• Journal of the Korean Society for Precision Engineering
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• v.28 no.6
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• pp.738-744
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• 2011

The reliability of blade root fixing section is required to endure the centrifugal force and vibration stress for the last stage blade of steam turbine in thermal power plant. Most of the domestic steam turbine last stage blades have finger type roots. The finger type blade is very complex, so the inspection had been performed only on the exposed fixing pin cross-section area due to the difficulty of inspection. But the centrifugal force and vibration stress are also applied at the blade root finger and the crack generates, so the inspection method for finger section is necessary. For the inspection of root finger, inspection points were decided by simulating ultra-sonic path with 3D modeling, curve-shape probe and fixing jig were invented, and the characteristics analysis method of ultrasonic reflection signal and defect signal disposition method were invented. This invented method was actually executed at site and prevented the blade liberation failure by detecting the cracks at the fingers. Also, the same type blades of the other turbines were inspected periodically and the reliability of the turbine increased.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.1
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• pp.32-37
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• 2016

Purpose: To determine the anatomical characteristic of C-shaped canal systems in Korean mandibular 2nd molars by cone beam computed tomography (CBCT). Materials and Methods: The 824 CBCT images were evaluated. These patients were taken CBCT for the diagnosis and treatment of dental implantation on 2013. The 711 mandibular 2nd molars were examined. The configuration of root canal systems were classified according to modified Melton's classifications. Results: Of the 711 mandibular 2nd molars, 21.5% had C-shaped canal systems. This prevalence did not differ with tooth position. Most of the C-shaped canals with bilateral molars were symmetrical. Of the C-shaped canal, the most common configuration Type were Melton's Type I (89%) in the orifice level and Melton's III (83.8%) in the apical level. The prevalence of C-shaped canal was higher in female (25%) than male (13.9%) (P < 0.05). Conclusion: A high prevalence of C-shaped canals were observed in Korean mandibular 2nd molars. For successful C-shaped root canal treatment, the comprehension of root canal systems was important.

• Korean Journal of Medicinal Crop Science
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• v.27 no.5
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• pp.307-314
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• 2019

Background: We measured the weight characteristics, intercellular space volume as a proportion of root volume, and quantities of the functional component in Angelica gigas Nakai, collected from four cultivation areas in Pyeongchang, including Tapdong-ri and SangjinBu-ri, and tested the results for correlations. Methods and Results: Dry weight was the highest in the Tapdong-ri group ($13.37{\pm}0.13g$) and the lowest in the SangjinBu-ri group ($11.90{\pm}0.57g$). The percentage of intercellular spaces within the roots, determined by micro-CT camera, was the highest in the Tapdong-ri group ($6.44{\pm}0.76%$) and the lowest in the SangjinBu-ri group ($9.01{\pm}2.15%$). The quantity of functional components were the highest in the Tapdong-ri group ($116.13{\pm}9.53mg/g$) and the lowest in the SangjinBu-ri group ($99.77{\pm}23.23mg/g$). Conclusions: The dry weight of A. gigas significantly correlated with the volume and percentage of intercellular space. An increase in the dry weight resulted in a negative correlation between the volume and ratio of the intercellular spaces. The volume of intercellular space correlated negatively with levels of the functional components, this was significant in the case of the nodakenin, decursin and decursinol angelate content (p < 0.016).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.489-493
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• 2000

Turbine blade has trouble of cracking at root region. Fracture surface of blade root is surveyed by SEM and AFM to clear relation between fracture mechanical parameter and surface parameter (striation width and surface roughness). Service stress is predicted by maximum height roughness $R_{max}$, on fractured surface and stress analysis on turbine blade. It is to thought that turbine blade is fractured by abnormal condition such as incorrect fittings between pin and pin hole but isn't fractured by normal service conditions such as steam pressure, centrifugal force and torsional force.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.1
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• pp.85-93
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• 2011

2010 trend of Web services is Social Network Service. What does Social Network Service are like this? What could really be used? I also take advantage of future can I do? To elicit answers to the question of Social Network Service and the overall status of the root is used in the case Learn about the current utilization plan after the proposed research. The use of practices being applied to Social Network Service, the three theories were derived positive and negative aspects. Research based on more than the utilization of Social Network Service to build a social safety net to take advantage and use of learning aids were divided into suggestions. Utilized for building a social safety net, and when the reported channel to channel, the use of learning aids to learning that one day, one-on learning by applying the proposed total of four kinds of utilization.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.141-148
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• 2008

This study was conducted to investigate nutrient content at shoot and root(contained runner in zoysiagrass) in creeping bentgrass, kentucky bluegrass and zoysiagrass before turfgrass dormancy. The shoot ratio of dry weight in creeping bentgrass, kentucky bluegrass and zoysiagrass was 12%, 27% and 25% and root ratio was 88%, 73% and 75%, respectively. The orders of nutrients contained in turf-grass were N>K>Ca>P>Mg>Na in plant tissues. The proportion of nutrients in tissue of creeping bentgrass, kentucky bluegrass and zoysiagrass was 17%, 28% and 34% in shoot and 83%, 72% and 66% in root, respectively. These results showed that nutrients in turf-grass tissue was contained more than 70% in root before grasses dormancy. In turf grass management, all grasses were required to fertilize sufficiently N, $K_2O$, CaO and $P_2O_5$ before winter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.505-510
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• 2014

This research investigated growth of ginseng regard to sunshade materials and micro metrological phenomena under the sunshade material to product high quality ginseng. Followings are results of investigation of active ingredient from raw ginseng producted under the sunshade materials. The highest temperature under the sunshade material from June to August was measured from a Three-layered blue and one-layered black polyethylene net (TBOBFN) followed by a aluminium-coated polyethylene sheet (ACPS) and blue polyethylene sheet (BPS). The highest light penetration of $381.7{\mu}mol/s/m^2$ was obtained from the BPS at August, also the temperature was highest at the ginseng field. Growth of above ground part of 2~3 year old ginseng under the ACPS was the highest, followed by the ACPS and the BPS. In case of 4 year old ginseng, the ACPS and the BPS was the same, followed by the TBOBPN. Root length and diameter of 2~3 year old ginseng showed difference among treatments, but 4 year old ginseng was not showed difference. Meanwhile, the highest amount of root of 4 year old ginseng of $896g/m^2$ was obtained from ACPS. The total amount of ginsenocide of 4 year old ginseng under the ACPS was highest, followed by the BPS and the TBOBPN. Chromaticity of ginseng root under the TBOBPN was highest, followed by the ACPS and the BPS.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.364-368
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• 2014

This study investigated ginseng growth and ginsenoside contents after control a reserved ginseng cultivation land using various green manure crops for stable ginseng cultivation. Followings are results obtained from this research. After cultivate the green manure crops, microbial flora in soil was diversified, organic matter and total-N content increased, but salt content decreased. The highest output obtained from the wheat cultivated area among various green manure corps. Growth of shoot and root of two years old ginseng increased significantly at the green manure crop cultivated area. Specially, the wheat cultivated area was the most effective in growth. Also, the rate of the leaf discoloration at the aerial part and the rusty root at the root was the least at the wheat cultivation area. Meanwhile, the ginsenoside content was the most at the wheat cultivation area. Thus, the reserved ginseng cultivation land could be managed by cultivating wheat for effective ginseng growth.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.1
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• pp.101-109
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• 2015

This paper suggests a procedure to define business process improvement (BPI) projects with analysis results based on the cause-and-effect chain. The procedure developed in this paper focuses on eliminating root causes of business problems resulted from abnormal events occurred in business process executions. First, we develop three criteria used to make clusters of the root causes where a cluster of root causes will be eliminated together by a BPI project defined based on the cluster. Second, we develop a method to formulate desired expectations from the BPI project. Also, we suggest a method to calculate the relative importance of the BPI projects that help a BPI organization determine priorities of them. We illustrate the procedure and the methods with some examples for the domestic mail delivery process in the postal service industry.

• Journal of Periodontal and Implant Science
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• v.48 no.5
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• pp.317-325
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• 2018

Purpose: We investigated correlations between the findings of oral examinations and panoramic radiography in order to determine the efficacy of using panoramic radiographs in screening examinations. Methods: This study included patients who visited dental clinics at National Health Insurance Service (NHIS) Ilsan Hospital for checkups during 2009-2015 and underwent panoramic radiographic examinations within 1 year prior to the oral examinations. Among the 48,006 patients who received checkups, 1,091 were included in this study. The data were evaluated using the Cohen kappa and interrater agreement coefficients. Accuracy, sensitivity, and specificity were calculated using data from the panoramic radiographs as true positive diagnoses. Results: The interrater agreement coefficient for occlusal caries was 28.8%, and the Cohen kappa coefficient was 0.043 between the oral and panoramic radiographic examinations. Root caries and subgingival calculus were only found on the radiographs, while gingival inflammation was found only by the oral examinations. The oral examinations had a specificity for detecting occlusal dental caries of 100%, while their sensitivity for proximal dental caries and supragingival calculus was extremely low (14.0% and 18.3%, respectively) compared to the panoramic radiographic examinations. The oral examinations showed a relatively low sensitivity of 66.2% and a specificity of 43.7% in detecting tooth loss compared with panoramic radiography. Conclusions: Panoramic radiography can provide information that is difficult to obtain in oral examinations, such as root caries, furcation involvement, and subgingival calculus, which are factors that can directly affect the survival rate of teeth. It therefore seems reasonable and necessary to add panoramic radiography to large-scale health checkup programs such as that provided by the NHIS.