Assessing machine learning performance in cryptocurrency market price prediction

Cryptocurrencies, which are digitally encrypted and decentralized, continue to attract attention of  nancial market players across the world. Because of high volatility in cryptocurrency market, predicting price of cryptocurrencies has become one of the most complicated  elds in  nancial markets. In this paper, we use Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) models to predict price of four well-known cryptocurrencies of Bitcoin (BTC), Ethereum(ETH), Litecoin (LTC), and Ripple (XRP). These models are subdivisions of Articial Intelligence, machine learning and data science. The main aim of this paper is to compare the accuracy of above-mentioned models in forecasting time series data, to  nd out which model can better predict price in these four cryptocurrencies. 43 variables consisting of 28 technical indicators and t+10 lags were calculated and appended to the Open, High, Low, Close and Volume (OHLCV) data for selected cryptocurrencies. Applying random forest as feature selection, 25 variables werechosen, 24 of them selected as feature (independent variables) and one as a dependent variable. Each attribute value was converted into a relative standard score, followed by Min-max scaling; we compare models and results of Dieblod Mariano test that is used to examine whether the differences in predictive accuracy with these two models are signi cant, reveal that LSTM reaches better accuracy than GRU for BTC and ETH, but both models convey the same accuracy for LTC and XRP

A practical guideline for intracranial volume estimation in patients with Alzheimer’s disease

Background Intracranial volume (ICV) is an important normalization measure used in morphometric analyses to correct for head size in studies of Alzheimer Disease (AD). Inaccurate ICV estimation could introduce bias in the outcome. The current study provides a decision aid in defining protocols for ICV estimation in patients with Alzheimer disease in terms of sampling frequencies that can be optimally used on the volumetric MRI data, and the type of software most suitable for use in estimating the ICV measure. Methods Two groups of 22 subjects are considered, including adult controls (AC) and patients with Alzheimer Disease (AD). Reference measurements were calculated for each subject by manually tracing intracranial cavity by the means of visual inspection. The reliability of reference measurements were assured through intra- and inter- variation analyses. Three publicly well-known software packages (Freesurfer, FSL, and SPM) were examined in their ability to automatically estimate ICV across the groups. Results Analysis of the results supported the significant effect of estimation method, gender, cognitive condition of the subject and the interaction among method and cognitive condition factors in the measured ICV. Results on sub-sampling studies with a 95% confidence showed that in order to keep the accuracy of the interleaved slice sampling protocol above 99%, the sampling period cannot exceed 20 millimeters for AC and 15 millimeters for AD. Freesurfer showed promising estimates for both adult groups. However SPM showed more consistency in its ICV estimation over the different phases of the study. Conclusions This study emphasized the importance in selecting the appropriate protocol, the choice of the sampling period in the manual estimation of ICV and selection of suitable software for the automated estimation of ICV. The current study serves as an initial framework for establishing an appropriate protocol in both manual and automatic ICV estimations with different subject populations

A probabilistic approach for pediatric epilepsy diagnosis using brain functional connectivity networks

Background The lives of half a million children in the United States are severely affected due to the alterations in their functional and mental abilities which epilepsy causes. This study aims to introduce a novel decision support system for the diagnosis of pediatric epilepsy based on scalp EEG data in a clinical environment. Methods A new time varying approach for constructing functional connectivity networks (FCNs) of 18 subjects (7 subjects from pediatric control (PC) group and 11 subjects from pediatric epilepsy (PE) group) is implemented by moving a window with overlap to split the EEG signals into a total of 445 multi-channel EEG segments (91 for PC and 354 for PE) and finding the hypothetical functional connectivity strengths among EEG channels. FCNs are then mapped into the form of undirected graphs and subjected to extraction of graph theory based features. An unsupervised labeling technique based on Gaussian mixtures model (GMM) is then used to delineate the pediatric epilepsy group from the control group. Results The study results show the existence of a statistically significant difference (p \u3c 0.0001) between the mean FCNs of PC and PE groups. The system was able to diagnose pediatric epilepsy subjects with the accuracy of 88.8% with 81.8% sensitivity and 100% specificity purely based on exploration of associations among brain cortical regions and without a priori knowledge of diagnosis. Conclusions The current study created the potential of diagnosing epilepsy without need for long EEG recording session and time-consuming visual inspection as conventionally employed

Psychiatric disorders in Iranian children and adolescents

Objective: The aim of the present study was to investigate the epidemiology of psychiatric disorders in children and adolescents in five provinces of Iran: Tehran, Shiraz, Isfahan, Tabriz and Mashhad. Method: In the present study, we selected 9,636 children and adolescents aged 6-18 years through multistage cluster random sampling method from Tehran, Shiraz, Isfahan, Tabriz and Mashhad. We instructed the clinical psychologists to complete the Strengths and Difficulties Questionnaire (SDQ) for the participants, and those who received a high score on SDQ, completed the Persian version of Kiddie-SADS-Present and Lifetime Version (K-SADS-PL). We used descriptive analysis and 95 confidence interval to investigate the relationship between scores of the K- SADS questionnaire and demographic factors . We used one-way ANOVA to test the significant differences among the disorders according to sex, age and province of residence. Results: Based on the results, oppositional defiant disorder (ODD) (4.45) had the highest prevalence of psychiatric disorders in the five provinces and substance abuse and alcohol abuse (0) had the lowest prevalence. In addition, attention deficit hyperactivity disorder (ADHD) had the most prevalence in boys (5.03) and ODD had the most prevalence in girls (4.05). Among the three age groups, 6 to 9 year olds had the highest rates of ADHD (5.69); 10 to 14 and 15 to 18 year olds had the highest rates of ODD (4.32 and 4.37 respectively). Among the five provinces, Tehran and Mashhad allocated the highest rates of ODD; Isfahan and Shiraz had the highest rates of ADHD; and Tabriz had the highest rates of social phobia. Conclusion: The current study revealed that the overall frequency of psychiatric disorders based on Kiddie- SADS-Present and Lifetime Version (K-SADS-PL) was higher than a similar study. Moreover, in this study, among the five provinces, Tehran and Mashhad allocated the highest rates of ODD; Isfahan and Shiraz had the highest rates of ADHD; and Tabriz had the highest rates of social phobia. Therefore, these percentage of psychiatric disorders in Iran lead us toward a greater use of consultation and mental health services

Psychological problems of Iranian children and adolescents: Parent report form of Strengths and Difficulties Questionnaire

Objective: The aim of this study was to evaluate the degree of psychological problems Iranian children and adolescents have, using parent report form of the Strengths and Difficulties Questionnaire (SDQ). Methods: In a community-based study, 9636 children and adolescents aged 6-17 years were selected using the multistage cluster random sampling method from five provinces of Iran: Tehran, Isfahan, Fars, Razavi Khorasan and East Azerbaijan. The parents completed the SDQ, which consisted of five subscales including emotional problems, conduct problems, hyperactivity, peer problems and prosocial behaviors. Result: The results revealed 21.4 of emotional problems, 32.9 of conduct problems, 20 of hyperactivity, 25.6 of peer problems, 7.6 of problems in prosocial behaviors and 16.7 of total difficulties among Iranian children and adolescents. We found that emotional problems were more prevalent among girls, while conduct problems, hyperactivity, total difficulties and problems in prosocial behaviors were more prevalent among boys. High educational level of parents was a protective factor against some psychological problems. Conclusion: Considering the proportion of psychological problems in Iranian children and adolescents, we need to develop and implement special policies and programs to provide appropriate mental health services. © 2014 Shadowfax Publishing and Informa UK Limited

Psychiatric disorders in Iranian children and adolescents

Objective: The aim of the present study was to investigate the epidemiology of psychiatric disorders in children and adolescents in five provinces of Iran: Tehran, Shiraz, Isfahan, Tabriz and Mashhad. Method: In the present study, we selected 9,636 children and adolescents aged 6-18 years through multistage cluster random sampling method from Tehran, Shiraz, Isfahan, Tabriz and Mashhad. We instructed the clinical psychologists to complete the Strengths and Difficulties Questionnaire (SDQ) for the participants, and those who received a high score on SDQ, completed the Persian version of Kiddie-SADS-Present and Lifetime Version (K-SADS-PL). We used descriptive analysis and 95 confidence interval to investigate the relationship between scores of the K- SADS questionnaire and demographic factors . We used one-way ANOVA to test the significant differences among the disorders according to sex, age and province of residence. Results: Based on the results, oppositional defiant disorder (ODD) (4.45) had the highest prevalence of psychiatric disorders in the five provinces and substance abuse and alcohol abuse (0) had the lowest prevalence. In addition, attention deficit hyperactivity disorder (ADHD) had the most prevalence in boys (5.03) and ODD had the most prevalence in girls (4.05). Among the three age groups, 6 to 9 year olds had the highest rates of ADHD (5.69); 10 to 14 and 15 to 18 year olds had the highest rates of ODD (4.32 and 4.37 respectively). Among the five provinces, Tehran and Mashhad allocated the highest rates of ODD; Isfahan and Shiraz had the highest rates of ADHD; and Tabriz had the highest rates of social phobia. Conclusion: The current study revealed that the overall frequency of psychiatric disorders based on Kiddie- SADS-Present and Lifetime Version (K-SADS-PL) was higher than a similar study. Moreover, in this study, among the five provinces, Tehran and Mashhad allocated the highest rates of ODD; Isfahan and Shiraz had the highest rates of ADHD; and Tabriz had the highest rates of social phobia. Therefore, these percentage of psychiatric disorders in Iran lead us toward a greater use of consultation and mental health services

Estimating Intracranial Volume in Brain Research: An Evaluation of Methods

Intracranial volume (ICV) is a standard measure often used in morphometric analyses to correct for head size in brain studies. Inaccurate ICV estimation could introduce bias in the outcome. The current study provides a decision aid in defining protocols for ICV estimation across different subject groups in terms of sampling frequencies that can be optimally used on the volumetric MRI data, and type of software most suitable for use in estimating the ICV measure. Four groups of 53 subjects are considered, including adult controls (AC, adults with Alzheimer's disease (AD), pediatric controls (PC) and group of pediatric epilepsy subjects (PE). Reference measurements were calculated for each subject by manually tracing intracranial cavity without sub-sampling. The reliability of reference measurements were assured through intra- and inter- variation analyses. Three publicly well-known software packages (FreeSurfer Ver. 5.3.0, FSL Ver. 5.0, SPM8 and SPM12) were examined in their ability to automatically estimate ICV across the groups. Results on sub-sampling studies with a 95 % confidence showed that in order to keep the accuracy of the inter-leaved slice sampling protocol above 99 %, sampling period cannot exceed 20 mm for AC, 25 mm for PC, 15 mm for AD and 17 mm for the PE groups. The study assumes a priori knowledge about the population under study into the automated ICV estimation. Tuning of the parameters in FSL and the use of proper atlas in SPM showed significant reduction in the systematic bias and the error in ICV estimation via these automated tools. SPM12 with the use of pediatric template is found to be a more suitable candidate for PE group. SPM12 and FSL subjected to tuning are the more appropriate tools for the PC group. The random error is minimized for FS in AD group and SPM8 showed less systematic bias. Across the AC group, both SPM12 and FS performed well but SPM12 reported lesser amount of systematic bias

Psychological problems in Iranian adolescents: application of the self report form of strengths and difficulties questionnaire.

Objective: The aim of the present study was to investigate the epidemiology of psychological problems in adolescents in five provinces of Tehran, Khorasan Razavi, Isfahan, East Azerbaijan and Fars in Iran. Methods: In the present cross-sectional and descriptive – analytical study, 5171 adolescents aged 12 to 17 years were selected through multistage cluster sampling method from Tehran, Isfahan, Fars, Khorasan Razavi and East Azarbaijan provinces. The self-report form of Strengths and Difficulties Questionnaire (SDQ) was used to obtain the demographic data of each adolescent. Descriptive analysis and 95% confidence interval were used to investigate the relationship between scores of the SDQ questionnaire and demographic factors. Result: Based on the results, the highest prevalence of psychological problems in the five provinces was related to conduct problems (24%), and the lowest prevalence was related to social problems (5.76%). Also, comparison of 95% confidence interval of prevalence of psychological probl ms between the two genders suggested a significant difference only in emotional problems of the self-report version of the SDQ between the two genders. The result revealed no significant difference in the psychological problems of the self-report version of the SDQ between the two age’s groups and between the middle and high school graduates (p≤0.05). Among the 5 provinces, Fars allocated the highest rates of conduct problems (28.4), hyperactivity problems (21.5%) and overall criterion problems (17.3%); Esfahan had the highest rates of emotional problems (9.1%) and problems with peers (8.1%); and Khorasan Razavi had the highest rates of social problems (7.6%). Conclusion: In this study, the highest prevalence of psychological problems in the five provinces was related to conduct problems, and the lowest prevalence was related to social problems. It was determined that girls have more emotional problems than boys. Also, no significant difference was found in the psychological problems of 12 to 14 and 15 to 17  ear old adolescents or between middle and high school graduates. In the current study, the prevalence of psychological problems in adolescents in the urban population in Fars province was higher than expected

The Effect of Host Country Nationals’ Social Support on Expatriates’ Adjustment—A Multiple Stakeholder Approach

The social support provided by host country nationals (HCNs) has been identified as an important source of successful expatriation. However, the roles of different HCN actors have not yet been sufficiently differentiated in this process. Drawing on social support theory and conservation of resources theory, this chapter aims to fill this void by investigating the impact of social support provided by five groups of HCN actors on expatriates’ cross-cultural adjustment: HCN top management team members, supervisors, colleagues, and subordinates in the work domain, as well as friends in the non-work domain. The resulting model suggests that all these HCN actors can increase expatriates’ adjustment; however, colleagues in the work domain and friends in the non-work domain have the highest influence on all types of adjustments