• 한국비블리아학회지
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• 제30권2호
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• pp.189-209
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• 2019

주경로 분석(Main Path Analysis, MPA)은 문헌의 인용정보를 기반으로 지식이 전달되는데 기여한 핵심 문헌을 추출하는 텍스트마이닝 기법 중 하나이다. 본 연구는 1990년부터 2018년까지 국내외에서 발행된 장소성 관련 논문의 인용정보와 초록을 토대로 주경로 분석과 단어동시출현빈도 연관어 네트워크 분석을 적용하여 연구동향을 파악하였다. 1990년부터 2018년까지 수집된 문헌을 5년씩 기간 구분하여 (마지막 기간은 3년) 각 기간 별로 국내외에서 장소성 관련 연구가 전반적으로 어떻게 진행되었는지 비교 분석하여 제시하였다. 주경로 분석 결과, 1990년부터 해외의 장소성 관련 연구는 개인 정체성, 공공 토지 관리, 환경 교육, 도시 개발 분야 순으로 진행되어 온 것으로 나타났다. 단어동시출현을 기반으로 한 연관어 네트워크를 통해서는 국내의 경우 도시 개발, 문화, 문학, 역사 등 다양한 차원에서 장소성이 논의되는 격변기를 겪는 것으로 해석할 수 있었다. 반면 국외에서는 건강, 정체성, 경관, 도시 개발 관련 논의가 90년대부터 꾸준히 이루어지고 있는 것으로 파악되었다. 본 연구는 장소성 연구동향을 기존의 특정 영역에 장소성 개념을 적용하여 분석하는 미시적 관점의 분석이 아닌 다양한 텍스트마이닝 기법을 적용하여 장소성을 주제로 삼고 있는 논문의 전반적인 흐름을 파악하는 통시적 접근의 방법을 제시하였다는 점에서 시사점을 지닌다.

• 한국정밀공학회지
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• 제31권11호
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• pp.1023-1030
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• 2014

This paper presents a new method to control swarm robots so that they can keep the formation while following a curved path. The main idea is to utilize the information on the instant center of gyration. For a given path, location of the instant center of the formation center is calculated, and individual robots follow the circular path around the calculated instant center. Performance of curvature-radius based method is compared with leader-follower referenced method via MATLAB simulation.

• 영어어문교육
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• 제13권1호
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• pp.87-110
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• 2007

Past studies conducted on the students' verbal participation both in and out of class have explored and identified variables affecting the process of learning to speak English. However, little is known about the causes and effects of these variables. A survey form developed from a previous study was administered to 468 university students taking English conversation classes from native speakers of English. To better understand the causes and effects of speaking barriers, path analysis was administered as the main tool of investigation. The results of the study indicate that familiarities toward NS (Native Speaker) teachers, learner faithfulness, che-myon, NS teachers' classroom management skills, and NS teacher's trustworthiness account for 50.72% of speaking grades. These factors are causally related to learner attitudes. However, with regard to speaking grades, all of the above factors except che-myon are also causally related with each other. Therefore, it was concluded that learner attitudes can be improved by minimizing che-myon, however, che-myon itself cannot be a predictor of speaking grades. To validate the findings of the study, related research work is discussed and implications are provided.

• 한국기계가공학회지
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• 제14권3호
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• pp.27-35
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• 2015

Recently, the work machine is widely used in the agricultural machine and to use the power source of the tractor, the mower had been widely used as a working machine for mowing. The mower is classified as a front mower, mid-mower, and rear mower according to the mounting position of the lower frame on tractor. The main structure of mower is composed of deck, gearbox, and blade. This study concerns a study on air flow characteristics of Mid-mower for tractor. An air flow characteristics of the Mid-mower deck was evaluated by the velocity vector, flow path, and total air flow according to the number of revolutions. As the analysis results, The inner path of designed deck had no effect on air flow.

• 소음진동
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• 제6권6호
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• pp.851-856
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• 1996

The active noise cancellation system showing the effective convergence and stability has been studied by simplifying the controller structures using the weighting factors of control error path to the multi-channel filtered-x LMS algorithm which needs a lot of calculations and the performance has been verified experimentally. Besides, to implement the system performance in a vehicle cabin, experimental work for selecting the suitable numbers and positions of the microphones and speakers was accomplished. Effectively combining a TMS 320C 31 main processor conducting real number calculations and having various functions with other components, the purpose-built system board for active noise cancellation has been designed and with this board, car active noise cancellation system showing maximum stable 10dB noise reduction has been obtained at the car idling conditions above 3000rpm range.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.743-747
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• 1996

A Potential Field Method is applied to the proposed algorithm for the planning of collision-free paths of redundant manipulators. The planning is carried out on the base of kinematic configuration. To make repulsive potentials, sources are distributed on the boundaries of obstacles. To escape from local minimum of the main potential and to attack other difficulties of the planning, various potentials are defined simultaneously, Inverse Kinematics Problems of the redundant manipulators are solved by unconstrained optimization method. Computer simulation result of the path planning is presented.

• 한국가구학회지
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• 제12권1호
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• pp.1-9
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• 2001

This study was carried out to elucidate the relationship between wood anatomy and the water flow path in P. koraiensis and L. leptolepis. through the experiment of penetration of the dye solution. The experiment was performed by permeating 1% acid, alkali and direct solution into the xylem just after being cut. The results obtained were summarized as follows : 1. In P. koraiensis and L. leptolepis, the dye solution penetrated into sapwood and annual rings adjacent to cambial zone were only dyed according to ascent of tree height. 2. The penetrability of latewood was better than that of earlywood. 3. In P. koraiensis and L. leptolepis, the main water flow path in longitudinal direction was the trachied and that in transverse direction was ray trachied and ray parenchyma. Also, the dye solution was found in resin canal. 4. P. koraiensis was more permeable than L. leptolepis. 5. Among the acid, alkali and direct dye solution, the acid dye solution was the most permeable.

• 로봇학회논문지
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• 제1권2호
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• pp.117-124
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• 2006

In this paper, we develope the navigation system for patrol robots in indoor environment. The proposed system consists of PDA map modelling, a localization algorithm based on a global position sensor and an automatic charging station. For the practical use in security system, the PDA is used to build object map on the given indoor map. And the builded map is downloaded to the mobile robot and used in path planning. The global path planning is performed with a localization sensor and the downloaded map. As a main controller, we use PXA270 based hardware platform in which embedded linux 2.6 is developed. Data handling for various sensors and the localization algorithm are performed in the linux platform. Also, we implemented a local path planning algorithm for object avoidance with ultra sonar sensors. Finally, for the automatic charging, we use an infrared ray system and develop a docking algorithm. The navigation system is experimented with the two-wheeled mobile robot using North-Star localization system.

• 대한임베디드공학회논문지
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• 제13권2호
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• pp.53-63
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• 2018

A novel real-time path planning algorithm suitable for implementation on a small mobile robot is introduced. The algorithm can be used as the basis for mapping unknown or partially known environments and is tested in a specially developed simulation environment in Matlab(R). Simulations results are presented demonstrating that the algorithm can readily be implemented to allow a small robot to navigate in various unknown and partially known environments. The main characteristics of the algorithm include simplicity, ease of implementation, speed, and efficiency, thereby being especially suitable for small robots. Furthermore, for partially known environments, another algorithm is proposed to predefine an optimal path taking into account information provided regarding the environment.

• International Journal of CAD/CAM
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• 제8권1호
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• pp.45-53
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• 2009

As the point sampling technology evolves rapidly, there has been increasing need in generating tool path from dense point set without creating intermediate models such as triangular meshes or surfaces. In this paper, we present a new tool path generation method from point set using Euclidean distance fields based on Algebraic Point Set Surfaces (APSS). Once an Euclidean distance field from the target shape is obtained, it is fairly easy to generate tool paths. In order to compute the distance from a point in the 3D space to the point set, we locally fit an algebraic sphere using moving least square method (MLS) for accurate and simple calculation. This process is repeated until it converges. The main advantages of our approach are : (1) tool paths are computed directly from point set without making triangular mesh or surfaces and their offsets, and (2) we do not have to worry about no local interference at concave region compared to the other methods using triangular mesh or surface model. Experimental results show that our approach can generate accurate enough tool paths from a point set in a robust manner and efficiently.