• The Journal of the Acoustical Society of Korea
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• v.22 no.8
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• pp.680-686
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• 2003

Digital waveguide model is a general method that is used in physical modeling of musical instruments. Wave motion is analyzed by time or by space in digital waveguide model. Because sampling is made via time, it is general that musical instrument model is described by wave motion of time. In this paper, we synthesized the musical instrument sound by adding instrument body model to the spatial based string model. In this way, we could improve sound quality and process musical instrument model's tone control variables effectively. We explained about delay error that happens in string and body in space based sampling and showed method to process fractional delay using FD (Fractional Delay)filter. Finally, we explained the relation between tone quality and number of delays. And we also compared the result with time base digital waveguide model.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1234-1242
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• 2010

In this study, the effect of noise and vibration, and influence of ground improvement are evaluated and its application is analyzed through the example of SCP designed at ground improvement in Song-Do international city. consequently, it showes even comfortable result that it is about 5.0m of inner space, when the LVSCP method is applied, rather than that it is about 30m of inner space when the existing SCP is applied in vibration control standards 2.0mm/sec. In the noise, now that the many differences according to environmental factors like other equipment noise, limited space and so on at the time of the construction by LVSCP method are coming out, so we think that appro itate measures are needed according to surroundings. By the way, when it comes to the estimation of the ground improvement work before and after an improvement of LVSCP method, its result shows that it is satisfacttion to all the standards of compaction control in dregded and reclaimed ground and sedimentary clay layer.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.442-444
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• 2007

How to observe the atmosphere is a subject of atmospheric research. The meteorological satellites and the ground states are used to do observation. However, both ways do not satisfy the requirement of scientists, especially the profiles of atmosphere on the ocean and the data for global atmosphere. Radio occultation (RO) technique, which has been used in planet science, is a method to solve the problem. In RO technique, the low Earth orbit (LEO) satellite receives the two frequency signal of Global Positioning System (GPS) satellite. The excess phase of the signal is calculated to retrieve the profiles of atmosphere parameters. In moist troposphere, the fluctuations appear in the phase of the signal and open loop (OL) is used to resolve it. The quality of the GPS signal generally deteriorates as the altitude decreases. In the procedure, the SNR of the GPS signal is used as the criterion. However, the SNR decreases with fluctuation which makes it difficult to locate the data of poor quality. In this paper, the phase of the signal will be used as part of the criterion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.478-489
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• 2016

Recently, there has been increasing interest in the remodecycling options of idle spaces around the central city through the urban regeneration. Various studies to create new added value through this way are ongoing. This study aims to analyze the impact relationship and structure on the regeneration of idle space by types affecting the quality of residents' life and local economy revitalization. The hypothesis was verified by a suitability test for setting the hypothesis and statistical significance test from the PLS 3.0 package. The results of this study drew 6 hypotheses from a total of 11 on the 'idle space regeneration of economy based type of PLS-SEM' and 4 hypotheses from a total of 11 on the 'idle space regeneration of neighborhood regeneration type PLS-SEM'. The results can be summarized into several parts. First, if cultural aspects should be considered, the regeneration of idle space (economy-based type and neighborhood-regeneration type) could meet 2 parts, such as the quality of residents' life and local economy revitalization at the same time. Second, improving the 'physical aspects' only affects the 'idle space regeneration of the economy-based type of PLS-SEM'. Third, improving the 'social aspects' only affects the 'idle space regeneration of neighborhood regeneration type of PLS-SEM'. This study has significance in that it provides the empirical analysis for the regeneration of idle space and there are differences according to types of PLS structural model.

• Journal of the Korean Institute of Educational Facilities
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• v.26 no.4
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• pp.3-10
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• 2019

In school facilities, space is the basic framework. The structure and arrangement of space will provide the form and feel of school facilities. In order to become a high-quality school facility, it is necessary to focus on the educational, human and ecological aspects of the instructor and learner until the space is conceived, designed and completed. However, even when public education was introduced in the past, it did not become a school space considering this aspect. The school space, which focuses on efficiency and labor production, is a school space that reflects the characteristics of a factory-type school, which has been occupied by a large number until recently. Although efforts to improve the quality of school facilities have been attempted in recent years, there is also a need to pursue more active changes. Future-oriented and progressive school spaces include flexibility, connectivity, individualization, diversity(creativity). In other words, space should be flexible so that it can be used faithfully according to the educational situation, not the fixed and limited school space as in the past. In the future, the school space should be open and securely linked to the place where it is essential to complete community relations with the community. In addition, space should be flexible so that the school can meet the needs of each student as much as possible. And the school space should be transformed from the space design of the past fixed pattern to reflect the close relationship between spatial, psychological, physiological, and behavioral areas. When school space needs to shift away from the past and change in a new future-oriented direction, the remaining tasks should be presented with specific characteristics and content of the direction. And the function of the consignment should be handled by related research. Although the text of this study reveals the characteristics of future-oriented school space, more concrete and empirical research results should be presented by subsequent research at home and abroad. It is necessary to reduce trial and error in creating a future-oriented school space where both professors and learners can be satisfied by analyzing the common points and differences between the results of the study. In order to do this, it is necessary to make efforts to approach such research based on the participation of the subjects who teach and learn directly at the school site.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.2
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• pp.188-194
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• 2010

In this paper, the typical Synthetic Aperture Radar (SAR) image quality parameters and analysis method are defined, and the SAR image analysis tool is presented for SAR image evaluation. The structure of the developed SAR image analysis tool consists of four key modules; point target analysis (PTA) module, distributed target analysis (DTA) module, ambiguity analysis (AMA) module, and NESZ analysis (NESZA) module. The developed tool is able to extract the various SAR system parameters from standard SAR product format files. Based on these extracted system parameters, typical SAR image quality parameters are derived from SAR image data.

• 한국터널공학회:학술대회논문집
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• 2005.04a
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• pp.131-141
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• 2005

Korea shotcrete technology has been developed by constructing underground space, roads and rails for expanding Social Overhead Capital. To late, importance of shotcrete is raised due to the efforts for semi-permanent use of underground structure and a long term safety. Shotcrete testing method and quality criterion have been developed continusously in abroad, but there are no standard and quality criterion of shotcrete in Korea. International quality criterion has been used to domestic conditions, so various problems are occurred in construction field, material, mixture, equipment, and so on. In this study, to establish standard of domestic shotcrete, both criteria and quality of shotcrete were investigated and opinion poll was performed in the construction field. Indoor and field test were performed to investigate appliance possibility of high-performance shotcrete.

• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.44-51
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• 2006

This study was conducted to investigate air quality in the underground parking lot of department store. Sampling sites were selected to the three sites in one department store. Measuring instrument started from November 3rd, 2005 to November 9, 2005. Target air quality parameters include a number of criteria pollutants such as NOx, $O_3$. The purpose of this study was to find out the present condition of indoor air quality in underground parking space of department store. Through the field measurement, the current situation and the behavior of contaminants were investigated and then was compared with the advice standards. The result of this study was as follows; The Average density of NOx gas and $O_3$ gas was maintained below the indoor air advice standards. The Average density of NOx gas and $O_3$ gas was highly measured during the weekend than during the week day. Average density of NOx gas and $O_3$ gas was highly measured at daytime than that of afternoon. Average density of NOx gas was highly measured in the center area than the other area. Average density of $O_3$ gas was highly measured at the entrance than the other area. NOx gas concentration was maintained below 0.3ppm, an average for 1 hours, as defined in the parking space law. $O_3$ gas concentration was maintained below 0.08ppm, an average for 1 hours, as defined in the parking space law.

• Journal of KIISE
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• v.42 no.10
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• pp.1294-1302
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• 2015

A lot of image quality assessment metrics that can precisely reflect the human visual system (HVS) have previously been researched. The Structural SIMilarity (SSIM) index is a remarkable HVS-aware metric that utilizes structural information, since the HVS is sensitive to the overall structure of an image. However, SSIM fails to deal with color difference in terms of the HVS. In order to solve this problem, the Structural and Hue SIMilarity (SHSIM) index has been selected with the Hue, Saturation, Intensity (HSI) model as a color space, but it cannot reflect the HVS-aware color difference between two color images. In this paper, we propose a new image quality assessment method for a color image by using a CIE Lab color space. In addition, by using a support vector machine (SVM) classifier, we also propose an optimization system for applying optimal metric according to the types of distortion. To evaluate the proposed index, a LIVE database, which is the most well-known in the area of image quality assessment, is employed and four criteria are used. Experimental results show that the proposed index is more consistent with the other methods.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.4
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• pp.417-430
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• 2014

A new rock excavation method using an abrasive waterjet system is under development for efficiently creating tunnels and underground spaces in urban areas. In addition, an appropriate abrasive flow rate and abrasive flow quality are important for the new rock excavation (cutting) method using an abrasive waterjet system. This study evaluated the factors influencing the abrasive flow rate and abrasive flow quality, specifically the abrasive pipe height, length, tortuosity and inner diameter, through experimental tests. Based on the experimental test results, this study suggested optimal conditions for the abrasive flow rate and abrasive flow quality. The experimental results can be effectively utilized as baseline data for rock excavation methods using an abrasive waterjet system in various construction locations such as tunnels near urban surroundings, utility tunnels, and shafts.