1,113 research outputs found
Toward Network-based DDoS Detection in Software-defined Networks
To combat susceptibility of modern computing systems to cyberattack, identifying and disrupting malicious traffic without human intervention is essential. To accomplish this, three main tasks for an effective intrusion detection system have been identified: monitor network traffic, categorize and identify anomalous behavior in near real time, and take appropriate action against the identified threat. This system leverages distributed SDN architecture and the principles of Artificial Immune Systems and Self-Organizing Maps to build a network-based intrusion detection system capable of detecting and terminating DDoS attacks in progress
The consequence of waiters' professional identity on passion for work and its effects on employee turnover: a qualitative approach
Purpose- This study aims to develop a comprehensive understanding of the relationship between waiters’ professional identity and its antecedents such as: extroversion, education, brand standard, identity interferences, authenticity and stigma. “Salience” will be used as a moderator of this relationship, in order to explain the prominence of the stimuli. The consequences of professional identity on passion and turnover intention will be analysed.
Design/methodology/approach- This study employed a qualitative methodology, which encompassed 3 focus group discussions (18 participants) and 11 in-depth interviews, (total 29 people). Participants will be based on Michelin starred restaurants in London. Founded on analysis of the qualitative data, the antecedents and consequences of professional identity were formulated.
Findings- Findings demonstrate that the main factors of the formation of waiters’ professional identity are: extroversion, education, brand standard, identity interferences, authenticity and stigma, its consequences (passion and turnover intention), and salience as a moderator of this relationship to clarify the relevance of the stimuli. These factors have been demonstrated to have an effect on the formation of professional identity.
Practical implications- This study is of significance in encouraging additional explorations for scholars and restaurateurs about the function of work in identity formation in connecting to waiters, and offers more practical resolutions for restaurateurs to develop passion for work and reduce turnover intention among the staff.
Originality/value- This study is relevant because the repercussion of perceptions, such as identity and identification for emerging exclusive job roles, is still under-examined in certain conditions. Restaurateurs need to work with and comprehend the quality of the individual framework of waiters in job roles because these have a stimulus on the fundamental interests, such as passion for work and turnover of the waiting workforce. Moreover, within the hospitality industry, there has been a predisposition to focus more on chefs than waiting staff
Caracteres preimaginales y aspectos bionómicos de Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae)
Se describe la morfología y microestructura coriónica del huevo y la morfología del primer estadio larvario de Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae, Nycteliini). También se exponen antecedentes bionómicos y distribucionales de la especie. Para la obtención de huevos y larvas, se recolectaron parejas en el terreno que fueron mantenidas en cajas de cria hasta la ovoposición y posterior eclosión. La estructura y ornamentación del exocorion del huevo y características morfológicas externas de la larva fueron analizadas mediante microscopía electrónica de barrido. Los resultados muestran que los huevos de G. luczotii presentan un micropilo redondeado y exocorion liso, con células hexagonales sin aeropilos. Las larvas de G. luczotii presentan características morfológicas adaptativas para la vida edáfica del tipo Pedobionta: cápsula cefálica con gran cantidad de sensillas, patas protorácicas de función cavadora, y pigopodio bien desarrollado. Se analiza la importancia de algunos caracteres morfológicos de la larva de primer estadio como criterio de diagnóstico específico y se establece que las diferencias interespecíficas referidas a las sensillas frontales, la forma del clípeo y el margen anterior del labro tienen valor taxonómico y probablemente filogenético.
Palabras clave: Tenebrionidae, Gyriosomus, Morfología, Estadios preimaginales, Desierto costero, Chile.Preimaginal characters and bionomical aspects of Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae)
We describe the morphology and microstructure of the egg chorion, and the morphology of the first instar larva of Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae, Nycteliini). Bionomical and distributional data on this species are also provided. To obtain eggs and larvae, couples were collected in the field and kept in rearing cages until oviposture and ecclosion. The structure and adornment of the egg exochorion, and the exterior morphological features of larvae were examined with electron scanning microscopy. The eggs of G. luczotii showed a rounded micropyle and a smooth exochorion, composed of hexagonal cells without aeropyles. The larvae of G. luczotii showed morphological characteristics suited for an edaphic life similar to that of Pedobionta: digging prothoracic legs, cephalic capsule with abundant sensilla, and well–developed pygopodium. We analysed the importance of larval morphology as an element for specific diagnosis and found that interspecific differences regarding frontal sensilla, clypeus shape, and anterior part of labrum, had a taxonomic value and possibly a phylogenetic value.
Key words: Tenebrionidae, Gyriosomus, Morphology, Preimaginal stages, Coastal desert, Chile.Se describe la morfología y microestructura coriónica del huevo y la morfología del primer estadio larvario de Gyriosomus luczotii Laporte, 1840 (Coleoptera, Tenebrionidae, Nycteliini). También se exponen antecedentes bionómicos y distribucionales de la especie. Para la obtención de huevos y larvas, se recolectaron parejas en el terreno que fueron mantenidas en cajas de cria hasta la ovoposición y posterior eclosión. La estructura y ornamentación del exocorion del huevo y características morfológicas externas de la larva fueron analizadas mediante microscopía electrónica de barrido. Los resultados muestran que los huevos de G. luczotii presentan un micropilo redondeado y exocorion liso, con células hexagonales sin aeropilos. Las larvas de G. luczotii presentan características morfológicas adaptativas para la vida edáfica del tipo Pedobionta: cápsula cefálica con gran cantidad de sensillas, patas protorácicas de función cavadora, y pigopodio bien desarrollado. Se analiza la importancia de algunos caracteres morfológicos de la larva de primer estadio como criterio de diagnóstico específico y se establece que las diferencias interespecíficas referidas a las sensillas frontales, la forma del clípeo y el margen anterior del labro tienen valor taxonómico y probablemente filogenético.
Palabras clave: Tenebrionidae, Gyriosomus, Morfología, Estadios preimaginales, Desierto costero, Chile
The beta function of the multichannel Kondo model
The beta function of the multichannel Kondo model is calculated exactly in
the limit of large spin N and channel number M=gamma*N, with constant gamma.
There are no corrections in any finite order of 1/N. One zero is found at a
finite coupling strength, showing directly the Non--Fermi liquid behavior of
the model. This renormalization group flow allows to introduce a variational
principle for the entropy, to obtain the low temperature thermodynamics. Such
in particular the low temperature thermodynamics of the non--crossing
approximation to the Kondo model becomes accessible.Comment: 4 page
Recommended from our members
Measuring Atmospheric Ozone and Nitrogen Dioxide Concentration by Differential Optical Absorption Spectroscopy
The main objective was to develop a procedure based on differential optical absorption spectroscopy (DOAS) to measure atmospheric total column of ozone, using the automated instrument developed at the University of North Texas (UNT) by Nebgen in 2006. This project also explored the ability of this instrument to provide measurements of atmospheric total column nitrogen dioxide. The instrument is located on top of UNT’s Environmental Education, Science and Technology Building. It employs a low cost spectrometer coupled with fiber optics, which are aimed at the sun to collect solar radiation. Measurements taken throughout the day with this instrument exhibited a large variability. The DOAS procedure derives total column ozone from the analysis of daily DOAS Langley plots. This plot relates the measured differential column to the airmass factor. The use of such plots is conditioned by the time the concentration of ozone remains constant. Observations of ozone are typically conducted throughout the day. Observations of total column ozone were conducted for 5 months. Values were derived from both DOAS and Nebgen’s procedure and compared to satellite data. Although differences observed from both procedures to satellite data were similar, the variability found in measurements was reduced from 70 Dobson units, with Nebgen’s procedure, to 4 Dobson units, with the DOAS procedure.A methodology to measure atmospheric nitrogen dioxide using DOAS was also investigated. Although a similar approach to ozone measurements could be applied, it was found that such measurements were limited by the amount of solar radiation collected by the instrument. Observations of nitrogen dioxide are typically conducted near sunrise or sunset, when solar radiation experiences most of the atmospheric absorption
Offshore aquaculture as climate change adaptation in coastal areas: sea surface temperature trends in the Western Mediterranean Sea
The warming of the Mediterranean Sea surface is currently estimated to have been 0.4°C per decade for the period 1985-2006, and the increase in water temperature may have negatively affected marine aquaculture, e.g. by decreasing productivity. Development of aquaculture without adequate planning can lead to unsustainable economic feasibility due to future climate stressors. In this sense, offshore mariculture could be an alternative for mitigating the effect of coastal warming. The purpose of this study was to evaluate the suitability of the coastline in terms of global warming and sea surface temperature trends in locations where fish aquaculture is currently being developed, as well as the spatial changes of thermal anomalies up to 30 km from the coast, during the last 31 yr in the western Mediterranean (Spanish coast). This study was conducted using EU Copernicus Marine Service Information, covering the period 1981-2018, with a spatial resolution of 4 × 4 km. The results show that, over the last decade, the Mediterranean coastal environment off the Iberian Peninsula has experienced an increase in temperature of around 1ºC due to global change, with a clear latitudinal pattern modified by mesoscale oceanographic processes. The development of offshore aquaculture at some latitudes mitigates the extreme aestival effects on surface water temperatures. Strategic plans for aquaculture development should be able to forecast and incorporate future climate projections and local oceanographic conditions, and offshore aquaculture may provide an alternative in some regions, depending on local oceanographic conditions
Assessing the Influence of Salmon Farming through Total Lipids, Fatty Acids, and Trace Elements in the Liver and Muscle of Wild Saithe Pollachius virens
Saithe Pollachius virens are attracted to uneaten salmon feed underneath cages at open-cage salmon farms in Norway. The aggregated Saithe have modified their feeding habits as they have switched from wild prey to uneaten food pellets, which could lead to physiological and biochemical changes in the Saithe. Variations in profiles of total lipids, fatty acids, and trace elements in Saithe liver and muscle were measured to evaluate the influence of fish feed from salmon farms on wild Saithe populations. Farm-aggregated Saithe had higher fat content in liver tissues than did individuals captured more than 25 km away from farms, but no clear differences were found in muscle tissues. High proportions of fatty acids of terrestrial origin, such as oleic, linoleic, and linolenic acids, in liver and muscle tissues of farm-aggregated Saithe reflected the presence of wild Saithe at farms. Accordingly, low proportions of arachidonic, eicosapentaenoic, and docosahexaenoic acids in Saithe tissues mirrored the feeding activity at farms. Variations in specific trace element signatures among fish groups also revealed the farming influence on wild Saithe. High levels of Fe, As, Se, Zn, and B in liver, but also As, B, Li, Hg, and Sr in muscle of Saithe captured away from farms indicated the absence of feeding at farms.This study was part of the project “Evaluation of actions to promote sustainable coexistence between salmon culture and coastal fisheries – ProCoEx” funded by The Norwegian Seafood Research Fund (FHF). The study was also supported by the Norwegian Research Council through the EcoCoast project
Performance assessment of borehole arrangements for the design of rectangular shallow foundation systems
This study proposes a framework to evaluate the performance of borehole arrangements for the design of rectangular shallow foundation systems under spatially variable soil conditions. Performance measures are introduced to quantify, for a fixed foundation layout and given soil sounding locations, the variability level of the foundation system bearing capacities in terms of their mean values and standard deviations. To estimate these measures, the recently proposed random failure mechanism method (RFMM) has been adopted and extended to consider any arrangement of rectangular foundations and boreholes. Hence, three-dimensional bearing capacity estimation under spatially variable soil can be efficiently performed. Several numerical examples are presented to illustrate the applicability of the proposed framework, including diverse foundation arrangements and different soil correlation structures. Overall, the proposed framework represents a potentially useful tool to support the design of geotechnical site investigation programs, especially in situations where very limited prior knowledge about the soil properties is available
- …