Help documents are important in an organization to use the technology applications licensed from a vendor. Customers and internal employees frequently use and interact with the help documents section to use the applications and know about the new features and developments in them. Help documents consist of various knowledge base materials, question and answer documents and help content. In day- to-day life, customers go through these documents to set up, install or use the product. Recommending similar documents to the customers can increase customer engagement in the product and can also help them proceed without any hurdles. The main aim of this study is to build a recommendation system by exploring different machine-learning techniques to recommend the most relevant and similar help document to the user. To achieve this, in this study a hybrid-based recommendation system for help documents is proposed where the documents are recommended based on similarity of the content using content-based filtering and similarity between the users using collaborative filtering. Finally, the recommendations from content-based filtering and collaborative filtering are combined and ranked to form a comprehensive list of recommendations. The proposed approach is evaluated by the internal employees of the company and by external users. Our experimental results demonstrate that the proposed approach is feasible and provides an effective way to recommend help documents.

Prvotním cílem tohoto projektu bylo prostudovat problematiku jazykového modelování pro rozpoznávání řeči a techniky pro získávání textových dat z Webu. Text představuje základní techniky rozpoznávání řeči a detailněji popisuje jazykové modely založené na statistických metodách. Zvláště se práce zabývá kriterii pro vyhodnocení kvality jazykových modelů a systémů pro rozpoznávání řeči. Text dále popisuje modely a techniky dolování dat, zvláště vyhledávání informací. Dále jsou představeny problémy spojené se získávání dat z webu, a v kontrastu s tím je představen vyhledávač Google. Součástí projektu byl návrh a implementace systému pro získávání textu z webu, jehož detailnímu popisu je věnována náležitá pozornost. Nicméně, hlavním cílem práce bylo ověřit, zda data získaná z Webu mohou mít nějaký přínos pro rozpoznávání řeči. Popsané techniky se tak snaží najít optimální způsob, jak data získaná z Webu použít pro zlepšení ukázkových jazykových modelů, ale i modelů nasazených v reálných rozpoznávacích systémech.

Ce travail porte sur la caractérisation des matériaux présents à l’intérieur d’amphores romaines. Il avait pour but de déterminer à la fois la nature de la matière étanchéisante des parois internes, mais aussi d’identifier leur contenu.Pour mener à bien cette étude, divers outils analytiques ont été employés tel l’infrarouge à Transformée de Fourier(IR-TF) ou bien encore la chromatographie gazeuse couplée à un spectromètre de masse (CPG-SM). Divers protocoles d’extraction ont été testés et optimisés en fonction des différentes classes chimiques de composés recherchés, comme par exemple pour la caractérisation de la présence de vin (ex : les acides tartrique et syringique)ou bien d’huile d’olive (acides oléique, palmitique, stéarique, …). Ce travail préliminaire a été réalisé sur un ensemble d’amphores romaines dites de référence, c’est-à-dire dont le contenu était avéré.Dans un second temps, les résultats obtenus ont été appliqués à des cas d’étude d’amphores du type Dressel 1 datant de la fin du IIème siècle ou du début du Ier siècle av. J.-C, estampillées du timbre Sestius. Elles provenaient de Cosa en Étrurie, l'actuelle Toscane.Les premiers échantillons étudiés correspondent à des amphores Dressel 1A de l’épave du Grand Congloué 2. L’étude en IR-TF a indiqué différentes bandes de matière organique, comme la liaison chimique de O-H à partir de l'acide carboxylique, C-H du groupe méthylène et C-O de l'ester méthylique. L'étude réalisée par CPG-SM a révélé des diterpènes, tels que l'acide déhydroabiétique et le rétène qui sont des marqueurs diterpéniques de la famille des Pinacées. Des dérivés esters méthyliques ont été également caractérisés. Cela indique une poix obtenue par pyrogénation de bois résineux (Pinus sp.). L’extraction du contenu a été optimisée et la technique par CPG-SM a été appliquée avec succès. On a observé la présence d’acide tartrique et d’acide syringique (principaux marqueurs du vin) dans la poix située en surface intérieure, mais aussi dans la matière des tessons. D’autres échantillons proviennent d’amphores Dressel 1C, retrouvées dans le complexe archéologique des fossés du« Verbe-Incarné » de Lyon. Pour vérifier leur contenu en vin, la technique de CPG-SM a été utilisée. Les résultats obtenus semblent confirmer la présence de vin. Enfin le dernier lot concerne des tessons amphores provenant de l’Oppidum de Châteaumeillant. Parmi les échantillons étudiés, l’un d’entre eux a particulièrement attiré notre attention de par la présence de vin et de résine sandaraque (Tetraclinis articulata). / This work relates the characterization of materials inside Roman amphorae. It aimed to determine at once thewaterproofing material on the internal walls, but also to identify their content.In this way, different analytical tools were used as infrared spectroscopy (FT-IR) and gas chromatography (GC/MS).Several types of extraction were tested to optimize the results concerning for example the presence of wine (tartric andsyringic acids) or olive oil (oleic, palmitic, stearic acids,…).This preliminary work has been developed with reference Roman amphorae, i.e. whose content was known.In a second time, the obtained results were applied to case studies: amphorae « Dressel 1 type » dating from the endof the IInd century or the beginning of Ist century BC, with the stamp « Sestius ». They come from Cosa in Étrurie, thecurrent Tuscany.The first studied samples correspond to amphorae Dressel 1A of the wreck of Grand Congloué 2. The study with FT-IRindicated different bands concerning organic matter, as the chemical link O-H from carboxylic acid, C-H of themethylene group and C-O of the methyl ester. The study carried out by GC-MS showed diterpenoids, such asdehydroabietic acid and reten, which are diterpenic markers of Pinaceae family. Methyl ester by products were alsocharacterized. It reveals a pitch pyrogenically prepared from resinous wood (Pinus sp.). The extraction of the contentswas optimized and GS-MS technique was successfully applied. We observed the presence of tartric and syringic acids(main markers of wine) in the pitched internal walls surface, but also in the potsherd matter.Other samples come from amphorae Dressel 1C found in the archaeological site of the gaps of the « Verbe Incarné »in Lyon. To verify their contents with wine, the GS-MS technique was used. The obtained results seem to confirm thepresence of wine. Finally the last group concerns amphora shards coming from the Oppidum of Châteaumeillant.Among the studied samples, one of them was particularly interesting, revealing the presence of wine and sandaracresin (Tetraclinis articulata).

Governments, military, corporations, financial institutions and others exchange a great deal of confidential information using Internet these days. Protecting such confidential information and ensuring their integrity and origin authenticity are of paramount importance. There exist protocols and solutions at different layers of the TCP/IP protocol stack to address these security requirements. Application level encryption viz. PGP for secure mail transfer, TLS based secure TCP communication, IPSec for providing IP layer security are among these security solutions. Due to scalability, wide acceptance of the IP protocol, and its application independent character, the IPSec protocol has become a standard for providing Internet security. The IPSec provides two protocols namely the Authentication header (AH) and the Encapsulating Security Payload (ESP). Each protocol can operate in two modes, viz. transport and tunnel mode. The AH provides data origin authentication, connectionless integrity and anti replay protection. The ESP provides all the security functionalities of AH along with confidentiality. The IPSec protocols provide end-to-end security for an entire IP datagram or the upper layer protocols of IP payload depending on the mode of operation. However, this end-to-end model of security restricts performance enhancement and security related operations of intermediate networking and security devices, as they can not access or modify transport and upper layer headers and original IP headers in case of tunnel mode. These intermediate devices include routers providing Quality of Service (QoS), TCP Performance Enhancement Proxies (PEP), Application level Proxy devices and packet filtering firewalls. The interoperability problem between IPSec and intermediate devices has been addressed in literature. Transport friendly ESP (TF-ESP), Transport Layer Security (TLS), splitting of single IPSec tunnel into multiple tunnels, Multi Layer IPSec (ML-IPSec) are a few of the proposed solutions. The ML-IPSec protocol solves this interoperability problem without violating the end-to-end security for the data or exposing some important header fields unlike the other solutions. The ML-IPSec uses a multilayer protection model in place of the single end-to-end model. Unlike IPSec where the scope of encryption and authentication applies to the entire IP datagram, this scheme divides the IP datagram into zones. It applies different protection schemes to different zones. When ML-IPSec protects a traffic stream from its source to its destination, it first partitions the IP datagram into zones and applies zone-specific cryptographic protections. During the flow of the ML-IPSec protected datagram through an authorized intermediate gateway, certain type I zones of the datagram may be decrypted and re-encrypted, but the other zones will remain untouched. When the datagram reaches its destination, the ML-IPSec will reconstruct the entire datagram. The ML-IPSec protocol, however suffers from the problem of static configuration of zones and zone specific cryptographic parameters before the commencement of the communication. Static configuration requires a priori knowledge of routing infrastructure and manual configuration of all intermediate nodes. While this may not be an issue in a geo-stationary satellite environment using TCP-PEP, it could pose problems in a mobile or distributed environment, where many stations may be in concurrent use. The ML-IPSec endpoints may not be trusted by all intermediate nodes in a mobile environment for manual configuration without any prior arrangement providing the mutual trust. The static zone boundary of the protocol forces one to ignore the presence of TCP/IP datagrams with variable header lengths (in case of TCP or IP headers with OPTION fields). Thus ML-IPSec will not function correctly if the endpoints change the use of IP or TCP options, especially in case of tunnel mode. The zone mapping proposed in ML-IPSec is static in nature. This forces one to configure the zone mapping before the commencement of the communication. It restricts the protocol from dynamically changing the zone mapping for providing access to intermediate nodes without terminating the existing ML-IPSec communication. The ML-IPSec endpoints can off course, configure the zone mapping with maximum number of zones. This will lead to unnecessary overheads that increase with the number of zones. Again, static zone mapping could pose problems in a mobile or distributed environment, where communication paths may change. Our extension to the ML-IPSec protocol, called Dynamic Multi Layer IPSec (DML-IPSec) proposes a multi layer variant with the capabilities of dynamic zone configuration and sharing of cryptographic parameters between IPSec endpoints and intermediate nodes. It also accommodates IP datagrams with variable length headers. The DML-IPSec protocol redefines some of the IPSec and ML-IPSec fundamentals. It proposes significant modifications to the datagram processing stage of ML-IPSec and proposes a new key sharing protocol to provide the above-mentioned capabilities. The DML-IPSec supports the AH and ESP protocols of the conventional IPSec with some modifications required for providing separate cryptographic protection to different zones of an IP datagram. This extended protocol defines zone as a set of non-overlapping and contiguous partitions of an IP datagram, unlike the case of ML-IPSec where a zone may consist of non-contiguous portions. Every zone is provided with cryptographic protection independent of other zones. The DML-IPSec categorizes zones into two separate types depending on the accessibility requirements at the intermediate nodes. The first type of zone, called type I zone, is defined on headers of IP datagram and is required for examination and modification by intermediate nodes. One type I zone may span over a single header or over a series of contiguous headers of an IP datagram. The second type of zone, called type II zone, is meant for the payload portion and is kept secure between endpoints of IPSec communications. The single type II zone starts immediately after the last type I zone and spans till the end of the IP datagram. If no intermediate processing is required during the entire IPSec session, the single type II zone may cover the whole IP datagram; otherwise the single type II zone follows one or more type I zones of the IP datagram. The DML-IPSec protocol uses a mapping from the octets of the IP datagram to different zones, called zone map for partitioning an IP datagram into zones. The zone map contains logical boundaries for the zones, unlike physical byte specific boundaries of ML-IPSec. The physical boundaries are derived on-the-fly, using either the implicit header lengths or explicit header length fields of the protocol headers. This property of the DML-IPSec zones, enables it to accommodate datagrams with variable header lengths. Another important feature of DML-IPSec zone is that the zone maps need not remain constant through out the entire lifespan of IPSec communication. The key sharing protocol may modify any existing zone map for providing service to some intermediate node. The DML-IPSec also redefines Security Association (SA), a relationship between two endpoints of IPSec communication that describes how the entities will use security services to communicate securely. In the case of DML-IPSec, several intermediate nodes may participate in defining these security protections to the IP datagrams. Moreover, the scope of one particular set of security protection is valid on a single zone only. So a single SA is defined for each zone of an IP datagram. Finally all these individual zonal SA’s are combined to represent the security relationship of the entire IP datagram. The intermediate nodes can have the cryptographic information of the relevant type I zones. The cryptographic information related to the type II zone is, however, hidden from any intermediate node. The key sharing protocol is responsible for selectively sharing this zone information with the intermediate nodes. The DML-IPSec protocol has two basic components. The first one is for processing of datagrams at the endpoints as well as intermediate nodes. The second component is the key sharing protocol. The endpoints of a DML-IPSec communication involves two types of processing. The first one, called Outbound processing, is responsible for generating a DML-IPSec datagram from an IP datagram. It first derives the zone boundaries using the zone map and individual header field lengths. After this partitioning of IP datagram, zone wise encryption is applied (in case of ESP). Finally zone specific authentication trailers are calculated and appended after each zone. The other one, Inbound processing, is responsible for generating the original IP datagram from a DML-IPSec datagram. The first step in the inbound processing, the derivation of zone boundary, is significantly different from that of outbound processing as the length fields of zones remain encrypted. After receiving a DML-IPSec datagram, the receiver starts decrypting type I zones till it decrypts the header length field of the header/s. This is followed by zone-wise authentication verification and zone-wise decryption. The intermediate nodes processes an incoming DML-IPSec datagram depending on the presence of the security parameters for that particular DML-IPSec communication. In the absence of the security parameters, the key sharing protocol gets executed; otherwise, all the incoming DML-IPSec datagrams get partially decrypted according to the security association and zone mapping at the inbound processing module. After the inbound processing, the partially decrypted IP datagram traverses through the networking stack of the intermediate node . Before the IP datagram leaves the intermediate node, it is processed by the outbound module to reconstruct the DML-IPSec datagram. The key sharing protocol for sharing zone related cryptographic information among the intermediate nodes is the other important component of the DML-IPSec protocol. This component is responsible for dynamically enabling intermediate nodes to access zonal information as required for performing specific services relating to quality or security. Whenever a DML-IPSec datagram traverses through an intermediate node, that requires access to some of the type I zones, the inbound security database is searched for cryptographic parameters. If no entry is present in the database, the key sharing protocol is invoked. The very first step in this protocol is a header inaccessible message from the intermediate node to the source of the DML-IPSec datagram. The intermediate node also mentions the protocol headers that it requires to access in the body portion of this message. This first phase of the protocol, called the Zone reorganization phase, is responsible for deciding the zone mapping to provide access to intermediate nodes. If the current zone map can not serve the header request, the DML-IPSec endpoint reorganizes the existing zone map in this phase. The next phase of the protocol, called the Authentication Phase is responsible for verifying the identity of the intermediate node to the source of DML-IPSec session. Upon successful authentication, the third phase, called the Shared secret establishment phase commences. This phase is responsible for the establishment of a temporary shared secret between the source and intermediate nodes. This shared secret is to be used as key for encrypting the actual message transfer of the DML-IPSec security parameters at the next phase of the protocol. The final phase of the protocol, called the Security parameter sharing phase, is solely responsible for actual transfer of the security parameters from the source to the intermediate nodes. This phase is also responsible for updation of security and policy databases of the intermediate nodes. The successful execution of the four phases of the key sharing protocol enables the DML-IPSec protocol to dynamically modify the zone map for providing access to some header portions for intermediate nodes and also to share the necessary cryptographic parameters required for accessing relevant type I zones without disturbing an existing DML-IPSec communication. We have implemented the DML-IPSec for ESP protocol according to the definition of zones along with the key sharing algorithm. RHEL version 4 and Linux kernel version 2.6.23.14 was used for the implementation. We implemented the multi-layer IPSec functionalities inside the native Linux implementation of IPSec protocol. The SA structure was updated to hold necessary SA information for multiple zones instead of single SA of the normal IPSec. The zone mapping for different zones was implemented along with the kernel implementation of SA. The inbound and outbound processing modules of the IPSec endpoints were re-implemented to incorporate multi-layer IPSec capability. We also implemented necessary modules for providing partial IPSec processing capabilities at the intermediate nodes. The key sharing protocol consists of some user space utilities and corresponding kernel space components. We use ICMP protocol for the communications required for the execution of the protocol. At the kernel level, pseudo character device driver was implemented to update the kernel space data structures and necessary modifications were made to relevant kernel space functions. User space utilities and corresponding kernel space interface were provided for updating the security databases. As DML-IPSec ESP uses same Security Policy mechanism as IPSec ESP, existing utilities (viz. setkey) are used for the updation of security policy. However, the configuration of the SA is significantly different as it depends on the DML-IPSec zones. The DML-IPSec ESP implementation uses the existing utilities (setkey and racoon) for configuration of the sole type II zone. The type I zones are configured using the DML-IPSec application. The key sharing protocol also uses this application to reorganize the zone mapping and zone-wise cryptographic parameters. The above feature enables one to use default IPSec mechanism for the configuration of the sole type II zone. For experimental validation of DML-IPSec, we used the testbed as shown in the above figure. An ESP tunnel is configured between the two gateways GW1 and GW2. IN acts as an intermediate node and is installed with several intermediate applications. Clients C11 and C21 are connected to GW1 and GW2 respectively. We carried out detailed experiments for validating our solution w.r.t firewalling service. We used stateful packet filtering using iptables along with string match extension at IN. First, we configured the firewall to allow only FTP communication (using port information of TCP header and IP addresses of Inner IP header ) between C11 and C21. In the second experiment, we configured the firewall to allow only Web connection between C11 and C21 using the Web address of C11 (using HTTP header, port information of TCP header and IP addresses of Inner IP header ). In both experiments, we initiated the FTP and WEB sessions before the execution of the key sharing protocol. The session could not be established as the access to upper layer headers was denied. After the execution of the key sharing protocol, the sessions could be established, showing the availability of protocol headers to the iptables firewall at IN following the successful key sharing. We use record route option of ping program to validate the claim of handling datagrams with variable header lengths. This option of ping program records the IP addresses of all the nodes traversed during a round trip path in the IP OPTION field. As we used ESP in tunnel mode between GW1 and GW2, the IP addresses would be recorded inside the encrypted Inner IP header. We executed ping between C11 and C21 and observed the record route output. Before the execution of the key sharing protocol, the IP addresses of IN were absent in the record route output. After the successful execution of key sharing protocol, the IP addresses for IN were present at the record route output. The DML-IPSec protocol introduces some processing overhead and also increases the datagram size as compared to IPSec and ML-IPSec. It increases the datagram size compared to the standard IPSec. However, this increase in IP datagram size is present in the case of ML-IPSec as well. The increase in IP datagram length depends on the number of zones. As the number of zone increases this overhead also increases. We obtain experimental results about the processing delay introduced by DML-IPSec processing. For this purpose, we executed ping program from C11 to C21 in the test bed setup for the following cases: 1.ML-IPSec with one type I and one type II zone and 2. DML-IPSec with one type I and one type II zone. We observe around 10% increase in RTT in DML-IPSec with two dynamic zones over that of ML-IPSec with two static zones. This overhead is due to on-the-fly derivation of the zone length and related processing. The above experiment analyzes the processing delay at the endpoints without intermediate processing. We also analyzed the effect of intermediate processing due to dynamic zones of DML-IPSec. We used iptables firewall in the above mentioned experiment. The RTT value for DML-IPSec with dynamic zones increases by less than 10% over that of ML-IPSec with static zones. To summarize our work, we have proposed an extension to the multilayer IPSec protocol, called Dynamic Multilayer IPSec (DML-IPSec). It is capable of dynamic modification of zones and sharing of cryptographic parameters between endpoints and intermediate nodes using a key sharing protocol. The DML-IPSec also accommodates datagrams with variable header lengths. The above mentioned features enable any intermediate node to dynamically access required header portions of any DML-IPSec protected datagrams. Consequently they make the DML-IPSec suited for providing IPSec over mobile and distributed networks. We also provide complete implementation of ESP protocol and provide experimental validation of our work. We find that our work provides the dynamic support for QoS and security services without any significant extra overhead compared to that of ML-IPSec. The thesis begins with an introduction to communication security requirements in TCP/IP networks. Chapter 2 provides an overview of communication security protocols at different layers. It also describes the details of IPSec protocol suite. Chapter 3 provides a study on the interoperability issues between IPSec and intermediate devices and discusses about different solutions. Our proposed extension to the ML-IPSec protocol, called Dynamic ML-IPSec(DML-IPSec) is presented in Chapter 4. The design and implementation details of DML-IPSec in Linux environment is presented in Chapter 5. It also provides experimental validation of the protocol. In Chapter 6, we summarize the research work, highlight the contributions of the work and discuss the directions for further research.

Thesis discusses data mining the social media. It gives an introduction about the topic of data mining and possible mining methods. Thesis also explores social media and social networks, what are they able to offer and what problems do they bring. Three different APIs of three social networking sites are examined with their opportunities they provide for data mining. Techniques of text mining and document classification are explored. An implementation of a web application that mines data from social site Twitter using the algorithm SVM is being described. Implemented application is classifying tweets based on their text where classes represent tweets' continents of origin. Several experiments executed both in RapidMiner software and in implemented web application are then proposed and their results examined.

Android is the second most targeted operating system for malware authors and to counter the development of Android malware, more knowledge about their behavior is needed. There are mainly two approaches to analyze Android malware, namely static and dynamic analysis. Recently in 2017, a study and well labeled dataset, named AMD (Android Malware Dataset), consisting of over 24,000 malware samples was released. It is divided into 135 varieties based on similar malicious behavior, retrieved through static analysis of the file classes.dex in the APK of each malware, whereas the labeled features were determined by manual inspection of three samples in each variety. However, static analysis is known to be weak against obfuscation techniques, such as repackaging or dynamic loading, which can be exploited to avoid the analysis. In this study the second approach is utilized and all malware in the dataset are analyzed at run-time in order to monitor their dynamic behavior. However, analyzing malware at run-time has known weaknesses as well, as it can be avoided through, for instance, anti-emulator techniques. Therefore, the study aimed to explore the available sandbox environments for dynamic analysis, study the effectiveness of fingerprinting Android malware using one of the tools and investigate whether static features from AMD and the dynamic analysis correlate. For instance, by an attempt to classify the samples based on similar dynamic features and calculating the Pearson Correlation Coefficient (r) for all combinations of features from AMD and the dynamic analysis. The comparison of tools for dynamic analysis, showed a need of development, as most popular tools has been released for a long time and the common factor is a lack of continuous maintenance. As a result, the choice of sandbox environment for this study ended up as Droidbox, because of aspects like ease of use/install and easily adaptable for large scale analysis. Based on the dynamic features extracted with Droidbox, it could be shown that Android malware are more similar to the varieties which they belong to. The best metric for classifying samples to varieties, out of four investigated metrics, turned out to be Cosine Similarity, which received an accuracy of 83.6% for the entire dataset. The high accuracy indicated a correlation between the dynamic features and static features which the varieties are based on. Furthermore, the Pearson Correlation Coefficient confirmed that the manually extracted features, used to describe the varieties, and the dynamic features are correlated to some extent, which could be partially confirmed by a manual inspection in the end of the study.

The continuity of the menace of mercury (Hg) is due to the continuous production and use of Hg and Hg containing products. Toxicity is just an outfall of use and exposure. Anthropogenic activities such as coal combustion and artisanal and small-scale gold mining have led to increasing Hg contamination and is the major source of Hg pollution into the environment that needs to be remediated. This study aimed to assess the phytoextraction capability of sweet sorghum (Sorghum bicolor) under different fertiliser treatments in Hg-contaminated soil. The potted experiment in a controlled environment included control S. bicolor and three phytoremediation treatments, i.e., Hg only; the addition of 4:1 green compost and; the addition of 0.2% NPK fertiliser. There were conspicuous signs of Hg phytotoxicity in plants with Hg only, namely wilting, senescent, inhibition of growth, and photosynthesis. There was stunted growth, but healthy plants observed in the treatment with the addition of green compost towards the end (day 60) of exposure. However, S. bicolor grew well until the last day of exposure in the treatment with the addition of 0.2% NPK fertiliser. Thus, this treatment showed the most effective phytoextraction potential of S. bicolor in Hg-contaminated soil. The effectiveness of S. bicolor in reducing the level of mercury was best assessed in the Hg bioavailable concentration in the spiked soil in which the Hg + NPK treatment has the lowest (0.77 mg kg−1). That resulted in the highest uptake (84.31%) percentage of Hg concentration recorded in the treatment with the addition of 0.2% NPK fertiliser compared to the other two treatments. The results suggest that the proportion of phosphate in the NPK fertiliser used, plays a huge role in the phytoextraction of Hg in the contaminated soil by S. bicolor. The Translocation Factor (TF) and Bioconcentration Factor (BCF), although higher within Days 20 and 40, was greater than 1 at the end of the exposure period suggesting a high probability that Hg was significantly transferred to the aerial parts of the plants. This is regarded as typical hyperaccumulator plant species. While S. bicolor was able to reduce the level of Hg in all three treatments, Hg + NPK treatment gave overall best results in physiological growth, the uptake, and reducing the level of Hg bioavailable in the spiked soil in terms of the effectiveness of phytoremediation method. / Environmental Sciences / M. Sc. (Environmental Science)

This thesis deals with a comparison of classification methods. At first, these classification methods based on machine learning are described, then a classifier comparison system is designed and implemented. This thesis also describes some classification tasks and datasets on which the designed system will be tested. The evaluation of classification tasks is done according to standard metrics. In this thesis is presented design and implementation of a classifier that is based on the principle of evolutionary algorithms.

At the beginning, the work describes DNS and SSL/TLS protocols, it mainly deals with communication between devices using these protocols. Then we'll talk about data preprocessing and data cleaning. Furthermore, the thesis deals with basic data mining techniques such as data classification, association rules, information retrieval, regression analysis and cluster analysis. The next chapter we can read something about how to identify mobile devices on the network. We will evaluate data sets that contain collected data from communication between the above mentioned protocols, which will be used in the practical part. After that, we finally get to the design of a system for analyzing network communication data. We will describe the libraries, which we used and the entire system implementation. We will perform a large number of experiments, which we will finally evaluate.

[ES] Paradigma: Entre el post-positivismo, cuyos hallazgos son probabilidades cuantitativas extraídos de las opiniones del alumnado, y el constructivismo, la realidad cualitativa se construye por interacción social, según las entrevistas en profundidad con el profesorado. Investigación mixta: Según los análisis de datos CUAL y CUAN, sus resultados y conclusiones. Posicionamiento: Ontológico, el investigador conoce la realidad de lo que pretende investigar, sobre una muestra de 17 IES públicos (provincia València), cuya reflexión sobre la E-A de la Tecnología, y los constructos que conforman la identidad STEM. Epistemológico, el investigador participa con conocimiento del hecho a investigar. Metodológico, el contraste de hipótesis y el refinamiento hermenéutico de los análisis CUAL y CUAN. La Teoría Fundamentada es la base del planteamiento CUAL, a través de entrevistas en profundidad y codificación abierta, axial y selectiva, de los temas a investigar: 1. Organización escolar y curricular; 2. Metodología PBL y sinergias STEM; 3. Multidisciplinariedad e interdisciplinariedad STEM; 4. Taxonomía de proyectos. Los datos cualitativos y sus resultados son tratados con Atlas.ti. La Teoría de Aprendizaje Cognitivo Social (SCT), y Teoría Cognitivo Social de Desarrollo de la Carrera (SCCT), son el planteamiento CUAN. El registro de datos CUAN, es a través del diseño de un cuestionario. El grupo "Juicio de expertos" validó estructura y contenido. Los datos y resultados CUAN, son tratados por estadística descriptiva e inferencial. La modelización de los aprendizajes, son tratados por ecuaciones estructurales (SEM). Objetivos: 1. Valorar la metodología por proyectos en un contexto de constantes cambios del currículo y de aprendizaje virtual. 2. Contrastar si el aprendizaje por competencias mejora la adquisición de conocimientos, habilidades y actitudes en un contexto de aprendizaje interdisciplinar. 3. Modelizar los aprendizajes SCT, SCCT, Multidisciplinar, Interdisciplinar y por Proyectos, mediante SEM. Obtención de datos: CUAL (grupos focales profesorado oct. 2019 - feb. 2020; expertos oct. 2019 - abril 2022). Participación 133 docentes (74H, 59M). Todas las sesiones fueron grabadas (audio 70 h). La transcripción audio-texto con AmberScript. CUAN (cuestionarios feb. 2020 - dic. 2020). Participación 1417 alumnos (537 chicas, 831 chicos, 49 errores). El diseño del cuestionario online con Question-Pro. La COVID'19 paralizó el proceso de obtención de datos desde marzo a nov. 2020. Capítulos: I: Introducción. II: Revisión del estado del arte. III: Marco teórico. IV: Metodología de la investigación. V: Análisis cualitativo. VI: Análisis cuantitativo. VII: Conclusiones generales. VIII: Referencias y Anexos. Conclusiones: 1. Currículo denso, rígido y fragmentado no favorece la adquisición de competencias. 2. Formación docente ágil, continua y arraigada a las necesidades. 3. Transición entre niveles educativos, predice la adquisición de competencias del alumnado y la satisfacción docente. 4. Continuidad de estudios no depende del género. No existen diferencias entre chicas y chicos por lo que aprenden, sino por la preferencia de estudios, metodologías aplicadas, expectativas de resultado, y distancia del IES a la metrópoli. 5. Sinergias son posibles, pero la organización de la jornada escolar dificulta compartir experiencias, innovar y divulgar conocimiento. 6. Aprendizaje por proyectos es eficiente y motivador, se aprende haciendo, experimentando soluciones a problemas reales. 7. Aprender buenas prácticas educativas, facilita la multidisciplinar. 8. Uso extensivo del aprendizaje virtual, entretiene más que crear contenido, y se pierde el saber hacer manual. 9. Satisfacción de los aprendizajes disminuye si no se sabe aplicarlos. 10. Dificultades de la interdisciplinariedad STEM, se superan después de un proceso multidisciplinariedad y no al revés. / [CA] Paradigma: Entre el postpositivisme, les troballes del qual són probabilitats quantitatives extrets de les opinions de l'alumnat, i el constructivisme, la realitat qualitativa es construeix per interacció social, segons les entrevistes en profunditat amb el professorat. Investigació mixta: Segons les anàlisis de dades QUAL i CUAN, els resultats i les conclusions. Posicionament: Ontològic, l'investigador coneix la realitat del que pretén investigar, sobre una mostra de 17 IES públics (província València), la reflexió dels quals sobre l'E-A de la Tecnologia, i els constructes que conformen la identitat STEM. Epistemològic, l'investigador participa amb coneixement del fet a investigar. Metodològic, el contrast d'hipòtesis i el refinament hermenèutic de les anàlisis QUAL i QUAN. La Teoria Fonamentada és la base del plantejament QUAL, mitjançant entrevistes en profunditat i codificació oberta, axial i selectiva, dels temes a investigar: 1. Organització escolar i curricular; 2. Metodologia PBL i sinergies STEM; 3. Multidisciplinarietat i interdisciplinarietat STEM; 4. Taxonomia de projectes. Les dades qualitatives i els seus resultats són tractats amb Atlas.ti. La Teoria d'Aprenentatge Cognitiu Social (SCT) i Teoria Cognitiu Social de Desenvolupament de la Carrera (SCCT) són el plantejament CUAN. El registre de dades CUAN és a través del disseny d'un qüestionari. El grup Judici d'experts va validar estructura i contingut. Les dades i resultats CUAN són tractats per estadística descriptiva i inferencial. La modelització dels aprenentatges són tractats per equacions estructurals (SEM). Objectius: 1. Valorar la metodologia per projectes en un context de canvis constants del currículum i d'aprenentatge virtual. 2. Contrastar si laprenentatge per competències millora ladquisició de coneixements, habilitats i actituds en un context daprenentatge interdisciplinari. 3. Modelitzar els aprenentatges SCT, SCCT, Multidisciplinar, Interdisciplinar i per Projectes, mitjançant SEM. Obtenció de dades: QUAL (grups focals professorat oct. 2019 - feb. 2020; experts oct. 2019 - abril 2022). Participació 133 docents (74H, 59M). Totes les sessions van ser gravades (àudio 70 h). La transcripció àudio-text amb AmberScript. QUAN (qüestionaris feb. 2020 - des. 2020). Participació 1417 alumnes (537 xiques, 831 xics, 49 errors). El disseny del qüestionari en línia amb Question-Pro. La COVID'19 va paralitzar el procés d'obtenció de dades des del març al nov. 2020. Capítols: I: Introducció. II: revisió de l'estat de l'art. III: Marc teòric. IV: Metodologia de la investigació. V: Anàlisi qualitativa. VI: Anàlisi quantitativa. VII: Conclusions generals. VIII: Referències i Annexos. Conclusions: 1. Currículum dens, rígid i fragmentat no afavoreix l'adquisició de competències. 2. Formació docent àgil, contínua i arrelada a les necessitats. 3. Transició entre nivells educatius, prediu l'adquisició de competències de l'alumnat i la satisfacció docent. 4. Continuïtat dels estudis no depèn del gènere. No hi ha diferències entre noies i nois pel que aprenen, sinó per la preferència d'estudis, metodologies aplicades, expectatives de resultat i distància de l'IES a la metròpoli. 5. Les sinèrgies són possibles, però l'organització de la jornada escolar dificulta compartir experiències, innovar i divulgar coneixement. 6. Aprenentatge per projectes és eficient i motivador, s'aprèn fent experimentant solucions a problemes reals. 7. Aprendre bones pràctiques educatives facilita la multidisciplinar. 8. Ús extensiu de l'aprenentatge virtual, entreté més que crear contingut, i es perd saber fer manual. 9. Satisfacció dels aprenentatges disminueix si no se sap aplicar-los. 10. Dificultats de la interdisciplinarietat STEM, se superen després d"un procés multidisciplinarietat i no al revés. / [EN] Paradigm: Between post-positivism, whose findings are quantitative probabilities extracted from the opinions of the students, and constructivism, qualitative reality is built by social interaction, according to in-depth interviews with teachers. Mixed research: According to the QUAL and QUAN data analyses, their results and conclusions. Positioning: Ontological, the researcher knows the reality of what he intends to investigate, on a sample of 17 public IES (Valencia province), whose reflection on the E-A of Technology, and the constructs that make up the STEM identity. Epistemological, the researcher participates with knowledge of the fact to be investigated. Methodology, the contrast of hypotheses and the hermeneutic refinement of the QUAL and QUAN analyses. The Grounded Theory is the basis of the QUAL approach, through in-depth interviews and open, axial and selective coding, of the topics to be investigated: 1. School and curricular organization; 2. PBL methodology and STEM synergies; 3. STEM multidisciplinarity and interdisciplinarity; 4. Taxonomy of projects. The qualitative data and its results are processed with Atlas.ti. Social Cognitive Learning Theory (SCT), and Social Cognitive Theory of Career Development (SCCT), are the QUAN approach. The CUAN data record is through the design of a questionnaire. The "Expert Judgment" group validated structure and content. The QUAN data and results are treated by descriptive and inferential statistics. The modeling of learning is treated by structural equations (SEM). Goals: 1. Evaluate the methodology by projects in a context of constant changes in the curriculum and virtual learning. 2. Test whether competency-based learning improves the acquisition of knowledge, skills and attitudes in an interdisciplinary learning context. 3. Model SCT, SCCT, Multidisciplinary, Interdisciplinary and Project learning, through SEM. Data collection: QUAL (teacher focus groups Oct. 2019 - Feb. 2020; experts Oct. 2019 - April 2022). Participation 133 teachers (74H, 59M). All sessions were recorded (audio 70 h). Audio-text transcription with AmberScript. QUAN (questionnaires Feb. 2020 - Dec. 2020). Participation 1417 students (537 girls, 831 boys, 49 errors). The design of the online questionnaire with Question-Pro. COVID'19 paralyzed the data collection process from March to Nov. 2020. Chapters: I. Introduction. II: Review of the state of the art. III: Theoretical framework. IV: Research methodology. V: Qualitative analysis. VI: Quantitative analysis. VII: General conclusions. VIII: References and Annexes. Conclusions: 1. Dense, rigid and fragmented curriculum does not favor the acquisition of skills. 2. Agile, continuous teacher training rooted in needs. 3. Transition between educational levels, predicts the acquisition of student skills and teacher satisfaction. 4. Continuity of studies does not depend on gender. There are no differences between girls and boys because of what they learn, but because of the preference of studies, applied methodologies, expectations of results, and distance from the IES to the metropolis. 5. Synergies are possible, but the organization of the school day makes it difficult to share experiences, innovate and disseminate knowledge. 6. Project-based learning is efficient and motivating, you learn by doing, experimenting with solutions to real problems. 7. Learning good educational practices facilitates multidisciplinary. 8. Extensive use of virtual learning, it entertains more than creating content, and manual know-how is lost. 9. Satisfaction of the learning decreases if one does not know how to apply it. 10. Difficulties of STEM interdisciplinarity are overcome after a multidisciplinary process and not the other way around. / Torres Barchino, E. (2023). Análisis y propuesta de mejora de la enseñanza de las tecnologías en la Educación Secundaria Obligatoria y Bachillerato: un enfoque desde el aprendizaje basado en proyectos (PBL) y la interdisciplinariedad de áreas STEM [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/199198