Several nonlinear, individual tree crown height increment equations were tested for their ability to predict annual crown height increment in loblolly pine plantations. The selected model contained tree height (HT), tree crown ratio (CR) raised to the one-half power, age (A), and a competition index (CI) for the distance-dependent model and the ratio of quadratic mean diameter to tree dbh (DR) for the distance-independent model. The distance-dependent and the distance-independent models were the same form, except for the expression for competition. Hypothesis tests revealed that thinning, both its intensity and the elapsed time since its occurrence, had a significant effect on crown height increment. A thinning variable, THIN1, which accounted for thinning intensity and the interval since thinning, was developed and incorporated into the final individual tree increment models. Predictions of crown height increment were improved using models with the THIN1 variable as compared to those with no thinning allowance. In another approach, existing crown height equation was modified to account for the effect of thinning on crown recession. Another thinning variable, THIN2, similar to THIN1, was added to the crown height model. This model yielded better results than its counterpart with no thinning variable; however, the improvement was not as great as for the increment models. The individual tree increment models were also used to form a stand level crown height increment model. The independent variables were collapsed to stand-level statistics; the final model contained average height of dominants and codominants (HD), average crown ratio (R), age (A), and the THIN1 variable. Unlike the individual tree models, raising the average crown ratio to .5 did not improve the fit; however, including THIN1 did improve the results. From this study it was concluded that better data, a standard definition of height to the live crown, and other crown variables, such as crown diameter, will be required to produce more refined individual tree crown height increment models. / Master of Science

Noncontingent reinforcement (NCR) is a possible alternative to differential reinforcement of other behaviors (DRO) that may operate through a similar mechanism. In the research, the participant's problem behaviors were maintained by automatic reinforcement or even multiply maintained. NCR is the method to intervene with the participant who had no clinical effect on using sensory integration therapy (SIT) to reduce problem behaviors in the previous study. The results showed that NCR is an effective way to decrease the problem behaviors without extinction burst.

An appropriate accounting for thinning effects on growth rate and wood quality requires a clear understanding and quantification of these effects. In this regard, four basic interrelated issues were addressed in this study: 1) thinning effects on ring specific gravity 2) thinning effects on ring width distribution 3) thinning effects on stem form, and 4) prediction models for these quantities. The study showed that thinning does not significantly affect ring specific gravity, whereas its effects on ring width distribution and stem form were significant. Thinning increases ring width significantly over most of the tree bole and increases the earlywood and latewood components proportionally maintaining an approximately constant latewood proportion. As a consequence, thinning effects on latewood proportion is not significant; confirming the results obtained in the specific gravity study and further dispelling the concern that thinning may substantially reduce wood specific gravity. Thinning affects stem form by increasing the form exponent especially near the tree base accentuating the neiloid form expected in that area. High up in the stem, the form exponent changes little within a tree and among thinning treatments, with a general tendency towards a paraboloid shape. Differences due to thinning intensities, in general, were not significant indicating the applicability of results within a wide range of densities. Prediction models for ring specific gravity, ring width, latewood proportion and stem profile based on ring, tree, stand and site factors were developed Influences of stand level factors, density measures in particular, in prediction models are minor probably because tree level factors such as, stem diameter at breast height, crown ratio, etc. themselves manifest stand conditions. The mixed-effects analysis technique was used in data analysis to account for correlation among observations from the same subject. Direct covariance modeling yielded better fits than accounting for correlation indirectly using random effects covariates in many cases; however, both could not be accommodated simultaneously. Structures which assume decreasing correlation with increasing distance between observations, such as the first-order autoregressive structure, performed better than alternative specifications. Results consistently showed that accounting for correlation among observations substantially improves the fits over ignoring correlation; effectively addressing the issue of bias in the standard errors of estimates. / Ph. D.

Vid avverkning av virke vid gallring börjat handla om två maskintyper stickvägs- och beståndsgående skördare för att utföra gallring. Studiens syfte var att se om det fanns någon skillnad i antalet kvarvarande stammar efter gallring mellan de olika maskintyperna. För att komma fram till om det fanns någon skillnad mellan maskintyperna användes cirkelprovytor 5,64 m för att räkna stammar. Resultatet visade på skillnader i antal stammar per ha och också på en skillnad i grundyta. Beståndsgående skördare skapar förutsättningar för stabilare bestånd då inte breda stickvägar tas upp. / In thinnings two types of machines, strip road and stand-thinning machines are used. The study's purpose was to see if there was any difference in the number of stems per ha after thinning with the various machine types. To find out whether there was any difference between the types of machines circular plots were used, 5,64 m, to count the stem number and basal area. The results showed differences in the number of stems per ha and also showed a difference in basal area. Stand-thinning machines creates conditions for stable stands since wide strip roads doesn`t occur.

Extensive air showers’ (EAS) observables sensible to primary cosmic ray mass are a valuable asset in constraining competing astrophysical and particle physics scenarios proposed both to explaining cosmic rays features, such as their all-particle spectra, as well as their origin. These observables, however, need to be interpreted by comparison to EAS simulations, which are a source of great uncertainty. Shower simulations need to rely on a technique called thinning, an algorithm created to reduce computing time and storage requirement. In this work, we evaluate the effects of thinning over the muon production profile of an EAS simulation. For heavier particles it appears that thinned showers generate profiles with a deeper maximum, while results were not conclusive for protons and photon primaries. We investigate the thinning technique by constructing a toy model for shower simulations in which we have full control of the thinning implementation. To that end, we parameterized the energy distribution and particle production multiplicity from proton-air interactions and proton-pion interactions. However, we find that thinning effects over our model were too severe, rendering it impossible to draw further conclusions about its effects on full air showers simulations. / Observáveis sensíveis à composição de raios cósmicos primários em chuveiros atmosféricos extensos são um recurso valioso na constrição de cenários competidores em astrofísica e física de partículas, propostos tanto para explicar características dos raios cósmicos, como o espectro de energia de todas as partículas, quanto sua origem. Estes observáveis, no entanto, precisam ser interpretados por comparação a simulações de chuveiros atmosféricos, que constituem fonte de grandes incertezas. Simulações de chuveiros são dependentes de uma técnica chamada thinning, um algoritmo criado para reduzir o tempo de computação e exigências de armazenamento. Neste trabalho, nós avaliamos os efeitos do thinning sobre o perfil de produção de múons em uma simulação de chuveiro atmosférico. Para partículas mais pesadas, aparentemente, chuveiros sujeitos ao thinning geram perfis com máximos mais profundos, e para prótons e fótons nossas análises foram inconclusivas. Nós investigamos a técnica do thinning construindo um simulador de chuveiros simplificado, em que o total controle sobre a implementação do thinning é garantido. Para este fim, parametrizamos a distribuição de energia e a multiplicidade de partículas em interações de próton com o ar e de píons com o ar. Entretanto, descobrimos que o efeito do thinning sobre o nosso modelo era muito severo, tornando impossível concluir seus efeitos sobre simulações completas.

Extensive air showers’ (EAS) observables sensible to primary cosmic ray mass are a valuable asset in constraining competing astrophysical and particle physics scenarios proposed both to explaining cosmic rays features, such as their all-particle spectra, as well as their origin. These observables, however, need to be interpreted by comparison to EAS simulations, which are a source of great uncertainty. Shower simulations need to rely on a technique called thinning, an algorithm created to reduce computing time and storage requirement. In this work, we evaluate the effects of thinning over the muon production profile of an EAS simulation. For heavier particles it appears that thinned showers generate profiles with a deeper maximum, while results were not conclusive for protons and photon primaries. We investigate the thinning technique by constructing a toy model for shower simulations in which we have full control of the thinning implementation. To that end, we parameterized the energy distribution and particle production multiplicity from proton-air interactions and proton-pion interactions. However, we find that thinning effects over our model were too severe, rendering it impossible to draw further conclusions about its effects on full air showers simulations. / Observáveis sensíveis à composição de raios cósmicos primários em chuveiros atmosféricos extensos são um recurso valioso na constrição de cenários competidores em astrofísica e física de partículas, propostos tanto para explicar características dos raios cósmicos, como o espectro de energia de todas as partículas, quanto sua origem. Estes observáveis, no entanto, precisam ser interpretados por comparação a simulações de chuveiros atmosféricos, que constituem fonte de grandes incertezas. Simulações de chuveiros são dependentes de uma técnica chamada thinning, um algoritmo criado para reduzir o tempo de computação e exigências de armazenamento. Neste trabalho, nós avaliamos os efeitos do thinning sobre o perfil de produção de múons em uma simulação de chuveiro atmosférico. Para partículas mais pesadas, aparentemente, chuveiros sujeitos ao thinning geram perfis com máximos mais profundos, e para prótons e fótons nossas análises foram inconclusivas. Nós investigamos a técnica do thinning construindo um simulador de chuveiros simplificado, em que o total controle sobre a implementação do thinning é garantido. Para este fim, parametrizamos a distribuição de energia e a multiplicidade de partículas em interações de próton com o ar e de píons com o ar. Entretanto, descobrimos que o efeito do thinning sobre o nosso modelo era muito severo, tornando impossível concluir seus efeitos sobre simulações completas.

<p>Den här uppsatsen grundar sig på två fältstudier i nyutlagda demonstrationsförsök på Asa försökspark som ska användas i utbildningssyfte. Studie 1 bestod av försöksytor i ett 13 år gammalt bestånd som röjts till samma röjningsförband men med tre skilda metoder; motormanuell selektiv röjning, maskinell stråkröjning och som en kombination av bägge metoderna. Syftet var att beskriva det nuvarande tillståndet, simulera fram prognoser för beståndsutvecklingen och beräkna dess ekonomiska konsekvenser fram till och med första gallring och jämföra de olika metoderna med varandra. Studie 2 bestod av försöksytor i ett 23 år gammalt eftersatt bestånd där fyra olika åtgärder testades; ingen röjning innan gallring, underröjning i samband med gallring, sen röjning och skogsbränsleuttag. Syftet var även här att jämföra de olika metoderna med varandra genom beskrivning av det nuvarande tillståndet, göra prognoser för beståndsutvecklingen och beräkna dess ekonomiska konsekvenser vid första gallring och i den här studien även fram till och med den andra gallringen. De två nya metoderna, stråkröjningsmetoderna i studie 1 och skogsbränsleuttag i studie 2, hade stor potential gentemot de konventionella metoderna.</p> / <p>This thesis is based on two field studies in a recently started demonstration experiment by the Asa Experimental Forest, where it will be used for educational purposes. Study 1 consisted of experimental plots in a 13 years old stand which have been pre-commercial thinned to the same number of tree stems but with three different methods: motor-manual selective pre-commercial thinning by brush saw, mechanical pre-commercial line thinning and as a combination of the both methods. The purpose was to describe the present status, run simulations and produce forecasts for the development of the stand and calculate the economical aspects up to and including the first thinning and then compare the different methods with each other. Study 2 consists of experimental plots in a 23 years old stand with a pre-commercial thinning backlog, where four different treatments were tested; no pre-commercial thinning at all before the first thinning, low pre-commercial thinning in connection with the first thinning, late pre-commercial thinning and extraction of wood fuel. The purpose was also here to compare the different methods with each other through describing the present status, run simulations and produce forecasts for the development of the stand and calculate the economical aspects at the first thinning and in this study also up to and including the second thinning. The two new methods, mechanical pre-commercial line thinning in study 1 and wood fuel extraction in study 2, showed a great potential in comparison with the conventional methods.</p>

Den här uppsatsen grundar sig på två fältstudier i nyutlagda demonstrationsförsök på Asa försökspark som ska användas i utbildningssyfte. Studie 1 bestod av försöksytor i ett 13 år gammalt bestånd som röjts till samma röjningsförband men med tre skilda metoder; motormanuell selektiv röjning, maskinell stråkröjning och som en kombination av bägge metoderna. Syftet var att beskriva det nuvarande tillståndet, simulera fram prognoser för beståndsutvecklingen och beräkna dess ekonomiska konsekvenser fram till och med första gallring och jämföra de olika metoderna med varandra. Studie 2 bestod av försöksytor i ett 23 år gammalt eftersatt bestånd där fyra olika åtgärder testades; ingen röjning innan gallring, underröjning i samband med gallring, sen röjning och skogsbränsleuttag. Syftet var även här att jämföra de olika metoderna med varandra genom beskrivning av det nuvarande tillståndet, göra prognoser för beståndsutvecklingen och beräkna dess ekonomiska konsekvenser vid första gallring och i den här studien även fram till och med den andra gallringen. De två nya metoderna, stråkröjningsmetoderna i studie 1 och skogsbränsleuttag i studie 2, hade stor potential gentemot de konventionella metoderna. / This thesis is based on two field studies in a recently started demonstration experiment by the Asa Experimental Forest, where it will be used for educational purposes. Study 1 consisted of experimental plots in a 13 years old stand which have been pre-commercial thinned to the same number of tree stems but with three different methods: motor-manual selective pre-commercial thinning by brush saw, mechanical pre-commercial line thinning and as a combination of the both methods. The purpose was to describe the present status, run simulations and produce forecasts for the development of the stand and calculate the economical aspects up to and including the first thinning and then compare the different methods with each other. Study 2 consists of experimental plots in a 23 years old stand with a pre-commercial thinning backlog, where four different treatments were tested; no pre-commercial thinning at all before the first thinning, low pre-commercial thinning in connection with the first thinning, late pre-commercial thinning and extraction of wood fuel. The purpose was also here to compare the different methods with each other through describing the present status, run simulations and produce forecasts for the development of the stand and calculate the economical aspects at the first thinning and in this study also up to and including the second thinning. The two new methods, mechanical pre-commercial line thinning in study 1 and wood fuel extraction in study 2, showed a great potential in comparison with the conventional methods.

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