• Title/Summary/Keyword: Physical disturbance

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Control of the flexible system under irregular disturbance by using of 『random gain』

  • Cho, Yun-Hyun;Yang, Jae-Hyuk;Kim, Dae-Jung;Park, Sang-Tae;Chung, Jae-Wook;Hoon Heo
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.435-439
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    • 1998
  • A control strategy for flexible structure under irregular disturbance by using of$\boxDr$random gain$\boxUl$is developed and implemented. System equation is transformed to stochastic domain by F-P-K approach from physical domain. A controller is designed in the stochastic domain, accordingly system is controlled by$\boxDr$random gain$\boxUl$in time domain. In the paper, a new control technique is successfully employed for flexible system under white noise, and the result is verified by Monte-Carlo simulation and compared with the performance via LQR controller.

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Chronic Fatigue Syndrme (만성 피로 증후군)

  • Song, Gwan-Gyu
    • Journal of muscle and joint health
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    • v.4 no.2
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    • pp.163-176
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    • 1997
  • Chronic fatigue syndrome Is a syndrome of unknown etiology and pathophysiology characterized by severe, chronic, debilitating fatigue as main symptom and numerous additional symptoms such as joint and muscle pain, headache, sleep disturbance. According to recent researches, it was suggested that chronic fatigue syndrome was developed by disturbance of interaction between neuropsychiatric system and immune system due to environmental factors and stress. Many patients experience gradual improvement but complete recovery from disorderd state is rare. There was no research elucidating the exact pathogenetic mechanism of chronic fatigue syndrome, so there was no established treatment. Several controlled studies about treatment was reported, but its results was not effective in all patients with chronic fatigue syndrome. For chronic fatigue syndrome, a comprehensive approach to physical, psychological, and social aspects is needed.

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Analysis of River Disturbance using a GIS (I) (GIS기법을 이용한 하천 교란 실태의 분석(I))

  • Park, Eun-Ji;Kim, Kye-Hyun;Lee, On-Kil
    • Journal of Korea Spatial Information System Society
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    • v.10 no.2
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    • pp.81-93
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    • 2008
  • Current re-arrangement of river and waterway has been made uniformly ignoring characteristics of individual rivers thereby aggravating artificial river restructuring. Subsequently this severely affects the rivers' physical, chemical, and biological phenomenon. On the contrary, quantitative techniques to evaluate the aftermath of artificial river disturbance such as uprising of river bed, intrusion of foreign fisheries, and changes of ecological habitats are not available. To establish such quantitative techniques, analysis of river changes to evaluate the major causes of the river disturbance and its impacts is essential. Therefore, this study mainly focused on proposing a method which can be applied for the development of techniques to investigate river disturbance according to the major factors for the domestic rivers using airphotos and GIS techniques. For the analysis, the study area on the downstream of the river was selected and airphotos of the area were converted into GIS format to generate 'shape' files to secure waterways, river banks, and auxiliary data required for analyzing river disturbance. Trend analysis of the waterway sinuosity and changes of the flow path leaded to detailed verification of the river disturbance for specific location or time period, and this enabled to relatively accurate numbers representing sinuosity of the waterway and relevant changes. As the major results from the analysis, the relocation of waterways and the level of river sinuosity were quantified and used to verify the impacts on the stability of the waterways especially in the downstream of the dam. The results from this study enabled effective establishing proper measures against waterways' unstability, and emphasized subsequent researches for identifying better alternatives against river disturbances.

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A primary study on the effect of artificial disturbance on a fishing area by shrimp beam trawl (새우조망에 의한 어업구역의 인위적인 영향에 대한 선행연구)

  • Cha, Bong-Jin;Yoon, Sang-Pil;Jung, Rae-Hong;Kim, Soung-gill;Lee, Jae-Soung;Yoon, Won-Duck;Shin, Jong-keun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.45 no.4
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    • pp.223-233
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    • 2009
  • It has been considered that fishing areas for shrimp beam trawl have been in ruin because Korean local governments have permitted trawling into the areas limited by the fisheries local regulations from 1994. Physical and biological effects of the trawling were investigated in the study. Physical effects were investigated by optical methods such as trawling tracking by side scan sonar and comparing the gear both before and after trawling. Biological aspects were investigated by grab sampling of benthic animals, concentration of trace metals in sediment and a flux evaluation of ${NH_4}^+,\;{PO_4}^-,\;and\;SiO_2$ by coring. The fishing activity had physical impacts on the seabed but these recovered naturally in less than fourty days naturally, which increased the benthic biodiversity, increases the trace metal concentration of and nutrient flux into the seawater, especially phosphate and silicate. This method and these results can help in further studies looking for disturbances by fishing.

An Experimental Study on the Stochastic Control of a Flexible Structural System (유연한 구조물의 확률론적 제어에 대한 실험적 연구)

  • Kim, Dae-Jung;Heo, Hoon
    • Journal of KSNVE
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    • v.9 no.3
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    • pp.502-508
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    • 1999
  • Newly developed control methodology applied to dynamic system under random disturbance is investigated and its performance is verified experimentall. Flexible cantilever beam sticked with piezofilm sensor and piezoceramic actuator is modelled in physical domain. Dynamic moment equation for the system is derived via Ito's stochastic differential equation and F-P-K equation. Also system's characteristics in stochastic domain is analyzed simultaneously. LQG controller is designed and used in physical and stochastic domain as wall. It is shown experimentally that randomly excited beam on the base is controlled effectively by designed LQG controller in physical domain. By comparing the result with that of LQG controller designed in stochastic domain, it is shown that new control method, what we called $\ulcorner$Heo-stochastic controller design technique$\lrcorner$, has better performance than conventional ones as a controller.

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The Effects of Disturbance Factors of Exercise on Leisure Satisfaction and Health Related Quality of Life(EQ-5D) in Sports Facility Users in the Era of COVID-19 (코로나-19시대 스포츠시설 이용고객의 운동방해요인이 여가만족과 건강관련 삶의 질(EQ-5D) 관계)

  • Shin, Jeong-Hun
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.8
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    • pp.203-211
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    • 2021
  • The purpose of this study is to analyze the effects of disturbance factors of exercise on leisure satisfaction and health-related quality of life in the era of COVID-19 in club members participating in sports for all and use for basic data for continuous exercise to keep and improve health. 353 sports for all club members who consented to the study participated in the study after the purposes and methods of the study were explained. The following conclusions were drawn. The disturbance factors of exercise had significant effects on leisure satisfaction and health-related quality of life in sports for all club members. Moreover, leisure satisfaction had significant effects on health-related quality of life. Although we hope to end COVID-19, we should prepare with Corona. Sports facilities should strive for quarantine and personal hygiene to help sports for all club members' continuous participation in exercise for their healthy life.

Network Technology-based Aesthetic Practices: Focused on the Digital Activism of Electronic Disturbance Theater (네트워크 테크놀로지 기반의 미적 실천: 전자교란극단의 디지털 행동주의를 중심으로)

  • Shan Lim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.2
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    • pp.215-220
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    • 2023
  • Network technology used as a physical interface to retrieve, store, and exchange data is leading the era of data capitalism in the 21st century. The capacity of network technology dominates almost all communication in everyday life, and makes social understanding and experiences in the physical world visible in cyberspace. The movements of human bodies and objects in cyberspace are placed in a social context. This paper paid attention to these phenomena and examined the cases of activism that raised real problems through cyberspace. In particular, the focus of the study is the digital activism of the Electronic Disturbance Theater, which combines critical art and thinking for democracy with the realm of information and demonstrates aesthetic imagination. The first chapter of the main body briefly outlines the meaning activism as a social movement in cyberspace. The second chapter looks back on the alternatives of <FloodNet>, which represents the early activism performance of EDT. And then in the last chapter, the poetic significance of the <Transborder Immigrant Tool> is analyzed. Through this process, this paper demonstrates that the activism performance of the EDT is a critical aesthetics that encourages imagination for alternatives. It also argues that Electronic Disturbance Theater has contemporary value as an avant-garde art that actively utilizes the medium of network technology and integrates performance art and politics.

Interpretation of Physical Properties of Marine Sediments Using Multi­Sensor Core Logger (MSCL): Comparison with Discrete Samples

  • Kim, Gil-Young;Kim, Dae-Choul
    • Journal of the korean society of oceanography
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    • v.38 no.4
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    • pp.166-172
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    • 2003
  • Multi­Sensor Core Logger (MSCL) is a useful system for logging the physical properties (compressional wave velocity, wet bulk density, fractional porosity, magnetic susceptibility and/or natural gamma radiation) of marine sediments through scanning of whole cores in a nondestructive fashion. But MSCL has a number of problems that can lead to spurious results depending on the various factors such as core slumping, gas expansion, mechanical stretching, and the thickness variation of core liner and sediment. For the verification of MSCL data, compressional wave velocity, wet bulk density, and porosity were measured on discrete samples by Hamilton Frame and Gravimetric method, respectively. Acoustic impedance was also calculated. Physical property data (velocity, wet bulk density, and impedance) logged by MSCL were slightly larger than those of discrete sample, and porosity is reverse. Average difference between MSCL and discrete sample at both sites is relatively small such as 22­24 m/s in velocity, $0.02­-0.08\;g/\textrm{cm}^3$ in wet bulk density, and 2.5­2.7% in porosity. The values also show systematic variation with sediment depth. A variety of factors are probably responsible for the differences including instrument error, various measurement method, sediment disturbance, and accuracy of calibration. Therefore, MSCL can be effectively used to collect physical property data with high resolution and quality, if the calibration is accurately completed.

Effects of the Brain waves according to participation in Therapeutic recreation programs on the Depression, Sleep Disturbance and Quality of Life in the Elderly with Dementia (치료레크리에이션 프로그램에 따른 치매노인의 뇌파 변화가 우울감 및 수면장애와 삶의 질에 미치는 영향)

  • Lee, Moon-Sook;Cho, Byung-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5096-5110
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    • 2015
  • The purpose of this study was to identify the effects of brain wave change through therapeutic recreation programs on depression, sleep disturbance and quality of life among elderly with dementia. The subjects of this quasi-experimental study consisted of two groups, one experimental group (N=14) and one control group (N=18), after excluding 8 participants from a total of 40 participants. The subjects of experimental group were randomly selected from the elderly (order than 65 years old) of senior care center in Daejoen and participated in 3-month therapeutic recreation program. On the other hand, the subjects of control group did not participated in any therapeutic recreation program. Each group's pre-post brain wave change, depression, sleep disturbance and quality of life were estimated. Through ANCOVA and Analysis of Structural Equation Modeling with SPSS window 17.0 and AMOS 7.0, this study found followings. Frist, the therapeutic recreation program group indicated significant improvement of brain waves, sleep disturbance and quality of Life. In addition, depression was significantly reduced in the therapeutic recreation program group. Second, significant causal relationships was found among brain waves, depression, sleep disturbance, and Quality of Life.

Post Discharge Nursing Needs of Patients with Open Heart Surgery (개심술 환자의 퇴원후 간호요구에 대한 조사연구)

  • 김명희
    • Journal of Korean Academy of Nursing
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    • v.23 no.4
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    • pp.664-677
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    • 1993
  • The purpose of this study was to provide basic data for the development of educational material in Korean for patient3 being discharge after open heart surgery. The subjects were 45 adult patients who were seen in the out -patient department of the thoracic surgery unit of P University hospital between February 1993 and May 1993. The data were collected through a chart review and interview. Nursing needs, and the patients status related to diet, activity, medication, physical and psychoemotional limitations were analyzed. The results are summarized as follows ; 1. Mitral valve replacement was the most frequent type of surgery(91.2%). In most cases, a mechanical valve was used (91.0%) . The duration of admission after the operation was two to four weeks for most of the patients(48.9%). The follow-up period was between one and two years for 28.9% of the patients and below 6 years for all of the patients. 2. Many Patients didn’t know the importance of a low salt diet(57.8%), and did not get any education on low salt diet (66.7%). Gimchi was included as one of the most commonly ingested foods (77.8%). All of the patients indicated nursing needs related to education about low salt diets and further they indicated a major interest in foods that are harmful (57.7%) or foods that are safe(51.1% ). 3. Most patients did not recognize the need for limitations on physical activity(84.4%). Further, 31.1% of them could not return to work at the time of the study. All patients had nursing needs related to physical activity, with the most frequent questions being about the permissble degree of activity and special cautions dictated by their illness (60.0%). 4. Many patients were ignorant of the necessity of medication(55.6%) . Forty percent of the patients were taking additional drugs, usually herb drugs. The time and duration of medication and the side effects of drugs were common concerns (57.7%) related to nursing. needs about medication and were mentioned by all of the patients. 5. All of the patients complained of physical discomfort including the following : memory disturbance(62.2%), weight gain(60.0%), chest tightness (55.6%), hair loss(51.1%), sleep disturbance(46.7%) and other symptoms in that order of frequency. Nursing needs related to physical condition were a concern for all of them. The viability and function of the replaced valve(53.3%) and weight gain(60.0%) were mal or concerns. 6. Looking at their psychoemotional condition it was found that 36 patients(80.0%) were emotionally unstable. The causes were physical discomfort(17 patients), insufficient knowlege of open heart surgery(6 patients), fear of death(6 patients), familial over protection(2 patients ) and lack of support (5 patients).

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