286 research outputs found
Generation and Handling of Hard Drive Duplicates as Piece of Evidence
An important area in digital forensics is images of hard disks. The correct production of the images as well as the integrity and authenticity of each hard disk image is essential for the probative force of the image to be used at court. Integrity and authenticity are under suspicion as digital evidence is stored and used by software based systems. Modifications to digital objects are hard or even impossible to track and can occur even accidentally. Even worse, vulnerabilities occur for all current computing systems. Therefore, it is difficult to guarantee a secure environment for forensic investigations. But intended deletions of dedicated data of disk images are often required because of legal issues in many countries.
This article provides a technical framework on the protection of the probative force of hard disk images by ensuring the integrity and authenticity using state of the art technology. It combines hardware-based security, cryptographic hash functions and digital signatures to achieve a continuous protection of the image together with a reliable documentation of the status of the device that was used for image creation. The framework presented allows to detect modifications and to pinpoint the exact area of the modification to the digital evidence protecting the probative force of the evidence at a whole. In addition, it also supports the deletion of parts of images without invalidating the retained data blocks.
Keywords: digital evidence, probative force hard disk image, verifiable deletion of image data, trusted imaging softwar
Phased-array wavelength demultiplexer with flattened wavelength response
A four-channel phased-array wavelength demultiplexer with a flattened wavelength response has been realised for the first time in InP/InGaAsP at 1.54 mu m by employing multimode output waveguides. The device has 2 nm channel spacing and a flat response (within 1 dB) of 17 n
Haplotyping, linkage mapping and expression analysis of barley genes regulated by terminal drought stress influencing seed quality
<p>Abstract</p> <p>Background</p> <p>The increasingly narrow genetic background characteristic of modern crop germplasm presents a challenge for the breeding of cultivars that require adaptation to the anticipated change in climate. Thus, high priority research aims at the identification of relevant allelic variation present both in the crop itself as well as in its progenitors. This study is based on the characterization of genetic variation in barley, with a view to enhancing its response to terminal drought stress.</p> <p>Results</p> <p>The expression patterns of drought regulated genes were monitored during plant ontogeny, mapped and the location of these genes was incorporated into a comprehensive barley SNP linkage map. Haplotypes within a set of 17 starch biosynthesis/degradation genes were defined, and a particularly high level of haplotype variation was uncovered in the genes encoding sucrose synthase (types I and II) and starch synthase. The ability of a panel of 50 barley accessions to maintain grain starch content under terminal drought conditions was explored.</p> <p>Conclusion</p> <p>The linkage/expression map is an informative resource in the context of characterizing the response of barley to drought stress. The high level of haplotype variation among starch biosynthesis/degradation genes in the progenitors of cultivated barley shows that domestication and breeding have greatly eroded their allelic diversity in current elite cultivars. Prospective association analysis based on core drought-regulated genes may simplify the process of identifying favourable alleles, and help to understand the genetic basis of the response to terminal drought.</p
ifo Konjunkturprognose 2005/2006: Nur zögerliche Erholung
Die Weltwirtschaft hat im laufenden Jahr merklich an Dynamik eingebĂŒĂt, nachdem sie 2004 auĂerordentlich stark gewachsen war. In Deutschland fehlen die binnenwirtschaftlichen AuftriebskrĂ€fte immer noch fast vollstĂ€ndig. Die gesamtwirtschaftliche Produktion kommt sofort aus dem Tritt, sobald vom Ausland geringere Impulse ausgehen. FĂŒr die deutsche Wirtschaft ist eine fundamentale WachstumsschwĂ€che zu diagnostizieren; das Produktionspotential steigt derzeit nur um 1%, das ist halb so hoch wie im restlichen Euroraum. Die Entwicklung dieses und des kommenden Jahres wird ungefĂ€hr dem Trend folgen. Das reale Bruttoinlandsprodukt dĂŒrfte im Jahresdurchschnitt 2005 um 0,8% expandieren, nach 1,6% im Jahr 2004. Im nĂ€chsten Jahr dĂŒrfte sich das Expansionstempo der gesamtwirtschaftlichen Produktion parallel zur Besserung der Weltkonjunktur wieder leicht beschleunigen; die Zuwachsrate des realen Bruttoinlandsprodukts dĂŒrfte sich dann auf 1,2% belaufen. Damit wird die gesamtwirtschaftliche Auslastung der ProduktionskapazitĂ€ten wieder zunehmen. Die Inflationsrate dĂŒrfte trotz des Ălpreisschubs im Durchschnitt des Prognosezeitraums unter der 2-Prozentmarke liegen. Auf dem deutschen Arbeitsmarkt ist bisher keine Wende eingetreten. Im Mai dieses Jahres gab es 4,81 Mill. registrierte Arbeitslose; das entspricht einem Anstieg von 510 000 gegenĂŒber dem vergleichbaren Vorjahresmonat. Der ĂŒberwiegende Teil dieser Zunahme (ca. 360 000) ist auf die im Zuge der Hartz-IV-Gesetzgebung erfolgte Zusammenlegung von Arbeitslosen- und Sozialhilfe zurĂŒckzufĂŒhren. Rechnet man dagegen, dass inzwischen rund 155 000 Zusatzjobs die Statistik entlasten, so dĂŒrfte die rein konjunkturelle Zunahme der Arbeitslosigkeit rund 300 000 betragen haben. Erst im nĂ€chsten Jahr ist eine leichte Besserung auf dem Arbeitsmarkt zu erwarten. Unter der Annahme, dass bis zum Jahresende 2006 etwa 300 000 Zusatzjobs geschaffen werden, dĂŒrfte sich die Zahl der registrierten Arbeitslosen in diesem Jahr auf 4,86 Millionen belauf
Accurate band mapping via photoemission from thin films
Electron bands in solids can be determined in angle-resolved photoemission experiments from thin films, where the perpendicular wave vector (kâ„) uncertainty that characterizes photoemission from bulk crystals is removed. However, the comparison with state-of-the-art quasiparticle band-structure calculations has never been done. In this work we have mapped both initial-state (occupied) and final-state (empty) E(kâ„) bands along the A axis of aluminum, from photon-energy- and thickness-dependent quantum-well spectra of aluminum films. For final states the best fit is obtained with inverse low-energy electron diffraction band structure calculations. For initial-state bands of Cu and Al, thin-film data display excellent agreement with bulk quasiparticle theory, suggesting the use of thin films as model systems to investigate fine effects in the crystal band structure.This work has been supported in part by the Universidad del PaĂs Vasco (A.Mu. and J.E.O. under Contract No. 00057.240-EA-13668/2001, and A.Ma., A.R., and F.J.G.A. under Contract No. 00206.215-13639/2001), the European Community (EC) research training network NANOPHASE [A.Ma. and A.R. (Grant No. HPRN-CT-2000-00167)], and the Spanish Ministerio de Ciencia y TecnologĂa [A.Ma., A.R., and F.J.G.A. (Grant No. MAT2001-0946), and J.L. and E.G.M. (BFM2001-0244)].Peer Reviewe
ifo Konjunkturprognose 2005/2006: Nur zögerliche Erholung
Die Weltwirtschaft hat im laufenden Jahr merklich an Dynamik eingebĂŒĂt, nachdem sie 2004 auĂerordentlich stark gewachsen war. In Deutschland fehlen die binnenwirtschaftlichen AuftriebskrĂ€fte immer noch fast vollstĂ€ndig. Die gesamtwirtschaftliche Produktion kommt sofort aus dem Tritt, sobald vom Ausland geringere Impulse ausgehen. FĂŒr die deutsche Wirtschaft ist eine fundamentale WachstumsschwĂ€che zu diagnostizieren; das Produktionspotential steigt derzeit nur um 1%, das ist halb so hoch wie im restlichen Euroraum. Die Entwicklung dieses und des kommenden Jahres wird ungefĂ€hr dem Trend folgen. Das reale Bruttoinlandsprodukt dĂŒrfte im Jahresdurchschnitt 2005 um 0,8% expandieren, nach 1,6% im Jahr 2004. Im nĂ€chsten Jahr dĂŒrfte sich das Expansionstempo der gesamtwirtschaftlichen Produktion parallel zur Besserung der Weltkonjunktur wieder leicht beschleunigen; die Zuwachsrate des realen Bruttoinlandsprodukts dĂŒrfte sich dann auf 1,2% belaufen. Damit wird die gesamtwirtschaftliche Auslastung der ProduktionskapazitĂ€ten wieder zunehmen. Die Inflationsrate dĂŒrfte trotz des Ălpreisschubs im Durchschnitt des Prognosezeitraums unter der 2-Prozentmarke liegen. Auf dem deutschen Arbeitsmarkt ist bisher keine Wende eingetreten. Im Mai dieses Jahres gab es 4,81 Mill. registrierte Arbeitslose; das entspricht einem Anstieg von 510 000 gegenĂŒber dem vergleichbaren Vorjahresmonat. Der ĂŒberwiegende Teil dieser Zunahme (ca. 360 000) ist auf die im Zuge der Hartz-IV-Gesetzgebung erfolgte Zusammenlegung von Arbeitslosen- und Sozialhilfe zurĂŒckzufĂŒhren. Rechnet man dagegen, dass inzwischen rund 155 000 Zusatzjobs die Statistik entlasten, so dĂŒrfte die rein konjunkturelle Zunahme der Arbeitslosigkeit rund 300 000 betragen haben. Erst im nĂ€chsten Jahr ist eine leichte Besserung auf dem Arbeitsmarkt zu erwarten. Unter der Annahme, dass bis zum Jahresende 2006 etwa 300 000 Zusatzjobs geschaffen werden, dĂŒrfte sich die Zahl der registrierten Arbeitslosen in diesem Jahr auf 4,86 Millionen belaufeWeltkonjunktur, Konjunkturprognose, Wirtschafstwachstum, Konjunkturumfrage, GeschĂ€ftsklima, Deutschland, Welt
Analysis of Agglomerative Clustering
The diameter -clustering problem is the problem of partitioning a finite
subset of into subsets called clusters such that the maximum
diameter of the clusters is minimized. One early clustering algorithm that
computes a hierarchy of approximate solutions to this problem (for all values
of ) is the agglomerative clustering algorithm with the complete linkage
strategy. For decades, this algorithm has been widely used by practitioners.
However, it is not well studied theoretically. In this paper, we analyze the
agglomerative complete linkage clustering algorithm. Assuming that the
dimension is a constant, we show that for any the solution computed by
this algorithm is an -approximation to the diameter -clustering
problem. Our analysis does not only hold for the Euclidean distance but for any
metric that is based on a norm. Furthermore, we analyze the closely related
-center and discrete -center problem. For the corresponding agglomerative
algorithms, we deduce an approximation factor of as well.Comment: A preliminary version of this article appeared in Proceedings of the
28th International Symposium on Theoretical Aspects of Computer Science
(STACS '11), March 2011, pp. 308-319. This article also appeared in
Algorithmica. The final publication is available at
http://link.springer.com/article/10.1007/s00453-012-9717-
Building an Assessment Use Argument for sign language: the BSL Nonsense Sign Repetition Test
In this article, we adapt a concept designed to structure language testing more effectively, the Assessment Use Argument (AUA), as a framework for the development and/or use of sign language assessments for deaf children who are taught in a sign bilingual education setting. By drawing on data from a recent investigation of deaf children's nonsense sign repetition skills in British Sign Language, we demonstrate the steps of implementing the AUA in practical test design, development and use. This approach provides us with a framework which clearly states the competing values and which stakeholders hold these values. As such, it offers a useful foundation for test-designers, as well as for practitioners in sign bilingual education, for the interpretation of test scores and the consequences of their use
Cue Reactivity in Active Pathological, Abstinent Pathological, and Regular Gamblers
Twenty-one treatment-seeking pathological gamblers, 21 pathological gamblers in recovery, and 21 recreational gamblers watched two video-taped exciting gambling scenarios and an exciting roller-coaster control scenario while their arousal (heart rate and subjective excitement) and urge to gamble were being measured. The gamblers did not differ significantly in cue-elicited heart rate elevations or excitement. However, the active pathological gamblers reported significantly greater urges to gamble across all cues compared to the abstinent pathological gamblers and, with marginal significance (p = 0.06), also compared to the social gamblers. Further exploration of these findings revealed that active pathological gamblers experience urges to gamble in response to exciting situations, whether or not they are gambling related, whereas abstinent and social gamblers only report urges to an exciting gambling-related cue. This suggests that for pathological gamblers excitement itself, irrespective of its source, may become a conditioned stimulus capable of triggering gambling behavior. Implications for treatment and future research are discussed
The genera Melanothamnus Bornet & Falkenberg and Vertebrata S.F. Gray constitute well-defined clades of the red algal tribe Polysiphonieae (Rhodomelaceae, Ceramiales).
Polysiphonia is the largest genus of red algae, and several schemes subdividing it into smaller taxa have been proposed since its original description. Most of these proposals were not generally accepted, and currently the tribe Polysiphonieae consists of the large genus Polysiphonia (190 species), the segregate genus Neosiphonia (43 species), and 13 smaller genera (< 10 species each). In this paper, phylogenetic relationships of the tribe Polysiphonieae are analysed, with particular emphasis on the genera Carradoriella, Fernandosiphonia, Melanothamnus, Neosiphonia, Polysiphonia sensu stricto, Streblocladia and Vertebrata. We evaluated the consistency of 14 selected morphological characters in the identified clades. Based on molecular phylogenetic (rbcL and 18S genes) and morphological evidence, two speciose genera are recognized: Vertebrata (including the type species of the genera Ctenosiphonia, Enelittosiphonia, Boergeseniella and Brongniartella) and Melanothamnus (including the type species of the genera Fernandosiphonia and Neosiphonia). Both genera are distinguished from other members of the Polysiphonieae by synapomorphic characters, the emergence of which could have provided evolutionarily selective advantages for these two lineages. In Vertebrata trichoblast cells are multinucleate, possibly associated with the development of extraordinarily long, photoprotective, trichoblasts. Melanothamnus has 3-celled carpogonial branches and plastids lying exclusively on radial walls of the pericentral cells, which similarly may improve resistance to damage caused by excessive light. Other relevant characters that are constant in each genus are also shared with other clades. The evolutionary origin of the genera Melanothamnus and Vertebrata is estimated as 75.7-95.78 and 90.7-138.66 Ma, respectively. Despite arising in the Cretaceous, before the closure of the Tethys Seaway, Melanothamnus is a predominantly Indo-Pacific genus and its near-absence from the northeastern Atlantic is enigmatic. The nomenclatural implications of this work are that 46 species are here transferred to Melanothamnus, six species are transferred to Vertebrata and 13 names are resurrected for Vertebrata
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