134 research outputs found
Singular hermitian metrics on holomorphic vector bundles
We introduce and study the notion of singular hermitian metrics on holomorphic vector bundles, following Berndtsson and Pun. We define what it means for such a metric to be positively and negatively curved in the sense of Griffiths and investigate the assumptions needed in order to locally define the curvature I similar to (h) as a matrix of currents. We then proceed to show that such metrics can be regularised in such a way that the corresponding curvature tensors converge weakly to I similar to (h) . Finally we define what it means for h to be strictly negatively curved in the sense of Nakano and show that it is possible to regularise such metrics with a sequence of smooth, strictly Nakano negative metrics
Çırağan
Taha Toros Arşivi, Dosya No: 120-Saraylarİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033
Chern forms of singular metrics on vector bundles
We study singular hermitian metrics on holomorphic vector bundles, following
Berndtsson-P{\u{a}}un. Previous work by Raufi has shown that for such metrics,
it is in general not possible to define the curvature as a current with measure
coefficients. In this paper we show that despite this, under appropriate
codimension restrictions on the singular set of the metric, it is still
possible to define Chern forms as closed currents of order 0 with locally
finite mass, which represent the Chern classes of the vector bundle.Comment: 18
Prospect of the use of checkpoint inhibitors in hepatocellular cancer treatments
Hepatocellular cancer (HCC) is a very fatal disease due to limited therapeutic options as well as due to its association with underlying chronic liver disease in the majority of cases. The immune evasion in HCC signifies a major barrier to the delivery of effective immunotherapy. Sorafenib is the only Food and Drug Administration-approved drug available with an overall response rate of 2%–3% and overall survival of 2.8 months. Chemotherapy has not been used routinely because of the relative refractoriness of advanced HCC. The introduction of immune checkpoint inhibitors (cytotoxic T-lymphocyte antigen 4, programmed death 1, and programmed death-ligand 1) has opened a new horizon for cancer immunotherapy. Future direction in immunotherapy for HCC is to rationally combine it with other treatment modalities, including surgery, radiofrequency ablation, and cytotoxic agents, to maximize its therapeutic efficacy
An Evaluation of the EEG Alpha-to-Theta and Theta-to-Alpha Band Ratios as Indexes of Mental Workload
Many research works indicate that EEG bands, specifically the alpha and theta bands, have been potentially helpful cognitive load indicators. However, minimal research exists to validate this claim. This study aims to assess and analyze the impact of the alpha-to-theta and the theta-to-alpha band ratios on supporting the creation of models capable of discriminating self-reported perceptions of mental workload. A dataset of raw EEG data was utilized in which 48 subjects performed a resting activity and an induced task demanding exercise in the form of a multitasking SIMKAP test. Band ratios were devised from frontal and parietal electrode clusters. Building and model testing was done with high-level independent features from the frequency and temporal domains extracted from the computed ratios over time. Target features for model training were extracted from the subjective ratings collected after resting and task demand activities. Models were built by employing Logistic Regression, Support Vector Machines and Decision Trees and were evaluated with performance measures including accuracy, recall, precision and f1-score. The results indicate high classification accuracy of those models trained with the high-level features extracted from the alpha-to-theta ratios and theta-to-alpha ratios. Preliminary results also show that models trained with logistic regression and support vector machines can accurately classify self-reported perceptions of mental workload. This research contributes to the body of knowledge by demonstrating the richness of the information in the temporal, spectral and statistical domains extracted from the alpha-to-theta and theta-to-alpha EEG band ratios for the discrimination of self-reported perceptions of mental workload
Prediction of damage intensity in moment frames by using wavelet analysis
After occurrence of an earthquake, one of the most important applications of recorded information in instrumented buildings is using these data in observation and estimation of damage in the structural systems of the building. A method using plastic hinge formation and wavelet analysis has been presented which directly makes use of rotational response history of frame nodes (rotation, angular velocity, angular acceleration) for extracting information of damage
An Evaluation of the EEG Alpha-to-Theta and Theta-to-Alpha Band Ratios as Indexes of Mental Workload
Many research works indicate that EEG bands, specifically the alpha and theta bands, have been potentially helpful cognitive load indicators. However, minimal research exists to validate this claim. This study aims to assess and analyze the impact of the alpha-to-theta and the theta-to-alpha band ratios on supporting the creation of models capable of discriminating self-reported perceptions of mental workload. A dataset of raw EEG data was utilized in which 48 subjects performed a resting activity and an induced task demanding exercise in the form of a multitasking SIMKAP test. Band ratios were devised from frontal and parietal electrode clusters. Building and model testing was done with high-level independent features from the frequency and temporal domains extracted from the computed ratios over time. Target features for model training were extracted from the subjective ratings collected after resting and task demand activities. Models were built by employing Logistic Regression, Support Vector Machines and Decision Trees and were evaluated with performance measures including accuracy, recall, precision and f1-score. The results indicate high classification accuracy of those models trained with the high-level features extracted from the alpha-to-theta ratios and theta-to-alpha ratios. Preliminary results also show that models trained with logistic regression and support vector machines can accurately classify self-reported perceptions of mental workload. This research contributes to the body of knowledge by demonstrating the richness of the information in the temporal, spectral and statistical domains extracted from the alpha-to-theta and theta-to-alpha EEG band ratios for the discrimination of self-reported perceptions of mental workload
The Eco-Thrifter’s Medley: Designing a low-waste lifestyle guide that seeks to address and overcome common barriers to sustainable living
Sustainability: a broad term that attempts to define societal effort toward ensuring future generations of humanity are able to survive and thrive on a healthy, livable planet Earth. In recent times, “sustainability” seems to have become little more than a buzzword, overused into oblivion by media and marketing campaigns. However, while I was developing my Interdisciplinary Concentration at Fairhaven College in which I explored the intersection between design, environmentalism, and communications, I found it difficult to avoid the word when I was explaining what I was trying to do through my studies. Despite its overuse, I find that the term remains a useful shorthand for any kind of effort on the part of the individual, community, or society to work toward environmental health, especially as it is understood in popular Western culture. The Eco-Thrifter’s Medley is a guide to developing eco-conscious habits at the individual level, but in a way that shifts away from individualistic narratives of “personal responsibility”. Instead, it is meant to encourage individual sustainable practices as part of a larger cultural shift toward sustainability on the communal and societal levels, with a particular focus on affordability and accessibility to students and working people. While conducting research to help inform the guide, I discovered that the two primary obstacles to achieving individual sustainability reported by my target audience were the viewpoint that adopting an eco-friendly lifestyle is not financially feasible for the average person, and the belief that personal habits have a negligible impact on the overall welfare of the environment. My general goal with this project was to identify and offer solutions to these and other mental, physical, and cultural barriers when it comes to adopting more environmentally sustainable habits, all while utilizing visual design communication to make these messages as accessible and aesthetically pleasing as possible to a popular audience. The full version of The Eco-Thrifter’s Medley, based on research and personal experience, will include tips on greener cooking, shopping, and energy usage, with integrated principles of personal health and well-being along with community involvement toward larger sociopolitical change. I began this project with a volume on food and sustainable eating, which I included a sample of in my presentation
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