Continuous data assimilation for the three-dimensional Brinkman-Forchheimer-extended Darcy model

In this paper we introduce and analyze an algorithm for continuous data assimilation for a three-dimensional Brinkman-Forchheimer-extended Darcy (3D BFeD) model of porous media. This model is believed to be accurate when the flow velocity is too large for Darcy's law to be valid, and additionally the porosity is not too small. The algorithm is inspired by ideas developed for designing finite-parameters feedback control for dissipative systems. It aims to obtaining improved estimates of the state of the physical system by incorporating deterministic or noisy measurements and observations. Specifically, the algorithm involves a feedback control that nudges the large scales of the approximate solution toward those of the reference solution associated with the spatial measurements. In the first part of the paper, we present few results of existence and uniqueness of weak and strong solutions of the 3D BFeD system. The second part is devoted to the setting and convergence analysis of the data assimilation algorithm

Effects of window-to-wall ratio on energy consumption: Application of numerical and ann approaches

Buildings account for a major part of Total Energy Consumption (TEC) in comparison to that of industry and other sections. The opening and envelope material can affect their TEC. Accordingly, this paper aims to study the effects of the window to external wall ratio (WWR) and the application of recycled panels as the building envelope on the total energy consumption in a one-floor residential building located in Iran and characterized by a semi-arid climate. To follow the sustainability criterion, we designed two concrete panels for the external walls’ envelope including a porous concrete panel and recycled ash concrete panel. The WWR varies between 5% to 95% and the optimal WWRs are separately presented for all the months. To develop the models, we used Design Builder software which its simulations are validated via field observations. For all the panels, the least energy consumption is obtained when the WWR is 5%. However, due to lighting issues, the most optimal WWR is calculated as 45-55% based on the results of the numerical simulations. Further, it is proved that the recycled ash concrete panel outperforms the porous concrete panel in terms of minimum energy consumption. Hence, it is recommended to use eco-friendly material as the external walls envelop with the WWR below 50%. The numerical simulations provided 240 data points for each panel which is exploited to develop an ANN model. The results suggested that the ANN models predict the TEC based on the month and WWR with high accuracy

Reply to “Comments on “Consensus and Cooperation in Networked Multi-Agent Systems””

[No abstract

Perturbative Analysis of Spectral Singularities and Their Optical Realizations

We develop a perturbative method of computing spectral singularities of a Schreodinger operator defined by a general complex potential that vanishes outside a closed interval. These can be realized as zero-width resonances in optical gain media and correspond to a lasing effect that occurs at the threshold gain. Their time-reversed copies yield coherent perfect absorption of light that is also known as an antilaser. We use our general results to establish the exactness of the n-th order perturbation theory for an arbitrary complex potential consisting of n delta-functions, obtain an exact expression for the transfer matrix of these potentials, and examine spectral singularities of complex barrier potentials of arbitrary shape. In the context of optical spectral singularities, these correspond to inhomogeneous gain media.Comment: 13 pages, 2 figures, one table, a reference added, typos correcte

On Steering Swarms

The main contribution of this paper is a novel method allowing an external observer/controller to steer and guide swarms of identical and indistinguishable agents, in spite of the agents' lack of information on absolute location and orientation. Importantly, this is done via simple global broadcast signals, based on the observed average swarm location, with no need to send control signals to any specific agent in the swarm

Impact of Immunotherapy on the Survival of Pancreatic Adenocarcinoma Patients: An Analysis of the National Cancer Database

Pancreatic adenocarcinoma (PDAC) represents 7.2% of all cancer deaths, and by 2030, it will become the second leading cause of death due to cancer. The median overall survival (OS) is 17-23 months in resectable and 4-6 months in metastatic PC [8-9]. The 5-year survival of resectable PC is 22%, and unresectable PC is 8%. A majority of patients treated with standard treatments such as surgery, chemotherapy, and radiation therapy eventually succumb to the disease due to widespread micrometastases at the time of diagnosis. Due to the minimal effect of the current treatments, novel treatment strategies such as immunotherapeutics have been proposed. Immunotherapy has shown excellent efficacy in many other malignancies, but its role in the survival of PC patients is unclear. The objectives of this dissertation were to investigate the impact of immunotherapy, including the sequence of treatments on the OS of PC patients stratified by definitive surgery of the pancreatic tumor. Data from the National Cancer Database was used to address these objectives. In this study, immunotherapy was associated with improved OS compared to no immunotherapy in both patients who received definitive surgery of the pancreatic tumor and patients who did not undergo surgery. In the surgery group, patients who received chemotherapy plus immunotherapy or chemoradiation plus immunotherapy had better OS compared to their counterparts without immunotherapy. In the no surgery group, patients who received chemoradiation plus immunotherapy had better OS compared to patients who received chemoradiation without immunotherapy. There was no significant difference in the OS of patients who started immunotherapy 31-90 days before chemotherapy, patients who started immunotherapy 91-180 days before chemotherapy, and patients who started chemotherapy and immunotherapy within 30 days of each other. There was also no significant difference in the OS of patients who started RT\u3e 30 days before the start of immunotherapy, patients who started immunotherapy \u3e 30 days before RT, and patients who started RT and immunotherapy within 30 days of each other. There was no significant difference in the OS of patients who received neoadjuvant immunotherapy and patients who received adjuvant immunotherapy. The study also highlighted the need for improving access to novel treatments as patients with older age, Black race, living in the rural areas, living in the areas with low education level, and diagnosis before 2011 were less likely to receive immunotherapy compared to their counterparts. The findings of the current study warrant future clinical trials of immunotherapy in PDAC patients

No Fare: Remedying the Member Business Loan Loophole

The member business loan exemption of the Federal Credit Union Act was the driving force behind the New York City taxi medallion loan crisis that led to over 950 bankrupt taxi drivers and eight suicides. This Note analyzes the exemption as the legislature’s balancing act to reconcile two competing policy aims: keeping lenders safe while encouraging them to lend to risky borrowers. Viewed through the lens of the taxi medallion crisis, this Note demonstrates the severe harm that this loophole creates. Exempting credit unions from regulatory limits has left vulnerable borrowers subject to the adverse designs of powerful actors. Ultimately, this Note proposes statutory loan protections with severe penalties for the exempt institutions to keep the credit unions and borrowers financially safe and sound