This thesis focuses on the mining of cryptocurrency with emphasis on analysis of communication between miner and server. It describes basic principles of cryptocurrencies, mining and employed communication protocols. The next part of thesis is about design and implement modification of existing system (catalogue). This modification will add temporality to the catalog, what increase reliability of stored metadata. Description, functionality and purpose of existing system is included in the next text.

Commonly, the day-ahead and intraday market on the electricity exchange are treated separately in academia. However, a model that forecasts the direction of the price spread between these two markets creates an opportunity for a market participant to leverage the price spread. In the neighbouring domain, electricity price forecasting, deep learning has proven to excel. Therefore, it is hypothesised that it will do so in directional price spread forecasting as well. A quantitative case study was performed to investigate how accurately a deep learning approach could be in directional electricity price spread forecasting. The case study was conducted on the Nordic electricity exchange Nord Pool in the SE3 region. The deep learning approach was compared with previously suggested machine learning models and a naive heuristic. The results show no statistical difference in error rate between the deep learning model and the machine learning model or naive heuristic. The results suggest that deep learning might not be a suitable approach to the task or that the implementation did not fully exhaust the potential of deep learning. / Vanligtvis behandlas marknaden för day-ahead och intraday på elbörsen separat i den akademiska litteraturen. En modell som prognostiserar riktningen för prisskillnaden mellan dessa två marknader skapar dock en möjlighet för en marknadsaktör att utnyttja prisskillnaden. I grannområdet elprisprognoser har djupinlärning visat sig överträffa andra typer av modeller. Därför antas det att djupinlärning även kommer göra det i riktade prisskillnadsprognoser. En kvantitativ fallstudie utfördes för att undersöka hur precis en djupinlärningsmetod kan vara i prognos för riktad elprisskillnad. Fallstudien genomfördes på den nordiska elbörsen Nord Pool i SE3-regionen. Djupinlärningsmetoden jämfördes med tidigare föreslagna maskininlärningsmodeller och en naiv heuristik. Resultaten visar ingen statistisk skillnad i fel-andel mellan djupinlärningsmodellen och maskininlärningsmodellen eller naiv heuristik. Resultaten antyder att djupinlärning kanske inte är ett lämpligt tillvägagångssätt för uppgiften eller att implementeringen inte helt utnyttjar potentialen för djupinlärning.

To enhance test security of high stakes tests, it is vital to understand the way various exposure control strategies function under various IRT models. To that end the present dissertation focused on the performance of several exposure control strategies under the generalized partial credit model with an item pool of 100 and 200 items. These procedures are relatively easy to implement and have shown promise as an alternative to more complex exposure control strategies. Through unique algorithms these procedures select an item for administration from a subset of items in the item pool. The five procedures examined for efficacy were the modified within .10 logits, restricted modified within .10 logits, randomesque, restricted randomesque, and progressive restricted procedures. The modified within .10 logits, restricted modified within .10 logits, and randomesque, and restricted randomesque procedures select an item for administration from a subset of optimal items. To test the effect of the number of items available for selection in this subset, 3, 6, and 9 items were made available for selection in these procedures. Maximum information item selection was used as a base line, no exposure control, condition. The progressive restricted, restricted randomesque, and restricted modified within .10 logits procedures were found to optimally protect test security while not significantly degrading measurement precision. The restricted forms of the randomesque and modified within .10 logits procedures proved superior to their base procedures, particularly in controlling average maximum exposure rate. The incrementation of item group size in the modified within .10 logits, restricted modified within .10 logits, and randomesque, and restricted randomesque procedures demonstrated that increasing the item group size provided better test security while not significantly degrading measurement precision. Additionally, in general, the increase of the item pool size from 100 to 200 improved measurement precision and test security. Implications towards practical application are discussed and directions for future research are suggested. / text

Platelet exocytosis is essential for hemostasis and for many of its sequelae. Platelets release numerous bioactive molecules stored in their granules enabling them to exert a wide range of effects on the vascular microenvironment. Are these granule cargo released thematically in a context-specific pattern or via a stochastic, kinetically-controlled process? My work describes platelet exocytosis using a systematic examination of platelet secretion kinetics. Platelets were stimulated for increasing times with different agonists (i.e. thrombin, PAR1-agonist, PAR4-agonist, and convulxin) and micro-ELISA arrays were used to quantify the release of 28 distinct α-granule cargo molecules. Agonist potency directly correlated with the speed and extent of release. PAR4-agonist induced slower release of fewer molecules while thrombin rapidly induced the greatest release. Cargo with opposing actions (e.g. pro- and anti-angiogenic) had similar release profiles, suggesting limited thematic response to specific agonists. From the release time-course data, rate constants were calculated and used to probe for underlying patterns. Probability density function and operator variance analyses were consistent with three classes of release events, differing in their rates. The distribution of cargo into these three classes was heterogeneous suggesting that platelet secretion is a stochastic process potentially controlled by several factors such as cargo solubility, granule shape, and/or granule-plasma membrane fusion routes. Sphingosine 1 phosphate (S1P) is a bioactive lipid that is stored in platelets. S1P is essential for embryonic development, vascular integrity, and inflammation. Platelets are an abundant source of S1P due to the absence of the enzymes that degrade it. Platelets release S1P upon stimulation. My work attempts to determine how this bioactive lipid is released from platelets. Washed platelets were stimulated with agonists for defined periods of time and the supernatant and pellet fractions were separated by centrifugation. Lipids were separated by liquid phase extraction and S1P was quantified with a triple quadrapole mass spectrometer. A carrier molecule (BSA) is required to detect release of S1P. Further, there is a dose-dependent increase in total S1P with increasing BSA. S1P release shows characteristics similar to other platelet granule cargo e.g. platelet factor IV (PF4). Platelets from Unc13-d Jinx mice and VAMP8-/- mice, which are secretion-deficient (dense granule, alpha granule and lysosome), were utilized to understand the process of S1P release. S1P release was more affected in Unc13-d Jinx mice mirroring their dense granule secretion defect. Fluorescence microscopy and sub-cellular fractionation were used to examine localization of S1P in platelets. S1P was observed to be enriched in a granule population. These studies indicate the existence of two pools of S1P, a readily extractable agranular pool, sensitive to BSA, and a granular pool that requires the secretion machinery for release. The secretion machinery of platelets in addition to being involved in the release of normal granule cargo is thus proved to be involved in the release of bioactive lipid molecules like S1P.

<p>This paper deals with relationship between irrigation and agriculture and conflicts within an irrigation system and as well between other stakeholders concerning the water. Irrigated lands are up to 2.5 times more productive compared to rain-fed agriculture. They are important element in the agriculture sector in Sub-Saharan Africa, and have been favoured by governments and donor agencies for their high rate of return. Without proper technical equipments or support negative impacts on the environment are linked to irrigation activities. Furthermore, a case study was made in Tanzania, Kiru Valley, regarding the tension between big scale and small-scale farmers as result from the water decline. The results demonstrate that the institutions do not have the power to solve the conflict. It is difficult to define the different stakeholders and the boundaries of the area that affect the amount of water in the valley.</p>

This dissertation examines the organizational aspects of fish and wildlife management for Native American nations. Fish and wildlife management is an arena of great importance to many Native nations in subsistence, economic and cultural realms. Additionally, fish and wildlife, being common-pool resources, offer interesting management challenges. My research focuses on what happens when Native American nations exercise self-determination in this arena which requires them for both political and practical reasons to interact with state and federal governments and for economic reasons to deal with markets, all while attempting to meet the needs of their nations. Using fuzzy-set qualitative comparative analysis and drawing upon survey and case study research with Native American fish and wildlife programs, I examine how tribes manage their fish and wildlife resources and with what results.This research helps identify under what conditions tribes may achieve various management goals. In some important ways, tribes are limited in what they can do, particularly in regards to land base size and degree of jurisdiction over non-Indians. More importantly, however, this research identifies some of the many ways tribes can work to take charge of or support tribal fish and wildlife management without having to appeal to outsiders. While there are some very real limitations to fish and wildlife management external to tribes, within those limits, tribes have opportunities to assume and be effective in resource management.This dissertation also provides evidence to suggest that as tribes are better able to determine their own management and governance paths, elements of clan structures and logics develop where the organizational literature would predict they would not. Studying tribal fish and wildlife programs in particular offers an examination of these clan-like features typically found only on the societal fringes. Perhaps even more importantly, this dissertation research demonstrates that there are different governance structures, or logics, co-existing and operating in hybrid forms. For tribes, these hybrid structures create some challenges and inconsistencies that more pure governance structures would not. Nevertheless, these hybrid structures also allow for flexibility and effectiveness in responding to the diverse stakeholders invested in or influencing tribal fish and wildlife management.

This research applied the social network approach to unveil the social structure underlying the members of two traditional irrigation systems (TISs) in Sonora. This research used two TIS case studies representing rural communities located in arid and semiarid lands in the Sonoran Desert region, in the northwestern part of Mexico. The irrigators represented a subset of rural villages where everyone knew everyone else. The theoretical framework in this study suggested that social embeddedness of the economic activities of TIS irrigators is an important factor supporting their local institutions. Irrigators who are socially embedded posses more social capital that help them in overcoming social dilemmas. Evidence of social embeddedness is theoretically incomplete when not related to a tangible dimension of the TIS's performance. This research also dealt with the difficulty of assessing the sustainability or successfulness of a TIS. The results showed that the irrigators sharing a rural village are entangled in a mesh of social ties developed in different social settings. The most salient variable was family; cooperative ties within the irrigation system tend to overlap more than the expected by chance with kinship relationships. Likewise, irrigators had a strong preference for peers geographically close or those within the same irrigation subsector. Finally, the qualitative part of the study did not reveal the presence of severe social dilemmas. Irrigators in each community have developed successful forms of local arrangements to overcome the provision and appropriation issues typical of common pool resources. Nevertheless, the qualitative analysis revealed that there are other socioeconomic variables undermining the sustainability of the systems, such as migration, water shortages and social capacity of the systems.

This dissertation explores some of the thousands of smaller Native American archaeological sites with meager architectural elements commonly found along part of the southern edge of the Colorado Plateau in east-central Arizona in an area known as the Mogollon Plateau. Small surface structures of less than five rooms were typically built of a combination of stone masonry and wattle and daub, and they are generally interpreted as evidence of repeated occupations of limited duration, primarily dating between AD 800 and 1300. Accordingly, these small sites have also served a number of roles in ongoing discussions of settlement systems and land use, and they present challenges for cultural resources management. The fundamental characteristics (or lack thereof) typically used to classify small sites have traditionally relegated them to settlement pattern studies rather than extensive excavation, generating a broad range of hypotheses concerning their significance and drawing heavily upon historical ecology. GIS methods are used to explore several ecologically and socially-driven models and examine the roles of small architectural sites in archaeological and systemic landscapes. Common pool resources offer some explanatory power regarding small sites, but some have suggested competition and conflict led to a "tragedy of the commons" and environmental degradation. Two primary site concentrations are identified, and the evidence supports an interpretation of extensive and sustainable use of the area, much of which seems to have been a frontier. Recommendations for research-driven management and preservation of cultural resources are provided.

There is growing interest in using additive manufacturing for various alloy systems and industrial applications. However, existing process development and part qualification techniques, both involve extensive experimentation-based procedures which are expensive and time-consuming. Recent developments in understanding the process control show promise toward the efforts to address these challenges. The current research uses the process mapping approach to achieve control of melt pool geometry and microstructure in different alloy systems, in addition to location specific control of microstructure in an additively manufactured part. Specifically, results demonstrate three levels of microstructure control, starting with the prior beta grain size control in Ti-6Al-4V, followed by cell (solidification structure) spacing control in AlSi10Mg, and ending with texture control in Inconel 718. Additionally, a prediction framework has been presented, that can be used to enable a preliminary understanding of melt pool geometry for different materials and process conditions with minimal experimentation. Overall, the work presented in this thesis has the potential to reduce the process development and part qualification time, enabling the wider adoption and use of additive manufacturing in industry.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.