• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.170-176
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• 1998

Nitrogen and phosphorus loads from an agricultural watershed of the Yulmun-chon tributary in the Buk-Han River Basin were quantified based on total amounts of water stream flow. The water quality and soil loss were estimated. Levels of the stream were recorded automatically using the water level meter. The flow velocities, along with the cross-sectional areas of the riverbed, were measured to estimate total amounts of water flow at three monitoring sites in this tributary. Water samples were collected at nine sites with two weeks interval from May to August and analyzed for the water quality parameters. Amounts of soil loss were estimated by the USLE. The size of the Yulmunchon watershed was 3,210 ha, of which paddy and upland soil areas were composed about 41%. The total amounts of soil loss from the watershed areas were estimated to be $13,273Mg\;year^{-1}$, showing 53%, 46% and 0.7% of the soil loss ratio from upland, forest, and paddy areas, respectively. Electrical conductivities and Nitrogen concentrations of the stream water were higher in the lower watershed area than in the upper area. Increments of N were higher for $NO_3-N$ than $NH_4-N$. Nitrate nitrogen was the major N form to pollute the water due to the agricultural activity. Total runoff was about 72% of the total precipitation in the watershed. The maximum loads of T-N and T-P due to the runoff were estimated to be 1,500 and $5kg\;day^{-1}$, respectively. Concentrations of $NO_3-N$ and $NH_4-N$ in the runoff were 13.5 and 1.8 times higher than those in precipitation. The N loads were mainly from soil loss, application of fertilizer, and livestock wastes, which were 52% of total N load. Results demonstrated that reduction of fertilizer use and the soil loss would be essential for water quality protection of the agricultural watershed.

• Economic and Environmental Geology
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• v.32 no.4
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• pp.353-363
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• 1999

The Cretaceous and the Upper Jurassic strata of the Korean Peninsula, entirely of continental facies, form a sedimentary mega-unit subdivided into three unconformity-bounded units. The lower, Upper Jurassic-early Lower Cretaceous unit (Jasong Synthem) occurs profusely in North Korea and is characterized by volcanic rocks of intermediate to acidic, calc-alkaline to alkaline compositions; but strata of this unit is very rare in South Korea. The middle, Hauterivian-Lower Albian unit occurs commonly in the Korean Peninsula, but some alkalinesubalkaline basalt and andesite occur only in South Korea. A recently obtained U-Pb isochron age about 113.6 Ma (Chang et at, 1998) from the zircon grains of the Kusandong Tuff in the uppermost part of the Haman Formation has thrown much light on the age of this unit. The stratotype of this Hauterivian-L. Albian unit is the Sindong and Hayang Groups of the Kyongsang Basin, where the unit is about twice thick and has more conglomerates than in sedimentary basins in North Korea. The unit shows various sedimentary cycles in different basins showing that the cyclicity is controlled by local crustal motion. The upper, Upper Albian-Upper Cretaceous unit is abundant in South Korea with prolific volcanic rocks which are intermediate to acidic and notably calc-alkaline. In North Korea, however, this unit occurs in only one locality without volcanic rocks and is not voluminous. The distribution of these three unconformity-bounded units shows a stepwise younging toward the Pacific Ocean: the lower unit occurs mainly in N Korea, the middle unit occurs in both N and S Korea, and the upper unit occurs mainly in the southern part of S Korea. The Cretaceous sedimentary basins of S Korea were genetically controlled by paralleling sinistral strike-slip faults parallel to the Pacific margin.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.197-205
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• 2011

Purpose: This study was to evaluate the accuracy of the implant torque controller used in dental clinics and to investigate whether it was applied appropriately. Materials and methods: Fifty dentists who work in dental clinics were enrolled in this study. Dental (implant) practice career, experience frequency of implant screw loosening and fracture, education of implant torque controller application and infection control methods were included in the survey. 25 Ncm and 30 Ncm of the tightening torque applied to the implant screw were measured by 50 clinicians. After measuring the torque value by using the torque controller, the torque mean according to where education about the implant torque controller was received was analyzed with independent t-test at the significance level of 0.05. Results: The torque controller used in private dental clinics showed 4.78% error ratio. When 50 dentists applied 25 Ncm to the implant screw was $29.0{\pm}8.4$ Ncm, and that in 30 Ncm was $34.3{\pm}9.1$ Ncm. Statistical significance was found between the group that was educated about implant torque application and the group that was not educated. Conclusion: During the prosthodontic treatment with implant, there was difference between actual applied torsion force and the amount torque controller indicated. Clinicians have to not only be well-informed about the accurate usage method of the torque controller, but also keep and manage the torque controller so as to maintain continuous and accurate torque values. Through this, it is considered to achieve clinical results to minimize problems of screw loosening or fracture.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.1
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• pp.53-64
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• 2008

Statement of problem: Peri-implant marginal bone loss is an important factor that affects the success of implants in esthetics and function. Various efforts have been made to reduce this bone loss by improving implant design and surface texture. Previous studies have shown that early marginal bone loss is affected by implant neck designs. Purpose: The purpose of this study was to examine the influence of laser microtexturing of implant collar on peri-implant marginal bone loss. Materials and methods: Radiographical marginal bone loss was examined in patients treated with implant-supported fixed partial dentures. Marginal bone level was examined with 101 implant fixtures installed in 53 patients at three periods(at the time of implantation, prosthetic treatment and 6-month after loading). Four types of implants were examined. The differences of bone loss between implants(ITI standard) with enough biologic width and implants(ITI esthetic plus, Silhouette IC, Silhouette IC Laser-$Lok^{TM}$) with insufficient biologic width have been compared. Resorption angles were examined at the time of prosthetic delivery and 6-month after loading. Results and Conclusion: Within the limitation of this study, the following results were drawn. 1. The marginal bone loss of ITI standard and Silhouette IC Laser-$Lok^{TM}$ was less than that of ITI esthetic plus and Silhouette IC(P<0.05). The marginal bone loss between ITI standard and Silhouette IC Laser-$Lok^{TM}$ had no significant statistical difference(P>0.05). There was no significant statistical difference between marginal bone loss of ITI esthetic plus and Silhouette IC(P>0.05). 2. There was no significant difference in marginal bone loss between maxilla and mandible(P>0.05). 3. There was no significant difference in resorption angle among four types of implants(P>0.05). The marginal bone of implants with supracrestal collar design of less than that of biologic width had resorbed more than those with sufficient collar length. The roughness and laser microtexturing of implant neck seem to affect these results. If an implant with collar length of biologic width, exposure of fixture is a possible complication especially in the anterior regions of dentition that demand high esthetics. Short smooth neck implant are often recommended in these areas which may lack the distance between microgap and the marginal bone level. In these cases, the preservation of marginal bone must be put into consideration. From the result of this study, it may be concluded that laser microtexturing of implant neck is helpful in the preservation of marginal bone.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.470-478
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• 2008

Statement of problem: Use of all-ceramic prostheses fabricated with CAD/CAM systems is increasing in the dentistry. Marginal fidelity in production of all-ceramic restoration has important clinical implications and is a key consideration issue in CAD/CAM production as well. Purpose: The objective of this study was to analyse marginal fidelities of $Procera^{(R)}$ Allceram Crown. Material and methods: On 56 patients treated with $Procera^{(R)}$ system Allceram Crown at Dankook Dental Hospital, marginal discrepancies of 101 abutments were measured by stereomicroscope at coping and final restoration stages. Paired t-test and one-way analysis of variance on marginal discrepancy data were conducted to determine the presence of significant differences between measurement and measuring point stages. Results: Marginal discrepancies of final restoration ($45.82{\pm}30.84\;{\mu}m$) were lower than alumina coping ($53.84{\pm}38.83\;{\mu}m$). Furthermore, the differences were found to be statistically significant at 95% confidence level. Anterior marginal discrepancies were lower than posterior marginal discrepancies, but they were not statistically significant. Lingual marginal discrepancies were higher than other measurement sites, and the differences were found to be statistically significant at 95% confidence level. Conclusion: Within the conditions of this study, marginal fidelities of $Procera^{(R)}$ Allceram Crown were acceptable, and after porcelain build-up, marginal fitness improved over alumina coping. More careful scanning is needed for better results.

• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.275-286
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• 2007

Background : Acute renal failure is one of the leading causes of postoperative morbidity and mortality. The purpose of this study was to determine the risk factors that are associated with acute renal failure after colorectal surgery. Materials and Methods : Five hundred seventy patients who operated colorectal surgery at the Yeungnam University Medical Center over three years from 2004 to 2006 were enrolled in this study. The effects of gender, age, ASA classification, concomitant disease, surgery type and duration, reoperation, urogenital manipulation, medication, hypotension, hypovolemia, transfusion, and postoperative ventilatory care on the occurrence of acute renal failure after colorectal surgery were studied. Results : The major risk factors of acute renal failure after colorectal surgery were age of patients (P=0.003), ASA classification (P<0.001), concomitant disease (P<0.001), duration of the time surgery (P=0.034), reoperation (P=0.001), use of intraoperative diuretics (P=0.005), use of postoperative diuretics (P<0.001), intraoperative hypotension (P=0.018), intraoperative transfusion (P<0.001), postoperative transfusion (P<0.001), and postoperative ventilatory care (P=0.001). Conclusion : Multiple factors cause synergistic effects on the development of acute renal failure after colorectal surgery. Therefore, efforts to reduce the risk factors associated with acute renal failure are needed. In addition, intensive postoperative care should be provided to all patients.

• Journal of Korean Society of Forest Science
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• v.55 no.1
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• pp.59-67
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• 1982

The objectives of this report is to evaluate the contribution of forest investments by the forest owners for the developments of private forests in the villages where the forest production, especially, chestnut production is active. The results obtained are as follows : 1) Newly purchased forest lands of 526 hectares, 71 percent, in 741 hectares by 96 farmers were replanted with chestnut trees for chestnut production. 2) As the chestnut production is considered to be the unique source of the early capital return in management of forests, selling and buying of forest lands in the area surveyed are enhanced to reforest the forest land with chestnut seedlings. 3) Most of new farmers being engaged in plantation and production of chestnuts in the forests are employees of private industries and government agencies, and merchants in neighboring towns. 4) All materials and expenses for formation of chestnut orchards are generally supplied by forest land owners. 5) Active buying and selling of newly established chestnut bushes are surely served as the estate in the area, thus, the trading of the bushes of young chestnut seedling also enhances the forest as the estate. 6) The management of forest established with chestnut orchards is a special form for forest investment, it makes possible to encourage imputing of capital to the new form of forests, chestnut orchards, and it could be a good possible model for private forest development as compared with that of government funding.

• Journal of Korean Home Economics Education Association
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• v.18 no.4 s.42
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• pp.173-192
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• 2006

The purpose of this study was to provide basic data for developing nutrition education program focusing on the health-oriented food choice and purchase which affect the adolescents' health. The data was collected by means of questionnaire from the total of 273 students who were living in cities and myun district and final 253 questionnaires were analyzed by using the SPSS/WIN 10.0 program. The results are summarized as follows. First, the major source of information on food was mass media, especially advertisement and students spent $20{\sim}30%$ of allowance on food purchase. The students purchased cookies or ice cream mainly, once every 2-3 days at the store near house, after school, for appeasing hunger or thirst. The influence of gender, mother's education level, economic status of family, the amount of allowance, the period of receiving allowance, the details of allowance recording, school location on food purchasing behavior were significant(p<.05). Second, the price and taste were the most important factors when the students purchase food. Nutrition and food sanitation/safety were considered less important by the students. The factors considered when the students purchase food were significantly different between Sender, father and mother's education level, and the amount of allowance(p<.05). Third, middle school students' food purchase behavior were influenced by advertizement, friends, parents. The influence of advertisement, friends, parents when the students purchase food were significantly different between gender, mother's career, economic status of family, and the amount of allowance(p.<05). From tile result of this study, the middle school students consider price and taste more than the other factors related nutrition and health in purchasing foods. Therefore, it will be necessary to develope and enforce nutrition education program focusing on how to choose and purchase safe, nutritious, delicious and cheap foot for adolescents.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.1
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• pp.16-22
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• 2018

Oats (Avena sativa L.), which are known as one of the forage crops of Korea, have good livestock palatability and are popular to cattle farmers because of their high dry matter. However, the cultivation of double cropping in the rice field was reluctant due to the late maturing for farmers to plant rice continuously. 'Hi-early', a winter oats for forage use, was developed by the breeding team at National Institute of Crop Science, RDA in 2016. It was derived from a cross between '517A2-121'(IT133383) and 'CI7604' (IT133379). Subsequent generations followed by the cross were handled in bulk and pedigree selection programs at Suwon, Iksan and Jeonju, respectively. After preliminary and advance yield test for 2 years, 'SO2004015-B-B-23-1-3-7', designated as a line name of 'Gwiri92', were subsequently evaluated for earliness and forage yield during 3 years in four parts such as Jeju (upland), Yesan (upland), Iksan (upland), and Jeonju (paddy), from 2014 to 2016, and finally named as 'Hi-early'. Cultivar 'Hi-early' has the characteristics of medium leaves of green color, thick diameter culm, and medium grain of brown color. Over 3 years, the heading date of 'Hi-early' was about 9 days earlier than that of check cultivar 'Samhan' (April 26 and May 5, respectively). Average forage fresh yield of 'Hi-early' harvested at milk-ripe stage was similar to check cultivar ($40.2tone\;ha^{-1}$ and 40.0 tone ha-1, respectively), and dry matter yield also was similar to check cultivar (14.2 tone ha-1 and $14.0tone\;ha^{-1}$, respectively). Cultivar 'Hi-early' was lower than the check cultivar 'Samhan' in terms of the protein content (6.2% and 7.0%, respectively) and total digestible nutrients (61.0%, and 62.5%, respectively), while the TDN yield was more than the check ($7.91tone\;ha^{-1}$ and $7.64tone\;ha^{-1}$, respectively). Fall sowing cropping of 'Hi-early' is recommended only in areas where average daily minimum mean temperatures in January are higher than $-6^{\circ}C$, and it should not be cultivated in mountain areas, where frost damage is likely to occur.

• Sijohaknonchong
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• v.23
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• pp.107-131
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• 2005

The purpose of this is to make sure what the scholar of the Choseon thought the object of aesthetics, and which psychological element did they use to clear the center of the aesthetics. In addition, I consider their way to recognize the human's aesthetic point of view. A literary man in Choseon regarded the five senses as an obstacle which interrupted to see the nature of all things. So they set up the spiritual condition as their aesthetic subject, with suppressing the pleasure through five senses. The goal to make one's mind calm was to cause someone's spirit to activate freely. The condition of the calmness was considered as a process of recovering the human's natural spirit, which was connected to the poetic spirit and became the aesthetic subject. Simultaneously, a literary man at that time set up the condition of the calmness as a subject of objective consciousness, and estimated the common things as a objective existence, which led to the result that all the materials of the poem and the poet could be unified. This aesthetic centra put a premium on the senses caused by contacting with all natural things, and adopted the 'Xing' as a method of expression. This 'Xing' is not a sense based upon one's experience, but a sense which is created of itself. The expression method of 'Xing' caused the reader to feel and express, encourage, and sublimate what they feel through the poem, as well as purified reader's mind.