• 제목/요약/키워드: disturbance factor

검색결과 314건 처리시간 0.034초

인천만의 검은머리갈매기(Larus saundersi) 번식개체군 변동 (Breeding Populations Trend of the Saunders' Gull (Larus saundersi Swinhoe) in Incheon Bay)

  • 박헌우
    • 환경생물
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    • 제28권2호
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    • pp.49-55
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    • 2010
  • 검은머리갈매기는 서식지 축소와 개발압력으로 10,000개체 내외가 생존하고 있는 종이다. 국내에서의 첫 번식 기록은 1998년이며 이후 지속적으로 연구되어 왔으나 아직은 부족한 실정이다. 이에 따라 1998년부터 2009년까지 11년간 번식 개체군의 변동 추세를 모니터링하고 경향을 예측하고자 하였다. 그 결과 국내에서는 1998년 시화호에서 300개체가 번식한 이후 2009년 1,300여 개체가 번식을 시도하여 해마다 증가되었다. 주번식지인 중국의 경우에도 개체수가 지속적으로 증가하고 있어 전체 개체군은 증가추세에 있다. 국내의 번식지는 인간에 의한 훼방과 간섭, 개발, 포식 동물들로 인하여 위협받고 있으며, 인천만의 경우 송도 신도시 매립지, 영종도 매립지 등 갯벌의 매립지에서 번식하고 있다. 그러나 이곳은 개발이 진행됨에 따라 번식 장소가 수시로 변동되고 서식지도 축소되고 있어 새로운 대체번식지와 서식지를 마련하지 않을 경우 번식개체군의 감소를 가져올 수 있을 것으로 예상된다.

유동교란인자(축소·확대관, Tee관)상하류에 설치된 다회선초음파 유량계의 특성 (Characteristics of Multipath Ultrasonic Flowmeter Installed Upstream and Downstream of Flow Disturbance Factors-Contraction, Expansion, and Tee Pipe)

  • 이동근;조용
    • 대한기계학회논문집B
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    • 제36권8호
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    • pp.877-883
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    • 2012
  • 정확한 유량측정의 목적으로 다회선방식을 이용한 초음파유량계의 설치가 점차 증가하는 추세에 있으나 이에 대한 설치기준이 아직까지는 수립되어 있지 않아 현장설치 시 많은 혼선을 일으키고 있다. 따라서 측정의 정확도 확보에 영향을 주는 유동교란인자 중에서 확대관, 축소관 및 Tee관이 다회선 초음파유량계의 상하류에 설치되어 있는 경우에 필요로 하는 직관거리를 결정하기 위한 실험을 실시하였다. 실험대상으로는 정확도가 ${\pm}0.5%$ 이하인 제품으로 국산 5회선 2개, 외산 2회선 1개, 4회선 1개 등 4개의 제품을 선정하고 유량 즉, 유속과 직관거리별로 반복적인 실험을 통해 허용오차를 만족하는 설치기준을 제시하였다.

The Relationship Between Symptoms of Oral Mucosal Diseases and Psychological Status

  • Park, Hye Sook
    • Journal of Oral Medicine and Pain
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    • 제46권1호
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    • pp.1-8
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    • 2021
  • Purpose: The purpose of this study was to assess the relationship between psychological factors and symptoms of oral mucosal diseases by means of the revised version of the Minnesota Multiphasic Personality Inventory (MMPI-2). Methods: Three hundred and eighteen college students in Gyeonggi-do completed the MMPI-2 and a questionnaire related to symptoms of oral mucosal diseases and collected data were analyzed by Student's t-test and one way ANOVA. Results: Subjects who have experienced herpetic stomatitis revealed significantly higher mean values of T-scores than subjects who have not on hypochondriasis (Hs) and hysteria (Hy) clinical scales of the MMPI-2 (p<0.05). In comparison with subjects who have had recurrent aphthous ulceration, subjects who have not had it manifested significantly higher elevations on the schizophrenia (Sc) clinical scale (p<0.05). Subjects who have suffered oral lichen planus (OLP) showed significantly higher mean values of T-scores than subjects who have not on paranoia (Pa) (p<0.05) and hypomania (Ma) (p<0.01) clinical scales. Mean values of T-scores on Ma clinical scale were significantly higher in subjects having experienced glossodynia than in subjects having not experienced (p<0.05). Subjects having felt taste disturbance exhibited significantly higher elevations on Hs (p<0.0001) and Hy (p<0.01) clinical scales compared to subjects having not. Conclusions: Symptoms of oral mucosal diseases such as herpetic stomatitis, taste disturbance, OLP, and glossodynia were found to be related to Hs, Hy, Pa, Ma clinical scales of the MMPI-2. Therefore, comprehensive psychological evaluations of those oral mucosal diseases may be beneficial in a therapeutic approach.

부정맥(不整脈)에 대(對)한 동서의학적(東西醫學的) 문헌고찰(文獻考察) (A Investigation into Arrhythmia between East and West medicine)

  • 정광식;김영균;권정남;김경민
    • 대한한방내과학회지
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    • 제21권5호
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    • pp.747-763
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    • 2000
  • through a literal study upon Arrhythmia between east and west medicine, the results were as follows 1. Arrhythmia is not only irregular cardiac beat but disorder of cardiac impulse making and conduction disturbance. it means almost irregularity of interval between two beat 2. In the east medicine, arrhythmia is represented various category as palpitation, continuous palpitation, dizziness, consumption which give the first consideration by the accompanied symptoms. A separate way in a diagnostics it become a base of diagnosis of diseases and decision of prognosis by the examination of pulse 3. In the west medicine, Arrhythmia is classified as disorder of heart rate, rhythm, conduction disturbance or tachycardia, bradycardia and it is concomitant with fatigue, palpitation, dyspnoea, syncope, chest discomfort 4. The diagnostic study of pulse condition which represent arrhythmia was started from $\mathbb{<}$Nae-Kyung$\mathbb{>}$ and it was revealed as pulse condition of rapid pulse, slow pulse, swift pulse, running pulse, knotted pulse, intermittent pulse etc. Out of them running pulse, knotted pulse, intermittent pulse which obviously are concomitant with irregularity of interval are clinically meaningful in a conditions of disease and decision of prognosis. and the significance of these pulse condition are transformed through the changes of the times 5. According to cause of disease it is classified by Arrhythmia(running pulse, knotted pulse, intermittent pulse) due to heat, cold, phlegm, deficiency(or insufficiency) and There are three categories of etiological factor that is, endogenous, exogenous and non-exo-endogenous factor. the endogenous factor is insufficiency of the heart Ki, deficiency of both Ki and blood, intemal stagnation of phlegm and fluid, stagnation of seven emotions. the exogenous factor is caused by stagnation of Ki and blood by six exogenous pathogenic factor and the non-exo-endgenous factors are improper diet, overstrain, traumatic injury. A cause of arrhythmia in western medicine are a organic and pathological change of the heart itself and malfunction of the autonomic nervous system.

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중환자실 환자의 수면양상, 수면장애특성 및 수면장애요인 (Sleep Patterns of ICU Patients, Characteristics and Factors Related to Sleep Disturbance)

  • 노원재;이영미;송경애
    • 기본간호학회지
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    • 제12권2호
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    • pp.247-254
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    • 2005
  • Purpose: This study was done to examine the sleep pattern of ICU patients, as well as characteristics of, and factors related to sleep disturbances, and state anxiety. It was done to provide the basic data fur effective nursing interventions to improve quality of sleep for these patients. Methods: The participants were 104 patients who were admitted to the surgical ICU in a hospital in Seoul. To measure sleep patterns, the Verran and Snyder-Halpern Sleep Scale and the Sleeping Scale developed by Oh et al.(1998) were used. Characteristics of sleep disturbances were measured using the Sleep characteristics scale developed by Park(1999). To measure factors related to sleep disturbances, thirty items developed by Oh(1998) were used. Results: There was no statistically significant difference in the sleep patterns according to the general characteristics of the patients. The characteristics of sleep disturbances showed statistically significant differences in general and specific characteristics of sleep patterns but there was no statistically significant difference according to the general characteristics of the patients. There were significant negative correlations between factors related to sleep disturbances and general and specific characteristics of sleep patterns but there were no statistically significant difference according to the general characteristics of the patients. Conclusion: The results showed that the majority of patients staying in the surgical ICU experienced sleep disturbances and that the physical factor was the major factor of sleep disturbances.

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Analysis and Design of Sliding Mode Control for a Single-Phase AC-DC Converter

  • Sawaengsinkasikit, Winyu;Tipsuwanporn, Vittaya;Tarasantisuk, Chanlit
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.2291-2294
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    • 2003
  • In this paper, analysis and control design of ac-dc converter, normally nonlinear time-varying system, using sliding mode controller to achieve fast output voltage response, disturbance rejection and robust system in the presence of load variation are demonstrated. The objective of this method is to develop methodology for output voltage to be constant and input current sinusoidal that results in nearly unity power factor, respectively. In addition the converter can be also bidirectional power flow. Simulation results using Matlab/Simulink show the effectiveness of sliding mode control system compared with linear feedback controller to guarantee enhanced PF>0.98, THD<5%, and ripple output voltage is less than 1% at the maximum output power.

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실측에 의한 특고압수용가의 전력품질 분석 (Analysis of Power Quality for Extra-High Voltage Customers by Field Tests)

  • 지평식;문종필
    • 전기학회논문지P
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    • 제61권2호
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    • pp.82-86
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    • 2012
  • Recently, due to the expansion of electric power demands, nonlinear load such as converters and inverters connected to the electric power distribution system, and extensive application of harmonic generation sources with power electric devices, disturbance of the electric power system and its influences on industries have been continuously increasing. In this research, power quality was analyzed for 11 extra-high voltage customers by considering voltage unbalance condition, power factor, THD and TDD. This research will be utilized as fundamental data to improve power quality for power utility.

수면측정 도구의 개발을 위한 연구 (Development and Validation of Korean Sleep Scale A)

  • 오진주;송미순;김신미
    • 대한간호학회지
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    • 제28권3호
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    • pp.563-572
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    • 1998
  • The purpose of study was to develop and validate Korean Sleep Scale A which can be easily administrated by nurses for a wide range of adult subjects. Dimensions of sleep concept were derived by literature review. Previously developed sleep sclaes were also analyzed in order to develop scale items. The Korean sleep scale A was structured as a 15 item, 4 point likert type scale. The Scale was tested an 298 female and male adult subjects after pilottest and content validation. The results showed reliability by internal consistency of Cronbach's α=.75 Construct validity was tested by factor analysis and known group technique. Factor analysis showed 4 factors-sleep pattern, sleep evaluation, sleep result, and cause of sleep disturbance. These four factors explained 55.9% of total variance. Correlations between factors ranged from .15-.32. There was correlation among Korean Sleep ScaleA score, Verran and Snyder-Halpern(VSH) Sleep Scale score, and sleep satisfaction scale score, r=.71(p=.00), r=.51(p=.03), respectively, These study results partially support reliability, construct validity, and criterion related validity of Korean Sleep Scale A. Further validation study is required with other subjects and other settings.

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2차 평활요소를 이용한 CDBC의 설계 (Design of a CDBC Using Second-order Smoothing Element)

  • 김진용;김성열;이금원
    • 융합신호처리학회논문지
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    • 제3권1호
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    • pp.67-73
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    • 2002
  • 본 논문은 2차 평활요소를 사용한 최적 연속계 유한정정 서보시스템의 새로운 설계법을 제시한다. 직렬 적분 보상기와 지역 귀환보상기를 상태귀환 루프에 도입하여 연속유한정정제어기를 만든다. 평활요소의 감쇄비와 고유 각주파 수의 결정법을 서술한다. 입출력 특성이 어떻게 개선되는지를 수치예제를 통하여 보인다. 특히 임의의 시간에 인가되는 외란 및 가변 입력에 대한 CDBC를 설계하는 방법을 제시한다.

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한국 중서부 지방에서의 서식지 환경요인에 따른 월동 청둥오리(Anas platyrhynchos)의 주간행동 (Habitat Quality Factors and Diurnal Activity Patterns of Wintering Mallards(Anas platyrhynchos) in Central-West, Korea.)

  • 김현태;김광훈;문형태;조삼래
    • The Korean Journal of Ecology
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    • 제20권1호
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    • pp.9-14
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    • 1997
  • Wintering behavior of mallards Anas platyrhynchos was studied from November 1995 to February 1996 at wintering habitats : Seosan reclaimed site, Oksan reservoir, and Kum river in Korea. The population of wintering mallards in maximum count was about 35, 000 at Sosan, 500 at Oksan and 1, 680 at Kum river, respectively. In Seosan area, mallards spent more time on water surface. In Kum river and Oksan reservoir, however, they spent more time in riversides. During the daylight hours, mallards spent more time in riversides and ground as the time passes by in the area. Behavioral patterns varied with habitat type, by days and months. Resting was a major time expenditure of mallards on water surface and riversides, and feeding occured occasionally on the ground. During the daytime, feeding and resting activities increased as time passed toward dusks However, time spendings for locmotion and comfort were decreased when it is close to the sun sets. Major disturbance factors within the habitats were identified the local traffics of humans, boats, aircrafts and motor vehicles. Among them, human was the most frequently affecting disturbance factor to the wintering mallards.

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