• 대한환경공학회지
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• 제36권8호
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• pp.570-578
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• 2014

수심이 낮은 하구에서 바람이 국부적인 해수면 상승/하강에 미치는 영향을 연구하기 위해 Mobile Bay에 3차원 해수 순환모델을 적용하였다. Mobile Bay의 남단 경계면, 즉 northern Gulf of Mexico에서 시작된 조위는 Mobile River system 북부까지 직접적인 영향을 준다. 그러나 Mobile Bay 남단에서 발생한 조위변화는 Mobile Bay 북부로 이동하면서 Mobile River system으로부터 들어오는 담수와 국부적 바람의 영향으로 왜곡된다. Mobile Bay 남단에 위치한 기상관측소에서의 바람정보를 Mobile Bay 전체에 적용하였을 경우 Mobile Bay 북부에서 실제보다 강한 바람의 영향으로 과대한 수위 상승과 하강 현상이 발생하였다. 그러나 Mobile Bay 남단과 중단에 위치한 두 개의 관측소에서 측정된 바람 정보를 활용하였을 경우 Mobile Bay 북부에서의 조위 변화를 보다 정확하게 재현하는 것으로 나타났다. 특히 바람의 강도가 센 경우 Mobile Bay 남단과 북단의 풍속이 현저하게 차이나는 것으로 나타났으며(~ 88%), 이는 Mobile Bay 북단에서 나무와 건물 등의 영향으로 바람의 강도가 급격하게 줄어들었기 때문으로 판단된다. 따라서 Mobile Bay와 같이 수심이 낮고 국부적으로 풍속이 다른 하구 또는 만에서의 수위변화 재현 또는 예측을 위해서는 국부적인 바람 정보가 매우 중요한 것으로 연구되었다.

• 한국산학기술학회논문지
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• 제16권8호
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• pp.5132-5142
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• 2015

본 연구는 뇌졸중 환자를 대상으로 지지 면에 따른 양측 상지 운동이 상지 기능의 개선을 알아보고자 하였다. 연구기간은 2012년 7월 5일부터 8월 1일 까지 이다. 대상자는 뇌졸중 환자 20명을 무작위로 두 그룹으로 나누어 움직이는 지지 면 군(10명), 고정된 지지 면 군(10명)으로 실시하였다. 움직이는 지지 면 군은 발란스 볼에 앉아 양측 상지 운동을, 고정된 지지 면 군은 고정된 의자에 앉아 양측 상지 운동을 4주간 주5회 30분 적용하였다. 실험 전과 후에는 상지 기능의 변화를 비교하기 위해 상지 기능 검사(Manual Functional Test: MFT)와 상지 운동 기능 평가(Fugl-Meyer Motor Function Assessment: FMA)로 측정하였고 다음과 같은 결과를 얻었다. 첫째, 움직이는 지지 면 군과 고정된 지지 면 군의 각 실험 전, 후 상지 기능은 통계학적으로 유의한 차이를 보였다(p<.05). 둘째, 실험 전, 후 두 군 간의 차이를 비교한 결과 상지 기능에 통계학적으로 유의한 차이를 보였다(p<.05). 이상의 결과로 보아 움직이는 지지 면에서의 양측 상지 운동이 뇌졸중 환자의 상지 기능 개선에 효과적임을 알 수 있었다.

• 제어로봇시스템학회논문지
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• 제14권8호
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• pp.842-847
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• 2008

This paper proposes a new sliding-surface-based tracking control system for nonholonomic mobile robots with disturbance. To design a robust controller, we consider the kinematic model and the dynamic model of mobile robots with disturbance. We also propose a new sliding surface to solve the problem of previous study. That is, since the new sliding surface is composed of differentiable functions unlike the previous study, we can obtain the control law for arbitrary trajectories without any constraints. From the Lyapunov stability theory, we prove that the position tracking errors and the heading direction error converge to zero. Finally, we perform the computer simulations to demonstrate the performance of the proposed control system.

• 한국표면공학회지
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• 제43권3호
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• pp.142-147
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• 2010

We evaluated characteristics of ENEPIG (Electroless Nickel Electroless Palladium Immersion Gold) surface treatment for mobile equipment that requires high reliability, in addition to investigating surface treatment processes for semiconductor boards that require high reliability such as regular PCB-package systems, board-on-chip, chip-scaled package (CSP), etc and application for semiconductor package board of SIP, BOC. As a result, it appeared that ENEPIG has superior properties compared to ENIG surface treatment in corrosion resistance, solder junction, wetting, etc. We anticipate that these results will be able to lend credibility to ENEPIG as a low-cost alternative for producing mobile devices such as the cell phones, especially when applied to mass production.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2852-2854
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• 2005

In this paper, we propose a method to a synchronization of chaotic mobile robots that have unstable limit cycles in a chaos trajectory surface. We assume all obstacles in the chaos trajectory surface have a VDP (Van der Pol) equation with an unstable limit cycle. The proposed methods are assumed that if one of two chaotic mobile robot receives the synchronization command, the other robot also follows the same trajectory during the chaotic robot search on the arbitrary surface.

• 제어로봇시스템학회논문지
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• 제22권7호
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• pp.543-551
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• 2016

This paper presents the analysis and implementation of traveling surface characteristics test equipment using optical mice in connection with the velocity estimation of a mobile robot equipped with optical mice. In the traveling surface characteristics test equipment, a traveling surface sample is made to rotate toward stationary optical mice instead of a mobile robot equipped with optical mice moving over a traveling surface. First, the conceptual design and operational principle of the traveling surface characteristics test equipment is explained. Second, the velocity kinematics of the traveling surface characteristics test equipment is formulated; based on this, the parameter setting of the traveling surface characteristics test equipment is described. Third, the implementation of the traveling surface characteristics test equipment is described in detail, including the mechanical design and construction and the hardware and software development. Fourth, using the prototype of the traveling surface characteristics test equipment, the experimental results of the statistical parameter extraction for different traveling surface samples are given. Finally, some potential usages of the traveling surface characteristics test equipment are discussed.

• 반도체디스플레이기술학회지
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• 제10권3호
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• pp.7-13
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• 2011

In Korea, the car mobile phone service had started in 1961 and with this Korea Mobile Telecommunications Services was established in 1984. Its service was mainly focused on the mobile phone service for the car which led the popularity of the full-scale mobile phone service. There are many kinds of materials, colors and patterns which are the elements of surface coating techniques. In light of that, we are focused on the UV coating that is ranked as an important part of the techniques in this study. In the first, the use of various materials for the cellular phone and surface processing techniques for the cellular phone were searched. On the basis of the results, the experiments of actual consumer experience with the exfoliation of the surface were done and through that we proposed the best way of processing the surface for the cellular phone and the materials. The result of the Wear Test showed that thick coating was detached more slowly and each company differed in their results with UV paints despite the same thickness of UV coating. The seal (UV) exfoliation of cellular phone is deeply related with the film thickness and the film formation when the users use the cellular phones and the exfoliation of the cellular phone surface will be decreased if the manufacturers meet the best conditions for the cellular phone.

• 제어로봇시스템학회논문지
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• 제18권3호
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• pp.243-250
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• 2012

This paper proposes a 3D map-building algorithm using one LRF (Laser Range Finder) while a mobile robot is navigating on the slanted surface. There are several researches on 3D map buildings using the LRF. However most of them are performing the map building only on the flat surface. While a mobile robot is moving on the slanted surface, the view angle of LRF is dynamically changing, which makes it very difficult to build the 3D map using encoder data. To cope with this dynamic change of the view angle in build 3D map, IMU and balance filters are fused to correct the unstable encoder data in this research. Through the real navigation experiments, it is verified that the fusion of multiple sensors are properly performed to correct the slope angle of the slanted surface. The effectiveness of the balance filter are also checked through the hill climbing navigations.

• ETRI Journal
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• 제38권6호
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• pp.1085-1094
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• 2016

In this work, we present interactive automultiscopic content with mobile surface haptics for multimodal interaction. Our system consists of a 40-view automultiscopic display and a tablet supporting surface haptics in an immersive room. Animated graphics are projected onto the walls of the room. The 40-view automultiscopic display is placed at the center of the front wall. The haptic tablet is installed at the mobile station to enable the user to interact with the tablet. The 40-view real-time rendering and multiplexing technology is applied by establishing virtual cameras in the convergence layout. Surface haptics rendering is synchronized with three-dimensional (3D) objects on the display for real-time haptic interaction. We conduct an experiment to evaluate user experiences of the proposed system. The results demonstrate that the system's multimodal interaction provides positive user experiences of immersion, control, user interface intuitiveness, and 3D effects.

• 제어로봇시스템학회논문지
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• 제20권1호
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• pp.58-69
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• 2014

This paper proposes a method for predicting maximum friction coefficients and optimal slip ratios as optimal control parameters for traction control or slip control of autonomous mobile robots on rough terrain. This paper focuses on strength of ground surface which indicates different characteristics depending on material types on surface. Strength of various material types can be estimated by Willoughby sinkage model and by a developed testbed which can measure forces, velocities, and displacements generated by wheel-terrain interaction. Estimated strength is collaborated on building improved Brixius model with friction-slip data from experiments with the testbed over sand and grass material. Improved Brixius model covers widespread material types in outdoor environments on predicting friction-slip characteristics depending on strength of ground surface. Thus, a prediction model for obtaining optimal control parameters is derived by partial differentiation of the improved Brixius model with respect to slip. This prediction model can be applied to autonomous mobile robots and finally gives secure maneuverability on rough terrain. Proposed method is verified by various experiments under similar conditions with the ones for real outdoor robots.