A Greedy Link Scheduler for Wireless Networks with Fading Channels

We consider the problem of link scheduling for wireless networks with fading channels, where the link rates are varying with time. Due to the high computational complexity of the throughput optimal scheduler, we provide a low complexity greedy link scheduler GFS, with provable performance guarantees. We show that the performance of our greedy scheduler can be analyzed using the Local Pooling Factor (LPF) of a network graph, which has been previously used to characterize the stability of the Greedy Maximal Scheduling (GMS) policy for networks with static channels. We conjecture that the performance of GFS is a lower bound on the performance of GMS for wireless networks with fading channel

Proportional Topology Optimization: A new non-gradient method for solving stress constrained and minimum compliance problems and its implementation in MATLAB

A new topology optimization method called the Proportional Topology Optimization (PTO) is presented. As a non-gradient method, PTO is simple to understand, easy to implement, and is also efficient and accurate at the same time. It is implemented into two MATLAB programs to solve the stress constrained and minimum compliance problems. Descriptions of the algorithm and computer programs are provided in detail. The method is applied to solve three numerical examples for both types of problems. The method shows comparable efficiency and accuracy with an existing gradient optimality criteria method. Also, the PTO stress constrained algorithm and minimum compliance algorithm are compared by feeding output from one algorithm to the other in an alternative manner, where the former yields lower maximum stress and volume fraction but higher compliance compared to the latter. Advantages and disadvantages of the proposed method and future works are discussed. The computer programs are self-contained and publicly shared in the website www.ptomethod.org.Comment: 18 pages, 8 figures, and 2 appendices (MATLAB codes

Delay Optimal Secrecy in Two-Relay Network

We consider a two-relay network in which a source aims to communicate a confidential message to a destination while keeping the message secret from the relay nodes. In the first hop, the channels from the source to the relays are assumed to be block-fading and the channel states change arbitrarily -possibly non-stationary and non-ergodic- across blocks. When the relay feedback on the states of the source-to-relay channels is available on the source with no delay, we provide an encoding strategy to achieve the optimal delay. We next consider the case in which there is one-block delayed relay feedback on the states of the source-to-relay channels. We show that for a set of channel state sequences, the optimal delay with one-block delayed feedback differs from the optimal delay with no-delayed feedback at most one block

Intermediation in Innovation

The paper offers a new theoretical framework to examine the role of intermediaries between creators and potential users of new inventions. Using a model of university-industry technology transfer, we demonstrate that technology transfer offices can provide an opportunity to economize on a critical component of efficient innovation investments: the expertise to locate new, external inventions and to overcome the problem of sorting ‘profitable’ from ‘unprofitable’ ones. The findings may help explain the surge in university patenting and licensing since the Bayh-Dole Act of 1980. Furthermore, the study identifies several limitations to the potential efficiency of intermediation in innovation. ZUSAMMENFASSUNG - In diesem Papier stellen wir ein neues theoretisches Modell zur Analyse der Rolle von Intermediären zwischen Erfindern und potentiellen Nutzern von Erfindungen vor. Für den Transfer von Erfindungen aus Universitäten in den Industriebereich zeigen wir, daß Technologietransfer-Stellen den Marktteilnehmern die Möglichkeit bieten, sich die Kosten für den Aufbau der Expertise, neue externe Erfindungen zu lokalisieren und evaluieren, zu teilen. Die Ergebnisse unserer Studie können dazu beitragen, die signifikante Zunahme der Universitätspatente und - lizensen seit dem Bayh-Dole-Act von 1980 in den USA zu erklären. Darüber hinaus diskutieren wir Wohlfahrtswirkungen der Aktivität von Innovations-Intermediären.Intermediation, Market Microstructure, Matching Uncertainty, Innovation, Patent Licensing