• KIEAE Journal
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• v.7 no.2
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• pp.31-37
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• 2007

Despite of many supportive research to the usefulness of slide evaluation on environment of outdoor lighting, study method of using slides have provoked many discussions of its manifestation of reality of field conditions. This study aims to compare the results of slide survey with that of field survey. Distant view and short range view of nightscape of Seoul were selected. Field measurement of luminance and chromaticity were conducted and questionnaire survey were conducted. Frequency analysis, T-test, factor analysis were conducted. Results shows that distant view and short range view of field survey have better visual atmosphere than slide survey. In addition, slide survey on distant view shows lowest values. Difference between field survey and slide survey on distant view is much bigger than the results of short range view.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.720-731
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• 2014

There are many kinds of optical systems to widen a field of view. Fisheye lenses with view angles of 180 degrees and omni-directional systems with the view angles of 360 degrees are recognized as proper systems to widen a field of view. In this study, we proposed a new optical system to overcome drawbacks of conventional omni-directional systems such as a limited field of view in the central area and difficulties in manufacturing. Thus we can eliminate the undesirable reflection components of the omni-directional system and solve the primary drawback of the conventional system. Finally, tolerance analysis using Zernike polynomial coefficients was performed to confirm the productivity of the new optical system. Furthermore, we established a method of optical axis alignment and compensation schemes for the proposed optical system as a result of tolerance analysis. In a sensitivity calculation, we investigated performance degradation due to manufacturing error using Code V(R) macro function. Consequently, we suggested compensation schemes using a lens group decentering. This paper gives a good guidance for the optical design and tolerance analysis including the compensation method in the extremely wide angle system.

• 한국전산유체공학회:학술대회논문집
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• 1998.05a
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• pp.99-109
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• 1998

This paper describes the analysis of flow and aeroacoustic field around a car-like body. The governing equations, 3-D unsteady incompressible Navier-Stokes equations, are solved with the iterative time marching scheme. The Chimera grid technique has been applied to efficiently simulate the flow around the side-view mirror, After the flow field analysis has been converged, the aerodynamic noise analysis of the side-view mirror has been performed by solving Ffowcs Williams and Hawkings equation. From the present numerical simulation, the A- and C-pillar vortex are evidently shown and the aerodynamic noise level induced by the side-view mirror is predicted to about 100dB.

• Journal of the Korean housing association
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• v.17 no.3
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• pp.99-109
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• 2006

The purpose of this study was to analyze the characteristic of each view in an apartment unit in terms of the quality. This study was accomplished by two research methods; the field survey on 181 apartment complexes in Daegu, and the preference evaluation on 24 cases sampled in the sense of its location, i.e. inside or outside of a complex. In the field survey, view targets were categorized into various items such as a building, a road, a mountain, a tree, another apartment, the sky, and so on, and the characteristics of the distance from a viewer to view targets and view of the level in an apartment were analyzed. In the preference evaluation, 24 cases, each one has one of the follows; the natural view, the artificial view, and the combined view of the both, were chosen and those were evaluated by 167 interviewees. As a result, the conclusions from the study were drawn as follows; 1) The view, the combination of buildings, roads, mountains, trees, apartments, and the sky, is usually seen in an apartment unit. 2) The type of view target is more significant to a person than its location. 3) The natural and combined view are preferred to the artificial one. 4) In the case of the same outside view, a person likes the open view more than the somewhat covered one.

• Science of Emotion and Sensibility
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• v.24 no.4
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• pp.17-28
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• 2021

The purpose of the research was to examine the effect of field of view on egocentric distance perception in the real and virtual environment. The replica that mimicked the real environment condition was used to create the virtual environment condition. We manipulated field of view levels equally in both viewing conditions using glasses that limit the field of view in real-world conditions and limiting the field of view in virtual-world conditions in a manner equivalent to real-world conditions via HMD. Eighteen participants observed the target with a limited field of view in a real and virtual environment without head movement. Then, we measured perceived distance using the timed imagined walking method, which measures the time taken by each participant to mentally walk to the target. The target was shown three times at three different distances from the participants: 3, 4, and 5 m. For the analysis, we converted time estimates into distance estimates. Consequently, the estimated distance in the virtual environment condition was less than the estimated distance in the real environment condition. And as the field of view shrank, the estimated distance also decreased. The estimated distance did not vary with field of view levels in real-world conditions. In the virtual environment, the estimated distance decreased as the field of view decreased, whereas in the real environment, the estimated distance increased. The implications of the results and some future research directions are discussed below.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1082-1087
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• 2006

This paper presents a gas turbine data acquisition and monitoring system using a LabVIEW programming. The developed real-time monitoring system entitled a C-Tune DAS Plays an important role to make an analysis of the real-time operation of the gas turbine under maintenance. the LabVIEW based software is divided into three parts according to their original functions; Data acquisition, Data analysis and display, and Data storage. The data acquisition part receives data from a PMS (Plant Management System) server and two cFPs (Compact-Field Point). To verify the validity of the developed system, it is applied to gas turbines in the combined cycle power plant in Korea.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.52-61
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• 2023

We designed a novel ultra-miniaturized microcolumn structure having an stigmator to significantly improve throughput per unit time, which is the biggest disadvantage of microcolumns. We adopted the structure of the stigmator in the form of an electrostatic octupole electrode, and used an electrostatic quadrupole deflector with a relatively simple structure considering the increase in wiring due to the introduction of the stigmator. We have dramatically reduced the effect of astigmatism that occurs when the electron beam probe is scanned to the periphery of the target by introducing the stigmator between the control electrode and the deflector. As our numerical analysis simulation results, the field of view obtained as a result of this study is about 46.3% improved compared to our previous study, and the electron beam probe size of less than 10 nm was achieved in the entire field of view.

• Progress in Superconductivity and Cryogenics
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• v.15 no.3
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• pp.13-19
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• 2013

Superconducting field coils using a high-temperature superconducting (HTS) wires with high current density generate high magnetic field of 2 to 5 [T] and electromagnetic force (Lorentz force) acting on the superconducting field coils also become a very strong from the point of view of a mechanical characteristics. Because mechanical stress caused by these powerful electromagnetic force is one of the factors which worsens the critical current performance and structural characteristics of HTS wire, the mechanical stress analysis should be performed when designing the superconducting field coils. In this paper, as part of structural design of superconducting field coils for 17 MW class superconducting ship propulsion motor, mechanical stress acting on the superconducting field coils was analyzed and structural safety was also determined by the coupling analysis system that is consists of commercial electromagnetic field analysis program and structural analysis program.

• Journal of Information Technology Applications and Management
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• v.13 no.3
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• pp.75-87
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• 2006

In this paper. we consider the multi-view video technology. The technology, which is a field of 3-Dimensional video processing, enables the user to watch the various view-point of video. We expect that the technology will be applicable to a lot of video services. The economic effects of new technology are very important concern for the technology developer and the technology development policy makers. We, therefore. propose a general method for the economic repercussion effects of the multi-view video technology. The method is based on the expert opinion and input-output analysis. The results for the multi-view video technology are included.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.281-284
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• 2005

This paper deals with the parametric analysis of electric and magnetic fields generated by lightning discharges. The measuring system consisted of the plate-type electric field and loop-type magnetic field sensor, the voltage follower, the active integrator and LabVIEW software. The parameters of the electric and magnetic field waveforms produced by intracloud lightning strokes were presented.