• Proceeding of KASS Symposium
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• 2006.05a
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• pp.246-255
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• 2006

In these days the floor vibration is beginning to make its appearance of the environmental dispute in apartment building. Standard floor system are suggested for the settlement of this issue by government. The sound of floor impact sound is needed to secure comfortable quality in housing. Also, it is required an accurate analysis and a proper evaluation for floor vibration. Refine model is necessary for the floor system of housing to analyze accurately the floor vibration. But this refine model is not efficient because it is required so much running time for vibration analysis and it is difficult of modeling of standard floor slab. In this paper, new modeling methods of standard floor slab are proposed for the accurate rigidity evaluation. By using the new modeling method, the accurate vibration response can be obtained and can accurately evaluate the rigidity of standard floor system with resilient materials. Therefore the proposed modeling method is of practical use for vibration analysis of floor system of apartment building.

• Wind and Structures
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• v.15 no.1
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• pp.27-41
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• 2012

Wind loads on low-rise buildings in general and residential homes in particular can differ significantly depending upon the laboratory in which they were measured. The differences are due in large part to inadequate simulations of the low-frequency content of atmospheric velocity fluctuations in the laboratory and to the small scale of the models used for the measurements. The imperfect spatial coherence of the low frequency velocity fluctuations results in reductions of the overall wind effects with respect to the case of perfectly coherent flows. For large buildings those reductions are significant. However, for buildings with sufficiently small dimensions (e.g., residential homes) the reductions are relatively small. A technique is proposed for simulating the effect of low-frequency flow fluctuations on such buildings more effectively from the point of view of testing accuracy and repeatability than is currently the case. Experimental results are presented that validate the proposed technique. The technique eliminates a major cause of discrepancies among measurements conducted in different laboratories. In addition, the technique allows the use of considerably larger model scales than are possible in conventional testing. This makes it possible to model architectural details, and improves Reynolds number similarity. The technique is applicable to wind tunnels and large scale open jet facilities, and can help to standardize flow simulations for testing residential homes as well as significantly improving testing accuracy and repeatability. The work reported in this paper is a first step in developing the proposed technique. Additional tests are planned to further refine the technique and test the range of its applicability.

• Korean Journal of Optics and Photonics
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• v.16 no.1
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• pp.56-62
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• 2005

Because of the wide plane and the curved field of CRT rear projection high definition television, its MTF(modulation transfer function) can't be easily measured by the usual forward testing method. Then we propose a backward testing method for the MTF so that the object plane and the image analyzer of forward testing are located at positions opposite each other. We prefer to use the backward testing method because the forward testing method has poor accuracy caused by very small numerical aperture, low spatial resolutions, and long depth of focus. We found that the backward testing method was very easy to align and had high repeatability. We confirmed the confidence of results obtained by the backward testing method in comparison with designed results.

• Korean Journal of Optics and Photonics
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• v.11 no.1
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• pp.58-64
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• 2000

Assuming that the performance of holographic storage media is ideal, we estimate the area storage density of disk-type holographic memories, when the method of either angle multiplexing, or rotational multiplexing, or both are used. The area storage density is strongly dependent on the f numbers (ratio of focal length to diameter) of both the Fourier transform lens in the signal arm, denoted by $F/#_2$, and the angle range over which the reference beam is incident (or, the equivalent f number corresponding to the angle range denoted by $F/#_1$). The area storage density is largely independent of the pixel pitch of the spatial light modulator when the Fourier plane holograms are recorded, while it is sensitive to the pixel pitch when the image plane holograms are recorded. In general, to obtain high area storage density, the Fourier or at least near Fourier plane holograms rather than the image plane holograms should be recorded. In addition, when the thickness of the recording materials are less than approximately $500\mu\extrm{m}$, rotational multiplexing gives higher area storage densities than angle multiplexing does. To increase the storage density further, however, it is desirable to use both of the two multiplexing methods in combination.nation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.365-371
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• 2003

Digital high resolution cameras are widely available, and are increasingly use in digital close-range photogrammetry. And photogrammetry instruments are developing rapidly and the precision is improving continuously. The building of 3D terrains of high precision are possible and the calculation of the areas or the earthwork volumes have high precision due to the development of the techlique of the spatial information system using computer. Using the digital camera which has capacity of keeping numerical value by itself and easy carrying, we analyze the positioning error according to various change of photographing condition. Also we try to find a effective method of acquiring basis data for 3D monitoring of high-accuracy in pixel degree through digital close-range photogrammetry with bundle adjustment for local terrain model generation and 3D embodiment of tumulus. In the study is about to efficient analysis of digital information data fer conservation of cultural properties.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.293-301
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• 2004

This study analyzes the interrelationship with air pollution quality and land used patterns, and analyzes the history and optimal allocation of TMS using GIS. Seasonal air pollution map are maded of TMS data in study area, and land used patterns based on Land Cover Classification Map are reclassified as residential area, commercial area, industrial area, traffic concentrated area, and non-Polluted area. Pollution sources can be identified through analyzing the correlation of air pollution and land used patterns by GIS spatial overlaying technique. Hence, the result shows that it coincides with the characteristics of conventional air pollution. Air pollution quality measured by TMS shows similar to that of its near stations or the same land used patterns, through the history and allocation analysis of TMS. Therefore, it is need to consider these characteristics in setting TMS positions in the future.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.2
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• pp.143-155
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• 2000

With the increasing needs for the integrated use of topographic and cadastral data in order to build an efficient geo-spatial information system. it is urgently necessary to research into its solution. The intention of this study is to detect error types of data and to propose adjustment methods for solving the problems caused by integrating topographic and cadastral data. For this purpose a primary integrated data model is created to link attribute data(land management system) and graphic data within cadastral information in the first step. In next, a secondary integrated data model based on the improved method is formed to coincide the graphic data of cadastral map with that of topographic map. At the first, because a numerous error types md sources caused by separate management of graphic and attribute data are easily checked, it is possible to suggest an improved method to correct these errors using the primary integrated data model. In addition, the accuracy in position and area with coordinate transformation method based on multi-block adjustment is more efficient than rubber-sheeting method. As a result, the secondary integrated data model could be built by harmonizing cadastral map with topographic map using the improved solution.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.2
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• pp.199-209
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• 2000

Recently, GSIS is introduced in the various fields. Especially in hydrology, the useful of GSIS is emphasized to analyze parameters, which are necessary for the analysis of watershed. In this paper, to estimate the direct runoff volume, I used the SCS-CN method which was useful to calculate direct runoff volume in a watershed that was not observed. But because SCS-CN method must treat a great number of spatial data, if we use the GSIS, we can treat numbers of the data easily. GSIS databases is constructed by using the data which is related to soil type, landuse. And runoff curve number was estimated by means of these databases in the study area. Also, the area of covered each subbasin rainfall gauge station was estimated by thiessen polygon network technique. The direct runoff volume was calculated by these subbasin area to the rainfall gauge station. I knew, from this study, that using GSIS, I can calculate parameters needed in direct runoff volume analysis, fast, exactly.

• Journal of electromagnetic engineering and science
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• v.16 no.2
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• pp.87-99
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• 2016

This paper describes an implementation method and the results of numerical mobile phone models representing real phone models that have been released on the Korean market since 2002. The aim is to estimate the electromagnetic absorption in the human brain for case-control studies to investigate health risks related to mobile phone use. Specific absorption rate (SAR) compliance test reports about commercial phone models were collected and classified in terms of elements such as the external body shape, the antenna, and the frequency band. The design criteria of a numerical phone model representing each type of phone group are as follows. The outer dimensions of the phone body are equal to the average dimensions of all commercial models with the same shape. The distance and direction of the maximum SAR from the earpiece and the area above -3 dB of the maximum SAR are fitted to achieve the average obtained by measuring the SAR distributions of the corresponding commercial models in a flat phantom. Spatial peak 1-g SAR values in the cheek and tilt positions against the specific anthropomorphic mannequin phantom agree with average data on all of the same type of commercial models. Second criterion was applied to only a few types of models because not many commercial models were available. The results show that, with the exception of one model, the implemented numerical phone models meet criteria within 30%.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.22-31
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• 2001

The purpose of this study is to compare calculated pollutant loadings using pollutant load unit factors and vector type coverage, and expected mean concentration(EMC) and raster type of digital elevation model(DEM). This study is also focusing on comparison of the advantages and the disadvantages of the two methods, and seeking for a method of calculation of pollutant loadings using DEM. Estimation of pollutant inputs using pollutant load unit factors has limitations in identifying seasonal variations of pollutant loadings. Seasonal changes of runoffs should be considered in the calculation of pollutant loadings from catchments into reservoirs. Evaluation of pollutant inputs using runoff-coefficient and EMC can overcome these drawbacks. Proper EMC and runoff-coefficient values for the Koeup stream catchments of the Koheung estuarine lake were drawn from review of related papers. Arc/Info was employed to establish database of spatial and attribute data of point and non-point pollutant sources and characteristics of the catchments. ArcView was used to calculate point and non-point pollutant loadings. Pollutant loads estimated with either unit factors-coverages, i.e., pollutant load unit factors and vector coverages f point sources and land use, or EMC and digital elevation mode(DEM) were compared with stream monitoring loads. We have found that some differences were shown between monitoring results and estimated loads by Unit Factors-Coverage and EMC-DEM. Monthly variations of pollutant loads evaluated with EMC-DEM were similar to those with monitoring result. The method using EMC-DEM can calculate accumulated flows and pollutant loads and can be utilized to identify stream networks. A future research on correcting the difference between vector type stream using flow direction grid and digitalizing vector type should be conducted in order to obtain more exact calculation of pollutant loadings.