• 제어로봇시스템학회논문지
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• 제10권4호
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• pp.312-316
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• 2004

In this paper, it is presented an adaptive robust control system to implement real-time control of a robot manipulator. There are Quantitative or qualitative differences between a real robot manipulator and a robot modeling. In order to compensate these differences, uncertain factors are added to a robot modeling. The uncertain factors come from imperfect knowledge of system parameters, payload change, friction, external disturbance, etc. Also, uncertainty is often nonlinear and time-varying. In the proceeding work, we proposed a class of robust control of a robot manipulator and provided the stability analysis. In the work, we propose a class of adaptive robust control of robot manipulator with bound estimation. Through experiments, the proposed adaptive robust control scheme is proved to be an efficient control technique for real-time control of a robot system using DSP.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.426-426
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• 2000

When real robot manipulators arc mathematically modeled, uncertainties are not avoidable. The uncertainties are often nonlinear and time varying, The uncertain factors come from imperfect knowledge of system parameters, payload change, friction, external disturbance and etc. We proposed a class of robust hybrid position/force control of manipulators and provided the stability analysis in the previous work. In the work, we propose a class of adaptive robust hybrid position/force control of manipulators with bound estimation and the stability based on Lyapunov function is presented. Especially, this controller does not need the information of uncertainty bound. The simulation results are provided to show the effectiveness of the algorithm.

• 제어로봇시스템학회논문지
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• 제7권12호
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• pp.980-984
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• 2001

When robot manipulatros as mathematically modeled. uncetainties may not be avoided. The uncertain factors come from imperfect knowledge of system parameters, payload change. friction, external disturbance and etc. In this work, we proposed a class of robust hybrid control of manipulatosrs. We propose a class of expanded robust hybrid control with the separated bound function and the simulation results are provided to show the effectiveness of the algorithm.

• 한국환경교육학회:학술대회논문집
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• 한국환경교육학회 2005년도 후반기 학술대회 발표논문집
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• pp.138-147
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• 2005

In the present study, the middle school students' perception on the environment course was surveyed before and after three different lessons. It was found that most students were taking environment related issues mainly from mass media including internet and broadcasting. The young students were satisfied at practical experiments, but at the same time a few old fashioned experimental programs would not be preferred. Utilization of multimedia such as audio-visual tools was one of the effective tools for the environment class, because it could help to understand even the profound principles of the chemical and physical processes. However, some students did not concentrate on the display, causing frequent disturbance of the class. Since the school for this investigation did not choose the environment as a selective course, practical tools and materials for the experiment should not be sufficient, and thereby a further detailed work must be followed with the students who are taking environment lessons.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1726-1727
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• 2007

In this paper, a systematic guideline is introduced to design a stable adaptive fuzzy wavelet controller with sliding mode for a class of uncertain nonlinear systems. Based on the Lyapunov synthesis approach, we construct the fuzzy wavelet controller such that it can basically control and guarantee the stability of the whole control system. On the other hand, a robust controller is design to restrain or eliminate the disturbance and assure the desired output accuracy of a control system. Some experimental results for a chaotic system are provided here to demonstrate the effectiveness of the control algorithm.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권3호
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• pp.153-165
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• 2021

The objective of this study was to provide basic data for the conservation of wetland ecosystems in the Civilian Control Zone and the management of Yongyangbo wetlands in South Korea. Yongyangbo wetlands have been designated as protected areas. A field survey was conducted across five sessions between April 2019 and August of 2019. A total of 248 taxa were identified during the survey, including 72 families, 163 genera, 230 species, 4 subspecies, and 14 varieties. Their life-forms were Th (therophytes) - R₅ (non-clonal form) - D₄ (clitochores) - e (erect form), with a disturbance index of 33.8%. Three taxa of rare plants were detected: Silene capitata Kom. and Polygonatum stenophyllum Maxim. known to be endangered species, and Aristolochia contorta Bunge, a least-concern species. S. capitata is a legally protected species designated as a Class II endangered species in South Korea. A total of 26 taxa of naturalized plants were observed, with a naturalization index of 10.5%. There was one endemic plant taxon (Salix koriyanagi Kimura ex Goerz). In terms of floristic target species, there was one taxon in class V, one taxon in Class IV, three taxa in Class III, five taxa in Class II, and seven taxa in Class I. Three invasive alien species (Ambrosia trifida L., Ambrosia artemisiifolia L., and Humulus japonicus Siebold & Zucc) were observed. For continuous conservation of Yongyangbo Wetlands, it is necessary to remove invasive alien plants and block the inflow of non-point pollutants.

• 한국환경생태학회지
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• 제3권1호
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• pp.81-94
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• 1989

가야산국립공원 등산로 및 야영장의 훼손과 주변 자연환경에 대한 이용영향을 파악하기 위해 1989년에 조사를 실시하였다. 등산로폭, 나지노출폭 및 최대 깊이는 이용강도에 따른 차이가 인정되었고, 전체 51개 조사지 점에서 관찰된 훼손형태는 매우 다양하였으며, 훼손된 지점의 등간로 상태중 최대깊이와 등산로물매는 건전한 지점의 상태와 유의한 차이를 보였다. 등산로주변 토양 및 식생인자의 변화경향을 이용영향의 형태에 따라 구분하여 파악할 수 있었고 등산로주변부에 미치는 이용영향은 약 15m에 이르는 것으로 생각된다. 야영장의 훼손은 심각하여 피해도 5등급의 비율이 약 36%이었고 3등급이상인 지역도 약 69%에 달하였다. 야영장에서의 이용활동이 수목의 직경생장을 크게 저해하는 것으로 나타났으며. 종구성의 이질화를 극심하게 진행시키고 있었다. 야영장의 이용강도의 차이나 이용영향의 범위를 파악하는데 적합한 토양 및 식생인자들을 확인할 수 있었으며, 이용간섭의 영향범위는 약 50m이었다. 야영행위에 대한 내성수종은 물푸레나무, 개옻나무, 노린재나무, 국수나무 등이었다.

• 한국습지학회지
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• 제11권2호
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• pp.17-28
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• 2009

광주광역시 도심 영산강 수계의 관속식물은 91과 265속 386종 49변종 및 2품종으로 총 437분류군이 확인되었다. 수생식물 중 정수식물은 16분류군, 부엽식물은 10분류군, 침수식물은 10분류군, 부유식물은 3분류군 그리고 습생식물은 14분류군으로 총 53분류군이었다. 희귀 및 멸종위기종은 자라풀, 가시연꽃, 낙지다리, 왕벚나무, 좀어리연꽃 등 5분류군이었다. 특정식물종 I급종은 10분류군, II급종 2분류군, III급종 2분류군, IV급종 3분류군 그리고 V급종 5분류군이 확인되었다. 귀화식물은 15과 44속 59종 3변종으로 총 62분류군이 확인되었고 귀화율은 14.19%였다. 환경부 생태계 교란종은 돼지풀, 물참새피 및 도깨비가지 등이었다.

• 한국환경생태학회지
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• 제37권1호
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• pp.13-34
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• 2023

Many ecologists try to understand plant communities and societies' changing processes by interacting with environmental factors. Plant communities formed in the sidings of streams, which are more dynamic than forest vegetation, are closely related to the disturbance regime of streams. U. pumila, which forms communities at the edges of streams, is distributed over the central and northern regions of the Korean Peninsula. In this study, we intended to explain the regeneration of U. pumila communities in the upstream region of the Namhangang River. Heights from the stream surface to the mid-high points of communities increased when the age class of U. pumila communities increased. On the other hand, the height of U. pumila tended to increase and decrease as the age class increased. The richness (S), evenness (J'), diversity (H'), and maximum diversity (H'max) also showed a tendency to increase and then decrease as the age class increased. On the other hand, the number of stems per individual and density (D) decreased as the age class increased. Seedlings of U. pumila failed to regenerate in the communities at the intermediate or higher stage of the age class. Regeneration of seedlings occurred in the spaces formed by the flooding, which occurred periodically in streams. After regeneration, U. pumila communities grew like a single organism. On the other hand, the plant species consisting of U. pumila communities exhibited a process in which the S and H' increased and then decreased as they developed. In other words, we determined that the changes in the species compositions were associated with changes in each species' environment and community. A space where seeds can regenerate seedlings should be provided for the regeneration of U. pumila communities. In the mid/upstream region of the Namhangang River, where the present study focused, newly formed communities were rare because the space required to regenerate U. pumila ceased to exist. Accordingly, we suggest securing an appropriate space for the regeneration of seedlings to maintain the U. pumila communities in the upstream region of the Namhangang River.

• Advances in robotics research
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• 제2권3호
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• pp.237-245
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• 2018

This study evaluates the efficacy of a class robust control scheme namely active force control in performing a joint based trajectory tracking of an upper limb exoskeleton in rehabilitating the elbow joint. The plant of the exoskeleton system is obtained via system identification method whilst the PD gains were tuned heuristically. The estimated inertial parameter that enables the AFC disturbance rejection effect is attained by means of a non-nature based metaheuristic optimisation technique known as simulated Kalman filter (SKF). It was demonstrated from the present investigation that the proposed PDAFC scheme outperformed the classical PD algorithm in tracking the prescribed trajectory both in the presence and without the presence of disturbance attributed by the mannequin limb weights (1 kg and 1.5 kg) that mimics the weight of actual human limb weight. Therefore, it is apparent from the results obtained from the present study that the proposed control scheme, i.e., PDAFC is suitable for the application of exoskeleton for stroke rehabilitation.