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1010 Uppsatser om Random Forest - Sida 15 av 68

Introduktion av buskskikt i ungskogar

Young stands in urban forests often lack a shrub layer, though shrubs play an important structural and biological role in forests. All layers interact with one another to form a multilayered stand, in which shrubs have a vital role.In this diploma thesis, theoretical models for forest dynamics are compared with four reference stands to detect factors, and principals for introduction of shrubs in young stands. In these stands four different ways of introduction were found. In one trees and shrubs were planted together at the same time. Shrubs spontaneous spread under a canopy of mature forest, in another.

Tillvaratagande av GROT i skärgårdsnära miljö :

The main aim of this study was to investigate and compare different methods for the extraction of forest fuel from environments close to an archipelago. The study was based on relevant literature and published reports as well as personal communications. Forestry has traditionally been characterized by intense efforts to rationalize and mechanize the cutting technique used for timber and pulpwood. In line with the increasing importance of forestry, more concentrated efforts can be expected in the area of techniques and methods, especially for the above-mentioned product lines. In Sweden, forestry is of major importance and the Swedish economy and standard of living have mainly been created based on the revenues generated from it. Thus, it is vital that Swedish forests are harvested in an efficient and responsible manner. The demand for biofuel is growing and today accounts for 15% of total Swedish energy production, a share that will probably increase. This study is based on three research questions, which are described under the heading of Aim. The results reveal that the most profitable method for handling forest fuel is the traditional one, which is also the most commonly used method in southern Sweden, namely the stockpiling of logs in a clearing by means of forwarders followed by splintering at the place from where they will be distributed. Today, the high cost of barge transport required for the extraction of forest fuel in an archipelago environment renders such operations unprofitable.

Nyheternas födelse : En kvantitativ undersökning av källor till lokala nyheter i lokaltidningar

The purpose of this thesis was to study the origin of the local news in local newspapers. Do the news originate mostly from the police, the municipality, from press releases or from the reporters own ideas? We also wanted to find out what kind of content predominated in texts with its origin in press releases respectively the reporters own ideas. Of course we also wanted to find out if there were any similarities or differences between the two studied newspapers.We used a type of constructed week, but with non random selection instead of random. We chose one of each weekday the newspapers were published and studied the news covered in the papers that specific day.

Kovariansskattningar vid portföljval - Utvärdering av fyra alternativa metoder för att skatta kovariansen

I denna uppsats beskrivs och implementeras tre alternativa metoder för att skatta kovariansen mellan finansiella tillgångar. De utvärderas sinsemellan och jämförs med stickprovskovariansen. Utvärderingsmodellen innebär simulering av en aktiv portföljförvaltare i en verklighetstrogen miljö. Då kovariansen mellan finansiella tillgångar beräknas med stickprovsskattning blir skattningsfelet stort. Detta fel, eller brus, försämrar portföljförvaltares resultat och alternativa metoder eftersöks.

Utvärdering av svensk vindkraft : Skillnaden mellan skogs- och traditionella placeringar

During the last years commercial Wind Power Turbines (WPT) has become larger regardingto the generator sizes and hub heights. Available hub heights around 100 meters is nowcommon, which has led to profitability for WPT located in forests where there normally are tolow wind speeds. The current knowledgement regarding turbulence and the variation in thewind profile for the outcome of the power production for the WPT in forests is limited.In this Master of Science thesis an investigation concerning forest located wind power plantshas been made. The purpose has been to investigate if plants located in forest perform lesscompared to wind power turbines located at more common locations.The analyses are based on statically material for determining the availability,production/generator size, production/hub height, production/swept area and how thetopography affect the production results.The analyses show that the variation in production result for WPT located in forest comparedto turbines located at other locations is small. The availability is high and the productionresults are good..

Omfattningen av icke avverkade områdeni samband med slutavverkning :

This final thesis is performed on commission of Torsby forestry administration, Stora Enso Skog. Stora Enso Skog is one of the major forestry companies of Sweden. The main business area is located in and around the region of Bergslagen. During the last decade the practice of forest management has rapidly changed due to a new forest legislation. The new law has resulted in that the production goal is equal to the environmental goal within forestry.

Gestaltningsförslag för Bölekläppen : utveckling av upplevelsevärden i ett friluftsområde i Umeå stads utkant

Taking a qualitative approach, this research investigates different theories and methods for creating parks that people will cherish and visit during their daily life. It also takes on the task to understand how principles of developing recreational values in a small forest is affected by the addition of a new element to the landscape, i.e. a major highway. Data was collected through the combination of focused literature review and study trips. This provided a framework which in turn was applied to the subject of the study, i.e.

Svamparnas roller i svenska barrskogsekosystem : hur ser kunskapsläget ut hos några olika grupper människor?

Fungi are everywhere around us and recently, there has been an increased interest in their role and importance in the forest. The fungi have several strategies to acquire energy and nutrition; one example is a mutual symbiosis with trees and plants - another being dissolving organic materials. Attempts have been made to better understand the circulation of nutrition in coniferous forests, and how fungi cooperate. Trees and plants have adapted with mycorrhizae and are now interdependent which is important to consider in forestry. A great number of fungi depend on dead wood and old trees to set fruiting bodies and spread further. These fungi also create environments for other species, such as birds and insects. The vegetation of a forest is determined by a series of factors; tree species, how old the forest is, soil type, as well as the ability of the fungal spores to spread and establish. Furthermore, in determining vegetation, the fungi?s ability to compete in the soil matters. These factors are nearly unexplored. Researching fungi knowledge and interest, a survey was distributed to five groups of people. The groups included forest owners, high school teachers, high school students, senior citizens, and a fifth group - ?o he ? - consisting of people of mixed ages and backgrounds.

En jämförelse avseende beståndsgående-och stickvägsgående gallringsmaskiner

The purpose of this report is to investigate and compare the difference between stand-thinning machines and strip-road thinning machines, and how they affect the stand on behalf of future growth, theoretical economic result, wind impact, snow pressure and density of stand. The investigation is regarding the first commercial thinning of pine stands, after pre-commercial thinning that was well conducted. The investigation area was located near Katrineholm, Sweden. The measurements that were measured were strength of thinning and amounts of wind throws, snow-breaks and hauling damages. The results that emerged, was that thinning with strip-road machines had a significantly higher strength of thinning over all, as compared with the stand- thinning machines (45 percent versus 30 percent). Comparisons between wind-throws, snow-breaks and hauling damages of the stand could not establish any significant differences between the two methods that were investigated. Conclusions, over all, were that if forest owners want to have more timber volume left for second thinning and final cut of the stand, the forest owners should choose the method with stand-thinning machines. From the point of view of gentle treatment of the stand and ground damages the choice should be the same. However, the method with strip-road thinning machines is the most common and accessible method in Sweden. Most likely it is the most economical way to manage the stand for forest owners in present time. If the method with stand-thinning machines is becoming more common in Sweden, it is suggested for forest owners to consider the stand-thinning method as a candidate for treatment due to economic aspects..

Habitat use and ranging behaviour of GPS tracked juvenile golden eagles (Aquila chrysaetos)

Throughout its wide distribution in the northern hemisphere, the golden eagle occurs in a diverse range of environments, e.g., mountainous, forest and open areas. The literature on juvenile golden eagles is limited, and this study provides further knowledge on habitat use and ranging behaviour during the post-fledging period in boreal Sweden. A total of 14 golden eagle juveniles were tagged with GPS transmitters during 2010 and 2011, and nine could be followed during the entire post-fledging period from fledging until migration. The juveniles fledged at the end of July and beginning of August and initiated migration during October and beginning of November. The length of the post-fledging period, until migration started, ranged from 49 to 97 days. During this period, the juveniles? distance from their natal nest and their GPS height increased with time as their flying abilities developed.

FSC certifiering vid BioEnergi i Luleå AB: livskraftigt bruk
av världens skogar

Bakgrunden till detta arbete är att Bioenergi i Luleå AB måste tillmötesgå kundkraven för att behålla sina marknadsandelar och ha möjlighet att utöka dessa. På senare tid har de stora kunderna börjat efterfråga bränslepellets som är certifierad enligt Forest Stewardship Council, FSC. Examensarbetets syfte var att hjälpa Bioenergi med framtagandet av en Forest Stewardship Council Chain of Custody certification. I den inledande kartläggningen användes i huvudsak intervjuer och observationer för att studera de anställda och tillverkningen. För att identifiera aktiviteter och brister i Bioenergis system studerades även interndokumentation och relevant litteratur.

Service Level Management : Equalize unloadingencrustation at Stora Enso ? Skoghalls bruk

The report is part of the university´engineer program within Industrial Organization and Economics with specialization in Logistics and Managment at Jönköping´s university.Skoghall´s mill underlies a large supply chain, which means there should be a lot of areas in need of small improvement measures. This report illustrates a small part of one of these areas and is focused on the loading distribution services in the terminal Vänern.At the moment there´s a very unequal load of the load carriers SECU box and Container at the terminal. Skoghall´s mill has the desire to equalize the high and low load levels of the 2 loading carriers named previously. One of the options to solve the problem is to set a limit of how much the carriers can load per week or per day. The mill also wants it to be investigated if the proposition would influence the customers in any way and if both the company and its customers could handle a lower level of delivery services in case the proposition was to be applied.The goal to be achieved with this thesis is to provide balance to the unequall loading of the 2 load carriers, SECU and Container, and investigate whether or not the Skoghall´s mill´s customers, could manage the lower degree of delivery service that the proposition would imply.For this goal to be achieved, random sample investigations were taken from orders of a customer that is provided with SECU load carriers and the same was made with a Container´s customer.

Vederlagsgrundande mätning med skördare

This study was performed in collaboration with Moelven Skog AB, Örebro district. The purpose of the study was to review existing literature in order to describe the current status of harvester based measurement technology as the way to provide information for calculating payment to the forest owners. In addition to this, a short survey was conducted to find out how a switch to harvester based measurement would affect the administrative workload on timber purchasers working for the district. The literature study shows that the harvester measurement technology is ready to use if it is combined with well-established routines for control of the harvesters, methods for automatic quality indexing of the timber and ways of creating pricelists specially adapted for harvester measurement. Pricing each stem seems to be the most promising method. Stem pricing has several benefits.

Följdeffekter av olika användningssätt för vedråvara : en ekonomisk studie

Since the turn of the millennium a sharp increase in the interest for bio energy has been observed. Important reasons for this growing interest can be due to the fact that fossil fuels are a finite resource. A net discharge of greenhouse gases occur when fossil fuels are burned. The discharge of greenhouse gases are considered to be the main reason to the greenhouse effect. Means of control to increase the use of bio energy has been introduced and, as intended, the use of bio energy has increased. As a result of the legal provisions the ability to pay for bio energy has increased, which the forest industry view as a problem.

Tätortsnära skogsbruksplan i Borås stad

This report is part of an Bachelor of Science work in forestry, conducted for the community of Borås, Sweden. In order to create a forest management plan for the area of Hestra, a survey was conducted. People living in the area were given the opportunity to reply to the survey. The questions in the survey are both personal and forestry-related. The aim is to reach out to the different categories of people when it comes to age, living and the different aspects of visiting the woods.

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