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A Study on the Garden Architectural Characteristics of Italian Renaissance Villa Medici a Fiesole (이탈리아 르네상스 빌라 메디치 피에졸레의 정원건축적 특성)

  • Choi, Jong-Hee;Choi, Yong-Won;Kim, Kyu-Yeon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.42 no.1
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    • pp.35-44
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    • 2024
  • The purpose of this study is to investigate the garden architectural characteristics of the Villa Medici a Fiesole, which occupies an important place in the Italian Renaissance garden, and it is concluded as follows. First, the Villa Medici a Fiesole was built between 1451 and 1457 for Giovanni, the son of Cosimo, and then owned by many people and came to the present. It was designed by Michelozzo and is the first newly built Renaissance villa to show Alberti's concept of rural residence. Second, the location is the biggest characteristic of the Villa, which was built on the steep slope of the Fiesole and offers a panoramic view of the landscape of Florence. Third, the overall composition of the garden created using the slope is based on three terraces of different heights, and the overall spatial arrangement is made up of an orthogonal axis at which the vertical and horizontal axes intersect around the villa. Fourth, in the case of vegetation and objects, old paulownia, roses, and potted lemon trees are placed on the first terrace on the three lawn flower beds. Fountain and niche are located at the middle and east end of the terrace. The second terrace cannot be reached through stairs, but only through a villa or a ramp outside the door. The second terrace has a wisteria pergola that leads to a secret garden, and in the center of the pergola, there is a staircase that leads to the third terrace. The Secret Garden takes the form of a quarter garden and consists of an oval pond, a coniferous flowerbed, and magnolias. On the third terrace at the bottom, a symmetrically geometric flowerbed spreads out on both sides of a circular fountain, and large lemon trees are in the center of each flowerbed and four magnolias are planted around the fountain.

A Bibliographical Study of Golden Manuscript Baegcheonin-dalanigyeong, Manufactured from Chunglyeol-King & Wonseong-Princess in 1284 (1284년 충렬왕(忠烈王), 원성공주(元成公主) 발원 금자대장(金字大藏) 『백천인다라니경(百千印陁羅尼經)(합부(合部))』의 서지적 연구)

  • 남권희;석혜영
    • Journal of Studies in Bibliography
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    • no.74
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    • pp.261-310
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    • 2018
  • This study attempted to introduce and analyze Baegcheonin-dalanigyeong(百千印陀羅尼經) which were recently confirmed among the golden manuscript in the Koryo Dynasty. The summary is as follows. (1) This is a book written in golden manuscript and it was manufactured by King Chunglyeol & Jegukdaejang-Princess in the 10th year of King Chongryeol's reign (1284). (2) This golden manuscript is written down on the blue paper(紺紙) with gold line border, has a scroll-form with a crystal axis on each end of it, and belongs to the part of the Scripture Tripitaka with the sign of "景". The text were formally written down in 17 letters in a line, however few 16 and 18 letters in one line were discovered. (3) The contents are consisted of following four scriptures in order; Baeg-cheon-in-dalanigyeong(百千印陀羅尼經), Gu-myeon-yeon-agwi-dalani-sinjugyeong (救面然餓鬼陁羅尼神呪經), Bul-seol- gam-lo-dalaniju (佛說甘露陁羅尼呪) 7 line and Jang-eom-wang-dalani-jugyeong (莊嚴王陁羅尼呪經), Hyang-wang-bosal-dalani-jugyeong (香王菩薩陁羅尼呪經). (4) There are unprecedented red signature and a stamp on the reverse side of the front page. The signature belongs to the King Chungryeol and it is the second name of him. The stamp shows 'Wonseongjeon(元成殿)' which is the Princess Jegukdaejang's original temple, and it could be the answer of the controversial debates about the original palace owner. (5) On the cover, there are a figure and floral pattern which seems to be made in the 13th century and the craftsman's name is '鄭(Zheng)[益迂(ig-u)]'. The figure's expression is similar to the other gold and silver manuscript version, but the postures and object hold in a hand are different. (6) Records of publications are similar to the other golden manuscripts, but showed some differences. In addition, the person who wrote this sutra is Choi jeong(崔楨), but the person is not confirmed in the historical data. Yet, it is presumed that he were in lower classes but had outstanding writing skills to be mobilized for the Scripture work. (7) The contents of '景' and four kinds of scriptures (including gamlosudalani(甘露水陁羅尼)) are included in the '景' of the 9th book sinjibjang-gyeong-eum-uisuhamlog (新集藏經音義隨函錄) and Bangsan-seoggyeong(房山石經). It is presumed that the narrative sequence of the scriptures corresponds to the order of The Khitan Tripitaka(契丹藏). In addition, these four types of scriptures are included in the "羔" of joseong-geumjang(趙成金藏), chojo Tripitaka(初雕大藏經), and jaejo Tripitaka(再雕大藏經) but the order of the scripture is recorded in reverse. In addition, this golden manuscript is a valuable data as it holds a lot of differentiator character and various sobriquet of Buddhist literature that can be utilized frequently in researches about Buddhist literature.

Analysis of water quality changes in the mainstream and major tributaries of the Youngsan River by AR6 climate change scenario with SWAT (SWAT을 이용한 AR6 기후변화 시나리오에 의한 영산강 및 주요 지천 수질 변화 분석)

  • Lee, Seungmoon;Lee, Eojin;Lee, Jihyung;Seo, Dongil
    • Journal of Korea Water Resources Association
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    • v.57 no.10
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    • pp.741-755
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    • 2024
  • This study was conducted to predict and analyze water quality changes due to climate change using the SWAT (Soil and Water Assessment Tool) model for the main stream and major tributaries of the Yeongsan River Basin. To enhance the reliability of the model, input data was constructed using weather and flow data provided by the government from 2007 to 2021, and the model was calibrated. The mid-emission scenario (SSP2-4.5) and extreme emission scenario (SSP5-8.5), derived using the WRF climate change model from the 6th IPCC report, were applied to SWAT to predict flow and nutrient loads. The water quality changes under future climate change scenarios were analyzed by categorizing them into short-term (2021-2040), mid-term (2041-2060), and long-term (2081-2100) periods. Water quality assessments were conducted based on the Living Environment Standards and the Real-Time Water Quality Index (RTWQI). As a result, in most areas of the Yeongsan River Basin, the concentration of TN was found to be at or above the "Poor" level, with the "Very Poor" level being predominant, especially in the main stream and downstream areas. While the concentration of TP showed some variation depending on the scenario, it exhibited a trend of improvement over the long term. The RTWQI assessment generally showed higher water quality levels compared to the evaluation based on living environment standards, with a trend of water quality improvement over time. This suggests that the concentration of TN can act as a major problem as agricultural regions are the main areas in water quality management in the Yeongsan River basin. Therefore, in order to improve water quality according to future climate change, it is expected that it is necessary to further reduce point and non-point sources such as agricultural non-point source reduction management such as fertilizer management and conservation agriculture, and improvement of roof greening and sewage treatment plants in urban areas.

A Study on the Stress Distribution of Tooth/Implant Connected with Konus Telescope Denture Using 3-Dimensional Finite Element Method (이중관으로 연결된 자연치와 임플랜트의 악골 내응력분포에 관한 3차원 유한요소분석)

  • Lee, Su-Ok;Choi, Dae-Gyun;Kwon, Kung-Rock;Woo, Yi-Hyung
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.4
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    • pp.381-395
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    • 2008
  • Purpoose: For decades dental implants have been used widely in the field of prosthetic dentistry. However there is confusion when establishing treatment plans in cases where some teeth are remained but an insufficient number of implants can be used due to limited anatomical status and ecomomical problems. Many clinicians have tried to connect natural teeth and implants, and it still has controversy. But, there have been few studies on mechanical analysis of connecting natural teeth and implants with konus telescopic removable partial dentures. The purpose of this study was to analyze the stress distribution of prosthesis, abutment and alveolar bone when teeth and implants were connected with the konus telescopic denture, by means of 3-dimensional finite element analysis. Material and methods: The assumption of this study was that there were 2 mandibular canine (11 mm in length, 4 mm in diameter) and 2 implants(10 mm in length, 4 mm in diameter) which are located in the second premolar region. The mandible, teeth, implants, abutments, and connectors are modeled, and analyzed with the commercial software, ANSYS Version 8.1(Swanson, Inc., USA). The control group used implants instead of natural teeth. 21038 elements, 23544 nodes were used in experimental group and 107595 elements, 21963 nodes were used in control group, Stress distribution was evaluated under 150 N vertical load on 3 experimental conditions - between teeth and implants (Load case 1), posterior to implants (Load case 2), between natural teeth (Load case 3). Results: 1. In all load cases, higher von mises stress value was observed in the experimental group. 2. Maximum von miss stress observed in all load cases and all locations were as follows ; a. 929.44 Mpa in the experimental group, 640.044 Mpa in the control group in outer crown and connector - The experimental group showed 1.45 times high value compared with the control group. b. 145,051 Mpa in the experimental group, 142.338 Mpa in the control group in abutment - The experimental group showed 1.02times high value compared with the control group. c. 32.489 Mpa in the experimental group, 25.765 Mpa in the control group in alveolar bone - The experimental group showed 1.26times higher value compared with the control group. 3. All maximum von mises stress was observed in load case 2, and maxim von mises stress in alveolar bone was 32.489 Mpa at which implant failure cannot occur. 4. If maximum von mises stress is compared between two groups, the value of the experimental group is 1.02 times higher than the control group in abutment, 1.26 times higher than the control group in alveolar bone. Conclusion: If natural teeth and implants are connected with the konus telescopic denture, maximum stress will be similar in abutment, 1.26 times higher in alveolar bone than the control group. With this result, there may be possible to make to avoid konus telescopic dentures where natural teeth and implants exist together.

Outcomes of Combined Mitral Valve Repair and Aortic Valve Replacement (대동맥판막 치환술과 동반시행한 승모판막 성형술 결과)

  • Baek, Man-Jong;Na, Chan-Young;Oh, Sam-Se;Kim, Woong-Han;Whang, Sung-Wook;Lee, Cheol;Chang, Yun-Hee;Jo, Won-Min;Kim, Jae-Hyun;Seo, Hong-Ju;Kim, Soo-Cheol;Lim, Cheong;Kim, Wook-Sung;Lee, Young-Tak;Choi, Hyun-Seok;Moon, Hyun-Soo;Park, Young-Kwan;Kim, Chong-Whan
    • Journal of Chest Surgery
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    • v.36 no.7
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    • pp.463-471
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    • 2003
  • The long-term results of combined mitral valve repair and aortic valve replacement (AVR) have not been well evaluated. This study was performed to investigate the early and long-term results of mitral valve repair with AVR. Material and Method: We retrospectively reviewed 45 patients who underwent mitral valve repair and AVR between September 1990 and April 2002. The average age was 47 years: 28 were men and 17 women. Twelve patients had atrial fibrillation and three had a previous cardiac operation. The mitral valve disease consisted of pure insufficiency (MR) in 34 patients, mitral stenosis (MS) in 3, and mixed lesion in 8. Mitral valve disease was due to rheumatic origin in 24 patients, degenerative in 11, annular dilatation in 8, and ischemia or endocarditis in 2. The functional anatomy of mitral valve was annular dilatation in 31 patients, chordal elongation in 19, leaflet thickening in 19, commissural fusion in 13, chordal fusion in 10, chordal rupture in 6, and so on. Aortic prostheses used included mechanical valve in 32 patients, tissue valve in 12, and pulmonary autograft in one. The techniques of mitral valve repair included annuloplasty in 32 patients and various valvuloplasty of 54 techniques in 29 patients. Total cardiopulmonary bypass and aortic cross clamp time were 204$\pm$62 minute and 153$\pm$57 minutes, respectively. Result: Early death was in one patient due to low output syndrome (2.2%). After follow up of 57$\pm$37 months, late death was in one patient and the actuarial survival at 10 years was 96$\pm$4%. Recurrent MR developed grade II or III in 11 patients and moderate MS in 3. Three patients required reoperation for valve-related complications. The actuarial freedom from recurrent MR, MS, and reoperation were 64$\pm$11%, 86$\pm$8%, and 89$\pm$7% respectively. Conclusion: Combined mitral valve repair with AVR offers good early and long-term survival, and adequate techniques and selection of indication of mitral valve repair, especially in rheumatic disease, are prerequisites for better long-term results.

Genetic Aspects of the Growth Curve Parameters in Hanwoo Cows (한우 암소의 성장곡선 모수에 대한 유전적 경향)

  • Lee, Chang-U;Choe, Jae-Gwan;Jeon, Gi-Jun;Kim, Hyeong-Cheol
    • Journal of Animal Science and Technology
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    • v.48 no.1
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    • pp.29-38
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    • 2006
  • The objective of this study was to estimate genetic variances of growth curve parameters in Hanwoo cows. The data used in this study were records from 1,083 Hanwoo cows raised at Hanwoo Experiment Station, National Livestock Research Institute(NLRI). First evaluation model(Model I) fit year-season of birth and age of dam as fixed effects and second model(Model II) added age at the final weight as a linear covariate to Model I. Heritability estimates of A, b and k from Gompertz model were 0.22, 0.11 and 0.07 using modelⅠ and 0.28, 0.11 and 0.12 using modelⅡ. Those from Von Bertalanffy model were 0.22, 0.11 and 0.07 using modelⅠ, 0.28, 0.11 and 0.12 using modelⅡ. Heritability estimates of A, b and k from Logistic model were 0.14, 0.07 and 0.05 using modelⅠ, 0.18, 0.07 and 0.12 using modelⅡ. Heritability estimates of A from Gompertz model were higher than those from Von Bertalanffy model or Logistic model in both model Ⅰand model Ⅱ. Heritability estimates of b from Logistic model were higher than those from Gompertz model or Von Bertalanffy model in both modelⅠand model Ⅱ. Heritability estimates of birth weight, weaning weight, 3 month weight, 6 month weight, 9 month weight, 12 month weight, 18 month weight, 24 month weight, 36 month weight were after linear age adjustment 0.27, 0.11, 0.19, 0.14, 0.16, 0.23, 0.52 and 0.32, respectively. Heritability estimates of birth weight, weaning weight, 3 month weight, 6 month weight, 9 month weight and 24 month weight fit by Gompertz model were larger than those estimated from linearly adjusted data. Heritability estimates of 12 month weight, 18 month weight and 36 month weight fit by Von Bertalanffy model were larger than those estimated from linearly adjusted data. In the multitrait analyses for parameters from Gompertz model, genetic and phenotypic correlations between A and k parameters were -0.47 and -0.67 using modelⅠand -0.56 and -0.63 using model Ⅱ. Those between the A and b parameters were 0.69 and 0.34 using modelⅠand 0.72 and 0.37 using model Ⅱ. Those between the b and k parameters were -0.26 and 0.01 using modelⅠand -0.30 and 0.01 using model Ⅱ. In the multitrait analyses for parameters from Von Bertalanffy model, genetic and phenotypic correlations between A and k parameters were -0.49 and -0.67 suing model Ⅰ and -0.57 and -0.70 using modelⅡ. Those between the A and b parameters were 0.61 and 0.33 using modelⅠ and 0.60 and 0.30 using model Ⅱ. Those between the b and k parameters were -0.20 and 0.02 using modelⅠ and 0.16 and 0.00 using modelⅡ. In the multitrait analyses for parameters from Logistic model, genetic and phenotypic correlations between A and k parameters were -0.43 and -0.67 using model Ⅰ and -0.50 and -0.63 using modelⅡ. Those between the A and b parameters were 0.47 and 0.22 using modelⅠ and 0.38 and 0.24 using modelⅡ. Those between the b and k parameters were -0.09 and 0.02 using model Ⅰ and -0.02 and 0.13 using model Ⅱ.

Stock Identification of Todarodes pacificus in Northwest Pacific (북서태평양에 서식하는 살오징어(Todarodes pacificus) 계군 분석에 대한 고찰)

  • Kim, Jeong-Yun;Moon, Chang-Ho;Yoon, Moon-Geun;Kang, Chang-Keun;Kim, Kyung-Ryul;Na, Taehee;Choy, Eun Jung;Lee, Chung Il
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.4
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    • pp.292-302
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    • 2012
  • This paper reviews comparison analysis of current and latest application for stock identification methods of Todarodes pacificus, and the pros and cons of each method and consideration of how to compensate for each other. Todarodes pacificus which migrates wide areas in western North Pacific is important fishery resource ecologically and commercially. Todarodes pacificus is also considered as 'biological indicator' of ocean environmental changes. And changes in its short and long term catch and distribution area occur along with environmental changes. For example, while the catch of pollack, a cold water fish, has dramatically decreased until today after the climate regime shift in 1987/1988, the catch of Todarodes pacificus has been dramatically increased. Regarding the decrease in pollack catch, overfishing and climate changes were considered as the main causes, but there has been no definite reason until today. One of the reasons why there is no definite answer is related with no proper analysis about ecological and environmental aspects based on stock identification. Subpopulation is a group sharing the same gene pool through sexual reproduction process within limited boundaries having similar ecological characteristics. Each individual with same stock might be affected by different environment in temporal and spatial during the process of spawning, recruitment and then reproduction. Thereby, accurate stock analysis about the species can play an efficient alternative to comply with effective resource management and rapid changes. Four main stock analysis were applied to Todarodes pacificus: Morphologic Method, Ecological Method, Tagging Method, Genetic Method. Ecological method is studies for analysis of differences in spawning grounds by analysing the individual ecological change, distribution, migration status, parasitic state of parasite, kinds of parasite and parasite infection rate etc. Currently the method has been studying lively can identify the group in the similar environment. However It is difficult to know to identify the same genetic group in each other. Tagging Method is direct method. It can analyse cohort's migration, distribution and location of spawning, but it is very difficult to recapture tagged squids and hard to tag juveniles. Genetic method, which is for useful fishery resource stock analysis has provided the basic information regarding resource management study. Genetic method for stock analysis is determined according to markers' sensitivity and need to select high multiform of genetic markers. For stock identification, isozyme multiform has been used for genetic markers. Recently there is increase in use of makers with high range variability among DNA sequencing like mitochondria, microsatellite. Even the current morphologic method, tagging method and ecological method played important rolls through finding Todarodes pacificus' life cycle, migration route and changes in spawning grounds, it is still difficult to analyze the stock of Todarodes pacificus as those are distributed in difference seas. Lately, by taking advantages of each stock analysis method, more complicated method is being applied. If based on such analysis and genetic method for improvement are played, there will be much advance in management system for the resource fluctuation of Todarodes pacificus.

Dose Response Relationship in Local Radiotherapy for Hepatocellular Carcinoma (원발성 간암의 국소 방사선치료 시 선량반응 관계)

  • Park Hee Chul;Seong Jinsil;Han Kwang Hyub;Chon Chae Yoon;Moon Young Myoung;Song Jae Seok;Suh Chang Ok
    • Radiation Oncology Journal
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    • v.19 no.2
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    • pp.118-126
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    • 2001
  • Purpose : In this study, it was investigated whether dose response relation existed or not in local radiotherapy for primary hepatocellular carcinoma. Materials and Methods : From January 1992 to March 2000, 158 patients were included in present study. Exclusion criteria included the presence of extrahepatic metastasis, liver cirrhosis of Child's class C, tumors occupying more than two thirds of the entire liver, and performance status on the ECOG scale of more than 3. Radiotherapy was given to the field including tumor with generous margin using 6, 10-MV X-ray. Mean tumor dose was $48.2{\pm}7.9\;Gy$ in daily 1.8 Gy fractions. Tumor response was based on diagnostic radiologic examinations such as CT scan, MR imaging, hepatic artery angiography at $4\~8$ weeks following completion of treatment. Statistical analysis was done to investigate the existence of dose response relationship of local radiotherapy when it was applied to the treatment of primary hepatocellular carcinoma. Results : An objective response was observed in 106 of 158 patients, giving a response rate of $67.1\%$. Statistical analysis revealed that total dose was the most significant factor in relation to tumor response when local radiotherapy was applied to the treatment of primary hepatocellular carcinoma. Only $29.2\%$ showed objective response in patients treated with dose less than 40 Gy, while $68.6\%\;and\;77.1\%$ showed major response in patients with $40\~50\;Gy$ and more than 50 Gy, respectively. Child-Pugh classification was significant factor in the development of ascites, overt radiation induced liver disease and gastroenteritis. Radiation dose was an important factor for development of radiation induced gastroduodenal ulcer. Conclusion : Present study showed the existence of dose response relationship in local radiotherapy for primary hepatocellular carcinoma. Only radiotherapy dose was a significant factor to predict the objective response. Further study is required to predict the maximal tolerance dose in consideration of liver function and non-irradiated liver volume.

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Depositional Environment and Formation Ages of Eurimji Lake Sediments in Jaechon City, Korea (제천 의림지 호저퇴적물 퇴적환경과 형성시기 고찰)

  • 김주용;양동윤;이진영;김정호;이상헌
    • The Korean Journal of Quaternary Research
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    • v.14 no.1
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    • pp.7-31
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    • 2000
  • Quaternary Geological and geophysical investigation was performed at the Eurimji reservoir of Jaechon City in order to interprete depositional environment and genesis of lake sediments. For this purpose, echo sounding, bottom sampling and columnar sampling by drilling on board and GPR survey were employed for a proper field investigation. Laboratory tests cover grain size population analysis, pollen analysis and $^{14}C$ datings for the lake sediments. The some parts of lake bottom sediments anthropogenically tubated and filled several times to date, indicating several mounds on the bottom surface which is difficult to explain by bottom current. Majority of natural sediments were accumulated both as rolling and suspended loads during seasonal flooding regime, when flash flow and current flow are relatively strong not only at bridge area of the western part of Eurimji, connected to stream valley, but at the several conduit or sewage system surrounding the lake. Most of uniform suspend sediments are accumulated at the lake center and lower bank area. Some parts of bottom sediments indicate the existence of turbid flow and mudflow probably due to piezometric overflowing from the lake bottom, the existence of which are proved by CM patterns of the lake bottom sediments. The columnar samples of the lake sediments in ER-1 and ER-3-1 boreholes indicate good condition without any human tubation. The grain size character of borehole samples shows poorly sorted population, predominantly composed of fine sand and muds, varying skewness and kurtosis, which indicate multi-processed lake deposits, very similar to lake bottom sediments. Borehole columnar section, echo sounding and GPR survey profilings, as well as processed data, indicate that organic mud layers of Eurimji lake deposits are deeper and thicker towards lower bank area, especially west of profile line-9. In addition the columnar sediments indicate plant coverage of the Eurimji area were divided into two pollen zones. Arboreal pollen ( AP) is predominant in the lower pollen zone, whreas non-aboreal pollen(NAP) is rich in the upper pollen zone. Both of the pollen zones are related to the vegetation coverage frequently found in coniferous and deciduous broad-leaved trees(mixed forest) surrounded by mountains and hilly areas and prevailing by aquatic or aquatic margin under the wet temperate climate. The $^{14}C$ age of the dark gray organic muds, ER1-12 sample, is 950$\pm$40 years B.P. As the sediments are anthropogenetically undisturbed, it is assumed that the reliability of age is high. Three $^{14}C$ ages of the dark gray organic muds, including ER3-1-8, ER3-1-10, ER3-1-11 samples, are 600$\pm$30 years B.P., 650$\pm$30 years B.P., 800$\pm$40 years B.P. in the descending order of stratigraphic columnar section. Based on the interpretation of depositional environments and formation ages, it is proved that Eurimji reservoir were constructed at least 950$\pm$40 years B.P., the calibrated ages of which ranges from 827 years, B.P. to 866 years B.P. Ancient people utilize the natural environment of the stream valley to meet the need of water irrigation for agriculture in the local valley center and old alluvium fan area.

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Evaluation of Puretone Threshold Using Periodic Health Examination Data on Noise-exposed Workers in Korea (소음 특수건강진단 자료를 이용한 순음청력검사 평가)

  • Kim, Yang-Ho;Choi, Jung-Keun;Park, Jung-Sun;Moon, Young-Han;Kim, Kyoo-Sang
    • Journal of Preventive Medicine and Public Health
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    • v.32 no.1
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    • pp.30-39
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    • 1999
  • Objectives. This study was carried out to evaluate hearing impairment judgement and to investigate the differences in various diagnostic criteria for noise-induced hearing loss (NIHL) among workers who required for close observation (C). Methods. Out of 731,029 workers who had taken the specific periodic health examination in 1994, we used the audiometric data on 37,999 workers (C) eliminating the employees who had previous otologic problems. Many investigators have being using different criteria for the evaluation of hearing impairment. In this study, we used the criteria of early (1989-1994), current, compensation for NIHL in Korea, 2-, 3-, 4-divided classification and hearing loss at 4,000 Hz and compared the evaluation results. Results. The prevalences of C and workers who had occupational disease $(D_1)$ diagnosed for NIHL were 11.1 % and 0.44 %. There were significant difference in the prevalences of C and $D_1$, depending on different province of Korea. Pure tone averages (PTAs) were not appropriately applied in their evaluation 97% of workers whom we studied on were below the level of mild hearing loss judged by ISO standard. However, there were wide variations in the prevalence rate of mild hearing loss by diagnostic criteria. Thus, there were different judgements in determining the degree of NIHL depending on which diagnostic criteria were utilized. PTAs were found 20.54 (Rt) and 20.74 (Lt) when the method of 3-divided classification was applied for audiometric data. The degree of hearing impairment of the left ear was more severe than that of right ear. The prevalence of normal hearing threshold below 20 dB was 75.4% and the range of difference in both ear was below 10 dB. Right sided hearing threshold levels were 21.08 dB (500 Hz), 18.44 dB (1,000 Hz), 22.09 (2,000 Hz) and 52.36 dB (4,000 Hz). There was typical high frequency loss (C5-dip at 4,000 Hz) above 30 - 40 dB in normal hearing level. The increasing trend in hearing threshold level was gradually decreased by the increase of PTAs. The difference between PTAs and threshold at 4,000 Hz was about 10 dB. Conclusions. We could found that PTAs in the previous examination were not appropriately evaluated. This study revealed that they did not use unique criteria for managing the workers of NIHL. For the prevention of NIHL, it was found that the quality control on diagnosis and comprehensive management program were required, especially for those of hearing loss (C).

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