• 한국동물위생학회지
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• 제31권1호
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• pp.79-86
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• 2008

In this study two stage investigation was used for seroprevalence of Neospora caninum in cattle between January, 2005 and November, 2007; first stage was to examine positiveness of the farms selected randomly, second was to test all individual cow in positive farms. A total of 850 sera were collected from 170 farms for the first stage, and positive rate of farm and head were 23.5% (40/170farms) and 7.5% (64/850heads), respectively. Seroprevalence of Holstein cattle was much higher than that of Hanwoo. In second stage positive rate of cow was 18.9% (246/1,303head), but seroprevalence of farm was very variable (1 - 90.5%). It was supposed that 3 farms with high positive rate had some risk factors to be infected; raising dogs in the same farm, location of hill-side where is easy to contact with wild animals.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.332-339
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• 2010

Maturity and spawning of the snailfish, Liparis ochotensis was investigated based on samples collected by gill net in the East Sea of Korea from December 2008 to December 2009. The average total length of L. ochotensis was 63.4 cm and 64.1 cm for females and males, respectively. Gonadosomatic index (GSI) began to increase in July, reaching a maximum in November, then began to decrease in December. Monthly changes in the GSI values of L. ochotensis were similar for females and males. Annual reproductive cycle of this species can be divided into five successive stages in females: early growing stage (May), late growing stage (June to July), mature stage (August to September), ripe and spent stage (September to December), and recovery and resting stage (January to April). Males show four successive stages; growing stage (May to July), mature stage (August to September), ripe and spent stage (September to December), and recovery and resting stage (January to April). Relationship between total length (TL) and fecundity (F) was F=$0.00003TL^{4.002}$ ($R^2$ = 0.703), and F increased with TL. Total length at 50% group maturity was estimated to be 55.8 cm. Our findings suggest that the spawning period takes place from September to December, with the main spawning period occurring from October to December.

• 스마트미디어저널
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• 제11권7호
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• pp.19-27
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• 2022

인공지능 소프트웨어 시장은 2020년부터 2025년까지 6배 규모로 성장할 것으로 예상된다. 그러나 소프트웨어의 개발 절차가 표준화 되어 있지 않고 비용 산정 기준이 없다. 이에 따라 인공지능 소프트웨어 개발 업체마다 각자의 개발 절차에 따른 투입 공수를 산정하고 이를 개발비용의 근거로 제시하고 있으나 개발업체마다 상이한 개발 절차와 소요 공수의 규모 때문에 품질과 비용에 대한 불신이 커지고 있다. 본 연구에서는 대량의 데이터로 학습을 진행하고 알고리즘을 도출하여 적용하는 인공지능 기반 소프트웨어의 개발단계를 정의하고 개발업체들을 대상으로 개발단계별 소요 공수에 대한 설문을 진행하여 소요 공수를 수집하였다. 수집된 개발단계별 소요 공수간의 상관분석과 회귀분석을 실시하여 개발단계별 소요 공수 예측 모형을 도출하였으며, 모형을 실험한 결과, 수집된 소요 공수 대비 92%의 정확도를 보였다. 본 연구에서 제안한 소요 공수 예측 모형은 공수와 비용을 추정하는데 간단하게 활용할 수 있는 도구가 될 것으로 기대된다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권7호
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• pp.873-879
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• 2010

We investigated the effect of various concentrations of taurine during in vitro fertilization (IVF) on the embryonic development up to the blastocyst stage of bovine oocytes fertilized with three different Japanese Black bulls (Bull A, B and C). In vitro matured oocytes were fertilized with various concentrations of taurine (0, 1, 10, 50 and 100 mM) in the presence of 2.5 or 5.0 mM caffeine plus $25{\mu}g$/ml heparin (CH) for 6 hr or $100{\mu}g$/ml heparin (H) for $24{\pm}2$ h. After IVF, the cleavage rates from the 2 to 16 cell stage determined at 3 days and the development rates up to the blastocyst stage determined at 7-8 days from the onset of IVF were assessed. Although the cleavage rates for the taurine concentration groups were not significantly increased in any of the three bulls in the CH groups, the development rates up to the blastocyst stage of the 50 mM taurine group of Bulls A and B, and of the 1 to 50 mM groups of Bull C were increased (p<0.05) compared to those of the control (0 mM taurine) groups. On the other hand, none of the bulls in the H groups showed any significant increase either in the cleavage rates or blastocyst formation rates in any taurine concentrations groups compared with those of the control groups. These results indicate that the addition of 50 mM taurine to a fertilization medium containing caffeine and heparin may stimulate embryonic development up to the blastocyst stage when fertilized with different bull semen.

• 한국패류학회지
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• 제29권2호
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• pp.97-103
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• 2013

In the present study, we monitored the early development of Saccostrea kegakia subtropical oyster species distributing on rocky intertidal off the northern Jeju Island using scanning electron microscope (SEM). The female oyster collected in early August, 2012 were fully mature exhibiting relatively small eggs ($46.5{\pm}1.4{\mu}m$ in diameter) in the gonad, while testis of the mature male oysters were filled with fully developed sperms of 36.9 ${\mu}m$ in length. The fertilized eggs developed into 2-cell stage with polar body after 1 hr 20 min of fertilization, then followed by Morula stage (3 hr 20 min), Blastula stage (4 hr 50 min), Gastrula stage (7 hr), and trochophore larvae stage (9 hr 30 min). The observed early development of S. kegaki in this study was similar the early development of other oysters, although size of the fertilized eggs were somewhat smaller.

• 드라이브 ㆍ 컨트롤
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• 제10권1호
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• pp.7-13
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• 2013

Port size 80mm or above large-flow type solenoid valves are extensively used in dust collector and power plants. These multi-stage solenoid valve have few problem. first, multi-solenoid valves are almost depend on imports and there are weak in the brine environment and the low energy efficiency. Because these problem, increased the necessity of research on the development of large flow and high pressure type solenoid valves. In this study, describe the design method of multi-stage solenoid test bench and confirm the influence valve performance on several parameter such as diaphragm orifice diameter. At first, each part has modeled by AMESim simulation tool and combining them. This AMESim virtual multi-stage solenoid valve found influence valve performance on the valve parameter. Finally developed the multi-stage solenoid valve and verified that performance on experimental result.

• 한국지역사회생활과학회지
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• 제26권1호
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• pp.51-61
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• 2015

This study introduces the possibility of the $9^{th}$ stage by Joan Erikson by adding Erikson's original theory of the $8^{th}$ stage and validates the gerotranscendece scale in later life. For this, 10 items from Erikson's scale was examined and the relationships among gerotranscendence, ego-integrity, and wisdom were examined using a sample of 244 elderly individuals over the age of 60. According to the results, the measurement of gerotranscendence based on Erikson was applicable to the Korean sample. In addition, ego-integrity and wisdom influenced gerotranscendence in later life. Based on these results, the validity of gerotranscedence, psychosocial development in the $9^{th}$ stage, discussed and the utility of Erikson's theory is emphasized.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.749-758
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• 2007

Learning has become an important aspect for any organization to stay relevant and competitive in the corporate world of survival. In construction industry, the international construction joint ventures (ICJVs) provide an excellent platform with opportunity of learning among partners seeking to develop new area of competency and improve their overall competitiveness for their next project endeavor. This paper discusses the development of a conceptual model of effective learning in ICJVs using four major stages of development in a typical joint venture (JV) 's process. The study identified that there are three key constructs that contribute to effective learning comprising learning conditions in the JV's pre-inception stage, success factors of JV for learning in the forming & organizing stage, and learning actions in the implementation & adjustment stage. The effective learning outcomes are measured by the characteristics of learning organization during the JV's completion & evaluation stage. Details and issues of each stage and the methodology of research will be presented and discussed.

• 한국가축번식학회지
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• 제16권4호
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• pp.341-346
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• 1993

The development of isolated blastomeres from mammalian preimplantation embryos has been basically studied for the multiplication of embryos from superior animals. Therefore, this study was investigated the effect of co-culture with mouse fetal fibroblast cells(MFFC) on in vitro development of blastomeres from mouse preimplantation embryos. Mature female ICR mice were treated with hormone to induce superovulation and embryos were collected at each 2, 4, and 8-cell stage. Then, after removing zona pellucida with protease, blastomeres were isolated by micropipetting, or reconstituted with different stage blastomere, and incubated for 72 hrs either in T6 or TCM199 or on the monolayer of MFFC, which was prepared with fibroblast cells from 14∼14 day mouse fetus. After incubation, we examined their development rates every day and the nuclei numbers of each blastocyst by Hoechst-33342 staining. In the development rates of blastomeres, there were no significant differences between media but the higher rateswere found in the monolayer of MFFC, regardless of reconsititution. In addition, blastomeres cultured with MFFC had slightly greater number of nuclei than those cultured in single media. Generally, the higher development rates of blastomeres were found from earlier stage embryos than the later ones, regardless of culture conditions. Reconsitituted blastomeres had more nuclei but did not show the higher development rates, compared to the single blastomeres. Taken together, our results suggest that co-culture with MFFC have a beneficial effect on the in vitro development of blastomeres from mouse embryos.

• 한국수정란이식학회지
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• 제14권1호
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• pp.23-29
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• 1999

The objectives of the study were to establish sperm separation method and duration of insemination for bovine IVF. Oocytes from slaughterhouse ovaries were matured and fertilized using general protocol. After 18 or 42 h of insemination, six to ten embryos were placed into a 30${mu}ell$ drop of each medium, and the embryos were examined 7~10d post in semination without medium renewal. First, we compared Percoll gradient will swim-up technique for sperm separation. There was no difference in cleavage rates between them, but the development rates over morula stage of oocytes fertilized with sperm separated by Percoll gradient was significantly higher than that sperm selected by swim-up technique (p<0.05). Second, we evaluated development of bovine embryos derived from the IVF procedure with different durations(18 vs 42 h) of fertilization. There was also no difference in cleavage rates, but the development to blastocyst stage of oocytes exposed in cleavage rates, but the development to blastocyst stage of oocytes exposed to sperm for 42 h was significantly higher than that exposed for 18 h (p<0.05). In conclusion, Percoll gradient can be used for sperm selecton, improving of embryonic development. Also, 42h of IVF may improve the development of bovine embryos.