• 한국패류학회지
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• 제1권1호
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• pp.5-12
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• 1985

The maturity of gonads, early development of the fertilized egg, spawning period, and morphogenesis of larvae in Limnoperua fortunei were studied from October, 1981 to November, 1982 as on attempt to identify its life cycle. 1) Active motility of its sperm was observed at late May, and matured egg could be found at late June. 2) It was estimated that the spawning was occured from late August. This species was belong to the short-term breeder because it finished its spawning within 20 days. 3) It has free-living trochophore and D-shaped larva stage. The shell lengths of early, middle, and D-larval stage were $140.0{\mu}m$, $167.6{\mu}m$ and $210.0{\mu}m$, respectively. The shell heigths of each stage were $97.3{\mu}m$, $137.6{\mu}m$ and $178.2{\mu}m$, respectively.

• 아동학회지
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• 제26권1호
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• pp.47-59
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• 2005

The Early Life Problems Scale consisting of 5-point rating for each item was prepared from the results of a questionnaire of 163 items with two sub scales constructed on the basis of Diagnostic Classification: 0-3. Respondents were 361 parents with newborn to 3-year-old children (197 boys and 164 girls). Hypothetical constructs of mental and developmental problems were identified by exploratory factor analysis. The resulting 22 factors explained 58.5% and 72.9% of the common variance for scales I and II, respectively. The rotation procedure yielded 134 items of which 118 had factor loadings of more than .30. Face validity was obtained on the basis of 18 items. The coefficients of correlation between and within factors suggest that there are interrelationships. The reliability of total scales by Cronbach's Alpha was relatively high.

• 아동학회지
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• 제26권1호
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• pp.155-167
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• 2005

Korean infants' use of gesture was examined with 45 10-to 17-month olds. The mothers of infants were asked to check each word in the MacArthur Communicative Development Inventory-Korean (MCDI-K) vocabulary checklist if their infant had a gesture for a given word and to indicate what kind of early communicative behavior she showed in 5 different situations. The results show that infants in this study have 11 gestures, of which many are learned within the context of routines or games. Referential gestures were rarely reported. There was no positive correlation between the number of gestures and the number of expressive words. However, more qualitative measures on early communicative behaviors show that there was a positive correlation between "frequent use of gestures" and "try to communicate by verbal means".

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.681-684
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• 2008

The way to shorten a construction period is considered to an very important technology element as reducing the form work removal periods with promoting strength revelation own concrete. This study presents an experimental study on the development method, material for early strength concrete. The result is as follow : In OPC, the compressive strength has over 5MPa after 26hours at 20$^{\circ}C$ curing and another 36hours at 10$^{\circ}C$ curing. Used with early strength potland cement, the compressive strength has over 5MPa after 15hours at 20$^{\circ}C$ curing temperature and another 30hours at 10$^{\circ}C$ curing temperature.

• 한국생산제조학회지
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• 제18권6호
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• pp.614-620
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• 2009

A fuel tank of a vehicle is an important part due to its flammable contents ant its importance during crash conditions. Therefore, the fuel tank's design should be assessed for durability and robustness to ensure safety during the early development phase. Previously, evaluation for the durability was done by testing in physical driving conditions which could only be done after the completion of the vehicle. Computation simulation is a more effective method to evaluate the strength and durability of the fuel tank during the early stage. In this paper, two outstanding computational simulation methods are studied. One evaluates PV cycle fatigue due to build up pressure in the fuel tank and the other evaluates the PSD vibration fatigue from modal characteristics. The results show that computational methods agree with physical tests and are thus suitable to analyze the strength and durability of the fuel tank at early development phase.

• 아동학회지
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• 제21권2호
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• pp.189-212
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• 2000

This study investigated the adaptability of 3rd grade children in Taejon who had started first grade at 5 years of age. Subjects were 64 third grade children, half of whom had started first grade at 5 years and half at 6 years of age. Thirty-four parents and 36 elementary school teachers were also sampled. The General Intelligence Test, the Learning and Thinking Ability Test, and the Socio-Emotional Development Checklist were administered to the children. Parents and Teachers responded to the Questionnaire on the Adaptability of Early Entrance Children. There were no statistically significant differences between children who started first grade at 5 and those who started at 6 years of age in their Intelligence scores, Learning and Thinking Ability scores, and the Socio-Emotional Development scores. Parents as sell as teachers felt that the early entrance system was positive for children.

• Food Science and Biotechnology
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• 제27권6호
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• pp.1865-1869
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• 2018

This study examined the effects of alfalfa seed germination on growth of Salmonella enterica. We investigated the population changes of S. enterica during early sprout development. We found that the population density of S. enterica, which was inoculated on alfalfa seeds was increased during sprout development under all experimental temperatures, whereas a significant reduction was observed when S. enterica was inoculated on fully germinated sprouts. To establish a model for predicting S. enterica growth during alfalfa sprout development, the kinetic growth data under isothermal conditions were collected and evaluated based on Baranyi model as a primary model for growth data. To elucidate the influence of temperature on S. enterica growth rates, three secondary models were compared and found that the Arrhenius-type model was more suitable than others. We believe that our model can be utilized to predict S. enterica behavior in alfalfa sprout and to conduct microbial risk assessments.

• 한국농촌건축학회논문집
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• 제26권1호
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• pp.33-40
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• 2024

In France, the popularization of social rental housing development for regional balanced growth has encountered difficulties due to the increasing costs of housing development in the regions. As a new solution, since 2010, efforts have been made to promote participatory housing in the regions. As of 2023, Strasbourg has 284 households participating in the participatory housing projects. The Strasbourg area has many abandoned houses, and the land is owned by local governments. The local authorities are providing such lands for participatory housing and have established the "Eco-quartier" support association to efficiently support the project and assist in resident-led participatory housing development. This study analyzes the development characteristics of 26 completed participatory housing projects in the Strasbourg area and examines the initial development stages of the representative case, the "Ecologis" project. The success factors of the "Ecologis" project were the active administrative support of the local government, promotion for member recruitment, and the role of "Eco-quartier" in providing expert support teams. In the initial development stage, it identifies the distinctions from a similar concept in Korea, "community housing," and presents implications for the revitalization of participatory housing.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.96-96
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• 2003

Nek2 (NIMA-related protein) is a mammalian cell cycle-regulated kinase that involves in chromosome condensation and centrosome regulation and NuMA (nuclear mitotic apparatus protein) is involved in spindle assembly during a cell cycle. The cellular distribution and organization of the centrosomal components is completely unknown during fertilization and embryonic development. We examined distribution of two well-known centrosomal proteins, Nek2 and NuMA in mouse gametes and embryos to get an insight in the reorganization of centrosomal proteins during germ cell development and early fertilization. Spermatogenic cells, gametes, and embryos were analyzed with anti-Nek2 or -NuMA antibodies by immunological assay, RT-PCR, and overexpression through gene transfection. Mitotically or meiotically active spermatogenic cells were intensively stained with these antibodies in both centrosomes and cytoplasm, whereas the oocytes showed different staining patterns depending on the meiotic stages. During maturation, GV, GVBD, and MI stage were clearly stained with NuMA antibody in the nucleus or cytoplasm at MII. Also, Nek2 was detectable in cytoplasm as scattered spots or chromosome associated at MII. In early developmental embryo, NuMA was detected in nucleus of each blastomere, while Nek2 was detected in cytoplasm. In contrast to previously reported results, Nek2 and NuMA were detected in both decondensing head, and the centriole of demembranated and decondensed sperm or whole body of trypsin-treated sperm for Nek2. During meiotic progress in oocytes, transcripts levels were the highest in MI stage and then downregulated in MII. Also, it shows dramatically change in early developmental embryos, firstly, it was increased until 4 cell stage and reduced in 8 cell stage, and finally, transcript levels were upregulated until blastoscyst. This finding suggests that cnetrosomal component may play an important role in reorganizing of functional centrosome during fertilization process and subsequent development.

• 한국수정란이식학회지
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• 제11권3호
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• pp.201-210
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• 1996

This experiment was carried out to evaluate the effect of early mouse embryonic development in vitro by co-culture with bovine and porcine oviductal epithelial cells (BOEC and POEC). The 2-cell embryos were collected from the oviducts of the superovulated and mated cultured in D-PBS /15% FCS at 48 hours after hCG injection. The in vitro developmental rate of blastocyst formation in the embryos were examined under the fllowing treatments; 1) TCM 199 added 15% HCS, 2) Ham's F-10 added 15% HCS, 3) MediCult IVF medium, 4) TCM 199 added 15% HCS + BOEC, 5) TCM 199 added 15% HCS + POEC, 6) Ham's F40 added 15% HCS + BOEC, 7) Ham's F-10 added 15% HCS + POEC,8) MediCult IVF medium + BOEC, 9) MediCult IVF medium + POEC. For a comparative study of in vitro development for 96 hours after hCG injection, were cultured with oviductal epithelial cell and media only. The obtained results were 2-cell embryos developed to the blastocyst stage in TCM 199, Ham's F-10 and MediCult IVF medium at the rates of 84.4,83.2 and 81.6%. respectively. The higher developmental rates(91~97%) of blastocyst formation was appeared when the embryos were co-cultured with a monolayer of bovine or porcine oviductal epithelial cells in TCM 199 or Ham's F-10 and MediCult IVF media. No significant difference in developmental rates was shown between bovine and porcine oviductal epithelial cells but significant difference in co-culture system in comparison between media only system and co-cultures. In conclusions, oviductal epithelial cells, BOEC and POEC, when co-culture with mouse early embryos improved the rates of development, blastocyst and hatching. Therefore, it is suggested that co-culture system using oviductal epithelial cells improve early embryonic developtnent in mouse.