• Title/Summary/Keyword: 변수별 효과

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Giving Behavior of Households - Effects of Asset, Income, and the Ratio of Income to Asset - (가구단위 기부행동에 관한 연구 - 자산, 소득, 자산 대비 소득의 효과 -)

  • Kang, Chul Hee;Choi, Jung Eun;Jang, Jae Hyuk
    • Korean Journal of Social Welfare
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    • v.68 no.4
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    • pp.53-74
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    • 2016
  • In this study, to verify influence that economic situations of a household unit have on donation behavior, after economic situations of a household unit were measured with income and assets by type and income to assets, effect which each variable has on secular giving was verified. This study used 3-year panel data of a total of 4,938 households based on the fifth to seventh year data as investigation data from 2012 to 2014 among data of financial panel investigation of Korea Institute of Public Finance of National Survey of Tax and Benefit. As an analysis method, a random effect tobit model was used. At the analysis result, it appeared that as scales of financial assets, earned income, property income, and transfer income become larger, the amount of donation increased. Also, it was represented that rates of income to assets had negative influence on secular giving. In case of demographic variables, education levels of householders and sizes of houses had relation of a positive direction. In case of ages, it appeared that they had inverted U-type relation. This study has meanings in that understanding of donation behavior of a household unit can be increased and expanded more and also implications related to intervention strategies of a household unit to expand sharing culture can be extracted by verifying influence which economic factors of a household unit have on donation behavior based on panel data.

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Damage Evaluation of Adjacent Structures for Detonation of Hydrogen Storage Facilities (수소저장시설의 폭발에 대한 인접 구조물의 손상도 평가)

  • Jinwon Shin
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.1
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    • pp.61-70
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    • 2023
  • This study presents an analytical study of investigating the effect of shock waves generated by the hydrogen detonation and damage to structures for the safety evaluation of hydrogen storage facilities against detonation. Blast scenarios were established considering the volume of the hydrogen storage facility of 10 L to 50,000 L, states of charge (SOC) of 50% and 100%, and initial pressures of 50 MPa and 100 MPa. The equivalent TNT weight for hydrgen detonation was determined considering the mechanical and chemical energies of hydrogen. A hydrogen detonation model for the converted equivalent TNT weight was made using design equations that improved the Kingery-Bulmash design chart of UFC 3-340-02. The hydrogen detonation model was validated for overpressure and impulse in comparison to the past experimental results associated with the detonation of hydrogen tank. A parametric study based on the blast scenarios was performed using the validated hydrogen detonation model, and design charts for overpressure and impulse according to the standoff distance from the center of charge was provided. Further, design charts of the three-stage structural damage and standoff distance of adjacent structures according to the level of overpressure and impact were proposed using the overpressure and impulse charts and pressure-impulse diagrams.

Impacts of Three-dimensional Land Cover on Urban Air Temperatures (도시기온에 작용하는 입체적 토지피복의 영향)

  • Jo, Hyun-Kil;Ahn, Tae-Won
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.3
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    • pp.54-60
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    • 2009
  • The purpose of this study is to analyze the impacts of three-dimensional land cover on changing urban air temperatures and to explore some strategies of urban landscaping towards mitigation of heat build-up. This study located study spaces within a diameter of 300m around 24 Automatic Weather Stations(AWS) in Seoul, and collected data of diverse variables which could affect summer energy budgets and air temperatures. The study also selected reflecting study objectives 6 smaller-scale spaces with a diameter of 30m in Chuncheon, and measured summer air temperatures and three-dimensional land cover to compare their relationships with results from Seoul's AWS. Linear regression models derived from data of Seoul's AWS revealed that vegetation volume, greenspace area, building volume, building area, population density, and pavement area contributed to a statistically significant change in summer air temperatures. Of these variables, vegetation and building volume indicated the highest accountability for total variability of changes in the air temperatures. Multiple regression models derived from combinations of the significant variables also showed that both vegetation and building volume generated a model with the best fitness. Based on this multiple regression model, a 10% increase of vegetation volume decreased the air temperatures by approximately 0.14%, while a 10% increase of building volume raised them by 0.26%. Relationships between Chuncheon's summer air temperatures and land cover distribution for the smaller-scale spaces also disclosed that the air temperatures were negatively correlated to vegetation volume and greenspace area, while they were positively correlated to hardscape area. Similarly to the case of Seoul's AWS, the air temperatures for the smaller-scale spaces decreased by 0.32% ($0.08^{\circ}C$) as vegetation volume increased by 10%, based on the most appropriate linear model. Thus, urban landscaping for the reduction of summer air temperatures requires strategies to improve vegetation volume and simultaneously to decrease building volume. For Seoul's AWS, the impact of building volume on changing the air temperatures was about 2 times greater than that of vegetation volume. Wall and rooftop greening for shading and evapotranspiration is suggested to control atmospheric heating by three-dimensional building surfaces, enlarging vegetation volume through multilayered plantings on soil surfaces.

The Effect of Single Mothers' Community Participation on Empowerment -Focused on the Mediation Effect of Gender Consciousness (한부모 여성의 조직 참여 특성이 임파워먼트 효과에 미치는 영향 분석 -젠더의식 변화의 매개효과를 중심으로-)

  • Lee, In-Sook
    • Korean Journal of Social Welfare Studies
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    • v.41 no.2
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    • pp.189-216
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    • 2010
  • This study is to show the effect of single mothers' community participation on empowerment and the mediation effect of gender consciousness that mediate the causal relationship between this two variables defining the organization, which single mothers have been participated, as a community based on that there are common goals, emotional bond, and reciprocal action between the members. 439 single mothers, who have been participated in one of 14 organizations in Pusan and Gyeongnam, have been surveyed and the practice elements of emporwerment, gender consciousness, and empowerment have been analyzed from it. The results are first, There was significant differences at the practice elements of empowerment, gender consciousness, and empowerment according to the types of single mothers' community. Mostly it was high among job training type community and low among social welfare institution type community. Second, it has been shown that the determinant factors of empowerment are the degree of community participation and the practical elements of empowerment. Third, The changes in gender consciousness should be proceeded before that the practice of community empowerment, which the changes in gender consciousness represent the full mediation in the relationship between the practical elements and empowerment effect, leads the improvement of single mothers' empowerment.

A Study on Perceived Government Support and Small and Medium-sized Ventures Performance: The Mediating Role of Entrepreneurial Persistence (중소벤처기업 정책지원의 인식이 성과에 미치는 영향에 관한 연구: 기업가 끈기의 매개효과를 중심으로)

  • Kim, Young Jin;Yang, Dong Woo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.6
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    • pp.105-116
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    • 2023
  • While there have been studies on the impact of government financial support on the performance of these enterprises, there is limited research on how entrepreneurs' perceptions of such policies affect business performance. Additionally, there is scarce domestic research on the role of entrepreneurial persistence in achieving and sustaining entrepreneurial goals and its impact on business performance. Therefore, the aim of this study is to analyze how entrepreneurs' perceptions of government policy support affect business performance and to explore the mediating effect of entrepreneurial persistence, shedding light on the significance of perceptions and deepening the understanding of entrepreneurial persistence. This study utilizes entrepreneurs' perceptions of government support for South Korean small and venture enterprises, and entrepreneurship as independent variables, with entrepreneurial persistence as a mediating variable and non-financial performance of businesses as the dependent variable. Data was collected through surveys targeting founders, CEOs, and executives of small and venture enterprises. After excluding incomplete responses, a total of 205 survey responses were used for hypothesis testing. The results of this study are as follows. First, it was verified that the perception of SME policy support and entrepreneurship have a significant positive impact on business performance. Second, it was verified that entrepreneurial persistence partially mediates the relationship between the perception of SME policy support and entrepreneurship and business performance. The theoretical implications of this study are twofold. First, it highlights the significant positive impact of entrepreneurs' perceptions of policy support on the non-financial performance of small and venture enterprises. This contributes to the theoretical understanding by demonstrating that entrepreneurs' perceptions play a role in affecting business performance, in contrast to previous research that focused on the impact of policy financial support on business performance. Second, this study extends the theoretical understanding of entrepreneurial persistence, a relatively understudied concept in domestic research, by demonstrating its mediating role in the relationship between entrepreneurs' perceptions of government support and, entrepreneurship, and business performance. Practically, the study suggests that to enhance the performance of small and venture enterprises, the government should not only expand policy support but also seek ways to increase entrepreneurs' perceptions of such support.

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Moderator Effects of e-Book Terminal Type on Factors Influencing Satisfaction of the e-Book User (전자책 사용자만족도 영향요인에 대한 단말기유형의 조절효과)

  • Kim, Keun Hyung;Kim, Seong In;Oh, Sung-Ryoel
    • The Journal of the Korea Contents Association
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    • v.13 no.5
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    • pp.408-419
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    • 2013
  • The terminals of e-Book(electronic Book) are classified into two types which consist of special-purpose terminal equipment and general-purpose terminal equipment. Although the terminal products inr the two types have had a strong race in the e-Book market each other, both enterprises and consumers want the two type to remain persistently with competition in good faith. Therefore, it is necessary for each type camps to find blue ocean by establishing differentiation strategies of each type. In this paper, we designed the research model that independent variables consist of hardware quality and software quality, dependent variable is user satisfaction, moderator variable is the terminal type. Through the research model, we investigated factors having a influence on the user satisfaction of the e-Book terminal that consists of hardware and software. In particular, we investigated if the degree of the influence is different between the two types. As a result, we got conclusions as followings. First, the quality of hardware and software in the terminal had significant influences on the user satisfaction. Second, the degree which the hardware quality has influenced user satisfaction was not different between the two types, but the degree which the software quality has influence on user satisfaction was different between the two types. As a implication of this result, we found that special-purpose terminal provider need to establish a strategies for raising the quality of e-Book viewer to provide different product from general-purpose terminal.

A Study of the Causal Relationship between Organizational Trust and Error Management Culture across Social Service Agencies (조직신뢰와 오류관리문화와의 관계에 대한 연구 - 사회복지이용시설을 중심으로 -)

  • Lee, Sangchul
    • Korean Journal of Social Welfare
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    • v.67 no.3
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    • pp.83-105
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    • 2015
  • This study has two objectives. First, it examines the relationship between organizational trust and error management culture. Second, it also examines the effect of social workers' perceived work value on the combined model by considering the unique characteristics of social work profession and social desirability. This study employs the stratified sampling method on social workers with more than two year work experiences in their current social service agencies that are located in Seoul and Kyungki province; finally it analyzes the responses from 564 social workers by using the method of multiple regression modeling. This study has the following results: (1) there is a causal relationship between social desirability and organizational trust perceived by social workers; (2) there is a positive causal relationship between social workers' perceived work value and organizational trust; and (3) there is also a positive causal relationship between factor structure of error management culture and organizational trust. This study discusses the theoretical and practical implications of the results.

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An Algorithm for Real-Traffic Signal Control at An Isolated-Intersection (실시간 신호제어알고리즘 개발에 관한 연구)

  • Shin, Eon-Kyo;Kim, Young-Chan;Lee, Jong-Man
    • Journal of Korean Society of Transportation
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    • v.22 no.7 s.78
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    • pp.161-167
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    • 2004
  • While most or fixed-time control systems such as UTCS produce the signal timing plans that either maximizing bandwidth or minimizing a disutility index of delay and stops, cannot consider the fluctuation of traffic flow. One category of the traffic-response control systems, which make small changes on a predefined signal plan such as SCOOT, cannot be easily modified for feedback real-time control schemes based on observation of variables other than traffic flow. The other category, which decide to whether switch the traffic lights or not at each step of time as in PRODYN, does not adequately consider the relations between traffic flows and traffic lights at each step of time. In this paper we present a complete formulation that adequately consider the relations between traffic flows and traffic lights at each step of time. The formulation is a binary mixed integer linear programing (BMILP) that obtain traffic lights at each step for minimizing delay. Since numarical examples for application of the proposed model illustrated that the model adequately produced dynamic traffic signal plans minimizing delay at each step, the model may be expected to contribute to advanced transportation management systems (ATMS) for dynamic traffic signal control.

Determination of Key Factors for the Pedestrian LOS Introducing the Accessibility Index (접근성 지표를 도입한 보행로 서비스 수준의 영향요인 규명)

  • CHOI, Sung Taek;CHOO, Sang Ho;JANG, Jin Young
    • Journal of Korean Society of Transportation
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    • v.33 no.6
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    • pp.584-597
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    • 2015
  • A considerable amount of literature has been published on pedestrian LOS. So far, however, there is a limitation that LOS analysis methodologies has concentrated on quantitative variables such as pedestrian flow rate, speed and space. This paper intended to suggest the accessibility variable which can not be considered on previous study. The factor was defined and quantified using public transport attributes in particular. This study was carried out in three phases: 1. defined accessibility employing public mode location and service information. 2. investigated the relationship between accessibility and pedestrian flow rate 3. developed the model to establish the factors affected to pedestrian LOS. The results showed that accessibility, walkway attribute and land use type affected the pedestrian LOS. Especially, accessibility and commercial area ratio had negative relationship with LOS. Futhermore, pedestrian LOS declined when obstacle of bus station located on the walkway. On the contrary, LOS was upgraded when sufficient effective width or residential area was secured. These results can receive considerable critical attentions related to determination of pedestrian LOS or effective walkway width.

A Statistical Correction of Point Time Series Data of the NCAM-LAMP Medium-range Prediction System Using Support Vector Machine (서포트 벡터 머신을 이용한 NCAM-LAMP 고해상도 중기예측시스템 지점 시계열 자료의 통계적 보정)

  • Kwon, Su-Young;Lee, Seung-Jae;Kim, Man-Il
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.4
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    • pp.415-423
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    • 2021
  • Recently, an R-based point time series data validation system has been established for the statistical post processing and improvement of the National Center for AgroMeteorology-Land Atmosphere Modeling Package (NCAM-LAMP) medium-range prediction data. The time series verification system was used to compare the NCAM-LAMP with the AWS observations and GDAPS medium-range prediction model data operated by Korea Meteorological Administration. For this comparison, the model latitude and longitude data closest to the observation station were extracted and a total of nine points were selected. For each point, the characteristics of the model prediction error were obtained by comparing the daily average of the previous prediction data of air temperature, wind speed, and hourly precipitation, and then we tried to improve the next prediction data using Support Vector Machine( SVM) method. For three months from August to October 2017, the SVM method was used to calibrate the predicted time series data for each run. It was found that The SVM-based correction was promising and encouraging for wind speed and precipitation variables than for temperature variable. The correction effect was small in August but considerably increased in September and October. These results indicate that the SVM method can contribute to mitigate the gradual degradation of medium-range predictability as the model boundary data flows into the model interior.