Sweden was one of the few countries in the EU that in most cases decided to keep their elementary schools open during the COVID-19 pandemic. The purpose of this study was to investigate potential outcomes COVID-19 has had on students´ average merit scores as well as group-specific effects across genders and school types. To further estimate which factors might have also influenced students´ success, we decided to consider the share of higher educated parents and the municipality income for compulsory schools in our research. Using the fixed effects method, a few models were constructed to analyze the different effects. We found that in general, COVID-19 had a significant and positive effect on the average merit score of students across all elementary schools in Sweden, suggesting that there have been other factors influencing their academic performance. Furthermore, it was found that gender disparities and the share of higher educated parents have affected the average academic performance, whereas the municipality income for compulsory schools did not. Lastly, private schools were found to perform less positively compared to public schools.

[pt] As condições hidrológicas desfavoráveis vivenciadas entre 2014 e 2019 levaram ao esgotamento dos principais sistemas de reservatórios no Brasil, causando um aumento na geração de energia proveniente de usinas térmicas. Todavia, uma parte relevante da geração térmica verificada foi comandada por entidades governamentais de forma heterodoxa (fora do mérito econômico calculado pelos modelos de otimização), baseada principalmente na percepção de risco tácita. Apesar do senso comum de que o armazenamento dos reservatórios está intrinsecamente ligado à segurança do sistema, as métricas utilizadas até o momento não conseguiram computar as reais necessidades do sistema em termos de energia armazenada mínima nas usinas hidrelétricas. Ao final de 2019, o ONS propôs um novo método para avaliar a necessidade de despacho térmico adicional, chamado Curva Referencial de Armazenamento (CREF). No entanto, este método considera hipóteses muito específicas de afluências e geração térmica, e com base em seu processo iterativo de tentativa e erro, pode resultar em resultados sub-ótimos para o cálculo dos armazenamentos mínimos necessários. Este trabalho propõe um novo método para avaliar a segurança do fornecimento de energia em sistemas predominantemente hidroelétricos. Este método é uma evolução do método CREF, e é baseado no desenvolvimento de um modelo de otimização que calcula os níveis mínimos de segurança para operação de usinas hidrelétricas em cada mês, a partir de uma simulação recursiva de séries históricas de afluências de 1931 a 2018. Além disso, com base nos resultados da simulação, foram sugeridas curvas de referência para o monitoramento contínuo da operação dos reservatórios, com o objetivo de subsidiar decisões de órgãos do Governo Brasileiro sobre o despacho heterodoxo de geração térmica. Espera-se que o monitoramento das curvas de referência propostas represente um critério mais robusto para decisões sobre geração térmica fora-do-mérito no Sistema Elétrico Brasileiro. / [en] Unfavorable hydrological conditions experienced from 2014 to 2019 led to the depletion of main reservoir systems in Brazil, causing an increase of thermal energy dispatch. However, an important share of the observed thermal generation was out of economic merit, commanded by government entities which risk perception relies mainly on experts tacit knowledge. Despite the common sense that storage in reservoirs is intrinsically linked to system security, the metrics employed so far failed to compute the system s real needs in terms of required stored energy in hydroelectric plants. By the end of 2019, ONS proposed a new method to assess the need for additional thermal dispatch the Referential Storage Curve (CREF - Curva Referencial de Armazenamento). However, it fails as a reference for the security of energy supply since it considers very specific assumptions of rivers inflows and thermal generation. Besides, based on its iterative trial and error process, it can result in sub-optimal results of minimum storage levels. This work proposes a new method to evaluate the security of power supply in systems with predominance of hydroelectricity. This method is intended to be an evolution to the CREF method, and it is based on the development of an optimization model that computes the minimum secure levels for hydroelectric plants operation in each month, from a recursive simulation of historical inflow series from 1931 to 2018. In addition, based on the simulation results, reference curves were suggested for the continuous monitoring of the reservoirs operation, with the purpose of subsidizing Brazilian government entities decisions on unorthodox thermal generation dispatch. The monitoring of the proposed reference curves is expected to represent a more robust criterion for decisions on out-of-merit thermal generation in Brazilian power system.

President Barack Obama committed hundreds of millions of dollars to the Teacher Incentive Fund (TIF), yet a few fundamental questions remain unanswered—was the federal program effective? Did student test scores improve? Since the late 19th century, teachers have been paid for their classroom services regardless of how well—or poorly— their students performed. Nearly a century later, advocates of education reform continue to champion teacher compensation policies that link salary to student achievement. Researchers have identified two motivation theories that must be present in order to have a successful incentive pay program: goal theory and expectancy theory. The presence or absence of these theories, have produced mixed results at both the federal and state levels. Although the Florida Department of Education crafted its own statewide incentive pay plan, three public school districts have received multimillion dollar awards via competitive TIF grants. The purpose of this dissertation was to determine if any differences in learning gains existed between the 2008 and 2009 Florida Comprehensive Assessment Test® (FCAT® ) Math scores among the students of math teachers at one urban Central Florida Title I middle school who participated in TIF when compared to the students of math teachers who did not participate in TIF. The dissertation also analyzed FCAT® Math scores from 2005 through 2009 in one Central Florida school district to determine if any trends existed among the Title I middle schools participating in TIF; if any trends existed iv among the Title I middle schools that did not participate in TIF; and if any trends existed between the two groups when compared to each other. The literature review and results of this study found that learning gains existed among students whose teachers participated in TIF. In fact, at one urban Central Florida middle school, students of math teachers who did not participate in TIF also demonstrated learning gains. In addition, seven of the ten Title I middle schools from the same Central Florida district had increased FCAT® Math scores with the implementation of the TIF grant along with the three Title I middle school that were not eligible to participate. This research suggested that the teacher incentive program implemented in a Central Florida district had a positive impact on learning gains of low-performing students. The results of the independent-samples tests revealed that there was no statistical difference in the math scores based on participation in TIF. Students of the math teachers who participated in TIF demonstrated at least one year‘s academic growth. Likewise, the findings were similar for students of teachers who opted not to participate as learning gains increased in this group as well. As a result of these findings, recommendations for further study include end-of-the-year interviews with TIF-eligible teachers whose students had learning gains, but chose not to participate. Suggestions for additional research include surveying teachers whose students had higher scores in the absence of an incentive program, analyzing the test scores of other subject areas, and researching other school districts in Florida that were awarded the TIF grant.

Auditory preemption theory suggests two competing assumptions for the attention-capturing and performance-altering properties of auditory tasks. In onset preemption, attention is immediately diverted to the auditory channel. Strategic preemption involves a decision process in which the operator maintains focus on more complex auditory messages. The limitation in this process is that the human auditory, or echoic, memory store has a limit of 2 to 5 seconds, after which the message must be processed or it decays. In contrast, multiple resource theory suggests that visual and auditory tasks may be efficiently time-shared because two different pools of cognitive resources are used. Previous research regarding these competing assumptions has been limited and equivocal. Thus, the current research focused on systematically examining the effects of complexity and timing of communication interruptions on visual detection tasks. It was hypothesized that both timing and complexity levels would impact detection performance in a multi-task environment. Study 1 evaluated the impact of complexity and timing of communications occurring before malfunctions in an ongoing visual detection task. Twenty-four participants were required to complete each of the eight timing blocks that included simple or complex communications occurring simultaneously, and at 2, 5, or 8 seconds before detection events. For simple communications, participants repeated three pre-recorded words. However, for complex communications, they generated three words beginning with the same last letter of a word prompt. Results indicated that complex communications at two seconds or less occurring before a visual detection event significantly impacted response time with a 1.3 to 1.6 second delay compared to all the other timings. Detection accuracy for complex communication tasks under the simultaneous condition was significantly degraded compared to simple communications at five seconds or more prior to the task. This resulted in a 20% decline in detection accuracy. Additionally, participants' workload ratings for complex communications were significantly higher than simple communications. Study 2 examined the timing of communications occurring at the corresponding seconds after the visual detection event. Twenty-four participants were randomly assigned to the communication complexity and timing blocks as in study 1. The results did not find significant performance effects of timing or complexity of communications on detection performance. However the workload ratings for the 2 and 5 second complex communication presentations were higher compared to the same simple communication conditions. Overall, these findings support the strategic preemption assumption for well-defined, complex communications. The onset preemption assumption for simple communications was not supported. These results also suggest that the boundaries of the multiple resource theory assumption may exist up to the limits of the echoic memory store. Figures of merit for task performance under the varying levels of timing and complexity are presented. Several theoretical and practical implications are discussed.

No description available.

In this study, I explored the different perceptions of teachers in a large urban school district in Texas towards a pay-for-performance program used on their respective campuses between 2011-2016. In total, 97 teachers from four different middle school campuses participated in this study. A descriptive analyst was conducted on teacher responses to an online survey to answer the research questions examined in this study: 1) What are teachers' perceptions of the pay-for-performance program's impact on teacher motivation?, 2) What are teachers' perceptions of the pay-for-performance program's impact on teacher retention?, and 3) What are the differences among teachers' perceptions of the pay-for-performance programs on the participating campuses? The results indicate 48.3% and 53.4% of the participants perceive pay-for-performance programs as having a positive impact on teacher motivation and teacher retention, respectively. Additionally, the results demonstrate 47.5% of participating teachers responded positively towards the pay-for-performance program on their respective campuses. This study has implications for policymakers and school district leaders who may consider implementing teacher pay-for-performance programs. Future research studies might explore school districts of different sizes throughout Texas and across the United States to gain a broader prospective of pay-for-performance programs.

This letter presents the design and characterization results of a multi-octave power amplifier fabricated in a 0.13μm SiGe-BiCMOS technology. The single stage power amplifier is implemented as the stack of a cascode amplifier combining broadband input matching network with resistive feedback, and a common-base amplifier with base capacitive feedback. Measurement results show that the design delivers a peak saturated output power level of 20.2 dBm, with output 1 dB compression at 19.4 dBm. The measured 3 dB power bandwidth is from 4 GHz to 32 GHz, covering three octaves. The corresponding power fractional bandwidth is 156 %. The measured peak power added efficiency is 20.6 %, and peak small signal gain is 18.6 dB. The fabricated integrated circuit occupies an area of 0.71mm2. To compare state-of-the-art multi-octave power amplifiers, the power amplifier figure of merit defined by the international technology roadmap for semiconductors is modified to include power fractional bandwidth and area. To the knowledge of the authors, the presented design achieves the highest figure of merit among multi-octave power amplifiers in a silicon based integrated circuit technology reported in literature.

The Nigeria economy is wholly dependent on revenue from oil. However, bitumen has been discovered in the country since 1903 and has remained untapped over the years. The need for the country to complement oil exploration with the huge bitumen deposit cannot be overemphasized. This will help to improve the country's gross domestic product (GDP) and revenue available to government. Bitumen is classifled as heavy crude with API (American petroleum Institute) number ranging between 50 and 110 and occurs in Nigeria, Canada, Saudi Arabia, Venezuela etc from which petroleum products could be derived. This dissertation looked at the Canadian experience by comparing the oil and tar sand deposit found in Canada with particular reference to Athabasca (Grosmont, Wabiskaw McMurray and Nsiku) with that in Nigeria with a view of transferring process technology from Canada to Nigeria. The Nigeria and Athabasca tar sands occur in the same type of environment. These are the deltaic, fluvial marine deposit in an incised valley with similar reservoir, chemical and physical properties. However, the Nigeria tar sand is more asphaltenic and also contains more resin and as such will yield more product volume during hydro cracking albeit more acidic. The differences in the components (viscosity, resin and asphaltenes contents, sulphur and heavy metal contents) of the tar sands is within the limit of technology adaptation. Any of the technologies used in Athabasca, Canada is adaptable to Nigeria according to the findings of this research. The techno-economics of some of the process technologies are. x-rayed using the PTAC (petroleum technology alliance Canada) technology recovery model in order to obtain their unit cost for Nigeria bitumen. The unit cost of processed bitumen adopting steam assisted gravity drainage (SAGD), in situ combustion (ISC) and cyclic steam stimulation (CSS) process technology is 40.59, 25.00 and 44.14 Canadian dollars respectively. The unit cost in Canada using the same process technology is 57.27, 25.00 and 61.33 Canadian dollars respectively. The unit cost in Nigeria is substantively lesser than in Canada. A trade off is thereafter done using life cycle costing so as to select the best process technology for the Nigeria oil/tar sands. The net present value/internal rate of return is found to be B$3,062/36.35% for steam assisted gravity drainage, B$I,570124.51 % for cyclic steam stimulation and B$3,503/39.64% for in situ combustion. Though in situ combustion returned the highest net present value and internal rate of return, it proved not to be the best option for Nigeria due to environmental concern and response time to production. The best viable option for the Nigeria tar sand was then deemed to be steam assisted gravity drainage. An integrated oil strategy coupled with cogeneration using MSAR was also seen to considerably amplify the benefits accruable from bitumen exploration; therefore, an investment in bitumen exploration in Nigeria is a wise economic decision. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2010.

The Nigeria economy is wholly dependent on revenue from oil. However, bitumen has been discovered in the country since 1903 and has remained untapped over the years. The need for the country to complement oil exploration with the huge bitumen deposit cannot be overemphasized. This will help to improve the country's gross domestic product (GDP) and revenue available to government. Bitumen is classifled as heavy crude with API (American petroleum Institute) number ranging between 50 and 110 and occurs in Nigeria, Canada, Saudi Arabia, Venezuela etc from which petroleum products could be derived. This dissertation looked at the Canadian experience by comparing the oil and tar sand deposit found in Canada with particular reference to Athabasca (Grosmont, Wabiskaw McMurray and Nsiku) with that in Nigeria with a view of transferring process technology from Canada to Nigeria. The Nigeria and Athabasca tar sands occur in the same type of environment. These are the deltaic, fluvial marine deposit in an incised valley with similar reservoir, chemical and physical properties. However, the Nigeria tar sand is more asphaltenic and also contains more resin and as such will yield more product volume during hydro cracking albeit more acidic. The differences in the components (viscosity, resin and asphaltenes contents, sulphur and heavy metal contents) of the tar sands is within the limit of technology adaptation. Any of the technologies used in Athabasca, Canada is adaptable to Nigeria according to the findings of this research. The techno-economics of some of the process technologies are. x-rayed using the PTAC (petroleum technology alliance Canada) technology recovery model in order to obtain their unit cost for Nigeria bitumen. The unit cost of processed bitumen adopting steam assisted gravity drainage (SAGD), in situ combustion (ISC) and cyclic steam stimulation (CSS) process technology is 40.59, 25.00 and 44.14 Canadian dollars respectively. The unit cost in Canada using the same process technology is 57.27, 25.00 and 61.33 Canadian dollars respectively. The unit cost in Nigeria is substantively lesser than in Canada. A trade off is thereafter done using life cycle costing so as to select the best process technology for the Nigeria oil/tar sands. The net present value/internal rate of return is found to be B$3,062/36.35% for steam assisted gravity drainage, B$I,570124.51 % for cyclic steam stimulation and B$3,503/39.64% for in situ combustion. Though in situ combustion returned the highest net present value and internal rate of return, it proved not to be the best option for Nigeria due to environmental concern and response time to production. The best viable option for the Nigeria tar sand was then deemed to be steam assisted gravity drainage. An integrated oil strategy coupled with cogeneration using MSAR was also seen to considerably amplify the benefits accruable from bitumen exploration; therefore, an investment in bitumen exploration in Nigeria is a wise economic decision. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2010.

L’auteur qui appose son nom à une publication universitaire sera reconnu pour sa contribution à la recherche et devra également en assumer la responsabilité. Il existe divers types d’agencements pouvant être utilisés afin de nommer les auteurs et souligner l’ampleur de leur contribution à ladite recherche. Par exemple, les auteurs peuvent être nommés en ordre décroissant selon l’importance de leurs contributions, ce qui permet d’allouer davantage de mérite et de responsabilité aux premiers auteurs (à l’instar des sciences de la santé) ou bien les individus peuvent être nommés en ordre alphabétique, donnant une reconnaissance égale à tous (tel qu’on le note dans certains domaines des sciences sociales). On observe aussi des pratiques émergeant de certaines disciplines ou des champs de recherche (tel que la notion d’auteur correspondant, ou directeur de recherche nommé à la fin de la liste d’auteurs). En science de la santé, lorsque la recherche est de nature multidisciplinaire, il existe différentes normes et pratiques concernant la distribution et l’ordre de la signature savante, ce qui peut donner lieu à des désaccords, voire à des conflits au sein des équipes de recherche. Même si les chercheurs s’entendent pour dire que la signature savante devrait être distribué de façon ‘juste’, il n’y a pas de consensus sur ce que l’on qualifie de ‘juste’ dans le contexte des équipes de recherche multidisciplinaire. Dans cette thèse, nous proposons un cadre éthique pour la distribution juste de la signature savante dans les équipes multidisciplinaires en sciences de la santé. Nous présentons une critique de la documentation sur la distribution de la signature savante en recherche. Nous analysons les enjeux qui peuvent entraver ou compliquer une distribution juste de la signature savante tels que les déséquilibres de pouvoir, les conflits d’intérêts et la diversité de cultures disciplinaires. Nous constatons que les normes internationales sont trop vagues; par conséquent, elles n’aident pas les chercheurs à gérer la complexité des enjeux concernant la distribution de la signature savante. Cette limitation devient particulièrement importante en santé mondiale lorsque les chercheurs provenant de pays développés collaborent avec des chercheurs provenant de pays en voie de développement. Afin de créer un cadre conceptuel flexible en mesure de s’adapter à la diversité des types de recherche multidisciplinaire, nous proposons une approche influencée par le Contractualisme de T.M. Scanlon. Cette approche utilise le respect mutuel et la force normative de la raison comme fondation, afin de justifier l’application de principes éthiques. Nous avons ainsi développé quatre principes pour la distribution juste de la signature savante en recherche: le mérite, la juste reconnaissance, la transparence et la collégialité. Enfin, nous proposons un processus qui intègre une taxonomie basée sur la contribution, afin de délimiter les rôles de chacun dans le projet de recherche. Les contributions peuvent alors être mieux comparées et évaluées pour déterminer l’ordre de la signature savante dans les équipes de recherche multidisciplinaire en science de la santé. / Authorship of scientific publications is a means of recognizing both a researcher’s contribution to a paper as well as their responsibility for the integrity of their work. Various approaches to author order may be used to rank individuals and convey the extent of their contribution. For example, authors may be listed by decreasing level of contribution, whereby most credit and responsibility are allocated to the first authors (common in the health sciences), or they may be named in alphabetical order, giving equal recognition to all (common in the social sciences). There are also “rules of thumb” or preferred practices that exist in the respective disciplines or research fields (e.g., corresponding author first, Principal Investigator last). In the case of multidisciplinary health research, differing norms and practices regarding authorship distribution may be held by the respective team members; and, this can give rise to disagreement and even conflict within research teams. Although researchers and scholarly organizations agree that authorship should be distributed “fairly”, a shared understanding or consensus as to what constitutes fairness, as well as its practical implementation in multidisciplinary research collaborations, remains a significant challenge. This thesis proposes a conceptual ethical framework for the fair distribution of authorship in multidisciplinary health sciences research. At the outset, the various methods recommended by journals, learned societies, as well as in the academic literature to distribute authorship are critically reviewed; issues that may impede or complicate fair authorship distribution in multidisciplinary research are highlighted; these include, for example, power differentials, conflicts of interests, and conflicting disciplinary norms and cultures. The analysis will show that current universal normative authorship guidelines are overly broad, and therefore, are insufficient to effectively resolve many of the diverse issues that are often specific to differing contexts of research. As will be discussed, the limitations of such guidelines are particularly significant in the case of global health collaborations that involve researchers from low and middle income countries and those from high income countries. A theoretical approach influenced by T.M. Scanlon’s Contractualism is proposed as a means of achieving the flexibility needed for the diversity of multidisciplinary research contexts; mutual agreement and reasonability are used to determine whether ethical principles are “fair”. Four central and interconnected principles – desert, just recognition, transparency and collegiality – are presented as the conceptual foundation to support the development of a process for the fair distribution of authorship. This authorship distribution process integrates the detailed research tasks commonly used in “contributorship” taxonomies to delineate individual duties and roles in the research project and subsequent publication. Contributions are then compared and valued more efficiently to determine authorship order while promoting fairness in multidisciplinary health sciences research.