• 한국수산과학회지
• /
• 제33권3호
• /
• pp.219-224
• /
• 2000

난소의 내부는 결체성 조직인 다수의 난소박판으로 구성되며, 이곳에서 난원세포가 유래한다 정소조직상은 정세관 형태이며, 각각의 정세관은 여러 개의 소낭구조를 가진다. 각 소낭내의 생식 세포들은 같은 단계의 발달상태를 보인다. 군 성숙도에 도달하는 크기는 암${cdot}$수 모두 전장 4.5 cm이다. 암컷의 GSI는 6월에 가장 높은 값을 나타냈으며, 수컷의 GSI는 7월에 가장 높은 값을 나타냈다. 생식주기는 성장기 ($1{\~}3$월), 성숙기 ($4{\~}5$월), 완숙 및 산란기 ($6{\~}7$월) 그리고 회복 및 휴지기 ($8{\~}12$월)로 나눌 수 있었다. 난모세포 발달양식은 난군동기발달형에 속하며, 초기 성장기 난모세포의 세포질에서 난황핵이 관찰되었다.

• 자원환경지질
• /
• 제26권4호
• /
• pp.507-518
• /
• 1993

Paleomagnetic investigations have been carried out on the Tertiary sedimentary formations (Yeonil Group) in Pohang basin, southeastern Korea. A total of 215 samples were collected from 26 sites. Progressive thermal demagnetization indicates that many samples have unstable magnetization and do not reveal a characteristic direction. However, some samples from the lower and upper Duho Formation show a characteristic direction $D/I=7.8^{\circ}/48.3^{\circ}$ (${\alpha}_{95}=3.7^{\circ}$, k=174.1). Stepwise thermal demagnetization data show that some samples from the Hagjeon and middle Duho Formations reveal great-circle distributions moving from the present to a reversed direction of geomagnetic field. The mean of intersection points of the great-circles is nearly antipodal to the characteristic normal direction of the lower and upper Duho Formation. We infer that the Hagjeon Formation was formed during the reversed polarity chron C5B (16.2~14.7 Ma) and the Duho Formation 14.7~11.6 Ma based on our results and previous paleontologic and age dating data. Paleomagnetic direction for the Middle Miocene of Korea, analysed from the combined results of stable endpoints and great circles, is $D/I=8.7^{\circ}/53.9^{\circ}$ (${\alpha}_{95}=4.2^{\circ}$, k=74.8), and the corresponding paleopole is Lat./Long.=$82.7^{\circ}/230.2^{\circ}$ (${\delta}p=2.8^{\circ}$, ${\delta}m=5.9^{\circ}$). On the basis of this, we interpret that the opening of the East sea (Japan sea) or the synchronous clockwise rotation of the Southwest Japan exerted no structural influence on the Yeonil Group in the Middle Miocene.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제21권2호
• /
• pp.120-130
• /
• 1999

This investigation studied the effect of ovariectomy on the temporomandibular joint (TMJ) of rat. Forty female Sprauge-Dawley strain white rats, each weighing about 200grams were used and divided into two groups. The one group was performed ovariectomy, and the other was performed sham operation. Both group were killed at the intervals of 3 days, 1, 2, 4, and 8 weeks postoperatively, paraffin section were stained with H&E, MT and histomorphometric study of the TMJ was performed in a synchronous manner with an sham operated control group The result were as follows: 1. At 4 weeks after ovariectomy, an adhesion between the inferior surface of the articular disc and the condyle was observed in the central portion. At 8 weeks after ovariectomy, a focal thickening of the bone (osteophyte) was observed in anterior portion and there was a marked decrease in the trabecular bone in the posterior region. 2. The thickness of cartilage zone was increased at 2 weeks postopratively in the central portion, and decreased at 4 weeks postopratively in the posterior portion. The thickness of transitional zone was decreased at 1 week postoperatively in the anterior and proliferating zone was decreased postoperatively. The thickness of articular zone was decreased at 3 days postopratively in the anterior portion, and decreased at 1 week postoperatively in the central portion. From the above finding, we could conclue that estrogen deficiency in rats causes alteration of TMJ in marked early stage.

• 한국발생생물학회지:발생과생식
• /
• 제22권1호
• /
• pp.111-117
• /
• 2018

The objective of this study was to determine the mitotic intervals (${\tau}_0$) of two consecutive cell divisions and synchronous embryonic cleavage in grass puffer, Takifugu niphobles at different water temperatures (18, 20, 22, and $24^{\circ}C$). The color of the fertilized egg was light yellowish. The egg type was demersal and unadhesive. Egg weight was $0.09{\pm}0.002mg$. The sizes of unfertilized eggs were smaller than fertilized eggs in major axis and minor axis at $20^{\circ}C$ (p<0.05). The size of the fertilized egg of $18^{\circ}C$ water temperature group at the blastodisc stage was the smallest (p<0.05), but no significant differences were observed in the other water temperatures group except $18^{\circ}C$ water temperature group (p>0.05). The first cleavage stages at 18, 20, 22, and $24^{\circ}C$ were at 75, 90, 105, and 120 mins, respectively. As water temperature was increased, embryonic development and formation time of the first cleavage furrow were accelerated. There were negative correlation between ${\tau}_0$ and water temperature for grass puffer (Y=-1.225X+70.05, $R^2=0.988$, n=10, where Y was ${\tau}_0$ and X was temperature). This study confirmed that successful hatching of grass puffer was related to water temperature. Chromosome manipulation will be helpful for this species using cleavage frequency and ${\tau}_0$.

• Journal of Korean Medical Science
• /
• 제33권45호
• /
• pp.283.1-283.10
• /
• 2018

Background: The role of sorafenib in patients with hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT) has been rarely studied. The aim of this study was to evaluate the efficacy of sorafenib in post-LT era. Methods: Consecutive patients with post-transplant HCC recurrence not eligible to resection or locoregional therapy were included. Patients receiving best supportive care (BSC) until 2007 were compared with those treated by sorafenib thereafter. Results: Of a total of 65 patients, 20 patients received BSC and 45 received sorafenib. Clinical characteristics were similar between two groups except that sorafenib group received tacrolimus and mammalian target-of-rapamycin inhibitors more frequently than BSC group. Treatment with sorafenib conferred a survival advantage as compared with BSC for survival after recurrence (median, 14.2 vs. 6.8 months; P = 0.01). In multivariate analyses, high serum ${\alpha}$-fetoprotein level, synchronous intrahepatic recurrence and distant metastasis at the time of recurrence, and BSC were independently associated with poorer survival after recurrence. Sorafenib treatment was associated with better survival after recurrence as compared with BSC (hazard ratio, 0.25; 95% confidence interval, 0.10-0.62; P = 0.002). In addition, sorafenib group showed tolerable toxicity in the post-transplant setting. Conclusion: Sorafenib may be beneficial in patients with post-transplant HCC recurrence.

• 한국산학기술학회논문지
• /
• 제15권7호
• /
• pp.4554-4561
• /
• 2014

최근에 기존의 컴퓨터 시스템에서 결함허용 분산 어플리케이션을 설계하는데 필요한 요소를 몇 개의 중요한 패러다임으로 구분하여 단순화 되어 왔다. 리더 선택 프로토콜은 그 중에서도 가장 눈에 띄고 비중 있는 프로토콜로 알려져 있다. 선택 프로토콜은 그룹통신이나, 데이터의 원자적인(atomic) 커밋(commit), 복제 데이터의 관리와 같은 프로토콜 코디네이터가 필요한 분야에서 기초적인 설계 초석으로 유용하게 이용 될 수 있기 때문이다. 그러나 이러한 유성성에도 불구하고 기지국 기반 무선 통신 환경에서 아직까지 리더 선택의 문제를 다룬 연구는 많지 않았다. 본 논문에서는 기지국 기반 무선 통신 환경에서 리더 선택 프로토콜을 위한 선택 알고리즘을 제시하고 설계하고자 한다. 또한 설계된 선택 알고리즘은 다른 알고리즘에 비해 결함허용 측면에서 매우 효율적임을 보인다.

• 영어어문교육
• /
• 제12권3호
• /
• pp.123-145
• /
• 2006

The purpose of this study is to propose an efficient vocabulary assessment model in task-based language learning and to verify the viability of this assessment model. Bachman and Palmer (1996) pointed out the fact that many language tests focus on just one of the areas of language knowledge. However, researchers suggested that it is necessary to acknowledge the needs of several analytic scales, which can provide separate ratings for different components of the language ability to be tested. Although there were many studies which tried to evaluate the various aspects of vocabulary ability, most of them measured only one or two factors. Based on previous research, this study proposed an assessment model of general construct of vocabulary ability and tried to measure vocabulary ability in four separate areas. The subjects were two classes of university level Korean EFL students. They participated in small group discussion via synchronous CMC. One class used a lexically focused task, which was proposed by Kim and Jeong (2006) and the other class used a non-lexically focused task. The results showed that the students with a lexically focused task significantly outperformed those with a non-lexically focused task in overall vocabulary ability as well as four subdivisions of vocabulary ability. In conclusion, the assessment model of separate ratings is a viable measure of vocabulary ability and this can provide elaborate interpretation of vocabulary ability.

• 식물조직배양학회지
• /
• 제27권4호
• /
• pp.245-258
• /
• 2000

Somatic embryogenesis has become a major tool in the study of plant embryology, as it is possible in culture to manipulate cells of many plant species to produce somatic embryos in a process that is remarkably similar to zygotic embryogenesis. Traditionally, the process has been studied by an examination of the ex vitro factors which influence embryo formation. Later structural, physiological and biochemical approaches have been applied. Host recently, molecular tools are being used. Together, these various approaches are giving valuable information on the process. This article gives an overview of somatic embryogenesis by reviewing information on the morphogenesis, physiology, biochemistry and molecular biology of the process. Topics covered include a brief description of the factors involved in the production of embryogenic cells. Carrot cell suspension is most commonly used, and the development of a high frequency and synchronous system is outlined. At the physiological and biochemical lev-els various topics, including the reactivation of the cell cycle, changes in endogenous growth regulators, amino acid, polyamine, DNA, RNA and protein metabolism, and embryogenic factors in conditioned medium are all discussed. Lastly, recent information on genes and molecular markers of the embryogenic process are outlined. Somatic embryogenesis, the best example of totipotency in plant cells, is not only an important tool in studies in basic biology, but is potentially of equal significance in the micropropagation of economically important plants.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
• /
• pp.389-393
• /
• 2000

Ethnography, a major research method in Anthropology, has been recently applied in human-centered design research. Since ethnography has empirical, naturalistic, holistic and eclectic characteristics, it is needed a guideline to apply ethnography into design research in accordance with a characteristic of project. Design project in which ethnography is applied can be categorized by two criteria; degree of newness of project goal(existing user-potential user) and limitedness of worksite(site-oriented-work-oriented). Among work-site activities, technology in use, and user group culture, it should be decided which content to content to focus more than others and thus what kinds of research techniques to apply in the ethnographic research.Case study was to design an interior of a Korean express train. This project is site-oriented and has an existing-potential users. Therefore, video ethnography was effectively applied to obtain chronological data of activity potential users. Therefore, video ethnography was effectively applied to obtain chronological data of activity flow, and participant observation was applied to obtain statistical data of synchronous activities. Case study shows a concrete process example of how to apply ethnography into design research.

• Journal of Power Electronics
• /
• 제10권3호
• /
• pp.313-319
• /
• 2010

This paper proposes a new compensation algorithm for the current measurement errors in a DFIG (Doubly Fed Induction Generator). Generally, current measurement path with current sensors and analog devices has non-ideal factors like offset and scaling errors. As a result, the dq-axis currents of the synchronous reference frame have one and two times ripple components of the slip frequency. In this paper, the main concept of the proposed algorithm is implemented by integrating the 3-phase rotor currents into the stationary reference frame to compensate for the measured current ripples in a DFIG. The proposed algorithm has several beneficial features: easy implementation, less computation time, and robustness with regard to variations in the electrical parameters. The effectiveness of the proposed algorithm is verified by several experiments.