• 한국작물학회지
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• 제61권2호
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• pp.104-112
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• 2016

A double-cropping system with soybean (Glycine max) following the cultivation of potato, garlic, and onion is widely adopted in the southern region of Korea. For this system, marginal dates for planting must be determined for profitable soybean yields, because the decision to plant soybean as a second crop is occasionally delayed by harvest of the first crop and weather conditions. In order to investigate the effect of planting date on soybean yield, three cultivars (early and late maturity) were planted on seven different dates from May 1 to July 30 in both paddy and upland fields across 2012 and 2013. Soybean yields were significantly different among the planting dates and the cultivars; however, the interaction between cultivar and planting date was not significant. Based on linear regression, the maximum yield of soybean was reached with a June 10 planting date, with a sharp decline in yield for crops planted after this date. The results of this study were consistent with those of a previous one that recommends early and mid-June as the optimum planting period. Regardless of soybean ecotype, a reduction in yield of greater than 20% occurred when soybean was planted after mid-July. Frost during soybean growth can reduce yields, and the late maturity cultivars planted on July 30 were damaged by frost before completing maturation and harvest; however, early maturity cultivars were safely harvested. For sufficient time to develop and reach profitable yields, the planting of soybean before mid-July is recommended.

• International Journal of Industrial Entomology and Biomaterials
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• 제47권1호
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• pp.51-62
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• 2023

The advantages of silkworms as functional foods are well known and various products are being developed. In general, silkworms sold in the market include silkworm powder (3 days of fifth instars) and SukJam (7 days or more of fifth instars), In other words, product classification is made according to the maturity of the fifth instar silkworms. In this study, we analyzed the gene expression changes in the fifth instar silkworms and attempted to validate the use of deregulated genes in maturity analysis. After rearing BaekokJam, transcriptome analysis was performed on days 1, 3, 5, and 8 days of the fifth instar, and differentially expressed genes showing differences at each period were selected. Of the 31,841 contigs analyzed, 4012 contigs were identified with a log2 fold change of two or more between 5 and 8 days of the fifth instar. RT-PCR was performed for 18 contigs, which showed increased or decreased expression, but in c127159, c97909, c96974, c119920, c42251, and c80216 showed clear differences. To identify SukJam, a combination of the contigs c127159 (180 bp), c97909 (143 bp), and c80216 (120 bp) was amplified. Taken together, these results suggest that the harvest time of silkworms can be determined using gene expression pattern analysis.

• 한국어류학회지
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• 제35권1호
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• pp.20-29
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• 2023

대륙종개의 산란특성과 산란행동을 규명하기 위해 경기도 가평군 청평면에 위치한 북한강의 지류 상천천에서 2021년 3월부터 5월까지 7회 조사하였다. 전체 조사기간 동안 대륙종개 890개체가 채집되었으며 성비(♂:♀)는 1 : 1.34로 수컷이 암컷보다 많았다. 상천천의 대륙종개는 수온 12~15.7℃인 3월 15일~4월 24일에 산란하였다. 최소 성적성숙개체는 전장 56.7 mm였고 만 1년생 개체였으며, 전장 80.5 mm 이상 개체부터 산란이 관찰되었고 만 2년생 개체였다. 50% 군성숙전장은 67.2 mm로 나타났다. 대륙종개의 복강에 HCG호르몬 10 IU/g으로 주사한 결과, 약 15시간 후에 산란이 유도되었으며 수컷이 암컷의 몸을 원형으로 감는 산란행동이 관찰되었다. 산란 후 암컷과 수컷은 바닥에서 휴식을 취하였고 바닥에 떨어진 수정란은 산란에 참여하지 않은 개체들에게 일부 섭식되었다.

• 정신신체의학
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• 제6권2호
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• pp.97-103
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• 1998

A dolescence can be defined as the period between pubescence and physical maturity, and the passage through adolescence(age of 12-19) forms a critical period. Major developmental tasks of adolescence are construction of an emancipated identity, realistic ambitions, and reasonable ideals, and the further development of sexual and social identities. In early adolescence one struggles to adjust psychologically to the spurt in growth and tensions filled with sexual and aggressive impulses. There are reshuffling of peer groups due to differing rates of maturation, early adolescence crushes, sublimation of sexuality, and the resurgence of oedipal feelings. One reaches so-called period of formal operations in cognitive development. In mid-adolescence one struggles to overcome family attachments and controls, and it is a time marked by revolt and conformity. One has to overcome sexual repression while caught in reactivation of oedipal attachment. Peer groups gains in importance, and the peer group changes into a youth group that carries the youth culture. Late adolescence is a period of achieving an ego identity and capacities for intimacy. One has to prevent premature closure : Identity foreclosure limits both opportunity and the ability to guide one's own life. Gradually adolescent begins to have a loss self-centered and narcissistic orientation to one's sexual and affectional needs, and becomes involved in love relationship.

• 대한산업공학회지
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• 제41권5호
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• pp.488-498
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• 2015

Research on stem cells can be divided into three categories : pluripotent stem cell, adult stem cell, and induced pluripotent stem cell. Technology life cycle (TLC) on research stage is analyzed for the three stem cell categories based on diffusion model. Three diffusion models-logistic, Bass, and Bass model with integration constant (BMIC)-are applied to the number of articles related to each stem cell category in SCOPUS lists. Two different parameter estimation methods is used for each of logistic and Bass model. Results show that (1) the current year, 2015, lies in growth period at pluripotent stem cell and adult stem cell, and lies in growth period or maturity period at induced pluripotent stem cell. (2) Model fitness is the highest at BMIC model. (3) Imitation effect works best at the research area of induced pluripotent stem cell.

• Animal cells and systems
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• 제13권3호
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• pp.339-344
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• 2009

This study aims to find out the effect of heavy metals, as is the case of EDCs (endocrine disrupting chemicals), on reproductive endocrine disruption of aquatic animals. In the present experiment zinc, which is a heavy metal well known for its androgenous activity, was used. The experimental period was 24 weeks, starting in November during the inactive stage of the clam's reproductive cycle. The experimental groups were composed of one control condition and three zinc exposure conditions (0.64, 1.07, and 1.79 mg/L). The sex ratio (F:M) was 1:1.06 in the control group and 1:1.70 in all the exposed group, illustrating the tendency for higher proportion of males with increases in zinc concentration. Gonad maturity was higher in 1.07, and 1.79 mg/L groups compared to the control group, with higher maturity observed in males than females. Intersex individuals made up 24.7% of the exposed group, while females exhibited a higher ratio than the males with increasing zinc concentration. The results of this study indicate that zinc functions as an androgenic effector on the reproduction of Gomphina veneriformis.

• 한국식생활문화학회지
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• 제19권6호
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• pp.605-610
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• 2004

This was aim to study the changes of components by different parts and maturity of tomato. Tomato include the green pigment chlorophyll, the yellow pigment-carotene. the red pigment lycopene and the other component. These colors of tomatoes are reported to have important functional roles to promote health in human. The main objective of this study was to define changes in the content of the four tomato maturation that is ascorbic acid, chlorophyll, carotene, lycopene. A ascorbic acid contents of tomato fruits was the highest at 50th day. Chlorophyll contents of tomatoes fruits was the highest at 10th days after flowering. ${\alpha}$-carotene contained low-quantity while all growth period. ${\beta}$-carotene contained the highest at 50th days after flowering, $1036.97{\mu}g$. Lycopene contained the highest at 50th days after flowering, $5800{\mu}g$.

• 한국초지조사료학회지
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• 제16권3호
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• pp.208-214
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• 1996

This trial was conducted at two locations to compare forage yield, plant height, disease reaction, lodging and maturity of oat(Avm sativa L.) cultivars introduced from Western Australia in comparison with the control cultivar of oat 'Cayuse" over a period of 3 yr. At Suweon, Swan and Murray cultivars gave the highest forage yield, followed by Winjardie and Hay cultivars during 3 years of trial, but Cayuse cultivar gave the lowest forage yield. At Sunghwan, Hay and Swan cultivars tended to forage yield more than other cultivars, but Cayuse cultivar was among the lowest yielding. AU the cultivars in the trial were moderately resistant to BYDV and lodging at two locations although differences exist among cultivars. Murray cultivar was early in maturity, while Swan, Hay and Winjardie cultivars showed medium, and Cayuse cultivar was later. Murray and Swan cultivars were tall in height and gave a higher dry matter percentage of 18~20% at harvest. The results of the trial indicated that Swan and Murray cultivars could be recommended as the national recommended forage oat cultivar when forage performance was considered.ered.

• Clinical and Experimental Reproductive Medicine
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• 제16권1호
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• pp.93-101
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• 1989

71 cycles of 67 women were treated for superovulation induction in our IVF & ET program from May to September in 1988. Endogenous LH surges were occurred in 21 cycles out of 71 cycles. And then, we selected 50 cycles without endogenous LH surge treated in the same period as control group. We compared egg recovery rate, egg maturity, fertilization rate, cleavage rate and pregnancy rate of study group with those of control group. We were able to detect more than 90% of endogenous LH surge by commencing daily LH monitoring on MCD 9. The egg recovery rate, egg maturity, fertilization rate, and pregnancy rate of the study group were not statistically different from those of the control group. Significantly lower cleavage rate was seen in the study group compared with that of control group. Above results suggested that the cycles with endogenous LH surge do not have to be abandoned and can be treated continuously to achieve successful pregnancy.

• 한국IT서비스학회지
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• 제8권2호
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• pp.229-245
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• 2009

The Korean mobile telecommunication service market is faced with a tremendous competitive period, in which the market is entering into the maturity stage with launching of the 3rd generation service and with introduction of mobile number portability. In general, it is more important to sustain the old customers than to attracting new customers, as the life cycle of an industry is entering the maturity stage in which the growth rate of new customers is decreasing gradually or becoming stagnant. Thus, mobile telecommunication business has to seek a way to maintain the existing customers instead of promoting new customers. So this study investigates whether the service quality of mobile telecommunication could have effects on the switching barrier of the industry. In order to test the hypothesis on the effects of service quality of mobile telecommunication in Korea on switching barrier, this study collected the questionnaire response data of students including middle and high school students and undergraduates, who are regarded as the major customers in that mobile telecommunication industry.