Search results for "erk"

Wireless Caching Aided 5G Networks

2018

Artificial Intelligence for Cybersecurity: A Systematic Mapping of Literature

2020

Due to the ever-increasing complexities in cybercrimes, there is the need for cybersecurity methods to be more robust and intelligent. This will make defense mechanisms to be capable of making real-time decisions that can effectively respond to sophisticated attacks. To support this, both researchers and practitioners need to be familiar with current methods of ensuring cybersecurity (CyberSec). In particular, the use of artificial intelligence for combating cybercrimes. However, there is lack of summaries on artificial intelligent methods for combating cybercrimes. To address this knowledge gap, this study sampled 131 articles from two main scholarly databases (ACM digital library and IEEE…

Recent advances in machine learning for maximal oxygen uptake (VO2 max) prediction : A review

2022

Maximal oxygen uptake (VO2 max) is the maximum amount of oxygen attainable by a person during exercise. VO2 max is used in different domains including sports and medical sciences and is usually measured during an incremental treadmill or cycle ergometer test. The drawback of directly measuring VO2 max using the maximal test is that it is expensive and requires a fixed and controlled protocol. During the last decade, various machine learning models have been developed for VO2 max prediction and numerous studies have attempted to predict VO2 max using data from submaximal and non-exercise tests. This article gives an overview of the machine learning models developed over the past five years (…

Asiakaskokemuksen muodostuminen ja johtaminen B2C-verkkokaupoissa : case: aiemmissa asiakaskokemus- ja verkkokauppavertailuissa menestyneet B2C-yrity…

2016

Tutkimuksen tavoitteena oli selvittää, miten aiemmissa asiakaskokemus- ja verkkokauppavertailuissa menestyneet B2C-yritykset johtavat asiakaskokemusta verkkokaupoissaan. Lisäksi tavoitteena oli selvittää miten nämä yritykset määrittelevät asiakaskokemuksen ja mistä tekijöistä he näkevät sen muodostuvan. Tutkimus pyrkii vastaamaan Verhoefin ym. (2009) esittämään tutkimustarpeeseen yritysten käyttämien asiakaskokemuksen johtamisstrategioiden hahmottamisesta sekä Marketing Science Instituten (2014) esittämään tutkimustarpeeseen asiakaskokemuksen ymmärryksen lisäämisestä. Tutkimuksen kuvailevan luonteen vuoksi tutkimusmetodiksi valikoitui laadullinen tutkimusmenetelmä. Tutkimus toteutettiin cas…

The novel HALO mini-DOAS instrument: inferring trace gas concentrations from airborne UV/visible limb spectroscopy under all skies using the scaling …

2017

Abstract. We report on a novel six-channel optical spectrometer (further on called mini-DOAS instrument) for airborne nadir and limb measurements of atmospheric trace gases, liquid and solid water, and spectral radiances in the UV/vis and NIR spectral ranges. The spectrometer was developed for measurements from aboard the German High-Altitude and Long-Range (HALO) research aircraft during dedicated research missions. Here we report on the relevant instrumental details and the novel scaling method used to infer the mixing ratios of UV/vis absorbing trace gases from their absorption measured in limb geometry. The uncertainties of the scaling method are assessed in more detail than before for …

SOUTHTRAC-GW: An airborne field campaign to explore gravity wave dynamics at the world’s strongest hotspot

2021

The southern part of South America and the Antarctic peninsula are known as the world’s strongest hotspot region of stratospheric gravity wave (GW) activity. Large tropospheric winds are deflected by the Andes and the Antarctic Peninsula and excite GWs that might propagate into the upper mesosphere. Satellite observations show large stratospheric GW activity above the mountains, the Drake Passage, and in a belt centered along 60°S. This scientifically highly interesting region for studying GW dynamics was the focus of the Southern Hemisphere Transport, Dynamics, and Chemistry–Gravity Waves (SOUTHTRAC-GW) mission. The German High Altitude and Long Range Research Aircraft (HALO) was deployed …

Microphysical and radiative characterization of a subvisible midlevel Arctic ice cluod by airborne observations - a case study

2009

During the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) campaign, which was conducted in March and April 2007, an optically thin ice cloud was observed south of Svalbard at around 3 km altitude. The microphysical and radiative properties of this particular subvisible midlevel cloud were investigated with complementary remote sensing and in situ instruments. Collocated airborne lidar remote sensing and spectral solar radiation measurements were performed at a flight altitude of 2300 m below the cloud base. Under almost stationary atmospheric conditions, the same subvisible midlevel cloud was probed with various in situ sensors roughly 30 min later. <br><br> …

Utility of Hovmöller diagrams to diagnose Rossby wave trains

2011

The study investigates and compares various methods that aim to diagnose Rossby wave trains with the help of Hovm¨ oller diagrams. Three groups of methods are distinguished: The first group contains trough-and-ridge Hovm¨ oller diagrams of the meridional wind; they provide full phase information, but differ in the method for latitudinal averaging or weighting. The second group aims to identify Rossby wave trains as a whole, discounting individual troughs and ridges. The third group contains diagnostics which focus on physical mechanisms during the different phases of a Rossby wave train life cycle; they include the analysis of eddy kinetic energy and methods for quantifying Rossby wave brea…

Properties of individual contrails: a compilation of observations and some comparisons

2017

International audience; Mean properties of individual contrails are characterized for a wide range of jet aircraft as a function of age during their life cycle from seconds to 11.5 h (7.4-18.7 km altitude, -88 to -31 °C ambient temperature), based on a compilation of about 230 previous in situ and remote sensing measurements. The airborne, satellite, and ground-based observations encompass exhaust contrails from jet aircraft from 1972 onwards, as well as a few older data for propeller aircraft. The contrails are characterized by mean ice particle sizes and concentrations, extinction, ice water content, optical depth, geometrical depth, and contrail width. Integral contrail properties includ…

ML-CIRRUS: The Airborne Experiment on Natural Cirrus and Contrail Cirrus with the High-Altitude Long-Range Research Aircraft HALO

2017

Abstract The Midlatitude Cirrus experiment (ML-CIRRUS) deployed the High Altitude and Long Range Research Aircraft (HALO) to obtain new insights into nucleation, life cycle, and climate impact of natural cirrus and aircraft-induced contrail cirrus. Direct observations of cirrus properties and their variability are still incomplete, currently limiting our understanding of the clouds’ impact on climate. Also, dynamical effects on clouds and feedbacks are not adequately represented in today’s weather prediction models. Here, we present the rationale, objectives, and selected scientific highlights of ML-CIRRUS using the G-550 aircraft of the German atmospheric science community. The first combi…