• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1320-1329
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• 2024

When wall-thinning occurs in nuclear Class 2 and 3 pipes, reinforcement is typically applied rather than replacement. To analyze the structural integrity of reinforced wall-thinned pipe, stress analysis results using full 3-D FE analysis are not compatible to the design code equation, ASME BPVC Sec. III NC/ND-3650. Therefore, the efficient stress evaluation method for the reinforced wall-thinned pipe, compatible to the design code equation, needs to be developed. In this paper, stress evaluation methods for the reinforced wall-thinned pipe are proposed using the equivalent straight pipe concept. Furthermore, for fatigue analysis of the reinforced wall-thinned pipe, the stress intensification factor of reinforced wall-thinned pipe is presented using the structural stress method given in ASME BPVC Sec. VIII Div.2.

• Journal of the Korean Society of Safety
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• v.25 no.5
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• pp.44-53
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• 2010

Recently, the external prestressed concrete structures are increasingly being built. The mechanical behavior of prestressed concrete beams with unbonded tendon is different from that of normal bonded PSC beams in that the increment of tendon stress was derived by whole member behavior. By this reason, the ultimate stress of external tendon is smaller than that of bonded tendon or internal unbonded tendon. However, in the domestic and abroad code, the equation of ultimate stress of external tendon is not suggested yet, and the equation of ultimate stress of internal unbonded tendon is used instead of that of external tendon. Therefore, in this paper, after effective variables of ultimate stress of external tendon were analyzed, the analytical equation of ultimate stress of external tendon was proposed. And the reasonable coefficients were proposed by statistical work of test results of 25 beam with external tendon. Finally, the practical proposed equation of ultimate stress of external tendon was proposed with analytical and statistical model. The equation of ACI-318 and AASHTO 1994 were not matched with test results and had no correlations, and the proposed equation was well matched with test results. So the proposed equation in this paper will be a effective basis for the evaluation of external tendons in analysis and design.

• Computers and Concrete
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• v.24 no.5
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• pp.423-436
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• 2019

Design equations to evaluate the bursting force in a post-tensioned anchorage zone have been introduced in many design codes, and one equation in AASHTO LRFD is widely used. However, this equation may not determine the bursting force exactly because it was designed on the basis of two-dimensional numerical analyses without considering various design parameters such as the duct hole and shape of the bearing plate. To improve the design equation, modification of the AASHTO LRFD design equation was considered. The behavior of the anchorage zone was investigated using three-dimensional linear elastic finite element analysis with design parameters such as bearing plate size and diameter of sheath hole. Upon the suggestion of a modified design equation for evaluating the bursting force in an anchorage block with a rectangular anchorage plate (Kim and Kwak 2018), additional influences of design parameters that could affect the evaluation of bursting force were investigated. An improved equation was introduced for determining the bursting force in an anchorage block with a circular anchorage plate, using the same procedure introduced in the design equation for an anchorage block with a rectangular anchorage plate. The validity of the introduced design equation was confirmed by comparison with AASHTO LRFD.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.1109-1119
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• 2018

In this paper, we report the development of a nondestructive prediction model for lean meat percentage (LMP) in Korean pig carcasses and in the major cuts using a machine vision technique. A popular vision system in the meat industry, the VCS2000 was installed in a modern Korean slaughterhouse, and the images of half carcasses were captured using three cameras from 175 selected pork carcasses (86 castrated males and 89 females). The imaged carcasses were divided into calibration (n=135) and validation (n=39) sets and a multilinear regression (MLR) analysis was utilized to develop the prediction equation from the calibration set. The efficiency of the prediction equation was then evaluated by an independent validation set. We found that the prediction equation - developed to estimate LMP in whole carcasses based on six variables - was characterized by a coefficient of determination ($R^2_v$) value of 0.77 (root-mean square error [RMSEV] of 2.12%). In addition, the predicted LMP values for the major cuts: ham, belly, and shoulder exhibited $R^2_v$ values${\geq}0.8$ (0.73 for loin parts) with low RMSEV values. However, lower accuracy ($R^2_v=0.67$) was achieved for tenderloin cuts. These results indicate that the LMP in Korean pig carcasses and major cuts can be predicted successfully using the VCS2000-based prediction equation developed here. The ultimate advantages of this technique are compatibility and speed, as the VCS2000 imaging system can be installed in any slaughterhouse with minor modifications to facilitate the on-line and real-time prediction of LMP in pig carcasses.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.129-143
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• 2011

In this study, to select the incoming solar radiation equation which is most suitable for the estimation of Penman evaporation, 12 incoming solar radiation equations were selected. The Penman evaporation rates were estimated using 12 selected incoming solar radiation equations, and the estimated Penman evaporation rates were compared with measured pan evaporation rates. The monthly average daily meteorological data measured from 17 meteorological stations (춘천, 강능, 서울, 인천, 수원, 서산, 청주, 대전, 추풍령, 포항, 대구, 전주, 광주, 부산, 목포, 제주, 진주) were used for this study. To evaluate the reliability of estimated evaporation rates, mean absolute bias error(MABE), root mean square error(RMSE), mean percentage error(MPE) and Nash-Sutcliffe equation were applied. The study results indicate that to estimate pan evaporation using Penman evaporation equation, incoming solar radiation equation using meteorological data such as precipitation, minimum air temperature, sunshine duration, possible duration of sunshine, and extraterrestrial radiation are most suitable for 11 study stations out of 17 study stations.

• Journal of the Ergonomics Society of Korea
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• v.20 no.2
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• pp.59-70
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• 2001

White uniformity is one of the important inspection factors determining the image quality of CRT screen. In the full white pattern, white uniformity means the degree of uniform distribution of white color across the whole screen. To elicit the sensitivity factors affecting the decision of the white uniformity quality, experiments in which participants were confronted with 6 evaluation points embedded in 3 measurement groups on a CRT screen were conducted to gather the psychophysical data that are the level of white uniformity subjects perceived and CA100 produced. These data were used to develop a modified CIE1976 equation for calculating white uniformity. Performance comparison between the original CIE1976 equation and the modified equation was conducted in terms of accuracy test and magnitude estimation. It was concluded the modified equation is more sensitive in the change of white uniformity, compared to the original CIE1976 equation.

• Korean Chemical Engineering Research
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• v.62 no.1
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• pp.53-69
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• 2024

The solubility of Cloxacillin sodium in ethanol, 1-propanol, isopropanol, and acetone solutions was measured at different temperatures. The melting property was also tested by using a differential scanning calorimeter (DSC). Then, the solubility data were fitted using Apelblat equation and λh equation, respectively. The Wilson model and NRTL model were not utilized to correlate the test data, since Cloxacillin sodium will decompose directly after melting. For comparison purposes, the four empirical models, i.e., Apelblat equation, λh equation, Wilson model and NRTL Model, were evaluated by using 1155 solubility curves of 103 solutes tested under different monosolvents and temperatures. The comparison results indicate that the Apelblat equation is superior to the others. Furthermore, a new method (named the calculation method) for determining the Apelblat equation using only three data points was proposed to solve the problem that there may not be enough solute in the determination of solubility. The log-logistic distribution function was used to further capture the trend of the correlation and to make better quantitative comparison between predicted data and the experimental ones for the Apelblat equation determined by different methods (fitting method or calculation method). It is found that the proposed calculation method not only greatly reduces the number of test data points, but also has satisfactory prediction accuracy.

• Computers and Concrete
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• v.9 no.4
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• pp.275-291
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• 2012

The service loads are often decisive in the design of concrete structures. The evaluation of the cracking moment, $M_{cr}$, is an important issue to predict the performance of the structure, such as, the deflections of the reinforced concrete beams and slabs. To neglect the steel bars of the section is a simplification that is normally used in the computation of the cracking moment. Such simplification leads to small errors in the value of this moment (typically less than 20%). However, these small errors can conduce to significant errors when the values of deflections need to be computed from $M_{cr}$. The article shows that an error of 10% on the evaluation of $M_{cr}$ can lead to errors over 100% in the deformation values. When the deformation of the structure is the decisive design parameter, the exact computing of the cracking moment is obviously very important. Such rigorous computing might lead to important savings in the cost of the structure. With this article the authors wish to draw the attention of the technical community to this fact. A simple equation to evaluate the cracking moment, $M_{cr}$, is proposed for a rectangular cross-section. This equation leads to cracking moments higher than those obtained by neglecting the reinforcement bars and is a simple rule that can be included in Eurocode 2. To verify the accuracy of the developed model, the results of the proposed equation was compared with a rigorous computational procedure. The proposed equation corresponds to a good agreement when compared with the previous approach and, therefore, this model can be used as a practical aid for calculating an accurate value of the cracking moment.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.31-37
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• 2003

The expanded uncertainties calculated by the application of GUM -approximation and Monte-Carlo simulation were compared about the model equation of one-point calibration which is widely used for the measurements and chemical analysis. For the comparisons, we assumed a set of artificial data at the various level of concentration and dispersion of t or normal distribution. Mistakes of more then 50 % was revealed at the values calculated by GUM-approximation in comparison with those of Monte-Carlo simulation because of the excess dispersion from t-distribution and non-linearity by division in the equation. In contrary, the mistake of calculation due to non-linearity of the equation was not observed in the level of detection limits with the equation of one-point calibration, because of the relatively large values of uncertainty in response.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.43-50
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• 2000

This paper shows the recent changes of national transportation policies in some developed countries and argues that the evaluation method of the effect of transportation investment on national economy should be improved to reveal real impact of the investment. The evaluation method should develope effective performance indicators of the goals set in national transportation policy. To estimate correctly the magnitude of transportation services in national economy, the evaluation method also provides a way to measure in-house transportation services and to overcome the limits of marginal effect equal equation.