• Title/Summary/Keyword: First passage time

검색결과 139건 처리시간 0.029초

역통계 방법론을 이용한 한반도의 강수 특성 분석 (Analysis of the Korean peninsula precipitation using inverse statistics methodology)

  • 민승식
    • 응용통계연구
    • /
    • 제29권3호
    • /
    • pp.425-435
    • /
    • 2016
  • 본 논문에서는 1973년부터 2014년까지 42년 간, 12개 지역의 일일 강수량 데이터의 역통계(inverse statistics) 분석을 실시하였다. 구체적으로 일일 강수량 x의 확률밀도함수 f(x)를 도출하였고, 특정 강수량 ${\rho}$를 처음으로 넘어서는 기간 ${\tau}_{\rho}$의 분포 $f({\tau}_{\rho})$를 도출하였다. 최종적으로 ${\tau}_{\rho}$의 대푯값인 ${\tau}_{mean}({\rho})$${\rho}$의 관계를 도출하였다. 분석 결과 x와 ${\tau}_{\rho}$는 확장된 지수분포(stretched exponential distribution)를 이루는 것을 확인하였다. 더불어 ${\rho}$${\tau}_{mean}({\rho})$도 확장된 지수함수의 관계를 이루는 것을 알 수 있었다. 이들 분포를 바탕으로 형태 모수(shape parameter) ${\beta}$ 값을 도출하고, 12개 지역의 강수 특성을 분석하였다.

악취 발산감소를 위한 필터의 이용 효과 (Effect of Biofilter on Reducing Malodor Emission)

  • 김원영;정광화;노진식;김원호;전병수;류호현;전영륜
    • 한국축산시설환경학회지
    • /
    • 제4권2호
    • /
    • pp.161-166
    • /
    • 1998
  • Controlling malodor originating from livestock feces has become a major issue, due to its influence on the health of man and livestock, together with its influences on atmospheric pollution. In this study, Five types of biofilters filled with saw-dust, night soil, fermented compost, leaf mold and a mixture(a compound of night soil, fermented compost and leaf mold at the same rates, respectively) were manufactured and tested. To study the effect of the biofilter on reducing malodor in a composting facility and swine building, a pilot scale composting facility enclosed with polyethylene film was constructed. Swine feces was composted in the facility and malodorous gas generated from the decomposition of organic matter in the feces was gathered by vacuum pump. Each biofilter achieved 87∼96% NH3 removal efficiency. This performance was maintained throughout 10 days of operation. The highest NH3 removal efficiency was achieved by leaf mold on the first day of operation period. It reduced the concentration of NH3 by about 96%. Night soil and fermented compost showed nearly equal performance of 93 to 94% for 10 days from the beginning of operation. The mixture achieved the lowest NH3 removal efficiency. It reduced NH3 concentration by about 89∼94% for 10 days from the beginning of operation. However NH3 removal efficiency of each biofilter declined with the passage of operational time. After 30 days from the beginning of operation, NH3 removal efficiency of each biofilter of each biofilter was below 60%, respectively. The concentration of H2S and CH3-SH originating from compost were equal to or less than 5mg/l and 3mg/l, respectively. After passing throughout the biofilter, the concentration of H2S and CH3-SH were not detected.

  • PDF

Random vibration analysis of train-slab track-bridge coupling system under earthquakes

  • Zeng, Zhi-Ping;He, Xian-Feng;Zhao, Yan-Gang;Yu, Zhi-Wu;Chen, Ling-Kun;Xu, Wen-Tao;Lou, Ping
    • Structural Engineering and Mechanics
    • /
    • 제54권5호
    • /
    • pp.1017-1044
    • /
    • 2015
  • This study aimed to investigate the random vibration characteristic of train-slab track-bridge interaction system subjected to both track irregularities and earthquakes by use of pseudo-excitation method (PEM). Each vehicle subsystem was modeled by multibody dynamics. A three-dimensional rail-slab- girder-pier finite element model was created to simulate slab track and bridge subsystem. The equations of motion for the entire system were established based on the constraint condition of no jump between wheel and rail. The random load vectors of equations of motion were formulated by transforming track irregularities and seismic accelerations into a series of deterministic pseudo-excitations according to their respective power spectral density (PSD) functions by means of PEM. The time-dependent PSDs of random vibration responses of the system were obtained by step-by-step integration method, and the corresponding extreme values were estimated based on the first-passage failure criterion. As a case study, an ICE3 high-speed train passing a fifteen-span simply supported girder bridge simultaneously excited by track irregularities and earthquakes is presented. The evaluated extreme values and the PSD characteristic of the random vibration responses of bridge and train are analyzed, and the influences of train speed and track irregularities (without earthquakes) on the random vibration characteristic of bridge and train are discussed.

Incidence of pterygospinous and pterygoalar bridges in dried skulls of Koreans

  • Ryu, Sol-Ji;Park, Min-Kyu;Lee, U-Young;Kwak, Hyun-Ho
    • Anatomy and Cell Biology
    • /
    • 제49권2호
    • /
    • pp.143-150
    • /
    • 2016
  • Understanding of morphological structures such as the sphenoid spine and pterygoid processes is important during lateral transzygomatic infratemporal fossa approach. In addition, osseous variations such as pterygospinous and pterygoalar bridges are significant in clinical practice because they can produce various neurological disturbances or block the passage of a needle into the trigeminal ganglion through the foramen ovale. Two hundred and eighty-four sides of Korean adult dry skulls were observed to carry out morphometric analysis of the lateral plate of the pterygoid process, to investigate, for the first time among Koreans, the incidence of the pterygospinous and pterygoalar bony bridges, to compare the results with those available for other regional populations, and to discuss their clinical relevance as described on literatures. The mean of maximum widths of the left and right lateral plates of the pterygoid process were 15.99 mm and 16.27 mm, respectively. Also, the mean of maximum heights of the left and right lateral plates were 31.02 mm and 31.01 mm, respectively. The ossified pterygospinous ligament was observed in 51 sides of the skulls (28.0%). Ossification of the pterygospinous ligament was complete in four sides (1.4%). In 47 sides (16.6%), the pterygospinous bridge was incomplete. The ossified pterygoalar ligament was observed in 24 sides of the skulls (8.4%). Ossification was complete in eight sides (2.8%) and incomplete in 16 sides (5.6%). This detailed analysis of the lateral plate of the pterygoid process and related ossification of ligaments can improve the understanding of complex clinical neuralgias associated with this region.

안동지역 동성문중의 불천위제례 공간활용의 양상 (A Spatial Using Aspect of Bulcheonwi Rites in Each Family Clan Group of Andong Area)

  • 이상민;조재모
    • 대한건축학회논문집:계획계
    • /
    • 제34권1호
    • /
    • pp.53-62
    • /
    • 2018
  • Bulcheonwi is determined by various ways. The first is certified by the state. Kings granted posthumous names to figures such as meritorious retainers, figures whose mortuary tablets were put into Jongmyo Shrine, and venerated figures with erudition and virtue whose mortuary tablets were put into Munmyo (Korean primary Confucian shrine The purpose of this study is to understand the spatial perception of Main head families (大宗家) and Sub head families (小宗家) have been divided for several centuries. This study was conducted under the assumption that it was possible to understand the mutual influence and relationship between perception and space by examining how methods for ritual ceremonies held in Main head families were conducted in different spaces of Sub head families or the process of ritual ceremonies changed with space. Bulcheonwi rites was performed by each family's own concepts of spaces such as Jeongchim or Cheongsa For actual ritual space, An-chae, Sarang-Chae and Byeoldang was utilized. This shows that one family's conception and utilization of each space was correspondent also different family s had their own idea of utilizing different spaces. In addition depends on the family in this study, there was differences on positon of Sa-dang upon the regions or time of construction. This can be concluded as familes had their own accommodations depends on building's space layout and traditons rather than following traditional Rites book's the rules of decorum.

Anti-inflammatory Effects of Low-frequency Stimulator using Superposition of Alternating Microcurrent Wave in the Animal Models

  • Kim, Yoo-Jeong;Lee, Seong gwang;Go, Shin Jee;An, Suyeon;Kim, Ye eun;Kim, Ye in;Hyun, Kyung-Yae;Cho, Dong Shik;Choi, Go-Eun
    • 대한의생명과학회지
    • /
    • 제27권2호
    • /
    • pp.99-104
    • /
    • 2021
  • Treatment techniques that affect homeostasis by non-invasive regulation in peripheral organs will advance disease research. Here, we demonstrate a non-invasive method of conditioning within an organ using a low-frequency stimulator superposition of alternating microcurrent wave in stages. It is first applied to the inflammatory response in H3N2-infected sinusitis mice. To check the progress of the treatment, mice were sacrificed every week for 3 weeks, nasal tissue was removed, and the inflammatory response was investigated through H & E staining. The low-frequency stimulation treatment group was found to alleviate the proliferation of epithelial cells and invasion of inflammatory cells compared to the control group as the passage of treatment time. The reduction of inflammatory cytokines in the nasal lavage fluid was observed in H3N2-infected sinusitis mice treated with of low-frequency stimulation using superposition of alternating microcurrent wave compared to H3N2-infected sinusitis mice after 3 weeks. These data demonstrate that low-frequency stimulation device in the form of using alternating current wave superposition on within organs provides a new method to regulate specific physiological functions. Therefore, it is necessary to prove the inhibitory effect of low-frequency stimulation using alternating current wave superposition on inflammatory diseases by various methods through further studies and clinical studies.

노인의 자산과 우울 및 삶의 만족 간의 종단적 인과관계: 자기회귀교차지연모형의 적용 (A Longitudinal Causal Rrelationship Study on the Elderly's Assets, Depression and Llife Satisfaction: : The Application of Autoregressive Cross-lagged Model)

  • 이형하
    • 디지털융복합연구
    • /
    • 제18권6호
    • /
    • pp.513-522
    • /
    • 2020
  • 본 연구의 목적은 노인의 자산과 우울 및 삶의 만족 간의 자기회귀효과를 분석하고, 노인의 삶에 영향을 미치는 자산과 우울의 영향력을 종단적 관점으로 접근하기 위함이다. 이를 위해 한국복지패널 제9차년도(2014년), 제11차년도(2016년), 제13차년도(2018년) 가구원용 데이터를 이용하였다. 분석결과, 첫째, 분석대상 기간에 걸쳐 이전 시점의 자산, 우울 및 삶의 만족은 이후 시점의 자산(B=.694, B=.725, p<.001), 우울(B=.258, B=.331, p<.001) 및 삶의 만족(B=.264, B=.265, p<.001)에 유의한 정(+)적인 영향을 미치는 것으로 나타났다. 둘째, 교차회귀계수를 통해 분석대상 기간에 걸쳐 노인의 자산과 우울 및 삶의 만족 간의 관계가 상호간 어떠한 영향을 미치는지 확인한 결과, 이전 시점의 노인의 자산은 이후 시점의 우울(B=.010, B=.011, p<.001), 이전 시점의 노인의 자산은 이후 시점의 삶의 만족(B=.128, B=.124, p<.001)에 유의한 정(+)적인 영향을 미치는 것으로 확인되었다. 이상의 분석결과를 토대로 노인의 자산관리서비스와 지속적인 자산활용 교육 등의 우울 예방서비스 지원이 필요함을 제안하였다.

Epidemiology of Breast Cancer among Females in Basrah

  • Habib, Omran S;Hameed, Lamis A;Ajeel, Narjis A;Al-Hawaz, Mazin H;Al-Faddagh, Zaki A;Nasr, Ghalib N;Al-Sodani, Ali H;Khalaf, Asaad A;Hasson, Hasson M;Abdul-Samad, Aida A
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제17권sup3호
    • /
    • pp.191-195
    • /
    • 2016
  • Breast cancer is the most frequent cancer in females. Its incidence is higher in developed countries than in developing ones partly due to variation in risk exposure and partly due to better detection methods. Scattered evidence in Basrah, Iraq, suggests that breast cancer has been increasing at a significant pace in recent years. This study aimed to measure the current level of risk of breast cancer among females in Basrah and to describe the time trend over almost a decade of years. Data on breast cancer cases from all sources of cancer registration in Basrah governorate were compiled for the years 2005-2012. The data for each year were first checked separately for duplicate reporting of cases among various sources. Then the eight files were pooled together and checked again for any duplicate cases among years of registration. The final set of data contained 2,284 cases of breast cancer (2,213 female cases and 71 male cases). All patients were inhabitants of Basrah governorate at the time of diagnosis. Figures on the Basrah population were obtained from various sources including the Ministry of Health, Ministry of Planning and Developmental Collaboration and local household surveys. It was possible to have total population estimates for each year and by age and sex. The data were imported into SPSS (version 17) software. Age specific and year specific incidence rates were calculated. The age standardized incidence rate was also calculated using world population as the standard population to be 34.9 per 100,000 females. Age-wise, no case was reported among children aged less than 15 years and the incidence increased with advancing age reaching a peak of 123.8/100,000 females at the age range of 50-54 years. The time trend of the crude incidence rate showed only modest increased risk with passage of years and no age shift could be documented in this study. Breast cancer in females in Basrah is a significant health problem. The current incidence rate (crude, 23.7/100,000, age-standardized, 34.9/100,000) is high and justifies intensive efforts to improve early detection of cases, provide better treatment amenities and introduce long term preventive measures. Using the age standardized incidence rate as reported in this paper, it is possible to put the risk in Basrah within a regional and international context.

체육시간과 청소년의 외현화·내재화 문제와의 관계에서 성별의 조절효과: 다층성장모형의 적용 (The Moderating Effect of Gender in the Relationship between Physical Education and Adolescents' Internalizing and Externalizing Problem Behaviors: Using Multi-level Growth Modeling)

  • 이택호;이석영;한윤선
    • 한국심리학회지 : 문화 및 사회문제
    • /
    • 제21권2호
    • /
    • pp.131-158
    • /
    • 2015
  • 본 연구는 체육시간이 청소년의 외현화(공격성) 및 내재화(사회적 위축, 우울) 문제에 어떠한 영향을 미치는지, 그리고 그 영향이 시간의 흐름과 성별에 따라 다른지에 대해 분석하였다. 분석 자료로 한국청소년정책연구원(NYPI)에서 실시하는 한국아동·청소년 패널조사(KCYPS)의 중학교 1학년 패널의 2차년도(2011) 데이터(N = 2,133), 3차년도(2012) 데이터(N = 2,151), 4차년도(2013)데이터(N = 1,979)를 활용하였다. 종속변수를 공격성, 사회적 위축, 우울로 설정하고, 독립변수를 성별, 체육시간으로, 통제변수를 학대, 학교적응, 가구연간소득, 보호자 최종학력으로 설정한 뒤 다층성장모형을 적용하여 변인간의 관계를 종단적으로 살펴 본 결과는 다음과 같다. 첫째, 공격성 및 사회적 위축에서 시간의 흐름에 따라 유의한 변화가 있었다. 둘째, 공격성 및 우울에서 성별 차이가 나타났다. 셋째, 체육시간은 우울 및 사회적 위축에만 부적인 영향을 주었다. 넷째, 외현화 및 내재화 문제 모두 시간에 대한 성별의 영향이 변하지 않았다. 다섯째, 시간에 대한 체육시간의 상호작용은 사회적 위축에서만 유의하게 나타났다. 여섯째, 우울에서 체육시간에 대한 성별의 상호작용이 통계적으로 유의하게 나타났다. 이와 같은 연구 결과는 체육시간이 중요하다는 정책적 방향을 제시함으로써 학교 체육시간의 증가를 도모할 수 있는 연구적 기반이 될 것으로 기대해 본다.

  • PDF

불규칙 단파에 의한 신월 빗물저류배수시설 내 압력상승에 관한 실험 연구 (An experimental study on increased pressure in Shinwol rainwater storage and drainage system by undular bore)

  • 오준오;박재현;전상미
    • 한국수자원학회논문집
    • /
    • 제53권4호
    • /
    • pp.303-312
    • /
    • 2020
  • 지하 대심도 터널은 도시 홍수방어구조물로 역 사이펀 형태의 시설물이다. 본 연구에서는 국내 최초로 건설중인 '신월 빗물저류배수시설'을 대상으로 다양한 홍수시나리오에서 불규칙 단파와 압축공기가 시설의 수리적 안정성에 미치는 영향을 확인하기 위하여 수리모형실험을 수행하였다. 본 연구 결과 하류에서 발생한 불규칙 단파가 상류로 이동하면서 시설 내 포집되어 있던 압축공기를 상류로 밀어내고 이 때 관내 압력이 상승하는 것으로 분석되었다. 또한 불규칙 단파가 통과할 때의 압력이 당시 정압력과 동압력의 합보다 큰 것으로 분석되었으며 압축공기 단면의 크기가 터널 단면적의 40% 이상인 경우 월류가 발생하는 것으로 분석되었다. 이는 시설 내 포집되어 있는 압축공기의 부피와 상관이 있는 것으로 판단되며 향후 불규칙 단파 속도와 압축공기 부피와의 관계에 대한 연구가 필요할 것으로 판단된다.