• Journal of Korean Association for Spatial Structures
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• v.22 no.2
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• pp.39-46
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• 2022

Recently, machine learning is widely used to solve optimization problems in various engineering fields. In this study, machine learning is applied to development of a control algorithm for a smart control device for reduction of seismic responses. For this purpose, Deep Q-network (DQN) out of reinforcement learning algorithms was employed to develop control algorithm. A single degree of freedom (SDOF) structure with a smart tuned mass damper (TMD) was used as an example structure. A smart TMD system was composed of MR (magnetorheological) damper instead of passive damper. Reward design of reinforcement learning mainly affects the control performance of the smart TMD. Various hyper-parameters were investigated to optimize the control performance of DQN-based control algorithm. Usually, decrease of the time step for numerical simulation is desirable to increase the accuracy of simulation results. However, the numerical simulation results presented that decrease of the time step for reward calculation might decrease the control performance of DQN-based control algorithm. Therefore, a proper time step for reward calculation should be selected in a DQN training process.

• Smart Media Journal
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• v.4 no.2
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• pp.68-76
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• 2015

Recently, research on indoor locating techniques using smart device sensors has been conducted actively, Owing to the exponential increase in the use of various smart devices. However, in order to develop indoor location techniques, there are limitations due to the requirement that the tracking system has to function without GPS. In this paper, we propose an accurate indoor locating system that does not require additional infrastructure. The proposed scheme is developed based on the idea that the advantages and disadvantages of "Wi-Fi Fingerprinting" and "Step Detection" techniques are complementary. In the proposed scheme, we track users with "Step Detection," and correct errors with "Wi-Fi Fingerprinting." In this paper, we demonstrate the effectiveness and feasibility of our proposed scheme through experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.471-479
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• 2015

This study examined the effects of smart phone use while young adults negotiated an obstacle (2 cm high). Seventy-four young adults (mean age: $23.76{\pm}3.17years$, age range: 20-27 years) participated in the study. They were allocated randomly into two groups; smart phone group and no smart phone group. The smart phone group negotiated an obstacle while simultaneously using a smart phone at a self-paced speed whereas the no smart phone group negotiated an obstacle with no special option. A motion analysis system were used to measure the gait parameters, such as toe clearance, cadence, step length, step width, stride length, and walking velocity in two groups. The toe clearance, and step-width, cadence, and step-length were significantly greater for the smart phone group than the no smart phone group (p<.05) and the walking velocity was significantly lower in the smart phone group (p<.05). On the other hand, there was no significant difference in the stride length between the two groups. This study suggests that smart phone use degrades the obstacle avoidance abilities of healthy young adults, which may increase risk of falls.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1088-1093
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• 2010

The Smart bi-directional pile load test with variable end plate overcomes the shortcoming of the Osterberg cell test. It is possible that the ultimate bearing capacity of piles can be known by using two different end plates. The first step is to measure end bearing capacity with smaller end plate and the second step is similar to the conventional O-cell test. In this study, model test was performed to evaluate the smart bi-directional pile load test in sand. Vertical displacement of the model pile were messured at the axial loading condition.

• Journal of Smart Tourism
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• v.2 no.3
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• pp.5-15
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• 2022

As the utilization of technology in the tourism field becomes familiar, it greatly impacts people's tourism activities. These changes could also affect the behavior of tourists during the pandemic. To investigate consumers' adaptation to the self-service technology (SST) environment during the coronavirus disease of 2019 (COVID-19) pandemic, we adopted a model of absorptive capacity as the main framework for empirical research. To track the social effects of COVID-19, consumers' behavioral intentions for four different points in time are collected. The analysis was conducted using latent growth and structural equation modeling. We set the organizational and environmental characteristics as the first step of the model, with assimilation and trust as a middle step. Intention to use a kiosk is placed at the final step as an exploit. Findings indicate that organizational characteristics and environmental characteristics positively influenced assimilation and trust, except for environmental characteristics. Consumers' assimilation in SST encourages immediate intention to use a kiosk. Consumers' trust in kiosks positively impacts both immediate and continuance intention to use a kiosk during COVID-19.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.143-154
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• 2023

The purpose of this study is to present the role and function of Smart Training Education Platform(STEP) as a public online platform that should be aimed at for the development of customized lifelong vocational skills as the existing Occupational Skills Development Act was revised to the National Lifelong Vocational Skills Development Act. To this end, the role and function of STEP's public service was derived based on domestic public online platform service case studies and expert FGI, and an expert verification meeting was held. Based on this, implications for the role and function of STEP as a public online platform were presented.

• Journal of The Korean Association of Information Education
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• v.17 no.2
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• pp.167-175
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• 2013

This paper examined various study case about smart grid and STEAM education. We develop this STEAM education of IT subject using smart grid for 3rd and 4th graders in elementary school. We make this program and teaching materials by considering about student's intellectual level and interests. We offered this program to 10 elementary 4th graders in Jeju island step by step for 6 period to evaluate the effectiveness of the developed program and teaching materials. Future work will include the follow-up and extended study. It will be expected that students will be able to develop their abilities by this STEAM education using IT.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.257-260
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• 2003

Dynamic simulation program for a smart UAV turbojet engine was developed. The transient simulation program utilized the CMP(Constant Mass flow) method and Euler integration method for integration of excess torque. The transient performance analysis was carried out by increasing from the idle to the maximum rotational speed of the gas generator. To observe engine dynamic behavior, fuel flow was monitored through a step and a ramp increase. When the fuel was increased as a step function the overshoot of the turbine inlet temperature exceeded the limit temperature.

• Nuclear Engineering and Technology
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• v.44 no.6
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• pp.689-696
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• 2012

A small integral reactor SMART (System Integrated Modular Advanced ReacTor), being developed in Korea since late 1990s and targeted to obtaining a standard design approval by the end of 2011, is introduced. The design scope and level for design certification (DC) is well described in the U.S. NRC SECY documents published the early 1990s. However, the documents are valid for a one-step licensing process called a combined operating license (COL) by the U.S. NRC, while Korea still uses a two-step licensing process. Thus, referencing the concept of the SECY documents, we have established the design scope and level for the SMART DC using the contexts of the standard review plan (SRP). Some examples of the results and issues raised during our review are briefly presented in this paper. The same methodology will be applied to other types of reactor under development in Korea, such as future VHTR reactors.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.151-151
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• 2001