179 research outputs found

    MODIS information, data and control system (MIDACS) operations concepts

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    The MODIS Information, Data, and Control System (MIDACS) Operations Concepts Document provides a basis for the mutual understanding between the users and the designers of the MIDACS, including the requirements, operating environment, external interfaces, and development plan. In defining the concepts and scope of the system, how the MIDACS will operate as an element of the Earth Observing System (EOS) within the EosDIS environment is described. This version follows an earlier release of a preliminary draft version. The individual operations concepts for planning and scheduling, control and monitoring, data acquisition and processing, calibration and validation, data archive and distribution, and user access do not yet fully represent the requirements of the data system needed to achieve the scientific objectives of the MODIS instruments and science teams. The teams are not yet formed; however, it is possible to develop the operations concepts based on the present concept of EosDIS, the level 1 and level 2 Functional Requirements Documents, and through interviews and meetings with key members of the scientific community. The operations concepts were exercised through the application of representative scenarios

    The effectiveness of multiple intelligences based teaching strategy in enhancing the multiple intelligences and science process skills of junior High School students

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    The study was aimed to investigate the effectiveness of teaching strategy based on Multiple Intelligences (MI) theory to improve multiple intelligences and science process skills of junior high school students in Indonesia. The study used quasi experimental design and the effectiveness of the teaching strategy was evaluated by pretest-posttest-control-group design. The samples consisted of two schools selected by Stratified Random Sampling. The experimental group (n=63) was taught using the MI strategy while the control group (n=61) was taught using the traditional strategy. This study was conducted in 12 weeks. Data were obtained from multiple intelligences test, science process skills test, and observation sheets. The hypotheses of student multiple intelligences and science process skills were tested using Wilcoxon’s Signed Rank Test and ANOVA test. The results indicated that students who were instructed by using MI strategy improved on four specific types of multiple intelligences namely visual spatial, intrapersonal, kinesthetic, and musical intelligences. However, the interpersonal logic remains unchanged, while the mathematical logic decreases after treatment. Also, these showed an improvement of the science process skills, specifically in the questioning ability.Peer Reviewe

    A closer look at Intrusion Detection System for web applications

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    Intrusion Detection System (IDS) is one of the security measures being used as an additional defence mechanism to prevent the security breaches on web. It has been well known methodology for detecting network-based attacks but still immature in the domain of securing web application. The objective of the paper is to thoroughly understand the design methodology of the detection system in respect to web applications. In this paper, we discuss several specific aspects of a web application in detail that makes challenging for a developer to build an efficient web IDS. The paper also provides a comprehensive overview of the existing detection systems exclusively designed to observe web traffic. Furthermore, we identify various dimensions for comparing the IDS from different perspectives based on their design and functionalities. We also provide a conceptual framework of an IDS with prevention mechanism to offer a systematic guidance for the implementation of the system specific to the web applications. We compare its features with five existing detection systems, namely AppSensor, PHPIDS, ModSecurity, Shadow Daemon and AQTRONIX WebKnight. The paper will highly facilitate the interest groups with the cutting edge information to understand the stronger and weaker sections of the web IDS and provide a firm foundation for developing an intelligent and efficient system

    Novel methods of utilizing Jitter for Network Congestion Control

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    This paper proposes a novel paradigm for network congestion control. Instead of perpetual conflict as in TCP, a proof-of-concept first-ever protocol enabling inter-flow communication without infrastructure support thru a side channel constructed on generic FIFO queue behaviour is presented. This enables independent flows passing thru the same bottleneck queue to communicate and achieve fair capacity sharing and a stable equilibrium state in a rapid fashion

    Protecting Systems From Exploits Using Language-Theoretic Security

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    Any computer program processing input from the user or network must validate the input. Input-handling vulnerabilities occur in programs when the software component responsible for filtering malicious input---the parser---does not perform validation adequately. Consequently, parsers are among the most targeted components since they defend the rest of the program from malicious input. This thesis adopts the Language-Theoretic Security (LangSec) principle to understand what tools and research are needed to prevent exploits that target parsers. LangSec proposes specifying the syntactic structure of the input format as a formal grammar. We then build a recognizer for this formal grammar to validate any input before the rest of the program acts on it. To ensure that these recognizers represent the data format, programmers often rely on parser generators or parser combinators tools to build the parsers. This thesis propels several sub-fields in LangSec by proposing new techniques to find bugs in implementations, novel categorizations of vulnerabilities, and new parsing algorithms and tools to handle practical data formats. To this end, this thesis comprises five parts that tackle various tenets of LangSec. First, I categorize various input-handling vulnerabilities and exploits using two frameworks. First, I use the mismorphisms framework to reason about vulnerabilities. This framework helps us reason about the root causes leading to various vulnerabilities. Next, we built a categorization framework using various LangSec anti-patterns, such as parser differentials and insufficient input validation. Finally, we built a catalog of more than 30 popular vulnerabilities to demonstrate the categorization frameworks. Second, I built parsers for various Internet of Things and power grid network protocols and the iccMAX file format using parser combinator libraries. The parsers I built for power grid protocols were deployed and tested on power grid substation networks as an intrusion detection tool. The parser I built for the iccMAX file format led to several corrections and modifications to the iccMAX specifications and reference implementations. Third, I present SPARTA, a novel tool I built that generates Rust code that type checks Portable Data Format (PDF) files. The type checker I helped build strictly enforces the constraints in the PDF specification to find deviations. Our checker has contributed to at least four significant clarifications and corrections to the PDF 2.0 specification and various open-source PDF tools. In addition to our checker, we also built a practical tool, PDFFixer, to dynamically patch type errors in PDF files. Fourth, I present ParseSmith, a tool to build verified parsers for real-world data formats. Most parsing tools available for data formats are insufficient to handle practical formats or have not been verified for their correctness. I built a verified parsing tool in Dafny that builds on ideas from attribute grammars, data-dependent grammars, and parsing expression grammars to tackle various constructs commonly seen in network formats. I prove that our parsers run in linear time and always terminate for well-formed grammars. Finally, I provide the earliest systematic comparison of various data description languages (DDLs) and their parser generation tools. DDLs are used to describe and parse commonly used data formats, such as image formats. Next, I conducted an expert elicitation qualitative study to derive various metrics that I use to compare the DDLs. I also systematically compare these DDLs based on sample data descriptions available with the DDLs---checking for correctness and resilience

    Dignitas: uso de reputação como moeda para avaliar a sensorização humana em cidades inteligentes

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    We live in an increasingly digital world, where Smart Cities have become a reality. One of the characteristics that make these cities smart is their ability to gather information and act upon it, improving their citizens lives. In this work, we present our system, Dignitas. A blockchain-based reputation system that allows citizens of a Smart City to assess the truthiness of information posted by other citizens. This assessment is based on a bet that reporters make, and all of those who agreed with him, that puts their gathered reputation at stake. This use of Reputation as a currency is a novel idea that allowed us to build an anonymous system. Using blockchain we were able to have multiple authorities, working with each other to make the system secure and thus avoiding centralized schemes. Our work was focused on developing our idea, a proof of concept, and testing the viability of our new solution.Vivemos num mundo cada vez mais digital, onde as cidades inteligentes passaram a ser uma realidade. Uma das características que permite a estas cidades serem inteligentes é a capacidade de adquirir informação e agir sobre ela, melhorando a vida de todos os cidadãos. Neste trabalho apresentamos o nosso sistema, Dignitas, um sistema de reputação baseado numa blockchain que permite aos cidadãos de uma cidade inteligente avaliar informação relatada por outras pessoas. Esta avaliação é baseada numa aposta feita pelo relator, e por todos os que com ele concordam, em que põe em risco parte da sua Reputação no sistema. Este uso da Reputação como uma moeda é o que nos permite construir um sistema anónimo. O uso de uma blockchain permite-nos ter múltiplas autoridades responsáveis, evitando por isso o uso de esquemas centralizados. O nosso trabalho focou-se em desenvolver a nossa ideia, uma prova de conceito, e testar a viabilidade desta nossa nova solução.Mestrado em Engenharia de Computadores e Telemátic
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