• Title/Summary/Keyword: uncertainty management

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A Study on Jeju High School Students' Health Perception and Health Promotion Behavior (제주지역 고등학생의 건강지각과 건강증진 행위에 관한 연구)

  • Kim, Ok-Sun;Choi, In-Sook
    • The Journal of Korean Society for School & Community Health Education
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    • v.3
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    • pp.79-110
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    • 2002
  • The purpose of this study was to provide basic data necessary for creating a more successful health enhancement program, health education and health policy which can enhance health management abilities and enable a healthy school life by examining relations between high school students' health perception, who are in early adolescence, and their health promotion behavior. The subjects in this study were 813 students from 8 high schools on Jeju Island. The collected data were analyzed with t-test and one-way ANOVA through questionnaires by researcher on the basis of advance research. The findings of this study were as belows : 1. When general characteristics were considered, health perception was more significantly affected by those who were boys, whose family income was on a higher level, who scored better in school, whose parents were more concerned about their children's health, and who had experiences of being hospitalized. Especially, the more parents were concerned about their children's health, the higher the child's self-confidence on health(p<.05), anxiety on health(p<.05), practicality on disease prevention(p<.05), self-confidence on future health(p<.01), health care ability(p<.01), and family roles on health(p<.05). The less parents were concerned about their children's health, the higher the child's anxiety on disease(p<.01) and uncertainty on future health(p<.01). 2. When students' health promotion behavior was concerned, in the area of Eating Habits, having regular meals(72.9%), moderate consumption of meat(89.7%) and a balanced diet(64%) were common, whereas having a regular breakfast(37.4%) and eating vegetables and fruits(43.6%) were rare. In the area of Exercise, all subareas such as exercising 3 or 4 times a week(76.7%), more than one hour of exercise at a time(74.9%), a short distance walk(51.8%), exercise within one hour after meals(87%), and whether wanning up or not(88.6%) were above average. In the area of Personal Hygiene, all subareas such as drinking boiled water(57.3%), washing hands after using the bathroom(71%), brushing teeth after eating(42.4%), washing up after going out(50.3%), and washing hair and taking a frequent bath(77.2%) were rare. In the area of Control of Personal Relations, consulting personal problems with family(78.7%) had a positive response, whereas meeting someone new(59.8%), maintaining sound relations with the opposite sex(47.3%), having respect for one's opinion(51.5%), and maintaining peaceful relations with people(58.4%) had rare negative results. In the area of Stress Management, not being competitive(69.4%), releasing problems(62.4%) and sleeping soundly(66.2%) were common, whereas having your own ways to relieve stress(46.8%) and having your own dreams and hopes(58.5%) were rare. 3. When general characteristics were considered, as far as relations of health promotion behavior were concerned, the boys were significantly different in the area of Eating Habits(p<0.01) and Exercise(p<0.01), and the girls were in the area of Personal Hygiene. As family economic status was high and parents were concerned about their children's health, the entire areas of health promotion behavior were significantly different. Whether or not they were hospitalized made no significant difference in statistics. 4. When their regions were considered, it comparing city to town, there was no statistically significant difference in health perception and relations of health promotion behavior according to general characteristics. As seen in the results above, high school students' level of health perception and level of practicing health promotion behavior were generally low. In conclusion, by enhancing health perception, a plan for activating health education, which can implement positive health promotion behavior, should be made.

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Detection of Irrigation Timing and the Mapping of Paddy Cover in Korea Using MODIS Images Data (MODIS 영상자료를 이용한 관개시기 탐지와 논 피복지도 제작)

  • Jeong, Seung-Taek;Jang, Keun-Chang;Hong, Seok-Yeong;Kang, Sin-Kyu
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.13 no.2
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    • pp.69-78
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    • 2011
  • Rice is one of the world's staple foods. Paddy rice fields have unique biophysical characteristics that the rice is grown on flooded soils unlike other crops. Information on the spatial distribution of paddy fields and the timing of irrigation are of importance to determine hydrological balance and efficiency of water resource management. In this paper, we detected the timing of irrigation and spatial distribution of paddy fields using the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the NASA EOS Aqua satellite. The timing of irrigation was detected by the combined use of MODIS-based vegetation index and Land Surface Water Index (LSWI). The detected timing of irrigation showed good agreement with field observations from two flux sites in Korea and Japan. Based on the irrigation detection, a land cover map of paddy fields was generated with subsidiary information on seasonal patterns of MODIS enhanced vegetation index (EVI). When the MODISbased paddy field map was compared with a land cover map from the Ministry of Environment, Korea, it overestimated the regions with large paddies but underestimated those with small and fragmented paddies. Potential reasons for such spatial discrepancies may be attributed to coarse pixel resolution (500 m) of MODIS images, uncertainty in parameterization of threshold values for discarding forest and water pixels, and the application of LSWI threshold value developed for paddy fields in China. Nevertheless, this study showed that an improved utilization of seasonal patterns of MODIS vegetation and water-related indices could be applied in water resource management and enhanced estimation of evapotranspiration from paddy fields.

Evaluation of the Accuracy for Respiratory-gated RapidArc (RapidArc를 이용한 호흡연동 회전세기조절방사선치료 할 때 전달선량의 정확성 평가)

  • Sung, Jiwon;Yoon, Myonggeun;Chung, Weon Kuu;Bae, Sun Hyun;Shin, Dong Oh;Kim, Dong Wook
    • Progress in Medical Physics
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    • v.24 no.2
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    • pp.127-132
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    • 2013
  • The position of the internal organs can change continually and periodically inside the body due to the respiration. To reduce the respiration induced uncertainty of dose localization, one can use a respiratory gated radiotherapy where a radiation beam is exposed during the specific time of period. The main disadvantage of this method is that it usually requests a long treatment time, the massive effort during the treatment and the limitation of the patient selection. In this sense, the combination of the real-time position management (RPM) system and the volumetric intensity modulated radiotherapy (RapidArc) is promising since it provides a short treatment time compared with the conventional respiratory gated treatments. In this study, we evaluated the accuracy of the respiratory gated RapidArc treatment. Total sic patient cases were used for this study and each case was planned by RapidArc technique using varian ECLIPSE v8.6 planning machine. For the Quality Assurance (QA), a MatriXX detector and I'mRT software were used. The results show that more than 97% of area gives the gamma value less than one with 3% dose and 3 mm distance to agreement condition, which indicates the measured dose is well matched with the treatment plan's dose distribution for the gated RapidArc treatment cases.

The Effects of Leader's Attitude and Job Characteristics on Subordinate's Creative Performance (상사의 태도와 직무 특성이 창의적 성과를 일으키는 과정에 관한 연구)

  • Ryu, Jeong-Ran
    • Management & Information Systems Review
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    • v.33 no.3
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    • pp.129-154
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    • 2014
  • We are making products and services that we didn't easily think or even imagine when young and living using them. Consumer needs become more diversified, markets and technologies are being constantly changed, and corporate global competitiveness is getting intensified. Now, companies that don't change nor create new values cannot survive. The cycle of new products is faster, and therefore corporations should improve previous products continuously or create new values according to such a trend. This era requires 'creativity' for companies to overcome uncertainty and survive. Corporate creativity is not easily activated as financial and physical compensation unlike the work ability or performance. When there is an environment that people with various abilities, experiences and backgrounds can express their opinions freely, it becomes possible. Despite the importance, the studies have focused on creativity education so far instead of the viewpoint of corporate business administration. In addition, most studies have dealt with job characteristics and employees' personality factors rather than the process that is connected to actual performance. In other words, the studies on environmental factors that can lead motivation as situational characteristics of the employee's company in a current non-monetary and non-physical way are very insufficient. Therefore, this study aims to comprehensively examine the process of creating creative performance in the environment inside the company that the employee could approach most closely from the corporate deinstitutional perspective. As the major variables, job characteristics and supervisor's ethical leadership were selected, and the process that is connected to the creative performance was explained by means of motivation necessary to understand creativity of the organization and creative process engagement(CPE). The summary of the verification results is following. First, job characteristics and supervisor's attitude(ethical leadership) had positive effects on intrinsic motivation and creativity process engagement. Second, intrinsic motivation and creativity process engagement had positive effects on creative performance. Third, intrinsic motivation and creativity process engagement had mediated the relationship between job characteristics, supervisor's attitude and intrinsic motivation, creativity process engagement

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A Study on the Measurement of the Dimensionless Light Extinction Constant for Particulate Matter from Fuel Oil for Marine and Land Diesel Engines (선박 및 육상 디젤 엔진용 연료유에서 발생하는 입자상물질에 대한 무차원 광소멸계수 계측에 관한 연구)

  • Rho, Beom-Seok;Choi, Jae-Hyuk;Cho, Kwon-Hae;Park, Seul-Hyun;Lee, Won-Ju
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.2
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    • pp.275-281
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    • 2018
  • It is known that he pollutant emitted from the combustion process of marine fuel oil causes air pollution and harmful effects to the human body. Accordingly, IMO regulates pollutants emitted from ships. However, the regulation of Particulate Matter (PM) is still in the process of debate, so preemptive action is needed. Fundamental research on PM is essential. In this study, the Dimensionless Light Extinction Constant ($K_e$) of fuel oil used in marine diesel engines was measured and analyzed to construct the basic data of the PM generated from marine-based fuel oil. The fuel oil used in the land diesel engine was measured in the same way for character comparison. Both fuel oils differ in sulfur content and density. The $K_e$ was measured via the optical method using a 633 nm laser and was determined by using the volume fraction of PM collected by the gravimetric filter method. The $K_e$ of the PM discharged from marine fuel oil is 8.28, and the land fuel oil is 8.44. The $K_e$ of two fuel oils was similar within the measurement uncertainty range. However, it was found by comparison with the value obtained by the Rayleigh-Limit solution that the light scattering portion could be large. Also, it was found that light extinction characteristics could be different due to the relationship between light transmittance and collected mass.

Revisiting the cause of unemployment problem in Korea's labor market: The job seeker's interests-based topic analysis (취업준비생 토픽 분석을 통한 취업난 원인의 재탐색)

  • Kim, Jung-Su;Lee, Suk-Jun
    • Management & Information Systems Review
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    • v.35 no.1
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    • pp.85-116
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    • 2016
  • The present study aims to explore the causes of employment difficulty on the basis of job applicant's interest from P-E (person-environment) fit perspective. Our approach relied on a textual analytic method to reveal insights from their situational interests in a job search during the change of labor market. Thus, to investigate the type of major interests and psychological responses, user-generated texts in a social community were collected for analysis between January 1, 2013 through December 31, 2015 by crawling the online-community in regard to job seeking and sharing information and opinions. The results of topic analysis indicated user's primary interests were divided into four types: perception of vocation expectation, employment pre-preparation behaviors, perception of labor market, and job-seeking stress. Specially, job applicants put mainly concerns of monetary reward and a form of employment, rather than their work values or career exploration, thus youth job applicants expressed their psychological responses using contextualized language (e.g., slang, vulgarisms) for projecting their unstable state under uncertainty in response to environmental changes. Additionally, they have perceived activities in the restricted preparation (e.g., certification, English exam) as determinant factors for success in employment and suffered form job-seeking stress. On the basis of these findings, current unemployment matters are totally attributed to the absence of pursing the value of vocation and job in individuals, organizations, and society. Concretely, job seekers are preoccupied with occupational prestige in social aspect and have undecided vocational value. On the other hand, most companies have no perception of the importance of human resources and have overlooked the needs for proper work environment development in respect of stimulating individual motivation. The attempt in this study to reinterpret the effect of environment as for classifying job applicant's interests in reference to linguistic and psychological theories not only helps conduct a more comprehensive meaning for understanding social matters, but guides new directions for future research on job applicant's psychological factors (e.g., attitudes, motivation) using topic analysis.

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A Study on the Influence of the Founder's Self-Efficacy on the Sales of the Founding Company (창업자의 자기효능감이 창업기업의 매출에 미치는 영향에 관한 연구)

  • Lee, Joonsung;Song, Inam
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.5
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    • pp.61-78
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    • 2019
  • This study is about the effect of the founder's self-efficacy on the sales of the founding company by focusing on the factors that are currently emphasized in the founding education. In particular, this paper starts from the consciousness of the problem that the education that is being implemented to achieve the purpose of successful start-up among various government-based start-up support projects is failing to produce many start-up failures. Entrepreneurs cannot be assessed by objective financial data, but there is a high degree of uncertainty that should be determined based on their personal and learning abilities. In addition, many previous studies, which are likely to be successful when there is a high self-efficacy in a specific field due to the influence of factors such as personal experience or learning, will answer the direction of support for start-up companies. This study focuses on the impact of the founder's self-efficacy on the sales of the founding firms, especially the sales that are the key to the survival of the founding firms. This study has six major studies. First, to analyze whether the self-efficacy of entrepreneurs with respect to entrepreneurship affects the sales of entrepreneurs. Second, to analyze whether the self-efficacy of entrepreneurs with respect to market orientation affects the sales of entrepreneurs. Analysis of whether the founder's self-efficacy affects the sales of the founding firms. Fourth, analysis of whether the founder's self-efficiency affects the sales of the founding firms' understanding of management environment changes. An analysis of whether efficacy affects the sales of a start-up company, and sixth, an analysis of whether the founder's self-efficacy of business model building ability affects the sales of a start-up company. As a result of the empirical analysis, this study found that the self-efficacy of entrepreneurs on product differentiation capability and business model building capacity had a positive influence on the sales of entrepreneurs. The self-efficacy had a positive effect on self-efficacy, and the customer orientation had a positive effect on self-efficacy on business model building capacity. Also, it was confirmed that a path exists between the components of self-efficacy and that self-efficacy through the path has a positive effect on the sales of the start-up company. Therefore, the results of this study suggest the implications of establishing such a path and strengthening self-efficacy to create the survival and start-up performance of a start-up company if the goal of the start-up company is to survive when implementing various support projects for the start-up company.

An Analysis of the Dynamics between Media Coverage and Stock Market on Digital New Deal Policy: Focusing on Companies Related to the Fourth Industrial Revolution (디지털 뉴딜 정책에 대한 언론 보도량과 주식 시장의 동태적 관계 분석: 4차산업혁명 관련 기업을 중심으로)

  • Sohn, Kwonsang;Kwon, Ohbyung
    • The Journal of Society for e-Business Studies
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    • v.26 no.3
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    • pp.33-53
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    • 2021
  • In the crossroads of social change caused by the spread of the Fourth Industrial Revolution and the prolonged COVID-19, the Korean government announced the Digital New Deal policy on July 14, 2020. The Digital New Deal policy's primary goal is to create new businesses by accelerating digital transformation in the public sector and industries around data, networks, and artificial intelligence technologies. However, in a rapidly changing social environment, information asymmetry of the future benefits of technology can cause differences in the public's ability to analyze the direction and effectiveness of policies, resulting in uncertainty about the practical effects of policies. On the other hand, the media leads the formation of discourse through communicators' role to disseminate government policies to the public and provides knowledge about specific issues through the news. In other words, as the media coverage of a particular policy increases, the issue concentration increases, which also affects public decision-making. Therefore, the purpose of this study is to verify the dynamic relationship between the media coverage and the stock market on the Korean government's digital New Deal policy using Granger causality, impulse response functions, and variance decomposition analysis. To this end, the daily stock turnover ratio, daily price-earnings ratio, and EWMA volatility of digital technology-based companies related to the digital new deal policy among KOSDAQ listed companies were set as variables. As a result, keyword search volume, daily stock turnover ratio, EWMA volatility have a bi-directional Granger causal relationship with media coverage. And an increase in media coverage has a high impact on keyword search volume on digital new deal policies. Also, the impulse response analysis on media coverage showed a sharp drop in EWMA volatility. The influence gradually increased over time and played a role in mitigating stock market volatility. Based on this study's findings, the amount of media coverage of digital new deals policy has a significant dynamic relationship with the stock market.

Application of deep learning method for decision making support of dam release operation (댐 방류 의사결정지원을 위한 딥러닝 기법의 적용성 평가)

  • Jung, Sungho;Le, Xuan Hien;Kim, Yeonsu;Choi, Hyungu;Lee, Giha
    • Journal of Korea Water Resources Association
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    • v.54 no.spc1
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    • pp.1095-1105
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    • 2021
  • The advancement of dam operation is further required due to the upcoming rainy season, typhoons, or torrential rains. Besides, physical models based on specific rules may sometimes have limitations in controlling the release discharge of dam due to inherent uncertainty and complex factors. This study aims to forecast the water level of the nearest station to the dam multi-timestep-ahead and evaluate the availability when it makes a decision for a release discharge of dam based on LSTM (Long Short-Term Memory) of deep learning. The LSTM model was trained and tested on eight data sets with a 1-hour temporal resolution, including primary data used in the dam operation and downstream water level station data about 13 years (2009~2021). The trained model forecasted the water level time series divided by the six lead times: 1, 3, 6, 9, 12, 18-hours, and compared and analyzed with the observed data. As a result, the prediction results of the 1-hour ahead exhibited the best performance for all cases with an average accuracy of MAE of 0.01m, RMSE of 0.015 m, and NSE of 0.99, respectively. In addition, as the lead time increases, the predictive performance of the model tends to decrease slightly. The model may similarly estimate and reliably predicts the temporal pattern of the observed water level. Thus, it is judged that the LSTM model could produce predictive data by extracting the characteristics of complex hydrological non-linear data and can be used to determine the amount of release discharge from the dam when simulating the operation of the dam.

High-resolution medium-range streamflow prediction using distributed hydrological model WRF-Hydro and numerical weather forecast GDAPS (분포형 수문모형 WRF-Hydro와 기상수치예보모형 GDAPS를 활용한 고해상도 중기 유량 예측)

  • Kim, Sohyun;Kim, Bomi;Lee, Garim;Lee, Yaewon;Noh, Seong Jin
    • Journal of Korea Water Resources Association
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    • v.57 no.5
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    • pp.333-346
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    • 2024
  • High-resolution medium-range streamflow prediction is crucial for sustainable water quality and aquatic ecosystem management. For reliable medium-range streamflow predictions, it is necessary to understand the characteristics of forcings and to effectively utilize weather forecast data with low spatio-temporal resolutions. In this study, we presented a comparative analysis of medium-range streamflow predictions using the distributed hydrological model, WRF-Hydro, and the numerical weather forecast Global Data Assimilation and Prediction System (GDAPS) in the Geumho River basin, Korea. Multiple forcings, ground observations (AWS&ASOS), numerical weather forecast (GDAPS), and Global Land Data Assimilation System (GLDAS), were ingested to investigate the performance of streamflow predictions with highresolution WRF-Hydro configuration. In terms of the mean areal accumulated rainfall, GDAPS was overestimated by 36% to 234%, and GLDAS reanalysis data were overestimated by 80% to 153% compared to AWS&ASOS. The performance of streamflow predictions using AWS&ASOS resulted in KGE and NSE values of 0.6 or higher at the Kangchang station. Meanwhile, GDAPS-based streamflow predictions showed high variability, with KGE values ranging from 0.871 to -0.131 depending on the rainfall events. Although the peak flow error of GDAPS was larger or similar to that of GLDAS, the peak flow timing error of GDAPS was smaller than that of GLDAS. The average timing errors of AWS&ASOS, GDAPS, and GLDAS were 3.7 hours, 8.4 hours, and 70.1 hours, respectively. Medium-range streamflow predictions using GDAPS and high-resolution WRF-Hydro may provide useful information for water resources management especially in terms of occurrence and timing of peak flow albeit high uncertainty in flood magnitude.