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35 results on '"a5"'

1. Multiple Posterior Insula Projections to the Brainstem Descending Pain Modulatory System.

Author

Liang, Despoina and Labrakakis, Charalampos

Subjects
*LIMBIC system, *SPINAL cord, *BRAIN stem, *RAPHE nuclei, *FLUORESCENT proteins, *LOCUS coeruleus, *INSULAR cortex
Abstract

The insular cortex is an important hub for sensory and emotional integration. It is one of the areas consistently found activated during pain. While the insular's connections to the limbic system might play a role in the aversive and emotional component of pain, its connections to the descending pain system might be involved in pain intensity coding. Here, we used anterograde tracing with viral expression of mCherry fluorescent protein, to examine the connectivity of insular axons to different brainstem nuclei involved in the descending modulation of pain in detail. We found extensive connections to the main areas of descending pain control, namely, the periaqueductal gray (PAG) and the raphe magnus (RMg). In addition, we also identified an extensive insular connection to the parabrachial nucleus (PBN). Although not as extensive, we found a consistent axonal input from the insula to different noradrenergic nuclei, the locus coeruleus (LC), the subcoereuleus (SubCD) and the A5 nucleus. These connections emphasize a prominent relation of the insula with the descending pain modulatory system, which reveals an important role of the insula in pain processing through descending pathways. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Enhanced A5 Algorithm for Secure Audio Encryption

Author

Joshi, Akshay, Mishra, Arun, Kacprzyk, Janusz, Series Editor, Pal, Nikhil R., Advisory Editor, Bello Perez, Rafael, Advisory Editor, Corchado, Emilio S., Advisory Editor, Hagras, Hani, Advisory Editor, Kóczy, László T., Advisory Editor, Kreinovich, Vladik, Advisory Editor, Lin, Chin-Teng, Advisory Editor, Lu, Jie, Advisory Editor, Melin, Patricia, Advisory Editor, Nedjah, Nadia, Advisory Editor, Nguyen, Ngoc Thanh, Advisory Editor, Wang, Jun, Advisory Editor, Luhach, Ashish Kumar, editor, Poonia, Ramesh Chandra, editor, Gao, Xiao-Zhi, editor, and Singh Jat, Dharm, editor

Published
2022
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3. Using Backward Design to Incorporate Technology into a Non-AIS Course.

Author

Lamberton, Barbara A. and Raschke, Robyn L.

Subjects
COST accounting, INFORMATION storage & retrieval systems
Abstract

The purpose of this paper is to present a prototype using the Backward Design methodology to enhance a non-Accounting Information Systems (AIS) course with accounting and technology learning objectives. The backward design framework also provides an effective means of documenting that technology-learning strategies are being deployed in the curriculum, an important benefit for accreditation purposes. By illustrating backward design in cost accounting, this paper provides a blueprint that can be adapted and applied to other non-AIS courses, a helpful tool for curriculum redesign—especially for those who hesitate to add technology topics to their accounting courses. [ABSTRACT FROM AUTHOR]

Published
2023
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4. Comparative Study of Various Cryptographic Algorithms Used for Text, Image, and Video

Author

Advani, Nilesh, Rathod, Chetan, Gonsai, Atul M., Kacprzyk, Janusz, Series Editor, Pal, Nikhil R., Advisory Editor, Bello Perez, Rafael, Advisory Editor, Corchado, Emilio S., Advisory Editor, Hagras, Hani, Advisory Editor, Kóczy, László T., Advisory Editor, Kreinovich, Vladik, Advisory Editor, Lin, Chin-Teng, Advisory Editor, Lu, Jie, Advisory Editor, Melin, Patricia, Advisory Editor, Nedjah, Nadia, Advisory Editor, Nguyen, Ngoc Thanh, Advisory Editor, Wang, Jun, Advisory Editor, Rathore, Vijay Singh, editor, Worring, Marcel, editor, Mishra, Durgesh Kumar, editor, Joshi, Amit, editor, and Maheshwari, Shikha, editor

Published
2019
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5. Criptografía y seguridad en M-COMMERCE

Author

Cristhian Romero Romero, Yasser Alvarado Salinas, and Nixon Paladines Enriquez

Subjects
criptografía, comercio móvil, ssl/set, a3, a5, rsa, 3des, md5, Social Sciences
Abstract

El presente trabajo analiza los parámetros de seguridad más utilizados en el comercio electrónico realizado a través de dispositivos móviles (m-commerce), dentro de este se hace referencia a los tipos de cifrados que se usan con el fin de precautelar la seguridad de la información, así como también los algoritmos más usados para mantener un alto nivel de confidencialidad, integridad y de disponibilidad de la información financiera de los usuarios. Se investigó el nivel de seguridad que se obtiene mediante el uso de los distintos sistemas criptográficos, y los protocolos más utilizados (SSL-TLS-SE) en las plataformas disponibles para el intercambio de la información. A partir del estudio realizado, se puede concluir que varios de los sistemas de protección de información a nivel criptográfico poseen ciertas falencias a nivel de los protocolos que son usados en las distintas plataformas. Por otra parte, los algoritmos A3, A5, RSA, 3DES y MD5 empleados de la manera correcta son útiles; resulta necesaria la investigación de los restantes, utilizados a nivel del cifrado para comercio electrónico, puesto que se emplean de acuerdo a su requerimiento y arquitectura.

Published
2017
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7. Wiretap of Mobile Subscribers’ Data

Author

A. V. Zuykov, D. M. Mikhailov, A. V. Starikovskiy, and M. I. Froimson

Subjects
GSM, A5, security of mobile technology, wiretap, Information technology, T58.5-58.64, Information theory, Q350-390
Abstract

The article deals with the vulnerability of standard GSM, allowing attackers to listen to the confidential talks of mobile phone owners. The authors justify the necessity of developing a trusted device to provide increased levels of data protection.

Published
2012

8. The emerging politics of the Arctic Ocean. Future management of the living marine resources.

Author

Wegge, Njord

Subjects
MARINE resources policy, POLITICAL entrepreneurship, POLITICAL participation, STAKEHOLDERS
Abstract

This article seeks to identify and analyze the most important political issues at stake with respect to the ongoing process regarding the future management of living resources in the high seas of the Arctic Ocean. Through assessing the potential for future commercial utilization of marine resources in the Arctic Ocean and analyzing the differences between the interests of engaged stakeholders in the process, the article seeks to answer whose interests and norms seem to most strongly influence the unfolding political processes and preliminary outcomes. The article concludes by identifying how the five Arctic coastal states have retained the upper hand in this process through skilled political entrepreneurship, the devotion of necessary resources and the political commitment of their respective governments. [ABSTRACT FROM AUTHOR]

Published
2015
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9. Enabling the Ciphering Indicator on Android.

Author

ALECU, Felician and POCATILU, Paul

Subjects
MOBILE operating systems, COMPUTER operating systems, COMPUTER software, DATA encryption
Abstract

This paper exemplifies the use of AT commands to retrieve (and eventually override) the ciphering indicator status on Android by directly communicating with the phone modem. Curiously, his indicator is disabled by default both at operating system level and SIM card settings. By turning it on, the mobile handset will inform the user each time the communication becomes unencrypted, so a proper decision could be made just in time. [ABSTRACT FROM AUTHOR]

Published
2014

10. Distribution and localisation of Gα proteins in the rostral ventrolateral medulla of normotensive and hypertensive rats: Focus on catecholaminergic neurons.

Author

Parker, L.M., Tallapragada, V.J., Kumar, N.N., and Goodchild, A.K.

Subjects
*G protein coupled receptors, *ADENYLATE cyclase, *BLOOD pressure, *GENE expression, *BRAIN stem, *CATECHOLAMINES, *LABORATORY rats
Abstract

About 860 G-protein-coupled receptors (GPCRs) mediate their actions via heterotrimeric G-proteins. Their activation releases Gα from Gβλ subunits. The type of Gα subunit dictates the major signalling proteins involved: adenylyl cyclase, PLC and rhoGEF. The rostral ventrolateral medulla (RVLM), containing the rostral C1 (rC1) cell group, sets and maintains the tonic and reflex control of blood pressure and a plethora of inputs converge onto these neurons. We determined the relative abundance of 10 Gα subunit mRNAs, representing the four major families, within the RVLM, using quantitative RT-PCR. In situ hybridisation (ISH) combined with immunohistochemistry (IHC) was used to quantify and compare this expression in rC1 with that in the A1 and A5 cell groups. The relative abundance of Gα subunit mRNAs and a comparison of gene expression levels were quantitatively determined in normotensive and hypertensive rat strains. All 10 Gα mRNAs were detected in the RVLM of Sprague–Dawley (SD) rats with relative abundance such that Gαs > Gαi2 > Gαo > Gαq > GαL > Gα11 > Gαi3 > Gαi1 > Gα12 > Gα13. The high abundance of Gα mRNAs signalling via adenylyl cyclase indicates the importance of associated GPCRs. Within the rC1 and A1 groups similar differential Gα mRNA expression profiles were seen with Gαs being found in all rC1 cells, Gα11 absent and Gαi3 rarely expressed. Thus functionally distinct subgroups exist within the rC1 and A1 cell groups as differing distributions of Gα subunits must reflect the array of GPCRs that influence their activity. In contrast, all A5 cells expressed all Gα mRNAs suggesting a functionally homogeneous group. When the 10 Gα mRNAs of the RVLM in spontaneously hypertensive rats (SHR) were compared quantitatively to Wistar-Kyoto (WKY), only Gαs and Gα12 were significantly elevated. However when the expression in normotensive SD and WKY was compared with SHR no significant differences were evident. These findings demonstrate a range of GPCR signalling capabilities in brainstem neurons important for homeostasis and suggest a prominent role for signalling via adenylyl cyclase. [ABSTRACT FROM AUTHOR]

Published
2012
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11. Novel neuropathologic findings in the Haddad syndrome.

Author

Tomycz, Nestor D., Haynes, Robin L., Schmidt, Edith F., Ackerson, Kate, and Kinney, Hannah C.

Subjects
*NEUROLOGICAL disorders, *TEMPORAL lobe, *CEREBRAL cortex, *NEURONS, *GENETIC mutation
Abstract

Haddad syndrome (congenital central hypoventilation syndrome and Hirschsprung’s disease) is a rare disorder for which in-depth neuropathologic analysis is lacking. We report the brain findings in a full-term male infant with Haddad syndrome who died at 27 days of life. Bilateral hypoplasia of the superior temporal lobe and gyral anomalies in the frontal cortex were present. Immunohistochemistry with an antibody to tyrosine hydroxylase (noradrenaline synthesis) demonstrated hypoplasia of the locus coeruleus (implicated in chemoreception) and A5 region. Other findings included delayed maturation of the arcuate nucleus (putative human homologue of ventral medullary neurons in animals critical for chemoreception) and aberrant fascicles in the nucleus of the solitary tract. Efforts to determine the putative gene mutation were unsuccessful. This study implicates novel brain findings in Haddad syndrome mimicking those in murine Phox2b null mutants. This case suggests that abnormalities occur in CCHS in a network of sites critical to chemoreception. [ABSTRACT FROM AUTHOR]

Published
2010
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12. Premotor sympathetic neurons of conditioned fear in the rat.

Author

Carrive, Pascal and Gorissen, Marika

Subjects
*NEURONS, *CONDITIONED response, *TYROSINE, *CHOLESTEROL hydroxylase, *CELLS, *RATS
Abstract

Conditioned fear to context, a pure form of psychological stress, is associated with sympathetically mediated changes including a marked hypertension. To identify the possible premotor sympathetic neurons mediating these changes, we conducted double-immunolabelling experiments combining fear-induced Fos with retrograde tracing from the thoracic cord (T2-L1). Presympathetic groups showing the greatest increase in the proportion of spinally projecting cells double-labelled with Fos compared with resting controls were the perifornical area (PeF; 22.7% vs. 0.4%) and paraventricular nucleus (Pa; 10.5% vs. 0.2%) in the hypothalamus, and the A5 noradrenergic group (33.6% vs. 0.2%) in the pons. In contrast, there was only a small increase in the presympathetic groups of the rostral ventral medulla, including the lateral paragigantocellular group (LPGi; 4.3% vs. 0.5%), raphe magnus and pallidus (1.1% vs. 0.6% and 1.8% vs. 0.5%), and the vasopressor group of the rostral ventrolateral medulla (RVLM; 1.9% vs. 0.8%). PeF, Pa, A5 and LPGi accounted for 21, 15, 16 and 6% of all the double-labelled cells, respectively, and RVLM for only 1%. Double-immunolabelling of Fos and tyrosine hydroxylase confirmed that many A5 neurons were activated (19%) and that practically no C1 neurons in RVLM were (1.3%). The results suggest that the main premotor sympathetic drive of the fear response comes from hypothalamic (PeF and Pa) and A5 neurons that project directly to the thoracic cord and bypass medullary presympathetic groups, and that the vasopressor premotor sympathetic neurons of the RVLM are unlikely to mediate the hypertensive pressure response of contextual fear. [ABSTRACT FROM AUTHOR]

Published
2008
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13. Neurokinin-1 receptor-expressing neurons in the ventral medulla are essential for normal central and peripheral chemoreception in the conscious rat.

Author

Nattie, Eugene and Aihua Li

Subjects
TACHYKININS, NEURONS, LABORATORY rats, CHEMICAL senses, RAPID eye movement sleep, SLEEP-wake cycle
Abstract

Neurokinin-1 receptor immunoreactive (NK1R-ir) neurons and processes are widely distributed within the medulla, prominently at central chemoreceptor sites. Focal lesions of NK1R-ir neurons in the medullary raphe or the retrotrapezoid nucleus partially reduced the CO2 response in conscious rats. We ask if NK1R-ir cells and processes over a wide region of the ventral medulla are essential for central and peripheral chemoreception by cisterna magna injection of SSP-SAP, a high-affinity version of substance P-saporin. After 22 days, NKIR-ir cell loss was -79% in the retrotrapezoid nucleus and -65% in the A5 region, which lie close to the ventral surface, and -38% in the medullary raphe and -49% in the pre-Bötzinger complex/rostral ventral respiratory group, which lie deeper. Dorsal chemoreceptor sites, the caudal nucleus tractus solitarius and the A6 region, were unaffected. At 8 and 22 days, these lesions produced 1) hypoventilation during air breathing in wakefulness (~8%) and in non-rapid eye movement (NREM) (~9%) and rapid eye movement (~14%) sleep, as measured over a 4-h period; 2) a substantially reduced ventilatory response to 7% CO2 by 61% in wakefulness and 46-57% in NREM sleep; and 3) a decreased ventilatory response to 12% O2 by 40% in wakefulness and 35% in NREM sleep at 8 days, with partial recovery by 22 days. NK1R-ir neurons in the ventral medulla are essential for normal central chemoreception, provide a drive to breathe, and modulate the peripheral chemoreceptor responses. These effects are not state dependent. [ABSTRACT FROM AUTHOR]

Published
2006
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14. Regulation of respiratory neuron development by neurotrophic and transcriptional signaling mechanisms

Author

Katz, David M.

Subjects
*NEURONS, *NERVOUS system, *RESPIRATORY organs, *NEUROGLIA, *GENETIC mutation
Abstract

Abstract: Functionally diverse populations of respiratory neurons appear to be targets of common neurotrophic and transcriptional signaling pathways. For example, peripheral chemoafferent neurons and noradrenergic neurons in the pontine A5 cell group both require co-signaling by brain derived neurotrophic factor (BDNF) and glial cell line derived neurotrophic factor (GDNF) for survival, growth and/or phenotypic differentiation. Moreover, these same cell groups are dependent on the Phox2 family of transcription factors for early cell type specification. In addition, BDNF and its receptor, TrkB, are expressed in the preBotzinger complex (pBC), a critical site for respiratory rhythm generation, and exogenous BDNF can modulate the activity of pBC neurons. This convergence of BDNF, GDNF and Phox2 dependencies may help to explain how mutations in each of these pathways can result in human developmental disorders of breathing. [Copyright &y& Elsevier]

Published
2005
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15. Glial cell line-derived neurotrophic factor (GDNF) is required for differentiation of pontine noradrenergic neurons and patterning of central respiratory output

Author

Huang, L., Guo, H., Hellard, D.T., and Katz, D.M.

Subjects
*NERVOUS system, *ACETYLTRANSFERASES, *RESPIRATION, *SPINAL cord
Abstract

Abstract: Genetic mutations affecting signaling by glial cell line-derived neurotrophic factor (GDNF) perturb development of breathing in mice and are associated with congenital central hypoventilation syndrome in humans. However, the role of GDNF in development of brainstem neurons that control breathing is largely unknown. The present study demonstrates that genetic loss of GDNF decreases the number of tyrosine hydroxylase (TH) neurons in the pontine A5 noradrenergic cell group, a major source of inhibitory input to the medullary respiratory pattern generator. This phenotype is associated with a significant increase in the frequency of central respiratory output recorded from the fetal medulla–spinal cord in vitro. In dissociate cultures of the A5 region from rat embryos, GDNF increases TH cell number and neurite growth without affecting total neuronal survival or proliferation of TH neurons. These effects of GDNF are inhibited by function blocking antibodies against endogenous brain-derived neurotrophic factor (BDNF), indicating that GDNF requires BDNF as a cofactor to stimulate differentiation of A5 neurons. Our findings demonstrate that GDNF is required for development of pontine noradrenergic neurons in vivo and indicate that defects in the A5 cell group may contribute to the effects of genetic disruption of GDNF signaling on respiratory control. [Copyright &y& Elsevier]

Published
2005
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16. Voluntary freewheel running selectively modulates catecholamine content in peripheral tissue and c-fos expression in the central sympathetic circuit following exposure to uncontrollable stress in rats

Author

Greenwood, B.N., Kennedy, S., Smith, T.P., Campeau, S., Day, H.E.W., and Fleshner, M.

Subjects
*BRAIN, *LABORATORY rats
Abstract

Modulation of sympathetic drive to the spleen is one potential mechanism whereby physical activity prevents stress-induced splenic immune suppression in rats. The current study tested the hypothesis that voluntary freewheel running reduces peripheral sympathetic drive by modulating stress-induced activity of brain regions synaptically linked to sympathetically innervated peripheral organs, including the adrenals and spleen. To this end, adrenal and splenic catecholamine content and activity of the central sympathetic circuit indexed by c-Fos protein induction, elicited by acute exposure to inescapable tail shock, were measured. Stressor exposure depleted adrenal and splenic norepinephrine content and elicited a robust increase in c-Fos in the brains of sedentary rats. Physical activity status had no effect on adrenal norepinephrine content. Indicative of attenuated sympathetic drive to the spleen, however, 6 weeks of voluntary freewheel running diminished stress-induced splenic norepinephrine depletion, and significantly attenuated stress-induced c-Fos in specific brain regions responsible for sympathetic regulation, including tyrosine hydroxylase-immunoreactive neurons of the locus coeruleus, A5 cell group and rostral ventrolateral medulla.Results suggest that voluntary activity attenuates sympathetic drive to the spleen during stressor exposure by selectively modulating stress-induced activity of the central sympathetic circuit. The attenuation of sympathetic responses observed in this study may be one important mechanism for the protective effect of physical activity against stress-related illness and immunosuppression. [Copyright &y& Elsevier]

Published
2003
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17. Promotion of flowering in the Pinaceae by gibberellins III. Seedlings of Douglas fir.

Author

Pharis, Richard P., Ross, Stephen D., and McMullan, Eleanor

Subjects
*PINACEAE, *PLANT hormones, *DOUGLAS fir, *PLANT regulators, *SEEDLINGS, *GIBBERELLINS
Abstract

Significant male and female flowering (cone bud production) by girdled branches of 6-year-old Douglas fir (Pseudotsuga menziesii (Mirb. Franco) seedlings was promoted by applications (mid-April to June) of 1.6 or 3.2 mg per branch (in total) of certain non-polar gibberellins (GA's). Girdling alone was ineffective. When tested alone, a mixture of GA4/7 was most effective, GA9 less so, while GA5 and the more polar GA3 were essentially ineffective. For female cone buds GA4/7 + GA9 were synergistically effective, but for male cone buds GA4/7 alone was best. The auxin naphthaleneacetic acid (NAA) was not tested alone, but at low dosage (0.175 mg/branch in total) NAA enhanced the flowering efficacy of GA's for both sexes; at a high dosage (0.875 mg/branch in total) male cone bud production was further enhanced, but only at the expense of females. For female flowering the best treatment (90% frequency of flowering 6.8 cone buds/branch), was GA4/7 + GA9 + low NAA; for male flowering, it was GA4/7 + high NAA (30% frequency and 4.2 cone buds/branch. Frequency of flowering for controls was 18% and 0%. average number of cone buds/branch was 0.9 and 0, for females and males, respectively. The successful treatments did not affect promordia initiation, rather they caused the differentiation of previously initiated, but undetermined, lateral primordia into cone and latent buds at the expense of vegetative bud differentiation. The lack of success reported by earlier workers in promoting flowering in Pinaceae species by GA's appears to be the unfortunate result of selecting GA3 for initial testing. The practical implications of this early and enhanced flowering by non-polar GA's seedlings of a commercially important conifer are discussed in relation to accelerating the processes of tree improvement. [ABSTRACT FROM AUTHOR]

Published
1980
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18. Oxidation of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) by Alcaligenes eutrophus A5.

Author

Nadeau, Lloyd J., Sayler, Gary S., and Spain, J. C.

Abstract

Previous studies demonstrated that Alcaligenes eutrophus A5 transforms 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) to 4-chlorobenzoate via a meta-ring fission product. The initial reactions could be catalyzed by either monooxygenase or dioxygenase enzymes. In the present study, a transient intermediate that accumulated during the transformation of DDT by the biphenyl-grown cells was identified as 1,1,1-trichloro-2-(4-chlorophenyl-2,3-dihydro-4,6-cyclohexadiene)-2-(4′-chlorophenyl)ethane (DDT-2,3-dihydrodiol) on the basis of mass spectral analysis after n-butylboronic acid derivatization. The dihydrodiol undergoes a characteristic acid-catalyzed dehydration to produce phenols. 1H-NMR indicated a cis-relative stereochemistry. The results indicate that the biphenyl dioxygenase from A. eutrophus A5 catalyzes the dihydroxylation of DDT at the unsubstituted carbons on the aromatic ring to produce DDT-2,3-dihydrodiol. [ABSTRACT FROM AUTHOR]

Published
1998
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19. Panel Bayesian VAR modeling for policy and forecasting when dealing with confounding and latent effects

Author

Pacifico, Antonio

Subjects
Structural Spillovers, D2, Panel VAR, D1, MCMC Implementations, ddc:330, A5, A4, Hierarchical Mixture Distributions in Normal Linear Model, Bayesian Model Averaging, A2, Forecasting
Abstract

The paper develops empirical implementations of the standard time-varying Panel Bayesian VAR model to deal with confounding and latent effects. Bayesian computations and mixed hierarchical distributions are used to generate posteriors of conditional impulse responses and conditional forecasts. An empirical application to Eurozone countries illustrates the functioning of the model. A survey on policy recommendations and business cycles convergence are also conducted. The paper would enhance the more recent studies to evaluate idiosyncratic business cycles, policy-making, and structural spillovers forecasting. The analysis confirms the importance to separate common shocks from propagation of country- and variable-specific shocks.

Published
2018

21. How has Arctic coastal state cooperation affected the Arctic Council?

Author

Rahbek-Clemmensen, Jon and Thomasen, Gry

Subjects
CIVIL service, COOPERATION, DIPLOMATS
Abstract

The Ilulissat Meeting in 2008 was widely seen as the onset of enhanced cooperation between the five Arctic coastal states (Canada, Denmark (via Greenland), Norway, Russia, and the United States, commonly known as the A5). At the time, many diplomats and analysts feared that this enhanced emphasis of coastal state cooperation would undermine existing governance structures in the region, most importantly the Arctic Council. This article looks back at the period between 2008 and 2019 in order to examine what impact the A5 has had on the Arctic Council. It demonstrates that the A5 has changed over time to become a functional supplement to the Arctic Council. The Ilulissat Meeting did not specify whether the A5 would become a competitor of the Arctic Council nor did the coastal states' behavior dispel the critics' fear that it would undermine the Arctic Council. However, from 2010, the coastal states changed how they use the A5, which has become a low level forum predominantly for scientists and civil servants to address issues that are not easily covered by the Arctic Council, and where other actors besides the coastal states are occasionally invited to attend meetings. This change of practice has thus diminished the tensions between the A5 and the Arctic Council. However, some of the underlying ambiguities of the key features of the A5 have not been addressed. The role of the A5 can change in the future, which could reactivate the tensions of the past. [ABSTRACT FROM AUTHOR]

Published
2020
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22. Pharmacological Treatment with Annexin A1 Reduces Atherosclerotic Plaque Burden in LDLR-/- Mice on Western Type Diet

Author

Mauro Perretti, Chris P. M. Reutelingsperger, Leon J. Schurgers, Dennis H. M. Kusters, Martijn L. Chatrou, Erik A.L. Biessen, Brecht A. G. Willems, Matthias Bauwens, Emiel P. C. van der Vorst, Marijke De Saint-Hubert, Stefania Bena, MUMC+: DA BV Medische staf (6), Biochemie, RS: NUTRIM - R1 - Metabolic Syndrome, RS: CARIM - R1 - Thrombosis and haemostasis, RS: CARIM - R3 - Vascular biology, Beeldvorming, Genetica & Celbiologie, and Pathologie

Subjects
genetic structures, SURFACE-EXPRESSED PHOSPHATIDYLSERINE, lcsh:Medicine, Pharmacology, Mice, Medicine, A5, Receptor, lcsh:Science, IN-VIVO, NEUTROPHILS, Annexin A1, Mice, Knockout, Multidisciplinary, Drug Administration Routes, Plaque, Atherosclerotic, Recombinant Proteins, medicine.anatomical_structure, Disease Progression, lipids (amino acids, peptides, and proteins), medicine.symptom, Research Article, endocrine system, Endothelium, Phagocytosis, Bone Marrow Cells, Inflammation, Immunophenotyping, MECHANISMS, PHAGOCYTOSIS, INFLAMMATION, In vivo, Animals, Humans, cardiovascular diseases, Blood Cells, FORMYL PEPTIDE RECEPTOR, business.industry, CLEAVAGE, Macrophages, Therapeutic effect, lcsh:R, nutritional and metabolic diseases, Disease Models, Animal, Receptors, LDL, Diet, Western, ENDOTHELIUM, Immunology, LDL receptor, lcsh:Q, business
Abstract

OBJECTIVE: To investigate therapeutic effects of annexin A1 (anxA1) on atherogenesis in LDLR-/- mice. METHODS: Human recombinant annexin A1 (hr-anxA1) was produced by a prokaryotic expression system, purified and analysed on phosphatidylserine (PS) binding and formyl peptide receptor (FPR) activation. Biodistribution of 99mTechnetium-hr-anxA1 was determined in C57Bl/6J mice. 12 Weeks old LDLR-/- mice were fed a Western Type Diet (WTD) during 6 weeks (Group I) or 12 weeks (Group P). Mice received hr-anxA1 (1 mg/kg) or vehicle by intraperitoneal injection 3 times per week for a period of 6 weeks starting at start of WTD (Group I) or 6 weeks after start of WTD (Group P). Total aortic plaque burden and phenotype were analyzed using immunohistochemistry. RESULTS: Hr-anxA1 bound PS in Ca2+-dependent manner and activated FPR2/ALX. It inhibited rolling and adherence of neutrophils but not monocytes on activated endothelial cells. Half lives of circulating 99mTc-hr-anxA1 were

Published
2015

25. Útoky na bitově orientované proudové šifry obsahující LFSR

Author

Jureček, Martin, Rudolf, Bohuslav, and Hojsík, Michal

Subjects
Data_CODINGANDINFORMATIONTHEORY, LFSR, A5, cryptanalysis of stream cipher, kryptoanalýza prúdovej šifry
Abstract

In this work we study cryptanalysis one of the most current stream ciphers A5/1. The cipher is used to provide mobile communication privacy in the GSM cellular telephone standard. An essential element of the cipher A5/1 is LFSR( Linear feedback shift register) which is used in stream ciphers because it produces a sequence of bits with high periodicity, has good statistical properties and is easily analyzed using various algebraic methods. At work, we describe and implement three known-plaintext attacks on the cipher. The first two attacks are of the type Guess and Determine and the last one is correlation attack. The focus of the work is cryptanalysis by Golić, which assumes only 64 bits of plaintext. The character of implementation allows to split the work and use parallel-computing, making it possible to use the program in practice. At the end of the work we devote to correlation attack, that is considerably faster, but it assumes knowledge of the relatively large amount of plaintext.

Published
2012

26. Cryptanalysis of ciphers used in GSM phones

Author

Barboriková, Jana, Tůma, Jiří, and Kechlibar, Marian

Subjects
macro process, Galton-Watson proces, multitype Galton-Watson process, kryptoanalýza v reálném čase, 1, A5, real time cryptanalysis, singletype Galton-Watson process, vícetypový Galton-Watson proces, makro proces
Abstract

The aim of this thesis is to introduce the family of A5 algorithm which is used in data encryption and decryption in GSM phones. It is focused on real time cryptanalysis of the stream cipher A5/1. It describes in detail the known plaintext attack published by A. Biryukov, A. Shamir and D. Wagner. Both the attack and the cipher are implemented. The implementation proves that the preprocessing stage of the attack is very time consuming, but the actual attack can be carried out in real time on a single PC. Then the problem of finding a good statistical model for the process of generating tree of predecessors of internal states of A5/1 is studied. We present reasons why the singletype Galton-Watson process is not suitable for the problem and introduce a multitype Galton-Watson process and a macro process. The models are applied to the process of generating predecessors and their predictions are compared with experimental data.

Published
2012

27. Site-specific labeling of 'second generation' annexin V with 99mTc(CO)3 for improved imaging of apoptosis in vivo

Author

Leonard Hofstra, Luc Mortelmans, Alfons Verbruggen, Felix M. Mottaghy, Kristof Prinsen, Chris P. M. Reutelingsperger, Humphrey Fonge, Dirk Rattat, Sigrid Stroobants, Johan Nuyts, Niko Deckers, Marijke De Saint-Hubert, Kathleen Vunckx, Beeldvorming, RS: GROW - R3 - Innovative Cancer Diagnostics & Therapy, Ondersteunend personeel CD, Cardiologie, Biochemie, and RS: CARIM School for Cardiovascular Diseases

Subjects
tumors, phosphatidylserine, Programmed cell death, Biodistribution, Clinical Biochemistry, Pharmaceutical Science, Apoptosis, chemotherapy, Biochemistry, Annexin V, Imaging, annexin v, Tricarbonyl labeling, chemistry.chemical_compound, Mice, Annexin, In vivo, Drug Discovery, cancer, Animals, Annexin A5, Molecular Biology, programmed cell-death, Tomography, Emission-Computed, Single-Photon, Technetium-99m, Binding protein, Organic Chemistry, apoptosis, imaging, Technetium, tc-99m, agent, Phosphatidylserine, Molecular biology, In vitro, chemistry, tricarbonyl labeling, exposure, Hepatocytes, a5, Molecular Medicine, technetium-99m, complex
Abstract

In this study 'second generation' AnxV was specifically labeled with Tc-99m in three different ways outside the binding region of the protein to obtain an improved target-to-background activity ratio. The compounds were tested in vitro and in vivo in normal mice and in a model of hepatic apoptosis (anti-Fas mAb). The apoptosis binding was most prominent for the HIS-tagged 'second generation' AnxV labeled with Tc-99m(CO)(3) in comparison to Tc-99m-HYNIC-cys-AnxV and Tc-99m(CO)(3)-DTPA-cys-AnxV. (C) 2009 Elsevier Ltd. All rights reserved. ispartof: Bioorganic & medicinal chemistry vol:18 issue:3 pages:1356-1363 ispartof: location:England status: published

Published
2009

29. Návrh hardwarového šifrovacího modulu

Author

Sobotka, Jiří, Stančík, Peter, Bayer, Tomáš, Sobotka, Jiří, Stančík, Peter, and Bayer, Tomáš

Abstract

Tato diplomová práce pojednává o problematice kryptografických systémů a šifrovacích algoritmů, u nichž je rozebráno, jak fungují, kde se využívají a jak se implementují v praxi. V první kapitole jsou uvedeny základní kryptografické pojmy, rozdělení algoritmů na symetrické a asymetrické a zhodnocení jejich použití a spolehlivostí. Následující kapitoly popisují substituční a transpoziční šifry, blokové a proudové šifry, z nichž je většina šifrovacích algoritmů odvozena. V neposlední řadě jsou jmenovány a popsány režimy, v nichž šifry pracují. Ve čtvrté kapitole jsou popsány principy některých konkrétních šifrovacích algoritmů. Cílem je přiblížit podstatu fungování jednotlivých algoritmů. U těch složitějších algoritmů jako DES a GOST jsou pro lepší představu přiložena bloková schémata popisující průběh a pořadí prováděných operací. V závěru každého algoritmu je uveden příklad jeho použití v praxi. Následující pátá kapitola pojednává o tématu hardwarové implementace šifer. V této kapitole je porovnána hardwarová implementace se softwarovou a to hlavně z praktického úhlu pohledu. Jsou popsány různé prostředky návrhu implementace a různé programovací jazyky pro návrh hardwarové implementace algoritmů. U programovacích jazyků jsou uvedeny jejich vývoj, výhody a nevýhody. Kapitola šestá pojednává o samotném návrhu vybraných šifrovacích algoritmů. Konkrétně se jedná o návrh hardwarové implementace proudové šifry s generátorem pseudonáhodné posloupnosti založeným na LFSR navrhnuté v jazyku VHDL a také v programu Matlab. Jako druhý návrh hardwarové implementace byla zvolena bloková šifra GOST. Tato byla navržena v jazyce VHDL. Funkce obou návrhů implementací šifrovacích algoritmů byly otestovány a výsledky zhodnoceny., This diploma’s thesis discourses the cryptographic systems and ciphers, whose function, usage and practical implementation are analysed. In the first chapter basic cryptographic terms, symmetric and asymetric cryptographic algorithms and are mentioned. Also usage and reliability are analysed. Following chapters mention substitution, transposition, block and stream ciphers, which are elementary for most cryptographic algorithms. There are also mentioned the modes, which the ciphers work in. In the fourth chapter are described the principles of some chosen cryptographic algorithms. The objective is to make clear the essence of the algorithms’ behavior. When describing some more difficult algorithms the block scheme is added. At the end of each algorithm’s description the example of practical usage is written. The chapter no. five discusses the hardware implementation. Hardware and software implementation is compared from the practical point of view. Several design instruments are described and different hardware design programming languages with their progress, advantages and disadvantages are mentioned. Chapter six discourses the hardware implementation design of chosen ciphers. Concretely the design of stream cipher with pseudo-random sequence generator is designed in VHDL and also in Matlab. As the second design was chosen the block cipher GOST, which was designed in VHDL too. Both designs were tested and verified and then the results were summarized.

30. Návrh hardwarového šifrovacího modulu

Author

Sobotka, Jiří, Stančík, Peter, Bayer, Tomáš, Sobotka, Jiří, Stančík, Peter, and Bayer, Tomáš

Abstract

Tato diplomová práce pojednává o problematice kryptografických systémů a šifrovacích algoritmů, u nichž je rozebráno, jak fungují, kde se využívají a jak se implementují v praxi. V první kapitole jsou uvedeny základní kryptografické pojmy, rozdělení algoritmů na symetrické a asymetrické a zhodnocení jejich použití a spolehlivostí. Následující kapitoly popisují substituční a transpoziční šifry, blokové a proudové šifry, z nichž je většina šifrovacích algoritmů odvozena. V neposlední řadě jsou jmenovány a popsány režimy, v nichž šifry pracují. Ve čtvrté kapitole jsou popsány principy některých konkrétních šifrovacích algoritmů. Cílem je přiblížit podstatu fungování jednotlivých algoritmů. U těch složitějších algoritmů jako DES a GOST jsou pro lepší představu přiložena bloková schémata popisující průběh a pořadí prováděných operací. V závěru každého algoritmu je uveden příklad jeho použití v praxi. Následující pátá kapitola pojednává o tématu hardwarové implementace šifer. V této kapitole je porovnána hardwarová implementace se softwarovou a to hlavně z praktického úhlu pohledu. Jsou popsány různé prostředky návrhu implementace a různé programovací jazyky pro návrh hardwarové implementace algoritmů. U programovacích jazyků jsou uvedeny jejich vývoj, výhody a nevýhody. Kapitola šestá pojednává o samotném návrhu vybraných šifrovacích algoritmů. Konkrétně se jedná o návrh hardwarové implementace proudové šifry s generátorem pseudonáhodné posloupnosti založeným na LFSR navrhnuté v jazyku VHDL a také v programu Matlab. Jako druhý návrh hardwarové implementace byla zvolena bloková šifra GOST. Tato byla navržena v jazyce VHDL. Funkce obou návrhů implementací šifrovacích algoritmů byly otestovány a výsledky zhodnoceny., This diploma’s thesis discourses the cryptographic systems and ciphers, whose function, usage and practical implementation are analysed. In the first chapter basic cryptographic terms, symmetric and asymetric cryptographic algorithms and are mentioned. Also usage and reliability are analysed. Following chapters mention substitution, transposition, block and stream ciphers, which are elementary for most cryptographic algorithms. There are also mentioned the modes, which the ciphers work in. In the fourth chapter are described the principles of some chosen cryptographic algorithms. The objective is to make clear the essence of the algorithms’ behavior. When describing some more difficult algorithms the block scheme is added. At the end of each algorithm’s description the example of practical usage is written. The chapter no. five discusses the hardware implementation. Hardware and software implementation is compared from the practical point of view. Several design instruments are described and different hardware design programming languages with their progress, advantages and disadvantages are mentioned. Chapter six discourses the hardware implementation design of chosen ciphers. Concretely the design of stream cipher with pseudo-random sequence generator is designed in VHDL and also in Matlab. As the second design was chosen the block cipher GOST, which was designed in VHDL too. Both designs were tested and verified and then the results were summarized.

31. Návrh hardwarového šifrovacího modulu

Author

Sobotka, Jiří, Stančík, Peter, Sobotka, Jiří, and Stančík, Peter

Abstract

Tato diplomová práce pojednává o problematice kryptografických systémů a šifrovacích algoritmů, u nichž je rozebráno, jak fungují, kde se využívají a jak se implementují v praxi. V první kapitole jsou uvedeny základní kryptografické pojmy, rozdělení algoritmů na symetrické a asymetrické a zhodnocení jejich použití a spolehlivostí. Následující kapitoly popisují substituční a transpoziční šifry, blokové a proudové šifry, z nichž je většina šifrovacích algoritmů odvozena. V neposlední řadě jsou jmenovány a popsány režimy, v nichž šifry pracují. Ve čtvrté kapitole jsou popsány principy některých konkrétních šifrovacích algoritmů. Cílem je přiblížit podstatu fungování jednotlivých algoritmů. U těch složitějších algoritmů jako DES a GOST jsou pro lepší představu přiložena bloková schémata popisující průběh a pořadí prováděných operací. V závěru každého algoritmu je uveden příklad jeho použití v praxi. Následující pátá kapitola pojednává o tématu hardwarové implementace šifer. V této kapitole je porovnána hardwarová implementace se softwarovou a to hlavně z praktického úhlu pohledu. Jsou popsány různé prostředky návrhu implementace a různé programovací jazyky pro návrh hardwarové implementace algoritmů. U programovacích jazyků jsou uvedeny jejich vývoj, výhody a nevýhody. Kapitola šestá pojednává o samotném návrhu vybraných šifrovacích algoritmů. Konkrétně se jedná o návrh hardwarové implementace proudové šifry s generátorem pseudonáhodné posloupnosti založeným na LFSR navrhnuté v jazyku VHDL a také v programu Matlab. Jako druhý návrh hardwarové implementace byla zvolena bloková šifra GOST. Tato byla navržena v jazyce VHDL. Funkce obou návrhů implementací šifrovacích algoritmů byly otestovány a výsledky zhodnoceny., This diploma’s thesis discourses the cryptographic systems and ciphers, whose function, usage and practical implementation are analysed. In the first chapter basic cryptographic terms, symmetric and asymetric cryptographic algorithms and are mentioned. Also usage and reliability are analysed. Following chapters mention substitution, transposition, block and stream ciphers, which are elementary for most cryptographic algorithms. There are also mentioned the modes, which the ciphers work in. In the fourth chapter are described the principles of some chosen cryptographic algorithms. The objective is to make clear the essence of the algorithms’ behavior. When describing some more difficult algorithms the block scheme is added. At the end of each algorithm’s description the example of practical usage is written. The chapter no. five discusses the hardware implementation. Hardware and software implementation is compared from the practical point of view. Several design instruments are described and different hardware design programming languages with their progress, advantages and disadvantages are mentioned. Chapter six discourses the hardware implementation design of chosen ciphers. Concretely the design of stream cipher with pseudo-random sequence generator is designed in VHDL and also in Matlab. As the second design was chosen the block cipher GOST, which was designed in VHDL too. Both designs were tested and verified and then the results were summarized.

32. Návrh hardwarového šifrovacího modulu

Author

Sobotka, Jiří, Stančík, Peter, Sobotka, Jiří, and Stančík, Peter

Abstract

Tato diplomová práce pojednává o problematice kryptografických systémů a šifrovacích algoritmů, u nichž je rozebráno, jak fungují, kde se využívají a jak se implementují v praxi. V první kapitole jsou uvedeny základní kryptografické pojmy, rozdělení algoritmů na symetrické a asymetrické a zhodnocení jejich použití a spolehlivostí. Následující kapitoly popisují substituční a transpoziční šifry, blokové a proudové šifry, z nichž je většina šifrovacích algoritmů odvozena. V neposlední řadě jsou jmenovány a popsány režimy, v nichž šifry pracují. Ve čtvrté kapitole jsou popsány principy některých konkrétních šifrovacích algoritmů. Cílem je přiblížit podstatu fungování jednotlivých algoritmů. U těch složitějších algoritmů jako DES a GOST jsou pro lepší představu přiložena bloková schémata popisující průběh a pořadí prováděných operací. V závěru každého algoritmu je uveden příklad jeho použití v praxi. Následující pátá kapitola pojednává o tématu hardwarové implementace šifer. V této kapitole je porovnána hardwarová implementace se softwarovou a to hlavně z praktického úhlu pohledu. Jsou popsány různé prostředky návrhu implementace a různé programovací jazyky pro návrh hardwarové implementace algoritmů. U programovacích jazyků jsou uvedeny jejich vývoj, výhody a nevýhody. Kapitola šestá pojednává o samotném návrhu vybraných šifrovacích algoritmů. Konkrétně se jedná o návrh hardwarové implementace proudové šifry s generátorem pseudonáhodné posloupnosti založeným na LFSR navrhnuté v jazyku VHDL a také v programu Matlab. Jako druhý návrh hardwarové implementace byla zvolena bloková šifra GOST. Tato byla navržena v jazyce VHDL. Funkce obou návrhů implementací šifrovacích algoritmů byly otestovány a výsledky zhodnoceny., This diploma’s thesis discourses the cryptographic systems and ciphers, whose function, usage and practical implementation are analysed. In the first chapter basic cryptographic terms, symmetric and asymetric cryptographic algorithms and are mentioned. Also usage and reliability are analysed. Following chapters mention substitution, transposition, block and stream ciphers, which are elementary for most cryptographic algorithms. There are also mentioned the modes, which the ciphers work in. In the fourth chapter are described the principles of some chosen cryptographic algorithms. The objective is to make clear the essence of the algorithms’ behavior. When describing some more difficult algorithms the block scheme is added. At the end of each algorithm’s description the example of practical usage is written. The chapter no. five discusses the hardware implementation. Hardware and software implementation is compared from the practical point of view. Several design instruments are described and different hardware design programming languages with their progress, advantages and disadvantages are mentioned. Chapter six discourses the hardware implementation design of chosen ciphers. Concretely the design of stream cipher with pseudo-random sequence generator is designed in VHDL and also in Matlab. As the second design was chosen the block cipher GOST, which was designed in VHDL too. Both designs were tested and verified and then the results were summarized.

33. Návrh hardwarového šifrovacího modulu

Author

Sobotka, Jiří, Stančík, Peter, Sobotka, Jiří, and Stančík, Peter

Abstract

Tato diplomová práce pojednává o problematice kryptografických systémů a šifrovacích algoritmů, u nichž je rozebráno, jak fungují, kde se využívají a jak se implementují v praxi. V první kapitole jsou uvedeny základní kryptografické pojmy, rozdělení algoritmů na symetrické a asymetrické a zhodnocení jejich použití a spolehlivostí. Následující kapitoly popisují substituční a transpoziční šifry, blokové a proudové šifry, z nichž je většina šifrovacích algoritmů odvozena. V neposlední řadě jsou jmenovány a popsány režimy, v nichž šifry pracují. Ve čtvrté kapitole jsou popsány principy některých konkrétních šifrovacích algoritmů. Cílem je přiblížit podstatu fungování jednotlivých algoritmů. U těch složitějších algoritmů jako DES a GOST jsou pro lepší představu přiložena bloková schémata popisující průběh a pořadí prováděných operací. V závěru každého algoritmu je uveden příklad jeho použití v praxi. Následující pátá kapitola pojednává o tématu hardwarové implementace šifer. V této kapitole je porovnána hardwarová implementace se softwarovou a to hlavně z praktického úhlu pohledu. Jsou popsány různé prostředky návrhu implementace a různé programovací jazyky pro návrh hardwarové implementace algoritmů. U programovacích jazyků jsou uvedeny jejich vývoj, výhody a nevýhody. Kapitola šestá pojednává o samotném návrhu vybraných šifrovacích algoritmů. Konkrétně se jedná o návrh hardwarové implementace proudové šifry s generátorem pseudonáhodné posloupnosti založeným na LFSR navrhnuté v jazyku VHDL a také v programu Matlab. Jako druhý návrh hardwarové implementace byla zvolena bloková šifra GOST. Tato byla navržena v jazyce VHDL. Funkce obou návrhů implementací šifrovacích algoritmů byly otestovány a výsledky zhodnoceny., This diploma’s thesis discourses the cryptographic systems and ciphers, whose function, usage and practical implementation are analysed. In the first chapter basic cryptographic terms, symmetric and asymetric cryptographic algorithms and are mentioned. Also usage and reliability are analysed. Following chapters mention substitution, transposition, block and stream ciphers, which are elementary for most cryptographic algorithms. There are also mentioned the modes, which the ciphers work in. In the fourth chapter are described the principles of some chosen cryptographic algorithms. The objective is to make clear the essence of the algorithms’ behavior. When describing some more difficult algorithms the block scheme is added. At the end of each algorithm’s description the example of practical usage is written. The chapter no. five discusses the hardware implementation. Hardware and software implementation is compared from the practical point of view. Several design instruments are described and different hardware design programming languages with their progress, advantages and disadvantages are mentioned. Chapter six discourses the hardware implementation design of chosen ciphers. Concretely the design of stream cipher with pseudo-random sequence generator is designed in VHDL and also in Matlab. As the second design was chosen the block cipher GOST, which was designed in VHDL too. Both designs were tested and verified and then the results were summarized.

34. Návrh hardwarového šifrovacího modulu

Author

Sobotka, Jiří, Stančík, Peter, Bayer, Tomáš, Sobotka, Jiří, Stančík, Peter, and Bayer, Tomáš

Abstract

Tato diplomová práce pojednává o problematice kryptografických systémů a šifrovacích algoritmů, u nichž je rozebráno, jak fungují, kde se využívají a jak se implementují v praxi. V první kapitole jsou uvedeny základní kryptografické pojmy, rozdělení algoritmů na symetrické a asymetrické a zhodnocení jejich použití a spolehlivostí. Následující kapitoly popisují substituční a transpoziční šifry, blokové a proudové šifry, z nichž je většina šifrovacích algoritmů odvozena. V neposlední řadě jsou jmenovány a popsány režimy, v nichž šifry pracují. Ve čtvrté kapitole jsou popsány principy některých konkrétních šifrovacích algoritmů. Cílem je přiblížit podstatu fungování jednotlivých algoritmů. U těch složitějších algoritmů jako DES a GOST jsou pro lepší představu přiložena bloková schémata popisující průběh a pořadí prováděných operací. V závěru každého algoritmu je uveden příklad jeho použití v praxi. Následující pátá kapitola pojednává o tématu hardwarové implementace šifer. V této kapitole je porovnána hardwarová implementace se softwarovou a to hlavně z praktického úhlu pohledu. Jsou popsány různé prostředky návrhu implementace a různé programovací jazyky pro návrh hardwarové implementace algoritmů. U programovacích jazyků jsou uvedeny jejich vývoj, výhody a nevýhody. Kapitola šestá pojednává o samotném návrhu vybraných šifrovacích algoritmů. Konkrétně se jedná o návrh hardwarové implementace proudové šifry s generátorem pseudonáhodné posloupnosti založeným na LFSR navrhnuté v jazyku VHDL a také v programu Matlab. Jako druhý návrh hardwarové implementace byla zvolena bloková šifra GOST. Tato byla navržena v jazyce VHDL. Funkce obou návrhů implementací šifrovacích algoritmů byly otestovány a výsledky zhodnoceny., This diploma’s thesis discourses the cryptographic systems and ciphers, whose function, usage and practical implementation are analysed. In the first chapter basic cryptographic terms, symmetric and asymetric cryptographic algorithms and are mentioned. Also usage and reliability are analysed. Following chapters mention substitution, transposition, block and stream ciphers, which are elementary for most cryptographic algorithms. There are also mentioned the modes, which the ciphers work in. In the fourth chapter are described the principles of some chosen cryptographic algorithms. The objective is to make clear the essence of the algorithms’ behavior. When describing some more difficult algorithms the block scheme is added. At the end of each algorithm’s description the example of practical usage is written. The chapter no. five discusses the hardware implementation. Hardware and software implementation is compared from the practical point of view. Several design instruments are described and different hardware design programming languages with their progress, advantages and disadvantages are mentioned. Chapter six discourses the hardware implementation design of chosen ciphers. Concretely the design of stream cipher with pseudo-random sequence generator is designed in VHDL and also in Matlab. As the second design was chosen the block cipher GOST, which was designed in VHDL too. Both designs were tested and verified and then the results were summarized.

35. Loi de comportement en fluage biaxial de l'aluminium (99,5 % en poids) à haute température ; identification du potentiel d'écoulement stationnaire Ω (σij, αstij, T)

Author

J. Birocheau, C. Oytana, and C. Lexcellent

Subjects
010302 applied physics, Materials science, aluminium, 02 engineering and technology, 021001 nanoscience & nanotechnology, stationary flow potential, 01 natural sciences, creep, internal stress, transient creep, 355 degree C, Al, rheological model, potential flow, [PHYS.HIST]Physics [physics]/Physics archives, 0103 physical sciences, A5, 0210 nano-technology, biaxial creep tests
Abstract

Nous étudions en fluage biaxial le comportement de l'aluminium A5 (99,5 % en poids) en régime stationnaire pour T = 355 °C. Nous vérifions : 1) • La possibilité d'écrire les vitesses obtenues sous la forme : εst ij =stij = K'(σ'ij-λ stij)[σsteq(σ-α)] n-1, avec n = 2. • La normalité du vecteur vitesse εst dans l'espace des contraintes à l'équipotentielle : σsteq(σ - αst) = constante , ce qui permet d'écrire : εst = 2/3K'[σ steq(σ - αst)]n grad (σsteq). 2) L'existence d'un « potentiel d'écoulement » au sens de Rice en régime stationnaire complètement déterminé dans le domaine des contraintes appliquées pas trop fortes (√J 2(σ) ≤ 0,9 × 107 N/m2) sous la forme : Ω(σij, α stij, T) = 2/3 K'/n + 1[σ st eq]n+1 + C/k + 1(√J2(αst))k +1 + Ω0, avec k = 5. 3) Le lien existant entre un modèle rhéologique et les mesures plus classiques telles celles de r et de h permettant d'accéder à des paramètres physiques pour identifier le modèle d'écoulement plastique à chaud. L'étude réalisée sur ce métal permet d'envisager une généralisation du potentiel Ω pour des matériaux ayant le même comportement en contrainte effective que l'aluminium A5 et son exploitation en fluage transitoire.

Published
1982
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