TY - JOUR A1 - Digel, Ilya A1 - Kurulgan Demirci, Eylem A1 - Linder, Peter A1 - Kayser, Peter T1 - Decrease in extracellular collagen crosslinking after NMR magnetic field application in skin fibroblasts JF - Medical and Biological Engineering and Computing. 45 (2007), H. 1 Y1 - 2007 SN - 1741-0444 SP - 91 EP - 97 ER - TY - JOUR A1 - Dielmann, Klaus-Peter A1 - Bock, Alexis A1 - Sonnek, Frederic T1 - Stand der CO2-Allokationspläne in Europa und Durchsetzung der Monitoring-Richtlinien JF - VGB PowerTech : international journal for electricity and heat generation Y1 - 2007 SN - 1435-3199 VL - 87 IS - 3 SP - 40 EP - 46 ER - TY - JOUR A1 - Dankelmann, Peter A1 - Hellwig, Angelika A1 - Volkmann, Lutz T1 - On the connectivity of diamond-free graphs JF - Discrete applied mathematics Y1 - 2007 SN - 0166-218X (E-Journal); 1872-6771 (E-Journal); 0166-218X (Print) VL - Vol. 155 IS - Iss. 16 SP - 2111 EP - 2117 ER - TY - JOUR A1 - Daniel, Bernd A1 - Starck, Andreas T1 - Kostenkontrolle und Kostensteuerung im Hochbau N2 - Textauszug: Nach dem Leistungsbild der HOAI hat der Architekt bei Planung und Baubetrieb vier Stationen der Kostenermittlung entsprechend der DIN 276, Abschnitt 2.3 abzuarbeiten. Der Architekt, der seiner Verantwortung gerecht werden will, wird hier weitere Kontrollmechanismen einbauen wollen. Über die genannten Kostenermittlungen hinaus kennt die DIN 276 daher noch das Erfordernis der Kostenkontrolle in Abschnitt 2.4 und der Kostensteuerung in Abschnitt 2.5. Die Kostensteuerung greift immer dann, wenn die Kostenkontrolle eine Abweichung des Kostenrahmens von den Sollwerten aufzeigt. Dazu müssen die Kontrollinstanzen dort eingebaut werden, wo Korrekturen noch möglich sind. Eine erste Kontrolle der Kosten ist daher zwischen Massenermittlung und Vergabe sinnvoll einzuflechten. Zu diesem Zeitpunkt kann die Planung noch verändert werden, was einen ersten steuernden Eingriff in die Baukosten ermöglicht, und zwar bevor die Angebotsunterlagen verschickt werden. Die Grundlagen zu einer effektiven Kostensteuerung werden in der Mengenermittlung der Leistungsphase 6 gelegt. Wenn dort die Mengen nicht sorgfältig und nachvollziehbar ermittelt wurden, wird der Soll- Ist- Abgleich während der Bauphase nicht frühzeitig genug gelingen, wenn nicht gar ganz entfallen. Es gilt also, dafür zu sorgen, dass die Mengenermittlung zur Vergabe mit entsprechender Sorgfalt und vor Allem „projektnah“ erfolgt. Schätzungen haben hier keine Berechtigung. KW - Projektsteuerung KW - Baukosten KW - Kostenkontrolle KW - Kostensteuerung KW - Kostenermittlung Y1 - 2007 ER - TY - JOUR A1 - Daniel, Bernd A1 - Starck, Andreas T1 - Die Anwendung der VOB in der baubetrieblichen Praxis N2 - Eine Einführung in die Anwendung der VOB in der baubetrieblichen Praxis im Rahmen der ergänzenden Schriften zu den Vorlesungen. Die Anwendung der VOB als Vertragsbedingung für einen Bauvertrag ist gängige Praxis, über die der Architekt im Baubetrieb umfassend informiert sein muß. Die Anwendung der VOB im Bauvertrag bedarf der vorherigen Vereinbarung zwischen den Vertragsparteien. Dabei muß die VOB im Ganzen vereinbart werden. Eine Veränderung dieser Bestimmungen führt zur teilweisen Unwirksamkeit der vertraglichen Vereinbarung. Der Architekt, der für seinen Bauherrn die Vergabeunterlagen zusammenstellen muß, haftet für Fehler bei der Formulierung oder der Zusammenstellung. Es ist daher für den Architekten unerläßlich, die vertraglichen Zusammenhänge zu kennen. Dieser Fachaufsatz soll zu einem sicheren Umgang mit der VOB als Vertragsgrundlage beitragen. KW - Baubetrieb KW - Bauvertrag KW - VOB KW - Vertragsbedingungen Y1 - 2007 ER - TY - BOOK A1 - Damrau, Karin T1 - Stadtspiele : 2 Städte, 5 Spielstätten ; eine spielerische Auseinandersetzung mit den Qualitäten des öffentlichen Raumes ; die Arbeiten entstanden während des Aufenthalts an der Akademie Schloss Solitude, Stuttgart 2006 = Urban games / Karin Damrau. [Hrsg.: Akademie Schloss Solitude] Y1 - 2007 SN - 9783937158242 N1 - Reihe Projektiv PB - Akademie Schloss Solitude CY - Solitude ER - TY - JOUR A1 - Dachwald, Bernd A1 - Wi, Bong T1 - Solar Sail Kinetic Energy Impactor Trajectory Optimization for an Asteroid-Deflection Mission JF - Journal of Spacecraft and Rockets. 44 (2007), H. 4 Y1 - 2007 SN - 0022-4650 N1 - 2. ISSN: 1533-6794 SP - 755 EP - 764 ER - TY - CHAP A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Loeb, Horst W. A1 - Schartner, Karl-Heinz T1 - A comparison of SEP and NEP for a main belt asteroid sample return mission T2 - 7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007 N2 - Innovative interplanetary deep space missions, like a main belt asteroid sample return mission, require ever larger velocity increments (∆V s) and thus ever more demanding propulsion capabilities. Providing much larger exhaust velocities than chemical high-thrust systems, electric low-thrust space-propulsion systems can significantly enhance or even enable such high-energy missions. In 1995, a European-Russian Joint Study Group (JSG) presented a study report on “Advanced Interplanetary Missions Using Nuclear-Electric Propulsion” (NEP). One of the investigated reference missions was a sample return (SR) from the main belt asteroid (19) Fortuna. The envisaged nuclear power plant, Topaz-25, however, could not be realized and also the worldwide developments in space reactor hardware stalled. In this paper, we investigate, whether such a mission is also feasible using a solar electric propulsion (SEP) system and compare our SEP results to corresponding NEP results. Y1 - 2007 SP - 1 EP - 10 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Ohndorf, A. T1 - 1st ACT Global Trajectory Optimisation Competition : Results found at DLR JF - Acta Astronautica. 61 (2007), H. 9 Y1 - 2007 SN - 0094-5765 N1 - Global Trajectory Optimization ; Results of the First Competition Organised by the Advanced Concept Team (ACT) of the European Space Agency (ESA) SP - 742 EP - 752 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Mengali, Giovanni A1 - Quarta, Alessandro A. A1 - Circi, Christian T1 - Refined Solar Sail Force Model with Mission Application / Giovanni Mengali ; Alessandro A. Quarta , Christian Circi ; Bernd Dachwald JF - Journal of Guidance, Control, and Dynamics. 30 (2007), H. 2 Y1 - 2007 SN - 0162-3192 N1 - 2. ISBN: 0731-5090 SP - 512 EP - 520 ER - TY - CHAP A1 - Dachwald, Bernd A1 - Mengali, Giovanni A1 - Quarta, Alessandro A A1 - Macdonald, Malcolm A1 - McInnes, Colin R T1 - Optical solar sail degradation modelling T2 - 1st International Symposium on Solar Sailing N2 - We propose a simple parametric OSSD model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. Y1 - 2007 N1 - 1st International Symposium on Solar Sailing 27–29 June 2007, Herrsching, Germany SP - 1 EP - 27 ER - TY - JOUR A1 - Dachwald, Bernd A1 - McDonald, Malcolm A1 - McInnes, Colin R. A1 - Mengali, Giovanni T1 - Impact of Optical Degradation on Solar Sail Mission Performance JF - Journal of Spacecraft and Rockets. 44 (2007), H. 4 Y1 - 2007 SN - 0022-4650 N1 - 2. ISSN: 1533-6794 SP - 740 EP - 749 ER - TY - JOUR A1 - Dachwald, Bernd A1 - MacDonald, Malcolm A1 - McInnes, Colin R. T1 - Heliocentric Solar Sail Orbit Transfers with Locally Optimal Control Laws / Malcolm Macdonald ; Colin McInnes ; Bernd Dachwald JF - Journal of Spacecraft and Rockets. 44 (2007), H. 1 Y1 - 2007 SN - 0022-4650 SP - 273 EP - 276 ER - TY - CHAP A1 - Dachwald, Bernd A1 - Kahle, Ralph A1 - Wie, Bong T1 - Head-on impact deflection of NEAs: a case study for 99942 Apophis T2 - Planetary Defense Conference 2007 N2 - Near-Earth asteroid (NEA) 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several less than 1 km-sized gravitational keyholes during its 2029-encounter. A pre-2029 kinetic impact is a very favorable option to nudge the asteroid out of a keyhole. The highest impact velocity and thus deflection can be achieved from a trajectory that is retrograde to Apophis orbit. With a chemical or electric propulsion system, however, many gravity assists and thus a long time is required to achieve this. We show in this paper that the solar sail might be the better propulsion system for such a mission: a solar sail Kinetic Energy Impactor (KEI) spacecraft could impact Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages. The spacecraft consists of a 160 m × 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. For a launch in 2020, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, the solar sail KEI concept is still feasible to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value Y1 - 2007 N1 - Planetary Defense Conference 2007, Wahington D.C., USA, 05-08 March 2007 SP - 1 EP - 12 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Carnelli, I. A1 - Vasile, M. T1 - Optimizing low-thrust gravity assist interplanetary trajectories using evolutionary neurocontrollers / I. Carnelli ; B. Dachwald ; M. Vasile JF - IEEE Congress on Evolutionary Computation, 2007 : CEC 2007 ; 25 - 28 September 2007, Singapore Y1 - 2007 SN - 978-1-424-41339-3 N1 - ISBN 10: 1-424-41339-7 ; IEEE Congress on Evolutionary Computation <2007, Singapore> ; Institute of Electrical and Electronics Engineers ; Nebent: CEC 2007 ; Parallel als Online-Ausg. erschienen SP - 965 EP - 972 PB - IEEE Service Center CY - Piscataway, NJ ER - TY - CHAP A1 - Dachwald, Bernd T1 - Low-Thrust Mission Analysis and Global Trajectory Optimization Using Evolutionary Neurocontrol: New Results T2 - European Workshop on Space Mission Analysis ESA/ESOC, Darmstadt, Germany 10 { 12 Dec 2007 N2 - Interplanetary trajectories for low-thrust spacecraft are often characterized by multiple revolutions around the sun. Unfortunately, the convergence of traditional trajectory optimizers that are based on numerical optimal control methods depends strongly on an adequate initial guess for the control function (if a direct method is used) or for the starting values of the adjoint vector (if an indirect method is used). Especially when many revolutions around the sun are re- quired, trajectory optimization becomes a very difficult and time-consuming task that involves a lot of experience and expert knowledge in astrodynamics and optimal control theory, because an adequate initial guess is extremely hard to find. Evolutionary neurocontrol (ENC) was proposed as a smart method for low-thrust trajectory optimization that fuses artificial neural networks and evolutionary algorithms to so-called evolutionary neurocontrollers (ENCs) [1]. Inspired by natural archetypes, ENC attacks the trajectoryoptimization problem from the perspective of artificial intelligence and machine learning, a perspective that is quite different from that of optimal control theory. Within the context of ENC, a trajectory is regarded as the result of a spacecraft steering strategy that maps permanently the actual spacecraft state and the actual target state onto the actual spacecraft control vector. This way, the problem of searching the optimal spacecraft trajectory is equivalent to the problem of searching (or "learning") the optimal spacecraft steering strategy. An artificial neural network is used to implement such a spacecraft steering strategy. It can be regarded as a parameterized function (the network function) that is defined by the internal network parameters. Therefore, each distinct set of network parameters defines a different network function and thus a different steering strategy. The problem of searching the optimal steering strategy is now equivalent to the problem of searching the optimal set of network parameters. Evolutionary algorithms that work on a population of (artificial) chromosomes are used to find the optimal network parameters, because the parameters can be easily mapped onto a chromosome. The trajectory optimization problem is solved when the optimal chromosome is found. A comparison of solar sail trajectories that have been published by others [2, 3, 4, 5] with ENC-trajectories has shown that ENCs can be successfully applied for near-globally optimal spacecraft control [1, 6] and that they are able to find trajectories that are closer to the (unknown) global optimum, because they explore the trajectory search space more exhaustively than a human expert can do. The obtained trajectories are fairly accurate with respect to the terminal constraint. If a more accurate trajectory is required, the ENC-solution can be used as an initial guess for a local trajectory optimization method. Using ENC, low-thrust trajectories can be optimized without an initial guess and without expert attendance. Here, new results for nuclear electric spacecraft and for solar sail spacecraft are presented and it will be shown that ENCs find very good trajectories even for very difficult problems. Trajectory optimization results are presented for 1. NASA's Solar Polar Imager Mission, a mission to attain a highly inclined close solar orbit with a solar sail [7] 2. a mission to de ect asteroid Apophis with a solar sail from a retrograde orbit with a very-high velocity impact [8, 9] 3. JPL's \2nd Global Trajectory Optimization Competition", a grand tour to visit four asteroids from different classes with a NEP spacecraft Y1 - 2007 ER - TY - JOUR A1 - Christiaens, P. A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Wagner, Torsten A1 - Bijnens, N. A1 - Williams, O. A. A1 - Daenen, M. A1 - Haenen, K. A1 - Schöning, Michael Josef A1 - Wagner, P. T1 - Nanocrystalline diamond-based field-effect capacitive pH sensor JF - Transducers '07 Eurosensors XXI : digest of technical papers ; the14th International Conference on Solid-State Sensors, Actuators and Microsystems, June 10-14, 2007, Lyon, France / Gilles Delapierre (Ed.) Y1 - 2007 SN - 1-4244-0841-5 N1 - Eurosensors 21, 2007, Lyon ; International Conference on Solid-State Sensors, Actuators and Microsystems 14, 2007, Lyon SP - 1891 EP - 1894 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Christiaens, P. A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Wagner, Torsten A1 - Bijnens, N. A1 - Williams, O. A. A1 - Daenen, M. A1 - Haenen, K. A1 - Douthéret, O. A1 - Haen, J. d´ A1 - Mekhalif, Z. A1 - Schöning, Michael Josef A1 - Wagner, P. T1 - pH sensitivity of nanocrystalline diamond films JF - Physica status solidi (A). 204 (2007), H. 9 Y1 - 2007 SN - 0031-8965 SP - 2925 EP - 2930 ER - TY - JOUR A1 - Call, Guido T1 - [Kapitel 3] : Marketing und Vetrieb JF - Business-Management für Ingenieure : beurteilen - entscheiden - gestalten / Rolf Grap (Hrsg.). - (REFA-Fachbuchreihe Unternehmensentwicklung) Y1 - 2007 SN - 978-3-446-41256-9 N1 - ISBN 10: 3-446-41256-5 SP - 34 EP - 57 PB - Hanser CY - München ER - TY - JOUR A1 - Bécret, P. A1 - Grossen, J. A1 - Trilla, J. A1 - Robinson, A. A1 - Bosschaerts, W. A1 - Funke, Harald A1 - Hendrick, P. T1 - Testing and numerical study of a 10 kW hydrogen micro combustor JF - International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau> ; PowerMEMS ; 7 Y1 - 2007 SP - 367 EP - 370 ER -