Robust Line Planning in case of Multiple Pools and Disruptions

We consider the line planning problem in public transportation, under a robustness perspective. We present a mechanism for robust line planning in the case of multiple line pools, when the line operators have a different utility function per pool. We conduct an experimental study of our mechanism on both synthetic and real-world data that shows fast convergence to the optimum. We also explore a wide range of scenarios, varying from an arbitrary initial state (to be solved) to small disruptions in a previously optimal solution (to be recovered). Our experiments with the latter scenario show that our mechanism can be used as an online recovery scheme causing the system to re-converge to its optimum extremely fast.Comment: To appear in TAPAS 201

Solid-state modification of isotactic polypropylene (iPP) via grafting of styrene. II. Morphology and melt processing

Grafting of vinyl monomers onto isotactic polypropylene (iPP) in the solid state represents a convenient route to chemically modify iPP and, consequently, its properties. Solid-state modification can be carried out on iPP powder directly from the polymerization reactor. The modified powder is then processed in the melt, usually with the addition of fillers and/or additives, to obtain the final product. In this work we have studied the effect of melt processing on the morphology of solid-state polymerized PP/polystyrene (PS) blends, i.e., of a iPP powder previously modified in the solid-state with styrene (St) and optionally in the presence of divinylbenzene (DVB). A series of samples containing different amounts of PS and displaying different grafting efficiencies were investigated before and after processing in the melt. Transmission electron microscopy, scanning electron microscopy, and solid-state NMR were used to investigate the morphology on different length scales. It was shown that PS coalescence during processing can be hindered, thereby stabilizing the initially polymerized iPP/PS blends morphology. Indeed, reducing the PS amount in the blend or increasing the grafting efficiency resulted in less coalescence of the PS domains. Crosslinking of the PS phase during the solid-state polymerization resulted also in a very fine but heterogeneous morphology. (c) 2005 Wiley Periodicals, Inc

Low-power micro-scale CMOS-compatible silicon sensor on a suspended membrane.

In this paper we describe a new, simple and cheap silicon device operating at high temperature at a very low power of a few mW. The essential part of the device is a nano-size conductive link 10-100 nm in size (the so-called antifuse) formed in between two poly-silicon electrodes separated by a thin SiO2 layer. The device can be utilized in chemical sensors or chemical micro-reactors requiring high temperature and very low power consumption e.g. in portable, battery operated systems. As a direct application, we mention a gas sensor (i.e. Pellistor) for hydrocarbons (butane, methane, propane, etc.) based on temperature changes due to the catalytic combustion of hydrocarbons. The power consumed by our device is at about 2% of the power consumed by conventional Pellistors

Hawking radiation in different coordinate settings: Complex paths approach

We apply the technique of complex paths to obtain Hawking radiation in different coordinate representations of the Schwarzschild space-time. The coordinate representations we consider do not possess a singularity at the horizon unlike the standard Schwarzschild coordinate. However, the event horizon manifests itself as a singularity in the expression for the semiclassical action. This singularity is regularized by using the method of complex paths and we find that Hawking radiation is recovered in these coordinates indicating the covariance of Hawking radiation as far as these coordinates are concerned.Comment: 18 pages, 2 figures, Uses IOP style file; final version; accepted in Class. Quant. Gra

Comparing league formats with respect to match importance in Belgian football

Recently, most clubs in the highest Belgian football division have become convinced that the format of their league should be changed. Moreover, the TV station that broadcasts the league is pleading for a more attractive competition. However, the clubs have not been able to agree on a new league format, mainly because they have conflicting interests. In this paper, we compare the current league format, and three other formats that have been considered by the Royal Belgian Football Association. We simulate the course of each of these league formats, based on historical match results. We assume that the attractiveness of a format is determined by the importance of its games; our importance measure for a game is based on the number of teams for which this game can be decisive to reach a given goal. Furthermore, we provide an overview of how each league format aligns with the expectations and interests of each type of club

Evaluation of Operative Notes Concerning Laparoscopic Cholecystectomy: Are Standards Being Met?

Background - Laparoscopic cholecystectomy (LC) is the most performed minimal invasive surgical procedure and has a relatively high complication rate. As complications are often revealed postoperatively, clear, accurate, and timely written operative notes are important in order to recall the procedure and start follow-up treatment as soon as possible. In addition, the surgeon’s operative notes are important to assure surgical quality and communication with other healthcare providers. The aim of the present study was to assess compliance with the Dutch guidelines for writing operative notes for LC. Methods - Nine hospitals were asked to send 20 successive LC operative notes. All notes were compared to the Dutch guideline by two reviewers and double-checked by a third reviewer. Statistical analyses on the ‘‘not described’’ items were performed. Results - All hospitals participated. Most notes complied with the Dutch guideline (52–69%); 19–30% of items did not comply. Negative scores for all hospitals were found, mainly for lacking a description of the patient’s posture (average 69%), bandage (94%), blood loss (98%), name of the scrub nurse (87%), postoperative conclusion (65%), and postoperative instructions (78%). Furthermore, notes from one community hospital and two teaching hospitals complied significantly less with the guidelines. Conclusions - Operative notes do not always fully comply with the standards set forth in the guidelines published in the Netherlands. This could influence adjuvant treatment and future patient treatment, and it may make operative notes less suitable background for other purposes. Therefore operative note writing should be taught as part of surgical training, definitions should be provided, and procedure-specific guidelines should be established to improve the quality of the operative notes and their use to improve patient safety.Industrial DesignIndustrial Design Engineerin