• Journal of electromagnetic engineering and science
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• v.12 no.1
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• pp.45-54
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• 2012

When the cylindrical wave is incident on a plane dielectric interface from a denser medium to a rarer one, the asymptotic solution for the transmitted wave in the near region is different from the one in the far region. In this paper, we have derived a novel uniform asymptotic solution represented by using the parabolic cylinder function for the transmitted and scattered waves observed in the rarer medium when the cylindrical wave is incident on the plane dielectric interface from the denser medium. The validity of the uniform asymptotic solution has been confirmed by comparing with the reference solution calculated numerically. It has been clarified that the transition wave plays an important role to connect smoothly the asymptotic solution in the near region to the one in the far region through the transition region. We have shown the very interesting phenomenon that the lateral wave type transmitted wave is observed in the far and shallow region.

• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.1-7
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• 2001

Mainly, Floating Breakwaters (FBs) have been constructed in many coastal regions due to the advantages of the coastal environment and construction cost. In general, the FB becomes fixed or its width broadened because the movement of the FB comes to be large and its the wave control function lower for the long period incident waves. This study discusses the wave control function of two-rowed Fixed Floating Breakwater (FFBs) that have narrower width than that of the one-rowed FFB by using numerical approach. Boundary Element Method (BEM) based on the Green formula and Eigenfunction Expansion Method (EEM) are applied to evaluate the three-dimensional wave transformation near the wave fields of two-rowed FFBs. The validity of the present study is confirmed by comparing it with the results of Ijima et al. (1974) and Yoshida et al. (1992) for the one-rowed Fixed Floating Structure. It is revealed that the wave control function of two-rowed FFBs is more effective than that of the one-rowed FFB.

• Restorative Dentistry and Endodontics
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• v.38 no.1
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• pp.21-25
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• 2013

Objectives: The aim of this study was to evaluate the shaping ability of newly marketed single-file instruments, Wave One (Dentsply-Maillefer) and Reciproc (VDW GmbH), in terms of maintaining the original root canal configuration and curvature, with or without a glide-path. Materials and Methods: According to the instruments used, the blocks were divided into 4 groups (n = 10): Group 1, no glide-path / Wave One; Group 2, no glide-path / Reciproc; Group 3, #15 K-file / Wave One; Group 4, #15 K-file / Reciproc. Pre- and post-instrumented images were scanned and the canal deviation was assessed. The cyclic fatigue stress was loaded to examine the cross-sectional shape of the fractured surface. The broken fragments were evaluated under the scanning electron microscope (SEM) for topographic features of the cross-section. Statistically analysis of the data was performed using one-way analysis of variance followed by Tukey's test (${\alpha}$ = 0.05). Results: The ability of instruments to remain centered in prepared canals at 1 and 2 mm levels was significantly lower in Group 1 (p < 0.05). The centering ratio at 3, 5, and 7 mm level were not significantly different. Conclusions: The Wave One file should be used following establishment of a glide-path larger than #15.

• Bulletin of the Society of Naval Architects of Korea
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• v.19 no.2
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• pp.33-39
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• 1982

It is one of the basic problems of naval architecture and ocean engineering how to describe the wave kinematics normally under the assumption of an ideal fluid. At present, there are many wave theories available for design purposes. These can be classified into two groups: One is the analytic theory and the other is the numerical theory. This paper briefly introduces the stream function method of R.G. Dean which belongs to the latter group and shows its numerical evaluations exemplified for two cases: One is applied to observed waves and the other is for design waves. In the former case, the wave profiles are calculated by the stream function method and compared with those of the observed waves and also with the results of R.G. Dean. They show good agreement. In the latter case, the wave kinematics and wave loads on a column of diameter 1m are calculated by the stream function method and these are compared with those resulted from the 5th-order gravity wave theory. As a result of comparison the values by the stream function method are slightly larger than those by the 5th-order gravity wave theory but the difference are negligible. From this it is concluded that the stream function method is very useful. And as characteristics of the numerical theories, the stream function method of R.G. Dean can be easily extended to the higher order terms and can include easily the current velocity and the pressure distribution on the free surface. In addition, when the data of observed wave profile are given, this method can reproduced the observed wave profile as closely as possible so that this method seems to describe the ocean wave more realistically. And from standpoint of a mathematical principle the stream function method exactly satisfies the kinematic free-surface boundary condition.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.565-572
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• 2004

Numerical stability analysis of one-dimensional axial flow in solid rocket motors is performed based on the Euler equation coupled with an unsteady combustion equation of solid propellant. In order to check the numerical scheme, behavior of a standing wave in a closed tube is examined. A standing wave in solid rocket motor decays or grows depending on the total effect of propellant combustion, nozzle flow, and so on. The stability boundary of the fundamental mode standing wave is determined by changing one of the combustion parameters. In addition growth rates of the wave are calculated numerically in relatively low Mach number flow region for the motors with different port and nozzle throat diameters. The results obtained here agree well with the approximate solution. The same scheme is applied to a motor with shorter length and L＊-instability is observed.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.103-109
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• 2003

Wave flumes are usually equipped with a wave generator at one end and a wave absorber at the other end. The absorbers could be broadly classified into two main categories： active and passive wave absorbers. A typical passive wave absorber to eliminate unwanted reflections is the beach of constant or varying slopes reaching the bottom. (omitted)

• Journal of Ocean Engineering and Technology
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• v.15 no.3
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• pp.107-113
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• 2001

This study is focused on the wave control by economical multi-rowed impermeable submerged breakwaters which need less materials than a one-rowed submerged breakwater. A boundary element method and eigenfunction expansion method based on the Green\`s theorem are appled to analyze the characteristics of wave transformation. Submerged breakwaters are consisted of one and two-row with rectangular section. Wave transformation characteristics are investigated by the various combinations of placement distance and crown water depth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.243-248
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• 2001

A radial artery pulse wave is well known as a good mans to diagnose human body condition in th field of Chinese medical science. Information about constitution as well as organs can be obtained by detecting the artery pulse wave. Recently, the information about the human body constitution may be utilized in accelerating the recovery process of the patient on the basis of comprehensive diagnosis. A radial artery pulse wave is considered as one of promising means in examining the human body constitution. Since the examination has been conducted by the feeling of finger, the diagnosis may occasionally have uncertainty or fatal error. In this paper, a new measuring system is suggested and developed to examine the pattern of a pulse wave correctly. The system is composed of four pressure vessels, pressure sensors and air supplying pumps. One of them is utilized for appropriately pressing the radial artery, three of them for detecting pressure change in several mmHg level. The detected data is shown and discussed.

• Bulletin of the Society of Naval Architects of Korea
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• v.18 no.1
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• pp.9-18
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• 1981

The wave-pattern analysis has been one of important research tools in the towing tank, and applied for hull form design. The longitudinal-cut method of Newman and Sharma is adopted in KRIS deep towing tank. Instrumentations and data acquisition systems are developed for that. Local effects and truncation effects are estimated by using calculated wave patterns of simple source distributions. Wigley model of 2m is used to check the accuracy of the whole system. Cut positions and truncation points are changed to investigate characteristics of the wave-pattern analysis. Coefficients of wave-pattern resistance are low-estimated in comparison with those of Maruo and Ikehata. The general quality of the system is very good, but some more efforts to increase the accuracy are required. Two full-form models(one basic form, the other with bulbous bow) are tested to show high application-possibilities of the wave-pattern analysis for the hull form design.

• Bulletin of the Society of Naval Architects of Korea
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• v.13 no.4
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• pp.11-18
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• 1976

In 1925 Havelock compared theoretical wave resistance with experimental one varying draft, in which the two ship's forms were different from each other. So, in this paper theoretical wave resistance was compared with the experimental one on the ship of the same form. And, though Havelock calculated theoretical wave resistance by mathematical artifice, in this paper it was calculated by computer using the method of numerical integration. In Havelock's paper, the increment of wave resistance decreased when the draft increased. but in this paper the conclusion is changed: the increment of wave resistance increases when the draft increases. The reason is supposed by the effect of the displacement of the ship.