• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.1
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• pp.41-49
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• 2014

This study spatially assesses the impact of trees on residential rooftop solar energy potential using urban three-dimensional models derived from Light Detection and Ranging(LiDAR) data in San Francisco, California. In recent years on-site solar energy generation in cities has become an essential agenda in municipal climate action plans. However, it can be limited by neighboring environments such as shade from topography, buildings and trees. Of all these effects, the impact of trees on rooftop photovoltaics(PVs) requires careful attention because improper situation of solar panels without considering trees can result in inefficient solar energy generation, tree removal, and/or increasing building energy demand and urban heat island effect. Using ArcMap 9.3.1, we calculated the incoming annual solar radiation on individual rooftops in San Francisco and the reduced insolation affected by trees. Furthermore, we performed a multiple regression analysis to see what attributes of trees in a neighborhood(tree density, tree heights, and the variance of tree heights) affect rooftop insolation. The result shows that annual total residential rooftops insolation in San Francisco is 18,326,671 MWh and annual total light-loss reduction caused by trees is 326,406 MWh, which is about 1.78%. The annual insolation shows a wide range of values from $34.4kWh/m^2/year$ to $1,348.4kWh/m^2/year$. The result spatially maps the locations that show the various levels of impact from trees. The result from multiple regression shows that tree density, average tree heights and the variation of tree heights in a neighborhood have statistically significant effects on the rooftop solar potential. The results can be linked to municipal energy planning in order to manage potential conflicts as cities with low to medium population density begin implementing on-site solar energy generation. Rooftop solar energy generation makes the best contribution towards achieving sustainability when PVs are optimally located while pursuing the preservation of urban trees.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.1
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• pp.53-68
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• 1990

The purpose of this study was to establish the more rational and practical basic theory for the landscape planning in the aparment complex. In this study, the actual conditions of exterior space, the residens' satisfaction degree and the correlation between exterior space and the residents' satisfaction defree were investigated and analyzed on the 13apartment complexes in Taegu City. Through the statistical analysis, the main results were obtained as fellows : It was found that the size of green area ratio in the apartment complexes were in the order of Jugong Apt. (Korean Housing Corporation), Siyoung Apt. (City Operation), Minyoung high-rise Apt. (Private Business) and Minyoung low-rise Apt. (Private Business) complex. The highest ratio of footway and Parking area were shown in Minyoung high-rise Apt. complex. The important factors at the exterior space of apartment complex were composed by 6 major factors, importance degrees of which are Visual, Practical, Convenient, Sentimental, Recreational and Spatial factors for teenagers in orders. The residents' satisfaction degrees to the exterior space were highly correlated with the spatil organization, size of green area and quantity of trees, view, management situation, defensibility of outside noise, rest place, water landscapings by turns. In order to get more than the average satisfaction degree 18 exterior space, the green area should be occupied by 35% of the apartment complex area and more than 76% of the green area (i. e. 16% of the apartment complex area) should be planted with trees. In the Taegu City regulation, the ratio of tree composition is proposed for only the number of tree. But it was shown that the satifaction degree are more correlated with the species and afforestation of trees than the nuts her of trees in this study. therefore, the species of tree and the afforestation of tree should be considered when the landscape planning of the apartment complex begins. It was found that the ratio of afforestation to make the more desirable exterior space In the apartment complex shoule be 8 to 2 in the ratio of arbor to shrub. It was also required that 30 species of arbor and 15 species of shrub should be planted for the more desirable landscape of the apartment complex.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.593-599
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• 1999

A mobile robot in FMS environment should be able to nevigate itself. Therefore, path planning is necessary for the mobile robot to perform its tasks without being lost. Path planning using a network model gives oprimal paths to every pair of nodes but building this model demands accurate information of environments. In this paper, a method to build a network model using sonar sensors is presented. The main idea is to build a quad tree model by using sonar sensors and convert the model to a network model for path planning. The new method has been implemented on a mobile robot. Experimental results show that the mobile robot constructs an accurate network model using inaccurate sonar data.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.120.3-120
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• 2001

We propose a new method of path planning for cleaning robots. Path planning problem for cleaning robots is different from conventional path planning problems in which finding a collision-free trajectory from a start point to a goal point is focused. In the case of cleaning robots, however, a planned path should cover all area to be cleaned. To resolve this problem in a systematic way, we propose a method based on a graph model as follows: at first, partition a given map into proper regions, then transform a divided region to a vertex and a connectivity between regions to an edge of a graph. Finally, a region is divided into sub-regions so that the graph has a unary tree which is the simplest Hamilton path. The effectiveness of the proposed method is shown by computer simulation results.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.3
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• pp.217-225
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• 2016

In this paper, we propose an improved path planning method and obstacle avoidance algorithm for two-wheel mobile robots, which can be effectively applied in an environment where obstacles can be represented by circles. Firstly, we briefly introduce the rapidly exploring random tree (RRT) and single polar polynomial (SPP) algorithm. Secondly, we present additional two methods for applying our proposed method. Thirdly, we propose a global path planning, smoothing and obstacle avoidance method that combines the RRT and SPP algorithms. Finally, we present a simulation using our proposed method and check the feasibility. This shows that proposed method is better than existing methods in terms of the optimality of the trajectory and the satisfaction of the kinematic constraints.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.76-78
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• 2019

Sampling-based algorithms are one of the most commonly approaches which give good results in robot path planning with many degree of freedom. So that many proposed methods as well as their improvement based on these approaches have been proposed. The purpose of this paper is to survey some current algorithms using for path planning, the original proposed methods as well as their improvement. Some advantages and disadvantages of these algorithms will be also mentioned, how the improved version of the proposed methods overcome the original proposed methods' drawback.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1039-1043
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• 2005

Despite the many significant advances made in robot architecture, the basic approaches are deliberative and reactive methods. They are quite different in recognizing outer environment and inner operating mechanism. For this reason, they have almost opposite characteristics. Later, researchers integrate these two approaches into hybrid architecture. In such architecture, Reactive module also called low-level motion control module have advantage in real-time reacting and sensing outer environment; Deliberative module also called high-level task planning module is good at planning task using world knowledge, reasoning and intelligent computing. This paper presents a framework of the integrated planning and control for mobile robot navigation. Unlike the existing hybrid architecture, it learns topological map from the world map by using MST (Minimum Spanning Tree)-based SOFM (Self-Organizing Feature Map) algorithm. High-level planning module plans simple tasks to low-level control module and low-level control module feedbacks the environment information to high-level planning module. This method allows for a tight integration between high-level and low-level modules, which provide real-time performance and strong adaptability and reactivity to outer environment and its unforeseen changes. This proposed framework is verified by simulation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.26-32
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• 2016

An autonomous car(driverless car, self-driving car, robotic car) is a vehicle that is capable of sensing its environment and navigating without human input. Autonomous cars can detect surroundings using a variety of techniques such as radar, lidar, GPS, odometry, and computer vision. Advanced control systems interpret sensory information to identify appropriate navigation paths, as well as obstacles and relevant signage. Autonomous cars have control systems that are capable of analyzing sensory data to distinguish between different cars on the road, which is very useful in planning a path to the desired destination. An issue tree, also called a logic tree, is a graphical breakdown of a question that dissects it into its different components vertically and that progresses into details as it reads to the right.Issue trees are useful in problem solving to identify the root causes of a problem as well as to identify its potential solutions. They also provide a reference point to see how each piece fits into the whole picture of a problem. Using Issue-Tree menthods, transportation safety policies were developed with autonompus vehicle in mind.

• Current Research on Agriculture and Life Sciences
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• v.24
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• pp.37-42
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• 2006

The purpose of this study was a biota research and analysis for Close-to-nature stream restoration planning of Shinchun. The summary of this study is as follows; 1) The vascular plants in research area recorded of 45 species and insect fauna recorded of 34 species of 8 orders. As a result of table of community classification, the communities were two group; Quercus variabilis community(I), Pinus densiflora-Quercus variabilis-Quercus dentata community(II). 2) As a result of analysis on correlation of tree species, the level of significance in positive correlation between Quercus dentata and Corylus heterophyll aindicated 1% and between Pinus densiflora and Lespedeza bicolor also indicated 1%. 3) As a result of DBH analysis, it is expected that Quercus variabilis and Quercus dentata will dominateover other species in competition and its succession continuously maintains from now on in community I. In community II, it is assumed that there is a high possibility of changing into community of Quercus such as Quercus mongolica, Quercus dentata, and Quercus variabilis. 4) As a result of analysis on insect fauna, insect fauna consists of 94% of whole species as 32 species, 23 families, 8 orders. And 7 species, 7 families 4 orders was found in highly urbanized area, the vicinity of Sang-Dong bridge. 5) As mentioned above, Based on A biota fundamental research, Close-to-nature stream restoration planning were full of suggestions: i) Designating ecosystem preservation area, ii) Making Close-to-nature stream revetments, iii) Making pool-and-riffle, vi) Making decks for observation and walks for nature experience, v) Creating wetland biotope. Through these methods, it is necessary to promote bio-diversity and lead people to the space for eco-learning.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.5
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• pp.30-44
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• 2002

This study is conducted to analyze the change of location and soil characteristics effect on the condition of urban forest in Urban Park and Green Open Space The results of this study are as fallows; 1. Soil acidity is indicated pH 3.88 in Sasang park, pH 4.38 in Hwaji park, pH 4.40 in Daeyeon park, pH 4.68 in Sanseong amusement park, pH 5.15 in Molundae amusement park. 2. Species diversity indices of indicated Sasang park 0.9932, Hwaji park 1.1975, Daeyeon park 1.2160, Sanseong amusement park 1.3080, Molundae amusement park 1.3233 is due to location and soil environment in addition to air pollution effects. 3. The vitality of Pinus thunbergii 27.5ER in Sasang park, 24.9ER in Hwaji park, 24.5ER in Daeyeon park, 23.6ER in Sanseong amusement park, 21.0ER in Molundae park. This shows that tree vitality are impacted by location and soil characteristics. On the basis of the result above, vegetation devices are suggested : 1) Robinica pseudo-acacia management, 2) removing the hazard plants; Smilax china, Humulus japonicus, Pueraria thungergiana, 3) improving soil hardness and soil acidity.