Search results for "modeling"
showing 10 items of 4489 documents
Modeling initial Neolithic dispersal. The first agricultural groups in West Mediterranean
2015
Abstract In previous research, the SE-NW time-trend in the age of the earliest Neolithic sites across Europe has been treated as a signal of a global-scale process that brought farming/herding economies to the continent. Residual variation from this global time-trend is generally treated as ‘noise’. A Complex Adaptive Systems perspective views this empirical record differently. The apparent time-trend is treated as an emergent consequence of the interactions of individuals and groups of different scale. Here, we examine the dynamics of agricultural dispersals, using the rich body evidence available from the Iberian Peninsula as a case study. We integrate two complementary approaches: (1) cr…
Kompleksy metali przejściowych z zasadami Lewisa jako prekursory katalizatorów polimeryzacji olefin. Cz. I. Postęp w komputerowym modelowaniu procesu…
2001
A review with 35 references covering molecular modeling in coordination polymerization over homogeneous and heterogeneous Ziegler-Natta catalysts. The study includes supports, cocatalysts, Lewis bases and solvents. Recent progress in elucidating the mechanisrn of elementary polymerization steps is presented against the background of rapidly deveIoping computational methods and available computational power. Theoretical studies on polymerization mcchanisms and structure of active centers are described (egns. 1-4). Authors own calculations are used to compare [MtC14(THF)2] complex-based (Mt = Ti, Hf or Zr) heterogeneous catalysts. The geometrical characteristics of precursors is presented (Ta…
Near-Infrared-Responsive Choline-Calix[4]arene-Gold Nanostructures for Potential Photothermal Cancer Treatment
2022
The development of novel chemical approaches for the fabrication of gold nanostructures with localized surface plasmon resonance (LSPR) falling in the near-infrared (NIR) region is one challenging topic in nanomaterials science. Due to their optical and photothermal properties triggered by light excitation in the therapeutic window (λmax = 650-1300 nm), gold-based nanostructures are appealing candidates in anticancer nanomedicine. Here, we report a novel method to prepare water-dispersible gold nanostructures with NIR-LSPR (λmax = 600-1000 nm) properties. The gold nanostructures were achieved in a single step by an unconventional method using NADH as a reducing agent and an amphiphilic chol…
Up-wind difference approximation and singularity formation for a slow erosion model
2020
We consider a model for a granular flow in the slow erosion limit introduced in [31]. We propose an up-wind numerical scheme for this problem and show that the approximate solutions generated by the scheme converge to the unique entropy solution. Numerical examples are also presented showing the reliability of the scheme. We study also the finite time singularity formation for the model with the singularity tracking method, and we characterize the singularities as shocks in the solution.
Helena Niemirowska Syrkus: Graphic analysis of the ‘House of Dr Nelken in Warsaw’
2017
In 1920s and 1930s, Warsaw was becoming one of the hubs of propagation of the new architecture, thanks to the geographical contiguity with the Weimar Republic, which allowed the formation of young minds aimed at a blending of architecture, art and music. In this cultural context, a young Helena Niemirowska Syrkus supported the idea that urban planning and architecture, conceived as art forms, had to target at the definition of a language able of expressing the great revolutionary step achieved in the social, economic and political life of that time, through new configurations. According to Helena Niemirowska, who shared the avant-garde thesis, to become an artist the modern architect had to…
The Impact of Green Roofs on the Parameters of the Environment in Urban Areas—Review
2019
This study presents the results of a review of publications conducted by researchers in a variety of climates on the implementation of ‘green roofs’ and their impact on the urban environment. Features of green roofs in urban areas have been characterized by a particular emphasis on: Filtration of air pollutants and oxygen production, reduction of rainwater volume discharged from roof surfaces, reduction of so-called ‘urban heat islands’, as well as improvements to roof surface insulation (including noise reduction properties). The review of the publications confirmed the necessity to conduct research to determine the coefficients of the impact of green roofs on the environment in the city c…
AI ethics:an empirical study on the views of practitioners and lawmakers
2023
Artificial intelligence (AI) solutions and technologies are being increasingly adopted in smart systems contexts; however, such technologies are concerned with ethical uncertainties. Various guidelines, principles, and regulatory frameworks are designed to ensure that AI technologies adhere to ethical well-being. However, the implications of AI ethics principles and guidelines are still being debated. To further explore the significance of AI ethics principles and relevant challenges, we conducted a survey of 99 randomly selected representative AI practitioners and lawmakers (e.g., AI engineers and lawyers) from 20 countries across five continents. To the best of our knowledge, this is the …
Examining Competing Entrepreneurial Concerns in a Social Question and Answer (SQA) Platform
2021
This study aims to determine the competing concerns of people interested in startup development and entrepreneurship by using topic modeling and sentiment analysis on a social question-and-answer (SQA) website. Understanding the underlying concerns of startup entrepreneurs is critical to society and economic growth. Therefore, greater scientific support for entrepreneurship remains necessary, including data mining from virtual social communities. In this study, an SQA platform was used to identify the sentiment of thirty concerns of people interested in startup entrepreneurship. Based on topic modeling and sentiment analysis of 18819 inquiries in various forums on an SQA, we identified addi…
A person-oriented approach to sport and school burnout in adolescent student-athletes: The role of individual and parental expectations
2017
Abstract Objectives The present study aimed to examine what kind of burnout profiles exist among student-athletes based on their sport and school burnout symptoms. Moreover, it was investigated whether athletes' expectations of success in sport and school, on the one hand, and parental expectations, on the other hand, were predictors of the likelihood of the athlete to show a certain profile, after taking into account the effects of gender, grade point average, type of sport, and level of competition. Design and methods The participants were 391 student-athletes (51% females) from six different upper secondary sport schools in Finland, and 448 parents (58% mothers). The athletes filled in q…
Towards a Real-time Mitigation of High Temperature while Drilling using a Multi-agent System
2018
International audience; In oilfield wells, while drilling for several kilometers below surface, high temperature damages the drilling tools. This costs money and time for tripping operations to change the damaged tool. Existing temperature mitigation techniques have several drawbacks including a long response time, analogue signal issues and human intervention. In this work, we empower the down-hole tools with a coordination mechanism to mitigate high temperature in soft real time by controlling a down-hole actuator through a voting process. The tools are represented by agents that control the sensors and actuators embedded in these tools. To implement the proposed system properly, a model …