Impulsive loads have been observed to cause brittle shear failure in reinforced concrete elements designed for ductile failure modes under static loads. Brittle failure modes exhibit poorer energy absorption capabilities compared to ductile flexural failure modes due to their limited deformation capacity, leading to premature failure. The discrepancy between the responses under static and extreme dynamic loads arises from inertia and wave propagation effects, which tend to increase as the load duration decreases relative to the fundamental period of the element.   This thesis investigated the occurrence of shear failures in reinforced concrete elements subjected to impulsive loads, both experimentally and numerically, and evaluated to what extent current analysis methods for impulse-loaded structures can predict shear failure. Furthermore, the study examined the influence of crucial parameters on the energy absorption capacity during flexural failure modes when shear failure was inhibited.   The results demonstrated that shear-plug damage, prevalent during impact loads, may lead to premature shear failure during sequential impact testing. This occurred for a statically flexure-critical beam with a significantly larger static flexural-shear capacity relative to its flexural capacity. Similar conclusions applied to the residual static capacity after an initial impact introduced shear-plug damage. These findings indicate potentially severe consequences of shear-plug damage, which should be considered when assessing structures damaged by impact loads.   The energy absorption capacity of reinforced concrete elements is closely related to the plastic work capacity of the reinforcement. The experimental study showed how the plastic work capacity varied with reinforcement properties, concrete properties, and impact velocity using static and dynamic four-point flexural tests. The results revealed that the reinforcement type, specifically whether the steel is mild or stiff, governs the strain distribution during static and low-velocity impact testing. Generally, stiff steels result in strain localization before rupturing, indicating a lower plastic work capacity. Factors such as stress and strain capacity also proved significant. However, as the impact velocity increased, wave propagation effects governed strain distribution rather than reinforcement type.    Numerical studies comparing results with outcomes using proposed design methods indicated agreement for support reactions used to verify the shear capacity in the later stages of the response. However, this agreement decreased in the initial stages of the response. This may be because the dynamic equilibrium method only considers a global response, while the local response due to wave propagation is influential in the initial stages of the response. Today, resources such as Biggs [8] and the Swedish Fortifications Agency [86] recommend using two stages of the response to determine the internal forces; an elastic global response and a later elastoplastic global response. From the observations in the papers, it is suggested to add a third initial stage of the response considering wave propagation effects. However, it is deemed that this response stage only has a significant effect for high-intensity blast loads with short rise times relative to the shear wave velocity. / Impulsiva laster har i litteraturen visats leda till spröda skjuvbrott for armerade betongelement designade for mjuka brott under statiska laster. Spröda brottmoder påvisar sämre energiupptagande förmågor jämfört med mjuka böjbrott på grund av dess lägre deformationskapacitet, vilket resulterar i tidigt brott. Skillnaden i respons under statisk och dynamisk belastning kommer från tröghetskrafter och vågutbredningseffekter, där effekten av båda ökar med en minskande lastvaraktighet i relation till fundamentala perioden av elementet.   Det här arbetet undersöker förekomsten av skjuvbrott under impulsiva laster experimentellt och med numeriska analyser. Hur väl befintliga beräkningsmetoder kan förutspå skjuvbrott utvärderas aven. Dessutom studeras effekten av viktiga parametrar på den energiupptagande förmågan när skjuvbrott hämmas.   Resultaten påvisade att skjuv-plugg-skada, allmänt förekommande under stötbelastning, kan leda till tidigt skjuvbrott under sekventiell stötbelastning. Detta förekom for en statiskt böj-kritisk balk med en markant högre skjuvkapacitet relativt till dess böjkapacitet. Liknande slutsatser kunde dras vid provning av den statiska residualhållfastheten efter att ett initiellt fallviktsförsök introducerade skjuv-plugg-skada. Dessa resultat indikerar potentiellt allvarliga konsekvenser av skjuv-plugg-skada, vilket bör beaktas vid bedömning av element skadade från stötbelastning.   Den energiupptagande förmågan hos armerade betongelement är nära relaterat till det plastiska arbetet som armeringen kan utföra. Den experimentella studien visade hur kapaciteten for plastiskt arbete hos armeringen berodde på armeringsegenskaperna, betongegenskaperna samt anslagshastigheten hos massan vid statisk och dynamisk fyrpunktsbelastning. Resultaten visade att armeringstypen, mer specifikt ifall stålet var mjukt eller styvt, styrde töjningslokaliseringen under statisk belastning samt dynamisk belastning med låg anslagshastighet. Generellt sett resulterade styvare stål i töjningslokalisering när stålet slets av, vilket ledde till en mindre kapacitet for plastiskt arbete hos armeringsstången. Faktorer som töjnings- och spänningskapaciteten visades även vara betydande. Däremot indikerade resultaten att allt eftersom anslagshastigheten ökade så var vågutbredningseffekter det som bestämde grad av töjningslokalisering, och inte styvheten hos stålet.   Numeriska studier där resultat jämfördes mot resultat från rekommenderade designmetoder indikerade överenskommelse för stödreaktioner som används för att verifiera skjuvkapaciteten i ett senare skede av responsen. Däremot så var överenskommelsen sämre i ett tidigare skede av responsen. Detta kan möjligen förklaras av att den dynamiska jämviktsmodellen endast tar hänsyn till den globala responsen, medans lokal respons från vågutbredning är dominerande tidigt. Idag använder referenser som Biggs [8] och Fortifikationsverket [86] två stadium av responsen for att bestämma interna krafter; ett globalt elastiskt stadie och ett globalt elasiskt-plastiskt stadie. Från observationer i artiklarna så rekommenderas det att ett tredje initiellt stadie som beaktar vågutbredningseffekter bör inkluderas. Detta stadie anses dock bara visa markant effekt for intensiva stötvågsbelastningar med kort stegtid relativt till skjuvvågshastigheten i materialet. / <p>QC 230828</p>

Background: The payment methods available to consumers for online purchases have evolved over time, with options ranging from debit and credit cards to e-wallets like PayPal and Apple Pay. Among these methods, Buy Now Pay Later (BNPL) has emerged as a significant payment method alternative. At the same time the global debt had a record jump between 2021 and 2022, with low-income households being the ones that suffer the most. The convenience offered by BNPL payment method, coupled with the accelerated uptake of this method in recent years, has created regulatory scrutiny concerning its contribution to the financial health of the society.   Purpose: The purpose of this study is to explore the relation between BNPL and financial wellbeing. The Generation Z cohort in the USA was specifically chosen as the target demographic due to their pronounced online purchasing behaviors and the notable tripling of their overall debt within the 2021-2022 period. Methodology: A quantitative approach for collecting data and data analysis was conducted using an online survey. The survey’s questions are influenced by previous research on financial wellbeing and debt levels. The survey’s populations are consisting of 150 individuals from different demographic backgrounds. The survey’s results have been analyzed by writing Python scripts and use relevant statistic libraries. Results and analysis: A significant portion of the study's respondents, irrespective of various demographic factors such as gender, education, and income level, answered that their use of BNPL had little to no impact on their financial wellbeing. Of particular significance is the answers of those familiar with BNPL who did not attribute any deterioration in their financial health by using BNPL. A subset of respondents acknowledged the potential for BNPL to cause overspending or regrettable purchases, but these sentiments were not predominant. Such findings challenge the common belief that BNPL inherently distributes to financial imprudence. However, nuances emerge when examining specific demographics. For instance, male respondents and those with lower educational attainment displayed a slightly heightened propensity to link BNPL with overspending. Conclusions: The overarching narrative suggests that while BNPL might influence purchasing behaviors to some extent, its direct impact on the broader financial wellbeing of individuals is not conclusively negative. Recommendations for future research: Future research can examine deeper behavioral insights on the effects of BNLP, investigate its effects on specific industries (e.g. luxury fashion) or examine global trends (given the present study is focused on USA).

Risk- och skyddsfaktorer förklarar varför vissa människor utvecklar psykisk hälsa respektive psykisk ohälsa. Syftet med föreliggande studie var att få en förståelse av vad det finns för samband mellan ett impulsivt beteende och individens självkänsla, mellan kön och impulsivt beteende samt mellan kön och självkänsla. I studien deltog 123 individer varav 74 var kvinnor och 49 var män. Deltagarnas ålder varierade mellan 17–61 år. Enkäten var uppbyggd med fem bakgrundsfrågor och tre skalor - en för självkänsla dels i allmänhet, dels efter ett utfört impulsivt beteende och en för impulsivt beteende. Studiens resultat visade att ju lägre grad av impulsivt beteende, desto högre grad av självkänsla i allmänhet och även ju lägre grad av impulsivt beteende, desto högre grad av självkänsla efter ett utfört impulsivt beteende. Resultatet visade även att kvinnor uppvisar en lägre grad av självkänsla i allmänhet och en lägre grad av självkänsla efter att ha utfört ett impulsivt beteende jämfört med män.

Electromagnetic disturbance can be detrimental to the performance of a radio communication system, and in today’s society where more and more electronic devices are present in our everyday life it is increasingly vital to consider man-made interference. A communication system can take into consideration the noise characteristics and by doing so will excel in such areas, however, this follows that the algorithms utilized in such systems are more computationally complex and are therefore slow. This master thesis aims to explore the possibility of a neural network-based solution that reaches the same accuracy, as existing methods, but more quickly. Numerous different existing model alternatives have been explored and a plethora of different improvement techniques have been outlined. Two models, Hannet and Lannet, have been designed and improved to enable adaptive demodulation both including or excluding decoding at the receiver in an end-to-end communication system. The evaluation results demonstrate that the proposed models are comparable and in some cases even more accurate than current standardized methods. However, the models are unable to fully learn the decoding algorithms present in the experiments. Thus even though demodulation by itself thrives, performing decoding in conjunction with demodulation is out of reach for these models.

Aim The authors seek to explore the impact of celebrity endorsement through social media on consumer behavior, specifically on impulsive buying. Methodology The quantitative research approach was adopted, and a questionnaire was administered to university students in 3 cities (Gavle, Uppsala, and Stockholm). The primary data was collected from the students’ responses to the questions (127-members survey). For achieving the results mentioned in the results chapter, SPSS 17 was used for the data analysis. In the study, secondary data was collected through scholarly journals, books, and articles. Findings The findings show that the popularity of the celebrity affects the buying behavior of customers (purchase motivation or purchase intention). The results revealed that marketers need to use recognized factors to motivate and influence consumers’ buying intention on social media as suggested by the consumer. The perception of the customers is that Marketers will do well to control the purchasing behavior of customers, and if possible the influence of celebrity endorsement through social media on impulsive buying. Contribution to the study Theoretical contribution This study adds a theoretical contribution to impulsive buying towards consumers’ buying behavior in the emerging field of marketing theory. Celebrities can play a vital role in influencing customers through using social media platforms which can impact their buying decision. In addition to the social media effect, the authors have chosen to continue the Pavlovian model for consumer behavior, adapting it to success, as did the other two separate factors that lead to an impulse purchase which is the convenience of e-commerce and impulse decision. The theory explores the actions of consumers in detail and aims at a much deeper understanding of thought and shifting attitudes based on both external and specific environmental factors. Managerial contribution Celebrities create positive awareness through their influence and arouse the need in the mind of customers. Motivated customers are interested in buying and making instant decisions. The attitude of graduate students could be vital for marketers to promote products through this channel.  The research asks actually that if, in the case of support for the chosen celebrity and not just any celebrity, details should be collected and a commonly known celebrity is strategically positioned then the research would change their preconceived ideas about certain target markets. Limitations and suggestions for future research The authors recommend that the results presented are not generalizable to other universities or countries. The focus of this study is limited to a particular segment with various constraints, in changing situations, to obtain students’ perceptions of different opinions and methods to influence the decision-making behavior of consumers with celebrities' help through social media. The point of view may differ from one demographic segment to another, so the authors will recommend extending/expanding the sample size with various demographic features for similar studies in the future. The impulsive buying behavior of customers is largely influenced but still, there is a gap between the product category and customers’ preference. Furthermore, the new study can be done on how consumer buying behavior may affect based on contextual influence such as involving time pressure, situational impact based on the channel of promotion(online and offline ), as the number of customers, is increasing very rapidly.

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This dissertation details the development and applications of two innovative types of optical filament-based impulsive Raman spectroscopy: filament-assisted Raman spectroscopy (FAIRS) and spectral-to-temporal amplitude mapping polarization spectroscopy (STAMPS). These techniques provide complimentary vibrational and rotational information on molecular systems of interest. Both are powerful due to their impulsive nature which allows for rapid measurement of entire Raman spectra. However, each type of spectroscopy utilizes the filament in a different manner. The recently reported vibrational technique, referred to as filament-assisted impulsive Raman spectroscopy, employs the pulse shortening and continuum generation of filamentation to impulsively excite a massive vibrational coherence in a molecular system for simultaneous measurement of all the Raman-active modes. In the first half of this dissertation, FAIRS is further developed and applied to a plethora of signature molecules. Radioactive decay signature molecules, including nitrogen oxides, ozone, and ions are detected via FAIR spectroscopy. Concurrent generation and detection of ozone, ionic, and excited-state molecules through filamentation is reported for the first time. Production of these species through the strong field chemistry of filamentation and their subsequent filament-driven excitation is a mark of sensitivity of FAIRS. Spatial studies of combustion species in a natural gas flame are also presented. FAIRS monitors the Raman signal intensities of known reactants and products as a function of vertical flame position. The appearance of combustion products as a function of flame height is also tracked. Spectral fringes overlapping the Raman-active modes are present in all measurements and enable more sensitive detection of low signal intensity species. The results described illustrate the potential of FAIRS for threat sensing applications. The rotational technique, referred to as spectral-to-temporal amplitude mapping polarization spectroscopy, temporally chirps the spectral content of the white-light continuum generated during filamentation to map the transient rotational rivals that are impulsively excited by a short pump pulse. In the second half of this dissertation, the initial development and testing, followed by the applications of STAMPS are described. STAMPS proves successful in mapping the rotational wavepacket rephasing of simple linear molecules, including nitrogen, oxygen, and carbon dioxide, as well as the more complicated asymmetric top molecules, ethylene and methanol. The application of STAMPS to the detection of nitrogen oxides and nitrous oxide, which are considered signatures of multiple threat substances and events, is demonstrated. A pressure study of nitrous oxide reveals dephasing effects as a function of time and pressure. These preliminary results also indicate the potential of STAMPS for hazard sensing applications. / Chemistry