rentabilidade e risco de investimento na produ o de palmito de pupunha (Bactris gasipaes Kunth.)
Sidney Araujo Cordeiro,Márcio Lopes da Silva
CERNE , 2010,
Abstract: This study carried out an economic study and a risk simulation analysis in a palm heart of pejibaye (Bactris gasipaes Kunth.) cultivation project. Economic analysis was made by using the project evaluation methods: NPV, VAE, TIR and B/C; and the risk analysis was carried out through the Monte Carlo simulation technique by @RISK software. It was concluded that the project of palm heart of pejibaye cultivation is viable, with NPV of R$ 3.549,08; TIR of 19%; B/C greater than 1; the VAE of R$ 1.049,12. The risk analysis showed that the project presents a probability of 5% of getting a negative value for VPL. The variables which affected Net Present Value (NPV) according to the ranking of importance were: selling price, productivity and discount rate.
Análise do repasse do ICMS Ecológico aos municípios do estado de Minas Gerais
Marco Antonio Monte,Márcio Lopes da Silva
CERNE , 2009,
Abstract: In Minas Gerais State, Brazil, the districts covered with the Ecological ICMS must have in its territory Conservation Unit registered and,or, projects for the environmental sanitation and garbage treatment. This study aimed to examine and discuss the transfer of the Ecological ICMS to the districts of Minas Gerais State, in order to consolidate this criterion as instrument to support the environmental management. The data were obtained at Jo o Pinheiro Foundation in the period 2002 to 2007. In 2007, R$ 41.184.967 were allocated to the districts through Ecological ICMS. Ipatinga was the district with largest collection. The districts of Malacacheta, Marliéria and S o Jo o das Miss es got over 40% of their revenues through the Ecological ICMS. This shows the importance of this criterion for districts of less economical expression and possess significant area as Conservation Units. This criterion contributed to the decentralization of the ICMS and benefitted the districts that have environmental activities in its territory. New discussions are necessary in order to increase the percentage of ICMS driven to this criterion, as an incentive and compensation to the districts that have protected areas or adopt measures to sanitation.
Problemas com o uso de programa o linear com posterior arredondamento da solu o ótima, em regula o florestal
Silva Gilson Fernandes da,Leite Helio Garcia,Silva Márcio Lopes da,Rodrigues Flávio Lopes
Revista árvore , 2003,
Abstract: O principal objetivo deste trabalho foi avaliar, com a ajuda da Programa o Inteira, as conseqüências do uso da Programa o Linear com posterior arredondamento das respostas, com ênfase na regula o de florestas eqüianeas. Para isto, um problema de regula o florestal simplificado foi idealizado e resolvido pelo modelo I, por meio de Programa o Linear, Programa o Linear com posterior arredondamento e Programa o Inteira. Ao final, concluiu-se que o arredondamento das respostas obtidas pelo modelo resolvido por Programa o Linear levou a uma solu o inviável para o problema de regula o proposto. O mesmo n o ocorreu com o modelo de Programa o Inteira, que apresentou um plano de regula o factível e otimizado, mostrando que, do ponto de vista matemático, respostas com arredondamento da solu o de modelos de Programa o Linear n o devem ser adotadas.
Planta??es florestais e a prote??o de florestas nativas em unidades de manejo certificadas no Brasil
Alves, Ricardo Ribeiro;Jacovine, Laércio Ant?nio Gon?alves;Silva, Márcio Lopes da;
Revista árvore , 2011, DOI: 10.1590/S0100-67622011000500011
Abstract: forest certification has expanded in several states in brazil both in the form of forest plantations and native forests. the main objective of this study was to analyze the contribution that certification of forest plantations has in the protection of native forests in brazilian states through the systems fsc and cerflor. it was consulted the public summaries of certified forest management units in the brazilian states, both concerning the certification of forest plantations and native forests. it was searched information on the total certified area of forest management unit and for the forest plantations, the effective area of plantations, the area of forest protection and forest area assigned for other uses. the total area of certified native forest is 2.78 million hectares whereas the area of forest plantations is a little over four million hectares. areas protected in the state of bahia are the largest by cerflor (46.35%) and the second largest by fsc (40.67%), whereas the smallest areas assigned for this use are in the state of s?o paulo, with 23.33% by cerflor and 21.02% by the fsc. states in the amazon region assign a higher percentage of area for forest conservation. it is concluded that enterprises which have certification of forest plantations have an important role in forest conservation because since in many cases, those enterprises comply with a percentage much higher than that required by law. to choose one or other certification system does not influence the degree of demand with respect to the conservation of native species.
INFLUêNCIA DE ESTIMATIVAS DE PRODU O DE MADEIRA EM PROCESSOS DE REGULA O FLORESTAL UTILIZANDO PROGRAMA O LINEAR
Gilson Fernandes da Silva,Helio Garcia Leite,Carlos Pedro Boechat Soares,Márcio Lopes da Silva
Ciência Florestal , 2002,
Abstract: Este trabalho teve como principal objetivo avaliar as conseqüências do uso de estimativas de produ o oriundas de diferentes modelos de crescimento e produ o em um modelo de Programa o Linear aplicado à regula o florestal. Assim, utilizando dados de um inventário florestal contínuo, obtiveram-se diferentes estimativas da produ o futura em volume, pelo ajuste de um modelo de produ o em fun o da idade, outro em fun o da idade e do índice de local e por um terceiro modelo que incluiu, além da idade e do índice de local, a densidade, representada pela área basal por hectare. Testou-se também um modelo baseado nos dados de inventário florestal contínuo que utiliza os dados de volume de um período para fazer proje es lineares da produ o para o período seguinte. Em seguida, um problema de regula o florestal simplificado foi idealizado e resolvido pelo modelo I por meio de Programa o Linear, utilizando dados oriundos dos quatro modelos de predi o do volume. Ao final, concluiu-se: a) que modelos de regula o florestal, alimentados por estimativas provenientes de diferentes modelos de produ o, quando resolvidos por Programa o Linear, resultam em diferentes maneiras de se conduzir a floresta; b) que a matriz de coeficientes tecnológicos, alimentada por diferentes dados de produ o e para uma mesma fun o objetivo, afeta, de maneira significativa, o processo de tomada de decis o.
Análise da atividade florestal no município de Vi?osa-MG
Fontes, Alessandro Albino;Silva, Márcio Lopes da;Valverde, Sebasti?o Renato;Souza, Agostinho Lopes de;
Revista árvore , 2003, DOI: 10.1590/S0100-67622003000400012
Abstract: forest activity was studied in vi?osa-mg, through a questionnaire applied to farmers who planted forests. a total of 63 farms were sampled, comprising an area of 2,096.95 ha. the natural and planted forest areas sampled were of 372.00 ha and 260.17 ha, corresponding to 17.74% and 12.41%, respectively. the predominant natural forest was the secondary forest (capoeira) (67.55%), and the species chosen for reforestation was eucalypt (92.68%). average labor use in the phases of implementation, maintenance and harvest of the forest plantations was estimated at 30.21, 13.64 and 61.25 days-man/hectare, respectively, totalling 105.10 days-man/hectare, with family labor participation of 25.24%. forest activity costs (r$/ha) were estimated at r$419.30 for implementation; r$146.49 and r$80.34 for first and second year maintenance, respectively, and r$2.11/m3 for wood harvesting cost. the forest plantations are concentrated at the hillside areas and the average number of jobs generated by reforestation (eucalypt) was 0.042 jobs/hectare. it was concluded that, overall, reforestation was considered a rather unattractive activity, with typical forest properties remaining unidentified. thus, it is recommended the elaboration of public policies to encourage reforestation.
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