• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.430-437
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• 1998

The existing design expressions for shear strength of reinforced concrete columns are lacking in consistent seismic design philosophy and very conservative. However, relatively not so many experiments have been conducted to verify the shear resisting mechanisms of columns. The previous researches concentrated on deriving an experimental model from their test results. So, there is a need to approach this problem from the analytical point of view to be balanced with the experimental effort. This paper presents a method of modeling reinforced concrete columns under seismic shear loading. Lower bound solutions are obtained by using an analogous truss model and concrete arch actions. This model agrees with the precedented test results by some margins.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.570-573
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• 1996

The evaluation test for the operation of rotary type surface mounters which consist of the reel axis, the index table and the X-Y table, has been performed by comparing the new method with the old one in only fields. Because the problem seeking for the optimal operation of rotary type surface mounters, is NP complete, it is almost impossible to get the optimal solutions of large problems. This paper deals with a dynamic network modeling, which can reduce the effort, the cost, and the time used for the performance test of rotary type surface mounters.

• Transactions of Materials Processing
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• v.26 no.2
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• pp.121-126
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• 2017

The hot stamping process is an innovative forming method that could prevent the cracking of high strength steel sheets. The formability test of boron steel sheet using forming limit diagrams at elevated temperature is very complicated and time consuming job. In this paper, an alternative test method to evaluate the formability of boron steel in hot stamping has proposed. It measured the FLD0 instead of whole strain combinations of FLD with the tensile test machine and specially designed test rig. Test results shows that the proposed test method can simulate the plain strain condition fracture and can make the FLD of boron steel sheet at elevated temperature with less effort.

• Nuclear Engineering and Technology
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• v.29 no.2
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• pp.158-166
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• 1997

Integrated performance test of Chemical and Volume Control System was successfully performed in 1994. However, an extensive effort to correct hardware and software problems in the letdown line was required mainly due to the lack of adequate simulation code to predict the test accurately. Although the LTC computer code was used during the YGN 3'||'&'||'4 NSSS design process, the code can not satisfactorily predict the test due to it insufficient letdown line modeling. This study developed a numerical model to simulate the letdown test by modifying the current LTC code, and then verified the model by comparing with the test data. The comparison shows that the modified LTC computer code can predict the transient behavior of letdown system lese very well. Especially, the model was verified to be able to predict the "Stiction (composition of stick and friction)" phenomena which caused instantaneous fluctuations in the letdown backpressure and flowrate. Therefore, it is concluded that the modified LTC computer code with the ability of calculating the "Stiction" phenomena will be very useful for future plant design and test predictions.predictions.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1671-1674
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• 2007

A PSD system has a lot of characteristic for safety. Trust of performance test is very important. But PSD performance test has an effect on trust by proficiency of test staff because it is difficult to automate. In that specially the effort test, manual opening and shutting test and abrasion measurement, test staff is demanded for proficiency. Therefore the paper repeated measurement in same condition and studied proficient factor of examiner according to increased measurement counter. As a result, measurement uncertainty has improved.

• Journal of the Korean Society of Safety
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• v.30 no.5
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• pp.92-99
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• 2015

The diameter of a new wheel in EMUs is 860mm and it can be used up to 773mm. To obtain an predefined acceleration despite wheel diameter changes, the tractive efforts of the vehicles must be properly controlled. In the commencement of this study, acceleration tests were performed for empty EMUs when the wheel diameter was changed to 860mm, 820mm and 780mm, respectively. In order to deal with more complicated running conditions, we developed dynamic simulation models of the EMUs using VI-Rail, and simulated the models in empty and full passenger loads, respectively. Using the simulation results, we analyzed the gradient of time-velocity graphs by considering the changes of the total weight vehicles and moment of inertia of the wheelsets as well as tractive effort according to the wheel diameter changes. As the results, it was found that there are significant differences in acceleration performances according to the wheel diameters and the payloads of EMUs. In case of 860mm which is the maximum wheel diameter, the test & simulation results show that the vehicle couldn't reach the predefined acceleration, 3.0km/h/s, due to lack of tractive effort.

• Asia pacific journal of information systems
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• v.13 no.1
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• pp.103-118
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• 2003

Software project planning is usually represented by a project activity network that is composed of stages of tasks to be done and precedence restrictions among them. The project network is very complex and its construction requires a vast amount of field knowledge and experience. So this study proposes a case-based reasoning approach that can generate the project network automatically based on the past cases and modification knowledge. For the case indexing, we have adopted 17 factors, each with a few alternative values. A special structure of this problem is that the modification effort can be identified by each factor independently. Thus it is manageable to identify 85 primitive modification actions(add and delete activities) and estimate its modification efforts in advance. A specific case requires a combination of primitive modifications. Based on the modification effort knowledge, we have adopted the Least Modification approach as a metric of similarity between a new project and past cases. Using the Least Modification approach and modification knowledge base, we can automatically generate the project network. To validate the performance of Least Modification approach, we have compared its performance with an ordinary minimal distance approach for 21 test cases. The experiment showed that the Least Modification approach could reduce the modification effort significantly.

• Journal of Korea Trade
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• v.25 no.7
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• pp.56-74
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• 2021

Purpose - This study aims to identify consumer tendencies in Korea and Vietnam, focusing on the online platform called cross-border, to derive revenue generation measures and use them for strategies to advance into ASEAN. Design/methodology - The questionnaire collected 420 copies from December 1 to December 31, 2020, of which 408 were used for statistical processing. The structural equation model (SEM) and moderating effect analysis with Amos was used to test hypothesis in this research. Findings - The hypotheses were set as factors that positively influence the intention to use e-commerce, such as effort expectancy, social influence, facilitating conditions and variety seeking showed statistically significant results. Among them, the social influence factor had the greatest influence, followed by facilitating condition. The sample was divided into countries, Korea and Vietnam, and these changes and differences in influence were confirmed through moderating effect analysis. Originality/value - The moderating effect on both countries (Korea and Vietnam) was found to have a moderating effect on the intention to use. For Korean consumers, significant results were found in the effort expectancy, social influence, facilitating conditions, and variety seeking, but for Vietnamese consumers, there were significant effects on the social influence and facilitating conditions, but the effort expectancy and variety seeking had no significant effect.

• The Journal of Information Systems
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• v.28 no.3
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• pp.159-202
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• 2019

Purpose The purpose of this study is to explain users' wearable healthcare device adoption using performance expectancy, effort expectancy, the hedonic motivation and price value of UTAUT2, and to identify the causal relationship between intention to use wearable healthcare device and innovation resistance formed by perceived risks. Design/methodology/approach The research model proposed in this study is based on UTAUT2(Extended Unified Theory of Acceptance and Use of Technology) and MIR(Model of Innovation Resistance). In specific, performance expectancy, effort expectancy, hedonic motivation and price value of UTAUT2 and innovation resistance formed by perceived risks of MIR are adopted in our research model. To validate the research model, we carry out the analysis of the survey data using Smart PLS 3.0 to test the hypotheses. Findings According to the empirical analysis results, this study confirms that the performance expectancy, effort expectancy, hedonic motivation, and price value have significant effects on the intention to use wearable healthcare devices. It also finds that perceived risk affects innovation resistance and in turn, innovation resistance affects the intention to use wearable healthcare devices.

• Journal of the Korean Chemical Society
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• v.53 no.4
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• pp.445-452
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• 2009

In this study, the influences of the context of discrepant events on the conceptual change process using cognitive conflict strategy were investigated in terms of students' cognitive and motivational variables such as cognitive conflict, situational interest, attention, effort, conceptual understanding. A preconception test was administered to 536 seventh graders. A test of response to a discrepant event and a situational interest questionnaire were then administered. The context of discrepant events, either scientific or everyday, was randomly presented to the subjects. After learning the concept of density, the tests of attention, effort, and conceptual understanding were administered. The reponses of 194 students who had been found to possess the target misconception were analyzed. The results revealed that the scientific-context discrepant event induced higher cognitive conflict than everyday-context one. The context of discrepant events, however, did not show significant correlations with situational interest, attention, effort, and/or conceptual understanding. The result of path analysis indicated that the context of discrepant events both directly influenced cognitive conflict and indirectly influenced conceptual understanding via cognitive conflict.