Search results for "varmuus"
showing 10 items of 78 documents
Comment on “A simple way to incorporate uncertainty and risk into forest harvest scheduling”
2017
In a recent research article, Robinson et al. (2016) described a method of estimating uncertainty of harvesting outcomes by analyzing the historical yield to the associated prediction for a large number of harvest operations. We agree with this analysis, and consider it a useful tool to integrate estimates of uncertainty into the optimization process. The authors attempt to manage the risk using two different methods, based on deterministic integer linear programming. The first method focused on maximizing the 10th quantile of the distribution of predicted volume subject to area constraint, while the second method focused on minimizing the variation of total quantity of volume harvested sub…
Guidelines for risk management in forest planning – what is risk and when is risk management useful?
2018
Managing forest resources occurs under various sources of uncertainty. Depending on the management problem, this uncertainty may have a substantial impact on the quality of the solution. As our knowledge on the sources and magnitude of uncertainty improves, integrating this knowledge into the development of management plans becomes increasingly useful, as additional information can improve the decision-making process. This adjustment requires a fundamental shift in how planning problems are viewed: instead of interpreting risk management as a technique needed only for addressing problems with natural hazards, risk management should be an integral part of most planning problems. Managing ri…
Data-Based Forest Management with Uncertainties and Multiple Objectives
2016
In this paper, we present an approach of employing multiobjective optimization to support decision making in forest management planning. The planning is based on data representing so-called stands, each consisting of homogeneous parts of the forest, and simulations of how the trees grow in the stands under different treatment options. Forest planning concerns future decisions to be made that include uncertainty. We employ as objective functions both the expected values of incomes and biodiversity as well as the value at risk for both of these objectives. In addition, we minimize the risk level for both the income value and the biodiversity value. There is a tradeoff between the expected val…
Epävarmuus, muutos ja ammatilliset jännitteet : suomalainen sosiaalityö 1990-luvulla sosiaalityöntekijöiden tulkinnoissa
2005
Hannu Piiroinen tarkasteli väitöskirjatyössään kahdessa suomalaisessa sosiaalialan ammattilehdessä (Sosiaaliturva ja Sosiaalityöntekijä) vuosina 1990 – 1997 julkaistujen sosiaalityöntekijöiden kirjoitusten kautta rakentuvaa kuvaa suomalaisesta sosiaalityöstä. Hän kiinnitti huomiota niihin tulkintatapoihin, joilla sosiaalityöntekijät tekevät ymmärrettäväksi sosiaalityöhön liittyviä epävarmuustekijöitä ja ammatillisia jännitteitä 1990-luvun Suomessa. Piiroinen osoittaa, että sosiaalityöntekijät tulkitsevat 1990-luvun laman ja yhteiskunnallis-kulttuurisen rakennemuutoksen saaneen aikaan epävarmuutta ja ammatillisia jännitteitä sosiaalityössä. Sosiaalityön epävarmuus liittyy laman mukanaan tuom…
Inattention and Uncertainty in the Predictive Brain
2021
Negative effects of inattention on task performance can be seen in many contexts of society and human behavior, such as traffic, work, and sports. In traffic, inattention is one of the most frequently cited causal factors in accidents. In order to identify inattention and mitigate its negative effects, there is a need for quantifying attentional demands of dynamic tasks, with a credible basis in cognitive modeling and neuroscience. Recent developments in cognitive science have led to theories of cognition suggesting that brains are an advanced prediction engine. The function of this prediction engine is to support perception and action by continuously matching incoming sensory input with to…
Stochastic analysis of the critical velocity of an axially moving cracked elastic plate
2014
In this study, a probabilistic analysis of the critical velocity for an axially moving cracked elastic and isotropic plate is presented. Axially moving materials are commonly used in modelling of manufacturing processes, like paper making and plastic forming. In such systems, the most serious threats to runnability are instability and material fracture, and finding the critical value of velocity is essential for efficiency. In this paper, a formula for the critical velocity is derived under constraints for the probabilities of instability and fracture. The significance of randomness in different model parameters is investigated for parameter ranges typical of paper material and paper machin…
Hitaan opiskelijan analyysi
2013
Tutkimuksen tarkoituksena oli tutkia luokanopettajaopiskelijan kokemusta opiskelusta ja ymmärtää opiskelussa koettuja jännitteitä. Niitä syntyi ympäristön odotusten ja oman kokemuksen välillä, kun opiskeluissa kesti suunniteltua pidempään. Opiskelun hitaus tuntuu ongelmalliselta, sillä yliopisto-opintoja on pyritty nopeuttamaan ja tehostamaan. Opiskelijoiden haluttaisiin valmistuvan nykyistä nopeammin. Hidas opiskelija määrittyy herkästi epäonnistujaksi, vaikka oma kokemus opiskelusta olisi toinen. Tutkimuksessa kuvattiin autoetnografisella otteella tutkijan omaa opiskelukokemusta. Tutkimusteksti muodostui aineiston ja analyysin vuoropuheluksi; kokemuksen näkyväksi tekeminen, analysointi ja…
LR-NIMBUS : an interactive algorithm for uncertain multiobjective optimization with lightly robust efficient solutions
2022
In this paper, we develop an interactive algorithm to support a decision maker to find a most preferred lightly robust efficient solution when solving uncertain multiobjective optimization problems. It extends the interactive NIMBUS method. The main idea underlying the designed algorithm, called LR-NIMBUS, is to ask the decision maker for a most acceptable (typical) scenario, find an efficient solution for this scenario satisfying the decision maker, and then apply the derived efficient solution to generate a lightly robust efficient solution. The preferences of the decision maker are incorporated through classifying the objective functions. A lightly robust efficient solution is generated …
Spatial trade-offs between ecological and economical sustainability in the boreal production forest
2022
Economically-oriented forestry aims to sustain timber harvest revenues, while ecologically-oriented management supplies suitable habitat for species using deadwood as primary habitat. As these objectives are conflicting, planning for economic and ecological sustainability involves compromise and trade-offs. We analyze the spatial trade-offs between the economic value from timber harvesting and the volume of deadwood in the boreal forest. We assess these trade-offs from three perspectives: (1) landscape characteristics, affected by conservation strategies; (2) forest management promoting either economic or ecological values; (3) uncertainty in inventory errors undermining the estimate of the…
Amidst Uncertainty–or Not? : Decision-Making in Early-Stage Software Startups
2019
It is commonly claimed that the initial stages of any startup business are dominated by continuous, extended uncertainty, in an environment that has even been described as chaotic. Consequently, decisions are made in uncertain circumstances, so making the right decision is crucial to successful business. However, little currently exists in the way of empirical studies into this supposed uncertainty. In this paper, we study decision-making in early-stage software startups by means of a single, in-depth case study. Based on our data, we argue that software startups do not work in a chaotic environment, nor are they characterized by unique uncertainty unlike that experienced by other firms. pe…