• Journal of Labour Economics
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• v.44 no.2
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• pp.33-69
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• 2021

This study estimates the employment relationship of domestic and foreign workers by establishing 16 municipal and provincial panel data for the period 2010-2018. It attempts to analyze industry-specific (manufacturing and construction), scale-specific (5-29, 5-29, 5-299 and 5 above) and uses the foreign worker's national share (foreigner's concentration index) as an instrumental variable to control the endogeneity of foreign workers. Finally, it compares the results of panel GLS, which does not consider the endogeneity of foreign workers, with the results using instrumental variable method that considers it. As a result of the analysis, the complementary relationship between domestic and foreign workers was confirmed in the panel GLS analysis. However, although the employment relationship between domestic and foreign workers was not statistically significant in the instrumental variable method, the analysis of the combination of manufacturing and construction industry showed a statistically significant substitute relationship. This study is highly regarded for the first time in Korea that an instrumental variable method was created to identify and control the endogeneity of foreign workers in estimating employment relationships between domestic and foreign workers.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.612-618
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• 1998

The success of a fuzzy logic control system solving any given problem critically depends on the architecture of th network. Various attempts have been made in optimizing its structure its structure using genetic algorithm automated designs. In a regular genetic algorithm , a difficulty exists which lies in the encoding of the problem by highly fit gene combinations of a fixed-length. This paper presents a new approach to structurally optimized designs of a fuzzy model. We use a messy genetic algorithm, whose main characteristics is the variable length of chromosomes. A messy genetic algorithms used to obtain structurally optimized fuzzy models. Structural optimization is regarded important before neural network based learning is switched into. We have applied the method to the exampled of a cart-pole balancing.

• Industrial Engineering and Management Systems
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• v.1 no.1
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• pp.79-86
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• 2002

This paper proposes a new algorithm for estimating ARMA model parameters. In estimating ARMA model parameters, several methods such as generalized least square method, instrumental variable method have been developed. Among these methods, the utilization of a bootstrap type algorithm is known as one of the effective approach for the estimation, but there are cases that it does not converge. Hence, in this paper, making use of a cross correlation function and utilizing the relation of structural a priori knowledge, a new bootstrap algorithm is developed. By introducing theoretical relations, it became possible to remove terms, which is liable to include much noise. Therefore, this leads to robust parameter estimation. It is shown by numerical examples that using this algorithm, all simulation cases converge while only half cases succeeded with the previous one. As for the calculation time, judging from the fact that we got converged solutions, our proposed method is said to be superior as a whole.

• East Asian Economic Review
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• v.27 no.1
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• pp.3-31
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• 2023

Dissemination of information can enhance smallholder farmers' agricultural outcomes and incomes in developing countries. However, the impact evaluation for new information can be inaccurate without considering pre-existing information that the indigenous people have used. This study explores qualitative causal links between existing agricultural information used by Lao smallholder farmers on rice yield and selling price with 180 household data. We categorized the pre-existing information into weather, farming technique, input, intermediate trader, and sales price. The source of each piece of information is used as an instrumental variable to overcome the endogeneity issue between information use and agricultural outcomes. Using farming technique information positively affects rice yields by 57.1% compared to those without that information. Moreover, intermediate trader and crop sales information result in 64.5% and 60.0% higher selling prices than non-user groups. A statistically significant causal relationship exists with agricultural outcomes. The more genuine impact should be measured with a newly updated impact evaluation approach that considers this pre-existing agricultural information.

• Korean Journal of Social Welfare
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• v.58 no.2
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• pp.57-85
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• 2006

This study tries to understand how the physical impairment develops to practical disabilities among adults with cerebral palsy through path analysis, based on the concept of disability by WHO that the physical impairment and "activities of daily living"(ADL) are affected by the combination of interrelated concept of personal health and environment. Pain and instrumental support are conceptualized as mediating variables for ADL among the adults with cerebral palsy, which are used in the analysis. As a result of surveying of 381 participants, paralyzed region is the only variable directly influencing ADL; other variables such as gender, age, and types of cerebral palsy do not have direct effect on ADL. However, it turns out that age, types of cerebral palsy, and paralyzed region influence on pain problems and also on ADL indirectly, when pain is introduced as a mediating variable. The study also shows that the extent of instrumental support works directly and indirectly toward pain and ADL. It means that individual impairment does not necessarily have influence on the limitations of ADL, but on the result of interrelatedness of individual factors and social factors. Finally, this study implies that the social work practice should be intervened with a new approach of the consideration of the effects of mediating variables.

• KDI Journal of Economic Policy
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• v.42 no.2
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• pp.31-56
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• 2020

This study investigates the impact of the use of the main local languages in Burkina Faso (Moore, Dioula, Fulfulde) on labor force participation. Using Ethnologue language data, I compute the relative language distance reduction index, after which I use a probit/logit model and instrumental variable approach to account for language use policy endogeneity. This study finds that the use of the Moore language increases the likelihood of labor force participation by 36 percent, with a strong impact on women at 59 percent, nine times higher than men, and 38.3 percent for rural individuals, five times higher than individuals living in urban areas. The Dioula language exhibits comparable trends, while Fulfulde has a negative impact on individuals. The study recommends the use of local language(s) as official language(s) to improve labor force participation. However, a bilingual approach combining local and international language(s) will be of use to account for globalization and international competitiveness. The findings here may be of use to researchers and policymakers as part of their effort to increase the labor force participation rates of women and rural individuals. Moreover, this research has significant implications with regard to the implementation of language use policies in a variety of postcolonial language contexts.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.131-148
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• 2023

Purpose - Since the 2020s, the management philosophy of Chinese firms' ESG has been rapidly established under the leadership of the Chinese government. We empirically analyze the ESG characteristics and effects on corporate value of Chinese firms. Design/methodology/approach - Using OLS and random effect panel regression analysis, we identify ESG determinants. In analyzing the impact on corporate value, likewise a large number of literatures, we adopt a 2SLS methodology using instrumental variables in the reason of endogeneity between ESG and firm value. We analyze using the G2SLS methodology, which is improving the efficiency of the estimation coefficients along with 2SLS. Findings - We find that ESG ratings are high in state-owned and foreign capital invested companies, ESG ratings are low in companies with a high proportion of non-floating stocks which implies information asymmetry. However, there are no significance in the institutional investor's, the major 10 largest shareholders' and manager's ownership. Furthermore, we can support most of the hypotheses that ESG ratings will be high in companies with high management performance. ESG ratings are significantly higher in companies with high ROA, rich in cash asset, low debt ratio, and large size. we strongly support the hypothesis that the higher the ESG rating, the higher the firm value, and ESG has a moderating effect on state-owned companies, non-floating shares, the ownership of institutional investors, manager, and the 10 major shareholder. In particular, state-owned companies, the proportion of non-floating shares, and the ownership of the 10 major shareholders have a negative impact on firm value, however, ESG attenuates this negative effect. Research implications or Originality - This study looks forward to enhancing our understanding of ESG characteristics in East Asia.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.1-7
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• 2011

The mode analysis of end-milling was introduced using recursive parametric modeling. Also, a numerical mode analysis of FRF in end-milling at different conditions was performed systematically. In this regard, a REIVM(recursive extended instrumental variable method) modeling algorithm was adopted and natural modes of real and imaginary part were discussed. This recursive approach can be used for the on-line system identification and monitoring of an end-milling for this purpose. For acquiring a cutting force, an experimental practice was performed. And these end-milling forces were used for the calculation of FRF(Frequency response function) and its mode analysis. Also, the FRF was analysed for the prediction of end-milling system. As a results, this algorithm was successful in each condition for the detection of natural modes of end-milling. After numerical analysis of the FRF, the tooth passing frequency was discriminated in their FRF, power spectrum and mode calculation.

• Journal of Korea Trade
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• v.25 no.8
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• pp.25-44
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• 2021

Purpose - This research aims to provide empirical evidence that highlights the importance of imported intermediate goods in long-term economic growth. To this end, this paper develops an index that measures the productivity gains associated with a country's intermediate goods imports using highly disaggregated trade data. Design/methodology - The basic hypothesis is that countries sourcing higher-productivity (or higher-quality) inputs from developed economies derive a larger benefit from foreign R&D. To explore this hypothesis, standard cross-country growth regressions are performed using the highly disaggregated data from the United Nations (UN) Commodity Trade Statistics Database (COMTRADE). To address the endogeneity issue, I apply an instrumental variable (IV) approach. Findings - The results of this study demonstrate that the index predicts subsequent economic growth in middle- and low-income countries. This finding is consistent with previous studies that have argued that developing countries can achieve substantial productivity gains by importing intermediate inputs from developed countries. By contrast, there is no evidence of a significant association between the index and economic growth in high-income countries. Originality/value - This paper contributes to our understanding of the causal relationship between international trade and economic growth. From an economic policy perspective, the results suggest that developing countries with limited technology endowment can boost growth from input-tariff liberalization.

• Korean Journal of Health Education and Promotion
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• v.23 no.3
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• pp.99-119
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• 2006

Objectives: This study intends to understand the difference within group of social support level and the effect of social support to health behaviors and health status of the elderly by selecting the old of local society as target. Methods: Data were obtained from self-administered questionnaire of 8,688 persons, older than 65 years, living in a community. We measured the sociodemographic characteristics, social support(family support, other support, quality of support), physical health state(subjective health status, number of chronic disease), physical function state(activities of daily living; ADL, instrumental activities of daily living; IADL), cognition state(mini-mental state examination-Korean; MMSE-K) and depression state(short form of geriatric depression scale; SGDS), health behaviors(smoking, drinking, exercise, eating habit). Univariate, multinominal logistic regression and covariance structure analysis were employed to analyze factors affecting on the social support of the elderly. Results: When considering the degree of social support by the sociodemographic characteristics of the older adults, the family support, other support and quality of support is better when the old is male, young, high education and self-reported living status is good and it has significance statistically. When considering the relation between social support and health status, the family support, other support and quality of support is better when the old's subjective and objective physical health status is good. The family support, other support and quality of support is better when the old's subjective health status is better. The other support and quality of support is better when the old's ADL(activities of daily living) and IADL(instrumental activities of daily living) are good. The family support, other support and quality of support is better when the old's cognitive function and depression state is better. When considering the relation between social support and health behaviors, in case of smoking and drinking, the quality of support, family support and other support is better when the old smokes and drinks rather than the old does not. In case of exercise and eating habit, the family support, other support and quality of support is better when the old exercises and eats regularly rather than the old does not. It has significance statistically. From the result of performing covariance structure analysis by structural equation modeling(SEM) with two endogenous variable(health behaviors and health status) and one exogenous variable(social support), factor loading of health status is 0.74 and factor loading of health behaviors is 0.05. The social support explains health status of 55.4% and health behaviors of 2.9%. Conclusions: This study has the meaning that it finds the difference of social support generating from inside of the group for the old residing in city and country and specifies the effect that the difference of social support influences to health status and health behaviors. From now on, in the development of health improvement strategy of the olds, it is necessary to approach from inclusive aspect while considering psychosocial factor such as social support and social economical factor as well as health status.