• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.54.2-54.2
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• 2017

We present the results of high-resolution optical (R ~ 30,000) and near-infrared (R ~ 45,000) spectroscopic monitoring observations of a new FU Orionis-like young stellar object, 2MASS J06593158-0405277. FU Orionis objects (FUors) are well-studied examples of episodic accretion because of their outburst phenomenon. Recently, 2MASS J06593158-0405277 exhibited an outburst and was identified as an FUor. It provides an important opportunity to investigate the whole FUors phenomenon from its pre-outburst to its post-outburst phase. We observed 2MASS J06593158-0405277 with the Bohyunsan Optical Echelle Spectrograph (BOES) of the Bohyunsan Optical Astronomy Observatory (BOAO) and the Immersion GRating INfrared Spectrograph (IGRINS) of Harlan J. Smith Telescope (HJST) at the McDonald observatory since December 24, 2014. We detected a number of lines and present here our analysis for time variations of those spectral lines.

• International journal of advanced smart convergence
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• v.7 no.2
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• pp.135-142
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• 2018

Virtual reality (VR) technology has been increasingly more frequently used day by day in industries, entertainment and performances due to the development of AR and MR technologies. Performance arts also actively utilize $360^{\circ}$ VR technology due to the free expression of stage settings and auditoriums. However, technologies for systems in which performers wear VR devices firsthand rather than being in the sandpoint of bystanders while audiences wear VR head mounted displays(HMDs) to see performance stages have been rarely studied yet. This study investigated the technical possibilities of possible methods of expression that will enable performers to appear on the stage wearing VR devices. Since VR can maximize the sense of immersion with its closed HMD structure unlike augmented reality (AR), VR was judged to be suitable for studies centered on the mental interactions in the inner side of humans. Among them, to implement shamanistic expression methods with the phantoms of the body and soul, a motion capture technology linked with VR display devices and real-time cameras was realized on the stage. In this process, the importance of body ownership experienced by the performers (participants), reactions when they lost it, and the mental phenomena of the desire to possess the subjects of gaze could be seen. In addition, high possibility of development of this technology hereafter could be expected because this technology includes the technical openness that enables the audience to appear on the stage firsthand to become performers.

• Journal of Ocean Engineering and Technology
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• v.19 no.2 s.63
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• pp.53-59
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• 2005

The effect of pH on the corrosion characteristics in the dissimilar friction welded zone of IN713LC-SCM440 in the loaded torsional stress was studied. The corrosion experiment was performed for 120 hours on the specimens with five steps of pH. The surface corrosion pattern of the SCM440 area showed global corrosion and narrow pitting, which was caused by galvanic corrosion between friction welded IN713LC and SCM440, but corrosion did not proceeded from the IN713LC area. The average relative electrode potential gradually tends to decrease with the elapse of the immersion time in the acidity area. The average corrosion current also gradually tend to decrease The corrosion rate showed a larger value when the average relative electrode potential was higher and the average relative current was lower. The corrosion rate showed a larger value when the average relative electrode potential was higher in the acidity area, and it showed large when the average relative electrode potential was lower in the alkalinity area.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.197-200
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• 2005

As Plasma Immersion ion Implantation (PIII) using a conducting grid is very useful to reduce the effect of capacitance and charging in surface modification. If the bias voltage applied to the conducting grid is in the range of hundreds of volts, the effects of surface charge and space charge substantially affect the incident ion energy and ion current to the surface. In this paper, through an 1d and a 2d PIC simulation the time varying formation of the space charge and surface charge is analyzed. Experiment with the optimally designed grid on the basis of the simulation results is conducted, and the results of both cases with grid and without grid are compared. In our work with Poly Urethane(PU), the improvement of adhesion is yielded by increasing surface roughness and decreasing Si component of PU.

• Journal of Aquaculture
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• v.9 no.1
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• pp.65-71
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• 1996

To estimate the variation of food organisms on the corrugated PVC sheets, we analysed the chlorophyll a and. pheopigments of the benthic microalgae on the sheets from the oyster culture ponds. We estimated the standing crops as the amounts of chlorophyll a, and the physiological state of cells as the pheopigments level in the benthic microalgae. The amount of chlorophyll a was increased by immersion time in winter but the peak was observed every two weeks in summer, while the ratio of pheopigments was highest in summer but the low level was observed in spring and autumn. These seasonal variation were well coincided with the natural spawning season and the good microalgae nutritional valance.

• Architectural research
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• v.20 no.1
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• pp.27-34
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• 2018

To improve the chloride ingress resistance of concrete, slag is widely used as a mineral admixture in concrete industry. And currently, most of experimental investigations about non steady state diffusion tests of chloride penetration are started after four weeks standard curing of concrete. For slag blended concrete, during submerged chloride penetration tests periods, binder reaction proceeds continuously, and chloride diffusivity decreases. However, so far the dependence of chloride ingress on curing ages are not detailed considered. To address this disadvantage, this paper shows a numerical procedure to analyze simultaneously binder hydration reactions and chloride ion penetration process. First, using a slag blended cement hydration model, degree of reactions of binders, combined water, and capillary porosity of hardening blended concrete are determined. Second, the dependences of chloride diffusivity on capillary porosity of slag blended concrete are clarified. Third, by considering time dependent chloride diffusivity and surface chloride content, chloride penetration profiles in hardening concrete are calculated. The proposed prediction model is verified through chloride immersion penetration test results of concrete with different water to binder ratios and slag contents.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.205.2-205.2
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• 2014

The effects of ion beam mixing of a SiC film coated on super alloys (hastelloy X substrates) were studied, aiming at developing highly sustainable materials at above $900^{\circ}C$ in decomposed sulfuric acid gas (SO2/SO3/H2O) channels of a process heat exchanger. The bonding between two dissimilar materials is often problematic, particularly in coating metals with a ceramics protective layer. A strong bonding between SiC and hastelloy X was achieved by mixing the atoms at the interface by an ion-beam: The film was not peeled-off at ${\geq}900^{\circ}C$, confirming excellent adhesion, although the thermal expansion coefficient of hastelloy X is about three times higher than that of SiC. Instead, the SiC film was cracked along the grain boundary of the substrate at above $700^{\circ}C$. At ${\geq}900^{\circ}C$, the film was crystallized forming islands on the substrate so that a considerable part of the substrate surface could be exposed to the corrosive environment. To cover the exposed areas and cracks multiple coating/IBM processes have been developed. An immersion corrosion test in 80% sulfuric acid at $300^{\circ}C$ for 100 h showed that the weight retain rate was gradually increased when increasing the processing time.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.58-66
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• 2005

Pseudo-Near Field Recording (Pseudo-NFR) system is proposed to prevent contamination and oxidation of media surface occurred in conventional NFR systems. To solve these critical problems of the NFR systems, we investigate the optimal thickness of cover layer for Pseudo NFR. This paper presents the theoretical analysis for cover layer thickness based on the measured length of dust particle and numerical simulation for the temperature distribution using Finite Difference Time Domain (FDTD) method and heat conduction equation. To verify the simulation results, we conduct and compare simulation results in case of far field MO recording and near field MO recording. A measured dust particle length in general environment was mostly less than $20{\mu}m$, and the optimal thickness of cover layer is $30{\mu}m$ in this case. Based on the designed optimal cover layer thickness, temperature distribution is simulated to have $800{\~}850^{\circ}C$.

• Journal of Distribution Science
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• v.17 no.12
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• pp.43-54
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• 2019

Purpose: Marine transportation companies must improve service quality to secure competitive advantage and continuous relationships with customers. This study explores the value and necessity of service quality in the industry by empirically identifying the factor that would have the largest effect on the improvement of service quality, also examining whether such improvement may actually influence continuous relationships. Research design, data and methodology: Based on an online survey with those in the Korean marine transportation industry, this study conducted statistical analyses using structural equation modeling. Based on relevant previous studies, the current study constructed a total of 55 survey questions. Finally, 281 questionnaires were collected, but 68 were excluded owing to invalid responses. Results: Information service attribute had the largest effect on service quality, whereas communication did not demonstrate a significant influence. In addition, distribution and information services exerted a positive effect on service satisfaction through service quality, and finally influenced relationship continuity. Conclusions: The results shows that marine logistics service quality strategies which were centered on time or local factors, should be considered in terms of the development of innovative services. In particular the improvement of information service systems and strategies in changed business environment.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.518-528
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• 2017

Quality characteristics of frozen cylindrical pork loin were evaluated following different tempering methods: 27.12 MHz curved-electrode radio frequency (RF) at 1000 and 1500 W, and forced-air convection (FC) or water immersion (WI) at $4^{\circ}C$ and $20^{\circ}C$. The developed RF tempering system with the newly designed curved-electrode achieved relatively uniform tempering compared to a parallel-plate RF system. FC tempering at $4^{\circ}C$ was the most time-consuming process, whereas 1500 W RF was the shortest. Pork sample drip loss, water holding capacity, color, and microbiological quality declined after WI tempering at $20^{\circ}C$. Conversely, RF tempering yielded minimal sample changes in drip loss, microstructure, color, and total aerobic bacteria counts, along with relatively uniform internal sample temperature distributions compared to those of the other tempering treatments. These results indicate that curved-electrode RF tempering could be used to provide rapid defrosting with minimal quality deterioration of cylindrical frozen meat block products.