Auctions for private congestible infrastructures

This paper investigates regulation by auctions of private supply of congestible infrastructures in two networks settings: 1) two serial facilities, where the consumer has to use both in order to consume; and 2) two parallel facilities that are imperfect substitutes. There are four market structures: a monopoly and 3 duopolies that differ in how firms interact. The effects of an auction depend on what the bidders compete. With a bid auction, the bidders compete on how much money they transfer to the government. This auction leads to the same outcome as the unregulated game (for a given market structure), since this gives the maximum profit to transfer. An auction on the capacity of a facility leads to an even lower welfare than no regulation, because firms set very high capacities and usage fees. Conversely, an auction on generalised price or number of users leads to the first-best outcome. Moreover, these two auctions are robust: they attain the first-best regardless of whether the facilities are auctioned off to a single firm or to two firms, and for all market and network structures. On the contrary, the performances (relative to the first-best) of the bid and capacity auctions strongly depend on these considerations

The effect of private road supply on the volume/capacity ratio when firms compete Stackelberg in Road Capacity

We study road supply by competing firms between a single origin and destination. In previous studies, firms simultaneously set their tolls and capacities while taking the actions of the others as given in a Nash fashion. Then, under some widely used technical assumptions, firms set the same volume/capacity ratio as a public operator would and thus have the same amount of congestion and travel time. We find that this result does not hold if capacity and toll setting are separate stages—as then firms want to limit the competition in the toll stage by setting lower capacities—or when firms set capacities one after the other in a Stackelberg fashion—as then firms want to limit their competitors’ capacities by setting higher capacities. In our Stackelberg competition, the firms that act last have few if any capacity decisions to influence. Hence, they are more concerned with the toll competition substage, and set a higher volume/capacity ratio than the public operator. The firms that act first care more about their competitors’ capacities they can influence: they set a lower ratio and have the largest capacities. The average volume/capacity ratio is below the public ratio, and hence the average private travel time is too short. Still, in our numerical model, for three or more firms, welfare is higher under Stackelberg competition than under Nash competition, because of the larger Stackelberg capacity expansion and lower tolls.

Wideband frequency domain detection using Teager-Kaiser energy operator

International audienceThis paper addresses wireless microphone sensing in the TV white space and efficient detection of narrowband FM modulation signals. To this end, a wideband frequency domain analysis is proposed. The required Fast Fourier Transform for this operation may be shared between sensing analysis and modulation functions. A particular decision metric is then studied for the analysis of wireless microphone signals based on the Teager-Kaiser energy operator. Simulation results show that 6 dB of detection gain could be achieved when using a frequency domain analysis compared to time domain methods. The Teager-Kaiser detection leads to further improvement of 1.5 dB. This performance could be reached at no extra cost in term of complexity

USB POWER MANAGEMENT

A power management system identifies a power source and a power recipient between a first device and a second device based on their respective states. The system identifies that the first device and the second device are connected using a universal serial bus (USB) type-C connectors. The system further determines a respective state for the first device and the second device, e.g., tilt or orientation of the devices. Based on the respective states, the system identifies the power source and the power recipient between the first device and the second device, e.g., using pre-stored information from a database. Further, the system causes energy to be transferred from the power source to the power recipient

Channel estimation strategy for LPWA transmission at low SNR: application to Turbo-FSK

International audienceTurbo Frequency Shift Keying has been considered as a promising physical layer for low power wide-area network connectivity. Because of its constant envelope amplitude and the efficiency of its iterative receiver performance close to Shannon's limit can be achieved. However, results published so far in the literature for the waveform have assumed perfect channel estimation or Signal-to-noise (SNR) levels that are higher than the SNR levels considered for these applications. This paper analyzes a channel estimation strategy based on a specifically adapted pilot sequence. Simulations have been performed to evaluate the performance of the proposed approach. Performance loss induced by imperfect channel estimation algorithms is estimated

Novel microstructures and technologies applied in chemical analysis techniques

Novel glass and silicon microstructures and their application in chemical analysis are presented. The micro technologies comprise (deep) dry etching, thin layer growth and anodic bonding. With this combination it is possible to create high resolution electrically isolating silicon dioxide structures with aspect ratio's similar to those possible in silicon. Main applications are chemical separation methods such as high performance liquid chromatography (HPLC) or electrophoresis (HPCE). Beside these channel structures, a capillary connector with very low dead and mixing volume has been designed and fabricated for use in (correlation) electrophoresis, and tested by means of precision of consecutive single injection

Choice of season cards in public transport: a study of a Stated Preference experiment

This paper studies a Stated Preference (SP) experiment on the choice of type of (Rail) season card, conducted among current Dutch Railways season cardholders. They were asked to choose from the following three alternatives: (1) an unrestricted season card, (2) a cheaper season card with peak travel and travel frequency restrictions, and (3) not buying a season card. Multinomial logit (MNL), nested logit and mixed logit models are used to analyse their choices. It is found that MNL underestimates the price sensitivities (as measured by the price elasticities) of the respondents and overestimates their Willingnessto- Pay (WTP) for reductions in the restrictions. The mixed logit estimation shows that there are (unobserved) differences in the marginal utilities of the price of the card (response heterogeneity), and the utility of owning a season card (preference heterogeneity). In the Netherlands a large share of commuters and business travellers receive travel cost compensation from their employer. However, empirical studies often do not control for the effect of travel cost compensation. We find, as expected, that travel cost compensation has a large impact on the price sensitivities and choices of the respondents

Turbo-FSK : une nouvelle technique de communication montante pour les réseaux longue portée basse consommation

National audienceThe Internet of Things aims to connect several billions of devices. Terminals are expected to be low cost, low power, and to be able to achieve successful communication at long range. While current Machine-to-Machine technologies tend to use spreading factors to meet the required specifications, we propose a more sophisticated use of redundant waveforms in a scheme called Turbo-FSK. This scheme involves Frequency-Shift-Keying (FSK) modulation at the transmission, and a turbo-decoding dedicated to the FSK waveforms at the receiver. Highly robust communication is achieved with a mere transmitter, as complexity is deported on the receiver side. Results are compared to common modulations using spreading factors, showing a significant gain in performance is achieved even with small packet sizes.L'internet des objets a pour vocation de connecter des milliards de terminaux entre eux. Ces derniers doivent être bon marché, économes en énergie, et capables de communiquer même à très longue portée. Alors que les technologies actuelles de communications machine-to-machine ont tendance à utiliser les techniques de répétition ou d'étalement afin de répondre aux contraintes notamment en termes de sensibilité, ce papier propose une utilisation plus sophistiquée de la répétition dans une technique dénommée Turbo-FSK. Cette dernière implique l'utilisation d'une modulation orthogonale de fréquence FSK et d'un turbo décodage spécifique aux formes d'onde FSK au niveau du récepteur. On montre alors qu'une communication robuste est possible même avec un émetteur très simple, la complexité étant déportée au niveau du récepteur. Les résultats de simulations sont comparés à des techniques de références, dont celles utilisant la répétition, démontrant qu'un gain significatif est obtenu même avec des petites tailles de paquets

Private road networks with uncertain demand

We study the efficiency of private supply of roads under demand uncertainty and evaluate various regulatory policies. Due to demand uncertainty, capacity is decided before demand is known but tolls can be adjusted after demand is known. Policy implications can differ from those under deterministic demand. For instance, for serial links, the toll in the second-best zero-profit case is no longer equal to the marginal external congestion cost. In the first-best scenario, the capacity under uncertain demand is higher than that under deterministic demand of the same expected value, though self-financing still holds in expected terms. Regulation by perfect competitive auction cannot replicate the second-best zero-profit result and thus leads to a lower welfare, whereas without uncertainty, various forms of competitive auctions can attain this second-best optimum. For more complex networks, when private firms add capacity in turn, contrary to the case without demand uncertainty, some forms of auction perform better than others with demand uncertainty

A Pilot and Feasibility Study to Evaluate Small and Large Bite Fascial Closure Techniques

Introduction. Few randomized controlled studies have been conducted comparing a small to large fascial bite technique, yet recommendations have been made to standardize small bite closures.  However, large scale randomized controlled trials require considerable effort and may benefit from a pilot study. Methods. This multi-center randomized controlled pilot study of adult patients undergoing median laparotomy incision investigated the feasibility of studying the outcomes between small and large surgical closure techniques. Results. Fifty of 100 planned patients consented, 32 patients completed surgery and 19 patients completed the one-year ultrasound.  Enrollment was 2.7 versus 8 patients per month pre/post addition of study coordinator.  Clinical results are summarized for feasibility demonstration purposes, but not analyzed for hypothesis testing.  The total cost of the pilot study was $19,152.50 and took 22 months from first surgery to final one-year ultrasound.  Conclusions. This feasibility assessment demonstrates the complexity of planning a large scale randomized trial evaluating small and large bite surgical closure technique.  To expand this pilot study to a full scaled sample size study would require dedicated personnel and large grant funding.