• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.526-538
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• 2007

Since air quality monitoring data sets are important base for developing of air quality management strategies including policy making and policy performance assessment, the environmental protection authorities need to organize and operate monitoring network properly. Air quality monitoring network of Busan, consisting of 18 stations, was allocated under unscientific and irrational principles. Thus the current state of air quality monitoring networks was reassessed the effect and appropriateness of monitoring objectives such as population protection and sources surveillance. In the process of the reassessment, a GIS-based decision support system was constructed and used to simulate air quality over complex terrain and to conduct optimization analysis for air quality monitoring network with multi-objective. The maximization of protection capability for population appears to be the most effective and principal objective among various objectives. The relocation of current monitoring stations through optimization analysis of multi-objective appears to be better than the network building for maximization of population protection capability. The decision support system developed in this study on the basis of GIS-based database appear to be useful for the environmental protection authorities to plan and manage air quality monitoring network over complex terrain.

• Journal of the Korean Solar Energy Society
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• v.23 no.4
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• pp.21-27
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• 2003

The comparative performance of the WAsP in calculating the wind climate in complex terrain has been examined in order to test the predictability of the wind resource assessment computer code in our country. An analysis was carried out of predicted and experimental 10-min averaged wind data collected over 8 months at four monitoring sites in SongDang province, Jeju island, composed of sea, inland flat terrain, a high and a low slope craters. The comparisons show that the WAsP preditions give better agreement with experimental data by adjusting the roughness descriptions, the obstacle list.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.385-388
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• 2004

Many environmental destruction factors are accompanied in the mining development work and the secondary environmental disaster and the induction factors are inhered. We aquired digital data using aerial photogrammetry to analyze the terrain current situation according to the development situation of the mining restoration plan. We made the object area to 3D model and conducted terrian change monitoring. Then, we presented the decision-making information to improve rational management according to the original state plan.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2581-2594
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• 2018

The microcell terrain is the most common wireless network terrain in our life. In order to solve wireless network optimization of weak coverage in the microcell terrain, improve call quality and reduce the cost of the premise, power amplifiers in base stations should be adjusted according to user volume. In this paper, characteristics of microcell topography are obtained after analysis. According to the topography characteristics of different microcells, changes in the number of users at different times have been estimated, meanwhile, the number of scatter users are also obtained by monitoring the PCCPCH RSCP and other parameters. Then B-Spline interpolation method has been applied to scatter users to obtain the continuous relationship between the number of users and time. On this basis, power amplification can be chosen according to changes in the number of users. The methods adopted by this paper are also applied in the engineering practice, sampling and interpolation are used to obtain the number of users at all times, so that the power amplification can be adjusted by the number of users in a microcell. Such a method is able to optimize wireless network and achieve a goal of expanding the area of base stations, reduce call drop rate and increase capacity.

• Wind and Structures
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• v.18 no.5
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• pp.549-566
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• 2014

In spite of progress in the numerical simulation of typhoon wind field in atmospheric boundary layer (ABL), using typhoon wind field model in conjunction with Monte Carlo simulation method can only accurately evaluate typhoon wind field over a general terrain. This method is not enough for a reliable evaluation of typhoon wind field over the actual complex terrain with surface roughness and topography variations. To predict typhoon wind field over the actual complex terrain in ABL, a hybrid numerical simulation method combined typhoon simulation used the typhoon wind field model proposed by Meng et al. (1995) and CFD simulation in which the Reynolds averaged Navier-Stokes (RANS) equations and k-${\varepsilon}$ turbulence model are used. Typhoon wind filed during typhoon Dujuan and Imbudo are simulated using the hybrid numerical simulation method, and compared with the results predicted by the typhoon wind field model and the wind field measurement data collected by Fugro Geotechnical Services (FGS) in Hong Kong at the bridge site from the field monitoring system of wind turbulence parameters (FMS-WTP) to validate the feasibility and accuracy of the hybrid numerical simulation method. The comparison demonstrates that the hybrid numerical simulation method gives more accurate prediction to typhoon wind speed and direction, because the effect of topography is taken into account in the hybrid numerical simulation method.

• Journal of IKEEE
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• v.25 no.3
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• pp.437-444
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• 2021

In this paper, we propose an autonomous driving algorithm that allows a robot to explore various terrains, and implement an application that can monitor the robot's movement path during terrain search. The implemented application consists of a status unit that indicates the position, direction, speed, and motion of the mobile robot, a map unit that displays terrain information obtained through terrain search, and a control unit that controls the movement of the mobile robot. In order to control the movement of the robot, only the start and stop of the search/return is commanded by the application, and all driving for the search is performed autonomously. The basic algorithm for terrain search uses an infrared sensor to check for obstacles in the order of left, front, right, and rear, and if there is no obstacle and the path traveled is a dead end, it returns to the previous position and moves in the other direction to continue the search. Repeat the process to explore the terrain.

• Journal of Information Processing Systems
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• v.16 no.3
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• pp.733-741
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• 2020

A smart dust monitoring system is useful for obtaining information on rough terrain that is difficult for humans to access. One of ways to deploy sensors to gather information in smart dust environment is to use an aircraft in the Amazon rainforest to scatter an enormous amount of small and cheap sensors (or smart dust devices), or to use an unmanned spacecraft to throw the sensors on the moon's surface. However, scattering an enormous amount of smart dust devices creates the difficulty of managing such devices as they can be scattered into inaccessible areas, and also causes problems such as bottlenecks, device failure, and high/low density of devices. Of the various problems that may occur in the smart dust environment, this paper is focused on solving the bottleneck problem. To address this, we propose and construct a three-layered hierarchical smart dust monitoring system that includes relay dust devices (RDDs). An RDD is a smart dust device with relatively higher computing/communicating power than a normal smart dust device. RDDs play a crucial role in reducing traffic load for the system. To validate the proposed system, we use climate data obtained from authorized portals to compare the system with other systems (i.e., non-hierarchical system and simple hierarchical system). Through this comparison, we determined that the transmission processing time is reduced by 49%-50% compared to other systems, and the maximum number of connectable devices can be increased by 16-32 times without compromising the system's operations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2D
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• pp.191-198
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• 2010

The displacement of slope is a key factor in predicting the risk of a landslide. Therefore, the slope displacement should be continuously observed with high accuracy. Recently, high-tech equipment such as optical fiber sensor, GPS, total station and measuring instrument have been used. However, such equipment is poorly used in fields due to economics, environment, convenience and management. Because of this, development of substantial observational techniques for varied slope observation and field applications is needed. This study analyzed the possibility of terrestrial LiDAR for slope monitoring and suggested it as information-obtaining technique for slope investigation and management. For that, this study evaluated the monitoring accuracy of terrestrial LiDAR and performed GRID analysis to read the displacement area with the naked eye. In addition, it suggested a methodology for slope monitoring.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.678-682
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• 2006

In order to analyze movement of soil moisture, Time Domain Reflectometry(TDR) with multiplex system has been installed at the Bumreunsa hillslope of Sulmachun Watershed to configure spatial-temporal variation pattern considering seasonal characteristic. An intensive surveying was performed to build a refined digital elevation model(DEM) and flow determination algorithms with inverse surveying have been applied to establish an efficient soil moisture monitoring system. Soil moisture data were collected through an intensive and long term monitoring 380 hrs in November of 2003 and 1037 hrs in May and June of 2004. Soil moisture data shows corresponding variation characteristics of soil moisture on the up slope, buffer, main channel zones of the hillslope which were classified from terrain analysis. Inferences and limitations of measured soil moisture data were discussed in conjunction with flow characteristic through terrain analysis.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.319-327
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• 2022

Robots for construction sites, although not deeply widespread, are finding applications in the duties of project monitoring, material movement, documentation, security, and simple repetitive construction-related tasks. A significant shortcoming in the use of robots is the complexity involved in programming and re-programming an automation routine. Robotic programming is not an expected skill set of the traditional construction industry professional. Therefore, this research seeks to deliver a low-cost approach toward re-programming that does not involve a programmer's skill set. The researchers in this study examined an approach toward programming a terrestrial-based drone so that it follows a taped path. By doing so, if an alternative path is required, programmers would not be needed to re-program any part of the automated routine. Changing the path of the drone simply requires removing the tape and placing a different path - ideally simplifying the process and quickly allowing practitioners to implement a new automated routine. Python programming scripts were used with a DJI Robomaster EP Core drone, and a terrain navigation assessment was conducted. The study examined the pass/fail rates for a series of trial run over different terrains. The analysis of this data along with video recording for each trial run allowed the researchers to conclude that the accuracy of the tape follow technique was predictable on each of the terrain surfaces. The accuracy and predictability inform a non-coding construction practitioner of the optimal placement of the taped path. This paper further presents limitations and suggestions for some possible extended research options for this study.