Selecting Telecommunication Carriers to Obtain Volume Discounts

During 2001 many European markets for mobile phones reached saturation. Hence, mobile phone operators have shifted their focus from growth and market share to cutting costs. One way of doing so is to reduce spending on international calls, which are routed via network operating companies (carriers). These carriers charge per call-minute for each destination and may use a discount on total business volume to price their services. We developed a software system that supports decisions on allocating destinations to carriers. The core of this system is a min-cost flow routine that is embedded in a branch-and-bound framework. Our system solves the operational problem to optimality and performs what-if analyses and sensitivity analyses. A major telecommunication services provider implemented the system, realizing two benefits: it has structured the business process of allocating carriers to destinations and cut the costs of routing international calls

Perturbed Rotations of a Rigid Body Close to the Lagrange Case under the Action of Unsteady Perturbation Torques

Perturbed rotations of a rigid body close to the Lagrange case under the action of perturbation torques slowly varying in time are investigated. Conditions are presented for the possibility of averaging the equations of motion with respect to the nutation angle and the averaged system of equations of motion is obtained. In the case of the rotational motion of the body in the linear-dissipative medium the numerical integration of the averaged system of equations is conducted

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

openlaws.eu: Final specification and vision of enrichment tools

This report describes the final specification of the OpenLaws.eu enrichment tools. It is a far more elaborate description than D2.2.d2 – Initial Specification. Not everything described in this report is part of the final OpenLaws.eu portal. Where it is, this is explicitly mentioned. The report describes BOLD objects and networks, the peculiarities of legal documents and data and then ways to analyse and visualize these, providing additional metadata (‘enrichment’), either by humans (‘crowd sourcing’) or automatic means

Challenge Balancing for a Kanji E-Tutoring System

In this paper, we investigate the potential of direct challenge balancing in e-tutoring, especially in domains where there are many skills to acquire. As a case study, we create an e-tutoring system for kanji. Our system estimates the perceived challenge level using both the correctness of the answers of the students and implicit feedback, and adapts accordingly. In order to make this estimation we train a classifier on labelled data collected via the same system. We show empirically that the perceived challenge can be estimated well using implicit feedback, and that the adaptive system based on challenge balancing is preferred over a system in which the student selects a difficulty setting, indicating that directchallenge balancing is a promising research direction for e-tutoring

Side‐effects related to adjuvant CAPOX treatment for colorectal cancer are associated with intermuscular fat area, not with total skeletal muscle or fat, a retrospective observational study

Abstract Aims Chemotherapeutic treatment is regularly accompanied by side‐effects. Hydrophilic chemotherapeutics such as capecitabine and oxaliplatin (CAPOX), often used in colorectal cancer treatment, predominantly accumulate in non‐adipose tissues. Therefore the aim of this paper was to investigate whether body composition and fat infiltration in the muscle (muscle attenuation and intermuscular‐adipose‐tissue [IMAT] content) are associated with chemotherapy‐induced toxicities. Methods In this retrospective observational study, we collected data from 115 colorectal cancer patients receiving adjuvant CAPOX chemotherapy between 2006 and 2015. Information on cancer characteristics were obtained from the Netherlands Cancer Registry. Diagnostic CT scans were retrieved to assess cross‐sectional areas of skeletal muscle and adipose tissue at the third lumbar vertebrae. Information on dose‐limiting toxicity [DLT] and relative administered dose (as % of BSA‐based‐planned‐dose) were retrieved from medical charts. Associations between body composition, muscle quality and chemotherapy‐induced toxicities were determined using Cox‐regression and linear‐regression analyses. Results We found that DLT incidence was 90% in our cohort: 50% had their dose reduced, 30% their next cycle postponed, 4% a full treatment stop and 6% was hospitalized at their first DLT. Most common were reductions in oxaliplatin dose whilst keeping the capecitabine dose constant. Cox regression analysis indicated no association between body composition or muscle quality and DLT during the first treatment cycle or time to the first DLT. Multiple linear regression showed that higher IMAT‐index and IMAT muscle percentage were associated with a lower relative administered dose of oxaliplatin. Conclusions In conclusion; only IMAT, not skeletal or fat area was associated with dose‐limiting toxicities among these CRC patients who received CAPOX treatment

Distinct patterns of bank erosion in a navigable regulated river

Distinct bankline patterns appeared after the removal of protection works along a navigable reach of the Meuse River. A series of oblique embayments now dominate the riverine landscape after ten years of bank erosion, but their location and asymmetry cannot be explained yet. This work analyses and integrates field measurements of flow, ship waves, bank composition, bed topography and historical maps to explain the observed patterns along two reaches of the river. An extraordinary low-water-level event generated by a ship accident provided the unique opportunity to also analyse the subaqueous bank topography. The results indicate that the formation of oblique embayments arises from the combination of floodplain heterogeneity, structured by scroll-bar deposits, and the regulation of water levels, resulting in ship-wave attack at a narrow range of bank elevation for 70% of the time. Substrate erodibility acts on the effectiveness of trees to slow down local bank erosion rates, which is possibly enhanced by a positive feedback between woody roots and cohesive soil. The strong regulation of water levels and the waves generated by the intense ship traffic produce an increasingly long mildly-sloping terrace at the bank toe and progressively dominate the bank erosion process. This study demonstrates the important role of floodplain and scroll bar formation in shaping later bank erosion, which has implications for predictive numerical models, restoration strategies, and understanding the role of vegetation in bank erosion processes