• Title/Summary/Keyword: context model

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A Bayesian Approach to Gumbel Mixture Distribution for the Estimation of Parameter and its use to the Rainfall Frequency Analysis (Bayesian 기법을 이용한 혼합 Gumbel 분포 매개변수 추정 및 강우빈도해석 기법 개발)

  • Choi, Hong-Geun;Uranchimeg, Sumiya;Kim, Yong-Tak;Kwon, Hyun-Han
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.2
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    • pp.249-259
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    • 2018
  • More than half of annual rainfall occurs in summer season in Korea due to its climate condition and geographical location. A frequency analysis is mostly adopted for designing hydraulic structure under the such concentrated rainfall condition. Among the various distributions, univariate Gumbel distribution has been routinely used for rainfall frequency analysis in Korea. However, the distributional changes in extreme rainfall have been globally observed including Korea. More specifically, the univariate Gumbel distribution based rainfall frequency analysis is often fail to describe multimodal behaviors which are mainly influenced by distinct climate conditions during the wet season. In this context, we purposed a Gumbel mixture distribution based rainfall frequency analysis with a Bayesian framework, and further the results were compared to that of the univariate. It was found that the proposed model showed better performance in describing underlying distributions, leading to the lower Bayesian information criterion (BIC) values. The mixed Gumbel distribution was more robust for describing the upper tail of the distribution which playes a crucial role in estimating more reliable estimates of design rainfall uncertainty occurred by peak of upper tail than single Gumbel distribution. Therefore, it can be concluded that the mixed Gumbel distribution is more compatible for extreme frequency analysis rainfall data with two or more peaks on its distribution.

A Study on the Effects of Perceived Value on Customer Satisfaction, and Repurchase Intention among Traditional Markets Users in KOREA (지각된 가치가 고객만족과 재구매 의도에 미치는 영향에 관한 연구 : 전통시장 이용 고객을 중심으로)

  • Cho, Joon-Sang
    • Journal of Distribution Science
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    • v.11 no.10
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    • pp.93-105
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    • 2013
  • Purpose - This empirical analysis determines the structured causal relations between perceived value, customer satisfaction, and repurchase intention among users of traditional markets. The results of this analysis would help merchants and market operators indevisingan appropriate strategy to successfully manage traditional markets. Research design, data, methodology - The perceived value model of traditional markets includes functional value (price), functional value (quality), emotional value, and social value. In this study, the perceived value of traditional markets is considered as an independent variable, while customer satisfaction and repurchase intention are shown as the dependent variables, where customer satisfaction is also considered as the mediating variable. The study aims to ascertain the extent of influence of the perceived value of traditional markets on customer satisfaction and repurchase intention. We use regression analysis to verify the effects. The measurement items were already deemed as reliable and valid in the previous study, but for this purpose, we made some modifications. We distributed questionnaires to 300 consumers on a national scale, and finally used 241 consumer responses among these as a sample. We analyzed the data using the SPSS 21.0 statistical program. Results - We obtained the following results. First, the order of perceived value dimensions of traditional markets that positively impact customer satisfaction is functional value (price), social value, emotional value, and functional value (quality). Second, the perceived value sometimes directly affects repurchase intention; its effect is typically strong with customer satisfaction as a parameter. The order of perceived value dimensions that positively impact repurchase intention is social value, functional value (price), emotional value, and functional value (quality). Third, the perceived value significantly influences repurchase intention, with customer satisfaction as the mediating variable. Conclusions - We should recognize the importance of perceived value in retail distribution markets, such as traditional markets. Moreover, we need to develop strategies to improve the perceived value. The practical implications of the study are as follows. First, with regards to functional value (quality; price) dimensions, we should have an appropriate assortment of high quality products that are reasonably priced. In addition, customers are satisfied with the friendly service, discounts, and other benefits provided by the merchants. Second, in terms of emotional value dimension, we need to develop differentiated events that provide fun and emotional experience to the customers. Third, in the context of social values dimension, we should strive to positively influence society to enhance social image through activities such as social services and contribution to community development. On the basis of these results, we present the implications, limitations, and future directions for the research. One of the policy implications of the study is that merchants of traditional markets must actively select customers and develop customer value. However, this study is limited in the fact that the population used for data collection is not fully representative, as the survey only covered some specific areas. Moreover, future studies could also benefit with additional research using moderating variables.

A Study on the Contextual Layout Process of Exhibit Space With a Focus on the expo Comm Wireless Korea '99-KT Pavilion (전시공간 맥락화 구성 프로세스 사례연구 expo Comm Wireless Korea '99 -한국통신관을 중심으로)

  • 김준호
    • Archives of design research
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    • v.13 no.1
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    • pp.121-130
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    • 2000
  • This study can be expressed by gathered and formed into the exhibition space's structure practical progress/ application. For the one model of fascinating exhibition's space thru inter-space's pertinent adjustment, production between spactator and exhibition constituent on an exhibition story-line, I adjusted the focus to follow mentioned methods systematically for the example; An exhibition space is completed to be very impressive and attractive space by proper adjustment and production of M-M/C interface in exhibition storyline. Quantity space is transfered into quality space through the transmission of an exhibition which can be define as the point of an exhibition structure. And also could de transferd into a bodily sensation space that inherent full of interactive constituent. Changeable exhibition constituents (exhibition item and text) that sporadically expatiated (not trimed, the original form) in the process of an exhibition structure draw much higer quality of the optimal solution in optimize process which is given when aggregate again to contextual flow of synthetic exhibition scenario. Reconstruction of individual exhibition constituents to the new story, that is, transference of exhibition text to exhibition context is inspirit to an exhibition by maximize the exhibition effect in connection can be systematized through carrying out an outcentripetalpart. However, since pattern of an exhibition structure that consequtively meet variety spacetime of an exhibittion environmental can't be exist, this study presents centralizing the exhibition plan of Korea communication pavilion of the annual Expo Comm Wireress Korea, sustained process from design proposal, research and analysis to synthesis, development, transmission and management to an example of an applying crystallization.

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The First Photometric Study of NSVS 1461538: A New W-subtype Contact Binary with a Low Mass Ratio and Moderate Fill-out Factor

  • Kim, Hyoun-Woo;Kim, Chun-Hwey;Song, Mi-Hwa;Jeong, Min-Ji;Kim, Hye-Young
    • Journal of Astronomy and Space Sciences
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    • v.33 no.3
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    • pp.185-196
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    • 2016
  • New multiband BVRI light curves of NSVS 1461538 were obtained as a byproduct during the photometric observations of our program star PV Cas for three years from 2011 to 2013. The light curves indicate characteristics of a typical W-subtype W UMa eclipsing system, displaying a flat bottom at primary eclipse and the O'Connell effect, rather than those of an Algol/b Lyrae eclipsing variable classified by the northern sky variability survey (NSVS). A total of 35 times of minimum lights were determined from our observations (20 timings) and the SuperWASP measurements (15 ones). A period study with all the timings shows that the orbital period may vary in a sinusoidal manner with a period of about 5.6 yr and a small semi-amplitude of about 0.008 day. The cyclical period variation can be interpreted as a light-time effect due to a tertiary body with a minimum mass of 0.71 M. Simultaneous analysis of the multiband light curves using the 2003 version of the Wilson-Devinney binary model shows that NSVS 1461538 is a genuine W-subtype W UMa contact binary with the hotter primary component being less massive and the system shows a low mass ratio of q(mc/mh)=3.51, a high orbital inclination of 88.7°, a moderate fill-out factor of 30 %, and a temperature difference of ΔT=412 K. The O'Connell effect can be similarly explained by cool spots on either the hotter primary star or the cool secondary star. A small third-light corresponding to about 5 % and 2 % of the total systemic light in the B and V bandpasses, respectively, supports the third-body hypothesis proposed by the period study. Preliminary absolute dimensions of the system were derived and used to look into its evolutionary status with other W UMa binaries in the mass-radius and mass-luminosity diagrams. A possible evolution scenario of the system was also discussed in the context of the mass vs mass ratio diagram.

Neutrophilic Respiratory Burst Contributes to Acute Lung Leak in Rats Given N-nitroso-N-methylurethane (N-nitroso-N-methylurethane으로 유도된 급성 폐손상에서 호중구에 의한 산화성 스트레스의 역할)

  • Kim, Seong-Eun;Kim, Dug-Young;Na, Bo-Kyung;Lee, Young-Man
    • Applied Microscopy
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    • v.33 no.1
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    • pp.1-16
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    • 2003
  • As is well known that N-nitroso-N-methylurethane (NNNMU) causes acute lung injury (ALI) in experimental animals. And ALI caused by NNNMU is very similar to ARDS in human being in its pathology and progress. In its context, we investigated the pathogenetic mechanism of ARDS associated with oxidative stress by neutrophils in Sprague-Dawley rat model of NNNMU-induced ALI. NNNMU had increased lung weight/body weight ratio (L/B ratio), lung myeloperoxidase (MPO) activity, protein content and number of neutrophils in bronchoalveolar fluid (BALF) compared with those of control rat (p<0.001, respectively). In contrast, the amount of pulmonary surfactant in BALF was decreased by NNNMU (p<0.001). Morphologically, light microscopic examination denoted pathological findings such as formation of hyaline membrane, infiltration of neutrophils and perivascular cuffing in the lungs of NNNMU-treated rats. In addition, ultrastructural changes such as the necrosis of endothelial cells, swelling and vacuolization of lamellar bodies of alveolar type II cells, and the degeneration of pulmonary surfactant were identified after treatment of NNNMU. Very interestingly, cerium chloride electron microscopic cytochemistry showed that NNNMU had increased the production of cerrous-peroxide granules in the lung, which signified the increased production of hydrogen peroxide in the lung. Collectively, we conclude that NNNMU causes acute lung leak by the mechanism of neutrophilic oxidative stress of the lung.

Consumer Purchase Decision in a Mobile Shopping Mall: An Integrative View of Trust and Theory of Planned Behavior (모바일 쇼핑몰 고객들의 구매 의사 결정에 관한 연구: TPB와 신뢰의 통합적 관점에서)

  • Hong, Seil;Li, Bin;Kim, Byoungsoo
    • Information Systems Review
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    • v.18 no.2
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    • pp.151-171
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    • 2016
  • With the widespread adoption of mobile devices, such as smart phones and smart pads, as well as the rapid growth of mobile technologies, consumer shopping patterns are changing. This study investigates key factors of consumer purchasing intention in a mobile shopping mall context by incorporating trust belief into the theory of planned behavior. We posit perceived usefulness, perceived enjoyment, perceived ease of use, and trust belief as antecedents of behavioral attitude toward mobile shopping malls. Moreover, social influence and security are identified as key enablers of trust belief on mobile shopping malls. Data collected from 154 consumers with purchasing experience in mobile shopping malls are empirically tested against a research model using partial least squares. Analysis results show that behavioral attitude and perceived behavioral control significantly influence purchasing intention. Moreover, this study reveals the significant effects of perceived usefulness and perceived enjoyment on behavioral attitude. Trust belief indirectly influences purchasing intention through behavioral attitude and is significantly affected by social influence. Understanding consumer purchasing decision-making processes in mobile shopping malls can help service providers to develop effective marketing and operation strategies and campaigns.

The analysis of characteristics and effects of contextual variables in terms of student achievement levels and gender based on the results of PISA 2015 science domain (PISA 2015 과학 영역에 나타난 학생 성취수준 집단 및 성별에 따른 교육맥락 변인의 특성 및 영향력 분석)

  • Ku, Jaok;Koo, Namwook
    • Journal of Science Education
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    • v.42 no.2
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    • pp.165-181
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    • 2018
  • This study compares and analyzes the characteristics and effects of various educational contextual variables according to students' achievement level and gender groups based on the results of PISA 2015 science domain. PISA 2015 included additional variables about teaching-learning and affective characteristics in the field of science, because science was the main domain of PISA 2015. The results of the mediation analysis using a multiple group structural equation model showed that the environment and strategy for the teaching and learning had a positive effect on the affective characteristics, and also positively affected science achievement through the mediator of the affective characteristics. Particularly, the environment and strategy for the teaching and learning was the most effective in improving the affective characteristics for the low achievement group. It was found that the difference of the mediated effect between achievement level groups was statistically significant, but that between male and female students was not. Therefore, the appropriate the environment and strategy for the teaching and learning will need to be emphasized consistently to improve students' cognitive and affective achievement. The implications and suggestions of these results were discussed.

A Study of Realistic Mathematics Education - Focusing on the learning of algorithms in primary school - (현실적 수학교육에 대한 고찰 - 초등학교의 알고리듬 학습을 중심으로 -)

  • 정영옥
    • Journal of Educational Research in Mathematics
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    • v.9 no.1
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    • pp.81-109
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    • 1999
  • This study aims to reflect the basic principles and teaching-teaming principles of Realistic Mathematics Education in order to suppose an way in which mathematics as an activity is carried out in primary school. The development of what is known as RME started almost thirty years ago. It is founded by Freudenthal and his colleagues at the former IOWO. Freudenthal stressed the idea of matheamatics as a human activity. According to him, the key principles of RME are as follows: guided reinvention and progressive mathematisation, level theory, and didactical phenomenology. This means that children have guided opportunities to reinvent mathematics by doing it and so the focal point should not be on mathematics as a closed system but on the process of mathematisation. There are different levels in learning process. One should let children make the transition from one level to the next level in the progress of mathematisation in realistic contexts. Here, contexts means that domain of reality, which in some particular learning process is disclosed to the learner in order to be mathematised. And the word of 'realistic' is related not just with the real world, but is related to the emphasis that RME puts on offering the students problem situations which they can imagine. Under the background of these principles, RME supposes the following five instruction principles: phenomenological exploration, bridging by vertical instruments, pupils' own constructions and productions, interactivity, and interwining of learning strands. In order to reflect how to realize these principles in practice, the teaming process of algorithms is illustrated. In this process, children follow a learning route that takes its inspiration from the history of mathematics or from their own informal knowledge and strategies. Considering long division, the first levee is associated with real-life activities such as sharing sweets among children. Here, children use their own strategies to solve context problems. The second level is entered when the same sweet problems is presented and a model of the situation is created. Then it is focused on finding shortcomings. Finally, the schema of division becomes a subject of investigation. Comparing realistic mathematics education with constructivistic mathematics education, there interaction, reflective thinking, conflict situation are many similarities but there are alsodifferences. They share the characteristics such as mathematics as a human activity, active learner, etc. But in RME, it is focused on the delicate balance between the spontaneity of children and the authority of teachers, and the development of long-term loaming process which is structured but flexible. In this respect two forms of mathematics education are different. Here, we learn how to develop mathematics curriculum that respects the theory of children on reality and at the same time the theory of mathematics experts. In order to connect the informal mathematics of children and formal mathematics, we need more teachers as researchers and more researchers as observers who try to find the mathematical informal notions of children and anticipate routes of children's learning through thought-experiment continuously.

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Analysis on the Public Perceptions about the Causes of the Poverty in Korea (한국사회 빈곤원인 인식의 실태와 결정요인)

  • Lee, Sangrok;Kim, Hyeongkwan
    • Korean Journal of Social Welfare
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    • v.66 no.1
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    • pp.163-189
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    • 2014
  • The public perceptions about the cause of the poverty are generally considered as the important subject because they are assumed to have profound influences on the anti-poverty strategies, the features of the welfare system, and the welfare politics. Yet, there have been few studies on the public perceptions about attributions for poverty in Korea. In this article, we explore the popular perceptions about the causes of the poverty and investigate the determinants of the various beliefs about the causes of the poverty in Korea. The data derive from the Welfare Attitudes data of the 8th Korea Welfare Panel Survey. The results indicates that Koreans are more likely to support the individualistic explanations on the causes of the poverty than the structural and the fatalistic explanations. The results of regression model analysis show that there are differences in the determinants of the three types of poverty explanations, but subjective variables have the strong effects on all of the poverty explanations in Korea. In this study we find that Koreans are more likely than the western european welfare states to endorse individualistic explanations. These findings suggest that the underdevelopment of the welfare system in Korea is assumed to have the connection with the popular individualistic explanations. And, they suggest that there are needed to have notices to changing the public perceptions of the poverty and the cultural context of the social welfare in order to advance the welfare state in Korea.

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Optimum Population Projection in Korea: An Environmental Perspective (환경 측면에서 한국의 적정인구 추계)

  • Jeong, Dae-Yuon
    • Korea journal of population studies
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    • v.29 no.1
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    • pp.269-292
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    • 2006
  • The current environmental problem is global, and threatens the very existence of human beings. Many factors have been argued as the causes of environmental problem. The examples include anthroponcentric human perspective on nature, increase in the knowledge on nature, development of technology, economic growth and unequal distribution, and population increase, etc. The scholars who argues population increase have focused on over-population. However, the estimation of optimum population size has not been attempted in terms of environmental carrying capacity. In such a context, this paper aims at estimating optimum population size in South Korea in terms of environmental carrying capacity. The estimation was done from two approaches. One was based on the state of environment, the other was based on 'the desirable state of environment' Koreans expect. The former is termed an objective approach, while the latter is termed an approach based on social consensus. About 47.5 millions were estimated from the former approach, and 48.5 millions from the latter approach. However, optimum population size increase by 50.5 millions if government increase environmental budget to 2.00% among total budget. As such, different optimum population size is estimated according to the values of variables. The most significant variable determining optimum population size is environmental budget, and followed by supply of clean energy. The estimated optimum population size was based on the time-series data from 1993 to 2002. Therefore, time-series data collected from other years will result in different estimation model, and then different optimum population size will be estimated.