• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.674-679
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• 1998

Small water leak experiment was carried out in liquid sodium atmosphere using a specimen of ferrite steel, which will be expected to be a material of the heat transfer tube of liquid metal fast breeder reactor. Self-plugging phenomena of leak path could be explained by the products of reaction and corrosion by sodium-water reaction. Also, re-opening mechanism of self-plugged path could be explained by the thermal transient and vibration of heat transfer tube. As a result, perfect re-opening time of self-plugged leak path was observed to be 129 minutes after water leak initiation. Re-opening shape of a specimen was appeared with double layer of circular type, and re-opening size of this specimen surface was about 2 mm diameter on sodium side.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.5
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• pp.66-71
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• 2012

The capacity criteria have been proposed in order to select a cooperative relay node in WSNs, under the environment where direct path has a poor link gain. This process may ensure the efficiency improvement of signal transfer between source and destination and reduction of energy consumption as well. Two criteria are incorporated to select a cooperative relay node. Firstly, calculate the energy gain ratio between the relay path and the direct path. These are defined as the ratio between the energy factors of 1/g and 1/B. Each stands for an inverse of direct path gain and relay path gain. Secondly, investigate the effects of relay node's usage in WSNs through the simulation in terms of energy consumption. In conclusion, using a selected cooperative relay node based on the selected criteria is effective in terms of both energy efficiency and capacity of WSNs especially when direct path gain is relatively low.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.9
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• pp.477-483
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• 2013

A numerical analysis of solid-liquid phase change was performed on a heat transfer module which consisted of circulating water path (BRINE), heat transfer plate (HTP) and phase change material (PCM) layers, such as high temperature PCM (HPCM, $78{\sim}79^{\circ}C$) and low temperature PCM (LPCM, $28{\sim}29^{\circ}C$). There were five arrangements, consisting of BRINE, HTP, LPCM and HPCM layers in the heat transfer module. The time and heat transfer rate for melting/solidification was compared to their arrangements, against each other. As results, the numerical time without convection was longer than the experimental one for melting/solidification. Moreover, the melting/solidification with the BRINE I-LPCM-BRINE II-HPCM arrangement was faster(10 hours) than the others; HPCM-BRINE-LPCM, BRINE I-HPCM-LPCM-BRINE II one.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.9 s.339
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• pp.19-28
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• 2005

We establish a statistical model for the ultra-wide bandwidth (UMB) indoor channel based on over 2000 frequency response measurements campaign in a Practical apartment. The approach is based on the investigation of the statistical properties of the multipath profiles measured in different place with different rooms. Based on the experimental results, a characterization of the propagation channel from theoretic view point is described. Also we describe a method for measurement of the channel impulse response and channel transfer function. Using the measured data, the authors compares channel impulse responses obtained from time-domain and channel transfer functions obtained from frequency-domain with statistical path loss model. The bandwidth of the signal used in this experiment is from 10MHz to 8.01 GHz. The time-domain results such as maximum excess delay, men excess delay and ms delay spread are presented. As well as, omni-directional biconical antenna were used for transmitter and receiver In addition, measurements presented here support m channel model including the antenna characteristics.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.453-463
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• 2016

This study examined the relationship among dropout, organizational trust, and intention to transfer in the department affiliated with Physical Education. Data were collected from 480 students in the department affiliated with Physical Education from 6 institutions of a 4-year university located in Seoul, Gyeonggi-do, Incheon, and ChungChong-do. For the research model analysis, a structural equation model and bootstrapping were conducted. Results indicated that the academic domain, the social domain, and the environmental domain of dropout had a positive effect on organizational trust. But the only the academic domain in the relationship between dropout and intention to transfer affected intention to transfer positively. The social domain and the environmental domain were not statistically significant on intention to transfer. Moreover, organizational trust had a positive effect on intention to transfer. Finally, organizational trust partially mediated the path between the academic domain and intention to transfer. It fully mediated the paths between the social domain and the environmental domain and intention to transfer.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.67-83
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• 2018

This research is motivated by the question, "Where, when, and through what mode does an individual passenger moving within a subway station use to travel from starting to final destinations ?" To answer this, the stations passed by the individual passenger, the path taken, and modes used need to be known beforehand. In the metropolitan integrated public transportation fare system, Automated Fare Collection System(AFC) can be a source of information on transit modes, stations, and paths of individual passengers. AFC calculates a fare for the passenger based on travel data such as boarding and alighting stations, time, and mode used. In this research, an Selected Station Analysis(SSA) method, in which AFC data is used to observe passenger movement in the metropolitan public transportation subway station from the perspective of subway transfer stations, is proposed. SSA subdivides individual passenger movement in transfer stations and analyzes initial station/time and final destination station/time information using the trip chain perspective.

• Journal of Auto-vehicle Safety Association
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• v.12 no.2
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• pp.27-32
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• 2020

This paper presents steering system requirements to ensure the stabilized lateral control of autonomous driving vehicles. The two main objectives of a lateral controller in autonomous vehicles are maintenance of vehicle stability and tracking of the desired path. Even if the desired steering angle is immediately determined by the upper level controller, the overall controller performance is greatly influenced by the specification of steering system actuators. Since one of the major inescapable traits that affects controller performance is the time delay of the steering actuator, our work is mainly focused on finding adequate parameters of high level control algorithm to compensate these response characteristics and guarantee vehicle stability. Actual vehicle steering angle response was obtained with Electric Power Steering (EPS) actuator test subject to various longitudinal velocity. Steering input and output response analysis was performed via MATLAB system identification toolbox. The use of system identification is advantageous since the transfer function of the system is conveniently obtained compared with methods that require actual mathematical modeling of the system. Simulation results of full vehicle model suggest that the obtained tuning parameter yields reduced oscillation and lateral error compared with other cases, thus enhancing path tracking performance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.609-615
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• 2008

A Pedestrian Space in the transit transfer center is compositively made of a variety of activities for pedestrians. The pedestrians avoid access to the transit transfer center and the revitalization of the transit transfer center is obstructed as the travel cost of the pedestrians increases. This study provides the pedestrians using the transit transfer center with the significant real-time routing service and helps the movement of pedestrians to minimize the economical loss considering the travel cost and congestion of the pedestrians in the transit transfer center. In this paper, we propose a solution to construct a spatial map for the pedestrians in the transit transfer center to receive the significant real-time routing service based on Ubiquitous technique which is big issue around the world.

• Structural Engineering and Mechanics
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• v.63 no.3
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• pp.293-302
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• 2017

This study deals with a numerical investigation of load transfer along interfaces of jacketed columns using finite element models. Appropriate plasticity and constitutive models are used to simulate the response of concrete and steel bars. Experimental data were used to calibrate the simulation of mechanical characteristics. The different compressive strength of core and jacket concrete, the confinement ratio, the dowels' diameter size and the load pattern shapes were considered. The path diagrams along the interfaces elucidate the areas around the dowel bars where due to stress concentration plastic hinges and intense discontinuities are created. The stress flow also depicts the contribution of confinement of the jacketed area to the overall resonant load capacity of the core column. The scope of the research is to identify and quantify the shear transfer along the interfaces of strengthened elements.

• International journal of advanced smart convergence
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• v.12 no.2
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• pp.127-134
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• 2023

Existing studies on this topic have focused on the effect of online content quality on consumer attitudes and behavior, with very few illustrating the effect of influencer image on consumer attitudes and behavior. The purpose of this study intents to reveal how influencer image affect consumer behavior. We have developed an image transfer theory-based research model to reveal how influencers transfer their image to endorsed products to influence consumer behavior. The results show that influencer image positively affects satisfaction, which in turn affects the product's cognitive and affective images in the vlog. Moreover, it was found that a product's cognitive image and affective image influence consumer behavior intention. Furthermore, purchase experience exhibits significant differences in its path. Based on these results, the social media-related research theoretical implication will be offered, and managerial implications will be provided for foreign brand promotion strategies