A Novel General Imaging Formation Algorithm for GNSS-Based Bistatic SAR.

Global Navigation Satellite System (GNSS)-based bistatic Synthetic Aperture Radar (SAR) recently plays a more and more significant role in remote sensing applications for its low-cost and real-time global coverage capability. In this paper, a general imaging formation algorithm was proposed for accurately and efficiently focusing GNSS-based bistatic SAR data, which avoids the interpolation processing in traditional back projection algorithms (BPAs). A two-dimensional point target spectrum model was firstly presented, and the bulk range cell migration correction (RCMC) was consequently derived for reducing range cell migration (RCM) and coarse focusing. As the bulk RCMC seriously changes the range history of the radar signal, a modified and much more efficient hybrid correlation operation was introduced for compensating residual phase errors. Simulation results were presented based on a general geometric topology with non-parallel trajectories and unequal velocities for both transmitter and receiver platforms, showing a satisfactory performance by the proposed method

A study on the development of guidelines for the production of bitumen emulsion stabilised RAPs for roads in the tropics

Eco-friendliness, energy efficiency and cost effectiveness are major drivers responsible for cold recycled asphalt mixtures being considered as alternatives to hot mixtures. Although such mixtures are still regarded in some quarters as second class asphalt, results from field trials on such materials under temperate climates have been reported to be highly impressive and encouraging. Some developed countries with temperate climates have since developed guidelines for the production and use of cold mixtures in road building. However, evidence from the literature shows that little or nothing has been done to ascertain the performance and suitability of such sustainable materials in developing countries located in hot tropical climates. Ascertaining the performances of such will, among other things enable the formulation of guidelines required for producing and using these alternative sustainable materials and methods in developing countries with hot tropical climates, where available funds for road building are increasingly inadequate to meet demand. The work reported in this thesis attempts to simulate what should be expected in terms of the performance of flexible pavements containing cold mixes of bitumen emulsion stabilized RAP as road base in hot climates. Cold recycling in-plant was deemed appropriate for the obvious reason that it enables control of the quality of mixtures produced. The challenge of sourcing severely aged RAPs required for this study afforded the opportunity of developing a laboratory ageing protocol for producing RAPs with controlled properties, typical of those found in hot tropical belts (with residual binders of very low penetration). The result of the physico-chemical and rheological studies showed that ageing hot mix asphalt at 125⁰C does not degrade the binder when compared to that aged at 85⁰C, which is the conventional protocol (for temperate climates). A target mix design based on Overseas Road Notes (ORN) 19 and 31 for 20mm DBM, which the literature suggests is suitable for road base layers of road pavements, yielded an aggregate gradation containing RAP (with residual bitumen of 20dmm penetration), 5mm granite dust and granite mineral filler in the proportion 65:30:5 respectively. Further investigations patterned after Marshall and Hveem mix design methods, indicated that a cationic bitumen emulsion content of 6.5% and pre-wetting water content of 1.5% were suitable. Unlike hot mixtures, cold mixtures due to their peculiarity i.e. intermediate nature (close to unbound granular materials in early life and close to fully bound materials when fully cured), require curing before being assessed for mechanical properties such as stiffness, strength etc. Performances of the five cold bituminous emulsions mixtures (CBEMs), one with 100% virgin aggregate, the others including RAP with binder penetrations 5, 10, 15 and 20dmm, manufactured at 20⁰C and 32⁰C (to reflect average minimum and maximum temperatures in hot tropical climates) showed that: • Properties of CBEM are dependent on the state of curing or maturation attained i.e. early life, intermediate life and fully cured or stable condition; • High air void content in CBEMs appears to be inevitable; • Mixing and compaction temperature is very important for achieving relatively low air void contents in CBEMs. For example, mixing and compacting CBEMs at 32⁰C gave better results than at 20⁰C; • Indirect Tensile Stiffness Modulus is useful for quickly ranking the CBEMs; • The RAP CBEMs performed better than the virgin aggregate CBEM in terms of water susceptibility; • An increase in stiffness modulus up the range from 10dmmCBEM to 15dmmCBEM and to 20dmmCBEM, with higher values than the virgin aggregate CBEM as observed in this work gives the impression that the residual binder in the studied RAPs is active as a result of possible softening or rejuvenation. Alternatively, the stiffness enhancements could possibly have been caused by the alteration of the volumetrics of such RAP CBEMs which consequently enhanced their compactability; • Overall, RAP CBEMs are better than virgin aggregate CBEM in mechanical performance and durability; • Fatigue lives of the CBEMs are generally lower than those for hot mix asphalt (HMA); • The CBEMs are stress-dependent as they all fitted the k-Θ model. The results of the analytical pavement design showed the importance of using tools such as KENLAYER which account for the non linearity of CBEMs. Although the structural design was a hypothetical case, the results confirmed that the virgin aggregate CBEM was inferior in terms of axle loads to failure compared to the RAP CBEMs, and the RAP CBEMs were inferior to HMA. The findings of this limited investigation suggest that the studied RAP CBEMs are suitable for low volume traffic roads, an indication of the great potential of these sustainable materials when properly harnessed. In the light of this, a short and concise set of guidelines for mix design of RAP CBEMs and structural design of pavements containing such non linear materials was proposed in the thesis

A study on the development of guidelines for the production of bitumen emulsion stabilised RAPs for roads in the tropics

Eco-friendliness, energy efficiency and cost effectiveness are major drivers responsible for cold recycled asphalt mixtures being considered as alternatives to hot mixtures. Although such mixtures are still regarded in some quarters as second class asphalt, results from field trials on such materials under temperate climates have been reported to be highly impressive and encouraging. Some developed countries with temperate climates have since developed guidelines for the production and use of cold mixtures in road building. However, evidence from the literature shows that little or nothing has been done to ascertain the performance and suitability of such sustainable materials in developing countries located in hot tropical climates. Ascertaining the performances of such will, among other things enable the formulation of guidelines required for producing and using these alternative sustainable materials and methods in developing countries with hot tropical climates, where available funds for road building are increasingly inadequate to meet demand. The work reported in this thesis attempts to simulate what should be expected in terms of the performance of flexible pavements containing cold mixes of bitumen emulsion stabilized RAP as road base in hot climates. Cold recycling in-plant was deemed appropriate for the obvious reason that it enables control of the quality of mixtures produced. The challenge of sourcing severely aged RAPs required for this study afforded the opportunity of developing a laboratory ageing protocol for producing RAPs with controlled properties, typical of those found in hot tropical belts (with residual binders of very low penetration). The result of the physico-chemical and rheological studies showed that ageing hot mix asphalt at 125⁰C does not degrade the binder when compared to that aged at 85⁰C, which is the conventional protocol (for temperate climates). A target mix design based on Overseas Road Notes (ORN) 19 and 31 for 20mm DBM, which the literature suggests is suitable for road base layers of road pavements, yielded an aggregate gradation containing RAP (with residual bitumen of 20dmm penetration), 5mm granite dust and granite mineral filler in the proportion 65:30:5 respectively. Further investigations patterned after Marshall and Hveem mix design methods, indicated that a cationic bitumen emulsion content of 6.5% and pre-wetting water content of 1.5% were suitable. Unlike hot mixtures, cold mixtures due to their peculiarity i.e. intermediate nature (close to unbound granular materials in early life and close to fully bound materials when fully cured), require curing before being assessed for mechanical properties such as stiffness, strength etc. Performances of the five cold bituminous emulsions mixtures (CBEMs), one with 100% virgin aggregate, the others including RAP with binder penetrations 5, 10, 15 and 20dmm, manufactured at 20⁰C and 32⁰C (to reflect average minimum and maximum temperatures in hot tropical climates) showed that: • Properties of CBEM are dependent on the state of curing or maturation attained i.e. early life, intermediate life and fully cured or stable condition; • High air void content in CBEMs appears to be inevitable; • Mixing and compaction temperature is very important for achieving relatively low air void contents in CBEMs. For example, mixing and compacting CBEMs at 32⁰C gave better results than at 20⁰C; • Indirect Tensile Stiffness Modulus is useful for quickly ranking the CBEMs; • The RAP CBEMs performed better than the virgin aggregate CBEM in terms of water susceptibility; • An increase in stiffness modulus up the range from 10dmmCBEM to 15dmmCBEM and to 20dmmCBEM, with higher values than the virgin aggregate CBEM as observed in this work gives the impression that the residual binder in the studied RAPs is active as a result of possible softening or rejuvenation. Alternatively, the stiffness enhancements could possibly have been caused by the alteration of the volumetrics of such RAP CBEMs which consequently enhanced their compactability; • Overall, RAP CBEMs are better than virgin aggregate CBEM in mechanical performance and durability; • Fatigue lives of the CBEMs are generally lower than those for hot mix asphalt (HMA); • The CBEMs are stress-dependent as they all fitted the k-Θ model. The results of the analytical pavement design showed the importance of using tools such as KENLAYER which account for the non linearity of CBEMs. Although the structural design was a hypothetical case, the results confirmed that the virgin aggregate CBEM was inferior in terms of axle loads to failure compared to the RAP CBEMs, and the RAP CBEMs were inferior to HMA. The findings of this limited investigation suggest that the studied RAP CBEMs are suitable for low volume traffic roads, an indication of the great potential of these sustainable materials when properly harnessed. In the light of this, a short and concise set of guidelines for mix design of RAP CBEMs and structural design of pavements containing such non linear materials was proposed in the thesis

A Generalized Phase Gradient Autofocus Algorithm

The phase gradient autofocus (PGA) algorithm has seen widespread use and success within the synthetic aperture radar (SAR) imaging community. However, its use and success has largely been limited to collection geometries where either the polar format algorithm (PFA) or range migration algorithm is suitable for SAR image formation. In this work, a generalized phase gradient autofocus (GPGA) algorithm is developed which is applicable with both the PFA and backprojection algorithm (BPA), thereby directly supporting a wide range of collection geometries and SAR imaging modalities. The GPGA algorithm preserves the four crucial signal processing steps comprising the PGA algorithm, while alleviating the constraint of using a single scatterer per range cut for phase error estimation which exists with the PGA algorithm. Moreover, the GPGA algorithm, whether using the PFA or BPA, yields an approximate maxi- mum marginal likelihood estimate (MMLE) of phase errors having marginalized over unknown complex-valued reflectivities of selected scatterers. Also, in this work a new approximate MMLE, termed the max-semidefinite relaxation (Max-SDR) phase estimator, is proposed for use with the GPGA algorithm. The Max-SDR phase estimator provides a phase error estimate with a worst-case approximation bound compared to the solution set of MMLEs (i.e., solution set to the non-deterministic polynomial- time hard (NP-hard) GPGA phase estimation problem). Moreover, in this work a specialized interior-point method is presented for more efficiently performing Max- SDR phase estimation by exploiting low-rank structure typically associated with the GPGA phase estimation problem. Lastly, simulation and experimental results produced by applying the GPGA algorithm with the PFA and BPA are presented

SMARTI - Sustainable Multi-functional Automated Resilient Transport Infrastructure

The world’s transport network has developed over thousands of years; emerging from the need of allowing more comfortable trips to roman soldiers to the modern smooth roads enabling modern vehicles to travel at high speed and to allow heavy airplanes to take off and land safely. However, in the last two decades the world is changing very fast in terms of population growth, mobility and business trades creating greater traffic volumes and demand for minimal disruption to users, but also challenges, such as climate change and more extreme weather events. At the same time, technology development to allow a more sustainable transport sector continue apace. It is within this environment and in close consultation with key stakeholders, that this consortium developed the vision to achieve the paradigm shift to Sustainable Multifunctional Automated and Resilient Transport Infrastructures. SMARTI ETN is a training-through-research programme that empowered Europe by forming a new generation of multi-disciplinary professionals able to conceive the future of transport infrastructures and this Special Issue is a collection of some of the scientific work carried out within this context. Enjoy the read

The effect of mutant replication initiation proteins and antisense RNA to the gene on maize streak virus replication

Maize (Zea mays L) is a major crop plant belonging to the family Poaceae, which includes other important cereals such as wheat, rice, barley and oats (Kellogg, 1998). Other grass crops are rye, common millet, finger millet, teff, sugarcane and sorghum. Many of these are important food crops in most parts of the world, including Africa. The sustainable production of sufficient and affordable food for a rapidly increasing population is one of Africa's greatest challenges

Determination of aggregate physical properties and its effects on cross-anisotropic behavior of unbound aggregate materials

Work done by several researchers reveals that unbound aggregate materials show nonlinear cross-anisotropic behavior. The incorporation of cross-anisotropic properties significantly improves the predictions of stress distribution by reducing tensile stresses computed within granular layers. Existing pavement analysis and design approaches, however, generally assume the pavement structure to be linear isotropic layered system. This assumption is motivated by the difficulties in determining cross-anisotropic resilient material properties from laboratory experiments and lack of pavement anisotropic analysis programs. Recently, the International Center for Aggregates Research (ICAR) developed a methodology to characterize unbound aggregate layers by considering stress-sensitivity and nonlinear cross-anisotropy. The ICAR model requires nine coefficients to account for stress-sensitivity and anisotropy of vertical, horizontal, and shear moduli. Unfortunately, ICAR testing protocol is time-consuming and expensive to perform and certainly do not lend themselves to routine testing. Since it is important to be able to consider the stress-sensitive and anisotropic nature of unbound granular materials, a simple procedure was proposed by accounting for the effects of aggregate gradation and shape properties in predicting the cross-anisotropic modular ratio of unbound granular materials. Variable confining pressure type repeated load triaxial tests were performed on six aggregate sources with three different gradations and three different moisture contents. The experimental results were analyzed within the framework of nonlinear cross-anisotropic elastic model in order to determine the model coefficients. Image analysis techniques were utilized to measure aggregate shape properties. The gradation and shape properties were fitted using a cumulative distribution function and nonlinear regression analysis, which is capable of capturing the complete distribution of these properties. The experimental and analytical results indicate that the vertical resilient modulus is greater than the horizontal resilient modulus and that aggregate physical properties significantly affect the anisotropic resilient behavior. Based on finite element analysis, the anisotropic resilient behavior has substantial effect on the critical pavement responses. Thus, it is extremely valuable to approximate the degree of cross-anisotropy in unbound aggregates and to use it as input in the pavement analysis programs to adequately model unbound aggregate bases for pavement design and analysis

Jahresbericht 2017 zur kooperativen DV-Versorgung

:Vorwort 13 Übersicht der Inserenten 16 Teil I Gremien der TU Dresden für Belange der Informationstechnik CIO der TU Dresden 21 CIO-Beirat 21 IT-Klausurtagung 23 Teil II Zentrum für Informationsdienste und Hochleistungsrechnen 1 Die Einrichtung 27 1.1 Aufgaben 27 1.2 Zahlen und Fakten 27 1.3 Haushalt 28 1.4 Struktur 30 1.5 Standorte 31 1.6 Gremienarbeit 32 2 IT-Infrastruktur 33 2.1 Kommunikationsdienste und Infrastrukturen 33 2.2 Infrastruktur-Server 43 2.3 Server-Virtualisierung 44 2.4 Housing 44 2.5 Datenspeicher und -sicherung 44 3 Hochleistungsrechnen 51 3.1 HRSK-II – HPC-Cluster Taurus 51 3.2 Shared-Memory-System Venus 53 3.3 Anwendungssoftware 54 3.4 Parallele Programmierwerkzeuge 54 4 Zentrales Diensteangebot 57 4.1 IT-Service-Management 57 4.2 Ticket-System und Service Desk 57 4.3 Identitätsmanagement 59 4.4 Login-Service 61 4.5 Microsoft Windows-Support 61 4.6 Kommunikations- und Kollaborationsdienste 65 4.7 Dresden Science Calendar 67 4.8 Drucken / Kopieren 68 4.9 Zentrale Software-Beschaffung für die TU Dresden 69 5 Forschung 71 5.1 Wissenschaftliche Projekte und Kooperationen 71 5.2 Publikationen 85 6 Ausbildungsbetrieb und Praktika 89 6.1 Ausbildung zum Fachinformatiker 89 6.2 Praktika 89 7 Veranstaltungen 91 7.1 Aus- und Weiterbildungsveranstaltungen 91 7.2 ZIH-Kolloquien 92 7.3 Workshops 92 7.4 Standpräsentationen/Vorträge/Führungen 92 Teil III Bereiche der TU Dresden Bereich Mathematik und Naturwissenschaften 97 1 Bereichsweite IT-Struktur 97 2 Weiterbildung und Informationsaustausch 97 3 Service Desk 98 4 Stand der DV-Ausstattung – allgemeine Hinweise 98 5 Anforderungen an das ZIH 98 5.1 Dienste 98 5.2 Vernetzung 99 5.3 Software 99 Fakultät Biologie 101 1 DV-Anforderungen aus Lehre und Forschung 101 1.1 Anforderungen aus der Lehre 101 1.2 Anforderungen aus der Forschung 102 2 Erreichter Stand der DV-Ausstattung 102 3 Anforderungen an das ZIH 102 Fakultät Chemie und Lebensmittelchemie 103 1 DV-Anforderungen aus Lehre und Forschung 103 1.1 Anforderungen aus der Lehre 103 1.2 Anforderungen aus der Forschung 103 2 Stand der DV-Ausstattung 104 2.1 Verzeichnisdienst und zentrales Management 104 2.2 Server-Systeme 104 2.3 PC-Arbeitsplätze und Messrechner 105 2.4 Datennetz 105 3 Leistungen und Angebote der Fakultät 105 3.1 PC-Pools 105 3.2 Messdaten und Datenbanken 105 3.3 Spezialsoftware 106 3.4 IT-Service-Teams 106 4 Anforderungen der Fakultät an ZIH und Verwaltung 106 4.1 Dienste und Software 106 4.2 Personelle Absicherung 106 Fakultät Mathematik 107 1 DV-Anforderungen aus Lehre und Forschung 107 1.1 Anforderungen aus der Lehre 107 1.2 Anforderungen aus der Forschung 107 2 Erreichter Stand der DV-Ausstattung an der Fakultät 108 2.1 Hardware und Vernetzung 108 2.2 Leistungen und Angebote des zentralen PC-Pools der Fakultät 108 3 Anforderungen der Fakultät an das ZIH 108 3.1 Dienste 108 3.2 Datenkommunikation 109 3.3 Software 109 3.4 Hardware- und Software-Service 109 Fakultät Physik 111 1 DV-Anforderungen aus Lehre und Forschung 111 1.1 Anforderungen aus der Lehre 111 1.2 Anforderungen aus der Forschung 112 2 Erreichter Stand der DV-Ausstattung 113 2.1 Hardware 113 2.2 Software 113 2.3 Vernetzung 113 2.4 PC-Pools 113 2.5 Weiteres 113 3 Anforderungen der Fakultät an das ZIH 114 Fakultät Psychologie 115 1 DV-Anforderungen aus Lehre und Forschung 115 1.1 Anforderungen aus der Lehre 115 1.2 Anforderungen aus der Forschung 115 2 Erreichter Stand der DV-Ausstattung an der Fakultät 115 3 Anforderungen der Fakultät an das ZIH 116 Bereich Geistes- und Sozialwissenschaften 117 1 Struktur und IT-Verantwortlichkeiten 117 2 Fazit und Entwicklungsperspektiven 118 Fakultät Erziehungswissenschaften 121 1 DV-Anforderungen aus Lehre und Forschung 121 1.1 Anforderungen aus der Lehre 121 1.2 Anforderungen aus der Forschung 123 2 Erreichter Stand der DV-Ausstattung an der Fakultät 124 3 Leistungen und Angebote des ZBT der Fakultät 124 4 Anforderungen an das ZIH 125 Juristische Fakultät 127 1 DV-Anforderungen aus Lehre und Forschung 127 1.1 Anforderungen aus der Lehre 127 1.2 Anforderungen aus der Forschung 127 2 Stand der DV-Ausstattung an der Fakultät 128 3 Anforderung an das ZIH sowie externe Ressourcen 128 Philosophische Fakultät 129 1 DV-Anforderungen aus Lehre und Forschung 129 1.1 Anforderungen aus der Lehre 129 1.2 Anforderungen aus der Forschung 129 2 Erreichter Stand der DV-Ausstattung an der Fakultät 130 3 Anforderungen an das ZIH 130 Fakultät Sprach-, Literatur- und Kulturwissenschaften 133 1 DV-Anforderungen aus Lehre und Forschung 133 1.1 Anforderungen aus der Lehre 133 1.2 Anforderungen aus der Forschung 133 2 Erreichter Stand der DV-Ausstattung an der Fakultät 134 3 Anforderung an das ZIH 134 4 E-Learning-Strategie 134 Bereich Bau und Umwelt 137 1 Struktur und IT-Verantwortlichkeiten 137 2 Kompetenzen, angebotene Dienstleistungen und mögliche Synergien 139 3 Fazit und Ausblick 141 Fakultät Architektur 143 1 DV-Anforderungen aus Lehre und Forschung 143 1.1 Anforderungen aus der Lehre 143 1.2 Anforderungen aus der Forschung 144 2 Erreichter Stand der DV-Ausstattung an der Fakultät 144 3 Leistungen und Angebote der Fakultät Architektur 145 4 Anforderungen an das ZIH sowie externe Ressourcen 145 4.1 Dienste 145 4.2 Datenkommunikation 145 4.3 Software 146 4.4 Hardware- und Software-Service 146 Fakultät Bauingenieurwesen 147 1 DV-Anforderungen aus Lehre und Forschung 147 1.1 Anforderungen aus der Lehre 147 1.2 Anforderungen aus der Forschung 148 1.3 Erreichter Stand der DV-Ausstattung an der Fakultät 150 2 Leistungen und Angebote des zentralen Fakultätsrechenzentrums 157 3 Anforderungen an das ZIH sowie externe Ressourcen 157 3.2 Datenkommunikation 158 3.3 Software 158 3.4 Hardware- und Software-Service 158 Fakultät Umweltwissenschaften 159 Fachrichtung Forstwissenschaften 159 1 DV-Anforderungen aus Lehre und Forschung 159 1.1 Anforderungen aus der Lehre 159 1.2 Anforderungen aus der Forschung (ausgewählte Beispiele) 159 2 Erreichter Stand der DV-Ausstattung an der Fachrichtung 160 3 Leistungen und Angebote der Rechenstation der Fachrichtung 161 4 Anforderungen an das ZIH sowie externe Ressourcen 161 4.1 Dienste 161 4.2 Datenkommunikation 161 4.3 Software 161 4.4 Hardware- und Software-Service 161 Fachrichtung Geowissenschaften 163 1 DV-Anforderungen aus Lehre und Forschung 163 1.1 Anforderungen aus der Lehre 163 1.2 Anforderung aus der Forschung 163 2 Anforderung an das ZIH 165 2.1 Dienste 165 2.2 Datenkommunikation 165 2.3 Software 165 2.4 Hardware- und Software-Service 167 3 Anforderung an die Rechenstation Tharandt 167 Fakultät Verkehrswissenschaften „Friedrich List“ 169 1 DV-Anforderungen aus Lehre und Forschung 169 1.1 Anforderungen aus der Lehre 169 1.2 Anforderung aus der Forschung 171 2 Anforderungen an das ZIH 175 Fakultät Wirtschaftswissenschaften 177 1 DV-Anforderungen aus Lehre und Forschung 177 1.1 Anforderungen aus der Lehre 177 1.2 Anforderungen aus der Forschung 179 2 Erreichter Stand der DV-Ausstattung an der Fakultät 180 3 Service-Leistungen des Informatiklabors der Fakultät 182 4 Anforderungen an das ZIH sowie externe Ressourcen 184 4.1 Dienste 184 4.2 Datenkommunikation 184 4.3 Software 185 4.4 Hardware- und Software-Service 185 Bereich Medizin 187 Medizinische Fakultät Carl Gustav Carus 187 1 DV-Anforderungen aus Lehre und Forschung 187 1.1 Anforderungen aus der Lehre 187 1.2 Anforderungen aus der Forschung 188 2 Erreichter Stand der DV-Versorgung 188 3 Anforderungen der Fakultät an das ZIH / MZ / SLUB 19