Exact methods for the resource levelling problem

We present a project scheduling problem subject to general temporal constraints where the utilization of a set of renewable resources has to be smoothed over time. For solving the NP-hard optimization problem, we point out some important structural properties and introduce a new enumeration scheme. Combining this enumeration scheme with some branch-and-bound techniques, we propose an appropriate solution procedure for the project scheduling problem at hand. To outline the practical importance of resource levelling, we sketch exemplary the optimization of mid-term planning schedules with regard to the resource requirements of IT projects. Finally, we present results from a comprehensive computational study on problem instances of the well-known rlp_j10 and rlp_j20 test sets devised by Kolisch et al. (Benchmark Instances for Project Scheduling Problems, Kluwer, Boston, 1999).     

Which new RSA-signatures can be computed from certain given RSA-signatures?

We consider the following problem. A signature authority issues RSA-signatures of certain types to an individual, and the individual tries, by using the signatures he received, to compute an RSA-signature of a type not issued by the authority. Is the individual able to do this? The RSA-signatures are products of rational powers of residue classes modulo the composite number N of the underlying RSA-system, and the residue classes are chosen at random by the signature authority. The rational exponents in the product determine the type of the signature. We prove that computing an RSA-signature of a particular type, from given RSA-signatures of other types, is polynomial time reducible to computing RSA-roots x ^1/d (mod N) for random x and some positive integer d. This extends results of Akl and Taylor [1] and Shamir [11] from one variable to arbitrarily many variables. As an application of this, under the assumption that for the individual it is infeasible to compute RSA-roots, we give necessary and sufficient conditions describing whether it is feasible for that individual to compute RSA-signatures of a prescribed type from signatures of other types that he received before from the authority.     

Physical properties of carbon nanotube sheets drawn from nanotube arrays

We report mechanical, thermal, and electrical properties of novel sheet materials composed of multiwalled carbon nanotubes, drawn from a CNT array. At low loading there is some slippage of CNTs but at higher loading tensile strength σ₀ = 7.9 MPa and Young’s modulus E = 310 MPa. The room-temperature thermal conductivity of the CNT sheet was 2.5 ± 0.5 W m^?1 K^?1, giving a thermal conductivity to density ratio of κ/ρ = 65 W m^?1 K^?1 g^?1 cm³. The heat capacity shows 1D behavior for T > 40 K, and 2D or 3D behavior at lower temperatures. The room-temperature specific heat was 0.83 J g^?1 K^?1. The iV curves above 10 K have Ohmic behavior while the iV curve at T = 2 K is non-Ohmic, and a model to explain both ranges is presented. Negative magnetoresistance was found, increasing in magnitude with decreasing temperature (?15% at T = 2 K and B = 9 T). The tensile strength, Young’s modulus and electrical conductivity of the CNT sheet are low, in comparison with other CNT materials, likely due to defects. Thermal conductivity is dominantly phononic but interfacial resistance between MWCNTs prevents the thermal conductivity from being higher.     

Grundbefähigungsgleichheit im Gesundheitswesen

Zusammenfassung  Die Frage nach der Gerechtigkeit im Gesundheitswesen wird aus der Perspektive einer allgemeinen Theorie der Gerechtigkeit betrachtet. Diese Theorie ist ein Befähigungsansatz, der zwischen 1) der Grundversorgung aller Bürger mit Grundbefähigungen, 2) einem gerechten Anteil an den Früchten gesellschaftlicher Kooperation und 3) individuell erstrebten Gütern und Leistungen differenziert. Die Anwendung dieser Theorie reagiert auf charakteristische Probleme der Allokation im Gesundheitssektor: den prinzipiell ungedeckten Bedarf, die mangelnde Zurechenbarkeit des Bedarfes und die asymmetrische Informationsstruktur zwischen Patienten und Leistungserbringern.

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XAD Resins for Increased Rebeccamycin Productivity in Cultivations of Lentzea aerocolonigenes

Lentzea aerocolonigenes produces the antitumor antibiotic rebeccamycin. For a medical application maximized titers and appropriate downstream processing are necessary. The addition of the adsorbents XAD 4, XAD 17 HP, and XAD 16 N was investigated for increased productivity and in situ product recovery. An increase in product titer was observed for XAD 7 HP and XAD 16 N. A combination of these particles with glass beads led to a further increase. Moreover, rebeccamycin can be adsorbed to these particles which facilitate the extraction since the liquid phase can be dispensed with.     

Autonomie als Rechtfertigungsgrund psychiatrischer Therapien

Definition of the problem Several medically indicated therapies, including coercive treatments, in psychiatric practice have been justified not only on the basis of relieving symptoms and therapeutic necessity but also on the basis—at least implicitly—of mitigating deficiencies in or even restoring autonomy. Since the new judgment of the German Federal Constitutional Court and the German Federal Supreme Court as well as a new law on coercive treatment in psychiatry passed by the German Bundestag 2013, an ethical debate has ensued concerning the manner with which psychiatric patients should be treated, who do not wish to undergo therapy even though they pose a threat to themselves and others. Argumentation This debate would profit from taking into account a differentiated account of the philosophical concept of autonomy in order to provide a comprehensive investigation of the question of justifying psychiatric coercion. To make some advance in this direction this article will present three different concepts of self-determination and their constitutive criteria. Conclusions The different concepts of autonomy and self-determination will be related to different psychiatric disorders in order to elucidate possible justifications of coercive therapies thereof.     

Towards Collaborative Group Activity Recognition Using Mobile Devices

In this paper, we present a novel approach for distributed recognition of collaborative group activities using only mobile devices and their sensors. Information must be exchanged between nodes for effective group activity recognition (GAR). Here we investigated the effects of exchanging that information at different data abstraction levels with respect to recognition rates, power consumption, and wireless communication volumes. The goal is to identify the tradeoff between energy consumption and recognition accuracy for GAR problems. For the given set of activities, using locally extracted features for global, group activity recognition is advantageous as energy consumption was reduced by 10 % without experiencing any significant loss in recognition rates. Using locally classified single-user activities, however, caused a 47 % loss in recognition capabilities, making this approach unattractive. Local clustering proved to be effective for recognizing group activities, by greatly reducing power consumption while incurring a loss of only 2.8 % in recognition accuracy.