• The Plant Pathology Journal
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• v.37 no.2
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• pp.173-181
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• 2021

The genus Streptomyces demonstrates enormous promise in promoting plant growth and protecting plants against various pathogens. Single and consortium treatments of two selected Streptomyces strains (Streptomyces shenzhenensis TKSC3 and Streptomyces sp. SS8) were evaluated for their growth-promoting potential on rice, and biocontrol efficiency through induced systemic resistance (ISR) mediation against Xanthomonas oryzae pv. oryzicola (Xoc), the causal agent of rice bacterial leaf streak (BLS) disease. Seed bacterization by Streptomyces strains improved seed germination and vigor, relative to the untreated seed. Under greenhouse conditions, seed bacterization with consortium treatment TKSC3 + SS8 increased seed germination, root length, and dry weight by 20%, 23%, and 33%, respectively. Single and consortium Streptomyces treatments also successfully suppressed Xoc infection. The result was consistent with defense-related enzyme quantification wherein single and consortium Streptomyces treatments increased peroxidase (POX), polyphenol oxidase, phenylalanine ammonia-lyase, and β,1-3 glucanase (GLU) accumulation compared to untreated plant. Within all Streptomyces treatments, consortium treatment TKSC3 + SS8 showed the highest disease suppression efficiency (81.02%) and the lowest area under the disease progress curve value (95.79), making it the best to control BLS disease. Consortium treatment TKSC3 + SS8 induced the highest POX and GLU enzyme activities at 114.32 µmol/min/mg protein and 260.32 abs/min/mg protein, respectively, with both enzymes responsible for plant cell wall reinforcement and resistant interaction. Our results revealed that in addition to promoting plant growth, these Streptomyces strains also mediated ISR in rice plants, thereby, ensuring protection from BLS disease.

• Geomechanics and Engineering
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• v.28 no.6
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• pp.599-611
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• 2022

Tendon reinforced cemented soil is applied extensively in foundation stabilisation and improvement, especially in areas with soft clay. To solve the deterioration problem led by steel corrosion, the glass fiber-reinforced polymer (GFRP) tendon is introduced to substitute the traditional steel tendon. The interface bond strength between the cemented soil matrix and GFRP tendon demonstrates the outstanding mechanical property of this composite. However, the lack of research between the influence factors and bond strength hinders the application. To evaluate these factors, back propagation neural network (BPNN) is applied to predict the relationship between them and bond strength. Since adjusting BPNN parameters is time-consuming and laborious, the particle swarm optimisation (PSO) algorithm is proposed. This study evaluated the influence of water content, cement content, curing time, and slip distance on the bond performance of GFRP tendon-reinforced cemented soils (GTRCS). The results showed that the ultimate and residual bond strengths were both in positive proportion to cement content and negative to water content. The sample cured for 28 days with 30% water content and 50% cement content had the largest ultimate strength (3879.40 kPa). The PSO-BPNN model was tuned with 3 neurons in the input layer, 10 in the hidden layer, and 1 in the output layer. It showed outstanding performance on a large database comprising 405 testing results. Its higher correlation coefficient (0.908) and lower root-mean-square error (239.11 kPa) were obtained compared to multiple linear regression (MLR) and logistic regression (LR). In addition, a sensitivity analysis was applied to acquire the ranking of the input variables. The results illustrated that the cement content performed the strongest influence on bond strength, followed by the water content and slip displacement.

• Structural Engineering and Mechanics
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• v.84 no.2
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• pp.143-154
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• 2022

Corrosion of steel reinforcement is considered as the main cause of concrete structures deterioration, especially those under humid environmental conditions. Hence, fiber reinforced polymer (FRP) bars are being increasingly used as a replacement for conventional steel owing to their non-corrodible characteristics. However, predicting the shear strength of beams reinforced with FRP bars still challenging due to the lack of robust shear theory. Thus, this paper aims to develop an explicit data driven based model to predict the shear strength of FRP reinforced beams using multi-objective evolutionary polynomial regression analysis (MOGA-EPR) as data driven models learn the behavior from the input data without the need to employee a theory that aid the derivation, and thus they have an enhanced accuracy. This study also evaluates the accuracy of predictive models of shear strength of FRP reinforced concrete beams employed by different design codes by calculating and comparing the values of the mean absolute error (MAE), root mean square error (RMSE), mean (𝜇), standard deviation of the mean (𝜎), coefficient of determination (R²), and percentage of prediction within error range of ±20% (a20-index). Experimental database has been developed and employed in the model learning, validation, and accuracy examination. The statistical analysis illustrated the robustness of the developed model with MAE, RMSE, 𝜇, 𝜎, R², and a20-index of 14.6, 20.8, 1.05, 0.27, 0.85, and 0.61, respectively for training data and 10.4, 14.1, 0.98, 0.25, 0.94, and 0.60, respectively for validation data. Furthermore, the developed model achieved much better predictions than the standard predictive models as it scored lower MAE, RMSE, and 𝜎, and higher R² and a20-index. The new model can be used in future with confidence in optimized designs as its accuracy is higher than standard predictive models.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.103-115
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• 1999

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease. Various periodontal procedures have been used throughout the years in an attempt to reestablish attachment of periodontal tissues to root surfaces affected by periodontitis. Flap debridement surgery has been demonstrated to be a successful procedure in gaining the probing attachment level and reducing probing depth. A tendency towards impaired wound healing following periodontal procedures in smokers has been clinically documented. But, previous clinical studies on healing response in smokers are based on a retrospective design. The purpose of this study was to evaluate the treatment outcome following flap debridement surgery in smokers compared to nonsmokers. 25 patients with moderate to advanced periodontitis were included for study. Among these patients, 13 patients were smokers, and 12 patients were nonsmokers. Mucoperiosteal flap was raised with the sulcular incision. No antibiotic treatment was administered postsurgery. The patients was recalled at monthly intervals during a period of 6 months following the surgery. The patients were received supragingival scaling and oral hygiene reinforcement. All the recordings, including modified O' Leary plaque control record, bleeding on probing, probing pocket depth, probing attachment level,were recorded, presurgery and 6 months postsurgery. The changes of all the recordings at 6 months after flap debridement surgery revealed the following results: 1. PI on all the dentitions and surgical sites showed no statistical significance between smokers and nonsmokers at presurgery. But, smokers demonstrated a significantly lower % of PI than nonsmokers at 6 months postsurgery. 2. Smokers demonstrated a greater % of BOP sites than nonsmokers on the surgical sites and all the dentitions, presurgery and 6 months postsurgery. But, there was no statistical significance between two groups. 3. Smokers exhibited significantly less reduction of probing depth in the 3 mm or less probing pocket depth(PPD) group, 6mm or more PPD group and total PPD group when compared to nonsmokers at 6 months postsurgery. 4. Smokers exhibited significantly less gain of probing attachment level(PAL) in the 3mm or less PPD group, 6 mm or more PPD group and total PPD group when compared to nonsmokers at 6 months postsurgery.

• Restorative Dentistry and Endodontics
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• v.35 no.4
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• pp.257-266
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• 2010

The purpose of this study was to determine the effect of post types and sizes on fracture resistance in immature tooth model with various restorative techniques. Bovine incisors were sectioned 8 mm above and 12 mm below the cementoenamel junction to simulate immature tooth model. To compare various post-and-core restorations, canals were restored with gutta-percha and resin core, or reinforced dentin wall with dual-cured resin composite, followed by placement of D.T. LIGHT-POST, ParaPost XT, and various sizes of EverStick Post individually. All of specimens were stored in the distilled water for 72 hours and underwent 6,000 thermal cycles. After simulation of periodontal ligament structure with polyether impression material, compressive load was applied at 45 degrees to the long axis of the specimen until fracture was occurred. Experimental groups reinforced with post and composite resin were shown significantly higher fracture strength than gutta-percha group without post placement (p < 0.05). Most specimens fractured limited to cervical third of roots. Post types did not influence on fracture resistance and fracture level significantly when cement space was filled with dual-cured resin composite. In addition, no statistically significant differences were seen between customized and standardized glass fiber posts, which cement spaces were filled with resin cement or composite resin individually. Therefore, root reinforcement procedures as above in immature teeth improved fracture resistance regardless of post types and sizes.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.1
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• pp.110-118
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• 2015

Borimsa Temple in Jangheung, one of the Goosanseonmoon of Shilla Dynasty, calls for a study in the field of landscape architecture because it has very significant elements in cultural and ecological landscaping aspects. This study examined the changes in landscaping elements of Borimsa Temple since the 17th century in order to newly recognize cultural landscaping value of space composition elements for traditional temple and to verify landscape architectural position. For research method, literatures such as Sajeonggi (事蹟記), Joongchanggi, a surveyed map by Fujishima Gaijiro in 1928 and Joseon Gojeogdobo (朝鮮古蹟圖譜) and modern documents including Borimsa Temple Precision Ground Survey Report and photographic records of National Archives of Korea and provincial governments were examined together with a field survey in order to trace changes in landscape elements such as buildings within the temple site, pond and temple forest. The results are as the following: First, for geographical locations of Borimsa Temple, it is located in an auspicious location and Shipyuknahansang and Cheonbul were placed in a supplementary purpose according to the contents of Bojoseonsatapbi. Compared to Namhwaseonsa Temple in China, it has a similar environmental composition but the fact that buildings were placed on platforms is a distinctive difference. Second, architectural landscape of Borimsa Temple went through the Japanese colonial era and Korean War and still going through changes today. Thus, there shall be some appropriate measures such as to establish an archive of past landscape data. Third, the contents of Borimsa Temple Sajeonggi suggests that the pond of Borimsa Temple had been in a indeterminate form with stones on the outer edge. Its name could have been Yongcheon (湧泉) according to the contents of Joongchanggi. Also, the current landscape, in comparison with past photographs, is a result of changes from surface raise occurred by ground reinforcement within the temple site. Fourth, Jangsaengpyoju (長生標柱) mentioned in Bojoseonsatapbi and Borimsa Temple Sajeonggi was thought to be the dried juniper tree in front of Daewoongbojeon, which can be found in past photographic documents but, it is now assumed to be Seokbihyeong (石碑形) considering the Gukjangsaeng and Hwangjangsaeng of Dogapsa Temple of the similar time period. Moreover, Hongsalmoon mentioned in Joongchanggi was established by King's order after the Manchu war of 1636 in praising of Buddhist monks those who had volunteered to fight for the country. Fifth, it is apparent in Borimsa Temple Joongchanggi that geomancy was a consideration in landscaping process of Borimsa Temple, and the record indicates that pine trees, bo trees and persimmon trees were planted. Sixth, tea tree forest was verified of its historical root that is Seongchailyeo from Unified Shilla through passing down of Jeong Yak-yong's Goojeunggoopo method and relevant documents of Seon Master Choui and Yi Yu-won. Seventh, nutmeg tree forest suggests that nutmegs were used in national ceremonies and for medical uses. The nutmeg tree forest was also verified of its role as Naehwasoorimdae (a forest built to prevent fire from spreading) through aerial photographs and placement of a forest reserve.