• Title/Summary/Keyword: First passage time

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

  • Min, Seungsik
    • The Korean Journal of Applied Statistics
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    • v.29 no.3
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    • pp.425-435
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    • 2016
  • In this paper, we analyze the inverse statistics of rainfall for 12 regions from 1973 to 2014. We obtain a probability density function f(x) of daily rainfall x, and $f({\tau}_{\rho})$ of the first passage time ${\tau}_{\rho}$ for a given ${\rho}$. Lastly, we derive the relation between ${\rho}$ and ${\tau}_{mean}({\rho})$, i.e., the averaged value of ${\tau}_{\rho}$. The analyses result in the x and ${\tau}_{\rho}$ have stretched exponential distributions. Also, ${\tau}_{mean}({\rho})$ has the form of a stretched exponential function. We derive the shape parameter ${\beta}$ of the distribution, and analyze the characteristics of 12 regional rainfalls.

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

  • 김원영;정광화;노진식;김원호;전병수;류호현;전영륜
    • Journal of Animal Environmental Science
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    • v.4 no.2
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    • pp.161-166
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    • 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.

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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
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    • v.54 no.5
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    • pp.1017-1044
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    • 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
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    • v.49 no.2
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    • pp.143-150
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    • 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.

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

  • Lee, Sang-Min;Cho, Jae-Mo
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.1
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    • pp.53-62
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    • 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
    • Biomedical Science Letters
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    • v.27 no.2
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    • pp.99-104
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    • 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.

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

  • Lee, Hyoung-Ha
    • Journal of Digital Convergence
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    • v.18 no.6
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    • pp.513-522
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    • 2020
  • The purpose of this study is to analyze the auto-regression effect between the elderly's assets and depression and life satisfaction, and to approach the influence of assets and depression on the elderly's life from a longitudinal perspective. For this purpose, the data for the 9th year (2014), 11th year (2016), and 13th year (2018) of the Korea Welfare Panel were used. As a result of the analysis, First, the assets, depression and life satisfaction of the elderly have a lasting effect on the passage of time, and the assets, depression and life satisfaction of the previous point in time (B=.694, B=.725, p<.001), depression (B=.258, B=.331 and p<.001) and life satisfaction (B=.264, B=.265, p<.001). Second, cross-recursion coefficients show how the relationship between the assets of the elderly and depression and the satisfaction of life affects each other over time, and the assets of the older person at the previous point in time (B=.010, B=.011, p<.001), the assets of the older persons at previous times are subsequently satisfied with their lives (B=.128, B=.124, p<.001). Based on the results of the above analysis, it is necessary to support the elderly's asset management service and education to prevent depression, such as continuous asset utilization education.

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
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    • v.17 no.sup3
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    • pp.191-195
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    • 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.

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

  • Taekho Lee;Seokyoung Lee;Yoonsun Han
    • Korean Journal of Culture and Social Issue
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    • v.21 no.2
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    • pp.131-158
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    • 2015
  • This study examined the relationship between physical education and externalizing(aggression) and internalizing(depression, social withdrawal) problem behaviors among adolescents. The moderating role of gender and time in the association between physical education and problem behavior was also identified. This study used data from the second, third, and fourth waves of the middle school student cohort (N=2,133, N=2,151, N=1,979) of the Korean Children-Youth Panel Survey(KCYPS). Main analyses involved multilevel growth model with interaction terms. The dependent variables were aggression, depression, and social withdrawal. The independent variables were gender and physical education (exercise hours) at school. The control variables were abuse, school-adjustment, annual household income and parents' highest level of education. The major longitudinal findings of this study are as follows: First, there was significant change according to the passage of time only in aggression among externalizing and internalizing problems. Second, gender differences exist in aggression and depression. Third, exercise hours of physical education had a negative relationship with internalizing problems. Fourth, there were no gender differences over time in both externalizing and internalizing problems. Fifth, the interaction between exercise hours of physical education and time was statistically significant for social withdrawal. Sixth, the interaction between exercise hours of physical education and gender was statistically significant for depression. The results of this study may become an academic basis for suggesting policy directions that promote increased exercise hours in physical education classes at school.

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

  • Oh, Jun Oh;Park, Jae Hyeon;Jun, Sang Mi
    • Journal of Korea Water Resources Association
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    • v.53 no.4
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    • pp.303-312
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    • 2020
  • An underground deep tunnel system is a facility in form of a reverse siphon for an under flood defense structure. In this study, the 'Shinwol rainwater storage and drainage system', which is under construction for the first time in South Korea, in order to confirm the effects of undular bore and pressurized air on the hydraulic stability of the facility in various flood scenarios a hydraulic model experiment was performed. As a result of this study, it was analyzed that the undular bore generated downstream pushed the pressurized air collected in the facility while moving upstream, and the pressure inside the pipe increased at this time. It was analyzed that the pressure during the passage of the undular bore was greater than the sum of the static pressure and dynamic pressure at the time and overflow occurred when the cross-sectional size of the pressurized air was more than 40% of the cross sectional area of the tunnel. It is determined that this is correlated with the volume of pressurized air collected in the facility, and it is determined that it is necessary to study the relationship between velocity of undular bore and the volume of pressurized air in the future.