• 제목/요약/키워드: First passage time

검색결과 139건 처리시간 0.037초

시계열자료의 효율적 군집분석을 위한 구간특징화와 계층적 베이지안 기법의 융합 (A Fusion of the Period Characterized and Hierarchical Bayesian Techniques for Efficient Cluster Analysis of Time Series Data)

  • 정영애;전진호
    • 디지털융복합연구
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    • 제13권7호
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    • pp.169-175
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    • 2015
  • 주가지표처럼 동적이며 시간흐름을 따르는 시계열자료들을 이해하는 효과적인 방법은 주어진 시계열자료들에 대하여 모델을 결정함으로서 이해하는 것이 좋다. 주어진 자료들에 대한 모델 결정과정은 수집되어진 대용량 시계열자료 전체를 한 번에 다 살펴보는 것보다 자료를 특정의 중요한 몇 개의 하위그룹으로 군집화하여 각 군집별 모델결정을 통해 자료 전체를 이해하는 것이 효율적이다. 본 연구에서는 주어진 시계열자료들에 대하여 하위그룹으로의 효율적 군집화 과정 그리고 각 군집별 모델결정의 두 과정 중 첫 번째 과정인 하위집단으로 군집화 과정에 자료의 구간특징화 기법과 휴리스틱 베이지안기법의 융합을 이용하여 시간 및 계산비용을 감소시킬 수 있는 기법을 제안하였으며 실제적인 주가지표를 이용한 실험을 통해 제안하는 기법의 유효성을 확인하였다.

Time-Lapse 촬영방법을 이용한 도심 광장의 이용행태에 관한 연구 -청량리 역광장을 사례로- (The Observationi of User Behaviors of the Urban Plaza using Time-Lapse Record-A case study of Chungryangri Station Plaza-)

  • 조창완;진양교
    • 한국조경학회지
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    • 제26권3호
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    • pp.199-212
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    • 1998
  • The ultimate goal of this study can be summed up as follows: First, the utility of Time-Lapse that observes and records people's behavior will be shown and its merits and demerits will be discussed through comparing with other data-collecting methods such as the naked- eye observation, and the specific way in which Time-Lapse can be put to use will be suggested. Second, analysis of use behavior boserved in the plaza of Chungryangri station by Time-Lapse will be made, on the basis of which suggestions will be made concerning planing, designing, layout, and management of the station plaza. Time-Lapse can observe and records the plaza of Chungryangri Staton through 6 different ways of recording in Time-Lapse: 30 seconds, every minute, every two minutes, second every five minutes, every one tenth of a second, and every one fifth of a second, and these different ways of recording were analyzed through comparison from one to each other to check their respective utilities. And also analysis of tracks of pedestrians, density, and use behavior of users were made, according to which the way in which Time-Lapse can be utilized was examined. Several useful results obtained from this study are shown as follows. First, Time-Lapse made it possible to continuously observe for a long time using minimu efforts, and a single tape which is able to cover from 12 hours up to 25 days is useful for observing variation of behavior in space with the passage of time and seasons. Second, among six ways of recording, the recording every one tenth of a second and every one fifth of a second are useful for finding the tracks of pedestrians, the number of users, the member compositions, the time spent in one place, and manner of use. And besides the moving direction and its purpose can be recognized in a short time, which makes it possile to see where crossings of moving directions occur. Third, the recording every thirty seconds, every minute, every two minutes, and every five minutes are useful for analyzing the density in space as well as for finding the number of users and frequency of facilities use. In particular the recording every thirty seconds made it possible to keep the track of pedestrians' walking, and to observe even slowly moving motions such as cleaning. But when the recording interval exceeds one minute, this was not possible. Fourth, time-lapse has advantages over the naked eye observation in several respects. Time-lapse can measure observed behavior and density in terms of number, and locate the position of users. Time-Lapse, if accompanied by other methods such as interviewing and question that can examine psychological aspects like satisfaction or the purpose of use and be a useful device for space studies.

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Macrophages Promote Coal Tar Pitch Extract-induced Tumorigenesis of BEAS-2B Cells and Tumor Metastasis in Nude Mice Mediated by AP-1

  • Zhang, Peng;Jin, Yue-Fei;Zhang, Qiao;Wu, Yi-Ming;Wu, Wei-Dong;Yao, Wu;Wu, Yong-Jun;Li, Zhi-Tao;Zhao, Yong;Liu, Yu;Feng, Fei-Fei
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권12호
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    • pp.4871-4876
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    • 2014
  • Background: We sought to evaluate the role of tumor associated macrophages (TAMs) on the promotion of coal tar pitch extract (CTPE)-induced tumorigenesis of human bronchial epithelial cells (BEAS-2B) and tumor metastasis in nude mice, and related mechanisms. Materials and Methods: BEAS-2B cells were first treated with 2.4 mg/mL CTPE for 72 hours. After removal of CTPE, the cells were continuously cultured and passaged using trypsin-EDTA. THP-1 cells were used as macrophage-like cells. BEAS-2B cells under different conditions (n=6/group) were injected into the back necks of nude mice, and alterations of tumor xenograft growth, indicative of tumorigenicity, and tumor metastasis were determined. Pathological changes (tumor nests and microvascular lesions) of HE-stained tumor tissues were also evaluated. The expression of AP-1(c-Jun) in xenografts and metastatic tumors was determined using immunohistochemistry. Results: Tumor size and weight in nude mice transplanted with the mixture of CTPE-induced passage 30 BEAS-2B and THP-1 cells (2:1) were increased compared to those from the CTPE-treated BEAS-2B cells at passage 30 alone at different observation time points. Tumor metastasis to lymph nodes and liver was only detected after transplantation of a mixture the two kinds of cells. The numbers of tumor nests and microvascular lesions, and the expression levels of AP-1 (c-Jun) in tumors from the mixture of two kinds of cells were increased apparently in contrast to those in tumor from the CTPE-treated BEAS-2B cells of passage 30 alone. In addition, there was positive correlation between AP-1 (c-Jun) expression level and the number of microvascular lesions, or between AP-1 (c-Jun) expression level and tumor metastasis in these two groups. Conclusions: TAMs not only facilitate tumorigenesis transformation of CTPE-induced BEAS-2B cells, but also promote tumor growth, angiogenesis and metastasis in nude mice in vivo, which may be mediated by AP-1.

Targeting of COX-2 Expression by Recombinant Adenovirus shRNA Attenuates the Malignant Biological Behavior of Breast Cancer Cells

  • Tu, Bo;Ma, Ting-Ting;Peng, Xiao-Qiong;Wang, Qin;Yang, Hong;Huang, Xiao-Ling
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권20호
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    • pp.8829-8836
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    • 2014
  • Background: Cyclooxygenase-2 (COX-2), considered to have tumor-promoting potential, is highly expressed in a variety of tumors, including breast cancer. Since the functions and action mechanisms of COX-2 in breast cancer have not been fully elucidated, in the present study, the effects of target inhibiting COX-2 with recombinant adenovirus Ad-COX-2-shRNA on malignant biological behavior were investigated in representative cell lines. Materials and Methods: Breast cancer MDA-MB-231 and MCF-7 cells were transfected with Ad-COX-2-shRNA and COX-2 expression was tested by RT-PCR and Western blotting. Changes in proliferation, apoptosis and invasion of breast cancer cells were detected with various assays including MTT, colony forming, flowcytometry and Transwell invasion tests. The expression of related proteins involved in the cell cycle, apoptosis, invasion and signaling pathways was assessed by Western blotting. Results: COX-2 expression was significantly reduced in both breast cancer cell lines infected with Ad-COX-2-shRNA, with obvious inhibition of proliferation, colony forming rate, G2/M phase passage and invasion, as well as induction of apoptosis, in MDA-MB-231 and MCF-7 cells, respectively. At the same time, proteins related to the cell cycle, anti-apoptosis and invasion were significantly downregulated. In addition, c-myc expression and phosphorylation activation of Wnt/${\beta}$-catenin and p38MAPK pathways were reduced by the Ad-COX-2-shRNA. Conclusions: COX-2 expression is associated with proliferation, apoptosis and invasion of breast cancer cells, and its mechanisms of action involve regulating expression of c-myc through the p38MAPK and Wnt/${\beta}$-catenin pathways.

경험적 직교함수를 이용한 북서태평양 열대저기압의 이동빈도 특성에 관한 연구 (A Study on the Characteristics of Tropical Cyclone Passage Frequency over the Western North Pacific using Empirical Orthogonal Function)

  • 최기선;강기룡;김도우;황호성;이상룡
    • 한국지구과학회지
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    • 제30권6호
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    • pp.721-733
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    • 2009
  • 북서태평양에서 발생하는 열대 저기압의 이동경로에 대한 변화패턴을 1951-2007년의 열대 저기압 경로 자료에 경험적 직교함수(Empirical Orthogonal Function, EOF)법을 적용하여 분석하였다. 북서태평양을 $5^{\circ}\times5^{\circ}$의 격자간격으로 나뉘어 연별 열대 저기압의 이동빈도를 각 격자에서의 변수로 정의하였다. 첫번째 모드는 동서성분(동경125도 기준)을, 두번째 모드는 남북성분(필리핀 동쪽해상에서 남지나해를 가로지르는 축 중심)을, 그리고 세번째 모드는 대각성분(타이완 동쪽 해상을 중심으로 동북방향과 동남방향을 축으로 하는)으로 나누어짐을 알 수 있었다. 첫번째와 두번째 모드의 주성분 시계열에서 각각 1997년과 1991년 부근을 기점으로 해서 주성분들의 부호가 교차되는 데, 이는 1990년대 이전 약 20년 동안에 남중국해 부근지역에서의 열대 저기압 이동 빈도가 동아시아 중위도 지역에서는 최근 20년 동안에 더 높았던 것과 관련성이 있는 것으로 보였다. 열대 저기압 발생의 경우, 첫번째와 두번째 모드에서 고유벡터 값이 음이고 진로가 북서태평양으로 주로 이동했던 열대 저기압은 고유벡터가 양의 값을 보였던 열대 저기압보다 더 동쪽에서 발생했던 것으로 나타났다. 이동특성에 있어 첫번째 모드는 바이칼호 남쪽에서 형성되는 기압 패턴에, 두번째 모드는 $30^{\circ}N$ 부근을 중심으로 남과 북 사이에 형성된 진동패턴에, 세번째 모드는 일본 부근에 위치한 기압패턴에 의해 열대 저기압의 이동경향이 많은 영향을 받는 것을 알 수 있었다. 또한, 해수면 온도 아노말리 값과 상관분석결과 첫번째 모드는 $Ni\tilde{n}o$-3.4 지수와 높은 음의 상관관계를 보여 ENSO의 영향을 받고 있음을 알 수 있었다.

부산지역 2021년 2월 1일~2일 연속적인 2개의 한랭전선 통과 시 기상요소와 미세먼지 농도의 특성 (Meteorological Parameters and Fine Particle Concentration during Two Successive Cold Fronts in Busan on 1~2 February 2021 )

  • 전병일
    • 한국환경과학회지
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    • 제31권12호
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    • pp.1069-1078
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    • 2022
  • This study investigated the weather conditions, fine particle concentration, and ion components in PM2.5 when two cold fronts passed through Busan in succession on February 1 and 2, 2021. A analysis of the surface weather chart, AWS, and backward trajectory revealed that the first cold front passed through the Busan at 0900 LST on February 1, 2021, with the second cold front arriving at 0100 LST on February 2, 2021. According to the PM10 concentration of the KMA, the timing of the cold front passage had a close relationship with the occurrence of the highest concentration of fine particles. The transport time of the cold front from Baengnyeongdo to Mt. Gudeok was approximately 11 hours . The PM10 and PM2.5 concentrations in Busan started to increase after the first cold front had passed, and the maximum concentration occurred two hours after the second cold front passed. The SO42-, NO3-, and NH4+ concentration in PM2.5 started to increase from 1100 to 1200 LST on February 1, after the first cold front passed, and peaked at 0100 LST to 0300 LST on February 2. However, the highest Ca2+ concentration was recorded 2-3 hours after the second cold front had passed.

아파트 단지(團地) 외부공간(外部空間)의 빛 환경(環境)에 관(關)한 연구(硏究) (A Luminous Environment of Outdoor Spaces in Apartment Complexes)

  • 권소영;하미경;이효창
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2006년도 추계학술발표대회 논문집
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    • pp.237-241
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    • 2006
  • The Qualitative improvements of outdoor spaces are unsatisfactory in comparison with that of indoor environment in existing apartments. Lately construction companies are differentiating the outdoor spaces of apartment complexes to meet needs of residents. However, high-rise buildings inherently have limitations on providing exposure to the outdoor settings and inappropriate lightings could have serious impacts on physical and psychological health of residents. Therefore, the purpose of this study is to provide useful information for the luminous environment of outdoor spaces through the analysis of current apartment complexes' lighting plans. Outdoor space of branded apartment complexes in Seoul, built after the year 2003, were researched. Through site visits, illumination level and lighting plans were investigated classified into entry area, passage area, plaza, rest area, exercise area, and play area. With the result, illumination level of apartment complexes researched was lower than KS illumination standard in all areas and the lighting plans were mostly shown in different condition of first intended lighting plan because of insufficiency of maintenance in lighting system. Therefore, it is need to provide better luminous environment to make outdoor space more lively and energetic at the night time.

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A new culture system for in situ observation of the growth and development of Eucyclops serrulatus (Copepoda: Cyclopoida)

  • PARK Sung-Hee;CHANG Cheon-Young;SHIN Sung-Shik
    • Parasites, Hosts and Diseases
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    • 제43권4호
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    • pp.141-147
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    • 2005
  • A practical and convenient method of rearing Eucyclops serrulatus in a microculture environment is described. A complete life cycle of E. serrulatus was maintained in a narrow space on a microscope slide glass on which a cover glass of $22{\times}40mm$ in size was mounted at a height of 0.8mm. The culture medium was constituted by bottled mineral water boiled with grains of Glycine max (soybean). Chilomonas paramecium, a free-living protozoan organism, was provided as live food. Growth of nauplii hatched from eggs to the first stage of copepodite took an average of 7.7 days, and the growth of copepodite 1 to the egg-bearing adult female took an average of 20.1 days in the microculture cell with an average life time of 44.7 days. Continuous passage of cope pods was successfully maintained as long as sufficient medium and food were provided. The microculture method enables an in situ microscopic observation on the growth and developmental process of helminth larvae experimentally infected to copepods as well as of copepod itself. Furthermore, it does not require anesthetization and, therefore, minimize the amount of stress exposed to cope pods during the handling process.

생간탕(生肝湯)의 효능(效能)에 관(關)한 임상적(臨床的) 연구(硏究) (A Clinical Study on the Effects of Saenggan-tang)

  • 이보형;김덕호;우홍정;김병운
    • 대한한방내과학회지
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    • 제11권1호
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    • pp.29-40
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    • 1990
  • In order to study the effect on liver diseases, Saenggan-tang has been applied to 26 patients of chronic hepatitis, 9 patients of liver cirrhosis, 5 patients of acute hepatitis, 8 patients of alcoholic liver diseases, 1 patient of hepatoma total 49 patients visiting the first internal medicine department of the hospital of Oriental Medicine, Kyung Hee University. The Saenggan-tang was taken every 4 weeks (ecept acute hepatitis every 2 weeks). 1. Saenggan-tang had decrease on activity of SGOTF SGPT, with the passage of time, 4, 8, and 12 weeks, showing statistically significant effect. 2. Saenggan-tang revealed sharp decrease on levels of total bilirubin and alkaline phosphatase no showing significance in relation to a few cases 3. Serum protein total and albumin levels were in normal limit before or after Saenggan-tang treatment 4. Triglyceride level was lowered remarkably after Saenggan-tang treatment, showing significance in alcoholic liver disease group whereas no significance in chornic hepatitis Judging from above results, it is proved that Saenggan-tang has curative effect of liver diseases such as acute, chronic hepatitis, liver cirrhosis, alcobolic liver diseases and so on.

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녹차의 정유성분에 대한 특성 및 분석 (Characteristics and Analysis on the Refined Oil Component of Green-Tea)

  • 성기천
    • 한국응용과학기술학회지
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    • 제22권3호
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    • pp.241-249
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    • 2005
  • This experiment extracted the natural green-tea using ethanol and obtained the refined oil component after filterated green-tea extract. This study tested the antimicrobial effect as characteristics experiment, and analyzed refined oil component with pH-meter and GC/MS. In the result of this experiment, it obtained the next conclusions. In the first result of extraction experiment, it could know that extraction ratio of refined oil component appeared about 9.0%. In the second result of characteristics experiment, it could certificate that in case of increasing the refined oil component in concentration of 100ppm and above, and according to passage of cultivation time, the number of S-aureus and E-coli in microbe decreased less and less. But in case of blank test not adding the refined oil component, the number of microbe increased more and more. In these phenomena, it could certificate that refined oil component of green-tea appeared antimicrobial effect against microbe. In the third result of instrumental analysis, refined oil component of green-tea appeared about 7.6 in 1% distilled water solution with pH-meter, and the aromatic components of benzene, bonyl acetate, campene, ${\alpha},{\beta},{\gamma}$-pinnene etcs from refined oil component of green-tea was detected with GC/MS.