• 제목/요약/키워드: first passage

검색결과 323건 처리시간 0.031초

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

  • 박구동;신종태;김태수
    • 한국광학회지
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    • 제5권2호
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    • pp.245-251
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    • 1994
  • 고리형 공진기의 색소레이저에서 시계방향 모드와 반시계 방향 모드 사이에 나타나는 switching 현상을 펌프 매개변수 a, 폄프요동의 세기 Q 및 진동수폭 등을 변화시켜 Monte Carlo 방법으로 수치 계산하여 고찰하였다. 덧셈형 noise만 고려할 때와 이 noise에다 여기요동을 나타내는 곱셈형 색 noise를 포함시켰을 때 FPT분포에 미치는 영향을 조사하였다. 두 경우에 있어서 FTP의 분포는 짧은 시간영역에서는 0에서 상승하여 최대값에 도달하고, 긴 시간영역에서는 지수함수적으로 감소하는 경향은 같았으나 덧셈의 noise만 존재할 때에 비하여 곱셈의 색 noise가 포함될 때는 FPT가 감소하였다. 한편, 평균 FTP는 펌프매개변수 a의 증가와 더불어 증대하였으며 곱셈형 noise의 세기Q 및 진동수폭 $\GAMMA$가 증가할 때는 감소함을 알 수 있었다.

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

  • 윤덕규;김재춘;김대현;이원석;정진택
    • 한국유체기계학회 논문집
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    • 제12권2호
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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.

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

  • 정혜경;우나리야;김미혜
    • 한국식생활문화학회지
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    • 제25권4호
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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.

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

  • 김미자;박금순
    • 한국식생활문화학회지
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    • 제25권6호
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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).

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

  • 장인우
    • 한국의상디자인학회지
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    • 제7권2호
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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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심층 강화학습 기반의 선박 항로계획 수립 (Generation of ship's passage plan based on deep reinforcement learning)

  • 이형탁;양현;조익순
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2023년도 추계학술대회
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    • pp.230-231
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    • 2023
  • 본 연구는 선박의 항해계획을 자동으로 수립하기 위한 심층 강화학습 기반 알고리즘을 제안한다. 먼저 부산항과 광양항을 대상지역으로 선정하고, 대상 선박으로 흘수 16m의 컨테이너선을 지정하였다. 실험 결과는 심층 강화학습을 사용하여 수립한 항해계획이 선행연구에서 활용한 Q-learning기반의 알고리즘보다 더 효율적인 것으로 분석되었다. 본 알고리즘은 선박의 항해계획을 자동으로 수립하는 방법을 제시하며, 해상 안전 및 효율성 향상에 기여할 수 있다.

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

  • 신지선;김종빈
    • 대한소아치과학회지
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    • 제44권3호
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    • pp.350-357
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    • 2017
  • 본 연구는 상악 정중과잉치에서 얻은 치수유래 줄기세포(human dental pulp stem cells from supernumerary tooth, sDPSCs)를 대상으로 분화능의 변화 특성을 알아보고자 하였다. 전신 병력이 없는 6세 남자아이 상악 중절치와 측절치 사이에 매복 된 과잉치를 발치하여 sDPSCs를 얻었다. 세포들을 16계대까지 배양하였고, 1 - 8계대는 Young군으로 9 - 16계대는 Old군으로 나누었다. 각 계대 배양에 소요된 시간은 Young군에서는 $2.25{\pm}0.46$일, Old군에서는 $3.25{\pm}0.46$일을 보였으며, 이는 통계적으로 유의한 차이를 보였다(p < 0.05). 각 계대 별로 세포 형태를 관찰하고 분화를 유도한 후 Alizarin-red solution 염색을 통해 골모세포(odontoblast)로 분화되는 정도를 관찰하였다. 1, 8, 9계대에서 분화제를 처리하지 않은 세포의 형태에서는 방추형의 섬유모세포와 유사한 길쭉한 형태로 과립(nodule)이 적었지만, 16계대에서는 세포의 크기가 커지고 넓적한 형태로 변하고 과립도 많아졌다. 1계대는 분화 7일부터 과립이 관찰되며, 8계대에서는 14일 동안 분화제를 처리한 후 과립이 명확히 관찰되었다. 그러나 9계대 이후에서는 과립의 빈도가 상당히 감소되었다. ARS 염색에서는 1, 8계대는 진한 붉은색으로 염색되었으나, 9, 16계대는 염색이 옅게 되었다. 이를 통해 sDPSCs는 8계대 이전의 세포를 줄기세포의 원천으로 우선 고려하는 것이 좋다고 사료된다.

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

  • 김귀곤;최준영
    • 한국조경학회지
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    • 제26권2호
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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
    • 한국동물위생학회지
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    • 제46권3호
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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.

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

  • 손영규;이창업;배광식;박문서;이선철
    • 대한기관식도과학회:학술대회논문집
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    • 대한기관식도과학회 1983년도 제17차 학술대회연제순서 및 초록
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    • pp.9.2-9
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    • 1983
  • 1972년 1월부터 1983년 3월까지 만 12년 3개월 동안 본원 이비인후과 내원한 식도 및 기도 이물 환자에 있어서 단순 흉부 방사선 검사상 발견되지 않았던 이물에 대한 임상 통계적 고찰을 한 결과 다음과 같은 성적을 얻었다. 1) 식도이물에 있어서 539례의 식도이물 중에서 56례 (10.4 %)가 기도이물, 25례 중 18례 (72.0 %)가 단순 흉부방사선 검사상 나타나지 않은 이물이었다. 2) 연령별로는 식도이물에서 21세 이상이 46례 (82.1 %) 였고, 기도이물은 5례 이하가 12례 (66.7 %) 이었다. 또한 위 연령군에서의 식도이물 중 육괴가 19례 (41.7 %), 골편이 15례 (32.6 %)로 주종을 이루었고, 아울러 양잿물 및 강산섭취 과거력을 가진 식도 협착증 환자가 7례 있었으며, 기도이물의 위 연령군에서는 플라스틱 제품이 7례 (58.3 %), 식물이 3례 (25.0 %)로 주종을 이루었다. 3) 성별빈도는 식도이물에서 여자 (55.4 %)가 남자(44.6 %) 보다 많았으며, 기도이물에서는 남자(55.5 %)가 여자 (44 5 %) 보다 많았다. 4) 이물의 종류별 빈도는 식도이물에서 육괴가 19례 (33.9 %), 골편이 17례 (30.4 %)순이었으며 ,기도이물에서는 플라스틱류가 9례 (49.9 %), 식물이 4례 (22.0%) 순으로 많았다. 5) 개재부위는 식도에서 제 1협착부가 가장 많았고(60.7 %), 기도에서는 기관지가 가장 많았으며(72.2 %) 특히 우측기관지가 많았다(50.0 %). 6) 개재기간은 식도이물의 경우 44례 (78.6 %)가 1 일이내에 내원하였고, 기도이물의 경우에서는 11례 (61.1 %)가 1 일이내 내원하였으며 25 일 경과후 내원한 경우도 1례가 있었다. 7)식도 및 기도이물의 전례에서 단순 흉부 방사선 촬영을 시행하였고, 이에 나타나지 않은 56례 식도이물을 대상으로 34례에서 식도조영술을 시행하였으며 이중 23례가 양성 소견을 나타냈다. 8) 식도경술에 의해 이물을 제거한 경우는 54례(96.4 %) 였으며, 기관지경술에 의해 이물을 제거한 경우는 14례 (77.8%) 였다. 9 ) 식도 이물에 의한, 또는 식도경술에 의한 합병증이 초래한 경우는 식도점막열상 1례 (1.8 %), 식도 천공 1례 (1.8 %) 였으며, 기도이물에 의한, 또는 기관지경술에 의한 합병증이 초래한 경우는 무기폐 2례 (11.1 %), 폐렴 3례 (16.7 %)로 나타났다.

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