• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.611-620
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• 2007

The beam-column connection is the critical design section of general steel frame structures owing to the behavioral characteristics of the structural system. As most members of a frame structure are composed of rolled section beams, the cross-section of the beam members is governed by the negative bending moment near beam-column connections. Such a design concept leaves a redundant load-carrying capacity at the positive bending regions of the beam members leading to design inefficiency. Therefore, it is of utmost importance to redistribute the beam end moments and reduce the stresses at the beam-column connections for a more efficient design of steel frame structures. In this study, reaction-moment prestressing method (RMPM) was proposed for the innovative design and construction of steel frame structures. The RMPM is a prestressing method utilizing the elastic bending deformation of a beam member induced by temporary prestressing for the distribution of a relatively large bending moment to other sections for the efficient use of the beam section. By the application of the RMPM, the negative bending moment at the beam-column connections can be significantly reduced, ultimately leading to possible use of smaller beam sections. Through a series of model tests and numerical analyses of steel frame structures, the moment distributing effect and feasibility of the RMPM was verified.

• The Korean Journal of Financial Management
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• v.27 no.2
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• pp.85-114
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• 2010

Using the financial institutions that have adopted performance-based stock option plan, this paper examines whether performance-based executive stock options improves effectively firm value. Over the period 2002~2005, we investigate short-term and long-term effects of the performance-based stock options on stock price. The empirical results are summarized as follows. First, the announcement of plain vanilla stock options generates no significant effects on firm value. Meanwhile, the announcement of performance-based stock options results in negative and significant abnormal returns, which is contrary to the expectation. In addition, we find that there are strong, significant and negative announcement effects when banks grant performance-based stock options. Secondly, there is no significant difference between the long-term performance of the sample granting stock options and that of the benchmarks, which is similar to the findings of the previous research. Also, we fail to get any evidence that performance-based stock option awards have improved the long-term firm value.

• Journal of the Korea Convergence Society
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• v.11 no.8
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• pp.99-106
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• 2020

The purpose of this study is to find out whether image similarity between celebrities and brands on social network service be a determinant to predict advertising effectiveness. To this end, an advertising effect prediction model for celebrity endorsed advertising was created and its validity was verified through a machine learning method which is a big data analysis technique. Firstly, the celebrity-brand image similarity, which was used as an independent variable, was quantified by the association network theory with social big data, and secondly a multiple regression model which used data representing advertising effects as a dependent variable was repeatedly conducted to generate an advertising effect prediction model. The accuracy of the prediction model was decided by comparing the prediction results with the survey outcomes. As for a result, it was proved that the validity of the predictive modeling of advertising effects was secured since the classification accuracy of 75%, which is a criterion for judging validity, was shown. This study suggested a new methodological alternative and direction for big data-based modeling research through celebrity-brand image similarity structure based on social network theory, and effect prediction modeling by machine learning.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.1
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• pp.107-120
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• 2020

In a performance-based evaluation of structures in use, the current performance is assessed by summing up the weighting of the evaluation indices for each performance. In this study, to suggest a performance-based evaluation technique for NATM tunnels in use, the performance evaluation indices were derived by examining the characteristics and similarities of each index developed from previous study. The weighting of the evaluation indices was derived by calculating the relative importance of each evaluation indices from the AHP analysis. In order to develop a quantitative evaluation model, grading criteria for each performance index was derived through literature review, and performance evaluation tables for road and railway tunnels were presented. In order to verify the significance of the proposed performance evaluation model, the correlation analysis was performed between each evaluation index and the final evaluation result. In the correlation analysis, the survey data measured through precision safety diagnosis in the tunnel in use was applied. It may be said that the proposed evaluation indices, weighting, criteria and evaluation models for tunnels in use can be applied to the performance-based maintenance system of tunnels.

• Journal of Korea Technology Innovation Society
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• v.18 no.3
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• pp.416-443
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• 2015

The resource-based view (RBV) explains that the competitive advantage is mainly based on the resources which have strategic characteristics. Therefore, finding, developing and maintaining strategically valuable resources has been one of main research topics and a starting point in the corporate strategy structure in RBV. In this regards, attempts to recognize strategically valuable resources have been one of crucial issues in RBV researches. Especially, Barney's VRIO has been widely used as a practical tool for finding strategically valuable resources. However, empirical studies on VRIO framework's effectiveness have not been sufficiently implemented, and there has been no proven relation among the components of the VRIO so far. This is mainly because the concepts or definitions on core components of the VRIO - Value, Rareness, Inimitability, and Organization - are too comprehensively explained and measurements of each component cannot be easily quantified. Considering these, this paper presents empirical results of the relation between VRIO components and competitive advantage, and tests effectiveness of VRIO Framework with utilizing sufficient technology evaluation cases and financial statements of 2,252 technology based SMEs in Korea. As a result, the components of the VRIO have a positive influence on competitive advantage. The attributes of strategic resources - Value, Rareness, and Inimitability - have a statistically meaningful positive effect on organization, while organization has a positive effect on the competitive advantage serving as a parameter between the attributes of strategic resources and competitive advantage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.73-81
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• 2020

This study demonstrated the effect of IT Ssupports for Iintegration Ccompetency(ITSIC) on organizational performance by using organizational temperance and absorption capacity as medium. The research model was verified with Smart PLS 3.0 based on the survey conducted overa total a total of of 126 pparticipantseople's surveys for the employees. First, the ITSIC had a positive effect on both the alignment and adaptability and also on absorption capacity. Second, it was confirmed that organizational temperance hads a positive effect on absorption capacity. Third, when the organizational temperance was mediated in the relationship between ITSIC and absorption capacity, it had a indicated a positive effect. Fourth, absorption capacity had a positive impact on organizational performance. The implications of this study differ from the existing studies through by validating validation of correlations correlations by extending IT technology and organizational performance to organizational ethical factors. In addition, it has been established that the ethical factors of the organization also act as leading factors of absorption capacity. ITSIC helps managers make balanced decision-making, which can contribute to improving absorption capacity by giving members a positive perception, ultimately having a positive impact on organizational performance. It suggests the importance of building appropriate IT infrastructure and cultivating organizational virtues in order to improve the performance of organizations in which absorption capacity is essential.

• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.17-24
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• 2018

The pullout test, a nondestructive testing(NDT), for pre-installed inserts is perhaps the most widely used technique to estimate the in-situ compressive strength of concrete. It measures the force needed to pullout a standardized metal insert embedded into concrete members. The pullout test was certified by the American Society for Testing and Materials(ASTM) and Canadian Standards Association(CSA) as a reliable method for determining the strength of concrete in concrete structures under construction. To easily estimate the strength of ultra-high-strength concrete, a simplified pullout tester, primarily composed of a standard 12mm bolt with a groove on the shaft as a break-off bolt, an insert nut, and a hydraulic oil pump without a load cell, was proposed. Four wall and two slab specimens were tested for two levels of concrete strength, 80MPa and 100MPa, using a simplified pullout tester with a load cell to verify the advantages of the pullout test and simplified pullout test. The compressive strength of concrete, pullout load, and the rupture of the break-off bolt were measured 11 times, day 1 to 7, 14, 21, 28, and 90. The correlation of the pullout load and the compressive strength of each specimen show a higher degree of reliability. Therefore, a simplified pullout test can be used to evaluate the in-place strength of ultra-high-strength concrete in structures. The prediction equation for the groove diameter of the break-off bolt(y) with the concrete strength(x) was proposed as y=0.0184x+5.4. The results described in this research confirm the simplified pullout's utility and potential for low cost, simplicity, and convenience.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.815-827
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• 2014

The current study was undertaken to verify appropriateness of muscle endurance test at three different angles ($30^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$) of isometric contraction position, and to sought valid and reliable testing method that provide an alternative to sit-ups. Total 92 young and healthy subjects (68 males and 24 females) were recruited, and the following results were obtained. 1. A low correlations in males, but a high correlations in females was found when the comparisons were made between aerobic and muscle endurance capability. 2. Measuring tolerance time, by using isometric contraction was showed a significant correlation with the repetition numbers of sit-ups. 3. The highest correlation was found at 40 inclined degrees of plane, and the lowest correlation was drawn from 50 inclined degrees of plane. Based on these results, it was concluded that measuring tolerance time during maintaining an isometric contraction at 40 inclined degrees of plane is a valid and effective tool for measuring abdominal muscle endurance, and it can be used as an alternative way of sit-up, which potentially risky for inducing many back-associated injuries. Further studies need to be undertaken to determine for optimal angles, that can safely be applied for people of various age groups and physical conditions.

• Information Systems Review
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• v.17 no.3
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• pp.95-111
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• 2015

The recommendation system automatically provides the predicted items which are expected to be purchased by analyzing the previous customer behaviors. This recommendation system has been applied to many e-commerce businesses, and it is generating positive effects on user convenience as well as the company's revenue. However, there are several limitations of the existing recommendation systems. They do not reflect specific criteria for evaluating products or the factors that affect customer buying decisions. Thus, our research proposes a collaborative recommendation model algorithm that utilizes each customer's online product reviews. This study deploys topic modeling method for customer opinion mining. Also, it adopts a kernel-based machine learning concept by selecting kernels explaining individual similarities in accordance with customers' purchase history and online reviews. Our study further applies a multiple kernel learning algorithm to integrate the kernelsinto a combined model for predicting the product ratings, and it verifies its validity with a data set (including purchased item, product rating, and online review) of BestBuy, an online consumer electronics store. This study theoretically implicates by suggesting a new method for the online recommendation system, i.e., a collaborative recommendation method using topic modeling and kernel-based learning.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.5
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• pp.551-557
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• 2021

Attached parking lots installation criteria is determined by use, total floor area, etc. according to the Parking Lot Act and local government ordinances. However, with traffic demand increase inconvenience about use of culture and assembly facilities have been raised. When planning number of parking lots for cultural and assembly facilities, legal parking lots and unit parking lots are used, but this causes inconvenience and traffic problems on the surrounding roads, because reality and convenience are not considered. Therefore, this study intend to present an realistic number of parking lots calculating equation for movie theater in Gwangju Metropolitan City. After investigating number of parking lots, number of screens, number of seats, total floor area, bus route and illegal parking for a cultural facility in Gwangju Metropolitan City, prediction model for calculating number of parking lots was presented using SPSS regression analysis. As a result of comparing prediction model and unit method, the prediction model was be closer actual cumulative parking space, so prediction model verification was completed. Based on the model verified in this study, Realistic number of parking lots will be installed. However, due to limitations of research on specific areas, research on various facilities should continue in consideration of regional, population, and urban characteristics