• Title/Summary/Keyword: growth modeling

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Exploring Spatial Dependence in Vacant Housing Growth (빈집 증가의 공간적 자기상관성에 대한 탐색적 연구)

  • Jung, Suyoung;Jun, Hee-Jung
    • Journal of Korea Planning Association
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    • v.54 no.7
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    • pp.89-102
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    • 2019
  • The growth of vacant housing has been problematic in both Korea and other countries as it causes various socio-economic problems and negatively affects residential environments. Despite the importance of effectively managing vacant housing, few studies have been undertaken regarding spatial patterns of vacant housing growth. This study aims to examine spatial dependence in vacant housing growth. We used 2005 and 2015 Population and Housing Census and employed spatial modeling. The empirical analysis shows that there is spatial dependence in vacant housing growth. Also, the spatial clusters of growing vacant housing are present in the non-capital region and nearby cities while the spatial clusters of declining vacant housing are present in the capital region. The policy implications of this study are as follows: First, local governments should make collaborate efforts with geographically proximate cities for more effective management of vacant housing. Second, given that vacant housing is more prevalent and growing in the non-capital region, it is necessary to employ differential policies to manage housing vacancy between the capital and non-capital regions.

The Impact of Globalization on CO2 Emissions in Malaysia

  • CHUAH, Soo Cheng;CHEAM, Chai Li;SULAIMAN, Saliza
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.5
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    • pp.295-303
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    • 2022
  • This study investigates the impact of globalization, coal consumption, and economic growth on CO2 emissions in Malaysia by applying the Kuznets Environmental Curve model. The study employed the Autoregressive Distributed Lag modeling technique on time series data over the period of 1970-2018 to determine the short and long-run relationship between CO2 emissions and a number of variables, including globalization, coal consumption, and economic growth. The results show that globalization increase CO2 emissions in both the short and long run in Malaysia. Furthermore, the results reveal that economic growth and coal consumption degrade the environmental quality by accelerating the CO2 emissions in the short-run and long run. As a result, the findings validate the Kuznets Environmental Curve hypothesis of an inverted U-shaped relationship between economic growth and CO2 emissions in the long run for Malaysia. The findings of this study suggest that higher globalization levels and usage of coal consumption degrade the environmental quality in Malaysia. The findings also indicate the effect of economic growth on environmental degradation is positive at the initial stage but improves after the economy achieves a threshold level of income per capita in the economic development process with an inverted U-shaped pattern in the long run.

Development of Predictive Growth Models for Staphylococcus aureus and Bacillus cereus on Various Food Matrices Consisting of Ready-to-Eat (RTE) Foods

  • Kang, Kyung-Ah;Kim, Yoo-Won;Yoon, Ki-Sun
    • Food Science of Animal Resources
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    • v.30 no.5
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    • pp.730-738
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    • 2010
  • We developed predictive growth models for Staphylococcus aureus and Bacillus cereus on various food matrices consisting primarily of ready-to-eat (RTE) foods. A cocktail of three S. aureus strains, producing enterotoxins A, C, and D, or a B. cereus strain, were inoculated on sliced bread, cooked rice, boiled Chinese noodles, boiled bean sprouts, tofu, baked fish, smoked chicken, and baked hamburger patties at an initial concentration of 3 log CFU/g and stored at 8, 10, 13, 17, 24, and $30^{\circ}C$. Growth kinetic parameters were determined by the Gompertz equation. The square-root and Davey models were used to determine specific growth rate and lag time values, respectively, as a function of temperature. Model performance was evaluated based on bias and accuracy factors. S. aureus and B. cereus growth were most delayed on sliced bread. Overall, S. aureus growth was significantly (p<0.05) more rapid on animal protein foods than carbohydrate-based foods and vegetable protein foods. The fastest growth of S. aureus was observed on smoked chicken. B. cereus growth was not observed at 8 and $10^{\circ}C$. B. cereus growth was significantly (p<0.05) more rapid on vegetable protein foods than on carbohydrate-based foods. The secondary models developed in this study showed suitable performance for predicting the growth of S. aureus and B. cereus on various food matrices consisting of RTE foods.

Indirect assessment of internal irradiation from tritium decay on Lemna Minor duckweed

  • Ifayefunmi, O.S.;Mirseabasov, O.A.;Synzynys, B.I.
    • Nuclear Engineering and Technology
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    • v.53 no.6
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    • pp.1991-1999
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    • 2021
  • The response changes of the specific growth rate of Lemna minor duckweed was modeled using the logarithms of frond numbers on tritium activity concentration and gamma radiation dose from cobalt 60. The concept of average specific growth rate depends on the general exponential growth pattern, where toxicity is estimated based on the effect on the growth rate. One of the main questions of the effect of the radiation dose on duckweed is how to correlate the effect of beta radiation with the effect of any other radiation for modeling radiation on Lemna minor. Experimental data were extrapolated by utilizing the OECD guidelines. A linear relationship of absorbed dose and activity concentration was obtained for the average dependency growth rate of Lemna minor as D = (0.1257)·A0.585. The dose rate of gamma irradiation from 60Co increases with tritium activity dependence, on the specific growth rate of the Lemna minor duckweed. An increase in the tritium activity causes a decrease in the specific growth rate of the Lemna minor duckweed. It indicates that as the quantity of the beta radiation dose increase in Lemna minor duckweed, a higher quantity of gamma radiation will be required to cause the same effect in the specific growth rate of Lemna minor duckweed. The relation between the inhibition of the Lemna minor seedling growth and gamma and beta radiation dosage agrees roughly with that between the decrease of survival rate or fertility and dosage.

Modeling of Various Digital Leaves Using Feature-based Image Warping (특징기반 영상 워핑을 활용한 다양한 디지털 잎 모델링)

  • Kim, Jin-Mo
    • Journal of Digital Contents Society
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    • v.16 no.2
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    • pp.235-244
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    • 2015
  • This study proposes a leaf modeling method that uses feature-based warping for efficient generation of various digital leaves. The proposed method uses warping method, one of image processing application techniques that can control various shapes of leaves in an easy, intuitive way, and generate natural patterns of veins efficiently. First, information on approximated contour is detected from a leaf blade image to identify the shape of a blade. Based on this, control line is automatically calculated to be used for feature-based warping. Then, control line-based warping is conducted to modify forms of leaf blade images in an intuitive way, automatically generating leaves of various shapes. And natural vein patterns are generated by applying a contour-based venation growth algorithm from contour information of the modified leaf blade images. This study performs experiments to verify whether various shape of leaves that comprise plants can be efficiently generated using a sample binary image of a blade. Also, we demonstrate that express the natural growth of leaves by applying warping to the growth of the leaf blade.

Trajectories of Self-rated Health among One-person Households: A Latent Class Growth Analysis (1인가구의 주관적 건강상태 변화: 잠재계층성장모형을 활용하여)

  • Kim, Eunjoo;Kim, Hyang;Yoon, Ju Young
    • Research in Community and Public Health Nursing
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    • v.30 no.4
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    • pp.449-459
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    • 2019
  • Purpose: The aim of this study is to explore different types of self-rated health trajectories among one-person households in Korea. Methods: We used five time-point data derived from Korea Health Panel (2011~2015). A latent growth curve modeling was used to assess the overall feature of self-rated health trajectory in one-person households, and a latent class growth modeling was used to determine the number and shape of trajectories. We then applied multinomial logistic regression on each class to explore the predicting variables. Results: We found that the overall slope of self-rated health in one-person households decreases. In addition, latent class analysis demonstrated three classes: 1) High-Decreasing class (i.e., high intercept, significantly decreasing slope), 2) Moderate-Decreasing class (i.e., average intercept, significantly decreasing slope), and 3) Low-Stable class (i.e., low intercept, flat and nonsignificant slope). The multinomial logistic regression analysis showed that the predictors of each class were different. Especially, one-person households with poor health condition early were at greater risk of being Low-Stable class compared with High-Decreasing class group. Conclusion: The findings of this study demonstrate that more attentions to one-person households are needed to promote their health status. Policymakers may develop different health and welfare programs depending on different characteristics of one-person household trajectory groups in Korea.

Visual Analytics Approach for Performance Improvement of predicting youth physical growth model (청소년 신체 성장 예측 모델의 성능 향상을 위한 시각적 분석 방법)

  • Yeon, Hanbyul;Pi, Mingyu;Seo, Seongbum;Ha, Seoho;Oh, Byungjun;Jang, Yun
    • Journal of the Korea Computer Graphics Society
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    • v.23 no.4
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    • pp.21-29
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    • 2017
  • Previous visual analytics researches has focused on reducing the uncertainty of predicted results using a variety of interactive visual data exploration techniques. The main purpose of the interactive search technique is to reduce the quality difference of the predicted results according to the level of the decision maker by understanding the relationship between the variables and choosing the appropriate model to predict the unknown variables. However, it is difficult to create a predictive model which forecast time series data whose overall trends is unknown such as youth physical growth data. In this paper, we pro pose a novel predictive analysis technique to forecast the physical growth value in small pieces of time series data with un certain trends. This model estimates the distribution of data at a particular point in time. We also propose a visual analytics system that minimizes the possible uncertainties in predictive modeling process.

The relationship between self-esteem and depression among Korean adults: Examining cognitive vulnerability model and the scar model (한국 성인의 우울과 자아존중감의 종단적 상호관계에 관한 연구: 인지취약모델과 상처모델 검증을 중심으로)

  • Kim, Hyemee
    • Korean Journal of Social Welfare Studies
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    • v.45 no.2
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    • pp.233-261
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    • 2014
  • There are two competing models explaining the causal relationship of depression and self-esteem, and they are cognitive vulnerability model and the scar model. Cognitive vulnerability model explains that low self-esteem poses as a risk factor for development of depressive symptoms/depression while the scar model asserts that the experiences of depression scars the cognitive function of individuals, resulting in negative self-perception. This study was set out to test two models on Korean adults, and to identify factors that are associated with depression and self-esteem relationship. The first four waves (wave 1~4) of the Korea Welfare Panel Study (KOWEPS) were used for analyses, and latent growth curve modeling was employed to examine the relationship. The findings show that the relationship was reciprocal, one affecting the growth trajectory of another over a four year period. Furthermore, education, poverty status, health status, and satisfaction with social relationships were found to be significantly associated with both depression and self-esteem trajectories. Implications for practice and theory are provided.

Stable Anisotropic Freezing Modeling Technique Using the Interaction between IISPH Fluids and Ice Particles (안정적이고 이방성한 빙결 모델링을 위한 암시적 비압축성 유체와 얼음 입자간의 상호작용 기법)

  • Kim, Jong-Hyun
    • Journal of the Korea Computer Graphics Society
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    • v.26 no.5
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    • pp.1-13
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    • 2020
  • In this paper, we propose a new method to stable simulation the directional ice shape by coupling of freezing solver and viscous water flow. The proposed ice modeling framework considers viscous fluid flow in the direction of ice growth, which is important in freezing simulation. The water simulation solution uses the method of applying a new viscous technique to the IISPH(Implicit incompressible SPH) simulation, and the ice direction and the glaze effect use the proposed anisotropic freezing solution. The condition in which water particles change state to ice particles is calculated as a function of humidity and new energy with water flow. Humidity approximates a virtual water film on the surface of the object, and fluid flow is incorporated into our anisotropic freezing solution to guide the growth direction of ice. As a result, the results of the glaze and directional freezing simulations are shown stably according to the flow direction of viscous water.

Longitudinal analysis of the direct and indirect influence of academic self-concept and academic support of teachers and parents on academic achievement in mathematics (학업적 자아개념 및 교사와 부모의 학업적 지원이 수학 학업성취도에 미치는 직·간접적인 영향력에 대한 종단적 분석)

  • Kim, YongSeok
    • The Mathematical Education
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    • v.61 no.1
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    • pp.127-156
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    • 2022
  • This study used the data of students from the 6th grade to the 3rd grade of middle schoolin the Korean Educational Longitudinal Study 2013 and classified them into subgroups with similar longitudinal changes in math academic achievement. In addition, the influence of longitudinal changes in the group's academic self-concept and teachers and parents academic support on the longitudinal changes in math academic achievement were analyzed, either directly or indirectly. As a result of the analysis, it was found that the academic self-concept of each group had a positive influence on the academic achievement in mathematics. In addition, the academic support of teachers and parents was found to have a positive influence on the academic achievement in mathematics through the mediating of the academic self-concept. In terms of direct and indirect influence on academic self-concept and math vertical scale scores, it was found that teachers' academic support had more influence than parents' academic support. The educational implications of these points were discussed.