Thèses sur le sujet « Scienza e fede »

Algorithmic curation is a growing influence on our information flows as it complements and sometimes supplants traditional mass media and personal information sharing. One of the primary agents of this rise in algorithmically-curated information flows is the Facebook News Feed, a onetime source of primarily entertainment that has, as of late, taken large strides towards the news business. It is fair to say that Facebook has a huge influence on our information, one that will likely expand in the future; even if not Facebook, similar systems will rule our information. Yet, we know next to nothing about how they work, as the algorithms that power them are sealed inside a black box. This thesis approaches the Facebook News Feed through a mix of qualitative and quantitative methods in a process dubbed “Negative Reverse Engineering” in an attempt to gain access to the contents of the black box not through traditional technical means, but through an analysis of Facebook’s values structure and needs. Components include an extensive, cross-disciplinary review of the literature, an experiment based around the generation of filter bubbles through the application of negative pressure, a grounded content analysis of Facebook’s statements and documents, an autoethnography of Facebook use, and a regression analysis of Facebook under duress. From this data, a Hierarchy of Needs for the News Feed is created, rejecting the model of News Feed filtering as an equation in favor of a holistic, values-based model.

This master thesis treats the research of a novel “generator with converter” design called “Doubly Fed Permanent Magnet Synchronous Machine”, DF-PMSM, patented by SmartMotor. The thesis includes an introduction to the machine, a state-of-the-art survey, a hydro power case, simulations and a laboratory experiment. The DF-PMSM concept adds an important feature to fixed speed PMSM systems; the reactive power can be regulated. Compared to a direct coupled PMSM the DF-PMSM concept can add voltage control (by controlling the reactive power) in addition to active power control. The concept is based on a 6-phase Permanent Magnet Synchronous Machine where the windings are grouped into two sets of 3-phase, both situated in the stator. These winding sets are named “control” and “power” winding, named after their purpose in the design. The “control winding” is routed through a converter with active-front-end rectifier. It will be used to control the reactive power and the active power from the control winding. The “power winding” will carry most of the generated power, directly coupled and in sync with the voltages of the connected grid. The state-of-the-art survey includes constant speed and variable speed generators utilized in hydro power generation today. It also includes some general info about doubly fed and multiphase machines. The grid regulations for Norway are also investigated to give a pointer to what requirements that the DF-PMSM needs to fulfill to be connected to the grid. The machine simulations are done in LTspice where machine simulation models are developed for this purpose. Simulation of machine startup and changes is load is done. The simulation models are developed as hierarchical sub blocks that can be re used in later simulation cases. The laboratory is done with two machines in back-to-back configuration with industry standard converters. The DF-PMSM is made from a 3-phase permanent magnet machine that is rewired to a 6-phase configuration. The laboratory exercise includes start up, synchronization of the power winding to the grid, machine loading and reactive power compensation by the active front end converter. The DF-PMSM is confirmed working and design considerations are given based experience gained from working with this design. All of this information is included in this report and the further work needed before this machine is constructed and sold is sketched in the conclusion.

The Internet and social media are tools that possess the ability to make communicating with celebrities, politicians and all types of important figures an actual possibility. This content analysis explores the use of then- presidential candidate Donald Trump’s use of Twitter to communicate with his followers. A random sample of tweets was selected following the time period after the Republican National Convention to a week after the general election. The study relies on Kent and Taylor’s (2001) principle strategies of how to create effective relationship building through dialogue. There is very little research available concerning political candidates and dialogic theory on social media. However, what is found in this study remains consistent with that of similar studies on dialogic theory and celebrities and organizations’ use of social media. Social media as a tool for building effective relationships through the use of dialogic principles is severely under-utilized. Despite the lack of dialogic principles, Trump’s followers remained highly engaged into his tweeting habits, especially with tweets that attacked an individual or the media. The findings prove that these types of tweets were published most often thus lending credence to assert that the aggressive rhetoric was popular amongst his followers.

Hampshire crosses of different genotype and sex were used to investigate the effects of rearing system, feed and handling on sensory quality, consumer preference and cooking loss. A selected and trained panel carried out descriptive tests. Two preference tests were carrieout by, in each case, 200 consumers.

The genotype had a major effect on sensory quality in all four studies irrespective of rearing system, feed and sex. In three of the four studies pork from RN¯ carriers scored higher for juicines, tenderness, acidulous taste and meat taste intensity.

Sex showed contradictory effects on sensory quality, while rearing system and feed had minor effects on sensory properties of pork.

Hams (M. biceps femoris) from pigs reared outdoors scored lower for juiciness and acidulous taste than hams from pigs reared indoors. Loins from pigs organically reared (KRAV) scored lower for juiciness and higher for crumbliness than ones from pigs conventionallreared.

Loins (M. longissimus dorsi) aged four days from conventionally fed pigs were juicier than ones from silage-fed pigs. When loins were aged eight days there was no difference in juicines while acidulous taste became weaker and tenderness and meat taste intensity increased.

In the case of loins stored frozen one year, those from silage-fed pigs scored higher for acidulous taste and off-flavour than those from conventionally fed pigs.

Cooking, thawing and total loss data showed minor and contradictory differences between genotypes, sexes, rearing systems and feeding regimes.

Organically and conventionally produced loins were equally liked and loins from RN¯ carrier pigs were preferred to loins from non-carriers.

Large White turkey breeder hens were tested in a 4 X 3 factorial design to evaluate the effect of three different levels of physical feed restriction on subsequent reproductive performance. The feed treatments comprised: Control Control (CC) - ad libitum fed throughout the study, Control Restricted (CR) - feed restricted from 16-24 WOA, Restricted Control (RC) - feed restricted from 3-16 WOA and Restricted Restricted (RR) - feed restricted from 3-24 WOA. Feed restriction was implemented so that restricted fed hens achieved a 45% reduction in BW as compared to Control hens at 16 WOA. From 16-24 WOA restriction was implemented to maintain a slight increase in BW. At the completion of the respective restriction period, hens were gradually released back to ad libitum feeding. At the time of photostimulation (30 WOA) all treatments were divided into sub-treatments by weight: HEAVY, MEDIUM and LIGHT, resulting in four treatments with three sub-treatments within each. All hens continued on ad libitum feeding throughout a 20 wk lay cycle. Body weight (BW) for all treatments differed significantly (P<.05) at 16 and 30 WOA. At the end of lay (53 WOA) treatment CR no longer significantly differed in BW from treatment CC as did treatment RR no longer significantly differ in BW from treatment RC. Treatment CC reached maximum feed consumption at 12-15 WOA, whereas restricted treatments CR, RC and RR did not reach maximum feed consumption until just prior to photostimulation (30 WOA). At the end of the study, cumulative feed consumption was significantly less for restricted treatments. Previous research reported (Trial 1), concluded that restricting hens early in rearing preceding a lay cycle in the Winter season resulted in numerical increases in egg production. The time period for this study (Trial 2) was inverted from that of Trial 1, in that hens were photostimulated for Summer season egg production. For Trial 2, RC and RR hens laid significantly more eggs than did CC and CR hens for the first 1-5 weeks of lay (wol). However, within Trial 2, once house temperature increased to over 80-85 oF RC and RR egg production suffered dramatically, cumulating in a significant decrease in production. Hens restricted early in rearing (3-16 WOA) also cumulatively laid more soft shelled eggs and reported a decrease in hatch of fertile eggs for Trial 2. Determining why hens restricted fed early in rearing decreased egg quality and production soon after peak lay in the Summer season was a focal point of this study. Due to the fact that hens considered ?out-of-production? had circulating levels of prolactin up to 5 times less than that of hens ?in-production?, incubation behavior and broodiness were not considered to be a factor. Therefore, body composition, carcass conformation and hormonal and enzyme activity were analyzed to determine the effect feed restriction had on each of these variables. Early feed restriction reduced the percent body fat of breeder candidates while increasing the percentage of moisture and ash. Relative weights of organ and tissues samples revealed that early feed restriction resulted in a larger percentage of crop, liver and total visera for restricted fed hens. Early feed restriction also increased the percentage of bone structure regarding femur and keel bone development. However, treatments which were restricted fed early exhibited a significant reduction in absolute and relative weight of breast and thigh muscles in comparison to ad libitum fed hens at 15 WOA. Although these differences were not reported at 30 WOA on a relative basis, absolute weights remained significantly different with respect to breast muscle. This same variation with regards to breast muscle was then noted throughout the 20 wk lay cycle. The sub-treatment ?weight?, LIGHT, MEDIUM and HEAVY hens responded very much in the same manner irrespective of their initial treatment (CC, CR, RC and RR). This analysis results in the conclusion that a LIGHT hen is destined to be a LIGHT hen irrespective of her feed allotment. This phenomena is more than likely attributed to the genetic material compiled by each hen. LIGHT hens within each treatment exhibited a greater tendency for compensatory growth as compared to MEDIUM and HEAVY hens. However, egg production suffered within LIGHT hens as these hens at times laid a significantly smaller and undesirable quality of an egg. MEDIUM hens expressed a larger portion of BW through breast muscle, therefore appearing to make them the more reproductively oriented sub-treatment. In fact, MEDIUM hens did lay at a numerically higher hen housed production percentage. In conclusion, if turkey breeder hens are to lay in the Winter season, restricting feed early in rearing can prove economically beneficial. However, if hens are to lay during the Summer season, feed restriction early in rearing appears to be detrimental to subsequent reproduction in that initial breast and fat loss is never fully recuperated for the lay cycle. Therefore, feed restriction should be limited to later in rearing if any economic benefits are to be reported.