• Communications for Statistical Applications and Methods
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• v.29 no.3
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• pp.333-351
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• 2022

The skew-t distribution is an attractive family of asymmetrical heavy-tailed densities that includes the normal, skew-normal and Student's-t distributions as special cases. In this work, we propose an EM-type algorithm for computing the maximum likelihood estimates for skew-t linear regression models with censored response. In contrast with previous proposals, this algorithm uses analytical expressions at the E-step, as opposed to Monte Carlo simulations. These expressions rely on formulas for the mean and variance of a truncated skew-t distribution, and can be computed using the R library MomTrunc. The standard errors, the prediction of unobserved values of the response and the log-likelihood function are obtained as a by-product. The proposed methodology is illustrated through the analyses of simulated and a real data application on Letter-Name Fluency test in Peruvian students.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.415-420
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• 2022

It is essential that continual assessments of the impact of mine-derived water as a long-lasting burden on freshwater environments. Abundance-based evaluations of benthic macroinvertebrates have been conducted to evaluate anthropogenic disturbances and devise policies to reduce their impact. In this study, the status of a stream habitat was evaluated based on the body length and biomass weight of benthic macroinvertebrates of the family Baetidae. Following the renewal of the mining water treatment plant, the abundance of Baetidae assemblages recovered to a level comparable to that of a reference site. However, relatively low values were found for both body length and biomass weight in Baetidae species inhabiting the reddened streambed area, suggesting that the habitat has not yet been completely recovered despite the recovery of the abundance of the Baetidae assemblages. Therefore, continuous investigation and evaluation of this disturbed stream are necessary until their growth conditions of the habitat have functionally recovered.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.3
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• pp.445-455
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• 2007

This study surveyed university students in the Seoul area regarding their awareness of family restaurants and visiting experiences. Frequency analysis was used to study the data. Most of the repliers (92.0%) had visiting experiences and visited on weekends (72.4%), paying \$10,000{\sim}15,000$ for meals. In correlation analysis of the general characteristics and reasons for visiting, there were significant differences according to gender (p<0.01) and major study area (p<0.005). During visits the factor considered most important relative to the surroundings was food styling. The factors valued most highly when selecting a family restaurant were "good taste" (43.5%) and "good discounts" (26.3%) respectively. The favorite family restaurant was Outback Steakhouse (34.7%), and 86.4% of repliers had used a membership card, with 46.9% being satisfied with using the membership card. The conditions for using a family restaurant and satisfaction differences in each category, included: the amount of food (p<0.1) for the number of visits, taste (p<0.01), food shape and styling (p<0.05), surroundings (p<0.1), and interior (p<0.05): and for the meal fee per person, price (p<0.05) and sanitation (p<0.05), all showing significant differences as reasons for using the restaurants. In the factor analysis of nine categories, three factors: service, food, and economics were acquired, and their Cronbach's ${\alpha}$ values were 0.778, 0.671, and 0.587. Satisfaction toward food and service had a positive correlation of 0.457. Satisfaction toward food and economics increased a family restaurant's overall satisfaction score, and satisfaction toward service did not have a significant influence.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.472-478
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• 2009

Pine (Pinus densiflora) forests of 58 sites on the ridge of the Baekdudaegan, South Korea were classified by applying the phytosociological method and TWINSPAN. The floristic composition and life-form characteristics of the vegetation types analyzed and documented. The vegetation types were classified into five groups including four groups of Carex humilis var nana type and one group of Abies koreana-Sasa borealis type. Compositae was the most diverse family (26 species), Liliaceae (21 species), Rosaceae (18 species) and Betulaceae (11 species) whereas 27 families were represented by only one species. Taxonomically, Compositae was the most diverse (17 genera), Liliaceae and Rosaceae(12 genera) whereas 41 families were represented by only one genus. The Fagaceae was the most important family in total coverage (19.0) and followed Pinaceae (16.7) and Ericaceae (15.1). Five families such as Compositae, Liliaceae, Rosaceae, Betulaceae, and Umbelliferae contributed little to total coverage, although represented by numerous species. In the correlation between species richness and life forms, the species richness was highly correlated with growth and disseminule forms. In general, the correlation coefficients between life forms represented lower values than those between species richness and life-forms.

• Journal of the Korean Home Economics Association
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• v.24 no.2
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• pp.37-50
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• 1986

A nutrition survey of 128 perschool children, 4 to 6 years old, in the Saemaul Youlgok day care center, located in one uplane, overpolulated, poor area of the city of Seoul, sponsered by the Korean Red Cross Society, was undertaken between August 21 and 31, 1984, to investigate dietary and nutritional status. RESULTS: Mean values of height, weight, arm circumference, girth of chest, and head circumference ranged from 95 to 100% of KIST mean. However, 4.8~14.2% of the subjects were assessed as undernourished in terms of 'weight for height'. Mean hemoglobin vcalue was 12.1±0.7gm%, and mean hematocrit value was 38.5±2.2%; 4.1% of the subjects were proven to be anemic according to the criterion of hemoglobin established by the ICNND. Mean urinary urea nitrogen/creatinine ratio was 11.4±3.8. Regarding mean energy and nutrient intake, the following percentages had intakes below two-thirds of the 1985 RDAs: 28.8% of children, for protein; 48.8% of children, for iron; and 28.8% of children, for calcium. About 25% of children had vitamin A intake below one-third of the recommended allowance. Carbohydrate provided 71% of total energy intake; protein accounted for 13%; fat provided 16%. Energy intake was divided among breakfast, lunch, dinner and snacks in a percentage ration of 19:26:21:34. The lunch, and snacks which were served at the day care center provided 36.5~79.1% of daily energy and nutrient intake. The survey clarified that the day care feding largely supplemented the inadequate dietary intakes of these young children at home. According to factor analysis of energy and nutrient intake, there were two factor groups : the first factor group, for energy, protein, carbohydrate, iron and niacin, mainly provided by grains; and the second factor group, for calcium, vitamin A, thamin, riboflavin and ascorbic acid, provided by vegetables, fruits, milk and milk products. The survey also revealed significant correlation coefficients between family factors such as family income, educational level of parents, and number of children; and dietary or nutritional status of the subjects.

• Korean Journal of Child Studies
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• v.11 no.1
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• pp.58-71
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• 1990

The purpose of the study was to investigate the mother-child interactions in terms of maternal child- rearing behavior, maternal self-esteem, and their school-age children's self-esteem. The subjects were, all living in the Seoul area. A pre-test was conducted twice on 98 subjects. Each time the values of Chronbach's ${\alpha}$ were obtained on maternal behavior, maternal self-esteem and children's self-esteem. Data analysis was by ANOVA, Pearson's product-moment correlation. multiple regression analysis. Chronbach's ${\alpha}$, and factor analysis. Children's self-esteem was positively related (1) to family background factors:educational level, employment status of mothers, social economic status, and number of siblings (2) to maternal self-esteem and (3) to maternal child-rearing behavior in the dimensions of affection, acceptance, and encouragement of independency. Children's self-esteem was negatively related to maternal child-rearing behavior in the dimensions of hostility, rejection and encouragement of dependency. The relative importance of independent variables on children's self-esteem was found to be in the following order:mother's educational level. social economic status, and number of siblings (${\beta}=0.5935$, p< .001), maternal child-rearing behavior in the affection-hostility dimension (${\beta}=0.0849$, p< .001), and in the acceptance-rejection dimension(${\beta}=0.0365$, p< .05). The regression model showed that 25 percent of the children's self-esteem could be accounted for by family background factors. and maternal child-rearing behavior in the affection-hostility dimension and the acceptance-rejection dimension ($R^2=0.25$).

• Journal of Families and Better Life
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• v.27 no.6
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• pp.125-139
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• 2009

This experiment was conducted in order to examine what consists of romantic beliefs of college students, the overall tendency of the beliefs and motivation of marriage, the differences in the belief and motivation of marriage, and the influence of the beliefs toward it. A survey method was used and 394 students participated in this study. The major results of this study were as follows: First of all, there are four components in students' romantic beliefs, which are almighty love, destined love, hopes for romantic love, and only one & true love. Second of all, the students somewhat showed high level of romantic beliefs. This resulted due to the high level of romantic love but low level of only one & true love. Moreover, their motivations toward marriage which consists of intimacy and economic needs, were seen as the most important values in determining marriage. However, marriage due to social impact and the needs for personal growth were found to be placed in the lowest. Thirdly, male students in particular, showed higher beliefs in almighty love and destined love. The students of religion reported higher beliefs in destined love and only one & true love. Moreover, students who have a partner also showed higher beliefs in almighty love and only one & true love. On the other hand, for motivation of marriage, students showed higher inclination to choose for the desire for large families and children as their motivations, particularly for males. Students in the lower age group also showed higher inclination to choose for intimacy and economic needs as their motivations. Finally, according to the result of the hierarchical regression analysis, the higher the students' beliefs for destined love and the lower it is for hopes for romantic love, predicted higher possibility for the social impact and the needs for personal growth as their motivation of marriage. Moreover, the higher the belief for destined love and hopes for romantic love, the higher it is of their inclination to consider intimacy and economic needs for their motivation of marriage. Lastly, the higher it is for the students' belief toward almighty love, the higher it is for one to marry with a consideration and desire for large families with children.

• Journal of the Korean Home Economics Association
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• v.41 no.10 s.188
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• pp.149-171
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• 2003

This study was carried out as a basic fundamental research to propose a theoretical framework for Home Economics curriculum. This research employed the Delphi Method to reach a consensus with the experts in each related educational field of study for putting forth a newly proposed theoretical framework of a Home Economics curriculum. The finally proposed theoretical framework will definitely play a crucial role in establishing a standard framework for educational goals and curriculum content for Home Economics curriculum since it is put forth with a strong agreement from a high proportion of the expert groups. Results on the nature and characteristics of, structural framework of curriculum contents, and literacy through Home Economics were drawn from the 3-round Delphi survey: 1. Home economics has a liberal and practical-critical nature and it promotes enhancement of quality of life through a practical problem-solving process in maintaining family life. 2. The structural framework of the home economics curriculum contents is organized with three-dimensional components of content area (dimension 1), process area (dimension 2), focus of organizing content (dimension 3). 3. One's empowering capability through home economics education is proposed: inquiring knowledge and understanding phenomena for future society, solving practical problems in family life, developing higher order thinking skill, cultivating a positive attitude and a values system toward life.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1753-1759
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• 2006

Paenibacillus sp. HY-8 isolated from the digestive tracts of the longicorn beetle, Moechotypa diphysis, produced an extracellular endoxylanase with a molecular weight of 20 kDa estimated by SDS-PAGE. The xylanase was purified to near electrophoretic homogeneity from the culture supernatant after ammonium sulfate precipitation, gel filtration, and ionexchange chromatography. The purified xylanase exhibited the highest activities at pH 6.0 and $50^{\circ}C$. The $K_m\;and\;V_{max}$ values were 7.2 mg/ml and 16.3 U/mg, respectively, for birchwood xylan as the substrate. Nucleotide sequence of the PCR-cloned gene was determined to have the open reading frame encoding a polypeptide of 212 amino acids. The N-terminal amino acid sequence and the nucleotide sequence analyses predicted that the precursor xylanase contained a signal peptide composed of 28 amino acids and a catalytically active 19.9-kDa peptide fragment. The deduced amino acid sequence shared extensive similarity with those of the glycoside hydrolase family 11 of xylanases from other bacteria. The predicted amino acid sequence contained two glutamate residues, previously identified as essential and conserved for active sites in other xylanases of the glycoside hydrolase family 11.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.905-912
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• 2007

A novel ${\beta}-glucosidase$ gene, bglA, was isolated from uncultured soil bacteria and characterized. Using genomic libraries constructed from soil DNA, a gene encoding a protein that hydrolyzes a fluorogenic analog of cellulose, 4-methylumbelliferyl ${\beta}-D-cellobioside$ (MUC), was isolated using a microtiter plate assay. The gene, bglA, was sequenced using a shotgun approach, and expressed in E. coli. The deduced 55-kDa amino acid sequence for bglA showed a 56% identity with the family 1 glycosyl hydrolase Chloroflexus aurantiacus. BglA included two conserved family 1 glycosyl hydrolase regions. When using $p-nitrophenyl-{\beta}-D-glucoside$ (pNPG) as the substrate, the maximum activity of the purified ${\beta}-glucosidase$ exhibited at pH 6.5 and $55^{\circ}C$, and was enhanced in the presence of $Mn^{2+}$. The $K_m\;and\;V_{max}$ values for the purified enzyme with pNPG were 0.16 mM and $19.10{\mu}mol/min$, respectively. The purified BglA enzyme hydrolyzed both pNPG and $p-nitrophenyl-{\beta}-D-fucoside$. The enzyme also exhibited substantial glycosyl hydrolase activities with natural glycosyl substrates, such as sophorose, cellobiose, cellotriose, cellotetraose, and cellopentaose, yet low hydrolytic activities with gentiobiose, salicin, and arbutin. Moreover, BglA was able to convert the major ginsenoside $Rb_1$ into the pharmaceutically active minor ginsenoside Rd within 24 h.