• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.12
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• pp.1521-1527
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• 2013

This study proposes a wearable master device that can measure the joint stiffness and the angular displacement of a human operator to enhance the adapting capability of a slave system. A lightweight inertial sensor and the exoskeleton mechanism of the master device can make an operator feel comfortable, and artificial pneumatic muscles having a working principle similar to that of human muscles improve the performance of the slave device on emulating what a human operator does. Experimental results revealed that the proposed master/slave system based on the muscle stiffness sensor yielded uniform tracking performance compared with a conventional position-feedback controller when the payload applied to the slave system changed.

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1298-1305
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• 2018

The use of System-on-Chip (SoC) solutions in the design of on-board data handling systems is an important step towards further miniaturization in space. However, the Total Ionizing Dose (TID) and Single Event Effects (SEE) characterization of these complex devices present new challenges that are either not fully addressed by current testing guidelines or may result in expensive, cumbersome test configurations. In this paper we report the test setups, procedures and results for TID testing of a SoC microcontroller both using standard $^{60}Co$ and low-energy protons beams. This paper specifically points out the differences in the test methodology and in the challenges between TID testing with proton beam and with the conventional gamma ray irradiation. New test setup and procedures are proposed which are capable of emulating typical mission conditions (clock, bias, software, reprogramming, etc.) while keeping the test setup as simple as possible at the same time.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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• pp.155-162
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• 2019

Hybrid precast concrete panel is a wall element that is able to quickly construct the core wall structure for moderate-rise modular buildings. Hybrid precast concrete panel has unique characteristics which is a pair of C-shaped steel beams combined at the top and bottom of a concrete wall, In this study, an improved anchorage detail for vertical rebar is proposed to ensure the lateral force resistance performance of hybrid precast concrete panel emulating monolithic concrete wall. Also, the structural performance of horizontal connection is investigated experimentally with the bolt spacing parameter. And the behavior of hybrid precast concrete panel with the improved detail is compared with the monolithic concrete wall tested in a previous study. Finally, the required thickness of C-shaped steel beam to eliminate or minimize the deformation in horizontal connection is calculated by prying action equation.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.42.4-43
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• 2020

The hydrogen-rich envelope mass of a dying massive star is the key factor that determines the type and properties of the resulting supernova. Emulating wind-driven mass loss of single stars with the MESA(Modules for Experiments in Stellar Astrophysics) stellar evolution code, we made a grid of models for a large parameter space of initial mass (12 M⊙ to 30M⊙), metallicity (solar, LMC and SMC), hydrogen envelope mass (0.01M⊙ to 10M⊙) for progenitor stars in their final step of evolution. Our results suggest the final luminosity of the progenitor is largely determined by the initial mass, which means there is luminosity degeneracy for stars with the same initial mass but with different hydrogen-rich envelope masses. Since we can break this degeneracy by correcting luminosity with surface gravity (spectroscopic HR diagram), we can infer the exact mass property of an observed progenitor. The surface temperature drastically varies near the envelope mass of ~0.1M⊙ and surface temperature of ~10000 K, where the demarcation between the hydrogen-rich envelope and the helium core lies, which explains the rarity of 'white' supergiants. There also exists a discontinuity in the chemical composition of the progenitor envelope around this critical hydrogen-rich envelope mass of ~0.1 M⊙, which can be tested in future observations of "flash spectroscopy" of supernovae.

• The Journal of the Acoustical Society of Korea
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• v.30 no.3
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• pp.142-148
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• 2011

The final aim of the present study is to develop the intelligent robot, emulating human synesthetic skills which make it possible to associate a color image with a specific sound. This can be done on the basis of the mutual conversion between color image and sound. As a first step of the final goal, this study focused on a basic system using a conversion of color image into sound. This study describes a proposed method to convert color image into sound, based on the likelihood in the physical frequency information between light and sound. The method of converting color image into sound was implemented by using HSI histograms through RGB-to-HSI color model conversion, which was done by Microsoft Visual C++ (ver. 6.0). Two different color images were used on the simulation experiments, and the results revealed that the hue, saturation and intensity elements of each input color image were converted into fundamental frequency, harmonic and octave elements of a sound, respectively. Through the proposed system, the converted sound elements were then synthesized to automatically generate a sound source with wav file format, using Csound.

• Journal of the Korean Geotechnical Society
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• v.30 no.10
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• pp.55-65
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• 2014

Recent researches on debris flow is focused on understanding its movement mechanism and building a numerical simulator to predict its behavior. However, previous simulators emulating fluid-like debris flow have limitations in numerical stability, geometric modeling and application of various boundary conditions. In this study, depth integration is applied to continuity equation and force equilibrium for debris flow. Thickness of sediment, and average velocities in x and y flow direction are chosen for main variables in the analysis, which improve numerical stability in the area with zero thickness. Petrov-Galerkin formulation uses a discontinuous test function of the weighted matrix from DG scheme. Presented mechanical constitutive model combines fluid and granular behaviors for debris flow. Effects on slope angle, inducing debris height, and bottom friction resistance are investigated for a simple slope. Numerical results also show the effect of embankment at the bottom of the slope. Developed numerical simulator can assess various risk factors for the expected area of debris flow, and facilitate embankment design in order to minimize damage.

• Science of Emotion and Sensibility
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• v.16 no.2
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• pp.187-194
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• 2013

The final aim of the present study is to build a system of converting a color image into musical elements based on a synesthetic perception, emulating human synesthetic skills, which make it possible to associate a color image with a specific sound. This can be done on the basis of the similarities between physical frequency information of both light and sound. As a first step, an input true color image is converted into hue, saturation, and intensity domains based on a color model conversion theory. In the next step, musical elements including note, octave, loudness, and duration are extracted from each domain of the HSI color model. A fundamental frequency (F0) is then extracted from both hue and intensity histograms. The loudness and duration are extracted from both intensity and saturation histograms, respectively. In experiments, the proposed system on the conversion of a color image into musical elements was implemented using standard C and Microsoft Visual C++(ver. 6.0). Through the proposed system, the extracted musical elements were synthesized to finally generate a sound source in a WAV file format. The simulation results revealed that the musical elements, which were extracted from an input RGB color image, reflected in its output sound signals.

• Journal of KIISE
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• v.43 no.6
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• pp.645-652
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• 2016

Joint Attention (JA) has been known to play a key role in human social learning. However, relative impact of different interaction types has yet to be rigorously examined because of limitation of existing methodologies to simulate human-to-human interaction. In the present study, we designed a new JA paradigm with emulating human-avatar interaction and virtual reality technologies, and tested the paradigm in two experiments with healthy adults. Our results indicated that initiating JA (IJA) condition was more effective than responding JA (RJA) condition for social learning in both head and hand interactions. Moreover, the hand interaction involved better information processing than the head interaction. The implication of the results, the validity of the new paradigm, and limitations of this study were discussed.

• Journal of Korea Multimedia Society
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• v.11 no.10
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• pp.1376-1384
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• 2008

Numerous researches on network self-configuration have been conducted on Wireless Sensor Network (WSN) and Ad Hoc network but the results have not been applied yet for factory automation. This paper presents development of intelligent process management systems conducting process monitoring and control irrelevant to physical position of a plant operator. The systems are indispensable for diagnosis of rotating machines which cannot exploit wired network. The system was implemented in a Personal Digital Assistant (PDA) using Bluetooth communication protocol. When a mobile terminal reaches to communication range of the process management server, the server detects the mobile terminal to reconfigure plant network automatically. The server authenticates a user of the terminal to download and installs monitoring and control program considering authorized level of the user. If the terminal leaves communication range of the server, it deletes the node from the network and removes the program automatically to save resources and prevent security problems such as missing terminal. Operation of developed functions was verified in a testbed emulating steel-making plant.

• Journal of IKEEE
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• v.23 no.4
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• pp.1140-1149
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• 2019

In general, there are various pulse width modulation(PWM) methods simply using the offset voltage injection in voltage source converter(VSC). In accordance with the AC side voltage synthesis method with the offset voltage, DC side voltage utilization factor in VSC is changed. Also, this can apply equally to the MMC system. In other words, if the DC side capacity of the high voltage DC(HVDC) transmission system is determined, the maximum reactive power which can be supplied to the AC side can be changed according to the applied output voltage synthesis method with the offset voltage. In this paper, the leg energy pulsation in MMC system according to the AC side output voltage synthesis method with offset voltage which several representative PWM are applied to are mathematically analyzed and compared with each other. Finally, the above results are verified by simulation emulating the 400MVA full-scale MMC system to determine the consistency of the mathematical analysis.