• Journal of the Korea Concrete Institute
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• v.19 no.6
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• pp.735-744
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• 2007

This study deals with literature review, developing a predicting equation for the ultimate stress of prestressing (PS) CFRP, and experimental test with the parameters affecting the ultimate stress of prestressing CFRF in prestressed concrete beams strengthened by external prestressing. The ACI (American Concrete Institute) predicting equation for the ultimate stress of unbonded prestressing CFRP is analyzed to develop a new integrated predicting equation. The proposed predicting equation takes rationally the effect of internal PS steel into consideration as a function of prestressing tendon depth to neutral depth ratio. In the experimental study, prestressed concrete beams strengthened using external prestressing CFRP are tested with the test parameters having a large effect on the ultimate stress of prestressing CFRP. The test parameters includes infernal prestressing steel and external prestressing CFRP tendon reinforcement ratios, and span to depth ratio. The test results are analyzed to confirm the rationality and applicability of the proposed equation for predicting the ultimate stress of external prestressing CFRP.

• Journal of the Korea Concrete Institute
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• v.15 no.4
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• pp.585-593
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• 2003

This study deals with literature review, developing a predicting equation for the ultimate stress of prestressing steel, and experimental test with the parameters affecting the ultimate stress of prestressing steel in reinforced concrete beams strengthened by external prestressing. The ACI predicting equation for the ultimate stress of unbonded prestressing steel is analyzed to develop a new integrated predicting equation. The proposed predicting equation takes rationally the effect of internal reinforcing bars into consideration as a function of prestressing steel depth to neutral depth ratio. In the experimental study, steel reinforced concrete beams strengthened using external prestressing steel are tested with the test parameters having a large effect on the ultimate stress of prestressing steel. The test parameters includes reinforcing bar and external prestressing steel reinforcement ratios, and span to depth ratio. The test results are analyzed to confirm the rationality and applicability of the proposed equation for predicting the ultimate stress of external prestressing steel.

• Physical Therapy Rehabilitation Science
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• v.7 no.1
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• pp.29-34
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• 2018

Objective: This study aimed to predict balance and gait abilities with the Trunk Impairment scales (TIS) in persons with stroke. Design: Cross-sectional study. Methods: Sixty-eight participants with stoke were assessed with the TIS, Berg Balance scale (BBS), and Functional Gait Assessment (FGA) by a therapist. To describe of general characteristics, we used descriptive and frequency analyses, and the TIS was used as a predictive variable to determine the BBS. In the simple regression analysis, the TIS was used as a predictive variable for the BBS and FGA, and the TIS and BBS were used as predictive variables to determine the FGA in multiple regression analysis. Results: In the group with a BBS score of >45 for regression equation for predicting BBS score using TIS score, the coefficient of determination ($R^2$) was 0.234, and the $R^2$ was 0.500 in the group with a BBS score of ${\leq}45$. In the group with an FGA score >15 for regression equation for predicting FGA score using TIS score, the $R^2$ was 0.193, and regression equation for predicting FGA score using TIS score, the $R^2$ was 0.181 in the group of FGA score ${\leq}15$. In the group of FGA score >15 for regression equation for predicting FGA score using TIS and BBS score, the $R^2$ was 0.327. In the group of FGA score ${\leq}15$ for regression equation for predicting FGA score using TIS and BBS score, the $R^2$ was 0.316. Conclusions: The TIS scores are insufficient in predicting the FGA and BBS scores in those with higher balance ability, and the BBS and TIS could be used for predicting variables for FGA. However, TIS is a strong predictive variable for persons with stroke who have poor balance ability.

• Geomechanics and Engineering
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• v.11 no.6
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• pp.879-896
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• 2016

A new earth pressure equation considering the arching effect in $c-{\phi}$ soils was proposed for the accurate calculation of earth pressure on circular vertical shafts. The arching effect and the subsequent load recovery phenomenon occurring due to multi-step excavation were quantitatively investigated through laboratory tests. The new earth pressure equation was verified by comparing the test results with the earth pressures predicted by new equation in various soil conditions. Resulting from testing by using multi-step excavation, the arching effect and load recovery were clearly observed. The test results in $c-{\phi}$ soil showed that even a small amount of cohesion can cause the earth pressure to decrease significantly. Therefore, predicting earth pressure without considering such cohesion can lead to overestimation of earth pressure. The test results in various ground conditions demonstrated that the newly proposed equation, which enables consideration of cohesion as appropriate, is the most reliable equation for predicting earth pressure in both ${\phi}$ soil and $c-{\phi}$ soil. The comparison of the theoretical equations with the field data measured on a real construction site also highlighted the best-fitness of the theoretical equation in predicting earth pressure.

• Journal of the Korea Concrete Institute
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• v.16 no.5 s.83
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• pp.677-686
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• 2004

This study deals with literature review, developing a predicting equation for the ultimate stress of internal and external prestressing steel, and an experimental test with the parameters affecting the ultimate stress of prestressing steel in prestressed concrete beams strengthened by external prestressing tendons. The proposed predicting equation takes rationally the effect of internal and external prestressing steels into consideration as a function of prestressing steel depth to neutral depth ratio. In the experimental study, prestressed concrete beams strengthened using external steel tendons are tested with the test parameters having a large effect on the ultimate stress of internal and external prestressing steel. The test parameters include internal and external prestressing steel reinforcement ratio and span to depth ratio. The test results are analyzed to confirm the rationality and applicability of the proposed equation for predicting the ultimate stress of internal and external prestressing steel. This research shows that the results obtained by the proposed equation for predicting the ultimate stress agreed very well with the test results.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.682-687
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• 2000

In this research the remaining service life of the concrete due to the steel corrosion was predicted by three cases; causing carbonation, using sea sand, using deicing salts. In case of deterioration by carbonation, effective carbonation depth, effective coverage depth and relative humidity are considered for predicting method. In case of using sea sand, predicting method is made of rust growth equation from polarization resistance method. In case of using deicing salts, predicting method is made of transformation of Fick's law. Three methods are very useful in predicting service life of concrete.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.129-141
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• 2003

The precise prediction of ground displacement plays an important role in planning and constructing tunnels. In this study, an equation for predicting the surface and crown settlement is suggested by examining the theories of ground movement caused by tunnel excavation. From the 3D numerical modeling, the reinforcement effect of UAM (Umbrella Arch Method) is quantitatively analyzed with respect to deformation modulus and overburden. By using a regression technique for the numerical results, an equation for predicting the settlement is suggested.

• KIEAE Journal
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• v.4 no.4
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• pp.11-18
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• 2004

In this study, the measurement system was developed for the measurement of pollutants from building materials, and specimens were made with concrete, gypsum board, mortar and wall paper. Characteristics of VOCs and TVOC concentration and Emission Factor as a function of time were assessed, and the conclusion was drawn as follows. (1) From predicting TVOC concentration decrease of specimen 7 with the wall paper attached to the concrete, the graph may become linear by converting the value of y-axis into the log function, and the prediction equation can be expressed as $y=34906{\ast}e^{-0.0093{\ast}time}$. Moreover, chi-square value was 0.83 which is relatively high value, indicating that TVOC concentration can be properly predicted if the same materials are used indoors. (2) From predicting VOCs Emission Factor decrease of specimen 7, the prediction equation can be expressed as $EF=15111{\ast}e^{-0.0093{\ast}time}$, and chi-square value was 0.83. (3) From predicting TVOC concentration decrease of specimen 7, prediction equation can be considered to be $y=254323{\ast}(1-e^{-0.1046{\ast}time})$, and chi-square was 0.994 which is significantly high value, indicating that indoor TVOC concentration can be properly predicted if the same materials are used indoors. Furthermore, the prediction of concentration decrease using cumulative value of hourly measured concentration is considered to be more accurate than that using just hourly measured value directly. (4) From predicting Emission Factor decrease with cumulative hourly data of Emission Factor, chi-square appeared to be higher than that by just using hourly data of Emission Factor directly. Therefore, the prediction of Emission Factor with cumulative hourly data can provide more reliable prediction equation than the case by using just hourly concentration directly.

• Journal of agriculture & life science
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• v.44 no.4
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• pp.1-7
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• 2010

Data was collected to develop equation for predicting stemp taper for Carpinus laxiflora in Jeju Experimental Forests. The Models tested for choosing the best-fit equations were Max & Burkhart's model, Kozak's model, and Lee's model. Performance of the equations in predicting stem diameter at a specific point along a stem was evaluated with fit and validation statistics and distribution of residuals on predicted values. In result, all the three models gave slightly better values of fitting statistics. In plotting residuals against predicted diameter, Max & Burkhart's model showed underestimation in predicting small diameter and Lee's Model did the same in predicting small diameter. Based on the above analysis of the three models in predicting stem taper, Kozak's model was chosen for the best-fit stem taper equations, and its parameters were given for C. laxiflora. Kozak's model was used to develop a stem volume table of outside bark for C. laxiflora.

• Journal of Forest and Environmental Science
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• v.36 no.1
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• pp.7-16
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• 2020

Tree size distribution modelling is an integral part of forest management. Most distribution yield systems rely on some flexible probability models. In this study, a simple finite mixture of two components two-parameter Weibull distribution was compared with complex four-parameter distributions in terms of their fitness to predict tree size distribution of teak (Tectona grandis Linn f) plantations. Also, a system of equation was developed using Seemingly Unrelated Regression wherein the size distributions of the stand were predicted. Generalized beta, Johnson's SB, Logit-Logistic and generalized Weibull distributions were the four-parameter distributions considered. The Kolmogorov-Smirnov test and negative log-likelihood value were used to assess the distributions. The results show that the simple finite mixture outperformed the four-parameter distributions especially in stands that are bimodal and heavily skewed. Twelve models were developed in the system of equation-one for predicting mean diameter, seven for predicting percentiles and four for predicting the parameters of the finite mixture distribution. Predictions from the system of equation are reasonable and compare well with observed distributions of the stand. This simplified mixture would allow for wider application in distribution modelling and can also be integrated as component model in stand density management diagram.