• The Transactions of the Korean Institute of Power Electronics
• /
• v.27 no.4
• /
• pp.332-338
• /
• 2022

This study proposes a battery state-of-health estimation method by applying a feature extraction technique. The technique that can improve estimation performance is the process of identifying and extracting meaningful data. To apply a data-driven-based aging state estimation method to batteries, health indicators are used as training data. However, limitations occur in extracting health indicators from charge/discharge cycles. This study proposes a deep-learning-based battery state-of-health estimation method that applies feature extraction techniques to compensate for this problem. According to the performance evaluation result of the proposed method, it has a low estimation error of 0.3887% based on an absolute error evaluation method.

• Journal of Preventive Medicine and Public Health
• /
• v.22 no.2 s.26
• /
• pp.248-258
• /
• 1989

As a result of cost-benefit analysis by making a macroscopic approach to the health screening projects conducted 4 times since 1950 for the insured people of the Korea Medical Insurance Corporation, the following conclusions were reached. 1. The direct costs put into the health screening project, and the time costs which were paid by examinees or calculated in terms of social costs have been estimated. The results is that the lowest estimation was 10,337 million won and the highest 15,141 million won when a minimum of 1.5 hours of time spent and a maximum 4 hours were applied. 2. In terms of the psychiatric benefits, the lowest estimation was 5,341 million won while the highest was 5,585 million won. 3. In terms of the benefits for each kind of diseases, the lowest estimation of 37,188 million won and highest estimation of 74,383 million won have been calculated for the liver diseases. And for the cardiovascular diseases, the minimum estimation was 14,475 million won while the maximum was 20,532 million won. In case of pulmonary tuberculosis, with external effect benefits being included, the estimation ranged from the minimum of 1,649 million won to the maximum of 1,832 million won. And the estimation of benefits for diabetes mellitus and renal diseases ranged from 89 million won to 92 million won and from 4,567 million won to 7,598 million won respectively. 4. In comparing costs and benefits, as a results of comparing each highest and lowet estimation a range of minimum 46,708 million won and maximum 98,071 million won of benefits has been gained.

• Health Policy and Management
• /
• v.5 no.2
• /
• pp.18-34
• /
• 1995

To clarify the relationship between the medical supply(medical persons and goods) and the use of bed, the author has made comparison among OECD 24 countries. Per Capita Bed-days can be divided into Average Length of Stay and Admission Rate, and these three variables were regressed upon both In-patient Care Beds of all medical institutions including acute somatic, psychiatric, special, nursing homes and other long-term care and Share of Total Health Employment in Total Employment. The result of regression analysis shows a statistically significant positive relationship between In-patient Care Beds and Average Length of Stay, and negative relationship between Share of Total Health Employment and Admission Rate. In addition to Ordinary Least Square(OLS) estimation, amended Bounded Influence Estimation(BIE) was also made to adjust the influence of outliers. Japan shows a very large number of In-patient Care Beds and a very low Share of Total Health Employment, and this medical situation is judged to have close relation to her long Average Length of Stay and low Admission Rate.

• Health Policy and Management
• /
• v.12 no.1
• /
• pp.1-20
• /
• 2002

National health expenditure account describes expenditure flows both public and private within the health sector. It describes the sources and uses and channels for all funds utilized in the health sector and is a basic requirement for optimal management of the allocation of health sector resources. Constructing a national health expenditure account should begin with sound estimates. This paper thoroughly examines the sources and discusses the estimation methods, and provides the national health expenditure account of Korea by function and source of funding category The national health expenditure account produced in this parer has, however, some drawbacks and followings are proposed fur enhancing the comprehensiveness and consistency of the account. First, comparable data un health related expenditures of local government and private sector should be produced because data sets on the sectors are very limited. Second, we need further study un overall scope and boundaries of health expenditure estimates in order to improve compatibility of other main aggregates.

• Journal of Auto-vehicle Safety Association
• /
• v.16 no.2
• /
• pp.51-59
• /
• 2024

This study presents a method for health monitoring of rotating objects for mobility based on multiple recursive least squares(RLS) algorithms. The performance degradation of the rotating objects causes low handing / low driving performances and even fatal accidents. Therefore, health monitoring algorithm of rotating objects is one of the important technologies for mobility fail-safe and maintenance areas. In order for health monitoring of rotating objects, four recursive least squares algorithms with forgetting factor were designed in this study. The health monitoring algorithm proposed in this study consists of two steps such as uncertainty estimation and parameter changes estimation. In order to improve estimation accuracy, time delay function was applied to the estimated signals based on the first order differential equation and forgetting factors used for the RLS were reasonably tuned. The health monitoring algorithm was constructed in Matlab/Simulink environment and simulation-based performance evaluation was conducted using DC motor model. The evaluation results showed that the proposed algorithm estimates the actual parameter differences reasonably using velocity and current information.

• Women's Health Nursing
• /
• v.30 no.1
• /
• pp.18-25
• /
• 2024

• Journal of Preventive Medicine and Public Health
• /
• v.55 no.1
• /
• pp.10-18
• /
• 2022

Disability-adjusted life-year (DALY) estimates may vary according to factors such as the standard life expectancy, age weighting, time preference and discount rate, calculation of disability weights, and selection of the estimation method. DALY estimation methods are divided into the following 3 approaches: the incidence-based approach, the pure prevalence-based approach, and the hybrid approach. These 3 DALY estimation approaches each reflect different perspectives on the burden of disease using unique characteristics, based on which the selection of a suitable approach may vary by the purpose of the study. The Global Burden of Disease studies, which previously estimated DALYs using the incidence-based approach, switched to using the hybrid approach in 2010, while the National Burden of Disease studies in Korea still mainly apply the incidence-based approach. In order to increase comparability with other international burden of disease studies, more DALY studies using the prevalence-based approach need to be conducted in Korea. However, with the limitations of the hybrid approach in mind, it is necessary to conduct more research using a disease classification system suitable for Korea. Furthermore, more detailed and valid data sources should be established before conducting studies using a broader variety of DALY estimation approaches. This review study will help researchers on burden of disease use an appropriate DALY estimation approach and will contribute to enhancing researchers' ability to critically interpret burden of disease studies.

• Journal of Environmental Science International
• /
• v.22 no.2
• /
• pp.151-161
• /
• 2013

The assessment of personal exposure is a critical component in population-based epidemiologic studies of air pollution. This study was conducted to apply and compare the four exposure estimation methods of individual-level to air pollution concentration in a cohort including 2,283 subjects in Gwangyang, Korea. Individual-level exposure of air pollution were estimated using multiple approaches, including average across all monitors, nearest monitor, and spatial interpolation by inverse distance weighting and kriging. The mean concentrations of $PM_{10}$, $NO_2$, $SO_2$, CO, $O_3$ by four exposure estimation methods were slightly different but not significantly different from each other. Cross-validation showed that kriging was more accurate than other exposure estimation methods because kriging has probably predicted individual exposure levels equivalent to residential locations after estimating the parameters of a model according to the spatial surface of air pollution concentration. These data support that spatial interpolation methods may provide better estimates than selecting the value from the nearest monitor and averaging across values from all monitors by reflecting spatial attributes of air pollution on personal level.

• Journal of Environmental Health Sciences
• /
• v.45 no.3
• /
• pp.273-284
• /
• 2019

Objective: This study was performed to estimate the number of those who used humidifier disinfectants (HDs) and experienced health effects from exposure to HDs in Korea between 1994 and 2011. Methods: A nationwide interview survey was conducted for the representative sample to identify the proportion of those who used HDs among the general population (n=3,001). Another online survey was conducted for those exposed to HDs to find the proportion of those who experienced health effects among those who were exposed to HDs (n=3,993). Statistics for population size by region and year (1994-2011) were used to estimate the cumulative number of those exposed to HDs and those who experienced health effects. In terms of the proportion of those exposed to HDs, those less than 30 years of age were excluded due to an issue related to information bias. Various approaches for estimation included the capture-recapture method for estimation of those who experienced health effects. Results: The cumulative proportion of those exposed to HDs was 6.7% among the general population, and the proportion of those who experienced health effects among those who were exposed to HDs was 13.9%. Based on these factors, it was estimated that 3.5 to 4.0 million people were exposed to HDs and 350 to 400 thousand experienced health effects at least requiring visiting a hospital. Conclusion: It is suggested that a nationwide representative sample may be essential for population size estimation of those exposed to environmental risk factors and of those who experienced health effects.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.6
• /
• pp.1802-1811
• /
• 2016

A novel battery SOH estimation algorithm based on outlier detection has been presented. The Battery state of health (SOH) is one of the most important parameters that describes the usability state of the power battery system. Firstly, a battery system model with lifetime fading characteristic was established, and the battery characteristic parameters were acquired from the lifetime fading process. Then, the outlier detection method based on angular distribution was used to identify the outliers among the battery behaviors. Lastly, the functional relationship between battery SOH and the outlier distribution was obtained by polynomial fitting method. The experimental results show that the algorithm can identify the outliers accurately, and the absolute error between the SOH estimation value and true value is less than 3%.