Location models for airline hubs behaving as M/D/c queues

Models are presented for the optimal location of hubs in airline networks, that take into consideration the congestion effects. Hubs, which are the most congested airports, are modeled as M/D/c queuing systems, that is, Poisson arrivals, deterministic service time, and {\em c} servers. A formula is derived for the probability of a number of customers in the system, which is later used to propose a probabilistic constraint. This constraint limits the probability of {\em b} airplanes in queue, to be lesser than a value $\alpha$. Due to the computational complexity of the formulation. The model is solved using a meta-heuristic based on tabu search. Computational experience is presented.

Improving QPF by blending techniques at the Meteorological Service of Catalonia

The current operational very short-term and short-term quantitative precipitation forecast (QPF) at the Meteorological Service of Catalonia (SMC) is made by three different methodologies: Advection of the radar reflectivity field (ADV), Identification, tracking and forecasting of convective structures (CST) and numerical weather prediction (NWP) models using observational data assimilation (radar, satellite, etc.). These precipitation forecasts have different characteristics, lead time and spatial resolutions. The objective of this study is to combine these methods in order to obtain a single and optimized QPF at each lead time. This combination (blending) of the radar forecast (ADV and CST) and precipitation forecast from NWP model is carried out by means of different methodologies according to the prediction horizon. Firstly, in order to take advantage of the rainfall location and intensity from radar observations, a phase correction technique is applied to the NWP output to derive an additional corrected forecast (MCO). To select the best precipitation estimation in the first and second hour (t+1 h and t+2 h), the information from radar advection (ADV) and the corrected outputs from the model (MCO) are mixed by using different weights, which vary dynamically, according to indexes that quantify the quality of these predictions. This procedure has the ability to integrate the skill of rainfall location and patterns that are given by the advection of radar reflectivity field with the capacity of generating new precipitation areas from the NWP models. From the third hour (t+3 h), as radar-based forecasting has generally low skills, only the quantitative precipitation forecast from model is used. This blending of different sources of prediction is verified for different types of episodes (convective, moderately convective and stratiform) to obtain a robust methodology for implementing it in an operational and dynamic way.

Quality of life, happiness and satisfaction with life of individuals 75 years old or older cared for by a home health care program

This case study identifies the elements that compose the Quality of Life (QofL) of individuals who were 75 years old or older and receive care at home. The study's sample was composed of individuals 75 years or older cared for by a home health care service in the primary health care unit in Vilafranca del Penedès, Spain (n=26). The variables included: a) socio-demographic data; b) concept of QofL; c) perception of QofL; d) reasons for their perception; d) satisfaction with life and related aspects; and f) feeling of happiness. Face to face interviews were conducted. A total of 76.9% of the individuals reported a good perception of QofL and the main reasons related to it were: health, family and social relationships, and the ability to adapt. Role Theory and Disengagement Theory explain the adaptation process of these individuals at this point in life.

Quality of life, happiness and satisfaction with life of individuals 75 years old or older cared for by a home health care program

This case study identifies the elements that compose the Quality of Life (QofL) of individuals who were 75 years old or older and receive care at home. The study's sample was composed of individuals 75 years or older cared for by a home health care service in the primary health care unit in Vilafranca del Penedès, Spain (n=26). The variables included: a) socio-demographic data; b) concept of QofL; c) perception of QofL; d) reasons for their perception; d) satisfaction with life and related aspects; and f) feeling of happiness. Face to face interviews were conducted. A total of 76.9% of the individuals reported a good perception of QofL and the main reasons related to it were: health, family and social relationships, and the ability to adapt. Role Theory and Disengagement Theory explain the adaptation process of these individuals at this point in life.

Quality of life, happiness and satisfaction with life of individuals 75 years old or older cared for by a home health care program

This case study identifies the elements that compose the Quality of Life (QofL) of individuals who were 75 years old or older and receive care at home. The study's sample was composed of individuals 75 years or older cared for by a home health care service in the primary health care unit in Vilafranca del Penedès, Spain (n=26). The variables included: a) socio-demographic data; b) concept of QofL; c) perception of QofL; d) reasons for their perception; d) satisfaction with life and related aspects; and f) feeling of happiness. Face to face interviews were conducted. A total of 76.9% of the individuals reported a good perception of QofL and the main reasons related to it were: health, family and social relationships, and the ability to adapt. Role Theory and Disengagement Theory explain the adaptation process of these individuals at this point in life.

VoIP: Making Secure Calls and Maintaining High Call Quality

Modern multimedia communication tools must have high security, high availability and high quality of service (QoS). Any security implementation will directly impact on QoS. This paper will investigate how end-to-end security impacts on QoS in Voice over Internet Protocol (VoIP). The QoS is measured in terms of lost packet ratio, latency and jitter using different encryption algorithms, no security and just the use of IP firewalls in Local and Wide Area Networks (LAN and WAN). The results of laboratory tests indicate that the impact on the overall performance of VoIP depends upon the bandwidth availability and encryption algorithm used. The implementation of any encryption algorithm in low bandwidth environments degrades the voice quality due to increased loss packets and packet latency, but as bandwidth increases encrypted VoIP calls provided better service compared to an unsecured environment.

Impact of quality and environmental investment on business competitiveness and profitability: The case of travel agencies

Few studies have examined the combined effect of implementing quality and environmental management within the service sector. This void is more evident if we focus on segments in which small businesses predominate and even more so if we look for highly competitive sectors that are very variable and that have high business mortality. After analysing 198 surveys of Spanish travel agency managers using structural equations, it can be concluded that practices of quality management have a significant direct impact on business competitiveness but not on this business's financial results, at least directly. However, there is a significant relationship between environmental management practices and economic benefits. This article suggests that commitment to quality and the environment can allow small businesses in the service sector to have a competitive advantage that will separate surviving and ceased operations, particularly in sectors that are rapidly evolving and highly competitive.

Degree of hermeticity of a multicompartment compliance aid: Implications for the quality of professional pharmaceutical services

A multicompartment compliance aid (MCA) is a blister-type repackaging system that aims to facilitate drug administration and thereby increase patient adherence. One of the characteristics of the MCA that should be taken into account is the moisture permeability, since this atmospheric condition is one of the most important factors that can modify the stability of medicines. In the current paper we report the moisture permeability tests performed on a MCA according to the US Pharmacopeia. This information on the suitability of the device will help pharmacists implement a high-quality professional service.