100 research outputs found
114 - Mahsa Ghorbani
No full textStock price prediction is one of the most challenging problems in finance and is receiving considerable attention from researchers. The literature provides strong evidence that prices can be predicted from past price data as well as other fundamental and macroeconomic variables. We propose a filtering operation using covariance information in order to predict future stock prices. We use daily historical price data for Generals Electric Company to illustrate our method, which shows promising results in terms of the estimation performance and volatility
An Integrated Modeling Framework to Estimate Time Series of Evapotranspiration on a Regional Scale Using MODIS Data and a Two-Source Energy Balance Model
No full textSatellite remote sensing has become an important tool for monitoring and evaluating the impacts of drought. In this study, a modeling framework aimed at estimating the time series of evapotranspiration (ET), a key variable for drought monitoring, at a regional scale is presented. A two-source energy balance (TSEB) model was used concurrently with Terra/Aqua MODIS data and the ERA5 atmospheric reanalysis dataset. The modeling framework is based on the SEN-ET scheme to calculate the surface energy balance of the soil-canopy-atmosphere continuum and estimate ET at 1 km spatial resolution. The model was applied for the whole Iberian Peninsula, and it was evaluated with a pistachio orchard flux tower data in Lleida (NE Iberian Peninsula). Preliminary daily ET evaluation results for the Terra dataset showed an RMSE, MBE, and R2 of around 1.43 W·m−2, −1.27 W·m−2, and 0.56, respectively, and for the Aqua dataset were 1.05 W·m−2, −0.84 W·m−2 and 0.48, respectively within 100 days in 2022. Ongoing evaluation is being carried out on two forested watersheds as well as mountain meadows and semi-arid vegetation flux towers
Time Series Analysis of Evapotranspiration for Assessing Drough Impact on Wheat Yield
No full textDrought is a devastating natural hazard which causes reductions in crop yields. This study aims to analyze the relationship between wheat yield and evapotranspiration (ET) dynamics across the last two decades in the Iberian Peninsula. A two-source energy balance (TSEB) model with Terra/Aqua MODIS data and the ERA5 atmospheric reanalysis dataset were used to calculate daily ET at 1 km spatial resolution. The Breaks for Additive Seasonal and Trend (BFAST) method was applied to detect drought events. The ET time series was decomposed into seasonal, trend, and remainder components using BFAST to identify changes in trend and seasonal components in the 22-year daily ET time series. Breakpoints were identified in the ET time series corresponding to the years of yield decline. Results showed ET anomalies can serve as an indicator for recognizing droughts. This research suggests the utility of time series analysis of ET for early drought detection, a practical approach for mitigating the impact of climatic change on crop yields
Nurturing success with learning disabilities in French immersion with teachers' and parents' support and collaboration
No full textThis paper draws upon my six years of teaching French as the second or foreign languages as well as my academic experiences in the Master of Education program. Within the past six years, I have perceived the second language acquisition to be an enjoyable and pleasant journey for all my students similar to what I experienced as a child. However, having faced various learning styles and needs as well as the uncertainty of some parents about the placement of their children with learning disabilities in French Immersion, I gravitated to inquire more into the compatibility of this program for my at-risk students. The French Immersion program is suitable for the students with learning disabilities if they can be provided with proper support in positive and motivating learning environments, such as school and home. This knowledge would benefit the teachers and parents who need to be ensured that the inclusion of the students with learning difficulties in French Immersion is educationally sound. Through the analysis of different strategies and accommodations, this paper discusses how the students with learning disabilities and their families can address their concerns and avoid some challenges, such as transition to English-only programs after having built several years of connections and friendships and the associated social-emotional impacts. This paper also seeks to convey the message to the teachers that learning disability should not hinder language acquisition. The implications emerged from this awareness are that educators and parents can advocate for the students with learning disabilities through their collaborative efforts, so that they can have equitable access to learning French in supportive and inspirational learning environments.Not peer reviewedcapstoneFrench immersionlearning disabilitysecond language acquisitioninclusionary practiceshome-school collaborationhome-school collaboratio
Evaluating the Two-Source Energy Balance Model Using MODIS Data for Estimating Evapotranspiration Time Series on a Regional Scale
No full textEstimating daily continuous evapotranspiration (ET) can significantly enhance the monitoring of crop stress and drought on regional scales, as well as benefit the design of agricultural drought early warning systems. However, there is a need to verify the models’ performance in estimating the spatiotemporal continuity of long-term daily evapotranspiration (ETd) on regional scales due to uncertainties in satellite measurements. In this study, a thermal-based two-surface energy balance (TSEB) model was used concurrently with Terra/Aqua MODIS data and the ERA5 atmospheric reanalysis dataset to calculate the surface energy balance of the soil–canopy–atmosphere continuum and estimate ET at a 1 km spatial resolution from 2000 to 2022. The performance of the model was evaluated using 11 eddy covariance flux towers in various land cover types (i.e., savannas, woody savannas, croplands, evergreen broadleaf forests, and open shrublands), correcting for the energy balance closure (EBC). The Bowen ratio (BR) and residual (RES) methods were used for enforcing the EBC in the EC observations. The modeled ET was evaluated against unclosed ET and closed ET (ETBR and ETRES) under clear-sky and all-sky observations as well as gap-filled data. The results showed that the modeled ET presented a better agreement with closed ET compared to unclosed ET in both Terra and Aqua datasets. Additionally, although the model overestimated ETd across all different land cover types, it successfully captured the spatiotemporal variability in ET. After the gap-filling, the total number of days compared with flux measurements increased substantially, from 13,761 to 19,265 for Terra and from 13,329 to 19,265 for Aqua. The overall mean results including clear-sky and all-sky observations as well as gap-filled data with the Aqua dataset showed the lowest errors with ETRES, by a mean bias error (MBE) of 0.96 mm.day−1, an average mean root square (RMSE) of 1.47 mm.day−1, and a correlation (r) value of 0.51. The equivalent figures for Terra were about 1.06 mm.day−1, 1.60 mm.day−1, and 0.52. Additionally, the result from the gap-filling model indicated small changes compared with the all-sky observations, which demonstrated that the modeling framework remained robust, even with the expanded days. Hence, the presented modeling framework can serve as a pathway for estimating daily remote sensing-based ET on regional scales. Furthermore, in terms of temporal trends, the intra-annual and inter-annual variability in ET can be used as indicators for monitoring crop stress and drought
Land surface temperature estimating in urbanized landscapes using artificial neural networks
No full textEvaluating the Two-Source Energy Balance Model Using MODIS Data for Estimating Evapotranspiration Time Series on a Regional Scale
No full textEstimating daily continuous evapotranspiration (ET) can significantly enhance the monitoring of crop stress and drought on regional scales, as well as benefit the design of agricultural drought early warning systems. However, there is a need to verify the models’ performance in estimating the spatiotemporal continuity of long-term daily evapotranspiration (ETd) on regional scales due to uncertainties in satellite measurements. In this study, a thermal-based two-surface energy balance (TSEB) model was used concurrently with Terra/Aqua MODIS data and the ERA5 atmospheric reanalysis dataset to calculate the surface energy balance of the soil–canopy–atmosphere continuum and estimate ET at a 1 km spatial resolution from 2000 to 2022. The performance of the model was evaluated using 11 eddy covariance flux towers in various land cover types (i.e., savannas, woody savannas, croplands, evergreen broadleaf forests, and open shrublands), correcting for the energy balance closure (EBC). The Bowen ratio (BR) and residual (RES) methods were used for enforcing the EBC in the EC observations. The modeled ET was evaluated against unclosed ET and closed ET (ETBR and ETRES) under clear-sky and all-sky observations as well as gap-filled data. The results showed that the modeled ET presented a better agreement with closed ET compared to unclosed ET in both Terra and Aqua datasets. Additionally, although the model overestimated ETd across all different land cover types, it successfully captured the spatiotemporal variability in ET. After the gap-filling, the total number of days compared with flux measurements increased substantially, from 13,761 to 19,265 for Terra and from 13,329 to 19,265 for Aqua. The overall mean results including clear-sky and all-sky observations as well as gap-filled data with the Aqua dataset showed the lowest errors with ETRES, by a mean bias error (MBE) of 0.96 mm.day−1, an average mean root square (RMSE) of 1.47 mm.day−1, and a correlation (r) value of 0.51. The equivalent figures for Terra were about 1.06 mm.day−1, 1.60 mm.day−1, and 0.52. Additionally, the result from the gap-filling model indicated small changes compared with the all-sky observations, which demonstrated that the modeling framework remained robust, even with the expanded days. Hence, the presented modeling framework can serve as a pathway for estimating daily remote sensing-based ET on regional scales. Furthermore, in terms of temporal trends, the intra-annual and inter-annual variability in ET can be used as indicators for monitoring crop stress and drought.This study was funded by the project ET4DROUGHT (No. PID2021-127345OR-C31) and DigiSPAC [TED2021-131237B-C21] both funded by the Ministry of Science and Innovation (MICIN-AEI).info:eu-repo/semantics/publishedVersio
Structural changes of conversion metal fluoride cathodes in lithium ion batteries
No full textCurrently, cathode materials for Li-ion batteries are based on intercalation processes where, during charge and discharge processes, Li intercalates into the crystal lattice while maintaining the host crystal structure. More recently, new cathode materials have been introduced based on conversion reactions involving phase transformation and complete reduction of the host transition metal. In addition, conversion reactions involve two or more Li ions with a resulting much higher capacity than obtainable for intercalation materials. However, mechanism of phase transformation and cycling reversibility are at present still poorly understood. In this study transmission electron microscopy (TEM) techniques including selected area electron diffraction (SAED) pattern, annular dark field (ADF) STEM image, and electron energy loss spectroscopy (EELS) with nanoscale spatial resolution were used to study the phase evolution and structural changes of iron fluorides (FeFe2, FeO0.7F1.3, FeF3) after various discharge/charge cycles. Additionally, the changes of the Fe valence states upon cycling were determined using EELS by measuring the L3/L2 intensity ratio of Fe-L edge. The structural transformations of FeO0.7F1.3 during the first lithiation show that litiahation contains two regions. The first region, lithiation is an intercalation reaction iii with reduction of Fe3+ to Fe2+. The second region of lithiation involves a conversion reaction, with the formation of metallic Fe, LiF, and Li0.7Fe2+0.5O0.7F0.3 (rocksalt type) phases. The first delithiation process follows a different conversion reaction path compared to the first lithiation reaction involving the formation an amorphous rutile-type phase along with with the rocksalt-type phase. Interestingly, upon full recharge (delithiated electrode), the measured average Fe valence state returns back to its initial value of Fe2.7+. The growth of a solid electrolyte interphase (SEI) layer formation at the electrode/electrolyte interface is observed for the iron fluoride compounds (FeF2, FeF3, and FeOF) after cycling. The evolution of the SEI layer formation after cycling has been studied for the FeF2 samples in details by EELS and XPS. We observed the growth of SEI layer with cycle number, which mainly contained LiF and Li2CO3 compounds. Two degradation mechanisms are identified. First, the increase in the decomposition product layer after cycling inhibits complete reconversion process. Second, dissolution of Fe into the SEI layer after cycling which leads to the loss of active material.Ph.D.Includes bibliographical referencesby Mahsa Sin
Nutrition and wound healing: vitamins
No full textSufficient nutrition is important for all medical surgical patients. In the clinical setting, many patients postoperative receive multivitamin and minerals to maintain adequate nutrition. This poster presentation will address the importance of supplementary vitamins to wound healing. Complications of delay wound healing includes adhesions, contractures, dehiscence, evisceration, granulation tissue, fistula formation, Infection, hemorrhage, formation of
hypertrophic scars and keloids (Lewis, Dirksen, Heitkemper, Bucher, & Camera, 2014). Conclusion: through this project we have learned that malnutrition contributes to delayed wound healing. Each vitamin we have discussed plays an important role in each stage of the healing process: inflammatory, proliferative and remodeling phase. Based on our literature review, patients who were receiving nutritional supplementation displayed a significant decrease in wound size as compared to those who did not. We now have a better understanding of supplemental nutrition (vitamins) on post surgical patients in our clinical setting and will further promote these findings through patient teaching.Not peer reviewedStudent Research Day Poster (2017
Triggering Social Entrepreneurship Initiatives: Investigating the role of Dutch national government policy in triggering social entrepreneurship initiatives focusing on delivering affordable owner-occupied housing
No full textThe Netherlands is currently facing a shortage of affordable housing, specifically for middle-income households. These households with too much income to qualify for social housing but not enough to buy a home tend to squeeze into the free rental market increasingly. Housing specifically targeted at this group is known as intermediate housing, which is provided at a cost above social rent but below market rates. In previous years, very few houses for this target group were developed due to the reluctance of the market to develop these homes due to lower profitability and strict regulations that made it difficult for local governments and social housing associations to build and distribute intermediate housing. This study's primary goal is to reduce the inequality gap in the Dutch housing market by designing a national government housing policy. As a response to the shortage of affordable housing among middle-income households, it has been proposed that more social enterprises should become active in the housing sector as well as in other industries which solve societal problems by combining economic mission and societal impact. Social housing enterprises can explicitly address the shortage of affordable housing for middle-income households, unlike commercial ones that are solely concerned with profits. Furthermore, these newly developed Social Housing Enterprises are not subject to strict rules regarding the distribution of housing to middle-income households. As a result, they might be able to address the housing shortage.The research question is "How can national government policy trigger social entrepreneurship initiatives focusing on delivering affordable owner-occupied housing?". For this research, a qualitative approach has been taken, in which primary and secondary data are used. The primary data came from ten semi-structured in-depth interviews, and the secondary data came from the literature review. In general, the national government's involvement increases the likelihood of individuals engaging in Social Entrepreneurship and its formation. The result showed that government support for removing barriers to social enterprise creation was the most important factor driving social entrepreneurship. Governments can lower barriers to social enterprises in the provision of intermediate housing by giving formal recognition, improving access to markets and finances, providing in-kind resources, and strengthening skills to trigger social entrepreneurship initiatives focusing on delivering affordable owner-occupied housing.Graduation laboratoryArchitecture, Urbanism and Building Sciences | Management in the Built Environmen
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