SPM limited long haul optical transmission in RZ-DPSK for varying input launch power with SMF, Monte Carlo Simulation

In this paper 10Gbps and 20Gb/s optical systems have been studied for return to zero differential phase shift keying. Observations are based on numerical simulations of dispersion compensated transmission link, for the range of optical signal power -2.5 to +2.5,-5 to +5,-10 to +10,-20 to +20dBm.Transmission over distances of four thousands of kilometers has been shown with amplified spontaneous emission (ASE) noise of the inline erbium doped fiber amplifier. Key words: DWDM, OSNR, ASE, RZ, DPS

Study in variable duty cycle return to zero pulse with multiplexed channels for SMFs

In this paper analysis has been done with varying return-to-zero (RZ) pulsed duty cycle, differential phase shift keying 640Gbps (16x40Gb/s) multiplexed channel optical transmission system using different SMFs viz standard Single mode fiber (SSMF), Non Zero Dispersion shifted fibers (normal NZDSF and anomalous NZDSF fiber), Corning SMF.Optical transmission used for sixteen users operates at 40Gbps per channel, 0.20nm spaced sixteen channels and fiber span analysis is done for test length of 200km. We tested system for detailed performance study for its behavior with different duty cycles for optical RZ pulse, results showing lowest bit error rate for 0.80 duty cycles among selection of 0.5, 0.8.0.99 for four types of SMFs tested for optical communication. Single repeater less mode fiber length is increased from 60km at duty cycle 0.5 to NZDSF fiber length of 140km at duty cycle 0.99.Results are also compared through 10dB Q improvement and corresponding improvement in average eye opening pattern. NZDSF fiber shows much improvement in average eye opening diagram for 0.99 duty cycle compared to other fibers tested and other duty cycles tested. Key words: DWDM, ASE, RZ, DPSK, OSNR

Comparative performance study in multiplexed RZDPSK for SMF's with FBG

The Fiber Bragg gratings have emerged as important components in several of light wave applications in the FBG becoming a ubiquitous and necessary element in equipment located throughout the network from the central office to the home. This paper explores comparative performance study with and without using FBG as an external dispersion compensator for sixteen channel return to zero differential phase shift keying modulation operating at 45Gbps per channel with channel spacing of 0.15nm. Simulations are done with various single mode fibers with and without external FBG.Better performance (Q, BER) for dispersion values used in simulation are -58ps/nm, 23ps/nm, and 100ps/nm for FBG's used at receiver channels. It is observed that FBG used with receiver channels support larger communication fiber length, also G655 (NZDSF) fiber shows much better performance as compared with other SMF's tested. Key Words: FBG, WDM, DCG, DCF, FOM, RZ

Investigation of nomophobia and smartphone addiction predictors among adolescents in Turkey: Demographic variables and academic performance

Most individuals spend a great amount of time on their smartphones. The intense usage of smartphones leads to some physical symptoms, good and bad feelings, pathological addiction, depression, symptoms such as fear-anxiety, productivity and low academic achievement. For this reason, prevention activities must be prioritized when dealing with the intense and uncontrolled usage of smartphones. The aim of this study is to determine nomophobia levels and smartphone addiction among 12-18 age group secondary and high school students and to investigate the demographic and academic variables predicting these levels. Designed with a relational model, the population of this research consists of 612 students studying at all levels of secondary school and high school. Personal information form and two different scales were used in the research. Descriptive analyses and hierarchical linear multiple regression analysis were used in the analysis of the data obtained by means of data collection in the research. As a result of the research, there is a significant relationship between smartphone addiction and nomophobia. In this study, Model 4 has been identified to be the most important predictor of smartphone addiction and nomophobia. In Model 4, variables related to smartphone usage are included in the analysis. Recommendations have been made according to the results of the study. (C) 2018 Western Social Science Association. Published by Elsevier Inc. All rights reserved