• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.26-40
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• 2021

This study aims to propose improvement plans and directions of existing policies to build a Barrier-Free city for the socially underprivileged. We conducted correlation analysis and T-test based on the results of a survey of the general public including the socially underprivileged to understand how their satisfaction with the use of facilities close to their daily lives, such as housing, sales·business facilities, affects their happiness. The results are as follows: First of all, the socially underprivileged experienced discomfort and barriers in urban life more than the privileged, and there was a negative(-) correlation between the degree of discomfort and barrier that the socially underprivileged experienced and happiness in urban life. Second, as a result of analyzing the difference in satisfaction with the life·welfare·leisure environment indicators, the satisfaction with the life environment showed a significant difference between the socially underprivileged and the privileged, and it was found that satisfaction in the life environment had the greatest effect on happiness to the socially underprivileged. We examined the current status and the spatial distribution of BF-certified facilities, one of the representative policies for the socially underprivileged to support their urban life without any obstacles, based on the above outcome, and most certified facilities were concentrated in welfare environment. In addition, we used ArcGIS to analyze that BF-certified facilities have been being supplied to people who really need them and saw that the spatial distribution of the socially underprivileged (elderly, children, and infant) and the distribution of BF certification facilities were somewhat consistent, but were intensively supplied to urban areas.

• Journal of Korea Water Resources Association
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• v.56 no.spc1
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• pp.1059-1069
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• 2023

Dam-break flow occurs when an elevated dam suddenly collapses, resulting in the catastrophic release of rapid and uncontrolled impounded water. This study compares laminar and turbulent closure models for simulating three-dimensional dam-break flows using OpenFOAM. The Reynolds-Averaged Navier-Stokes (RANS) model, specifically the k-ε model, is employed to capture turbulent dissipation. Two scenarios are evaluated based on a laboratory experiment and a modified multi-layered block obstacle scenario. Both models effectively represent dam-break flows, with the turbulent closure model reducing oscillations. However, excessive dissipation in turbulent models can underestimate water surface profiles. Improving numerical schemes and grid resolution enhances flow recreation, particularly near structures and during turbulence. Model stability is more significantly influenced by numerical schemes and grid refinement than the use of turbulence closure. The k-ε model's reliance on time-averaging processes poses challenges in representing dam-break profiles with pronounced discontinuities and unsteadiness. While simulating turbulence models requires extensive computational efforts, the performance improvement compared to laminar models is marginal. To achieve better representation, more advanced turbulence models like Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) are recommended, necessitating small spatial and time scales. This research provides insights into the applicability of different modeling approaches for simulating dam-break flows, emphasizing the importance of accurate representation near structures and during turbulence.

• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.324-333
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• 2013

The purpose of this study was to investigate the need of home modification for outpatient with stroke and spinal cord injury. The subjects of this study were 54 outpatients who have experience in rehabilitation therapy at hospitals in Seoul and Gyeonggi-do. A questionnaire was distributed and collected form January 2th to February 4th, 2012. Descriptive statistics and $x^2$-test were used to analyze data. There were statistically significant difference in stairs of access, in width of front door, in bathroom, space of room according diagnosis. There were statistically significant difference in light of sensor, tissue holder and socket cover in bathroom for the comparison of demands for home modification by living type. There were statistically significant difference in width and threshold of front door, tissue holder and towel bar, nonslip floor in bathroom, space and table, chair of kitchen, space and threshold of porch, light for the comparison of demands for home modification according score of MBI. Based on the results of the survey, needs of home modification is different according disability level, diagnosis, living type, ADL performance. The results of this study show a need for the further occupational therapy of home modification and supporting policies in home modification.

• Journal of Broadcast Engineering
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• v.19 no.3
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• pp.372-384
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• 2014

DTV field tests have been performed to measure field strength and to check reception ratio on indoor and outdoor sites. They use an antenna of 9m to measure DTV signal in case of outdoor measurement on the road. Modern skyscrapers require the analysis of vertical-directional wave propagation by measuring vertical-directional DTV signal. Even if the field strength is above the reception threshold of $43dB{\mu}V/m$, the reception is impossible in case of strong multi-path or high impulse noise. So, vertical-directional field measurement is essential in environment of tall buildings. In this paper, we developed an octo type multi-copter to measure vertical-directional DTV signal level. A compact and portable DTV signal level meter, an antenna, a microwave transmitter for data transmission, and a recording equipment are equipped in the multi-copter. Three different sites are selected to test the measurement system. Developed measurement system using the multi-copter is very useful in measuring vertical-directional DTV signal, especially in apartments, non-accessible area by vehicles, and forbidden areas.

• Culinary science and hospitality research
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• v.21 no.5
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• pp.109-118
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• 2015

The main purpose of this study is to get insight into the essential cognitive basis of local food purchase behavior based on Ajzen's (1991) theory of planned behavior. By asking open-ended questions using an online survey, participants' (n=163) salient behavioral, normative, and control beliefs in regard to local food purchase were assessed and analyzed. The most salient advantage was supporting local economy, followed by freshness, knowledge of where the food came from and how it was handled, environmental benefits, and health benefits. Assessing to consumers' normative beliefs found that local businesses, local farmers, family, local people, and friends were the most frequently mentioned individuals or groups who would approve consumers' local food purchasing. In contrast, the most salient barrier was inconvenient store location and time, followed by higher prices, limited availability and variety, and limited knowledge about where to buy local food.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.1
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• pp.41-47
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• 2012

In this paper, we proposed a new method which analyzes and eliminates errors occurring by multi-reflection of ultrasonic firing in mobile robot application. This new method allows ultrasonic sensors to fire at rates that are three times faster than those customary in conventional applications readings due to ultrasonic noise disturbance. It is possible them to collect and predict sensor data much faster than conventional methods. Furthermore, this method's capability allows mobile robot to navigate in a complex and unknown environment and to collaborate in the same environment with multiple mobile robot, even if their ultrasonic sensors operate. And it's usefulness to avoid moving obstacles by capability of rapid collecting data. Finally, we present experimental results that demonstrate the performances of the new proposed method by experiments in a multi-reflective environment.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.45-51
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• 2003

The ship's signal sound dispersed by air, obstacles, and noises due to absorption, reflection, and disturbances, respectively. It is one of the factors of marine casualties by misjudgment if receiving direction The last target of this study is to prevent inherent marine casualty using the analysis-evaluation techniques if the interferences of ship's signal sound. In this work, three-dimensional sound field control model is proposed to simulate various sound transmitting characteristics according to sea environments at sea The efficiency test of the model was carried out using VR-based ship simulator.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.6
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• pp.1511-1519
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• 2010

In this paper, we proposed and analyzed a RSSI based cooperative localization algorithm considering wireless propagation characteristics in indoor and outdoor environments for wireless sensor networks, which can estimate the BN position. The conventional RSSI based estimation scheme has low precision ranging due to instability propagation characteristics by time variable. Hence, we implemented ray-launching simulator for analysis of propagation characteristics in 4 case, and experimented proposed localization scheme with 4 RN and 1 to 5 BN. Simulation results show that NLCA has estimation error as 2m-3.5m, however, proposed CLA/ECLA has 1.3m-2.5m/0.5m-1.2m by same environments. Therefore, if we can consider channel characteristics, the proposed algorithm provides higher localization accuracy than RSSI based conventional one.

• The Journal of the Korea Contents Association
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• v.4 no.2
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• pp.21-27
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• 2004

In an urban area telecommunication using wireless system, the accurate prediction and analysis of wave propagation characteristics are very important to determine the service area optimized selection of base station, and eel design, etc. In the stage of these analyses, we have to present the propagation prediction mood which is varied with the type of antenna, directional angle, and configuration of the ground in our urban area in addition we need to perform an analysis of the conventional mode which is similar to ours and dig out the parameters to evaluate the wave environment before the cell design for the selected area. In this paper, we propose a wave propagation prediction model concerning the topography and obstacles in our urban area. We extract the parameters and apply them to the proposed wave environment for the simulation analyzing the propagation characteristics. Throughout these analyzing procedure, we extracted the essential parameters such as the position of the base station, the height of topography, and adequate type and height of the antenna with our preferable cuteness.

• Journal of IKEEE
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• v.24 no.1
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• pp.147-153
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• 2020

Conventional lane detection algorithms have problems in that the detection rate is lowered in road environments having a large change in curvature and illumination. The probabilistic Hough transform method has low lane detection rate since it exploits edges and restrictive angles. On the other hand, the method using a sliding window can detect a curved lane as the lane is detected by dividing the image into windows. However, the detection rate of this method is affected by road slopes because it uses affine transformation. In order to detect lanes robustly and avoid obstacles, we propose driving assist system using semantic segmentation based on deep learning. The architecture for segmentation is SegNet based on VGG-16. The semantic image segmentation feature can be used to calculate safety space and predict collisions so that we control a vehicle using adaptive-MPC to avoid objects and keep lanes. Simulation results with CARLA show that the proposed algorithm detects lanes robustly and avoids unknown obstacles in front of vehicle.