Search results for "Lee"
showing 10 items of 1847 documents
Associations Between Online Learning, Smartphone Addiction Problems, and Psychological Symptoms in Chinese College Students After the COVID-19 Pandem…
2022
BackgroundSmartphone-based online education gained popularity during and after the COVID-19 pandemic. Although recent studies have highlighted the association between problematic smartphone use (PSU) and mental health symptoms, the potential role of online learning in this relationship remains unclear. This study aimed to analyze the relationships between higher education modes, PSU, and related psychological symptoms in university students.MethodsA total of 1,629 Chinese university students from five provinces completed a web-based questionnaire survey between March 2020 and October 2021. Demographic characteristics and learning conditions were recorded. All participants completed the Smar…
SURATRAM - Intelligent Transport System for freight management in urban areas
2022
The project developed in the framework of this thesis is part of a more global and ambitious research program that aims at proposing a new type of goods management system in urban centers. In order to do so, the project aims to approach the management of goods from a systemic point of view, by integrating the management into the field of Intelligent Goods Transport Systems (ITS). This systemic vision of the management of goods in urban areas requires the use of electric and autonomous vehicles to ensure the tasks of delivery and collection of goods. In addition, these vehicles will be able to use the existing public transport network of the cities to move from an urban distribution center (…
Replacement of Vehicle Fleet with EVs Using PV Energy
2016
The diffusion of Electric Vehicles (EVs), the reduction of environmental pollution and the production of energy from renewable sources (RES), in particular photovoltaic system, wind farm, hydroelectric plants, bioenergy and geothermal plants are the principal aspects discussed in the world. For this reason, the goal of this work is to study for 2014 year in all Italy's Regions; the energy production obtained to photovoltaic systems (PV) and the possibility to use with different percentage this energy for recharge the electric vehicles. In particular, they have been considered different scenarios in function to the km travelled per year from the population. This paper examines the integratio…
Effects of pulsed electromagnetic fields on cognitive processes - a pilot study on pulsed field interference with cognitive regeneration.
2004
Background – Due to the ubiquitous use of cellular phones much has been speculated on secondary effects of electromagnetic irradiation emitted by those. Additionally, several studies have reported vegetative alterations as well as effects on the neuronal and molecular levels in humans. Here, using a psycho–physiological test paradigm, we examined effects of exposure to pulsed electromagnetic fields on cognitive performance. Materials and methods – In 11 volunteers, we tested cognitive processing under field exposure (GSM standard) and under field-free conditions. To examine the hypothesized effect of pulsed fields, we applied an auditory discrimination task and determined the participant's …
Effects of pulsed high-frequency electromagnetic fields on the neuroendocrine system.
1998
The influence of pulsed high-frequency electromagnetic fields emitted from a circularly polarized antenna on the neuroendocrine system in healthy humans was investigated (900 MHz electromagnetic field, pulsed with 217 Hz, average power density 0.02 mW/cm<sup>2</sup>). Nocturnal hormone profiles of growth hormone (GH), cortisol, luteinizing hormone (LH) and melatonin were determined under polysomnographic control. An alteration in the hypothalamo-pituitary-adrenal axis activity was found with a slight, transient elevation in the cortisol serum level immediately after onset of field exposure which persisted for 1 h. For GH, LH and melatonin, no significant effects were found under…
Human Sleep EEG under the Influence of Pulsed Radio Frequency Electromagnetic Fields
2000
Former exploratory investigations of sleep alterations due to global system for mobile communications (GSM) signals have shown a hypnotic and REM-suppressive effect under field exposure. This effect was observed in a first study using a power flux density of 0.5 W/m<sup>2</sup>, and the same trend occurred in a second study with a power flux density of 0.2 W/m<sup>2</sup>. For the present study, we applied a submaximal power flux density of 50 W/m<sup>2</sup>. To investigate putative effects of radio frequency electromagnetic fields (EMFs) of cellular GSM phones on human sleep EEG pattern, all-night polysomnographies of 20 healthy male subjects both with …
Besteht eine Beeinträchtigung der ZNS-Aktivität durch gepulste elektromagnetische Felder? - Do Pulsed Electromagnetic Fields Impair CNS Activity?
2001
In the present pilot study we examined the effects of electromagnetic fields on the biological organism. The study was prompted by discussions on the possible effects on the nervous system and cognitive processes of fields produced by mobile phones. The experiments were performed in an electrophysiological laboratory. Eleven volunteers were exposed to pulsed electromagnetic fields (GSM standard). The psychophysiological method of assessing the order threshold (Ordnungsschwelle = OS) was used to examine cognitive performance. Under the test conditions, nine of the subjects showed a loss of mental regeneration, as reflected by an increase in the OS, in comparison with the field-free situation…
Cognitive performance and emotion are indifferent to ambient color
2017
Folklore has it that ambient color has the power to relax or arouse the observer and enhance performance when executing cognitive tasks. We picked a number of commercially available colors that allegedly have the power to alter cognitive performance and the emotional state, and exposed subjects to them while solving a battery of cognitive tasks. The colors were “Cool Down Pink”, which is said to produce relaxing effects and reduce effort, “Energy Red”, allegedly enhancing performance via increased arousal, “Relaxing Blue”, which is said to enhance attention and concentration, as well as white as a control. In a between-subjects design, a total of 170 high school students carried out five ta…
DNA barcodes reveal the presence of the introduced freshwater leechHelobdella europaeain Spain
2013
Abstract We report the finding of the freshwater leech Helobdella europaea in Spain for the first time. Three leech specimens were found attached to the European pond turtle Emys orbicularis. Helobdella europaea is not a blood feeder and, like all members of the genus, feeds on the hemolymph of aquatic invertebrates including snails and worms. Despite the fact that the original geographical distribution or source population of this species is unknown, the close relationship between H. europaea and leeches of the "triserialis" series (sensu Sawyer, 1986) suggests a New World origin. Given its ability to invade and persist in new environments, this leech has been described as a new species by…
First record of the alien leech Myzobdella lugubris Leidy, 1851 (Hirudinea, Piscicolidae) in the Palearctic
2018
espanolEn este estudio reportamos la aparicion de la sanguijuela Neartica Myzobdella lugubris en un cuerpo de agua salobre de la reserva natural Riserva Naturale dello Stato “Le Cesine” (Apulia, Italy). Dos especimenes de la especie fueren recolectados en el cuello y las extremidades anteriores de una tortuga de estanque europea Emys orbicularis hellenica en Octubre del 2016. La identificacion de los dos especimenes fue basada en datos morfologicos y de secuenciacion molecular. En su distribucion natural, M. lugubris es conocida por ser huesped y vector de bacterias y virus, de los cuales algunos son patogenos de gravedad en peces. En vista de los posibles efectos nocivos, que ejercen sobre…