• Journal of Korean Society of Rural Planning
• /
• v.10 no.4 s.25
• /
• pp.19-28
• /
• 2004

In order to revitalize rural areas fundamentally through multifunctional utilization of their resources, it should be necessary to prepare the rational development plan to the areal characteristics and conditions, and the first priority of its planning works should be given to spatial planning. The space syntax method, a powerful objective and quantitative analysis tool on the relationship between social and spatial characteristics, was introduced in this study. Five Comprehensive Rural Clustered Villages Development Areas in the Jeonnam-province were selected as case study areas, of which total area's and included villages' spatial variables were measured and analyzed. Rural villages analyzed in this study have the spatial structure badly systematized and much complicated, which results from low integration and deep spatial depth of them. And, by virtue of relatively many axial lines, there should be few differences between villages in terms of local integration, connectivity and control, while being significant difference in terms of global integration showing the whole areal characteristics. Intelligibility, the correlation coefficient between connectivity(local variable) and integration(global one) is low, which means that the spatial structure of the study areas is difficult for visitors to understand the area or village well. Spatial configuration analysis results in the case study areas showed that each development area has a unique spatial structure and is differentiated in terms of not only local spatial variables but also global spatial variables. Therefore, global and local characteristics should be considered in spatial analysis of development areas.

• The Mathematical Education
• /
• v.52 no.4
• /
• pp.531-547
• /
• 2013

The purpose of the study is to examine how effects of activities using Google SketchUp on students' spatial ability and 3D geometric thinking in measuring the volume of solid figures. By comparing the results from pre- and post-tests between the experimental group and control group, we found that activities using Google SketchUp help students improve their spatial ability in the spatial orientation and visualization. In addition, more than half students in the experimental group moved from level 4 up to level 7 in thinking process of measuring the volume in terms of Battista(2004)'s levels. This study suggests that the instruction with Google SketchUp can help to improve students' spatial ability and 3D geometric thinking in the regular class in middle school. In addition, SketchUp can be an advanced technological tool to support students' self-directed learning, which create an efficient educational environment and a great opportunity to learn geometry in an effective manner.

• Advances in Computational Design
• /
• v.3 no.1
• /
• pp.35-47
• /
• 2018

Design of settlement space is a complicated process while reasonable spatial layout bears great significance on the development and resource allocation of a settlement. The study proposes a weighted L-system generation algorithm based on CA (Cellular Automation) model which tags the spatial attributes of cells through changes in their state during the evolution of CA and thus identifies the spatial growth mode of a settlement. The entrance area of the Caidian Botanical and Animal Garden is used a case study for the model. A design method is proposed which starts from the internal logics of spatial generation, explores possibility of spatial rules and realizes the quantitative analysis and dynamic control of the design process. Taking a top-down approach, the design method takes into account the site information, studies the spatial generation mechanism of settlements and further presents a engine for the generation of multiple layout proposals based on different rules. A optimal solution is acquired using GA (Genetic Algorithm) which generates a settlement spatial layout carrying site information and dynamically linked to the surround environment. The study aims to propose a design method to optimize the spatial layout of the complex settlement system based on parametric generation.

• Spatial Information Research
• /
• v.16 no.1
• /
• pp.113-127
• /
• 2008

This paper proposes an efficient spatial index, named $AR^*$-tree(Area $R^*$-tree) which is a variant of the $R^*$-tree, for mobile software. A MBR(Minimum Bounding Rectangle) structure of the $AR^*$-tree has additional min and max values of area axis as well as x and y axes. The value of area axis is used to determine the significance of a spatial data. If area of a spatial data is large, then it is significant when drawing a map. To reduce complexity of a map on a small screen of mobile device, only significant spatial data can be found by the $AR^*$-tree. The result of a series of tests indicates that the $AR^*$-tree provides a method for control of readability of a map and guarantees an efficient performance at the same time.

• Education of Primary School Mathematics
• /
• v.9 no.2 s.18
• /
• pp.119-134
• /
• 2005

The goals of this study is to analyze develop the materials which help students develop spatial sense in elementary school and to investigate its effects. To accomplish those goals, the 7th National Curriculum was analyzed to identify the contents of spatial sense. After analyzing the 7th National Curriculum, the principle for developing the teaching aids focusing the realization of the contents in the spatial sense was set up. And then various teaching materials which can enhance students' spatial sense was developed. It is consist of 17 kinds of concretely operating materials, 7 kinds of tangram papers, one web-material. To verify the effect of the materials, surveyed the usability of the materials and two classes was selected and tests were administered before and after the treatment. Through this application, several conclusion were drawn. First, a survey result says that teachers thought materials developed would be effective in developing spatial sense. Second, the materials developed were effective to develop spatial sense. The score gained by the experiment group after the treatment was statistically meaningfully higher than the control group. This means that the materials developed helped children to develop spatial sense.

• Journal of Korea Planning Association
• /
• v.54 no.2
• /
• pp.76-83
• /
• 2019

This study aims to empirically identify the effect of spatial accessibility, based on travel, on housing prices in the Korean capital region. More specifically, it has two research purposes: First, investigating the effect of comprehensive spatial accessibility, based on road network and actual trips from origin to destination, on average apartment price (Korean Won per square meter) at the level of Eup, Myeon and Dong; Second, identifying better accessibility index between Hansen's and Kalogirou and Foley's ones. The former represents a road-based travel time decay function with destination trips, while the latter is a function with origin trips as well as destination ones. The study employs spatial economic models considering spatial auto-correlative relationship as an appropriate methodology with such control independent indicators as population density, road density, educational environment and distances from CBDs. Analysis results demonstrate that spatial accessibility, based on road network and actual trips from origin to destination, has a statistically significant impacts on housing price in the region. Our empirical evidence proves that the Hansen index is more appropriate than the other in estimating housing price impacts.

• Journal of Korean Association for Spatial Structures
• /
• v.21 no.2
• /
• pp.41-48
• /
• 2021

A smart tuned mass damper (TMD) is widely studied for seismic response reduction of various structures. Control algorithm is the most important factor for control performance of a smart TMD. This study used a Deep Deterministic Policy Gradient (DDPG) among reinforcement learning techniques to develop a control algorithm for a smart TMD. A magnetorheological (MR) damper was used to make the smart TMD. A single mass model with the smart TMD was employed to make a reinforcement learning environment. Time history analysis simulations of the example structure subject to artificial seismic load were performed in the reinforcement learning process. Critic of policy network and actor of value network for DDPG agent were constructed. The action of DDPG agent was selected as the command voltage sent to the MR damper. Reward for the DDPG action was calculated by using displacement and velocity responses of the main mass. Groundhook control algorithm was used as a comparative control algorithm. After 10,000 episode training of the DDPG agent model with proper hyper-parameters, the semi-active control algorithm for control of seismic responses of the example structure with the smart TMD was developed. The simulation results presented that the developed DDPG model can provide effective control algorithms for smart TMD for reduction of seismic responses.

• Journal of Korean Association for Spatial Structures
• /
• v.21 no.1
• /
• pp.79-86
• /
• 2021

Control performance of a smart tuned mass damper (TMD) mainly depends on control algorithms. A lot of control strategies have been proposed for semi-active control devices. Recently, machine learning begins to be applied to development of vibration control algorithm. In this study, a reinforcement learning among machine learning techniques was employed to develop a semi-active control algorithm for a smart TMD. The smart TMD was composed of magnetorheological damper in this study. For this purpose, an 11-story building structure with a smart TMD was selected to construct a reinforcement learning environment. A time history analysis of the example structure subject to earthquake excitation was conducted in the reinforcement learning procedure. Deep Q-network (DQN) among various reinforcement learning algorithms was used to make a learning agent. The command voltage sent to the MR damper is determined by the action produced by the DQN. Parametric studies on hyper-parameters of DQN were performed by numerical simulations. After appropriate training iteration of the DQN model with proper hyper-parameters, the DQN model for control of seismic responses of the example structure with smart TMD was developed. The developed DQN model can effectively control smart TMD to reduce seismic responses of the example structure.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.82-86
• /
• 2004

A fuzzy rule-based hand-motion estimation algorithm is proposed for a 6 dimensional spatial tracker in which low cost accelerometers and gyros are employed. To be specific, beginning and stopping of hand motions needs to be accurately detected to initiate and terminate integration process to get position and pose of the hand from accelerometer and gyro signals, since errors due to noise and/or hand-shaking motions accumulated by integration processes. Fuzzy rules of yes or no of hand-motion-detection are here proposed for rules of accelerometer signals, and sum of derivatives of accelerometer and gyro signals. Several experimental results and shown to validate our proposed algorithms.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.12
• /
• pp.1217-1224
• /
• 2014

This paper presents a modified track guidance algorithm for formation flight of multiple UAVs. The suggested guidance algorithm is the spatial version of the first order dynamic characteristics for a time-dependent system so the algorithm is able to generate a path without overshoot to track the desired line. A crucial design parameter is a spatial constant that controls the shape of the convergence to an assigned flight path similarly to a time constant. Reference flight trajectories are designed based on a two-dimensional vehicle model, and the performance of the proposed guidance law is verified by numerical simulation using rigid body UAV dynamics with MATLAB/Simulink Aerosim Blockset.