Quantify and account for field reference errors in forest remote sensing studies

Field inventoried data are often used as references (ground truth) in forest remote sensing studies. However, the reference values are affected by various kinds of errors, which tend to make the reported accuracies of the remote sensing-based predictions worse than they are. The more accurate the remote sensing techniques are becoming, the more pronounced this problem will be. This paper addresses the impact of uncertainties in field reference data due to measurement errors, model errors, and position errors when evaluating the accuracy of biomass predictions from airborne laser scanning at plot level. We present novel theoretical analysis methods that take the interactions of the error sources into account. Further, an error characterization model (ECM) is used to describe the error structure of the remote sensing-based predictions, and we show how the parameters of the ECM can be adjusted when field references contain errors. We also show how root mean square error (RMSE) estimates can be adjusted. Based on data from Scandinavian forests, we conclude that the field reference errors have an impact on the remote sensing-based predictions. By accounting for these errors the RMSE of the remote sensing-based predictions was reduced by 6-18%. The most influential sources of error in the field references were found to be the residual errors of the allometric biomass model and the field plot position errors. Together, these two sources accounted for 97% of the variance while measurement errors and biomass model parameter uncertainties were negligible in our study

Här lades grunden till den arabiska våren

Mohamed Bouazizi lit himself on fire in December 2010 in Tunisia. That was the starting point for what would then be known as the Arabic Spring where public mass protests managed to oust the leaders of countries such as Tunisia, Egypt, Libya and Yemen. Protests arose in virtually all arabic states during the following months. In this essay it will not be the revolution itself in focus. Instead it will focus on how the civil society in Tunisia re-emerged after being heavily crippled by President Ben Ali and was politicized once again and made the revolution possible

Vattenlogistik vid stubbehandling i slutavverkning

Water logistics has long been a problem in order to effectively carry out stump treatment in both thinning and final felling. It is important that the stump treatment‐ equipment is configured as well as a sufficient amount of water is carried out on the harvester to get a cost‐ effective treatment. The flow control of the equipment has improved and water can be dispensed more efficient, but still the amount of water on the machine is a crucial factor in the total cost estimate. The knowledge of the tools available to bring water as well as the internal logistics of loading and transport to the felling site is deficient. Increased focus on "smart" solutions to manage water cost is of great importance in order to combat Hetrobasidion spp in both thinning and final felling. The purpose of the study is to describe and summarize different solutions of water logistics at stump treatment in final felling. Holmen Skog's goal is to find good ways and a possible equipment to get a cost‐ effective solution of water logistics. The two contractors Thörnwalls and MJN have developed their own ways to get an effective water logistics and their solutions will be studied in more detail. The results of the study show that the duration of Thörnwalls water logistics requires about 50 minutes per working day. The water Logistics of MJN requires about 20 minutes per working day. Both contractors have developed a water logistics with a few and effective moments. Thörnwalls has managed to develop a way to work that is free from physical handling of water, MJN have the same goal. To get an efficient water logistics requires primarily an approach based on procedures and division of responsibility. The equipment must be properly adjusted and all the physical lifting moments with water should be avoided to make logistics easy and efficient

Both deterioration and improvement in activities of daily living are related to falls: a 6-year follow-up of the general elderly population study Good Aging in Skåne.

To determine the relationship between long-term change in activities of daily living (ADL) and falls in the elderly and to identify characteristics of groups at risk for falls

Vitryssland och Litauen - tro och tvivel i två forna sovjetstater

1991 blev både Litauen och Vitryssland självständiga från Sovjetunionen. Därefter har ländernas demokratiska utveckling sett ut på diametralt olika sätt. I denna uppsats utreder vi hur det kunnat ske och vi gör det med ett fokus på civilsamhället i de olika länderna. Det litauiska civilsamhället byggdes upp redan under sovjettiden och strävade efter demokrati och självständighet medan någon sådan strävan knappt existerade i Vitryssland. Istället fick man i Vitrysland sin självständighet motvilligt till skänks och det fanns inget civilsamhälle redo att förvalta den och utveckla Vitryssland demokratiskt. Konsekvenserna av vad som skedde med länderna och deras respektive civilsamhällen före-, under- och efter sin självständighet ser vi 2015 då Litauen är med i såväl Nato, som EU och eurosamarbetet medan Vitrysslands president Lukasjenko omnämns som Europas siste diktator

Comparing TanDEM-X InSAR Forest Stand Volume Prediction Models Trained Using Field and ALS Data

Remote sensing (RS) techniques have been used for mapping forest variables, such as stem volume (important for forest management activities associated with timber production), over large areas which can be updated more frequently than with field inventory (FI) data. In this study, wall-to-wall TanDEM-X synthetic aperture radar images were used as auxiliary RS data for model-based prediction of stand-level volumes for two models, trained using volumes computed from FI (A) and airborne laser scanning estimations (B), respectively. The models were validated with harvester data available for independent stands. It was observed that the performance of model B was slightly better compared to model A based on adjusted R 2 and root mean squared error values. Therefore, it can be concluded that a completely RS based approach for prediction and mapping of stand volumes would be as promising as a method based on FI data along with being cost- and labour-efficient

Perceived home is associated with psychological well-being in a cohort aged 67–70 years

Research on very old people has shown that perceived aspects of home are important for health, but research on such associations in younger cohorts of older people is lacking. The aim of this study was to investigate whether perceived aspects of home were associated with psychological well-being among community-living people aged 67–70. Interview data were collected with 371 individuals living in ordinary housing in southern Sweden. Statistical analyses revealed that depression was less common among participants who reported cognitive-emotional and social bonding to the home, and among those who felt that they had control over their housing situation. The behavioral, social and physical aspects of meaning of home as well as external control beliefs were associated with psychological well-being. Showing that perceived aspects of home are relevant for psychological well-being among people aged 67–70, this study adds to the knowledge on home and health dynamics during the ageing process

Исследование влияния состава материала на основе эпоксиполиэфирной смолы на его свойства

Материалы XX Междунар. науч.-техн. конф. студентов, аспирантов и молодых ученых, Гомель, 23–24 апр. 2020 г