• Journal of applied mathematics & informatics
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• 제8권3호
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• pp.829-840
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• 2001

Generally it is not easy task whether the stable systems governed by nonlinear ordinary differential equations are asymptotically stable or not. This problem often appears in studying a collision and avoidance control problem based on the stability theory. In this paper we devoted to finding conditions that the stable system obtained from the collision and avoidance control problem is asymptotically stable.

• International Journal of Control, Automation, and Systems
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• 제4권1호
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• pp.77-86
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• 2006

A new method in robot path generation is presented using an analysis of the characteristics of multi-robot collision avoidance. The research is based on the concept of the collision map, where the collision between two robots is presented by a collision region and a crossing curve TLVSTC (traveled length versus servo time curve). Analytic collision avoidance is considered by translating the collision region in the collision map. The 4 different translations of collision regions correspond to the 4 parallel movements of the actual original robot path in the real world. This analysis is applied to path modifications where the analysis of collision characteristics is crucial and the resultant path for collision avoidance is generated. Also, the correlations between the translations of the collision region and robot paths are clarified by analyzing the collision/non-collision areas. The influence of the changes of robot velocity is investigated analytically in view of collision avoidance as an example.

• 산경연구논집
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• 제13권11호
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• pp.47-64
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• 2022

Purpose: This study's goal is to investigate how perceived risk of Japanese electronic product affect the negative emotion and the avoidance intentions. In addition, this is difference in the effect of perceived risk on negative emotions and avoidance intentions according to the presence or absence of substitutes. Research design, data and methodology: Perceived risks of Japan products are decided by four dimensions, they are economic risk, social risk, psychological risk and physical risk. The reach model is made by the theory of risk-avoid. We requested this survey to 5808 customers by panel and web site, received 559 replied. We used 528 questionnaires excluding unreliable data. For the analysis, smart PLS is used. Results: Psychological risk has influence on negative emotion and avoidance intension. Social risk and physical risk affected negative emotion, but did not directly affect avoidance intention. Economic risk affects avoidance intension, but it has no effect of negative emotion. The existence of Japanese products' substitute only effects the relationship of economic risk and avoidance intention. Conclusions: Korean consumers behavior their buying and using of Japan product as financial benefit and satisfaction, not only risk. It is suggested that Korean company should make and develop unique product with good price.

• 한국산업융합학회 논문집
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• 제22권2호
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• pp.209-218
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• 2019

This study proposes a new approach to Control the Orientation and position based on obstacle avoidance technology by multi sensors fusion and autonomous travelling control of mobile robot system for implimentation of Smart FA. The important focus is to control mobile robot based on by the multiple sensor module for autonomous travelling and obstacle avoidance of proposed mobile robot system, and the multiple sensor module is consit with sonar sensors, psd sensors, color recognition sensors, and position recognition sensors. Especially, it is proposed two points for the real time implementation of autonomous travelling control of mobile robot in limited manufacturing environments. One is on the development of the travelling trajectory control algorithm which obtain accurate and fast in considering any constraints. such as uncertain nonlinear dynamic effects. The other is on the real time implementation of obstacle avoidance and autonomous travelling control of mobile robot based on multiple sensors. The reliability of this study has been illustrated by the computer simulation and experiments for autonomous travelling control and obstacle avoidance.

• Journal of Photoscience
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• 제9권2호
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• pp.326-328
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• 2002

In many plant cells, the positions of chloroplasts change in response to changes in light conditions. In the epidermal cells of the aquatic angiosperm Vallisneria gigantea, the avoidance response of chloroplasts is induced specifically by irradiation with blue light of high intensity. Possible roles of actin cytoskeleton in the blue-light-induced avoidance response of chloroplasts were investigated by partial irradiation and phalloidin staining. We showed that the blue-light-dependent redistribution of chloroplasts was induced only in the limited area, where exposed to blue light, even in individual cells. In addition. in the exposed area, the configuration of actin filaments strikingly changed compared with that before the irradiation. Short and thick bundles of actin filaments surrounding the chloroplasts changed to much longer and thinner bundles with a more stretched array. In contrast, in the unexposed area, neither the distribution of chloroplasts nor the configuration of actin filaments exhibited any changes. Cytochalasin D and latrunculin B inhibited the avoidance response of chloroplasts concomitantly with the fragmentation of actin filaments. These results indicate that the reorganization of actin filaments plays a crucial role in the induction of avoidance response of chloroplasts.

• 한국항행학회논문지
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• 제10권2호
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• pp.145-151
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• 2006

본 논문에서는 동적인 환경에서 돌발 장애물을 회피하는 방법으로 Nearness Diagram, Limit-Cycle 및 벡터장법을 혼합한 새로운 항법을 제안한다. Limit-Cycle 항법은 정면장애물을 회피 하는데 사용되고, 벡터장법은 측면장애물을 회피 하는데 이용된다. 그리고 Nearness Diagram 항법은 로봇의 근접지역장애물을 회피하는데 사용된다. 제안된 항법은 시뮬레이션을 통해 그 성능을 증명하였다.

• International Journal of Aeronautical and Space Sciences
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• 제12권3호
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• pp.274-282
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• 2011

This paper is focused on dynamic modeling and control system design as well as vision based collision avoidance for multi-rotor unmanned aerial vehicles (UAVs). Multi-rotor UAVs are defined as rotary-winged UAVs with multiple rotors. These multi-rotor UAVs can be utilized in various military situations such as surveillance and reconnaissance. They can also be used for obtaining visual information from steep terrains or disaster sites. In this paper, a quad-rotor model is introduced as well as its control system, which is designed based on a proportional-integral-derivative controller and vision-based collision avoidance control system. Additionally, in order for a UAV to navigate safely in areas such as buildings and offices with a number of obstacles, there must be a collision avoidance algorithm installed in the UAV's hardware, which should include the detection of obstacles, avoidance maneuvering, etc. In this paper, the optical flow method, one of the vision-based collision avoidance techniques, is introduced, and multi-rotor UAV's collision avoidance simulations are described in various virtual environments in order to demonstrate its avoidance performance.

• International Journal of Contents
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• 제15권4호
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• pp.44-49
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• 2019

This study is designed to examine antecedents and consequences of mobile advertising avoidance. However, to date, research on mobile advertising avoidance has been scarce. Thus, this study makes significant contributions by addressing understudied areas in mobile advertising. Study results show that the perceived mobile advertising risk is positively related to mobile advertising avoidance. This study found that the perceived trust in mobile advertising is negatively linked to mobile advertising avoidance. The study results show that the perceived Internet users' data privacy concerns is positively linked to mobile advertising avoidance. Finally, study results suggest that mobile advertising avoidance is positively linked to intention to delete the ad.

• 대한가정학회지
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• 제48권10호
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• pp.25-35
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• 2010

본 연구는 또래 괴롭힘 피해와 학교적응의 관계에서 자아 및 또래 지각의 매개효과를 검증하고자 하였다. 연구대상은 초등학교 5, 6학년 남녀 아동 521명이다. 또래 지명법을 사용하여 또래 괴롭힘의 피해가 측정되었고 자기 보고법을 사용하여 자아 및 또래 지각과 학교 회피가 측정되었다. 연구결과를 보면, 자아 및 또래 지각은 또래 괴롭힘 피해와 학교적응의 관계에서 완전 매개 효과가 있었으며, 반면에 또래 괴롭힘 피해는 학업 성취에 직접적인 영향을 미치는 것으로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2461-2466
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• 2003

This paper presents a simple sensor fusion algorithm using neural network for navigation of mobile robots with obstacle avoidance and trap recovery. The multiple sensors input sensor data to the input layer of neural network activating the input nodes. The multiple sensors used include optical encoders, ultrasonic sensors, infrared sensors, a magnetic compass sensor, and GPS sensors. The proposed sensor fusion algorithm is combined with the VFH(Vector Field Histogram) algorithm for obstacle avoidance and AGPM(Adaptive Goal Perturbation Method) which sets adaptive virtual goals to escape trap situations. The experiment results show that the proposed low-level fusion algorithm is effective for real-time navigation of mobile robot.