• Korean Journal of Cognitive Science
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• v.32 no.2
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• pp.55-73
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• 2021

Psychological essentialism states that people believe some categories to have hidden and defining essential features which cause other features of the category (Gelman, 2003; Hirschfeld, 1996; Medin & Ortony, 1989). Essentialist belief on categories questions the Roschian argument (Rosch, 1973, 1978) that categories merely consist of clusters of correlated features. Unlike family resemblance categories, essentialized categories are likely to have clear between-category boundaries and high within-category coherence (Gelman, 2003; Prentice & Miller, 2007). Two experiments were conducted to test the effects of essentialist belief on category representation (i.e., between-category boundary, within-category coherence). Participants learned family resemblance and essentialized categories in their assigned conditions and then performed categorization task (Expt. 1) and frequency estimation task of category exemplars (Expt. 2). The results showed, in essentialized categories, both boundary intensification and greater category coherence. Theses results are likely to have arisen due to increased cue and category validity in essentialized categories and suggest that essentialist belief influences macroscopic representation of category structure.

• Korean Journal of Human Ecology
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• v.7 no.1
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• pp.25-38
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• 1998

The purpose of this study was to examine developmental trends in script-based organization strategy and relative influences of age, use of organizational strategy and category typicality of lists on children's recall. The subjects were 120 infant children, -40 four years old, 40 five years old, 40 six years old. All subjects were received 1 of 2 slot-filler lists of items differing in category representativness. Data were analysed by two-way Anova, Duncan's post-hoc test and Multiple Regression analysis. The major findings were as follows. 1. Recall and use of organizational strategy were increased with age. 2. At each age level, children showed high level of recall and organization strategy for category typical than category atypical. 3. Children's age, use of organizational strategy and category typicality of list significantly predicted children's recall. 42% of the variance of children's recall was explained by three variables. The relative influence of age to the prediction of children's recall was the strongest.

• Bulletin of the Korean Mathematical Society
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• v.36 no.4
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• pp.671-682
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• 1999

Using a base-point free version of the infinite symmetric product we define a fibrewise infinite symmetric product for any fibration $E\;\longrightarrow\;B$. The construction works for any commutative ring R with unit and is denoted by $R_f(E)\;l\ongrightarrow\;B$. For any pointed space B let $G_I(B)\;\longrightarrow\;B$ be the i-th Ganea fibration. Defining $M_R-cat(B):= inf{i\midR_f(G_i(B))\longrihghtarrow\;B$ admits a section} we obtain an approximation to the Lusternik-Schnirelmann category of B which satisfies .g.a product formula. In particular, if B is a 1-connected rational space of finite rational type, then $M_Q$-cat(B) coincides with the well-known (purely algebraically defined) M-category of B which in fact is equal to cat (B) by a result of K.Hess. All the constructions more generally apply to the Ganea category of maps.

• Journal of the Korean Mathematical Society
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• v.52 no.1
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• pp.67-80
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• 2015

For a pomonoid S, let us denote Pos-S the category of S-posets and S-poset maps. In this paper, we consider the slice category Pos-S/B for an S-poset B, and study some categorical ingredients. We first show that there is no non-trivial injective object in Pos-S/B. Then we investigate injective objects with respect to the class of regular monomorphisms in this category and show that Pos-S/B has enough regular injective objects. We also prove that regular injective objects are retracts of exponentiable objects in this category. One of the main aims of the paper is to draw attention to characterizing injectivity in the category Pos-S/B under a particular case where B has trivial action. Among other things, we also prove that the necessary condition for a map (an object) here to be regular injective is being convex and present an example to show that the converse is not true, in general.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.351-355
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• 2009

The amount of incoming e-mails is increasing rapidly due to the wide usage of Internet. We often group e-mails into categories for maintaining e-mail efficiently. However reading the email messages and classifying them is still tedious task. Moreover, the number of e-mails and manual classifying is increasing everyday. So, automatic e-mail classification is important techniques. In this paper, we propose a multi-way e-mail classification method that uses PCA for automatic category generation and dynamic category hierarchy for re-organizing e-mail categories. It classifies a huge amount of receiving e-mail messages automatically, efficiently, and accurately.

• Journal of information and communication convergence engineering
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• v.11 no.4
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• pp.268-273
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• 2013

In this paper, we propose a document classification model using Web documents as a part of the training corpus in order to resolve the imbalance of the training corpus size per category. For the purpose of retrieving the Web documents closely related to each category, the proposed document classification model calculates the matching score between word features and each category, and generates a Web search query by combining the higher-ranked word features and the category title. Then, the proposed document classification model sends each combined query to the open application programming interface of the Web search engine, and receives the snippet results retrieved from the Web search engine. Finally, the proposed document classification model adds these snippet results as Web documents to the training corpus. Experimental results show that the method that considers the balance of the training corpus size per category exhibits better performance in some categories with small training sets.

• Kyungpook Mathematical Journal
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• v.62 no.4
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• pp.657-671
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• 2022

Where S is a pomonoid, let Pos-S be the category of S-posets and S-poset maps. We start off by characterizing the pomonoids S for which all projectives in this category are either generators or free. We then study the notions of regular injectivity and weakly regularly d-injectivity in this category. This leads to homological classification results for pomonoids. Among other things, we get find relationships between regular injectivity in the slice category Pos-S/BS, for any S-poset BS, and generators and cyclic projectives in Pos-S.

• Journal of the Korean Mathematical Society
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• v.61 no.3
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• pp.409-425
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• 2024

The category of pairs is the category whose objects are maps between two based spaces and morphisms are pair-maps from one object to another object. To study the self-homotopy equivalences in the category of pairs, we use covariant functors from the category of pairs to the group category whose objects are groups and morphisms are group homomorphisms. We introduce specific subgroups of groups of self-pair homotopy equivalences and put these groups together into certain sequences. We investigate properties of these sequences, in particular, the exactness and split. We apply the results to two special functors, homotopy and homology functors and determine the suggested several subgroups of groups of self-pair homotopy equivalences.

• Journal of Families and Better Life
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• v.25 no.5
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• pp.167-183
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• 2007

The purpose of this study was to investigate the changes in infant-mother interactions and to measure infant-mother interaction, mutuality, and reciprocity at the 2nd and 6th postnatal monthperiods. Infant-mother interaction was assessed in the mornings, afternoons, and evenings in the 2nd and 6th postnatal months, by filming unstructured free play in the home and analyzing 28 of these infant-mother film recordingsusing two trained observers. This study can be summarized in five points. First, the separate frequency distribution of each category in MIIBR's maternal behavior was as follows: the frequencies of vocalization category, the kinesthetic exercise & physical contact category, the physical caregiving category, and theuse of play tool category. These all showed changes in the 6th postnatal month compared to the 2nd postnatal month. Second, the separate frequency distribution of each category in MIIBR's infant behavior was as follows: the frequencies of physical behavior category, the vocalization category, and the play behavior category. These also all showed changes in the 6th postnatal month compared to the 2nd postnatal month. Third, the mutuality and reciprocity of mother interaction decreased in the 2nd postnatal month compared to the 6th postnatal month. Fourth, mutuality and reciprocity in the infant interaction increased in 2nd postnatal month compared to the 6th postnatal month. Fifth, mutuality and reciprocity in the infant-mother interaction increased in 2nd postnatal month compared to the 6th postnatal month. In conclusion, it is evident that infant-mother interactions change over time. This study bears particular significance in setting a foundation for the theoretical basis of the interaction between infant and mother by observation.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.3
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• pp.102-107
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• 2013

Hepatitis A (HA) is an acute infectious disease of the liver caused by the Hepatitis A virus (HAV). In acute HA, the presence of anti-HAV IgM is detectable and about 3 weeks after exposure, its titre increases over 4 to 6 weeks. Anti-HAV IgG is detectable within a few days of the onset of symptoms. IgG antibodies continue to last for years after infection and provide lifelong immunity to the host. This study was performed to investigate the current seroprevalence of anti-HAV antibodies in Jeonbuk province, South Korea. A total of 591 (male 322, female 269) serum samples were collected in July 2011 to June 2012. We tested the antibodies of anti-HAV IgG and IgM using a Modular E170 (Roche Diagnostics, Germany), and analysed the serum alanine aminotransferase (ALT) levels by HITACH 7600-100 (HITACH, Japan). The overall seroprevalence of anti-HAV IgG was 84.6% (500/591), and the rate of females (85.9%) was higher than males (83.5%). According to the decade of age, seroprevalence of anti-HAV IgG were as follows; 68.8% (11/16) in the under 10 years old category, 100% (19/19) in the 10~19 category, 96% (48/50) in the 20~29 category, 83.6% (56/67) in the 30~39 category, 84.3% (123/146) in the 40~49 category, 83.3% (135/162) in the 50~59 category, 83.1% (54/65) in the 60~69 category, 78.1% (32/41) in the 70~79 category, and 88% (22/25) in the over 80 category. Total seroprevalence of anti-HAV IgM was 3.4% (20/591), and according to gender, the seroprevalence of male (3.1%) was very similar to that of female (3.7%). Through this study, we know that the seroprevalence of anti-HAV antibody in north-west Jeonbuk province, South Korea, was high. Only children under the age of 10 remain susceptible to HAV infection. Vaccination against HAV is not needed at the present time for the people of Jeonbuk province, South Korea, but a vaccination should be recommended and the improvement in sanitary conditions and personal hygiene should be highlighted.