• Title/Summary/Keyword: First Passage

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Switching and first-passage-time distributions in a two-mode ring dye laser (2모드 색소레이저 출력의 switching과 First-Passage-Time(FPT) 분포)

  • 박구동;신종태;김태수
    • Korean Journal of Optics and Photonics
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    • v.5 no.2
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    • pp.245-251
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    • 1994
  • The charateristics of switching between two modes in a ring dye laser has been analyzed by the Monte-Carlo computer simulation. The effect of including pump fluctuations in the first-passage-time (FPT) distributions was compared with the distribution with the quantum fluctuation. The results show the same tendency in both cases, such as steep increases from 0 to peak an exponential decrease in long time range. However the introduction of pumping fluctuation is turned out to shorten the mean FPT. The variation of the mean FPT is examined for the various fluctuationrelated parameters. The mean FPT is lengthened when pump parameter a is increased while it is shorted when Q. $\GAMMA$ are decreased. eased.

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Numerical Analysis on Effects of the Boundary Layer Fence Equipped on the Hub of Rotor in the First Stage Axial Flow Gas Turbine (1단 축류 가스터빈내 동익의 허브면에 장착된 경계층 펜스의 효과에 대한 수치 해석적 연구)

  • Yoon, Deok-Kyu;Kim, Jae-Choon;Kim, Dae-Hyun;Lee, Won-Suk;Chung, Jin-Taek
    • The KSFM Journal of Fluid Machinery
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    • v.12 no.2
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    • pp.8-16
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    • 2009
  • The objective of this study is to investigate the three-dimensional turbulence flow characteristics of a rotor passage of an one-stage axial flow gas turbine and to investigate the effects of a boundary layer fence installed on the hub endwall of the rotor passage. Secondary flows occurring within the rotor passage (e.g. horseshoe vortex, passage vortex, and cross flow) cause secondary loss and reduce turbine efficiency. To control these secondary flows, a boundary layer fence measuring half the height of the thickness of the inlet boundary layer was installed on the hub endwall of the rotor passage. This study was performed numerically. The results show that the wake and secondary flows generated by the stator reduced the rotor load to constrain the development of cross flow and secondary flow reinforced by the rotor passage. In addition, the secondary vortices occurring within the rotor passage were reduced by the rotation of the rotor. Although, the boundary layer fence induced additional vortices, giving rise to an additional loss of turbine, its presence was shown to reduce the total pressure loss when compared to effects of the case without fence regardless of the relative position of blades by enervating secondary vortices occurred within the rotor passage.

Cultural Characteristics of Korean Food in the Novel "Hon-bool" - Focused on 'rites of passage' Foods - (소설 "혼불" 속 전통음식의 문화적 이해 - 통과의례음식을 중심으로 -)

  • Chung, Hae-Kyung;Woo, Na-Ri-Ya;Kim, Mi-Hye
    • Journal of the Korean Society of Food Culture
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    • v.25 no.4
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    • pp.416-427
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    • 2010
  • In this study, we attempted to elucidate the cultural characteristics of Korean food based on a traditional understanding on the Korean novel. To achieve this, food characteristics related to 'rites of passage' were analyzed in the representative Korean literary work "Hon-bool", which describes the life of a first-son's wife every three generations in the going to ruin but historic 'Lee's family of Maean district' family and the life of the common 'Geomeong-gul' people who lived with farming on the Lee's land at Namwon of Junbook province in the 1930~1940s, during the Japanese Colonial rule. Every nation possesses rites of passage at important points in life, such as at birth, age of majority, wedding and death. Korean culture, in particular, has several memorial rites relating to birth, death and passage into the afterlife in which special foods are prepared. In this manner, ceremonial foods represent the Korean peoples' traditional vision of the universe and life. The book "Hon-bool" describes these traditions. Especially, the book describes the table-settings related to the main character's childbirth, first birthday, wedding and death. Therefore "Hon-bool" represents a living history of Korean traditional food and the work of storytelling through the traditional understanding is expected that perform an important role in making of cultural contents of Korean foods.

A Survey on Public Preference for Image Styles of Dining Space Depending on Types of Passage Rites in Korea - Focused on University Students - (통과 의례 종류에 따른 식 공간 이미지 스타일 선호도 조사 - 대학생 대상으로 -)

  • Kim, Mi-Ja;Park, Geum-Soon
    • Journal of the Korean Society of Food Culture
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    • v.25 no.6
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    • pp.719-724
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    • 2010
  • The purpose of this study was to survey public preferences for dining space image styles depending on the types of passage rites in Korea and to determine potential differences in public preferences for dining space image styles depending on the types of passage rites in terms of various general characteristics such as gender, age, family type, and preference for the image and color styles of the dining space. As a result, this study determined the following: According to a public preference survey of dining space image styles depending on the type of passage rites, our respondents showed the highest preference for casual images (27.1%) at a party for a 100-day-old baby. Additionally, our respondents showed the highest preference for casual images (27.4%) when celebrating a baby's first birthday but showed the highest preference for romantic images (35.8%) when celebrating a baby girl's first birthday. Our respondents showed the highest preference for casual images (21.4%) for graduation ceremonies. Our respondents showed the highest preference for classic images (21.7%) at coming-of-age ceremonies for new adult men, but also showed highest preference for elegant images (26.2%) at coming-of-age ceremonies for new adult women. Moreover, the respondents showed highest preference for classic images (41.0%) at traditional wedding ceremonies but elegant images (24.1%) at modern wedding ceremonies. In contrast, the respondents showed highest preference for classic images (31.3%) for a 60th birthday party. The highest preference for classic images (28.9%) was found for a diamond wedding ceremony. Respondents showed highest preference for classic images (30.4%) for a funeral ceremony Finally, our respondents showed highest preference for classic images (32.5%) at memorial services (religious ceremonies).

Ethnographies of Clothing in Incheon Province( I )- Focus on passage ritual clothes - (민속조사를 통해 본 인천지 역의 의생활( I ) - 통과의례복식 중심 -)

  • Chang In-Woo
    • Journal of the Korea Fashion and Costume Design Association
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    • v.7 no.2
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    • pp.51-60
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    • 2005
  • This ethnography is on the passage ritual clothes in Incheon province. This ethnography invatigates in two villages of people who has same family name -Family 'Cheung' (from Young-il) in Yeonsoo-dong and Family 'Lee'(from Cheun-joo) in dongyang-dong- in August to December 2003. The object of examination is 80's and 70's old women who have lived and had lived up to recent in two villages. (grand mother Sung, Cho, Cheung and yoon) The clothes of passage ritual are Baenaeoht is the first clothes of the newborn baby(swaddling), A wedding ceremony clothe is the clothing for the coming-of-age ceremony, Honryebouk is the clothing for wedding, Sangbouk in the clothing for mourning, shroud is the clothing for the dead, sacrificial robes. The result of ethnogrphy is the passage ritual clothes in Incheon Province similar with other Provinces in aspect of the name and the form and wearing of the clothes. there are remarkable differences in making method from making by oneself to purchase(swaddling$\cdot$shroud), westernize(clothes for wedding and mourning), simplification (sacrificial) between ritual for their parents and their husband and children.

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Generation of ship's passage plan based on deep reinforcement learning (심층 강화학습 기반의 선박 항로계획 수립)

  • Hyeong-Tak Lee;Hyun Yang;Ik-Soon Cho
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2023.11a
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    • pp.230-231
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    • 2023
  • This study proposes a deep reinforcement learning-based algorithm to automatically generate a ship's passage plan. First, Busan Port and Gwangyang Port were selected as target areas, and a container ship with a draft of 16m was designated as the target vessel. The experimental results showed that the ship's passage plan generated using deep reinforcement learning was more efficient than the Q-learning-based algorithm used in previous research. This algorithm presents a method to generate a ship's passage plan automatically and can contribute to improving maritime safety and efficiency.

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Comparison of Mineralization in Each Passage of Dental Pulp Stem Cells from Supernumerary Tooth (과잉치 치수 세포의 계대별 석회화 비교)

  • Shin, Jisun;Kim, Jongbin
    • Journal of the korean academy of Pediatric Dentistry
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    • v.44 no.3
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    • pp.350-357
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    • 2017
  • The purpose of this study was to evaluate the difference of differentiation potential in each passage of dental pulp stem cells from supernumerary tooth (sDPSCs). The sDPSCs were obtained from a healthy 6-year-old male patient under the guidelines and got the informed consent. Cells were cultured until passage number 16 and divided into two groups; 1 - 8 passages as a young group and 9 - 16 passages as an old group. It was taken $2.25{\pm}0.46days$ in a young group and $3.25{\pm}0.46days$ in an old group to propagate cells of each passage until confluence and there were statistically significant differences between two groups (p < 0.05). In every passage, cell morphology was observed with microscope and evaluated the capacity to form high levels of minerals by alizarin red solution staining after treating differentiation medium. Fibroblast-like, spindle shaped, elongated cells and a few nodules were found in uninduced cultures of passage number 1, 8 and 9. But at 16 passage culture, cell size became larger and broader and observed with more nodules. After inducing differentiation, mineralized nodules were detected at the first passage of 7th day culture whereas at the 8 passage culture, nodules were seen clearly at 14th day culture. In addition, the amount of mineralized nodules were remarkably decreased after passage 9. From the data presented in this study, it is recommended to use sDPSCs of passage number within 8 for utilizing as stem cells.

A Theoretical Study on the Wildlife Passage for Connecting Fragmented Habitat(I)- In the case of Wildlife Passage Types and Design Process (분절된 서식처의 연결을 위한 생태이동통로에 관한 이론적 연구(I) - 유형구분 및 조성절차를 중심으로 -)

  • 김귀곤;최준영
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.2
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    • pp.293-307
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    • 1998
  • This study has been divided into two parts, 1) literature review and 2) a case study. Based on literature review and case studies found in Korea and abroad, this study aimed at classifying wildlife passages and establishing their development procedures in order to establish a theoretical ground for the development of wildlife passage as a way to link habitats that have been fragmented by the construction of roads and other developments. The results of the literature review are as follows : 1) Impact of road construction on surrounding ecological environment is found in various aspects. Along with damage of habitats as direct impact, decrease of biodiversity and simplification of species due to limited breeding and movement are cited as possible indirect impact. 2) In order to lessen the impact generated from fragmented habitats, various types of wildlife passage are being developed in Europe and are showing positive results. 3) In Korea, interests on animal passages have been rising recently. The ministry of Environment and local authorities are establishing development plans for the passages. However, practical materials on the usefulness of adoped methods are not available.4) In order to create an effective wildlife passage, decisions have to be made first on basic factors of planning and designing such as ecosystem rehabilitation methods and surveys on wildlife movement routes and habitat environment. Based on this, in a planning and designing stage, the location and type of a passage, size and measures to attract animals and prevent a collision need to be finalized. This should be followed by a series of process of maintenance, management and monitoring after the development. Based on the results of a theoretical study to develop an wildlife passage, Part 2 of this study deals with the results of an experiment through a specific planning and design that includes a process of ecological surveys, site selection, type selection, ecosystem infrastructure, planting design and construction details on an actual study area and presents them as a model project.

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Evaluation of virulence reversion of an attenuated porcine epidemic diarrhea vaccine strain by serial passages in suckling piglets

  • Da-Jeong Kim;Seung-Chai Kim;Hwan-Ju Kim;Gyeong-Seo Park;Sang Chul Kang;Won-Il Kim
    • Korean Journal of Veterinary Service
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    • v.46 no.3
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    • pp.193-202
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    • 2023
  • Porcine epidemic diarrhea is an infectious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). Especially, when suckling piglets are infected, the mortality rate is close to 100%. PEDV is classified into G1 and G2 types based on genetic differences. The G2 type PEDV outbreak in the United States in 2013 was highly pathogenic and contagious, and it has spread worldwide and caused continuous economic losses. Most commercial vaccines used are G1 type vaccines, and existing vaccines do not fully protect piglets due to genetic differences. In this study, we evaluated the safety of the newly developed G2 type attenuated HSGP vaccine strain by inoculating it into piglets and testing whether the vaccine virus spreads to the non-vaccinated, negative pigs and whether the vaccine reverts to its virulence during serial passage experiments. Each experiment lasted for 7 days for each passage, and fecal viral titers, clinical symptoms, and weight gain were measured daily. After the experiment, necropsy was performed to measure intestinal virus titer and pathological evaluation. As a result of the first passage, no transmission of the vaccine virus to negative pigs co-housed with vaccinated pigs was observed. In addition, after four consecutive passage experiments, the clinical symptoms and small intestine lesions were gradually alleviated, and no virus was detected in the feces in the fourth passage experiment. Therefore, it was concluded that the vaccine was safe without virulence reversion in accordance with the guidelines of the current licensing authority. However, further studies are needed on the genetic changes and biological characteristics of the mutant virus that occur during successive passages of the attenuated vaccine since the replication and clinical symptoms of the virus increased until the third passage during successive passages of the vaccine virus. Based on this study, it was concluded that virulence reversion and safety evaluation of attenuated vaccines through serial passage in target animals can be useful to evaluate the safety of attenuated viruses.

A Statistical Study of Radiolucent Foreign Bodies in Food and Air Passage (단순 흉부 방사선 검사상 발견되지 않은 식도 및 기도 이물의 임상 통계적 고찰)

  • 손영규;이창업;배광식;박문서;이선철
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1983.05a
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    • pp.9.2-9
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    • 1983
  • We have observed 74 cases of radiolucent foreign bodies in food and air passage in E. N. T. department of Hang Gang Sacred Hospital, from Jan. 1972 to Mar. 1983. The following results were obtained. 1) Distribution of location was 56 cases(75.6 %) in food passage and 18 cases (24.4 %) in air passage. 2) In age distribution, 46 cases (82.1 %) of F. B. in food passage were found in patient over 21 years old and 12 cases (66.7 %) of F. B. in air passage were found in patient under 5 years old. 3) Female seems to be more frequently involved than male in cases of F. B. of food passage and in cases of air passage, male is more frequent. Food passage male: female - - - 25 : 31 Air passage male: female - - - 10 : 8 4) Meats was the most frequent foreign body in food passage (19 cases-33.9%), and the bony pieces was next (17 cases-30.4 %). Plastic material was the most frequent foreign body in air passage (9 cases-49.9 %), and the vegetable seed was the second (4cases-22.0 %). 5) In the location of F. B. in food passage, the first narrowing of the esophagus was the most frequent site and in air passage, the bronchus-especially right bronchus-was the most frequent site. 6) In the duration of lodgement, 44 cases(78.6 %) of F.B. in food passage were visited with - in 24 hours, and 11 cases (61 %) of F. B. in air passage were visited with - in 24 hours. 7) Simple chest PA was checked in all patient and then, esophagogram was checked in 34 cases of F.B. in food passage, among them positive finding was noticed in 23 cases. 8) Removal of F. B. in food passage by esophagoscopy was performed in 54 cases (96.4 %), but in the cases of air passage, removal of F. B. by bronchoscopy was performed in 14 cases (77.8 %). 9) Complications of food passage by the F. B. itself or esophagoscopy were esophageal mucosal laceration (1 cases-1.8 %) and esophageal perforation (1 case -1. 8 %) and complication of air passage by F. B. itself or bronchoscopy were atelectasis (2 cases -11.1 %) and pneumonia (3 cases-16.7 %).

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