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Distribution by Scientific Domains

Information Science and Computing	31%
Chemistry	27%
Engineering	11%
Medical Sciences	9%
Life Sciences	5%
Humanities and Social Sciences	5%
Business, Economics, Finance and Accounting	5%

Terms modified by Authentication

authentication protocol

Selected Abstracts

Book Review: Oils and Fats Authentication by Michael Jee

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2003
Franz Ulberth
No abstract is available for this article. [source]

First Authentication of Kostanecki's Triketone and Multimolecular Reaction of Aromatic Aldehydes with Acetophenone

HELVETICA CHIMICA ACTA, Issue 6 2009
Zixing Shan
Abstract A double-component, multimolecular reaction between acetophenone and aromatic aldehydes was achieved under catalysis by the solid-base mixture NaOH/K2CO3, and Kostanecki's triketone, supposed to exist for more than 110 years, was successfully separated for the first time as an accompaniment of a pentane-1,5-dione or a 1,2,3,4,5-pentasubstituted cyclohexanol (Scheme,1) and authenticated by spectroscopic and single-crystal X-ray diffraction analysis. Thus, the multimolecular-reaction mechanism of the formation of 1,2,3,4,5-pentasubstituted cyclohexanols from 1-phenylalkan-1-ones and aromatic aldehydes was fully validated based on the results (Scheme,3). [source]

TK-AKA: using temporary key on Authentication and Key Agreement protocol on UMTS

INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 4 2009
Hsia-Hung Ou
Mobile communication is definitely one of the major high-technology applications that offer present-day people a modern life of appropriate convenience. In recent years, the third-generation cell phone system has approached maturity. The Universal Mobile Telecommunication System (UMTS) is currently the most widely used system around the world. The Third Generation Partnership Project is equipped with the Authentication and Key Agreement (AKA) protocol to maintain secrecy and security both during the authentication process and during the telecommunication session through UMTS. However, Hung and Li have pointed out that the UMTS-AKA protocol has three problems, involving bandwidth consumption, space overhead and synchronization of the sequence number, which are yet to be resolved. In addition, they have proposed an extension of the UMTS-AKA protocol, named the X-AKA protocol, to overcome these obstacles. Nevertheless, the X-AKA protocol too appears to have problems of its own. In this article, the weaknesses of X-AKA are enumerated. In addition, a more practical AKA protocol for UMTS is presented. The new protocol, based on the same framework as its predecessor, proves to be more efficient and practical, satisfying the requirements of modern living. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Authentication of Green Asparagus Varieties by Near-Infrared Reflectance Spectroscopy

JOURNAL OF FOOD SCIENCE, Issue 2 2001
D.P. Perez
ABSTRACT: Near-infrared reflectance spectroscopy (NIRS) was used for the authentication of 2 green asparagus varieties (Taxara and UC-157), grown in Huetor-Tajar (Granada, Spain) protected by the Quality Specific Appellation "Espárragos de Huétor-Tájar". To develop the prediction model, the method chosen was modified partial least square (MPLS) regression. Two sample sets (N = 219 and N2 = 145 samples, respectively) were used to obtain the calibration equations. The standard error of cross-validation (SECV) and the r2 value were 0.082 and 0.97, respectively, for the 1st calibration set and 0.077 and 0.97 for the 2nd calibration set. The 2nd chemometric model obtained was tested with independent validation sample set (N3 = 74 samples), and the resulting values for standard error of prediction (SEP) and for r2 were 0.07 and 0.96, respectively. These results prove that NIRS is an accurate technology for identification and authentication of asparagus varieties and easily implemented in industry. [source]

Trace Element Fingerprinting of Australian Ocher Using Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) for the Provenance Establishment and Authentication of Indigenous Art,

JOURNAL OF FORENSIC SCIENCES, Issue 4 2007
Rachel L. Green B.Sc.
Abstract:, The expansion of indigenous art and the interest it has generated both at a domestic and international level means large monetary transactions are taking place between art galleries or centers and purchasers. As such, an accurate and conclusive method for provenance determination of traditional indigenous artistic materials must be established that can, if necessary, be used to assist in authentication of artworks. Laser ablation inductively coupled plasma mass spectrometry was utilized for elemental differentiation and provenance establishment of ocher samples. This research was used to develop a robust scientific protocol which facilitates definitive and accurate determination of provenance of Australian ochers and the artworks created using them. Analysis of the results obtained through this study show that the trace metal distribution patterns alone appear to be sufficient evidence to establish provenance of specific ochers, although additional differentiation between ocher samples, using major element distribution patterns, was achieved through the utilization of X-ray analytical techniques. [source]

Cross-domain authorization for federated virtual organizations using the myVocs collaboration environment

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 4 2009
Jill Gemmill
Abstract This paper describes our experiences building and working with the reference implementation of myVocs (my Virtual Organization Collaboration System). myVocs provides a flexible environment for exploring new approaches to security, application development, and access control built from Internet services without a central identity repository. The myVocs framework enables virtual organization (VO) self-management across unrelated security domains for multiple, unrelated VOs. By leveraging the emerging distributed identity management infrastructure. myVocs provides an accessible, secure collaborative environment using standards for federated identity management and open-source software developed through the National Science Foundation Middleware Initiative. The Shibboleth software, an early implementation of the Organization for the Advancement of Structured Information Standards Security Assertion Markup Language standard for browser single sign-on, provides the middleware needed to assert identity and attributes across domains so that access control decisions can be determined at each resource based on local policy. The eduPerson object class for lightweight directory access protocol (LDAP) provides standardized naming, format, and semantics for a global identifier. We have found that a Shibboleth deployment supporting VOs requires the addition of a new VO service component allowing VOs to manage their own membership and control access to their distributed resources. The myVocs system can be integrated with Grid authentication and authorization using GridShib. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Augmenting LZ-77 with authentication and integrity assurance capabilities

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11 2004
Mikhail J. Atallah
Abstract The formidable dissemination capability allowed by the current network technology makes it increasingly important to devise new methods to ensure authenticity and integrity. Nowadays it is common practice to distribute documents in compressed form. In this paper, we propose a simple variation on the classic LZ-77 algorithm that allows one to hide, within the compressed document, enough information to warrant its authenticity and integrity. The design is based on the unpredictability of a certain class of pseudo-random number generators, in such a way that the hidden data cannot be retrieved in a reasonable amount of time by an attacker (unless the secret bit-string key is known). Since it can still be decompressed by the original LZ-77 algorithm, the embedding is completely ,transparent' and backward-compatible, making it possible to deploy it without disrupting service. Experiments show that the degradation in compression due to the embedding is almost negligible. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Identification and authentication of integrated circuits

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11 2004
Blaise Gassend
Abstract This paper describes a technique to reliably and securely identify individual integrated circuits (ICs) based on the precise measurement of circuit delays and a simple challenge,response protocol. This technique could be used to produce key-cards that are more difficult to clone than ones involving digital keys on the IC. We consider potential venues of attack against our system, and present candidate implementations. Experiments on Field Programmable Gate Arrays show that the technique is viable, but that our current implementations could require some strengthening before it can be considered as secure. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Stepwise geographical traceability of virgin olive oils by chemical profiles using artificial neural network models

EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 10 2009
Diego L. García-González
Abstract The geographical traceability of virgin olive oils implies the use of analytical methods that allow the identification of the origin of the oil and the authentication of the information boasted on the labels. In this work, the geographical identification of the virgin olive oils has been addressed by complete chemical characterisation of samples (64 compounds analysed by GC and HPLC) and the design of artificial neural network (ANN) models for each one of the levels of a proposed classification scheme. A high number of samples (687) from Spain, Italy and Portugal served as training and test sets for the ANN models. The highest classification level, focused on the grouping of samples by country, was achieved through analysis of fatty acids, with 99.9% of samples classified. Other levels (region, province, Protected Designations of Origin or PDO) were focused on Spanish oils and required additional series of compounds (sterols, alcohols, hydrocarbons) as well as the fatty acids to obtain classification rates higher than 90%. The classification of oils into different PDOs , the last and most difficult level of classification , showed the highest root mean square errors. The classification percentages, however, were still higher than 90% in the test set, which proves the application of the traceability methodology for a chemical verification of PDO claims. [source]

A new mutual authentication and key exchange protocol with balanced computational power for wireless settings

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 2 2004
Chou-Chen Yang
Mutual authentication and key exchange protocols (MAKEP) provide two parties in communication with guarantee of true identity. And then the two parties end up sharing a common session key for privacy and data integrity during the session. In MAKEP, public-key-based schemes and symmetric-key-based schemes are often used. However, the former requires high computation complexity and hence, it is not suitable for applications in wireless settings. The latter has to maintain many distinct keys for different parties. Wong et al. proposed the Linear MAKEP to solve these problems. But in term of storage space, it is not optimal. In this paper, we propose a scheme that uses the geometric properties of line to achieve mutual authentication and key exchange. Compared with Wong et al.'s scheme, our scheme is efficient and requires less storage space. It can withstand the replay attack and the unknown key-share attack, and the server does not bear much more computation cost than the client in each session, hence we call it a protocal with balanced computational power. Copyright © 2004 AEI [source]

MLCC: A new hash-chained mechanism for multicast source authentication

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 9 2009
H. Eltaief
Abstract Asymmetric cryptography has been widely used to generate a digital signature for message authentication. However, such a strategy cannot be used for packet authentication. Neither the source nor the receiver will be capable of handling the computational cost of asymmetric cryptography. For unicast communication, the solution adopted is based on symmetric cryptography. Solutions based on symmetric cryptography do not scale for multicast communication. Several solutions have been reported to authenticate multicast streams, with the possibility of packet losses. Proposed solutions are based on the concept of signature amortization, where a single signature is amortized on several packets. In this paper we present a new mechanism for multicast data source authentication based on signature amortization. Multi-layers connected chains divides the packet stream into a multi-layer structure, where each layer is a two-dimensional matrix. The hash of a packet is included into a forward chain of packets within the same layer as well as a downward chain of packets across multiple layers. The values of the key parameters that influence the mechanism efficiency as well as its performance are selected following a mathematical analysis. Comparisons of performance results with the well-known efficient multi-chained stream signature scheme as well as a recently reported scheme multiple connected chains model show that the proposed mechanism achieves a stronger resistance to packet losses with low overhead and high authentication probability. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Secure fast WLAN handoff using time-bound delegated authentication

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2009
Hung-Yu Chien
Abstract To support multimedia applications with good quality of services for roaming wireless local area network users, it is imperative to reduce the long re-authentication latency that users experience during handoff among access points (APs). Athough a great deal of research resources have been put into the reduction of the re-authentication latency, these schemes developed so far seem to either suffer from heavy overhead problems or have weak security. In this paper, we propose a novel approach to reducing the re-authentication latency. With the authentication server (AS) periodically delegating its authentication authority to the authenticated APs, the APs can authenticate the roaming users on behalf of the AS. As our performance analysis and simulation results demonstrate, our new approach is capable of greatly reducing the latency and overhead while achieving a high security level. Furthermore, it does not increase the complexity on the AP side because only the already existing four-way handshake with new keying mechanism is required. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Finger vein recognition using minutia-based alignment and local binary pattern-based feature extraction

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 3 2009
Eui Chul Lee
Abstract With recent increases in security requirements, biometrics such as fingerprints, faces, and irises have been widely used in many recognition applications including door access control, personal authentication for computers, Internet banking, automatic teller machines, and border-crossing controls. Finger vein recognition uses the unique patterns of finger veins to identify individuals at a high level of accuracy. This article proposes a new finger vein recognition method using minutia-based alignment and local binary pattern (LBP)-based feature extraction. Our study makes three novelties compared to previous works. First, we use minutia points such as bifurcation and ending points of the finger vein region for image alignment. Second, instead of using the whole finger vein region, we use several extracted minutia points and a simple affine transform for alignment, which can be performed at fast computational speed. Third, after aligning the finger vein image based on minutia points, we extract a unique finger vein code using a LBP, which reduces false rejection error and thus the equal error rate (EER) significantly. Our resulting EER was 0.081% with a total processing time of 118.6 ms. © 2009 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 19, 179,186, 2009 [source]

A constant rounds group key agreement protocol without using hash functions

INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 6 2009
Hua Zhang
It is important to encrypt and authenticate messages sent over networks to achieve security. Network users must therefore agree upon encryption keys and authentication keys. The authenticated Diffie,Hellman key agreement protocol is used to provide authentication in communication systems. In this paper we present a group key agreement protocol without using one-way hash functions that are based on the DDH problem. The protocol achieves efficiency in both communication and computation aspects. We analyzed the security in the security model formalized by Bresson et al. Copyright © 2009 John Wiley & Sons, Ltd. [source]

AAA architecture for mobile IPv6 based on WLAN

INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 5 2004
R. C. Wang
Mobility support for Internet devices is quite important for consumer electronics. The number of the hand-held devices is growing quickly. However, there are not enough IP addresses for the number of the rapidly growing devices in the All-IP generation. Internet Protocol version 6 (IPv6) was therefore adopted to solve these problems. Our purposed structure is based on IEEE 802.11. However, IEEE 802.11 has a serious security drawback. Further, from the Internet Service Providers' point of view, accounting is a potential problem. A mechanism combining Mobile IPv6 and AAA based on IEEE 802.11 to overcome these problems is essential. Both Internet Protocol version 4 (IPv4) and IPv6 support IP security (IPsec) when data packets are exchanged across the IP network. IPsec operates at the IP layer. It can support system authentication and authorization, However, it lacks a system accounting function. Therefore ISPs cannot establish correct billing for their services. This is the reason why we chose to combine the wireless network and AAA functions. In this paper, the AAA mechanism is used to protect security, with the architecture having authentication, authorization, and accounting functions. We will discuss the benefits of AAA and state the reason why we choose to combine AAA with the mobility architecture.,Copyright © 2004 John Wiley & Sons, Ltd. [source]

Using ancient DNA analysis in palaeopathology: a critical analysis of published papers, with recommendations for future work

INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 6 2008
C. Roberts
Abstract Despite an observable increase in the number of studies using ancient DNA analysis to diagnose disease in human remains, there remain issues to be addressed about the quality of the resulting publications. This paper describes the qualitative analysis of published papers that describe the detection of pathogenic DNA in human skeletal and mummified remains from archaeological sites. Its ultimate goal is to provide an overview of the main problematic issues in relationship to standards developed in molecular biology and to make recommendations for future work. Sixty-five papers published between 1993 and 2006 were surveyed and the quality of each was assessed using 15 criteria. Interesting results emerged. Of particular note was the high number of papers that did not acknowledge the use of even basic contamination control (90%) or procedures to validate results independently (85%). This study illustrates that attention to contamination control and authentication of results is needed in future research, if confidence in aDNA analysis in palaeopathology is to be increased. Additionally, methods of analysis must be described in published papers to ensure transparency in processes utilised to generate the data. Copyright © 2008 John Wiley & Sons, Ltd. [source]

DETECTION OF OLIVE OIL ADULTERATION WITH RAPESEED AND SUNFLOWER OILS USING MOS ELECTRONIC NOSE AND SMPE-MS

JOURNAL OF FOOD QUALITY, Issue 1 2010
SYLWIA MILDNER-SZKUDLARZ
ABSTRACT The study analyzed the effectiveness of two types of electronic nose systems to detect adulteration of extra virgin olive oil (EVOO) with rapeseed and sunflower oils. Tested methods included volatile analysis with the electronic nose based on MOS sensors (HS-E nose) and by direct coupling of SPME to MS (SPME-MS). Volatile compounds were analyzed also by SPME-GC/MS. Samples of EVOO were mixed with different proportions, ranging from 5 to 50% (v/v), of seed oils and fingerprints of volatile profiles of all samples were generated. In order to obtain as much chemical information as possible and to find a volatile marker to detect adulterations of EVOO with seed oils, principal component analysis (PCA) and partial least squares (PLS) analyses were applied to the data. The application of PCA and PLS analyses to the data from two electronic noses and SMPE-GC/MS were sufficient to differentiate the adulterated samples from pure EVOO. Excellent results were obtained in the prediction of the percentage of adulteration by PLS analysis. SPME-GC-MS analysis with subsequent PCA yielded good results; however, it was time-consuming. The two electronic noses, with subsequent PCA treatment of data, offering the advantages of rapidity and reliability, enabled detection of olive oil adulteration with different contents of seed oils. PRACTICAL APPLICATIONS Virgin olive oil is highly appreciated by consumers due to its nutritional benefits. Thus, its adulteration with low-grade olive oils or cheaper vegetable oils could potentially be very profitable for sellers or raw material suppliers and may yield large economic profits. In this way, authentication of virgin olive oils has become an interesting subject from both commercial and health perspectives. It has been proved that the two proposed types of electronic nose systems facilitate reliable detection of rapeseed and sunflower oils in extra virgin olive oil. Both MOS and MS electronic noses are faster than the conventional SMPE-GC/MS analysis. These well-correlated methodologies, offering the advantages of rapidity and reliability, opened up a new way of detecting adulteration of virgin olive oils. [source]

Development of a Monoclonal Antibody for Grouper (Epinephelus marginatus) and Wreck Fish (Polyprion americanus) Authentication Using an Indirect ELISA

JOURNAL OF FOOD SCIENCE, Issue 6 2003
L. Asensio
ABSTRACT: A monoclonal antibody generated against soluble muscle proteins from grouper (Epinephelus marginatus) has been used in 2 indirect ELISA formats (microtiter plates and immunostick tubes) for the rapid authentication of grouper and wreck fish (Polyprion americanus). This monoclonal antibody (1A4-MAb) was tested against native and heat-treated (cooked and sterilized) soluble muscle protein extracts from several commonly marketed fish species and only reacted with grouper and wreck fish samples. [source]

Authentication of Green Asparagus Varieties by Near-Infrared Reflectance Spectroscopy

Speech Watermarking: An Approach for the Forensic Analysis of Digital Telephonic Recordings,

JOURNAL OF FORENSIC SCIENCES, Issue 4 2010
Marcos Faundez-Zanuy Ph.D
Abstract:, In this article, the authors discuss the problem of forensic authentication of digital audio recordings. Although forensic audio has been addressed in several articles, the existing approaches are focused on analog magnetic recordings, which are less prevalent because of the large amount of digital recorders available on the market (optical, solid state, hard disks, etc.). An approach based on digital signal processing that consists of spread spectrum techniques for speech watermarking is presented. This approach presents the advantage that the authentication is based on the signal itself rather than the recording format. Thus, it is valid for usual recording devices in police-controlled telephone intercepts. In addition, our proposal allows for the introduction of relevant information such as the recording date and time and all the relevant data (this is not always possible with classical systems). Our experimental results reveal that the speech watermarking procedure does not interfere in a significant way with the posterior forensic speaker identification. [source]

Trace Element Fingerprinting of Australian Ocher Using Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) for the Provenance Establishment and Authentication of Indigenous Art,

Research Article: Fingerprinting Analysis of Saposhnikovia divaricata using 1H Nuclear Magnetic Resonance Spectroscopy and High Performance Liquid Chromatography

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 9 2010
Yue-Yang Xin
The 1H nuclear magnetic resonance (1H NMR) fingerprints of fractionated non-polar and polar extracts (control substance for plant drug [CSPD] A and B) from the roots of 12 specimens of Saposhnikovia divaricata (Turcz.) Schischk were achieved with Fourier Transform (FT)-NMR spectrometer and assigned by comparison to each other and to the 1H NMR spectra of the isolated individual compounds. These fingerprints were found to be uniform in terms of the specificity for the implication of all 12 specimens being systematically of the same origin. The uniformity was further affirmed by high performance liquid chromatography (HPLC), which also revealed exactly identical specificity for the identified S. divaricata species with the 1H NMR appearances of corresponding CSPD on the part of the composition of characteristic constituents when comparing to corresponding individual compounds. This investigation unambiguously shows that the specific signals from the chemotaxonomically significant compounds of chromones and coumarins in S. divaricata are exhibited distinctively in the composite features of both 1H NMR fingerprints and HPLC profiles. The 1H NMR and HPLC profiles established can successfully be used as reference for the authentication of the origin of S. divaricata species as well as for chemotaxonomic studies. [source]

Simulation and multi-attribute utility modelling of life cycle profit

JOURNAL OF MULTI CRITERIA DECISION ANALYSIS, Issue 4 2001
Tony RosqvistArticle first published online: 16 NOV 200
Abstract Investments on capital goods are assessed with respect to the life cycle profit as well as the economic lifetime of the investment. The outcome of an investment with respect to these economic criteria is generally non-deterministic. An assessment of different investment options thus requires probabilistic modelling to explicitly account for the uncertainties. A process for the assessment of life cycle profit and the evaluation of the adequacy of the assessment is developed. The primary goal of the assessment process is to aid the decision-maker in structuring and quantifying investment decision problems characterized by multiple criteria and uncertainty. The adequacy of the assessment process can be evaluated by probabilistic criteria indicating the degree of uncertainty in the assessment. Bayesian inference is used to re-evaluate the initial assessment, as evidence of the system performance becomes available. Thus authentication of contracts of guarantee is supported. Numerical examples are given to demonstrate features of the described life cycle profit assessment process. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Trialling of the Partnership in Coping system

JOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 3 2007
M. JUBB-SHANLEY mn bn pgcertcmhn rgn rpn
The paper describes the results of a preliminary trial of a system of mental health nursing, the Partnership in Coping system, based on the subjective experiences of the participating mental health nurses and service users. The community mental health study involved action research, with data being collected through individual interviews and focus groups. Data analysis, using thematic content analysis, resulted in the emergence of two main dimensions. These dimensions are centred around a shift in responsibility from the service to the service user, and the authentication and clarification of the roles of the nurse and the service user. [source]

Fingerprint chromatogram analysis of Pseudostellaria heterophylla (Miq.) Pax root by high performance liquid chromatography

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 14 2006
Chao Han
Abstract A simple and reliable high performance liquid chromatographic (HPLC) method has been developed and validated for the fingerprinting of extracts from the root of Pseudostellaria heterophylla (Miq.) Pax. HPLC with gradient elution was performed on an authentic reference standard of powdered P. heterophylla (Miq.) Pax root and 11 plant samples of the root were collected from different geographic locations. The HPLC chromatograms have been standardized through the selection and identification of reference peaks and the normalization of retention times and peak intensities of all the common peaks. The standardized HPLC fingerprints show high stability and reproducibility, and thus can be used effectively for the screening analysis or quality assessment of the root or its derived products. Similarity index calculations based on cosine angle values or correlation methods have been performed on the HPLC fingerprints. As a group, the fingerprints of the P. heterophylla (Miq.) Pax samples studied are highly correlated with closely similar fingerprints. Within the group, the samples can be further divided into subgroups based on hierarchical clustering analysis (HCA). Sample grouping based on HCA coincides nicely with those based on the geographical origins of the samples. The HPLC fingerprinting techniques thus have high potential in authentication or source-tracing types of applications. [source]

,I'm Mexican, remember?' Constructing ethnic identities via authenticating discourse1

JOURNAL OF SOCIOLINGUISTICS, Issue 2 2007
Petra Scott Shenk
This paper examines how an ideology of cultural authenticity emerges in the casual but playful conversations of a bilingual Mexican American friendship group. Authenticating discourse, as illustrated here, is part of an ongoing, ordinary interactional routine through which speakers take overt (authentication) stances, which I call authenticating moves, to display, impugn, vie for, and enact forms of ethnic identity. In the data, issues of authenticity in relation to Mexicanness emerge as a result of the interactional exploitation of three ideological constructs: purity of bloodline, purity of nationality, and Spanish linguistic fluency. [source]

A public-key based authentication and key establishment protocol coupled with a client puzzle

JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 9 2003
M.C. Lee
Network Denial-of-Service (DoS) attacks, which exhaust server resources and network bandwidth, can cause the target servers to be unable to provide proper services to the legitimate users and in some cases render the target systems inoperable and/or the target networks inaccessible. DoS attacks have now become a serious and common security threat to the Internet community. Public Key Infrastructure (PKI) has long been incorporated in various authentication protocols to facilitate verifying the identities of the communicating parties. The use of PKI has, however, an inherent problem as it involves expensive computational operations such as modular exponentiation. An improper deployment of the public-key operations in a protocol could create an opportunity for DoS attackers to exhaust the server's resources. This paper presents a public-key based authentication and key establishment protocol coupled with a sophisticated client puzzle, which together provide a versatile solution for possible DoS attacks and various other common attacks during an authentication process. Besides authentication, the protocol also supports a joint establishment of a session key by both the client and the server, which protects the session communications after the mutual authentication. The proposed protocol has been validated using a formal logic theory and has been shown, through security analysis, to be able to resist, besides DoS attacks, various other common attacks. [source]

31P NMR spectroscopy in the quality control and authentication of extra-virgin olive oil: A review of recent progress

MAGNETIC RESONANCE IN CHEMISTRY, Issue 5 2007
Photis Dais
Abstract This review is a brief account on the application of a novel methodology to the quality control and authentication of extra-virgin olive oil. This methodology is based on the derivatization of the labile hydrogens of functional groups, such as hydroxyl and carboxyl groups, of olive oil constituents with the phosphorus reagent 2-chloro-4,4,5,5-tetramethyldioxaphospholane, and the use of the 31P chemical shifts to identify the phosphitylated compounds. Various experimental aspects such as pertinent instrumentation, sample preparation, acquisition parameters and properties of the phosphorus reagent are reviewed. The strategy to assign the 31P signals of the phosphitylated model compounds and olive oil constituents by employing 1D and 2D NMR experiments is presented. Finally, the capability of this technique to assess the quality and the genuineness of extra-virgin olive oil and to detect fraud is discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Characterization of shapes for use in classification of starch grains images

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 9 2008
Chong-Sze Tong
Abstract As tradition Chinese herbal medicine becomes increasingly popular, there is an urgent need for efficient and accurate methods for the authentication of the Chinese Materia Medica (CMM) used in the herbal medicine. In this work, we present a denoising filter and introduce the use of chord length distribution (CLD) for the classification of starch grains in microscopic images of Chinese Materia Medica. Our simple denoising filter is adaptive to the background and is shown to be effective to remove noise, which appears in CMM microscopic starch grains images. The CLD is extracted by considering the frequency of the chord length in the binarized starch grains image, and we shall show that the CLD is an efficient and effective characterization of the starch grains. Experimental results on 240 starch grains images of 24 classes show that our method outperforms benchmark result using the current state-of-the-art method based on circular size distribution extracted by morphological operators at much higher computational cost. cost. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc. [source]

Application of microscopy in authentication of traditional Tibetan medicinal plant Halenia elliptica

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 1 2008
Jie Li
Abstract Halenia elliptica D. Don, a popularly used ethnodrug from Qinghai-Tibetan plateau, was studied to reveal the indispensable morphoanatomic details. The fixed, sectioned, and stained plant materials as well as the epidermis, powder, and maceration materials were studied using light microscope according to the usual microscopic techniques. The results of the microscopic features were systematic described and illustrated. In the root, an endodermal cell was divided into 8-16-22 and 38-50-62 daughter cells in transverse section and in face view, respectively, and 9-11-13 phloem strands were present in primary structure; in the stem, stone cells were observed in the cortex, pericycle, and external phloem while 17-19-21 internal phloem strands were present in an incontinuous ring; in the pedicel, 8-10-12 internal phloem strands were observed to form an incontinuous ring; anisocytic and anomocytic stomata were present in leaf and sepal epidermis; pollen grain was with three germinal apertures and furrows; a few tracheids, a large number of spiral vessels, and various fibers were observed. Also, semiquantitative and quantitative micrographic parameter tables were simultaneously presented. Further, the key authentication parameters were concluded. The study indicated that light microscopy and related techniques could be unambiguously applied to the authentication of Halenia elliptica. Microsc. Res. Tech., 2008. © 2007 Wiley-Liss, Inc. [source]