• Title/Summary/Keyword: mean change

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A Study on Characteristics of Climate Variability and Changes in Weather Indexes in Busan Since 1904 (1904년 이래의 부산 기후 변동성 및 생활기상지수들의 기후변화 특성 연구)

  • Ha-Eun Jeon;Kyung-Ja Ha;Hye-Ryeom Kim
    • Atmosphere
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    • v.33 no.1
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    • pp.1-20
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    • 2023
  • Holding the longest observation data from April 1904, Busan is one of the essential points to understand the climate variability of the Korean Peninsula without missing data since implementing the modern weather observation of the South Korea. Busan is featured by coastal areas and affected by various climate factors and fluctuations. This study aims to investigate climate variability and changes in climatic variables, extremes, and several weather indexes. The statistically significant change points in daily mean rainfall intensity and temperature were found in 1964 and 1965. Based on the change point detection, 117 years were divided into two periods for daily mean rainfall intensity and temperature, respectively. In the long-term temperature analysis of Busan, the increasing trend of the daily maximum temperature during the period of 1965~2021 was larger than the daily mean temperature and the daily minimum temperature. Applying Ensemble Empirical Mode Decomposition, daily maximum temperature is largely affected by the decadal variability compared to the daily mean and minimum temperature. In addition, the trend of daily precipitation intensity from 1964~2021 shows a value of about 0.50 mm day-1, suggesting that the rainfall intensity has increased compared to the preceding period. The results in extremes analysis demonstrate that return values of both extreme temperatures and precipitation show higher values in the latter than in the former period, indicating that the intensity of the current extreme phenomenon increases. For Wet-Bulb Globe Temperature (effective humidity), increasing (decreasing) trend is significant in Busan with the second (third)-largest change among four stations.

Review on Impacts and Possible Adaptation Strategies for Climate Change (기후변화 영향과 향후 적응대책방향에 대한 소고)

  • Choi, Kwang-Ho
    • Journal of Environmental Impact Assessment
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    • v.17 no.3
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    • pp.201-211
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    • 2008
  • According to IPCC fourth assessment report in 2007, global mean temperatures have risen by 0.74 degrees Celsius over the past 100 years. Moreover, in the recent 25 years, global mean temperatures have risen by 0.45 degrees Celsius, which is 2.4-times larger than those in the past 100 years. The evidences for climate change, such as sea level rise, arctic glacier melt, and desertification in Asia, have occurred and increased over the globe. In Korea, because regional climate has been changed, types of agriculture and fishery should be replaced. And as precipitation pattern behave differently from the past decades, water management would be more difficult, furthermore, atmospheric environment, related to concentrations for ozone, sulfate, etc., could be worse. Nevertheless, we have only focused on greenhouse gas reduction duty for the Convention of Climate Change. Fortunately, in the fourth plan on climate change, we have planned to manage climate change more actively since 2007. In Korea, the emission of carbon dioxide has increased about 1.9-times more, from 311million ton in 1990 to 591million ton in 2004. And also about 2 ppm rise every year for concentrations of carbon dioxide in the atmosphere. As a result, ecosystem, quality of water and atmosphere would be affected. Here, the emission of greenhouse gases over the globe is examined, and the effect of greenhouse gases for climate change is reviewed from the results of previous studies. In addition, the countermeasures of mitigation and adaptation on climate change were discussed for the understanding.

Comparison of Change-point Estimators with Scores

  • Kim, Jae-Hee;Seo, Hyun-Joo
    • Journal of the Korean Data and Information Science Society
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    • v.13 no.1
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    • pp.165-175
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    • 2002
  • We consider the problem of estimating the change-point in mean change model with the one change-point. Lombard (1987) suggested change-point estimation based on score functions. Gombay and Huskova (1998) derived a class of change-point estimators with the score function of rank. Various change-point estimators with the log score functions of ranks are suggested and compared via simulation.

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Effects of Sour Tastes on Blood Components in Anemic mice - Animal Experiment for Nursing Intervention of Female Anemia - (신맛(酸味)이 용혈성 빈혈흰쥐의 혈액성분에 미치는 효과 - 여성빈혈의 간호중재개발을 위한 동물실험 -)

  • 신혜숙;김상우
    • Journal of Korean Academy of Nursing
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    • v.31 no.2
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    • pp.268-278
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    • 2001
  • Many women in the world have suffered from anemia produced by menstruation, pregnancy and delivery. In the theory of oriental medicine, a sour taste is believed to have a tonic effect on the blood. Thus this paper is to investigate the effect of sour tastes on the improvement in anemia-induced female mice, using citric acid and Fructus schizandrae(五味子). The method used in this experiment was the change of RBC, WBC, Hemoglobin, Hematocrit, Fe, and TIBC in the blood of female mice who were fed citric acid and Fructus schizandrae(五味子). The results obtained were as follows ; 1. Compared with the control group (anemia- induced group without treatment), the mean number of RBC in the blood of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae (五味子) 500mg/kg. 2. Compared with the control group (anemia- induced group without treatment), the mean number of WBC in the blood of mice was not significantly larger in both sample groups fed citric acid and Fructus schizandrae(五味子). 3. Compared with the control group (anemia- induced group without treatment), the mean number of Hemoglobin in the blood of mice was significantly larger only in evaluating the change of the sample group fed Fructus schizandrae(五味子). 4. Compared with the control group (anemia- induced group without treatment), the mean percentage of Hematocrit in blood of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg and sample group fed Fructus schizandrae(五味子) 250mg/kg for 3days. 5. Compared with control group (anemia- induced group without treatment), the mean volume of Fe in serum of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg. 6. Compared with control group (anemia- induced group without treatment), the mean TIBC in serum of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg and sample group fed Fructus schizandrae(五味子) 250mg/kg for 7days. According to these results, a sour taste is presumed to have a general tonic effect on anemia, but more study must be taken on the effects of citric acid in improving female anemia.

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Features Related to Smoking and Psychological Characteristics of Coronary Artery Patients Associated with the Stage of Change in Smoking Cessation (금연변화단계에 따른 관상동맥질환자들의 흡연관련 특성과 심리적 특성)

  • Kim, Hwa Soon
    • Korean Journal of Adult Nursing
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    • v.17 no.4
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    • pp.592-601
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    • 2005
  • Purpose: The purpose of this study was to investigate differences in smoking related characteristics and psychological features of coronary artery patients by the stages of change in smoking cessation behaviors. Method: Subjects for this survey were 97 patients who were smoking when doctors diagnosed them to have coronary artery diseases. Result: Subjects were distributed 21.6% in precontemplation stage, 24.7% in contemplation stage, 17.5% in preparation stage, 19.6% in action stage, and 16.5% in maintenance stage respectively. The numbers of previous attempts to quit smoking of subjects in precontemplation stage(mean=3.00, SD=3.71) and contemplation stage(mean=2.63, SD=2.32) were significantly lower than that of subjects in preparation stage(mean=5.82, SD=6.20). Benefit scores of subjects in maintenance stage were significantly greater than those of subjects in precontemplation stage. Self-efficacy, barriers, seriousness, and nicotine dependency were not significantly different by the stages of change. Number of signs and symptoms related to smoking which subjects were experiencing were not significant by the stages of change too. Conclusion: Future intervention programs for smoking cessation should be focused on the strategies to enhance the realization of health benefits that patients might acquire from smoking cessation.

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A Study on the Trend Change Point of NBUE-property

  • Kim, Dae-Kyung
    • Communications for Statistical Applications and Methods
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    • v.3 no.2
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    • pp.275-282
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    • 1996
  • A life distribution F with survival function $\overline{F}$=1-F, finite mean $\mu$ and mean residual life m(t) is said to be NBUE(NWUE) if m(t)$\leq$($\geq$) .$\mu$ for t$\geq$0. This NBUE property can equivalently be characterized by the fact that $\varphi$(u)$\geq$($\leq$)u for 0$\leq$u$\leq$1, where $\varphi$(u) is the scaled total-time-on test transform of F. A generalization of the NBUE properties is that there is a value of p such that $\varphi$(u)\geq.u$ for 0$\leq$u$\leq$p and $\varphi$(u)\leq$$\leq$u$\leq$1, or vice versa. This means that we have a trend change in the NBUE property. In this paper we point out an error of Klefsjo's paper (1988). He erroneously takes advantage of trend change point of failure rate to calculate the empirical test size and power in lognormal distribution. We solves the trend change point of mean residual lifetime and recalculate the empirical test size and power of Klefsjo (1988) in mocensoring case.

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Inhomogeneities in Korean Climate Data (II): Due to the Change of the Computing Procedure of Daily Mean (기상청 기후자료의 균질성 문제 (II): 통계지침의 변경)

  • Ryoo, Sang-Boom;Kim, Yeon-Hee
    • Atmosphere
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    • v.17 no.1
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    • pp.17-26
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    • 2007
  • The station relocations, the replacement of instruments, and the change of a procedure for calculating derived climatic quantities from observations are well-known nonclimatic factors that seriously contaminate the worthwhile results in climate study. Prior to embarking on the climatological analysis, therefore, the quality and homogeneity of the utilized data sets should be properly evaluated with metadata. According to the metadata of the Korea Meteorological Administration (KMA), there have been plenty of changes in the procedure computing the daily mean values of temperature, humidity, etc, since 1904. For routine climatological work, it is customary to compute approximate daily mean values for individual days from values observed at fixed hours. In the KMA, fixed hours were totally 5 times changed: at four-hourly, four-hourly interval with additional 12 hour, eight-hourly, six-hourly, three-hourly intervals. In this paper, the homogeneity in the daily mean temperature dataset of the KMA was assessed with the consistency and efficiency of point estimators. We used the daily mean calculated from the 24 hourly readings as a potential true value. Approximate daily means computed from temperatures observed at different fixed hours have statistically different properties. So this inhomogeneity in KMA climate data should be kept in mind if you want to analysis secular aspects of Korea climate using this data set.

Estimation of Spatial-Temporal Net Primary Productivity and Soil Carbon Storage Change in the Capital area of South Korea under Climate Change (기후변화에 따른 수도권 산림의 순일차생산량과 토양탄소저장량의 시공간적 변화 추정)

  • Kwon, Sun-Soon;Choi, Sun-Hee;Lee, Sang-Don
    • Journal of Environmental Impact Assessment
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    • v.21 no.5
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    • pp.757-765
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    • 2012
  • The purpose of this study was to estimate the spatial-temporal NPP(Net Primary Productivity) and SCS(Soil Carbon Storage) of forest ecosystem under climate change in the capital area of South Korea using Mapss-Century1 (MC1), one of Dynamic Global Vegetation Models (DGVMs). The characteristics of the NPP and SCS changes were simulated based on a biogeochemical module in this model. As results of the simulation, the NPP varies from 2.02 to 7.43 tC $ha^{-1}\;yr^{-1}$ and the SCS varies from 34.55 to 84.81 tC $ha^{-1}$ during 1971~2000 respectively. Spatial mean NPP showed a little decreasing tendency in near future (2021~2050) and then increased in far future (2071~2100) under the condition of increasing air temperature and precipitation which were simulated by the A1B climate change scenario of Intergovernmental Panel on Climate Change (IPCC). But it was estimated that the temporal change of spatial mean NPP indicates 4.62% increasing tendency in which elevation is over 150m in this area. However, spatial mean SCS was decreased in the two future periods under same climate condition.

Adaptive Shot Change Detection Technique Using Histogram Mean within Extension Sliding Window and Its Implementation on Portable Multimedia Player (확장 참조 구간의 히스토그램 평균값을 이용한 적응적인 장면 전환 검출 기법과 휴대용 멀티미디어 재생기에서의 구현)

  • Kim, Won-Hee;Cho, Gyeong-Yeon;Kim, Jong-Nam
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.4
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    • pp.23-33
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    • 2009
  • A shot change detection technique is an important technique for effective management of video data, thus it requires an adaptive algorithm for various video sequences to detect an accurate shot change frames. In this paper, we propose an adaptive shot change detection algorithm using histogram mean of frames within extension sliding window. Our algorithm calculates a frame feature value using histogram and defines an adaptive threshold using an average of histogram mean of frames within the extension sliding window and determines a shot change by comparing the feature value and the threshold. We obtained better detection rate than the conventional methods maximally by 15% in the experiment with the same test sequence. We verified real-time operation of shot change detection in the hardware platform with low performance by implementing it on TVUS HM-900 PLUS model of Homecast. The Proposed algorithm can be useful in the hardware platform such as portable multimedia player(PMP) or cellular phone with low CPU performance.

Nurse호s Adoption on a Planned Organizational Change (간호업무개선에 대한 간호사의 변화수용도)

  • 이태화;김조자;박정숙;김소선
    • Journal of Korean Academy of Nursing
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    • v.32 no.2
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    • pp.155-164
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    • 2002
  • With the dynamically changing environment of society, managing change is the vital element of organizations's survival and growth. Health care organizations have expended enormous resources to restructure patient care delivery. Despite the growing literature describing these organizational innovations, there is a paucity of credible data that reflects systematic measurement and evaluation of such changes. This study examined the nurses' psychological response toward the work process redesign, newly introduced by the nursing department in a acute care hospital. The aim of the study was to figure out how nurses's general perception of change and perceived attributes of change affected their acceptance of change during the organizational transition. This was descriptive- correlational. The sample for the study included 50 head nurses and 135 staff nurses. Data was analyzed using SPSS PC+, version 10.0. The major findings of the study were as follows: First, the mean score of the perception of change was 71.2(SD=13.8) with the range of 0-100, which means nurses generally perceived change positively. There were significant differences in perception of change by gender and education level. Head nurses perceived change more positively than staff nurses. The higher education level showed the more positive view of change. Second, among the perceived attributes of change, trialability had the highest mean score, which means nurses perceived the change more positively if it is testable on a limited basis. Relative advantage was perceived the most negatively. Finally, factors influencing the acceptability of the work-process redesign were perceived comparability, complexity, relative advantage, and observability, which accounted for 43.7% of the variance in the acceptability of change. This study evaluated the preliminary effects of the nursing process for reengineering, focusing on nurses' acceptability towards change. The usefulness of this research study was to determine the factors influencing acceptance of organizational members during transitional periods of change and to suggest effective strategies for increasing adoption as well as for decreasing resistance to change.