Internet Usage Habits and Cyberbullying Related Opinions of Secondary School Students

Abstract The purpose of this research is to examine the internet usage habits of secondary school students and their awareness of cyberbullying in terms of different variables. Of the probabilistic sampling methods, research sampling identified by stratified sampling method has been formed by 559 students from two branches (56 branches in total) selected with simple random sampling method (For example; 5/A and 5/C) at each grade level (5th, 6th, 7th and 8th grades) from 7 schools in Merzifon. Data in the research have been obtained by the form related to the personal information and "Cyberbullying Scale". Due to the absence of normal distribution of data, the frequency tables in the analysis of data, Mann-Whitney U and Kruskal-Wallis H tests were used. According to the results of the research, it has been detected that the cyberbullying related awareness of the secondary school students is low ( x =20.24 out of 42); there is no significant difference in terms of gender, having personal computer and mobile phone and there are some significant differences in terms of the variables such as the type of school and class level. While the internet use purposes of the students is mostly making research and doing homework, it is seen that using social network such as Facebook is common among the students despite being illegal due to their ages

Analysis of the Relationship between Multipath Fading and Optimum Subcarrier Spacing for Generalized MC DS-CDMA Systems

Generalized multicarrier direct sequence code-division multiple-access (MC DS-CDMA) system is a model which includes a number of specific MC DS-CDMA schemes by varying the normalized subcarrier spacing. In the generalized MC DS-CDMA scheme, for a given system bandwidth and a given channel environment, there exists an optimum subcarrier spacing, which results in a minimum bit error rate. In this paper, as an extension of a previous study, detailed analysis on the variation of the optimum normalized subcarrier spacing for the generalized MC DS-CDMA in multipath Nakagami-m fading channels is performed. The results show that the optimum subcarrier spacing is almost independent of the variation of the fading parameter when the number of subcarriers is small. On the contrary, it is observed that the fading parameter has a clear effect on the settling of the optimum subcarrier spacing for large number of subcarriers

Further performance analysis of the generalized MC DS-CDMA system in Nakagami-m fading channels

The generalized multicarrier direct sequence code-division multiple-access (MC DS-CDMA) is a well known model that can be extended to different MC DS-CDMA schemes by simply varying a single parameter called as normalized subcarrier spacing. In this paper, the effect of the rate of average power decay on the bit error rate (BER) performance of the generalized MC DS-CDMA system is presented. Two specific schemes known as multitone DS-CDMA and orthogonal MC DS-CDMA are considered for the BER performance analysis. Simulation results show that I lie rate of average power decay has an important effect on the BER performance comparisons between the multitone DS-CDMA system and the orthogonal MC DS-CDMA system. (C) 2008 Elsevier Ltd. All rights reserved.The generalized multicarrier direct sequence code-division multiple-access (MC DS-CDMA) is a well known model that can be extended to different MC DS-CDMA schemes by simply varying a single parameter called as normalized subcarrier spacing. In this paper, the effect of the rate of average power decay on the bit error rate (BER) performance of the generalized MC DS-CDMA system is presented. Two specific schemes known as multitone DS-CDMA and orthogonal MC DS-CDMA are considered for the BER performance analysis. Simulation results show that the rate of average power decay has an important effect on the BER performance comparisons between the multitone DS-CDMA system and the orthogonal MC DS-CDMA system

Preconcentration/Separation of Some Trace Metal Ions From Water Samples by a New Synthesized Chelating Resin

A solid phase extractor, poly(N,N'-dipropionitrile methacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid), was synthesized and used for separation/preconcentration of traces of Ni(II), Co(II), Cu(II), Mn(II), Cd(II), Zn(II), and Pb(II) from various water samples prior to their determination by flame atomic absorption spectrometry. The characterization of the synthesized resin was performed by elemental analysis and IR spectrometry. Parameters such as pH, volume and concentration of the eluent, flow rate of the sample solution, sample volume, and interfering ions affecting the column SPE were examined. The optimum pH was found to be 3. The retained metal ions were desorbed from the column with 10 mL of 1 M HCl eluent. A high preconcentration factor, 40-100; low RSD, <= 2.8%; and low LOD values, <= 1.74 mu g/L, were obtained. The adsorption capacity of the resin was in the range of 6.80-12.4 mg/g for all the elements. The reusability of the resin was excellent. The accuracy of the method was confirmed by analyzing certified reference materials (TMDA-70 Lake Water and SPS-WW1 Batch 111-Wastewater) and spiked water samples. The method was successfully applied to the determination of metal ions in tap, lake, and dam waters