• International Journal of Contents
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• v.15 no.4
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• pp.36-43
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• 2019

This is an integrative review paper of Augmented Reality (AR)/Virtual Reality (VR) simulation programs in the mental health area including the analysis of the general characteristics, contents, and the impact of the interventions studies. The keywords used to search the studies were "AR/VR" and "medical/nursing students". The author and a postdoctoral research fellow searched four electronic databases: Web of Science, PubMed, EmBase, and CINHA, and as a result nine studies met the inclusion criteria. Among the selected studies AR/VR simulation programs in the mental health area for healthcare professionals were found to be effective in clinical skills as well as for the interpersonal relationship and the stigma of mentally ill patients. Providing an opportunity to experience a safe and effective tool is important when educating health professionals and AR/VR simulation programs are safe and effective. Thus, standardized AR/VR simulation programs are needed to be developed for health professionals.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.4
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• pp.35-40
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• 1987

The experimental study, using constant pressure injection system, is carried out to investigate the effect of the geometrical shape changes of the needle valve of the effective flow area, the spray angle and the Sauter's Mean Diameter according to needle valve lift for a pintle-type injection nozzle. The results are as follows: 1) With the increase of the needle valve lift, the effective flow area is increased, the spray angle is at first increased and later decreased, and the Sauter's Mean Diameter is decreased. 2) It is also shown that the spray angle is maximum at the rapidly increased region of the effective flow area.

• Current Optics and Photonics
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• v.2 no.6
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• pp.525-531
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• 2018

The effect of eccentricity on dispersion and nonlinear properties of a photonic crystal fiber having elliptical air holes is investigated using a fully vectorial effective index method. It is found that the effective refractive index increases with increase of eccentricity. The dependence of dispersion and nonlinear properties of the PCF on the eccentricity of the air hole is investigated. It is revealed that eccentricity of the air hole affects the zero dispersion wavelength. Further, the nonlinear properties such as mode field area, nonlinear coefficient and self phase modulation of the Photonic crystal fibers are analyzed. The mode field area increases and the nonlinear coefficient decreases with increase in eccentricity. The variation of the self phase modulation with elliptical air hole is also discussed.

• IE interfaces
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• v.16 no.4
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• pp.507-514
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• 2003

In personal communication systems location management of mobile terminals is required to connect incoming calls to the mobile terminals. Investigation of effective location update and paging strategies is important to reduce the cost of location management. In this study, we propose a paging strategy considering the mobile terminals' residence patterns. The first paging area is characterized by the set of cells in the location area where mobile terminals usually stay for a significant period of time. The rest of cells in the location area are included into the second paging area. To reduce the paging cost the first paging area is decided by reflecting various residence patterns of mobile terminals. For an incoming call, the sequential paging is performed in the order of the paging area. Thus the paging cost is greatly reduced, especially when the called mobile terminal is located in the first paging area. The proposed strategy is expected to be more effective than an existing strategy that uses the anchor cell in the location area.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.425-432
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• 2003

In personal communication systems, location management of mobile terminals is required to connect incoming calls to the mobile terminals. Investigation of effective location update and paging strategies is important to reduce the cost of location management. In this study, we propose a paging strategy considering the mobile terminals' residence patterns. The first paging area is introduced, which is characterized by the set of cells in the location area where mobile terminals usually stay for a significant period of time. We propose the decision criterion of the first paging area by comparing the cost against zone-based strategy. For an incoming call. we perform the sequential paging by the order of the first paging area and the rest of cells in the location area called by the second paging area. Thus the paging cost is greatly reduced, especially when the called mobile terminal is located in the first paging area. The proposed strategy is expected to be more effective than existing strategy using anchor cell in the location area because it reflects various residence patterns of mobile terminals.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.3 s.357
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• pp.6-11
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• 2007

This paper proposes CMOS optical receivers to reduce effective area and pulse width distortion (PWD) in high definition digital audio interfaces. To mitigate effective area and PWD, proposed receivers include a frans-impedance amplifier (TIA) with dual output and a level shifter with threshold convergence, respectively. Proposed circuits are fabricated using $0.25{\mu}m$ CMOS process and measured result demonstrated the effective area of $270\times120{\mu}m^2$ and PWD of ${\pm}3%$ for the receiver with a dual output TIA, and the effective area of $410\times140{\mu}m^2$ and PWD of ${\pm}2%$ for the receiver with a threshold convergence level shifter.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.83-90
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• 1996

A diffusion process is often the main mechanism of soil gas/vapor movement in the vadose zone. The diffusion coefficients in the porous soil media are different from those in the free air phase by the reduction of available area for diffusion, tortuous diffusion path and variable cross section area along the diffusion path. To take account those effects of the diffusion process in the porous media, usually the terms of effective diffusion coefficient and tortuosity are have been used. However, as there are many differents definitions for the tortuosity, when the term of tortuosity is used, it is necessary to examine it throughly. Moreover, there are many different equations for the effective diffusion coefficient according to the investigators and the differences in the values of effective diffusion coefficients between the equations are not insignificant, the selection of the equation should be done with caution. In this paper, the different definitions of effective diffusion coefficient are examined and discussed. As well as definitions, the lots of availabe models for the diffusion coefficient in terms of porosities are compared. Also, the constrictiviy which explains the effect of cross sectional area change over the diffusion path was discussed.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1693-1706
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• 2008

It is of importance to determine the zero effective stress void ratio($e_{00}$), which is the void ratio at effective stress equal to zero, and the relationships of void ratio-effective stress and of void ratio-hydraulic conductivity for characterizing non-liner finite strain consolidation behavior for ultra-soft dredged materials. The zero effective stress void ratio means a transitional status from sedimentation to self-weight consolidation of very soft soil deposits, and acts as a starting point for self-weight consolidation in the non-linear finite strain numerical analysis such as PSDDF. In this paper, a new method for determining the zero effective stress void ratio has been introduced with the aid of measuring electrical resistivity of the specimen. A correlation between the zero effective stress void ratio and the initial slurry void ratio has been proposed, which can be used in PSDDF analysis as an input parameter. Combining all of the accessible experimental data, the consolidation characteristics of a dredged soil from the Incheon area has been studied in detail.

• Journal of the Korean Institute of Navigation
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• v.24 no.3
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• pp.157-165
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• 2000

When the GPS system was come to the operation, the U.S Coast Guard initiated development of differential GPS system based on a marine radiobeacon. It has rapidly been spread out to many countries. DGPS equals to P(Y) code in a positioning accuracy. USA has recently determined to expand the coverage of DGPS to inland in order to install a nationwide DGPS chain. Korea is under processing for improving the DGPS as a nationwide positioning system. Before expanding the service area inside Korea, we need to verify the relation between the field strength and DGPS accuracy for the service area. The Japanese DGPS data is received in the southern Part of the Korean peninsula. The Korean DGPS was not a complete system, so we selected the Japanese DGPS data as a model for the study. This paper investigate accuracy and reliability characteristics of RBN/DGPS over the effective service area. Through the experimental and simulation study, we obtained the reliable and stable positioning accuracy in the southern part of the Korean peninsula. In addition, the characteristics of RBN/DGPS were examined in the land over the effective coverage from Japan. The results would be a basic reference to research the RBN/NDGPS in Korea.

• Journal of Korean Society on Water Environment
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• v.30 no.2
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• pp.159-165
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• 2014

Vegetative Filter Strip (VFS) is one of effective Best Management Practices (BMPs) to prevent sediment-laden water problem, is installed at the edge of source area such agricultural area so that sediment occurred in source area is trapped by VFS before it flow into stream or river. Appropriate scale of it needs to be simulated before it is installed, considering various field conditions. In this study, a model using VFSMOD-w model and Genetic Algorithm to determine effective VFS length was developed, it is available to calibrate input parameter related to source area sediment yield through thousands of VFSMOD-w simulations. Useful DBs, moreover, are stored in the model so that very specific input parameters can be used with reasonable values. Compared simulated values to observed data values for calibration, R2 and Nash-Stucliffe model efficiency coefficient were 0.74 and 0.65 in flow comparison, and 0.89 and 0.79 in sediment comparison. The model determined 1.0 m of Filter Length, 0.18 of Filter Slope, and 0.2 cm of Filter Media Spacing to reduce 80% of sediment by VFS. The model has not only Auto-Calibration module also DBs for specific input parameters, thus, the model is expected to be used for effective VFS scale.