• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.637-641
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• 1991

One of the most difficult problems in depth control for underwater vehicle is the effect of seaway disturbance. When a underwater vehicle operates in a near surface environment, the seaway generates essentially two types of stochastic disturbances that influence the boat notion. One component of the seaway forces is of large magnitude with a relatively narrow-band, first order component. The other component is generally of somewhat smaller magnitude, second order component. Since the magnitude of the first order component is generally such greater than the compensating force that can be generating by the planes, it is undesirable for the controller to generate a control command. In this paper, we used LPC(Linear Predictive Coding) processing to uncontrollable seaway disturbance. This method can be used extensively in sensor signal processing of underwater vehicles.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.827-832
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• 2000

Bridge structure is known as one of important infrafacilities for comfortable human life. Recent long-span bridges, such as Kwang-Ahn Grand bridge, Seo-hae Grand Bridge, Young-Jong Grand Bridge, etc, have been designed and constructed near the seaside without in-depth consideration of concrete durability problem. It is in particular noted tat corrosion of reinforcement steel in concrete is very important for the durability enhancement of concrete structures. The objective of this experimental study is to investigate the corrosion behavior of reinforcing steels in concrete specimens which are exposed to cyclic wet and dry saltwaters, and then to develop pertinent corrosion protection system such as rational cover depth, corrosion inhibitors, cathodic system for reinforced bridges exposed to marine environment.

• Economic and Environmental Geology
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• v.20 no.3
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• pp.159-168
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• 1987

Some physico-chemical properties such as surface area, moisture content, cation exchange capacity, swelling rate, pH, viscosity and liquid limit have been determined for evaluation of Cabentonite deposit occurring in four localities; Yonil, Gampo, Haseo and Pohang, in Gyeongsang-do. Montmorillonite contents can be derived from surface area measurement. Enhancement of liquid limit values and swelling volume were observed in the samples which had higher exchangeable Na ion and finer particle-size distribution. Identical results were observed even in the Na-exchanged samples. This suggests that aggregation effects have a great influence on physico-chemical properties. Aggregation of montmorillonite were controlled not only burial depth but also composition of exchangeable cation. Consequently, sample occurred in Yonil area where has the greatest burial depth in the area show somewhat lower physico-chemical properties than those of samples occurred in the other localities. However, the basic test applied in this study provides very useful preliminary information relating to its commercial potential.

• Current Optics and Photonics
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• v.2 no.4
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• pp.378-382
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• 2018

In most previous investigations of plasmonic and metamaterial applications, the metallic film has been regarded as a perfect electrical conductor. Here we demonstrate the resonance characteristics of THz metamaterials fabricated from metal film that has a finite dielectric constant, using finite-difference time-domain simulations. We found strong redshift and spectral broadening of the resonance as we decrease the metal's plasma frequency in the Drude free-electron model. The frequency shift can be attributed to the effective thinning of the metal film, originating from the increase in penetration depth as the plasma frequency decreases. On the contrary, only peak broadening occurs with an increase in the scattering rate. The metal-thickness dependence confirms that the redshift and spectral broadening occur when the effective metal thickness drops below the skin-depth limit. The electromagnetic field distribution illustrates the reduced field enhancement and reduced funneling effects near the gap area in the case of low plasma frequency, which is associated with reduced charge density in the metal film.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.59.2-59.2
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• 2014

Radiative transfer models in a spherical, turbulent interstellar medium (ISM), in which the photon source is situated at the center, are calculated to investigate the correlation between the scattered light and the dust column density. The medium is modeled using fractional Brownian motion structures that are appropriate for turbulent ISM. The correlation plot between the scattered light and optical depth shows substantial scatter and deviation from simple proportionality. It was also found that the overall density contrast is smoothed out in scattered light. In other words, there is an enhancement of the dust-scattered flux in low-density regions, while the scattered flux is suppressed in high-density regions. The correlation becomes less significant as the scattering becomes closer to being isotropic and the medium becomes more turbulent. Therefore, the scattered light observed in near-infrared wavelengths would show much weaker correlation than the observations in optical and ultraviolet wavelengths. We also find that the correlation plot between scattered lights at two different wavelengths shows a tighter correlation than that of the scattered light versus the optical depth.

• Journal of the Semiconductor & Display Technology
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• v.14 no.4
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• pp.92-97
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• 2015

The purpose of this work is to support a solution of optimizing TMO (tone mapping operator). JPEG XT Profile A and C utilize Erik Reinhard TMO that works well in most cases, however, detailed information of a scene is lost in some cases. Reinhard TMO only calculates its coefficient to have tone-mapping curve from log-average luminance, and this lead to lose details of bright and dark area of scenes in turn. Thus, this paper proposes an enhancement of the default TMO for JPEG XT Profile C to optimize tone-mapping curve. Main idea is that we divide tone mapping curve into several ranges, and set reasonable parameters for each range. By the experimental results, the proposed scheme shows and obtains better performance within a dark scene, compared to the default Reinhard TMO.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.210-215
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• 2003

Seismic capacity of reinforced concrete bearing wall subjected to high axial loading and moment can be attained by improving the deformability of compression zone or by reducing the neutral axis depth. For this two existing options for ductility enhancement were reviewed and improved to conveniently apply to the seismic improvement of compression zone of the wall: (1) end confinement of concrete due to transverse steel and (2) boundary element.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.36-40
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• 2005

Integral imaging is an attractive three-dimensional display technique providing full-parallax full-color three-dimensional images in real-time without any viewing aids. In this paper, we present the recent progress on the three-dimensional display based on integral imaging focusing on its depth and viewing angle enhancement and the three-dimension/twodimension convertibility.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.4
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• pp.247-249
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• 2016

In this study, we investigated the color change of the normal light gray granite as the high value color granite. By coating the metal catalyst liquid on the surface of granite stone, the metal particles were penetrated into the granite and the color of granite was changed permanently through the annealing treatment. To increase penetration depth into the granite, we used DC (direct current) bias. Two kinds of bias were used such as DC bias and pulse DC bias. And the penetration time was changed as 30 and 60 min. In all cases, the color granite were successfully obtained. Regardless of the catalyst reaction time, the penetration depth was increased by using the bias treatment. We obtained a penetration depth of 21 mm with the DC pulse bias during 60 min.

• Women's Health Nursing
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• v.27 no.2
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• pp.128-140
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• 2021

Purpose: The purpose of this study was to develop a self-transcendence enhancement program and examine its effect on self-transcendence, spiritual well-being, and psychological well-being in elderly women who live alone. Methods: A self-transcendence enhancement program was developed through theory, literature review, and in-depth interviews. The theoretical framework came from the Psychoeducational Approach to Transcendence and Health intervention model based on Reed's middle-range theory of self-transcendence. The program consisted of multiple modalities in a structured, theory-based program lasting for eight weekly sessions. Using a single-group pretest-posttest design, the program was tested on a group of 40 elderly women aged 75 to 84 years living alone in Daejeon, Korea. Participants completed self-reported study questionnaires before and after the program at the elderly welfare center. Data were analyzed using SPSS version 24.0, with significance level set at .05. Paired t-test was used to compare mean differences before and after the program. Results: The mean age of the study participants was 79.1 years. After completing the program, the participants showed higher levels of self-transcendence (t=8.78, p<.001), overall spiritual well-being (t=8.30, p=.002), religious spiritual well-being (t=1.79, p=.040), existential spiritual well-being (t=6.75, p=.002), and positive affect (t=3.77, p=.001) than they did before the program. They also reported lower levels of depression (t=-7.59, p<.001) and negative affect (t=-6.15, p<.001). Conclusion: The self-transcendence enhancement program developed in this study may be effective for improving the level of self-transcendence in elderly women living alone and helping them to attain spiritual and psychological well-being.