• Journal of Ocean Engineering and Technology
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• v.19 no.2 s.63
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• pp.34-39
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• 2005

All of the design criterion are not only formulated by an internal study, concerning the design of maritime structures, but also by the guarantee that internal design technology is essential, at least according to theoretical and experimental studies. Furthermore, the basic data, which is necessary for the development of a more stable design of breakwater structures, should be ensured, according to current research and analysis of damage created by water waves. According to the necessity to solve the problems that occur in the design and construction of ocean structures, until now, it is recognized that the hydraulic experiments are important. This paper provides the design of structures to decrease the energy created by waves. Suggestions to make contributions to the development of ocean/fisheries technology are also discussed. It is better to use S-type coastal structures/breakwaters than to use uniform type breakwaters, concerning stability, reflection, and overtopping.

• Near Infrared Analysis
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• v.1 no.2
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• pp.35-39
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• 2000

The purpose of this research was to find out suitable soil sample preparation and sample holding tools for NIR reflection radiation for estimating soil components. NIR reflectance was scanned at 2nm intervals from 1,100 to 2,500nm with an InfraAlyzer 500(Bran+Luebbe Co.). Coarse(2.0mm) and fine(0.5mm) soil sample and various sample holding tools were used to obtain mean diffuse reflection of the soil for the calibration and validation of the calibration set in estimating moisture, organic matter and total nitrogen of the soils. Multiple linear regression was used to obtain the best correlation of NIR spectroscopy method. Correlation of NIR spectroscopy method. Correlation of NIR spectra for finely and coarsely sized soil did not show much difference. The standard errors of prediction(SE) using different types of sample holding tools for organic matter, total nitrogen and soil moisture were better than 0.765, 0.041 and 0.63% respectively. From the results it can be concluded that NIR spectroscopy with flow type cell could be used as a fast routine testing method in quantitative determination of organic matter, total nitrogen and soil moisture.

• Steel and Composite Structures
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• v.22 no.3
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• pp.567-587
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• 2016

The present investigation is to study the plane wave propagation and reflection of plane waves in a homogeneous transversely isotropic magnetothermoelastic medium with two temperature and rotation in the context of GN Type-II and Type-III (1993) theory of thermoelasticity. It is found that, for two dimensional assumed model, there exist three types of coupled longitudinal waves, namely quasi-longitudinal wave (QL), quasi-transverse wave (QTS) and quasi-thermal waves (QT). The different characteristics of waves like phase velocity, attenuation coefficients, specific loss and penetration depth are computed numerically and depicted graphically. The phenomenon of reflection coefficients due to quasi-waves at a plane stress free with thermally insulated boundary is investigated. The ratios of the linear algebraic equations. These amplitude ratios are used further to calculate the shares of different scattered waves in the energy of incident wave. The modulus of the amplitude and energy ratios with the angle of incidence are computed for a particular numerical model. The conservation of energy at the free surface is verified. The effect of energy dissipation and two temperatures on the energy ratios are depicted graphically and discussed. Some special cases of interest are also discussed.

• Journal of Information Display
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• v.2 no.4
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• pp.19-22
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• 2001

In this paper, we describe the electro-optic effects of photonic crystals made of a synthetic opal filled with a nematic liquid crystal(LC). By applying an external electric field, a shift in the Bragg reflection peak position(stop band) and a field-induced change in its peak reflectivity are observed. These significant surface alignment effects of the opal-LC composite are discussed in a similar manner for Freederick-type transitions of LC within a confined geometry in the presence of external fields.

• Journal of The Korean Association of Information Education
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• v.19 no.3
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• pp.261-270
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• 2015

In this paper, a strategy of cooperation activities was conducted to analyze on the impact of what effect appears in teacher training. We classified with satisfaction, effectiveness and academic achievement as effects of teacher training. We were divided into three groups that are cooperative-reflection activity group using the SNS, self-reflection activity group and general training group. Depending on the type of reflection activity, we have one-way ANOVA analysis for the effectiveness of teacher training. By the results of the analysis, we found to have a positive impact that cooperative reflection activity group were more an academic achievement, satisfaction and effectiveness of training. Accordingly, we have found the SNS-based collaborative reflection activity is very effective in teacher training.

• Korean Journal of Optics and Photonics
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• v.17 no.4
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• pp.335-341
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• 2006

A modified Michelson interferometer type digital holography microscopy system is developed. There is a problem about recording and numerical reconstruction area at the microscopy application of Michelson type interferometer structure in the digital holography field. In this paper, to overcome this problem, we developed a new reflection type digital holography microscope system and increased recording and numerical reconstruction area of target object.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.3
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• pp.308-315
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• 2002

In this paper, the 5-bit digital phase shiftier with 10 InGaAs HEMTs is designed and fabricated for U.S. mobile DBS receiving active phased array antenna system in 12 GHz band. 11.25 $^{\circ}$, 22.5$^{\circ}$ and 45$^{\circ}$ phase bits are designed in leaded-line type. 90$^{\circ}$ and 180$^{\circ}$ phase bits are designed in reflection type combined with ring hybrid. The return loss more than 17.5 ㏈, insertion louts less than 7.8 ㏈, and maximum phase error of $\pm$6$^{\circ}$for 32 phase responses are measured in 12.2 GHz~ 12.7 GHz band.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.306-311
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• 2019

This paper presents the temperature dependence of transmission-type and reflection-type PPG measurement devices that have been developed in the previous research. PPG signal can be distorted by external temperature such as skin temperature so that many of research was focused on the skin temperature effect. However, this paper focuses on the temperature of the device itself and we studied on the effect of device internal temperature. Experimental results showed that the temperature was increased like an irrational function graph and the transmission-type was not affected by the internal temperature but the reflection-type was affected by the internal temperature.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.7
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• pp.564-572
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• 2002

This article describes the ultrasonic range sensor for the recognition of the Indoor environment, especially utilizing the multiple reflection properties of the sonar usually ignored as disturbances or noises. In this paper, we endow the ultrasonic range sensor with the active motion using the stepping servomechanism in order to get the multiple reflections with environment objects. Environment features such as target type, distance and azimuth based on the scanned one frame data of that multiple reflection patterns are recognized simultaneously.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.2141-2145
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• 2008

Three kind of system composed with buoyant flap hinged at the sea floor are modeled experimentally. The mechanically coupled system provides shelter by reflecting incident waves and by attenuating wave energy through structural and viscous damping. The characteristics of wave reflection, transmission and dynamic angle of the flap oscillation for various conditions were investigated. The structure can minimize wave transmission by attaching offshore wing wall.