| 1. |
- Kormi-Nouri, Reza, 1954-, et al.
(författare)
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The effect of childhood bilingualism on episodic and semantic memory tasks
- 2008
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Ingår i: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564 .- 1467-9450. ; 49:2, s. 93-109
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Tidskriftsartikel (refereegranskat)abstract
- Kormi-Nouri, Moniri and Nilsson (2003) demonstrated that Swedish-Persian bilingual children recalled at a higher level than Swedish monolingual children, when they were tested using Swedish materials. The present study was designed to examine the bilingual advantage of children who use different languages in their everyday life but have the same cultural background and live in their communities in the same way as monolingual children. In four experiments, 488 monolingual and bilingual children were compared with regard to episodic and semantic memory tasks. In experiments 1 and 2 there were 144 boys and 144 girls in three school groups (aged 9-10 years, 13-14 years and 16-17 years) and in three language groups (Persian monolingual, Turkish-Persian bilingual, and Kurdish-Persian bilingual). In experiments 3 and 4, there were 200 male students in two school groups (aged 9-10 years and 16-17 years) and in two language groups (Persian monolingual and Turkish-Persian bilingual). In the episodic memory task, children learned sentences (experiments 1-3) and words (Experiment 4). Letter and category fluency tests were used as measures of semantic memory. To change cognitive demands in memory tasks, in Experiment 1, the integration of nouns and verbs within sentences was manipulated by the level of association between verb and noun in each sentence. At retrieval, a recognition test was used. In experiments 2 and 3, the organization between sentences was manipulated at encoding in Experiment 2 and at both encoding and retrieval in Experiment 3 through the use of categories among the objects. At retrieval, free recall or cued recall tests were employed. In Experiment 4, the bilingual children were tested with regard to both their first and their second language. In all four experiments, a positive effect of bilingualism was found on episodic and semantic memory tasks; the effect was more pronounced for older than younger children. The bilingual advantage was not affected by changing cognitive demands or by using first/second language in memory tasks. The present findings support the cross-language interactivity hypothesis of bilingual advantage.
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| 2. |
- Gholami, Mohammad Reza, 1976, et al.
(författare)
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Diffusion Estimation Over Cooperative Multi-Agent Networks With Missing Data
- 2016
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Ingår i: IIEEE Transactions on Signal and Information Processing over Networks. - : IEEE. - 2373-776X. ; 2:3, s. 276-289
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Tidskriftsartikel (refereegranskat)abstract
- In many fields, and especially in the medical and social sciences and in recommender systems, data are gathered through clinical studies or targeted surveys. Participants are generally reluctant to respond to all questions in a survey or they may lack information to respond adequately to some questions. The data collected from these studies tend to lead to linear regression models where the regression vectors are only known partially: some of their entries are either missing completely or replaced randomly by noisy values. In this work, assuming missing positions are replaced by noisy values, we examine how a connected network of agents, with each one of them subjected to a stream of data with incomplete regression information, can cooperate with each other through local interactions to estimate the underlying model parameters in the presence of missing data. We explain how to adjust the distributed diffusion strategy through (de)regularization in order to eliminate the bias introduced by the incomplete model. We also propose a technique to recursively estimate the (de)regularization parameter and examine the performance of the resulting strategy. We illustrate the results by considering two applications: one dealing with a mental health survey and the other dealing with a household consumption survey.
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| 3. |
- Gholami, Mohammad Reza, 1976, et al.
(författare)
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Diffusion Estimation over Cooperative Networks with Missing Data
- 2013
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Ingår i: IEEE Global SIP 2013. - 9781479902484 ; , s. 411-414
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Konferensbidrag (refereegranskat)abstract
- In many fields, and especially in the medical and social sciences and in various recommender systems, data are often gathered through clinical studies or targeted surveys. Participants are generally reluctant to respond to all questions in a survey or they may lack information to respond adequately to the questions. The data collected from these studies tend to lead to linear regression models where the regression vectors are only known partially: some of their entries are either missing completely or replaced randomly by noisy values. There are also situations where it is not known beforehand which entries are missing or censored. There have been many useful studies in the literature on techniques to perform estimation and inference with missing data. In this work, we examine how a connected network of agents, with each one of them subjected to a stream of data with incomplete regression information, can cooperate with each other through local interactions to estimate the underlying model parameters in the presence of missing data. We explain how to modify traditional distributed strategies through regularization in order to eliminate the bias introduced by the incomplete model. We also examine the stability and performance of theresulting diffusion strategy and provide simulations in support of the findings. We consider two applications: one dealing with a mental health survey and the other dealing with a household consumption survey.
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