• Imaging Science in Dentistry
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• v.54 no.1
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• pp.43-48
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• 2024

Purpose: Oral hygiene, maintained through plaque control, helps prevent periodontal disease and dental caries. This study was conducted to examine the accuracy of plaque detection with an intraoral scanner(IOS) compared to images captured with an optical camera. Materials and Methods: To examine the effect of color tone, artificial tooth resin samples were stained red, blue, and green, after which images were acquired with a digital single-lens reflex (DSLR) camera and an IOS device. Stained surface ratios were then determined and compared. Additionally, the deviation rate of the IOS relative to the DSLR camera was computed for each color. In the clinical study, following plaque staining with red disclosing solution, the staining was captured by the DSLR and IOS devices, and the stained area on each image was measured. Results: The stained surface ratios did not differ significantly between DSLR and IOS images for any color group. Additionally, the deviation rate did not vary significantly across colors. In the clinical test, the stained plaque appeared slightly lighter in color, and the delineation of the stained areas less distinct, on the IOS compared to the DSLR images. However, the stained surface ratio was significantly higher in the IOS than in the DSLR group. Conclusion: When employing IOS with dental plaque staining, the impact of color was minimal, suggesting that the traditional red stain remains suitable for plaque detection. IOS images appeared relatively blurred and enlarged relative to the true state of the teeth, due to inferior sharpness compared to camera images.

• Journal of the Korean Wood Science and Technology
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• v.52 no.4
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• pp.375-382
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• 2024

The study focuses on evaluating the bending creep performance of laminated veneer lumber (LVL) formwork in timber concrete composite (TCC) structures. Timber-framed construction is highlighted for its environmental benefits and seismic resistance, but limitations such as poor tensile strength and brittle failure in bending hinder its use in high-rise buildings. Wood-concrete hybrid structures, particularly those using reinforced concrete slabs with TCC floors, emerge as a potential solution. The research aims to understand the time-dependent behavior of TCC components, considering factors like wood and concrete shrinkage and connection creep. The experiment was conducted in western Japan on the TCC floor designed for use in the Kama-city Inatsuki-higashi compulsory education school. The LVL formwork, measuring 9,000 mm by 900 mm, and concrete is loaded onto it for testing. The creep test periods are examined using concrete loading. It employs a comprehensive creep analysis, adhering to Japanese standards, involving deflection measurements and regression analysis to estimate the creep coefficient. Results indicate substantial deformation after shoring removal, suggesting potential reinforcement needs. The study recommends extending test periods for improved accuracy and recognizing regional climate impacts. Overall, the research provides valuable insights into the potential of LVL formwork in TCC structures, emphasizing safety considerations and paving the way for further experimentation under varied conditions to validate structural integrity.

• Steel and Composite Structures
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• v.53 no.2
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• pp.209-226
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• 2024

In the present study, the third-order shear deformation theory (TSDT) is presented to investigate time-dependent thermo-elastic creep behavior and life assessment of rotating thick cylindrical shells with variable thickness made of 304L austenitic stainless steel (304L SS). The cylindrical shells are subjected to non-uniform internal pressure, distributed temperature field, and a centrifugal body force due to rotating speed. Norton's law is used to describe the material creep constitutive model. A system of differential equations in terms of displacement and boundary conditions is derived by employing the minimum total potential energy principle based on TSDT. Then, the resulting equations are solved as semi-analytically using the multilayered method (MLM), which leads to an accurate solution. Subsequently, an iterative procedure is also proposed to investigate the stresses and deformations at different creep times. Larson-Miller Parameter (LMP) and Robinson's linear life fraction damage rule are employed to estimate the creep damages and the remaining life of cylindrical shells. In this research, the creep model uses Norton's law, LMP, and Robinson's approach which is the most accurate and reasonable model. To the best of the researcher's knowledge, in the previous studies, there is no study carried out on third-order shear deformation theory for thermo-elastic creep analysis and life assessment of thick cylinders with variable thickness. The results obtained from the multilayered approach are compared and validated with those determined from the finite element method (FEM) to confirm the accuracy of the suggested method based on TSDT and very good agreement is found. The results indicate that the present analysis is accurate and computationally efficient.

• Computers and Concrete
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• v.34 no.3
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• pp.279-296
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• 2024

In this study, ensemble machine learning (ML) models are employed to estimate the hardened properties of Self-Compacting Geopolymer Concrete (SCGC). The input variables affecting model development include the content of the SCGC such as the binder material, the age of the specimen, and the ratio of alkaline solution. On the other hand, the output parameters examined includes compressive strength, flexural strength, and split tensile strength. The ensemble machine learning models are trained and validated using a database comprising 396 records compiled from 132 unique mix trials performed in the laboratory. Diverse machine learning techniques, notably K-nearest neighbours (KNN), Random Forest, and Extreme Gradient Boosting (XGBoost), have been employed to construct the models coupled with Bayesian optimisation (BO) for the purpose of hyperparameter tuning. Furthermore, the application of nested cross-validation has been employed in order to mitigate the risk of overfitting. The findings of this study reveal that the BO-XGBoost hybrid model confirms better predictive accuracy in comparison to other models. The R² values for compressive strength, flexural strength, and split tensile strength are 0.9974, 0.9978, and 0.9937, respectively. Additionally, the BO-XGBoost hybrid model exhibits the lowest RMSE values of 0.8712, 0.0773, and 0.0799 for compressive strength, flexural strength, and split tensile strength, respectively. Furthermore, a SHAP dependency analysis was conducted to ascertain the significance of each parameter. It is observed from this study that GGBS, Flyash, and the age of specimens exhibit a substantial level of influence when predicting the strengths of geopolymers.

• Journal of Advanced Navigation Technology
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• v.28 no.5
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• pp.640-649
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• 2024

In this study, we introduce an interactive multi-model-probabilistic data association filter (IMM-PDAF), a multi-target tracking algorithm that integrates multiple dynamic models for accurate real-time maritime target tracking. Multi-target tracking in the maritime environment requires high accuracy due to the complex dynamic environment and various movement patterns. The existing CV-PDAF (constant velocity model) and CT-PDAF (circling model) each assume a constant movement pattern, but it is difficult to handle all the complex movements occurring in various maritime environments with these single models. To solve this problem, this study proposes an interactive multi-model-probabilistic data association filter (IMM-PDAF), and the results of this paper applied to maritime RADAR data show that the proposed IMM-PDAF has relatively lower RMSE values than CV-PDAF and CT-PDAF, and has strong positioning performance even in complex dynamic environments. Therefore, this study results highlight the potential of the proposed IMM-PDAF to improve the reliability and efficiency of maritime surveillance systems and provide a multi-target tracking solution for complex tracking environments.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.264-270
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• 2024

In the construction industry, steel structures are prominent due to their exceptional strength and high bearing capacity, making them resilient against natural calamities. However, the stability and overall structural integrity of these steel structures depend significantly on the precision of the individual steel members used. Presently, the dimensions of these steel members are typically measured manually using mechanical instruments such as steel tape and vernier calipers. This conventional approach is not only time-consuming but also highly vulnerable to human error. Consequently, there is a growing need for more accurate and reliable methods for assessing the dimensions of steel members. This paper aims to measure the dimensions of key checklists of the cross-section surface of the steel H-beams using Terrestrial Laser Scan (TLS) data. This study involves the automatic extraction of scan points associated with the cross-section surface of the H-beam members using RANSAC. By the end, an algorithm was developed to predict the actual edge points belonging to the boundary of the extracted surface and introduced an edge loss compensation model to compensate the losses occurred due to uncertainties. Experimental evaluations were conducted using various scan data collected from steel H-beam and the measured dimensions were subsequently compared with manual measurements and dimensions obtained through the previously proposed method, demonstrating that the measurements meet 1mm accuracy and are within the allowable tolerance range followed in industry. This research underscores the efficiency and reliability of the introduced approach, offering a promising solution to enhance the dimensional quality assessment of steel H-beams in the construction industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1186-1194
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• 2017

Recently, many people have demanded reliable nutritional data even for minor-components. On the other hand, an analytical method for the analyses of vitamin $B_5$ and $B_6$ is lacking. Therefore, this study attempted to validate with accuracy and precision the analysis of vitamin $B_5$ and $B_6$ using a high-performance liquid chromatography (HPLC) method. The vitamin $B_5$ and $B_6$ contents were analyzed using an Agilent 1260 series HPLC system. YMC-Pack ODS-AM ($250{\times}4.6mm$ I.D.) and YMC-Pack Pro RS $C_{18}$ ($250{\times}4.6mm$ I.D.) columns were used for the analyses of vitamin $B_5$ and $B_6$, respectively. In the case of vitamin $B_5$, the flow rate was set to 1.0 mL/min by isocratic elution using the 50 mM $KH_2PO_4$ solution (pH 3.5)/acetonitrile (ACN) (95:5, v/v) with monitoring at 200 nm using HPLC/DAD, whereas the flow rate for vitamin $B_6$ was set to 1.0 mL/min of flow rate by isocratic elution using a 20 mM $CH_3CO_2Na$ solution (pH 3.6)/ACN (97:3, v/v) with monitoring by excitation at 290 nm and emission at 396 nm using HPLC/FLD. The column temperature was set to $30^{\circ}C$. The injection volume was $20{\mu}L$ for each experiment. The specificity of the accuracy and precision for vitamin $B_5$ and $B_6$ were also validated by HPLC. The results showed high linearity in the calibration curve for vitamin $B_5$ ($R^2=0.9998^{{\ast}{\ast}}$), the limit of detection (LOD) and limit of quantitation (LOQ) were 0.4 mg/L and 1.3 mg/L, respectively, In contrast, for the calibration curve of vitamin $B_6$, which showed high linearity ($R^2=0.9999^{{\ast}{\ast}}$), the LOD and LOQ were 0.006 mg/L and 0.02 mg/L, respectively.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.223-232
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• 2012

Purpose: Validating a new research method to determine posterior corneal curvature and asphericity(Q) in vivo, based on measurements of anterior corneal topography and corneal thickness. Methods: Anterior corneal topographic data, derived from the Medmont E300 corneal topographer, and total corneal thickness data measured along the horizontal corneal meridian using the Holden-Payor optical pachometer, were used to calculate the anterior and posterior corneal apical radii of curvature and Q. To calculate accurate total corneal thickness the local radius of anterior corneal curvature, and an exact solution for the relationship between real and apparent thickness were taken into consideration. This method differs from previous approach. An elliptical curve for anterior and posterior cornea were calculated by using best fit algorism of the anterior corneal topographic data and derived coordinates of the posterior cornea respectively. For validation of the calculations of the posterior corneal topography, ten polymethyl methacrylate (PMMA) lenses and right eyes of five adult subjects were examined. Results: The mean absolute accuracy (${\pm}$standard deviation(SD)) of calculated posterior apical radius and Q of ten PMMA lenses was $0.053{\pm}0.044mm$ (95% confidence interval (CI) -0.033 to 0.139), and $0.10{\pm}0.10$ (95% CI -0.10 to 0.31) respectively. The mean absolute repeatability coefficient (${\pm}SD$) of the calculated posterior apical radius and Q of five human eyes was $0.07{\pm}0.06mm$ (95% CI -0.05 to 0.19) and $0.09{\pm}0.07$ (95% CI -0.05 to 0.23), respectively. Conclusions: The result shows that acceptable accuracy in calculations of posterior apical radius and Q was achieved. This new method shows promise for application to the living human cornea.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.288-294
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• 2011

BACKGROUND: Methylmercury is analyzed by HPLC-ICP/MS because of the simplicity for sample preparation and interference. However, most of the pre-treatment methods for methylmercury need a further pH adjustment of the extracted solution and removal of organic matter for HPLC. The purpose of this study was to establish a rapid and accurate analytical method for determination of methylmercury in fish by using HPLC-ICP/MS. METHOD AND RESULTS: We conducted an experiment for pre-treatment and instrument conditions and analytical method verification. Pre-treatment condition was established with aqueous 1% L-cysteine HCl and heated at $60^{\circ}C$ in microwave for 20 min. Methylmercury in $50{\mu}L$ of filtered extract was separated by a C18 column and aqueous 0.1% L-cysteine HCl + 0.1% L-cysteine mobile phase at $25^{\circ}C$. The presence of cysteine in mobile phase and sample solution was essential to eliminate adsorption, peak tailing and memory effect problems. Correlation coefficient($r^2$) for the linearity was 0.9998. The limits of detection and quantitation for this method were 0.15 and $0.45{\mu}g/kg$ respectively. CONCLUSION: Result for analytical method verification, accuracy and repeatability of the analytes were in good agreement with the certified reference materials values of methylmercury at a 95% confidence level. The advantage of the established method is that the extracted solution can be directly injected into the HPLC column without additional processes and the memory effect of mercury in the ICP-MS can be eliminated.

• Korean Journal of Veterinary Research
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• v.10 no.1
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• pp.11-23
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• 1970

Recently Carter(1952) reported the capsule antigens of Pasteurella multocida could be divided into four serological types A,B,C and D by means of precipitation tests. Subsequently he showed that the most sensitive for identification of these types involved the use of capsule substance adsorbed by erythrocytes in hemagglutination test. It may be somewhat difficult to conduct the hemagglutination test in small laboratory, because relatively large amounts of antisera and erythrocytes of the human O type are required for the test. A simple method for serological typing of P. multocida was the slide agglutination test employed by Little et al. (1943) and Namioka et al. (1962), but this method is still in controversy. The author tried adapting Carter's hemagglutination method to the slide method so called "micromethod technique", and studied on the stabilization of erythrocytes for use of slide hemagglutination to P. multocida although many invesigators reported the stabilization of erythrocytes. The results obtained are summarized as follows: 1. A simplified method (slide method) for capsule typing of the organism was developed by adapting Carter's hemagglutination reaction(tube method). Antibody-containing serum can be diluted serially on Boerner's microtest slide with capillary or serological pipetts with a considerable accuracy. The slide reaction can be carried out with case on the slide by adding $0.05m{\ell}$ of antigen-sensitized erythrocytes suspension diluted to one percent on $0.05m{\ell}$ of serially diluted antibody-containing sera, and the final result can be read after 60 minutes at the room temperature ($15^{\circ}C$). 2. It is difficult to determine superiority of inferiority between the slide method and the tube method on the pattern of the reaction of hemagglutination. 3. The pH range of 6.6 to 8.3 is optimal for the slide hemagglutination reaction. 4. The antigen-sensitization against erythrocytes at $37^{\circ}C$ is optimal for the slide hemagglutination. 5. Both the doses and concentration of antigen do not influence the antigen-adsorbing capacity of erythrocytes. 6. The reduction of antigen-sensitizing hours does not influence the antigen-adsorbing capacity of erythrocytes even 30 minutes. 7. The tannic acid treatment against formalinized and non-formalinized erythrocytes showed no effect on the reaction of hemagglutination. 8. The erythrocytes preserved at $4^{\circ}C$ in the ACD solution do not decrease the reactivity on the reaction of hemagglutination for 60 days, while they begin slight hemolysis 30 days after preserving. 9. The stable preparation of erythrocytes can be obtained by treating the cells at $37^{\circ}C$ for 20 hours with from 4 to 8 percent of formalin in saline or buffer. These cells can be preserved at $4^{\circ}C$ for more than 8 months experimented without hemolysis. With low concentration of formalin, the cells were not sufficiently stabilized resulting in the hemolysis after short period of preservation at $4^{\circ}C$. 10. The erythrocytes treated with 16 percent of formalin remain constantly or increase the reactivity for the reaction of hemagglutination. On the contrary, the cells treated with I to 8 percent of formalin decrease the reactivity. 11. There is no difference between nontreated fresh erythrocytes and the erythrocytes preserved in the ACD solution on the reactivity against the hemagglutination, and the erythrocytes treated with 16 percent of formalin showed the reactivity of higher level than that of the above two kinds of erythrocytes. 12. There is no difference between the saline and the isotonic buffer solution on the reaction of hemagglutination.