• Title/Summary/Keyword: Background variability

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A Brief Introduction to Marine Ecosystem Modeling (해양 생태모델링 고찰)

  • Kim, Hae-Cheol;Cho, Yang-Ki
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.1
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    • pp.21-31
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    • 2013
  • Ecosystem models are mathematical representations of underlying mechanistic relationships among ecological components and processes. Ecosystem modeling is a useful tool to visualize inherent complexities of ecological relationships among components and the characteristic variability in ecological systems, and to quantitatively predict effects of modification of systems due to human activities and/or climate change. A number of interdisciplinary programs in recent 20 to 30 years motivated oceanographic communities to explore and employ systematic and holistic approaches, and as an outcome of these efforts, synthesis and modeling became a popular and important way of integrating lessons learned from many on-going projects. This is a brief review that includes: background information of ecosystem dynamics model; what needs to be considered in building a model framework; biologically-physically coupled processes; end-to-end modeling efforts; and parameterization and related issues.

Trends of Nursing Research in the Journal of Oncology Nursing (종양간호학회지 논문 내용과 경향 분석;창간호에서 2007년까지)

  • Chung, Bok-Yae;Yi, Myung-Sun;Choi, Eun-Hee
    • Asian Oncology Nursing
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    • v.8 no.1
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    • pp.61-66
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    • 2008
  • Purpose: Purpose of study was to analyze the research articles in the Journal of Korean Oncology Nursing in order to provide an direction for the future research, Methods: This study analyzed 93 studies published in the Journal of Korean Oncology Nursing, from its beginning year to the year 2007, according to the research objectives. The frame of evaluation included years and types of publication, the theoretical frameworks, research design, subject, data collection method, keyword analysis by MeSH. Results: 45.2% of studies was non-degree based studies. 95.7% of studies was not described theoretical framework in the articles. 71.0% was utilized a non-experimental design. 57% of subjects in researches was patients. 76.3% of studies were used the questionnaire for data collection. Concepts as human, nursing, and health were consistently appeared in research. But concepts of environment has been insufficiently conducted. Conclusion: Researches in the Journal of Korean Oncology Nursing has been changed in methodology and the topics of research for the last 7 yr. It progresses in both quantity and quality. But, it is necessary to conduct research founded on theoretical background, various research design, variability of study subjects and topics as supported by scientifically and empirically.

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Meteorologically Adjusted Ozone Trends in the Seoul and Susan Metropolitan Areas (서울과 부산지역 기상의 영향을 제거한 오존농도 추세)

  • 김유근;오인보;황미경
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.5
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    • pp.561-568
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    • 2003
  • Surface ozone concentrations are highly sensitive to meteorological variability. Therefore, in order to reveal the long-term changes in ozone due to the changes in precursor emissions, we need to remove the effects of meteorological fluctuations on the annual distribution of surface ozone. In this paper, the meteorologically adjusted trends of daily maximum surface ozone concentrations in two major Korean cities (Seoul and Busan) are investigated based on ozone data from 11 (Seoul) and 6 (Busan) sites over the period 1992 ∼ 2000. The original time series consisting of the logarithm of daily maximum ozone concentrations are splitted into long-term, seasonal and short-term component using Kolmogorov-Zurbenko (KZ) filter. Meteorological effects are removed from filtered ozone series using multiple linear regression based on meteorologcial variables. The long-term evolution of ozone forming capability due to changes in precursor emission can be obtained applying the KZ filter to the residuals of the regression. The results indicated that meteorologically adjusted long-term daily maximum ozone concentrations had a significant upward trend (Seoul: + 3.02% yr$^{-1}$ , Busan: + 3.45% yr$^{-1}$ ). These changes of meteorologically adjusted ozone concentrations represent the effects of changing background ozone concentrations as well as the more localized changes in emissions.

Assessment of Driver's Emotional Stability by Using Bio-signals (생체신호 측정을 통한 운전자의 감정적 안정상태 평가)

  • Kim, Jung-Yong;Park, Ji-Soo;Yoon, Sang-Young
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.1
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    • pp.203-211
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    • 2011
  • Objective: The aim of this study is to introduce a methodology to assess driver's emotion stability by using bio-signals. Background: Psychophysiological analysis of driver's behavior has been conducted to improve the driving safety and comfort. However, the variability of bio-signal and individual difference made it difficult to assess the psychophysiological status of drivers that can be expressed as emotional stability of drivers. Method: Two experimental studies were reviewed and summarized. New techniques assessing emotional stability of drivers were explained. Statistical concept and multidimensional space were used to identify the emotionally stable conditions. Conclusion: Psychophysiological approach can provide information of driver's emotional status. The experimental methodology and algorithm used in this study showed the possibility of parameterization of psychophysiological response. Application: Currently measured statistical and geometrical data can be further applied to develop an interactive device monitoring and reacting driver's emotion when driver experiences emotionally unstable or uncomfortable situation.

The Reliability of Preoperative Simulation Surgery Planning for Distraction Osteogensis in Craniosynostosis Patients

  • Hussein, Mohammed Ahmed;Kim, Yong Oock
    • Journal of International Society for Simulation Surgery
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    • v.3 no.1
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    • pp.22-27
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    • 2016
  • Background Craniosynostosis management using distraction osteogensis represent a challenge for surgeons due to the great variability of the skull deformity even within the same etiology. The ability to apply the simulation surgery for improving the preoperative planning for distraction osteogensis could improve the results.Planning and Simulation 14 patients presented with craniosynostosis had been subjected to simulation surgery prior to real surgery. 3D CT scans was obtained upon patient admission. Adjustment of all skull position to Frankfort horizontal plane was done. 3 different distraction osteogensis plans were done for each patient according to the skull morphology. For each plane, movement for each bone segment was done according to the pre-planned distraction vectors. Also the distances of distractions were pre-determined according to the cephalic index as well as brain volume. Intraoperatively, we choose the most appropriate plan for the patient by the surgeon. At the end of distraction, 3D CT scan was obtained, and was compared to the simulation plan. Also the distance and the direction of distraction was compared to that of the plan. Accordingly, the distance was almost matching that of the simulation surgery, however the vector of distraction was not matched.Conclusion Preoperative stimulation planning for craniosynostosis patient is very valuable tool in the surgical management of craniosynostosis patients.

Nonlinear Correlation Dimension Analysis of EEG and HRV (뇌파의 상관차원과 HRV의 상관분석)

  • Kim, Jung-Gyun;Park, Young-Bae;Park, Young-Jae;Kim, Min-Yong
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.11 no.2
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    • pp.84-95
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    • 2007
  • Background and Purpose: We have studied the trends of EEG signals in the voluntary breathing condition by applying the fractal analysis. According to chaos theory, irregularity of EEG signals can result from low dimensional deterministic chaos. A principal parameter to quantify the degree of Chaotic nonlinear dynamics is correlation dimension. The aim of this study was to analyze correlation between the correlation dimension of EEG and HRV(heart rate variability). We have studied the trends of EEG signals in the voluntary breathing condition by applying the fractal analysis. Methods: EEG raw data were measured by moving windows during 15 minutes. Then, the correlation dimension(D2) was calculated by each 40-seconds-segment in 15 minutes data, totally 36 segments. 8 channels EEG study on the Fp, F, T, P was carried out in 30 subjects. Results and Conclusion: Correlation analysis of HRV was calculated with deterministic non-linear data and stochastic non-linear data. 1. Ch1(Fp1), Ch4(F3), Ch4(F4) is positive correlated with In LF. 2. Ch1(Fp1), Ch3(F3) is positive correlated with In TF.

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Estimation of carbon storage in coastal wetlands and comparison of different management schemes in South Korea

  • Byun, Chaeho;Lee, Shi-Hoon;Kang, Hojeong
    • Journal of Ecology and Environment
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    • v.43 no.1
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    • pp.61-72
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    • 2019
  • Background: Organic carbon stored in coastal wetlands, which comprises the major part of oceanic "blue carbon," is a subject of growing interest and concern. In this study, organic carbon storage in coastal wetlands and its economic value were estimated using the raw data of 25 studies related to soil carbon storage. Data were collected from three tidal flats (one protected and two developed areas) and two estuarine salt marshes (one protected and one restored area). Bulk density, soil organic matter content, and standing biomass of vegetation were all considered, with Monte Carlo simulation applied to estimate the uncertainty. Results: Mean carbon storage in two salt marshes ranged between 14.6 and $25.5kg\;C\;m^{-2}$. Mean carbon storage in tidal flats ranged from 18.2 to $28.6kg\;C\;m^{-2}$, with variability possibly related to soil texture. The economic value of stored carbon was estimated by comparison with the price of carbon in the emission trading market. The value of US $ $6600\;ha^{-1}$ is ~ 45% of previously estimated ecosystem services from fishery production and water purification functions in coastal areas. Conclusions: Although our study sites do not cover all types of large marine ecosystem, this study highlights the substantial contribution of coastal wetlands as carbon sinks and the importance of conserving these habitats to maximize their ecosystem services.

Comparison of PET image quality using simultaneous PET/MR by attenuation correction with various MR pulse sequences

  • Park, Chan Rok;Lee, Youngjin
    • Nuclear Engineering and Technology
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    • v.51 no.6
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    • pp.1610-1615
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    • 2019
  • Positron emission tomography (PET)/magnetic resonance (MR) scanning has the advantage of less additional exposure to radiation than does PET/computed tomography (CT). In particular, MR based attenuation correction (MR AC) can greatly affect the image quality of PET and is frequently obtained using various MR sequences. Thus, the purpose of the current study was to quantitatively compare the image quality between MR non-AC (MR NAC) and MR AC in PET images with three MR sequences. Percent image uniformity (PIU), percent contrast recovery (PCR), and percent background variability (PBV) were estimated to evaluate the quality of PET images with MR AC. Based on the results of PIU, 15.2% increase in the average quality was observed for PET images with MR AC than for PET images with MR NAC. In addition, 28.6% and 71.1% improvement in the average results of PCR and PBV respectively, was observed for PET images with MR AC compared with that with MR NAC. Moreover, no significant difference was observed among the average values using three MR sequences. In conclusion, the current study demonstrated that PET with MR AC improved the image quality and can be help diagnosis in all MR sequence cases.

Effects of HR-AC Techniques and Kinesio Taping on Pain Changes in Delayed Onset Muscle Soreness (지연성근육통에 적용한 HR-AC기법과 키네시오 테이핑이 통증 변화에 미치는 영향)

  • Bae, Sea-hyun;Kim, Kyung-yoon
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.26 no.2
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    • pp.1-10
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    • 2020
  • Background: This study aimed to investigate the effect of hold-relax and antagonist contraction (HR-AC) technique and Kinesio taping on pain changes in delayed-onset muscle soreness (DOMS) of 20's adults. Methods: Based on voluntary participation, 14 participants with induced-DOMS were randomly divided into control (non-treatment, n=7) and experiment group (HR-AC technique and kinesio taping, n=7). Measurement were used visual analogue scale (VAS), heart rate variability (HRV), and brain wave (alpha). There were 5 sets of the HR-AC technique application on the 5th day from the day of DOMS induction (rest for 30s between sets). Kinesio taping was applied to the same area after HR-AC. Results: The VAS showed significant changes according to the period and in the interaction between the period and the group (p<.01). HRV and alpha wave (Fp1) showed significant changes according to the period (p<.001). The analgesic effect was more rapid and continuous in the experimental group than in the control group. Conclusion: This study showed that the HR-AC technique and Kinesio taping are effective interventions for the management of pain and stress caused by DOMS.

Safety-II and Resilience Engineering in a Nutshell: An Introductory Guide to Their Concepts and Methods

  • Ham, Dong-Han
    • Safety and Health at Work
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    • v.12 no.1
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    • pp.10-19
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    • 2021
  • Background: Traditional safety concept, which is called Safety-I, and its relevant methods and models have much contributed toward enhancing the safety of industrial systems. However, they have proved insufficient to be applied to complex socio-technical systems. As an alternative, Safety-II and resilience engineering have emerged and gained much attention for the last two decades. However, it seems that safety professionals have still difficulty understanding their fundamental concepts and methods. Accordingly, it is necessary to offer an introductory guide to them that helps safety professionals grasp them correctly in consideration of their current practices. Methods: This article firstly explains the limitations of Safety-I and how Safety-II can resolve them from the four points of view. Next, the core concepts of resilience engineering and Functional Resonance Analysis Method are described. Results: Workers' performance adjustment and performance variability due to it should be the basis for understanding human-related accidents in socio-technical systems. It should be acknowledged that successful and failed work performance have the same causes. However, they are not well considered in the traditional safety concept; in contrast, Safety-II and resilience engineering have conceptual bases and practical approaches to reflect them systematically. Conclusion: It is necessary to move from a find-and-fix and reactive approach to a proactive approach to safety management. Safety-II and resilience engineering give a set of useful concepts and methods for proactive safety management. However, if necessary, Safety-I methods need to be properly used for situations where they can still be useful as well.