Revisiting Norm Optimization for Multi-Objective Black-Box Problems: A Finite-Time Analysis

The complexity of Pareto fronts imposes a great challenge on the convergence analysis of multi-objective optimization methods. While most theoretical convergence studies have addressed finite-set and/or discrete problems, others have provided probabilistic guarantees, assumed a total order on the solutions, or studied their asymptotic behaviour. In this paper, we revisit the Tchebycheff weighted method in a hierarchical bandits setting and provide a finite-time bound on the Pareto-compliant additive $\epsilon$-indicator. To the best of our knowledge, this paper is one of few that establish a link between weighted sum methods and quality indicators in finite time.Comment: submitted to Journal of Global Optimization. This article's notation and terminology is based on arXiv:1612.0841

Risk Factors for Hyperfunctional Voice Disorders Among Teachers

The aim of the study was to assess the prevalence of voice problems among teachers, and identify risk factors for developing voice pathology. In this study we evaluated 448 teachers (400 females and 48 males) between the age range of 25 to 55 years, from primary school as well as secondary school which were selected randomly. A questionnaire was given to them to find out how many of them had a voice problem. All the positive cases were further evaluated by an Otorhinolaryngologist, an Audiologist and a Speech Language Pathologist. Out of the 448 teachers, 39 of them(9%) had an indication of voice disorder based on the positive respose got from the questionnaire. Among the 39 cases identified 11 were males (28%) and 28 were females (71%). We tried to investigate on the factors that would have contributed to voice problem in the identified 9% of cases .Detailed history was taken and was examined by an otorhinolaryngologist, an audiologist and a Speech Language Pathologist.Out of the 39 cases identified 26% had history of recurrent allergic rhinitis and laryngitis, 18% had sinusitis and post nasal drip, 18% had asthma, 26% had gastoesophageal reflux disorder, (8%) had minimal sensori neural hearing loss and hypothyroidism was found in 8%. Interaction of multiple factors like hereditory, behavioral, lifestyle, medical and environmental can contribute to voice disorders in occupational voice users. Teachers need to be educated regarding vocal mechanism, vocal hygiene and effective voice use , dust free and noise free work environment, diet modification like drinking adequate water, avoiding spicy and deep fried food, regularizing meals and avoiding sleeping immediately after food. The underlying medical issues like allergy, sinusitis, laryngitis, hypothyroidism, gastroesophageal reflux, hearing loss etc also need to be addressed , since vocal hygiene alone will not help until and unless the underlying cause is taken care of

Phase error statistics of a phase-locked loop synchronized direct detection optical PPM communication system

Receiver timing synchronization of an optical Pulse-Position Modulation (PPM) communication system can be achieved using a phased-locked loop (PLL), provided the photodetector output is suitably processed. The magnitude of the PLL phase error is a good indicator of the timing error at the receiver decoder. The statistics of the phase error are investigated while varying several key system parameters such as PPM order, signal and background strengths, and PPL bandwidth. A practical optical communication system utilizing a laser diode transmitter and an avalanche photodiode in the receiver is described, and the sampled phase error data are presented. A linear regression analysis is applied to the data to obtain estimates of the relational constants involving the phase error variance and incident signal power

Analysis of ITU-R Performance and Characterization of Ku Band Satellite Downlink Signals during Rainy Season over Chennai Region of India

In this paper, we present the analysis of Ku band Satellite signal reception during rainy season over Chennai region, India (Latitude: 12° 56' 60 N, Longitude: 80° 7' 60 E). We also examine the effectiveness of International Telecommunication Union – Radio communication (ITU-R) model in predicting the rainfall induced attenuation in Ku band, over this region. An improved Simulink model for Digital Video Broadcast – Satellite (DVB-S2) downlink channel incorporating rain attenuation and Cross Polarization Discrimination (XPD) effects is developed to study the rain attenuation effects, by introducing the experimental data in the ITU-R model pertaining to that region. Based on the improved model, a Monte Carlo simulation of the DVB–S2 signal link is carried out and the performance is analyzed by received constellation and Bit Error Rate (BER) parameters