• Title/Summary/Keyword: Panal model

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An Analysis of Impacts of Climate Change on Rice Damage Occurrence by Insect Pests and Disease (기후변화가 벼 병해충 피해면적 발생에 미치는 영향분석)

  • Jeong, Hak-Kyun;Kim, Chang-Gil;Moon, Dong-Hyun
    • Korean Journal of Environmental Agriculture
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    • v.33 no.1
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    • pp.52-56
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    • 2014
  • BACKGROUND: It is known that impacts of climate change on damage occurrence by insect pests and diseases are increasing. The negative effects of climate change on production will threaten our food security. It is needed that on the basis of analysis of the impacts, proper strategies in response to climate change are developed. METHODS AND RESULTS: The objective of this paper is to estimate impacts of climate change on rice damage occurrence by insect pests and diseases, using the panal model which analyzes both cross-section data and time series data. The result of an analysis on impacts of climate change on rice damage occurrence by pest insect and disease showed that the damage occurrence by Rice leaf roller and Rice water weevil increased if temperature increased, and damage occurrence by Stripe, Sheath blight, and Leaf Blast increased if precipitation(or amount of sunshine) increased(or decreased). CONCLUSION: Adaptation strategies, supplying weather forecasting information by region, developing systematical strategies for prevention of damage occurrence by pest insect and disease, analyzing the factors of damage occurrence by unexpected pest insect and disease, enforcing international cooperation for prevention of damage occurrence are needed to minimize the impacts of damage occurrence on rice production.

A Study on the Similitude of Precast Concrete Panel Structure Using one-third Scale Subassemblage Model (1/3 축적 모형실험에 의한 프리캐스트 콘크리트 판구조의 상사성에 관한 연구)

  • 윤재진
    • Magazine of the Korea Concrete Institute
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    • v.4 no.3
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    • pp.123-134
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    • 1992
  • 본연구는 실물크기의 프리캐스트 콘크리트 판구조물의 부분구조체를 모형화하여 실험한 결과를 분석한 것이다. 구조물의 역학적 특성과 파괴성상을 파악하기 위한 구조실험은 실물크기의 구조물과 부재로써 실시하는 것이 가장 좋은 방법이지만, 이것은 치수가 크므로 공간적으로 제한을 받고 많은 시간과 비용을 필요로 하기 때문에 모형실험을 이용하게 된다. 이러한 모형실험을 최소한의 오차범위내에서 원형실험과 같은 재현하고 예측하도록 실험을 준비하는 데에는 상사법칙이 필요하게 된다. 모형은 무엇보다도 원형과의 응력-변형도 관계 등 구성재료에 대한 상사요구조건을 만족시키는 것이 중요하지만, 본 연구의 대상은 1/3축척으로써 기하학적인 요소와 사용재료에 대한 강도의 상사성만을 고려한 모형이다. 본 연구에서는 이러한 모형구조물의 거동을 원형실험결과와 비교하여 상사성 확보의 문제와 가능성을 조사하였다.

A Study on Structural Relationship between Adolescents' Multicultural Acceptability Change and Its Influencing Factors

  • Kim, Hyung-Hee;Park, Hwieseo
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.4
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    • pp.189-195
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    • 2021
  • The point of this research is verifing the longitudinal changes in youth multicultural acceptance and to verify predictive variables of multicultural acceptance. Among the Korean Children and Youth Panal data collected by the Korea Institute for Children and Youth Policy, 1,972 data from the 3rd, 5th, and 6th data of the first-year middle school panal were used, and the data were analyzed by applying the latent growth model, and the following analysis results were obtained. First, adolescents' multicultural acceptability showed an increasing pattern, and the extent of the increase was large at the point of transition from the 3rd year(3rd year of middle school) to the 5th year. Second, predicting the change of multicultural acceptability were found to be significant in the initial values of peer communication, community consciousness and in the rate of change, life-satisfaction, peer communication, community consciousness. This study proposed some plans to improve multicultural acceptance in adolescence basing on these results.

A study on the effect of economic indicators on container freight rates (경제지표가 컨테이너 운임에 미치는 영향에 관한 연구)

  • Young-Kyou HA
    • Korea Trade Review
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    • v.47 no.1
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    • pp.13-24
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    • 2022
  • This study was conducted because the global economic downturn caused by COVID-19 caused a surge in logistics costs and it was no longer possible to predict logistics costs using existing methods. For this study, we made the assumption that economic indicators affect logistics cost. Chapter 2 examines the current status of the liner market and factors affecting logistics costs. Based on this, Chapter 3 collects independent and dependent variables to determine the analysis model. As the independent variable, economic indicators of major countries constituting the SCFI were selected, and the dependent variables were the SCFI Europe Index and the SCFI USA Index. In Chapter 4, a panel analysis was conducted based on this, and it was confirmed that major economic indicators had a negative (-) effect on SCFI. This is contrary to the existing research results, which can be attributed to the special situation caused by COVID-19 and the imbalance of demand and supply by region. The results of this study are meaningful in that they can predict long-term logistics cost volatility without analyzing supply and demand, and can be applied to other studies as well.

Analysis of the Relationships among Energy, Economic Growth and Greenhouse Gas Emissions Using Metropolitan City/Province Level Data (광역시·도별 자료를 이용한 에너지, 경제성장, 온실가스 배출 간의 관계 분석)

  • Lee, Jaeseok;Lee, Keun-Dae;Yu, Bok-Keun
    • Environmental and Resource Economics Review
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    • v.30 no.3
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    • pp.503-533
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    • 2021
  • This paper analyzes the relationships among the energy consumption, renewable energy production, real gross regional domestic product(GRDP), and greenhouse gas(GHG) emissions. It uses the metropolitan city and province level data for Korea from 2010 to 2018, employing a panal vector autoregressive(VAR) model. We find that an increase in energy consumption has a limited impact on boosting renewable energy production or gross regional domestic product, while it leads to an increase in greenhouse gas emissions. A rise in renewable energy production can increase gross regional domestic product, but it has no meaningful effects on energy consumption and the reduction of green house gas emissions. Our finding indicates that it is crucial to expand the supply of renewable energy as well as to decrease energy consumption in order to achieve the goal of reducing greenhouse gas emissions and reaching economic growth.

Regional Analysis of Unemployment Hazard Rate and the Influencing Factors on It (지역별 실업탈출확률 및 요인에 관한 연구)

  • Jeong, Insoo
    • Journal of Labour Economics
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    • v.26 no.1
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    • pp.111-151
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    • 2003
  • This study attempted to analize the hazard rate from unemployment and the influncing factors on the rate by regions. The data this study uses is Korea Labor Institute Panal Study(1998-2001) and the models are hazard analysis and Cox model. The results of hazard analysis are as follow. In capital and it's vicinity, the duration of unemployment is shorter than other regions even if the unemployment rate is higher. The labor market segmentation is confirmed between capital and it's vicinity region and other regions. Kyungsang region is higher in the unemployment hazard rate than Chunla or Chungchung regions. The duration of unemployment in capital and it's vicinity is 9.29 months comparing 11.86 months in the other region. The difference is statistically significant by the significance level 0.001. The duration of unemployment in Kyungsang is 6.96 months comparing 10.95 months in Chunla region. The Cox results which indicate the influncing factors on the hazard rate are as follow. In the regions like non-metro cities and non-capital and vicinitiy, the factors such as female, tenure, wage earners, manufacturing, wholesale and retale decrease the hazard rate. The results indicate that active labor market policies region by region are needed in Korea, especially for the marginal unemployed workes from non flourishing sectors.

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A Study on the Effects of Livestock Disease News on the Purchase of Beef and Pork (축산 질병 보도가 소, 돼지고기 구입에 미치는 영향에 관한 연구)

  • Shin, Jeong-Seop
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.10
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    • pp.425-432
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    • 2019
  • This study examined the effects of livestock disease news, such as foot-and-mouth disease (FMD), collected by the Korea Press Foundation on BIGKinds on the consumption of beef and pork. The consumer purchase data were obtained from the Rural Development Administration's Agrifood consumer panel data. Survival analysis showed that the FMD news noted beef and pork, and the first purchase rate decreased due to FMD news. The time-dependent Cox proportional hazards model revealed all models to be significant. FMD news was significant in each model. In 2010, the Hazard Ratio of domestic and imported pork was 0.999, and the first purchase rate decreased 0.999 times for each additional FMD news item. On the other hand, the Hazard Ratio of pork in 2015 was 1.001, and the first purchase rate increased. In the case of beef, results similar to pork were shown. This study estimated the impact of consumer meat consumption disease news on the first purchases according to origin and meat. These results provide the necessary information for rational production and consumption activities. In addition, it can also be used for promotion by estimating the duration of livestock disease news.

A Study of Selection of Self-employment in Korea (자영업 선택의 결정 요인에 관한 연구)

  • Cheon, Byung-you
    • Journal of Labour Economics
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    • v.26 no.3
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    • pp.149-179
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    • 2003
  • This study is analysing the factors determining individuals' behavior of selecting self-employment not only at the micro-level but also at the macro-level to put a particular emphasis on the financial constraint and unemployment rate representing business cycle. The data used in this study are "Korean Labor and Income Panal Study" of the Korea Labor Institute and "Economically Active Population Survey" of National Statistical Office. The main findings are as follows. First, human capital such as educational attainment and job experience has positive effects on male's selection of self-employment. The effects of job experience, however, changed negative for female's selection of self-employment. Second, real estate is significantly enhancing the selection probabilities of employer selection while the income from financial assets has negative effects. Third, entrepreneurial culture and environment are also raising the self-employment selection probability. Lastly, the regional unemployment rate representing the business cycle has positive effects on the self-employment selection after the financial crisis in 1997 both at the micro and macro level. Moreover, the coefficient of regional unemployment rate has changed positive in the structural model of self-employment selection controlling for selection bias and income opportunities, which means that individual's behavior of self-employment selection is rather complex when accounting for the uncertainties of income opportunities and diverse characteristics of self-employment workforce.

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