An Open Ended Tree

An open ended list is a well known data structure in Prolog programs. It is frequently used to represent a value changing over time, while this value is referred to from several places in the data structure of the application. A weak point in this technique is that the time complexity is linear in the number of updates to the value represented by the open ended list. In this programming pearl we present a variant of the open ended list, namely an open ended tree, with an update and access time complexity logarithmic in the number of updates to the value

Gender and the Value of Trees in Mutoko Communal Area, Zimbabwe

This study examined the gender based differences in valuation of trees, as indicated by differences between men and women in the planting, care and use of tree resources. An analysis of differences in tree related behaviours between male headed households and female headed households was also undertaken. The study used a combination of quantitative and qualitative methodologies, including an interview schedule and card sort, supplemented by open-ended interviews and observations. The survey data were analysed using SPSS Windows. The study results indicate that trees were being planted and cared for in both male and female headed households and the majority of heads of households preferred multipurpose, fruit bearing tree species. There were differences in the types of tasks undertaken by men and women in both male and female headed households, the locus of decision making authority in the two types of households, and the uses of tree resources by men and women.Labor and Human Capital,

Induced subgraphs of graphs with large chromatic number. XII. Distant stars

The Gyarfas-Sumner conjecture asserts that if H is a tree then every graph with bounded clique number and very large chromatic number contains H as an induced subgraph. This is still open, although it has been proved for a few simple families of trees, including trees of radius two, some special trees of radius three, and subdivided stars. These trees all have the property that their vertices of degree more than two are clustered quite closely together. In this paper, we prove the conjecture for two families of trees which do not have this restriction. As special cases, these families contain all double-ended brooms and two-legged caterpillars

Permittivity-Based Water Content Calibration Measurement in Wood-Based Cultural Heritage: A Preliminary Study

In this work, the dielectric permittivity of four kinds of wood (Fir, Poplar, Oak, and Beech Tree), used in Italian Artworks and structures, was characterized at different humidity levels. Measurements were carried out using three different probes connected to a bench vector network analyzer: a standard WR90 X-band waveguide, a WR430 waveguide, and an open-ended coaxial probe. In particular, we investigated the dispersion model for the four wood species, showing how a log-fit model of the open-ended data presents a determination coefficient R2 > 0.990 in the 1–12 GHz frequency range. This result has proven helpful to fill the frequency gap between the measurements obtained at different water contents with the two waveguide probes showing an R2 > 0.93. Furthermore, correlating the log-fit vertical shift with the water content, it was possible to find a calibration curve with a linear characteristic. These experimental results will be helpful for on-site non-invasive water monitoring of wooden artworks or structures. Moreover, the final results show how the open-ended coaxial probe, with a measurement deviation lower than 7% from the waveguide measurements, may be used directly as a non-invasive sensor for on-site measurements

The Experiences of women tree planters in Northern Ontario

This thesis is an examination of the experiences of women tree planters in northern Ontario. Using open-ended interviews and participant observation, I explore the ways female tree planters negotiate their femininity within a male dominated work force

Modelling contingent valuation iterated elicitation data with an MCMC approach

The valuation of non-market goods involves iterated elicitation questions which obtain more information from the sample respondents and lead to more efficient welfare estimates. In this paper we consider the improvements which could be obtained by utilising a Bayesian MCMC approach to model this type of data. A fully informative prior resulting from previous stages is compared with a flat non-informative prior utilising both simulated and empirical data. These priors are combined with data in each stage to form the posteriors which are simulated with Gibbs sampling algorithms. The models are applied to an elicitation tree involving two successive dichotomous choice questions followed by an open-ended question. Monte Carlo simulations show that taking into account the information process implicit in successive elicitation improves the performance of the results at each stage and increases efficiency. Thus, the model allows the researcher to consider the evolving process along the elicitation tree, while increasing useful information obtained from the individual.Bayesian methods, Contingent valuation, Gibbs sampling, Iterated Elicitation, National Parks.

Measurement of agarwood using magnetic induction mechanism

Aquilaria malaccensis (agarwood) in Malaysia is well known as “gaharu” and is a scented tree that produces fragrant resinous wood. Agarwood is a high-value wood that has extensive uses as perfumes, incense, and medicine. Due to its economic value and high demand from the industry, agarwood has been exposed to exploitation by agarwood hunters. The usual method of obtaining agarwood is cutting down the whole tree without examining the existence of agarwood. This may lead to natural treasure loss, money loss, and species extinction. To prevent these losses, a non-destructive method is desirable to replace the usual method. Magnetic induction mechanism is introduced as a non-destructive method to detect the formation of agarwood. This technique offers a great deal to visualise the distribution of electrical impedance. Developing the elemental magnetic circuit started with obtaining the dielectric properties via the open-ended coaxial probe method. The open-ended coaxial probe method had a limited frequency of between 200 MHz and 1 GHz. Therefore, the data underwent extrapolation for the target frequency of 10 MHz. These data were used to observe the agarwood reaction in a virtual simulation. Second, a virtual magnetic induction using COMSOL simulation was constructed, with 10 MHz frequency being used as the transmission frequency. There were two main observations conducted for this simulation, which were magnetic field and induced current. In COMSOL simulation, also observed were the parameters for designing the coils. Coil diameter and coil layers gave a great impact on the performance of the magnetic field and induced current. Lastly, an elemental transceiver circuit was designed. The peak-to�peak voltage was observed to see the voltage changes between the transmitter and the receiver. The magnetic induction circuit was successfully able to sense frequency changes. The voltage readings for the sample without agarwood were high (1.02 V– 1.30 V) compared with samples with agarwood formation, whose voltage readings were low (Sample A: 976 mV–1.20 V, Sample B: 940 mV–1.17 V, Sample C: 840m V–1.18 V)