• The Korean Journal of Zoology
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• v.33 no.1
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• pp.45-52
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• 1990

In order to determine whether maturation inhibiting activity(MIA) in the cytoplasm of growing follicular oocytes would suppress the cleavage of the embryonal cells, the growing oocytes were fused with the 2 or 4 cell blastomeres and then examined for the nuclear phase of the fused giant cells 24 hr after culture. A significant number of the giant cells(60%) composed of growing mouse oocyte and 2 cell mouse blastomere(1/2) in interphase has contained 2 nuclei 24 hr after culture and most of the giant cells (90%) composed of the growing oocyte and 4 cell blastomere(1/4) also contained 2 nuclei after culture. The unfused blastomeres or the isolated blastomeres cultured without fusion treatment cleaved one cell cycle under the same culture condition. In contrast, the nucleus of the growing oocytes was disintegrated and the chromosome condensed when fused with 2 cell blastomere in mitosis. The growing rat oocytes also suppressed the nuclear disintegration of the mouse embryonal cells during culture. The data presented here showed that MIA in the growing mammalian oocyte inhibited the cleavage of the embryonal cells in interphase stage, but not in milosis stage.

• Proceedings of the Technology Innovation Conference
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• 1997.07a
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• pp.124-159
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• 1997

This paper examines a significant example of accumulation of technology in post war Japan - the development process of the videocasstte recorder (VCR) for home use, and the dynamic evolution process of the mass market. The purpose of analyzing the Japanese home VCR industry is to clarify how and why only the Japanese makers had succeeded in developing home VCR and dominated. the global mass market and to make clear the dynamic process of industrial evolution. This study found out the following facts; 1) Japanese inter-firm interactions in the VCR have been carried out by the structure of "the competition and cooperation among the engaged players" form the initial stage, to growing, and maturing stage. 2) The process of competition and cooperation produced the revolutionary innovation through a continuous systematic development process in the R&D phase. 3) The process of competition and cooperation accelerated the speed of technological progress and the rapid growth of the industry in the growing and maturing stage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.399-406
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• 1997

This research was carried out to investigate the effect of zeranol injection on dry matter(DM) and nutrient intake requirement by growth stage of early castrated bull with 3 treatments(bul1, steer, steer+zeranol) with 28 Holstein bull at National Livestock Research Institute. The main results were as follows: DM intake at growing and fatting stage was the highest in steer groups, that the highest in bull groups at finishing stage and overall mean DM intake was 5% lower at steer+zeranol groups compared to bull and steer, respectively. Net energy intake at finishing stage was the highest as 35.49 Mcal at bull groups, while overall mean net energy intake was 101 - 109% of NRC requirement without significant difference. Concentrate intake to body weight was 1.68- 1.82, 1.91 -2.08 and 1.81 -2.05% at growing, fatting and finishing stage, respectively. Overall mean concentrate intake to body weight at steer groups was 1.94%, which is 1.8 and 1.81% higher compared to bull and steer+zeranol groups, respectively. Feed conversion ratio(DM) during overall period was the worst at steer groups as 9.321g, and also net energy conversion ratio was similar to DM conversion ratio.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.200-206
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• 2010

Banaba, Lagerstroemia speciosa (L.) Pers. (Lythraceae) is a tree that grows in the tropic islands of the Pacific. This plants are used for medical purposes in the world. The components of L. speciosa were analyzed for the contents according to growing stages at leaves. The distributions of the corosolic acid ($2{\alpha}$, $3{\beta}$-dihydroxyurs-12-en-28-oic acid), phytol, campestrol, and vitamin E were rich among samples in this study. These were contained much fatty acids. The mean content of palmitic acid was from 2.4% across all growing stages, varying from 2.15% for young leaves with the lowest content and 2.86% for fallen leaves with the highest content. Oleic acid, linoleic acid, and linolenic acid were contained nearly mean 2.0% in all leaves of banaba. Our results have shown that the phytochemical profile of young L. speciosa leaves differs quite radically from that of old L. speciosa leaves. In addition, these subdividing results according to plant growth should allow future researches to conduct targeted experimental studies and use of particular medical components of interest, examining chemical variation on the inter-developmental levels.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.2
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• pp.117-122
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• 1997

This experiment was conducted to evaluate the forage yield and quality and the possibility to provide Festulolium bmunii(Festuca pratensis $Huds{\times}Lolium$ mult~jlotum Lam.) as forage source in Korea. The Festuloliurn braunii were harvested at boot, heading and anthesis stage, respectively. The field trials were performed 6om 1994 to 1996 at the forage experimental field, College of agriculture, Chunpam National University. The results obtained were summarized as follows: 1. The date of boot, heading and anthesis stage of Festulolium bmunii observed in Taejon were May 12, May 23 and June 1 in 1995, and June 1, June 4 and June 9 in 1996, respectively. Winter survival percentage of Festulolium bmunii war ranged 6om 96% to 98% and summer survival percentage were 75-86%. It would suggest that Festulolium brawlii persisted well in the aspect of overwintering, while it wasn' t widely adapted to drought and high temperature in Taejon regions. 2. The CP content and DMD of Festulolium bmunii tended to decline as the growth stage advanced. The CP content and DMD of Festulolium bmunii were high at the boot stage and those at the anthesis stage were low. But fiber contents at the boot stage were lower than those at anthesis stage(P< 0.05). The yields of the DM and DDM with advancing the growing stage tended to increase, while there was no difference in the CPDM yields among stages. On the otherhand, the yields of DM and DDM at the anthesis stage were the highest (P< 0.05), but there was no difference in CPDM yield among stages. Based on the results mentioned above, it is suggested that Festulolium b m n i i has a possibility to use until the anthesis stage under the cutting regimes and that it has a potentiality to provide one of a good forage sources. %'ifqqiZ 43q *(College of Agriculture, Chungnam National Un~versity, Taejon 305-764, Korea)

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.659-662
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• 1999

As utility pollution take a growing interest, ac/dc converter optimizing utility condition has been vigorously studied in decades. In this paper three phase DCM converter is analyzed and equations for average input currents are presented. Also relationships of voltage gain & duty according to angular velocity are presented and variable frequency controller is implemented using reset integrator which is designed in detail. In result power factor and THD characteristics of 3-stage and 4-stage operation ae compared respectively.

• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.455-462
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• 1999

This study was designed to investigate the number of the growing and mature follicles in each stage of estrus cycle in mature rats. Eighteen mature rats(Sprague-Dawley, initially 190~230gm) were randomly alloted into 4 groups(proestrus, estrus, metestrus, and diestrus) according to estrus cycles. The uteri and ovaries of rats were collected and then alternative sections of paraffin embedding ovaries were stained with H-E. Numbers of large, middle and small follicles or only large and middle follicles from secondary and tertiary follicles were investigated by LM photography of preparations. Small follicles were defined as secondary follicles with 2~5 cell layers of granulosa cells surrounding the oocyte, and middle follicles were defined as secondary follicles with more than 5 cell layers or with early signs of antral cavity or with more than one small cleft on either side of the oocytes and large follicles were defined as tertiary follicles with a single medium or large antral cavity. The number of follicles in a pair ovary per rat was appeared to be ranged from 207 to 370 and the mean number of these follicles was $270.4{\pm}52.6$ and the mean number of follicles per ovary was $134.9{\pm}32.0$. The mean number of large, middle and small follicles per ovary was appeared to be $16.4{\pm}4.4$($12.2{\pm}3.3%$), $36.2{\pm}8.6$($26.8{\pm}6.4%$), and $82.7{\pm}24.0$($61.3{\pm}17.8%$), respectively. The mean number of large and middle follicles in each stage group of estrus cycle was appeared to be $17.8{\pm}2.1$ and $38.3{\pm}7.4$ at proestrus stage group, $15.7{\pm}5.2$ and $38.0{\pm}10.0$ at estrus stage group, $16.5{\pm}3.5$ and $33.8{\pm}7.0$ at metestrus stage group, $16.7{\pm}5.8$ and $29.7{\pm}5.5$ at diestrus group, respectively. In histological findings of large follicles during each estrus cycle, the large follicles in proestrus group contain single small antrum, thick granulosa cell layers, and were $300{\sim}500{\mu}m$ in diameter and were growing follicles with PCNA-positive cells in the granulosa cell layers, and other luteinizing follicles of proestrus cycle stage were decreased in size and were thicker in wall thickness and more luteinized than those in metestrus and diestrus stage groups. The large follicles in estrus stage group contain thick granulosa cell layers and nonprominent cumulus-oocyte complexes in antrum, and were $400{\sim}700{\mu}m$ in diameter and were growing follicles with PCNA-positive cells in the granulosa cell layers. The large follicles in metestrus and diestrus stage groups contain enlarged antrums, thinner layers of walls and prominent cumulus-oocyte complexes, and were $700-950{\mu}m$ in diameter, and were nongrowing follicles without PCNA-positive cells or another large follicles contain cells with dark stainability and distinct boundary.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.5
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• pp.393-399
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• 2004

Annual reproductive cycle of Siganus canaliculatus was studied based on monthly variation of gonadosomatic index (GSI) and histological changes of gonads. Samples were monthly collected by a set net along the southern coast of Jeju Island, Korea from January to December, 1996. Variation of the monthly mean GSI values showed similar trends in female and male. The GSI values increased from June and reached a peak in the spawning season in July $(9.65{\pm}1.96\;in\;females,\;10.00{\pm}4.27\;in\;males)$, and decreased rapidly thereafter. Female hepatosomatic index (HSI) values ranged from $1.26{\pm}0.22\;(in\;April)\;to\;2.34{\pm}0.39$ (in July), and male HSI values ranged from $1.27{\pm}0.21\;(in\;April)\;to\;1.87{\pm}0.30$ (in October). Annual reproductive cycle was classified into the following successive stages: in female, growing stage (from February to June), mature stage (from June to July), ripe and spawning stage (from July to August), recovery stage (from August to March); and in male, growing stage (from January to June), mature stage (from June to July), ripe and spent stage (from July to August), and recovery stage (from August to April). Based on these data, this species has a group-synchronous oocyte development and one spawning season a year.

• Korean Journal of Ichthyology
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• v.12 no.1
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• pp.62-70
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• 2000

Annual reproductive cycle of the file fish, Stephanolepis cirrhifer (Temminck et Schlegel), was histologically investigated. Samples were collected monthly in the coastal waters of Chungmun, south of Cheju Island, Korea from July 1997 to June 1999. In males and females of S. cirrhifer, the values of GSI (gonadosomatic index) were similar to the changes of water temperature and day length. GSI values in males and females were reached the maximum in June. Reproductive cycle could be divided into the following successive stages: in females, growing stage (February to May), mature stage (May to June), spawning stage (June to August), degenerative and resting stage (September to December), and in males, growing stage (February to April), mature stage (May to June), spent stage (June to August), degenerative and resting stage (September to January), respectively. Throughout histological observation of the ovary in the spawning period, the species belong to an asynchronous and multiple spawner.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.2
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• pp.113-118
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• 1989

This experiment was carried out to compare chemical composition, TDN yield of corn-soybean intercropping and corn monocropping forage plants at different harvesting time and obtained the following results. 1. In both cropping systems, the content of chemical composition of forage were changed same pattern in growing stage. The content of crude protein in corn-soybean intercropping forage at yellow stage increased more than that of corn nonocropping forage, while the crude fat in corn monocropping forage plants increased than that of corn-soybean intercropping forage plants at mature stage. 2. The crude fiber, crude ash, ADF content of forage plants in both cropping system decreased same pattern in growing period, however, NFE content of forage increased with maturity. 3. TDN yield of corn-soybean intercropping and corn monocropping forage plants at yellow stage obtained similar results and TDN yield per 10a in intercropping and monocropping were 1006.lkg and 978.6kg, respectively. 4. Consequently, corn-soybean interaopping system could be increased crude protein yield without decreasing of dry matter yield in comparison with corn monocropping system for corn silage.