• The Journal of the Korean dental association
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• v.49 no.11
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• pp.660-669
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• 2011

Er: YAG laser irradiation utilizing the newly developed RCLase side-firing spiral tip was used for the cleansing of root canals following their bio-mechanical preparation with ProTaper Ni-Ti files. The distal and palatal roots of 20 freshly extracted molar teeth were instrumented to size F3 with ProTaper files. In the experimental group (10 teeth) the pulp chamber and the root canals were filled with EDTA 17% and the root canals were lased for 30 s using the Er: YAG laser irradiation at 600 mJ per pulse and a frequency of 12 Hz. In the control group (10 teeth) the root canals were not lased. Scanning electron microscope analysis showed clean wall surfaces of the lased root canals with open dentinal tubules, free of smear layer and debris. In the scanning electron microscope photographs of the walls of the non-lased root canals a considerable amount of debris could be detected. It appears that an efficient cleansing of the root canal system can be achieved by using the Er: YAG laser irradiation with the RCLase Side-firing Spiral Tip following bio-mechanical preparation of the root canal with Ni-Ti Taper files.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.103-103
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• 2017

Vigorous root growth at the seedling stage in dry direct-seeded conditions is considered as a critical trait because it is involved in seedling emergence, early vegetative vigour, nutrient uptake as well as drought tolerance. In this study, we performed QTL mapping using the recombinant inbred lines obtained from the cross between Tongil-type Dasan and temperate japonica TR22183 (DT-RILs) to identify QTL underlying early root development. TR22183, which was previously reported to have high nitrogen utility and cold tolerance, showed vigorous root growth at the seedling stage in semi-drought conditions. Root length, fresh weight and dry weight of TR22183 were significantly higher than in Dasan. By QTL analysis with genotyping-by-sequencing method, we identified two QTLs for root fresh weight (RFW) in chromosome 7 and root dry weight (RDW) in chromosome 8, explaining phenotypic variances of 13.5% and 10.6%, respectively. These QTLs would be used to develop rice varieties adapted to direct-seeded cultivating system.

• The KIPS Transactions:PartC
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• v.15C no.4
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• pp.239-244
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• 2008

It is not enough to reduce damages of computer systems by just patching vulnerability codes after incidents occur. It is necessary to detect and block intrusions by boosting the durability of systems even if there are vulnerable codes in systems. This paper proposes a robust real-time intrusion detection method by monitoring root privileged processes instead of system administrators in Linux systems. This method saves IP addresses of users in the process table and monitors IP addresses of every root privileged process. The proposed method is verified to protect vulnerable programs against the buffer overflow by using KON program. A configuration protocol is proposed to manage systems remotely and host IP addresses are protected from intrusions safely through this protocol.

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.09a
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• pp.21-21
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• 2019

Approximately 80% of rice field in Africa conducts in rainfed (Nishimaki 2017). The rice is damaged by water stress because fields like rainfed lowland repeat drying and humidity of soil because of impossible water control. Then water stress is one of the major limiting factors for decreasing rice yield. So, in initial growth stage, quick and efficient root development is useful way to avoid drought stress by getting water from deeper soil layer with roots elongation as the hypothesis. Daniel et al (2016) reported that NERICA1 and NERICA4 show different patterns of root plasticity for drought stress. NERICA1 has greater development of lateral root in shallow soil layer, while NERICA4 has greater development in deep root elongation to underground. This study was aimed to evaluate the effect of root development in initial growth stage on growing NERICA1 and NERICA4 under different soil moisture condition in rainfed lowland rice field. They were grown in same water condition until 35 days after sowing (35DAS), and after that each varieties were separated in dry and wet condition. The rice plants were grown until 60DAS. The results of soil moisture, the root extension angle, shoot dry weight and bleeding ratio showed that NERICA4 can mitigate dry stress from surface soil compered to NERICA1.

• Journal of the Korean Institute of Landscape Architecture
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• v.31 no.5
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• pp.11-19
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• 2003

The main purpose of this study was to examine the application of the root system as a shore protection material through the measurement of the 개ot growth curve of Salix gracilisyla Miq. depending on the cutting size. As materials and methodology, nine group of cuttings were classified by the length(l0cm, 20cm, 40cm) and the diameter(0.72cmm$\pm$0,02, 0.58cm$\pm$0.02, 0.35cm$\pm$0.02), Each group was stuck to a flooding bed of sandy loam(Sand 60,36%, Silt 28%, Clay 11.64%) on 27th March 2001, After 65 growing days, the weight and length of the newly developed roots, shoots, and leaves were measured and analysed, This was repeated at 99, 129, 159, and 190 growing days. The major findings were as follows. The primary determinant of the root growth rate was on the weight of cutting, The secondary determinant was on the number of growing days. In addition, the dominant dimension of the cutting was the diameter rather than the length, The thicker cutting caused more rapid and stable growth however the longer cutting made the growth of the root slower and more unstable.

• Journal of Power System Engineering
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• v.12 no.4
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• pp.57-63
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• 2008

The last stage blade of the low pressure steam turbine remarkably affects turbine plant performance and availability Turbine manufacturers are continuously developing the low pressure last stage blades using the latest technology in order to achieve higher reliability and improved efficiency. They tend to lengthen the last stage blade and apply shrouds at the blades to enhance turbine efficiency. The long blades increase the blade tip circumferential speed and water droplet erosion at shroud is anticipated. Parts of integral shrouds of the last stage 40 inch blades were cracked and liberated recently in a combined cycle power plant. In order to analyze the root cause of the last stage blades shroud cracks, we investigated operational history, heat balance diagram, damaged blades shape, fractured surface of damaged blades, microstructure examination and design data, etc. Root causes were analyzed as the improper material and design of the blade. Notches induced by erosion and blade shroud were failed eventually by high cycle fatigue. This paper describes the root cause analysis and countermeasures for the steam turbine last stage blade shroud cracks of the combined cycle power plant.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.1
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• pp.37-43
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• 2015

PURPOSE: The purpose of this study is to investigate the effect of the physical therapy treatment room environment using microwave diathermy on the autonomic nervous system of human body. METHODS: Participants were 24 healthy adults. Standard deviation of all normal R-R intervals(SDNN), root mean square of successive differences(RMSSD), low frequency(LF), high frequency(HF), LF/HF ratio were compared in microwave irradiation and non-irradiation group. Data were analyzed in Wilcoxon's signed-ranks test and Mann-Whitney U test. RESULTS: Standard deviation of all normal R-R intervals (SDNN), root mean square of successive differences (RMSSD), low frequency(LF), high frequency(HF), LF/HF ratio were not significantly different in microwave irradiation group. Standard deviation of all normal R-R intervals(SDNN), root mean square of successive differences (RMSSD), low frequency(LF), high frequency(HF), LF/HF ratio were not significantly different in microwave non-irradiation group. Standard deviation of all normal R-R intervals(SDNN), root mean square of successive differences (RMSSD), low frequency(LF), high frequency(HF), LF/HF ratio were not significantly different between two groups. CONCLUSION: There was no significant change in the sympathetic nervous system and parasympathetic nervous system regardless of the presence of microwave irradiation. There was no significant change in the autonomic nervous system adaptability regardless of the presence of microwave irradiation.According to this study, microwave diathermy does not have significant effect on the autonomic nervous system.Future study is necessary to investigate the long term effect of the physical therapy treatment room environment using microwave diathermy on the autonomic nervous system of the human body.

• Journal of Biomedical Engineering Research
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• v.14 no.2
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• pp.107-112
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• 1993

This paper describes the design and implementation of the Motorized wheelchair. The designed vision system can run 7 Km/h When the obstacle is not on the root. There is the obstacle on the root, this system can judge pass detour or stop.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.3
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• pp.299-304
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• 1983

It has been ascertained by a few researchers that soil conditions under which the rice plants were cultivated have some effects upon the root formation of the rice plants. But, much is not known about the root formation of the rice plants cultivated in the saline paddy fields. The goal of the present investigation is to study morphological effects of the soil salinity on the development of the rice root system. The following results were obtained: 1. Under the conditions of higher soil salinity, root systems developed well at surface soil, however, root systems developed well and distributed evenly through surface and sub-soil at the saline fields where soil salinity was lower. 2. The rice plants cultivated in the higher soil salinity form less crown roots than the rice plants which cultivated at the lower soil salinity. 3. As for the formation of the stunted roots, it was found out that relatively rice plant cultivated in higher soil salinity forms more stunted roots than the rice plants cultivated in lower soil salinity. 4. The crown root cultivated in the higher soil salinity forms more lateral roots per unit langth than the root cultivated in lower soil salinity. 5. As for the root hair formation, the crown root cultivated in higher soil salinity bears less haired epidermis and shorter root hairs than the root cultivated in lower soil salinity.

• Plant Disease and Agriculture
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• v.5 no.2
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• pp.77-83
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• 1999

In 1997 surveys 82 out of 180 crucifer fields were infected with clubroot disease in a range of 1-100% of diseased plants and among crucifier crops Chinese cabbage was the most severe, In cropping systems Chinese cabbage-monocropping of Chinese cabbage-radish were found to be most common in major Chinese cabbage production areas. Welsh onion squash or paddy rice were also planted between cropping of Chinese cabbage. Paddy fields converted to upland were lowered in incidence of clubroot disease and fields with loam to silty loam soil were more severe in disease than those with sandy soil. Soil pH and organic contents were nor related to clubroot disease severity. Soil fauua such as total fungi bacteria actinomyces Pseudomonads and Bascillus were not correlated with severity of the disease. Root rall development on Chinese cabbage seedlings was initifially observed under a microscope 13 days after inoculation with Plasmodiophora brassicae but 18 days by naked eyes after inoculation. Root galls were formed mostly around collar roots and gradually spread to main root lateral roots and secondary root branches. Root galls started to enlarge greatly in size and weight from 23 days after inoculation. Chinese cabbage plants at mid-growth stage with root gall development were reduced to 1/2 of that of healthy plants in number of leaves 1/4-1/5 in above ground fresh weight 1/6 in root length but increased to 3 times in diameter of collar root. Diseased plants had little root hairs. Diseased Chinese cabbage plants at harvest were reduced by 9,1-11.8% in head weight compared to healthy plants a positive correlation was observed between root and head weight but those relationships were rot found in the diseased plants.