• Title/Summary/Keyword: change of variables

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기후변화와 국가별 총요소생산성의 관계 (Relationship Between Climate Change and Total Factor Productivity)

  • 최영준;박현용
    • 자원ㆍ환경경제연구
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    • 제24권2호
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    • pp.343-363
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    • 2015
  • 본 연구는 기후변화가 국가의 총요소생산성에 미치는 영향을 분석하였다. 구체적으로 대표적 기후변수인 기온와 강수량이 국가의 총요소생산성에 미치는 영향을 분석하였다. 기존 연구와는 달리 본 연구는 최근 기후변화의 패턴인 기후 변동성이 높아지는 현상을 고려하기 위해 기후변수들의 평균값뿐만 아니라 최고값을 고려하여 분석하였다. 선형회귀분석 결과 평균기온의 상승은 생산성에 부정적 영향을 미치는 것으로 나타났으나 강수량의 평균적 증가는 긍정적 영향을 미치는 것으로 분석되었다. 하지만 최대 강수량은 평균 강수량과는 달리 총요소생산성을 증가시키는 것으로 분석되었다. 이러한 결과는 기존의 연구와 부합하는 것으로 나타났다. 하지만 패널자료를 분석한 결과 평균기온 이외에 다른 기후변수들(평균 강수량, 최대기온, 최대 강수량)은 유의미하게 영향을 주지 않는 것으로 나타났다. 또한 평균기온의 상승은 총요소생산성을 증가시키는 것으로 분석되었다. 이는 본 연구가 장기시계열 자료를 이용하여 국가들의 기후변화 적응능력에 의해 영향을 받은 것으로 분석된다.

경조비에 대한 의식 및 지출 변화 - IMF경제위기 이후 제주지역을 중심으로 - (The Change in Consciousness and Expenditure on Kyung-Jo after IMF Economic Crisis on Cheju Island)

  • 김혜연;김미성
    • 대한가정학회지
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    • 제39권1호
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    • pp.65-80
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    • 2001
  • This study aimed to investigate the changed consciousness and expenditure on Kyong-Jo after IMF economic crisis and the some factors which have effects on the change. The expenditure on Kyong-Jo included donations and gifts associated with congratulations and condolences. The data were collected through the personal questionnaire on Cheju Island. The sample consisted of 400 married adults whose age were between 20 to 65. The independent variables were some individual characteristics, household related variables, and Kyong-Jo related variables. The dependent variables included the change in consciousness and expenditure on Kyong-Jo. The data were analyzed by methods such as frequencies, means, Multiple Regression and Logistic Regression analysis. Major results were as follows. The respondents perceived that Kyong-Jo is fundamentally a good custom to help each other when some one is in the hard time. Their perception of the expenditure on Kyong-Jo has not been changed even since IMF economic crisis. 70% of the respondents staid that there was little difference of the expenditure on Kyong-Jo before and after IMF economic crisis. This trend is in contrast to the perception and the expenditure of the people who lived in the other residences after IMF economic crisis. The factors which had significant effects on the respondent's consciousness of the expenditure on Kyong-Jo were occupation, whether owns a house or not, household income, and household assets. The change of household expenditure on Kyong-Jo was effected by the respondent's sex, occupation, household income, household assets, and social network. These results suggested that the respondents on Cheju Island more strongly hold the conservative perception to the expenditure on Kyong-Jo rather than the people in other residences.

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논문 - 기후변화에 따른 농업생산기반 재해 취약성 평가를 위한 대리변수 선정 (The Proxy Variables Selection of Vulnerability Assessment for Agricultural Infrastructure According to Climate Change)

  • 김성재;박태양;김성민;김상민
    • 한국관개배수논문집
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    • 제18권2호
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    • pp.33-42
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    • 2011
  • Climate change has impacts on not only the average temperature rise but also the intensity and frequency of extreme events such as flood and drought. It is also expected that the damages on agricultural infrastructure will be increased resulting from increased rainfall intensity and frequency caused by climate change. To strengthen the climate change adaptation capacity, it is necessary to identify the vulnerability of a given society's physical infrastructures and to develop appropriate adaptation strategies with infrastructure management because generally facilities related to human settlements are vulnerable to climate changes and establishing an adaptive public infrastructure would reduce the damages and the repair cost. Therefore, development of mitigation strategies for agricultural infrastructure against climatic hazard is very important, but there are few studies on agricultural infrastructure vulnerability assessment and adaptation strategies. The concept of vulnerability, however, is difficult to functionally define due to the fact that vulnerability itself includes many aspects (biological, socioeconomic, etc.) in various sectors. As such, much research on vulnerability has used indicators which are useful for standardization and aggregation. In this study, for the vulnerability assessment for agricultural infrastructure, 3 categories of climate exposure, sensitivity, and adaptation capacity were defined which are composed of 16 sub-categories and 49 proxy variables. Database for each proxy variables was established based on local administrative province. Future studies are required to define the weighting factor and standardization method to calculate the vulnerability indicator for agricultural infrastructure against climate change.

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Estimating Wood Weight Change on Air Drying Times for Three Coniferous Species of South Korea

  • Lee, Daesung;Choi, Jungkee
    • Journal of Forest and Environmental Science
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    • 제32권3호
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    • pp.262-269
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    • 2016
  • The purposes of this study are to calculate the green and dried weight using wood discs, to figure out weight change on air drying times, and to develop the model of wood disc weight change for Larix kaempferi, Pinus koraiensis, and Pinus densiflora. The variables affecting the weight change were investigated, and the pattern of weight change over time was figured out through linear models. When comparing the stem green weight calculated using wood discs in this study with the weight table of Korea Forest Service, the weight was not significantly different for L. kaempferi and P. koraiensis. On the other hand, in comparison of stem dried weight, the weight was significantly different in all of three species. In addition, various measurement factors were examined to figure out the relationship with weight change, and air drying times and disc diameter were found as significant independent variables. Finally, two linear models were developed to estimate air drying times of three species, fit statistics were significant for practical use.

Study on sensitivity of modal parameters for suspension bridges

  • Liu, Chunhua;Wang, Ton-Lo;Qin, Quan
    • Structural Engineering and Mechanics
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    • 제8권5호
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    • pp.453-464
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    • 1999
  • Safety monitoring systems of structures generally resort to detecting possible changes of dynamic system parameters. Sensitivity analysis of these dynamic system parameters may implement these techniques. Conventional structural eigenvalue problems are discussed in the scope of those systems with deterministic parameters. Large and flexible structures, such as suspension bridges, actually possess stochastic material properties and these random properties unavoidably affect the dynamic system parameters. The sensitivity matrix of structural modal parameters to basic design variables has been established in this paper. Moreover, second order statistics of natural frequencies due to the randomness of material properties have been discussed. It is concluded from numerical analysis of a modem suspension bridge that although the second order statistics of frequencies are small relatively to the change of basic design variables, such as density of mass and modulus of elasticity, the sensitivities of modal parameters to these variables at different locations change in magnitude.

가계 재무전략의 유형화에 관한 연구 -1999년과 2000년 한국노동패널자료를 중심으로- (A Study on the Classification Of the Household Financial Strategies)

  • 박진영;문숙재
    • 가정과삶의질연구
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    • 제22권2호
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    • pp.85-95
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    • 2004
  • The purpose of this study was to classify the household financial strategies and find out variables affecting the type of the household financial strategies. The data of 3994 households from Korean Labor and Income Panel Study(1999-2000) were used. The major findings were as follows: (1) the household financial strategies were Residual Saver Type(44.6%), Unformal Institute Saver Type(13.3%), Financial asset Saver Type(16.7%), Real estate Saver Type(13.4%) and Diversities(12.0%). (2) The household financial strategy types were changed rapidly during short term. (3) In 3994 households, the variables which influence on the change of the household financial strategies were education, job, numbers of children, place of residence, home ownership. Similarly, in each type, the change of household financial strategies was significantly different according to the household characteristics variables.

절차적 프로그램으로부터의 객체 추출 방법론 (A Method of Object Identification from Procedural Programs)

  • 진윤숙;마평수;신규상
    • 한국정보처리학회논문지
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    • 제6권10호
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    • pp.2693-2706
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    • 1999
  • Reengineering to object-oriented system is needed to maintain the system and satisfy requirements of structure change. Target systems which should be reengineered to object-oriented system are difficult to change because these systems have no design document or their design document is inconsistent of source code. Using design document to identifying objects for these systems is improper. There are several researches which identify objects through procedural source code analysis. In this paper, we propose automatic object identification method based on clustering of VTFG(Variable-Type-Function Graph) which represents relations among variables, types, and functions. VTFG includes relations among variables, types, and functions that may be basis of objects, and weights of these relations. By clustering related variables, types, and functions using their weights, our method overcomes limit of existing researches which identify too big objects or objects excluding many functions. The method proposed in this paper minimizes user's interaction through automatic object identification and make it easy to reenginner procedural system to object-oriented system.

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SC-CNN을 이용한 임베딩 구동 동기기법의 PSpice 구현 (PSpice Implementation of Embedding Drive Synchronization using SC-CNN)

  • 배영철;김주완;손영우
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2003년도 춘계종합학술대회
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    • pp.505-508
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    • 2003
  • 본 논문에서는 SC-CNN의 특성을 이용한 임베딩 구동 카오스 동기화 방법을 소개한다. SC-CNN은 Chua 회로의 미분방정식에서의 세가지 상태변수중 전류성분과 같이 동기화와 신호 합성에 어려운 상태변수를 전압성분으로 분리하여 다룰 수 있는 방법을 제공하고 있다. 여기서 지금까지 이용되오던 결합 동기나 구동동기화의 방법에 새로운 임베딩 구동 동기방식을 제안한다. 제안하는 Embedding Drive Synchronization(임베딩 구동동기)은 구동동기에서 미분상태변수를 완전히 대체하는 것이 아닌 한 성분만을 대체하여 구성되며 그 타당성을 검증하였다.

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탄소세 부과에 따른 국내 에너지-경제-환경(3E) 변화 분석 및 예측을 위한 시스템다이내믹스 모델 개발 (System Dynamics Model for Analyzing and Forecasting the National Energy-Economy-Environment(3E) Changes under Levying of Carbon Tax)

  • 송재호;정석재;김경섭;박진원
    • 한국시스템다이내믹스연구
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    • 제7권2호
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    • pp.149-170
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    • 2006
  • In this paper, an energy-economy-environment dynamic simulation model was developed to using system dynamics methodology. It describes current energy-economy-environment systems and forecasts changes caused by levying of carbon tax. The model is composed of three modules: an energy module, an economic module and an environmental module. Variables are interrelated in each module, and three modules are linked by several linkage variables. Setting up the linkage variables is an important factor for the composition of the model. The simulation result shows a change of the national GDP, usage of energy, and $CO_2$ emissions under levying and reinvestment of carbon tax considering various scenarios for the charging cost.

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콘덴싱가스보일러 제어를 위한 공급수알고리즘 (The Supply Water Algorithm for a Condensing Gas Boiler Control)

  • 한도영;유병강
    • 설비공학논문집
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    • 제23권6호
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    • pp.441-448
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    • 2011
  • The energy consumption of a condensing gas boiler may be greatly reduced by the effective operation of the unit. In this study, the supply water algorithm for a condensing gas boiler control was developed by using the fuzzy logic. This includes the supply water set temperature algorithm, and the control algorithms of a gas valve, a blower and a pump. For the set temperature algorithm, the outside air temperature and the return water temperature were used as input variables. The supply water temperature difference and its slope were used as input variables of the gas valve and blower control algorithm. And the supply water temperature and the return water temperature were used as input variables of the pump control algorithm. In order to analyse performances of these algorithms, the dynamic model of a condensing gas boiler was used. The initial start-up test, the supply water set temperature change test, the outside air temperature change test, and the return water temperature change test were performed. Simulation results showed that algorithms developed in this study may be practically applied for the effective control of a condensing gas boiler.