• Title/Summary/Keyword: DISTURBANCE FACTOR

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

  • Park, Heon-Woo
    • Korean Journal of Environmental Biology
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    • v.28 no.2
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    • pp.49-55
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    • 2010
  • There are only 10,000 Saunders' Gull's (Larus saundersi Swinhoe) surviving in the world today. But they are being threatened by coastal habitat, degradation, development pressure and disturbance by humans. Their first breeding record in Korea was in 1998 and the breeding status has been studied, however, the breeding status is not sufficient for this species. This study was performed from May 1999 to June 2009 to clarify breeding populations and trend of the Saunders' Gull population in Korea. The results indicate that the breeding population has been increasing gradually from 300 to 1,300 individuals, though disturbance increased. As threats to the breeding birds, physical environmental factors such as development and human disturbance were identified as a major threatening factors. Also, as a secondary factor, eggs and chicks are falling pray to predators. Incheon bay breeding places have been created by a landfill projects for the purpose of urban and industrial development, thus, these places will no longer be available for this species. In addition, the breeding habitat has been reduced and changed by expansions of development on the ground. Therefore, well planed management schemes should be provided for the species' breeding population to be continually breed and survive.

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

  • Lee, Dong-Keun;Cho, Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.8
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    • pp.877-883
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    • 2012
  • Multipath ultrasonic flowmeters are increasingly being used for the purpose of accurate flow measurement. However, an installation standard has not yet been established for these flowmeters, and this can cause considerable confusion during field installation. There is a need for a minimum straight run to ensure the measurement accuracy of a flowmeter installed upstream and downstream of flow disturbance factors-expansion, contraction, and tee pipes. Experiments were performed by using multipath flowmeters that have less than ${\pm}0.5%$ accuracy-4-paths 1-unit and 2-paths 1-unit are of foreign make, whereas 5-paths 2-units are of domestic make-to determine the straight run under the above conditions. We carried out experiments repeatedly by considering a straight run, velocity, and suggested installation standards for a multipath ultrasonic flowmeter that satisfies the tolerance limits.

The Relationship Between Symptoms of Oral Mucosal Diseases and Psychological Status

  • Park, Hye Sook
    • Journal of Oral Medicine and Pain
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    • v.46 no.1
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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.

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

  • Jeong, Gwang-Sik;Kim, Young-Guen;Kwon, Jung-Nam;Kim, Kyoung-Min
    • The Journal of Internal Korean Medicine
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    • v.21 no.5
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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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Sleep Patterns of ICU Patients, Characteristics and Factors Related to Sleep Disturbance (중환자실 환자의 수면양상, 수면장애특성 및 수면장애요인)

  • Noh Won-Jae;Lee Young-Mee;Sohng Kyeong-Yae
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.12 no.2
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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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    • 2003.10a
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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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Analysis of Power Quality for Extra-High Voltage Customers by Field Tests (실측에 의한 특고압수용가의 전력품질 분석)

  • Ji, Pyeong-Shik;Moon, Jong-Fil
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.61 no.2
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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.

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

  • 오진주;송미순;김신미
    • Journal of Korean Academy of Nursing
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    • v.28 no.3
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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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Design of a CDBC Using Second-order Smoothing Element (2차 평활요소를 이용한 CDBC의 설계)

  • 김진용;김성열;이금원
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.1
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    • pp.67-73
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    • 2002
  • This paper presents a new design method of optimal continuous deadbeat controller by using second-order smoothing elements. The continuous deadbeat controller is made of a serial integral compensator and a local feedback compensator introduced into the state feedback loop. The decision method of the damping factor and the natural angular frequency of the smoothing element is described. A numerical example is given to show how well input-output characteristics are improved. Especially according to the variable input and disturbance, corresponding CDBC design method is suggested. By computer simulations, control inputs and system outputs are shown to have desirable property such as smoothness.

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

  • 김현태;김광훈;문형태;조삼래
    • The Korean Journal of Ecology
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    • v.20 no.1
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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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