• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.6
• /
• pp.393-398
• /
• 2005

Codium fragile is commercially farmed in Korea by natural blooming zygote attachment. Experiments found optimum conditions for artificial seed production and nursery culture of C. fragile by asexual reproduction. Isolated utricles and medullary filaments were regenerated to erect thalli using both indoor and outdoor culture experiments. Under the indoor culture conditions, irradiance was an important factor to control the development of erect thalli. Formation of erect thallus from the isolated medullary filaments in the indoor culture was induced after 30 days under $20^{\circ}C$ and $60{\mu}mol/m^2/sec$. The detachment of isolated utricles and medullary filaments from the substrates of seed strings was reduced by exposure to the air during 2 hrs before the indoor culture of seed strings. The maximum growth and development of erect thalli in the nursery culture was induced at a water depth of 0.5 m. Depending on the substrates of the seed strings the growth of erect thalli was not significantly different (p>0.05).

• The Korean Journal of Malacology
• /
• v.27 no.1
• /
• pp.29-33
• /
• 2011

This study was conducted to investigate the recruitment pattern of sessile organisms on the artificial substrates of PVC in Jangmok Bay, Geoje Island, southern coast of Korea. Five PVC plates were submerged from March to October, 2007 at one month interval, and two plates were retrieved after one month. The dominant recruiters were a green algae, Entermorpha prolifera in March, Mytilus galloprovincialis in April, M. galloprovincialis and Styela plicata in May, S. plicata and Bugula sp. in June. During August, Balanus amphtrite and anthozoans were dominant recruiters, and a serpulid worm, Hydroides ezoensis in October. There was a clear specific recruiting period of sessile faunas depending on their reproduction cycles in a sheltered embayment like Jangmok Bay.

• International Journal of Advanced Culture Technology
• /
• v.10 no.1
• /
• pp.230-235
• /
• 2022

This study is to select an optimal object detection algorithm for designing a self-checkout counter to improve the inconvenience of payment systems for products without existing barcodes. To this end, a performance comparison analysis of YOLO v2, Tiny YOLO v2, and the latest YOLO v5 among deep learning-based object detection algorithms was performed to derive results. In this paper, performance comparison was conducted by forming learning data as an example of 'donut' in a bakery store, and the performance result of YOLO v5 was the highest at 96.9% of mAP. Therefore, YOLO v5 was selected as the artificial intelligence object detection algorithm to be applied in this paper. As a result of performance analysis, when the optimal threshold was set for each donut, the precision and reproduction rate of all donuts exceeded 0.85, and the majority of donuts showed excellent recognition performance of 0.90 or more. We expect that the results of this paper will be helpful as the fundamental data for the development of an automatic payment system using AI self-service technology that is highly usable in the non-face-to-face era.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.7
• /
• pp.1071-1086
• /
• 2003

Reproductive biotechnologies continue to be developed for genetic improvement of both river and swamp buffalo. Although artificial insemination using frozen semen emerged some decades back, there are still considerable limitations. The major problem appears to be the lack of efficient methods for estrus detection and timely insemination. Controlled breeding experiments in the buffalo had been limited and similar to those applied in cattle. Studies on multiple ovulation and embryo transfer are essentially a replica of those in cattle, however with inherent problems such as lower number of primordial follicles on the buffalo ovary, poor fertility and seasonality of reproduction, lower population of antral follicles at all stages of the estrous cycle, poor endocrine status and a high incidence of deep atresia in ovarian follicles, the response in terms of transferable embryo recovery has remained low with 0.51 to 3.0 per donor and pregnancy rates between 15 to 30%. In vitro production of buffalo embryos is a valid alternative to recovery of embryos by superovulation. This aspect received considerable attention during the past decade, however the proportion of embryos that develops to the blastocyst stage is still around 25-30% and hence the in vitro culture procedures need substantial improvement. Embryo cryopreservation procedures for direct transfer post thaw need to be developed for bubaline embryos. Nuclear transfer and embryo cloning is a technique that has received attention in various species during recent years and can be of immense value in buffaloes as they have a low rate of embryo recoveries by both in vitro and in vivo procedures. Gender pre-selection, genome analysis, gene mapping and gene transfer are a few of the techniques that have been studied to a limited extent during recent years and are likely to be included in future studies on buffaloes. Very recently, reproductive biotechnologies have been applied to feral buffaloes as well, but the results obtained so far are modest. When fully exploited they can play an important role in the preservation of endangered species.

• Journal of the Korea Concrete Institute
• /
• v.16 no.5 s.83
• /
• pp.591-596
• /
• 2004

In order to evaluate the applicability of steel slag aggregates for tetrapod concrete, the properties of concrete as structural material were investigated. The biochemical research of marine concrete using steel slag aggregates was also carried out. The tested concrete properties are slump, ai content, compressive strength, splitting tensile strength, elastic modulus, carbonation, hydration heat, freezing and thawing, sulfate attack, drying shrinkage, etc. The biochemical experiments are carried to research the propagation and reproduction of seaweeds and survival of bottom dwelling species. According to this experiment results, the steel slag aggregate content did not have a significant effect on compressive strength, splitting tensile strength and elastic modulus. The durability of concrete was not influenced by the steel slag aggregate content. From the biochemical research, steel slag aggregate can be evaluated as the material that is ideally suited for promoting propagation and reproduction of seaweeds and sessile benthos.

• Korean Journal of Animal Reproduction
• /
• v.15 no.2
• /
• pp.109-115
• /
• 1991

This experiment was conducted to find out the time to farrowing induction after PGF2$\alpha$ treatment, the rate of farrowing induction, the effect of kids born by the induced farrowing on birth weight and development with study on artificial control of parturition in Korean native goats. A total of 24 pluriparous goats were offered for this experiment. The animals were divided into 4 goats per treatment by administration time(142, 145 or 148 day of pregnancy) and dosage (5 or 7.5mg). The results obtained in this experiments were as follows : 1. The effect of synchronization of estrus was induced 23 goats(95.1%), 16 goats(66.6%) in the 1st treatment and 7 goats(28.5%) in the 2nd treatment PGF2$\alpha$ and exhibited estrus at a mean interval of 75$\pm$5 hours after PGF2$\alpha$ injection. 2. The time to farrowing induction after PGF2$\alpha$ treatment on day 145 or 148 was significantly(P<0.01) shorter than that of the 5mg treatment, but there was no significant difference(P>0.01). 3. Parturition was induced in all goats(100%) treated 5 or 7.5mg of PGF2$\alpha$ on day 148 and 7.5mg of PGF2$\alpha$ on day 145, but was induced 75% in treatment with 5mg of PGF2$\alpha$ on day 145 and 5 or 7.5mg of F2$\alpha$ on day 142. 4. The birth weight and development of kids induced farrowing was heaviest (P<0.01) on days 148 among treatment, but there was no significant difference in dosage.

• Korean Journal of Animal Reproduction
• /
• v.9 no.1
• /
• pp.40-45
• /
• 1985

Eight 2-yr old bulls from Artificial Breeding Center, NLCF were used to determine the effectof collection frequency on semen characteristics and sexual activity. Two successive ejaculates per day were collected by artificial vagina for 4 weeks on weekly or twice a week. Total ejaculate volume included 2nd ejaculates for one time and two time bulls was 6.8ml and 6.0ml, but there was no significant difference between collection intervals. Sperm concentration of one time and two time bulls averaged 0.79$\times$109/ml and 0.89$\times$109/ml, respectively. Total sperm per ejaculate was 5.14$\times$109 for one time bulls and 5.45$\times$10 for two time bulls. Two time bulls had slight more sperm per ml and ejaculate than one time bulls, but there were no significant differences between two group bulls. Sperm motility and semen pH of two time bulls was slightly better than that of one time bulls. In changes of bulk minerals in semen, solium concentration of two time bulls was similar to that of one time bulls. Potassium and calcium was more concentrated in one time bulls than in two time bulls, but these concentrations did not differ significantly. Libido score for two time bulls was higher than that for one time bulls. However, there was no difference between two groups and these scores did not change for 4 weeks in two goups. Total time to 2nd ejaculation was 16.3 sec for one time bulls and 20.5 sec for two time bulls.

• Korean Journal of Animal Reproduction
• /
• v.16 no.2
• /
• pp.103-107
• /
• 1992

The present study was conducted to find out the changes of progesterone levels in pre and post partum by the PGF2$\alpha$ administration to control artificial parturition in Korean native goats. A total of 24 goats were offered for this experiment. The animals were divided into 4 goats per treatment by the administration time(142, 145 or 148 day of pregnancy). Blood samples were taken from jagular vein pre-post partum by the PGF2$\alpha$ intramuscular administration. The progesterone in serum was assayed by radioimmunoassay. The serum progesterone level in late-pregnant goats averaged 4.85$\pm$0.55ng/ml, 4.05$\pm$0.47ng/ml or 2.76$\pm$0.25ng/ml on 142, 145 or 148 days of gestation. After the intramuscular injection with PGF2$\alpha$ for inducing parturition, it decreased remarkably to below 1.0ng/ml and to the base level(0.4~0.6ng/ml) at day 1 after parturition. And then this base level of progesterone was maintained until the final examination at 9 days of postpartum. No significant difference was found in the serum levels of progesterone between the doses treated for parturition induction. It was concluded that exogenous PGF2$\alpha$, administrated intramuscularly, induced premature parturition with causing withdrawal of progesterone levels for triggering luteolysis.

• Korean Journal of Animal Reproduction
• /
• v.9 no.1
• /
• pp.9-30
• /
• 1985

The study was carried out to find out the changes of the sex hormone levels in the milk of Holstein cows during the reproductive stages such as the estrous cycle, pregnancy and periparturient period. The FSH, LH, estradiol-17$\beta$ and progesterone from the milk samples were assayed by radioimmunoassay methods. The results of this study were summarized as follows: 1. The levels of progesterone and estradiol-17$\beta$ were similar among inter-quarters, but they were higher in after milking than before milking times, with no statistical significance. 2. The milk progesterone levels during the estrous cycles reached a peak mean level of 3.55$\pm$0.26ng/$m\ell$ at 15 days after estrus and they did not show any differences among the length of estrous cycles. The estradiol-17$\beta$ levels during the estrous cycles showed a peak level of 36.40$\pm$2.38pg/$m\ell$ at estrus, and decreased(17.20$\pm$0.46 pg/$m\ell$ to 18.65$\pm$1.26pg/$m\ell$) at luteal phase. 3. The FSH levels during the estrous cycles ranged from 2.25$\pm$0.23mIU/$m\ell$ to 4.35$\pm$0.24mIU/$m\ell$ showing significant changes. The LH levels during the estrous cycles gradually increased and remained a peak level of 10.90$\pm$0.36mIU/$m\ell$ from 20 to 25 days after estrus. 4. The progesterone levels during the pregnancy were decreased from 30 to 60 days after artificial insemination, and therafter continuously increased until 240 days. The estradiol-17$\beta$ levels during the pregnancy were 24.56$\pm$1.19pg/$m\ell$ at day 30 after artificial inseminaton, and increased rapidly until 180 days. The levles were agagin decreased by 26.17$\pm$3.03pg/$m\ell$ until 210 days and markedly increased by 68.00$\pm$8.70pg/$m\ell$ until 240 days. 5. The prolactin levels during the pregnancy were 31.27$\pm$2.31ng/$m\ell$ and 42.60$\pm$2.37ng/$m\ell$ at day 150 and 240 after artificial insemination respectively. The LH levels during the pregnancy reached a peak of 27.47$\pm$7.90mIU/$m\ell$ at day 30 after artificial insemination, and thereafter gradually decreased. 6. The progesterone levels during the periparturient period reached a peak of 4.61$\pm$0.34ng/$m\ell$ at day 3 prepartum, and thereafter gradually decreased, and showed 2.05$\pm$0.60ng/$m\ell$ at day 7 postpartum. The estradiol-17$\beta$ levels during the periparturient period showed high level from 207.23$\pm$6.04pg/$m\ell$ at day 1 prepartum to 239.90$\pm$13.90pg/$m\ell$ at day 2 prepartum, and thereafter began to decline and reached 51.87$\pm$1.72pg/$m\ell$ at by 7 postpartum. 7. The prolactin levels during the periparturient period showed relatively higher level at the time of parturition. The LH levels during the periparturient period rnage from 6.32$\pm$0.32mIU/$m\ell$ to 13.90$\pm$1.37mIU/$m\ell$ showing significant changes. 8. The progesterone levels(4.6$\pm$0.8ng/$m\ell$) of the pregnant cows were significantly higher than those (1.84$\pm$1.4ng/$m\ell$) of nonpregnant cows. The cows of artificial insemination from 61 to 90 days after parturition showed higher progesterone levels. 9. During 20 to 25 days after artificial insemination, the accuracy of pregnancy diagnosis from milk progesterone levels were 94.4% for nonpregnant cows(<2.3ng/$m\ell$), and 75.0% for pregnant cows( 3.2ng/$m\ell$). The average overall accuracy of pregnancy prediction for nonpregnant and pregnant cows 83.3% 10. The results obtained this study suggest that the understanding of the endocrinological mechanisms by means of milk hormone analysis during the estrous cycle, pregnancy and parturition would give the basic information needed for increasing efficiency of reproduction. This study would not only provide an accurate method of the early pregnancy diagnosis by milk progesterone levels but also contribute to the research of providing the method of detecting of FSH levels in milk, which was difficult in blood serum.

• Korean Journal of Environmental Agriculture
• /
• v.14 no.1
• /
• pp.82-87
• /
• 1995

The standardization of test procedures and reproducibility of the toxicity data are prerequisite for the toxicity testing with the earthworm culturing in the laboratory. No in-depth study on culturing conditions of earthworms has been conducted in Korea, even of massive cultural practice is common for composting and production of biochemicals. The earthworms, Lumbricus rubellus and Eisenia foetida, were cultured in three kinds of artificial soil substrates(I, II and III) based on the OECD Guideline, which consist of different ratios of components (sand, sphagnum peat and kaolinite), and fed with a mixture of grain powders. During the period of culturing, the body weight and reproduction parameters were measured. L. rubellus showed the best results for increasing body weight and cocoon production in the artificial soil substrate(I) compared with E. foetida. The cocoon production was significantly high in both species cultured in the artificial soil substrate(I) among the three kinds of soil substrates, but the cumulative cocoon production of L. rubellus was 11 cocoon per worm compared with 3.7 cocoons per worm of E.foetida. L. rubellus, therefore, was more prolific than E. foetida in these culture schemes. The cumulative mortality in both species was less than 10%, and the number of juvenile worms per cocoon ranged from 1.5 to 2.3 and thus did not show any relationships with soil substrates or species. From these data, the culture of L. rubellus in the laboratory could be standardized, but for E. foetida, further study would be necessary to establish the optimal growth conditions in the laboratory.