249 research outputs found
A machine learning approach with verification of predictions and assisted supervision for a rule-based network intrusion detection system
Network security is a branch of network management in which network intrusion detection systems provide attack detection features by monitorization of traffic data. Rule-based misuse detection systems use a set of rules or signatures to detect attacks that exploit a particular vulnerability. These rules have to be handcoded by experts to properly identify vulnerabilities, which results in misuse detection systems having limited extensibility. This paper proposes a machine learning layer on top of a rule-based misuse detection system that provides automatic generation of detection rules, prediction verification and assisted classification of new data. Our system offers an overall good performance, while adding an heuristic and adaptive approach to existing rule-based misuse detection systems
A Study Regarding the Representation of the Sun in Young Children’s Spontaneous Drawings
Drawing has historically been the preeminent way of portraying the observations of the sun. The study of the early stages of the development of astronomical thought and the examination of human graphic expression indicate this. With that in mind, it is interesting to note that young children very frequently draw the sun in their spontaneous depictions and, also, that there are preliminary indications that this fact might be related to their conceptual development. This study examines 279 pictures that children aged 4 to 8 spontaneously depicted, paying particular attention to their solar representations and the relationship that they have with other pictorial elements. The data is also related to children’s understanding of the inanimate nature of the sun. The results lend weight to the assumption that children do not draw the sun without intent and allow for adding fresh data to the growing body of research showing the importance of considering young children’s graphical expression when it comes to gaining insight into their understanding regarding natural phenomena
Sistema de detección de intrusiones con mantenimiento asistido de bases de datos de ataques mediante aprendizaje automático
Los sistemas de detecci´on de intrusiones (o IDS, del ingl´es Intrusion Detection System) tienen como fin la detecci´on de ataques en redes de comunicaciones. Como tales, constituyen un elemento de inter´es en la provisi´on de seguridad en gesti´on de redes ante la asunci´on de existencia de agujeros de seguridad en los sistemas hardware y software. Por otro lado, existen sistemas de detecci´on de intrusiones de c´odigo abierto basados en reglas, cuya principal desventaja consiste en el esfuerzo t´ecnico de matenimiento de la base de datos de reglas. En este documento se analizan las t´ecnicas m´as utilizadas en sistemas de detecci´on de intrusiones y se reutilizan sistemas de intrusiones basados en reglas para proponer un sistema de detecci´on de intrusiones con mantenimiento asistido de bases de datos de ataques mediante aprendizaje autom´atico
De interior
Proxecto de curtametraxe de ficción coa súa preprodución e a produción e posprodución do seu teaserTraballo fin de grao (UDC.COM). Comunicación audiovisual. Curso 2020/202
The phenomenon of brine rejection: a practical proposal for prospective primary teacher training
The fact that sea ice may be a suitable source for fresh water is nothing new; in fact, sailors were aware of this long ago. Nevertheless, the issue that ice does reject the ions of a saline solution is not a well known topic by both novice learners and prospective teachers. This paper describes a practical activity carried out in the regular chemistry training course aimed at teachers-to-be with the objectives of, on the one hand, getting to know the phenomenon of brine rejection and, on the other hand, taking advantage of the utilized experimental design to gain insight into the colligative properties of solutions. This activity might also be adequate for secondary and high school levels.El hielo proveniente de la congelación del agua de mar es una fuente de agua potable. Este es un hecho bien conocido por pescadores y gentes de la mar desde antaño. Sin embargo, el fenómeno de la exclusión de la salmuera durante la congelación de disolución de agua salada es un tema poco conocido entre el profesorado en formación. Este artículo presenta una actividad práctica diseñada para ser llevada a cabo en un curso de formación básica en química para el alumnado de magisterio, con el objetivo de, por un lado, conocer más de cerca el fenómeno de la exclusión de la salmuera, y por otro, ayudar a lograr una mejor comprensión de las propiedades coligativas de las disoluciones. La actividad que se presenta también puede ser adecuada para el aula de secundaria
Actividad física y autoconcepto, físico y general, a lo largo de la edad adulta1
The purpose of this study consists in determining differences in self-concept and physical self-perceptions, as well as the relationship between these differences and physical activity and gender at three times during adulthood. A total number of 912 people (350 men, 560 women) between the ages of 23 and 64 (M = 45.41; SD = 13.41) participated in the study. The sample group was divided into three age ranges: 23-34; 35-49; and 50-64. The participants classified themselves as either active or non-active. Self-concept was measured by the Physical Self-Concept Questionnaire (CAF) made up of the following scales: physical ability, physical condition, physical attractiveness, physical strength, general physical self-concept and general self-concept. The results reveal that: a. various dimensions of self-concept decreased as age increased in all three groups studied; b. This decrease is less pronounced in females than in males; c. a subjective perception of oneself as an active person is positively associated with physical self-concept; d. the decrease in self-concept associated with age affects active people less than their non-active counterparts. These data provide new information for both research and the personal and physical education of adults
Deep learning method for aortic root detection
Background: Computed tomography angiography (CTA) is a preferred imaging technique for a wide range of vascular diseases. However, extensive manual analysis is required to detect and identify several anatomical landmarks for clinical application. This study demonstrates the feasibility of a fully automatic method for detecting the aortic root, which is a key anatomical landmark in this type of procedure. The approach is based on the use of deep learning techniques that attempt to mimic expert behavior.
Methods: A total of 69 CTA scans (39 for training and 30 for validation) with different pathology types were selected to train the network. Furthermore, a total of 71 CTA scans were selected independently and applied as the test set to assess their performance.
Results: The accuracy was evaluated by comparing the locations marked by the method with benchmark locations (which were manually marked by two experts). The interobserver error was 4.6 ± 2.3 mm. On an average, the differences between the locations marked by the two experts and those detected by the computer were 6.6 ± 3.0 mm and 6.8 ± 3.3 mm, respectively, when calculated using the test set. Conclusions: From an analysis of these results, we can conclude that the proposed method based on pre-trained CNN models can accurately detect the aortic root in CTA images without prior segmentationThis work was partially financed by Consellería de Cultura, Educación e Universidade (reference 2019–2021, ED431C 2018/19)S
Ranking web services using centralities and social indicators
Nowadays, developers of web application mashups face a sheer overwhelming variety and pluralism of web services. Therefore, choosing appropriate web services to achieve specific goals requires a certain amount of knowledge as well as expertise. In order to support users in choosing appropriate web services it is not only important to match their search criteria to a dataset of possible choices but also to rank the results according to their relevance, thus minimizing the time it takes for taking such a choice. Therefore, we investigated six ranking approaches in an empirical manner and compared them to each other. Moreover, we have had a look on how one can combine those ranking algorithms linearly in order to maximize the quality of their outputs
Relación entre motivaciones y cambio conceptual en el aprendizaje de las propiedades físicas de la materia en alunos de Secundaria
El objetivo de este estudio es verificar si las concepciones que el alumno tiene sobre sí mismo y sobre el aprendizaje se relacionan con el cambio conceptual en el aprendizaje de conceptos de Química. Se analiza cómo alumnos de Educación Obligatoria usan modelos microscópicos y macroscópicos para entender las propiedades físicas de la materia y como el empleo de estos modelos se relaciona con tres estilos diferentes de motivación hacia las tareas escolares. Los resultados obtenidos apoyan la tesis de que, dada la relación que las variables motivacionales tienen con el aprendizaje de Química, el cambio conceptual no puede ser considerado como un "cambio frío", al margen de variables afectivas.; The aim of this paper is to improve the understanding how motivational believes relate to conceptual change in the field of chemical education. The study analyses how compulsory students use macroscopic and microscopic models in order to understand physical properties of the matter and relatives the usage of these models with three different motivational styles. The general observation of this article is that due to the relation that these motivational believes can have with conceptual learning in chemical, the conceptual change can not be considered as a "cold change" without any connection with affective variables
The impact of melting icebergs on sea level
Contrariamente a la creencia, muy extendida, de que la fusión de las grandes masas de hielo a la deriva en el
océano no repercute en un aumento del nivel del mar, lo cierto es que el deshielo de icebergs, barreras de hielo e
incluso de la banquisa tiene, en el actual contexto de calentamiento global, un impacto nada despreciable en el
nivel de los océanos. Se presenta a continuación una revisión de este fenómeno y se propone un experimento
ilustrativo que puede resultar útil para ofrecer una experiencia directa relativa al impacto que sobre el nivel del
mar tiene la fusión del hielo flotante en el océano.The idea that the melting process of large masses of ice that drift in the oceans has zero impact on the sea level is
a very widespread belief. However, the truth is that in the current global warming situation, the melting of
icebergs, ice shelves and sea ice, does have a significant impact on sea level. The following is a revision of this
phenomenon as well as an illustrative experiment which can be useful to understand the impact that melting of
icebergs has on sea level
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