• Title/Summary/Keyword: Performed position

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Hypoxemia In Liver Cirrhosis And Intrapulmonary Shunt Determination Using Tc-99m-MAA Whole Body Scan (간경화 환자에서의 저산소혈증과 Tc-99m-MAA 주사를 이용한 폐내단락 측정)

  • Lee, Kye-Young;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo;Kim, Keun-Youl;Han, Yong-Chol
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.5
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    • pp.504-512
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    • 1994
  • Background: It is well known that severe hypoxemia is often associated with liver cirrhosis without preexisting cardiac or pulmonary diseases. Pulmonary vascular impairments, more specifically, intrapulmonary shunting have been considered as a major mechanism. Intrapulmonary shunting arises from pulmonary vascular dilatation at the precapillary level or direct arteriovenous communication and has relationship with the characteristic skin findings of spider angioma. However, these results are mainly from Western countries where alcoholic and primary biliary cirrhosis are dominant cuases of cirrhosis. It is uncertain that the same is true in viral hepatitiss associated liver cirrhosis, which is dominant causes of liver cirrhosis in Korea. We investigated the incidences of hypoxemia and orthodeoxia in Korean cirrhotic patients dominantly composed of postnecrotic cirrhosis and the significance of intrapulmonary shunting as the suggested mechanism of hypoxemia, Method: We performed the arterial blood gas analysis separately both at the supine and errect position in 48 stable cirrhotic patients without the evidences of severe complications such as ascites, variceal bleeding, and hepatic coma. According to the results of arterial blood gas analysis, all patients were divided into hypoxemic and normoxemic group. In each group, pulmonary function test and Tc-99m-MAA whole body scan were performed. The shunting fraction was calculated based on the fact that the sum of cerebral and bilateral renal blood flow is 32% of the systemic blood flow. Results: The hypoxemia of $PaO_2$ less than 80 mmHg was observed in 9 patients(18.8%) and Orthodeoxia more than 10 mmHg was observed in 8 patients(16.7%). But there was no patient with significant hypoxemia of $PaO_2$ less than 60 mmHg. $PaO_2$ was significantly decreased in the patients with spider angioma than the pathients without spider angioma and showed no correlation with the serologic type and severities of liver function test findings. Any parameters of pulmonary function test did not demonstrate the difference between normoxemic and hypoxemic group. But hypoxemic group showed significantly increased shunt fraction of $11.4{\pm}4.1%$ than normoxemic group of $4.1{\pm}2.0%$ (p<0.05). Conclusions: Hypoxemia is not infrequently observed complication in liver cirrhosis and intrapulmonary shunting is suggested to p1ay a major ro1e in the development of hypxemia. But there was no great likelihood of clinically significant hypoxemia in our domestic cirrhotic patients predominantly composed of postnecrotic type.

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The Precision Test Based on States of Bone Mineral Density (골밀도 상태에 따른 검사자의 재현성 평가)

  • Yoo, Jae-Sook;Kim, Eun-Hye;Kim, Ho-Seong;Shin, Sang-Ki;Cho, Si-Man
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.1
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    • pp.67-72
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    • 2009
  • Purpose: ISCD (International Society for Clinical Densitometry) requests that users perform mandatory Precision test to raise their quality even though there is no recommendation about patient selection for the test. Thus, we investigated the effect on precision test by measuring reproducibility of 3 bone density groups (normal, osteopenia, osteoporosis). Materials and Methods: 4 users performed precision test with 420 patients (age: $57.8{\pm}9.02$) for BMD in Asan Medical Center (JAN-2008 ~ JUN-2008). In first group (A), 4 users selected 30 patient respectively regardless of bone density condition and measured 2 part (L-spine, femur) in twice. In second group (B), 4 users measured bone density of 10 patients respectively in the same manner of first group (A) users but dividing patient into 3 stages (normal, osteopenia, osteoporosis). In third group (C), 2 users measured 30 patients respectively in the same manner of first group (A) users considering bone density condition. We used GE Lunar Prodigy Advance (Encore. V11.4) and analyzed the result by comparing %CV to LSC using precision tool from ISCD. Check back was done using SPSS. Results: In group A, the %CV calculated by 4 users (a, b, c, d) were 1.16, 1.01, 1.19, 0.65 g/$cm^2$ in L-spine and 0.69, 0.58, 0.97, 0.47 g/$cm^2$ in femur. In group B, the %CV calculated by 4 users (a, b, c, d) were 1.01, 1.19, 0.83, 1.37 g/$cm^2$ in L-spine and 1.03, 0.54, 0.69, 0.58 g/$cm^2$ in femur. When comparing results (group A, B), we found no considerable differences. In group C, the user_1's %CV of normal, osteopenia and osteoporosis were 1.26, 0.94, 0.94 g/$cm^2$ in L-spine and 0.94, 0.79, 1.01 g/$cm^2$ in femur. And the user_2's %CV were 0.97, 0.83, 0.72 g/$cm^2$ L-spine and 0.65, 0.65, 1.05 g/$cm^2$ in femur. When analyzing the result, we figured out that the difference of reproducibility was almost not found but the differences of two users' several result values have effect on total reproducibility. Conclusions: Precision test is a important factor of bone density follow up. When Machine and user's reproducibility is getting better, it’s useful in clinics because of low range of deviation. Users have to check machine's reproducibility before the test and keep the same mind doing BMD test for patient. In precision test, the difference of measured value is usually found for ROI change caused by patient position. In case of osteoporosis patient, there is difficult to make initial ROI accurately more than normal and osteopenia patient due to lack of bone recognition even though ROI is made automatically by computer software. However, initial ROI is very important and users have to make coherent ROI because we use ROI Copy function in a follow up. In this study, we performed precision test considering bone density condition and found LSC value was stayed within 3%. There was no considerable difference. Thus, patient selection could be done regardless of bone density condition.

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Usefulness of Gated RapidArc Radiation Therapy Patient evaluation and applied with the Amplitude mode (호흡 동조 체적 세기조절 회전 방사선치료의 유용성 평가와 진폭모드를 이용한 환자적용)

  • Kim, Sung Ki;Lim, Hhyun Sil;Kim, Wan Sun
    • The Journal of Korean Society for Radiation Therapy
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    • v.26 no.1
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    • pp.29-35
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    • 2014
  • Purpose : This study has already started commercial Gated RapidArc automation equipment which was not previously in the Gated radiation therapy can be performed simultaneously with the VMAT Gated RapidArc radiation therapy to the accuracy of the analysis to evaluate the usability, Amplitude mode applied to the patient. Materials and Methods : The analysis of the distribution of radiation dose equivalent quality solid water phantom and GafChromic film was used Film QA film analysis program using the Gamma factor (3%, 3 mm). Three-dimensional dose distribution in order to check the accuracy of Matrixx dosimetry equipment and Compass was used for dose analysis program. Periodic breathing synchronized with solid phantom signals Phantom 4D Phantom and Varian RPM was created by breathing synchronized system, free breathing and breath holding at each of the dose distribution was analyzed. In order to apply to four patients from February 2013 to August 2013 with liver cancer targets enough to get a picture of 4DCT respiratory cycle and then patients are pratice to meet patient's breathing cycle phase mode using the patient eye goggles to see the pattern of the respiratory cycle to be able to follow exactly in a while 4DCT images were acquired. Gated RapidArc treatment Amplitude mode in order to create the breathing cycle breathing performed three times, and then at intervals of 40% to 60% 5-6 seconds and breathing exercises that can not stand (Fig. 5), 40% While they are treated 60% in the interval Beam On hold your breath when you press the button in a way that was treated with semi-automatic. Results : Non-respiratory and respiratory rotational intensity modulated radiation therapy technique absolute calculation dose of using computerized treatment plan were shown a difference of less than 1%, the difference between treatment technique was also less than 1%. Gamma (3%, 3 mm) and showed 99% agreement, each organ-specific dose difference were generally greater than 95% agreement. The rotational intensity modulated radiation therapy, respiratory synchronized to the respiratory cycle created Amplitude mode and the actual patient's breathing cycle could be seen that a good agreement. Conclusion : When you are treated Non-respiratory and respiratory method between volumetric intensity modulated radiation therapy rotation of the absolute dose and dose distribution showed a very good agreement. This breathing technique tuning volumetric intensity modulated radiation therapy using a rotary moving along the thoracic or abdominal breathing can be applied to the treatment of tumors is considered. The actual treatment of patients through the goggles of the respiratory cycle to create Amplitude mode Gated RapidArc treatment equipment that does not automatically apply to the results about 5-6 seconds stopped breathing in breathing synchronized rotary volumetric intensity modulated radiation therapy facilitate could see complement.

M-mode Ultrasound Assessment of Diaphragmatic Excursions in Chronic Obstructive Pulmonary Disease : Relation to Pulmonary Function Test and Mouth Pressure (만성폐쇄성 폐질환 환자에서 M-mode 초음파로 측정한 횡격막 운동)

  • Lim, Sung-Chul;Jang, Il-Gweon;Park, Hyeong-Kwan;Hwang, Jun-Hwa;Kang, Yu-Ho;Kim, Young-Chul;Park, Kyung-Ok
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.4
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    • pp.736-745
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    • 1998
  • Background: Respiratory muscle interaction is further profoundly affected by a number of pathologic conditions. Hyperinflation may be particularly severe in chronic obstructive pulmonary disease(COPD) patients, in whom the functional residual capacity(FRC) often exceeds predicted total lung capacity(TLC). Hyperinflation reduces the diaphragmatic effectiveness as a pressure generator and reduces diaphragmatic contribution to chest wall motion. Ultrasonography has recently been shown to be a sensitive and reproducible method of assessing diaphragmatic excursion. This study was performed to evaluate how differences of diaphragmatic excursion measured by ultrasonography associate with normal subjects and COPD patients. Methods: We measured diaphragmatic excursions with ultrasonography on 28 healthy subjects(l6 medical students, 12 age-matched control) and 17 COPD patients. Ultrasonographic measurements were performed during tidal breathing and maximal respiratory efforts approximating vital capacity breathing using Aloka KEC-620 with 3.5 MHz transducer. Measurements were taken in the supine posture. The ultrasonographic probe was positioned transversely in the midclavicular line below the right subcostal margin. After detecting the right hemidiaphragm in the B-mode the ultrasound beam was then positioned so that it was approximately parallel to the movement of middle or posterior third of right diaphragm. Recordings in the M-mode at this position were made throughout the test. Measurements of diaphragmatic excursion on M-mode tracing were calculated by the average gap in 3 times-respiration cycle. Pulmonary function test(SensorMedics 2800), maximal inspiratory(PImax) and expiratory mouth pressure(PEmax, Vitalopower KH-101, Chest) were measured in the seated posture. Results: During the tidal breathing, diaphragmatic excursions were recorded $1.5{\pm}0.5cm$, $1.7{\pm}0.5cm$ and $1.5{\pm}0.6cm$ in medical students, age-matched control group and COPD patients, respectively. Diaphragm excursions during maximal respiratory efforts were significantly decreased in COPD patients ($3.7{\pm}1.3cm$) when compared with medical students, age-matched control group($6.7{\pm}1.3cm$, $5.8{\pm}1.2cm$, p< 0.05}. During maximal respiratory efforts in control subjects, diaphragm excursions were correlated with $FEV_1$, FEVl/FVC, PEF, PIF, and height. In COPD patients, diaphragm excursions during maximal respiratory efforts were correlated with PEmax(maximal expiratory pressure), age, and %FVC. In multiple regression analysis, the combination of PEmax and age was an independent marker of diaphragm excursions during maximal respiratory efforts with COPD patients. Conclusion: COPD subjects had smaller diaphragmatic excursions during maximal respiratory efforts than control subjects. During maximal respiratory efforts in COPD patients, diaphragm excursions were well correlated with PEmax. These results suggest that diaphragm excursions during maximal respiratory efforts with COPD patients may be valuable at predicting the pulmonary function.

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Derivation of Digital Music's Ranking Change Through Time Series Clustering (시계열 군집분석을 통한 디지털 음원의 순위 변화 패턴 분류)

  • Yoo, In-Jin;Park, Do-Hyung
    • Journal of Intelligence and Information Systems
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    • v.26 no.3
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    • pp.171-191
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    • 2020
  • This study focused on digital music, which is the most valuable cultural asset in the modern society and occupies a particularly important position in the flow of the Korean Wave. Digital music was collected based on the "Gaon Chart," a well-established music chart in Korea. Through this, the changes in the ranking of the music that entered the chart for 73 weeks were collected. Afterwards, patterns with similar characteristics were derived through time series cluster analysis. Then, a descriptive analysis was performed on the notable features of each pattern. The research process suggested by this study is as follows. First, in the data collection process, time series data was collected to check the ranking change of digital music. Subsequently, in the data processing stage, the collected data was matched with the rankings over time, and the music title and artist name were processed. Each analysis is then sequentially performed in two stages consisting of exploratory analysis and explanatory analysis. First, the data collection period was limited to the period before 'the music bulk buying phenomenon', a reliability issue related to music ranking in Korea. Specifically, it is 73 weeks starting from December 31, 2017 to January 06, 2018 as the first week, and from May 19, 2019 to May 25, 2019. And the analysis targets were limited to digital music released in Korea. In particular, digital music was collected based on the "Gaon Chart", a well-known music chart in Korea. Unlike private music charts that are being serviced in Korea, Gaon Charts are charts approved by government agencies and have basic reliability. Therefore, it can be considered that it has more public confidence than the ranking information provided by other services. The contents of the collected data are as follows. Data on the period and ranking, the name of the music, the name of the artist, the name of the album, the Gaon index, the production company, and the distribution company were collected for the music that entered the top 100 on the music chart within the collection period. Through data collection, 7,300 music, which were included in the top 100 on the music chart, were identified for a total of 73 weeks. On the other hand, in the case of digital music, since the cases included in the music chart for more than two weeks are frequent, the duplication of music is removed through the pre-processing process. For duplicate music, the number and location of the duplicated music were checked through the duplicate check function, and then deleted to form data for analysis. Through this, a list of 742 unique music for analysis among the 7,300-music data in advance was secured. A total of 742 songs were secured through previous data collection and pre-processing. In addition, a total of 16 patterns were derived through time series cluster analysis on the ranking change. Based on the patterns derived after that, two representative patterns were identified: 'Steady Seller' and 'One-Hit Wonder'. Furthermore, the two patterns were subdivided into five patterns in consideration of the survival period of the music and the music ranking. The important characteristics of each pattern are as follows. First, the artist's superstar effect and bandwagon effect were strong in the one-hit wonder-type pattern. Therefore, when consumers choose a digital music, they are strongly influenced by the superstar effect and the bandwagon effect. Second, through the Steady Seller pattern, we confirmed the music that have been chosen by consumers for a very long time. In addition, we checked the patterns of the most selected music through consumer needs. Contrary to popular belief, the steady seller: mid-term pattern, not the one-hit wonder pattern, received the most choices from consumers. Particularly noteworthy is that the 'Climbing the Chart' phenomenon, which is contrary to the existing pattern, was confirmed through the steady-seller pattern. This study focuses on the change in the ranking of music over time, a field that has been relatively alienated centering on digital music. In addition, a new approach to music research was attempted by subdividing the pattern of ranking change rather than predicting the success and ranking of music.

The Implications of Changes in Learning of East Coast Gut Successors (동해안굿 전승자 학습 변화의 의미)

  • Jung, Youn-rak
    • (The) Research of the performance art and culture
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    • no.36
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    • pp.441-471
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    • 2018
  • East Coast Gut, Korean shamanism ritual on its east coastal area, is a Gut held in fishing villages alongside Korean east coastal area from Goseong area in Gangwon-Do to Busan area. East Coast Gut is performed in a series mainly by a successor shaman, Korean shaman, who hasn't received any spiritual power from a God, and the implications of this thesis lie in that we look over the learning aspects of Seokchool Kim shaman group among other East Coast Gut successor shaman groups after dividing it into 2 categories, successor shaman and learner shaman and based upon this, we reveal the meaning of the learning aspects of East Coast Gut. For successor shamans, home means the field of education. Since they are little, they chased Gut events performing dance in a series to accumulate onsite experiences. However, in the families of successor shamans that have passed their shaman work down from generation to generation, their descendents didn't inherit shaman work any longer, which changed the way of succession and learning of shaman work. Since 1980's, Gut has been officially acknowledged as a kind of general art embracing songs, dance and music and designated as a cultural asset of the state and each city and province, and at art universities, it was adopted as a required course for its related major, which caused new learner shamans who majored in shamanism to emerge. These learner shamans are taking systematical succession lessons on the performance skills of East Coast Byeolshin Gut at universities, East Coast Byeolshin Gut preservation community, any places where Guts are held and etc.. As changes along time, the successor shamans accepted the learner shamans to pass shaman work down and changes appeared in the notion of towners who accept the performer groups of Gut and Gut itself. Unlike the past, as Gut has been acknowledged as the origin of Korean traditional arts and as the product of compresensive learning on songs, dance and music and it was designated as a national intangible cultural asset, shaman's social status and personal pride and dignity has become very high. As shaman has become positioned as the traditional artist getting both national and international recognition unlike its past image of getting despised, at the site of Gut event or even in the relation with towners, their status and the treatment they get became far different. Even towners, along with shift in shaman groups' generation, take position to acknowledge and accept the addition of new learning elements unlike the past. Even in every town, rather than just insisting on the type or the event purpose of traditional Gut, they think over on the type of festival and the main direction of a variety of Guts with which all of towners can mingle with each other. They are trying to find new meanings in the trend of changing Gut and the adaptation of new generation to this. In our reality of Gut events getting minimalized along with rapid change of times, East Coast Gut is still very actively performed in a series until now compared to Guts in other regions. This is because following the successor shamans who have struggled to preserve the East Coast Gut, the learner shamans are actively inflowing and the series performance groups preserve the origin of Gut and try hard to use Gut as art contents. Besides, the learner shamans systematically organize what they learned on shamanism from the successor shamans and get prepared and try to hand it down to descendents in the closest possible way to preserve its origin. In the future, East Coast Gut will be succeeded by the learner shamans from the last successor shamans to inherit its tradition and develop it to adapt to the times.

Semantic Interpretation of the Name "Cheomseongdae" (첨성대 이름의 의미 해석)

  • Chang, Hwalsik
    • Korean Journal of Heritage: History & Science
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    • v.53 no.4
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    • pp.2-31
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    • 2020
  • CheomSeongDae (瞻星臺) is a stone structure built in Gyeongju, the former Silla Dynasty capital, during the reign of Queen Seondeok (632~647AD). There exist dozens of hypotheses regarding its original purpose. Depending on to whom you ask, the answer could be a celestial observatory, a religious altar, a Buddhist stupa, a monumental tower symbolizing scientific knowledge, and so on. The most common perception of the structure among lay people is a stargazing tower. Historians, however, have suggested that it was intended as "a gateway to the heavens", specifically the Trāyastriṃśa or the second of the six heavens of Kāmadhātu located on the top of Mountain Sumeru. The name "Cheom-seong-dae" could be interpreted in many different ways. 'Cheom (瞻)' could refer to looking up, staring, or admiring, etc.; 'Seong (星)' could mean a star, heaven, night, etc.; and 'heaven' in that context can be a physical or religious reference. 'Dae (臺)' usually refers to a high platform on which people stand or things are placed. Researchers from the science fields often read 'cheom-seong' as 'looking at stars'; while historians read it as 'admiring the Trāyastriṃśa' or 'adoring Śakra'. Śakra is said to be the ruler of Trāyastriṃśa' who governs the Four Heavenly Kings in the Cāturmahārājika heaven, the first of the six heavens of Kāmadhātu. Śakra is the highest authority of the heavenly kings in direct contact with humankind. This paper examined the usages of 'cheom-seong' in Chinese literature dated prior to the publication of 『Samguk Yusa』, a late 13th century Korean Buddhist historical book that contains the oldest record of the structure among all extant historical texts. I found the oldest usage of cheom-seong (瞻星臺) in 『Ekottara Āgama』, a Buddhist script translated into Chinese in the late 4th century, and was surprised to learn that its meaning was 'looking up at the brightness left by Śakra'. I also found that 'cheom-seong' had been incorporated in various religious contexts, such as Hinduism, Confucianism, Buddhist, Christianism, and Taoism. In Buddhism, there was good, bad, and neutral cheom-seong. Good cheom-seong meant to look up to heaven in the practice of asceticism, reading the heavenly god's intentions, and achieving the mindfulness of Buddhism. Bad cheom-seong included all astrological fortunetelling activities performed outside the boundaries of Buddhism. Neutral cheom-seong is secular. It may help people to understand the nature of the physical world, but was considered to have little meaning unless relating to the spiritual world of Buddhism. Cheom-seong had been performed repetitively in the processes of constructing Buddhist temples in China. According to Buddhist scripts, Queen Māyā of Sakya, the birth mother of Gautama Buddha, died seven days after the birth of Buddha, and was reborn in the Trāyastriṃśa heaven. Buddha, before reaching nirvana, ascended from Jetavana to Trāyastriṃśa and spent three months together with his mother. Gautama Buddha then returned to the human world, stepping upon the stairs built by Viśvakarman, the deity of the creative power in Trāyastriṃśa. In later years, King Asoka built a stupa at the site where Buddha descended. Since then, people have believed that the stairway to the heavens appears at a Buddhist stupa. Carefully examining the paragraphic structure of 『Samguk Yusa』's records on Cheomseongdae, plus other historical records, the fact that the alignment between the tomb of Queen Seondeok and Cheomseongdae perfectly matches the sunrise direction at the winter solstice supports this paper's position that Chemseongdae, built in the early years of Queen SeonDeok's reign (632~647AD), was a gateway to the Trāyastriṃśa heaven, just like the stupa at the Daci Temple (慈恩寺) in China built in 654. The meaning of 'Cheom-seong-dae' thus turns out to be 'adoring Trāyastriṃśa stupa', not 'stargazing platform'.

Various Life Conditions of Actors of Joseon Periods in Unofficial Historical Stories (야담 문학에 나타난 조선 배우의 삶)

  • Choi, Nakyong
    • (The) Research of the performance art and culture
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    • no.23
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    • pp.281-312
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    • 2011
  • The aim of this study is to examine various life conditions of actors of Joseon periods in unofficial historical stories. Yadam Literature(Korean unofficial historical stories) had been collected Sadaebu(the past Korean nobility and Confucian intelligentsia) among the people that stories had been handed down orally. and they had been wrote them. So Yadam Literature was heterozygous between the folk culture and the ruling class. And it was mixed and adapted legends and folktales, adding literary imagination. had a decisive role to cultivating novel that owed much to prosaic inspiration during A. D. 18~19. Besides, set a high value on excellent novel itself. Yadam Literature had a verisimilitude because it described a contemporary reality as it was founded on freely prosaic inspiration. In those days, so called Suchok and Seunggwangdae had performed Uhee(a comic theatrical performance) in Joseon periods. Suchok was the lowest class of people and Seunggwangdae was performing Buddhist monk in that time. Uhee had performed three kinds of comedies. One satirized and insinuated kings. Other satirized corrupt officials, too. Another had mimic everything. It is famous at that time as a king knew repertoire. Confucian scholars very were fond of Uhee in those ages. Because they favored a criticism of Uhee's satire. They thought that it gave people good lesson or instruction. Heri Bergson said that comic and Humor included lesson. At that time, those thought were universal in the world whether east or west. At any rate, I classify six kinds of types Uhee in Yadam Literature. First, satirizing and accusing corrupt officials. Second, an actor who use a satire in order to appeal secure a government position of his lord to a king. Third, shamans and actors who use a satire in order to appeal sufferings themselves to a king. Forth, actors and performing Buddhist monks that skillfully mimic anything. Fifth, describing actor's extremely miserable life. Sixth, wit and humor of actors. The contents of Uhee were various. Korean traditional actors adeptly dealt with aspects comic of wit, satire, humor, etc. Sometimes they used changeable transition them. By doing that, a great number of people enjoyed fully the sense of freedom. Korean traditional actors were the lowest class of people. They had lived extremely miserable life. But they had been exist as actions, interactions, and relationship in society those days. they were not only open to people, but also might foster community to peoples.

Development of a New Cardiac and Torso Phantom for Verifying the Accuracy of Myocardial Perfusion SPECT (심근관류 SPECT 검사의 정확도 검증을 위한 새로운 심장.흉부 팬텀의 개발)

  • Yamamoto, Tomoaki;Kim, Jung-Min;Lee, Ki-Sung;Takayama, Teruhiko;Kitahara, Tadashi
    • Journal of radiological science and technology
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    • v.31 no.4
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    • pp.389-399
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    • 2008
  • Corrections of attenuation, scatter and resolution are important in order to improve the accuracy of single photon emission computed tomography (SPECT) image reconstruction. Especially, the heart movement by respiration and beating cause the errors in the corrections. Myocardial phantom is used to verify the correction methods, but there are many different parts in the current phantoms in actual human body. Therefore the results using a phantom are often considered apart from the clinical data. We developed a new phantom that implements the human body structure around the thorax more faithfully. The new phantom has the small mediastinum which can simulate the structure in which the lung adjoins anterior, lateral and apex of myocardium. The container was made of acrylic and water-equivalent material was used for mediastinum. In addition, solidified polyurethane foam in epoxy resin was used for lung. Five different sizes of myocardium were developed for the quantitative gated SPECT (QGS). The septa of all different cardiac phantoms were designed so that they can be located at the same position. The proposed phantom was attached with liver and gallbladder, the adjustment was respectively possible for the height of them. The volumes of five cardiac ventricles were 150.0, 137.3, 83.1, 42.7 and 38.6ml respectively. The SPECT were performed for the new phantom, and the differences between the images were examined after the correction methods were applied. The three-dimensional tomography of myocardium was well reconstructed, and the subjective evaluations were done to show the difference among the various corrections. We developed the new cardiac and torso phantom, and the difference of various corrections was shown on SPECT images and QGS results.

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A Characterization of Oil Sand Reservoir and Selections of Optimal SAGD Locations Based on Stochastic Geostatistical Predictions (지구통계 기법을 이용한 오일샌드 저류층 해석 및 스팀주입중력법을 이용한 비투멘 회수 적지 선정 사전 연구)

  • Jeong, Jina;Park, Eungyu
    • Economic and Environmental Geology
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    • v.46 no.4
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    • pp.313-327
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    • 2013
  • In the study, three-dimensional geostatistical simulations on McMurray Formation which is the largest oil sand reservoir in Athabasca area, Canada were performed, and the optimal site for steam assisted gravity drainage (SAGD) was selected based on the predictions. In the selection, the factors related to the vertical extendibility of steam chamber were considered as the criteria for an optimal site. For the predictions, 110 borehole data acquired from the study area were analyzed in the Markovian transition probability (TP) framework and three-dimensional distributions of the composing media were predicted stochastically through an existing TP based geostatistical model. The potential of a specific medium at a position within the prediction domain was estimated from the ensemble probability based on the multiple realizations. From the ensemble map, the cumulative thickness of the permeable media (i.e. Breccia and Sand) was analyzed and the locations with the highest potential for SAGD applications were delineated. As a supportive criterion for an optimal SAGD site, mean vertical extension of a unit permeable media was also delineated through transition rate based computations. The mean vertical extension of a permeable media show rough agreement with the cumulative thickness in their general distribution. However, the distributions show distinctive disagreement at a few locations where the cumulative thickness was higher due to highly alternating juxtaposition of the permeable and the less permeable media. This observation implies that the cumulative thickness alone may not be a sufficient criterion for an optimal SAGD site and the mean vertical extension of the permeable media needs to be jointly considered for the sound selections.