• The Journal of Asian Finance, Economics and Business
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• 제7권6호
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• pp.379-385
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• 2020

The effect of research and development (R&D) expenditure on firm output is an interesting topic, but hardly explored in developing countries due to the unavailability of data. This study investigates this topic in the context of Vietnam by utilizing a novel dataset of 343 firms listed on the Vietnam Stock Exchange in the 2010-2018 period. The effect of R&D expenditure is examined under the production function framework. In order to obtain the robustness of the quantitative results, we estimate the production function with two coherent techniques including the OLS and 2-SLS. An instrumental variable regression technique is adopted to avoid the endogeneity problem between R&D expenditure and other variables. In our empirical analysis, we find that R&D expenditure has a positive and significant impact on output growth. The finding is robust in both OLS and 2-SLS frameworks. Besides, the output elasticity to R&D expenditure of our result is much higher than the estimated elasticity of other countries. The results imply that a 1% increase in R&D expenditure in Vietnam will help to expand the output more than a 1% increase in R&D investment in other countries. The findings from our paper provide important implications for firm managers, investors, and policymakers in Vietnam.

• 대한간호학회지
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• 제46권5호
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• pp.663-674
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• 2016

Purpose: The purposes of this study were to develop and test a prediction model for caregiving experiences including caregiving satisfaction and burden in dementia family caregivers. Methods: The stress process model and a two factor model were used as the conceptual frameworks. Secondary data analysis was done with 320 family caregivers who were selected from the Seoul Dementia Management Survey (2014) data set. In the hypothesis model, the exogenous variable was patient symptomatology which included cognitive impairment, behavioral problems, dependency in activity of daily living and in instrumental activity of daily living. Endogenous variables were caregiver's perception of dementia patient's unmet needs, caregiving satisfaction and caregiving burden. Data were analysed using SPSS/WINdows and AMOS program. Results: Caregiving burden was explained by patient symptomatology and caregiving satisfaction indicating significant direct effects and significant indirect effect from unmet needs. The proposed model explained 37.8% of the variance. Caregiving satisfaction was explained by patient symptomatology and unmet needs. Mediating effect of unmet needs was significant in the relationship between patient symptomatology and caregiving satisfaction. Conclusion: Results indicate that interventions focusing on relieving caregiving burden and enhancing caregiver satisfaction should be provided to caregivers with high levels of dementia patients' unmet needs and low level of caregiving satisfaction.

• 한국기계가공학회지
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• 제10권4호
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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.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.186-194
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• 2004

Experiments were conducted to determine the structural static and dynamic characteristics of air foil bearings. The housing of the bearing on the journal was driven by an impact hammer which was used to simulate dynamic forces acting on the bump loll with various leading condition. Two different bump foils (Cu-coated bump and viscoelastic bump) were tested and the static and dynamic coefficients of two bump foils compared, based on the experimental measurements for a wide range of operating conditions. The static and dynamic characteristics of air foil bearings were extracted 0rpm the frequency response function by least square method and IV(Instrumental Variable) method. The experiment was tested at 0rpm and $10,000\~16,000rpm$, and loaded on $50\~150N$. From the test results, the possibility of the application of high load and high speed condition is suggested.

• 노동경제논집
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• 제32권2호
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• pp.1-25
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• 2009

본 연구는 2006년도 고령화연구패널 자료를 이용하여 자녀 수가 자녀의 교육성과에 미치는 영향을 실증분석한다. OLS 추정 결과, 자녀 수가 증가함에 따라 자녀의 질, 즉 교육수준이 낮아진 것으로 나타났다. 이러한 실증 결과는 자녀의 수와 질의 대체관계 모형에 부합한다. 그러나 자녀 수의 내생성을 통제하기 위해 첫째 자녀의 성별을 도구변수로 이용한 추정 결과에서는 자녀 수의 증가가 자녀의 교육수준에 통계적으로 유의한 영향을 미치지 않는 것으로 나타났다. 이러한 결과는 자녀 1인당 교육투자액의 감소에 따른 교육수준의 저하가 자녀 수 증가로 인한 다른 효과에 의해 상쇄될 수 있음을 보여준다.

• 보건행정학회지
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• 제24권1호
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• pp.13-23
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• 2014

Background: A need arises to efficiently control health expenditure for medical aid due to a sharp increase in medical aid expenditure. This study experimently analyzes the impact of physician behavior on medical use for medical aid beneficiaries using supplier induced demand (SID) theory. Methods: This study looks into analyze SID effect using expenditure factor analysis of medical aid for the years between 2003 and 2010 in comparison with health insurance. Moreover, this study analyzes the existence and scale of SID using econometrics modeling with panel data on 16 cities and provinces's health expenditure data for medical aid from 2003 1/4 to 2010 4/4. Results: This study finds that the growth rate of visit days per capita and treatment amount per visit days for medical aid is higher than health insurance. Furthermore, the result of econometrics modeling analysis shows the existence of SID in general hospital, hospital, clinic, oriental clinic. Conclusion: In order to efficiently control expenditure for medical aid, it is required to reinforce macro polices such as the introduction of 'target management' and micro policies such as the strengthen of management on medical institutes in the perspective of suppliers as well as regulations of demanders.

• The Journal of Asian Finance, Economics and Business
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• 제7권5호
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• pp.119-130
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• 2020

The study seeks to evaluate the impacts of three types of credit - formal, semi-formal, and informal credits - on the well-being of households in Vietnam's rural areas. Based on data from the Vietnam Household Living Standard Surveys in 2014 and 2016, the research uses the instrumental variable fixed-effect models to estimate the effects of three kinds of credit on household's per capita income and expenditure. There are some significant findings. First, in rural areas, formal credit is the most popular source with stable and cheap borrowing costs. Informal credit is a complement to formal credit to meet urgent needs. Funding agriculture activities is the most commonly cited purpose of borrowing, followed by purchasing assets. The highest misuse rate belongs to the group of loans for agriculture production. Second, the results show that credit helps smoothen consumption rather than generate income for rural households. Three types of credit have insignificant or negative effects on household's per capita income. Formal loans significantly improve total expenditure and spending on healthcare and education. Informal and semi-formal credits show a little influence on consumption. Informal loans have a significantly positive effect on healthcare expenditure. In contrast, having semi-formal loans tends to decrease spending on foods.

• 물과 미래
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• 제25권4호
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• pp.109-119
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• 1992

본 연구에서는 호우시 홍수예경보 및 수자원의 효율적 관리를 위한 실시간 유출예측모형을 개발하고자 하였다. 그 방법으로 강우-유출과저의 추계학적 시스템모형을 구성하고 모형의 매개변수를 순환 최적추정할 수 있는 RLS 및 IV-AML 알고리즘을 적용하였다. 또한 기존에 관측된 시간별 강우-유출자료로부터 매개변수 및 추정오차의 공분산행렬의 초기치들을 산정하여 유출예측의 성과도를 향상시키고자 하였으며, 1단계전 유출예측치를 분석함으로서 본 연구에서 개발된 모형의 정확성과 적용가능성을 검토해 보았다.

• 전기학회논문지
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• 제64권3호
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• pp.445-450
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• 2015

In the moving target problem, the velocity information of the moving target is very important as well as the high accuracy position information. To solve this problem, active researches are being conducted recently with combine the Time Difference of Arrival (TDOA) and Frequency Delay of Arrival(FDOA) measurements. However, since the FDOA measurement is utilizing the Doppler effect due to the relative velocity between the target source and the receiver sensor, it may be difficult to use the FDOA measurement if the moving target speed is not sufficiently fast. In this paper, we propose a method for estimating the position and the velocities of the target by using only the TDOA measurements for the low speed moving target in the indoor environment with sensor network. First, the target position and heading angle are obtained from the estimated positions of two attached transmitters on the target. Then, the target angular and linear velocities are also estimated. In addtion, we apply the Instrumental Variable (IV) technique to compensate the estimation error of the estimated target velocity. In simulation, the performance of the proposed algorithm is verified.

• 한국지역사회생활과학회지
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• 제22권4호
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• pp.557-572
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• 2011

This study examines the effect of adult-children support network on the psychological well-being of the single and couple elderly households in rural areas. Adult-children support networks include both structural and functional characteristics. For the purpose of this research, 476 participants, who are older than 60 years old, living in rural areas, were selected. The results of this study are summarized as follows: the average degree of psychological well-being of the rural elderly was high. Emotional support from adult children was higher than economic or instrumental support. In the case of the single elderly households, adult children's economic support was the strongest variable affecting the psychological well-being. In the case of the couple elderly households, adult children's emotional support had the greater effect on psychological well-being. On the basis of this analysis, policy implications regarding the single and couple elderly households in rural areas were discussed.