• Title/Summary/Keyword: change of variables

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A Study on the Establishment of Quantitative Standards of Landslides Vulnerability by Climate Change (기후변화에 따른 산사태 취약성의 정량적 평가기준 설정 연구)

  • Lee, Dong-Kun;Kim, Hogul;Seo, Changwan;Song, Changkeun;Yu, Jeong Ah;Park, Chan
    • Journal of Climate Change Research
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    • v.4 no.2
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    • pp.95-104
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    • 2013
  • Average cumulative precipitation in summer have increased by 350 mm compared with 1980s. As precipitation is expected to increase, the risk of landslides by heavy rainfall also is expected to rise. Therefore, establishment of adaptation plan for landslides is urgently needed. In 2011, Korea Ministry of Environment(KME) conducted vulnerability assessment to support establishment of adaptation plan for local governments. However, the result of vulnerability assessment had three limitations. First, KME didn't use standard scenario of Korea Meteorological Administration(KMA). Second, They conducted same standardization method for all variables. Third, They derived relative vulnerability which is not quantitative. The purpose of this study is to improve the limitations of existing vulnerability assessment and identify quantitative criteria to ensure scientific reliability. To achieve this purpose, we carried out three ways of advancement. First, application of new climate scenario, which is RCP 8.5 from KMA. Second, improvement of variables of vulnerability assessment. Third, derivation of quantitative criteria of vulnerability. The findings can support establishment of adaptation plan for local governments more effectively.

Effects of Impact of Climate Change on Livestock Productivity - For bullocks, dairy, pigs, laying hens, and broilers - (기후변화가 축산 생산성에 미치는 영향 -거세우, 낙농, 양돈, 산란계, 육계를 대상으로-)

  • Lee, H.K.;Park, H.M.;Shin, Y.K.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.20 no.1
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    • pp.107-123
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    • 2018
  • The global impact of climate change on agriculture is now increasing. The purpose of this study was to investigate the effect of climate change on livestock productivity. The variables that have the greatest influence on climate change factors were examined through previous studies and expert surveys. We also used the actual productivity data of livestock farmers to investigate the relationship with climate change. In order to evaluate the climate for changes in livestock productivity, national representative data (such as bullocks, dairy, pigs, laying hens, and broilers) were surveyed in Korea. Also, to select and classify evaluation indexes, we selected climate change factor variables as prior studies and studied the weighting factor of climate variable factors. In this study, the researchers of industry, academia, and farmers in the livestock sector conducted questionnaires on the indicators of vulnerability to climate change using experts, and then weighed the selected indicators using the hierarchical analysis process (AHP). In order to verify the validity of the evaluation index, was examined using domestic climate data (temperature, precipitation, humidity, etc.). Correlation and regression analysis were performed. The empirical relationship between climate change and livestock productivity was examined through this study. As a result, we used data with high reliability of statistical analysis and found that there are significant variables.

A Study on the Factors related to postpartum Depression in Postpartum Women (산욕기 산모의 산후 우울증에 영향을 미치는 요인)

  • Choi, Euy-Soon;Oh, Jeong-Ah
    • Women's Health Nursing
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    • v.6 no.3
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    • pp.358-371
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    • 2000
  • The purpose of this study was to provide the basic, data for developing a program for effective prevention for Postpartum Depression (PPD) by investigating the level of PPD in postpartum 2 weeks women. The subjects were 384 women who visited obstetrical clinics for postnatal care. The data were collected from June 29. 1999 to April. 2000, using a 46-item questionnaire related to PPD, and analyzed by SAS program for t-test, ANOVA, Scheffe test, stepwise multiple regressions. The results were as follows : 1. The level of PPD according to general characteristics Women had mild PPD (Min score; 46.0, Max score; 124.0). The PPD levels were significantly differences according to religion and marital satisfaction (p<0.05). 2. The level of PPD according to obstetrical characteristics 1) Characteristics related to pregnancy The PPD levels were significantly differences according to mood change, confidence of body weight recovery, depression related to appearance change, husband's help to housework, and husband's emotional support (p<0.05). 2) Stressful events during pregnancy The PPD levels were significantly differences according to financial problem, conflict between partners, conflict between family, and husband's job change (p<0.05). 3) Characteristics related to delivery and post natal period The PPD levels were significantly differences according to baby's health state, parenting confidence, and difficulties related to postpartum care (p<0.05). 3. The variables to predict postpartum depression in postpartum women are depression related to appearance change (10.4%), parenting confidence (8.8%), husband's help to housework (2.7%), confidence of body weight recovery (2.4%), husband's job change (1.9%), baby's health state (1.9%), difficulties related to postpartum care (1.6%), mood change (1.2%), conflict between partners (0.6%), marital satisfaction (0.5%), financial problem (0.4%). The sum total of all the above variables can account for 32.4% of postpartum depression. 4. The level of PPD according to PPD factors. Women had the highest degree of PPD in biophysiological phenomena-disturbance of physical functioning factor. The factors of relationship to baby-negative feeling and cognitive phenomena-self concept disturbance were showed the lowest degree of PPD. As a result of the above findings, a systemic and individualized program is strongly recommended for PPD prevention, diagnosis, and care for PPD in postpartum women. In near future, this study should be expanded to investigate the coping skills according to the PPD levels in postpartum women.

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Mutual Fund Performance and Fund Flows: Medium-Term Relations in Korean Market (한국시장에서의 뮤추얼펀드의 성과와 현금흐름 간의 중기적 관계)

  • Kwon, Kyoung-Min;Kim, Noolee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6534-6542
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    • 2015
  • This study examines the relation between mutual fund performance and fund flows in Korean market using weekly and monthly data. The results are as follows. First, the relation between the two variables varies across fund types. Even the relations in equity fund and index fund are different from each other. Second, the structural change in the mutual fund market affect significantly the relation between the two variables. Third, return chasing flow is observed constantly in bond fund and it is observed only after the structural change for equity fund and MMF. However, no return chasing flow is observed for index fund. Fourth, mutual fund flows affect subsequent fund returns only in MMF after the structural change.

Prediction of Shift in Fish Distributions in the Geum River Watershed under Climate Change (기후변화에 따른 금강 유역의 어류 종분포 변화 예측)

  • Bae, Eunhye;Jung, Jinho
    • Ecology and Resilient Infrastructure
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    • v.2 no.3
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    • pp.198-205
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    • 2015
  • Impacts of climate change on aquatic ecosystems range from changes in physiological processes of aquatic organisms to species distribution. In this study, MaxEnt that has high prediction power without nonoccurrence data was used to simulate fish distribution changes in the Geum river watershed according to climate change. The fish distribution in 2050 and 2100 was predicted with RCP 8.5 climate change scenario using fish occurrence data (a total of 47 species, including 17 endemic species) from 2007 to 2009 at 134 survey points and 9 environmental variables (monthly lowest, highest and average air temperature, monthly precipitation, monthly lowest, highest and average water temperature, altitude and slope). The fitness of MaxEnt modeling was successful with the area under the relative operating characteristic curve (AUC) of 0.798, and environmental variables that showed a high level of prediction were as follows: altitude, monthly average precipitation and monthly lowest water temperature. As climate change proceeds until 2100, the probability of occurrence for Odontobutis interrupta and Acheilognathus yamatsuatea (endemic species) decreases whereas the probability of occurrence for Microphysogobio yaluensis and Lepomis macrochirus (exotic species) increases. In particular, five fish species (Gnathopogon strigatus, Misgurnus mizolepis, Erythroculter erythropterus, A. yamatsuatea and A. koreensis) were expected to become extinct in the Geum river watershed in 2100. In addition, the species rich area was expected to move to the northern part of the Geum river watershed. These findings suggest that water temperature increase caused by climate change may disturb the aquatic ecosystem of Geum river watershed significantly.

Relationship Between Job Stress and Turnover Intention Among Nurses in University Hospitals (대학병원 간호사들의 직무스트레스와 이직의도와의 관련성)

  • Shin, Hyun-Ran;Cho, Young-Chae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.3958-3970
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    • 2013
  • This study was carried out to grasp the job stress and intention to change their jobs of nurses at general hospitals by their socio-demographic, job-related and health-related behavior characteristics and especially to investigate their relationship to the job stress and intention to change their jobs. The subjects were 355 nurses working at three university hospitals located in Daejeon City, and data were collected by a survey using self-administered questionnaires structured from April 1 to May 31, 2012. As a results, the average point of the nurses' intention to change jobs by the causes for job stress was significantly higher in the boss group with low support than in that with high support while it was higher in colleague group with low support than in that with high support. To look into the correlation between the points of intention to change their jobs and the causes for job stress, their intention to change their jobs showed a significant negative correlation to the boss's support and colleagues' support while there was no significant relationship with job demands and job autonomy. As a result of hierarchical multiple regression, age, drinking coffee, department, job satisfaction, the boss's support and colleagues' support were selected as significant related variables affecting the nurses' intention to change their jobs and these variables' descriptive power was 29.4%. Viewed from the above results, it is suggested that the nurses' job stress and intention to change their jobs has a significant relationship with various variables such as socio-demographic, health-related behavior and job-related characteristics. In addition, there were a significant positive correlation between the causes for the job stress cause and intention to change their jobs, and among the causes for the job stress, support by their boss or colleagues turned out to be those affecting their intention to change their jobs. Thus, it is considered that it is necessary to minimize the nurses' job stress and at the same time to seek for specific measures for preventing their turnover.

Evaluation of Environmental Factors to Determine the Distribution of Functional Feeding Groups of Benthic Macroinvertebrates Using an Artificial Neural Network

  • Park, Young-Seuk;Lek, Sovan;Chon, Tae-Soo;Verdonschot, Piet F.M.
    • Journal of Ecology and Environment
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    • v.31 no.3
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    • pp.233-241
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    • 2008
  • Functional feeding groups (FFGs) of benthic macroinvertebrates are guilds of invertebrate taxa that obtain food in similar ways, regardless of their taxonomic affinities. They can represent a heterogeneous assemblage of benthic fauna and may indicate disturbances of their habitats. The proportion of different groups can change in response to disturbances that affect the food base of the system, thereby offering a means of assessing disruption of ecosystem functioning. In this study, we used benthic macroinvertebrate communities collected at 650 sites of 23 different water types in the province of Overijssel, The Netherlands. Physical and chemical environmental factors were measured at each sampling site. Each taxon was assigned to its corresponding FFG based on its food resources. A multilayer perceptron (MLP) using a backpropagation algorithm, a supervised artificial neural network, was applied to evaluate the influence of environmental variables to the FFGs of benthic macroinvertebrates through a sensitivity analysis. In the evaluation of input variables, the sensitivity analysis with partial derivatives demonstrates the relative importance of influential environmental variables on the FFG, showing that different variables influence the FFG in various ways. Collector-filterers and shredders were mainly influenced by $Ca^{2+}$ and width of the streams, and scrapers were influenced mostly with $Ca^{2+}$ and depth, and predators were by depth and pH. $Ca^{2+}$ and depth displayed relatively high influence on all four FFGs, while some variables such as pH, %gravel, %silt, and %bank affected specific groups. This approach can help to characterize community structure and to ecologically assess target ecosystems.

Effects of Induced Fatigue of Ankle Joint Muscle on the Capability and Recovery of Postural Control during Single-Leg Stance (발목 관절 근육의 유도된 피로가 외발서기 자세제어 능력과 회복에 미치는 영향)

  • Youm, Chang-Hong;Kim, Tae-Hyeon
    • Korean Journal of Applied Biomechanics
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    • v.22 no.2
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    • pp.219-228
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    • 2012
  • The purpose of this study was to investigate how induced fatigue of the ankle joint muscles affects the capability and recovery of postural control during single-leg stance in healthy adults. The study population included 22 randomly recruited men and women. Postural control was performed on single-leg stance with eyes open. Ankle joint muscle was fatigued by repeated heel raises. According to the results of this study, for the anteroposterior variables, both men and women showed significantly increased center of mass velocity and decreased center of pressure 95% edge frequency immediately after fatigue. For the mediolateral variables, both men and women showed significantly increased center of mass velocity and decreased center of pressure 95% edge frequency immediately after fatigue. For the total variables, both men and women showed significantly increased center of mass averaged-velocity immediately after fatigue, and also, the center of pressure 95% confidence ellipse area significantly increased in women. Postural control variables were not significantly different for men and women at any time (Pre, P0, P10, and P20). In conclusion, the gender does not affect the capability and recovery after induced fatigue of ankle joint muscles. The effect of fatigue found for the anteroposterior and the mediolateral variables in both men and women. Furthermore ankle joint muscle fatigue led to change of postural control strategy from an ankle joint strategy towards a hip joint strategy. These changes are believed to damage postural control. The ankle joint muscle recovered from fatigue within 20 min during single-leg stance.

Studies on the Predictability of Heavy Rainfall Using Prognostic Variables in Numerical Model (모델 예측변수들을 이용한 집중호우 예측 가능성에 관한 연구)

  • Jang, Min;Jee, Joon-Beom;Min, Jae-sik;Lee, Yong-Hee;Chung, Jun-Seok;You, Cheol-Hwan
    • Atmosphere
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    • v.26 no.4
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    • pp.495-508
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    • 2016
  • In order to determine the prediction possibility of heavy rainfall, a variety of analyses was conducted by using three-dimensional data obtained from Korea Local Analysis and Prediction System (KLAPS) re-analysis data. Strong moisture convergence occurring around the time of the heavy rainfall is consistent with the results of previous studies on such continuous production. Heavy rainfall occurred in the cloud system with a thick convective clouds. The moisture convergence, temperature and potential temperature advection showed increase into the heavy rainfall occurrence area. The distribution of integrated liquid water content tended to decrease as rainfall increased and was characterized by accelerated convective instability along with increased buoyant energy. In addition, changes were noted in the various characteristics of instability indices such as K-index (KI), Showalter Stability Index (SSI), and lifted index (LI). The meteorological variables used in the analysis showed clear increases or decreases according to the changes in rainfall amount. These rapid changes as well as the meteorological variables changes are attributed to the surrounding and meteorological conditions. Thus, we verified that heavy rainfall can be predicted according to such increase, decrease, or changes. This study focused on quantitative values and change characteristics of diagnostic variables calculated by using numerical models rather than by focusing on synoptic analysis at the time of the heavy rainfall occurrence, thereby utilizing them as prognostic variables in the study of the predictability of heavy rainfall. These results can contribute to the identification of production and development mechanisms of heavy rainfall and can be used in applied research for prediction of such precipitation. In the analysis of various case studies of heavy rainfall in the future, our study result can be utilized to show the development of the prediction of severe weather.

Effects of process variables on aqueous-based AlOx insulators for high-performance solution-processed oxide thin-film transistors

  • Huh, Jae-Eun;Park, Jintaek;Lee, Junhee;Lee, Sung-Eun;Lee, Jinwon;Lim, Keon-Hee;Kim, Youn Sang
    • Journal of Industrial and Engineering Chemistry
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    • v.68
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    • pp.117-123
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    • 2018
  • Recently, aqueous method has attracted lots of attention because it enables the solution-processed metal oxide thin film with high electrical properties in low temperature fabrication condition to various flexible devices. Focusing the development of aqueous route, many researchers are only focused on metal oxide materials. However, for expansive application of the aqueous-based metal oxide films, the systematic study of performance change with process variables for the development of aqueous-based metal oxide insulator film is urgently required. Here, we propose importance of process variables to achieve high electrical-performance metal oxide insulator based on the aqueous method. We found that the significant process variables including precursor solution temperature and humidity during the spincoating process strongly affect chemical, physical, and electrical properties of $AlO_x$ insulators. Through the optimization of significant variables in process, an $AlO_x$ insulator with a leakage current value approximately $10^5$ times smaller and a breakdown voltage value approximately 2-3 times greater than un-optimized $AlO_x$ was realized. Finally, by introducing the optimized $AlO_x$ insulators to solutionprocessed $InO_x$ TFTs, we successfully achieved $InO_x/AlO_x$ TFTs with remarkably high average field-effect mobility of ${\sim}52cm^2V^{-1}\;s^{-1}$ and on/off current ratio of 106 at fabrication temperature of $250^{\circ}C$.