• Structural Engineering and Mechanics
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• v.85 no.6
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• pp.825-835
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• 2023

The effective buckling length factor is an important parameter in the elastic buckling analysis of steel structures. The present article aims at developing a new method that allows the determination of the buckling factor values for frames. The novelty of the method is that it considers the interaction between the bracing and the elastic supports for asymmetrical frames in particular. The approach consists in isolating a critical column within the frame and evaluating the rotational and translational stiffness of its restraints to obtain the critical buckling load. This can be achieved by introducing, through a dimensionless parameter 𝜙_i, the effects of coupling between the axial loading and bending stiffness of the columns, on the classical stability functions. Subsequently, comparative, and parametric studies conducted on several frames are presented for assessing the influence of geometry, loading, bracing, and support conditions of the frame columns on the value of the effective buckling length factor K. The results show that the formulas recommended by different approaches can give rather inaccurate values of K, especially in the case of asymmetric frames. The expressions used refer solely to local stiffness distributions, and not to the overall behavior of the structure.

• Journal of The Korean Society of Clinical Toxicology
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• v.18 no.2
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• pp.78-84
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• 2020

Purpose: In acute acetaminophen poisoning, the administration of N-acetylcysteine (NAC) can effectively treat the main complications, such as kidney injury and liver failure. In the current situation, measurements of the acetaminophen concentration are not checked in the usual medical facilities. Therefore, this study examined the factors of determining the administration of NAC in addition to the stated amount of intake. Methods: The medical records of patients who visited Ajou University Hospital emergency center with acetaminophen poisoning from January 2015 to December 2019 were reviewed retrospectively. One hundred and seventy-nine patients were initially included. Among these patients, 82 patients were finally selected according to the inclusion criteria in the study. The inclusion criteria were as follows: patients who were 15 years of age or older; those whose ingested dose, ingested time, and body weight were clearly identified; and patients whose acetaminophen sampling time was within 24 hours. Patients were divided into two groups: NAC administered vs. non-NAC administered. The following variables were compared in these two groups: ingested dose, ingested dose per body weight, hospital arrival time after ingestion, suicide attempt history, psychiatric disease history, classification of toxic/non-toxic groups, duration of hospitalization, and laboratory results. Results: Univariate analysis revealed the ingested dose per body weight, hospital arrival time after ingestion, suicide attempt history, and psychiatric disease history to be the determining factors in administering NAC. Logistic regression analysis confirmed that the ingested dose per body weight was the only significant factor leading to an NAC treatment decision. (Odds ratio=1.039, 95% Confidential interval=1.009-1.070, p=0.009) Conclusion: The ingested dose per body weight was the only determining factor for administering NAC in patients with acute acetaminophen poisoning. On the other hand, additional criteria or indicators for the NAC administration decision will be necessary considering the inaccuracy of the ingested dose per body weight and the efficiency of NAC administration.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.6
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• pp.55-65
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• 2019

Universal Soil Loss Equation (USLE) is to estimate potential soil loss and has benefit in use with its simplicity. The equation is composed of five factors, one of the factors is the slope length and steepness factor (LS factor) that is for topographic property of fields to estimate potential soil loss. Since the USLE was developed, many equations to compute LS was suggested with field measurement. Nowadays the factor is often computed in GIS software with digital elevation model, however it was reported that the factor is very sensitive to the resolution of digital elevation model. In addition, the digital elevation model of high resolution less than 3 meter is required in small field application, however these inputs are not associate with the empirical models' backgrounds since the empirical models were derived in 22.1 meter field measurements. In the study, four equation to compute LS factor and two approaches to determine slope length and steepness were examined, and correction factor was suggested to provide reasonable precision in LS estimations. The correction factor is computed with field area and cell size of digital elevation model, thus the correction factor can be adapted in any USLE-based models using LS factor at field level.

• Journal of Korea Port Economic Association
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• v.31 no.4
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• pp.107-120
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• 2015

This study analyzes Korea's Free Economic Zone (FEZ), by particularly focusing on Incheon and Busan-Jinhae zones, using the Analytic Hierarchy Process (AHP) method and a questionnaire survey analysis. The study compares important selection criteria and satisfaction of resident companies in Incheon and Busan-Jinhae FEZs. The findings are as follows. First, the AHP method results suggest that companies in both Incheon and Busan-Jinhae FEZs are affected by location, economic society, and policy. In subordinate determining factor for land, it is ordered by ease of gaining land, inexpensive rental fee in Incheon and by convenient access to close markets and inexpensive rental fee in Busan-Jinhae. Second, the questionnaire survey results suggest high adjacent market size and easy access in Incheon FEZ and sound logistics infrastructure in Busan-Jinhae FEZ. For this reason, Incheon has a high value of logistics infrastructure and potential market near metropolitan area and Busan-Jinhae, has a high value of transportation Infrastructure near industrial district. These findings will contribute to policy data for activating and promoting the Free Economic Zone.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.6 no.2
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• pp.19-27
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• 1988

In determining the horizontal positions, economic, speedy, and accurate analytical adjustment methods have studied and developed for a long time. From now on, the adjustment methods using both angles and distances are expected because the development of more precise instruments, E.D.M, and electronic total station provide us with more advantages than the conventional measurement system. The objective of this paper is to study the characteristics of triangulation, trilateration, and combination method due to change of the weight factor of angles, distances, azimuthes, and control point coordinates of combined geodetic network. The results of this study show that combined method is more accurate and effective than other methods in case of combined geodetic network as the other simple networks.

• International Journal of Concrete Structures and Materials
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• v.8 no.2
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• pp.99-116
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• 2014

The American Concrete Institute (ACI) 318-11 permits the use of the moment magnifier method for computing the design ultimate strength of slender reinforced concrete columns that are part of braced frames. This computed strength is influenced by the column effective length factor K, the equivalent uniform bending moment diagram factor $C_m$ and the effective flexural stiffness EI among other factors. For this study, 2,960 simple braced frames subjected to short-term loads were simulated to investigate the effect of using different methods of calculating the effective length factor K when computing the strength of columns in these frames. The theoretically computed column ultimate strengths were compared to the ultimate strengths of the same columns computed from the ACI moment magnifier method using different combinations of equations for K and EI. This study shows that for computing the column ultimate strength, the current practice of using the Jackson-Moreland Alignment Chart is the most accurate method for determining the effective length factor. The study also shows that for computing the column ultimate strength, the accuracy of the moment magnifier method can be further improved by replacing the current ACI equation for EI with a nonlinear equation for EI that includes variables affecting the column stiffness and proposed in an earlier investigation.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.4
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• pp.460-465
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• 2013

Electrical equipments of nuclear power plant are divided into class 1E and non-class 1E. Electrical equipment and systems that are essential to emergency reactor shutdown, containment isolation, reactor core cooling, and containment and reactor heat removal, are classified as class 1E. batteries of nuclear power plant are divided into four channels, which are physically and electrically separate and independent. The battery bank of class 1E DC power system of the nuclear power plant use lead-acid batteries in present. The lead acid battery, which has a high energy density, is the most popular form of energy storage. Kt factor of lead-acid battery is used to determine battery size and it is one of calculatiing coefficient for capacity. this paper analyzes Kt factor of lead-acid battery for the DC power system of nuclear power plant. In addition, correlation between Kt parameter and peukert's exponent of lead-acid battery for nuclear plant are discussed. The analytical results contribute to optimize of determining size Lead-acid battery bank.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.4
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• pp.419-426
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• 2001

Concrete mix proportioning is a process of selecting the right combination of many materials such as cement, fine aggregates, coarse aggregates, water, and admixtures to make concrete satisfying for specification and cost. In determining proportioning of concrete mixes, code information, specification, and the experience of experts are needed. However, all factors regarding mix proportioning factor cannot be considered. Therefore, the final acceptance depends on concrete quality control test results. The proportioning of concrete mixes and the adjustments are somewhat complicated, time-consuming, and uncertain tasks. In this paper, as a tool to predict the factor of the proportioning of concrete mixes, an artificial neural network is used. To consider the varieties of material properties, the standard mixed table of two companies of ready mixed concrete are used. The results show that neural net works is successfully applied to the prediction of concrete mix proportioning factor.

• Journal of the Korean Geographical Society
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• v.49 no.6
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• pp.884-896
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• 2014

This study aims to identify the factors that contribute to the regional innovative capacity and to analyze the effects on the regional economic development including newly-established corporation and job creation. The results are as follows. First, as a result of factor analysis, the 14 variables were grouped into 3 factors, i.e. innovative input, infrastructure, and linkage. Second, the panel models were developed using the above factor scores and economic performance variables such as the number of newly-established corporation and employees. As a result, innovative capacity factors positively contributed to the newlyestablished corporation and job creation. The innovative input was the most influential factor determining the regional economic performance, followed by linkage and infrastructure. This study suggests several policy implications for the reinforcement of innovative capacity and regional competitiveness.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.165-172
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• 1995

Twenty six subject drove screws with a screw driver into thick wooden sheet at three vertical and horizontal locations. Subjects drive screws for 3 minutes at each location and they assessed the conditon using the psychophysical scale. An ANOVA showed that only vertical location was a signicant factor in determining the pain ratings of various body parts. Driving screws at elbow height on the vertical surface ans with the lower arm close to the body on the horizontal surface were the work locations with the smallest ratings of perceived pain and discomfort. Wearing gloves had significant effects on reducing the pain of the hand.