• The Korean Journal of Ecology
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• 제17권3호
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• pp.311-318
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• 1994

치화화 사막에서 몇 가지 식물 뿌리의 분해율과 분해 과정에 따른 질소함량의 변화를 조사하였다 (1986년 10월 ~ 1990년 4월). 뿌리의 분해는 리그닌 함량과 역상관 관계를 보였다(r=-0.84, n=5, p<0.05). 1년생 광엽초본인 Baileya multiradiata의 분해율이 가장 높았고 다년생 협엽 초본인 Panicum obtusum의 분해율이 가장 낮았다. 지역에 따른 분해율은 playa에서 가장 낮았다. Baileya multiradiata를 제외하고 모두 분해 초기에 질소의 무기화가 있은 다음 질소의 부동화가 나타났다. Baileya multirdiata의 뿌리는 분해 초기부터 질소함량이 계속 증가하는 것으로 나타났다. 다년생 협엽초본 뿌리의 리그닌 함량은 광엽초본 뿌리의 리그닌 함량보다 높았다.

• Applied Biological Chemistry
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• 제38권2호
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• pp.157-162
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• 1995

감마핵종분석을 통하여 깊이에 따른 Cs-137의 농도 분포를 조사함으로써 전라남도 해남군 화원면 소재 산수저수지에서의 연간 퇴적률, 퇴적물의 총량 및 유역에서의 추정토양유실량을 정량적으로 밝히고자 수행한 본 연구의 결과는 다음과 같다. -퇴사는 대부분 미사 크기의 입자로 구성되었고 퇴사의 pH, 유기물함량, CEC 및 치환성양이온함량은 우리나라 밭토양 및 저수지 상류지역 경작지 평균과 비슷한 수준이었으나 유효인산함량은 우리나라 밭토양 및 저수지 상류지역 경작지 평균보다 매우 낮았다. -시료채취지점에 따라 Cs-137은 $15{\sim}60\;cm$ 깊이까지 분포하였으며, $920.0{\sim}8928.4\;Bq$ $m^{-2}$의 농도 분포를 보였다. -1963/64년부터 1994년까지 이 저수지의 연간 퇴적률은 1.56 cm $yr^{-1}$였고, 퇴적량은 $166530\;m^3$이었다. -저수지 유역에서 고르게 유실이 일어났다고 가정할 때 전체 면적에서 연평균 2 mm 두께의 토양이 유실되었으며, 무게로는 ha당 25 ton의 토양이 유실 되었다.

• Journal of Preventive Medicine and Public Health
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• 제39권1호
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• pp.21-29
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• 2006

Objectives: We wanted to estimate the annual socioeconomic costs of alcohol drinking in Korea. Methods: The costs were classified as direct costs, indirect costs and the other costs. The direct costs consisted of direct medical costs, indirect medical costs and subsidiary medical costs. Particularly, the medical costs and population attributable fraction for disease were considered to reflect the calculation of the direct medical costs. The indirect costs were computed by the extent to which the loss of productivity and loss of the workforce might have occurred due to changes in mortality and morbidity according to alcohol drinking. The other costs consisted of property loss, administration costs and costs of alcoholic beverage. Results: The annual costs, which seemed to be attributable to alcohol drinking, were estimated to be 149,352 hundred million won (2.86% of GDP). In case of the latter, the amount includes 9,091 hundred million won for direct costs (6.09%), 62,845 hundred million won for the reduction and loss of productivity (42.08%), 44,691 hundred million won for loss of the workforce (29.92%), and the other costs (21.91%). Conclusions: Our study confirms that compared with the cases of Japan (1.9% of GNP) and the other advanced countries (1.00-1.42% of GDP), alcohol drinking incurs substantial socioeconomic costs to the Korean society. Therefore, this study provides strong support for government interventions to control alcohol drinking in Korea.

• Spatial Information Research
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• 제14권4호
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• pp.363-377
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• 2006

본 연구에서는 개정범용토양유실공식(RUSLE: Revised Universal Soil Loss Equation)을 이용하여 미국 South Carolina 주 Congaree 유역에 대한 평균 연간 토양 유실량을 산출 하였으며 비점오염원 토양 유실 민감지역을 추출하였다. 평균 연간 토양 유실량은 강우-유출 침식성 인자, 토양침식성 인자, 지면특성 인자, 식생피복 인자, 그리고 토양보존 인자의 곱으로 계산할 수 있으며, 토양 유실 민감지역은 토양 유실량이 토양침식 허용량을 초과하는 지역으로 추출할 수 있다. 연구 결과, 전체 면적의 10% 이상의 면적이 비점오염원 토양 유실 민감 지역으로 확인되었으며, Congaree 유역의 7개 소유역중 Congaree Creek, Gills Creek 소유역의 도심지역과 Cedar Creek 소유역의 농업지역에서 가장 심각한 토양 유실의 위험이 나타났다. 관심 지역의 인위적, 자연적 변화가 토양 유실에 가져오는 영향을 살펴보기 위한 시범 모형으로서, 개정범용토양유실공식에 기초한 내장형 모형이 Visual Basic for Applications (VBA)를 이용하여 ESRI사의 ArcGIS ArcMap 9.0에서 사용할 수 있도록 개발되었다. 이 내장형 모형에서 사용자는 각 소유역의 토지 피복, 식생 유형, 지표 식생 유형, 경사, 작물 유형, 경작 방식 등을 변경시킴으로써 C, LS, P 인자를 변화시킬 수 있으며, 계산된 평균 연간 토양 유실량과 민감 지역을 현재 상태의 값들과 비교하여 앞으로의 토양유실 관리를 위한 주요 정보로 사용할 수 있다.

• 한국농공학회논문집
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• 제59권6호
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• pp.109-125
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• 2017

This study aimed to develop a parcel-unit soil loss estimation tool embedded in Excel worksheet, USLExls, required for the design of contaminated farmland restoration project and to analyze the impact of the project carried out soil-filling work on soil loss. USLE method was adopted for the estimation of average annual soil loss in a parcel unit, and each erosivity factor in the USLE equation was defined through the review of previous studies. USLExls was implemented to allow an engineer to try out different combinations just by selecting one among the popular formulas by each factor at a combo box and to simply update parameters by using look-up tables. This study applied it to the estimation of soil loss before and after soil-filling work at Dong-a project area. The average annual soil loss after the project increased by about 2.4 times than before on average, and about 60 % of 291 parcels shifted to worse classes under the classification criteria proposed by Kwak (2005). Although average farmland steepness was lower thanks to land grading work, the soil loss increased because the inappropriate texture of the cover soil induced the soil erosion factor K to increase from 0.33 before to 0.78 after the soil-filling work. The results showed that the selection of cover soil for soil-filling work should be carefully considered in terms soil loss control and the estimation of change in soil loss should be mandatory in planning a contaminated farmland restoration project.

• Journal of Plant Biology
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• 제15권4호
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• pp.1-12
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• 1972

To study on the annual height growth of Pinus densiflora within natural pine stands in central Korea, twenty two pure closed Pinus densiflora stands were selected subjectively in the west-central region of Korea. In each stand twenty trees were chosen randomly. For each tree, abotu ten to fifteen measurements of internodal lengths were made from leader top to trunk base. A total of one hundred thirty four soil samples was collected. Each soil sample was bulked with three subsamples. The ranges of the growth measurements per stand, per tree and per observation were 14.9-35.4cm, 9.0cm-54.4cm and 2.4cm-69.0cm respectively. The total mean value was 23.5cm. The Student-Newman-Keul's tests for the multiple comparison among the mean values of the height growth per stand were very highly significant. The resutls of the analysis of variance of the height growth data for the selected fifteen stands among the twenty two stands indicate that sampling efficiency might be increased to 744% if measurement of the growth were made on fifteen trees per stand from twenty stands instead of twenty trees per stand from fifteen stands. The annual height growths of Pinus densiflora and Pinus koraiensis for the period from 1960 to 1968 were 21.74$\pm$5.29cm (10) and 20.56$\pm$5.59cm (10) respectively. The total means of easily-soluble phosphorus, total nitrogen, loss on ignition and pH for the soil samples were 2.8 ppm, 0.09%, 5.4% and 4.7 respectively. The ranges of those amounts were 18.7-1.7ppm, 0.17-0.05%, 11.6%-3.1%, 3.9-5.1 respectively. The relationship of the annual height growth of P. densiflora to soil was studied in terms of standard partial multiple regression. Among soil properties such as non-capillary pore space, capillary pore space, maximum field capacity, loss on ignition, soil reaction, total nitrogen and easily-soluble phosphoros investigated, the easily soluble phosphorus in one analysis and loss on ignition and soil reaction in the other analysis seem to have significant positive influence on the annual height growth.

• 대한치과보철학회지
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• 제45권6호
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• pp.760-768
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• 2007

Statement of problem. Conventional denture treatment for totally edentulous patients is associated with a variety of functional and psychosocial problems. The placement of implants in the anterior region of the maxilla and mandible and the fabrication of an implant-retained overdenture might solve these problems. Purpose. This study compared the marginal bone loss around the implant and evaluated the implant survival rate and complications in patients treated with overdentures retained by implants for 2 years. Material and methods. Patients who had received implant-retained overdentures using a Dolder bar at Samsung Medical Center from January 1999 to June 2005 and had participated in the annual recall programs for two years were selected for this study. A total of 18 patients and 56 $Br{\aa}ne-mark\;system^{(R)}$ implants were used, and their data were reviewed. Evaluations of the survival rate, bone quality, marginal bone loss, and complications were performed. The data on the Dolder bar length and clip length were measured. The change in marginal bone loss and the correlation between the marginal bone loss and bar length, clip length, or bone quality were investigated. Results. Implants placed in this study showed a 100% survival rate. The average annual bone loss was 1.12mm in the first year and 0.27mm in the second year in the maxilla, and 0.58mm in the first year and 0.22mm in the second year in the mandible. The marginal bone loss in the maxilla showed no significant association with those in the mandible. (P>.05). There was no significant difference in marginal bone loss around implants between the first and second year. (P>.05) There was no statistically significant relationship (P>.05) between the marginal bone loss and bone quality, clip length, or Dolder bar length. The Dolder bar length showed a high correlation with the clip length. (P<.05) Various complications were noted. Conclusion. These results confirmed the favorable outcome for patients treated with implant-retained overdentures.

• 환경영향평가
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• 제20권3호
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• pp.313-324
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• 2011

The purpose of this study is to present the raw data for establishing the plan of top soil conservation in soil environment and preventing the soil loss by establishing the potential amount of soil loss using RUSLE. The results are as follows. To apply the RUSLE model, we calculated the potential amount of soil loss by using 5 factors; rainfall erosion factor(R), topographical factor(LS), soil erosion factor(K), land cover factor(C) and erosion control factor(P). The assessment map of soil loss was drawn up by classifying 5 grades. According to the soil loss estimation by the RUSLE, it showed that approximately 83.9% of the study area had relatively lower possibility of soil loss which was the 1 ton/ha in annual soil loss. Whereas, the 7.0% of the study area was defined as high risk area which was the 10 ton/ha in annual. Therefore, this area was needed that there was environment-friendly construction of farm land, improvement of cultivation environment and so forth. In future, if we will analyze the amount of soil loss of Gyeongju national park and Hyeongsan river watershed, we will offer the help to establishing the conservation plan of soil environment in Gyeongsangbuk-do.

• 한국구조물진단유지관리공학회지
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• 제19권2호
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• pp.14-18
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• 2015

• Journal of Biosystems Engineering
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• 제14권1호
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• pp.41-48
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• 1989

In order to provide a basic information for the government policy in the future, rice milling costs of Small Capacity Farm-house Rice Whiteners (SCFRW) were estimated by surveying and analyzing the major factors to affect their costs. Two types of SCFRW having one stage and two stage milling process and two rice varieties, Tong-il and Akibare, were considered for their cost estimation, respectively. Also, their costs were compared with those of Private Custom-work Mill in order to determine its economical feasibility. The results were concluded as follows; 1. Major factors to affect the costs were annual milling quantity, purchase price of SCFRW and grain milling loss. 2. Total milling costs of SCFRW were a function of annual milling quantity. These costs decreased rapidly as annual milling quantity increased. 3. In comparison of milling costs between single pass type and double pass type SCFRW, the former was more economical than the latter. 4. Also, in comparison of milling costs between two varieties by using SCFRW, Akibare was less expensive than Tong-il. 5. In comparison with private Custom-work Mill, both single pass and double pass type SCFRW were less economical than private Custom-work Mill. 6. In order to have an economical feasibility, SCFRW should be designed and developed to reduce its milling loss and purchase price.