23 research outputs found
Optimal Design and Control of Multi-Motor Drive System for Industrial Application
In this paper, the topology of the adjustable speed drive with active front end rectifier is considered in terms of application in multi-motor drives. A dynamic model of the rectifier with a coupled LCL filter is presented. A simulation model has been developed for the analysis of multi-motor drive system dynamics and power flow. Based on the simulation model, the functional possibilities of reversible induction motor drive with active front end converter and multiple voltage source inverters on a common DC bus at the motor side are analysed. One example of the application of a complex full regenerative multi-motor drive system on a common DC bus for an industrial crane, implemented with Siemens converters, is shown. The motor and generator mode of operation from the aspect of energy saving as well as the influence of drives on the distribution network from the aspect of higher harmonics and power factors are analysed. Siemens\u27s original software, Starter commissioning tool, for drives configuration and data acquisition is used
THE MONOSPIRAL MOTORISED CABLE REEL IN CRANE APPLICATIONS
The main consideration of any reeling system is the effect it has on cable tensions and hence cable life. This paper explains the relationship of reel torque to cable tensions and the reasons why this relationship is so important. Such system is characterized by variable parameters, primarily a variable moment of inertia and a variable diameter of the coiled cable. For these reasons, in order to ensure proper dimensioning of the drive, it is necessary to know the motor torques that need to be developed as a function of the coiled cable. The motor should be able to develop the required torques in a very wide speed range. It is shown that for properly sizing the motor it is necessary take into account the dynamics of the cable reel drive. In this paper monospiral motorized cable reel for winding power cable in crane applications with frequency converter fed induction motor is analyzed. Also, the equipment selection procedure for the real crane with concrete data is shown. Experimental results are recorded during the crane commissioning in real condition
VOLTAGE SAG SENSITIVITY OF INDUSTRIAL VECTOR CONTROLLED INDUCTION MOTOR DRIVES ā A COMPARATIVE STUDY
Sensitivity of adjustable speed drives (ASDs) on voltage sag events represents one of the most challenging problems in modern industrial facilities. In this paper, a comprehensive experimental verification of vector-controlled ASDs is conducted under the most-frequent sag types. The obtained results are faced with static and dynamic requirements in speed and torque controlled applications. Besides influence of DC-link parameters, selection of the applied control method and the controller settings can have crucial impact on performance deterioration. Examined industrial ASDs exhibited voltage sag susceptibility with fault error codes under the deeper voltage sags, while under the voltage sags with residual voltage above under-voltage limit they showed speed degradation
Flowers in the attic ā adverse childhood experiences and their relations with life-outcome
This is an introductory abstract for other papers within this symposium, which are all part of
the same study, Research on Adverse Childhood Experiences (ACE) in Serbia. ACE is a
traumatic experience in oneās life occurring before the age of 18 that the person remembers as
an adult. The purpose of this survey was to explore the prevalence of ACEs and their correlates
on a sample of 18-65 years old in Serbia. We used multistage random sampling, with a stratified
cluster sample in the first (187 settlements were sampled from 4 regions), and random sample
in the second stage (a random-walk technique for sampling participants). The final sample
consisted of 2792 respondents (57.4% females), interviewed face-to-face. Instrument package
included: ACE International Questionnaire, Health Appraisal, Family Health History, Trauma
Symptom Checklist, Benevolent Childhood experience, Experiences in Close Relationships-
Revised, HEXACO, DELTA9, and Non-suicidal self-injury. Each ACE was represented by a
binary score, in two ways: (1) any ACE score implies that participant had a specific event at
least āonce or twiceā; (2) frequent ACE implies that participant had specific events āmany
timesā. Factor analysis, principal axis with varimax rotation extracted three dimensions:
violence (involvement in physical fight, bullying, community violence, physical abuse,
collective violence, psychological abuse), neglect (depression in family, suicide in family,
psychological neglect, sexual abuse and parental separation) and abuse (alcoholism in family,
abuse of mother or father by the partner, incarceration of family member, drug abuse in family
and physical neglect). If we use ACEs as predictors of various life events in multiple regression
analysis, the highest prediction is gained for a number of suicidal attempts (R2 = .53, F = 2.38;
df = 17, 36; p < 0.05) - more ACEs lead to more attempts, with psychological neglect as
strongest predictor. Most frequent ACEs in Serbia are community violence (any 69.4%;
frequent 37.7%), psychological abuse (any 43.7%; frequent 26.3%), and involvement in a
physical fight (any 37.7%; frequent 19.7%). For comparison, physical abuse and domestic
violence appeared more frequently in Serbia than in Wales study, while parent separation and
sexual abuse appeared a bit more frequently in Wales sample. Possible higher prevalence of This is an introductory abstract for other papers within this symposium, which are all part of
the same study, Research on Adverse Childhood Experiences (ACE) in Serbia. ACE is a
traumatic experience in oneās life occurring before the age of 18 that the person remembers as
an adult. The purpose of this survey was to explore the prevalence of ACEs and their correlates
on a sample of 18-65 years old in Serbia. We used multistage random sampling, with a stratified
cluster sample in the first (187 settlements were sampled from 4 regions), and random sample
in the second stage (a random-walk technique for sampling participants). The final sample
consisted of 2792 respondents (57.4% females), interviewed face-to-face. Instrument package
included: ACE International Questionnaire, Health Appraisal, Family Health History, Trauma
Symptom Checklist, Benevolent Childhood experience, Experiences in Close Relationships-
Revised, HEXACO, DELTA9, and Non-suicidal self-injury. Each ACE was represented by a
binary score, in two ways: (1) any ACE score implies that participant had a specific event at
least āonce or twiceā; (2) frequent ACE implies that participant had specific events āmany
timesā. Factor analysis, principal axis with varimax rotation extracted three dimensions:
violence (involvement in physical fight, bullying, community violence, physical abuse,
collective violence, psychological abuse), neglect (depression in family, suicide in family,
psychological neglect, sexual abuse and parental separation) and abuse (alcoholism in family,
abuse of mother or father by the partner, incarceration of family member, drug abuse in family
and physical neglect). If we use ACEs as predictors of various life events in multiple regression
analysis, the highest prediction is gained for a number of suicidal attempts (R2 = .53, F = 2.38;
df = 17, 36; p < 0.05) - more ACEs lead to more attempts, with psychological neglect as
strongest predictor. Most frequent ACEs in Serbia are community violence (any 69.4%;
frequent 37.7%), psychological abuse (any 43.7%; frequent 26.3%), and involvement in a
physical fight (any 37.7%; frequent 19.7%). For comparison, physical abuse and domestic
violence appeared more frequently in Serbia than in Wales study, while parent separation and
sexual abuse appeared a bit more frequently in Wales sample. Possible higher prevalence of This is an introductory abstract for other papers within this symposium, which are all part of
the same study, Research on Adverse Childhood Experiences (ACE) in Serbia. ACE is a
traumatic experience in oneās life occurring before the age of 18 that the person remembers as
an adult. The purpose of this survey was to explore the prevalence of ACEs and their correlates
on a sample of 18-65 years old in Serbia. We used multistage random sampling, with a stratified
cluster sample in the first (187 settlements were sampled from 4 regions), and random sample
in the second stage (a random-walk technique for sampling participants). The final sample
consisted of 2792 respondents (57.4% females), interviewed face-to-face. Instrument package
included: ACE International Questionnaire, Health Appraisal, Family Health History, Trauma
Symptom Checklist, Benevolent Childhood experience, Experiences in Close Relationships-
Revised, HEXACO, DELTA9, and Non-suicidal self-injury. Each ACE was represented by a
binary score, in two ways: (1) any ACE score implies that participant had a specific event at
least āonce or twiceā; (2) frequent ACE implies that participant had specific events āmany
timesā. Factor analysis, principal axis with varimax rotation extracted three dimensions:
violence (involvement in physical fight, bullying, community violence, physical abuse,
collective violence, psychological abuse), neglect (depression in family, suicide in family,
psychological neglect, sexual abuse and parental separation) and abuse (alcoholism in family,
abuse of mother or father by the partner, incarceration of family member, drug abuse in family
and physical neglect). If we use ACEs as predictors of various life events in multiple regression
analysis, the highest prediction is gained for a number of suicidal attempts (R2 = .53, F = 2.38;
df = 17, 36; p < 0.05) - more ACEs lead to more attempts, with psychological neglect as
strongest predictor. Most frequent ACEs in Serbia are community violence (any 69.4%;
frequent 37.7%), psychological abuse (any 43.7%; frequent 26.3%), and involvement in a
physical fight (any 37.7%; frequent 19.7%). For comparison, physical abuse and domestic
violence appeared more frequently in Serbia than in Wales study, while parent separation and
sexual abuse appeared a bit more frequently in Wales sample. Possible higher prevalence of ACEs in our study might occur due to the context of the collective experience of wars, civil
unrest, insecurity, etc.Knjiga rezimea / XXV nauÄni skup Empirijska istraživanja u psihologiji
29ā31. mart 2019
The research was supported and fully funded by UNICEF, Serbi
Impact of depression on gait variability in Parkinson's disease
Objective
The goal of this study was to analyze how depression associated with Parkinsonās disease (PD) affected gait variability in these patients using a dual-task paradigm. Additionally, the dependency of the executive functions and the impact of depression on gait variability were analyzed.
Patients and Methods
Three subject groups were included: patients with PD, but no depression (PD-NonDep; 14 patients), patients with both PD and depression (PD-Dep; 16 patients) and healthy controls (HC; 15 subjects). Gait was recorded using the wireless sensors. The participants walked under four conditions: single-task, motor dual- task, cognitive dual-task, and combined dual-task. Variability of stride length, stride duration, and swing time was calculated and analyzed using the statistical methods.
Results
Variability of stride duration and stride length were not significantly different between PD-Dep and PD-NonDep patients. The linear mixed model showed that swing time variability was statistically significantly higher in PD-Dep patients compared to controls (pāÆ=āÆ0.001). Hamilton Disease Rating Scale scores were significantly correlated with the swing time variability (pāÆ=āÆ0.01). Variability of all three parameters of gait was significantly higher while performing combined or cognitive task and this effect was more pronounced in PD-Dep group of patients.
Conclusions
Depression in PD was associated with swing time variability, and this effect was more prominent while performing a dual-task.
Significance
Diagnosing and treating depression might be important for gait improvement and fall reduction in PD patients
Social Cognition in Patients With Cerebellar Neurodegenerative Disorders
ObjectiveCerebellar neurodegenerative disorders (CDs) are a heterogeneous group of disorders. It is known that the cerebellum plays a role not only in motor, but also in cognitive and social cognitive functions. The aim of this study was to investigate social cognition in patients with different CDs.Materials and MethodsSocial cognition was examined in 34 patients, 12 with spinocerebellar ataxia type 1 (SCA1), 6 with spinocerebellar ataxia type 2 (SCA2), and 16 with idiopathic late onset cerebellar ataxia (ILOCA). All patients were clinically evaluated using the Scale for the Rating and Assessment of Ataxia. In addition, 34 age, sex, and education-matched healthy control (HC) subjects were similarly analyzed. Social cognition was studied using two tests: the Faux Pas Recognition Test and the Reading the Mind in the Eyes Test (RMET). An appropriate array of neuropsychological tests was used to assess the global cognitive status as well as the frontal functions and mood.ResultsCD patients achieved significantly worse results on both tests of social cognition compared to the HCs. The SCA1 + 2 group achieved the poorest results on the Faux Pas Recognition Test and exhibited poor performance on all cognitive tests, but was only significantly worse compared to the ILOCA group on the Free and Cued Selective Reminding Test (FCSRT) ā recognition. The patients in the SCA1 + 2 and ILOCA groups obtained similar scores on RMET. In the SCA1 + 2 group the findings significantly correlated with clinical parameters of disease severity and duration and executive functions (EFs), and with mood and executive functions in the ILOCA group. In the SCA group EFs appeared as the only significant predictor of RMET achievement. The Boston Naming Test (BTN) was a significant predictor of the CD patientsā achievement on RMET, while the BTN, the Trail Making Test Part A and FCSRT ā Delayed free recall predicted their performance on the Faux Pas Recognition Test.ConclusionPatients with CD have social cognitive impairments as demonstrated by the Faux Pas Test and the RMET test results. The SCA1 and 2 patients exhibited a more pronounced impairment compared with the ILOCA patients. The independent cognitive predictors of social cognition impairment were EFs and language
INFLUENCE OF PSYCHO-SOCIAL FACTORS ON THE EMERGENCE OF DEPRESSION AND SUICIDAL RISK IN PATIENTS WITH SCHIZOPHRENIA
Background: The aim of this study was to investigate the influence of certain psychosocial factors ā insight, psycho-education,
family and social support, loneliness and social isolation ā on the appearance of depression and suicidal risk in schizophrenia.
Subjects and methods: This was a cross-sectional study that comprised hospitalized patients with schizophrenia in the initial
remission phase. The assessment of depression and suicidal risk was made by applying a semi-structured psychiatric interview that
included scrutinized factors (insight, psycho-education, family and social support, loneliness and social isolation), Positive and
Negative Syndrome Scale (PANSS), and Calgary Depression Scale for Schizophrenia (CDSS). On the basis of the assessment results,
the sample was divided into two groups: Group of patients with depression and suicidal risk in schizophrenia (N=53) and Control
group (N = 159) of patients with schizophrenia without depression and suicidal risk.
Results: In the Group of patients with depression and suicidal risk, compared with the Control group, there was significantly
higher frequency of insight in the mental status
Nonsuicidal Self-Injury (NSSI) in Serbia: Nationally representative sample study
Although NSSI has been drawing the attention of researchers intensely for the last 30 years, to date there is no published study about rates of NSSI behaviors in countries of south-eastern Europe. The study aimed to explore NSSI in the Republic of Serbia. Data were collected using multistage random sampling. The final sample consisted of 2792 participants (57.4% female) while the NSSI subsample consisted of 405 participants (54.3% males). Results showed the NSSI rate in Serbia is 4.3% based on a percentage of people who answered affirmatively to lifetime NSSI engagement. However, when the percentage of people who reported at least one positive answer through the NSSI behaviors checklist, the rate rises to 14.5%. The most frequent NSSI behavior is wound picking. NSSI rate drops to 8.8% when wound picking is excluded. Those engaged in NSSI were more likely to report suicide attempts and seek professional help than those who did not report NSSI. Gender differences in NSSI frequency are found only in cases of headbanging and burning oneself. This study showed the scope of NSSI-related problems is similar in Serbia compared to other countries. It also raised questions about the lack of preventive programs and treatment strategies for dealing with NSSI in Serbia.[https://www.sciencedirect.com/science/article/pii/S2772598722000320]Corresponding author. Institute for Educational Research, Dobrinjska 11/3, 11 000, Belgrade, Serbia. E-mail addresses: [email protected], [email protected] (A. RadanoviÄ)
ENIGMA-anxiety working group : Rationale for and organization of large-scale neuroimaging studies of anxiety disorders
Altres ajuts: Anxiety Disorders Research Network European College of Neuropsychopharmacology; Claude Leon Postdoctoral Fellowship; Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, 44541416-TRR58); EU7th Frame Work Marie Curie Actions International Staff Exchange Scheme grant 'European and South African Research Network in Anxiety Disorders' (EUSARNAD); Geestkracht programme of the Netherlands Organization for Health Research and Development (ZonMw, 10-000-1002); Intramural Research Training Award (IRTA) program within the National Institute of Mental Health under the Intramural Research Program (NIMH-IRP, MH002781); National Institute of Mental Health under the Intramural Research Program (NIMH-IRP, ZIA-MH-002782); SA Medical Research Council; U.S. National Institutes of Health grants (P01 AG026572, P01 AG055367, P41 EB015922, R01 AG060610, R56 AG058854, RF1 AG051710, U54 EB020403).Anxiety disorders are highly prevalent and disabling but seem particularly tractable to investigation with translational neuroscience methodologies. Neuroimaging has informed our understanding of the neurobiology of anxiety disorders, but research has been limited by small sample sizes and low statistical power, as well as heterogenous imaging methodology. The ENIGMA-Anxiety Working Group has brought together researchers from around the world, in a harmonized and coordinated effort to address these challenges and generate more robust and reproducible findings. This paper elaborates on the concepts and methods informing the work of the working group to date, and describes the initial approach of the four subgroups studying generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobia. At present, the ENIGMA-Anxiety database contains information about more than 100 unique samples, from 16 countries and 59 institutes. Future directions include examining additional imaging modalities, integrating imaging and genetic data, and collaborating with other ENIGMA working groups. The ENIGMA consortium creates synergy at the intersection of global mental health and clinical neuroscience, and the ENIGMA-Anxiety Working Group extends the promise of this approach to neuroimaging research on anxiety disorders
Cortical and subcortical brain structure in generalized anxiety disorder: findings from 28 research sites in the enigma-anxiety working group
The goal of this study was to compare brain structure between individuals with generalized anxiety disorder (GAD) and healthy controls. Previous studies have generated inconsistent findings, possibly due to small sample sizes, or clinical/analytic heterogeneity. To address these concerns, we combined data from 28 research sites worldwide through the ENIGMA-Anxiety Working Group, using a single, pre-registered mega-analysis. Structural magnetic resonance imaging data from children and adults (5ā90 years) were processed using FreeSurfer. The main analysis included the regional and vertex-wise cortical thickness, cortical surface area, and subcortical volume as dependent variables, and GAD, age, age-squared, sex, and their interactions as independent variables. Nuisance variables included IQ, years of education, medication use, comorbidities, and global brain measures. The main analysis (1020 individuals with GAD and 2999 healthy controls) included random slopes per site and random intercepts per scanner. A secondary analysis (1112 individuals with GAD and 3282 healthy controls) included fixed slopes and random intercepts per scanner with the same variables. The main analysis showed no effect of GAD on brain structure, nor interactions involving GAD, age, or sex. The secondary analysis showed increased volume in the right ventral diencephalon in male individuals with GAD compared to male healthy controls, whereas female individuals with GAD did not differ from female healthy controls. This mega-analysis combining worldwide data showed that differences in brain structure related to GAD are small, possibly reflecting heterogeneity or those structural alterations are not a major component of its pathophysiology