• 환경생물
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• 제22권3호
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• pp.376-380
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• 2004

In August 2003, the water quality of offshore waters along the Incheon coast of Korea was evaluated by biological evaluation using gametes, embryos and early development systems of a starfish species (Asterina pectinifera). As the result of performing biological evaluations on seawater samples from a total thirteen sites, the formation rate of normal larva was 16-68%. At seawater sample from site 5 and 13, formation rate of normal larva averaged 16%, the most abnormal rate hindering the early embryo development of the experimental animal, while that of site 3 averaged 68%, the highest formation rate of normal larva. At seawater sample from site 2, 4, 7, 9, 10, 11, 12, formation rate of normal larva averaged 33-54%, those which damage the development of early embryos slightly. At seawater sample from site 1, 5, 6, 8, 13, formation rate of normal larva averaged 16-28%, those which damage the development of early embryos strongly.

• Journal of Ceramic Processing Research
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• 제20권1호
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• pp.59-62
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• 2019

Y2O3-MgO nanocomposites are promising materials for hypersonic infrared windows and domes due to their excellent midIR transmittance and mechanical properties. In this work, influence of SPS heating rate on the microstructure, IR transmittance, and mechanical properties of Y2O3-MgO nanocomposites was investigated. It was found that the average grain size decreases with a decreasing heating rate, which can be attributed to high defect concentration by rapid heating and deformation during densification. Also, the residual porosity decreases with a decreasing heating rate, which is ascribed to the enhancement of grain boundary diffusion by a large grain-boundary area (a small grain size). Consequently, high transmittance and hardness were attained by the low heating rate. On the other hand, the mechanical strength showed little difference with the heating rate change, which is somewhat different from the general knowledge on ceramics and will be discussed in this letter.

• 한국군사과학기술학회지
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• 제18권2호
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• pp.109-114
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• 2015

A method to compensate a bias hysteresis error of the ring laser gyro using the rate of temperature is proposed in this paper. Until now, we generally have measured and compensated the error of gyro and accelerometer using the temperature. However, we utilize the measured values of the temperature dependent error elements on the temperature rate in navigation system level. We show through experiments that the proposed method can improve the navigation performance and be very effective.

• 한국수정란이식학회지
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• 제23권4호
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• pp.291-298
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• 2008

We separately cultured follicular oocytes collected from individual ovaries of slaughtered Korean native cows and examined both the embryonic development rate and pregnancy rate after embryo transplantation according to the meat yield and quality grades of the source beef carcass. Oocytes from meat yield grade B cows exhibited a higher fertilization rate and embryonic developmental rate to the eight-cell stage than oocytes from grade A or C animals (p<0.05), but there was no significant difference in rate of development to the blastocyst stage among meat yield grades A, Band C. The oocyte cleavage rate and development rate to the eight-cell stage from meat quality grade 3 cattle was higher than grades 1++, 1+, 1 and 2 (p<0.05). Embryos derived from grade animals displayed a development rate to the blastocyst stage of 19.4%, which was also higher than all other meat quality grades (p<0.05). Transplantation of in vitro-cultured oocytes from meat yield grade A ovaries led to a higher pregnancy rate (64.2%) than in vitro-cultured oocytes from meat yield grade B ovaries (56.5%), but there was no significant difference between the two groups in pregnancy or abortion rates. In conclusion, embryonic development rate and pregnancy rate has a close relation to meat quality grades of the source beef carcass, this results is to give information for the Korean native cows improvement of breed.

• 한국발생생물학회지:발생과생식
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• 제20권2호
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• pp.127-133
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• 2016

Purine metabolism is known factor for nuclear maturation of oocytes through both follicle cells and oocyte itself. However, it is largely unknown the roles of purine metabolism in the oocyte competence for fertilization and early development. In this study, the effects of adenosine in oocyte competence for development were examined using adenosine and its synthetic inhibitors. Adenosine treatment from GV intact stage for 18 hr (fGV) caused of decrease the fertilization rate but of increase the cleavage rate compared from the other stage treatment groups. Hadacidin did not effect on fertilization rate but increased cleavage rate without stage specificity. Adenosine did not block the effects of hadacidin with the exception of fGV group. Inhibition of purine synthetic pathways the fertilization rate was decreased in the fGV and fGVB groups but increased in the fMII group. Exogenous adenosine caused of decrease fertilization rate in the fGVB group but increase in the fMII group. Cleavage rate was dramatically increased in the adenosine treatment with synthetic inhibitors. It means that the metabolism of purine has stage specific effects on fertilization and cleavage. Exogenous adenosine had only can improve oocyte developmental competence when it treated at GV intact stage. On the other hand, endogenous synthesis in all maturation stage cause of increase the cleavage rate without effects on fertilization. These data suggest that adenosine at GV stage as a paracrine fashion and inhibitions of endogenous adenosine in all stage improve oocyte developmental competence.

• Journal of Animal Science and Technology
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• 제58권3호
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• pp.13.1-13.7
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• 2016

Background: In the present study, various freezing containers were tested for mouse embryos of respective developmental stages; embryos were vitrified and then their survival rate and developmental rate were monitored. Mouse two cell, 8 cell, and blastula stage embryos underwent vitrification freezing-thawing and then their recovery rate, survival rate, development rate, and hatching rate were investigated. Methods: EM-grid, OPS, and cryo-loop were utilized for vitrification freezing-thawing of mouse embryos. Results: It was found that recovery rate and survival rate were higher in the group of cryo-loop compared to those of EM-grid (p < 0.05). Embryonic development rate, two cell embryos to blastocyst, as well as hatching rate were higher in the control group compared to the EM-grid group and OPS group (p < 0.05), yet no difference was noted between the control group and cryo-loop group. Development rate and hatching rate of eight cell morulae and blastocysts were all lower in the treatment groups than the control group whilst hatching rate of blastocysts was higher in the control group compared to the groups of EM-grid and OPS (p < 0.05); although the cryo-loop group was shown to be slightly higher than other groups, it was not statistically significant. Conclusions: In the study, we investigate effects of freezing containers on vitrified embryos of respective developmental stages; it was demonstrated that higher developmental rate was shown in more progressed (or developed) embryos with more blastomeres. There was however, no difference in embryonic development rate was shown amongst containers. Taken together, further additional studies are warranted with regards to 1) manipulation techniques of embryos for various vitrification freezing containers and 2) preventive measures against contamination via liquid nitrogen.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.3003-3011
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• 2021

A FAC (flow-accelerated corrosion) test was performed for a straight pipe composed of the SA335 Gr P22 and SA106 Gr B (SA106-SA335-SA106) types of steel with welds as a function of the flow rate in the range of 7-12 m/s at 150 ℃ and with DO < 5 ppb at pH levels ranging from 7 to 9.5 up to a cumulative test time of 7200 h using the FAC demonstration test facility. Afterward, the experimental pipe was examined destructively to investigate opposite effects as well as entrance effects. In addition, the FAC rate obtained using a pipe specimen with a 50 mm inner diameter was compared with the rate obtained from a rotating cylindrical electrode. The effects of the complicated fluid flows at the elbow and orifice of the pipeline were also evaluated using another test section designed to examine the independent effects of the orifice and the elbow depending on the distance and the combined effects on orifice and elbow. The tests were performed under the following conditions: 130-150 ℃, DO < 5 ppb, pH 7 and a flow rate of 3 m/s. The FAC rate was determined using the thickness change obtained from commercial room-temperature ultrasonic testing (UT).

• 한국작물학회지
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• 제52권1호
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• pp.112-121
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• 2007

Grain filling is a crucial factor that determines grain yield in crops since it is the final process directly associated with crops' yield performance. Grain filling process can be characterized by the interaction of rate and duration of grain filling. This study was conducted, using 16 temperate japonica rice genotypes, with aims to (1) seek variations in grain filling duration and rate on area basis, (2) compare the contribution of grain filling duration and rate to grain yield, and (3) examine the influence of temperature and solar radiation for effective grain filling on grain yield in relation to grain filling duration and rate. Grain filling rate and duration exhibited highly significant variations in the ranges of $20.7{\sim}46.3\;g\;m^{-2}d^{-1}\;and\;11.2{\sim}35.5$ days, respectively, depending on rice genotypes. Grain yield on unit area basis was associated positively with grain filling duration but negatively with grain filling rate. Grain filling rate and duration were negatively correlated with each other. Final grain weight increased linearly with the rise in both cumulative mean temperature and cumulative solar radiation for effective grain filling. Higher cumulative mean temperature and cumulative solar radiation for effective grain filling were the results of longer grain filling duration, but not necessarily higher daily mean temperature and daily solar radiation for effective grain filling. Grain filling rate demonstrated an increasing tendency with the rise in daily mean temperature for effective grain filling but their relationship was not obviously clear. It was concluded that grain filling duration, which influenced cumulative mean temperature and cumulative solar radiation for effective grain filling, was the main factor that determined grain yield on unit area basis in temperate Japonica rice.

• 보건의료산업학회지
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• 제9권4호
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• pp.197-206
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• 2015

Objectives : This study presents comparison results of the correlations between ODA grants and health indicators among 23 countries in Asia. Methods : Data from 2005~2013 were collected through the World Development Indicator (WDI) provided by the World Bank (WB). The health-related variables used in this study included the maternal mortality ratio, infant mortality rate under five, infant mortality rate, incidence of tuberculosis, and prevalence of AIDS. Results : Based on the results, there were positive correlations between ODA grants and health indicators, which means that the overall ODA grants would drop when the health indicators improved. As for differences in the health indicators by income groups among the countries, there were differences in the maternal mortality ratio, infant mortality rate under five, infant mortality rate, and overall ODA grants. The maternal mortality ratio, infant mortality rate under five, and infant mortality rate were lower in the order of upper middle, lower middle, and poorest income countries. Conclusions : The findings raise a need for the integrated and horizontal development of Goals 4, 5 and 6 of MDGs in the ODA projects of health sector in the future.

• 정보처리학회논문지D
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• 제13D권5호
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• pp.709-716
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• 2006

소프트웨어 복잡도가 증가할수록 소프트웨어 성공률은 기하급수적으로 감소하며, 반대로 실패율은 증가한다. 소프트웨어 규모 증가에 따른 실패율은 성장곡선으로 표현할 수 있다. 이 현상에 따라, 본 논문은 Gompertz 성장곡선으로 개발 성공률과 완료율을 추정하였다. 먼저, 수치적으로 제시된 $10^n$의 소프트웨어 규모를 로그값으로 변환시켜 데이터 간격을 일정하게 하였다 로그값의 소프트웨어 규모 변화에 따른 개발 성공률과 완료율의 함수관계를 유도하고자 하였다. 그러나 이 관계를 적절히 표현하는 함수를 찾지 못하였다. 따라서 본 논문에서는 개발 성공률의 역 개념인 실패율과 완료율의 역 개념인 취소율을 도입하였다. 로그값의 소프트웨어 규모 변화에 따른 개발 실패율과 취소율 관계는 성장곡선 형태를 나타내었다. 결론적으로, 개발 취소율과 실패율을 적절히 표현하는 함수로 Gompertz 성장곡선을 적용한 결과 실측 데이터를 적절히 표현할 수 있었다. 본 모델을 적용하면 특정 규모의 소프트웨어에 대한 개발 성공률과 완료율을 보다 정확히 얻을 수 있을 것이다.