• Journal of Digital Convergence
• /
• v.18 no.3
• /
• pp.111-121
• /
• 2020

The purpose of this study is to examine the satisfaction of consumers using the mobile navigation service which is continuously growing. This study examined variables that affect the service use behaviors and satisfaction of 1200 consumers using service. According to the results of the study, consumers used the service 1-2 or 3-4 times per week, more frequently used in the lunch time(weekends) and in the morning(weekdays). The core functional dimension was shown to have the largest effect on satisfaction with the service. Among consumption emotions, positive emotions had effects in the positive direction while negative emotions had effects in the negative direction, and the effect of innovativeness was not significant. Through the foregoing, the use behavior and the formation of satisfaction could be analyzed and the results of this study can be used in establishing service strategies later and can be also used as basic data of the navigation industry.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.4A
• /
• pp.497-505
• /
• 2008

Corrugated steel webs resist only shear force because of the accordion effects. The shear force in the web can cause three different buckling mode: local, global, and interactive shear buckling modes. The shear behavior of the corrugated steel webs have been investigated by several researchers. However, shear buckling behavior of the corrugated webs are not clearly explained yet. And, it lead the conservative design. This paper presents shear strength of trapezoidally corrugated steel webs. A series of the tests were also conducted to verified proposed shear strength. Firstly, local, global, and interactive shear buckling equations provided by previous researchers were rearranged as a simple form considering the profiles of the existing bridges with corrugated steel webs. And, global and interactive shear buckling coefficient, and shear buckling parameter for corrugated webs were suggested in this study. Inelastic buckling strength can be determined from buckling curves based on the proposed shear buckling parameter. From the test results of this study and those of previous researchers, it can be found that suggested shear strength provides good estimation of those of trapezoidally corrugated steel webs.

• Structural Engineering and Mechanics
• /
• v.53 no.4
• /
• pp.745-765
• /
• 2015

A nonlinear Finite Element (FE) algorithm is proposed to analyze the Reinforced Concrete (RC) columns subjected to Cyclic Loading (CL), Cyclic Oriented Lateral Force and Axial Loading (COLFAL), Monotonic Loading (ML) or Oriented Pushover Force and Axial Loading (OPFAL) in any direction. In the proposed algorithm, the following parameters are considered: uniaxial behavior of concrete and steel elements, the pseudo-plastic hinge produced in the critical sections, and global behavior of RC columns. In the proposed numerical simulation, the column is discretized into two Macro-Elements (ME) located between the pseudo-plastic hinges at critical sections and the inflection point. The critical sections are discretized into Fixed Rectangular Finite Elements (FRFE) in general cases of CL, COLFAL or ML and are discretized into Variable Oblique Finite Elements (VOFE) in the particular cases of ML or OPFAL. For pushover particular case, a fairly fast converging and properly accurate nonlinear simulation method is proposed to assess the behavior of RC columns. The proposed algorithm has been validated by the results of tests carried out on full-scale RC columns.

• Korea-Australia Rheology Journal
• /
• v.15 no.4
• /
• pp.197-208
• /
• 2003

Two measures of distributive mixing are examined: the standard deviation $\sigma$ and the maximum error E, among average concentrations of finite-sized samples. Curves of E versus sample size L are easily interpreted in terms of the size and intensity of the worst flaw in the mixture. E(L) is sensitive to the size of this flaw, regardless of the overall size of the mixture. The measures are used to study distributive mixing for time-periodic flows in a rectangular cavity, using the mapping method. Globally chaotic flows display a well-defined asymptotic behavior: E and $\sigma$ decrease exponentially with time, and the curves of E(L) and $\sigma$ (L) achieve a self-similar shape. This behavior is independent of the initial configuration of the fluids. Flows with large islands do not show self-similarity, and the final mixing result is strongly dependent on the initial fluid configuration.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.520-523
• /
• 2004

The finite element method(FEM) models were developed for the reinforced concrete flexural walls and analysed under constant axial and monotonic lateral load using ABAQUS. The major objective of the present study is to determine if the ABAQUS finite element program can be used to accurately model the post-cracked mode of failure in plastic regions of walls, and, if so, to develop practical failure criteria in the plastic range of the material response. The research comprises constitutive models to represent behavior of the materials that compose a wall on the basis of experimental data, development of techniques that are appropriate for analysis of reinforced concrete structures, verification, and calibration of the global model for reinforced concrete walls of increasing complexity. Results from the analyses of these FEM models offers significant insight into the flexural behavior of benchmark data.

• Journal of Information Technology Services
• /
• v.13 no.2
• /
• pp.19-34
• /
• 2014

As the global smartphones market is growing at a brisk pace, their associated mobile applications are becoming increasingly ubiquitous in our daily life. The growth of mobile application business is explosive. Like other digital contents businesses, illegal downloads of copyrighted mobile applications become major obstacle in the future of the industry. In spite of anti-piracy efforts, the phenomenon has been getting worse. It is necessary to change the focus of current deterrence policies and strategies. This study investigates the factors influencing smartphone applications piracy behavior. For better understanding of illegal behavior, a research model of potential determinants for the piracy behavior is developed and empirically tested via path analysis using structural equation modeling. Findings show that social factors, beliefs concerning benefits from piracy, self-efficacy, and habit have significant effects on attitude toward smartphone application piracy. The result also shows perceived risks and facilitating conditions were not significantly related to their attitude. Implications for research and practice are discussed.

• International Journal of Control, Automation, and Systems
• /
• v.1 no.2
• /
• pp.229-235
• /
• 2003

We designed a family of completely autonomous mobile robots with local intelligence. Each robot has a number of on-board sensors, including vision, and does not rely on global positioning systems The on-board embedded controller is sufficient to analyze several low-resolution color images per second. This enables our robots to perform several complex tasks such as navigation, map generation, or providing intelligent group behavior. Not being limited to playing the game of soccer and being completely autonomous, we are also looking at a number of other interesting scenarios. The robots can communicate with each other, e.g. for exchanging positions, information about objects or just the local states they are currently in (e.g. sharing their current objectives with other robots in the group). We are particularly interested in the differences between a behavior-based approach versus a traditional control algorithm at this still very low level of action.

• Hwankyungkyoyuk
• /
• v.25 no.2
• /
• pp.149-160
• /
• 2012

This study examined the effects of reflective writing activities utilizing environmental related mass media. Two classes participated as an experimental group (n=31) and a control group (n=30). Both groups of students learned five different topics on environment, such as diversity of ecosystem, global warming, desertification, reduction of the amount of carbon, and eco-friendly behavior. The experimental group students was taught utilizing mass media about each topic and had opportunities of reflective writing about each topic, while the control group of students was taught through lectures. The results indicated that students in the experimental group represented significantly better scores on environmental worldview, environmental sensitivity, and eco-friendly behavior compared to the control group students (p<.01).

• Structural Engineering and Mechanics
• /
• v.65 no.3
• /
• pp.327-334
• /
• 2018

In the steel structures design, beam-to-column connections are usually considered either rigid or pinned, while their actual behavior lies between these two ideal cases. This consideration has a major influence on the results of the local and the global behavior of steel structures. This influence is noticed in the case of a static analysis, and has an important effect in the case of a dynamic analysis. In fact, pinned and rigid nodes can be considered as two specific cases of a semi-rigid behavior. To study the efficiency of the classification adopted in Eurocode 3, a numerical simulation of semi-rigid nodes has been carried out using the software ANSYS. In the aim to validate this simulation, the numerical results are compared to those of an analytical approach. After that, the validated numerical simulation has been used, to evaluate the efficiency of the classification adopted by the Eurocode 3, regarding semi-rigid connections. Finally, a new method is proposed to define a more accurate evaluation about semi-rigid connections.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.05a
• /
• pp.493-498
• /
• 2003

The 3D nonlinear analysis for steel-concrete hybrid deck is carried out by utilizing 2D plane interface element. The effect of the slip occurred between steel and concrete can be modeled by this element. This analysis focuses on not only global behavior of steel-concrete hybrid deck but also local behaviors of members of it such as lower steel plate, I-beam, and concrete which are varied by slip modulus. In this analysis, it was founded that the limit slip modulus could classify the states of steel-concrete hybrid deck into three parts such as full-composite, partial-composite, and non-composite, considering the behavior of lower steel plate, I-beam, and concrete at the mid span and the support as well as the yield load and ultimate load of it.