• Title/Summary/Keyword: simultaneous equation model

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An Exploration on Individual Giving and Volunteering : Focus on the Relationship with Trust (기부 및 자원봉사와 신뢰의 관계에 관한 연구 : Simultaneous Equation Model을 이용한 분석)

  • Kang, Chul-Hee
    • Korean Journal of Social Welfare
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    • v.59 no.3
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    • pp.5-32
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    • 2007
  • Using a national survey data conducted by the Beautiful Foundation, this study attempts to examine the bilateral relationships between philanthropic effort and social trust and between volunteering effort and social trust by using simultaneous equation model. This study also attempts to examine the socialization effect and intergenerational effect of philanthropy and volunteering in family, school, and community. This study found that both philanthropic effort and volunteering effort have a bilateral relationship with social trust. The bilateral relationship between giving and volunteering and social trust suggests that not only can social trust affect the increase of giving and volunteering but giving and volunteering can also influence social trust. Thus, by strengthening trust and facilitating giving and volunteering, we can construct and promote culture of sharing in our society. On the other hand, in the analysis on individual's educational experience in giving and volunteering during school years and individual's family experience (parental practice) in giving and volunteering during school years, it was found that family experience was statistically significant on philanthropic effort and volunteering effort. The result suggests that considering the validity of intergenerational effect in giving and volunteering, it is strategically vital for our society to facilitate and promote family practice in giving and volunteering throughout diverse programs and social marketing. Although this study has a limitation due to the limitedness of the original data, it made a significant contribution to advancing knowledge on the relationship between giving and volunteering and social trust by using elaborate analysis methods. This study emphasizes the necessity of continuous research; more advanced and systematic study based on a more elaborate model and solid data such panel data should be continued for a better understanding of philanthropic and volunteering behavior that can be an important soil for the development of nonprofit human service organizations. Finally, based on the results of the study, this study discusses research directions and practical implications to deepen and broaden the culture of sharing in Korea.

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Dynamical behaviour of electrically actuated microcantilevers

  • Farokhi, Hamed;Ghayesh, Mergen H.
    • Coupled systems mechanics
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    • v.4 no.3
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    • pp.251-262
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    • 2015
  • The current paper aims at investigating the nonlinear dynamical behaviour of an electrically actuated microcantilever. The microcantilever is excited by a combination of AC and DC voltages. The nonlinear equation of motion of the microcantilever is obtained by means of force and moment balances. A high-dimensional Galerkin scheme is then applied to reduce the equation of motion to a discrete model. A numerical technique, based on the pseudo-arclength continuation method, is used to solve the discretized model. The electrostatic deflection of the microcantilever and static pull-in instabilities, due to the DC voltage, are analyzed by plotting the so-called DC voltage-deflection curves. At the simultaneous presence of the DC and AC voltages, the nonlinear dynamical behaviour of the microcantilever is analyzed by plotting frequency-response and force-response curves.

4-stroke 디젤엔진의 성능예측에 관한 연구

  • 오태식;오세종;양재신
    • Journal of the korean Society of Automotive Engineers
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    • v.4 no.2
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    • pp.58-68
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    • 1982
  • It is well known to diesel engineers that the heat release pattern is one of the most important factors affecting engine performance. Thorough research in heat release pattern has materially helped the progress in high-speed diesel engine development . This paper is based on the research conducted at KAIST and Daewoo Heavy Industry last year. The purpose of this paper is to determine the heat release pattern in combustion chamber of MAN M type, the famous low-noise engine. Thermodynamic cycle simulation was performed using Whitehous-Way's heat release pattern with modified coefficients and Annand's heat transfer model. Instantaneous temperature and pressure of gas in cylinder could be determined by the numerical solution of simultaneous equation of mass conservation, equation of energy conservation, and state equation of ideal gas. Calculated results were compared with measured values in some details emphasizing upon the factors affecting rate of heat release. The agreement was fairly good and revealed why M type should have lower burning velocity at the early part of combustion in spite of high injection rate. Additional results by parametric studies were given in relation to fuel injection conditions for further application to engine development.

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Structural Change Analysis in a Real Interest Rate Model (실질금리 결정모형에서의 구조변화분석)

  • 전덕빈;박대근
    • Korean Management Science Review
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    • v.18 no.1
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    • pp.119-133
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    • 2001
  • It is important to find the equilibrium level of real interest rate for it affects real and financial sector of economy. However, it is difficult to find the equilibrium level because like the most macroeconomic model the real interest model has parameter instability problem caused by structural change and it is supported by various theories and definitions. Hence, in order to cover these problems structural change detection model of real interest rate is developed to combine the real interest rate equilibrium model and the procedure to detect structural change points. 3 equations are established to find various effects of other interest-related macroeconomic variables and from each equation, structural changes are found. Those structural change points are consistent with common expectation. Oil Crisis (December, 1987), the starting point of Economic Stabilization Policy (January, 1982), the starting point of capital liberalization (January, 1988), the starting and finishing points of Interest deregulation (January, 1992 and December, 1994), Foreign Exchange Crisis (December, 1977) are detected as important points. From the equation of fisher and real effects, real interest rate level is estimated as 4.09% (October, 1988) and dependent on the underlying model, it is estimated as 0%∼13.56% (October, 1988), so it varies so much. It is expected that this result is connected to the large scale simultaneous equations to detect the parameter instability in real time, so induces the flexible economic policies.

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A Study of Consumer Attitude and Purchasing Behavior toward Agricultural Products using Social Network Service (소셜 네트워크 서비스를 이용한 농식품 구매의 소비자태도와 행동에 대한 연구)

  • Chung, Soo-Yeon;Kim, Gi-Hwan;Yang, Sung-Bum;Oh, Sang-Heon;Hwang, Dea-Yong;Kim, Young-Chul;Lee, Seog-Won
    • The Korean Journal of Food And Nutrition
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    • v.25 no.3
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    • pp.650-655
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    • 2012
  • This purposes of this study were to explain consumer attitudes and purchasing behaviors towards agricultural products using a social network service and to determine the influencing factors such as experience, technology ability, innovation, self-efficacy, perception of usefulness, perception of trust, attitude, purpose of purchase and individual characteristics on them. We analyzed the survey data set, using the 'logit model', 'simultaneous equation model', and 'LISREL-Type model' In this study, the results obtained are summarized as follows. The result for the comprehensive statement of "Trust" was the biggest influence on the purchase agricultural products using the social network service. Therefore, in order to expand agricultural e-commerce using SNS, trust should be to the fore of marketing and publicity campaigns, in order to promote and stabilize the market.

An Analysis on the Effect of Having a Usual Source of Care for the Elderly: Focusing on the Healthcare Expenditure and the Subjective Health Status (노년기 상용치료원 보유의 효과 분석: 의료비와 주관적 건강상태에 대한 효과를 중심으로)

  • Jeon, Yeji;Sakong, Jin
    • Health Policy and Management
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    • v.31 no.4
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    • pp.531-543
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    • 2021
  • Background: Population aging is a serious problem in Korea. And we have experienced a rapid increase in the health expenditures of the elderly. The purpose of this paper is to analyze the effect of having a usual source of care (USC) for the elderly. Methods: This study used the Korea Health Panel Survey data of 2012, 2013, 2016, 2017, and 2018. The sample was the person who answered the USC questions among the elderly. The panel logit model was used to analyze the determinants of having USC and the panel simultaneous equation model was used to analyze the effect of having USC among the elderly on the medical expenses, medical utilization, and subjective health status. Results: The estimation result shows that age, income, marriage, and so forth turn out to be the factors of having USC. Having the clinic level USC is estimated to reduce the health care utilization and the health expenditure and to improve the subjective health status. Conclusion: It is expected that the result of our analysis will provide evidence for encouraging having USC.

The Effects of Government Environmental Subsidies and Corporate Environmental Expenditure for Globalization on the Profitability of Chinese Firms (글로벌 기업에 대한 환경보조금과 환경투자지출이 중국 기업의 수익성에 미치는 영향)

  • Li, Wen-Xi;Huang, Yi;Kim, Sung-Hwan
    • Asia-Pacific Journal of Business
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    • v.12 no.3
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    • pp.175-192
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    • 2021
  • Purpose - In this study, we investigate the effects of government environmental subsidies and the globalization Chinese firms on their profitability using return on assets (ROA). Design/methodology/approach - In this study, a merged data including accounting, financial market, subsidization of the Chinese governments, local and the central, and export activities of 19,563 year-firms, for those listed on Shanghai Stock and Shenzhen Stock Exchange for 11 years from 2008 to 2018 is used. We collect subsidy data from RESSET database and financial data from CSMAR database. Then, we empirically test the test hypotheses using fixed effects models (FEM) separately and in a simultaneous equation model (SEM). Findings - Firstly, the globalization of Chinese firms has a negative impact on their profitability for some years after the year. Secondly, environmental subsidies just like other subsidies have ameliorating effects on financial performance for global firms. Such effects have lasted some years. Thirdly, environmental investments have a mostly negative impact on short- and long-term profitability for global firms. Lastly, the government's environmental subsidies in China have a positive effect on their profitability for both global and domestic firms. Research implications or Originality - We can infer that environmental investments with the help of the governmental subsidies can help Chinese firms deploy global strategies to expand markets to surpass competitors in the long run despite worsening profitability in global markets in the short run.

Empirical Study of Dynamic Corporate Governance: New Evidence from Chinese-listed SMEs

  • Shao, Lin;Yu, Xiaohong
    • The Journal of Industrial Distribution & Business
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    • v.6 no.4
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    • pp.27-37
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    • 2015
  • Purpose - This study first explores the possible dynamic relationship between ownership structure and firm performance using a panel of 4,900 Chinese-listed small- and medium-sized enterprises (SMEs) from 1999 to 2012. Research design, data, and methodology - We address this issue through a dynamic panel model using a method of moments (GMM) technique and dynamic simultaneous equations to alleviate the potential endogenous problem: unobserved heterogeneity, simultaneity, and dynamic endogeneity. Results - Under the framework of dynamic endogeneity, firm performance has a significantly positive influence on ownership, but not vice versa. Ownership and performance can be explained by their owned lagged values, respectively. Moreover, intertemporal endogeneity exists among ownership, investment, and performance through the application of system dynamic equations, which implies that the relationship among ownership structure, investment, and firm performance is dynamic by nature. Conclusions - This study also significantly contributes to a better understanding of dynamic corporate governance by providing further empirical evidence from the largest capital market in the Asian region.

Analysis of Spectral Characteristics of Semiconductor Lasers under Strong Optical Injection Locking for Tens of Giga Hz Signal Generation

  • Kim, Jung-Tae
    • Journal of information and communication convergence engineering
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    • v.8 no.4
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    • pp.457-460
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    • 2010
  • we have analyzed tens of Giga pulse signal generation using sideband injection locking scheme. The numerical model for semiconductor lasers under the strong optical injection is based on the Lang's equation and has been extended in order to take into account the simultaneous injection of the multiple sidebands of the current-modulated laser. The numerical simulation results show that the unselected sidebands will affect the optical and RF-spectral characteristics even though the semiconductor laser is locked to the target sidebands.

Analyses of Short Pulse Generation Using Heterodyne Techniques

  • Kim, Jung-Tae
    • Journal of information and communication convergence engineering
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    • v.5 no.3
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    • pp.281-284
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    • 2007
  • We have analyzed the short pulse generation using heterodyne techniques. The numerical model for semiconductor lasers under the heterodyne technique is based on the Lang's equation and has been extended in order to take into account the simultaneous injection of the multiple sidebands of the current-modulated laser. The unselected sidebands will affect the optical and RF-spectral characteristics even when the semiconductor laser is locked to the target sidebands.