• 제목/요약/키워드: Normal variability

검색결과 353건 처리시간 0.03초

2009년 태풍 특징 (Characteristics of Tropical Cyclones Over the Western North Pacific in 2009)

  • 차은정;권혁조;김세진
    • 대기
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    • 제20권4호
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    • pp.451-466
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    • 2010
  • This edition has continued since 2006 tropical cyclone season our effort to provide standard tropical cyclone summaries by the western North Pacific basin and detailed reviews of operationally or meteorologically significant tropical cyclones to document significant challenges and shortfalls in the tropical cyclone warning system to serve as a focal point for research and development efforts. The tropical cyclone season of 2009 in the western North Pacific basin is summarized and the main characteristics of general atmospheric circulation are described. Also, the official track and intensity forecasts of these cyclones are verified. The total number is less than 59-year (1951~2009) average frequency of 26.4. The 2009 western North Pacific season was an inactive one, in which 22 tropical storms generated. Of these, 13 TCs reached typhoon (TY) intensity, while the rest 9 TCs only reached severe tropical storm (STS) and tropical storm (TS) intensity - three STS and six TS storms. On average of 22 TCs in 2009, the Korea Meteorological Administration official track forecast error for 48 hours was 219 km. There was a big challenge for individual cyclones such as 0902 CHAN-HOM, 0909 ETAU, and 0920 LUPIT resulting in significant forecast error, with both intricate tracks and irregular moving speed. There was no tropical cyclone causing significant direct impact to the country. The tropical cyclone season in 2009 began in May with the formation of KUJIRA (0901). In September and October, ten TSs formed in the western North Pacific in response to enhanced convective activity. On the other hand, the TC activity was very weak from June to July. It is found that the unusual anti-cyclonic circulation in the lower level and weak convection near the Philippines are dominant during summertime. The convection and atmospheric circulation in the western North Pacific contributed unfavorable condition for TC activity in the 2009 summertime. Year 2009 has continued the below normal condition since mid 1990s which is apparent in the decadal variability in TC activity.

GMS 상층운량의 40~50일 계절만 진동 (The 40~50Day Intraseasonal Oscillation of the Geostationary Meteorological Satellite High Cloud Amount)

  • 하경자;서애숙
    • 한국환경과학회지
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    • 제5권5호
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    • pp.619-633
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    • 1996
  • 인도양 및 서태평양 부근의 적도 대류의 계절안 변동을 GMS 상층운량을 사용하여 연구되었다. 이 연구는 90E-l7IW와 495-5ON 영역에서의 여름 몬순의 계절안 및 경년 변동 주기내의 열대-중위도 상호 관계를 찾는데 방향이 맞추어져 있다. 특히 상층운량에서 적도 대류와 연관된 동아시아 몬순의 계절안 상호작용을 이해하기 위해 대규모 대류의 이동과 진화에 대한 공간 및 시간 구조의 분석이 이루어졌다. 공간과 시간 발전을 동시에 보기 위해 연장 경험적 직교함수 분석이 적용되었다. 그 첫째는 정규 구조로 간주될 수 있는, 90E-l2OE의 강한 대류의 동쪽 확장이 뚜렷한 모드이나 우리나라와 일본 부근에서는 해마다 변동하는 모드이다. 둘째, 세째 및 네째 모드들은 여름 몬순 동안 계절안 변동성을 가지고 증폭되는 모드들이다. 적도 대류에서 가장 강력한 계절안 모드가 바로 40~50일 부근에 탁월 주기를 갖고 있는 공간 구조로 구성되는 것이 확인되었다.

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심박변이도를 통한 급성, 기능성, 기질성 소화불량증의 비교연구 (Comparative Study of Acute Dyspepsia, Functional Dyspepsia, Organic Dyspepsia by HRV(Heart Rate Variability))

  • 김효진;김보경;김원일
    • 동의신경정신과학회지
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    • 제21권2호
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    • pp.75-85
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    • 2010
  • Objectives : This study was designed to evaluate the correlation between patterns of dyspepsia(acute dyspepsia, functional dyspepsia, dyspepsia with the organic disease) and autonomic nerve system dysfunction using HRV analysis. Methods : The patient group consisted of 88 patients diagnosed as a dyspepsia (Acute dyspepsia group-35 patients, Functional dyspepsia group-28 patients, Dyspepsia with the organic disease group-28 patients) who visited in the Oriental Medical Hospital of Dong-eui University from 2005.3.OO to 2008.8.OO. And the control group consisted of 33 patients diagnosed as a normal state of stomach during the same period. We checked HRV of the 4 groups over 5 minutes and compared the HRV index between groups. Results : 1. HF, LF, VLF and TP were significantly lower in the acute dyspepsia, functional dyspepsia and organic dyspepsia patient group than in the control group. 2. HF, LF, VLF and TP were higher in the acute dyspepsia patient group than in the organic dyspepsia patient group, but the differences were not statistically significant. 3. HF, LF, VLF and TP were higher in the acute dyspepsia patient group than in the functional dyspepsia patient group, but the differences were not statistically significant. 4. HF, LF, VLF and TP were lower in the functional dyspepsia patient group than in the organic dyspepsia patient group, but the differences were not statistically significant. Conclusions : Compared to the control group, all of the dyspepsia patient groups showed the tendency that the overall activity of the autonomic nervous system and the activity of sympathetic nerves decreased. Although there was no significant difference in the suppression of the autonomic nervous system, chronic dyspepsia patient group was lower than acute dyspepsia patient group, functional dyspepsia patient group was lower than the organic dyspepsia patient group in HRV.

An Experimental Study of Comfortable Pitch and Loudness with Target Matching: Effects on Electroglottographic and Acoustic Measures

  • 최성희
    • 말소리와 음성과학
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    • 제4권4호
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    • pp.139-146
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    • 2012
  • This study was designed to examine comfort levels of pitch and loudness with target matching and their effects on electroglottographic (EGG) and acoustic measures. Twelve speakers, six males and six females, were instructed to produce /a/ sustained vowel for three seconds at a comfortable pitch and loudness level without any instruction and with a target matching procedure of either a certain f0 or SPL separately with visual and auditory feedback. The range of pitch for females and males were presented by progressing up and down randomly at intervals of 5Hz from 150 Hz to 310 Hz (total 33 frequency targets) and from 85 Hz to 190 Hz (total 22 frequency targets), respectively. The loudness levels were 65, 75, 85, 95 dB (total of four intensity targets) for both males and females. Subjective estimations of comfortable levels were obtained using a 10-point equal-appearing interval rating scale following each phonation. The results showed that males and females demonstrated similar trends in loudness levels with greatest comfort at 75 dB, whereas pitch comfort ratings showed a greater variability with females having a wider range with target matching. In the comfort levels of individuals, most male and female speakers rated higher comfort at soft, rather than loud phonations. On the other hand, most male speakers perceived highest comfort levels below the comfort pitch levels they phonated under natural conditions. Higher frequency ranges, however, were perceived to be more comfortable than those of natural condition in most female speakers, although the comfortable pitch levels in spontaneous phonations were within the comfort level ranges determined by targeted phonations. When comparing acoustic (%jitter, %shimmer, SNR) and EGG measures (CQ%) between spontaneous comfortable phonations and targeted phonations produced by the same subject at similar f0 and intensity, no significant differences were observed (p>0.05). Thus, target matching procedures may be considered a compatible and alternative method to reduce the variability of comfortable pitch and loudness levels by eliciting consistent comfortable phonations.

심박변이도를 통한 침자극과 스트레스의 상관관계 연구 (A Study on the Relationship with Acupuncture Stimulation and Stress Using Heart Rate Variability)

  • 이승기;박경모;최우진
    • 동의신경정신과학회지
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    • 제15권1호
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    • pp.197-209
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    • 2004
  • Objectives : The purpose of this case-control research was to investigate the effects of acupuncture stimulation on autonomic nervous system for patients with HRV and to find out relationship with anti-stress effects. Methods : The study group consists of 24 patients with self-recognition of stress as the case group, and 20 normal person as the control group by similar age. We measured HRV of case and control groups before acupuncture stimulation, prick acupuncture in Hegu(LI4), Taichong(Liv3), Shenme(H7), Neiguan(P6), Zusanli(S36). After treating for 20 minutes, measurement values of HRV and PSV were compared for pre-acupuncture and post-acupuncture. Results : 1. LF norm, HF norm, LF/HF between the case and control groups were significant different in HRV before acupuncture stimulation in the 1st experiment. 2. HRT, SDNN, SDSD, LF norm, HF norm, and LF/HF of the case group were significant different in HRV after acupuncture stimulation in the 1st experiment. HRT of the case group was significantly different in HRV after acupuncture stimulation in the 1st experiment. 3. LF norm, HF norm, LF/HF of the case group were significant different between the 1st and 2nd experiment in HRV before acupuncture stimulation. 4. LF norm, HF norm, and LF/HF were significant different between the 1st and 2nd experiment in HRV of patients whose symptoms improved. But HRV of patients whose symptoms unimproved didn't show significant difference. Conclusion : The results suggest that acupuncture stimulation is associated with changed activity in the sympathetic and parasympathetic nervous system. Measurement values of HRV is suitable to estimate the activity of automatic nervous system.

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A Study at Investigating the Climate Change in East Asia with Changing Sea Surface Temperature

  • Park, Geun-Yeong;Lim, Yong-Jae
    • 통합자연과학논문집
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    • 제13권1호
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    • pp.27-33
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    • 2020
  • The unsustainable human activities like increased use of automobiles, heavy industrialization and the use of large volumes of fertilizers, chemicals and pesticides in the agricultural land cause climate change problems in one way or another. Under normal circumstances, the heat radiations from the sun will be reflected back. An excessive volume of GHGs in the atmosphere would prevent these radiations from reflecting back. East Asia is facing severe climate change issues in recent times. A lot of climate change problems such as hurricanes and floods have been reported from this region in the last couple of decades. The study aimed at investigating the climate change in East Asia with changing Sea Surface Temperature (SST). The study adopted a quantitative research method with a case study research design where a deliberate focus was made on the East Asia Region. Secondary data was gathered and analyzed to yield both descriptive and inferential statistics. The study concluded that the impact of East Asia Climate variability was significant mainly for some extreme events. Also, the study concluded that there was a significant link between the change of the East Asia climate variability and that of the sea surface temperature. Further, the study concluded that a linear relationship existed between the sea surface temperature and the climate of East Asia. Hence, a linear regression was a significant predictor of the East Asia Climate (EAC) based on changing sea surface temperature. The model revealed that 37.4% of the variations in the climate change index were explained by the changes in the sea surface temperature. The climate was expected to change with a value of 49.48 for a unit change in the sea surface temperature.

생체 신호를 이용한 열차 승차감 평가 시스템 연구 (Study of Ride Comfort on Train through Physiological Parameter)

  • 송용수;오석문;이재호;김용규
    • 대한인간공학회지
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    • 제30권1호
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    • pp.237-250
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    • 2011
  • The train transportation has a lot of advantages-energy efficiency is high, it is eco-friendly, safety is better than normal roads and it is possible for people to arrive on time. In these days, the valuation of ride comfort, which is only limited to road transportation, is newly recognized in order to having competitiveness from other transportation. Especially, in the development of the Korean high-speed railroad business, the ride comfort enhancement of train is very important problem to be solved. Currently, there are international standards of ride comfort such as UIC13, ISO2631. In Korea case, although it has own standard like KS R9216, it mainly depends on the physical parameter such as vibration and noise. So recently, in the valuation of ride comfort, the movements of living parameter technique introduction are increasing on the base of Japan and many developed countries of Europe techniques. Presently, the method of train ride comfort is mainly based of vibration, that is, mechanical parameter adding selection of variable acceleration and noise. This paper would like to show biological parameter; heart rate and blood pressure variation. This method is more direct, based on human body response, than mechanical parameter method. In this experiment, the variability of heart rate and blood pressure of passengers according to tilting angle change of Train, the Korean tilting train, we are supposed to know that the extent of tilting on the simulation has influence on variability of heart rate and blood pressure, which are living parameter of heart's blood.

Mentolabial angle and aesthetics: a quantitative investigation of idealized and normative values

  • Naini, Farhad B.;Cobourne, Martyn T.;Garagiola, Umberto;McDonald, Fraser;Wertheim, David
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제39권
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    • pp.4.1-4.7
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    • 2017
  • Background: This study is a quantitative evaluation of the influence of the mentolabial angle on perceived attractiveness and threshold values of desire for surgery. Methods: The mentolabial angle of an idealized silhouette male Caucasian profile image was altered incrementally between $84^{\circ}$ and $162^{\circ}$. Images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), lay people (n = 75) and clinicians (n = 35). Results: A mentolabial angle of approximately $107^{\circ}$ to $118^{\circ}$ was deemed the most attractive, with a range of up to $140^{\circ}$ deemed acceptable. Angles above or below this range were perceived as unattractive, and anything outside the range of below $98^{\circ}$ or above $162^{\circ}$ was deemed very unattractive. A deep mentolabial angle ($84^{\circ}$) or an almost flat angle ($162^{\circ}$) was deemed the least attractive. In terms of threshold values of desire for surgery, for all groups, a threshold value of ${\geq}162^{\circ}$ and ${\leq}84^{\circ}$ indicated a preference for surgery, although clinicians were least likely to suggest surgery. The clinician group was the most consistent, and for many of the images, there was some variation in agreement between clinicians and lay people as to whether surgery is required. There was even more variability in the assessments for the patient group. Conclusions: It is recommended that in orthognathic and genioplasty planning, the range of normal variability of the mentolabial angle, in terms of observer acceptance, is taken into account as well as threshold values of desire for surgery. The importance of using patients as observers in attractiveness research is stressed.

Electrocardiographic characteristics of significant factors of detected atrial fibrillation using WEMS

  • 김민수;김윤년;조영창
    • 한국산업정보학회논문지
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    • 제20권6호
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    • pp.37-46
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    • 2015
  • The wireless electrocardiographic monitoring system(WDMS) is designed to be long term monitoring for the early detection of cardiac disorders. The current version of the WDMS can identify two types of cardiac rhythms in real-time, such as atrial fibrillation(AF) and normal sinus rhythm(NSR), which are very important to track cardiac-rhythm disorders. In this study, we proposed the analysis method to discriminate the characteristics statistically evaluated in both time and frequency domains between AF and NSR using various parameters in the heart rate variability(HRV). And we applied various ECG detection methods (e.g., difference operation method) and compared the results with those of the discrete wavelet transform(DWT) method. From the statistically results, we found that the parameters such as STD RR, STD HR, RMSSD, NN50, pNN50, RR Trian, and TNN(p<0.05) are significantly different between the AF and NSR patients in time domain. On the other hand, the frequency domain analysis results showed a significant difference in VLF power($ms^2$), LF power($ms^2$), HF power($ms^2$), VLF(%), LF(%), and HF(%). In particular, the parameters such as STD RR, RMSSD, NN50, pNN50, VLF power, LF power and HF power were considered as the most useful parameters in both AF and NSR patient groups. Our proposed method can be efficiently applied to early detection of abnormal conditions and prevent the such abnormals from becoming serious.

Relation of Various Parameters Used to Estimate Cardiac Vagal Activity and Validity of pNN50 in Anesthetized Humans

  • Lee, Jae Ho;Huh, In Young;Lee, Jae Min;Lee, Hyung Kwan;Han, Il Sang;Kang, Ho Jun
    • 고신대학교 의과대학 학술지
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    • 제33권3호
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    • pp.369-379
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    • 2018
  • Objectives: Analysis of heart rate variability (HRV) has been used as a measure of cardiac autonomic function. According to the pNN50 statistic, the percentage of differences between successive normal RR intervals (RRI) that exceed 50 ms, has been known to reflect cardiac vagal modulation. Relatively little is known about the validity of pNN50 during general anesthesia (GA). Therefore, we evaluated the correlation of pNN50 with other variables such as HF, RMSSD, SD1 of HRV reflecting the vagal tone, and examined the validity of pNN50 in anesthetized patients. Methods: We assessed changes in RRI, pNN50, root mean square of successive differences of RRI (RMSSD), high frequency (HF) and standard deviation 1 (SD1) of $Poincar{\acute{e}}$ plots after GA using sevoflurane anesthesia. We also calculated the probability distributions for the family of pNNx statistics (x: 2-50 ms). Results: All HRV variables were significantly decreased during GA. HF power was not correlated with pNN50 during GA (r = 0.096, P = 0.392). Less than pNN47 was shown to have a correlation with other variables. Conclusions: These data suggest that pNN50 can not reflect the level of vagal tone during GA.