Optimization of the Logistics of Extra-Curricular Activities

Most of the children engage in extra-curricular activities in the afternoon after the school. These activities are generally organized by the school itself, however sometimes the number of schoolchildren interested in an activity is very limited; the school has a few available resources or the preferences of their schoolchildren do not match with the facilities. To expand the number of activities offered to the schoolchildren in a school the creation of clusters that group different schools is proposed. But also a transport problem appears as the children should be moved from one school to another, where they can enjoy their preferred activities. Therefore, this can be considered a School Bus Routing Problem (SBRP). We developed a procedure for the problem in several steps. First, a heuristic is implemented to obtain the clusters, then the assignment of activities and the optimal path between cluster members are determined. The proposed schoolchildren transport is based on the availability of one or two buses per cluster. This model has been applied to the schools in Barcelona.

http://ift.tt/2ptilY2

Molecular and morphological characterization of the Achnanthidium minutissimum complex (Bacillariophyta) in Petuniabukta (Spitsbergen, High Arctic) including the description of A. digitatum sp. nov.

http://ift.tt/2omwpRo

A dramatic response to a single dose of infliximab in a patient with prolonged pustular psoriasis derived from inverse psoriasis

Abstract

We report a case of a 25-year-old Chinese man with an exceptionally prolonged history of pustular psoriasis derived from inverse psoriasis who was unsatisfied with conventional treatment and was successfully treated with a single dose of infliximab without noticeable adverse effects. No recurrence or flaring was observed after 3 months of follow-up. This case illustrates that infliximab may be an effective and safe therapeutic option for patients with refractory pustular psoriasis derived from inverse psoriasis.

http://ift.tt/2ppf1jS

Correction to: Atypical presentation of a spontaneous celiac artery dissection resulting in jejuna ischaemia

George J, Nathani H, Hu A et al. Atypical presentation of a spontaneous celiac artery dissection resulting in jejuna ischaemia. BMJ Case Reports 2017;doi:10.1136/bcr-2016-218182.

We would like to issue a correction to the acknowledgements of this paper. The published article misspelled the name of a collaborator. The authors would like to thank Dr Fred Lee, Consultant Radiologist for his help in gaining some of the images.

http://ift.tt/2oDhC6W

Design Considerations and Loss Analysis of DC Chokes

The paper presents design considerations and a loss analysis of dc chokes in kW range, realized by different magnetic materials. Five designs under the same input parameters are realized with three different materials: ferrite (3F3), powder (sendust MS) and amorphous material (Microlite 245). An optimal design procedure is considered aimed at minimizing losses and volume of the component. A set of operating and construction parameters is analyzed. The obtained design results are verified by carried out simulations. Three of the compared DC chokes are realized, experimented and measured under the real operating conditions. The comparison of the three different materials is summarized and design recommendations are formulated regarding their use is such applications.

http://ift.tt/2psVI62

Comparative Study of Winding Arrangements for Power Electronic Transformers

The paper presents comparative study of winding arrangements for power electronic transformers. The designs are based on an improved design algorithm consisting of 15 steps. Four different winding arrangements are considered for a transformer design, 1200W, 25kHz. The approaches applied are interleaved windings, fully wound winding layers and using Litz wire. The material used is ferrite (N87). A set of operating and construction parameters is defined to compare the obtained designs. Design conclusions and recommendations are derived based on the comparison of the studied winding arrangements of transformers for power electronics.

http://ift.tt/2nUbaet

Modeling and Lyapunov-Designed based on Adaptive Gain Sliding Mode Control for Wind Turbines

In this paper, modeling and the Lyapunov-designed control approach are studied for the Wind Energy Conversion Systems (WECS). The objective of this study is to ensure the maximum energy production of a WECS while reducing the mechanical stress on the shafts (turbine and generator). Furthermore, the proposed control strategy aims to optimize the wind energy captured by the wind turbine operating under rating wind speed, using an Adaptive Gain Sliding Mode Control (AG-SMC). The adaptation for the sliding gain and the torque estimation are carried out using the sliding surface as an improved solution that handles the conventional sliding mode control. Furthermore, the resultant WECS control policy is relatively simple, meaning the online computational cost and time are considerably reduced. Time-domain simulation studies are performed to discuss the effectiveness of the proposed control strategy

http://ift.tt/2pt2skJ