• Journal of KSNVE
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• v.5 no.4
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• pp.515-524
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• 1995

Tubes in heat exchanger of fuel rods in reactor core are supported at intemediate point by support p0lates or springs. Current practice is, in case of heat exchanger, to allow clearance between tube and support plate for design and manufacturing consideration. And in case of fuel rod the clearance in support point can be generated due to the support spring force relaxation. Flow-induced vibration of a tube can cause it to impact or rub against support plate or against adjacent tubes and can result in fretting-wear. The tube-to- support dynamic interaction is used to relate experimental wear data from single-span test rigs to real multi-span heat exchanger configurations. The dynamic interaction cna be measured during experimental wear tests. However, the dynamic interaction is difficult to measure in real heat exchangers and, therefore, analytical techniques are required to estimate this interaction. This paper describels the nonlinear impact model of DAGS(Dynamic Analysis of Gapped Structure) code which simulates the tube response to external sinusodial or step excitation and predicts tube motion and tube-to-support dynamic interaction. Three experimental measurements-two single span rods excited by sinusodial force and a two span rod impacted by a steel ball are compared from the simulation nonlinear model of DAGS code. The simulation results from DAGS code are in good agreement with measurements. Therefore, the developed model of DAGS code is good analytical tool for estimating tube-to-support dynamic interaction in real heat exchangers.

• Asia Marketing Journal
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• v.17 no.2
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• pp.73-96
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• 2015

This paper investigates how servicescape perception influences customer experience quality in hedonic service settings. In addition to the direct effect of servicescape quality on customer experience quality, the indirect effects of servicescape quality on customer experience quality via employee-to-customer interaction quality and peer-to-peer interaction quality are also investigated. We collected data through a self-administered survey. The proposed relationships were tested using structural equation modeling. The results show that servicescape quality influences customer experience quality both directly and indirectly through employee-to-customer interaction quality and peer-to-peer interaction quality, and customer experience quality influences customer loyalty. Additionally, we find that the indirect path via peer-to-peer interaction quality is significant only in a low-satisfaction customer group. The indirect effect of servicescape quality perception through peer-to-peer interaction quality is significant only in low-satisfaction customer groups. Therefore, if evaluations for this indirect effect fall below an acceptable level, it should be addressed first before improving on other attributes. However, after this point, further improvements offer few if any gains; therefore, service firms should allocate their resources to quality improvements to other factors. This study is the first to investigate the indirect effects of servicescape quality on customer experience quality via peer-to-peer interaction quality in hedonic service settings. Additionally, this study demonstrates that the significance of this indirect effect applies only to a low-satisfaction customer group.

• Earthquakes and Structures
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• v.4 no.5
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• pp.557-585
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• 2013

The recent huge earthquake ground motion records in Japan result in the reconsideration of seismic design forces for nuclear power stations from the view point of seismological research. In addition, the seismic design force should be defined also from the view point of structural engineering. In this paper it is shown that one of the occurrence mechanisms of such large acceleration in recent seismic records (recorded in or near massive structures and not free-field ground motions) is due to the interaction between a massive building and its surrounding soil which induces amplification of local mode in the surface soil. Furthermore on-site investigation after earthquakes in the nuclear power stations reveals some damages of soil around the building (cracks, settlement and sand boiling). The influence of plastic behavior of soil is investigated in the context of interaction between the structure and the surrounding soil. Moreover the amplification property of the surface soil is investigated from the seismic records of the Suruga-gulf earthquake in 2009 and the 2011 off the Pacific coast of Tohoku earthquake in 2011. Two methods are introduced for the analysis of the non-stationary process of ground motions. It is shown that the non-stationary Fourier spectra can detect the temporal change of frequency contents of ground motions and the displacement profile integrated from its acceleration profile is useful to evaluate the seismic behavior of the building and the surrounding soil.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.3
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• pp.241-246
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• 2016

Nowadays many people have an interest in facial expression and the behavior of people. These are human-robot interaction (HRI) researchers utilize digital image processing, pattern recognition and machine learning for their studies. Facial feature point detector algorithms are very important for face recognition, gaze tracking, expression, and emotion recognition. In this paper, a cascade facial feature point detector is used for finding facial feature points such as the eyes, nose and mouth. However, the detector has difficulty extracting the feature points from several images, because images have different conditions such as size, color, brightness, etc. Therefore, in this paper, we propose an algorithm using a modified cascade facial feature point detector using a convolutional neural network. The structure of the convolution neural network is based on LeNet-5 of Yann LeCun. For input data of the convolutional neural network, outputs from a cascade facial feature point detector that have color and gray images were used. The images were resized to $32{\times}32$. In addition, the gray images were made into the YUV format. The gray and color images are the basis for the convolution neural network. Then, we classified about 1,200 testing images that show subjects. This research found that the proposed method is more accurate than a cascade facial feature point detector, because the algorithm provides modified results from the cascade facial feature point detector.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.8
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• pp.2561-2571
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• 1996

The flow in the turbomachinery is very unsteady due to the stator-rotor interaction. It has been indicated that the stator-rotor interaction has three distinct causes of unsteadiness: that is, the viscous vortex shedding, wake rotor interaction and potential stator-rotor interaction. In this paper, the mechanism of unsteady potential interaction and wake interaction in the stator-rotor stage flow is numerically investigated in two-dimensional view point. The numerical technique used is the upwind scheme of Van Leer's Flux Vector Splitting(FVS) and cubic spline interpolation is applied on zonal interface. Then, the flow field of a compressor stage composed of NACA 65410 is analyzed. Flow fields are found to be simulated reasonably by this method and the sensitivity due to back-pressure variation is more stronger than rotor-velocity variation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.11
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• pp.1518-1526
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• 2001

In this paper, the mechanism of unsteady potential interaction and wake interaction in one stage axial turbine is numerically investigated at design point in two-dimensional viewpoint. The numerical technique used is the upwind scheme of Van-Leer's Flux Vector Splitting (FVS) and Cubic spline interpolation is applied on zonal interface between stator and rotor. The inviscid analysis is used to embody the influence of potential interaction only and viscous analysis is used to embody the influences of both potential interaction and wake interaction at the same time. The potential-flow disturbance from the stator into a rotor passage and the periodic blockage effect of rotor produce the unsteady pressure on the blade surface in inviscid analysis. After the wake is cut by rotor, two counterrotating votical patterns flanking the wake centerline in the passage are generated. So, these phenomena magnify the unsteady pressure in viscous analysis than that in inviscid analysis. The resulting unsteady forces on the rotor, generated by the combined interaction of the two effects by potential and wake interaction, are discussed.

• Journal of Biomedical Engineering Research
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• v.35 no.2
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• pp.14-18
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• 2014

This study is about e-Book program based on human-computer interaction(HCI) system for physically handicapped person. By acquiring background knowledge of HCI, we know that if we use vision-based interface we can replace current computer input devices by extracting any characteristic point and tracing it. We decided betweeneyes as a characteristic point by analyzing facial input image using webcam. But because of three-dimensional structure of glasses, the person who is wearing glasses wasn't suitable for tracing between-eyes. So we changed characteristic point to the bridge of the nose after detecting between-eyes. By using this technique, we could trace rotation of head in real-time regardless of glasses. To test this program's usefulness, we conducted an experiment to analyze the test result on actual application. Consequently, we got 96.5% rate of success for controlling e-Book under proper condition by analyzing the test result of 20 subjects.

• Journal of Educational Research in Mathematics
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• v.14 no.3
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• pp.327-345
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• 2004

This study attempts to discuss holistic information in order to identify the characteristics of interactions using a graphing calculator. The use of a graphing calculator was divided into three stages: Visual, Analytical, and Self-regulated. The last stage can be called the Self-regulated instrument stage, because this last stage, the use of the calculator, is generally characterized as students actively controlling their ongoing efforts through self-regulating. The accomplishments of the operation can be divided into three levels: Immature, Maturing, and finally, Mature level. First, the characteristics of the Leading Statements were investigated to figure out who has the main role in cooperative learning. This study can support the previous study, which showed that computers could help improve the self-esteem of low-level students. Second, the point of transformation is referred to as the Turning Point. Several functions were observed in the Turning Point: student, instrument, and teacher. Third, when the students convert-sations reach a lull in class and then resume due to certain primary factors without the teachers intervention, this is a case of what is referred to as Structuralization. And last, in this study, the graphing calculator can be used as an auxiliary stimulus to help students control their stress and their attitudes, which in turn can also improve students social interaction.

• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.61-67
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• 1998

The significance of point defects as relevant centers concerning electrochemical function is highlighted. Starting from the most simple case of dilute equilibrium bulk defect chemistry, influence of defect interaction and in particular the impact of interfaces on point defect redistribution are considered. Then recent progress in the field of kinetics in bulk and at boundaries is discussed. Finally, selected applications with emphasis on battery and sensor technology are presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.10
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• pp.1452-1455
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• 2021

Recently, point clouds are generated by capturing real space in 3D, and it is actively applied and serviced for performances, exhibitions, education, and training. These point cloud data require post-correction work to be used in virtual environments due to errors caused by the capture environment with sensors and cameras. In this paper, we propose an enhancement technique for 3D point cloud data by applying generative adversarial network(GAN). Thus, we performed an approach to regenerate point clouds as an input of GAN. Through our method presented in this paper, point clouds with a lot of noise is configured in the same shape as the real object and environment, enabling precise interaction with the reconstructed content.