Forecasting telecommunications data with linear models

For telecommunication companies to successfully manage their business, companies rely on mapping future trends and usage patterns. However, the evolution of telecommunications technology and systems in the provision of services renders imperfections in telecommunications data and impinges on a company’s’ ability to properly evaluate and plan their business. ITU Recommendation E.507 provides a selection of econometric models for forecasting these trends. However, no specific guidance is given. This paper evaluates whether simple extrapolation techniques in Recommendation E.507 can generate accurate forecasts. Standard forecast error statistics—mean absolute percentage error, median absolute percentage error and percentage better—show the ARIMA, Holt and Holt-D models provide better forecasts than a random walk and other linear extrapolation methods.linear models; ITU Recommendations; telecommunications forecasting

Forecasting international bandwidth capacity using linear and ANN methods

An artificial neural network (ANN) can improve forecasts through pattern recognition of historical data. This article evaluates the reliability of ANN methods, as opposed to simple extrapolation techniques, to forecast Internet bandwidth index data that is bursty in nature. A simple feedforward ANN model is selected as a nonlinear alternative, as it is flexible enough to model complex linear or nonlinear relationships without any prior assumptions about the data generating process. These data are virtually white noise and provides a challenge to forecasters. Using standard forecast error statistics, the ANN and the simple exponential smoothing model provide modestly better forecasts than other extrapolation methodsForecasting; international bandwidth capacity

Optimal forecasting model selection and data characteristics

Selection protocols such as Box–Jenkins, variance analysis, method switching and rules-based forecasting measure data characteristics and incorporate them in models to generate best forecasts. These protocol selection methods are judgemental in application and often select a single (aggregate) model to forecast a collection of series. An alternative is to apply individually selected models for to series. A multinomial logit (MNL) approach is developed and tested on Information and communication technology share price data. The results suggest the MNL model has the potential to predict the best forecast method based on measurable data characteristics.

Risk factors for mortality in infancy and childhood in children with major congenital anomalies: A European population-based cohort study

Background: Preterm birth and young maternal age are known risk factors for infant and childhood mortality. There is limited knowledge of the impact of these risk factors in children born with major congenital anomalies (CAs), who have inherently higher risks of death compared with other children. Objectives: To investigate the risk factors for mortality up to age 10 years in children born with specific major CAs. Methods: This population-based cohort study involved 150,198 livebirths from 1995 to 2014 in 13 European CA registries linked to mortality data. Cox proportional hazards models estimated the association of gestational age, maternal age and child's sex with death <1 year and 1–9 years for the whole cohort and by CA subgroup. Hazard ratios (HR) from each registry were pooled using multivariate meta-analysis. Results: Preterm birth had a dose–response association with mortality; compared with infants born at 37+ weeks gestation, those born at <28, 28–31 and 32–36 weeks had 14.88 (95% CI 12.57, 17.62), 8.39 (95% CI 7.16, 9.85) and 3.88 (95% CI 3.40, 4.43) times higher risk of death <1 year, respectively. The corresponding risks at 1–9 years were 4.99 (95% CI 2.94, 8.48), 3.09 (95% CI 2.28, 4.18) and 2.04 (95% CI 1.69, 2.46) times higher, respectively. Maternal age <20 years (versus 20–34 years) was a risk factor for death <1 year (HR 1.30, 95% CI 1.09, 1.54) and 1–9 years (HR 1.58, 95% CI 1.19, 2.10). Females had 1.22 (95% CI: 1.07, 1.39) times higher risk of death between 1 and 9 years than males. Conclusion: Preterm birth was associated with considerably higher infant and childhood mortality in children with CAs, comparable to estimates reported elsewhere for the background population. Additional risk factors included young maternal age and female sex. Information on risk factors could benefit clinical care and guide counselling of parents following CA diagnoses

Mobile telephony and internet growth: impacts on consumer welfare

Innovation in digital technology has allowed rapid growth in mobile telephone and Internet adoption among consumers. The implication underlying the high rates of subscription growth is that consumers generally place a high valuation on telecommunication services. Moreover, since mobile telephone and Internet are predominantly telecommunication services, it is reasonable to presume that the network effect may be largely responsible for this growth. The implication of the network effect, where the consumer’s valuation of service increases with the size of the network is that subscription growth is endogenous. However, to date there have been few attempts to measure the change in consumer welfare as networks increase. Following Hausman (1981), this paper measures the change in consumer surplus based on the compensating variations approach. The result is an annual measure of the change in consumer surplus for the representative consumer for the OECD region. In addition, the approach reveals whether marginal consumer surplus is a decreasing or increasing function of network size. Measurement of the change in consumer welfare thus provides an additional tool for public policy analysis.Consumer welfare; network effect; compensating variation

Neuroprotective Effects of Alpha Lipoic Acid on Haloperidol-Induced Oxidative Stress in the Rat Brain

Haloperidol is an antipsychotic drug that exerts its' antipsychotic effects by inhibiting dopaminergic neurons. Although the exact pathophysiology of haloperidol extrapyramidal symptoms are not known, the role of reactive oxygen species in inducing oxidative stress has been proposed as one of the mechanisms of prolonged haloperidol-induced neurotoxicity. In the present study, we evaluate the protective effect of alpha lipoic acid against haloperidol-induced oxidative stress in the rat brain. Sprague Dawley rats were divided into control, alpha lipoic acid alone (100 mg/kg p.o for 21 days), haloperidol alone (2 mg/kg i.p for 21 days), and haloperidol with alpha lipoic acid groups (for 21 days). Haloperidol treatment significantly decreased levels of the brain antioxidant enzymes super oxide dismutase and glutathione peroxidase and concurrent treatment with alpha lipoic acid significantly reversed the oxidative effects of haloperidol. Histopathological changes revealed significant haloperidol-induced damage in the cerebral cortex, internal capsule, and substantia nigra. Alpha lipoic acid significantly reduced this damage and there were very little neuronal atrophy. Areas of angiogenesis were also seen in the alpha lipoic acid-treated group. In conclusion, the study proves that alpha lipoic acid treatment significantly reduces haloperidol-induced neuronal damage

Forecasting telecommunications data with linear models

For telecommunication companies to successfully manage their business, companies rely on mapping future trends and usage patterns. However, the evolution of telecommunications technology and systems in the provision of services renders imperfections in telecommunications data and impinges on a company’s’ ability to properly evaluate and plan their business. ITU Recommendation E.507 provides a selection of econometric models for forecasting these trends. However, no specific guidance is given. This paper evaluates whether simple extrapolation techniques in Recommendation E.507 can generate accurate forecasts. Standard forecast error statistics—mean absolute percentage error, median absolute percentage error and percentage better—show the ARIMA, Holt and Holt-D models provide better forecasts than a random walk and other linear extrapolation methods

Reference Measurements of the Longitudinal Impedance in the CERN SPS

First reference measurements of the longitudinal impedance were made with beam in the SPS machine in 1999 to quantify the results of the impedance reduction programme, completed in 2001. The 2001 data showed that the low-frequency inductive impedance had been reduced by a factor 2.5 and that bunch lengthening due to the microwave instability was absent up to the ultimate LHC bunch intensity. Measurements of the quadrupole frequency shift with intensity in the following years suggest a significant increase in impedance (which nevertheless remains below the 1999 level) due to the installation of eight extraction kickers for beam transfer to the LHC. The experimental results are compared with expectations based on the known longitudinal impedance of the SPS

Controlled-release nanoencapsulating microcapsules to combat inflammatory diseases

The World Health Organization (WHO) has reported that globally 235 million people suffer from chronic and other inflammatory diseases. The short half-lives of nonsteroidal anti-inflammatory drugs (NSAIDs) and their notoriety in causing gastrointestinal discomforts, warrants these drugs to be released in a controlled and sustained manner. Although polymeric particles have been widely used for drug delivery, there are few reports that showcase their ability in encapsulating and sustaining the release of NSAIDs. In this paper, polymeric nanoencapsulating microcapsules loaded with NSAIDs were fabricated using solid/water/oil/water emulsion solvent evaporation method. Two NSAIDs, ibuprofen and naproxen, were first pre-loaded into nanoparticles and then encapsulated into a larger hollow microcapsule that contained the third NSAID, celecoxib. A high encapsulation efficiency (%) of these NSAIDs was achieved and a sustained release (up to 30 days) of these drugs in phosphate-buffered saline was observed. Then, a gastrointestinal drug – cimetidine (CIM) – was co-loaded with the NSAIDs. This floating delivery system exhibited excellent buoyancy (~88% up to 24 h) in simulated gastric fluid. It also allowed a sequential release of the drugs, whereby an immediate release of CIM followed by NSAIDs was observed. Drug release of the NSAIDs observed Fickian diffusion mechanism, whereas CIM observed non-Fickian diffusion. Therefore, this delivery system is a promising platform to control the delivery of NSAIDs to combat inflammatory diseases, thereby protecting against possible gastrointestinal side effects that may arise from the overuse of NSAIDs.MOE (Min. of Education, S’pore)Published versio