• 제목/요약/키워드: change of variables

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기후변화에 따른 극한기상의 취약성 지수 정량화 연구 - 태풍을 중심으로 - (Quantification of Climate Change Vulnerability Index for Extreme Weather - Focused on Typhoon case -)

  • 김철희;남기표;이종재
    • 환경영향평가
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    • 제24권2호
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    • pp.190-203
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    • 2015
  • 기후노출, 민감도, 적응능력의 3가지 항목의 함수로 정의되는 취약성-탄력성 지수인 VRI(Vulnerability-Resilience Index)를 이용하여 기후변화로 더 심각해 질 것으로 예상되는 극한 기상 현상인 태풍을 대상으로 기후변화 취약성 지수 정량화 연구를 수행하였다. 기존 취약성 지수인 VRI는 기후변화 취약성에 대한 지자체별 상대적 차이만을 보여 주므로 그 정량화 연구는 매우 필수불가결하며 우리나라 기후변화 대응 정책에도 매우 중요하다. VRI의 정량화를 위하여 과거 20년간 태풍으로 인한 피해액, 발생횟수, 주요 피해지역 등의 통계 정보가 사용되었고, 기후노출 대용변수들에 가중치를 부여하기 이전과 이후의 계산되는 VRI를 각각 지자체별로 분석하였다. VRI의 정량화를 위하여 각 기후노출 대용변수를 하나씩 이용하여 계산한 다음 계산된 VRI를 태풍 피해액과의 상관계수(R)를 구하였고, 이 값에 비례하여 각 기후노출 대용변수들의 가중치를 결정하였다. 그 결과 가중치 없이 계산한 지역별 VRI는 상당 지역에서 피해액과의 상관성이 없는 등 상당한 차이를 보였으나 가중치를 부여한 결과 계산된 VRI는 지역별 피해액과 높은 상관관계를 보이는 등 많은 오류가 크게 줄었다. 이 결과를 토대로 VRI를 정량화하여 그 피해액을 추정해본 결과 VRI=1 일 경우 약 5백억원의 지자체 피해액을 유발하는 것으로 해석할 수 있었다. 이러한 기후변화 취약성 지수의 정량화 연구는 우리나라 미래기후 시나리오연구에 효과적으로 활용될 수 있을 것으로 판단된다.

Effect of Gender Difference on the Functional Asymmetry during Preferred Walking Speed

  • Hyun, Seunghyun;Ryew, Checheong
    • International journal of advanced smart convergence
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    • 제9권2호
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    • pp.49-57
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    • 2020
  • We have not identified on what gender difference during gait at a pace of one's preferred velocity effects on the function of bilateral lower limb. This study was undertaken to investigate a difference of gait strategy by gender during gait at a one's preferred velocity of participants of adult male and female (n=20). Cinematographic data for motion analysis, ground reaction force (GRF) variables, and muscle volume of lower limb were analyzed. Significant difference of variables on movement of center of mass whole body, joint angle and moment of lower limb, and ground reaction force were tested by 2-way ANOVA analysis (P<0.05). Male group showed more muscle volume than female, and both showed more volume in dominant leg than non-dominant. Main effect by bilateral leg during gait showed higher difference in right than left leg in change of vertical position of center of mass (maximal, minimal). Main effect by gender in vertical change of position and velocity of center of mass showed higher difference in male than female (maximal, minimal). Hip joint showed more flexed and extended angle in male than female, and also dorsiflexion of ankle and flexion moment of knee and hip joint showed higher in male than female group. Therefore, this result was assumed that dominant showed furthermore more contribution for propulsive function than non-dominant leg. Gender difference showed in strategy controlling of biomechanical characteristics, and perhaps influenced by muscle volume.

사회변동에 따른 한국고유의 발효식품의 관리의 변화에 관한 연구 - 1960년대 이후의 문헌조사를 중심으로- (A Study on the Influence of Social Changes on the Management of Indigenous Fermented Foods in Korean Families)

  • 한경선;윤서석
    • 한국식품조리과학회지
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    • 제7권1호
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    • pp.1-9
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    • 1991
  • The purpose of this study is to investigate the management of Indigenous fermented foods during the period of economic development starting from 1960 until now, and to specify their correlation, while paying special concern to the variables of social change such as the increase of people's income, ceaseless migration of population, change in the family structure, heightening up of the educational level of women and the resulting increase of chances for getting employment, all of which may affect the management of Indigenous fermerted foods in korean families. The result is as follows. Basic seasonings and dishes such as soy bean sauce, red pepper paste, pickled seafoods, and Kimchi, are inclined to be bought as readymade products or provided by relatives in case of many nuclear families rather than made at home, which is a traditional way of home life. However, Kimchi and basic sauces or redpepper paste still show high rate of being made at home. Social variables which affect such tendency are the number of family members, the age and educational level of housewife, and the type of residence.

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상관성과 단순선형회귀분석 (Correlation and Simple Linear Regression)

  • 박선일;오태호
    • 한국임상수의학회지
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    • 제27권4호
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    • pp.427-434
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    • 2010
  • Correlation is a technique used to measure the strength or the degree of closeness of the linear association between two quantitative variables. Common misuses of this technique are highlighted. Linear regression is a technique used to identify a relationship between two continuous variables in mathematical equations, which could be used for comparison or estimation purposes. Specifically, regression analysis can provide answers for questions such as how much does one variable change for a given change in the other, how accurately can the value of one variable be predicted from the knowledge of the other. Regression does not give any indication of how good the association is while correlation provides a measure of how well a least-squares regression line fits the given set of data. The better the correlation, the closer the data points are to the regression line. In this tutorial article, the process of obtaining a linear regression relationship for a given set of bivariate data was described. The least square method to obtain the line which minimizes the total error between the data points and the regression line was employed and illustrated. The coefficient of determination, the ratio of the explained variation of the values of the independent variable to total variation, was described. Finally, the process of calculating confidence and prediction interval was reviewed and demonstrated.

Escape Behavior of Medaka (Oryzias latipes) in Response to Aerial Predators of Different Sizes and with Different Attack Speeds

  • Lee, Sang-Hee
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제3권1호
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    • pp.47-53
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    • 2022
  • The escape behavior of prey fish to predator attack is directly linked to the survival of the fish. In this study, I explored the escape behavior of Medaka fish to bird attacks. To simulate the attack, I designed a model triangular-shaped bird to slide along a fishing line connected between rods at both ends of the tank. The triangular shape was set to 10×15 (S=1), 15×20 (S=2), and 20×25 cm (S=3) with base×height. The slope (θ) of the fishing line, which determines the attack speed of the model bird, was set to values of 15° (θ=1), 30° (θ=2), and 45° (θ=3). The escape behavior was characterized using five variables: escape speed (ν), escape acceleration (α), responsiveness (γ), branch length similarity entropy (ε), and alignment (ϕ). The experimental results showed when (S, θ)=(fixed, varied), the change in values of the five variables were not significant. Thus, the fish respond more sensitively to S than to θ In contrast, when (S, θ)=(varied, fixed), ν, α, and γ showed increasing trends but ε and ϕ did not change much. This indicates the nature of fish escape behavior irrespective of the threat is inherent in ε and ϕ. I found that fish escape behavior can be divided into two types for the five physical quantities. In particular, the analysis showed that the type was mainly determined by the size of the model bird.

디지털날염용 고속 구동형 잉크젯 프린팅 헤드의 특성해석 (Characteristic Analysis of High Speed Inkjet Printing Head for Digital Textile Printing)

  • 이덕규;허신
    • 센서학회지
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    • 제27권6호
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    • pp.421-426
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    • 2018
  • To develop a piezoelectric inkjet printhead for high-resolution and high-speed printing, we studied the characteristics of an inkjet printhead by analyzing the major design parameters. An analytical model for the inkjet printhead was established, and numerical analysis of the coupled first-order differential equation for the defined state variables was performed using state equations. To design the dimension of the inkjet printhead with a driving frequency of 100 kHz, the characteristics of the flow rate and discharge pressure of the nozzle were analyzed with respect to design variables of the flow chamber, effective sound wave velocity, driving voltage, and voltage waveform. It was predicted that the change in the height of the flow chamber does not significantly affect the Helmholtz resonance frequency and discharge speed of the nozzle. From the analysis of change in flow chamber width, it is observed that as the width of the flow chamber increases, the ejection speed greatly increases and the Helmholtz resonance frequency decreases considerably, thereby substantially affecting the performance of the inkjet printhead.

국제비즈니스에서 비교문화 연구의 재검토 (Cross-cultural Studies Revisited in International Business)

  • 조호현
    • 이베로아메리카
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    • 제12권1호
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    • pp.407-439
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    • 2010
  • Growth of researches addressing cross-culture in international business is exponential. This article reviews the extant researches around the national culture and describes the various conceptualization of culture through discussion of some of popular models of national culture. This article presented some of the most important issues in international business surrounding globalization, especially convergence and divergence of cultures and cultural changes. Global rapid changes in international business environment request the reconsideration of the assumption of cultural stability and the simple view of culture, which tends to examine the static influence of a few cultural factors in isolation form other cultural factors and contextual elements. This paper identifies a valid cultural grouping and proposes the following typology of the possible methodologies in international business; Ethnological description, Use of proxies, Direct values inference, and Indirect values inference. Rather than selecting a single methodology, it appears to be more appropriate to use multi-method in the cross-cultural international business research. It has been shown that cultural change is intertwined with socioeconomic-institutional variables, and that these variables may also add to determine culture contemporarily. This paper also explained the dynamics of culture as multi-level, multi-layer constructs. According to this model, we may understand how the dynamic nature of culture conveys the top-down-bottom-up processes where one cultural level affects changes in other level of culture.

인라인 스케이트 500m 출발동작 분석 (An Analysis of 500m Inline Skate Starting Motions)

  • 박기범;이중숙
    • 한국운동역학회지
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    • 제17권2호
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    • pp.23-29
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    • 2007
  • The purpose of this study was to examine if there are kinematic variables differences between national representative players (NRP) and non national representative players (NNRP) during 500 m inline skate starting motion. Four NRP and six NNRP were recruited for the study. Each subject executed starting motion five times on a $2{\times}12m$ start way in a gymnasium. Kinematic variables were analyzed by the three-dimensional motion analysis system (60Hz). It was hypothesized that there are difference in elapsed time and center of mass acceleration in starting phase between groups since starting phase has been considered important in sprinting. The results showed that the NRP had significantly shorter starting phase time than that of NNRP. 1) An elapsed time in phase P1 of NRP was shorter than that of NNRP, and excellent players have early started their first stroke. 2) Both NRP and NNRP have started at the same spot, and displacement of the center of gravity in starting posture of NRP group was at the front compared to NNRP group. 3) Average step lengths of NRP were longer than those of NNRP, and a step change of NRP was stabler compared to that of NNRP. 4) In a speed change of the center of gravity NRP showed comparatively high speed from P1 to P4.

수상태양광발전시스템의 출력 특성 분석에 관한 연구 (A Study on the Analysis of the Output Characteristics of the Floating Photovoltaic System)

  • 최원용;이재형;좌성훈
    • 한국전기전자재료학회논문지
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    • 제30권5호
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    • pp.312-317
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    • 2017
  • In this paper, the effects of environmental variables on the output of the floating photovoltaic water systems, which were installed at the Hapcheon dam in South Korea, were investigated, and the correlations between them were analyzed. The system output was linearly proportional to the solar radiation or irradiance. The output was large in spring and autumn because of high irradiance, but low in the summer when the solar module temperature was high. The influence of the module temperature on the system output was limited in the summer, during which the module temperature change affected the system output more than the change of the irradiance did. In addition, in winter and summer, the module temperature tended to decrease with increasing windspeed, but windspeed did not affect module temperature significantly in the spring and autumn. On the other hand, in winter and spring, the irradiance decreased as the windspeed increased because of movement (or circulation) of the photovoltaic modules.

제1소구치 발거가 II급 1류 부정교합자의 안모와 치열궁에 미치는 영향에 관한 연구 (A STUDY ON THE EFFECTS OF THE 1st BICUSPID EXTRACTION ON THE CHANGES IN FACE AND DENIAL ARCH FORM IN ANGLE CLASS II DIV. 1 MALOCCLUSIONS)

  • 최낙준;남동석
    • 대한치과교정학회지
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    • 제16권1호
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    • pp.167-177
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    • 1986
  • This study was undertaken to compare the main differences and its effects of the 4 first bicuspid extraction on the face and dental arch of the class II div 1 malocclusion. The subjects consisted of twenty two class II div 1 malocclusion, four males, eighteen females, were 14 Years 2 Months old at the stan of the treatment 16 Year 3 Months old at the end of the treatment. (mean age) Twenty one variables were observed by comparing the statistical data of the pretreatment records with postteratment records, which were consited of eight varibles on the study model digitation, thirteen variables on the tracing of the lateral cephalogram. The following results were obtained. 1. No significant change was observed in the intercanine width. 2. Intercuspal widths of the 1st. premolar and 2nd. premolar were decreased. 3. Change of the overjet was dependant upon upper anterior rather than lower anterior. 4. No significant changes were observed in facial plane angle and ANB angle. 5. Uprighting of the lower 1st. molar had an effect on the increase of the facial height.

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