122 research outputs found
Stil privrženosti i dijadiÄka prilagodba kod žena: medijacijska uloga percipirane uÄinkovitosti u rjeÅ”avanju braÄnih sukoba
In this study, we examined perceived efficacy in solving marital
conflicts as a mediator between adult attachment style and
dyadic adjustment, while controlling for the effects of duration of
marriage. A total of 1921 married women participated in the
research. The results suggest that women with high attachment
avoidance are more likely to perceive themselves as inefficient in
marital conflict resolution and maladjusted to the dyadic relationship, compared to women with high attachment anxiety. Furthermore, the results suggest that perceived efficacy in solving marital conflicts mediates the effects of insecure attachment styles
on dyadic adjustment. Finally, there is evidence for a reciprocal
causation between efficacy expectations and dyadic adjustment.U ovoj smo studiji ispitali doprinos percipirane uÄinkovitosti u
rjeÅ”avanju braÄnih sukoba kao posrednika u objaÅ”njenju veze
izmeÄu stila privrženosti odraslih i dijadiÄke prilagodbe,
istodobno kontrolirajuÄi uÄinak duljine braka. U istraživanju je
sudjelovala 1921 udana žena. Rezultati sugeriraju da Äe se
žene sklone izbjegavajuÄoj privrženosti vjerojatno smatrati
neuÄinkovitima u rjeÅ”avanju braÄnih sukoba te slabije
prilagoÄenom partnerskom odnosu u usporedbi sa ženama s
visokom anksioznom privrženosti. Nadalje, rezultati sugeriraju
da uoÄena uÄinkovitost u rjeÅ”avanju braÄnih sukoba posreduje
uÄincima nesigurnih stilova privrženosti na dijadiÄku
prilagodbu. KonaÄno, možemo pretpostaviti postojanje
uzajamne uzroÄne veze izmeÄu oÄekivanja uÄinkovitosti u
rjeÅ”avanju braÄnih sukoba i dijadiÄke prilagodbe
Local Intrinsic Dimensionality Measures for Graphs, with Applications to Graph Embeddings
The notion of local intrinsic dimensionality (LID) is an important
advancement in data dimensionality analysis, with applications in data mining,
machine learning and similarity search problems. Existing distance-based LID
estimators were designed for tabular datasets encompassing data points
represented as vectors in a Euclidean space. After discussing their limitations
for graph-structured data considering graph embeddings and graph distances, we
propose NC-LID, a novel LID-related measure for quantifying the discriminatory
power of the shortest-path distance with respect to natural communities of
nodes as their intrinsic localities. It is shown how this measure can be used
to design LID-aware graph embedding algorithms by formulating two LID-elastic
variants of node2vec with personalized hyperparameters that are adjusted
according to NC-LID values. Our empirical analysis of NC-LID on a large number
of real-world graphs shows that this measure is able to point to nodes with
high link reconstruction errors in node2vec embeddings better than node
centrality metrics. The experimental evaluation also shows that the proposed
LID-elastic node2vec extensions improve node2vec by better preserving graph
structure in generated embeddings
Analiza i predviÄanje toka vremenskih serija pomoÄu āCase-BasedReasoningā tehnologije.
This thesis describes one promising approach where a problem of time series analysis and prediction was solved by using Case Based Reasoning (CBR) technology. Foundations and main concepts of this technology are described in detail. Furthermore, a detailed study of different approaches in time series analysis is given. System CuBaGe (Curve Base Generator) - A robust and general architecture for curve representation and indexing time series databases, based on Case based reasoning technology, was developed. Also, a corresponding similarity measure was modelled for a given kind of curve representation. The presented architecture may be employed equally well not only in conventional time series (where all values are known), but also in some non-standard time series (sparse, vague, non-equidistant). Dealing with the non-standard time series is the highest advantage of the presented architecture.U ovoj doktorskoj disertaciji prikazan je interesantan i perspektivan pristup reÅ”avanja problema analize i predviÄanja vremenskih serija koriÅ”Äenjem Case Based Reasoning (CBR) tehnologije. Detaljno su opisane osnove i glavni koncepti ove tehnologije. TakoÄe, data je komparativna analiza razliÄitih pristupa u analizi vremenskih serija sa posebnim osvrtom na predviÄanje. Kao najveÄi doprinos ove disertacije, prikazan je sistem CuBaGe (Curve Base Generator) u kome je realizovan originalni naÄin reprezentacije vremenskih serija zajedno sa, takoÄe originalnom, odgovarajuÄom merom sliÄnosti. Robusnost i generalnost sistema ilustrovana je realnom primenom u domenu finansijskog predviÄanja, gde je pokazano da sistem jednako dobro funkcioniÅ”e sa standardnim, ali i sa nekim nestandardnim vremenskim serijama (neodreÄenim, retkim i neekvidistantnim)
The Influence of Global Constraints on Similarity Measures for Time-Series Databases
A time series consists of a series of values or events obtained over repeated
measurements in time. Analysis of time series represents and important tool in
many application areas, such as stock market analysis, process and quality
control, observation of natural phenomena, medical treatments, etc. A vital
component in many types of time-series analysis is the choice of an appropriate
distance/similarity measure. Numerous measures have been proposed to date, with
the most successful ones based on dynamic programming. Being of quadratic time
complexity, however, global constraints are often employed to limit the search
space in the matrix during the dynamic programming procedure, in order to speed
up computation. Furthermore, it has been reported that such constrained
measures can also achieve better accuracy. In this paper, we investigate two
representative time-series distance/similarity measures based on dynamic
programming, Dynamic Time Warping (DTW) and Longest Common Subsequence (LCS),
and the effects of global constraints on them. Through extensive experiments on
a large number of time-series data sets, we demonstrate how global constrains
can significantly reduce the computation time of DTW and LCS. We also show
that, if the constraint parameter is tight enough (less than 10-15% of
time-series length), the constrained measure becomes significantly different
from its unconstrained counterpart, in the sense of producing qualitatively
different 1-nearest neighbor graphs. This observation explains the potential
for accuracy gains when using constrained measures, highlighting the need for
careful tuning of constraint parameters in order to achieve a good trade-off
between speed and accuracy
UÄinak razlike u procjeni osobne i supružnikove vrijednosti kao partnera na procjenu kvalitete braÄnog odnosa: dijadni pristup
The main aim of this study was to investigate the effects of
mate value assessment and mate value discrepancy on
perceived marital quality, using an assessment of personal
and partner mate value obtained by both partners. The
sample included 442 heterosexual couples that have lived
together for at least a year. The Actor-Partner
Interdependence Model (APIM) was used to investigate the
effects of personal and partner mate value assessment on
the evaluation of marital quality. In addition, two interaction
effects were added to the model to examine the effect of
mate value discrepancy on perceived marital quality. The
APIM model showed significant actor and partner effects of
the partner\u27s mate value assessment on the evaluation of
both husbands\u27 and wives\u27 marital quality. The model also
showed a significant effect of personal mate value assessed
by wives on husbands\u27 marital quality assessment. However,
the current evidence does not confirm the assumption of a
possible combination of partners\u27 mate value promoting
marital quality above and beyond the contribution of both
partners\u27 mate value.Glavni cilj ovog istraživanja bio je istražiti uÄinke procjene
osobne i supružnikove vrijednosti kao partnera i razlike u
spomenutim vrijednostima na procjenu kvalitete braÄnog
odnosa, koristeÄi se procjenom osobne i supružnikove
vrijednosti dobivene od oba partnera. Uzorak istraživanja
obuhvaÄao je 442 heteroseksualna para, koji su zajedno živjeli najmanje godinu dana. Model meÄuovisnosti aktora i
partnera (APIM) iskoriÅ”ten je za istraživanje uÄinaka procjene
osobne i supružnikove vrijednosti kao partnera na procjenu
kvalitete braka. Osim navedenoga, modelu su dodana dva
interakcijska uÄinka, kako bi se istražio uÄinak razlike u
procjeni osobne i supružnikove vrijednosti kao partnera na
procijenjenu kvalitetu braka. APIM model pokazao je
znaÄajne aktorske i partnerske uÄinke procjene supružnikove
vrijednosti kao partnera na procijenjenu kvalitetu braka
obaju supružnika. Model je pokazao i znatan uÄinak
procjene osobne vrijednosti supruge kao partnerice na
suprugovu procjenu kvalitete braÄnog odnosa. MeÄutim,
model ne potvrÄuje pretpostavku o interakcijskom uÄinku
procjene osobne i supružnikove vrijednosti kao partnera na
procjenu kvalitete braka
The effect of lead on the developmental stability of Drosophila subobscura through selection in laboratory conditions
Fluctuating asymmetry (FA), the increased variation of bilateral symmetry in a sample of individuals, can indicate disturbance in developmental stability caused by environmental and/or genomic stress. This developmental instability was analyzed in Drosophila subobscura maintained for seven generations on two different concentrations of lead in laboratory conditions. The FA4 index showed that the genotypes reared on the higher lead concentration were in developmental homeostasis, except for males in the F7 generation, for both wing size parameters. The results show that different degrees of lead pollution cause different responses to selection of the exposed population in laboratory conditions
Inversion polymorphism in populations of Drosophila subobscura from urban and non-urban environments
Populations of Drosophila subobscura from the urban area of Belgrade and from the locality, Deliblato, which is not under strong anthropogenic influence, were studied with the aim to characterize and compare their genetic structure by examining chromosomal inversion polymorphism. Additional analysis and comparison of this type of polymorphism with several other populations from different habitats in the central Balkans, was done. The obtained results indicate higher heterozygosity in the population from Belgrade. Despite being ecologically marginal and under strong and complex influences, this population did not show a decline in the number of inversions and it is not highly differentiated compared to the referent populations.
Intra-species differentiation among Drosophila subobscura from different habitats in Serbia
Adaptation to different environmental conditions is a natural phenomenon that potentially leads to population subdivision. We surveyed genetic differentiation in inversion polymorphism within populations of Drosophila subobscura sampled in three ecologically different forest communities. The analysis of inversion polymorphism revealed significant differences between some pairs of samples in some gene arrangement frequencies of the A, U, and E chromosomes and some karyotype combination frequencies of the U chromosome, but significant differentiation within populations was not observed. It cannot be decided which evolutionary forces are responsible for the observed variability in inversion polymorphism.Adaptacija na razliÄite sredinske uslove može uticati na diferencijaciju u okviru populacija. U ovom radu analizirana je genetiÄka diferencijacija po inverzionom polimorfizmu u okviru populacija D. subobscura sakupljenih u tri ekoloÅ”ki razliÄita staniÅ”ta. UtvrÄene su znaÄajne razlike u uÄestalosti pojedinih hromozomskih aranžmana A, U i E hromozoma, i uÄestalosti pojedinih kombinacija kariotipova U hromozoma, ali nije utvrÄena diferencijacija u okviru populacija. Razmatrani su evolutivni faktori koji bi mogli da budu odgovorni za uoÄenu varijabilnost u inverzionom polimorfizmu.Projekat ministarstva br. 14301
Does inbreeding affects developmental stability in Drosophila subobscura populations?
In the present paper, we focused on the coadaptive aspect of genetic variability at population level and its relation to genomic stress such as inbreeding. The paper evaluates the effects of an experimental reduction of average heterozygosity after fourteen generations of systematic inbreeding in laboratory conditions, on developmental stability in Drosophila subobscura populations from two ecologically and topologically distinct habitats, knowing that they possess a certain degree of genetic differences due to their different evolutionary histories. The aims were to analyze: (i) the variability change of wing size (length and width) among the inbred lines from both populations; (ii) the relations between homozigosity and level of fluctuating asymmetry as a potential measure of developmental instability, in inbred lines originating from two populations. Results for the wing size showed similar between line variability pattern across generations of systematic inbreeding in both populations. The obtained results suggest that variability of fluctuating asymmetry as a measure of developmental instability can not be related to homozygosity due to inbreeding per se, in both experimental populations.Rad je fokusiran na ko adaptivni aspekt genetiÄke varijabilnosti na nivou populacije i u odnosu na genomski stres kao Å”to je inbriding. Analizirani su efekti eksperimentalnog smanjenja proseÄne heterozigotnosti nakon 14 generacija sistematskog inbridinga u laboratorijskim uslovima na razvojnu stabilnost Drosophila subobscura populacija sa dva ekoloÅ”ki i topoloÅ”ki odvojena staniÅ”ta, znajuÄi da one poseduju odredjeni stepen genetiÄke diferencijacije usled razliÄitih evolutivnih istorija. Ciljevi rada su bili da se analizira: (i) varijabilnost u promeni veliÄine krila (dužine i Å”irine) medju inbidingovanim linijama i populacijama; (ii) odnosi izmedju homozigotizacije i nivoua fluktuirajuÄe asimetrije kao potencijalne mere razvojne nestabilnosti u inbridingovanim linijama obe populacije. Rezultati veliÄine krila pokazuju sliÄnu varijabilnost medju linijama obe populacije kroz generacije inbridinga. Dobijeni rezultati sugeriÅ”u da varijabilnost fluktuirajuÄe asimetrije kao mere razvojne nestabilnosti ne mogu biti povezani sa homozigotizacijom usled inbridinga per se, u obe eksperimentalne populacije.Projekat ministarstva br. 17301
The effect of developmental temperature fluctuation on wing traits and stressed locomotor performance in Drosophila melanogaster, and its dependence on heterozygosity
Background: Natural environments fluctuate and all organisms experience some degree of environmental variance. Global climate models predict increasing environmental variance in the future. Yet we do not fully understand how environmental variation affects performance traits. Questions: Does temperature fluctuation during development affect adult size and wing shape in Drosophila melanogaster? If so, are the effects predictable? Do they depend on heterozygosity? Do fluctuations in developmental temperature affect adult physiological performance at high temperature? Methods: We tested the effect of one fluctuating (21 degrees C/29 degrees C) and several constant (21 degrees C, 23 degrees C, 25 degrees C, 27 degrees C, 29 degrees C) developmental temperature regimes on three wing morphometric traits (wing length, wing width, and wing shape) in an experiment using three inbred lines of D. melanogaster and their first-generation hybrids. We also tested the effect of fluctuating and constant developmental temperature on adult locomotor performance at several high and stressful test temperatures (32 degrees C, 34 degrees C, 36 degrees C, 38 degrees C, 40 degrees C). Results: Performance mostly declined if the flies were reared under the fluctuating temperature regime versus the constant temperature regime with the same mean (25 degrees C). Heterozygosity level also affected the traits investigated, with crossbreds usually having higher trait values. Crossbred genotypes compared across constant temperatures also showed greater plasticity in wing aspect. Conclusion: The widespread use of constant developmental temperatures in laboratory experiments may lead to overestimation of performance.Danish Council for Independent Research \ Natural Sciences [11-107166]; Danish Natural Science Research Council [11-103926, 09-065999, 95095995]; Carlsberg Foundation [2011-01-0059
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