Search results for "luu"
showing 10 items of 614 documents
A Survey on Technologies Which Make Bitcoin Greener or More Justified
2022
According to recent estimates, one bitcoin transaction consumes as much energy as 1.5 million Visa transactions. Why is bitcoin using so much energy? Most of the energy is used during the bitcoin mining process, which serves at least two significant purposes: a) distributing new cryptocurrency coins to the cryptoeconomy and b) securing the Bitcoin blockchain ledger. In reality, the comparison of bitcoin transactions to Visa transactions is not that simple. The amount of transactions in the Bitcoin network is not directly connected to the amount of bitcoin mining power nor the energy consumption of those mining devices; for example, it is possible to multiply the number of bitcoin transactio…
Bitcoinin historiallinen kehitys vuosina 2008-2018
2018
Kryptovaluutta Bitcoinista on kasvanut sen kymmenvuotisen historiansa aikana merkittävä vaihtoehtoisvaluutta, joka on saanut aikaan valtavan, globaalin ilmiön. Ihmiset, yritykset eivätkä yhteiskunnat kuitenkaan ymmärrä Bitcoinin historiaa, tarkoitusta saati teknologiaa, mikä johtaa monenlaisiin väärinkäsityksiin tästä virtuaalivaluutasta. Tässä kirjallisuuskatsauksena toteutetussa kandidaatintutkielmassa tarkasteltiin kryptovaluutta Bitcoinin historiallista kehitystä sen alkuvuodesta 2008 vuoteen 2018 asti. Historian tunteminen on tärkeää, kun pyritään ymmärtä-mään nykypäivää. Tutkielmassa pystyttiin käymään läpi Bitcoinin koko histo-ria aivan sen alkuvuosista asti, koska Bitcoinin ensiaske…
Regular Strength and Sprint Training Counteracts Bone Aging: a 10- year Follow-up in Male Masters Athletes
2021
According to cross-sectional and interventional studies, high-intensity strength and impact-type training provide a powerful osteogenic stimulus even in old age. Longitudinal evidence on the ability of high-intensity training to attenuate age-related bone deterioration is currently lacking, however. This follow-up study assessed the role of continued strength and sprint training on bone aging in 40- to 85-year-old male sprinters (n=69) with long-term training background. pQCT-derived bone structural, strength and densitometric parameters of the distal tibia (5% distal-proximal tibia length) and tibial midshaft (50% length) were assessed at baseline and after 10 years. The groups of well-tra…
IS evolution benefit assessment: Challenges with economic investment criteria
2007
Maintenance and system evolution activities have a significant role in the information system (IS) life cycle. It has been estimated that approximately 80% of the total IT expenses are allocated for maintenance activities [20]. According to Lehman’s first law, maintenance is necessary, because software needs to be continuously improved or it will get out of date and cannot respond to the requirements of its environment [19]. Despite the importance of IS evolution investments, there is a gap between the IT related costs and company profitability [27]. Brynjolfssen [10] described this as a productivity paradox: information technology utilization has increased since the 70’s but simultaneously…
Ecological and evolutionary consequences of selective interspecific information use
2023
Recent work has shown that animals frequently use social information from individuals of their own species as well as from other species; however, the ecological and evolutionary consequences of this social information use remain poorly understood. Additionally, information users may be selective in their social information use, deciding from whom and how to use information, but this has been overlooked in an interspecific context. In particular, the intentional decision to reject a behaviour observed via social information has received less attention, although recent work has indicated its presence in various taxa. Based on existing literature, we explore in which circumstances selective i…
The joint evolution of learning and dispersal maintains intraspecific diversity in metapopulations
2021
The evolution of dispersal tendencies and of cognitive abilities have both been intensely studied. Yet little attention has been given to the question of how these two aspects may relate to each other, as a result of their joint evolution. On the one hand, learning abilities may help dispersers to cope with their new habitat. On the other hand, dispersal may sometimes reduce the need for learning, because local environments may differ in how much there is to learn. To get a better understanding of this relationship, we built an individual‐based simulation in which both learning speed and dispersal tendency were free to evolve. We found that both positive and negative correlations could evol…
When is money not a currency? Developments from Finland of proto-community currencies
2020
The article is a case study of several digitally based schemes recently operating in Finland where some functions and properties of money are evident. While working effectively as designed, they do not fully meet the criteria of a well-functioning community currency. The schemes include: sysmä, a digitally based hyperlocal system of account introduced by the rural Sysmä municipality; Pisteet kotiin®, a housing association points system in the city of Tampere, copied from a working Dutch model; BookMooch, a global book-swapping site that has extended its operations throughout Finland. Explored in the article are the institutional enabling and inhibitory factors and implications for and from …
Images of the other in Finnish primary school geography books
2016
Jatkuvasti kansainvälistyvässä maailmassa, jossa kulttuurienvälisillä kohtaamisilla voi olla kauaskantoisiakin seurauksia, on tärkeää olla tietoinen taustalla vaikuttavista asenteista. Tässä tutkielmassa kartoitetaan kuvaa, joka suomalaisissa viidennen ja kuudennen luokan maantiedon oppikirjoissa annetaan ihmisistä Euroopan ulkopuolella. Tutkielma on tehty sisällönanalyysin keinoin. Selkeiden stereotyyppisten kuvien lisäksi pyritään löytämään myös piileviä, vähemmän selviä stereotypioita. Stereotypioiden lisäksi myös alueista, kansoista tai muista ihmisryhmistä annetut kokonaiskuvat ovat tutkimuksen kohteena. Analysoitujen oppikirjojen välillä oli merkittäviäkin eroja sekä sisällössä, että …
Effects of a progressive aquatic resistance exercise program on the biomechanical composition and morphology of cartilage in women with mild knee ost…
2013
Background. Symptoms associated with osteoarthritis of the knee result in decreased function, loss of working capacity and extensive social and medical costs. There is a need to investigate and develop effective interventions to minimise the impact of and even prevent the progression of osteoarthritis. Aquatic exercise has been shown to be effective at reducing the impact of osteoarthritis. The purpose of this article is to describe the rationale, design and intervention of a study investigating the effect of an aquatic resistance exercise intervention on cartilage in postmenopausal women with mild knee osteoarthritis. Methods. A minimum of 80 volunteers who meet the inclusion criteria will…
Data-Driven Evolutionary Optimization: An Overview and Case Studies
2019
Most evolutionary optimization algorithms assume that the evaluation of the objective and constraint functions is straightforward. In solving many real-world optimization problems, however, such objective functions may not exist, instead computationally expensive numerical simulations or costly physical experiments must be performed for fitness evaluations. In more extreme cases, only historical data are available for performing optimization and no new data can be generated during optimization. Solving evolutionary optimization problems driven by data collected in simulations, physical experiments, production processes, or daily life are termed data-driven evolutionary optimization. In this…