• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.210-215
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• 1998

In this paper, systemaic approach is studied about assembility and disassemblility of parts of the gear system in order to reduce the assembly cost, and to disassemble products easily which is possible to recycle the parts. That is, an estimation of disassembly and assembly with considering of reliability life. In this study, we use symbolic chart method for an economic model for optimal disassembly and assembly.

• Journal of Applied Reliability
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• v.2 no.2
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• pp.113-119
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• 2002

The estimation of mean lifetimes in presence of interval censoring with replacement procedure are examined when the distributions of lifetimes are exponential. It is assumed that, due to physical restrictions and/or economic constraints, the number of failures is investigated only at several inspection times during the lifetime test. The maximum likelihood estimator is found in an implicit form. The Cramer-Rao lower bounds of the estimates are found in places of variances and by simulations the properties of the estimates are examined.

• Journal of the military operations research society of Korea
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• v.22 no.2
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• pp.215-226
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• 1996

The estimation of lifetimes are examined when the distribution of lifetimes are Weibull. It is assumed that, due to physical restrictions and/or economic requirements, the lifetimes are investigated only at certain time intervals during the test period with 'mixed replacement' experiment, even though it is well known that 'with replacement' experiment produces better accuracy than 'without replacement' one. The maximum likelihood estimators are derived through the iterative method like as Lawless(1982). Also Cramer-Rao lower bounds are found as the asymptotic variances of the estimates.

• Journal of the Korean Statistical Society
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• v.34 no.4
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• pp.345-366
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• 2005

This paper considers the cointegrating vector estimator in the error correction model with stationary covariates, which combines the stationary vector autoregressive model and the nonstationary error correction model. The cointegrating vector estimator is shown to follow the locally asymptotically mixed normal distribution. The variance of the estimator depends on the co­variate effect of stationary regressors, and the asymptotic efficiency improves as the magnitude of the covariate effect increases. An economic application of the money demand equation is provided.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.541-548
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• 2020

This study aimed to explain the factors that influenced an individual's decision to migrate. The method of analysis in this study was the estimation of the probit regression model with data from the Indonesian Family Life Survey (IFLS-5), which covered 30,000 individuals from 13 provinces in Indonesia. Data from IFLS-5 were longitudinal data, meaning that the study was looking for data consistently to get reliable data from respondents. The research variables to determine the individual's decision to migrate were education level, income level, employment status, marital status, land ownership status, health quality, gender, residence status, and poverty status. Individual decision to migrate as a dependent variable was placed as a dummy variable. The results showed that the level of education, income level, employment status, marital status, land ownership status, health quality, and poverty status significantly influenced an individual's decision to migrate. Meanwhile, gender and residence status did not significantly affect an individual's decision to migrate. This research recommends that it is necessary to pursue a policy of economic equality between regions because economic factors are the main trigger for an individual's decision to migrate. Policies to overcome economic disparities among regions will reduce the individual's decision to migrate.

• Journal of Korean Society of Rural Planning
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• v.20 no.4
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• pp.101-112
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• 2014

The public value of agriculture and rural areas is closely associated with the concept of multifunctionality of agriculture and rural areas, which in turn signifies economic values other than the production function of agriculture and rural areas. Based on the survey results, virtual scenarios were set up and the contingent valuation method (CVM) was used to estimate the amount consumers are willing to pay (WTP) for the public functions of agriculture and rural areas. This study selected five domains of the public value (environment conservation, maintenance of landscape and cultural tradition, enhancement of national prestige, local community maintenance and socio-economic functions, and food security) and 21 value items as components of the public value. An economic assessment of the public value of agriculture and rural areas was conducted using a binomial logistic regression model. The estimation results showed that the public value consumers are willing to pay ranges from a minimum of 6,346.8 billion won to a maximum of 9,327.2 billion won.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.12
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• pp.295-303
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• 2021

The aim of this study is to analyze the effects of oil prices on economic growth and exchange rate in Saudi Arabia during the period 1980-2020. For this purpose, the linear and nonlinear ARDL models are estimated. The linear ARDL model shows that the oil price and economic growth are cointegrated. Moreover, the two variables have a significant positive association in the long run. However, the oil price has no significant impact on the exchange rate. When estimating the nonlinear ARDL model, it has been shown that oil price is only cointegrated with economic growth but not with the exchange rate. The estimation of nonlinear effects using the nonlinear ARDL model shows that economic growth is affected by both positive and negative oil shocks in the long run. However, the impact of positive shocks is higher than those of negative shocks. Moreover, results show that the short-run effects of positive and negative oil shocks are not statistically significant. Regarding the exchange rate, our results show that the effects of positive and negative oil shocks are not statistically significant. Consequently, this study concludes that the oil price has an asymmetric effect on economic growth in Saudi Arabia, but not on the exchange rate.

• KDI Journal of Economic Policy
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• v.45 no.4
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• pp.23-56
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• 2023

To investigate the causes of Korea's growth slowdown over the past thirty years, we estimate the contributions of major developmental factors, including i) demographic factors (changes in population growth and workforce age due to the demographic transition), ii) quality-of-life-related choice factors (changes in working hours, education, and the female employment rate), iii) structural change, and iv) the effects of productivity catch-up. Our estimates show that these four groups of factors account for approximately 90 percent of the growth slowdown, with demographic factors contributing approximately 30 percent and the other three groups of factors each contributing about 20 percent. We also show that the same factors explain most of Korea's high growth in the 1980s. These results suggest that Korea's growth slowdown is basically a consequence of its successful economic development and that the high growth and subsequent slowdown can be regarded as a single process. In addition, given that the factors examined here exhibit similar patterns of change in the course of economic development of most countries, we think that our estimation results of the relationship between economic development and changes in economic growth trends could have more general implications that go beyond Korea's experience.

• Journal of the Korean Home Economics Association
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• v.29 no.2
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• pp.121-134
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• 1991

The farm housewive's labor has not been properly evaluated, although it has traditionally shared and devoted a substantial portion of the farm household economy. The objective of this study is to estimate the money value of rural women's labor. The data were got from the result of time analysis of farm housewives in 1988. Among the four estimation methods used in this study, the mixed approach of houskeeper replacement cost with individual function cost showed the greatest value in the decision criteria of different farming region, farming size, housewive's age, family size and children number. The opportunity cost approach showed the lowest value, however, is considered as the most appropriate estimation approach in rural situation in this study. It is expected that the appropriate estimation approach should be estimate the money value of rural housewive's labor and their economic position.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.2
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• pp.86-88
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• 2002

An estimation method for the characteristic parameters in the low frequency signal is proposed in this paper. A low frequency signal is assumed to be modulated or distorted by high frequency terms. The algorithm proposed in this paper is designed to select set of local maximums in a successive manner, hence it is denoted as the iterative peak picking(IPP) algorithm. The IPP algorithm is operating in the time domain and is using only the comparison operation between two neighboring samples. Therefore, its computational complexity is very low and the delay caused by the computation is negligible, which make the real-time operation possible with economic hardware. The proposed algorithm is verified on the pitch estimation of speech signal and blood pulse estimation.