Most integer programming problems can be formulated in several ways. Some formulations are better suited for solution by exact methods, because they have either (i) a strong LP relaxation, (ii) few symmetries in the solution space, or both. However, solving one formulation, we can often branch and/or add cutting planes which are implicitly based on variables of other formulations, working in fa...

Fundamental particles, atoms, and ions combine in interesting ways to build the universe. SGML/XML has long been recognized as a means of representing hierarchical tree structures, but how can its methods be adapted to represent some of the other interesting structures, such as cyclic graphs, needed to represent the physical universe? Most prior efforts at DTD design have concentrated on either...

the investigation was conducted on wet and dry seasons of ethiopia during the year 2012/2013 at wondo genet agricultural research center nursery site. four levels of cutting size and three levels of cutting positions were arranged in randomized complete block design with three replications. data on seedling height, branch number/seedling, root number/seedling, root weigh/seedling, root length/s...

This study was conducted in Central Europe (Poland) pine forests that were subjected to the process of resin harvesting 1970s. Forty trees designated for study, which had one or two blazes. The objectives experiment determine effect tapping on changes annual growth, wood density, and mechanical strength damaged trees. Resin affected development dynamics, especially with a single blaze. In addit...

Commercial harvests can threaten tree species harvested for their bark. Amphipterygium adstringens is a dioecious tree, endemic to the tropical dry forests of Mexico, where it intensively its medicinal Limited information hinders developing sustainable management strategies A. adstringens. We assessed bark regeneration male and female trees, evaluated effect sex diameter, debarking treatments c...

Spruce budworm (Choristoneura fumiferana (Clem)) is the main defoliator in boreal forest of North America, and its outbreaks have major ecological economic consequences represent a challenge for management. Numerous studies addressed effects this on mature trees, whereas spruce regeneration remain elusive. Furthermore, intensive exploitation practices during last decades left large area Canadia...

We examined effects of mist quantity, topophysis (origin of cutting in the crown of 6-year-old trees), maturation state of the donor stock, and time of sticking on rooting and root system quality of cuttings representing five full-sib hybrid larch families obtained with Larix decidua Mill., L. laricina (du Roi) K. Koch, and L. kaempferi (Lamb.) Sarg. (Sieb. and Zucc.) Gord., as parents. Mist fr...

BACKGROUND Coppicing was one of the most important forest management systems in Europe documented in prehistory as well as in the Middle Ages. However, coppicing was gradually abandoned by the mid-20(th) century, which has altered the ecosystem structure, diversity and function of coppice woods. METHODOLOGY/PRINCIPAL FINDINGS Our aim was to disentangle factors shaping the historical growth dy...

This vignette shows the use of HCsnip package for extracting clusters from the Hierarchical Clustering (HC) tree in semi-supervised way. Rather than cutting the HC tree at a fixed highest (as existing methods do), it snips the tree at variable heights to extract hidden clusters. Cluster extraction process uses both the data matrix from which HC tree is derived and the available follow-up inform...

A new measurement concept for cut-to-length forest harvesters is presented in this paper. The cut-to-length method means that the trees are felled, delimbed and cut-to-length by the single-grip harvester before logs are transported to the roadside. The concept includes measurements done to standing trees before felling to calculate optimal length of logs. The modern forest harvesters use mechan...