• Title/Summary/Keyword: first-passage time

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Effect of Landfill Site Characteristics on Siloxane Production in Landfill Gas (매립지 특성이 매립가스 내 siloxane 발생에 미치는 영향)

  • Nam, Sangchul;Kang, Jeong-Hee;Hur, Kwang-Beom;Lee, Nam-Hoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.19 no.3
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    • pp.44-53
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    • 2011
  • Siloxane, organo-silicon compound, is used in the various forms of products such as cosmetics and detergents due to its quality physical chemistry attributes. Siloxane included in landfill gas which is caused in the process of decomposing of such products after landfill has imposed negative impacts on the operation of landfill gas utility facilities. The objective of this study was to investigate the siloxane production characteristics depending on the features of various landfill site in Korea so that the analysis was made on the landfilling age and landfill waste by in terms of its concentration, structure and composition. As for the concentration of siloxane depending on time passage, 12 landfill sites were reviewed by landfilling age. As for production attributes change of siloxane by landfill wastes, the source of wastes, physical production ration and siloxane concentration were compared in 6 landfills. The average concentration of total-siloxane within LFG is $6.75mg/m^3$ and cyclic-siloxane out of it occupies over 93%. By element, D4 and D5 in order take the highest proportion regardless of total-siloxane concentration and landfilling age. Even though this study is not able to verify the different impact of each kind of wastes on the generation of siloxane, it is confirmed that total-siloxane and cyclic-siloxane decrease in line with the increase of landfilling age as it does in the first order decay model for landfill gas.

Permanent Hypothyroidism after Radioactive Iodine($^{131}I$) Treatment in Diffuse Toxic Goiter (독성미만성갑상선종환자에서 방사성옥소(放射性沃素)($^{131}I$)투여후(投與後) 발생(發生)하는 영구적갑상선기능저하증(永久的甲狀腺機能低下症))

  • Park, Seon-Yang;Lee, Jung-Sang;Lee, Hong-Kyu;Koh, Chang-Soon;Lee, Mun-Ho
    • The Korean Journal of Nuclear Medicine
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    • v.11 no.1
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    • pp.39-48
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    • 1977
  • Radioactive iodine(RAI), principally $^{131}I$, effectively controls hyperthyroidism in the majority of patients. The subsequent development of hypothyroidism, however, has been of increasing concern since it was first pointed out by Chapman and Maloof in 1955. And the steady increase of late hypothyroidism during the passage of time was known with its relation with dosage of RAI. The authors have investigated the development of hypothyroidism in 935 patients with diffuse toxic goiter(DTG) who were treated with ($RAI^{131}I$) at the Seoul National University Hospital from 1960 to 1977 to reveal its relation with the number of RAI treatments, dosage of RAI, age of patients and exophthalmos with the following results. 1) The incidence of hypothyroidism by year after RAI therapy among 631 patients with DTG who were treated with single RAI regimen was 7.4%(1 year), 11.8%(2 year), 16.2%(3 year), 22.1%(4 year) and 25.5%(5 year), and that among 163 patients given multiple RAI treatments was 8.6%(1 year), 10.4%(2 year), 13.3%(3 year), 29.1%(4 year), and 54.1%(5 year)respectively showing much higher year1y increments from 4 years after RAI treatment. in comparison with the former. 2) Among 550 patients in the lower dose group treated with single RAI regimen less than 5.0mCi ($Mean{\pm}S.D.:\;4.3{\pm}0.6mCi$), the incidence of hypothyroidism by year after RAI treatment was 6.8%(1 year), 11.4%(2 year), 15.4%(3 year), while among 81 patients in the higher dose group given single RAI treatment not less than 5.5 mCi ($Mean{\pm}S.D.:\;6.3{\pm}0.5mCi$) it was 12.0%(1 year), 15.4%(2 year) and 20.4%(3 year) respectively. However, the duration till euthyroid state after RAI therapy in the two groups was $5.1{\pm}3.6$ months and $4.8{\pm}2.8$ months respectively showing no statistically signficant difference (p>0.1). 4) The incidence of hypothyroidism after RAI treatment in patients younger than 30 years of age was 4.3%(1 year) and 7.7%(2 year); in patients from 30 years to 49 years of age, 5.8%(1 year) and 11.1%(2 year); and in those older than 50 years, 11.0%(1 year) and 14.4%(2 year). The data revealed rising incidence of hypothyroidism with increase of patients' age. 4) Among 116 patients with exophthalmos the incidence of hypothyroidism by year after RAI treatment was 7.1%(1 year) and 12.1%(2 year) while that among 184 patients without exophthalmos was 7.3%(1 year) and 12.2%(2 year) respectively. With the above data the authors could conclude that the hypothyroidism in patients with DTG who were treated by RAI developed more frequently than reported by others in Korea till now, and increased with the passage of time, the yearly increments from 4 years after RAI treatment increasing markedly in the multiple dose group, and the incidence could be reduced by decreasing the administered RAI doe not increasing the duration till euthyroid state after RAI therapy.

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Treatment Characteristics Using Full-Scale SBR System (Full-Scale SBR 공법을 이용한 처리특성)

  • Choo, Tai-Ho;Lee, Yong-Doo;Cho, Yong-Hyun
    • The Journal of the Korea Contents Association
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    • v.6 no.10
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    • pp.34-40
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    • 2006
  • In this study, the treatment of organic matters and nutrients like Nitrogen and Phosphorus with sequencing batch reactors (SBR) was conducted. The following conclusions can be summarized from the study. The influent BOD concentration was varied 19.6 to 40.0mg/L and the effluent was 3.0 to 14.8mg/L. The variations of BOD removal efficiency during the experimental period was $47.9{\sim}88.4%$ and the average was 80.8%. The average removal efficiency was stabilized with the passage of time. Also the COD concentration was flowed into as $12.2{\sim}32.0mg/L$ and the effluent concentration was varied 3.3 to 18.6 mg/L, and then the average COD removal efficiency was 57.3%(minimun 19.2% and maximum 78.6%). But fortunately, the COD removal efficiency was also stabilized as 70.2% after 79days. In the case of T-N, the influent concentration range was $7.53{\sim}14.99mg/L$ and the effluent concentration was 6.59mg/L(the average removal efficiency was 40.3%) until the first experiment time 79days. But after normalizing the system, it was 4.44mg/L (the average removal efficiency was 56.4%). Also the influent T-P concentration was varied from 0.77 to 1.91mg/L and the effluent concentration was $0.26{\sim}1.53mg/L$. The removal efficiency was varied from 5.3 to 71.7%. considerably, therefore the average removal efficiency was 42.6%. The reason was concluded that the sludge wasn't discharged for increasing MLSS concentration.

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Estimation of Road-Network Performance and Resilience According to the Strength of a Disaster (재난 강도에 따른 도로 네트워크의 성능 및 회복력 산정 방안)

  • Jung, Hoyong;Choi, Seunghyun;Do, Myungsik
    • International Journal of Highway Engineering
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    • v.20 no.1
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    • pp.35-45
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    • 2018
  • PURPOSES : This study examines the performance changes of road networks according to the strength of a disaster, and proposes a method for estimating the quantitative resilience according to the road-network performance changes and damage scale. This study also selected high-influence road sections, according to disasters targeting the road network, and aimed to analyze their hazard resilience from the network aspect through a scenario analysis of the damage recovery after a disaster occurred. METHODS : The analysis was conducted targeting Sejong City in South Korea. The disaster situation was set up using the TransCAD and VISSIM traffic-simulation software. First, the study analyzed how road-network damage changed the user's travel pattern and travel time, and how it affected the complete network. Secondly, the functional aspects of the road networks were analyzed using quantitative resilience. Finally, based on the road-network performance change and resilience, priority-management road sections were selected. RESULTS : According to the analysis results, when a road section has relatively low connectivity and low traffic, its effect on the complete network is insignificant. Moreover, certain road sections with relatively high importance can suffer a performance loss from major damage, for e.g., sections where bridges, tunnels, or underground roads are located, roads where no bypasses exist or they exist far from the concerned road, including entrances and exits to suburban areas. Relatively important roads have the potential to significantly degrade the network performance when a disaster occurs. Because of the high risk of delays or isolation, they may lead to secondary damage. Thus, it is necessary to manage the roads to maintain their performance. CONCLUSIONS : As a baseline study to establish measures for traffic prevention, this study considered the performance of a road network, selected high-influence road sections within the road network, and analyzed the quantitative resilience of the road network according to scenarios. The road users' passage-pattern changes were analyzed through simulation analysis using the User Equilibrium model. Based on the analysis results, the resilience in each scenario was examined and compared. Sections where a road's performance loss had a significant influence on the network were targeted. The study results were judged to become basic research data for establishing response plans to restore the original functions and performance of the destroyed and damage road networks, and for selecting maintenance priorities.

The development of parallel computation method for the fire-driven-flow in the subway station (도시철도역사에서 화재유동에 대한 병렬계산방법연구)

  • Jang, Yong-Jun;Lee, Chang-Hyun;Kim, Hag-Beom;Park, Won-Hee
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.1809-1815
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    • 2008
  • This experiment simulated the fire driven flow of an underground station through parallel processing method. Fire analysis program FDS(Fire Dynamics Simulation), using LES(Large Eddy Simulation), has been used and a 6-node parallel cluster, each node with 3.0Ghz_2set installed, has been used for parallel computation. Simulation model was based on the Kwangju-geumnan subway station. Underground station, and the total time for simulation was set at 600s. First, the whole underground passage was divided to 1-Mesh and 8-Mesh in order to compare the parallel computation of a single CPU and Multi-CPU. With matrix numbers($15{\times}10^6$) more than what a single CPU can handle, fire driven flow from the center of the platform and the subway itself was analyzed. As a result, there seemed to be almost no difference between the single CPU's result and the Multi-CPU's ones. $3{\times}10^6$ grid point one employed to test the computing time with 2CPU and 7CPU computation were computable two times and fire times faster than 1CPU respectively. In this study it was confirmed that CPU could be overcome by using parallel computation.

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Internet health information of kindergarten teachers Conditions for recognition and utilization (유치원 교사의 인터넷 건강지식에 대한 정보 인식 및 실태)

  • Yoo, Ji-Eun;Son, Eun-Kyoung;Kim, Sook-Hee;Son, Hae-Kyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.5931-5941
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    • 2015
  • It should be given the opportunity to acquire information about the health of infants for a new type of way of life with the passage of time, of which the internet is a lot of people are required to use the media in the modern world. So, we want to find out the status of kindergarten teachers' internet utilizing and how to utilize the internet health information on field. The purpose of this study is to explore the direction of improvement. We produce this research based on a precedent study about perception and actual condition of health information utilizing. The objects of this study are 180 kindergarten teachers working in Dae-jeon and most of them have experience of searching health information through internet. The collected data calculated frequency and percentage with SPSS 18.0 program. As a result, first, kindergarten teachers think the information of infants' health is relatively important, still they obtain it from the Internet. But they feel a difficulty in finding the proper information because it takes so much time. Second, they utilize the Internet whenever necessary to find health information and they could find it. However, health information obtained from the Internet, have not been unexpectedly useful. Therefore, training about the content of infant's health and utilizing method of internet health information is needed.

The development of the theory of yin and yang in the ancient East Asian culture (东亚古代文化中的阴阳理论之嬗变)

  • 刘萍
    • Journal of the Daesoon Academy of Sciences
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    • v.18
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    • pp.101-122
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    • 2004
  • When people discuss the continental cultural elements in the ancient East Asian culture, people always attach great importance to the two major cultures of Confucianism and Taoism, but offer little explanation to the significant influence of the theory of yin and yang, the important philosophical base of the two major cultures. The theory of yin and yang, existing as the theoretical source at a profounder level, possesses philosophical connotations that are always embedded into the mainstream of thought, religions and customs, displaying its unique glamour in its unique way. Its influence is more than that, however. It has exerted far-reaching influence on and is of significant importance to the development of the ancient culture of East Asia. This article aims at exploring this field of study. After the erudite scholar of The Five Classics made a voyage to the east in the early sixth century, The Book of Changes, the most important Chinese ancient classic expounding the theory of yin and yang, started to circulate among the Japanese court, via Baiji in the Korea Peninsula. As a result, the theory of yin and yang found its way to Japan. Examining the spreading channels, we learn that the theory's dissemination was largely related to the activities of Buddhist monks. Shoutoku Prince, regent of Japan at the time, was himself an enthusiastic supporter of Buddhism and was excelled in the study of The Book of Changes and the theory of yin and yang. In the Twelve Ranks System and Seventeen-article Constitution promulgated by Shoutoku Prince, the influence of the theory of yin and yang and of the theory of the five elements can be visibly discerned. This obviously proves the sublime status of the Chinese theory of yin and yang in Japan, thanks to the victory of the political clique that adored Buddhism. In the shaping course of ancient Japanese culture, the theory of yin and yang served as an important philosophical source of its development. Mythology based on Kojiki and Nihon Shoki, two earliest Japanese books that exist today, record mythological stories about the emergence of the Japanese nation. The notion about the birth of heaven and earth and the forming of Japanese Shinto, expressed in the mythological stories, not only tell us the source and historical progress of the Japanese nation but also the nation's world outlook in the transition from barbarian period to civilized period, as well as the basis for its philosophical thinking. All these were marked with profound influence of the Chinese theory of yin and yang. The theory of yin and yang, as one of the ancient Chinese academic thoughts, was accepted asa political belief when it first spread to Japan. The emergence and establishment of both the Mikado system and the centralized regime in ancient Japan drew largely on the theory of yin and yang and adopted it as an important philosophical basis to deify and aggrandize the "imperial power" so as to protect the authority of the imperial ruling and consolidate the established regime. Following the continuous strengthening and expansion of the centralized state power, the theory of yin and yang was further employed, and gradually "hidden" in Japanese culture with the passage of time, finally becoming the edge tool of ancient Japanese Mikados in exercising political power and controlling the country.

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A Longitudinal Study on the Parenting Effectiveness of Multicultural Families and Self-esteem and Achievement Motivation of Multicultural Adolescents: Verification of Autoregressive Cross-lagged Model

  • Lee, Hyoung-Ha
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.11
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    • pp.209-218
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    • 2019
  • The purpose of this study is to longitudinally analyze the relationship between parenting effectiveness of parents of multicultural families and self-esteem and achievement motivation of multicultural adolescents. The study used the data of Multi-cultural Adolescent Panel Survey (MAPS). Of the six years of data from the 1st survey (elementary grade 4 students) in 2011 to the 6th survey ($3^{rd}$ year middle school students) in 2016, this study employed and analyzed the data from year 2012 ($2^{nd}$ survey, fifth graders), year 2014 ($4^{th}$ survey, 1st year middle school students), and year 2016 ($6^{th}$ survey, $3^{rd}$ year middle school students). The results of applying the Autoregressive Cross-lagged Model to examine the longitudinal relationship between parenting effectiveness of multicultural families and self-esteem and achievement motivation of multicultural adolescents are as follows. First, parenting effectiveness of parents of multicultural families, and self-esteem of multicultural adolescents, and autoregressive effects of achievement motivation were found to have a positive (+) effect with the passage of time. Second, the parenting effectiveness of parents of multicultural families at the previous time was found to have a significant positive (+) effect on the cross-lagged effect on self-esteem and achievement motivation of multicultural adolescents at a later time. Third, the self-esteem of multicultural adolescents at the previous time at the previous time was found to have a significant effect in the positive (+) direction on the cross-lagged effect affecting achievement motivation of multicultural adolescents at a later time. Fourth, it was found that the cross-lagged effect of the parenting effectiveness of parents of multicultural families on achievement motivation of multicultural adolescents was greater than the cross-lagged effect of self-esteem on achievement motivation of multicultural adolescents. This study is meaningful in that the longitudinal data are used to verify the causal orientation between three variables over time to examine the relationship between parenting effectiveness of parents of multicultural families and self-esteem and achievement motivation of multicultural adolescents.

A Study on the Naejeong (內庭) of Daesoon Jinrihoe Temple Complexes: Focusing on Literary Sources and Context (대순진리회 도장 건축물 내정(內庭)에 대한 연구 - 내정의 문헌 출처와 그 맥락을 중심으로 -)

  • Cha, Seon-keun
    • Journal of the Daesoon Academy of Sciences
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    • v.37
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    • pp.1-52
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    • 2021
  • The Naejeong, the inner court, which is one of the structures found in the temple complexes of Daesoon Jinrihoe. It serves the function of leading and controlling the operation and direction of Korean religions in general. Considering that the dictionary meaning of 'Naejeong' is 'a place to manage the affairs of the state from inside a palace,' the name and function of the structure appear to be in harmony. However, in the Daesoon Jinrihoe context, it is said that the name 'Naejeong (內庭 'Neiting' in Chinese)' is related to a verse from a Daoist scripture. It has not been revealed whether or not the scripture is historical, and what contents or contextual meanings it contains. This study tries to pursue this matter and introduce the original source of the Naejeong in Daesoon Jinrihoe as likely coming from Qianbapinxianjing (前八品仙經, The Former Scripture of the Eight Phases That Reveal the Means to Acquire Immortality). This scripture was compiled in Lüzu-quanshu(呂祖全書, The Entire Collection of Ancestor Lü). This text and its contextual meanings will also be examined. The origin of Qianbapinxianjing dates back to either the late Ming Dynasty or the early Qing. In those days, there existed a group of literati who worshipped Ancestor Lü because he had saved people and taught the art of immortality. The group organized Daoist Spirit-Writing Altars (鸞壇道敎) and invoked the spirit of Ancestor Lü. They were said to have been taught through messages received from spirit-writing sessions (降乩) with Ancestor Lü and several Daoist scriptures were composed by them in this manner. At Immortals-Gathering Pavilion (集仙樓) of Wandian (萬店) in Guangling (廣陵), China, some literati in that group conducted a spirit-writing session with Ancestor Lü between 1589 and 1626, and they produced a scripture which contained the passage, "A crow and a rabbit gather in the middle valley (烏兎結中谷) while a turtle entwined with a snake is in the inner court (龜蛇盤內庭)." They titled the scripture, The Five Movements and Filial Piety (五行端孝). This passage symbolically expresses the accomplishment of immortality in Neidan (internal alchemy) which, within the human body, combines the two energies of yin and yang which are Water and Fire in the Five Movements scheme. This kind of cultivation is said to be achieved only by maintaining the highest possible degree of filial piety. In this context, the Naejeong where a turtle is entwined with a snake (龜蛇合體) was a term that symbolically depicted a place wherein one transforms into an immortal through cultivation. The Five Movements and Filial Piety was included in Qianbapinxianjing after it had been compiled with the other scriptures containing Ancestor Lü's teachings. In 1744, Qianbapinxianjing was included in Lüzu-quanshu, the entire 32-volume collection of Ancestor Lü and printed for the first time. This underlies the belief in Ancestor Lü (呂祖信仰) which embraces the idea of the redemption of people, teaches the arts of immortality, and features Daoist Spirit-Writing Altars, filial piety, the art of Neidan, and the combination of Water and Fire.

Aspects of Design and Construction in Entrance Space of the World Heritage Royal Tombs of the Joseon Dynasty (세계유산 조선왕릉 입구공간의 조성 양상)

  • So, Hyun-Su;Park, Hyun-Sook
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.41 no.3
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    • pp.47-58
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    • 2023
  • This study was conducted through reviewing Aspects of Design and Construction in Entrance Space of the World Heritage Royal Tombs of the Joseon Dynasty, which is equipped with parking lots, ticket offices, toilets, exhibition halls, information boards, and rest facilities for the convenience of visitors and the purpose of this study was to propose a direction for improvement. The results of the study are as follows: First, the reduced area of Royal Tombs of the Joseon Dynasty was unable to fully accommodate the ritual movement line, and as a result, the location of the entrance space in the current royal tomb was decided to accommodate minimal convenience functions. In the meantime, the entrance space of the royal tombs has been relocated or renovated in order to achieve its integrity as a World Heritage Site, rational arrangement of movement lines and spatial utility. Second, the size of the entrance space ranges from 1,000 square meters in Jeongneung in Seoul to 16,000 square meters in Hongyuneung in Namyangju, and the number of annual users varies greatly from 12,000 in Onneung in Yangju to 410,000 in Seonjeongneung in Seoul. Considering the conditions of the 16 royal tombs, the entrance space should be provided at an appropriate scale, reflecting the surrounding land use and accessibility that affect the influx of users, the size of the site, and the king's awareness and preferences. Third, the location of the parking lot, the presence or absence of an outer courtyard and an internal courtyard bordering the ticket and check offices, and the location of the Historical and Cultural Museum made it possible to know the aspects of entrance space of the Joseon Royal Tombs, where the spatial configuration is determined Fourth, according to the royal tombs, it was found that the entrance space should have essential parking, access control, information, and convenience functions, and that support, exhibition, passage, and recess functions should be optional. At this time, the management office and the Historical and Cultural Center are in charge of support and exhibition functions. The function of passage can be a strategy that provides a sense of entry and the function of recess which has been introduced in only four royal tombs requires an appropriate location and landscape access.