385,175 research outputs found

    Field spectroradiometer data : acquisition, organisation, processing and analysis on the example of New Zealand native plants : a thesis presented in fulfilment of the requirements for the degree of Master of Philosophy in Earth Science at Massey University, Palmerston North, New Zealand

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    The purpose of this research was to investigate the acquisition, storage, processing and analysis of hyperspectral data for vegetation applications on the example of New Zealand native plants. Data covering the spectral range 350nm-2500nm were collected with a portable spectroradiometer. Hyperspectral data collection results in large datasets that need pre-processing before any analysis can be carried out. A review of the techniques used since the advent of hyperspectral field data showed the following general procedures were followed: 1. Removal of noisy or uncalibrated bands 2. Data smoothing 3. Reduction of dimensionality 4. Transformation into feature space 5. Analysis techniques Steps 1 to 4 which are concerned with the pre-processing of data were found to be repetitive procedures and thus had a high potential for automation. The pre-processing had a major impact on the results gained in the analysis stage. Finding the ideal pre-processing parameters involved repeated processing of the data. Hyperspectral field data should be stored in a structured way. The utilization of a relational database seemed a logical approach. A hierarchical data structure that reflected the real world and the setup of sampling campaigns was designed. This structure was transformed into a logical data model. Furthermore the database also held information needed for pre-processing and statistical analysis. This enabled the calculation of separability measurements such as the JM (Jeffries Matusila) distance or the application of discriminant analysis. Software was written to provide a graphical user interface to the database and implement pre-processing and analysis functionality. The acquisition, processing and analysis steps were applied to New Zealand native vegetation. A high degree of separability between species was achieved and using independent data a classification accuracy of 87.87% was reached. This outcome required smoothing, Hyperion synthesizing and principal components transformation to be applied to the data prior to the classification which used a generalized squared distance discriminant function. The mixed signature problem was addressed in experiments under controlled laboratory conditions and revealed that certain combinations of plants could not be unmixed successfully while mixtures of vegetation and artificial materials resulted in very good abundance estimations. The combination of a relational database with associated software for data processing was found to be highly efficient when dealing with hyperspectral field data

    Forensic Analysis of Fitbit Versa: Android vs iOS

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    Fitbit Versa is the most popular of its predecessors and successors in the Fitbit faction. Increasingly data stored on these smart fitness devices, their linked applications and cloud datacenters are being used for criminal convictions there is limited research for investigators on wearable devices and specifically exploring evidence identification and methods of extraction. In this paper we present our analysis of Fitbit Versa using Cellebrite UFED and MSAB XRY. We present a clear scope for investigation and data significance based on the findings from our experiments the data recovery will include logical and physical extractions using devices running Android 9 and iOS 12, comparing between Cellebrite and XRY capabilities. This paper discusses databases and datatypes that can be recovered using different extraction and analysis techniques, providing a robust outlook of data availability. We also discuss the accuracy of recorded data compared to planned test instances, verifying the accuracy of individual data types the verifiable accuracy of some datatypes could prove useful if such data was required during the evidentiary processes of a forensic investigation

    Data Product Specification Proposal for Architectural Heritage Documentation with Photogrammetric Techniques: A Case Study in Brazil

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    peer reviewedPhotogrammetric documentation can provide a sound database for the needs of architectural heritage preservation. However, the major part of photogrammetric documentation production is not used for subsequent architectural heritage projects, due to lack of knowledge of photogrammetric documentation accuracy. In addition, there are only a few studies with rigorous analysis of the requirements for photogrammetric documentation of architectural heritage. In particular, requirements focusing on the geometry of the models generated by fully digital photogrammetric processes are missing. Considering these needs, this paper presents a procedure for architectural heritage documentation with photogrammetric techniques based on a previous review of existing standards of architectural heritage documentation. The data product specification proposed was elaborated conforming to ISO 19131 recommendations. We present the procedure with two case studies in the context of Brazilian architectural heritage documentation. Quality analysis of the produced models were performed considering ISO 19157 elements, such as positional accuracy, logical consistency and completeness, meeting the requirements. Our results confirm that the proposed requirements for photogrammetric documentation are viable

    PRIVAFRAME: A Frame-Based Knowledge Graph for Sensitive Personal Data

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    The pervasiveness of dialogue systems and virtual conversation applications raises an important theme: the potential of sharing sensitive information, and the consequent need for protection. To guarantee the subject’s right to privacy, and avoid the leakage of private content, it is important to treat sensitive information. However, any treatment requires firstly to identify sensitive text, and appropriate techniques to do it automatically. The Sensitive Information Detection (SID) task has been explored in the literature in different domains and languages, but there is no common benchmark. Current approaches are mostly based on artificial neural networks (ANN) or transformers based on them. Our research focuses on identifying categories of personal data in informal English sentences, by adopting a new logical-symbolic approach, and eventually hybridising it with ANN models. We present a frame-based knowledge graph built for personal data categories defined in the Data Privacy Vocabulary (DPV). The knowledge graph is designed through the logical composition of already existing frames, and has been evaluated as background knowledge for a SID system against a labeled sensitive information dataset. The accuracy of PRIVAFRAME reached 78%. By comparison, a transformer-based model achieved 12% lower performance on the same dataset. The top-down logical-symbolic frame-based model allows a granular analysis, and does not require a training dataset. These advantages lead us to use it as a layer in a hybrid model, where the logical SID is combined with an ANNs SID tested in a previous study by the authors

    Finding the Fuel of the Arab Spring Fire: A Historical Data Analysis

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    Purpose: This paper aims to address the reasons behind the varying levels of volatile conflict and peace as seen during the Arab Spring of 2011 to 2015. During this time, higher rates of conflict transition occurred than normally observed in previous studies for certain Middle Eastern and North African countries. Design/Methodology/Approach: Previous prediction models decrease in accuracy during times of volatile conflict transition. Also, proper strategies for handling the Arab Spring have been highly debated. This paper identifies which countries were affected by the Arab Spring and then applies data analysis techniques to predict a country’s tendency to suffer from high-intensity, violent conflict. A large number of open-source variables are incorporated by implementing an imputation methodology useful to conflict prediction studies in the future. The imputed variables are implemented in four model building techniques: purposeful selection of covariates, logical selection of covariates, principal component regression and representative principal component regression resulting in modeling accuracies exceeding 90 per cent. Findings: Analysis of the models produced by the four techniques supports hypotheses which propose political opportunity and quality of life factors as causations for increased instability following the Arab Spring

    Identifying Aspects of the Integration of Gus Durs’s Religious Tourism Area with Regionalism Approaches

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    Religious tourism is not separated from the activities which can affect the development of the region and can make it uncontrolled. Developments that can change significantly and uneven can harm various parties around the tourist area. Such developments can lead to a change in function and result in lifestyle shifts surrounding tourist areas. Therefore, integration is necessary for the establishment of a quality tourism plan in urban areas. Integration is an important aspect of changing in urban environments as it can create a space that has the attractiveness and mutual benefit between regions one and the other regions. The research method used is logical argumentation where the research relies on the argument as a reference in the aspects and results of research. Data collection techniques in research with interviews, observations, cognitive mapping and literature studies, after that done with data analysis using legibility analysis to identify the urban form in local and regional, sense of community identity and contributions or its role in the city then proceed with triangulation which aims to check the results of data test or data accuracy, then interpreted according to the context. This study results in what aspects can affect the change in tourist area functions and can be used as an integrated aspect of the surrounding environment

    Identifying e-Commerce in Enterprises by means of Text Mining and Classification Algorithms

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    Monitoring specific features of the enterprises, for example, the adoption of e-commerce, is an important and basic task for several economic activities. This type of information is usually obtained by means of surveys, which are costly due to the amount of personnel involved in the task. An automatic detection of this information would allow consistent savings. This can actually be performed by relying on computer engineering, since in general this information is publicly available on-line through the corporate websites. This work describes how to convert the detection of e-commerce into a supervised classification problem, where each record is obtained from the automatic analysis of one corporate website, and the class is the presence or the absence of e-commerce facilities. The automatic generation of similar data records requires the use of several Text Mining phases; in particular we compare six strategies based on the selection of best words and best n-grams. After this, we classify the obtained dataset by means of four classification algorithms: Support Vector Machines; Random Forest; Statistical and Logical Analysis of Data; Logistic Classifier. This turns out to be a difficult case of classification problem. However, after a careful design and set-up of the whole procedure, the results on a practical case of Italian enterprises are encouraging

    Logical analysis of data as a tool for the analysis of probabilistic discrete choice behavior

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    Probabilistic Discrete Choice Models (PDCM) have been extensively used to interpret the behavior of heterogeneous decision makers that face discrete alternatives. The classification approach of Logical Analysis of Data (LAD) uses discrete optimization to generate patterns, which are logic formulas characterizing the different classes. Patterns can be seen as rules explaining the phenomenon under analysis. In this work we discuss how LAD can be used as the first phase of the specification of PDCM. Since in this task the number of patterns generated may be extremely large, and many of them may be nearly equivalent, additional processing is necessary to obtain practically meaningful information. Hence, we propose computationally viable techniques to obtain small sets of patterns that constitute meaningful representations of the phenomenon and allow to discover significant associations between subsets of explanatory variables and the output. We consider the complex socio-economic problem of the analysis of the utilization of the Internet in Italy, using real data gathered by the Italian National Institute of Statistics
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