256 research outputs found
Air quality degradation in Alaska wilderness areas due to emission changes
The increasing trends in aerosol concentrations observed by the Interagency Monitoring of Protected Visual Environments (IMPROVE) network in the wilderness areas along the Gulf of Alaska during low insolation periods and in Denali National Park and Preserve (Denali NP) during high insolation periods have raised the concerns about air quality degradation and visibility impairment in these pristine areas. This dissertation aims to investigate the reason for those observed increases in aerosol concentrations in Alaska wilderness areas by performing a series of simulation sets with the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). These simulation sets use the same meteorological conditions but change the emission scenarios. The model evaluation analysis showed that WRF-Chem performed well in simulating meteorological conditions over Alaska and the North Pacific under both low and high insolation conditions. Performance skill-scores of the WRF-Chem model in simulating aerosol concentrations for the coastal monitoring sites along the Gulf of Alaska were consistent with state-of-the-science air-quality model performance. During low insolation periods, domestic and international ship emissions were the most important contributors to aerosol concentrations in the coastal regions along the Gulf of Alaska. The increases/decreases in ship emissions led to subsequent increases/decreases in aerosol concentrations in the coastal areas along the Gulf of Alaska during low insolation periods. During high insolation periods, in Interior Alaska, the contributions of local wildfire emissions to aerosol concentrations were notable even during the weak Alaska fire activity scenario. Under the strong Alaska fire activity scenario, local wildfire emissions were the dominant source of aerosols in Interior Alaska. The increases in Alaskan wildfire emissions led to significant increases in aerosol concentrations in Interior Alaska. During both low and high insolation periods, Japanese anthropogenic and Siberian wildfire emissions were not important contributors to total aerosol concentrations in all regions of Alaska. Overall in the wilderness areas along the Gulf of Alaska, the increases in aerosol concentrations observed during low insolation periods stemmed from increases in domestic and international ship emissions in the North Pacific. In contrast, the increases in aerosol concentrations observed at Denali NP during high insolation periods stemmed from increases in Alaskan wildfire emissions.1. Introduction -- 2. Experimental design and methodology -- 3. Emission inventory -- 4. Impacts of emission changes on sulfate aerosols in Alaska -- 5. Potential impacts of an emission control area on air quality in Alaska coastal regions -- 6. Impacts of wildfire emissions and their changes on PM₂.₅ concentrations and speciation in Alaska -- 7. Conclusions
Immigration and Reverse Brain Drain in South East Asia
In recent years, governments around the world have shown increasing concerns about brain drain, the shift in human intelligence of many of their best educated citizens from developing countries to developed countries, as it causes negative effects on social and economic sectors of the source country. Nonetheless, Kuhn and McAusland (2006) argue that talent might often be wasted at home; migration to more supportive environments raises global innovation. Saxenian (2003) finds that gains may flow back to the developing country via returnees with enhanced skills, personal connections, and ideas for innovation. This thesis studies the causes of immigration. The study focuses on migrants from South East Asian countries to 50 states in United States excluding District of Columbia. Using a sample from the American Community Survey of people living in the United States, together with the source country data from World Development Indicator, U.S. Department of Agriculture, Bureau of Labor Statistics, International Labor Organization, and Heritage Foundation, this thesis constructs a gravity model of immigration to analyze the factors affecting the immigration flow. The dependent variable of the model is the number of immigrants flowing into each of the 50 states from each of the 8 source countries. The result shows that for high-skilled immigrants, GDP per capita differentials between U.S. states and the source country, the political factor, population of both the U.S. and the source country, the distance between the destination and the origin, as well as the corruption freedom index have a positive influence on the immigration flow. On the other hand, income inequality in the U.S. has a negative effect on the immigration flow, suggesting that the immigration flow looks for a more socially balanced lifestyle. This thesis also suggests that the source country’s government implement changes to improve the gender inequality as well as the income inequality to mitigate the outflow of residents
THE PRICE OF NON-COOPERATION IN RESERVATION-BASED BANDWIDTH SHARING PROTOCOLS
ABSTRACTIn reservation-based bandwidth sharing protocols, the base station relies on the stations’ requests to allocate time slots to them. Like most other protocols, reservation-based protocols were designed with the assumption that all stationsrespect the rules of the protocols. However, as mobile devices are becoming more intelligent andprogrammable, they can selfishly optimize their operations to obtain a larger share of commonbandwidth. Here, we study reservation-based bandwidth sharing protocols considering the existence of selfish stations through game-theoretic perspectives. We show that this game admits a Nash equilibrium. Then, we prove the inefficiency of the Nash equilibrium. Game-theoretical analysis shows that local optimization in the bandwidth sharing problem with conflicted interests does not lead to any global optimization.Keywords. Nash equilibrium, Repeated game, Reservation-based
The debates and the long-awaited reform
Trung Tran, Phuong-Thao T. Trinh, Thu-Trang Vuong, Hiep-Hung Pham (2019). Chapter 1. The debates and the long-awaited reform. In Quan-Hoang Vuong, Trung Tran (Eds.), The Vietnamese Social Sciences at a Fork in the Road (pp. 17–32). Warsaw, Poland: De Gruyter / Sciendo. DOI:10.2478/9783110686081-006
Online ISBN: 9783110686081
© 2019 De Gruyter / Sciend
Co-doping red-emitting Sr2Si5N8:Eu2+ into yellow-emitting phosphor-packaging for enhancing the optical properties of the 8500 K remote-phosphor packaging wleds
In the last decades, WLEDs attract more and more consideration in both academic and industrial purposes because of its advantages such as fast response time, environment friendliness, small size, long lifetime, and high efficiency. In this research, by doping the red-emitting Sr2Si5N8:Eu2+ phosphor particles into yellow-emitting YAG:Ce phosphor-packaging, a new recommendation for enhancing the optical properties (color uniformity, color rendering index, and lumen output) of the 8500 K remote-phosphor packaging WLEDs is presented, investigated, and demonstrated. By using Mat Lab and Light Tools software based on Mie Theory, the obtained results show that the optical properties of the 8500 K remote-phosphor packaging WLEDs significantly depended on Sr2Si5N8:Eu2+ concentration. The results have provided a potential practical recommendation for manufacturing remote-phosphor W-LEDs.Web of Science1341034102
‘The painting can be fake, but not the feeling’: an overview of the Vietnamese market through the lens of fake, forgery and copy paintings
A work of Vietnamese art crossed a million-dollar mark in the international art market in early 2017. The event was reluctantly seen as a sign of maturity from the Vietnamese art amidst the many existing problems. Even though the Vietnamese media has discussed the issues enthusiastically, there is a lack of literature from the Vietnamese academics examining the subject, and even rarer in from the market perspective. This paper aims to contribute an insightful perspective on the Vietnamese art market, and hesitantly the Vietnamese art as well, through the lens of fake, forgery and copy artworks. 35 cases of fake, forgery and copy paintings were found on the news and from the experts' wisdom. Through the examples, we argue that the Vietnamese art market is a temporary reaction to the immaturely rising of the Vietnamese art and the economy. Therefore, the art market is unable to function healthily unless the Vietnamese art and the economy developed
A comprehensive evaluation of polygenic score and genotype imputation performances of human SNP arrays in diverse populations
publishedVersio
On how religions could accidentally incite lies and violence: folktales as a cultural transmitter
Folklore has a critical role as a cultural transmitter, all the while being a socially accepted medium for the expressions of culturally contradicting wishes and conducts. In this study of Vietnamese folktales, through the use of Bayesian multilevel modeling and the Markov chain Monte Carlo technique, we offer empirical evidence for how the interplay between religious teachings (Confucianism, Buddhism, and Taoism) and deviant behaviors (lying and violence) could affect a folktale’s outcome. The findings indicate that characters who lie and/or commit violent acts tend to have bad endings, as intuition would dictate, but when they are associated with any of the above Three Teachings, the final endings may vary. Positive outcomes are seen in cases where characters associated with Confucianism lie and characters associated with Buddhism act violently. The results supplement the worldwide literature on discrepancies between folklore and real-life conduct, as well as on the contradictory human behaviors vis-à-vis religious teachings. Overall, the study highlights the complexity of human decision-making, especially beyond the folklore realm
How Digital Natives Learn and Thrive in the Digital Age: Evidence from an Emerging Economy
As a generation of ‘digital natives,’ secondary students who were born from 2002 to 2010 have various approaches to acquiring digital knowledge. Digital literacy and resilience are crucial for them to navigate the digital world as much as the real world; however, these remain under-researched subjects, especially in developing countries. In Vietnam, the education system has put considerable effort into teaching students these skills to promote quality education as part of the United Nations-defined Sustainable Development Goal 4 (SDG4). This issue has proven especially salient amid the COVID−19 pandemic lockdowns, which had obliged most schools to switch to online forms of teaching. This study, which utilizes a dataset of 1061 Vietnamese students taken from the United Nations Educational, Scientific, and Cultural Organization (UNESCO)’s “Digital Kids Asia Pacific (DKAP)” project, employs Bayesian statistics to explore the relationship between the students’ background and their digital abilities. Results show that economic status and parents’ level of education are positively correlated with digital literacy. Students from urban schools have only a slightly higher level of digital literacy than their rural counterparts, suggesting that school location may not be a defining explanatory element in the variation of digital literacy and resilience among Vietnamese students. Students’ digital literacy and, especially resilience, also have associations with their gender. Moreover, as students are digitally literate, they are more likely to be digitally resilient. Following SDG4, i.e., Quality Education, it is advisable for schools, and especially parents, to seriously invest in creating a safe, educational environment to enhance digital literacy among students
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