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Study of East Asia Climate Change for the Last Glacial Maximum Using Numerical Model (수치모델을 이용한 Last Glacial Maximum의 동아시아 기후변화 연구)

  • Kim, Seong-Joong;Park, Yoo-Min;Lee, Bang-Yong;Choi, Tae-Jin;Yoon, Young-Jun;Suk, Bong-Chool
    • The Korean Journal of Quaternary Research
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    • v.20 no.1 s.26
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    • pp.51-66
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    • 2006
  • The climate of the last glacial maximum (LGM) in northeast Asia is simulated with an atmospheric general circulation model of NCAR CCM3 at spectral truncation of T170, corresponding to a grid cell size of roughly 75 km. Modern climate is simulated by a prescribed sea surface temperature and sea ice provided from NCAR, and contemporary atmospheric CO2, topography, and orbital parameters, while LGM simulation was forced with the reconstructed CLIMAP sea surface temperatures, sea ice distribution, ice sheet topography, reduced $CO_2$, and orbital parameters. Under LGM conditions, surface temperature is markedly reduced in winter by more than $18^{\circ}C$ in the Korean west sea and continental margin of the Korean east sea, where the ocean exposed to land in the LGM, whereas in these areas surface temperature is warmer than present in summer by up to $2^{\circ}C$. This is due to the difference in heat capacity between ocean and land. Overall, in the LGM surface is cooled by $4{\sim}6^{\circ}C$ in northeast Asia land and by $7.1^{\circ}C$ in the entire area. An analysis of surface heat fluxes show that the surface cooling is due to the increase in outgoing longwave radiation associated with the reduced $CO_2$ concentration. The reduction in surface temperature leads to a weakening of the hydrological cycle. In winter, precipitation decreases largely in the southeastern part of Asia by about $1{\sim}4\;mm/day$, while in summer a larger reduction is found over China. Overall, annual-mean precipitation decreases by about 50% in the LGM. In northeast Asia, evaporation is also overall reduced in the LGM, but the reduction of precipitation is larger, eventually leading to a drier climate. The drier LGM climate simulated in this study is consistent with proxy evidence compiled in other areas. Overall, the high-resolution model captures the climate features reasonably well under global domain.

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Developing the Process and Characteristics of Preservation of Area-Based Heritage Sites in Japan (일본 면형 유산 보존제도의 확산과정과 특성)

  • Sung, Wonseok;Kang, Dongjin
    • Korean Journal of Heritage: History & Science
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    • v.53 no.4
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    • pp.32-59
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    • 2020
  • South Korea's area-based heritage preservation system originates from the "Preservation of Traditional Buildings Act" enacted in 1984. However, this system was abolished in 1996. As there was a need for protection of ancient cities in the 1960s, Japan enacted the Historic City Preservation Act in 1966, and 'Preservation Areas for Historic Landscapes' and 'Special Preservation Districts for Historic Landscapes' were introduced. For the preservation of area-based heritage sites, the 'Important Preservation Districts for Groups of Traditional Buildings' system introduced as part of the revision of the Cultural Heritage Protection Act in 1975 was the beginning. Then, in the early-2000s, discussions on the preservation of area-based heritage sites began in earnest, and the 'Important Cultural Landscape' system was introduced for protection of the space and context between heritage sites. Also, '33 Groups of Modernization Industry Heritage Sites' were designated in 2007, covering various material and immaterial resources related to the modernization of Japan, and '100 Beautiful Historic Landscapes of Japan' were selected for protection of local landscapes with historic value in the same year. In 2015, the "Japanese Heritage" system was established for the integrated preservation and management of tangible and intangible heritage aspects located in specific areas; in 2016, the "Japanese Agricultural Heritage" system was established for the succession and fostering of the disappearing agriculture and fishery industries; and in 2017, "the 20th Century Heritage," was established, representing evidence of modern and contemporary Japanese technologies in the 20th century. As a result, presently (in September 2020), 30 'Historic Landscape Preservation Areas', 60 'Historic Landscape Special Districts,' 120 'Important Preservation Districts for Groups of Traditional Buildings," 65 'Important Cultural Landscapes,' 66 'Groups of Modernization Industry Heritage Sites,' 264 "100 Beautiful Historic Landscapes of Japan,' 104 'Japanese Heritage Sites,' and 15 'Japanese Agricultural Heritage Sites' have been designated. According to this perception of situations, the research process for this study with its basic purpose of extracting the general characteristics of Japan's area-based heritage preservation system, has sequentially spread since 1976 as follows. First, this study investigates Japan's area-based heritage site preservation system and sets the scope of research through discussions of literature and preceding studies. Second, this study investigates the process of the spread of the area-based heritage site preservation system and analyzes the relationship between the systems according to their development, in order to draw upon their characteristics. Third, to concretize content related to relationships and characteristics, this study involves in-depth analysis of three representative examples and sums them up to identify the characteristics of Japan's area-based heritage system. A noticeable characteristic of Japan's area-based heritage site preservation system drawn from this is that new heritage sites are born each year. Consequently, an overlapping phenomenon takes place between heritage sites, and such phenomena occur alongside revitalization of related industries, traditional industry, and cultural tourism and the improvement of localities as well as the preservation of area-based heritage. These characteristics can be applied as suggestions for the revitalization of the 'modern historical and cultural space' system implemented by South Korea.

Research on the Chapter Titled "Gongsa" from the Jeon-gyeong (『전경』 「공사」편 연구)

  • Ko, Nam-sik
    • Journal of the Daesoon Academy of Sciences
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    • v.30
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    • pp.163-199
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    • 2018
  • Jeon-gyeong was published under the command of Dojeon Park Wudang in 1974. The scripture consists of 7 parts and each part has 17 chapters. The earliest record of Gucheon Sangje (1871~1909) can be found in Jeungsan Cheonsa Gongsagi, which was published by Lee Sangho (1888~1967) in 1926. The book was the first oral literature that he created by collecting information and materials on Jeungsan as he personally met with many direct disciples of Gucheon Sangje. In 1929, after three years, Lee complemented the book with additional materials and published the first edition of Daesoon Jeon-gyeong. It was a form of didactic literature stylistically presented as scripture. Lee continued this long journey of work by revising and publishing 6 editions of Daesoon Jeon-gyeong until he published the last one in 1965. The chapter titled, "Cheonji-gongsa (Reordering Works of the Universe)" from Daesoon Jeon-gyeong as the sixth chapter out of a total of 13 chapters in the first edition, but in the last edition, it appears as chapter 4 out of a total of 9 chapters. Here it is shown that the last edition has been shortened when compared to the first edition. Also the number of verses in the chapter has largely increased by almost twice its original size over the 37 years; as it was 81 in the first edition, 94 in the second, 148 in the third, 151 in the fifth, and 175 in the sixth. In this paper, I studied how the verses of "Gongsa (Reordering Works)" from the Jeon-gyeong, which was first published in 1974, have been revised in comparison to the chapter titled "Cheonji-gongsa" from the Daesoon Jeon-gyeong. As the result of comparing each verse of "Gongsa" from the Jeon-gyeong to those of "Cheonji-gongsa" from all six editions of the Daesoon Jeon-gyeong, I could find the following revisions or changes. First, when "Cheonji-gongsa" from the Daesoon Jeon-gyeong is compared to "Gongsa" from the Jeon-gyeong, it can be seen that the number of verses has been changed and some contents have been deleted or added. Second, the sixth edition of the Daesoon Jeon-gyeong has 69 more verses than the Jeon-gyeong, and most of the additions were made in the chapters titled "Haengrok (analects)," "Gyoun (conveyance of teachings)," and "Yesi (forseeing)". These additions show how the verses regarding religious and predictional teachings developed over the years. Third, the verses from "Gongsa" from the Jeon-gyeong contain many descriptions from chapter 2, "Enlightenment of Dao and Miraculous Deeds of Cheonsa (Heavenly Teacher)," chapter 3, "Followers in the Dao School and Precepts," and chapter 5, "Opening of New World and Paradise," from the 6 th edition of the Daesoon Jeon-gyeong. This indicates that "Cheonji-gongsa (Reordering Works of the Universe)" was related to miraculous acts, enlightenment to Dao, teachings given to the followers, the opening of new world, and the building of a paradise. Fourth, some chapters in the section "Cheonji-gongsa" from Daesoon Jeon-gyeong are omitted in "Gongsa" from Jeon-gyeong, and "Gongsa" has some new contents that were not included in previous texts. This shows that there had been adoptions of different materials in the process of transmission.

Larvae Growth and Biochemical Composition Change of the Pacific Oyster Crassostra gigas, Larvae during Artificial Seed Production (참굴 Crassostrea gigas 인공종묘생산 시 유생의 성장과 체성분 변화)

  • Hur, Young-Baek;Min, Kwang-Sik;Kim, Tae-Eic;Lee, Seung-Ju;Hur, Sung-Bum
    • Journal of Aquaculture
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    • v.21 no.4
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    • pp.203-212
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    • 2008
  • A nutritional demand of oyster, Crassostrea gigas larva as part of research for improving of utilization of microalgae being used for the artificial oyster seed production. The change of body growth and biochemical compositions of larvae were investigated during larvae rearing in hatchery. The larvae were cultured in 60 M/T tank and fed mixture 6 different phytoplankton species, Isochrysis galbana (30%), Cheatoceros gracilis (20%), Pavlova lutheri (20%), Phaeodactylum triconutum (10%), Nannochryis oculata (10%) and Tetraselmis tetrathele (10%). The initial feeding amount was $0.3{\times}10^4cells/mL$ at three times a day to D-shaped larva and the feeding amount had been increased 30% gradually every two day since the larvae were raising. The larvae were developed from D shape to pediveliger stage for 12 days. The daily growth of shell length and hight were $5.8{\sim}30.8\;{\mu}m$ and $8.7{\sim}31.4\;{\mu}m$, respectively and weight gains were changed from D shape to pediveliger as follow: wet weight was $0.52{\sim}15.0\;{\mu}g/larva$, dry weight was $0.2{\sim}6.5\;{\mu}g/larva$, and ash free dry weight was $0.1{\sim}8.5\;{\mu}g/larva$. The larvae growth pattern shown a logarithmic phase from D shape to umbone stage but after that stage shown a exponential growth aspect. The crude protein, crude lipid and nitrogen free extract (NFE) of larvae during rearing periods were analyzed as $6.1{\sim}10.6%$, $0.6{\sim}1.1%$ and 1.0-2.7%, respectively. And the total amino acid contents of the larvae during rearing periods were in order as glutamic acid $1.26{\sim}2.24%$, aspartic acid $0.97{\sim}1.70%$, and methionine $0.12{\sim}0.33%$. Of the total fatty acid in the analyzed larvae, the saturated fatty acid (SSAFA) was decreased from 54.3% (D shaped larvae) to 17.1 % (pediveliger) as larvae development but the total mono-unsaturated fatty acid (${\Sigma}MOFA$) and Poly-unsaturated fatty acid (${\Sigma}PUFA$) were increased from 29.9% and 7.8% to 40.6% and 45.6%, respectively. By the way the each fatty acid of the larvae were composed of palmitic acid $9.89{\sim}36.95%$, oleic acid $12.17{\sim}32.29%$, linoleic acid $1.96{\sim}33.55%$, EPA $2.17{\sim}11.58%$ and DHA $1.95{\sim}4.51%$. As a result of this study, the larvae of oyster were demanded a various nutrients for healthy growth and the feeding control, expecially after umbone stage larvae are a rapidly growing time, is very important for success of artificial seed production.

A Study on Chinese Traditional Auspicious Fish Pattern Application in Corperate Identity Design (중국 전통 길상 어(魚)문양을 응용한 중국 기업의 아이덴티티 디자인 동향)

  • ZHANG, JINGQIU
    • Cartoon and Animation Studies
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    • s.50
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    • pp.349-382
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    • 2018
  • China is a great civilization which is a combination of various ethnic groups with long history change. As one of these important components of traditional culture, the lucky shape has been going through the ideological upheaval of the history change of China. Up to now, it has become the important parts which can stimulate the emotion of Chinese nation. The lucky shape becomes the basis of the rich traditional culture by long history of the Chinese nation. Even say it is the centre of this traditional culture resource. The lucky shape is a way of expressing the Chinese history and national emotions. It is the important part of people's living habits, emotion, as well as the cultural background. What's more, it has the value of beliefs of Surname totem. Meanwhile, it also has the function of passing on information. The symbol of information finally was created by the being of lucky shape to indicate its conceptual content. There are various kinds of lucky shapes. It will have its limitations when researching all kinds of them professionally. So, here the lucky shape of FISH will be researched. The shape of fish is the first good shape created by the Chinese nation. It is about 6000 years. Its special shape and lucky meaning embody the peculiar inherent culture and intension of the Chinese nation. It's the important component of the Chinese traditional culture. The traditional shape of fish was focused on the continuation of history and the patterns recognition, etc. It seldom indicated the meaning of the shape into the using of the modern design. So by searching the lucky meaning & the way of fish shape, the purpose of the search is to explore the real analysis of value of the fish shape in the modern enterprise identity design. The way of search is through the development of the history, the evolvement and the meaning of lucky of the traditional fish shape to analyse the symbolic meaning and the cultural meaning from all levels in nation, culture, art and life, etc. And by using the huge living example of the enterprise identity design of the traditional shape of the fish to analyse that how it works in positive way by those enterprise which is based on the trust with good image. In the modern Chinese enterprise identity design, the lucky image will be reinterpreted in the modern way. It will be proofed by the national perceptual knowledge of the consumer and the way of enlarge the goodwill of corporate image. It will be the conclusion. The traditional fish shape is the important core of modern design.So this search is taken through the instance of the design of enterprise image of the traditional fish shape to analysis the idea of the majority Chinese people of the traditional luck and the influence of corporation which based on trust and credibility. In modern image design of Chinese corporation, the auspicious sign reappear. The question survey is taken by people through the perceptual knowledge of the consumer and the cognition the enterprise image. According the result, people can speculate the improvement of consumer's recognition and the possibility of development of traditional concept.

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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The Late Quaternary Environmental Change in Youngyang Basin, South Eastern Part of Korea Penninsula (第四紀 後期 英陽盆地의 自然環境變化)

  • Yoon, Soon-Ock;Jo, Wha-Ryong
    • Journal of the Korean Geographical Society
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    • v.31 no.3
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    • pp.447-468
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    • 1996
  • The peat layer was deposited on the abandoned channel of incised meander of River Banbyuncheon with 7 meter thickness on Youngyang basin. The late Quaternary environmental change on the study area was discussed based on pollen anaalysis and radiocarbon-dating from this peat. The swamp which was caused to sediment the peat, was produced by which the fan debris from the adjacent slope damed the waterflow on the abandoned channel. The peat layer contains continuous vegetational history from 60,000y.B.P. to Recent. The peat deposit was divided into two layers by the organic thin sand horizon, which was sedimented at one time and made unconformity between the lower decomposed compact peat layers and the upper fresh fiberous peat layer. As the result of the pollen analysis, both peat layers from the two boring sites, Profile YY1 and Profile YY2 were divided into five Pollenzones(Pollenzone I, II, III, IV and V) and 12 Subzones which were mainly corresponded by the AP (Arboreal Pollen)-Dominance. The two profiles have some differences on the sedimentary facies and on the pollen composition as well. Therefore these were in common with the Pollenone III, however the Pollenzone I and II existed only on the Profile YY1 and the Pollenzone IV and V existed only on the Profile YY2. The lower layer containing the Pollenzone I, II and III revealed vegetational records of Pleistocene, which was characterized as tundra-like landscape and thin forested landscapes. It represented the NAP (Non-Arboreal Pollen)-period with a plenty of Artemisia sp., Sanguisorba sp., Umbelliferae, Gramineae and Cyperaceae. However a relatively high proportion of the boreal trees with Picea sp., Pinus sp. and Betula sp. as AP was observed in the lower layer. The upper layer contained the Pollenzone IVb and V and vegetational history in Holocene which was characterized by thick forested landscape with rich tree pollen. It represented AP-period with plenty of Pinus sp. and Quercus sp. as temperate trees. The temperature fluctuation supposed from the vegetational records is as follows; the Pollenzone I(Betula-Dominance, about 57,000y.B.P.) represents relatively cold period. The Pollenzone II(EMW-Domi-nance, 57,000-43,000y.B.P.)represents relatively warm period. This period is supposed to be Interstadial, the transi-tional stage from Alt- to Mittel Wurm. The Pollenzone III(Butula-, Pinus- and Picea-Dominace in turns, 43,000-15,000y.B.P.) reproesents cold period which had been built from Mittel-to Jung Wurm. Especially the Subzone IIId represents the coldest period throughout the Pollenzone III. It is corresponds to Wurm Glacial Maximu. It is supposed that the mean temperature in July of this period was coller about 10${^\circ}$C than present. The Pollenzone IV and V represent the vegetational history of Holocene. Tilia, Quercus and Pinus were dominant in turns during this period. Subzone IVb and Pollenzone I and II at east coastal plain of Korean penninsula reported by JO(1979).

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Usefulness Evaluation of Artifacts by Bone Cement of Percutaneous Vertebroplasty Performed Patients and CT Correction Method in Spine SPECT/CT Examinations (척추 뼈 SPECT/CT검사에서 경피적 척추성형술 시행 환자의 골 시멘트로 인한 인공물과 CT보정방법의 유용성 평가)

  • Kim, Ji-Hyeon;Park, Hoon-Hee;Lee, Juyoung;Nam-Kung, Sik;Son, Hyeon-Soo;Park, Sang-Ryoon
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.49-61
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    • 2014
  • Purpose: With the aging of the population, the attack rate of osteoporotic vertebral compression fracture is in the increasing trend, and percutaneous vertebroplasty (PVP) is the most commonly performed standardized treatment. Although there is a research report of the excellence of usefulness of the SPECT/CT examination in terns of the exact diagnosis before and after the procedure, the bone cement material used in the procedure influences the image quality by forming an artifact in the CT image. Therefore, the objective of the research lies on evaluating the effect the bone cement gives to a SPECT/CT image. Materials and Methods: The images were acquired by inserting a model cement to each cylinder, after setting the background (3.6 kBq/mL), hot cylinder (29.6 kBq/mL) and cold cylinder (water) to the NEMA-1994 phantom. It was reconstructed with Astonish (Iterative: 4 Subset: 16), and non attenuation correction (NAC), attenuation correction (AC+SC-) and attenuation and scatter correction (AC+SC+) were used for the CT correction method. The mean count by each correction method and the count change ratio by the existence of the cement material were compared and the contrast recovery coefficient (CRC) was obtained. Additionally, the bone/soft tissue ratio (B/S ratio) was obtained after measuring the mean count of the 4 places including the soft tissue(spine erector muscle) after dividing the vertebral body into fracture region, normal region and cement by selecting the 20 patients those have performed PVP from the 107 patients diagnosed of compression fracture. Results: The mean count by the existence of a cement material showed the rate of increase of 12.4%, 6.5%, 1.5% at the hot cylinder of the phantom by NAC, AC+SC- and AC+SC+ when cement existed, 75.2%, 85.4%, 102.9% at the cold cylinder, 13.6%, 18.2%, 9.1% at the background, 33.1%, 41.4%, 63.5% at the fracture region of the clinical image, 53.1%, 61.6%, 67.7% at the normal region and 10.0%, 4.7%, 3.6% at the soft tissue. Meanwhile, a relative count reduction could be verified at the cement adjacent part at the inside of the cylinder, and the phantom image on the lesion and the count increase ratio of the clinical image showed a contrary phase. CRC implying the contrast ratio and B/S ratio was improved in the order of NAC, AC+SC-, AC+SC+, and was constant without a big change in the cold cylinder of the phantom. AC+SC- for the quantitative count, and AC+SC+ for the contrast ratio was analyzed to be the highest. Conclusion: It is considered to be useful in a clinical diagnosis if the application of AC+SC+ that improves the contrast ratio is combined, as it increases the noise count of the soft tissue and the scatter region as well along with the effect of the bone cement in contrast to the fact that the use of AC+SC- in the spine SPECT/CT examination of a PVP performed patient drastically increases the image count and enables a high density of image of the lesion(fracture).

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Summer-Time Behaviour and Flux of Suspended Sediments at the Entrance to Semi-Closed Hampyung Bay, Southwestern Coast of Korea (만 입구에서 부유퇴적물 거동과 플럭스: 한반도 서해 남부 함평만의 여름철 특성)

  • Lee, Hee-Jun;Park, Eun-Sun;Lee, Yeon-Gyu;Jeong, Kap-Sik;Chu, Yong-Shik
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.2
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    • pp.105-118
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    • 2000
  • Anchored measurements (12.5 hr) of suspended sediment concentration and other hydrodynamic parameters were carried out at two stations located at the entrance to Hampyung Bay in summer (August 1999). Tidal variations in water temperature and salinity were in the range of 26.0-27.9$^{\circ}C$ and 30.9-31.5, respectively, indicating exchange offshore and offshore water mass. Active tidal mixing processes at the entrance appear to destroy the otherwise vertical stratification in temperature and salinity in spite of strong solar heating in summer. On the contrary, suspended sediment concentrations show a marked stratification with increasing concentrations toward bottom layer. Clastic particles in suspended sediments consist mostly of very fine to fine silt (4-16 ${\mu}$m) with a poorly-sorted value of 14.7-25.9 ${\mu}$m. However, at slack time with less turbulent energy, flocs larger than 40 ${\mu}$m are formed by cohesion and inter-collision of particles, resulting in a higher settling velocity. Strong ebb-dominated and weak flood dominated tidal currents, in the southwestern and the northeastern part, respectively, result in a seaward residual flow of -10${\sim}$-20 cm $s^{-1}$ at station H1 and a bayward residual flow less than 5.0 cm $s^{-1}$ at station H2. However, mean concentration of suspended sediments at station H1 is higher at flood (95.0-144.1 mg $1^{-1}$) than in ebb (75.8-120.9 mg $1^{-1}$). On the contrary, at the station H2, the trend is reversed with higher concentration at the ebb (84.7-158.4 mg $1^{-1}$) than that at the flood (53.0-107.9 mg $1^{-1}$). As a result, seaward net suspended sediment fluxes ($f_{s}$) are calculated to be -1.7 ${\sim}$-$15.610^{3}$ kg $m^{-2}$ $s^{-1}$ through the whole water column. However, the stations H1 and H2 show definitely different values of the flux with higher ones in the former than in the latter. Alternatively, depth-integrated net suspended sediment loads ($\c{Q}_{s}$) for one tidal cycle are also toward the offshore with ranges of 0.37${\times}$$10^{3}$ kg $m^{-1}$ and 0.21${\times}$$10^{3}$ kg $m^{-1}$, at station H1 and H2, respectively. This seaward transport of suspended sediment in summer suggests that summer-time erosion in the Hampyung muddy tidal flats is a rather exceptional phenomenon compared to the general deposition reported for many other tidal flats on the west coast of Korea.

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An Appreciation of Functional Role of Macrophage in the Acute Lung Injury in the Neutropenic Rat. (호중구 감소증을 보이는 백서의 급성폐손상에서 대식세포의 기능적 역할)

  • Kim, Yong-Hoon;Ki, Sin-Young;Im, Keon-Il;Moon, Seung-Hyug;Cheong, Seung-Whan;Kim, Hyeon-Tae;Uh, Soo-Taek;Park, Choon-Sik;Jin, Byung-Won
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.2
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    • pp.379-390
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    • 1997
  • Background : It has long been suggested that neutrophils and their products are implicated as the central mediators of the acute lung injuries. Contrary to the dominant role of neutrophils in ARDS, many cases of ARDS has occurred in the setting of severe neutropenia without pulmonary neutrophil infiltration. Therefore it is certain that effector cell(s) other than neutrophil play an important role in the pathogenesis of ARDS. This experiment was performed to define the mechanism of ARDS in the setting of neutropenia, 1) by comparing the severity of endotoxin-induced lung injury, 2) by measurement of hydrogen peroxide production and cytokine concentration in the bronchoalveolar lavage cells and fluids obtained from different rats with and without cyclophosphamide-pretreatment. Method : The male Sprague-Dawleys were divided into the normal control (NC)-, endotoxin (ETX)-, and cyclophosphamide (CPA)-group in which neutropenia was induced by injecting cyclophosphamide intraperitoneally. Acute lung injury was evoked by injecting lipopolysaccharide (LPS) into a tail vein. The bronchoalveolar lavage (BAL) was performed at 3 and 6 hour after administration of LPS to measure the change of cell counts and concentrations of protein and cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Hydrogen peroxide (HPO) production from BAL cells was measured at 6 hour after LPS administration by phenol red microassay with and without zymosan stimulation. Results : The results were as follows. A change of leukocyte counts in the peripheral blood after treatment with CPA : More than 95% of total leukocytes and neutrophils were reduced after CPA administration, resulting in severe neutropenia. A change of BAL cells : In the ETX-group, the number of total cells (p < 0.01) and of macrophage and neutrophil (p < 0.05) were increased at 3 and 6 hour after LPS administration compared to those of NC-group. In the CPA-group, the number of total leukocyte and macrophage were not changed after LPS administration, but neutrophil counts were significantly reduced and it took part in less than 0.1% of total BAL cells (p < 0.01 vs NC-group). BAL cells in this group were almost all macrophages (99.7%). A change of protein concentration in the BALF : In the ETX-group, protein concentration was increased at 3 hour and was more increased at 6 hour after LPS administration (p < 0.05 and < 0.01 vs NC-group, respectively). In the CPA-group, it was also significantly elevated at 3 hour after LPS administration (p < 0.05 vs NC-group), but the value was statistically not different from that of ETX-group. The value measured at 6 hour after LPS administration in the CPA-group became lower than that of ETX-group (p < 0.05), but showed still a higher value compared to that of NC-group (p < 0.05). A change of cytokine concentration in the BALF : TNF -alpha and IL-6 were elevated in the ETX - and CPA-group compared to those of NC-group at both time intervals. There was no statistical difference in the values of both cytokines between the ETX- and CPA-groups. Measurement of hydrogen peroxide production from BAL cells : There was no intergroup difference of HPO production from resting cells. HPO production after incubation with opsonized zymosan was significantly elevated in all groups. The percent increment of HPO production was highest in the ETX-group (89.0%, p < 0.0008 vs NC-group), and was 42.85 in the CPA-group (p = 0.003 vs NC-group ). Conclusion : Acute lung injury in the setting of neutropenia might be caused by functional activation of resident alveolar macrophages.

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