• Title/Summary/Keyword: Disturbance Index

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Seed Germination of Surface Soil for Restoration of Disturbance Place - Bare Land and abandoned Field, Yesan-gun, Korea - (교란지 복구를 위한 표토의 매토종자 발아특성 - 예산군의 나지와 묵밭 토양-)

  • Kang, Hee-Kyoung;Cho, Nam-Kyoung;Song, Hong-Seon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.20 no.6
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    • pp.79-92
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    • 2017
  • To offer the basic data of vegetation restoration by buried seed of soil, this research was conducted at bare land and abandoned field in Yesan-gun. Germination plants of buried seed were consisted of 40 taxa (37 species, 3 varieties) in bare land, and 41 taxa (37 species, 4 varieties) in abandoned field. Classification of germination plants by family was the most in Gramineae, and emergent frequency of plots was the highest of Digitaria ciliaris. The soil depth of the most plants appearance was 2~5cm in bare land and 5~10cm in abandoned field, and the soil depth of the most population appearance was 0~2cm both in bare land and in abandoned field. Population number of buried seed germination was decreased according to soil depth. Crepidiastrum sonchifolium was a plant that population number of buried seed germination is the most. Similarity index was 0.33 in aerial part plants and buried seed plants, and 0.55 in bare land and abandoned field.

Data-driven modeling of the anaerobic wastewater treatment plant using robust adaptive dynamic PLS method

  • Lee Hae Woo;Lee Min Woo;Joung Jea Youl;Park Jong Moon
    • 한국생물공학회:학술대회논문집
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    • 2004.07a
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    • pp.47-84
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    • 2004
  • Principal Component Analysis나 Partial Least Squares와 같은 다변량 통계 기법은 변수간의 correlation structure로부터 공정의 variance를 설명할 수 있는 latent variable를 얻고 이를 이용하여 공정을 효과적으로 modeling할 수 있는 방법으로 최근 들어 많은 관심을 얻고 있다. 하지만 PLS는 공정이 stationary state에 있다고 가정하기 때문에, 생물학적 공정의 non-stationary and time-varying behavior를 설명하기에 부적절하다. 본 논문에서는 PLS 알고리즘의 혐기성 폐수처리 공정에의 적용에 있어, 이와 같은 문제를 해결하기 위해서 adaptive PLS 알고리즘을 사용함으로써 변화하는 공정의 특성에 대응하여 모델을 update하는 방법을 이용하였다. 하지만 실시간 데이터로부터 adaptive PLS 방법을 적용하는 데에는 많은 어려움이 존재하며, 특히 outlier나 abnormal disturbance에 모델이 부적절하게 adaptation하는 문제가 발생할 수 있다. 따라서 이의 해결을 위해 adaptive PLS를 적용하는데 있어 robustness를 향상시키기 위해 monitoring index를 이용하여 abnormal data에 weight를 주고 안정적인 모델의 update가 가능하게 하는 방법을 제안하였으며, 이를 적용하여 성공적으로 혐기성 폐수처리 공정의 Output을 예측하고 효과적으로 공정을 모니터링할 수 있었다. 만들어진 PLS 모델은 산업폐수를 처리하기 위한 industrial plan에서 측정된 실제 데이터에 적용하여 그 효용성을 입증하였으며, 그 결과는 mechanistic model을 적용하기 힘든 실공정에 비교적 쉽게 implementation할 수 있는 장점이 있다.

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Ecological characteristics of areas naturally inhabited by Dolbae trees(Pyrus pyrifolia) on Mt. Kaya

  • Ahn, Young-Hee;Chung, Kyu-Hwan
    • Journal of Environmental Science International
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    • v.11 no.11
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    • pp.1149-1156
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    • 2002
  • The ecological characteristics of Dolbae trees, a valuable genetic resource for native pyrus fruit trees, were investigated at four naturally inhabited areas on Mount Kaya, Gyeongsangnam-Do. Most Dolbae trees were found on the southwest side of an old hiking path to a mountain valley at altitudes of 610∼670 m. The surrounding flora consisted of 46 families, 69 genera, 75 species, and 10 varieties. The natural habitat of the Dolbae trees was basically a deciduous broad-leaved forest with a predominance of Quercus serrata and ligneous plants(xylophytes) from the Fagaceae and Betulaceae families. The habitat was also found to be in a second transition resulting from forest disturbance and exhibited a degree of diversity of 2.901-5.065, based on Shannon-Weiner's index. Examination of the Dolbae trees found in Mount Kaya revealed diameter breast heights(DBHs) ranging from 10 to 60 cm, including six old and large Dolbae trees with a DBH of 50∼60 cm, which will be particularly valuable as a genetic resource. Accordingly, the current results suggest that the study areas are a secondary forest in a typical mid-temperate zone resulting from forest damage about 10 years earlier.

Development of the Adaptive PPF Controller for the Vibration Syppression of Smart Structures (지능구조물 제어를 위한 적응형 PPF 제어기의 개발)

  • Lee, Seung-Bum;Heo, Seok;Kwak, Moom Ku
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.302-307
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    • 2001
  • This research is concerned with the development of a real-time adaptive PPF controller for the active vibration suppression of smart structure. In general, the tuning of the PPF controller is carried out off-line. In this research, the real-time learning algorithm is developed to find the optimal filter frequency of the PPF controller in real time and the efficacy of the algorithm is proved by implementing it in real time. To this end, the adaptive algorithm is developed by applying the gradient descent method to the predefined performance index, which is similar to the method used popularly in the optimization and neural network controller design. The experiment was carried out to verify the validity of the adaptive PPF controller developed in this research. The experimental results showed that adaptive PPF controller is effective for active vibration control of the structure which is excited by either impact or harmonic disturbance. The filter frequency of the PPF controller can be tuned in a very short period of time thus proving the efficiency of the adaptive PPF controller.

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The Clinical Study of Stress Perceived by 50 patients with Bell's palsy (구안와사 환자 50례의 스트레스 정도에 관한 임상적 연구)

  • Ock, Min-Keun;Huh, Yeon-Sik;Kim, Chang-Hwan;Park, Soo-Eun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.19 no.3 s.31
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    • pp.146-157
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    • 2006
  • Objective : This study is to explore the various of the stress by perceived by paitents with Bell's palsy Methods : 50 patients who were diagnosed as Bell's palsy were sequentially interviewed and examined Results : The results were as follows 1. The mean average PWI(Psychosocial well-being index, total : score)was $41.58{\pm}17.53$ :Factor I(Social performance and self-confidence) with a mean of $11.18{\pm}8.38$, Fact II( Depression) with a mean of $8.94{\pm}6.26$, Factor III(Sleeping disturbance and anxiety) with a mean $of7.56{\pm}5.20$, Factor IV(General well-being and vatality)with a mean $of9.90{\pm}4.44$ 2. With the respect to the general characteristics of subjects, there were statistically significant differences in the patients's stress perception by sex, having an occupation and the amount of sleeping time. Conclusions : We needed the further study about the relation between stress and Bell's palsy

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A Study on the Road Traffic Noise in Residential Area (주거지역 도로교통경음에 관한 조사연구)

  • 김종오
    • Journal of Environmental Health Sciences
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    • v.8 no.1
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    • pp.13-23
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    • 1982
  • This Study was designed to investigate Traffic condition, Traffic Noise level, Traffic Noise Index (TNI) and Response for dissatisfactions of residents as part of assesment of Noise by 12 Sites in Seoul from July 1st to the end of August 1981. As the resut of this Study, the following Conclusion were obtained 1. The mean traffic Volume of Seoul was 3076/hour ranging 1440/hour to 5772/hour. 2. The range of Road Traffic Noise Level in Residential area was from 73.0dB (A) to 80.2dB (A). The highest level was 80.2dB (A) on Heugseog-dong and the lowest level was 73.0dB (A) on Suyu-dong. 3. Comparision of Road traffic noise level in the day and evening, the range of traffic noise level in day was from 73.9dB (A) to 80.2dB (A), and evening was ranging 73.0 to 79.9dB (A). 4. The range of TNI in Residential area was from 77.5 to 100.0. The highest TNI was 100.0 on Suyu-dong including Heugseog-dong, the lowest TNI was 77.5 on Hyuikyung-dong. 5. Respose of Noise by 360 householders has been examined in Residential Area: Sourse of Noise Causing bothersome to residents was 52.5% of traffic, the types of road traffic Cousing annoyance to residents residents were 84.8% of passing cars and 81.1% of horns, and 71.7% of reading interfered and 68.1% appeal dissatisfactions due to the sleeping disturbance by road traffic noise.

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A Study on the Load Frequency Control of 2-Area Power System using Fuzzy-Neural Network Controller (퍼지-신경망 제어기를 이용한 2지역 계통의 부하주파수제어에 관한연구)

  • Chung, Hyeng-Hwan;Kim, Sang-Hyo;Joo, Seok-Min;Lee, Jeong-Phil;Lee, Dong-Chul
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.2
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    • pp.97-106
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    • 1999
  • This paper proposes the structure and the algorithm of the Fuzzy-Neural Controller(FNNC) which is able to adapt itself to unknown plant and the change of circumstances at the Fuzzy Logic Controller(FLC) with the Neural Network. This Learning Fuzzy Logic Controller is made up of Fuzzy Logic controller in charge of a main role and Neural Network of an adaptation in variable circumstances. This construct optimal fuzzy controller applied to the 2-area load frequency control of power system, and then it would examine fitness about parameter variation of plant or variation of circumstances. And it proposes the optimal Scale factor method wsint three preformance functions( E, , U) of system dynamics of load frequency control with error back-propagation learning algorithm. Applying the controller to the model of load frequency control, it is shown that the FNNC method has better rapidity for load disturbance, reduces load frequency maximum deviation and tie line power flow deviation and minimizes reaching and settling time compared to the Optimal Fuzzy Logic Controller(OFLC) and the Optimal Control for optimzation of performance index in past control techniques.

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Acoustic-Resonance Reduction of Metal Halide Lamps Using Amplitude Modulation (진폭변조에 의한 메탈핼라이드 램프의 음향공명 감소)

  • 이치환
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.5
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    • pp.43-49
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    • 2000
  • In this paper, a new control method is presented to reduce acoustic resonance phenomena of metal halide lamps with electronic ballasts. A behavior of frequency controlled resonant inverter is analyzed and the transfer function is obtained. An integrator as a current controller for ballast is employed. By using both a disturbance of the lamp power and spread spectrum effects for reducing acoustic resonance, an amplitude modulation is done by using the current controller with 200[Hz] sinusoidal wave. Arc stabilities of MH 250[W] lamps are studied with changing the modulation index. Experiments with two MH 250[W] lamps, made by different manufacturers, showed the validity of the proposed method.

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A Study of Optimal Design of the Proportional Load-Frequency Controller for a Self-service Power Station (주파수제어를 위한 비열제어기구의 최적설계에 관한 연구)

  • 장세훈;임화영
    • 전기의세계
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    • v.26 no.2
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    • pp.99-103
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    • 1977
  • The object of this work is to study an optimal design problem of the proportional load-frequency controller for the single-control area power system. The selfservice power station is still a popular means as a power supplying source on ships or in a certain manufacturing area. The power system of this kind can be formulated as a single control-area system and it attracts a certain academic interest in controlling the system frequency under disturbances. In this paper, the single control-area system is mathematically formulated as a linear, time-invariant system in state-space under certain assumptions. The optimal proportional control law and the realization of the controller in closed loop-version is studied so that the final system designed can attain the system frequency to the nominal stationing value after the small load-disturbance. As in general cases of optimal design problems, the performance index is assumed to be quadratic in states and the control effort, and the infinite time control process is assumed in this work. The final control system realized depicts certain improvements in case study; in stability, transient responses and in steady-state frequency deviation, even though the steady state error did not attain the zero value.

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Construction of Orthogonal Basis Functions with Non-Divergent Barotropic Rossby-Haurwitz Waves

  • Cheong, Hyeong-Bin;Jeong, Hanbyeol;Kim, Wonho
    • Journal of the Korean earth science society
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    • v.35 no.5
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    • pp.333-341
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    • 2014
  • A new set of basis functions was constructed using the Rossby-Haurwitz waves, which are the eigenfunctions of nondivergent barotropic vorticity equations on the sphere. The basis functions were designed to be non-separable, that is, not factored into functions of either the longitude or the latitude. Due to this property, the nodal lines of the functions are aligned neither along with the meridian nor the parallel. The basis functions can be categorized into groups of which members have the same degree or the total wavenumber-like index on the sphere. The orthonormality of the basis functions were found to be close to the machine roundoffs, giving the error of $O(10^{-15})$ or $O(10^{-16})$ for double-precision computation (64 bit arithmetic). It was demonstrated through time-stepping procedure that the basis functions were also the eigenfunctions of the non-divergent barotropic vorticity equations. The projection of the basis functions was carried out onto the low-resolution geopotential field of Gaussian bell, and compared with the theory. The same projections were performed for the observed atmospheric-geopotential height field of 500 hPa surface to demonstrate decomposition into the fields that contain disturbance of certain range of horizontal scales. The usefulness of the new basis functions was thus addressed for application to the eigenmode analysis of the atmospheric motions on the global domain.