• Title/Summary/Keyword: ARTIFICIAL DISTURBANCE

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Analysis of Land Cover Composition and Change Patterns in Islands, South Korea (우리나라 도서지역의 토지피복과 변화패턴 분석)

  • Kim, Jaebeom;Lee, Bora;Lee, Ho-Sang;Cho, Nanghyun;Park, Chanwoo;Lee, Kwang-Soo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.24 no.3
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    • pp.190-200
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    • 2022
  • In this study, the island's land-use and land-cover change (LULCC) is analyzed in South Korea using remotely sensed land cover data(Globeland 30) acquired from 2000 to 2020 to meet the requirement of providing practical information for forest management. Analysis of LULCC between the 2000 and 2020 images revealed that changes to agricultural land were the most common type of change (7.6% of pixels), followed by changes to the forest (5.7%). The islands forests maintain 157,246 ha (42.2% of the total island area). Land cover types that changed to the forest from grasslands were 262 islands, while reverse cases have occurred on 421 islands. These 683 islands have a possibility of transition and disturbance. The artificial land class was newly calculated in 22 islands. The forests, which account for 42.2% of the 22 island area, turned into grassland, and 27.8% of agricultural land and grassland turned into forests. The development of artificial land often affects developed areas and surrounding areas, resulting in deforestation, management of agriculture, and landscaping. This study can provide insights concerning the fundamental data for assessing ecological functions and constructing forest management plans in islands ecosystems.

A Comparative Study on the Relationship between Tree Form and Volume in Stands of Pinus koraiensis and Larix leptolepis (잣나무의 낙엽송림(落葉松林)에 있어서 수형(樹型)과 재적간(材積間)의 관계(關係) 비교(比較))

  • Kim, Ji Hong;Lee, Chong Koo
    • Journal of Korean Society of Forest Science
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    • v.74 no.1
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    • pp.82-87
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    • 1986
  • Noticed that large number of the Korean white pine (Pinus koraiensis S. et Z.) has lost its typical excurrent tree from by removal of apical shoot in the process of cone harvesting, the investigation and analysis for the species were made on the basis of the relationship among DBH, total height, merchantable height, and merchantable volume, compared with normally grown Japanese larch (Larix leptolepis Gordon). One hundred sample trees for each species were selected in the same aged stands for the study. Results have indicated that the pine has shown abnormal height growth pattern mainly by the disturbance of external artificial force. The pine's forked and/or crooked stems by the reason lave led the result of less merchantable volume in the same DBH classes. Consequently, the pine would have undesirable tree form in terms of timber production, unless free from apical shoot disturbances. Considered to the merit of the Korean white pine that can produce timber and pine nuts, management alternatives for the pine stand were suggested to achieve maximum rate of return for the silvicultural investment.

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The First Web Space Free Flap of the Foot to Reconstruct the Pulp of Fingers (수지 수질부 재건을 위한 족부의 제 1물갈퀴부 유리 피판술)

  • Kong, Byeong Seon;Kim, Yun Seok;Lee, Hyeong Seok;Jung, Dae Won;Kwak, Jae Yong;Lee, Hyun Suk
    • Archives of Reconstructive Microsurgery
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    • v.21 no.2
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    • pp.153-158
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    • 2012
  • Purpose: The first web space of the foot has a similar thickness and skin texture of the pulp of the fingers. Moreover, it has a reliable blood vessel and sensory nerve. The purpose of this study was to evaluate the clinical results of the first web space free flap to reconstruct the pulp of fingers. Materials and Methods: Authors have performed 23 cases of first web space free flap to reconstruct the pulp defect of the fingers between June 2004 and May 2009. The age of the patients ranged from 20 years old to 55 years old. The size of the flap ranged from $1{\times}1.5cm$ to $8.5{\times}2.5cm$. The mean flap area was 5.4 cm2. In 4 cases, we elevated the flap including lateral aspect of the big toe and medial aspect of the second toe. And then we made an artificial syndactyly to reconstruct the pulps on two fingers at the same time. In all cases, we performed 1 digital artery and 1 dorsal vein anastomosis. Every donor site that had a small defect healed spontaneously without any additional operations to cover it. Results: Of this type of surgery 21 flaps (91.3%) survived, 2 flaps (8.7%) failed. There was no severe complication in the donor sites. There was no walking disturbance due to the skin defect of the donor site. The static 2 point discrimination in 11 cases that we could check ranged from 3 mm to 15 mm. Conclusion: The authors believe that the first web space free flap of the foot is a good option for the reconstruction of the pulp of the fingers and it has a minimal donor site morbidity.

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Implementation of Active Sound Enrichment Control for Improving Engine Sound Quality Inside the Cabin of a Passenger Car (차량 실내공간의 가속 시 엔진음 음질 향상을 위한 실시간 능동음향증강 제어 구현)

  • Lee, Young-Sup;Kim, Jeakwan;Ryu, Seokhoon;Kim, Seonghyeon;Park, Dong Chul
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.2
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    • pp.195-202
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    • 2016
  • In this study, a concept of active sound enrichment (ASE) control system was implemented and demonstrated for improving engine sound quality inside the cabin of a passenger car during acceleration. Unlike the active noise control cancels the noise for disturbance rejection, the ASE adds additional sound to the noise for tracking control. This approach requires a new algorithm to provide additional artificial sound to the original engine sound using active control strategy to achieve a target sound profile, which is predefined to satisfy required interior sound quality. The ASE algorithm was implemented in a digital controller dSPACE DS1401 and real-time control experiment was accomplished in an actual car. The ASE control results show that the actively enriched sound of each engine order against RPM tracks the target profiles precisely and quickly and improves the discontinuity, the level ratios and the sound pressure level of each engine order. Thus it is anticipated the ASE system can be applied for the improvement of the engine sound quality inside the cabin during acceleration.

A Study on the Biotope's Characters of the Mixed Rural City(I) - In the case of Maejuri area in Sunghwan eup, Chonan city - (도농통합형 도시에 있어서 생물서식처 공간특성에 관한 연구(I) - 천안시 성환읍 매주리지역을 중심으로 -)

  • Lee, Haeng-Youl;Bang, Kwang-Ja;Lee, Jae-Keun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.2 no.2
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    • pp.78-87
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    • 1999
  • This study was aimed to establish the method and process of the Biotope Mapping System.(B.M.S.) The main aspects of research for biotope were divided by 4 schemes such as biosphere, geosphere, antroposphere and evaluation informations. The cartographic function of GIS(geographic information system) was also used to mapping them. The B.M.S. had been progressed with 5 steps : (1) making research goals, (2) constructing the graphic and attribute databases, (3) classifying 3 types of biotope such as tree/shrub biotop, grass biotop and wetland biotop. (4) cross-analyzing biotope types against land use, habitat characters, relief characters and danger/disturbance elements, (5) evaluating the biotope's potentialities. Only 3 steps of them were done in this study. The results of applicating the B.M.S on the research site as followings : 1. The interdisciplinary researches were needed to develop the B.M.S in Korea since ecological habitat conditions of Germany, England are differed from them of Korea. 2. The distributions of the land uses in Maejuri, Seunghwan eup in Chonan city were mainly recorded by forest(29.82%), orchard(14.11%) and landscaping around building site(9.05%). 3. The percentages of the Tree/Shrub Biotope type were ranged by the orchard type(23.8%), natural and artificial deciduous type with natural coniferous(23.6%) and etc. 4. The Grass Biotope type was mainly recorded by the wild grassland type(27.99%), garden type(14.21%) and peddy field with wild grassland(13.24%). 5. The distributions of the wetland were pointed high at the wetland type with reed marsh and edge vegetation around wetland(54.79%) and etc.

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Status of Riparian Vegetation and Implication for Restoration in the Seunggi Stream, Incheon (인천 승기천에서 하안식생의 현황과 복원 방안)

  • Cho, Kang-Hyun;Kim, Jaai;Lee, Hyo Hye Mi;Kwon, Oh Byung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.2
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    • pp.62-73
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    • 2001
  • The riparian environments of urban streams in Korea have been disturbed through the channelization for flood control and artificial land use as well as water pollution and flow decrease due to industrialization and urbanization. The flora and vegetation structure were investigated and an implication of stream restoration was discussed for the conservation of biodiversity in the riparian area of the Seunggi stream in Incheon. Naturalized plants and ruderal plants were widely distributed in the riparian area which was disturbed from cultivating, trampling, dumping etc. Submerged and floating hydrophytes were not found in the stream due to channelization and water pollution. Some halophytes were remained in downstream and reservoir after reclamation and embankment. The communities of Humulus japonicus, Panicum dichotomiflorum, Digitaria sanguinalis, Artemisia montana, Amaranthus retroflexus, and Aster pilosus were distributed in the disturbed area of bank slope and floodplain in the stream. As a natural potential vegetation, Phragmites australis in the wet meadow, Typha latifolia, Typha angustifolia, Oenanthe javanica, Persicaria thunbergii, and Penthorum chinense in the marsh, and Salix babylonica and Salix matsudana for. tortuosa in the woodland appeared in the floodplain. The topography in the stream played an important role on the distribution of riparian vegetation in the Seunggi stream. Appropriate methods for conservation and restoration of the riparian ecosystems must be planned on the basis of the actual vegetation in the disturbed urban stream.

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A development of an assessment system for stream physical environments in Korea (하천의 물리 환경 평가체계의 구축)

  • Jung, Hea-Reyn;Kim, Ki-Heung
    • Journal of Korea Water Resources Association
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    • v.51 no.8
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    • pp.713-727
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    • 2018
  • This study is to develop an assessment system for stream physical environments by considering stream characteristics. Comprehensively, the descriptions of and steam classification, assessing reach selection, contents of assessment categories and indexes are summarized. Since the physical structure of stream is results of reaction by stream power, streams were classified into three types (as high gradient stream, mid gradient stream and low gradient stream) according to the slope of channel, the grain size of bed material and the characteristics of channel topography. The scale of assessment reach was selected based on 10 or 25 times of channel width according to typical characteristics such as interval of step or riffle and sinuosity in each stream type. The assessment indexes were organized into common indicators such as channel stability, flow status, cross-section shape, bank stability, channel alteration and stream crossing structure, and characteristic indicators by stream type such as effective habitats, bed embeddedness, diversity of flow and frequency of step or riffle. To evaluate the applicability, the assessment system was applied to 9 streams and the results were analyzed and presented.

STPI Controller of IPMSM Drive using Neural Network (신경회로망을 이용한 IPMSM 드라이브의 STPI 제어기)

  • Ko, Jae-Sub;Choi, Jung-Sik;Chung, Dong-Hwa
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.2 s.314
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    • pp.24-31
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    • 2007
  • This paper presents self tuning PI(STPI) controller of IPMSM drive using neural network. In general, PI controller in computer numerically controlled machine process fixed gain. They may perform well under some operating conditions, but not all. To increase the robustness of fixed gain PI controller, STPI controller proposes a new method based neural network. STPI controller is developed to minimize overshoot, rise time and settling time following sudden parameter changes such as speed, load torque and inertia. Also, this paper is proposed speed control of IPMSM using neural network and estimation of speed using artificial neural network(ANN) controller. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The results on a speed controller of IPMSM are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.

Fault Diagnosis System based on Sound using Feature Extraction Method of Frequency Domain

  • Vununu, Caleb;Kwon, Oh-Heum;Moon, Kwang-Seok;Lee, Suk-Hwan;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
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    • v.21 no.4
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    • pp.450-463
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    • 2018
  • Sound based machine fault diagnosis is the process consisting of detecting automatically the damages that affect the machines by analyzing the sounds they produce during their operating time. The collected sounds being inevitably corrupted by random disturbance, the most important part of the diagnosis consists of discovering the hidden elements inside the data that can reveal the faulty patterns. This paper presents a novel feature extraction methodology that combines various digital signal processing and pattern recognition methods for the analysis of the sounds produced by the drills. Using the Fourier analysis, the magnitude spectrum of the sounds are extracted, converted into two-dimensional vectors and uniformly normalized in such a way that they can be represented as 8-bit grayscale images. Histogram equalization is then performed over the obtained images in order to adjust their very poor contrast. The obtained contrast enhanced images will be used as the features of our diagnosis system. Finally, principal component analysis is performed over the image features for reducing their dimensions and a nonlinear classifier is adopted to produce the final response. Unlike the conventional features, the results demonstrate that the proposed feature extraction method manages to capture the hidden health patterns of the sound.

The Clinical Effect of High Voltage AC Reid Therapy(HEALTHTRON) on Peripheral Circulatory Disturbance and Functional Outcome of Rehabilitation in CVA Patients (교류고압전계요법이 뇌졸중환자의 말초혈류 및 재활기능에 미치는 효과에 대한 임상연구)

  • Sung Kang Keyng;Hwang Choong Yeon;Lee Sang Kwan;Lee So Young;Cheong Sang Su;Kang Se Young;Lee Jong Deck
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.3
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    • pp.609-615
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    • 2002
  • A medical treatment of alternating current high-voltage electric field therapy is a method in which we get a healing effect, applying electric field to an organism through an artificial device. In order to estimate the clinical effects of alternating current high-voltage electric field load(HEALTHTRON) on the rehabilitation of stroke patients, improvement of a peripheral blood circulation, and psychogenic symptom, we used BEUNZEUNGHEYNG Instrument, NIHSS(the National Institutes of Health Stroke Scale), FIM(Functional Independence Measure)lnstrument to research BEUNZEUNGHEYNG and recovery of rehabilitative funation. and also we used Thermography, Pulse Meter to measure body temperature and pulse, blood elements, and neuro modulators. We have reached the following conclusions after researching the clinical effects of alternating current high-voltage electric field therapy on the recovery of rehabilitative function and peripheral blood circulation. 1. HEALTHTRON efficiently has increased the volume of peripheral blood circulation in stroke patients. 2. HEALTHTRON rapidly has treated the symptoms of sleeplessness, alertness, and dizziness of stroke patients. 3. HEALTHTRON rapidly has improved rehabilitative function of stroke patients and the adjustment to their activities.