• Title/Summary/Keyword: Coherence Effect

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Analysis of Characteristics of Air Pollution Over Asia with Satellite-derived $NO_2$ and HCHO using Statistical Methods (환경 위성관측자료의 통계분석을 통한 동아시아 대기오염특성 연구)

  • Baek, K.H.;Kim, Jae Hwan
    • Atmosphere
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    • v.20 no.4
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    • pp.495-503
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    • 2010
  • Satellite data have an intrinsic problem due to a number of various physical parameters, which can have a similar effect on measured radiance. Most evaluations of satellite performance have relied on comparisons with limited spatial and temporal resolution of ground-based measurements such as soundings and in-situ measurements. In order to overcome this problem, a new way of satellite data evaluation is suggested with statistical tools such as empirical orthogonal function(EOF), and singular value decomposition(SVD). The EOF analyses with OMI and OMI HCHO over northeast Asia show that the spatial pattern show high correlation with population density. This suggests that human activity is a major source of as well as HCHO over this region. However, this analysis is contradictory to the previous finding with GOME HCHO that biogenic activity is the main driving mechanism(Fu et al., 2007). To verify the source of HCHO over this region, we performed the EOF analyses with vegetation and HCHO distribution. The results showed no coherence in the spatial and temporal pattern between two factors. Rather, the additional SVD analysis between $NO_2$ and HCHO shows consistency in spatial and temporal coherence. This outcome suggests that the anthropogenic emission is the main source of HCHO over the region. We speculate that the previous study appears to be due to low temporal and spatial resolution of GOME measurements or uncertainty in model input data.

A Path Model Predicting Medication Adherence and Self-care of Low-income Older Adults with Hypertension (저소득층 고혈압 노인의 약물복용행위와 자가간호 예측 경로모형)

  • Suh, Soon-Rim;Lee, Eun-Hyun
    • Korean Journal of Adult Nursing
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    • v.23 no.4
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    • pp.374-385
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    • 2011
  • Purpose: The purpose of this study was to identify the factors that influence medication adherence and self-care among low-income older adults with hypertension. Methods: A sample of 297 low-income older adults with hypertension was recruited from June 30 to July 30, 2010. Data collection was done using a face-to-face interview with structured questions. The data were analyzed using descriptive statistics, Pearson's correlation coefficient, and path analysis. Results: Subjective health status, duration of hypertension, number of drugs excluding antihypertensives, body mass index, knowledge about hypertension, sense of coherence, benefit, barrier, and self-efficacy were identified as significant predictors. Subjective health status and duration of hypertension, knowledge, depression, and self-care showed direct effects on medication adherence. Depression had the strongest direct influence on medication adherence. Body mass index, benefit, self-efficacy, and depression showed a direct effect on self-care. Sense of coherence was a strong predictor of depression which significantly influenced on medication adherence and self-care. Conclusion: For enhancing medication adherence and self-care, it is suggested that a psycho-education program reducing depression and increasing knowledge about hypertension should be provided into low-income older adults with hypertension.

Analysis of Data Rate on Optical Communication Links between Geo-Satellite and Earth Station (정지궤도 위성과 지구국간 광통신 링크의 전송속도 해석)

  • Han, Jong-Seok;Jung, Jin-Ho;Kim, Yung-Kwon
    • Journal of IKEEE
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    • v.1 no.1 s.1
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    • pp.120-137
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    • 1997
  • Han's model, which is able to analyze optical communication between earth station and geo-satellite as a function of atmospheric conditions and elevation angles. is presented. In Han's model, atmospheric conditions are roughly classified into six basic types; clear sky, cloud, haze, fog, rain and snow. Data rate satisfying for the BER below $10^{-7}$ is analyzed by Han's model in case of up-link and down-link, respectively. Data rate is more limited by up-link than by down-link because the pointing loss caused by atmosphere on the up-link is greater than the spatial coherence degradation caused by atmosphere on the down-link.

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Identification of Fungus-infected Tomato Seeds Based on Full-Field Optical Coherence Tomography

  • Bharti, Bharti;Yoon, Taeil;Lee, Byeong Ha
    • Current Optics and Photonics
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    • v.3 no.6
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    • pp.571-576
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    • 2019
  • The morphological changes of anthracnose (fungus) -infected tomato seeds have been studied to identify the infection and characterize its effect. Full-field optical coherence tomography (FF-OCT) has been utilized as a nondestructive but efficient modality for visualizing the effects of fungal infection. The cross-sectional images extracted from a stack of en face FF-OCT images showed significant changes with infection in the seed structure. First of all, the seed coat disappeared with the infection. The thickness of the seed coat of a healthy seed was measured as 28.2 ㎛, with a standard deviation of 1.2 ㎛. However, for infected seeds the gap between surface and endosperm was not appreciably observed. In addition, the measurements confirmed that the dryness of seeds did not affect the internal seed structure. The reconstructed three-dimensional (3D) image revealed that the permeability of the seed coat, which plays the vital role of protecting the seed, is also affected by the infection. These results suggest that FF-OCT has good potential for the identification of fungus-infected tomato seeds, and for many other tasks in agriculture.

Characteristics of the Marriage and Marital Stability among Elderly Couples (노년기 부부의 결혼특성요인과 결혼안정성)

  • 김태현;전길양
    • Journal of Families and Better Life
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    • v.20 no.4
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    • pp.197-206
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    • 2002
  • The purpose of this study was to examine the effect of marital characteristics on the marital stability among the elderly couples. Each participant was measured using a scale for the concept of marriage, a scale for marital coherence, a marital stress scale, a coping behavior scale and a marital stability scale. Elderly people who have a living spouse and who are living In Seoul were recruited. The data from two hundred and forty participants over 60-years-old were used in the final analyses. Major findings are as follows First, demographic factors such as educational level, health, economic status, the main source of income, and employment status appeared to significantly predict the elderly folks'marital stability Second, gender seems to be a factor In elderly couples'experience of marital stability. Husbands perceived marital stability to be higher than wives did. Third, the perception of marital stress, positive coping behavior and marital coherence influence the marital stability of the elderly couples. That is, the less elderly couples perceived marital stress and the less they relied on negative coping behaviors, the higher they perceived marital stability. These results imply that a healthful coping behavior to marital stress is important in enhancing marital stability for elderly couples.

Analysis of drought in Northwestern Bangladesh using standardized precipitation index and its relation to Southern oscillation index

  • Nury, Ahmad Hasan;Hasan, Khairul
    • Environmental Engineering Research
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    • v.21 no.1
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    • pp.58-68
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    • 2016
  • The study explored droughts using the Standardized Precipitation Index (SPI) in the northwestern region of Bangladesh, which is the drought prone area. In order to assess the trend and variability of monthly rainfall, as well as 3-month scale SPI, non-parametric Mann-Kendall (MK) tests and continuous wavelet transform were used respectively. The effect of climatic parameters on the drought in this region was also evaluated using SPI, with the Southern Oscilation Index (SOI) by means of the wavelet coherence technique, a relatively new and powerful tool for describing processes. The MK test showed no statistically significant monthly rainfall trends in the selected stations, whereas the seasonal MK test showed a declining rainfall trend in Bogra, Ishurdi, Rangpur and Sayedpur stations respectively. Sen's slope of six stations also provided a decreasing rainfall trend. The trend of the SPI, as well as Sen's slope indicated an increasing dryness trend in this area. Dominant periodicity of 3-month scale SPI at 8 to 16 months, 16 to 32 months, and 32 to 64 months were observed in the study area. The outcomes from this study contribute to hydrologists to establish strategies, priorities and proper use of water resources.

A Study on the Performance Analysis of Cache Coherence Protocols in a Multiprocessor System Using HiPi Bus (HiPi 버스를 사용한 멀티프로세서 시스템에서 캐쉬 코히어런스 프로토콜의 성능 평가에 관한 연구)

  • 김영천;강인곤;황승욱;최진규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.1
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    • pp.57-68
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    • 1993
  • In this paper, we describe a multiprocessor system using the HiPi bus with pended protocol and multiple cache memories, and evalute the performance of the multiprocessor system in terms of processor utilization for various cache coherence protocols. The HiPi bus is delveloped as the shared bus of TICOM II which is a main computer system to establish a nation-wide computing network in ETRI. The HiPi bus has high data transfer rate, but it doesn't allow cache-to-cache transfer. In order to evaluate the effect of cache-to-cache transfer upon the performance of system and to choose a best-performed protocol for HiPi bus, we simulate as follows: First, we analyze the performance of multiprocessor system with HiPi bus in terms of processor utilizatIOn through simulation. Each of cache coherence protocol is described by state transition diagram, and then the probability of each state is calculated by Markov steady state. The calculated probability of each state is used as input parameters of simulation, and modeling and simulation are implemented and performed by using SLAM II graphic symbols and language. Second, we propose the HiPi bus which supports cache-to-cache transfer, and analyze the performance of multiprocessor system with proposed HiPi bus in terms of processor utilization through simulation. Considered cache coherence protocols for the simulation are Write-through, Write-once, Berkely, Synapse, Illinois, Firefly, and Dragon.

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Aerodynamic Investigation of Three-Dimensional Wings in Ground Effect for Aero-levitation Electric Vehicle (공기부상 전동 운행체의 지면효과를 받는 3차원 날개에 대한 공력해석 연구)

  • Oh H. J.;Seo J. H.;Moon Y. J.;Cho J. S.;Yoon Y. H.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.03a
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    • pp.196-201
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    • 2004
  • Aerodynamic characteristics of three-dimensional wings in ground effect for Aero-levitation Electric Vehicle(AEV) are numerically investigated for various ground clearances and wing spans at the Reynolds number of $2\times10^6$. Numerical results show that a sizeable three-dimensional flow separation occurs with formation of an arch vortex at the junction of main and vertical wings, and that this is conjectured a primary cause for the high lift-to-drag(L/D) reduction rate of the main wing, when the wing span is decreased. Improvements on L/D ratios of the wings with small spans are pursued by breaking the coherence of superimposed adverse pressure gradients at the wing junction.

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Boundary Layer Separation Control with Fairing at the Junction of 3D Wings Under Ground Effect (페어링을 이용한 지면효과를 받는 3차원 날개 접합부의 경계층 박리 제어)

  • Cho Ji. H.;Moon Young. J.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.57-64
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    • 2005
  • Aerodynamic characteristics of three-dimensional wings in ground effect for Aero-levitation Electric Vehicle(AEV) are numerically investigated for various fairing shapes at the junctions of 3D Wings. Numerical results show that a sizeable three-dimensional comer flow separation occurs with formation of an arch vortex at the junction of main and vertical wings, and also that this is predicted the main cause of the high lift-to-drag(L/D) reduction rate of the main wing. To avoid the comer flow separation, the main idea of this study is to reduce the cross section gradient of the comer flow tube near the trailing edge for various fairing shapes. Improvements on L/D ratios of the wings are pursued by breaking the coherence of superimposed adverse pressure gradients at the wing junction when the cross section gradient is changed slowly at the trailing edge.

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The Effect of Dictation and Dramatization on Children's Story Construction and Decontextualized Language (유아의 이야기 짓기와 극화 활동의 연계가 유아의 이야기 구조 및 탈상황적 언어 발달에 미치는 영향)

  • Lee, Moom-jung
    • Korean Journal of Child Studies
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    • v.22 no.1
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    • pp.241-249
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    • 2001
  • This study examined the effect of story dictation and dramatization on children's story construction and decontextualized language. For 12 weeks, the 22 five-year-old children in the experimental group participated in story dictation and dramatization activities while another 22 same-age children participated only in story dictation. The instruments were the children's Decontextualized Language Test(Foley, 1992) and children's Story Analysis(Knipping, 1987), revised to fit Korean grammar. Story dictation and dramatization facilitated high level story construction by children: it raised levels of story coherence and narrative form. Story dictation and dramatization also enhanced decontextualized language of children, raising their use of decontextualized language on a picture description task.

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