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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Chemi-code : an innovative method for wood product tracking

Smiley, Bryce Carson 05 1900 (has links)
Chain of custody in the forest sector is very dependent on effectively tracking products though the supply chain and manufacturing processes, including sawmilling, drying, planing, and pulp processes. The effectiveness of a tracking system is largely influenced by the characteristics of the process it works within, the nature of the tracking system being used, and increasingly by the penetration of technologically advanced material tracking methods into on-the-ground CoC practices. A variety of CoC systems that exist in the global marketplace accommodate the use of advanced materials tracking systems as a tool for their their implementation. These advances not only offer the potential to reinforce the traceability of products in inventory, but also promote maintenance of their certified status between the various organizations that exist along the wood product supply chain, and ultimately to the end consumer. In the past, a number of different product tracking methods have been used, all of which suffer certain shortcomings in the challenging environment of the forest industry, and the extremely complex nature of Chain of Custody tracking. This work explores the development of a novel material tracking method using the innate IR signatures of polymeric compounds, varied by compound and concentration to develop millions of potential combinations, and consequently millions of unique identities. The combined variation of multiple IR peak frequencies and magnitudes provide the conceptual basis of a chemical barcode system, named "Chemi-Code", to be explored. To prove the validity of this concept, a series of polymers were assayed for suitability in such a system by tracking their IR response stability in the presence of solar UV radiation and over time. As well, the feasibility of varying polymer concentration, and subsequently identification of concentrations by DRIFT spectroscopy was explored by constructing response curves between polymer concentration and peak absorbance, and assessing associated error. Seven polymers were identified and assessed. Only two of these polymers were found to be sufficiently stable for use in the context of the forest industry, and of those two, only one behaved in a manner that would allow peak absorbance to be used as an identifiable chemical variable. Although only one of the seven polymers was suitable for use in the "Chemi-Code" system, the study did demonstrate the validity of the concept by showing that polymers can be exploited for use in such a system.
32

Chemi-code : an innovative method for wood product tracking

Smiley, Bryce Carson 05 1900 (has links)
Chain of custody in the forest sector is very dependent on effectively tracking products though the supply chain and manufacturing processes, including sawmilling, drying, planing, and pulp processes. The effectiveness of a tracking system is largely influenced by the characteristics of the process it works within, the nature of the tracking system being used, and increasingly by the penetration of technologically advanced material tracking methods into on-the-ground CoC practices. A variety of CoC systems that exist in the global marketplace accommodate the use of advanced materials tracking systems as a tool for their their implementation. These advances not only offer the potential to reinforce the traceability of products in inventory, but also promote maintenance of their certified status between the various organizations that exist along the wood product supply chain, and ultimately to the end consumer. In the past, a number of different product tracking methods have been used, all of which suffer certain shortcomings in the challenging environment of the forest industry, and the extremely complex nature of Chain of Custody tracking. This work explores the development of a novel material tracking method using the innate IR signatures of polymeric compounds, varied by compound and concentration to develop millions of potential combinations, and consequently millions of unique identities. The combined variation of multiple IR peak frequencies and magnitudes provide the conceptual basis of a chemical barcode system, named "Chemi-Code", to be explored. To prove the validity of this concept, a series of polymers were assayed for suitability in such a system by tracking their IR response stability in the presence of solar UV radiation and over time. As well, the feasibility of varying polymer concentration, and subsequently identification of concentrations by DRIFT spectroscopy was explored by constructing response curves between polymer concentration and peak absorbance, and assessing associated error. Seven polymers were identified and assessed. Only two of these polymers were found to be sufficiently stable for use in the context of the forest industry, and of those two, only one behaved in a manner that would allow peak absorbance to be used as an identifiable chemical variable. Although only one of the seven polymers was suitable for use in the "Chemi-Code" system, the study did demonstrate the validity of the concept by showing that polymers can be exploited for use in such a system.
33

Eficiência da análise multifractal na verificação de assinaturas dinâmicas / Effectiveness of multifractal analysis for online signature verification

Canuto, Jânio Coutinho 08 December 2010 (has links)
Orientador: Lee Luan Ling / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-16T11:24:26Z (GMT). No. of bitstreams: 1 Canuto_JanioCoutinho_M.pdf: 5638185 bytes, checksum: a7de3e11ab9d81ea1011ac08ccef240a (MD5) Previous issue date: 2010 / Resumo: A verificação de identidades de forma confiável é cada vez mais necessária em nossa sociedade amplamente interconectada. Nesse contexto, a verificação biométrica é uma proposta alternativa, e mais segura, aos métodos tradicionalmente utilizados, como senhas e cartões. A análise multifractal, por sua vez, tem sido usada com sucesso em diversas aplicações de processamento de sinais, além disso, diversos estudos mostram a presença de características multifractais em processos naturais. Este trabalho tem como objetivo analisar os sinais referentes às assinaturas dinâmicas, provenientes de equipamentos como PDAs e tablet-pcs, sob o prisma da teoria multifractal. É estudada a capacidade de discriminação da característica multifractal na detecção de falsificações de assinaturas, tanto quando usadas isoladamente quanto em conjunto com características tradicionais, num contexto de fusão de informação, com resultados equivalentes ao estado da arte deste tema. Além disso, é realizada uma quantificação, através da teoria da informação, desta capacidade discriminatória. Por fim, é apresentada uma aplicação alternativa da informação multifractal no contexto da biometria: a análise de qualidade das amostras / Abstract: Reliable identity verification is an increasing necessity in our largely networked society. On this topic, biometric verification is a safer alternative to the traditional methods, such as passwords and ID cards. On the other hand, multifractal analysis has been successfully used in a wide range of signal processing applications; moreover, many works show the occurrence of multifractal traits on biological processes. This work aims at analyzing dynamic signature signals collected through devices such as PDAs and tablet-pcs, from a multifractal perspective. A study of the multifractal features discriminative capabilities on signature forgery detection is realized on two scenarios: when it is the unique feature used by the system, and in tandem with traditional features on an information fusion scheme; with results as good as those found in the state of the art of this area. Furthermore, an information theoretic quantification of the discrimination capability is realized. Finally, an alternative application for such features is presented: the evaluation of samples quality / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica
34

Securing the digital signing process

Van den Berg, James Richard 25 March 2010 (has links)
M.Comm. / Worldwide an increasing amount of legal credibility is being assigned to digital signatures and it is therefore of utmost importance to research and develop additional measures to secure the technology. The main goal of this dissertation is to research and identify areas in which the user’s private key, used for the digital signing of messages, is exposed to the risk of being compromised and then develop a prototype system (SecureSign) to overcome the identified vulnerabilities and secure the digital signing process. In order to achieve the above stated, use will be made of a cryptographic token, which will provide secure storage and a secure operational environment to the user’s private key. The cryptographic token is at the heart of SecureSign and it is where the user’s private key will be created, stored and used. All operations requiring the user’s private key will be performed on the token, which is equipped with its own processor for this purpose.
35

Chemi-code : an innovative method for wood product tracking

Smiley, Bryce Carson 05 1900 (has links)
Chain of custody in the forest sector is very dependent on effectively tracking products though the supply chain and manufacturing processes, including sawmilling, drying, planing, and pulp processes. The effectiveness of a tracking system is largely influenced by the characteristics of the process it works within, the nature of the tracking system being used, and increasingly by the penetration of technologically advanced material tracking methods into on-the-ground CoC practices. A variety of CoC systems that exist in the global marketplace accommodate the use of advanced materials tracking systems as a tool for their their implementation. These advances not only offer the potential to reinforce the traceability of products in inventory, but also promote maintenance of their certified status between the various organizations that exist along the wood product supply chain, and ultimately to the end consumer. In the past, a number of different product tracking methods have been used, all of which suffer certain shortcomings in the challenging environment of the forest industry, and the extremely complex nature of Chain of Custody tracking. This work explores the development of a novel material tracking method using the innate IR signatures of polymeric compounds, varied by compound and concentration to develop millions of potential combinations, and consequently millions of unique identities. The combined variation of multiple IR peak frequencies and magnitudes provide the conceptual basis of a chemical barcode system, named "Chemi-Code", to be explored. To prove the validity of this concept, a series of polymers were assayed for suitability in such a system by tracking their IR response stability in the presence of solar UV radiation and over time. As well, the feasibility of varying polymer concentration, and subsequently identification of concentrations by DRIFT spectroscopy was explored by constructing response curves between polymer concentration and peak absorbance, and assessing associated error. Seven polymers were identified and assessed. Only two of these polymers were found to be sufficiently stable for use in the context of the forest industry, and of those two, only one behaved in a manner that would allow peak absorbance to be used as an identifiable chemical variable. Although only one of the seven polymers was suitable for use in the "Chemi-Code" system, the study did demonstrate the validity of the concept by showing that polymers can be exploited for use in such a system. / Forestry, Faculty of / Graduate
36

The Needed Input Data for Accurate On-line Signature Verification : The relevance of pressure and pen inclination for on-line signature verification / Indatan som behövs för bra signaturverifiering : Relevansen av tryckkänslighet och pennvinklar för signaturverifiering

Sjöholm, Thomas January 2015 (has links)
Signatures have been used to authenticate documents and transactions for over 1500 years and are still being used today. In this project a method for verifying signatures written on a tablet has been developed and tested in order to test whether pressure information is vital for a well performing on-line signature verification systems. First a background study was conducted to learn about the state-of-the-art methods and what features several research systems used, then the method was developed. The method is a Dynamic Time Warp with 8 local features, 2 of them were pressure values or derived from pressure, and 1 global feature. The developed method was tested on SUSig visual corpus containing signatures from 94 persons. The Equal Error Rate (EER) when not using pressure was 5.39 % for random forgeries and 3.24 % for skilled forgeries. EER when using pressure was 5.19 % for random forgeries and 2.80 % for skilled forgeries. The background study concluded that pen inclination is not required for a well performing system. Considering the result of this project and the result of others, it seems that pressure information is not vital, but provide some valuable information that can be used to classify signatures more accurately. / Signaturer har blivit använda för att autentisera dokument och transaktioner i över 1500 år och används än idag. En metod för att testa signaturer skrivna på en digital platta har utvecklats för att testa huruvida tryckkänslighet och vinkeln på pennan är kritiskt för ett välpresterande on-line signature verification system. Först så genomfördes en bakgrundsstudie för att se hur andra moderna metoder gör och vad för features de använder för att sen utveckla metoden. Den använda metoden är en Dynamic Time Warp med 8 lokala features varav 2 är tyckkänslighet eller utvunna från tryckkänslighet samt en global feature. Metoden testades sedan på SUSig visual corpus som har signaturer från 94 personer. Equal Error Rate (EER) för de feature kombinationerna som inte använde tryckkänslighet blev 5.39 % för slumpmässiga signaturer och 3.24 % för förfalskningar. EER för kombinationer av features som innehåller tryckkänslighet blev 5.19 % för slumpmässiga signaturer och 2.80 % för förfalskningar. Givet resultatet av det här projektet samt andra projekt utforskade i bakgrundsstudien så verkar tryckkänslighet inte vara kritiskt men ger en del värdeful information för klassificera signaturer mer träffsäkert. Bakgrundsstudien gav att vinkeln på pennan inte var kritisk för att välpresterande system.
37

The symmetric signature

Caminata, Alessio 02 March 2016 (has links)
We define two related invariants for a d-dimensional local ring (R,m,k) called syzygy and differential symmetric signature by looking at the maximal free splitting of reflexive symmetric powers of two modules: the top dimensional syzygy module of the residue field and the module of Kähler differentials of R over k. We compute these invariants for two-dimensional ADE singularities obtaining 1/|G|, where |G| is the order of the acting group, and for cones over elliptic curves obtaining 0 for the differential symmetric signature. These values coincide with the F-signature of such rings in positive characteristic.
38

Quantitative Analysis of Microbial Species in a Metagenome Based onTheir Signature Sequences

Yadav, Pooja 26 July 2017 (has links)
No description available.
39

Fast Signature Schemes Over Odd Characteristic

Baena Giraldo, John Bayron 17 July 2009 (has links)
No description available.
40

La régime fiscal des activités de commerce électronique : étude comparative / The taxation of electronic commerce activities

Shaaban, Hossam 13 December 2010 (has links)
La question de cette étude est de savoir si les activités électroniques peuvent être soumises à l'impôt ou non. Si la réponse est positive, cela pose un autre problème : quel cadre fiscal pour les activités de commerce électronique ? Il est à mentionner que la politique fiscale américaine repose sur une règle qui ne soumet pas les activités du commerce électronique à l'impôt. Ces activités ont pour caractéristique d'être dématérialisées, ce qui pose plusieurs difficultés en matière de l'établissement de l'impôt. Tout d'abord, la nature dématérialisée des activités du commerce électronique peut poser le problème de la localisation des parties et par conséquent la difficulté d'identification du contribuable et des transactions électroniques. Or, cette nature dématérialisée et transfrontalière soulève un problème de détermination des règles de territorialité applicables. Ensuite, cette étude souhaite démontrer si les principes généraux d'imposition, soit en droit français soit en droit égyptien, peuvent être appliqués aux activités du commerce électronique. Enfin, et après avoir exposé tous les problèmes relatifs à l'établissement de l'impôt sur les activités du commerce électronique, cette étude propose un certain nombre de moyens permettant de résoudre les difficultés liées à l'imposition des activités de commerce électronique. / The question of this study is that if these electronic activities can be submitted to the tax or not. If the answer is positive, it poses another problem is how the taxation framework for electronic commerce activities is. It is worth mentioning that American fiscal policy rested on a rule whose e-commerce activities do not subject to tax. These activities are characterized as being dematerialized, which poses several difficulties in establishing the tax. First, the nature of paperless electronic commerce activities may pose the problem of localization of parts and later the difficulty in identifying the taxpayer and electronic transactions. Yet such is a cross-border paperless and difficulty of determining the rules of territoriality applicable. Second, this study requires showing whether the general principles of tax law either Egyptian law or French law can be applied to electronic commerce activities or not. Finally, and after exposing all the problems relating to the establishment of tax e-commerce activities, the methodology of this research leads the researcher to address the means to solve these problems.

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